ide-tape.c 110.0 KB
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/*
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 * IDE ATAPI streaming tape driver.
 *
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 * Copyright (C) 1995-1999  Gadi Oxman <gadio@netvision.net.il>
 * Copyright (C) 2003-2005  Bartlomiej Zolnierkiewicz
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 *
 * This driver was constructed as a student project in the software laboratory
 * of the faculty of electrical engineering in the Technion - Israel's
 * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David.
 *
 * It is hereby placed under the terms of the GNU general public license.
 * (See linux/COPYING).
 *
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 * For a historical changelog see
 * Documentation/ide/ChangeLog.ide-tape.1995-2002
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 */

#define IDETAPE_VERSION "1.19"

#include <linux/module.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
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#include <linux/jiffies.h>
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#include <linux/major.h>
#include <linux/errno.h>
#include <linux/genhd.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/ide.h>
#include <linux/smp_lock.h>
#include <linux/completion.h>
#include <linux/bitops.h>
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#include <linux/mutex.h>
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#include <scsi/scsi.h>
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#include <asm/byteorder.h>
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#include <linux/irq.h>
#include <linux/uaccess.h>
#include <linux/io.h>
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#include <asm/unaligned.h>
#include <linux/mtio.h>

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enum {
	/* output errors only */
	DBG_ERR =		(1 << 0),
	/* output all sense key/asc */
	DBG_SENSE =		(1 << 1),
	/* info regarding all chrdev-related procedures */
	DBG_CHRDEV =		(1 << 2),
	/* all remaining procedures */
	DBG_PROCS =		(1 << 3),
	/* buffer alloc info (pc_stack & rq_stack) */
	DBG_PCRQ_STACK =	(1 << 4),
};

/* define to see debug info */
#define IDETAPE_DEBUG_LOG		0

#if IDETAPE_DEBUG_LOG
#define debug_log(lvl, fmt, args...)			\
{							\
	if (tape->debug_mask & lvl)			\
	printk(KERN_INFO "ide-tape: " fmt, ## args);	\
}
#else
#define debug_log(lvl, fmt, args...) do {} while (0)
#endif

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/**************************** Tunable parameters *****************************/


/*
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 * Pipelined mode parameters.
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 *
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 * We try to use the minimum number of stages which is enough to keep the tape
 * constantly streaming. To accomplish that, we implement a feedback loop around
 * the maximum number of stages:
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 *
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 * We start from MIN maximum stages (we will not even use MIN stages if we don't
 * need them), increment it by RATE*(MAX-MIN) whenever we sense that the
 * pipeline is empty, until we reach the optimum value or until we reach MAX.
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 *
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 * Setting the following parameter to 0 is illegal: the pipelined mode cannot be
 * disabled (idetape_calculate_speeds() divides by tape->max_stages.)
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 */
#define IDETAPE_MIN_PIPELINE_STAGES	  1
#define IDETAPE_MAX_PIPELINE_STAGES	400
#define IDETAPE_INCREASE_STAGES_RATE	 20

/*
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 * After each failed packet command we issue a request sense command and retry
 * the packet command IDETAPE_MAX_PC_RETRIES times.
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 *
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 * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries.
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 */
#define IDETAPE_MAX_PC_RETRIES		3

/*
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 * With each packet command, we allocate a buffer of IDETAPE_PC_BUFFER_SIZE
 * bytes. This is used for several packet commands (Not for READ/WRITE commands)
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 */
#define IDETAPE_PC_BUFFER_SIZE		256

/*
 *	In various places in the driver, we need to allocate storage
 *	for packet commands and requests, which will remain valid while
 *	we leave the driver to wait for an interrupt or a timeout event.
 */
#define IDETAPE_PC_STACK		(10 + IDETAPE_MAX_PC_RETRIES)

/*
 * Some drives (for example, Seagate STT3401A Travan) require a very long
 * timeout, because they don't return an interrupt or clear their busy bit
 * until after the command completes (even retension commands).
 */
#define IDETAPE_WAIT_CMD		(900*HZ)

/*
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 * The following parameter is used to select the point in the internal tape fifo
 * in which we will start to refill the buffer. Decreasing the following
 * parameter will improve the system's latency and interactive response, while
 * using a high value might improve system throughput.
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 */
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#define IDETAPE_FIFO_THRESHOLD		2
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/*
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 * DSC polling parameters.
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 *
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 * Polling for DSC (a single bit in the status register) is a very important
 * function in ide-tape. There are two cases in which we poll for DSC:
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 *
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 * 1. Before a read/write packet command, to ensure that we can transfer data
 * from/to the tape's data buffers, without causing an actual media access.
 * In case the tape is not ready yet, we take out our request from the device
 * request queue, so that ide.c could service requests from the other device
 * on the same interface in the meantime.
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 *
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 * 2. After the successful initialization of a "media access packet command",
 * which is a command that can take a long time to complete (the interval can
 * range from several seconds to even an hour). Again, we postpone our request
 * in the middle to free the bus for the other device. The polling frequency
 * here should be lower than the read/write frequency since those media access
 * commands are slow. We start from a "fast" frequency - IDETAPE_DSC_MA_FAST
 * (1 second), and if we don't receive DSC after IDETAPE_DSC_MA_THRESHOLD
 * (5 min), we switch it to a lower frequency - IDETAPE_DSC_MA_SLOW (1 min).
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 *
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 * We also set a timeout for the timer, in case something goes wrong. The
 * timeout should be longer then the maximum execution time of a tape operation.
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 */
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/* DSC timings. */
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#define IDETAPE_DSC_RW_MIN		5*HZ/100	/* 50 msec */
#define IDETAPE_DSC_RW_MAX		40*HZ/100	/* 400 msec */
#define IDETAPE_DSC_RW_TIMEOUT		2*60*HZ		/* 2 minutes */
#define IDETAPE_DSC_MA_FAST		2*HZ		/* 2 seconds */
#define IDETAPE_DSC_MA_THRESHOLD	5*60*HZ		/* 5 minutes */
#define IDETAPE_DSC_MA_SLOW		30*HZ		/* 30 seconds */
#define IDETAPE_DSC_MA_TIMEOUT		2*60*60*HZ	/* 2 hours */

/*************************** End of tunable parameters ***********************/

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/* Read/Write error simulation */
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#define SIMULATE_ERRORS			0

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/* tape directions */
enum {
	IDETAPE_DIR_NONE  = (1 << 0),
	IDETAPE_DIR_READ  = (1 << 1),
	IDETAPE_DIR_WRITE = (1 << 2),
};
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struct idetape_bh {
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	u32 b_size;
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	atomic_t b_count;
	struct idetape_bh *b_reqnext;
	char *b_data;
};

typedef struct idetape_packet_command_s {
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	/* Actual packet bytes */
	u8 c[12];
	/* On each retry, we increment retries */
	int retries;
	/* Error code */
	int error;
	/* Bytes to transfer */
	int request_transfer;
	/* Bytes actually transferred */
	int actually_transferred;
	/* Size of our data buffer */
	int buffer_size;
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	struct idetape_bh *bh;
	char *b_data;
	int b_count;
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	/* Data buffer */
	u8 *buffer;
	/* Pointer into the above buffer */
	u8 *current_position;
	/* Called when this packet command is completed */
	ide_startstop_t (*callback) (ide_drive_t *);
	/* Temporary buffer */
	u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE];
	/* Status/Action bit flags: long for set_bit */
	unsigned long flags;
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} idetape_pc_t;

/*
 *	Packet command flag bits.
 */
/* Set when an error is considered normal - We won't retry */
#define	PC_ABORT			0
/* 1 When polling for DSC on a media access command */
#define PC_WAIT_FOR_DSC			1
/* 1 when we prefer to use DMA if possible */
#define PC_DMA_RECOMMENDED		2
/* 1 while DMA in progress */
#define	PC_DMA_IN_PROGRESS		3
/* 1 when encountered problem during DMA */
#define	PC_DMA_ERROR			4
/* Data direction */
#define	PC_WRITING			5

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/* A pipeline stage. */
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typedef struct idetape_stage_s {
	struct request rq;			/* The corresponding request */
	struct idetape_bh *bh;			/* The data buffers */
	struct idetape_stage_s *next;		/* Pointer to the next stage */
} idetape_stage_t;

/*
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 * Most of our global data which we need to save even as we leave the driver due
 * to an interrupt or a timer event is stored in the struct defined below.
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 */
typedef struct ide_tape_obj {
	ide_drive_t	*drive;
	ide_driver_t	*driver;
	struct gendisk	*disk;
	struct kref	kref;

	/*
	 *	Since a typical character device operation requires more
	 *	than one packet command, we provide here enough memory
	 *	for the maximum of interconnected packet commands.
	 *	The packet commands are stored in the circular array pc_stack.
	 *	pc_stack_index points to the last used entry, and warps around
	 *	to the start when we get to the last array entry.
	 *
	 *	pc points to the current processed packet command.
	 *
	 *	failed_pc points to the last failed packet command, or contains
	 *	NULL if we do not need to retry any packet command. This is
	 *	required since an additional packet command is needed before the
	 *	retry, to get detailed information on what went wrong.
	 */
	/* Current packet command */
	idetape_pc_t *pc;
	/* Last failed packet command */
	idetape_pc_t *failed_pc;
	/* Packet command stack */
	idetape_pc_t pc_stack[IDETAPE_PC_STACK];
	/* Next free packet command storage space */
	int pc_stack_index;
	struct request rq_stack[IDETAPE_PC_STACK];
	/* We implement a circular array */
	int rq_stack_index;

	/*
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	 * DSC polling variables.
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	 *
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	 * While polling for DSC we use postponed_rq to postpone the current
	 * request so that ide.c will be able to service pending requests on the
	 * other device. Note that at most we will have only one DSC (usually
	 * data transfer) request in the device request queue. Additional
	 * requests can be queued in our internal pipeline, but they will be
	 * visible to ide.c only one at a time.
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	 */
	struct request *postponed_rq;
	/* The time in which we started polling for DSC */
	unsigned long dsc_polling_start;
	/* Timer used to poll for dsc */
	struct timer_list dsc_timer;
	/* Read/Write dsc polling frequency */
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	unsigned long best_dsc_rw_freq;
	unsigned long dsc_poll_freq;
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	unsigned long dsc_timeout;

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	/* Read position information */
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	u8 partition;
	/* Current block */
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	unsigned int first_frame;
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	/* Last error information */
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	u8 sense_key, asc, ascq;

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	/* Character device operation */
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	unsigned int minor;
	/* device name */
	char name[4];
	/* Current character device data transfer direction */
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	u8 chrdev_dir;
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	/* tape block size, usually 512 or 1024 bytes */
	unsigned short blk_size;
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	int user_bs_factor;
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	/* Copy of the tape's Capabilities and Mechanical Page */
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	u8 caps[20];
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	/*
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	 * Active data transfer request parameters.
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	 *
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	 * At most, there is only one ide-tape originated data transfer request
	 * in the device request queue. This allows ide.c to easily service
	 * requests from the other device when we postpone our active request.
	 * In the pipelined operation mode, we use our internal pipeline
	 * structure to hold more data requests. The data buffer size is chosen
	 * based on the tape's recommendation.
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	 */
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	/* ptr to the request which is waiting in the device request queue */
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	struct request *active_data_rq;
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	/* Data buffer size chosen based on the tape's recommendation */
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	int stage_size;
	idetape_stage_t *merge_stage;
	int merge_stage_size;
	struct idetape_bh *bh;
	char *b_data;
	int b_count;
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	/*
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	 * Pipeline parameters.
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	 *
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	 * To accomplish non-pipelined mode, we simply set the following
	 * variables to zero (or NULL, where appropriate).
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	 */
	/* Number of currently used stages */
	int nr_stages;
	/* Number of pending stages */
	int nr_pending_stages;
	/* We will not allocate more than this number of stages */
	int max_stages, min_pipeline, max_pipeline;
	/* The first stage which will be removed from the pipeline */
	idetape_stage_t *first_stage;
	/* The currently active stage */
	idetape_stage_t *active_stage;
	/* Will be serviced after the currently active request */
	idetape_stage_t *next_stage;
	/* New requests will be added to the pipeline here */
	idetape_stage_t *last_stage;
	/* Optional free stage which we can use */
	idetape_stage_t *cache_stage;
	int pages_per_stage;
	/* Wasted space in each stage */
	int excess_bh_size;

	/* Status/Action flags: long for set_bit */
	unsigned long flags;
	/* protects the ide-tape queue */
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	spinlock_t lock;
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	/* Measures average tape speed */
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	unsigned long avg_time;
	int avg_size;
	int avg_speed;

	/* the door is currently locked */
	int door_locked;
	/* the tape hardware is write protected */
	char drv_write_prot;
	/* the tape is write protected (hardware or opened as read-only) */
	char write_prot;

	/*
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	 * Limit the number of times a request can be postponed, to avoid an
	 * infinite postpone deadlock.
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	 */
	int postpone_cnt;

	/*
	 * Measures number of frames:
	 *
	 * 1. written/read to/from the driver pipeline (pipeline_head).
	 * 2. written/read to/from the tape buffers (idetape_bh).
	 * 3. written/read by the tape to/from the media (tape_head).
	 */
	int pipeline_head;
	int buffer_head;
	int tape_head;
	int last_tape_head;

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	/* Speed control at the tape buffers input/output */
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	unsigned long insert_time;
	int insert_size;
	int insert_speed;
	int max_insert_speed;
	int measure_insert_time;

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	/* Speed regulation negative feedback loop */
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	int speed_control;
	int pipeline_head_speed;
	int controlled_pipeline_head_speed;
	int uncontrolled_pipeline_head_speed;
	int controlled_last_pipeline_head;
	unsigned long uncontrolled_pipeline_head_time;
	unsigned long controlled_pipeline_head_time;
	int controlled_previous_pipeline_head;
	int uncontrolled_previous_pipeline_head;
	unsigned long controlled_previous_head_time;
	unsigned long uncontrolled_previous_head_time;
	int restart_speed_control_req;

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	u32 debug_mask;
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} idetape_tape_t;

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static DEFINE_MUTEX(idetape_ref_mutex);
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static struct class *idetape_sysfs_class;

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#define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref)

#define ide_tape_g(disk) \
	container_of((disk)->private_data, struct ide_tape_obj, driver)

static struct ide_tape_obj *ide_tape_get(struct gendisk *disk)
{
	struct ide_tape_obj *tape = NULL;

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	mutex_lock(&idetape_ref_mutex);
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	tape = ide_tape_g(disk);
	if (tape)
		kref_get(&tape->kref);
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	mutex_unlock(&idetape_ref_mutex);
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	return tape;
}

static void ide_tape_release(struct kref *);

static void ide_tape_put(struct ide_tape_obj *tape)
{
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	mutex_lock(&idetape_ref_mutex);
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	kref_put(&tape->kref, ide_tape_release);
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	mutex_unlock(&idetape_ref_mutex);
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}

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/* Tape door status */
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#define DOOR_UNLOCKED			0
#define DOOR_LOCKED			1
#define DOOR_EXPLICITLY_LOCKED		2

/*
 *	Tape flag bits values.
 */
#define IDETAPE_IGNORE_DSC		0
#define IDETAPE_ADDRESS_VALID		1	/* 0 When the tape position is unknown */
#define IDETAPE_BUSY			2	/* Device already opened */
#define IDETAPE_PIPELINE_ERROR		3	/* Error detected in a pipeline stage */
#define IDETAPE_DETECT_BS		4	/* Attempt to auto-detect the current user block size */
#define IDETAPE_FILEMARK		5	/* Currently on a filemark */
#define IDETAPE_DRQ_INTERRUPT		6	/* DRQ interrupt device */
#define IDETAPE_READ_ERROR		7
#define IDETAPE_PIPELINE_ACTIVE		8	/* pipeline active */
/* 0 = no tape is loaded, so we don't rewind after ejecting */
#define IDETAPE_MEDIUM_PRESENT		9

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/* A define for the READ BUFFER command */
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#define IDETAPE_RETRIEVE_FAULTY_BLOCK	6

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/* Some defines for the SPACE command */
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#define IDETAPE_SPACE_OVER_FILEMARK	1
#define IDETAPE_SPACE_TO_EOD		3

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/* Some defines for the LOAD UNLOAD command */
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#define IDETAPE_LU_LOAD_MASK		1
#define IDETAPE_LU_RETENSION_MASK	2
#define IDETAPE_LU_EOT_MASK		4

/*
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 * Special requests for our block device strategy routine.
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 *
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 * In order to service a character device command, we add special requests to
 * the tail of our block device request queue and wait for their completion.
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 */

enum {
	REQ_IDETAPE_PC1		= (1 << 0), /* packet command (first stage) */
	REQ_IDETAPE_PC2		= (1 << 1), /* packet command (second stage) */
	REQ_IDETAPE_READ	= (1 << 2),
	REQ_IDETAPE_WRITE	= (1 << 3),
	REQ_IDETAPE_READ_BUFFER	= (1 << 4),
};

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/* Error codes returned in rq->errors to the higher part of the driver. */
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#define	IDETAPE_ERROR_GENERAL		101
#define	IDETAPE_ERROR_FILEMARK		102
#define	IDETAPE_ERROR_EOD		103

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/* Structures related to the SELECT SENSE / MODE SENSE packet commands. */
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#define IDETAPE_BLOCK_DESCRIPTOR	0
#define	IDETAPE_CAPABILITIES_PAGE	0x2a

/*
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 * The variables below are used for the character device interface. Additional
 * state variables are defined in our ide_drive_t structure.
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 */
static struct ide_tape_obj * idetape_devs[MAX_HWIFS * MAX_DRIVES];

#define ide_tape_f(file) ((file)->private_data)

static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
{
	struct ide_tape_obj *tape = NULL;

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	mutex_lock(&idetape_ref_mutex);
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	tape = idetape_devs[i];
	if (tape)
		kref_get(&tape->kref);
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	mutex_unlock(&idetape_ref_mutex);
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	return tape;
}

static int idetape_chrdev_release (struct inode *inode, struct file *filp);
static void idetape_write_release (ide_drive_t *drive, unsigned int minor);

/*
 * Too bad. The drive wants to send us data which we are not ready to accept.
 * Just throw it away.
 */
static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount)
{
	while (bcount--)
		(void) HWIF(drive)->INB(IDE_DATA_REG);
}

static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
{
	struct idetape_bh *bh = pc->bh;
	int count;

	while (bcount) {
		if (bh == NULL) {
			printk(KERN_ERR "ide-tape: bh == NULL in "
				"idetape_input_buffers\n");
			idetape_discard_data(drive, bcount);
			return;
		}
		count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount);
		HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count);
		bcount -= count;
		atomic_add(count, &bh->b_count);
		if (atomic_read(&bh->b_count) == bh->b_size) {
			bh = bh->b_reqnext;
			if (bh)
				atomic_set(&bh->b_count, 0);
		}
	}
	pc->bh = bh;
}

static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount)
{
	struct idetape_bh *bh = pc->bh;
	int count;

	while (bcount) {
		if (bh == NULL) {
			printk(KERN_ERR "ide-tape: bh == NULL in "
				"idetape_output_buffers\n");
			return;
		}
		count = min((unsigned int)pc->b_count, (unsigned int)bcount);
		HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count);
		bcount -= count;
		pc->b_data += count;
		pc->b_count -= count;
		if (!pc->b_count) {
			pc->bh = bh = bh->b_reqnext;
			if (bh) {
				pc->b_data = bh->b_data;
				pc->b_count = atomic_read(&bh->b_count);
			}
		}
	}
}

static void idetape_update_buffers (idetape_pc_t *pc)
{
	struct idetape_bh *bh = pc->bh;
	int count;
	unsigned int bcount = pc->actually_transferred;

	if (test_bit(PC_WRITING, &pc->flags))
		return;
	while (bcount) {
		if (bh == NULL) {
			printk(KERN_ERR "ide-tape: bh == NULL in "
				"idetape_update_buffers\n");
			return;
		}
		count = min((unsigned int)bh->b_size, (unsigned int)bcount);
		atomic_set(&bh->b_count, count);
		if (atomic_read(&bh->b_count) == bh->b_size)
			bh = bh->b_reqnext;
		bcount -= count;
	}
	pc->bh = bh;
}

/*
 *	idetape_next_pc_storage returns a pointer to a place in which we can
 *	safely store a packet command, even though we intend to leave the
 *	driver. A storage space for a maximum of IDETAPE_PC_STACK packet
 *	commands is allocated at initialization time.
 */
static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;

622 623
	debug_log(DBG_PCRQ_STACK, "pc_stack_index=%d\n", tape->pc_stack_index);

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	if (tape->pc_stack_index == IDETAPE_PC_STACK)
		tape->pc_stack_index=0;
	return (&tape->pc_stack[tape->pc_stack_index++]);
}

/*
 *	idetape_next_rq_storage is used along with idetape_next_pc_storage.
 *	Since we queue packet commands in the request queue, we need to
 *	allocate a request, along with the allocation of a packet command.
 */
 
/**************************************************************
 *                                                            *
 *  This should get fixed to use kmalloc(.., GFP_ATOMIC)      *
 *  followed later on by kfree().   -ml                       *
 *                                                            *
 **************************************************************/
 
static struct request *idetape_next_rq_storage (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;

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	debug_log(DBG_PCRQ_STACK, "rq_stack_index=%d\n", tape->rq_stack_index);

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	if (tape->rq_stack_index == IDETAPE_PC_STACK)
		tape->rq_stack_index=0;
	return (&tape->rq_stack[tape->rq_stack_index++]);
}

static void idetape_init_pc (idetape_pc_t *pc)
{
	memset(pc->c, 0, 12);
	pc->retries = 0;
	pc->flags = 0;
	pc->request_transfer = 0;
	pc->buffer = pc->pc_buffer;
	pc->buffer_size = IDETAPE_PC_BUFFER_SIZE;
	pc->bh = NULL;
	pc->b_data = NULL;
}

/*
666 667
 * called on each failed packet command retry to analyze the request sense. We
 * currently do not utilize this information.
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 */
669
static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
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{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t *pc = tape->failed_pc;

674 675 676
	tape->sense_key = sense[2] & 0xF;
	tape->asc       = sense[12];
	tape->ascq      = sense[13];
677 678 679

	debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
		 pc->c[0], tape->sense_key, tape->asc, tape->ascq);
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	/* Correct pc->actually_transferred by asking the tape.	 */
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	if (test_bit(PC_DMA_ERROR, &pc->flags)) {
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		pc->actually_transferred = pc->request_transfer -
684
			tape->blk_size *
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			be32_to_cpu(get_unaligned((u32 *)&sense[3]));
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		idetape_update_buffers(pc);
	}

	/*
	 * If error was the result of a zero-length read or write command,
	 * with sense key=5, asc=0x22, ascq=0, let it slide.  Some drives
	 * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes.
	 */
694
	if ((pc->c[0] == READ_6 || pc->c[0] == WRITE_6)
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	    /* length == 0 */
	    && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) {
		if (tape->sense_key == 5) {
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			/* don't report an error, everything's ok */
			pc->error = 0;
			/* don't retry read/write */
			set_bit(PC_ABORT, &pc->flags);
		}
	}
704
	if (pc->c[0] == READ_6 && (sense[2] & 0x80)) {
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		pc->error = IDETAPE_ERROR_FILEMARK;
		set_bit(PC_ABORT, &pc->flags);
	}
708
	if (pc->c[0] == WRITE_6) {
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		if ((sense[2] & 0x40) || (tape->sense_key == 0xd
		     && tape->asc == 0x0 && tape->ascq == 0x2)) {
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			pc->error = IDETAPE_ERROR_EOD;
			set_bit(PC_ABORT, &pc->flags);
		}
	}
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	if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
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		if (tape->sense_key == 8) {
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			pc->error = IDETAPE_ERROR_EOD;
			set_bit(PC_ABORT, &pc->flags);
		}
		if (!test_bit(PC_ABORT, &pc->flags) &&
		    pc->actually_transferred)
			pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
	}
}

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static void idetape_activate_next_stage(ide_drive_t *drive)
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{
	idetape_tape_t *tape = drive->driver_data;
	idetape_stage_t *stage = tape->next_stage;
	struct request *rq = &stage->rq;

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	debug_log(DBG_PROCS, "Enter %s\n", __func__);

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	if (stage == NULL) {
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		printk(KERN_ERR "ide-tape: bug: Trying to activate a non"
				" existing stage\n");
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		return;
	}

	rq->rq_disk = tape->disk;
	rq->buffer = NULL;
	rq->special = (void *)stage->bh;
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	tape->active_data_rq = rq;
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	tape->active_stage = stage;
	tape->next_stage = stage->next;
}

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/* Free a stage along with its related buffers completely. */
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static void __idetape_kfree_stage (idetape_stage_t *stage)
{
	struct idetape_bh *prev_bh, *bh = stage->bh;
	int size;

	while (bh != NULL) {
		if (bh->b_data != NULL) {
			size = (int) bh->b_size;
			while (size > 0) {
				free_page((unsigned long) bh->b_data);
				size -= PAGE_SIZE;
				bh->b_data += PAGE_SIZE;
			}
		}
		prev_bh = bh;
		bh = bh->b_reqnext;
		kfree(prev_bh);
	}
	kfree(stage);
}

static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage)
{
	__idetape_kfree_stage(stage);
}

/*
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 * Remove tape->first_stage from the pipeline. The caller should avoid race
 * conditions.
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 */
static void idetape_remove_stage_head (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_stage_t *stage;
783 784 785

	debug_log(DBG_PROCS, "Enter %s\n", __func__);

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	if (tape->first_stage == NULL) {
		printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n");
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		return;
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	}
	if (tape->active_stage == tape->first_stage) {
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		printk(KERN_ERR "ide-tape: bug: Trying to free our active "
				"pipeline stage\n");
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		return;
	}
	stage = tape->first_stage;
	tape->first_stage = stage->next;
	idetape_kfree_stage(tape, stage);
	tape->nr_stages--;
	if (tape->first_stage == NULL) {
		tape->last_stage = NULL;
		if (tape->next_stage != NULL)
			printk(KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n");
		if (tape->nr_stages)
			printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n");
	}
}

/*
 * This will free all the pipeline stages starting from new_last_stage->next
 * to the end of the list, and point tape->last_stage to new_last_stage.
 */
static void idetape_abort_pipeline(ide_drive_t *drive,
				   idetape_stage_t *new_last_stage)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_stage_t *stage = new_last_stage->next;
	idetape_stage_t *nstage;

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	debug_log(DBG_PROCS, "%s: Enter %s\n", tape->name, __func__);

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	while (stage) {
		nstage = stage->next;
		idetape_kfree_stage(tape, stage);
		--tape->nr_stages;
		--tape->nr_pending_stages;
		stage = nstage;
	}
	if (new_last_stage)
		new_last_stage->next = NULL;
	tape->last_stage = new_last_stage;
	tape->next_stage = NULL;
}

/*
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 * Finish servicing a request and insert a pending pipeline request into the
 * main device queue.
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 */
static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects)
{
	struct request *rq = HWGROUP(drive)->rq;
	idetape_tape_t *tape = drive->driver_data;
	unsigned long flags;
	int error;
	int remove_stage = 0;
	idetape_stage_t *active_stage;

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	debug_log(DBG_PROCS, "Enter %s\n", __func__);
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	switch (uptodate) {
		case 0:	error = IDETAPE_ERROR_GENERAL; break;
		case 1: error = 0; break;
		default: error = uptodate;
	}
	rq->errors = error;
	if (error)
		tape->failed_pc = NULL;

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	if (!blk_special_request(rq)) {
		ide_end_request(drive, uptodate, nr_sects);
		return 0;
	}

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	spin_lock_irqsave(&tape->lock, flags);
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	/* The request was a pipelined data transfer request */
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	if (tape->active_data_rq == rq) {
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		active_stage = tape->active_stage;
		tape->active_stage = NULL;
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		tape->active_data_rq = NULL;
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		tape->nr_pending_stages--;
		if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
			remove_stage = 1;
			if (error) {
				set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
				if (error == IDETAPE_ERROR_EOD)
					idetape_abort_pipeline(drive, active_stage);
			}
		} else if (rq->cmd[0] & REQ_IDETAPE_READ) {
			if (error == IDETAPE_ERROR_EOD) {
				set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
				idetape_abort_pipeline(drive, active_stage);
			}
		}
		if (tape->next_stage != NULL) {
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			idetape_activate_next_stage(drive);
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			/* Insert the next request into the request queue. */
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			(void)ide_do_drive_cmd(drive, tape->active_data_rq,
						ide_end);
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		} else if (!error) {
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			/*
			 * This is a part of the feedback loop which tries to
			 * find the optimum number of stages. We are starting
			 * from a minimum maximum number of stages, and if we
			 * sense that the pipeline is empty, we try to increase
			 * it, until we reach the user compile time memory
			 * limit.
			 */
			int i = (tape->max_pipeline - tape->min_pipeline) / 10;

			tape->max_stages += max(i, 1);
			tape->max_stages = max(tape->max_stages,
						tape->min_pipeline);
			tape->max_stages = min(tape->max_stages,
						tape->max_pipeline);
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		}
	}
	ide_end_drive_cmd(drive, 0, 0);
//	blkdev_dequeue_request(rq);
//	drive->rq = NULL;
//	end_that_request_last(rq);

	if (remove_stage)
		idetape_remove_stage_head(drive);
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	if (tape->active_data_rq == NULL)
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		clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
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	spin_unlock_irqrestore(&tape->lock, flags);
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	return 0;
}

static ide_startstop_t idetape_request_sense_callback (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;

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	debug_log(DBG_PROCS, "Enter %s\n", __func__);

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	if (!tape->pc->error) {
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		idetape_analyze_error(drive, tape->pc->buffer);
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		idetape_end_request(drive, 1, 0);
	} else {
		printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - Aborting request!\n");
		idetape_end_request(drive, 0, 0);
	}
	return ide_stopped;
}

static void idetape_create_request_sense_cmd (idetape_pc_t *pc)
{
	idetape_init_pc(pc);	
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	pc->c[0] = REQUEST_SENSE;
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	pc->c[4] = 20;
	pc->request_transfer = 20;
	pc->callback = &idetape_request_sense_callback;
}

static void idetape_init_rq(struct request *rq, u8 cmd)
{
	memset(rq, 0, sizeof(*rq));
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	rq->cmd_type = REQ_TYPE_SPECIAL;
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	rq->cmd[0] = cmd;
}

/*
954 955 956 957 958
 * Generate a new packet command request in front of the request queue, before
 * the current request, so that it will be processed immediately, on the next
 * pass through the driver. The function below is called from the request
 * handling part of the driver (the "bottom" part). Safe storage for the request
 * should be allocated with ide_tape_next_{pc,rq}_storage() prior to that.
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 *
960 961 962
 * Memory for those requests is pre-allocated at initialization time, and is
 * limited to IDETAPE_PC_STACK requests. We assume that we have enough space for
 * the maximum possible number of inter-dependent packet commands.
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 *
964 965 966
 * The higher level of the driver - The ioctl handler and the character device
 * handling functions should queue request to the lower level part and wait for
 * their completion using idetape_queue_pc_tail or idetape_queue_rw_tail.
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 */
static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct request *rq)
{
	struct ide_tape_obj *tape = drive->driver_data;

	idetape_init_rq(rq, REQ_IDETAPE_PC1);
	rq->buffer = (char *) pc;
	rq->rq_disk = tape->disk;
	(void) ide_do_drive_cmd(drive, rq, ide_preempt);
}

/*
 *	idetape_retry_pc is called when an error was detected during the
 *	last packet command. We queue a request sense packet command in
 *	the head of the request list.
 */
static ide_startstop_t idetape_retry_pc (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t *pc;
	struct request *rq;

989
	(void)ide_read_error(drive);
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	pc = idetape_next_pc_storage(drive);
	rq = idetape_next_rq_storage(drive);
	idetape_create_request_sense_cmd(pc);
	set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
	idetape_queue_pc_head(drive, pc, rq);
	return ide_stopped;
}

/*
999 1000
 * Postpone the current request so that ide.c will be able to service requests
 * from another device on the same hwgroup while we are polling for DSC.
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 */
static void idetape_postpone_request (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;

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	debug_log(DBG_PROCS, "Enter %s\n", __func__);

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	tape->postponed_rq = HWGROUP(drive)->rq;
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	ide_stall_queue(drive, tape->dsc_poll_freq);
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}

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typedef void idetape_io_buf(ide_drive_t *, idetape_pc_t *, unsigned int);

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/*
1015 1016 1017 1018
 * This is the usual interrupt handler which will be called during a packet
 * command. We will transfer some of the data (as requested by the drive) and
 * will re-point interrupt handler to us. When data transfer is finished, we
 * will act according to the algorithm described before
1019
 * idetape_issue_pc.
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 */
1021
static ide_startstop_t idetape_pc_intr(ide_drive_t *drive)
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{
	ide_hwif_t *hwif = drive->hwif;
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t *pc = tape->pc;
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	xfer_func_t *xferfunc;
	idetape_io_buf *iobuf;
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	unsigned int temp;
#if SIMULATE_ERRORS
	static int error_sim_count = 0;
#endif
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	u16 bcount;
1033
	u8 stat, ireason;
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	debug_log(DBG_PROCS, "Enter %s - interrupt handler\n", __func__);
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	/* Clear the interrupt */
1038
	stat = ide_read_status(drive);
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	if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
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		if (hwif->ide_dma_end(drive) || (stat & ERR_STAT)) {
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			/*
			 * A DMA error is sometimes expected. For example,
			 * if the tape is crossing a filemark during a
			 * READ command, it will issue an irq and position
			 * itself before the filemark, so that only a partial
			 * data transfer will occur (which causes the DMA
			 * error). In that case, we will later ask the tape
			 * how much bytes of the original request were
			 * actually transferred (we can't receive that
			 * information from the DMA engine on most chipsets).
			 */

			/*
			 * On the contrary, a DMA error is never expected;
			 * it usually indicates a hardware error or abort.
			 * If the tape crosses a filemark during a READ
			 * command, it will issue an irq and position itself
			 * after the filemark (not before). Only a partial
			 * data transfer will occur, but no DMA error.
			 * (AS, 19 Apr 2001)
			 */
			set_bit(PC_DMA_ERROR, &pc->flags);
		} else {
			pc->actually_transferred = pc->request_transfer;
			idetape_update_buffers(pc);
		}
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		debug_log(DBG_PROCS, "DMA finished\n");

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	}

	/* No more interrupts */
1073
	if ((stat & DRQ_STAT) == 0) {
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		debug_log(DBG_SENSE, "Packet command completed, %d bytes"
				" transferred\n", pc->actually_transferred);
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		clear_bit(PC_DMA_IN_PROGRESS, &pc->flags);
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		local_irq_enable();

#if SIMULATE_ERRORS
1081
		if ((pc->c[0] == WRITE_6 || pc->c[0] == READ_6) &&
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		    (++error_sim_count % 100) == 0) {
			printk(KERN_INFO "ide-tape: %s: simulating error\n",
				tape->name);
1085
			stat |= ERR_STAT;
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		}
#endif
1088
		if ((stat & ERR_STAT) && pc->c[0] == REQUEST_SENSE)
1089 1090 1091
			stat &= ~ERR_STAT;
		if ((stat & ERR_STAT) || test_bit(PC_DMA_ERROR, &pc->flags)) {
			/* Error detected */
1092 1093
			debug_log(DBG_ERR, "%s: I/O error\n", tape->name);

1094
			if (pc->c[0] == REQUEST_SENSE) {
1095 1096
				printk(KERN_ERR "ide-tape: I/O error in request"
						" sense command\n");
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				return ide_do_reset(drive);
			}
1099 1100 1101
			debug_log(DBG_ERR, "[cmd %x]: check condition\n",
					pc->c[0]);

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			/* Retry operation */
			return idetape_retry_pc(drive);
		}
		pc->error = 0;
		if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) &&
1107
		    (stat & SEEK_STAT) == 0) {
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			/* Media access command */
			tape->dsc_polling_start = jiffies;
1110
			tape->dsc_poll_freq = IDETAPE_DSC_MA_FAST;
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			tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT;
			/* Allow ide.c to handle other requests */
			idetape_postpone_request(drive);
			return ide_stopped;
		}
		if (tape->failed_pc == pc)
			tape->failed_pc = NULL;
		/* Command finished - Call the callback function */
		return pc->callback(drive);
	}
	if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) {
		printk(KERN_ERR "ide-tape: The tape wants to issue more "
				"interrupts in DMA mode\n");
		printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n");
1125
		ide_dma_off(drive);
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		return ide_do_reset(drive);
	}
	/* Get the number of bytes to transfer on this interrupt. */
1129 1130
	bcount = (hwif->INB(IDE_BCOUNTH_REG) << 8) |
		  hwif->INB(IDE_BCOUNTL_REG);
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	ireason = hwif->INB(IDE_IREASON_REG);
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	if (ireason & CD) {
1135
		printk(KERN_ERR "ide-tape: CoD != 0 in %s\n", __func__);
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		return ide_do_reset(drive);
	}
1138
	if (((ireason & IO) == IO) == test_bit(PC_WRITING, &pc->flags)) {
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		/* Hopefully, we will never get here */
		printk(KERN_ERR "ide-tape: We wanted to %s, ",
1141
				(ireason & IO) ? "Write" : "Read");
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		printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n",
1143
				(ireason & IO) ? "Read" : "Write");
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		return ide_do_reset(drive);
	}
	if (!test_bit(PC_WRITING, &pc->flags)) {
		/* Reading - Check that we have enough space */
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		temp = pc->actually_transferred + bcount;
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		if (temp > pc->request_transfer) {
			if (temp > pc->buffer_size) {
1151 1152 1153
				printk(KERN_ERR "ide-tape: The tape wants to "
					"send us more data than expected "
					"- discarding data\n");
1154
				idetape_discard_data(drive, bcount);
1155 1156
				ide_set_handler(drive, &idetape_pc_intr,
						IDETAPE_WAIT_CMD, NULL);
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				return ide_started;
			}
1159 1160
			debug_log(DBG_SENSE, "The tape wants to send us more "
				"data than expected - allowing transfer\n");
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		}
1162 1163
		iobuf = &idetape_input_buffers;
		xferfunc = hwif->atapi_input_bytes;
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	} else {
1165 1166
		iobuf = &idetape_output_buffers;
		xferfunc = hwif->atapi_output_bytes;
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	}
1168 1169 1170 1171 1172 1173

	if (pc->bh)
		iobuf(drive, pc, bcount);
	else
		xferfunc(drive, pc->current_position, bcount);

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	/* Update the current position */
1175 1176
	pc->actually_transferred += bcount;
	pc->current_position += bcount;
1177 1178 1179 1180

	debug_log(DBG_SENSE, "[cmd %x] transferred %d bytes on that intr.\n",
			pc->c[0], bcount);

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	/* And set the interrupt handler again */
	ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
	return ide_started;
}

/*
1187
 * Packet Command Interface
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 *
1189 1190 1191
 * The current Packet Command is available in tape->pc, and will not change
 * until we finish handling it. Each packet command is associated with a
 * callback function that will be called when the command is finished.
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 *
1193
 * The handling will be done in three stages:
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 *
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 * 1. idetape_issue_pc will send the packet command to the drive, and will set
 * the interrupt handler to idetape_pc_intr.
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 *
1198 1199
 * 2. On each interrupt, idetape_pc_intr will be called. This step will be
 * repeated until the device signals us that no more interrupts will be issued.
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 *
1201 1202 1203 1204 1205 1206 1207
 * 3. ATAPI Tape media access commands have immediate status with a delayed
 * process. In case of a successful initiation of a media access packet command,
 * the DSC bit will be set when the actual execution of the command is finished.
 * Since the tape drive will not issue an interrupt, we have to poll for this
 * event. In this case, we define the request as "low priority request" by
 * setting rq_status to IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and
 * exit the driver.
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 *
1209 1210
 * ide.c will then give higher priority to requests which originate from the
 * other device, until will change rq_status to RQ_ACTIVE.
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 *
1212
 * 4. When the packet command is finished, it will be checked for errors.
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 *
1214 1215 1216
 * 5. In case an error was found, we queue a request sense packet command in
 * front of the request queue and retry the operation up to
 * IDETAPE_MAX_PC_RETRIES times.
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 *
1218 1219 1220
 * 6. In case no error was found, or we decided to give up and not to retry
 * again, the callback function will be called and then we will handle the next
 * request.
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 */
static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive)
{
	ide_hwif_t *hwif = drive->hwif;
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t *pc = tape->pc;
	int retries = 100;
	ide_startstop_t startstop;
1229
	u8 ireason;
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	if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) {
		printk(KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n");
		return startstop;
	}
1235 1236
	ireason = hwif->INB(IDE_IREASON_REG);
	while (retries-- && ((ireason & CD) == 0 || (ireason & IO))) {
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		printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing "
				"a packet command, retrying\n");
		udelay(100);
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		ireason = hwif->INB(IDE_IREASON_REG);
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		if (retries == 0) {
			printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while "
					"issuing a packet command, ignoring\n");
1244 1245
			ireason |= CD;
			ireason &= ~IO;
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		}
	}
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	if ((ireason & CD) == 0 || (ireason & IO)) {
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		printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing "
				"a packet command\n");
		return ide_do_reset(drive);
	}
	/* Set the interrupt routine */
	ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL);
#ifdef CONFIG_BLK_DEV_IDEDMA
	/* Begin DMA, if necessary */
	if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags))
		hwif->dma_start(drive);
#endif
	/* Send the actual packet */
	HWIF(drive)->atapi_output_bytes(drive, pc->c, 12);
	return ide_started;
}

1265
static ide_startstop_t idetape_issue_pc(ide_drive_t *drive, idetape_pc_t *pc)
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{
	ide_hwif_t *hwif = drive->hwif;
	idetape_tape_t *tape = drive->driver_data;
	int dma_ok = 0;
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	u16 bcount;
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	if (tape->pc->c[0] == REQUEST_SENSE &&
	    pc->c[0] == REQUEST_SENSE) {
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		printk(KERN_ERR "ide-tape: possible ide-tape.c bug - "
			"Two request sense in serial were issued\n");
	}

1278
	if (tape->failed_pc == NULL && pc->c[0] != REQUEST_SENSE)
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		tape->failed_pc = pc;
	/* Set the current packet command */
	tape->pc = pc;

	if (pc->retries > IDETAPE_MAX_PC_RETRIES ||
	    test_bit(PC_ABORT, &pc->flags)) {
		/*
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		 * We will "abort" retrying a packet command in case legitimate
		 * error code was received (crossing a filemark, or end of the
		 * media, for example).
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		 */
		if (!test_bit(PC_ABORT, &pc->flags)) {
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			if (!(pc->c[0] == TEST_UNIT_READY &&
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			      tape->sense_key == 2 && tape->asc == 4 &&
			     (tape->ascq == 1 || tape->ascq == 8))) {
				printk(KERN_ERR "ide-tape: %s: I/O error, "
						"pc = %2x, key = %2x, "
						"asc = %2x, ascq = %2x\n",
						tape->name, pc->c[0],
						tape->sense_key, tape->asc,
						tape->ascq);
			}
			/* Giving up */
			pc->error = IDETAPE_ERROR_GENERAL;
		}
		tape->failed_pc = NULL;
		return pc->callback(drive);
	}
1307
	debug_log(DBG_SENSE, "Retry #%d, cmd = %02X\n", pc->retries, pc->c[0]);
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	pc->retries++;
	/* We haven't transferred any data yet */
	pc->actually_transferred = 0;
	pc->current_position = pc->buffer;
	/* Request to transfer the entire buffer at once */
1314
	bcount = pc->request_transfer;
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	if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) {
		printk(KERN_WARNING "ide-tape: DMA disabled, "
				"reverting to PIO\n");
1319
		ide_dma_off(drive);
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	}
	if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma)
		dma_ok = !hwif->dma_setup(drive);

1324 1325 1326
	ide_pktcmd_tf_load(drive, IDE_TFLAG_NO_SELECT_MASK |
			   IDE_TFLAG_OUT_DEVICE, bcount, dma_ok);

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	if (dma_ok)			/* Will begin DMA later */
		set_bit(PC_DMA_IN_PROGRESS, &pc->flags);
	if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) {
1330 1331
		ide_execute_command(drive, WIN_PACKETCMD, &idetape_transfer_pc,
				    IDETAPE_WAIT_CMD, NULL);
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		return ide_started;
	} else {
		hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG);
		return idetape_transfer_pc(drive);
	}
}

static ide_startstop_t idetape_pc_callback (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
1342 1343

	debug_log(DBG_PROCS, "Enter %s\n", __func__);
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	idetape_end_request(drive, tape->pc->error ? 0 : 1, 0);
	return ide_stopped;
}

1349
/* A mode sense command is used to "sense" tape parameters. */
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static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code)
{
	idetape_init_pc(pc);
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	pc->c[0] = MODE_SENSE;
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	if (page_code != IDETAPE_BLOCK_DESCRIPTOR)
1355 1356
		/* DBD = 1 - Don't return block descriptors */
		pc->c[1] = 8;
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	pc->c[2] = page_code;
	/*
	 * Changed pc->c[3] to 0 (255 will at best return unused info).
	 *
	 * For SCSI this byte is defined as subpage instead of high byte
	 * of length and some IDE drives seem to interpret it this way
	 * and return an error when 255 is used.
	 */
	pc->c[3] = 0;
1366 1367
	/* We will just discard data in that case */
	pc->c[4] = 255;
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	if (page_code == IDETAPE_BLOCK_DESCRIPTOR)
		pc->request_transfer = 12;
	else if (page_code == IDETAPE_CAPABILITIES_PAGE)
		pc->request_transfer = 24;
	else
		pc->request_transfer = 50;
	pc->callback = &idetape_pc_callback;
}

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static void idetape_calculate_speeds(ide_drive_t *drive)
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{
	idetape_tape_t *tape = drive->driver_data;

	if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) {
		tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head;
		tape->controlled_previous_head_time = tape->controlled_pipeline_head_time;
		tape->controlled_last_pipeline_head = tape->pipeline_head;
		tape->controlled_pipeline_head_time = jiffies;
	}
	if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ))
		tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time);
	else if (time_after(jiffies, tape->controlled_previous_head_time))
		tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time);

	if (tape->nr_pending_stages < tape->max_stages /*- 1 */) {
		/* -1 for read mode error recovery */
		if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) {
			tape->uncontrolled_pipeline_head_time = jiffies;
			tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time);
		}
	} else {
		tape->uncontrolled_previous_head_time = jiffies;
		tape->uncontrolled_previous_pipeline_head = tape->pipeline_head;
		if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) {
			tape->uncontrolled_pipeline_head_time = jiffies;
		}
	}
	tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed);
1406 1407

	if (tape->speed_control == 1) {
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		if (tape->nr_pending_stages >= tape->max_stages / 2)
			tape->max_insert_speed = tape->pipeline_head_speed +
				(1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages;
		else
			tape->max_insert_speed = 500 +
				(tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages;
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		if (tape->nr_pending_stages >= tape->max_stages * 99 / 100)
			tape->max_insert_speed = 5000;
	} else
		tape->max_insert_speed = tape->speed_control;
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	tape->max_insert_speed = max(tape->max_insert_speed, 500);
}

static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t *pc = tape->pc;
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	u8 stat;
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	stat = ide_read_status(drive);

1431 1432
	if (stat & SEEK_STAT) {
		if (stat & ERR_STAT) {
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			/* Error detected */
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			if (pc->c[0] != TEST_UNIT_READY)
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				printk(KERN_ERR "ide-tape: %s: I/O error, ",
						tape->name);
			/* Retry operation */
			return idetape_retry_pc(drive);
		}
		pc->error = 0;
		if (tape->failed_pc == pc)
			tape->failed_pc = NULL;
	} else {
		pc->error = IDETAPE_ERROR_GENERAL;
		tape->failed_pc = NULL;
	}
	return pc->callback(drive);
}

static ide_startstop_t idetape_rw_callback (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	struct request *rq = HWGROUP(drive)->rq;
1454
	int blocks = tape->pc->actually_transferred / tape->blk_size;
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	tape->avg_size += blocks * tape->blk_size;
	tape->insert_size += blocks * tape->blk_size;
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	if (tape->insert_size > 1024 * 1024)
		tape->measure_insert_time = 1;
	if (tape->measure_insert_time) {
		tape->measure_insert_time = 0;
		tape->insert_time = jiffies;
		tape->insert_size = 0;
	}
	if (time_after(jiffies, tape->insert_time))
		tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
1467
	if (time_after_eq(jiffies, tape->avg_time + HZ)) {
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		tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024;
		tape->avg_size = 0;
		tape->avg_time = jiffies;
	}
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	debug_log(DBG_PROCS, "Enter %s\n", __func__);
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	tape->first_frame += blocks;
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	rq->current_nr_sectors -= blocks;

	if (!tape->pc->error)
		idetape_end_request(drive, 1, 0);
	else
		idetape_end_request(drive, tape->pc->error, 0);
	return ide_stopped;
}

static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
{
	idetape_init_pc(pc);
1487
	pc->c[0] = READ_6;
1488
	put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
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	pc->c[1] = 1;
	pc->callback = &idetape_rw_callback;
	pc->bh = bh;
	atomic_set(&bh->b_count, 0);
	pc->buffer = NULL;
1494 1495
	pc->buffer_size = length * tape->blk_size;
	pc->request_transfer = pc->buffer_size;
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	if (pc->request_transfer == tape->stage_size)
		set_bit(PC_DMA_RECOMMENDED, &pc->flags);
}

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static void idetape_create_read_buffer_cmd(idetape_tape_t *tape,
		idetape_pc_t *pc, struct idetape_bh *bh)
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{
	int size = 32768;
	struct idetape_bh *p = bh;

	idetape_init_pc(pc);
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	pc->c[0] = READ_BUFFER;
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	pc->c[1] = IDETAPE_RETRIEVE_FAULTY_BLOCK;
	pc->c[7] = size >> 8;
	pc->c[8] = size & 0xff;
	pc->callback = &idetape_pc_callback;
	pc->bh = bh;
	atomic_set(&bh->b_count, 0);
	pc->buffer = NULL;
	while (p) {
		atomic_set(&p->b_count, 0);
		p = p->b_reqnext;
	}
1519 1520
	pc->request_transfer = size;
	pc->buffer_size = size;
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}

static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh)
{
	idetape_init_pc(pc);
1526
	pc->c[0] = WRITE_6;
1527
	put_unaligned(cpu_to_be32(length), (unsigned int *) &pc->c[1]);
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	pc->c[1] = 1;
	pc->callback = &idetape_rw_callback;
	set_bit(PC_WRITING, &pc->flags);
	pc->bh = bh;
	pc->b_data = bh->b_data;
	pc->b_count = atomic_read(&bh->b_count);
	pc->buffer = NULL;
1535 1536
	pc->buffer_size = length * tape->blk_size;
	pc->request_transfer = pc->buffer_size;
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	if (pc->request_transfer == tape->stage_size)
		set_bit(PC_DMA_RECOMMENDED, &pc->flags);
}

static ide_startstop_t idetape_do_request(ide_drive_t *drive,
					  struct request *rq, sector_t block)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t *pc = NULL;
	struct request *postponed_rq = tape->postponed_rq;
1547
	u8 stat;
L
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1548

1549 1550
	debug_log(DBG_SENSE, "sector: %ld, nr_sectors: %ld,"
			" current_nr_sectors: %d\n",
L
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			rq->sector, rq->nr_sectors, rq->current_nr_sectors);

1553
	if (!blk_special_request(rq)) {
1554
		/* We do not support buffer cache originated requests. */
L
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		printk(KERN_NOTICE "ide-tape: %s: Unsupported request in "
1556
			"request queue (%d)\n", drive->name, rq->cmd_type);
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		ide_end_request(drive, 0, 0);
		return ide_stopped;
	}

1561
	/* Retry a failed packet command */
L
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1562
	if (tape->failed_pc != NULL &&
1563
	    tape->pc->c[0] == REQUEST_SENSE) {
1564
		return idetape_issue_pc(drive, tape->failed_pc);
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	}
	if (postponed_rq != NULL)
		if (rq != postponed_rq) {
			printk(KERN_ERR "ide-tape: ide-tape.c bug - "
					"Two DSC requests were queued\n");
			idetape_end_request(drive, 0, 0);
			return ide_stopped;
		}

	tape->postponed_rq = NULL;

	/*
	 * If the tape is still busy, postpone our request and service
	 * the other device meanwhile.
	 */
1580
	stat = ide_read_status(drive);
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	if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2))
		set_bit(IDETAPE_IGNORE_DSC, &tape->flags);

	if (drive->post_reset == 1) {
		set_bit(IDETAPE_IGNORE_DSC, &tape->flags);
		drive->post_reset = 0;
	}

	if (time_after(jiffies, tape->insert_time))
		tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time);
1592
	idetape_calculate_speeds(drive);
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1593
	if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) &&
1594
	    (stat & SEEK_STAT) == 0) {
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		if (postponed_rq == NULL) {
			tape->dsc_polling_start = jiffies;
1597
			tape->dsc_poll_freq = tape->best_dsc_rw_freq;
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			tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT;
		} else if (time_after(jiffies, tape->dsc_timeout)) {
			printk(KERN_ERR "ide-tape: %s: DSC timeout\n",
				tape->name);
			if (rq->cmd[0] & REQ_IDETAPE_PC2) {
				idetape_media_access_finished(drive);
				return ide_stopped;
			} else {
				return ide_do_reset(drive);
			}
1608
		} else if (time_after(jiffies, tape->dsc_polling_start + IDETAPE_DSC_MA_THRESHOLD))
1609
			tape->dsc_poll_freq = IDETAPE_DSC_MA_SLOW;
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		idetape_postpone_request(drive);
		return ide_stopped;
	}
	if (rq->cmd[0] & REQ_IDETAPE_READ) {
		tape->buffer_head++;
		tape->postpone_cnt = 0;
		pc = idetape_next_pc_storage(drive);
		idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
		goto out;
	}
	if (rq->cmd[0] & REQ_IDETAPE_WRITE) {
		tape->buffer_head++;
		tape->postpone_cnt = 0;
		pc = idetape_next_pc_storage(drive);
		idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special);
		goto out;
	}
	if (rq->cmd[0] & REQ_IDETAPE_READ_BUFFER) {
		tape->postpone_cnt = 0;
		pc = idetape_next_pc_storage(drive);
1630 1631
		idetape_create_read_buffer_cmd(tape, pc,
				(struct idetape_bh *)rq->special);
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		goto out;
	}
	if (rq->cmd[0] & REQ_IDETAPE_PC1) {
		pc = (idetape_pc_t *) rq->buffer;
		rq->cmd[0] &= ~(REQ_IDETAPE_PC1);
		rq->cmd[0] |= REQ_IDETAPE_PC2;
		goto out;
	}
	if (rq->cmd[0] & REQ_IDETAPE_PC2) {
		idetape_media_access_finished(drive);
		return ide_stopped;
	}
	BUG();
out:
1646
	return idetape_issue_pc(drive, pc);
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}

1649
/* Pipeline related functions */
L
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static inline int idetape_pipeline_active (idetape_tape_t *tape)
{
	int rc1, rc2;

	rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
1655
	rc2 = (tape->active_data_rq != NULL);
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	return rc1;
}

/*
1660 1661 1662 1663
 * The function below uses __get_free_page to allocate a pipeline stage, along
 * with all the necessary small buffers which together make a buffer of size
 * tape->stage_size (or a bit more). We attempt to combine sequential pages as
 * much as possible.
L
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1664
 *
1665 1666
 * It returns a pointer to the new allocated stage, or NULL if we can't (or
 * don't want to) allocate a stage.
L
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1667
 *
1668 1669
 * Pipeline stages are optional and are used to increase performance. If we
 * can't allocate them, we'll manage without them.
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 */
static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape, int full, int clear)
{
	idetape_stage_t *stage;
	struct idetape_bh *prev_bh, *bh;
	int pages = tape->pages_per_stage;
	char *b_data = NULL;

1678
	if ((stage = kmalloc(sizeof (idetape_stage_t),GFP_KERNEL)) == NULL)
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		return NULL;
	stage->next = NULL;

1682
	bh = stage->bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL);
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	if (bh == NULL)
		goto abort;
	bh->b_reqnext = NULL;
	if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
		goto abort;
	if (clear)
		memset(bh->b_data, 0, PAGE_SIZE);
	bh->b_size = PAGE_SIZE;
	atomic_set(&bh->b_count, full ? bh->b_size : 0);

	while (--pages) {
		if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL)
			goto abort;
		if (clear)
			memset(b_data, 0, PAGE_SIZE);
		if (bh->b_data == b_data + PAGE_SIZE) {
			bh->b_size += PAGE_SIZE;
			bh->b_data -= PAGE_SIZE;
			if (full)
				atomic_add(PAGE_SIZE, &bh->b_count);
			continue;
		}
		if (b_data == bh->b_data + bh->b_size) {
			bh->b_size += PAGE_SIZE;
			if (full)
				atomic_add(PAGE_SIZE, &bh->b_count);
			continue;
		}
		prev_bh = bh;
1712
		if ((bh = kmalloc(sizeof(struct idetape_bh), GFP_KERNEL)) == NULL) {
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			free_page((unsigned long) b_data);
			goto abort;
		}
		bh->b_reqnext = NULL;
		bh->b_data = b_data;
		bh->b_size = PAGE_SIZE;
		atomic_set(&bh->b_count, full ? bh->b_size : 0);
		prev_bh->b_reqnext = bh;
	}
	bh->b_size -= tape->excess_bh_size;
	if (full)
		atomic_sub(tape->excess_bh_size, &bh->b_count);
	return stage;
abort:
	__idetape_kfree_stage(stage);
	return NULL;
}

static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape)
{
	idetape_stage_t *cache_stage = tape->cache_stage;

1735
	debug_log(DBG_PROCS, "Enter %s\n", __func__);
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	if (tape->nr_stages >= tape->max_stages)
		return NULL;
	if (cache_stage != NULL) {
		tape->cache_stage = NULL;
		return cache_stage;
	}
	return __idetape_kmalloc_stage(tape, 0, 0);
}

1746
static int idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n)
L
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{
	struct idetape_bh *bh = tape->bh;
	int count;
1750
	int ret = 0;
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	while (n) {
		if (bh == NULL) {
			printk(KERN_ERR "ide-tape: bh == NULL in "
				"idetape_copy_stage_from_user\n");
1756
			return 1;
L
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		}
		count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n);
1759 1760
		if (copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count))
			ret = 1;
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		n -= count;
		atomic_add(count, &bh->b_count);
		buf += count;
		if (atomic_read(&bh->b_count) == bh->b_size) {
			bh = bh->b_reqnext;
			if (bh)
				atomic_set(&bh->b_count, 0);
		}
	}
	tape->bh = bh;
1771
	return ret;
L
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}

1774
static int idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n)
L
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{
	struct idetape_bh *bh = tape->bh;
	int count;
1778
	int ret = 0;
L
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1779 1780 1781 1782 1783

	while (n) {
		if (bh == NULL) {
			printk(KERN_ERR "ide-tape: bh == NULL in "
				"idetape_copy_stage_to_user\n");
1784
			return 1;
L
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1785 1786
		}
		count = min(tape->b_count, n);
1787 1788
		if  (copy_to_user(buf, tape->b_data, count))
			ret = 1;
L
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		n -= count;
		tape->b_data += count;
		tape->b_count -= count;
		buf += count;
		if (!tape->b_count) {
			tape->bh = bh = bh->b_reqnext;
			if (bh) {
				tape->b_data = bh->b_data;
				tape->b_count = atomic_read(&bh->b_count);
			}
		}
	}
1801
	return ret;
L
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1802 1803 1804 1805 1806 1807 1808
}

static void idetape_init_merge_stage (idetape_tape_t *tape)
{
	struct idetape_bh *bh = tape->merge_stage->bh;
	
	tape->bh = bh;
1809
	if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
L
Linus Torvalds 已提交
1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826
		atomic_set(&bh->b_count, 0);
	else {
		tape->b_data = bh->b_data;
		tape->b_count = atomic_read(&bh->b_count);
	}
}

static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage)
{
	struct idetape_bh *tmp;

	tmp = stage->bh;
	stage->bh = tape->merge_stage->bh;
	tape->merge_stage->bh = tmp;
	idetape_init_merge_stage(tape);
}

1827
/* Add a new stage at the end of the pipeline. */
L
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1828 1829 1830 1831
static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage)
{
	idetape_tape_t *tape = drive->driver_data;
	unsigned long flags;
1832 1833 1834

	debug_log(DBG_PROCS, "Enter %s\n", __func__);

1835
	spin_lock_irqsave(&tape->lock, flags);
L
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1836 1837 1838 1839 1840 1841 1842 1843 1844 1845
	stage->next = NULL;
	if (tape->last_stage != NULL)
		tape->last_stage->next=stage;
	else
		tape->first_stage = tape->next_stage=stage;
	tape->last_stage = stage;
	if (tape->next_stage == NULL)
		tape->next_stage = tape->last_stage;
	tape->nr_stages++;
	tape->nr_pending_stages++;
1846
	spin_unlock_irqrestore(&tape->lock, flags);
L
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1847 1848
}

1849 1850 1851
/* Install a completion in a pending request and sleep until it is serviced. The
 * caller should ensure that the request will not be serviced before we install
 * the completion (usually by disabling interrupts).
L
Linus Torvalds 已提交
1852 1853 1854
 */
static void idetape_wait_for_request (ide_drive_t *drive, struct request *rq)
{
1855
	DECLARE_COMPLETION_ONSTACK(wait);
L
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1856 1857
	idetape_tape_t *tape = drive->driver_data;

1858
	if (rq == NULL || !blk_special_request(rq)) {
L
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1859 1860 1861
		printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n");
		return;
	}
1862
	rq->end_io_data = &wait;
L
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1863
	rq->end_io = blk_end_sync_rq;
1864
	spin_unlock_irq(&tape->lock);
L
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1865 1866
	wait_for_completion(&wait);
	/* The stage and its struct request have been deallocated */
1867
	spin_lock_irq(&tape->lock);
L
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1868 1869
}

1870
static ide_startstop_t idetape_read_position_callback(ide_drive_t *drive)
L
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1871 1872
{
	idetape_tape_t *tape = drive->driver_data;
1873
	u8 *readpos = tape->pc->buffer;
1874 1875

	debug_log(DBG_PROCS, "Enter %s\n", __func__);
L
Linus Torvalds 已提交
1876 1877

	if (!tape->pc->error) {
1878 1879 1880 1881 1882 1883 1884 1885
		debug_log(DBG_SENSE, "BOP - %s\n",
				(readpos[0] & 0x80) ? "Yes" : "No");
		debug_log(DBG_SENSE, "EOP - %s\n",
				(readpos[0] & 0x40) ? "Yes" : "No");

		if (readpos[0] & 0x4) {
			printk(KERN_INFO "ide-tape: Block location is unknown"
					 "to the tape\n");
L
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			clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
			idetape_end_request(drive, 0, 0);
		} else {
1889
			debug_log(DBG_SENSE, "Block Location - %u\n",
1890 1891 1892
					be32_to_cpu(*(u32 *)&readpos[4]));

			tape->partition = readpos[1];
1893
			tape->first_frame =
1894
				be32_to_cpu(*(u32 *)&readpos[4]);
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			set_bit(IDETAPE_ADDRESS_VALID, &tape->flags);
			idetape_end_request(drive, 1, 0);
		}
	} else {
		idetape_end_request(drive, 0, 0);
	}
	return ide_stopped;
}

/*
1905 1906
 * Write a filemark if write_filemark=1. Flush the device buffers without
 * writing a filemark otherwise.
L
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1907 1908 1909 1910
 */
static void idetape_create_write_filemark_cmd (ide_drive_t *drive, idetape_pc_t *pc,int write_filemark)
{
	idetape_init_pc(pc);
1911
	pc->c[0] = WRITE_FILEMARKS;
L
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1912 1913 1914 1915 1916 1917 1918 1919
	pc->c[4] = write_filemark;
	set_bit(PC_WAIT_FOR_DSC, &pc->flags);
	pc->callback = &idetape_pc_callback;
}

static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc)
{
	idetape_init_pc(pc);
1920
	pc->c[0] = TEST_UNIT_READY;
L
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1921 1922 1923 1924
	pc->callback = &idetape_pc_callback;
}

/*
1925 1926 1927 1928 1929 1930
 * We add a special packet command request to the tail of the request queue, and
 * wait for it to be serviced. This is not to be called from within the request
 * handling part of the driver! We allocate here data on the stack and it is
 * valid until the request is finished. This is not the case for the bottom part
 * of the driver, where we are always leaving the functions to wait for an
 * interrupt or a timer event.
L
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 *
1932 1933 1934 1935
 * From the bottom part of the driver, we should allocate safe memory using
 * idetape_next_pc_storage() and ide_tape_next_rq_storage(), and add the request
 * to the request list without waiting for it to be serviced! In that case, we
 * usually use idetape_queue_pc_head().
L
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1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950
 */
static int __idetape_queue_pc_tail (ide_drive_t *drive, idetape_pc_t *pc)
{
	struct ide_tape_obj *tape = drive->driver_data;
	struct request rq;

	idetape_init_rq(&rq, REQ_IDETAPE_PC1);
	rq.buffer = (char *) pc;
	rq.rq_disk = tape->disk;
	return ide_do_drive_cmd(drive, &rq, ide_wait);
}

static void idetape_create_load_unload_cmd (ide_drive_t *drive, idetape_pc_t *pc,int cmd)
{
	idetape_init_pc(pc);
1951
	pc->c[0] = START_STOP;
L
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	pc->c[4] = cmd;
	set_bit(PC_WAIT_FOR_DSC, &pc->flags);
	pc->callback = &idetape_pc_callback;
}

static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t pc;
	int load_attempted = 0;

1963
	/* Wait for the tape to become ready */
L
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	set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
	timeout += jiffies;
	while (time_before(jiffies, timeout)) {
		idetape_create_test_unit_ready_cmd(&pc);
		if (!__idetape_queue_pc_tail(drive, &pc))
			return 0;
		if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2)
1971 1972
		    || (tape->asc == 0x3A)) {
			/* no media */
L
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			if (load_attempted)
				return -ENOMEDIUM;
			idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
			__idetape_queue_pc_tail(drive, &pc);
			load_attempted = 1;
		/* not about to be ready */
		} else if (!(tape->sense_key == 2 && tape->asc == 4 &&
			     (tape->ascq == 1 || tape->ascq == 8)))
			return -EIO;
1982
		msleep(100);
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	}
	return -EIO;
}

static int idetape_queue_pc_tail (ide_drive_t *drive,idetape_pc_t *pc)
{
	return __idetape_queue_pc_tail(drive, pc);
}

static int idetape_flush_tape_buffers (ide_drive_t *drive)
{
	idetape_pc_t pc;
	int rc;

	idetape_create_write_filemark_cmd(drive, &pc, 0);
	if ((rc = idetape_queue_pc_tail(drive, &pc)))
		return rc;
	idetape_wait_ready(drive, 60 * 5 * HZ);
	return 0;
}

static void idetape_create_read_position_cmd (idetape_pc_t *pc)
{
	idetape_init_pc(pc);
2007
	pc->c[0] = READ_POSITION;
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	pc->request_transfer = 20;
	pc->callback = &idetape_read_position_callback;
}

static int idetape_read_position (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t pc;
	int position;

2018
	debug_log(DBG_PROCS, "Enter %s\n", __func__);
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	idetape_create_read_position_cmd(&pc);
	if (idetape_queue_pc_tail(drive, &pc))
		return -1;
2023
	position = tape->first_frame;
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	return position;
}

static void idetape_create_locate_cmd (ide_drive_t *drive, idetape_pc_t *pc, unsigned int block, u8 partition, int skip)
{
	idetape_init_pc(pc);
2030
	pc->c[0] = POSITION_TO_ELEMENT;
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	pc->c[1] = 2;
2032
	put_unaligned(cpu_to_be32(block), (unsigned int *) &pc->c[3]);
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	pc->c[8] = partition;
	set_bit(PC_WAIT_FOR_DSC, &pc->flags);
	pc->callback = &idetape_pc_callback;
}

static int idetape_create_prevent_cmd (ide_drive_t *drive, idetape_pc_t *pc, int prevent)
{
	idetape_tape_t *tape = drive->driver_data;

2042 2043
	/* device supports locking according to capabilities page */
	if (!(tape->caps[6] & 0x01))
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		return 0;

	idetape_init_pc(pc);
2047
	pc->c[0] = ALLOW_MEDIUM_REMOVAL;
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	pc->c[4] = prevent;
	pc->callback = &idetape_pc_callback;
	return 1;
}

static int __idetape_discard_read_pipeline (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	unsigned long flags;
	int cnt;

2059
	if (tape->chrdev_dir != IDETAPE_DIR_READ)
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		return 0;

	/* Remove merge stage. */
2063
	cnt = tape->merge_stage_size / tape->blk_size;
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	if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
		++cnt;		/* Filemarks count as 1 sector */
	tape->merge_stage_size = 0;
	if (tape->merge_stage != NULL) {
		__idetape_kfree_stage(tape->merge_stage);
		tape->merge_stage = NULL;
	}

	/* Clear pipeline flags. */
	clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
2074
	tape->chrdev_dir = IDETAPE_DIR_NONE;
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	/* Remove pipeline stages. */
	if (tape->first_stage == NULL)
		return 0;

2080
	spin_lock_irqsave(&tape->lock, flags);
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	tape->next_stage = NULL;
	if (idetape_pipeline_active(tape))
2083 2084
		idetape_wait_for_request(drive, tape->active_data_rq);
	spin_unlock_irqrestore(&tape->lock, flags);
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	while (tape->first_stage != NULL) {
		struct request *rq_ptr = &tape->first_stage->rq;

		cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors; 
		if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
			++cnt;
		idetape_remove_stage_head(drive);
	}
	tape->nr_pending_stages = 0;
	tape->max_stages = tape->min_pipeline;
	return cnt;
}

/*
2100 2101 2102 2103
 * Position the tape to the requested block using the LOCATE packet command.
 * A READ POSITION command is then issued to check where we are positioned. Like
 * all higher level operations, we queue the commands at the tail of the request
 * queue and wait for their completion.
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 */
static int idetape_position_tape (ide_drive_t *drive, unsigned int block, u8 partition, int skip)
{
	idetape_tape_t *tape = drive->driver_data;
	int retval;
	idetape_pc_t pc;

2111
	if (tape->chrdev_dir == IDETAPE_DIR_READ)
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		__idetape_discard_read_pipeline(drive);
	idetape_wait_ready(drive, 60 * 5 * HZ);
	idetape_create_locate_cmd(drive, &pc, block, partition, skip);
	retval = idetape_queue_pc_tail(drive, &pc);
	if (retval)
		return (retval);

	idetape_create_read_position_cmd(&pc);
	return (idetape_queue_pc_tail(drive, &pc));
}

static void idetape_discard_read_pipeline (ide_drive_t *drive, int restore_position)
{
	idetape_tape_t *tape = drive->driver_data;
	int cnt;
	int seek, position;

	cnt = __idetape_discard_read_pipeline(drive);
	if (restore_position) {
		position = idetape_read_position(drive);
		seek = position > cnt ? position - cnt : 0;
		if (idetape_position_tape(drive, seek, 0, 0)) {
			printk(KERN_INFO "ide-tape: %s: position_tape failed in discard_pipeline()\n", tape->name);
			return;
		}
	}
}

/*
2141 2142
 * Generate a read/write request for the block device interface and wait for it
 * to be serviced.
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 */
static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, struct idetape_bh *bh)
{
	idetape_tape_t *tape = drive->driver_data;
	struct request rq;

2149 2150
	debug_log(DBG_SENSE, "%s: cmd=%d\n", __func__, cmd);

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	if (idetape_pipeline_active(tape)) {
2152 2153
		printk(KERN_ERR "ide-tape: bug: the pipeline is active in %s\n",
				__func__);
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		return (0);
	}

	idetape_init_rq(&rq, cmd);
	rq.rq_disk = tape->disk;
	rq.special = (void *)bh;
2160
	rq.sector = tape->first_frame;
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	rq.nr_sectors = rq.current_nr_sectors = blocks;
	(void) ide_do_drive_cmd(drive, &rq, ide_wait);

	if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0)
		return 0;

	if (tape->merge_stage)
		idetape_init_merge_stage(tape);
	if (rq.errors == IDETAPE_ERROR_GENERAL)
		return -EIO;
2171
	return (tape->blk_size * (blocks-rq.current_nr_sectors));
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}

2174 2175
/* start servicing the pipeline stages, starting from tape->next_stage. */
static void idetape_plug_pipeline(ide_drive_t *drive)
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{
	idetape_tape_t *tape = drive->driver_data;

	if (tape->next_stage == NULL)
		return;
	if (!idetape_pipeline_active(tape)) {
		set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags);
2183
		idetape_activate_next_stage(drive);
2184
		(void) ide_do_drive_cmd(drive, tape->active_data_rq, ide_end);
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	}
}

static void idetape_create_inquiry_cmd (idetape_pc_t *pc)
{
	idetape_init_pc(pc);
2191
	pc->c[0] = INQUIRY;
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	pc->c[4] = pc->request_transfer = 254;
	pc->callback = &idetape_pc_callback;
}

static void idetape_create_rewind_cmd (ide_drive_t *drive, idetape_pc_t *pc)
{
	idetape_init_pc(pc);
2199
	pc->c[0] = REZERO_UNIT;
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	set_bit(PC_WAIT_FOR_DSC, &pc->flags);
	pc->callback = &idetape_pc_callback;
}

static void idetape_create_erase_cmd (idetape_pc_t *pc)
{
	idetape_init_pc(pc);
2207
	pc->c[0] = ERASE;
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	pc->c[1] = 1;
	set_bit(PC_WAIT_FOR_DSC, &pc->flags);
	pc->callback = &idetape_pc_callback;
}

static void idetape_create_space_cmd (idetape_pc_t *pc,int count, u8 cmd)
{
	idetape_init_pc(pc);
2216
	pc->c[0] = SPACE;
2217
	put_unaligned(cpu_to_be32(count), (unsigned int *) &pc->c[1]);
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	pc->c[1] = cmd;
	set_bit(PC_WAIT_FOR_DSC, &pc->flags);
	pc->callback = &idetape_pc_callback;
}

static void idetape_wait_first_stage (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	unsigned long flags;

	if (tape->first_stage == NULL)
		return;
2230
	spin_lock_irqsave(&tape->lock, flags);
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	if (tape->active_stage == tape->first_stage)
2232 2233
		idetape_wait_for_request(drive, tape->active_data_rq);
	spin_unlock_irqrestore(&tape->lock, flags);
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}

/*
2237 2238 2239
 * Try to add a character device originated write request to our pipeline. In
 * case we don't succeed, we revert to non-pipelined operation mode for this
 * request. In order to accomplish that, we
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 *
2241 2242 2243 2244 2245
 * 1. Try to allocate a new pipeline stage.
 * 2. If we can't, wait for more and more requests to be serviced and try again
 * each time.
 * 3. If we still can't allocate a stage, fallback to non-pipelined operation
 * mode for this request.
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 */
static int idetape_add_chrdev_write_request (ide_drive_t *drive, int blocks)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_stage_t *new_stage;
	unsigned long flags;
	struct request *rq;

2254
	debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
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2256
	/* Attempt to allocate a new stage. Beware possible race conditions. */
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	while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) {
2258
		spin_lock_irqsave(&tape->lock, flags);
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		if (idetape_pipeline_active(tape)) {
2260 2261
			idetape_wait_for_request(drive, tape->active_data_rq);
			spin_unlock_irqrestore(&tape->lock, flags);
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		} else {
2263
			spin_unlock_irqrestore(&tape->lock, flags);
2264
			idetape_plug_pipeline(drive);
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			if (idetape_pipeline_active(tape))
				continue;
			/*
2268 2269
			 * The machine is short on memory. Fallback to non-
			 * pipelined operation mode for this request.
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			 */
			return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
		}
	}
	rq = &new_stage->rq;
	idetape_init_rq(rq, REQ_IDETAPE_WRITE);
	/* Doesn't actually matter - We always assume sequential access */
2277
	rq->sector = tape->first_frame;
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	rq->nr_sectors = rq->current_nr_sectors = blocks;

	idetape_switch_buffers(tape, new_stage);
	idetape_add_stage_tail(drive, new_stage);
	tape->pipeline_head++;
2283
	idetape_calculate_speeds(drive);
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	/*
2286 2287 2288 2289 2290
	 * Estimate whether the tape has stopped writing by checking if our
	 * write pipeline is currently empty. If we are not writing anymore,
	 * wait for the pipeline to be almost completely full (90%) before
	 * starting to service requests, so that we will be able to keep up with
	 * the higher speeds of the tape.
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	 */
	if (!idetape_pipeline_active(tape)) {
		if (tape->nr_stages >= tape->max_stages * 9 / 10 ||
2294 2295 2296
			tape->nr_stages >= tape->max_stages -
			tape->uncontrolled_pipeline_head_speed * 3 * 1024 /
			tape->blk_size) {
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			tape->measure_insert_time = 1;
			tape->insert_time = jiffies;
			tape->insert_size = 0;
			tape->insert_speed = 0;
2301
			idetape_plug_pipeline(drive);
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		}
	}
	if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
		/* Return a deferred error */
		return -EIO;
	return blocks;
}

/*
2311 2312
 * Wait until all pending pipeline requests are serviced. Typically called on
 * device close.
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 */
static void idetape_wait_for_pipeline (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	unsigned long flags;

	while (tape->next_stage || idetape_pipeline_active(tape)) {
2320
		idetape_plug_pipeline(drive);
2321
		spin_lock_irqsave(&tape->lock, flags);
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		if (idetape_pipeline_active(tape))
2323 2324
			idetape_wait_for_request(drive, tape->active_data_rq);
		spin_unlock_irqrestore(&tape->lock, flags);
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	}
}

static void idetape_empty_write_pipeline (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	int blocks, min;
	struct idetape_bh *bh;
2333

2334
	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
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		printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline, but we are not writing.\n");
		return;
	}
	if (tape->merge_stage_size > tape->stage_size) {
		printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n");
		tape->merge_stage_size = tape->stage_size;
	}
	if (tape->merge_stage_size) {
2343 2344
		blocks = tape->merge_stage_size / tape->blk_size;
		if (tape->merge_stage_size % tape->blk_size) {
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			unsigned int i;

			blocks++;
2348 2349
			i = tape->blk_size - tape->merge_stage_size %
				tape->blk_size;
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			bh = tape->bh->b_reqnext;
			while (bh) {
				atomic_set(&bh->b_count, 0);
				bh = bh->b_reqnext;
			}
			bh = tape->bh;
			while (i) {
				if (bh == NULL) {

					printk(KERN_INFO "ide-tape: bug, bh NULL\n");
					break;
				}
				min = min(i, (unsigned int)(bh->b_size - atomic_read(&bh->b_count)));
				memset(bh->b_data + atomic_read(&bh->b_count), 0, min);
				atomic_add(min, &bh->b_count);
				i -= min;
				bh = bh->b_reqnext;
			}
		}
		(void) idetape_add_chrdev_write_request(drive, blocks);
		tape->merge_stage_size = 0;
	}
	idetape_wait_for_pipeline(drive);
	if (tape->merge_stage != NULL) {
		__idetape_kfree_stage(tape->merge_stage);
		tape->merge_stage = NULL;
	}
	clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);
2378
	tape->chrdev_dir = IDETAPE_DIR_NONE;
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	/*
2381 2382 2383 2384
	 * On the next backup, perform the feedback loop again. (I don't want to
	 * keep sense information between backups, as some systems are
	 * constantly on, and the system load can be totally different on the
	 * next backup).
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	 */
	tape->max_stages = tape->min_pipeline;
	if (tape->first_stage != NULL ||
	    tape->next_stage != NULL ||
	    tape->last_stage != NULL ||
	    tape->nr_stages != 0) {
		printk(KERN_ERR "ide-tape: ide-tape pipeline bug, "
			"first_stage %p, next_stage %p, "
			"last_stage %p, nr_stages %d\n",
			tape->first_stage, tape->next_stage,
			tape->last_stage, tape->nr_stages);
	}
}

static void idetape_restart_speed_control (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;

	tape->restart_speed_control_req = 0;
	tape->pipeline_head = 0;
2405
	tape->controlled_last_pipeline_head = 0;
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	tape->controlled_previous_pipeline_head = tape->uncontrolled_previous_pipeline_head = 0;
	tape->pipeline_head_speed = tape->controlled_pipeline_head_speed = 5000;
	tape->uncontrolled_pipeline_head_speed = 0;
	tape->controlled_pipeline_head_time = tape->uncontrolled_pipeline_head_time = jiffies;
	tape->controlled_previous_head_time = tape->uncontrolled_previous_head_time = jiffies;
}

2413
static int idetape_init_read(ide_drive_t *drive, int max_stages)
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{
	idetape_tape_t *tape = drive->driver_data;
	idetape_stage_t *new_stage;
	struct request rq;
	int bytes_read;
2419
	u16 blocks = *(u16 *)&tape->caps[12];
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	/* Initialize read operation */
2422 2423
	if (tape->chrdev_dir != IDETAPE_DIR_READ) {
		if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
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			idetape_empty_write_pipeline(drive);
			idetape_flush_tape_buffers(drive);
		}
		if (tape->merge_stage || tape->merge_stage_size) {
			printk (KERN_ERR "ide-tape: merge_stage_size should be 0 now\n");
			tape->merge_stage_size = 0;
		}
		if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
			return -ENOMEM;
2433
		tape->chrdev_dir = IDETAPE_DIR_READ;
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		/*
2436 2437 2438 2439
		 * Issue a read 0 command to ensure that DSC handshake is
		 * switched from completion mode to buffer available mode.
		 * No point in issuing this if DSC overlap isn't supported, some
		 * drives (Seagate STT3401A) will return an error.
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		 */
		if (drive->dsc_overlap) {
			bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh);
			if (bytes_read < 0) {
				__idetape_kfree_stage(tape->merge_stage);
				tape->merge_stage = NULL;
2446
				tape->chrdev_dir = IDETAPE_DIR_NONE;
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				return bytes_read;
			}
		}
	}
	if (tape->restart_speed_control_req)
		idetape_restart_speed_control(drive);
	idetape_init_rq(&rq, REQ_IDETAPE_READ);
2454
	rq.sector = tape->first_frame;
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	rq.nr_sectors = rq.current_nr_sectors = blocks;
	if (!test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags) &&
	    tape->nr_stages < max_stages) {
		new_stage = idetape_kmalloc_stage(tape);
		while (new_stage != NULL) {
			new_stage->rq = rq;
			idetape_add_stage_tail(drive, new_stage);
			if (tape->nr_stages >= max_stages)
				break;
			new_stage = idetape_kmalloc_stage(tape);
		}
	}
	if (!idetape_pipeline_active(tape)) {
		if (tape->nr_pending_stages >= 3 * max_stages / 4) {
			tape->measure_insert_time = 1;
			tape->insert_time = jiffies;
			tape->insert_size = 0;
			tape->insert_speed = 0;
2473
			idetape_plug_pipeline(drive);
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		}
	}
	return 0;
}

/*
2480 2481
 * Called from idetape_chrdev_read() to service a character device read request
 * and add read-ahead requests to our pipeline.
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2482 2483 2484 2485 2486 2487 2488 2489
 */
static int idetape_add_chrdev_read_request (ide_drive_t *drive,int blocks)
{
	idetape_tape_t *tape = drive->driver_data;
	unsigned long flags;
	struct request *rq_ptr;
	int bytes_read;

2490
	debug_log(DBG_PROCS, "Enter %s, %d blocks\n", __func__, blocks);
L
Linus Torvalds 已提交
2491

2492
	/* If we are at a filemark, return a read length of 0 */
L
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2493 2494 2495
	if (test_bit(IDETAPE_FILEMARK, &tape->flags))
		return 0;

2496
	/* Wait for the next block to reach the head of the pipeline. */
2497
	idetape_init_read(drive, tape->max_stages);
L
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2498 2499 2500
	if (tape->first_stage == NULL) {
		if (test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags))
			return 0;
2501 2502
		return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks,
					tape->merge_stage->bh);
L
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2503 2504 2505
	}
	idetape_wait_first_stage(drive);
	rq_ptr = &tape->first_stage->rq;
2506 2507
	bytes_read = tape->blk_size * (rq_ptr->nr_sectors -
					rq_ptr->current_nr_sectors);
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2508 2509 2510 2511 2512 2513 2514 2515 2516
	rq_ptr->nr_sectors = rq_ptr->current_nr_sectors = 0;


	if (rq_ptr->errors == IDETAPE_ERROR_EOD)
		return 0;
	else {
		idetape_switch_buffers(tape, tape->first_stage);
		if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK)
			set_bit(IDETAPE_FILEMARK, &tape->flags);
2517
		spin_lock_irqsave(&tape->lock, flags);
L
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2518
		idetape_remove_stage_head(drive);
2519
		spin_unlock_irqrestore(&tape->lock, flags);
L
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2520
		tape->pipeline_head++;
2521
		idetape_calculate_speeds(drive);
L
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2522
	}
2523
	if (bytes_read > blocks * tape->blk_size) {
L
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2524
		printk(KERN_ERR "ide-tape: bug: trying to return more bytes than requested\n");
2525
		bytes_read = blocks * tape->blk_size;
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2526 2527 2528 2529 2530 2531 2532 2533 2534
	}
	return (bytes_read);
}

static void idetape_pad_zeros (ide_drive_t *drive, int bcount)
{
	idetape_tape_t *tape = drive->driver_data;
	struct idetape_bh *bh;
	int blocks;
2535

L
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2536 2537 2538 2539 2540 2541
	while (bcount) {
		unsigned int count;

		bh = tape->merge_stage->bh;
		count = min(tape->stage_size, bcount);
		bcount -= count;
2542
		blocks = count / tape->blk_size;
L
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2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563
		while (count) {
			atomic_set(&bh->b_count, min(count, (unsigned int)bh->b_size));
			memset(bh->b_data, 0, atomic_read(&bh->b_count));
			count -= atomic_read(&bh->b_count);
			bh = bh->b_reqnext;
		}
		idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh);
	}
}

static int idetape_pipeline_size (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_stage_t *stage;
	struct request *rq;
	int size = 0;

	idetape_wait_for_pipeline(drive);
	stage = tape->first_stage;
	while (stage != NULL) {
		rq = &stage->rq;
2564 2565
		size += tape->blk_size * (rq->nr_sectors -
				rq->current_nr_sectors);
L
Linus Torvalds 已提交
2566
		if (rq->errors == IDETAPE_ERROR_FILEMARK)
2567
			size += tape->blk_size;
L
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2568 2569 2570 2571 2572 2573 2574
		stage = stage->next;
	}
	size += tape->merge_stage_size;
	return size;
}

/*
2575 2576 2577
 * Rewinds the tape to the Beginning Of the current Partition (BOP). We
 * currently support only one partition.
 */
L
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2578 2579 2580 2581
static int idetape_rewind_tape (ide_drive_t *drive)
{
	int retval;
	idetape_pc_t pc;
2582 2583 2584 2585 2586
	idetape_tape_t *tape;
	tape = drive->driver_data;

	debug_log(DBG_SENSE, "Enter %s\n", __func__);

L
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2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598
	idetape_create_rewind_cmd(drive, &pc);
	retval = idetape_queue_pc_tail(drive, &pc);
	if (retval)
		return retval;

	idetape_create_read_position_cmd(&pc);
	retval = idetape_queue_pc_tail(drive, &pc);
	if (retval)
		return retval;
	return 0;
}

2599
/* mtio.h compatible commands should be issued to the chrdev interface. */
L
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2600 2601 2602 2603 2604
static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, unsigned long arg)
{
	idetape_tape_t *tape = drive->driver_data;
	void __user *argp = (void __user *)arg;

2605 2606 2607 2608 2609 2610
	struct idetape_config {
		int dsc_rw_frequency;
		int dsc_media_access_frequency;
		int nr_stages;
	} config;

2611 2612
	debug_log(DBG_PROCS, "Enter %s\n", __func__);

L
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2613 2614
	switch (cmd) {
		case 0x0340:
2615
			if (copy_from_user(&config, argp, sizeof(config)))
L
Linus Torvalds 已提交
2616
				return -EFAULT;
2617
			tape->best_dsc_rw_freq = config.dsc_rw_frequency;
L
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2618 2619 2620
			tape->max_stages = config.nr_stages;
			break;
		case 0x0350:
2621
			config.dsc_rw_frequency = (int) tape->best_dsc_rw_freq;
L
Linus Torvalds 已提交
2622
			config.nr_stages = tape->max_stages; 
2623
			if (copy_to_user(argp, &config, sizeof(config)))
L
Linus Torvalds 已提交
2624 2625 2626 2627 2628 2629 2630 2631 2632
				return -EFAULT;
			break;
		default:
			return -EIO;
	}
	return 0;
}

/*
2633 2634 2635 2636 2637
 * The function below is now a bit more complicated than just passing the
 * command to the tape since we may have crossed some filemarks during our
 * pipelined read-ahead mode. As a minor side effect, the pipeline enables us to
 * support MTFSFM when the filemark is in our internal pipeline even if the tape
 * doesn't support spacing over filemarks in the reverse direction.
L
Linus Torvalds 已提交
2638 2639 2640 2641 2642 2643 2644
 */
static int idetape_space_over_filemarks (ide_drive_t *drive,short mt_op,int mt_count)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t pc;
	unsigned long flags;
	int retval,count=0;
2645
	int sprev = !!(tape->caps[4] & 0x20);
L
Linus Torvalds 已提交
2646 2647 2648 2649

	if (mt_count == 0)
		return 0;
	if (MTBSF == mt_op || MTBSFM == mt_op) {
2650
		if (!sprev)
L
Linus Torvalds 已提交
2651 2652 2653 2654
			return -EIO;
		mt_count = - mt_count;
	}

2655
	if (tape->chrdev_dir == IDETAPE_DIR_READ) {
2656
		/* its a read-ahead buffer, scan it for crossed filemarks. */
L
Linus Torvalds 已提交
2657 2658 2659 2660 2661 2662 2663 2664 2665
		tape->merge_stage_size = 0;
		if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags))
			++count;
		while (tape->first_stage != NULL) {
			if (count == mt_count) {
				if (mt_op == MTFSFM)
					set_bit(IDETAPE_FILEMARK, &tape->flags);
				return 0;
			}
2666
			spin_lock_irqsave(&tape->lock, flags);
L
Linus Torvalds 已提交
2667 2668
			if (tape->first_stage == tape->active_stage) {
				/*
2669 2670 2671 2672
				 * We have reached the active stage in the read
				 * pipeline. There is no point in allowing the
				 * drive to continue reading any farther, so we
				 * stop the pipeline.
L
Linus Torvalds 已提交
2673
				 *
2674 2675 2676 2677
				 * This section should be moved to a separate
				 * subroutine because similar operations are
				 * done in __idetape_discard_read_pipeline(),
				 * for example.
L
Linus Torvalds 已提交
2678 2679
				 */
				tape->next_stage = NULL;
2680
				spin_unlock_irqrestore(&tape->lock, flags);
L
Linus Torvalds 已提交
2681 2682 2683
				idetape_wait_first_stage(drive);
				tape->next_stage = tape->first_stage->next;
			} else
2684
				spin_unlock_irqrestore(&tape->lock, flags);
L
Linus Torvalds 已提交
2685 2686 2687 2688 2689 2690 2691 2692
			if (tape->first_stage->rq.errors == IDETAPE_ERROR_FILEMARK)
				++count;
			idetape_remove_stage_head(drive);
		}
		idetape_discard_read_pipeline(drive, 0);
	}

	/*
2693 2694
	 * The filemark was not found in our internal pipeline;	now we can issue
	 * the space command.
L
Linus Torvalds 已提交
2695 2696 2697 2698 2699 2700 2701 2702
	 */
	switch (mt_op) {
		case MTFSF:
		case MTBSF:
			idetape_create_space_cmd(&pc,mt_count-count,IDETAPE_SPACE_OVER_FILEMARK);
			return (idetape_queue_pc_tail(drive, &pc));
		case MTFSFM:
		case MTBSFM:
2703
			if (!sprev)
L
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2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716
				return (-EIO);
			retval = idetape_space_over_filemarks(drive, MTFSF, mt_count-count);
			if (retval) return (retval);
			count = (MTBSFM == mt_op ? 1 : -1);
			return (idetape_space_over_filemarks(drive, MTFSF, count));
		default:
			printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",mt_op);
			return (-EIO);
	}
}


/*
2717
 * Our character device read / write functions.
L
Linus Torvalds 已提交
2718
 *
2719 2720 2721
 * The tape is optimized to maximize throughput when it is transferring an
 * integral number of the "continuous transfer limit", which is a parameter of
 * the specific tape (26kB on my particular tape, 32kB for Onstream).
L
Linus Torvalds 已提交
2722
 *
2723 2724 2725 2726 2727 2728 2729
 * As of version 1.3 of the driver, the character device provides an abstract
 * continuous view of the media - any mix of block sizes (even 1 byte) on the
 * same backup/restore procedure is supported. The driver will internally
 * convert the requests to the recommended transfer unit, so that an unmatch
 * between the user's block size to the recommended size will only result in a
 * (slightly) increased driver overhead, but will no longer hit performance.
 * This is not applicable to Onstream.
L
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2730 2731 2732 2733 2734 2735 2736
 */
static ssize_t idetape_chrdev_read (struct file *file, char __user *buf,
				    size_t count, loff_t *ppos)
{
	struct ide_tape_obj *tape = ide_tape_f(file);
	ide_drive_t *drive = tape->drive;
	ssize_t bytes_read,temp, actually_read = 0, rc;
2737
	ssize_t ret = 0;
2738
	u16 ctl = *(u16 *)&tape->caps[12];
L
Linus Torvalds 已提交
2739

2740
	debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
L
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2741

2742
	if (tape->chrdev_dir != IDETAPE_DIR_READ) {
L
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2743
		if (test_bit(IDETAPE_DETECT_BS, &tape->flags))
2744 2745 2746
			if (count > tape->blk_size &&
			    (count % tape->blk_size) == 0)
				tape->user_bs_factor = count / tape->blk_size;
L
Linus Torvalds 已提交
2747
	}
2748 2749
	rc = idetape_init_read(drive, tape->max_stages);
	if (rc < 0)
L
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2750 2751 2752 2753 2754
		return rc;
	if (count == 0)
		return (0);
	if (tape->merge_stage_size) {
		actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count);
2755 2756
		if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read))
			ret = -EFAULT;
L
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2757 2758 2759 2760 2761
		buf += actually_read;
		tape->merge_stage_size -= actually_read;
		count -= actually_read;
	}
	while (count >= tape->stage_size) {
2762
		bytes_read = idetape_add_chrdev_read_request(drive, ctl);
L
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2763 2764
		if (bytes_read <= 0)
			goto finish;
2765 2766
		if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read))
			ret = -EFAULT;
L
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2767 2768 2769 2770 2771
		buf += bytes_read;
		count -= bytes_read;
		actually_read += bytes_read;
	}
	if (count) {
2772
		bytes_read = idetape_add_chrdev_read_request(drive, ctl);
L
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2773 2774 2775
		if (bytes_read <= 0)
			goto finish;
		temp = min((unsigned long)count, (unsigned long)bytes_read);
2776 2777
		if (idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp))
			ret = -EFAULT;
L
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2778 2779 2780 2781 2782
		actually_read += temp;
		tape->merge_stage_size = bytes_read-temp;
	}
finish:
	if (!actually_read && test_bit(IDETAPE_FILEMARK, &tape->flags)) {
2783 2784
		debug_log(DBG_SENSE, "%s: spacing over filemark\n", tape->name);

L
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2785 2786 2787
		idetape_space_over_filemarks(drive, MTFSF, 1);
		return 0;
	}
2788 2789

	return (ret) ? ret : actually_read;
L
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2790 2791 2792 2793 2794 2795 2796
}

static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf,
				     size_t count, loff_t *ppos)
{
	struct ide_tape_obj *tape = ide_tape_f(file);
	ide_drive_t *drive = tape->drive;
2797 2798
	ssize_t actually_written = 0;
	ssize_t ret = 0;
2799
	u16 ctl = *(u16 *)&tape->caps[12];
L
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2800 2801 2802 2803 2804

	/* The drive is write protected. */
	if (tape->write_prot)
		return -EACCES;

2805
	debug_log(DBG_CHRDEV, "Enter %s, count %Zd\n", __func__, count);
L
Linus Torvalds 已提交
2806 2807

	/* Initialize write operation */
2808 2809
	if (tape->chrdev_dir != IDETAPE_DIR_WRITE) {
		if (tape->chrdev_dir == IDETAPE_DIR_READ)
L
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2810 2811 2812 2813 2814 2815 2816 2817
			idetape_discard_read_pipeline(drive, 1);
		if (tape->merge_stage || tape->merge_stage_size) {
			printk(KERN_ERR "ide-tape: merge_stage_size "
				"should be 0 now\n");
			tape->merge_stage_size = 0;
		}
		if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL)
			return -ENOMEM;
2818
		tape->chrdev_dir = IDETAPE_DIR_WRITE;
L
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2819 2820 2821
		idetape_init_merge_stage(tape);

		/*
2822 2823 2824 2825
		 * Issue a write 0 command to ensure that DSC handshake is
		 * switched from completion mode to buffer available mode. No
		 * point in issuing this if DSC overlap isn't supported, some
		 * drives (Seagate STT3401A) will return an error.
L
Linus Torvalds 已提交
2826 2827
		 */
		if (drive->dsc_overlap) {
2828
			ssize_t retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh);
L
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2829 2830 2831
			if (retval < 0) {
				__idetape_kfree_stage(tape->merge_stage);
				tape->merge_stage = NULL;
2832
				tape->chrdev_dir = IDETAPE_DIR_NONE;
L
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2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846
				return retval;
			}
		}
	}
	if (count == 0)
		return (0);
	if (tape->restart_speed_control_req)
		idetape_restart_speed_control(drive);
	if (tape->merge_stage_size) {
		if (tape->merge_stage_size >= tape->stage_size) {
			printk(KERN_ERR "ide-tape: bug: merge buffer too big\n");
			tape->merge_stage_size = 0;
		}
		actually_written = min((unsigned int)(tape->stage_size - tape->merge_stage_size), (unsigned int)count);
2847 2848
		if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written))
				ret = -EFAULT;
L
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2849 2850 2851 2852 2853
		buf += actually_written;
		tape->merge_stage_size += actually_written;
		count -= actually_written;

		if (tape->merge_stage_size == tape->stage_size) {
2854
			ssize_t retval;
L
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2855
			tape->merge_stage_size = 0;
2856
			retval = idetape_add_chrdev_write_request(drive, ctl);
L
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2857 2858 2859 2860 2861
			if (retval <= 0)
				return (retval);
		}
	}
	while (count >= tape->stage_size) {
2862 2863 2864
		ssize_t retval;
		if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size))
			ret = -EFAULT;
L
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2865 2866
		buf += tape->stage_size;
		count -= tape->stage_size;
2867
		retval = idetape_add_chrdev_write_request(drive, ctl);
L
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		actually_written += tape->stage_size;
		if (retval <= 0)
			return (retval);
	}
	if (count) {
		actually_written += count;
2874 2875
		if (idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count))
			ret = -EFAULT;
L
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2876 2877
		tape->merge_stage_size += count;
	}
2878
	return (ret) ? ret : actually_written;
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}

static int idetape_write_filemark (ide_drive_t *drive)
{
	idetape_pc_t pc;

	/* Write a filemark */
	idetape_create_write_filemark_cmd(drive, &pc, 1);
	if (idetape_queue_pc_tail(drive, &pc)) {
		printk(KERN_ERR "ide-tape: Couldn't write a filemark\n");
		return -EIO;
	}
	return 0;
}

/*
2895 2896
 * Called from idetape_chrdev_ioctl when the general mtio MTIOCTOP ioctl is
 * requested.
L
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2897
 *
2898 2899 2900 2901
 * Note: MTBSF and MTBSFM are not supported when the tape doesn't support
 * spacing over filemarks in the reverse direction. In this case, MTFSFM is also
 * usually not supported (it is supported in the rare case in which we crossed
 * the filemark during our read-ahead pipelined operation mode).
L
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2902
 *
2903
 * The following commands are currently not supported:
L
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2904
 *
2905 2906
 * MTFSS, MTBSS, MTWSM, MTSETDENSITY, MTSETDRVBUFFER, MT_ST_BOOLEANS,
 * MT_ST_WRITE_THRESHOLD.
L
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2907
 */
2908
static int idetape_mtioctop(ide_drive_t *drive, short mt_op, int mt_count)
L
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2909 2910 2911 2912 2913
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t pc;
	int i,retval;

2914 2915
	debug_log(DBG_ERR, "Handling MTIOCTOP ioctl: mt_op=%d, mt_count=%d\n",
			mt_op, mt_count);
2916
	/* Commands which need our pipelined read-ahead stages. */
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2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980
	switch (mt_op) {
		case MTFSF:
		case MTFSFM:
		case MTBSF:
		case MTBSFM:
			if (!mt_count)
				return (0);
			return (idetape_space_over_filemarks(drive,mt_op,mt_count));
		default:
			break;
	}
	switch (mt_op) {
		case MTWEOF:
			if (tape->write_prot)
				return -EACCES;
			idetape_discard_read_pipeline(drive, 1);
			for (i = 0; i < mt_count; i++) {
				retval = idetape_write_filemark(drive);
				if (retval)
					return retval;
			}
			return (0);
		case MTREW:
			idetape_discard_read_pipeline(drive, 0);
			if (idetape_rewind_tape(drive))
				return -EIO;
			return 0;
		case MTLOAD:
			idetape_discard_read_pipeline(drive, 0);
			idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK);
			return (idetape_queue_pc_tail(drive, &pc));
		case MTUNLOAD:
		case MTOFFL:
			/*
			 * If door is locked, attempt to unlock before
			 * attempting to eject.
			 */
			if (tape->door_locked) {
				if (idetape_create_prevent_cmd(drive, &pc, 0))
					if (!idetape_queue_pc_tail(drive, &pc))
						tape->door_locked = DOOR_UNLOCKED;
			}
			idetape_discard_read_pipeline(drive, 0);
			idetape_create_load_unload_cmd(drive, &pc,!IDETAPE_LU_LOAD_MASK);
			retval = idetape_queue_pc_tail(drive, &pc);
			if (!retval)
				clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags);
			return retval;
		case MTNOP:
			idetape_discard_read_pipeline(drive, 0);
			return (idetape_flush_tape_buffers(drive));
		case MTRETEN:
			idetape_discard_read_pipeline(drive, 0);
			idetape_create_load_unload_cmd(drive, &pc,IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK);
			return (idetape_queue_pc_tail(drive, &pc));
		case MTEOM:
			idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD);
			return (idetape_queue_pc_tail(drive, &pc));
		case MTERASE:
			(void) idetape_rewind_tape(drive);
			idetape_create_erase_cmd(&pc);
			return (idetape_queue_pc_tail(drive, &pc));
		case MTSETBLK:
			if (mt_count) {
2981 2982
				if (mt_count < tape->blk_size ||
				    mt_count % tape->blk_size)
L
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2983
					return -EIO;
2984 2985
				tape->user_bs_factor = mt_count /
							tape->blk_size;
L
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2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019
				clear_bit(IDETAPE_DETECT_BS, &tape->flags);
			} else
				set_bit(IDETAPE_DETECT_BS, &tape->flags);
			return 0;
		case MTSEEK:
			idetape_discard_read_pipeline(drive, 0);
			return idetape_position_tape(drive, mt_count * tape->user_bs_factor, tape->partition, 0);
		case MTSETPART:
			idetape_discard_read_pipeline(drive, 0);
			return (idetape_position_tape(drive, 0, mt_count, 0));
		case MTFSR:
		case MTBSR:
		case MTLOCK:
			if (!idetape_create_prevent_cmd(drive, &pc, 1))
				return 0;
			retval = idetape_queue_pc_tail(drive, &pc);
			if (retval) return retval;
			tape->door_locked = DOOR_EXPLICITLY_LOCKED;
			return 0;
		case MTUNLOCK:
			if (!idetape_create_prevent_cmd(drive, &pc, 0))
				return 0;
			retval = idetape_queue_pc_tail(drive, &pc);
			if (retval) return retval;
			tape->door_locked = DOOR_UNLOCKED;
			return 0;
		default:
			printk(KERN_ERR "ide-tape: MTIO operation %d not "
				"supported\n", mt_op);
			return (-EIO);
	}
}

/*
3020 3021 3022
 * Our character device ioctls. General mtio.h magnetic io commands are
 * supported here, and not in the corresponding block interface. Our own
 * ide-tape ioctls are supported on both interfaces.
L
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3023
 */
3024 3025
static int idetape_chrdev_ioctl(struct inode *inode, struct file *file,
				unsigned int cmd, unsigned long arg)
L
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3026 3027 3028 3029 3030 3031
{
	struct ide_tape_obj *tape = ide_tape_f(file);
	ide_drive_t *drive = tape->drive;
	struct mtop mtop;
	struct mtget mtget;
	struct mtpos mtpos;
3032
	int block_offset = 0, position = tape->first_frame;
L
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3033 3034
	void __user *argp = (void __user *)arg;

3035
	debug_log(DBG_CHRDEV, "Enter %s, cmd=%u\n", __func__, cmd);
L
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3036 3037

	tape->restart_speed_control_req = 1;
3038
	if (tape->chrdev_dir == IDETAPE_DIR_WRITE) {
L
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3039 3040 3041 3042
		idetape_empty_write_pipeline(drive);
		idetape_flush_tape_buffers(drive);
	}
	if (cmd == MTIOCGET || cmd == MTIOCPOS) {
3043 3044
		block_offset = idetape_pipeline_size(drive) /
			(tape->blk_size * tape->user_bs_factor);
L
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3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056
		if ((position = idetape_read_position(drive)) < 0)
			return -EIO;
	}
	switch (cmd) {
		case MTIOCTOP:
			if (copy_from_user(&mtop, argp, sizeof (struct mtop)))
				return -EFAULT;
			return (idetape_mtioctop(drive,mtop.mt_op,mtop.mt_count));
		case MTIOCGET:
			memset(&mtget, 0, sizeof (struct mtget));
			mtget.mt_type = MT_ISSCSI2;
			mtget.mt_blkno = position / tape->user_bs_factor - block_offset;
3057 3058 3059 3060
			mtget.mt_dsreg =
				((tape->blk_size * tape->user_bs_factor)
				 << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK;

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3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072
			if (tape->drv_write_prot) {
				mtget.mt_gstat |= GMT_WR_PROT(0xffffffff);
			}
			if (copy_to_user(argp, &mtget, sizeof(struct mtget)))
				return -EFAULT;
			return 0;
		case MTIOCPOS:
			mtpos.mt_blkno = position / tape->user_bs_factor - block_offset;
			if (copy_to_user(argp, &mtpos, sizeof(struct mtpos)))
				return -EFAULT;
			return 0;
		default:
3073
			if (tape->chrdev_dir == IDETAPE_DIR_READ)
L
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3074 3075 3076 3077 3078
				idetape_discard_read_pipeline(drive, 1);
			return idetape_blkdev_ioctl(drive, cmd, arg);
	}
}

3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090
/*
 * Do a mode sense page 0 with block descriptor and if it succeeds set the tape
 * block size with the reported value.
 */
static void ide_tape_get_bsize_from_bdesc(ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t pc;

	idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR);
	if (idetape_queue_pc_tail(drive, &pc)) {
		printk(KERN_ERR "ide-tape: Can't get block descriptor\n");
3091
		if (tape->blk_size == 0) {
3092 3093
			printk(KERN_WARNING "ide-tape: Cannot deal with zero "
					    "block size, assuming 32k\n");
3094
			tape->blk_size = 32768;
3095 3096 3097
		}
		return;
	}
3098
	tape->blk_size = (pc.buffer[4 + 5] << 16) +
3099 3100 3101 3102
				(pc.buffer[4 + 6] << 8)  +
				 pc.buffer[4 + 7];
	tape->drv_write_prot = (pc.buffer[2] & 0x80) >> 7;
}
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3103 3104 3105 3106 3107 3108 3109 3110 3111

static int idetape_chrdev_open (struct inode *inode, struct file *filp)
{
	unsigned int minor = iminor(inode), i = minor & ~0xc0;
	ide_drive_t *drive;
	idetape_tape_t *tape;
	idetape_pc_t pc;
	int retval;

3112 3113 3114 3115 3116 3117 3118 3119 3120
	if (i >= MAX_HWIFS * MAX_DRIVES)
		return -ENXIO;

	tape = ide_tape_chrdev_get(i);
	if (!tape)
		return -ENXIO;

	debug_log(DBG_CHRDEV, "Enter %s\n", __func__);

L
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3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147
	/*
	 * We really want to do nonseekable_open(inode, filp); here, but some
	 * versions of tar incorrectly call lseek on tapes and bail out if that
	 * fails.  So we disallow pread() and pwrite(), but permit lseeks.
	 */
	filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE);

	drive = tape->drive;

	filp->private_data = tape;

	if (test_and_set_bit(IDETAPE_BUSY, &tape->flags)) {
		retval = -EBUSY;
		goto out_put_tape;
	}

	retval = idetape_wait_ready(drive, 60 * HZ);
	if (retval) {
		clear_bit(IDETAPE_BUSY, &tape->flags);
		printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name);
		goto out_put_tape;
	}

	idetape_read_position(drive);
	if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags))
		(void)idetape_rewind_tape(drive);

3148
	if (tape->chrdev_dir != IDETAPE_DIR_READ)
L
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3149 3150 3151
		clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags);

	/* Read block size and write protect status from drive. */
3152
	ide_tape_get_bsize_from_bdesc(drive);
L
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3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169

	/* Set write protect flag if device is opened as read-only. */
	if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
		tape->write_prot = 1;
	else
		tape->write_prot = tape->drv_write_prot;

	/* Make sure drive isn't write protected if user wants to write. */
	if (tape->write_prot) {
		if ((filp->f_flags & O_ACCMODE) == O_WRONLY ||
		    (filp->f_flags & O_ACCMODE) == O_RDWR) {
			clear_bit(IDETAPE_BUSY, &tape->flags);
			retval = -EROFS;
			goto out_put_tape;
		}
	}

3170
	/* Lock the tape drive door so user can't eject. */
3171
	if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
L
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3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194
		if (idetape_create_prevent_cmd(drive, &pc, 1)) {
			if (!idetape_queue_pc_tail(drive, &pc)) {
				if (tape->door_locked != DOOR_EXPLICITLY_LOCKED)
					tape->door_locked = DOOR_LOCKED;
			}
		}
	}
	idetape_restart_speed_control(drive);
	tape->restart_speed_control_req = 0;
	return 0;

out_put_tape:
	ide_tape_put(tape);
	return retval;
}

static void idetape_write_release (ide_drive_t *drive, unsigned int minor)
{
	idetape_tape_t *tape = drive->driver_data;

	idetape_empty_write_pipeline(drive);
	tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0);
	if (tape->merge_stage != NULL) {
3195 3196
		idetape_pad_zeros(drive, tape->blk_size *
				(tape->user_bs_factor - 1));
L
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3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213
		__idetape_kfree_stage(tape->merge_stage);
		tape->merge_stage = NULL;
	}
	idetape_write_filemark(drive);
	idetape_flush_tape_buffers(drive);
	idetape_flush_tape_buffers(drive);
}

static int idetape_chrdev_release (struct inode *inode, struct file *filp)
{
	struct ide_tape_obj *tape = ide_tape_f(filp);
	ide_drive_t *drive = tape->drive;
	idetape_pc_t pc;
	unsigned int minor = iminor(inode);

	lock_kernel();
	tape = drive->driver_data;
3214 3215

	debug_log(DBG_CHRDEV, "Enter %s\n", __func__);
L
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3216

3217
	if (tape->chrdev_dir == IDETAPE_DIR_WRITE)
L
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3218
		idetape_write_release(drive, minor);
3219
	if (tape->chrdev_dir == IDETAPE_DIR_READ) {
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3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230
		if (minor < 128)
			idetape_discard_read_pipeline(drive, 1);
		else
			idetape_wait_for_pipeline(drive);
	}
	if (tape->cache_stage != NULL) {
		__idetape_kfree_stage(tape->cache_stage);
		tape->cache_stage = NULL;
	}
	if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags))
		(void) idetape_rewind_tape(drive);
3231
	if (tape->chrdev_dir == IDETAPE_DIR_NONE) {
L
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3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245
		if (tape->door_locked == DOOR_LOCKED) {
			if (idetape_create_prevent_cmd(drive, &pc, 0)) {
				if (!idetape_queue_pc_tail(drive, &pc))
					tape->door_locked = DOOR_UNLOCKED;
			}
		}
	}
	clear_bit(IDETAPE_BUSY, &tape->flags);
	ide_tape_put(tape);
	unlock_kernel();
	return 0;
}

/*
3246
 * check the contents of the ATAPI IDENTIFY command results. We return:
L
Linus Torvalds 已提交
3247
 *
3248 3249
 * 1 - If the tape can be supported by us, based on the information we have so
 * far.
L
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3250
 *
3251
 * 0 - If this tape driver is not currently supported by us.
L
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3252
 */
3253
static int idetape_identify_device(ide_drive_t *drive)
L
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3254
{
3255
	u8 gcw[2], protocol, device_type, removable, packet_size;
L
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3256 3257 3258 3259

	if (drive->id_read == 0)
		return 1;

3260
	*((unsigned short *) &gcw) = drive->id->config;
L
Linus Torvalds 已提交
3261

3262 3263 3264 3265
	protocol	=   (gcw[1] & 0xC0) >> 6;
	device_type	=    gcw[1] & 0x1F;
	removable	= !!(gcw[0] & 0x80);
	packet_size	=    gcw[0] & 0x3;
L
Linus Torvalds 已提交
3266

3267 3268
	/* Check that we can support this device */
	if (protocol != 2)
3269
		printk(KERN_ERR "ide-tape: Protocol (0x%02x) is not ATAPI\n",
3270 3271
				protocol);
	else if (device_type != 1)
3272
		printk(KERN_ERR "ide-tape: Device type (0x%02x) is not set "
3273 3274
				"to tape\n", device_type);
	else if (!removable)
L
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3275
		printk(KERN_ERR "ide-tape: The removable flag is not set\n");
3276
	else if (packet_size != 0) {
3277
		printk(KERN_ERR "ide-tape: Packet size (0x%02x) is not 12 "
3278
				"bytes long\n", packet_size);
L
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3279 3280 3281 3282 3283
	} else
		return 1;
	return 0;
}

3284
static void idetape_get_inquiry_results(ide_drive_t *drive)
L
Linus Torvalds 已提交
3285 3286 3287
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t pc;
3288
	char fw_rev[6], vendor_id[10], product_id[18];
3289

L
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3290 3291
	idetape_create_inquiry_cmd(&pc);
	if (idetape_queue_pc_tail(drive, &pc)) {
3292 3293
		printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n",
				tape->name);
L
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3294 3295
		return;
	}
3296 3297 3298 3299 3300 3301 3302 3303
	memcpy(vendor_id, &pc.buffer[8], 8);
	memcpy(product_id, &pc.buffer[16], 16);
	memcpy(fw_rev, &pc.buffer[32], 4);

	ide_fixstring(vendor_id, 10, 0);
	ide_fixstring(product_id, 18, 0);
	ide_fixstring(fw_rev, 6, 0);

3304
	printk(KERN_INFO "ide-tape: %s <-> %s: %s %s rev %s\n",
3305
			drive->name, tape->name, vendor_id, product_id, fw_rev);
L
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3306 3307 3308
}

/*
3309 3310
 * Ask the tape about its various parameters. In particular, we will adjust our
 * data transfer buffer	size to the recommended value as returned by the tape.
L
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3311 3312 3313 3314 3315
 */
static void idetape_get_mode_sense_results (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;
	idetape_pc_t pc;
3316 3317
	u8 *caps;
	u8 speed, max_speed;
3318

L
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3319 3320
	idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE);
	if (idetape_queue_pc_tail(drive, &pc)) {
3321 3322
		printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming"
				" some default values\n");
3323
		tape->blk_size = 512;
3324 3325 3326
		put_unaligned(52,   (u16 *)&tape->caps[12]);
		put_unaligned(540,  (u16 *)&tape->caps[14]);
		put_unaligned(6*52, (u16 *)&tape->caps[16]);
L
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3327 3328
		return;
	}
3329 3330 3331 3332 3333
	caps = pc.buffer + 4 + pc.buffer[3];

	/* convert to host order and save for later use */
	speed = be16_to_cpu(*(u16 *)&caps[14]);
	max_speed = be16_to_cpu(*(u16 *)&caps[8]);
L
Linus Torvalds 已提交
3334

3335 3336 3337 3338
	put_unaligned(max_speed, (u16 *)&caps[8]);
	put_unaligned(be16_to_cpu(*(u16 *)&caps[12]), (u16 *)&caps[12]);
	put_unaligned(speed, (u16 *)&caps[14]);
	put_unaligned(be16_to_cpu(*(u16 *)&caps[16]), (u16 *)&caps[16]);
L
Linus Torvalds 已提交
3339

3340 3341 3342 3343
	if (!speed) {
		printk(KERN_INFO "ide-tape: %s: invalid tape speed "
				"(assuming 650KB/sec)\n", drive->name);
		put_unaligned(650, (u16 *)&caps[14]);
L
Linus Torvalds 已提交
3344
	}
3345 3346 3347 3348
	if (!max_speed) {
		printk(KERN_INFO "ide-tape: %s: invalid max_speed "
				"(assuming 650KB/sec)\n", drive->name);
		put_unaligned(650, (u16 *)&caps[8]);
L
Linus Torvalds 已提交
3349 3350
	}

3351 3352
	memcpy(&tape->caps, caps, 20);
	if (caps[7] & 0x02)
3353
		tape->blk_size = 512;
3354
	else if (caps[7] & 0x04)
3355
		tape->blk_size = 1024;
L
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3356 3357
}

3358
#ifdef CONFIG_IDE_PROC_FS
L
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3359 3360 3361 3362
static void idetape_add_settings (ide_drive_t *drive)
{
	idetape_tape_t *tape = drive->driver_data;

3363 3364
	ide_add_setting(drive, "buffer", SETTING_READ, TYPE_SHORT, 0, 0xffff,
			1, 2, (u16 *)&tape->caps[16], NULL);
3365 3366 3367 3368 3369
	ide_add_setting(drive,	"pipeline_min",		SETTING_RW,	TYPE_INT,	1,			0xffff,			tape->stage_size / 1024,	1,		&tape->min_pipeline,			NULL);
	ide_add_setting(drive,	"pipeline",		SETTING_RW,	TYPE_INT,	1,			0xffff,			tape->stage_size / 1024,	1,		&tape->max_stages,			NULL);
	ide_add_setting(drive,	"pipeline_max",		SETTING_RW,	TYPE_INT,	1,			0xffff,			tape->stage_size / 1024,	1,		&tape->max_pipeline,			NULL);
	ide_add_setting(drive,	"pipeline_used",	SETTING_READ,	TYPE_INT,	0,			0xffff,			tape->stage_size / 1024,	1,		&tape->nr_stages,			NULL);
	ide_add_setting(drive,	"pipeline_pending",	SETTING_READ,	TYPE_INT,	0,			0xffff,			tape->stage_size / 1024,	1,		&tape->nr_pending_stages,		NULL);
3370 3371
	ide_add_setting(drive, "speed", SETTING_READ, TYPE_SHORT, 0, 0xffff,
			1, 1, (u16 *)&tape->caps[14], NULL);
3372 3373 3374 3375 3376
	ide_add_setting(drive, "stage", SETTING_READ, TYPE_INT,	0, 0xffff, 1,
			1024, &tape->stage_size, NULL);
	ide_add_setting(drive, "tdsc", SETTING_RW, TYPE_INT, IDETAPE_DSC_RW_MIN,
			IDETAPE_DSC_RW_MAX, 1000, HZ, &tape->best_dsc_rw_freq,
			NULL);
3377 3378 3379 3380
	ide_add_setting(drive,	"dsc_overlap",		SETTING_RW,	TYPE_BYTE,	0,			1,			1,				1,		&drive->dsc_overlap,			NULL);
	ide_add_setting(drive,	"pipeline_head_speed_c",SETTING_READ,	TYPE_INT,	0,			0xffff,			1,				1,		&tape->controlled_pipeline_head_speed,	NULL);
	ide_add_setting(drive,	"pipeline_head_speed_u",SETTING_READ,	TYPE_INT,	0,			0xffff,			1,				1,		&tape->uncontrolled_pipeline_head_speed,NULL);
	ide_add_setting(drive,	"avg_speed",		SETTING_READ,	TYPE_INT,	0,			0xffff,			1,				1,		&tape->avg_speed,			NULL);
3381 3382
	ide_add_setting(drive, "debug_mask", SETTING_RW, TYPE_INT, 0, 0xffff, 1,
			1, &tape->debug_mask, NULL);
L
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3383
}
3384 3385 3386
#else
static inline void idetape_add_settings(ide_drive_t *drive) { ; }
#endif
L
Linus Torvalds 已提交
3387 3388

/*
3389
 * The function below is called to:
L
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3390
 *
3391 3392 3393 3394
 * 1. Initialize our various state variables.
 * 2. Ask the tape for its capabilities.
 * 3. Allocate a buffer which will be used for data transfer. The buffer size
 * is chosen based on the recommendation which we received in step 2.
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3395
 *
3396 3397
 * Note that at this point ide.c already assigned us an irq, so that we can
 * queue requests here and wait for their completion.
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3398 3399 3400 3401 3402 3403
 */
static void idetape_setup (ide_drive_t *drive, idetape_tape_t *tape, int minor)
{
	unsigned long t1, tmid, tn, t;
	int speed;
	int stage_size;
3404
	u8 gcw[2];
L
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3405
	struct sysinfo si;
3406
	u16 *ctl = (u16 *)&tape->caps[12];
L
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3407

3408
	spin_lock_init(&tape->lock);
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3409
	drive->dsc_overlap = 1;
3410 3411 3412 3413
	if (drive->hwif->host_flags & IDE_HFLAG_NO_DSC) {
		printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n",
				 tape->name);
		drive->dsc_overlap = 0;
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	}
	/* Seagate Travan drives do not support DSC overlap. */
	if (strstr(drive->id->model, "Seagate STT3401"))
		drive->dsc_overlap = 0;
	tape->minor = minor;
	tape->name[0] = 'h';
	tape->name[1] = 't';
	tape->name[2] = '0' + minor;
3422
	tape->chrdev_dir = IDETAPE_DIR_NONE;
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3423 3424 3425 3426
	tape->pc = tape->pc_stack;
	tape->max_insert_speed = 10000;
	tape->speed_control = 1;
	*((unsigned short *) &gcw) = drive->id->config;
3427 3428 3429

	/* Command packet DRQ type */
	if (((gcw[0] & 0x60) >> 5) == 1)
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3430 3431 3432
		set_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags);

	tape->min_pipeline = tape->max_pipeline = tape->max_stages = 10;
3433

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3434 3435
	idetape_get_inquiry_results(drive);
	idetape_get_mode_sense_results(drive);
3436
	ide_tape_get_bsize_from_bdesc(drive);
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3437
	tape->user_bs_factor = 1;
3438
	tape->stage_size = *ctl * tape->blk_size;
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3439 3440
	while (tape->stage_size > 0xffff) {
		printk(KERN_NOTICE "ide-tape: decreasing stage size\n");
3441
		*ctl /= 2;
3442
		tape->stage_size = *ctl * tape->blk_size;
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3443 3444 3445 3446 3447 3448 3449 3450
	}
	stage_size = tape->stage_size;
	tape->pages_per_stage = stage_size / PAGE_SIZE;
	if (stage_size % PAGE_SIZE) {
		tape->pages_per_stage++;
		tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE;
	}

3451 3452
	/* Select the "best" DSC read/write polling freq and pipeline size. */
	speed = max(*(u16 *)&tape->caps[14], *(u16 *)&tape->caps[8]);
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3453 3454 3455

	tape->max_stages = speed * 1000 * 10 / tape->stage_size;

3456
	/* Limit memory use for pipeline to 10% of physical memory */
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3457 3458 3459 3460 3461 3462 3463 3464 3465 3466
	si_meminfo(&si);
	if (tape->max_stages * tape->stage_size > si.totalram * si.mem_unit / 10)
		tape->max_stages = si.totalram * si.mem_unit / (10 * tape->stage_size);
	tape->max_stages   = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES);
	tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES);
	tape->max_pipeline = min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES);
	if (tape->max_stages == 0)
		tape->max_stages = tape->min_pipeline = tape->max_pipeline = 1;

	t1 = (tape->stage_size * HZ) / (speed * 1000);
3467
	tmid = (*(u16 *)&tape->caps[16] * 32 * HZ) / (speed * 125);
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3468 3469 3470 3471 3472 3473 3474 3475
	tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000);

	if (tape->max_stages)
		t = tn;
	else
		t = t1;

	/*
3476 3477
	 * Ensure that the number we got makes sense; limit it within
	 * IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX.
L
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3478
	 */
3479 3480 3481
	tape->best_dsc_rw_freq = max_t(unsigned long,
				min_t(unsigned long, t, IDETAPE_DSC_RW_MAX),
				IDETAPE_DSC_RW_MIN);
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3482 3483
	printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, "
		"%dkB pipeline, %lums tDSC%s\n",
3484 3485
		drive->name, tape->name, *(u16 *)&tape->caps[14],
		(*(u16 *)&tape->caps[16] * 512) / tape->stage_size,
L
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3486 3487
		tape->stage_size / 1024,
		tape->max_stages * tape->stage_size / 1024,
3488
		tape->best_dsc_rw_freq * 1000 / HZ,
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3489 3490 3491 3492 3493
		drive->using_dma ? ", DMA":"");

	idetape_add_settings(drive);
}

3494
static void ide_tape_remove(ide_drive_t *drive)
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3495 3496 3497
{
	idetape_tape_t *tape = drive->driver_data;

3498
	ide_proc_unregister_driver(drive, tape->driver);
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3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510

	ide_unregister_region(tape->disk);

	ide_tape_put(tape);
}

static void ide_tape_release(struct kref *kref)
{
	struct ide_tape_obj *tape = to_ide_tape(kref);
	ide_drive_t *drive = tape->drive;
	struct gendisk *g = tape->disk;

3511 3512
	BUG_ON(tape->first_stage != NULL || tape->merge_stage_size);

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3513 3514
	drive->dsc_overlap = 0;
	drive->driver_data = NULL;
3515 3516
	device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor));
	device_destroy(idetape_sysfs_class, MKDEV(IDETAPE_MAJOR, tape->minor + 128));
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3517 3518 3519 3520 3521 3522
	idetape_devs[tape->minor] = NULL;
	g->private_data = NULL;
	put_disk(g);
	kfree(tape);
}

3523
#ifdef CONFIG_IDE_PROC_FS
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3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542
static int proc_idetape_read_name
	(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	ide_drive_t	*drive = (ide_drive_t *) data;
	idetape_tape_t	*tape = drive->driver_data;
	char		*out = page;
	int		len;

	len = sprintf(out, "%s\n", tape->name);
	PROC_IDE_READ_RETURN(page, start, off, count, eof, len);
}

static ide_proc_entry_t idetape_proc[] = {
	{ "capacity",	S_IFREG|S_IRUGO,	proc_ide_read_capacity, NULL },
	{ "name",	S_IFREG|S_IRUGO,	proc_idetape_read_name,	NULL },
	{ NULL, 0, NULL, NULL }
};
#endif

3543
static int ide_tape_probe(ide_drive_t *);
L
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3544 3545

static ide_driver_t idetape_driver = {
3546
	.gen_driver = {
3547
		.owner		= THIS_MODULE,
3548 3549 3550
		.name		= "ide-tape",
		.bus		= &ide_bus_type,
	},
3551 3552
	.probe			= ide_tape_probe,
	.remove			= ide_tape_remove,
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3553 3554 3555 3556 3557 3558 3559
	.version		= IDETAPE_VERSION,
	.media			= ide_tape,
	.supports_dsc_overlap 	= 1,
	.do_request		= idetape_do_request,
	.end_request		= idetape_end_request,
	.error			= __ide_error,
	.abort			= __ide_abort,
3560
#ifdef CONFIG_IDE_PROC_FS
L
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3561
	.proc			= idetape_proc,
3562
#endif
L
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3563 3564
};

3565
/* Our character device supporting functions, passed to register_chrdev. */
3566
static const struct file_operations idetape_fops = {
L
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3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614
	.owner		= THIS_MODULE,
	.read		= idetape_chrdev_read,
	.write		= idetape_chrdev_write,
	.ioctl		= idetape_chrdev_ioctl,
	.open		= idetape_chrdev_open,
	.release	= idetape_chrdev_release,
};

static int idetape_open(struct inode *inode, struct file *filp)
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct ide_tape_obj *tape;

	if (!(tape = ide_tape_get(disk)))
		return -ENXIO;

	return 0;
}

static int idetape_release(struct inode *inode, struct file *filp)
{
	struct gendisk *disk = inode->i_bdev->bd_disk;
	struct ide_tape_obj *tape = ide_tape_g(disk);

	ide_tape_put(tape);

	return 0;
}

static int idetape_ioctl(struct inode *inode, struct file *file,
			unsigned int cmd, unsigned long arg)
{
	struct block_device *bdev = inode->i_bdev;
	struct ide_tape_obj *tape = ide_tape_g(bdev->bd_disk);
	ide_drive_t *drive = tape->drive;
	int err = generic_ide_ioctl(drive, file, bdev, cmd, arg);
	if (err == -EINVAL)
		err = idetape_blkdev_ioctl(drive, cmd, arg);
	return err;
}

static struct block_device_operations idetape_block_ops = {
	.owner		= THIS_MODULE,
	.open		= idetape_open,
	.release	= idetape_release,
	.ioctl		= idetape_ioctl,
};

3615
static int ide_tape_probe(ide_drive_t *drive)
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3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634
{
	idetape_tape_t *tape;
	struct gendisk *g;
	int minor;

	if (!strstr("ide-tape", drive->driver_req))
		goto failed;
	if (!drive->present)
		goto failed;
	if (drive->media != ide_tape)
		goto failed;
	if (!idetape_identify_device (drive)) {
		printk(KERN_ERR "ide-tape: %s: not supported by this version of ide-tape\n", drive->name);
		goto failed;
	}
	if (drive->scsi) {
		printk("ide-tape: passing drive %s to ide-scsi emulation.\n", drive->name);
		goto failed;
	}
3635
	tape = kzalloc(sizeof (idetape_tape_t), GFP_KERNEL);
L
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3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646
	if (tape == NULL) {
		printk(KERN_ERR "ide-tape: %s: Can't allocate a tape structure\n", drive->name);
		goto failed;
	}

	g = alloc_disk(1 << PARTN_BITS);
	if (!g)
		goto out_free_tape;

	ide_init_disk(g, drive);

3647
	ide_proc_register_driver(drive, &idetape_driver);
L
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3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658

	kref_init(&tape->kref);

	tape->drive = drive;
	tape->driver = &idetape_driver;
	tape->disk = g;

	g->private_data = &tape->driver;

	drive->driver_data = tape;

3659
	mutex_lock(&idetape_ref_mutex);
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3660 3661 3662
	for (minor = 0; idetape_devs[minor]; minor++)
		;
	idetape_devs[minor] = tape;
3663
	mutex_unlock(&idetape_ref_mutex);
L
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3664 3665 3666

	idetape_setup(drive, tape, minor);

3667 3668 3669 3670
	device_create(idetape_sysfs_class, &drive->gendev,
		      MKDEV(IDETAPE_MAJOR, minor), "%s", tape->name);
	device_create(idetape_sysfs_class, &drive->gendev,
			MKDEV(IDETAPE_MAJOR, minor + 128), "n%s", tape->name);
3671

L
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3672 3673 3674 3675
	g->fops = &idetape_block_ops;
	ide_register_region(g);

	return 0;
3676

L
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3677 3678 3679
out_free_tape:
	kfree(tape);
failed:
3680
	return -ENODEV;
L
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3681 3682 3683 3684
}

static void __exit idetape_exit (void)
{
3685
	driver_unregister(&idetape_driver.gen_driver);
3686
	class_destroy(idetape_sysfs_class);
L
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3687 3688 3689
	unregister_chrdev(IDETAPE_MAJOR, "ht");
}

3690
static int __init idetape_init(void)
L
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3691
{
3692 3693 3694 3695 3696 3697 3698 3699 3700
	int error = 1;
	idetape_sysfs_class = class_create(THIS_MODULE, "ide_tape");
	if (IS_ERR(idetape_sysfs_class)) {
		idetape_sysfs_class = NULL;
		printk(KERN_ERR "Unable to create sysfs class for ide tapes\n");
		error = -EBUSY;
		goto out;
	}

L
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3701 3702
	if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) {
		printk(KERN_ERR "ide-tape: Failed to register character device interface\n");
3703 3704
		error = -EBUSY;
		goto out_free_class;
L
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3705
	}
3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718

	error = driver_register(&idetape_driver.gen_driver);
	if (error)
		goto out_free_driver;

	return 0;

out_free_driver:
	driver_unregister(&idetape_driver.gen_driver);
out_free_class:
	class_destroy(idetape_sysfs_class);
out:
	return error;
L
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3719 3720
}

3721
MODULE_ALIAS("ide:*m-tape*");
L
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3722 3723 3724
module_init(idetape_init);
module_exit(idetape_exit);
MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR);
3725 3726
MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver");
MODULE_LICENSE("GPL");