dasd.c 95.1 KB
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/*
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *		    Horst Hummel <Horst.Hummel@de.ibm.com>
 *		    Carsten Otte <Cotte@de.ibm.com>
 *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
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 * Copyright IBM Corp. 1999, 2009
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 */

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#define KMSG_COMPONENT "dasd"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

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#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ctype.h>
#include <linux/major.h>
#include <linux/slab.h>
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#include <linux/hdreg.h>
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#include <linux/async.h>
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#include <linux/mutex.h>
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#include <linux/debugfs.h>
#include <linux/seq_file.h>
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#include <linux/vmalloc.h>
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#include <asm/ccwdev.h>
#include <asm/ebcdic.h>
#include <asm/idals.h>
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#include <asm/itcw.h>
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#include <asm/diag.h>
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/* This is ugly... */
#define PRINTK_HEADER "dasd:"

#include "dasd_int.h"
/*
 * SECTION: Constant definitions to be used within this file
 */
#define DASD_CHANQ_MAX_SIZE 4

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#define DASD_SLEEPON_START_TAG	(void *) 1
#define DASD_SLEEPON_END_TAG	(void *) 2

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/*
 * SECTION: exported variables of dasd.c
 */
debug_info_t *dasd_debug_area;
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static struct dentry *dasd_debugfs_root_entry;
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struct dasd_discipline *dasd_diag_discipline_pointer;
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void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
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MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
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		   " Copyright IBM Corp. 2000");
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MODULE_SUPPORTED_DEVICE("dasd");
MODULE_LICENSE("GPL");

/*
 * SECTION: prototypes for static functions of dasd.c
 */
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static int  dasd_alloc_queue(struct dasd_block *);
static void dasd_setup_queue(struct dasd_block *);
static void dasd_free_queue(struct dasd_block *);
static void dasd_flush_request_queue(struct dasd_block *);
static int dasd_flush_block_queue(struct dasd_block *);
static void dasd_device_tasklet(struct dasd_device *);
static void dasd_block_tasklet(struct dasd_block *);
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static void do_kick_device(struct work_struct *);
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static void do_restore_device(struct work_struct *);
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static void do_reload_device(struct work_struct *);
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static void dasd_return_cqr_cb(struct dasd_ccw_req *, void *);
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static void dasd_device_timeout(unsigned long);
static void dasd_block_timeout(unsigned long);
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static void __dasd_process_erp(struct dasd_device *, struct dasd_ccw_req *);
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static void dasd_profile_init(struct dasd_profile *, struct dentry *);
static void dasd_profile_exit(struct dasd_profile *);
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/*
 * SECTION: Operations on the device structure.
 */
static wait_queue_head_t dasd_init_waitq;
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static wait_queue_head_t dasd_flush_wq;
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static wait_queue_head_t generic_waitq;
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static wait_queue_head_t shutdown_waitq;
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/*
 * Allocate memory for a new device structure.
 */
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struct dasd_device *dasd_alloc_device(void)
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{
	struct dasd_device *device;

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	device = kzalloc(sizeof(struct dasd_device), GFP_ATOMIC);
	if (!device)
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		return ERR_PTR(-ENOMEM);

	/* Get two pages for normal block device operations. */
	device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
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	if (!device->ccw_mem) {
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		kfree(device);
		return ERR_PTR(-ENOMEM);
	}
	/* Get one page for error recovery. */
	device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
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	if (!device->erp_mem) {
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		free_pages((unsigned long) device->ccw_mem, 1);
		kfree(device);
		return ERR_PTR(-ENOMEM);
	}

	dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
	dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
	spin_lock_init(&device->mem_lock);
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	atomic_set(&device->tasklet_scheduled, 0);
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	tasklet_init(&device->tasklet,
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		     (void (*)(unsigned long)) dasd_device_tasklet,
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		     (unsigned long) device);
	INIT_LIST_HEAD(&device->ccw_queue);
	init_timer(&device->timer);
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	device->timer.function = dasd_device_timeout;
	device->timer.data = (unsigned long) device;
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	INIT_WORK(&device->kick_work, do_kick_device);
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	INIT_WORK(&device->restore_device, do_restore_device);
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	INIT_WORK(&device->reload_device, do_reload_device);
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	device->state = DASD_STATE_NEW;
	device->target = DASD_STATE_NEW;
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	mutex_init(&device->state_mutex);
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	spin_lock_init(&device->profile.lock);
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	return device;
}

/*
 * Free memory of a device structure.
 */
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void dasd_free_device(struct dasd_device *device)
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{
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	kfree(device->private);
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	free_page((unsigned long) device->erp_mem);
	free_pages((unsigned long) device->ccw_mem, 1);
	kfree(device);
}

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/*
 * Allocate memory for a new device structure.
 */
struct dasd_block *dasd_alloc_block(void)
{
	struct dasd_block *block;

	block = kzalloc(sizeof(*block), GFP_ATOMIC);
	if (!block)
		return ERR_PTR(-ENOMEM);
	/* open_count = 0 means device online but not in use */
	atomic_set(&block->open_count, -1);

	spin_lock_init(&block->request_queue_lock);
	atomic_set(&block->tasklet_scheduled, 0);
	tasklet_init(&block->tasklet,
		     (void (*)(unsigned long)) dasd_block_tasklet,
		     (unsigned long) block);
	INIT_LIST_HEAD(&block->ccw_queue);
	spin_lock_init(&block->queue_lock);
	init_timer(&block->timer);
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	block->timer.function = dasd_block_timeout;
	block->timer.data = (unsigned long) block;
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	spin_lock_init(&block->profile.lock);
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	return block;
}

/*
 * Free memory of a device structure.
 */
void dasd_free_block(struct dasd_block *block)
{
	kfree(block);
}

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/*
 * Make a new device known to the system.
 */
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static int dasd_state_new_to_known(struct dasd_device *device)
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{
	int rc;

	/*
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	 * As long as the device is not in state DASD_STATE_NEW we want to
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	 * keep the reference count > 0.
	 */
	dasd_get_device(device);

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	if (device->block) {
		rc = dasd_alloc_queue(device->block);
		if (rc) {
			dasd_put_device(device);
			return rc;
		}
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	}
	device->state = DASD_STATE_KNOWN;
	return 0;
}

/*
 * Let the system forget about a device.
 */
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static int dasd_state_known_to_new(struct dasd_device *device)
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{
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	/* Disable extended error reporting for this device. */
	dasd_eer_disable(device);
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	/* Forget the discipline information. */
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	if (device->discipline) {
		if (device->discipline->uncheck_device)
			device->discipline->uncheck_device(device);
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		module_put(device->discipline->owner);
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	}
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	device->discipline = NULL;
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	if (device->base_discipline)
		module_put(device->base_discipline->owner);
	device->base_discipline = NULL;
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	device->state = DASD_STATE_NEW;

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	if (device->block)
		dasd_free_queue(device->block);
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	/* Give up reference we took in dasd_state_new_to_known. */
	dasd_put_device(device);
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	return 0;
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}

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static struct dentry *dasd_debugfs_setup(const char *name,
					 struct dentry *base_dentry)
{
	struct dentry *pde;

	if (!base_dentry)
		return NULL;
	pde = debugfs_create_dir(name, base_dentry);
	if (!pde || IS_ERR(pde))
		return NULL;
	return pde;
}

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/*
 * Request the irq line for the device.
 */
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static int dasd_state_known_to_basic(struct dasd_device *device)
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{
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	struct dasd_block *block = device->block;
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	int rc;

	/* Allocate and register gendisk structure. */
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	if (block) {
		rc = dasd_gendisk_alloc(block);
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		if (rc)
			return rc;
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		block->debugfs_dentry =
			dasd_debugfs_setup(block->gdp->disk_name,
					   dasd_debugfs_root_entry);
		dasd_profile_init(&block->profile, block->debugfs_dentry);
		if (dasd_global_profile_level == DASD_PROFILE_ON)
			dasd_profile_on(&device->block->profile);
	}
	device->debugfs_dentry =
		dasd_debugfs_setup(dev_name(&device->cdev->dev),
				   dasd_debugfs_root_entry);
	dasd_profile_init(&device->profile, device->debugfs_dentry);

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	/* register 'device' debug area, used for all DBF_DEV_XXX calls */
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	device->debug_area = debug_register(dev_name(&device->cdev->dev), 4, 1,
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					    8 * sizeof(long));
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	debug_register_view(device->debug_area, &debug_sprintf_view);
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	debug_set_level(device->debug_area, DBF_WARNING);
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	DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");

	device->state = DASD_STATE_BASIC;
	return 0;
}

/*
 * Release the irq line for the device. Terminate any running i/o.
 */
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static int dasd_state_basic_to_known(struct dasd_device *device)
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{
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	int rc;
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	if (device->block) {
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		dasd_profile_exit(&device->block->profile);
		if (device->block->debugfs_dentry)
			debugfs_remove(device->block->debugfs_dentry);
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		dasd_gendisk_free(device->block);
		dasd_block_clear_timer(device->block);
	}
	rc = dasd_flush_device_queue(device);
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	if (rc)
		return rc;
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	dasd_device_clear_timer(device);
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	dasd_profile_exit(&device->profile);
	if (device->debugfs_dentry)
		debugfs_remove(device->debugfs_dentry);
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	DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
	if (device->debug_area != NULL) {
		debug_unregister(device->debug_area);
		device->debug_area = NULL;
	}
	device->state = DASD_STATE_KNOWN;
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	return 0;
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}

/*
 * Do the initial analysis. The do_analysis function may return
 * -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
 * until the discipline decides to continue the startup sequence
 * by calling the function dasd_change_state. The eckd disciplines
 * uses this to start a ccw that detects the format. The completion
 * interrupt for this detection ccw uses the kernel event daemon to
 * trigger the call to dasd_change_state. All this is done in the
 * discipline code, see dasd_eckd.c.
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 * After the analysis ccw is done (do_analysis returned 0) the block
 * device is setup.
 * In case the analysis returns an error, the device setup is stopped
 * (a fake disk was already added to allow formatting).
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 */
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static int dasd_state_basic_to_ready(struct dasd_device *device)
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{
	int rc;
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	struct dasd_block *block;
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	rc = 0;
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	block = device->block;
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	/* make disk known with correct capacity */
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	if (block) {
		if (block->base->discipline->do_analysis != NULL)
			rc = block->base->discipline->do_analysis(block);
		if (rc) {
			if (rc != -EAGAIN)
				device->state = DASD_STATE_UNFMT;
			return rc;
		}
		dasd_setup_queue(block);
		set_capacity(block->gdp,
			     block->blocks << block->s2b_shift);
		device->state = DASD_STATE_READY;
		rc = dasd_scan_partitions(block);
		if (rc)
			device->state = DASD_STATE_BASIC;
	} else {
		device->state = DASD_STATE_READY;
	}
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	return rc;
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}

/*
 * Remove device from block device layer. Destroy dirty buffers.
 * Forget format information. Check if the target level is basic
 * and if it is create fake disk for formatting.
 */
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static int dasd_state_ready_to_basic(struct dasd_device *device)
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{
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	int rc;

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	device->state = DASD_STATE_BASIC;
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	if (device->block) {
		struct dasd_block *block = device->block;
		rc = dasd_flush_block_queue(block);
		if (rc) {
			device->state = DASD_STATE_READY;
			return rc;
		}
		dasd_flush_request_queue(block);
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		dasd_destroy_partitions(block);
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		block->blocks = 0;
		block->bp_block = 0;
		block->s2b_shift = 0;
	}
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	return 0;
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}

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/*
 * Back to basic.
 */
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static int dasd_state_unfmt_to_basic(struct dasd_device *device)
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{
	device->state = DASD_STATE_BASIC;
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	return 0;
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}

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/*
 * Make the device online and schedule the bottom half to start
 * the requeueing of requests from the linux request queue to the
 * ccw queue.
 */
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static int
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dasd_state_ready_to_online(struct dasd_device * device)
{
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	int rc;
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	struct gendisk *disk;
	struct disk_part_iter piter;
	struct hd_struct *part;
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	if (device->discipline->ready_to_online) {
		rc = device->discipline->ready_to_online(device);
		if (rc)
			return rc;
	}
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	device->state = DASD_STATE_ONLINE;
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	if (device->block) {
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		dasd_schedule_block_bh(device->block);
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		if ((device->features & DASD_FEATURE_USERAW)) {
			disk = device->block->gdp;
			kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
			return 0;
		}
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		disk = device->block->bdev->bd_disk;
		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
		while ((part = disk_part_iter_next(&piter)))
			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
		disk_part_iter_exit(&piter);
	}
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	return 0;
}

/*
 * Stop the requeueing of requests again.
 */
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static int dasd_state_online_to_ready(struct dasd_device *device)
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{
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	int rc;
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	struct gendisk *disk;
	struct disk_part_iter piter;
	struct hd_struct *part;
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	if (device->discipline->online_to_ready) {
		rc = device->discipline->online_to_ready(device);
		if (rc)
			return rc;
	}
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	device->state = DASD_STATE_READY;
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	if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
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		disk = device->block->bdev->bd_disk;
		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
		while ((part = disk_part_iter_next(&piter)))
			kobject_uevent(&part_to_dev(part)->kobj, KOBJ_CHANGE);
		disk_part_iter_exit(&piter);
	}
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	return 0;
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}

/*
 * Device startup state changes.
 */
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static int dasd_increase_state(struct dasd_device *device)
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{
	int rc;

	rc = 0;
	if (device->state == DASD_STATE_NEW &&
	    device->target >= DASD_STATE_KNOWN)
		rc = dasd_state_new_to_known(device);

	if (!rc &&
	    device->state == DASD_STATE_KNOWN &&
	    device->target >= DASD_STATE_BASIC)
		rc = dasd_state_known_to_basic(device);

	if (!rc &&
	    device->state == DASD_STATE_BASIC &&
	    device->target >= DASD_STATE_READY)
		rc = dasd_state_basic_to_ready(device);

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	if (!rc &&
	    device->state == DASD_STATE_UNFMT &&
	    device->target > DASD_STATE_UNFMT)
		rc = -EPERM;

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	if (!rc &&
	    device->state == DASD_STATE_READY &&
	    device->target >= DASD_STATE_ONLINE)
		rc = dasd_state_ready_to_online(device);

	return rc;
}

/*
 * Device shutdown state changes.
 */
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static int dasd_decrease_state(struct dasd_device *device)
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{
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	int rc;

	rc = 0;
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	if (device->state == DASD_STATE_ONLINE &&
	    device->target <= DASD_STATE_READY)
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		rc = dasd_state_online_to_ready(device);
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	if (!rc &&
	    device->state == DASD_STATE_READY &&
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	    device->target <= DASD_STATE_BASIC)
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		rc = dasd_state_ready_to_basic(device);
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	if (!rc &&
	    device->state == DASD_STATE_UNFMT &&
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	    device->target <= DASD_STATE_BASIC)
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		rc = dasd_state_unfmt_to_basic(device);
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	if (!rc &&
	    device->state == DASD_STATE_BASIC &&
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	    device->target <= DASD_STATE_KNOWN)
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		rc = dasd_state_basic_to_known(device);
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	if (!rc &&
	    device->state == DASD_STATE_KNOWN &&
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	    device->target <= DASD_STATE_NEW)
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		rc = dasd_state_known_to_new(device);
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	return rc;
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}

/*
 * This is the main startup/shutdown routine.
 */
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static void dasd_change_state(struct dasd_device *device)
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{
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	int rc;
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	if (device->state == device->target)
		/* Already where we want to go today... */
		return;
	if (device->state < device->target)
		rc = dasd_increase_state(device);
	else
		rc = dasd_decrease_state(device);
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	if (rc == -EAGAIN)
		return;
	if (rc)
		device->target = device->state;
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	if (device->state == device->target)
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		wake_up(&dasd_init_waitq);
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	/* let user-space know that the device status changed */
	kobject_uevent(&device->cdev->dev.kobj, KOBJ_CHANGE);
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}

/*
 * Kick starter for devices that did not complete the startup/shutdown
 * procedure or were sleeping because of a pending state.
 * dasd_kick_device will schedule a call do do_kick_device to the kernel
 * event daemon.
 */
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static void do_kick_device(struct work_struct *work)
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{
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	struct dasd_device *device = container_of(work, struct dasd_device, kick_work);
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	mutex_lock(&device->state_mutex);
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	dasd_change_state(device);
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	mutex_unlock(&device->state_mutex);
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	dasd_schedule_device_bh(device);
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	dasd_put_device(device);
}

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void dasd_kick_device(struct dasd_device *device)
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{
	dasd_get_device(device);
	/* queue call to dasd_kick_device to the kernel event daemon. */
	schedule_work(&device->kick_work);
}

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/*
 * dasd_reload_device will schedule a call do do_reload_device to the kernel
 * event daemon.
 */
static void do_reload_device(struct work_struct *work)
{
	struct dasd_device *device = container_of(work, struct dasd_device,
						  reload_device);
	device->discipline->reload(device);
	dasd_put_device(device);
}

void dasd_reload_device(struct dasd_device *device)
{
	dasd_get_device(device);
	/* queue call to dasd_reload_device to the kernel event daemon. */
	schedule_work(&device->reload_device);
}
EXPORT_SYMBOL(dasd_reload_device);

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/*
 * dasd_restore_device will schedule a call do do_restore_device to the kernel
 * event daemon.
 */
static void do_restore_device(struct work_struct *work)
{
	struct dasd_device *device = container_of(work, struct dasd_device,
						  restore_device);
	device->cdev->drv->restore(device->cdev);
	dasd_put_device(device);
}

void dasd_restore_device(struct dasd_device *device)
{
	dasd_get_device(device);
	/* queue call to dasd_restore_device to the kernel event daemon. */
	schedule_work(&device->restore_device);
}

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/*
 * Set the target state for a device and starts the state change.
 */
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void dasd_set_target_state(struct dasd_device *device, int target)
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{
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	dasd_get_device(device);
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	mutex_lock(&device->state_mutex);
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	/* If we are in probeonly mode stop at DASD_STATE_READY. */
	if (dasd_probeonly && target > DASD_STATE_READY)
		target = DASD_STATE_READY;
	if (device->target != target) {
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		if (device->state == target)
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			wake_up(&dasd_init_waitq);
		device->target = target;
	}
	if (device->state != device->target)
		dasd_change_state(device);
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	mutex_unlock(&device->state_mutex);
	dasd_put_device(device);
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}

/*
 * Enable devices with device numbers in [from..to].
 */
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static inline int _wait_for_device(struct dasd_device *device)
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{
	return (device->state == device->target);
}

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void dasd_enable_device(struct dasd_device *device)
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{
	dasd_set_target_state(device, DASD_STATE_ONLINE);
	if (device->state <= DASD_STATE_KNOWN)
		/* No discipline for device found. */
		dasd_set_target_state(device, DASD_STATE_NEW);
	/* Now wait for the devices to come up. */
	wait_event(dasd_init_waitq, _wait_for_device(device));
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	dasd_reload_device(device);
	if (device->discipline->kick_validate)
		device->discipline->kick_validate(device);
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}

/*
 * SECTION: device operation (interrupt handler, start i/o, term i/o ...)
 */

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unsigned int dasd_global_profile_level = DASD_PROFILE_OFF;
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#ifdef CONFIG_DASD_PROFILE
struct dasd_profile_info dasd_global_profile_data;
static struct dentry *dasd_global_profile_dentry;
static struct dentry *dasd_debugfs_global_entry;
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/*
 * Add profiling information for cqr before execution.
 */
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static void dasd_profile_start(struct dasd_block *block,
			       struct dasd_ccw_req *cqr,
			       struct request *req)
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{
	struct list_head *l;
	unsigned int counter;
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	struct dasd_device *device;
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	/* count the length of the chanq for statistics */
	counter = 0;
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	if (dasd_global_profile_level || block->profile.data)
		list_for_each(l, &block->ccw_queue)
			if (++counter >= 31)
				break;

	if (dasd_global_profile_level) {
		dasd_global_profile_data.dasd_io_nr_req[counter]++;
		if (rq_data_dir(req) == READ)
			dasd_global_profile_data.dasd_read_nr_req[counter]++;
	}

	spin_lock(&block->profile.lock);
	if (block->profile.data)
		block->profile.data->dasd_io_nr_req[counter]++;
		if (rq_data_dir(req) == READ)
			block->profile.data->dasd_read_nr_req[counter]++;
	spin_unlock(&block->profile.lock);

	/*
	 * We count the request for the start device, even though it may run on
	 * some other device due to error recovery. This way we make sure that
	 * we count each request only once.
	 */
	device = cqr->startdev;
	if (device->profile.data) {
		counter = 1; /* request is not yet queued on the start device */
		list_for_each(l, &device->ccw_queue)
			if (++counter >= 31)
				break;
	}
	spin_lock(&device->profile.lock);
	if (device->profile.data) {
		device->profile.data->dasd_io_nr_req[counter]++;
		if (rq_data_dir(req) == READ)
			device->profile.data->dasd_read_nr_req[counter]++;
	}
	spin_unlock(&device->profile.lock);
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}

/*
 * Add profiling information for cqr after execution.
 */
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#define dasd_profile_counter(value, index)			   \
{								   \
	for (index = 0; index < 31 && value >> (2+index); index++) \
		;						   \
}

static void dasd_profile_end_add_data(struct dasd_profile_info *data,
				      int is_alias,
				      int is_tpm,
				      int is_read,
				      long sectors,
				      int sectors_ind,
				      int tottime_ind,
				      int tottimeps_ind,
				      int strtime_ind,
				      int irqtime_ind,
				      int irqtimeps_ind,
				      int endtime_ind)
{
	/* in case of an overflow, reset the whole profile */
	if (data->dasd_io_reqs == UINT_MAX) {
			memset(data, 0, sizeof(*data));
			getnstimeofday(&data->starttod);
	}
	data->dasd_io_reqs++;
	data->dasd_io_sects += sectors;
	if (is_alias)
		data->dasd_io_alias++;
	if (is_tpm)
		data->dasd_io_tpm++;

	data->dasd_io_secs[sectors_ind]++;
	data->dasd_io_times[tottime_ind]++;
	data->dasd_io_timps[tottimeps_ind]++;
	data->dasd_io_time1[strtime_ind]++;
	data->dasd_io_time2[irqtime_ind]++;
	data->dasd_io_time2ps[irqtimeps_ind]++;
	data->dasd_io_time3[endtime_ind]++;

	if (is_read) {
		data->dasd_read_reqs++;
		data->dasd_read_sects += sectors;
		if (is_alias)
			data->dasd_read_alias++;
		if (is_tpm)
			data->dasd_read_tpm++;
		data->dasd_read_secs[sectors_ind]++;
		data->dasd_read_times[tottime_ind]++;
		data->dasd_read_time1[strtime_ind]++;
		data->dasd_read_time2[irqtime_ind]++;
		data->dasd_read_time3[endtime_ind]++;
	}
}

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static void dasd_profile_end(struct dasd_block *block,
			     struct dasd_ccw_req *cqr,
			     struct request *req)
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{
	long strtime, irqtime, endtime, tottime;	/* in microseconds */
	long tottimeps, sectors;
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	struct dasd_device *device;
	int sectors_ind, tottime_ind, tottimeps_ind, strtime_ind;
	int irqtime_ind, irqtimeps_ind, endtime_ind;
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	device = cqr->startdev;
	if (!(dasd_global_profile_level ||
	      block->profile.data ||
	      device->profile.data))
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		return;

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	sectors = blk_rq_sectors(req);
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	if (!cqr->buildclk || !cqr->startclk ||
	    !cqr->stopclk || !cqr->endclk ||
	    !sectors)
		return;

	strtime = ((cqr->startclk - cqr->buildclk) >> 12);
	irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
	endtime = ((cqr->endclk - cqr->stopclk) >> 12);
	tottime = ((cqr->endclk - cqr->buildclk) >> 12);
	tottimeps = tottime / sectors;

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	dasd_profile_counter(sectors, sectors_ind);
	dasd_profile_counter(tottime, tottime_ind);
	dasd_profile_counter(tottimeps, tottimeps_ind);
	dasd_profile_counter(strtime, strtime_ind);
	dasd_profile_counter(irqtime, irqtime_ind);
	dasd_profile_counter(irqtime / sectors, irqtimeps_ind);
	dasd_profile_counter(endtime, endtime_ind);

	if (dasd_global_profile_level) {
		dasd_profile_end_add_data(&dasd_global_profile_data,
					  cqr->startdev != block->base,
					  cqr->cpmode == 1,
					  rq_data_dir(req) == READ,
					  sectors, sectors_ind, tottime_ind,
					  tottimeps_ind, strtime_ind,
					  irqtime_ind, irqtimeps_ind,
					  endtime_ind);
	}

	spin_lock(&block->profile.lock);
	if (block->profile.data)
		dasd_profile_end_add_data(block->profile.data,
					  cqr->startdev != block->base,
					  cqr->cpmode == 1,
					  rq_data_dir(req) == READ,
					  sectors, sectors_ind, tottime_ind,
					  tottimeps_ind, strtime_ind,
					  irqtime_ind, irqtimeps_ind,
					  endtime_ind);
	spin_unlock(&block->profile.lock);

	spin_lock(&device->profile.lock);
	if (device->profile.data)
		dasd_profile_end_add_data(device->profile.data,
					  cqr->startdev != block->base,
					  cqr->cpmode == 1,
					  rq_data_dir(req) == READ,
					  sectors, sectors_ind, tottime_ind,
					  tottimeps_ind, strtime_ind,
					  irqtime_ind, irqtimeps_ind,
					  endtime_ind);
	spin_unlock(&device->profile.lock);
}

void dasd_profile_reset(struct dasd_profile *profile)
{
	struct dasd_profile_info *data;

	spin_lock_bh(&profile->lock);
	data = profile->data;
	if (!data) {
		spin_unlock_bh(&profile->lock);
		return;
	}
	memset(data, 0, sizeof(*data));
	getnstimeofday(&data->starttod);
	spin_unlock_bh(&profile->lock);
}

void dasd_global_profile_reset(void)
{
	memset(&dasd_global_profile_data, 0, sizeof(dasd_global_profile_data));
	getnstimeofday(&dasd_global_profile_data.starttod);
}

int dasd_profile_on(struct dasd_profile *profile)
{
	struct dasd_profile_info *data;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;
	spin_lock_bh(&profile->lock);
	if (profile->data) {
		spin_unlock_bh(&profile->lock);
		kfree(data);
		return 0;
	}
	getnstimeofday(&data->starttod);
	profile->data = data;
	spin_unlock_bh(&profile->lock);
	return 0;
}

void dasd_profile_off(struct dasd_profile *profile)
{
	spin_lock_bh(&profile->lock);
	kfree(profile->data);
	profile->data = NULL;
	spin_unlock_bh(&profile->lock);
}

char *dasd_get_user_string(const char __user *user_buf, size_t user_len)
{
	char *buffer;

894
	buffer = vmalloc(user_len + 1);
895 896 897
	if (buffer == NULL)
		return ERR_PTR(-ENOMEM);
	if (copy_from_user(buffer, user_buf, user_len) != 0) {
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		vfree(buffer);
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		return ERR_PTR(-EFAULT);
	}
	/* got the string, now strip linefeed. */
	if (buffer[user_len - 1] == '\n')
		buffer[user_len - 1] = 0;
	else
		buffer[user_len] = 0;
	return buffer;
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}
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static ssize_t dasd_stats_write(struct file *file,
				const char __user *user_buf,
				size_t user_len, loff_t *pos)
{
	char *buffer, *str;
	int rc;
	struct seq_file *m = (struct seq_file *)file->private_data;
	struct dasd_profile *prof = m->private;

	if (user_len > 65536)
		user_len = 65536;
	buffer = dasd_get_user_string(user_buf, user_len);
	if (IS_ERR(buffer))
		return PTR_ERR(buffer);

	str = skip_spaces(buffer);
	rc = user_len;
	if (strncmp(str, "reset", 5) == 0) {
		dasd_profile_reset(prof);
	} else if (strncmp(str, "on", 2) == 0) {
		rc = dasd_profile_on(prof);
		if (!rc)
			rc = user_len;
	} else if (strncmp(str, "off", 3) == 0) {
		dasd_profile_off(prof);
	} else
		rc = -EINVAL;
936
	vfree(buffer);
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	return rc;
}

static void dasd_stats_array(struct seq_file *m, unsigned int *array)
{
	int i;

	for (i = 0; i < 32; i++)
		seq_printf(m, "%u ", array[i]);
	seq_putc(m, '\n');
}

static void dasd_stats_seq_print(struct seq_file *m,
				 struct dasd_profile_info *data)
{
	seq_printf(m, "start_time %ld.%09ld\n",
		   data->starttod.tv_sec, data->starttod.tv_nsec);
	seq_printf(m, "total_requests %u\n", data->dasd_io_reqs);
	seq_printf(m, "total_sectors %u\n", data->dasd_io_sects);
	seq_printf(m, "total_pav %u\n", data->dasd_io_alias);
	seq_printf(m, "total_hpf %u\n", data->dasd_io_tpm);
	seq_printf(m, "histogram_sectors ");
	dasd_stats_array(m, data->dasd_io_secs);
	seq_printf(m, "histogram_io_times ");
	dasd_stats_array(m, data->dasd_io_times);
	seq_printf(m, "histogram_io_times_weighted ");
	dasd_stats_array(m, data->dasd_io_timps);
	seq_printf(m, "histogram_time_build_to_ssch ");
	dasd_stats_array(m, data->dasd_io_time1);
	seq_printf(m, "histogram_time_ssch_to_irq ");
	dasd_stats_array(m, data->dasd_io_time2);
	seq_printf(m, "histogram_time_ssch_to_irq_weighted ");
	dasd_stats_array(m, data->dasd_io_time2ps);
	seq_printf(m, "histogram_time_irq_to_end ");
	dasd_stats_array(m, data->dasd_io_time3);
	seq_printf(m, "histogram_ccw_queue_length ");
	dasd_stats_array(m, data->dasd_io_nr_req);
	seq_printf(m, "total_read_requests %u\n", data->dasd_read_reqs);
	seq_printf(m, "total_read_sectors %u\n", data->dasd_read_sects);
	seq_printf(m, "total_read_pav %u\n", data->dasd_read_alias);
	seq_printf(m, "total_read_hpf %u\n", data->dasd_read_tpm);
	seq_printf(m, "histogram_read_sectors ");
	dasd_stats_array(m, data->dasd_read_secs);
	seq_printf(m, "histogram_read_times ");
	dasd_stats_array(m, data->dasd_read_times);
	seq_printf(m, "histogram_read_time_build_to_ssch ");
	dasd_stats_array(m, data->dasd_read_time1);
	seq_printf(m, "histogram_read_time_ssch_to_irq ");
	dasd_stats_array(m, data->dasd_read_time2);
	seq_printf(m, "histogram_read_time_irq_to_end ");
	dasd_stats_array(m, data->dasd_read_time3);
	seq_printf(m, "histogram_read_ccw_queue_length ");
	dasd_stats_array(m, data->dasd_read_nr_req);
}

static int dasd_stats_show(struct seq_file *m, void *v)
{
	struct dasd_profile *profile;
	struct dasd_profile_info *data;

	profile = m->private;
	spin_lock_bh(&profile->lock);
	data = profile->data;
	if (!data) {
		spin_unlock_bh(&profile->lock);
		seq_printf(m, "disabled\n");
		return 0;
	}
	dasd_stats_seq_print(m, data);
	spin_unlock_bh(&profile->lock);
	return 0;
}

static int dasd_stats_open(struct inode *inode, struct file *file)
{
	struct dasd_profile *profile = inode->i_private;
	return single_open(file, dasd_stats_show, profile);
}

static const struct file_operations dasd_stats_raw_fops = {
	.owner		= THIS_MODULE,
	.open		= dasd_stats_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
	.write		= dasd_stats_write,
};

static ssize_t dasd_stats_global_write(struct file *file,
				       const char __user *user_buf,
				       size_t user_len, loff_t *pos)
{
	char *buffer, *str;
	ssize_t rc;

	if (user_len > 65536)
		user_len = 65536;
	buffer = dasd_get_user_string(user_buf, user_len);
	if (IS_ERR(buffer))
		return PTR_ERR(buffer);
	str = skip_spaces(buffer);
	rc = user_len;
	if (strncmp(str, "reset", 5) == 0) {
		dasd_global_profile_reset();
	} else if (strncmp(str, "on", 2) == 0) {
		dasd_global_profile_reset();
		dasd_global_profile_level = DASD_PROFILE_GLOBAL_ONLY;
	} else if (strncmp(str, "off", 3) == 0) {
		dasd_global_profile_level = DASD_PROFILE_OFF;
	} else
		rc = -EINVAL;
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	vfree(buffer);
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	return rc;
}

static int dasd_stats_global_show(struct seq_file *m, void *v)
{
	if (!dasd_global_profile_level) {
		seq_printf(m, "disabled\n");
		return 0;
	}
	dasd_stats_seq_print(m, &dasd_global_profile_data);
	return 0;
}

static int dasd_stats_global_open(struct inode *inode, struct file *file)
{
	return single_open(file, dasd_stats_global_show, NULL);
}

static const struct file_operations dasd_stats_global_fops = {
	.owner		= THIS_MODULE,
	.open		= dasd_stats_global_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
	.write		= dasd_stats_global_write,
};

static void dasd_profile_init(struct dasd_profile *profile,
			      struct dentry *base_dentry)
{
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	umode_t mode;
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	struct dentry *pde;

	if (!base_dentry)
		return;
	profile->dentry = NULL;
	profile->data = NULL;
	mode = (S_IRUSR | S_IWUSR | S_IFREG);
	pde = debugfs_create_file("statistics", mode, base_dentry,
				  profile, &dasd_stats_raw_fops);
	if (pde && !IS_ERR(pde))
		profile->dentry = pde;
	return;
}

static void dasd_profile_exit(struct dasd_profile *profile)
{
	dasd_profile_off(profile);
	if (profile->dentry) {
		debugfs_remove(profile->dentry);
		profile->dentry = NULL;
	}
}

static void dasd_statistics_removeroot(void)
{
	dasd_global_profile_level = DASD_PROFILE_OFF;
	if (dasd_global_profile_dentry) {
		debugfs_remove(dasd_global_profile_dentry);
		dasd_global_profile_dentry = NULL;
	}
	if (dasd_debugfs_global_entry)
		debugfs_remove(dasd_debugfs_global_entry);
	if (dasd_debugfs_root_entry)
		debugfs_remove(dasd_debugfs_root_entry);
}

static void dasd_statistics_createroot(void)
{
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	umode_t mode;
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	struct dentry *pde;

	dasd_debugfs_root_entry = NULL;
	dasd_debugfs_global_entry = NULL;
	dasd_global_profile_dentry = NULL;
	pde = debugfs_create_dir("dasd", NULL);
	if (!pde || IS_ERR(pde))
		goto error;
	dasd_debugfs_root_entry = pde;
	pde = debugfs_create_dir("global", dasd_debugfs_root_entry);
	if (!pde || IS_ERR(pde))
		goto error;
	dasd_debugfs_global_entry = pde;

	mode = (S_IRUSR | S_IWUSR | S_IFREG);
	pde = debugfs_create_file("statistics", mode, dasd_debugfs_global_entry,
				  NULL, &dasd_stats_global_fops);
	if (!pde || IS_ERR(pde))
		goto error;
	dasd_global_profile_dentry = pde;
	return;

error:
	DBF_EVENT(DBF_ERR, "%s",
		  "Creation of the dasd debugfs interface failed");
	dasd_statistics_removeroot();
	return;
}

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#else
1149 1150
#define dasd_profile_start(block, cqr, req) do {} while (0)
#define dasd_profile_end(block, cqr, req) do {} while (0)
1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183

static void dasd_statistics_createroot(void)
{
	return;
}

static void dasd_statistics_removeroot(void)
{
	return;
}

int dasd_stats_generic_show(struct seq_file *m, void *v)
{
	seq_printf(m, "Statistics are not activated in this kernel\n");
	return 0;
}

static void dasd_profile_init(struct dasd_profile *profile,
			      struct dentry *base_dentry)
{
	return;
}

static void dasd_profile_exit(struct dasd_profile *profile)
{
	return;
}

int dasd_profile_on(struct dasd_profile *profile)
{
	return 0;
}

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#endif				/* CONFIG_DASD_PROFILE */

/*
 * Allocate memory for a channel program with 'cplength' channel
 * command words and 'datasize' additional space. There are two
 * variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
 * memory and 2) dasd_smalloc_request uses the static ccw memory
 * that gets allocated for each device.
 */
1193
struct dasd_ccw_req *dasd_kmalloc_request(int magic, int cplength,
1194 1195
					  int datasize,
					  struct dasd_device *device)
L
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{
	struct dasd_ccw_req *cqr;

	/* Sanity checks */
1200
	BUG_ON(datasize > PAGE_SIZE ||
1201
	     (cplength*sizeof(struct ccw1)) > PAGE_SIZE);
L
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1203
	cqr = kzalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
L
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	if (cqr == NULL)
		return ERR_PTR(-ENOMEM);
	cqr->cpaddr = NULL;
	if (cplength > 0) {
1208
		cqr->cpaddr = kcalloc(cplength, sizeof(struct ccw1),
L
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				      GFP_ATOMIC | GFP_DMA);
		if (cqr->cpaddr == NULL) {
			kfree(cqr);
			return ERR_PTR(-ENOMEM);
		}
	}
	cqr->data = NULL;
	if (datasize > 0) {
1217
		cqr->data = kzalloc(datasize, GFP_ATOMIC | GFP_DMA);
L
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		if (cqr->data == NULL) {
J
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			kfree(cqr->cpaddr);
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			kfree(cqr);
			return ERR_PTR(-ENOMEM);
		}
	}
1224
	cqr->magic =  magic;
L
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	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	dasd_get_device(device);
	return cqr;
}

1230
struct dasd_ccw_req *dasd_smalloc_request(int magic, int cplength,
1231 1232
					  int datasize,
					  struct dasd_device *device)
L
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{
	unsigned long flags;
	struct dasd_ccw_req *cqr;
	char *data;
	int size;

	size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
	if (cplength > 0)
		size += cplength * sizeof(struct ccw1);
	if (datasize > 0)
		size += datasize;
	spin_lock_irqsave(&device->mem_lock, flags);
	cqr = (struct dasd_ccw_req *)
		dasd_alloc_chunk(&device->ccw_chunks, size);
	spin_unlock_irqrestore(&device->mem_lock, flags);
	if (cqr == NULL)
		return ERR_PTR(-ENOMEM);
	memset(cqr, 0, sizeof(struct dasd_ccw_req));
	data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
	cqr->cpaddr = NULL;
	if (cplength > 0) {
		cqr->cpaddr = (struct ccw1 *) data;
		data += cplength*sizeof(struct ccw1);
		memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
	}
	cqr->data = NULL;
	if (datasize > 0) {
		cqr->data = data;
 		memset(cqr->data, 0, datasize);
	}
1263
	cqr->magic = magic;
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	set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	dasd_get_device(device);
	return cqr;
}

/*
 * Free memory of a channel program. This function needs to free all the
 * idal lists that might have been created by dasd_set_cda and the
 * struct dasd_ccw_req itself.
 */
1274
void dasd_kfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
L
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{
1276
#ifdef CONFIG_64BIT
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	struct ccw1 *ccw;

	/* Clear any idals used for the request. */
	ccw = cqr->cpaddr;
	do {
		clear_normalized_cda(ccw);
	} while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
#endif
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	kfree(cqr->cpaddr);
	kfree(cqr->data);
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	kfree(cqr);
	dasd_put_device(device);
}

1291
void dasd_sfree_request(struct dasd_ccw_req *cqr, struct dasd_device *device)
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{
	unsigned long flags;

	spin_lock_irqsave(&device->mem_lock, flags);
	dasd_free_chunk(&device->ccw_chunks, cqr);
	spin_unlock_irqrestore(&device->mem_lock, flags);
	dasd_put_device(device);
}

/*
 * Check discipline magic in cqr.
 */
1304
static inline int dasd_check_cqr(struct dasd_ccw_req *cqr)
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{
	struct dasd_device *device;

	if (cqr == NULL)
		return -EINVAL;
1310
	device = cqr->startdev;
L
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	if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
S
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		DBF_DEV_EVENT(DBF_WARNING, device,
L
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			    " dasd_ccw_req 0x%08x magic doesn't match"
			    " discipline 0x%08x",
			    cqr->magic,
			    *(unsigned int *) device->discipline->name);
		return -EINVAL;
	}
	return 0;
}

/*
 * Terminate the current i/o and set the request to clear_pending.
 * Timer keeps device runnig.
 * ccw_device_clear can fail if the i/o subsystem
 * is in a bad mood.
 */
1328
int dasd_term_IO(struct dasd_ccw_req *cqr)
L
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{
	struct dasd_device *device;
	int retries, rc;
S
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	char errorstring[ERRORLENGTH];
L
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1333 1334 1335 1336 1337 1338

	/* Check the cqr */
	rc = dasd_check_cqr(cqr);
	if (rc)
		return rc;
	retries = 0;
1339
	device = (struct dasd_device *) cqr->startdev;
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	while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
		rc = ccw_device_clear(device->cdev, (long) cqr);
		switch (rc) {
		case 0:	/* termination successful */
1344
			cqr->status = DASD_CQR_CLEAR_PENDING;
L
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			cqr->stopclk = get_clock();
1346
			cqr->starttime = 0;
L
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			DBF_DEV_EVENT(DBF_DEBUG, device,
				      "terminate cqr %p successful",
				      cqr);
			break;
		case -ENODEV:
			DBF_DEV_EVENT(DBF_ERR, device, "%s",
				      "device gone, retry");
			break;
		case -EIO:
			DBF_DEV_EVENT(DBF_ERR, device, "%s",
				      "I/O error, retry");
			break;
		case -EINVAL:
		case -EBUSY:
			DBF_DEV_EVENT(DBF_ERR, device, "%s",
				      "device busy, retry later");
			break;
		default:
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			/* internal error 10 - unknown rc*/
			snprintf(errorstring, ERRORLENGTH, "10 %d", rc);
			dev_err(&device->cdev->dev, "An error occurred in the "
				"DASD device driver, reason=%s\n", errorstring);
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			BUG();
			break;
		}
		retries++;
	}
1374
	dasd_schedule_device_bh(device);
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	return rc;
}

/*
 * Start the i/o. This start_IO can fail if the channel is really busy.
 * In that case set up a timer to start the request later.
 */
1382
int dasd_start_IO(struct dasd_ccw_req *cqr)
L
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{
	struct dasd_device *device;
	int rc;
S
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	char errorstring[ERRORLENGTH];
L
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	/* Check the cqr */
	rc = dasd_check_cqr(cqr);
1390 1391
	if (rc) {
		cqr->intrc = rc;
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		return rc;
1393
	}
1394
	device = (struct dasd_device *) cqr->startdev;
1395 1396 1397 1398 1399 1400 1401 1402 1403 1404
	if (((cqr->block &&
	      test_bit(DASD_FLAG_LOCK_STOLEN, &cqr->block->base->flags)) ||
	     test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags)) &&
	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
		DBF_DEV_EVENT(DBF_DEBUG, device, "start_IO: return request %p "
			      "because of stolen lock", cqr);
		cqr->status = DASD_CQR_ERROR;
		cqr->intrc = -EPERM;
		return -EPERM;
	}
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	if (cqr->retries < 0) {
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		/* internal error 14 - start_IO run out of retries */
		sprintf(errorstring, "14 %p", cqr);
		dev_err(&device->cdev->dev, "An error occurred in the DASD "
			"device driver, reason=%s\n", errorstring);
1410
		cqr->status = DASD_CQR_ERROR;
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		return -EIO;
	}
	cqr->startclk = get_clock();
	cqr->starttime = jiffies;
	cqr->retries--;
1416 1417 1418 1419 1420
	if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
		cqr->lpm &= device->path_data.opm;
		if (!cqr->lpm)
			cqr->lpm = device->path_data.opm;
	}
1421 1422 1423 1424 1425 1426 1427
	if (cqr->cpmode == 1) {
		rc = ccw_device_tm_start(device->cdev, cqr->cpaddr,
					 (long) cqr, cqr->lpm);
	} else {
		rc = ccw_device_start(device->cdev, cqr->cpaddr,
				      (long) cqr, cqr->lpm, 0);
	}
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	switch (rc) {
	case 0:
		cqr->status = DASD_CQR_IN_IO;
		break;
	case -EBUSY:
1433
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
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			      "start_IO: device busy, retry later");
		break;
	case -ETIMEDOUT:
1437
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
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			      "start_IO: request timeout, retry later");
		break;
	case -EACCES:
1441 1442 1443 1444 1445 1446
		/* -EACCES indicates that the request used only a subset of the
		 * available paths and all these paths are gone. If the lpm of
		 * this request was only a subset of the opm (e.g. the ppm) then
		 * we just do a retry with all available paths.
		 * If we already use the full opm, something is amiss, and we
		 * need a full path verification.
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1447
		 */
1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467
		if (test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags)) {
			DBF_DEV_EVENT(DBF_WARNING, device,
				      "start_IO: selected paths gone (%x)",
				      cqr->lpm);
		} else if (cqr->lpm != device->path_data.opm) {
			cqr->lpm = device->path_data.opm;
			DBF_DEV_EVENT(DBF_DEBUG, device, "%s",
				      "start_IO: selected paths gone,"
				      " retry on all paths");
		} else {
			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
				      "start_IO: all paths in opm gone,"
				      " do path verification");
			dasd_generic_last_path_gone(device);
			device->path_data.opm = 0;
			device->path_data.ppm = 0;
			device->path_data.npm = 0;
			device->path_data.tbvpm =
				ccw_device_get_path_mask(device->cdev);
		}
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		break;
	case -ENODEV:
1470
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1471 1472
			      "start_IO: -ENODEV device gone, retry");
		break;
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	case -EIO:
1474
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1475
			      "start_IO: -EIO device gone, retry");
L
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		break;
1477 1478
	case -EINVAL:
		/* most likely caused in power management context */
1479
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
1480 1481 1482
			      "start_IO: -EINVAL device currently "
			      "not accessible");
		break;
L
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1483
	default:
S
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1484 1485 1486 1487 1488
		/* internal error 11 - unknown rc */
		snprintf(errorstring, ERRORLENGTH, "11 %d", rc);
		dev_err(&device->cdev->dev,
			"An error occurred in the DASD device driver, "
			"reason=%s\n", errorstring);
L
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1489 1490 1491
		BUG();
		break;
	}
1492
	cqr->intrc = rc;
L
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	return rc;
}

/*
 * Timeout function for dasd devices. This is used for different purposes
 *  1) missing interrupt handler for normal operation
 *  2) delayed start of request where start_IO failed with -EBUSY
 *  3) timeout for missing state change interrupts
 * The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
 * DASD_CQR_QUEUED for 2) and 3).
 */
1504
static void dasd_device_timeout(unsigned long ptr)
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{
	unsigned long flags;
	struct dasd_device *device;

	device = (struct dasd_device *) ptr;
	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
	/* re-activate request queue */
1512
	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
L
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1513
	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
1514
	dasd_schedule_device_bh(device);
L
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}

/*
 * Setup timeout for a device in jiffies.
 */
1520
void dasd_device_set_timer(struct dasd_device *device, int expires)
L
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{
1522 1523 1524 1525
	if (expires == 0)
		del_timer(&device->timer);
	else
		mod_timer(&device->timer, jiffies + expires);
L
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1526 1527 1528 1529 1530
}

/*
 * Clear timeout for a device.
 */
1531
void dasd_device_clear_timer(struct dasd_device *device)
L
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1532
{
1533
	del_timer(&device->timer);
L
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1534 1535
}

1536 1537
static void dasd_handle_killed_request(struct ccw_device *cdev,
				       unsigned long intparm)
L
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{
	struct dasd_ccw_req *cqr;
	struct dasd_device *device;

1542 1543
	if (!intparm)
		return;
L
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	cqr = (struct dasd_ccw_req *) intparm;
	if (cqr->status != DASD_CQR_IN_IO) {
1546 1547 1548
		DBF_EVENT_DEVID(DBF_DEBUG, cdev,
				"invalid status in handle_killed_request: "
				"%02x", cqr->status);
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		return;
	}

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	device = dasd_device_from_cdev_locked(cdev);
	if (IS_ERR(device)) {
		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
				"unable to get device from cdev");
		return;
	}

	if (!cqr->startdev ||
	    device != cqr->startdev ||
	    strncmp(cqr->startdev->discipline->ebcname,
		    (char *) &cqr->magic, 4)) {
1563 1564
		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
				"invalid device in request");
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		dasd_put_device(device);
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		return;
	}

	/* Schedule request to be retried. */
	cqr->status = DASD_CQR_QUEUED;

1572 1573
	dasd_device_clear_timer(device);
	dasd_schedule_device_bh(device);
L
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	dasd_put_device(device);
}

1577
void dasd_generic_handle_state_change(struct dasd_device *device)
L
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{
1579 1580 1581
	/* First of all start sense subsystem status request. */
	dasd_eer_snss(device);

1582
	dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
1583 1584 1585
	dasd_schedule_device_bh(device);
	if (device->block)
		dasd_schedule_block_bh(device->block);
L
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}

/*
 * Interrupt handler for "normal" ssch-io based dasd devices.
 */
1591 1592
void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
		      struct irb *irb)
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{
	struct dasd_ccw_req *cqr, *next;
	struct dasd_device *device;
	unsigned long long now;
	int expires;

	if (IS_ERR(irb)) {
		switch (PTR_ERR(irb)) {
		case -EIO:
			break;
		case -ETIMEDOUT:
1604 1605
			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
					"request timed out\n", __func__);
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			break;
		default:
1608 1609 1610
			DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s: "
					"unknown error %ld\n", __func__,
					PTR_ERR(irb));
L
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1611
		}
1612
		dasd_handle_killed_request(cdev, intparm);
L
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		return;
	}

	now = get_clock();
1617
	cqr = (struct dasd_ccw_req *) intparm;
1618 1619 1620 1621
	/* check for conditions that should be handled immediately */
	if (!cqr ||
	    !(scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
	      scsw_cstat(&irb->scsw) == 0)) {
1622 1623
		if (cqr)
			memcpy(&cqr->irb, irb, sizeof(*irb));
1624
		device = dasd_device_from_cdev_locked(cdev);
1625 1626 1627 1628
		if (IS_ERR(device))
			return;
		/* ignore unsolicited interrupts for DIAG discipline */
		if (device->discipline == dasd_diag_discipline_pointer) {
L
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			dasd_put_device(device);
1630
			return;
L
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1631
		}
1632 1633 1634 1635
		device->discipline->dump_sense_dbf(device, irb, "int");
		if (device->features & DASD_FEATURE_ERPLOG)
			device->discipline->dump_sense(device, cqr, irb);
		device->discipline->check_for_device_change(device, cqr, irb);
1636
		dasd_put_device(device);
L
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1637
	}
1638 1639
	if (!cqr)
		return;
L
Linus Torvalds 已提交
1640

1641 1642
	device = (struct dasd_device *) cqr->startdev;
	if (!device ||
L
Linus Torvalds 已提交
1643
	    strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
1644 1645
		DBF_EVENT_DEVID(DBF_DEBUG, cdev, "%s",
				"invalid device in request");
L
Linus Torvalds 已提交
1646 1647 1648 1649
		return;
	}

	/* Check for clear pending */
1650
	if (cqr->status == DASD_CQR_CLEAR_PENDING &&
1651
	    scsw_fctl(&irb->scsw) & SCSW_FCTL_CLEAR_FUNC) {
1652 1653
		cqr->status = DASD_CQR_CLEARED;
		dasd_device_clear_timer(device);
1654
		wake_up(&dasd_flush_wq);
1655
		dasd_schedule_device_bh(device);
L
Linus Torvalds 已提交
1656 1657 1658
		return;
	}

1659
	/* check status - the request might have been killed by dyn detach */
L
Linus Torvalds 已提交
1660
	if (cqr->status != DASD_CQR_IN_IO) {
S
Stefan Haberland 已提交
1661 1662
		DBF_DEV_EVENT(DBF_DEBUG, device, "invalid status: bus_id %s, "
			      "status %02x", dev_name(&cdev->dev), cqr->status);
L
Linus Torvalds 已提交
1663 1664
		return;
	}
S
Stefan Haberland 已提交
1665

1666
	next = NULL;
L
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1667
	expires = 0;
1668 1669
	if (scsw_dstat(&irb->scsw) == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
	    scsw_cstat(&irb->scsw) == 0) {
1670 1671
		/* request was completed successfully */
		cqr->status = DASD_CQR_SUCCESS;
L
Linus Torvalds 已提交
1672 1673
		cqr->stopclk = now;
		/* Start first request on queue if possible -> fast_io. */
1674 1675 1676
		if (cqr->devlist.next != &device->ccw_queue) {
			next = list_entry(cqr->devlist.next,
					  struct dasd_ccw_req, devlist);
L
Linus Torvalds 已提交
1677
		}
1678
	} else {  /* error */
1679 1680 1681
		/*
		 * If we don't want complex ERP for this request, then just
		 * reset this and retry it in the fastpath
1682
		 */
1683
		if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags) &&
1684
		    cqr->retries > 0) {
1685
			if (cqr->lpm == device->path_data.opm)
S
Stefan Haberland 已提交
1686 1687 1688 1689
				DBF_DEV_EVENT(DBF_DEBUG, device,
					      "default ERP in fastpath "
					      "(%i retries left)",
					      cqr->retries);
1690 1691
			if (!test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))
				cqr->lpm = device->path_data.opm;
1692 1693 1694
			cqr->status = DASD_CQR_QUEUED;
			next = cqr;
		} else
L
Linus Torvalds 已提交
1695
			cqr->status = DASD_CQR_ERROR;
1696 1697 1698 1699 1700
	}
	if (next && (next->status == DASD_CQR_QUEUED) &&
	    (!device->stopped)) {
		if (device->discipline->start_IO(next) == 0)
			expires = next->expires;
L
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1701 1702
	}
	if (expires != 0)
1703
		dasd_device_set_timer(device, expires);
L
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1704
	else
1705 1706
		dasd_device_clear_timer(device);
	dasd_schedule_device_bh(device);
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1707 1708
}

1709 1710 1711 1712 1713 1714 1715 1716 1717 1718
enum uc_todo dasd_generic_uc_handler(struct ccw_device *cdev, struct irb *irb)
{
	struct dasd_device *device;

	device = dasd_device_from_cdev_locked(cdev);

	if (IS_ERR(device))
		goto out;
	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
	   device->state != device->target ||
1719
	   !device->discipline->check_for_device_change){
1720 1721 1722
		dasd_put_device(device);
		goto out;
	}
1723 1724 1725
	if (device->discipline->dump_sense_dbf)
		device->discipline->dump_sense_dbf(device, irb, "uc");
	device->discipline->check_for_device_change(device, NULL, irb);
1726 1727 1728 1729 1730 1731
	dasd_put_device(device);
out:
	return UC_TODO_RETRY;
}
EXPORT_SYMBOL_GPL(dasd_generic_uc_handler);

L
Linus Torvalds 已提交
1732
/*
1733 1734
 * If we have an error on a dasd_block layer request then we cancel
 * and return all further requests from the same dasd_block as well.
L
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1735
 */
1736 1737
static void __dasd_device_recovery(struct dasd_device *device,
				   struct dasd_ccw_req *ref_cqr)
L
Linus Torvalds 已提交
1738
{
1739 1740
	struct list_head *l, *n;
	struct dasd_ccw_req *cqr;
L
Linus Torvalds 已提交
1741

1742 1743 1744 1745 1746
	/*
	 * only requeue request that came from the dasd_block layer
	 */
	if (!ref_cqr->block)
		return;
L
Linus Torvalds 已提交
1747

1748 1749 1750 1751 1752 1753 1754 1755
	list_for_each_safe(l, n, &device->ccw_queue) {
		cqr = list_entry(l, struct dasd_ccw_req, devlist);
		if (cqr->status == DASD_CQR_QUEUED &&
		    ref_cqr->block == cqr->block) {
			cqr->status = DASD_CQR_CLEARED;
		}
	}
};
L
Linus Torvalds 已提交
1756 1757

/*
1758 1759
 * Remove those ccw requests from the queue that need to be returned
 * to the upper layer.
L
Linus Torvalds 已提交
1760
 */
1761 1762
static void __dasd_device_process_ccw_queue(struct dasd_device *device,
					    struct list_head *final_queue)
L
Linus Torvalds 已提交
1763 1764 1765 1766 1767 1768
{
	struct list_head *l, *n;
	struct dasd_ccw_req *cqr;

	/* Process request with final status. */
	list_for_each_safe(l, n, &device->ccw_queue) {
1769 1770
		cqr = list_entry(l, struct dasd_ccw_req, devlist);

L
Linus Torvalds 已提交
1771
		/* Stop list processing at the first non-final request. */
1772 1773 1774
		if (cqr->status == DASD_CQR_QUEUED ||
		    cqr->status == DASD_CQR_IN_IO ||
		    cqr->status == DASD_CQR_CLEAR_PENDING)
L
Linus Torvalds 已提交
1775 1776
			break;
		if (cqr->status == DASD_CQR_ERROR) {
1777
			__dasd_device_recovery(device, cqr);
1778
		}
L
Linus Torvalds 已提交
1779
		/* Rechain finished requests to final queue */
1780
		list_move_tail(&cqr->devlist, final_queue);
L
Linus Torvalds 已提交
1781 1782 1783 1784
	}
}

/*
1785 1786
 * the cqrs from the final queue are returned to the upper layer
 * by setting a dasd_block state and calling the callback function
L
Linus Torvalds 已提交
1787
 */
1788 1789
static void __dasd_device_process_final_queue(struct dasd_device *device,
					      struct list_head *final_queue)
L
Linus Torvalds 已提交
1790
{
1791
	struct list_head *l, *n;
L
Linus Torvalds 已提交
1792
	struct dasd_ccw_req *cqr;
1793
	struct dasd_block *block;
1794 1795
	void (*callback)(struct dasd_ccw_req *, void *data);
	void *callback_data;
S
Stefan Haberland 已提交
1796
	char errorstring[ERRORLENGTH];
1797

1798 1799 1800
	list_for_each_safe(l, n, final_queue) {
		cqr = list_entry(l, struct dasd_ccw_req, devlist);
		list_del_init(&cqr->devlist);
1801
		block = cqr->block;
1802 1803
		callback = cqr->callback;
		callback_data = cqr->callback_data;
1804 1805
		if (block)
			spin_lock_bh(&block->queue_lock);
1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816
		switch (cqr->status) {
		case DASD_CQR_SUCCESS:
			cqr->status = DASD_CQR_DONE;
			break;
		case DASD_CQR_ERROR:
			cqr->status = DASD_CQR_NEED_ERP;
			break;
		case DASD_CQR_CLEARED:
			cqr->status = DASD_CQR_TERMINATED;
			break;
		default:
S
Stefan Haberland 已提交
1817 1818 1819 1820 1821
			/* internal error 12 - wrong cqr status*/
			snprintf(errorstring, ERRORLENGTH, "12 %p %x02", cqr, cqr->status);
			dev_err(&device->cdev->dev,
				"An error occurred in the DASD device driver, "
				"reason=%s\n", errorstring);
1822
			BUG();
L
Linus Torvalds 已提交
1823
		}
1824
		if (cqr->callback != NULL)
1825
			(callback)(cqr, callback_data);
1826 1827
		if (block)
			spin_unlock_bh(&block->queue_lock);
L
Linus Torvalds 已提交
1828 1829 1830 1831 1832 1833 1834
	}
}

/*
 * Take a look at the first request on the ccw queue and check
 * if it reached its expire time. If so, terminate the IO.
 */
1835
static void __dasd_device_check_expire(struct dasd_device *device)
L
Linus Torvalds 已提交
1836 1837 1838 1839 1840
{
	struct dasd_ccw_req *cqr;

	if (list_empty(&device->ccw_queue))
		return;
1841
	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1842 1843 1844 1845
	if ((cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) &&
	    (time_after_eq(jiffies, cqr->expires + cqr->starttime))) {
		if (device->discipline->term_IO(cqr) != 0) {
			/* Hmpf, try again in 5 sec */
S
Stefan Haberland 已提交
1846
			dev_err(&device->cdev->dev,
1847
				"cqr %p timed out (%lus) but cannot be "
S
Stefan Haberland 已提交
1848 1849
				"ended, retrying in 5 s\n",
				cqr, (cqr->expires/HZ));
1850 1851
			cqr->expires += 5*HZ;
			dasd_device_set_timer(device, 5*HZ);
1852
		} else {
S
Stefan Haberland 已提交
1853
			dev_err(&device->cdev->dev,
1854
				"cqr %p timed out (%lus), %i retries "
S
Stefan Haberland 已提交
1855 1856
				"remaining\n", cqr, (cqr->expires/HZ),
				cqr->retries);
L
Linus Torvalds 已提交
1857 1858 1859 1860 1861 1862 1863 1864
		}
	}
}

/*
 * Take a look at the first request on the ccw queue and check
 * if it needs to be started.
 */
1865
static void __dasd_device_start_head(struct dasd_device *device)
L
Linus Torvalds 已提交
1866 1867 1868 1869 1870 1871
{
	struct dasd_ccw_req *cqr;
	int rc;

	if (list_empty(&device->ccw_queue))
		return;
1872
	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
1873 1874
	if (cqr->status != DASD_CQR_QUEUED)
		return;
1875 1876 1877 1878 1879 1880 1881 1882
	/* when device is stopped, return request to previous layer
	 * exception: only the disconnect or unresumed bits are set and the
	 * cqr is a path verification request
	 */
	if (device->stopped &&
	    !(!(device->stopped & ~(DASD_STOPPED_DC_WAIT | DASD_UNRESUMED_PM))
	      && test_bit(DASD_CQR_VERIFY_PATH, &cqr->flags))) {
		cqr->intrc = -EAGAIN;
1883 1884
		cqr->status = DASD_CQR_CLEARED;
		dasd_schedule_device_bh(device);
1885
		return;
1886
	}
1887 1888 1889

	rc = device->discipline->start_IO(cqr);
	if (rc == 0)
1890
		dasd_device_set_timer(device, cqr->expires);
1891
	else if (rc == -EACCES) {
1892
		dasd_schedule_device_bh(device);
1893 1894
	} else
		/* Hmpf, try again in 1/2 sec */
1895
		dasd_device_set_timer(device, 50);
1896 1897
}

1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914
static void __dasd_device_check_path_events(struct dasd_device *device)
{
	int rc;

	if (device->path_data.tbvpm) {
		if (device->stopped & ~(DASD_STOPPED_DC_WAIT |
					DASD_UNRESUMED_PM))
			return;
		rc = device->discipline->verify_path(
			device, device->path_data.tbvpm);
		if (rc)
			dasd_device_set_timer(device, 50);
		else
			device->path_data.tbvpm = 0;
	}
};

L
Linus Torvalds 已提交
1915
/*
1916 1917 1918 1919 1920 1921 1922 1923
 * Go through all request on the dasd_device request queue,
 * terminate them on the cdev if necessary, and return them to the
 * submitting layer via callback.
 * Note:
 * Make sure that all 'submitting layers' still exist when
 * this function is called!. In other words, when 'device' is a base
 * device then all block layer requests must have been removed before
 * via dasd_flush_block_queue.
L
Linus Torvalds 已提交
1924
 */
1925
int dasd_flush_device_queue(struct dasd_device *device)
L
Linus Torvalds 已提交
1926
{
1927 1928
	struct dasd_ccw_req *cqr, *n;
	int rc;
L
Linus Torvalds 已提交
1929 1930 1931 1932
	struct list_head flush_queue;

	INIT_LIST_HEAD(&flush_queue);
	spin_lock_irq(get_ccwdev_lock(device->cdev));
1933
	rc = 0;
1934
	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
1935 1936 1937 1938 1939 1940
		/* Check status and move request to flush_queue */
		switch (cqr->status) {
		case DASD_CQR_IN_IO:
			rc = device->discipline->term_IO(cqr);
			if (rc) {
				/* unable to terminate requeust */
S
Stefan Haberland 已提交
1941 1942 1943
				dev_err(&device->cdev->dev,
					"Flushing the DASD request queue "
					"failed for request %p\n", cqr);
1944 1945 1946 1947 1948
				/* stop flush processing */
				goto finished;
			}
			break;
		case DASD_CQR_QUEUED:
L
Linus Torvalds 已提交
1949
			cqr->stopclk = get_clock();
1950
			cqr->status = DASD_CQR_CLEARED;
1951
			break;
1952
		default: /* no need to modify the others */
1953 1954
			break;
		}
1955
		list_move_tail(&cqr->devlist, &flush_queue);
1956 1957 1958
	}
finished:
	spin_unlock_irq(get_ccwdev_lock(device->cdev));
1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971
	/*
	 * After this point all requests must be in state CLEAR_PENDING,
	 * CLEARED, SUCCESS or ERROR. Now wait for CLEAR_PENDING to become
	 * one of the others.
	 */
	list_for_each_entry_safe(cqr, n, &flush_queue, devlist)
		wait_event(dasd_flush_wq,
			   (cqr->status != DASD_CQR_CLEAR_PENDING));
	/*
	 * Now set each request back to TERMINATED, DONE or NEED_ERP
	 * and call the callback function of flushed requests
	 */
	__dasd_device_process_final_queue(device, &flush_queue);
1972
	return rc;
L
Linus Torvalds 已提交
1973 1974 1975 1976 1977
}

/*
 * Acquire the device lock and process queues for the device.
 */
1978
static void dasd_device_tasklet(struct dasd_device *device)
L
Linus Torvalds 已提交
1979 1980 1981 1982 1983 1984 1985
{
	struct list_head final_queue;

	atomic_set (&device->tasklet_scheduled, 0);
	INIT_LIST_HEAD(&final_queue);
	spin_lock_irq(get_ccwdev_lock(device->cdev));
	/* Check expire time of first request on the ccw queue. */
1986 1987 1988
	__dasd_device_check_expire(device);
	/* find final requests on ccw queue */
	__dasd_device_process_ccw_queue(device, &final_queue);
1989
	__dasd_device_check_path_events(device);
L
Linus Torvalds 已提交
1990 1991
	spin_unlock_irq(get_ccwdev_lock(device->cdev));
	/* Now call the callback function of requests with final status */
1992 1993
	__dasd_device_process_final_queue(device, &final_queue);
	spin_lock_irq(get_ccwdev_lock(device->cdev));
L
Linus Torvalds 已提交
1994
	/* Now check if the head of the ccw queue needs to be started. */
1995 1996
	__dasd_device_start_head(device);
	spin_unlock_irq(get_ccwdev_lock(device->cdev));
1997 1998
	if (waitqueue_active(&shutdown_waitq))
		wake_up(&shutdown_waitq);
L
Linus Torvalds 已提交
1999 2000 2001 2002 2003 2004
	dasd_put_device(device);
}

/*
 * Schedules a call to dasd_tasklet over the device tasklet.
 */
2005
void dasd_schedule_device_bh(struct dasd_device *device)
L
Linus Torvalds 已提交
2006 2007
{
	/* Protect against rescheduling. */
2008
	if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
L
Linus Torvalds 已提交
2009 2010 2011 2012 2013
		return;
	dasd_get_device(device);
	tasklet_hi_schedule(&device->tasklet);
}

2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027
void dasd_device_set_stop_bits(struct dasd_device *device, int bits)
{
	device->stopped |= bits;
}
EXPORT_SYMBOL_GPL(dasd_device_set_stop_bits);

void dasd_device_remove_stop_bits(struct dasd_device *device, int bits)
{
	device->stopped &= ~bits;
	if (!device->stopped)
		wake_up(&generic_waitq);
}
EXPORT_SYMBOL_GPL(dasd_device_remove_stop_bits);

L
Linus Torvalds 已提交
2028
/*
2029 2030
 * Queue a request to the head of the device ccw_queue.
 * Start the I/O if possible.
L
Linus Torvalds 已提交
2031
 */
2032
void dasd_add_request_head(struct dasd_ccw_req *cqr)
L
Linus Torvalds 已提交
2033 2034 2035 2036
{
	struct dasd_device *device;
	unsigned long flags;

2037
	device = cqr->startdev;
L
Linus Torvalds 已提交
2038
	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2039 2040
	cqr->status = DASD_CQR_QUEUED;
	list_add(&cqr->devlist, &device->ccw_queue);
L
Linus Torvalds 已提交
2041
	/* let the bh start the request to keep them in order */
2042
	dasd_schedule_device_bh(device);
L
Linus Torvalds 已提交
2043 2044 2045 2046
	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}

/*
2047 2048
 * Queue a request to the tail of the device ccw_queue.
 * Start the I/O if possible.
L
Linus Torvalds 已提交
2049
 */
2050
void dasd_add_request_tail(struct dasd_ccw_req *cqr)
L
Linus Torvalds 已提交
2051 2052 2053 2054
{
	struct dasd_device *device;
	unsigned long flags;

2055
	device = cqr->startdev;
L
Linus Torvalds 已提交
2056
	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
2057 2058
	cqr->status = DASD_CQR_QUEUED;
	list_add_tail(&cqr->devlist, &device->ccw_queue);
L
Linus Torvalds 已提交
2059
	/* let the bh start the request to keep them in order */
2060
	dasd_schedule_device_bh(device);
L
Linus Torvalds 已提交
2061 2062 2063 2064
	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}

/*
2065
 * Wakeup helper for the 'sleep_on' functions.
L
Linus Torvalds 已提交
2066
 */
2067
void dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
L
Linus Torvalds 已提交
2068
{
2069 2070 2071 2072
	spin_lock_irq(get_ccwdev_lock(cqr->startdev->cdev));
	cqr->callback_data = DASD_SLEEPON_END_TAG;
	spin_unlock_irq(get_ccwdev_lock(cqr->startdev->cdev));
	wake_up(&generic_waitq);
L
Linus Torvalds 已提交
2073
}
2074
EXPORT_SYMBOL_GPL(dasd_wakeup_cb);
L
Linus Torvalds 已提交
2075

2076
static inline int _wait_for_wakeup(struct dasd_ccw_req *cqr)
L
Linus Torvalds 已提交
2077 2078 2079 2080
{
	struct dasd_device *device;
	int rc;

2081
	device = cqr->startdev;
L
Linus Torvalds 已提交
2082
	spin_lock_irq(get_ccwdev_lock(device->cdev));
2083
	rc = (cqr->callback_data == DASD_SLEEPON_END_TAG);
L
Linus Torvalds 已提交
2084 2085 2086 2087 2088
	spin_unlock_irq(get_ccwdev_lock(device->cdev));
	return rc;
}

/*
2089
 * checks if error recovery is necessary, returns 1 if yes, 0 otherwise.
L
Linus Torvalds 已提交
2090
 */
2091
static int __dasd_sleep_on_erp(struct dasd_ccw_req *cqr)
L
Linus Torvalds 已提交
2092 2093
{
	struct dasd_device *device;
2094
	dasd_erp_fn_t erp_fn;
2095

2096 2097
	if (cqr->status == DASD_CQR_FILLED)
		return 0;
2098
	device = cqr->startdev;
2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117
	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
		if (cqr->status == DASD_CQR_TERMINATED) {
			device->discipline->handle_terminated_request(cqr);
			return 1;
		}
		if (cqr->status == DASD_CQR_NEED_ERP) {
			erp_fn = device->discipline->erp_action(cqr);
			erp_fn(cqr);
			return 1;
		}
		if (cqr->status == DASD_CQR_FAILED)
			dasd_log_sense(cqr, &cqr->irb);
		if (cqr->refers) {
			__dasd_process_erp(device, cqr);
			return 1;
		}
	}
	return 0;
}
2118

2119 2120 2121 2122 2123 2124 2125 2126 2127 2128
static int __dasd_sleep_on_loop_condition(struct dasd_ccw_req *cqr)
{
	if (test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags)) {
		if (cqr->refers) /* erp is not done yet */
			return 1;
		return ((cqr->status != DASD_CQR_DONE) &&
			(cqr->status != DASD_CQR_FAILED));
	} else
		return (cqr->status == DASD_CQR_FILLED);
}
2129

2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148
static int _dasd_sleep_on(struct dasd_ccw_req *maincqr, int interruptible)
{
	struct dasd_device *device;
	int rc;
	struct list_head ccw_queue;
	struct dasd_ccw_req *cqr;

	INIT_LIST_HEAD(&ccw_queue);
	maincqr->status = DASD_CQR_FILLED;
	device = maincqr->startdev;
	list_add(&maincqr->blocklist, &ccw_queue);
	for (cqr = maincqr;  __dasd_sleep_on_loop_condition(cqr);
	     cqr = list_first_entry(&ccw_queue,
				    struct dasd_ccw_req, blocklist)) {

		if (__dasd_sleep_on_erp(cqr))
			continue;
		if (cqr->status != DASD_CQR_FILLED) /* could be failed */
			continue;
2149 2150 2151 2152 2153 2154
		if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
			cqr->status = DASD_CQR_FAILED;
			cqr->intrc = -EPERM;
			continue;
		}
2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173
		/* Non-temporary stop condition will trigger fail fast */
		if (device->stopped & ~DASD_STOPPED_PENDING &&
		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
		    (!dasd_eer_enabled(device))) {
			cqr->status = DASD_CQR_FAILED;
			continue;
		}
		/* Don't try to start requests if device is stopped */
		if (interruptible) {
			rc = wait_event_interruptible(
				generic_waitq, !(device->stopped));
			if (rc == -ERESTARTSYS) {
				cqr->status = DASD_CQR_FAILED;
				maincqr->intrc = rc;
				continue;
			}
		} else
			wait_event(generic_waitq, !(device->stopped));

2174 2175 2176
		if (!cqr->callback)
			cqr->callback = dasd_wakeup_cb;

2177
		cqr->callback_data = DASD_SLEEPON_START_TAG;
2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199
		dasd_add_request_tail(cqr);
		if (interruptible) {
			rc = wait_event_interruptible(
				generic_waitq, _wait_for_wakeup(cqr));
			if (rc == -ERESTARTSYS) {
				dasd_cancel_req(cqr);
				/* wait (non-interruptible) for final status */
				wait_event(generic_waitq,
					   _wait_for_wakeup(cqr));
				cqr->status = DASD_CQR_FAILED;
				maincqr->intrc = rc;
				continue;
			}
		} else
			wait_event(generic_waitq, _wait_for_wakeup(cqr));
	}

	maincqr->endclk = get_clock();
	if ((maincqr->status != DASD_CQR_DONE) &&
	    (maincqr->intrc != -ERESTARTSYS))
		dasd_log_sense(maincqr, &maincqr->irb);
	if (maincqr->status == DASD_CQR_DONE)
2200
		rc = 0;
2201 2202
	else if (maincqr->intrc)
		rc = maincqr->intrc;
2203 2204
	else
		rc = -EIO;
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Linus Torvalds 已提交
2205 2206 2207
	return rc;
}

2208 2209 2210 2211 2212 2213 2214 2215 2216
/*
 * Queue a request to the tail of the device ccw_queue and wait for
 * it's completion.
 */
int dasd_sleep_on(struct dasd_ccw_req *cqr)
{
	return _dasd_sleep_on(cqr, 0);
}

L
Linus Torvalds 已提交
2217
/*
2218 2219
 * Queue a request to the tail of the device ccw_queue and wait
 * interruptible for it's completion.
L
Linus Torvalds 已提交
2220
 */
2221
int dasd_sleep_on_interruptible(struct dasd_ccw_req *cqr)
L
Linus Torvalds 已提交
2222
{
2223
	return _dasd_sleep_on(cqr, 1);
L
Linus Torvalds 已提交
2224 2225 2226 2227 2228 2229 2230 2231
}

/*
 * Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
 * for eckd devices) the currently running request has to be terminated
 * and be put back to status queued, before the special request is added
 * to the head of the queue. Then the special request is waited on normally.
 */
2232
static inline int _dasd_term_running_cqr(struct dasd_device *device)
L
Linus Torvalds 已提交
2233 2234
{
	struct dasd_ccw_req *cqr;
2235
	int rc;
L
Linus Torvalds 已提交
2236 2237 2238

	if (list_empty(&device->ccw_queue))
		return 0;
2239
	cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, devlist);
2240 2241 2242 2243 2244 2245 2246 2247 2248
	rc = device->discipline->term_IO(cqr);
	if (!rc)
		/*
		 * CQR terminated because a more important request is pending.
		 * Undo decreasing of retry counter because this is
		 * not an error case.
		 */
		cqr->retries++;
	return rc;
L
Linus Torvalds 已提交
2249 2250
}

2251
int dasd_sleep_on_immediatly(struct dasd_ccw_req *cqr)
L
Linus Torvalds 已提交
2252 2253 2254
{
	struct dasd_device *device;
	int rc;
2255

2256
	device = cqr->startdev;
2257 2258 2259 2260 2261 2262
	if (test_bit(DASD_FLAG_LOCK_STOLEN, &device->flags) &&
	    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
		cqr->status = DASD_CQR_FAILED;
		cqr->intrc = -EPERM;
		return -EIO;
	}
L
Linus Torvalds 已提交
2263 2264 2265 2266 2267 2268 2269
	spin_lock_irq(get_ccwdev_lock(device->cdev));
	rc = _dasd_term_running_cqr(device);
	if (rc) {
		spin_unlock_irq(get_ccwdev_lock(device->cdev));
		return rc;
	}
	cqr->callback = dasd_wakeup_cb;
2270
	cqr->callback_data = DASD_SLEEPON_START_TAG;
L
Linus Torvalds 已提交
2271
	cqr->status = DASD_CQR_QUEUED;
2272 2273 2274 2275 2276
	/*
	 * add new request as second
	 * first the terminated cqr needs to be finished
	 */
	list_add(&cqr->devlist, device->ccw_queue.next);
2277

L
Linus Torvalds 已提交
2278
	/* let the bh start the request to keep them in order */
2279
	dasd_schedule_device_bh(device);
2280

L
Linus Torvalds 已提交
2281 2282
	spin_unlock_irq(get_ccwdev_lock(device->cdev));

2283
	wait_event(generic_waitq, _wait_for_wakeup(cqr));
2284

2285 2286 2287 2288 2289 2290
	if (cqr->status == DASD_CQR_DONE)
		rc = 0;
	else if (cqr->intrc)
		rc = cqr->intrc;
	else
		rc = -EIO;
L
Linus Torvalds 已提交
2291 2292 2293 2294 2295 2296 2297 2298
	return rc;
}

/*
 * Cancels a request that was started with dasd_sleep_on_req.
 * This is useful to timeout requests. The request will be
 * terminated if it is currently in i/o.
 * Returns 1 if the request has been terminated.
2299 2300 2301 2302
 *	   0 if there was no need to terminate the request (not started yet)
 *	   negative error code if termination failed
 * Cancellation of a request is an asynchronous operation! The calling
 * function has to wait until the request is properly returned via callback.
L
Linus Torvalds 已提交
2303
 */
2304
int dasd_cancel_req(struct dasd_ccw_req *cqr)
L
Linus Torvalds 已提交
2305
{
2306
	struct dasd_device *device = cqr->startdev;
L
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2307 2308 2309 2310 2311 2312 2313
	unsigned long flags;
	int rc;

	rc = 0;
	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
	switch (cqr->status) {
	case DASD_CQR_QUEUED:
2314 2315
		/* request was not started - just set to cleared */
		cqr->status = DASD_CQR_CLEARED;
L
Linus Torvalds 已提交
2316 2317 2318
		break;
	case DASD_CQR_IN_IO:
		/* request in IO - terminate IO and release again */
2319 2320
		rc = device->discipline->term_IO(cqr);
		if (rc) {
S
Stefan Haberland 已提交
2321 2322 2323
			dev_err(&device->cdev->dev,
				"Cancelling request %p failed with rc=%d\n",
				cqr, rc);
2324 2325 2326
		} else {
			cqr->stopclk = get_clock();
		}
L
Linus Torvalds 已提交
2327
		break;
2328
	default: /* already finished or clear pending - do nothing */
L
Linus Torvalds 已提交
2329
		break;
2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353
	}
	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
	dasd_schedule_device_bh(device);
	return rc;
}


/*
 * SECTION: Operations of the dasd_block layer.
 */

/*
 * Timeout function for dasd_block. This is used when the block layer
 * is waiting for something that may not come reliably, (e.g. a state
 * change interrupt)
 */
static void dasd_block_timeout(unsigned long ptr)
{
	unsigned long flags;
	struct dasd_block *block;

	block = (struct dasd_block *) ptr;
	spin_lock_irqsave(get_ccwdev_lock(block->base->cdev), flags);
	/* re-activate request queue */
2354
	dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
2355 2356 2357 2358 2359 2360 2361 2362 2363
	spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
	dasd_schedule_block_bh(block);
}

/*
 * Setup timeout for a dasd_block in jiffies.
 */
void dasd_block_set_timer(struct dasd_block *block, int expires)
{
2364 2365 2366 2367
	if (expires == 0)
		del_timer(&block->timer);
	else
		mod_timer(&block->timer, jiffies + expires);
2368 2369 2370 2371 2372 2373 2374
}

/*
 * Clear timeout for a dasd_block.
 */
void dasd_block_clear_timer(struct dasd_block *block)
{
2375
	del_timer(&block->timer);
2376 2377 2378 2379 2380
}

/*
 * Process finished error recovery ccw.
 */
2381 2382
static void __dasd_process_erp(struct dasd_device *device,
			       struct dasd_ccw_req *cqr)
2383 2384 2385 2386 2387 2388
{
	dasd_erp_fn_t erp_fn;

	if (cqr->status == DASD_CQR_DONE)
		DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
	else
S
Stefan Haberland 已提交
2389
		dev_err(&device->cdev->dev, "ERP failed for the DASD\n");
2390 2391 2392
	erp_fn = device->discipline->erp_postaction(cqr);
	erp_fn(cqr);
}
L
Linus Torvalds 已提交
2393

2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416
/*
 * Fetch requests from the block device queue.
 */
static void __dasd_process_request_queue(struct dasd_block *block)
{
	struct request_queue *queue;
	struct request *req;
	struct dasd_ccw_req *cqr;
	struct dasd_device *basedev;
	unsigned long flags;
	queue = block->request_queue;
	basedev = block->base;
	/* No queue ? Then there is nothing to do. */
	if (queue == NULL)
		return;

	/*
	 * We requeue request from the block device queue to the ccw
	 * queue only in two states. In state DASD_STATE_READY the
	 * partition detection is done and we need to requeue requests
	 * for that. State DASD_STATE_ONLINE is normal block device
	 * operation.
	 */
2417 2418 2419
	if (basedev->state < DASD_STATE_READY) {
		while ((req = blk_fetch_request(block->request_queue)))
			__blk_end_request_all(req, -EIO);
2420
		return;
2421
	}
2422
	/* Now we try to fetch requests from the request queue */
J
Jens Axboe 已提交
2423
	while ((req = blk_peek_request(queue))) {
2424 2425 2426 2427 2428
		if (basedev->features & DASD_FEATURE_READONLY &&
		    rq_data_dir(req) == WRITE) {
			DBF_DEV_EVENT(DBF_ERR, basedev,
				      "Rejecting write request %p",
				      req);
2429
			blk_start_request(req);
2430
			__blk_end_request_all(req, -EIO);
2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447
			continue;
		}
		cqr = basedev->discipline->build_cp(basedev, block, req);
		if (IS_ERR(cqr)) {
			if (PTR_ERR(cqr) == -EBUSY)
				break;	/* normal end condition */
			if (PTR_ERR(cqr) == -ENOMEM)
				break;	/* terminate request queue loop */
			if (PTR_ERR(cqr) == -EAGAIN) {
				/*
				 * The current request cannot be build right
				 * now, we have to try later. If this request
				 * is the head-of-queue we stop the device
				 * for 1/2 second.
				 */
				if (!list_empty(&block->ccw_queue))
					break;
2448 2449 2450 2451 2452 2453
				spin_lock_irqsave(
					get_ccwdev_lock(basedev->cdev), flags);
				dasd_device_set_stop_bits(basedev,
							  DASD_STOPPED_PENDING);
				spin_unlock_irqrestore(
					get_ccwdev_lock(basedev->cdev), flags);
2454 2455 2456 2457 2458 2459 2460
				dasd_block_set_timer(block, HZ/2);
				break;
			}
			DBF_DEV_EVENT(DBF_ERR, basedev,
				      "CCW creation failed (rc=%ld) "
				      "on request %p",
				      PTR_ERR(cqr), req);
2461
			blk_start_request(req);
2462
			__blk_end_request_all(req, -EIO);
2463 2464 2465 2466 2467 2468 2469 2470
			continue;
		}
		/*
		 *  Note: callback is set to dasd_return_cqr_cb in
		 * __dasd_block_start_head to cover erp requests as well
		 */
		cqr->callback_data = (void *) req;
		cqr->status = DASD_CQR_FILLED;
2471
		blk_start_request(req);
2472 2473 2474 2475 2476 2477 2478 2479 2480
		list_add_tail(&cqr->blocklist, &block->ccw_queue);
		dasd_profile_start(block, cqr, req);
	}
}

static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
{
	struct request *req;
	int status;
2481
	int error = 0;
2482 2483 2484

	req = (struct request *) cqr->callback_data;
	dasd_profile_end(cqr->block, cqr, req);
2485
	status = cqr->block->base->discipline->free_cp(cqr, req);
2486 2487
	if (status <= 0)
		error = status ? status : -EIO;
2488
	__blk_end_request_all(req, error);
2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519
}

/*
 * Process ccw request queue.
 */
static void __dasd_process_block_ccw_queue(struct dasd_block *block,
					   struct list_head *final_queue)
{
	struct list_head *l, *n;
	struct dasd_ccw_req *cqr;
	dasd_erp_fn_t erp_fn;
	unsigned long flags;
	struct dasd_device *base = block->base;

restart:
	/* Process request with final status. */
	list_for_each_safe(l, n, &block->ccw_queue) {
		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
		if (cqr->status != DASD_CQR_DONE &&
		    cqr->status != DASD_CQR_FAILED &&
		    cqr->status != DASD_CQR_NEED_ERP &&
		    cqr->status != DASD_CQR_TERMINATED)
			continue;

		if (cqr->status == DASD_CQR_TERMINATED) {
			base->discipline->handle_terminated_request(cqr);
			goto restart;
		}

		/*  Process requests that may be recovered */
		if (cqr->status == DASD_CQR_NEED_ERP) {
2520
			erp_fn = base->discipline->erp_action(cqr);
2521 2522
			if (IS_ERR(erp_fn(cqr)))
				continue;
2523 2524 2525
			goto restart;
		}

2526 2527 2528 2529 2530
		/* log sense for fatal error */
		if (cqr->status == DASD_CQR_FAILED) {
			dasd_log_sense(cqr, &cqr->irb);
		}

2531 2532 2533 2534 2535 2536 2537 2538 2539
		/* First of all call extended error reporting. */
		if (dasd_eer_enabled(base) &&
		    cqr->status == DASD_CQR_FAILED) {
			dasd_eer_write(base, cqr, DASD_EER_FATALERROR);

			/* restart request  */
			cqr->status = DASD_CQR_FILLED;
			cqr->retries = 255;
			spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
2540
			dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
2541 2542 2543 2544 2545 2546 2547
			spin_unlock_irqrestore(get_ccwdev_lock(base->cdev),
					       flags);
			goto restart;
		}

		/* Process finished ERP request. */
		if (cqr->refers) {
2548
			__dasd_process_erp(base, cqr);
2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575
			goto restart;
		}

		/* Rechain finished requests to final queue */
		cqr->endclk = get_clock();
		list_move_tail(&cqr->blocklist, final_queue);
	}
}

static void dasd_return_cqr_cb(struct dasd_ccw_req *cqr, void *data)
{
	dasd_schedule_block_bh(cqr->block);
}

static void __dasd_block_start_head(struct dasd_block *block)
{
	struct dasd_ccw_req *cqr;

	if (list_empty(&block->ccw_queue))
		return;
	/* We allways begin with the first requests on the queue, as some
	 * of previously started requests have to be enqueued on a
	 * dasd_device again for error recovery.
	 */
	list_for_each_entry(cqr, &block->ccw_queue, blocklist) {
		if (cqr->status != DASD_CQR_FILLED)
			continue;
2576 2577 2578 2579 2580 2581 2582
		if (test_bit(DASD_FLAG_LOCK_STOLEN, &block->base->flags) &&
		    !test_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags)) {
			cqr->status = DASD_CQR_FAILED;
			cqr->intrc = -EPERM;
			dasd_schedule_block_bh(block);
			continue;
		}
2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636
		/* Non-temporary stop condition will trigger fail fast */
		if (block->base->stopped & ~DASD_STOPPED_PENDING &&
		    test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
		    (!dasd_eer_enabled(block->base))) {
			cqr->status = DASD_CQR_FAILED;
			dasd_schedule_block_bh(block);
			continue;
		}
		/* Don't try to start requests if device is stopped */
		if (block->base->stopped)
			return;

		/* just a fail safe check, should not happen */
		if (!cqr->startdev)
			cqr->startdev = block->base;

		/* make sure that the requests we submit find their way back */
		cqr->callback = dasd_return_cqr_cb;

		dasd_add_request_tail(cqr);
	}
}

/*
 * Central dasd_block layer routine. Takes requests from the generic
 * block layer request queue, creates ccw requests, enqueues them on
 * a dasd_device and processes ccw requests that have been returned.
 */
static void dasd_block_tasklet(struct dasd_block *block)
{
	struct list_head final_queue;
	struct list_head *l, *n;
	struct dasd_ccw_req *cqr;

	atomic_set(&block->tasklet_scheduled, 0);
	INIT_LIST_HEAD(&final_queue);
	spin_lock(&block->queue_lock);
	/* Finish off requests on ccw queue */
	__dasd_process_block_ccw_queue(block, &final_queue);
	spin_unlock(&block->queue_lock);
	/* Now call the callback function of requests with final status */
	spin_lock_irq(&block->request_queue_lock);
	list_for_each_safe(l, n, &final_queue) {
		cqr = list_entry(l, struct dasd_ccw_req, blocklist);
		list_del_init(&cqr->blocklist);
		__dasd_cleanup_cqr(cqr);
	}
	spin_lock(&block->queue_lock);
	/* Get new request from the block device request queue */
	__dasd_process_request_queue(block);
	/* Now check if the head of the ccw queue needs to be started. */
	__dasd_block_start_head(block);
	spin_unlock(&block->queue_lock);
	spin_unlock_irq(&block->request_queue_lock);
2637 2638
	if (waitqueue_active(&shutdown_waitq))
		wake_up(&shutdown_waitq);
2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686
	dasd_put_device(block->base);
}

static void _dasd_wake_block_flush_cb(struct dasd_ccw_req *cqr, void *data)
{
	wake_up(&dasd_flush_wq);
}

/*
 * Go through all request on the dasd_block request queue, cancel them
 * on the respective dasd_device, and return them to the generic
 * block layer.
 */
static int dasd_flush_block_queue(struct dasd_block *block)
{
	struct dasd_ccw_req *cqr, *n;
	int rc, i;
	struct list_head flush_queue;

	INIT_LIST_HEAD(&flush_queue);
	spin_lock_bh(&block->queue_lock);
	rc = 0;
restart:
	list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
		/* if this request currently owned by a dasd_device cancel it */
		if (cqr->status >= DASD_CQR_QUEUED)
			rc = dasd_cancel_req(cqr);
		if (rc < 0)
			break;
		/* Rechain request (including erp chain) so it won't be
		 * touched by the dasd_block_tasklet anymore.
		 * Replace the callback so we notice when the request
		 * is returned from the dasd_device layer.
		 */
		cqr->callback = _dasd_wake_block_flush_cb;
		for (i = 0; cqr != NULL; cqr = cqr->refers, i++)
			list_move_tail(&cqr->blocklist, &flush_queue);
		if (i > 1)
			/* moved more than one request - need to restart */
			goto restart;
	}
	spin_unlock_bh(&block->queue_lock);
	/* Now call the callback function of flushed requests */
restart_cb:
	list_for_each_entry_safe(cqr, n, &flush_queue, blocklist) {
		wait_event(dasd_flush_wq, (cqr->status < DASD_CQR_QUEUED));
		/* Process finished ERP request. */
		if (cqr->refers) {
2687
			spin_lock_bh(&block->queue_lock);
2688
			__dasd_process_erp(block->base, cqr);
2689
			spin_unlock_bh(&block->queue_lock);
2690 2691 2692 2693 2694
			/* restart list_for_xx loop since dasd_process_erp
			 * might remove multiple elements */
			goto restart_cb;
		}
		/* call the callback function */
2695
		spin_lock_irq(&block->request_queue_lock);
2696 2697 2698
		cqr->endclk = get_clock();
		list_del_init(&cqr->blocklist);
		__dasd_cleanup_cqr(cqr);
2699
		spin_unlock_irq(&block->request_queue_lock);
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2700 2701 2702 2703 2704
	}
	return rc;
}

/*
2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720
 * Schedules a call to dasd_tasklet over the device tasklet.
 */
void dasd_schedule_block_bh(struct dasd_block *block)
{
	/* Protect against rescheduling. */
	if (atomic_cmpxchg(&block->tasklet_scheduled, 0, 1) != 0)
		return;
	/* life cycle of block is bound to it's base device */
	dasd_get_device(block->base);
	tasklet_hi_schedule(&block->tasklet);
}


/*
 * SECTION: external block device operations
 * (request queue handling, open, release, etc.)
L
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2721 2722 2723 2724 2725
 */

/*
 * Dasd request queue function. Called from ll_rw_blk.c
 */
2726
static void do_dasd_request(struct request_queue *queue)
L
Linus Torvalds 已提交
2727
{
2728
	struct dasd_block *block;
L
Linus Torvalds 已提交
2729

2730 2731
	block = queue->queuedata;
	spin_lock(&block->queue_lock);
L
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2732
	/* Get new request from the block device request queue */
2733
	__dasd_process_request_queue(block);
L
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2734
	/* Now check if the head of the ccw queue needs to be started. */
2735 2736
	__dasd_block_start_head(block);
	spin_unlock(&block->queue_lock);
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2737 2738 2739 2740 2741
}

/*
 * Allocate and initialize request queue and default I/O scheduler.
 */
2742
static int dasd_alloc_queue(struct dasd_block *block)
L
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2743 2744 2745
{
	int rc;

2746 2747 2748
	block->request_queue = blk_init_queue(do_dasd_request,
					       &block->request_queue_lock);
	if (block->request_queue == NULL)
L
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2749 2750
		return -ENOMEM;

2751
	block->request_queue->queuedata = block;
L
Linus Torvalds 已提交
2752

2753
	elevator_exit(block->request_queue->elevator);
2754
	block->request_queue->elevator = NULL;
2755
	rc = elevator_init(block->request_queue, "deadline");
L
Linus Torvalds 已提交
2756
	if (rc) {
2757
		blk_cleanup_queue(block->request_queue);
L
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2758 2759 2760 2761 2762 2763 2764 2765
		return rc;
	}
	return 0;
}

/*
 * Allocate and initialize request queue.
 */
2766
static void dasd_setup_queue(struct dasd_block *block)
L
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2767 2768 2769
{
	int max;

2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783
	if (block->base->features & DASD_FEATURE_USERAW) {
		/*
		 * the max_blocks value for raw_track access is 256
		 * it is higher than the native ECKD value because we
		 * only need one ccw per track
		 * so the max_hw_sectors are
		 * 2048 x 512B = 1024kB = 16 tracks
		 */
		max = 2048;
	} else {
		max = block->base->discipline->max_blocks << block->s2b_shift;
	}
	blk_queue_logical_block_size(block->request_queue,
				     block->bp_block);
2784
	blk_queue_max_hw_sectors(block->request_queue, max);
2785
	blk_queue_max_segments(block->request_queue, -1L);
2786 2787 2788 2789 2790
	/* with page sized segments we can translate each segement into
	 * one idaw/tidaw
	 */
	blk_queue_max_segment_size(block->request_queue, PAGE_SIZE);
	blk_queue_segment_boundary(block->request_queue, PAGE_SIZE - 1);
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2791 2792 2793 2794 2795
}

/*
 * Deactivate and free request queue.
 */
2796
static void dasd_free_queue(struct dasd_block *block)
L
Linus Torvalds 已提交
2797
{
2798 2799 2800
	if (block->request_queue) {
		blk_cleanup_queue(block->request_queue);
		block->request_queue = NULL;
L
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2801 2802 2803 2804 2805 2806
	}
}

/*
 * Flush request on the request queue.
 */
2807
static void dasd_flush_request_queue(struct dasd_block *block)
L
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2808 2809 2810
{
	struct request *req;

2811
	if (!block->request_queue)
L
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2812
		return;
2813

2814
	spin_lock_irq(&block->request_queue_lock);
2815
	while ((req = blk_fetch_request(block->request_queue)))
2816
		__blk_end_request_all(req, -EIO);
2817
	spin_unlock_irq(&block->request_queue_lock);
L
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2818 2819
}

A
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2820
static int dasd_open(struct block_device *bdev, fmode_t mode)
L
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2821
{
2822
	struct dasd_device *base;
L
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2823 2824
	int rc;

2825 2826
	base = dasd_device_from_gendisk(bdev->bd_disk);
	if (!base)
2827 2828
		return -ENODEV;

2829
	atomic_inc(&base->block->open_count);
2830
	if (test_bit(DASD_FLAG_OFFLINE, &base->flags)) {
L
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2831 2832 2833 2834
		rc = -ENODEV;
		goto unlock;
	}

2835
	if (!try_module_get(base->discipline->owner)) {
L
Linus Torvalds 已提交
2836 2837 2838 2839 2840
		rc = -EINVAL;
		goto unlock;
	}

	if (dasd_probeonly) {
S
Stefan Haberland 已提交
2841 2842 2843
		dev_info(&base->cdev->dev,
			 "Accessing the DASD failed because it is in "
			 "probeonly mode\n");
L
Linus Torvalds 已提交
2844 2845 2846 2847
		rc = -EPERM;
		goto out;
	}

2848 2849
	if (base->state <= DASD_STATE_BASIC) {
		DBF_DEV_EVENT(DBF_ERR, base, " %s",
L
Linus Torvalds 已提交
2850 2851 2852 2853 2854
			      " Cannot open unrecognized device");
		rc = -ENODEV;
		goto out;
	}

2855 2856 2857 2858 2859 2860 2861
	if ((mode & FMODE_WRITE) &&
	    (test_bit(DASD_FLAG_DEVICE_RO, &base->flags) ||
	     (base->features & DASD_FEATURE_READONLY))) {
		rc = -EROFS;
		goto out;
	}

2862
	dasd_put_device(base);
L
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2863 2864 2865
	return 0;

out:
2866
	module_put(base->discipline->owner);
L
Linus Torvalds 已提交
2867
unlock:
2868 2869
	atomic_dec(&base->block->open_count);
	dasd_put_device(base);
L
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2870 2871 2872
	return rc;
}

A
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2873
static int dasd_release(struct gendisk *disk, fmode_t mode)
L
Linus Torvalds 已提交
2874
{
2875
	struct dasd_device *base;
L
Linus Torvalds 已提交
2876

2877 2878 2879 2880 2881 2882 2883
	base = dasd_device_from_gendisk(disk);
	if (!base)
		return -ENODEV;

	atomic_dec(&base->block->open_count);
	module_put(base->discipline->owner);
	dasd_put_device(base);
L
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2884 2885 2886
	return 0;
}

2887 2888 2889
/*
 * Return disk geometry.
 */
2890
static int dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
2891
{
2892
	struct dasd_device *base;
2893

2894 2895
	base = dasd_device_from_gendisk(bdev->bd_disk);
	if (!base)
2896 2897
		return -ENODEV;

2898
	if (!base->discipline ||
2899 2900
	    !base->discipline->fill_geometry) {
		dasd_put_device(base);
2901
		return -EINVAL;
2902 2903 2904 2905
	}
	base->discipline->fill_geometry(base->block, geo);
	geo->start = get_start_sect(bdev) >> base->block->s2b_shift;
	dasd_put_device(base);
2906 2907 2908
	return 0;
}

2909
const struct block_device_operations
L
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2910 2911
dasd_device_operations = {
	.owner		= THIS_MODULE,
A
Al Viro 已提交
2912 2913
	.open		= dasd_open,
	.release	= dasd_release,
2914 2915
	.ioctl		= dasd_ioctl,
	.compat_ioctl	= dasd_ioctl,
2916
	.getgeo		= dasd_getgeo,
L
Linus Torvalds 已提交
2917 2918
};

2919 2920 2921
/*******************************************************************************
 * end of block device operations
 */
L
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2922 2923 2924 2925 2926 2927 2928

static void
dasd_exit(void)
{
#ifdef CONFIG_PROC_FS
	dasd_proc_exit();
#endif
2929
	dasd_eer_exit();
2930 2931 2932 2933
        if (dasd_page_cache != NULL) {
		kmem_cache_destroy(dasd_page_cache);
		dasd_page_cache = NULL;
	}
L
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2934 2935 2936 2937 2938 2939
	dasd_gendisk_exit();
	dasd_devmap_exit();
	if (dasd_debug_area != NULL) {
		debug_unregister(dasd_debug_area);
		dasd_debug_area = NULL;
	}
2940
	dasd_statistics_removeroot();
L
Linus Torvalds 已提交
2941 2942 2943 2944 2945 2946
}

/*
 * SECTION: common functions for ccw_driver use
 */

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
/*
 * Is the device read-only?
 * Note that this function does not report the setting of the
 * readonly device attribute, but how it is configured in z/VM.
 */
int dasd_device_is_ro(struct dasd_device *device)
{
	struct ccw_dev_id dev_id;
	struct diag210 diag_data;
	int rc;

	if (!MACHINE_IS_VM)
		return 0;
	ccw_device_get_id(device->cdev, &dev_id);
	memset(&diag_data, 0, sizeof(diag_data));
	diag_data.vrdcdvno = dev_id.devno;
	diag_data.vrdclen = sizeof(diag_data);
	rc = diag210(&diag_data);
	if (rc == 0 || rc == 2) {
		return diag_data.vrdcvfla & 0x80;
	} else {
		DBF_EVENT(DBF_WARNING, "diag210 failed for dev=%04x with rc=%d",
			  dev_id.devno, rc);
		return 0;
	}
}
EXPORT_SYMBOL_GPL(dasd_device_is_ro);

2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985
static void dasd_generic_auto_online(void *data, async_cookie_t cookie)
{
	struct ccw_device *cdev = data;
	int ret;

	ret = ccw_device_set_online(cdev);
	if (ret)
		pr_warning("%s: Setting the DASD online failed with rc=%d\n",
			   dev_name(&cdev->dev), ret);
}

2986 2987 2988 2989
/*
 * Initial attempt at a probe function. this can be simplified once
 * the other detection code is gone.
 */
2990 2991
int dasd_generic_probe(struct ccw_device *cdev,
		       struct dasd_discipline *discipline)
L
Linus Torvalds 已提交
2992 2993 2994 2995 2996
{
	int ret;

	ret = dasd_add_sysfs_files(cdev);
	if (ret) {
2997 2998 2999
		DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
				"dasd_generic_probe: could not add "
				"sysfs entries");
3000
		return ret;
L
Linus Torvalds 已提交
3001
	}
3002
	cdev->handler = &dasd_int_handler;
L
Linus Torvalds 已提交
3003

3004 3005 3006 3007 3008 3009
	/*
	 * Automatically online either all dasd devices (dasd_autodetect)
	 * or all devices specified with dasd= parameters during
	 * initial probe.
	 */
	if ((dasd_get_feature(cdev, DASD_FEATURE_INITIAL_ONLINE) > 0 ) ||
3010
	    (dasd_autodetect && dasd_busid_known(dev_name(&cdev->dev)) != 0))
3011
		async_schedule(dasd_generic_auto_online, cdev);
3012
	return 0;
L
Linus Torvalds 已提交
3013 3014
}

3015 3016 3017 3018
/*
 * This will one day be called from a global not_oper handler.
 * It is also used by driver_unregister during module unload.
 */
3019
void dasd_generic_remove(struct ccw_device *cdev)
L
Linus Torvalds 已提交
3020 3021
{
	struct dasd_device *device;
3022
	struct dasd_block *block;
L
Linus Torvalds 已提交
3023

3024 3025
	cdev->handler = NULL;

L
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3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041
	dasd_remove_sysfs_files(cdev);
	device = dasd_device_from_cdev(cdev);
	if (IS_ERR(device))
		return;
	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
		/* Already doing offline processing */
		dasd_put_device(device);
		return;
	}
	/*
	 * This device is removed unconditionally. Set offline
	 * flag to prevent dasd_open from opening it while it is
	 * no quite down yet.
	 */
	dasd_set_target_state(device, DASD_STATE_NEW);
	/* dasd_delete_device destroys the device reference. */
3042
	block = device->block;
L
Linus Torvalds 已提交
3043
	dasd_delete_device(device);
3044 3045 3046 3047 3048 3049
	/*
	 * life cycle of block is bound to device, so delete it after
	 * device was safely removed
	 */
	if (block)
		dasd_free_block(block);
L
Linus Torvalds 已提交
3050 3051
}

3052 3053
/*
 * Activate a device. This is called from dasd_{eckd,fba}_probe() when either
L
Linus Torvalds 已提交
3054
 * the device is detected for the first time and is supposed to be used
3055 3056
 * or the user has started activation through sysfs.
 */
3057 3058
int dasd_generic_set_online(struct ccw_device *cdev,
			    struct dasd_discipline *base_discipline)
L
Linus Torvalds 已提交
3059
{
3060
	struct dasd_discipline *discipline;
L
Linus Torvalds 已提交
3061
	struct dasd_device *device;
3062
	int rc;
3063

3064 3065
	/* first online clears initial online feature flag */
	dasd_set_feature(cdev, DASD_FEATURE_INITIAL_ONLINE, 0);
L
Linus Torvalds 已提交
3066 3067 3068 3069
	device = dasd_create_device(cdev);
	if (IS_ERR(device))
		return PTR_ERR(device);

3070
	discipline = base_discipline;
3071
	if (device->features & DASD_FEATURE_USEDIAG) {
L
Linus Torvalds 已提交
3072
	  	if (!dasd_diag_discipline_pointer) {
S
Stefan Haberland 已提交
3073 3074 3075
			pr_warning("%s Setting the DASD online failed because "
				   "of missing DIAG discipline\n",
				   dev_name(&cdev->dev));
L
Linus Torvalds 已提交
3076 3077 3078 3079 3080
			dasd_delete_device(device);
			return -ENODEV;
		}
		discipline = dasd_diag_discipline_pointer;
	}
3081 3082 3083 3084 3085 3086 3087 3088 3089 3090
	if (!try_module_get(base_discipline->owner)) {
		dasd_delete_device(device);
		return -EINVAL;
	}
	if (!try_module_get(discipline->owner)) {
		module_put(base_discipline->owner);
		dasd_delete_device(device);
		return -EINVAL;
	}
	device->base_discipline = base_discipline;
L
Linus Torvalds 已提交
3091 3092
	device->discipline = discipline;

3093
	/* check_device will allocate block device if necessary */
L
Linus Torvalds 已提交
3094 3095
	rc = discipline->check_device(device);
	if (rc) {
S
Stefan Haberland 已提交
3096 3097 3098
		pr_warning("%s Setting the DASD online with discipline %s "
			   "failed with rc=%i\n",
			   dev_name(&cdev->dev), discipline->name, rc);
3099 3100
		module_put(discipline->owner);
		module_put(base_discipline->owner);
L
Linus Torvalds 已提交
3101 3102 3103 3104 3105 3106
		dasd_delete_device(device);
		return rc;
	}

	dasd_set_target_state(device, DASD_STATE_ONLINE);
	if (device->state <= DASD_STATE_KNOWN) {
S
Stefan Haberland 已提交
3107 3108
		pr_warning("%s Setting the DASD online failed because of a "
			   "missing discipline\n", dev_name(&cdev->dev));
L
Linus Torvalds 已提交
3109 3110
		rc = -ENODEV;
		dasd_set_target_state(device, DASD_STATE_NEW);
3111 3112
		if (device->block)
			dasd_free_block(device->block);
L
Linus Torvalds 已提交
3113 3114 3115
		dasd_delete_device(device);
	} else
		pr_debug("dasd_generic device %s found\n",
3116
				dev_name(&cdev->dev));
S
Stefan Haberland 已提交
3117 3118 3119

	wait_event(dasd_init_waitq, _wait_for_device(device));

L
Linus Torvalds 已提交
3120 3121 3122 3123
	dasd_put_device(device);
	return rc;
}

3124
int dasd_generic_set_offline(struct ccw_device *cdev)
L
Linus Torvalds 已提交
3125 3126
{
	struct dasd_device *device;
3127
	struct dasd_block *block;
3128
	int max_count, open_count;
L
Linus Torvalds 已提交
3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143

	device = dasd_device_from_cdev(cdev);
	if (IS_ERR(device))
		return PTR_ERR(device);
	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
		/* Already doing offline processing */
		dasd_put_device(device);
		return 0;
	}
	/*
	 * We must make sure that this device is currently not in use.
	 * The open_count is increased for every opener, that includes
	 * the blkdev_get in dasd_scan_partitions. We are only interested
	 * in the other openers.
	 */
3144
	if (device->block) {
3145 3146
		max_count = device->block->bdev ? 0 : -1;
		open_count = atomic_read(&device->block->open_count);
3147 3148
		if (open_count > max_count) {
			if (open_count > 0)
S
Stefan Haberland 已提交
3149 3150 3151
				pr_warning("%s: The DASD cannot be set offline "
					   "with open count %i\n",
					   dev_name(&cdev->dev), open_count);
3152
			else
S
Stefan Haberland 已提交
3153 3154 3155
				pr_warning("%s: The DASD cannot be set offline "
					   "while it is in use\n",
					   dev_name(&cdev->dev));
3156 3157 3158 3159
			clear_bit(DASD_FLAG_OFFLINE, &device->flags);
			dasd_put_device(device);
			return -EBUSY;
		}
L
Linus Torvalds 已提交
3160 3161 3162
	}
	dasd_set_target_state(device, DASD_STATE_NEW);
	/* dasd_delete_device destroys the device reference. */
3163
	block = device->block;
L
Linus Torvalds 已提交
3164
	dasd_delete_device(device);
3165 3166 3167 3168 3169 3170
	/*
	 * life cycle of block is bound to device, so delete it after
	 * device was safely removed
	 */
	if (block)
		dasd_free_block(block);
L
Linus Torvalds 已提交
3171 3172 3173
	return 0;
}

3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217
int dasd_generic_last_path_gone(struct dasd_device *device)
{
	struct dasd_ccw_req *cqr;

	dev_warn(&device->cdev->dev, "No operational channel path is left "
		 "for the device\n");
	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "last path gone");
	/* First of all call extended error reporting. */
	dasd_eer_write(device, NULL, DASD_EER_NOPATH);

	if (device->state < DASD_STATE_BASIC)
		return 0;
	/* Device is active. We want to keep it. */
	list_for_each_entry(cqr, &device->ccw_queue, devlist)
		if ((cqr->status == DASD_CQR_IN_IO) ||
		    (cqr->status == DASD_CQR_CLEAR_PENDING)) {
			cqr->status = DASD_CQR_QUEUED;
			cqr->retries++;
		}
	dasd_device_set_stop_bits(device, DASD_STOPPED_DC_WAIT);
	dasd_device_clear_timer(device);
	dasd_schedule_device_bh(device);
	return 1;
}
EXPORT_SYMBOL_GPL(dasd_generic_last_path_gone);

int dasd_generic_path_operational(struct dasd_device *device)
{
	dev_info(&device->cdev->dev, "A channel path to the device has become "
		 "operational\n");
	DBF_DEV_EVENT(DBF_WARNING, device, "%s", "path operational");
	dasd_device_remove_stop_bits(device, DASD_STOPPED_DC_WAIT);
	if (device->stopped & DASD_UNRESUMED_PM) {
		dasd_device_remove_stop_bits(device, DASD_UNRESUMED_PM);
		dasd_restore_device(device);
		return 1;
	}
	dasd_schedule_device_bh(device);
	if (device->block)
		dasd_schedule_block_bh(device->block);
	return 1;
}
EXPORT_SYMBOL_GPL(dasd_generic_path_operational);

3218
int dasd_generic_notify(struct ccw_device *cdev, int event)
L
Linus Torvalds 已提交
3219 3220 3221 3222
{
	struct dasd_device *device;
	int ret;

3223
	device = dasd_device_from_cdev_locked(cdev);
L
Linus Torvalds 已提交
3224 3225 3226 3227 3228
	if (IS_ERR(device))
		return 0;
	ret = 0;
	switch (event) {
	case CIO_GONE:
3229
	case CIO_BOXED:
L
Linus Torvalds 已提交
3230
	case CIO_NO_PATH:
3231 3232 3233 3234
		device->path_data.opm = 0;
		device->path_data.ppm = 0;
		device->path_data.npm = 0;
		ret = dasd_generic_last_path_gone(device);
L
Linus Torvalds 已提交
3235 3236 3237
		break;
	case CIO_OPER:
		ret = 1;
3238 3239
		if (device->path_data.opm)
			ret = dasd_generic_path_operational(device);
L
Linus Torvalds 已提交
3240 3241 3242 3243 3244 3245
		break;
	}
	dasd_put_device(device);
	return ret;
}

3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271
void dasd_generic_path_event(struct ccw_device *cdev, int *path_event)
{
	int chp;
	__u8 oldopm, eventlpm;
	struct dasd_device *device;

	device = dasd_device_from_cdev_locked(cdev);
	if (IS_ERR(device))
		return;
	for (chp = 0; chp < 8; chp++) {
		eventlpm = 0x80 >> chp;
		if (path_event[chp] & PE_PATH_GONE) {
			oldopm = device->path_data.opm;
			device->path_data.opm &= ~eventlpm;
			device->path_data.ppm &= ~eventlpm;
			device->path_data.npm &= ~eventlpm;
			if (oldopm && !device->path_data.opm)
				dasd_generic_last_path_gone(device);
		}
		if (path_event[chp] & PE_PATH_AVAILABLE) {
			device->path_data.opm &= ~eventlpm;
			device->path_data.ppm &= ~eventlpm;
			device->path_data.npm &= ~eventlpm;
			device->path_data.tbvpm |= eventlpm;
			dasd_schedule_device_bh(device);
		}
3272 3273 3274 3275 3276 3277
		if (path_event[chp] & PE_PATHGROUP_ESTABLISHED) {
			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
				      "Pathgroup re-established\n");
			if (device->discipline->kick_validate)
				device->discipline->kick_validate(device);
		}
3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294
	}
	dasd_put_device(device);
}
EXPORT_SYMBOL_GPL(dasd_generic_path_event);

int dasd_generic_verify_path(struct dasd_device *device, __u8 lpm)
{
	if (!device->path_data.opm && lpm) {
		device->path_data.opm = lpm;
		dasd_generic_path_operational(device);
	} else
		device->path_data.opm |= lpm;
	return 0;
}
EXPORT_SYMBOL_GPL(dasd_generic_verify_path);


3295 3296 3297 3298 3299 3300 3301 3302 3303
int dasd_generic_pm_freeze(struct ccw_device *cdev)
{
	struct dasd_ccw_req *cqr, *n;
	int rc;
	struct list_head freeze_queue;
	struct dasd_device *device = dasd_device_from_cdev(cdev);

	if (IS_ERR(device))
		return PTR_ERR(device);
3304

3305 3306 3307
	/* mark device as suspended */
	set_bit(DASD_FLAG_SUSPENDED, &device->flags);

3308 3309 3310
	if (device->discipline->freeze)
		rc = device->discipline->freeze(device);

3311
	/* disallow new I/O  */
3312
	dasd_device_set_stop_bits(device, DASD_STOPPED_PM);
3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359
	/* clear active requests */
	INIT_LIST_HEAD(&freeze_queue);
	spin_lock_irq(get_ccwdev_lock(cdev));
	rc = 0;
	list_for_each_entry_safe(cqr, n, &device->ccw_queue, devlist) {
		/* Check status and move request to flush_queue */
		if (cqr->status == DASD_CQR_IN_IO) {
			rc = device->discipline->term_IO(cqr);
			if (rc) {
				/* unable to terminate requeust */
				dev_err(&device->cdev->dev,
					"Unable to terminate request %p "
					"on suspend\n", cqr);
				spin_unlock_irq(get_ccwdev_lock(cdev));
				dasd_put_device(device);
				return rc;
			}
		}
		list_move_tail(&cqr->devlist, &freeze_queue);
	}

	spin_unlock_irq(get_ccwdev_lock(cdev));

	list_for_each_entry_safe(cqr, n, &freeze_queue, devlist) {
		wait_event(dasd_flush_wq,
			   (cqr->status != DASD_CQR_CLEAR_PENDING));
		if (cqr->status == DASD_CQR_CLEARED)
			cqr->status = DASD_CQR_QUEUED;
	}
	/* move freeze_queue to start of the ccw_queue */
	spin_lock_irq(get_ccwdev_lock(cdev));
	list_splice_tail(&freeze_queue, &device->ccw_queue);
	spin_unlock_irq(get_ccwdev_lock(cdev));

	dasd_put_device(device);
	return rc;
}
EXPORT_SYMBOL_GPL(dasd_generic_pm_freeze);

int dasd_generic_restore_device(struct ccw_device *cdev)
{
	struct dasd_device *device = dasd_device_from_cdev(cdev);
	int rc = 0;

	if (IS_ERR(device))
		return PTR_ERR(device);

3360
	/* allow new IO again */
3361 3362
	dasd_device_remove_stop_bits(device,
				     (DASD_STOPPED_PM | DASD_UNRESUMED_PM));
3363

3364 3365
	dasd_schedule_device_bh(device);

3366 3367 3368 3369 3370
	/*
	 * call discipline restore function
	 * if device is stopped do nothing e.g. for disconnected devices
	 */
	if (device->discipline->restore && !(device->stopped))
3371
		rc = device->discipline->restore(device);
3372
	if (rc || device->stopped)
3373 3374 3375 3376 3377
		/*
		 * if the resume failed for the DASD we put it in
		 * an UNRESUMED stop state
		 */
		device->stopped |= DASD_UNRESUMED_PM;
3378

3379 3380 3381
	if (device->block)
		dasd_schedule_block_bh(device->block);

3382
	clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
3383
	dasd_put_device(device);
3384
	return 0;
3385 3386 3387
}
EXPORT_SYMBOL_GPL(dasd_generic_restore_device);

H
Heiko Carstens 已提交
3388 3389 3390
static struct dasd_ccw_req *dasd_generic_build_rdc(struct dasd_device *device,
						   void *rdc_buffer,
						   int rdc_buffer_size,
3391
						   int magic)
3392 3393 3394
{
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
3395
	unsigned long *idaw;
3396 3397 3398 3399

	cqr = dasd_smalloc_request(magic, 1 /* RDC */, rdc_buffer_size, device);

	if (IS_ERR(cqr)) {
S
Stefan Haberland 已提交
3400 3401 3402 3403
		/* internal error 13 - Allocating the RDC request failed*/
		dev_err(&device->cdev->dev,
			 "An error occurred in the DASD device driver, "
			 "reason=%s\n", "13");
3404 3405 3406 3407 3408
		return cqr;
	}

	ccw = cqr->cpaddr;
	ccw->cmd_code = CCW_CMD_RDC;
3409 3410 3411 3412 3413 3414 3415 3416 3417
	if (idal_is_needed(rdc_buffer, rdc_buffer_size)) {
		idaw = (unsigned long *) (cqr->data);
		ccw->cda = (__u32)(addr_t) idaw;
		ccw->flags = CCW_FLAG_IDA;
		idaw = idal_create_words(idaw, rdc_buffer, rdc_buffer_size);
	} else {
		ccw->cda = (__u32)(addr_t) rdc_buffer;
		ccw->flags = 0;
	}
3418

3419
	ccw->count = rdc_buffer_size;
3420 3421
	cqr->startdev = device;
	cqr->memdev = device;
3422
	cqr->expires = 10*HZ;
3423
	cqr->retries = 256;
3424 3425 3426 3427 3428 3429
	cqr->buildclk = get_clock();
	cqr->status = DASD_CQR_FILLED;
	return cqr;
}


3430
int dasd_generic_read_dev_chars(struct dasd_device *device, int magic,
3431
				void *rdc_buffer, int rdc_buffer_size)
3432 3433 3434 3435
{
	int ret;
	struct dasd_ccw_req *cqr;

3436
	cqr = dasd_generic_build_rdc(device, rdc_buffer, rdc_buffer_size,
3437 3438 3439 3440 3441
				     magic);
	if (IS_ERR(cqr))
		return PTR_ERR(cqr);

	ret = dasd_sleep_on(cqr);
3442
	dasd_sfree_request(cqr, cqr->memdev);
3443 3444
	return ret;
}
C
Cornelia Huck 已提交
3445
EXPORT_SYMBOL_GPL(dasd_generic_read_dev_chars);
3446

3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480
/*
 *   In command mode and transport mode we need to look for sense
 *   data in different places. The sense data itself is allways
 *   an array of 32 bytes, so we can unify the sense data access
 *   for both modes.
 */
char *dasd_get_sense(struct irb *irb)
{
	struct tsb *tsb = NULL;
	char *sense = NULL;

	if (scsw_is_tm(&irb->scsw) && (irb->scsw.tm.fcxs == 0x01)) {
		if (irb->scsw.tm.tcw)
			tsb = tcw_get_tsb((struct tcw *)(unsigned long)
					  irb->scsw.tm.tcw);
		if (tsb && tsb->length == 64 && tsb->flags)
			switch (tsb->flags & 0x07) {
			case 1:	/* tsa_iostat */
				sense = tsb->tsa.iostat.sense;
				break;
			case 2: /* tsa_ddpc */
				sense = tsb->tsa.ddpc.sense;
				break;
			default:
				/* currently we don't use interrogate data */
				break;
			}
	} else if (irb->esw.esw0.erw.cons) {
		sense = irb->ecw;
	}
	return sense;
}
EXPORT_SYMBOL_GPL(dasd_get_sense);

3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506
static inline int _wait_for_empty_queues(struct dasd_device *device)
{
	if (device->block)
		return list_empty(&device->ccw_queue) &&
			list_empty(&device->block->ccw_queue);
	else
		return list_empty(&device->ccw_queue);
}

void dasd_generic_shutdown(struct ccw_device *cdev)
{
	struct dasd_device *device;

	device = dasd_device_from_cdev(cdev);
	if (IS_ERR(device))
		return;

	if (device->block)
		dasd_schedule_block_bh(device->block);

	dasd_schedule_device_bh(device);

	wait_event(shutdown_waitq, _wait_for_empty_queues(device));
}
EXPORT_SYMBOL_GPL(dasd_generic_shutdown);

3507
static int __init dasd_init(void)
L
Linus Torvalds 已提交
3508 3509 3510 3511
{
	int rc;

	init_waitqueue_head(&dasd_init_waitq);
3512
	init_waitqueue_head(&dasd_flush_wq);
3513
	init_waitqueue_head(&generic_waitq);
3514
	init_waitqueue_head(&shutdown_waitq);
L
Linus Torvalds 已提交
3515 3516

	/* register 'common' DASD debug area, used for all DBF_XXX calls */
3517
	dasd_debug_area = debug_register("dasd", 1, 1, 8 * sizeof(long));
L
Linus Torvalds 已提交
3518 3519 3520 3521 3522
	if (dasd_debug_area == NULL) {
		rc = -ENOMEM;
		goto failed;
	}
	debug_register_view(dasd_debug_area, &debug_sprintf_view);
H
Horst Hummel 已提交
3523
	debug_set_level(dasd_debug_area, DBF_WARNING);
L
Linus Torvalds 已提交
3524 3525 3526 3527 3528

	DBF_EVENT(DBF_EMERG, "%s", "debug area created");

	dasd_diag_discipline_pointer = NULL;

3529 3530
	dasd_statistics_createroot();

L
Linus Torvalds 已提交
3531 3532 3533 3534 3535 3536 3537 3538 3539
	rc = dasd_devmap_init();
	if (rc)
		goto failed;
	rc = dasd_gendisk_init();
	if (rc)
		goto failed;
	rc = dasd_parse();
	if (rc)
		goto failed;
3540 3541 3542
	rc = dasd_eer_init();
	if (rc)
		goto failed;
L
Linus Torvalds 已提交
3543 3544 3545 3546 3547 3548 3549 3550
#ifdef CONFIG_PROC_FS
	rc = dasd_proc_init();
	if (rc)
		goto failed;
#endif

	return 0;
failed:
S
Stefan Haberland 已提交
3551
	pr_info("The DASD device driver could not be initialized\n");
L
Linus Torvalds 已提交
3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564
	dasd_exit();
	return rc;
}

module_init(dasd_init);
module_exit(dasd_exit);

EXPORT_SYMBOL(dasd_debug_area);
EXPORT_SYMBOL(dasd_diag_discipline_pointer);

EXPORT_SYMBOL(dasd_add_request_head);
EXPORT_SYMBOL(dasd_add_request_tail);
EXPORT_SYMBOL(dasd_cancel_req);
3565 3566
EXPORT_SYMBOL(dasd_device_clear_timer);
EXPORT_SYMBOL(dasd_block_clear_timer);
L
Linus Torvalds 已提交
3567 3568 3569 3570 3571
EXPORT_SYMBOL(dasd_enable_device);
EXPORT_SYMBOL(dasd_int_handler);
EXPORT_SYMBOL(dasd_kfree_request);
EXPORT_SYMBOL(dasd_kick_device);
EXPORT_SYMBOL(dasd_kmalloc_request);
3572 3573
EXPORT_SYMBOL(dasd_schedule_device_bh);
EXPORT_SYMBOL(dasd_schedule_block_bh);
L
Linus Torvalds 已提交
3574
EXPORT_SYMBOL(dasd_set_target_state);
3575 3576
EXPORT_SYMBOL(dasd_device_set_timer);
EXPORT_SYMBOL(dasd_block_set_timer);
L
Linus Torvalds 已提交
3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589
EXPORT_SYMBOL(dasd_sfree_request);
EXPORT_SYMBOL(dasd_sleep_on);
EXPORT_SYMBOL(dasd_sleep_on_immediatly);
EXPORT_SYMBOL(dasd_sleep_on_interruptible);
EXPORT_SYMBOL(dasd_smalloc_request);
EXPORT_SYMBOL(dasd_start_IO);
EXPORT_SYMBOL(dasd_term_IO);

EXPORT_SYMBOL_GPL(dasd_generic_probe);
EXPORT_SYMBOL_GPL(dasd_generic_remove);
EXPORT_SYMBOL_GPL(dasd_generic_notify);
EXPORT_SYMBOL_GPL(dasd_generic_set_online);
EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
3590 3591 3592 3593
EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
EXPORT_SYMBOL_GPL(dasd_flush_device_queue);
EXPORT_SYMBOL_GPL(dasd_alloc_block);
EXPORT_SYMBOL_GPL(dasd_free_block);