atari_NCR5380.c 90.5 KB
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/*
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 * NCR 5380 generic driver routines.  These should make it *trivial*
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 *	to implement 5380 SCSI drivers under Linux with a non-trantor
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 *	architecture.
 *
 *	Note that these routines also work with NR53c400 family chips.
 *
 * Copyright 1993, Drew Eckhardt
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 *	Visionary Computing
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 *	(Unix and Linux consulting and custom programming)
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 *	drew@colorado.edu
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 *	+1 (303) 666-5836
 *
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 * DISTRIBUTION RELEASE 6.
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 *
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 * For more information, please consult
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 *
 * NCR 5380 Family
 * SCSI Protocol Controller
 * Databook
 *
 * NCR Microelectronics
 * 1635 Aeroplaza Drive
 * Colorado Springs, CO 80916
 * 1+ (719) 578-3400
 * 1+ (800) 334-5454
 */

/*
 * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
 * this file, too:
 *
 *  - Some of the debug statements were incorrect (undefined variables and the
 *    like). I fixed that.
 *
 *  - In information_transfer(), I think a #ifdef was wrong. Looking at the
 *    possible DMA transfer size should also happen for REAL_DMA. I added this
 *    in the #if statement.
 *
 *  - When using real DMA, information_transfer() should return in a DATAOUT
 *    phase after starting the DMA. It has nothing more to do.
 *
 *  - The interrupt service routine should run main after end of DMA, too (not
 *    only after RESELECTION interrupts). Additionally, it should _not_ test
 *    for more interrupts after running main, since a DMA process may have
 *    been started and interrupts are turned on now. The new int could happen
 *    inside the execution of NCR5380_intr(), leading to recursive
 *    calls.
 *
 *  - I've added a function merge_contiguous_buffers() that tries to
 *    merge scatter-gather buffers that are located at contiguous
 *    physical addresses and can be processed with the same DMA setup.
 *    Since most scatter-gather operations work on a page (4K) of
 *    4 buffers (1K), in more than 90% of all cases three interrupts and
 *    DMA setup actions are saved.
 *
 * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
 *    and USLEEP, because these were messing up readability and will never be
 *    needed for Atari SCSI.
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 *
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 * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
 *   stuff), and 'main' is executed in a bottom half if awoken by an
 *   interrupt.
 *
 * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
 *   constructs. In my eyes, this made the source rather unreadable, so I
 *   finally replaced that by the *_PRINTK() macros.
 *
 */

/*
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 * Further development / testing that should be done :
 * 1.  Test linked command handling code after Eric is ready with
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 *     the high level code.
 */
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#include <scsi/scsi_dbg.h>
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#include <scsi/scsi_transport_spi.h>
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#if (NDEBUG & NDEBUG_LISTS)
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#define LIST(x, y)						\
	do {							\
		printk("LINE:%d   Adding %p to %p\n",		\
		       __LINE__, (void*)(x), (void*)(y));	\
		if ((x) == (y))					\
			udelay(5);				\
	} while (0)
#define REMOVE(w, x, y, z)					\
	do {							\
		printk("LINE:%d   Removing: %p->%p  %p->%p \n",	\
		       __LINE__, (void*)(w), (void*)(x),	\
		       (void*)(y), (void*)(z));			\
		if ((x) == (y))					\
			udelay(5);				\
	} while (0)
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#else
#define LIST(x,y)
#define REMOVE(w,x,y,z)
#endif

#ifndef notyet
#undef LINKED
#endif

/*
 * Design
 * Issues :
 *
 * The other Linux SCSI drivers were written when Linux was Intel PC-only,
 * and specifically for each board rather than each chip.  This makes their
 * adaptation to platforms like the Mac (Some of which use NCR5380's)
 * more difficult than it has to be.
 *
 * Also, many of the SCSI drivers were written before the command queuing
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 * routines were implemented, meaning their implementations of queued
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 * commands were hacked on rather than designed in from the start.
 *
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 * When I designed the Linux SCSI drivers I figured that
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 * while having two different SCSI boards in a system might be useful
 * for debugging things, two of the same type wouldn't be used.
 * Well, I was wrong and a number of users have mailed me about running
 * multiple high-performance SCSI boards in a server.
 *
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 * Finally, when I get questions from users, I have no idea what
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 * revision of my driver they are running.
 *
 * This driver attempts to address these problems :
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 * This is a generic 5380 driver.  To use it on a different platform,
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 * one simply writes appropriate system specific macros (ie, data
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 * transfer - some PC's will use the I/O bus, 68K's must use
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 * memory mapped) and drops this file in their 'C' wrapper.
 *
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 * As far as command queueing, two queues are maintained for
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 * each 5380 in the system - commands that haven't been issued yet,
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 * and commands that are currently executing.  This means that an
 * unlimited number of commands may be queued, letting
 * more commands propagate from the higher driver levels giving higher
 * throughput.  Note that both I_T_L and I_T_L_Q nexuses are supported,
 * allowing multiple commands to propagate all the way to a SCSI-II device
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 * while a command is already executing.
 *
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 * To solve the multiple-boards-in-the-same-system problem,
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 * there is a separate instance structure for each instance
 * of a 5380 in the system.  So, multiple NCR5380 drivers will
 * be able to coexist with appropriate changes to the high level
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 * SCSI code.
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 *
 * A NCR5380_PUBLIC_REVISION macro is provided, with the release
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 * number (updated for each public release) printed by the
 * NCR5380_print_options command, which should be called from the
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 * wrapper detect function, so that I know what release of the driver
 * users are using.
 *
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 * Issues specific to the NCR5380 :
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 *
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 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
 * piece of hardware that requires you to sit in a loop polling for
 * the REQ signal as long as you are connected.  Some devices are
 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
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 * while doing long seek operations.
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 *
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 * The workaround for this is to keep track of devices that have
 * disconnected.  If the device hasn't disconnected, for commands that
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 * should disconnect, we do something like
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 *
 * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
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 *
 * Some tweaking of N and M needs to be done.  An algorithm based
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 * on "time to data" would give the best results as long as short time
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 * to datas (ie, on the same track) were considered, however these
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 * broken devices are the exception rather than the rule and I'd rather
 * spend my time optimizing for the normal case.
 *
 * Architecture :
 *
 * At the heart of the design is a coroutine, NCR5380_main,
 * which is started when not running by the interrupt handler,
 * timer, and queue command function.  It attempts to establish
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 * I_T_L or I_T_L_Q nexuses by removing the commands from the
 * issue queue and calling NCR5380_select() if a nexus
 * is not established.
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 *
 * Once a nexus is established, the NCR5380_information_transfer()
 * phase goes through the various phases as instructed by the target.
 * if the target goes into MSG IN and sends a DISCONNECT message,
 * the command structure is placed into the per instance disconnected
 * queue, and NCR5380_main tries to find more work.  If USLEEP
 * was defined, and the target is idle for too long, the system
 * will try to sleep.
 *
 * If a command has disconnected, eventually an interrupt will trigger,
 * calling NCR5380_intr()  which will in turn call NCR5380_reselect
 * to reestablish a nexus.  This will run main if necessary.
 *
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 * On command termination, the done function will be called as
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 * appropriate.
 *
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 * SCSI pointers are maintained in the SCp field of SCSI command
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 * structures, being initialized after the command is connected
 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
 * Note that in violation of the standard, an implicit SAVE POINTERS operation
 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
 */

/*
 * Using this file :
 * This file a skeleton Linux SCSI driver for the NCR 5380 series
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 * of chips.  To use it, you write an architecture specific functions
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 * and macros and include this file in your driver.
 *
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 * These macros control options :
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 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
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 *	for commands that return with a CHECK CONDITION status.
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 *
 * LINKED - if defined, linked commands are supported.
 *
 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
 *
 * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
 *
 * These macros MUST be defined :
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 *
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 * NCR5380_read(register)  - read from the specified register
 *
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 * NCR5380_write(register, value) - write to the specific register
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 *
 * Either real DMA *or* pseudo DMA may be implemented
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 * REAL functions :
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 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
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 * Note that the DMA setup functions should return the number of bytes
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 *	that they were able to program the controller for.
 *
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 * Also note that generic i386/PC versions of these macros are
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 *	available as NCR5380_i386_dma_write_setup,
 *	NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
 *
 * NCR5380_dma_write_setup(instance, src, count) - initialize
 * NCR5380_dma_read_setup(instance, dst, count) - initialize
 * NCR5380_dma_residual(instance); - residual count
 *
 * PSEUDO functions :
 * NCR5380_pwrite(instance, src, count)
 * NCR5380_pread(instance, dst, count);
 *
 * If nothing specific to this implementation needs doing (ie, with external
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 * hardware), you must also define
 *
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 * NCR5380_queue_command
 * NCR5380_reset
 * NCR5380_abort
 * NCR5380_proc_info
 *
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 * to be the global entry points into the specific driver, ie
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 * #define NCR5380_queue_command t128_queue_command.
 *
 * If this is not done, the routines will be defined as static functions
 * with the NCR5380* names and the user must provide a globally
 * accessible wrapper function.
 *
 * The generic driver is initialized by calling NCR5380_init(instance),
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 * after setting the appropriate host specific fields and ID.  If the
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 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
 * possible) function may be used.  Before the specific driver initialization
 * code finishes, NCR5380_print_options should be called.
 */

static struct Scsi_Host *first_instance = NULL;
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static struct scsi_host_template *the_template = NULL;
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/* Macros ease life... :-) */
#define	SETUP_HOSTDATA(in)				\
    struct NCR5380_hostdata *hostdata =			\
	(struct NCR5380_hostdata *)(in)->hostdata
#define	HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)

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#define	NEXT(cmd)		((Scsi_Cmnd *)(cmd)->host_scribble)
#define	SET_NEXT(cmd,next)	((cmd)->host_scribble = (void *)(next))
#define	NEXTADDR(cmd)		((Scsi_Cmnd **)&(cmd)->host_scribble)
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#define	HOSTNO		instance->host_no
#define	H_NO(cmd)	(cmd)->device->host->host_no

#ifdef SUPPORT_TAGS

/*
 * Functions for handling tagged queuing
 * =====================================
 *
 * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
 *
 * Using consecutive numbers for the tags is no good idea in my eyes. There
 * could be wrong re-usings if the counter (8 bit!) wraps and some early
 * command has been preempted for a long time. My solution: a bitfield for
 * remembering used tags.
 *
 * There's also the problem that each target has a certain queue size, but we
 * cannot know it in advance :-( We just see a QUEUE_FULL status being
 * returned. So, in this case, the driver internal queue size assumption is
 * reduced to the number of active tags if QUEUE_FULL is returned by the
 * target. The command is returned to the mid-level, but with status changed
 * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
 * correctly.
 *
 * We're also not allowed running tagged commands as long as an untagged
 * command is active. And REQUEST SENSE commands after a contingent allegiance
 * condition _must_ be untagged. To keep track whether an untagged command has
 * been issued, the host->busy array is still employed, as it is without
 * support for tagged queuing.
 *
 * One could suspect that there are possible race conditions between
 * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
 * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
 * which already guaranteed to be running at most once. It is also the only
 * place where tags/LUNs are allocated. So no other allocation can slip
 * between that pair, there could only happen a reselection, which can free a
 * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
 * important: the tag bit must be cleared before 'nr_allocated' is decreased.
 */

/* -1 for TAG_NONE is not possible with unsigned char cmd->tag */
#undef TAG_NONE
#define TAG_NONE 0xff

typedef struct {
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	DECLARE_BITMAP(allocated, MAX_TAGS);
	int nr_allocated;
	int queue_size;
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} TAG_ALLOC;

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static TAG_ALLOC TagAlloc[8][8];	/* 8 targets and 8 LUNs */
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static void __init init_tags(void)
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{
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	int target, lun;
	TAG_ALLOC *ta;

	if (!setup_use_tagged_queuing)
		return;

	for (target = 0; target < 8; ++target) {
		for (lun = 0; lun < 8; ++lun) {
			ta = &TagAlloc[target][lun];
			bitmap_zero(ta->allocated, MAX_TAGS);
			ta->nr_allocated = 0;
			/* At the beginning, assume the maximum queue size we could
			 * support (MAX_TAGS). This value will be decreased if the target
			 * returns QUEUE_FULL status.
			 */
			ta->queue_size = MAX_TAGS;
		}
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	}
}


/* Check if we can issue a command to this LUN: First see if the LUN is marked
 * busy by an untagged command. If the command should use tagged queuing, also
 * check that there is a free tag and the target's queue won't overflow. This
 * function should be called with interrupts disabled to avoid race
 * conditions.
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 */
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static int is_lun_busy(Scsi_Cmnd *cmd, int should_be_tagged)
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{
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	SETUP_HOSTDATA(cmd->device->host);

	if (hostdata->busy[cmd->device->id] & (1 << cmd->device->lun))
		return 1;
	if (!should_be_tagged ||
	    !setup_use_tagged_queuing || !cmd->device->tagged_supported)
		return 0;
	if (TagAlloc[cmd->device->id][cmd->device->lun].nr_allocated >=
	    TagAlloc[cmd->device->id][cmd->device->lun].queue_size) {
		TAG_PRINTK("scsi%d: target %d lun %d: no free tags\n",
			   H_NO(cmd), cmd->device->id, cmd->device->lun);
		return 1;
	}
	return 0;
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}


/* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
 * must be called before!), or reserve the LUN in 'busy' if the command is
 * untagged.
 */

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static void cmd_get_tag(Scsi_Cmnd *cmd, int should_be_tagged)
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{
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	SETUP_HOSTDATA(cmd->device->host);

	/* If we or the target don't support tagged queuing, allocate the LUN for
	 * an untagged command.
	 */
	if (!should_be_tagged ||
	    !setup_use_tagged_queuing || !cmd->device->tagged_supported) {
		cmd->tag = TAG_NONE;
		hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
		TAG_PRINTK("scsi%d: target %d lun %d now allocated by untagged "
			   "command\n", H_NO(cmd), cmd->device->id, cmd->device->lun);
	} else {
		TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];

		cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
		set_bit(cmd->tag, ta->allocated);
		ta->nr_allocated++;
		TAG_PRINTK("scsi%d: using tag %d for target %d lun %d "
			   "(now %d tags in use)\n",
			   H_NO(cmd), cmd->tag, cmd->device->id,
			   cmd->device->lun, ta->nr_allocated);
	}
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}


/* Mark the tag of command 'cmd' as free, or in case of an untagged command,
 * unlock the LUN.
 */

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static void cmd_free_tag(Scsi_Cmnd *cmd)
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{
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	SETUP_HOSTDATA(cmd->device->host);

	if (cmd->tag == TAG_NONE) {
		hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
		TAG_PRINTK("scsi%d: target %d lun %d untagged cmd finished\n",
			   H_NO(cmd), cmd->device->id, cmd->device->lun);
	} else if (cmd->tag >= MAX_TAGS) {
		printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
		       H_NO(cmd), cmd->tag);
	} else {
		TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
		clear_bit(cmd->tag, ta->allocated);
		ta->nr_allocated--;
		TAG_PRINTK("scsi%d: freed tag %d for target %d lun %d\n",
			   H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun);
	}
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}


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static void free_all_tags(void)
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{
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	int target, lun;
	TAG_ALLOC *ta;

	if (!setup_use_tagged_queuing)
		return;

	for (target = 0; target < 8; ++target) {
		for (lun = 0; lun < 8; ++lun) {
			ta = &TagAlloc[target][lun];
			bitmap_zero(ta->allocated, MAX_TAGS);
			ta->nr_allocated = 0;
		}
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	}
}

#endif /* SUPPORT_TAGS */


/*
 * Function: void merge_contiguous_buffers( Scsi_Cmnd *cmd )
 *
 * Purpose: Try to merge several scatter-gather requests into one DMA
 *    transfer. This is possible if the scatter buffers lie on
 *    physical contiguous addresses.
 *
 * Parameters: Scsi_Cmnd *cmd
 *    The command to work on. The first scatter buffer's data are
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 *    assumed to be already transferred into ptr/this_residual.
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 */

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static void merge_contiguous_buffers(Scsi_Cmnd *cmd)
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{
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	unsigned long endaddr;
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#if (NDEBUG & NDEBUG_MERGING)
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	unsigned long oldlen = cmd->SCp.this_residual;
	int cnt = 1;
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#endif

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	for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
	     cmd->SCp.buffers_residual &&
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	     virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
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		MER_PRINTK("VTOP(%p) == %08lx -> merging\n",
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			   page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
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#if (NDEBUG & NDEBUG_MERGING)
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		++cnt;
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#endif
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		++cmd->SCp.buffer;
		--cmd->SCp.buffers_residual;
		cmd->SCp.this_residual += cmd->SCp.buffer->length;
		endaddr += cmd->SCp.buffer->length;
	}
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#if (NDEBUG & NDEBUG_MERGING)
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	if (oldlen != cmd->SCp.this_residual)
		MER_PRINTK("merged %d buffers from %p, new length %08x\n",
			   cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
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#endif
}

/*
 * Function : void initialize_SCp(Scsi_Cmnd *cmd)
 *
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 * Purpose : initialize the saved data pointers for cmd to point to the
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 *	start of the buffer.
 *
 * Inputs : cmd - Scsi_Cmnd structure to have pointers reset.
 */

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static inline void initialize_SCp(Scsi_Cmnd *cmd)
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{
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	/*
	 * Initialize the Scsi Pointer field so that all of the commands in the
	 * various queues are valid.
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	 */
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	if (scsi_bufflen(cmd)) {
		cmd->SCp.buffer = scsi_sglist(cmd);
		cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
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		cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
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		cmd->SCp.this_residual = cmd->SCp.buffer->length;
		/* ++roman: Try to merge some scatter-buffers if they are at
		 * contiguous physical addresses.
		 */
		merge_contiguous_buffers(cmd);
	} else {
		cmd->SCp.buffer = NULL;
		cmd->SCp.buffers_residual = 0;
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		cmd->SCp.ptr = NULL;
		cmd->SCp.this_residual = 0;
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	}
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}

#include <linux/delay.h>

#if NDEBUG
static struct {
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	unsigned char mask;
	const char *name;
} signals[] = {
	{ SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
	{ SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD,  "CD" }, { SR_IO, "IO" },
	{ SR_SEL, "SEL" }, {0, NULL}
}, basrs[] = {
	{BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
}, icrs[] = {
	{ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
	{ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
	{ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
	{0, NULL}
}, mrs[] = {
	{MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
	{MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
	"MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
	{MR_MONITOR_BSY, "MODE MONITOR BSY"},
	{MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
	{0, NULL}
};
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/*
 * Function : void NCR5380_print(struct Scsi_Host *instance)
 *
 * Purpose : print the SCSI bus signals for debugging purposes
 *
 * Input : instance - which NCR5380
 */

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static void NCR5380_print(struct Scsi_Host *instance)
{
	unsigned char status, data, basr, mr, icr, i;
	unsigned long flags;

	local_irq_save(flags);
	data = NCR5380_read(CURRENT_SCSI_DATA_REG);
	status = NCR5380_read(STATUS_REG);
	mr = NCR5380_read(MODE_REG);
	icr = NCR5380_read(INITIATOR_COMMAND_REG);
	basr = NCR5380_read(BUS_AND_STATUS_REG);
	local_irq_restore(flags);
	printk("STATUS_REG: %02x ", status);
	for (i = 0; signals[i].mask; ++i)
		if (status & signals[i].mask)
			printk(",%s", signals[i].name);
	printk("\nBASR: %02x ", basr);
	for (i = 0; basrs[i].mask; ++i)
		if (basr & basrs[i].mask)
			printk(",%s", basrs[i].name);
	printk("\nICR: %02x ", icr);
	for (i = 0; icrs[i].mask; ++i)
		if (icr & icrs[i].mask)
			printk(",%s", icrs[i].name);
	printk("\nMODE: %02x ", mr);
	for (i = 0; mrs[i].mask; ++i)
		if (mr & mrs[i].mask)
			printk(",%s", mrs[i].name);
	printk("\n");
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}

static struct {
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	unsigned char value;
	const char *name;
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} phases[] = {
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	{PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
	{PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
	{PHASE_UNKNOWN, "UNKNOWN"}
};
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/*
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 * Function : void NCR5380_print_phase(struct Scsi_Host *instance)
 *
 * Purpose : print the current SCSI phase for debugging purposes
 *
 * Input : instance - which NCR5380
 */

static void NCR5380_print_phase(struct Scsi_Host *instance)
{
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	unsigned char status;
	int i;

	status = NCR5380_read(STATUS_REG);
	if (!(status & SR_REQ))
		printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
	else {
		for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
		     (phases[i].value != (status & PHASE_MASK)); ++i)
			;
		printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
	}
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}

#else /* !NDEBUG */

/* dummies... */
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static inline void NCR5380_print(struct Scsi_Host *instance)
{
};
static inline void NCR5380_print_phase(struct Scsi_Host *instance)
{
};
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#endif

/*
 * ++roman: New scheme of calling NCR5380_main()
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 *
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 * If we're not in an interrupt, we can call our main directly, it cannot be
 * already running. Else, we queue it on a task queue, if not 'main_running'
 * tells us that a lower level is already executing it. This way,
 * 'main_running' needs not be protected in a special way.
 *
 * queue_main() is a utility function for putting our main onto the task
 * queue, if main_running is false. It should be called only from a
 * interrupt or bottom half.
 */

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#include <linux/gfp.h>
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#include <linux/workqueue.h>
#include <linux/interrupt.h>

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static volatile int main_running;
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static DECLARE_WORK(NCR5380_tqueue, NCR5380_main);
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static inline void queue_main(void)
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{
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	if (!main_running) {
		/* If in interrupt and NCR5380_main() not already running,
		   queue it on the 'immediate' task queue, to be processed
		   immediately after the current interrupt processing has
		   finished. */
		schedule_work(&NCR5380_tqueue);
	}
	/* else: nothing to do: the running NCR5380_main() will pick up
	   any newly queued command. */
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}


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static inline void NCR5380_all_init(void)
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{
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	static int done = 0;
	if (!done) {
		INI_PRINTK("scsi : NCR5380_all_init()\n");
		done = 1;
	}
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}

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/*
 * Function : void NCR58380_print_options (struct Scsi_Host *instance)
 *
 * Purpose : called by probe code indicating the NCR5380 driver
 *	     options that were selected.
 *
 * Inputs : instance, pointer to this instance.  Unused.
 */

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static void __init NCR5380_print_options(struct Scsi_Host *instance)
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{
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	printk(" generic options"
#ifdef AUTOSENSE
	       " AUTOSENSE"
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#endif
#ifdef REAL_DMA
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	       " REAL DMA"
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#endif
#ifdef PARITY
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	       " PARITY"
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#endif
#ifdef SUPPORT_TAGS
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	       " SCSI-2 TAGGED QUEUING"
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#endif
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	       );
	printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
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}

/*
 * Function : void NCR5380_print_status (struct Scsi_Host *instance)
 *
 * Purpose : print commands in the various queues, called from
 *	NCR5380_abort and NCR5380_debug to aid debugging.
 *
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 * Inputs : instance, pointer to this instance.
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 */

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static void NCR5380_print_status(struct Scsi_Host *instance)
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{
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	char *pr_bfr;
	char *start;
	int len;

	NCR_PRINT(NDEBUG_ANY);
	NCR_PRINT_PHASE(NDEBUG_ANY);

	pr_bfr = (char *)__get_free_page(GFP_ATOMIC);
	if (!pr_bfr) {
		printk("NCR5380_print_status: no memory for print buffer\n");
		return;
	}
	len = NCR5380_proc_info(instance, pr_bfr, &start, 0, PAGE_SIZE, 0);
	pr_bfr[len] = 0;
	printk("\n%s\n", pr_bfr);
	free_page((unsigned long)pr_bfr);
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}


/******************************************/
/*
 * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
 *
 * *buffer: I/O buffer
 * **start: if inout == FALSE pointer into buffer where user read should start
 * offset: current offset
 * length: length of buffer
 * hostno: Scsi_Host host_no
 * inout: TRUE - user is writing; FALSE - user is reading
 *
 * Return the number of bytes read from or written
*/

#undef SPRINTF
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#define SPRINTF(fmt,args...)							\
	do {									\
		if (pos + strlen(fmt) + 20 /* slop */ < buffer + length)	\
			pos += sprintf(pos, fmt , ## args);			\
	} while(0)
static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length);

static int NCR5380_proc_info(struct Scsi_Host *instance, char *buffer,
			     char **start, off_t offset, int length, int inout)
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{
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	char *pos = buffer;
	struct NCR5380_hostdata *hostdata;
	Scsi_Cmnd *ptr;
	unsigned long flags;
	off_t begin = 0;
#define check_offset()					\
	do {						\
		if (pos - buffer < offset - begin) {	\
			begin += pos - buffer;		\
			pos = buffer;			\
		}					\
	} while (0)

	hostdata = (struct NCR5380_hostdata *)instance->hostdata;

	if (inout)			/* Has data been written to the file ? */
		return -ENOSYS;		/* Currently this is a no-op */
	SPRINTF("NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
	check_offset();
	local_irq_save(flags);
	SPRINTF("NCR5380: coroutine is%s running.\n",
		main_running ? "" : "n't");
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	check_offset();
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	if (!hostdata->connected)
		SPRINTF("scsi%d: no currently connected command\n", HOSTNO);
	else
		pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected,
				       pos, buffer, length);
	SPRINTF("scsi%d: issue_queue\n", HOSTNO);
	check_offset();
	for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr)) {
		pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
		check_offset();
	}
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	SPRINTF("scsi%d: disconnected_queue\n", HOSTNO);
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	check_offset();
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	for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
	     ptr = NEXT(ptr)) {
		pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
		check_offset();
	}
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	local_irq_restore(flags);
	*start = buffer + (offset - begin);
	if (pos - buffer < offset - begin)
		return 0;
	else if (pos - buffer - (offset - begin) < length)
		return pos - buffer - (offset - begin);
	return length;
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}

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static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length)
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{
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	int i, s;
	unsigned char *command;
	SPRINTF("scsi%d: destination target %d, lun %d\n",
		H_NO(cmd), cmd->device->id, cmd->device->lun);
	SPRINTF("        command = ");
	command = cmd->cmnd;
	SPRINTF("%2d (0x%02x)", command[0], command[0]);
	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
		SPRINTF(" %02x", command[i]);
	SPRINTF("\n");
	return pos;
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}


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/*
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 * Function : void NCR5380_init (struct Scsi_Host *instance)
 *
 * Purpose : initializes *instance and corresponding 5380 chip.
 *
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 * Inputs : instance - instantiation of the 5380 driver.
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 *
 * Notes : I assume that the host, hostno, and id bits have been
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 *	set correctly.  I don't care about the irq and other fields.
 *
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 */

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static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
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{
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	int i;
	SETUP_HOSTDATA(instance);

	NCR5380_all_init();

	hostdata->aborted = 0;
	hostdata->id_mask = 1 << instance->this_id;
	hostdata->id_higher_mask = 0;
	for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
		if (i > hostdata->id_mask)
			hostdata->id_higher_mask |= i;
	for (i = 0; i < 8; ++i)
		hostdata->busy[i] = 0;
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#ifdef SUPPORT_TAGS
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	init_tags();
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#endif
#if defined (REAL_DMA)
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	hostdata->dma_len = 0;
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#endif
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	hostdata->targets_present = 0;
	hostdata->connected = NULL;
	hostdata->issue_queue = NULL;
	hostdata->disconnected_queue = NULL;
	hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;

	if (!the_template) {
		the_template = instance->hostt;
		first_instance = instance;
	}
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#ifndef AUTOSENSE
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	if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
		printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
		       "        without AUTOSENSE option, contingent allegiance conditions may\n"
		       "        be incorrectly cleared.\n", HOSTNO);
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#endif /* def AUTOSENSE */

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	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(TARGET_COMMAND_REG, 0);
	NCR5380_write(SELECT_ENABLE_REG, 0);
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	return 0;
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}

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/*
 * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd,
 *	void (*done)(Scsi_Cmnd *))
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 *
 * Purpose :  enqueues a SCSI command
 *
 * Inputs : cmd - SCSI command, done - function called on completion, with
 *	a pointer to the command descriptor.
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 *
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 * Returns : 0
 *
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 * Side effects :
 *      cmd is added to the per instance issue_queue, with minor
 *	twiddling done to the host specific fields of cmd.  If the
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 *	main coroutine is not running, it is restarted.
 *
 */

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static int NCR5380_queue_command_lck(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
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{
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	SETUP_HOSTDATA(cmd->device->host);
	Scsi_Cmnd *tmp;
	unsigned long flags;
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#if (NDEBUG & NDEBUG_NO_WRITE)
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	switch (cmd->cmnd[0]) {
	case WRITE_6:
	case WRITE_10:
		printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
		       H_NO(cmd));
		cmd->result = (DID_ERROR << 16);
		done(cmd);
		return 0;
	}
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#endif /* (NDEBUG & NDEBUG_NO_WRITE) */

#ifdef NCR5380_STATS
# if 0
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	if (!hostdata->connected && !hostdata->issue_queue &&
	    !hostdata->disconnected_queue) {
		hostdata->timebase = jiffies;
	}
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# endif
# ifdef NCR5380_STAT_LIMIT
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	if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
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# endif
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		switch (cmd->cmnd[0]) {
		case WRITE:
		case WRITE_6:
		case WRITE_10:
			hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
946
			hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
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			hostdata->pendingw++;
			break;
		case READ:
		case READ_6:
		case READ_10:
			hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
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			hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
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			hostdata->pendingr++;
			break;
		}
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#endif

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	/*
	 * We use the host_scribble field as a pointer to the next command
	 * in a queue
	 */

964
	SET_NEXT(cmd, NULL);
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	cmd->scsi_done = done;

	cmd->result = 0;

	/*
	 * Insert the cmd into the issue queue. Note that REQUEST SENSE
	 * commands are added to the head of the queue since any command will
	 * clear the contingent allegiance condition that exists and the
	 * sense data is only guaranteed to be valid while the condition exists.
	 */

	local_irq_save(flags);
	/* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
	 * Otherwise a running NCR5380_main may steal the lock.
	 * Lock before actually inserting due to fairness reasons explained in
	 * atari_scsi.c. If we insert first, then it's impossible for this driver
	 * to release the lock.
	 * Stop timer for this command while waiting for the lock, or timeouts
	 * may happen (and they really do), and it's no good if the command doesn't
	 * appear in any of the queues.
	 * ++roman: Just disabling the NCR interrupt isn't sufficient here,
	 * because also a timer int can trigger an abort or reset, which would
	 * alter queues and touch the lock.
	 */
	if (!IS_A_TT()) {
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		/* perhaps stop command timer here */
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		falcon_get_lock();
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		/* perhaps restart command timer here */
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	}
	if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
		LIST(cmd, hostdata->issue_queue);
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		SET_NEXT(cmd, hostdata->issue_queue);
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		hostdata->issue_queue = cmd;
	} else {
		for (tmp = (Scsi_Cmnd *)hostdata->issue_queue;
		     NEXT(tmp); tmp = NEXT(tmp))
			;
		LIST(cmd, tmp);
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		SET_NEXT(tmp, cmd);
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	}
	local_irq_restore(flags);

	QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
		  (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");

	/* If queue_command() is called from an interrupt (real one or bottom
	 * half), we let queue_main() do the job of taking care about main. If it
	 * is already running, this is a no-op, else main will be queued.
	 *
	 * If we're not in an interrupt, we can call NCR5380_main()
	 * unconditionally, because it cannot be already running.
	 */
	if (in_interrupt() || ((flags >> 8) & 7) >= 6)
		queue_main();
	else
		NCR5380_main(NULL);
	return 0;
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}

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static DEF_SCSI_QCMD(NCR5380_queue_command)

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/*
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 * Function : NCR5380_main (void)
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 *
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 * Purpose : NCR5380_main is a coroutine that runs as long as more work can
 *	be done on the NCR5380 host adapters in a system.  Both
 *	NCR5380_queue_command() and NCR5380_intr() will try to start it
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 *	in case it is not running.
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 *
 * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should
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 *  reenable them.  This prevents reentrancy and kernel stack overflow.
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 */

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static void NCR5380_main(struct work_struct *work)
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{
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	Scsi_Cmnd *tmp, *prev;
	struct Scsi_Host *instance = first_instance;
	struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
	int done;
	unsigned long flags;

	/*
	 * We run (with interrupts disabled) until we're sure that none of
	 * the host adapters have anything that can be done, at which point
	 * we set main_running to 0 and exit.
	 *
	 * Interrupts are enabled before doing various other internal
	 * instructions, after we've decided that we need to run through
	 * the loop again.
	 *
	 * this should prevent any race conditions.
	 *
	 * ++roman: Just disabling the NCR interrupt isn't sufficient here,
	 * because also a timer int can trigger an abort or reset, which can
	 * alter queues and touch the Falcon lock.
	 */

	/* Tell int handlers main() is now already executing.  Note that
	   no races are possible here. If an int comes in before
	   'main_running' is set here, and queues/executes main via the
	   task queue, it doesn't do any harm, just this instance of main
	   won't find any work left to do. */
	if (main_running)
		return;
	main_running = 1;

	local_save_flags(flags);
	do {
		local_irq_disable();	/* Freeze request queues */
		done = 1;

		if (!hostdata->connected) {
			MAIN_PRINTK("scsi%d: not connected\n", HOSTNO);
			/*
			 * Search through the issue_queue for a command destined
			 * for a target that's not busy.
			 */
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#if (NDEBUG & NDEBUG_LISTS)
1083 1084 1085 1086 1087 1088 1089
			for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL;
			     tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
				;
			/*printk("%p  ", tmp);*/
			if ((tmp == prev) && tmp)
				printk(" LOOP\n");
			/* else printk("\n"); */
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#endif
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			for (tmp = (Scsi_Cmnd *) hostdata->issue_queue,
			     prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
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#if (NDEBUG & NDEBUG_LISTS)
1095 1096 1097 1098
				if (prev != tmp)
					printk("MAIN tmp=%p   target=%d   busy=%d lun=%d\n",
					       tmp, tmp->device->id, hostdata->busy[tmp->device->id],
					       tmp->device->lun);
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#endif
1100 1101 1102
				/*  When we find one, remove it from the issue queue. */
				/* ++guenther: possible race with Falcon locking */
				if (
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#ifdef SUPPORT_TAGS
1104
				    !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
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#else
1106
				    !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))
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#endif
1108 1109 1110 1111 1112
				    ) {
					/* ++guenther: just to be sure, this must be atomic */
					local_irq_disable();
					if (prev) {
						REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1113
						SET_NEXT(prev, NEXT(tmp));
1114 1115 1116 1117
					} else {
						REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
						hostdata->issue_queue = NEXT(tmp);
					}
1118
					SET_NEXT(tmp, NULL);
1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142
					falcon_dont_release++;

					/* reenable interrupts after finding one */
					local_irq_restore(flags);

					/*
					 * Attempt to establish an I_T_L nexus here.
					 * On success, instance->hostdata->connected is set.
					 * On failure, we must add the command back to the
					 *   issue queue so we can keep trying.
					 */
					MAIN_PRINTK("scsi%d: main(): command for target %d "
						    "lun %d removed from issue_queue\n",
						    HOSTNO, tmp->device->id, tmp->device->lun);
					/*
					 * REQUEST SENSE commands are issued without tagged
					 * queueing, even on SCSI-II devices because the
					 * contingent allegiance condition exists for the
					 * entire unit.
					 */
					/* ++roman: ...and the standard also requires that
					 * REQUEST SENSE command are untagged.
					 */

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#ifdef SUPPORT_TAGS
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					cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
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#endif
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					if (!NCR5380_select(instance, tmp,
					    (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE :
					    TAG_NEXT)) {
						falcon_dont_release--;
						/* release if target did not response! */
						falcon_release_lock_if_possible(hostdata);
						break;
					} else {
						local_irq_disable();
						LIST(tmp, hostdata->issue_queue);
1156
						SET_NEXT(tmp, hostdata->issue_queue);
1157
						hostdata->issue_queue = tmp;
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#ifdef SUPPORT_TAGS
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						cmd_free_tag(tmp);
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#endif
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						falcon_dont_release--;
						local_irq_restore(flags);
						MAIN_PRINTK("scsi%d: main(): select() failed, "
							    "returned to issue_queue\n", HOSTNO);
						if (hostdata->connected)
							break;
					}
				} /* if target/lun/target queue is not busy */
			} /* for issue_queue */
		} /* if (!hostdata->connected) */

		if (hostdata->connected
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#ifdef REAL_DMA
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		    && !hostdata->dma_len
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#endif
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		    ) {
			local_irq_restore(flags);
			MAIN_PRINTK("scsi%d: main: performing information transfer\n",
				    HOSTNO);
			NCR5380_information_transfer(instance);
			MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
			done = 0;
		}
	} while (!done);
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	/* Better allow ints _after_ 'main_running' has been cleared, else
	   an interrupt could believe we'll pick up the work it left for
	   us, but we won't see it anymore here... */
	main_running = 0;
	local_irq_restore(flags);
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}


#ifdef REAL_DMA
/*
 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
 *
 * Purpose : Called by interrupt handler when DMA finishes or a phase
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 *	mismatch occurs (which would finish the DMA transfer).
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 *
 * Inputs : instance - this instance of the NCR5380.
 *
 */

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static void NCR5380_dma_complete(struct Scsi_Host *instance)
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{
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	SETUP_HOSTDATA(instance);
	int transfered, saved_data = 0, overrun = 0, cnt, toPIO;
	unsigned char **data, p;
	volatile int *count;

	if (!hostdata->connected) {
		printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
		       "no connected cmd\n", HOSTNO);
		return;
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	}
1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261

	if (atari_read_overruns) {
		p = hostdata->connected->SCp.phase;
		if (p & SR_IO) {
			udelay(10);
			if ((NCR5380_read(BUS_AND_STATUS_REG) &
			     (BASR_PHASE_MATCH|BASR_ACK)) ==
			    (BASR_PHASE_MATCH|BASR_ACK)) {
				saved_data = NCR5380_read(INPUT_DATA_REG);
				overrun = 1;
				DMA_PRINTK("scsi%d: read overrun handled\n", HOSTNO);
			}
		}
	}

	DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
		   HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
		   NCR5380_read(STATUS_REG));

	(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

	transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
	hostdata->dma_len = 0;

	data = (unsigned char **)&hostdata->connected->SCp.ptr;
	count = &hostdata->connected->SCp.this_residual;
	*data += transfered;
	*count -= transfered;

	if (atari_read_overruns) {
		if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
			cnt = toPIO = atari_read_overruns;
			if (overrun) {
				DMA_PRINTK("Got an input overrun, using saved byte\n");
				*(*data)++ = saved_data;
				(*count)--;
				cnt--;
				toPIO--;
			}
			DMA_PRINTK("Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
			NCR5380_transfer_pio(instance, &p, &cnt, data);
			*count -= toPIO - cnt;
		}
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	}
}
#endif /* REAL_DMA */


/*
 * Function : void NCR5380_intr (int irq)
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 *
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 * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
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 *	from the disconnected queue, and restarting NCR5380_main()
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 *	as required.
 *
 * Inputs : int irq, irq that caused this interrupt.
 *
 */

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static irqreturn_t NCR5380_intr(int irq, void *dev_id)
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{
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	struct Scsi_Host *instance = first_instance;
	int done = 1, handled = 0;
	unsigned char basr;

	INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);

	/* Look for pending interrupts */
	basr = NCR5380_read(BUS_AND_STATUS_REG);
	INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
	/* dispatch to appropriate routine if found and done=0 */
	if (basr & BASR_IRQ) {
		NCR_PRINT(NDEBUG_INTR);
		if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
			done = 0;
			ENABLE_IRQ();
			INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
			NCR5380_reselect(instance);
			(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
		} else if (basr & BASR_PARITY_ERROR) {
			INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
			(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
		} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
			INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
			(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
		} else {
			/*
			 * The rest of the interrupt conditions can occur only during a
			 * DMA transfer
			 */
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#if defined(REAL_DMA)
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			/*
			 * We should only get PHASE MISMATCH and EOP interrupts if we have
			 * DMA enabled, so do a sanity check based on the current setting
			 * of the MODE register.
			 */

			if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
			    ((basr & BASR_END_DMA_TRANSFER) ||
			     !(basr & BASR_PHASE_MATCH))) {

				INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
				NCR5380_dma_complete( instance );
				done = 0;
				ENABLE_IRQ();
			} else
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#endif /* REAL_DMA */
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			{
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/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
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				if (basr & BASR_PHASE_MATCH)
					printk(KERN_NOTICE "scsi%d: unknown interrupt, "
					       "BASR 0x%x, MR 0x%x, SR 0x%x\n",
					       HOSTNO, basr, NCR5380_read(MODE_REG),
					       NCR5380_read(STATUS_REG));
				(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
			}
		} /* if !(SELECTION || PARITY) */
		handled = 1;
	} /* BASR & IRQ */ else {
		printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
		       "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
		       NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
		(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	}

	if (!done) {
		INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
		/* Put a call to NCR5380_main() on the queue... */
		queue_main();
	}
	return IRQ_RETVAL(handled);
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}

#ifdef NCR5380_STATS
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static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd *cmd)
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{
# ifdef NCR5380_STAT_LIMIT
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	if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
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# endif
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		switch (cmd->cmnd[0]) {
		case WRITE:
		case WRITE_6:
		case WRITE_10:
			hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
1364
			/*hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);*/
1365 1366 1367 1368 1369 1370
			hostdata->pendingw--;
			break;
		case READ:
		case READ_6:
		case READ_10:
			hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
1371
			/*hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);*/
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			hostdata->pendingr--;
			break;
		}
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}
#endif

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/*
 * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
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 *	int tag);
 *
 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1383 1384
 *	including ARBITRATION, SELECTION, and initial message out for
 *	IDENTIFY and queue messages.
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 *
1386 1387 1388
 * Inputs : instance - instantiation of the 5380 driver on which this
 *	target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
 *	new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
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 *	the command that is presently connected.
1390
 *
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 * Returns : -1 if selection could not execute for some reason,
1392 1393
 *	0 if selection succeeded or failed because the target
 *	did not respond.
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 *
1395 1396
 * Side effects :
 *	If bus busy, arbitration failed, etc, NCR5380_select() will exit
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 *		with registers as they should have been on entry - ie
 *		SELECT_ENABLE will be set appropriately, the NCR5380
 *		will cease to drive any SCSI bus signals.
 *
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 *	If successful : I_T_L or I_T_L_Q nexus will be established,
 *		instance->connected will be set to cmd.
 *		SELECT interrupt will be disabled.
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 *
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 *	If failed (no target) : cmd->scsi_done() will be called, and the
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 *		cmd->result host byte set to DID_BAD_TARGET.
 */

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static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag)
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{
1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433
	SETUP_HOSTDATA(instance);
	unsigned char tmp[3], phase;
	unsigned char *data;
	int len;
	unsigned long timeout;
	unsigned long flags;

	hostdata->restart_select = 0;
	NCR_PRINT(NDEBUG_ARBITRATION);
	ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
		   instance->this_id);

	/*
	 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
	 * data bus during SELECTION.
	 */

	local_irq_save(flags);
	if (hostdata->connected) {
		local_irq_restore(flags);
		return -1;
	}
	NCR5380_write(TARGET_COMMAND_REG, 0);
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	/*
	 * Start arbitration.
	 */
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	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
	NCR5380_write(MODE_REG, MR_ARBITRATE);
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	local_irq_restore(flags);
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	/* Wait for arbitration logic to complete */
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#if defined(NCR_TIMEOUT)
1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458
	{
		unsigned long timeout = jiffies + 2*NCR_TIMEOUT;

		while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
		       time_before(jiffies, timeout) && !hostdata->connected)
			;
		if (time_after_eq(jiffies, timeout)) {
			printk("scsi : arbitration timeout at %d\n", __LINE__);
			NCR5380_write(MODE_REG, MR_BASE);
			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
			return -1;
		}
	}
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#else /* NCR_TIMEOUT */
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	while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
	       !hostdata->connected)
		;
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#endif

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	ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);

	if (hostdata->connected) {
		NCR5380_write(MODE_REG, MR_BASE);
		return -1;
	}
	/*
	 * The arbitration delay is 2.2us, but this is a minimum and there is
	 * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
	 * the integral nature of udelay().
	 *
	 */

	udelay(3);

	/* Check for lost arbitration */
	if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
	    (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
	    hostdata->connected) {
		NCR5380_write(MODE_REG, MR_BASE);
		ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
			   HOSTNO);
		return -1;
	}
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	/* after/during arbitration, BSY should be asserted.
	   IBM DPES-31080 Version S31Q works now */
	/* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
	NCR5380_write(INITIATOR_COMMAND_REG,
		      ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);

	if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
	    hostdata->connected) {
		NCR5380_write(MODE_REG, MR_BASE);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
			   HOSTNO);
		return -1;
	}

	/*
	 * Again, bus clear + bus settle time is 1.2us, however, this is
	 * a minimum so we'll udelay ceil(1.2)
	 */
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#ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
1512 1513
	/* ++roman: But some targets (see above :-) seem to need a bit more... */
	udelay(15);
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#else
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	udelay(2);
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#endif
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	if (hostdata->connected) {
		NCR5380_write(MODE_REG, MR_BASE);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		return -1;
	}

	ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);

	/*
	 * Now that we have won arbitration, start Selection process, asserting
	 * the host and target ID's on the SCSI bus.
	 */

	NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));

	/*
	 * Raise ATN while SEL is true before BSY goes false from arbitration,
	 * since this is the only way to guarantee that we'll get a MESSAGE OUT
	 * phase immediately after selection.
	 */

	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
		      ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
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	NCR5380_write(MODE_REG, MR_BASE);

1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553
	/*
	 * Reselect interrupts must be turned off prior to the dropping of BSY,
	 * otherwise we will trigger an interrupt.
	 */

	if (hostdata->connected) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		return -1;
	}

	NCR5380_write(SELECT_ENABLE_REG, 0);
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	/*
	 * The initiator shall then wait at least two deskew delays and release
	 * the BSY signal.
	 */
	udelay(1);        /* wingel -- wait two bus deskew delay >2*45ns */

	/* Reset BSY */
	NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
		      ICR_ASSERT_ATN | ICR_ASSERT_SEL));

	/*
	 * Something weird happens when we cease to drive BSY - looks
	 * like the board/chip is letting us do another read before the
	 * appropriate propagation delay has expired, and we're confusing
	 * a BSY signal from ourselves as the target's response to SELECTION.
	 *
	 * A small delay (the 'C++' frontend breaks the pipeline with an
	 * unnecessary jump, making it work on my 386-33/Trantor T128, the
	 * tighter 'C' code breaks and requires this) solves the problem -
	 * the 1 us delay is arbitrary, and only used because this delay will
	 * be the same on other platforms and since it works here, it should
	 * work there.
	 *
	 * wingel suggests that this could be due to failing to wait
	 * one deskew delay.
	 */
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1582
	udelay(1);
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1584
	SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
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1586 1587 1588 1589
	/*
	 * The SCSI specification calls for a 250 ms timeout for the actual
	 * selection.
	 */
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1591
	timeout = jiffies + 25;
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1593 1594 1595 1596 1597
	/*
	 * XXX very interesting - we're seeing a bounce where the BSY we
	 * asserted is being reflected / still asserted (propagation delay?)
	 * and it's detecting as true.  Sigh.
	 */
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#if 0
1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618
	/* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
	 * IO while SEL is true. But again, there are some disks out the in the
	 * world that do that nevertheless. (Somebody claimed that this announces
	 * reselection capability of the target.) So we better skip that test and
	 * only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
	 */

	while (time_before(jiffies, timeout) &&
	       !(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
		;

	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		NCR5380_reselect(instance);
		printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
		       HOSTNO);
		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		return -1;
	}
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#else
1620 1621
	while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
		;
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#endif

1624 1625 1626 1627 1628
	/*
	 * No less than two deskew delays after the initiator detects the
	 * BSY signal is true, it shall release the SEL signal and may
	 * change the DATA BUS.                                     -wingel
	 */
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1630
	udelay(1);
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1632
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
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1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644
	if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		if (hostdata->targets_present & (1 << cmd->device->id)) {
			printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
			if (hostdata->restart_select)
				printk(KERN_NOTICE "\trestart select\n");
			NCR_PRINT(NDEBUG_ANY);
			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
			return -1;
		}
		cmd->result = DID_BAD_TARGET << 16;
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#ifdef NCR5380_STATS
1646
		collect_stats(hostdata, cmd);
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#endif
#ifdef SUPPORT_TAGS
1649
		cmd_free_tag(cmd);
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#endif
1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681
		cmd->scsi_done(cmd);
		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		return 0;
	}

	hostdata->targets_present |= (1 << cmd->device->id);

	/*
	 * Since we followed the SCSI spec, and raised ATN while SEL
	 * was true but before BSY was false during selection, the information
	 * transfer phase should be a MESSAGE OUT phase so that we can send the
	 * IDENTIFY message.
	 *
	 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
	 * message (2 bytes) with a tag ID that we increment with every command
	 * until it wraps back to 0.
	 *
	 * XXX - it turns out that there are some broken SCSI-II devices,
	 *	     which claim to support tagged queuing but fail when more than
	 *	     some number of commands are issued at once.
	 */

	/* Wait for start of REQ/ACK handshake */
	while (!(NCR5380_read(STATUS_REG) & SR_REQ))
		;

	SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
		   HOSTNO, cmd->device->id);
	tmp[0] = IDENTIFY(1, cmd->device->lun);
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#ifdef SUPPORT_TAGS
1684 1685 1686 1687 1688 1689
	if (cmd->tag != TAG_NONE) {
		tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
		tmp[2] = cmd->tag;
		len = 3;
	} else
		len = 1;
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#else
1691 1692
	len = 1;
	cmd->tag = 0;
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#endif /* SUPPORT_TAGS */

1695 1696 1697 1698 1699 1700 1701
	/* Send message(s) */
	data = tmp;
	phase = PHASE_MSGOUT;
	NCR5380_transfer_pio(instance, &phase, &len, &data);
	SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
	/* XXX need to handle errors here */
	hostdata->connected = cmd;
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#ifndef SUPPORT_TAGS
1703 1704
	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
#endif
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1706
	initialize_SCp(cmd);
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1708
	return 0;
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}

1711 1712
/*
 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
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 *      unsigned char *phase, int *count, unsigned char **data)
 *
 * Purpose : transfers data in given phase using polled I/O
 *
1717 1718
 * Inputs : instance - instance of driver, *phase - pointer to
 *	what phase is expected, *count - pointer to number of
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 *	bytes to transfer, **data - pointer to data pointer.
1720
 *
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 * Returns : -1 when different phase is entered without transferring
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 *	maximum number of bytes, 0 if all bytes are transferred or exit
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 *	is in same phase.
 *
1725
 *	Also, *phase, *count, *data are modified in place.
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 *
 * XXX Note : handling for bus free may be useful.
 */

/*
1731
 * Note : this code is not as quick as it could be, however it
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 * IS 100% reliable, and for the actual data transfer where speed
 * counts, we will always do a pseudo DMA or DMA transfer.
 */

1736 1737 1738
static int NCR5380_transfer_pio(struct Scsi_Host *instance,
				unsigned char *phase, int *count,
				unsigned char **data)
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{
1740 1741 1742 1743 1744 1745 1746 1747
	register unsigned char p = *phase, tmp;
	register int c = *count;
	register unsigned char *d = *data;

	/*
	 * The NCR5380 chip will only drive the SCSI bus when the
	 * phase specified in the appropriate bits of the TARGET COMMAND
	 * REGISTER match the STATUS REGISTER
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	 */

1750
	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
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1752 1753 1754 1755 1756 1757 1758
	do {
		/*
		 * Wait for assertion of REQ, after which the phase bits will be
		 * valid
		 */
		while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
			;
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1760
		HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);
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1762 1763 1764 1765 1766 1767
		/* Check for phase mismatch */
		if ((tmp & PHASE_MASK) != p) {
			PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
			NCR_PRINT_PHASE(NDEBUG_PIO);
			break;
		}
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1769 1770 1771 1772 1773
		/* Do actual transfer from SCSI bus to / from memory */
		if (!(p & SR_IO))
			NCR5380_write(OUTPUT_DATA_REG, *d);
		else
			*d = NCR5380_read(CURRENT_SCSI_DATA_REG);
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1775
		++d;
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1777 1778 1779 1780 1781 1782
		/*
		 * The SCSI standard suggests that in MSGOUT phase, the initiator
		 * should drop ATN on the last byte of the message phase
		 * after REQ has been asserted for the handshake but before
		 * the initiator raises ACK.
		 */
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1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800
		if (!(p & SR_IO)) {
			if (!((p & SR_MSG) && c > 1)) {
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
				NCR_PRINT(NDEBUG_PIO);
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
					      ICR_ASSERT_DATA | ICR_ASSERT_ACK);
			} else {
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
					      ICR_ASSERT_DATA | ICR_ASSERT_ATN);
				NCR_PRINT(NDEBUG_PIO);
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
					      ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
			}
		} else {
			NCR_PRINT(NDEBUG_PIO);
			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
		}
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1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843
		while (NCR5380_read(STATUS_REG) & SR_REQ)
			;

		HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);

		/*
		 * We have several special cases to consider during REQ/ACK handshaking :
		 * 1.  We were in MSGOUT phase, and we are on the last byte of the
		 *	message.  ATN must be dropped as ACK is dropped.
		 *
		 * 2.  We are in a MSGIN phase, and we are on the last byte of the
		 *	message.  We must exit with ACK asserted, so that the calling
		 *	code may raise ATN before dropping ACK to reject the message.
		 *
		 * 3.  ACK and ATN are clear and the target may proceed as normal.
		 */
		if (!(p == PHASE_MSGIN && c == 1)) {
			if (p == PHASE_MSGOUT && c > 1)
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
			else
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		}
	} while (--c);

	PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, c);

	*count = c;
	*data = d;
	tmp = NCR5380_read(STATUS_REG);
	/* The phase read from the bus is valid if either REQ is (already)
	 * asserted or if ACK hasn't been released yet. The latter is the case if
	 * we're in MSGIN and all wanted bytes have been received.
	 */
	if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
		*phase = tmp & PHASE_MASK;
	else
		*phase = PHASE_UNKNOWN;

	if (!c || (*phase == p))
		return 0;
	else
		return -1;
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}

/*
 * Function : do_abort (Scsi_Host *host)
1848 1849 1850 1851
 *
 * Purpose : abort the currently established nexus.  Should only be
 *	called from a routine which can drop into a
 *
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 * Returns : 0 on success, -1 on failure.
 */

1855
static int do_abort(struct Scsi_Host *host)
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{
1857 1858 1859 1860
	unsigned char tmp, *msgptr, phase;
	int len;

	/* Request message out phase */
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	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872

	/*
	 * Wait for the target to indicate a valid phase by asserting
	 * REQ.  Once this happens, we'll have either a MSGOUT phase
	 * and can immediately send the ABORT message, or we'll have some
	 * other phase and will have to source/sink data.
	 *
	 * We really don't care what value was on the bus or what value
	 * the target sees, so we just handshake.
	 */

1873
	while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897
		;

	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));

	if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
			      ICR_ASSERT_ACK);
		while (NCR5380_read(STATUS_REG) & SR_REQ)
			;
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
	}

	tmp = ABORT;
	msgptr = &tmp;
	len = 1;
	phase = PHASE_MSGOUT;
	NCR5380_transfer_pio(host, &phase, &len, &msgptr);

	/*
	 * If we got here, and the command completed successfully,
	 * we're about to go into bus free state.
	 */

	return len ? -1 : 0;
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}

#if defined(REAL_DMA)
1901 1902
/*
 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
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 *      unsigned char *phase, int *count, unsigned char **data)
 *
 * Purpose : transfers data in given phase using either real
 *	or pseudo DMA.
 *
1908 1909
 * Inputs : instance - instance of driver, *phase - pointer to
 *	what phase is expected, *count - pointer to number of
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 *	bytes to transfer, **data - pointer to data pointer.
1911
 *
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 * Returns : -1 when different phase is entered without transferring
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 *	maximum number of bytes, 0 if all bytes or transferred or exit
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 *	is in same phase.
 *
1916
 *	Also, *phase, *count, *data are modified in place.
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 *
 */


1921 1922 1923
static int NCR5380_transfer_dma(struct Scsi_Host *instance,
				unsigned char *phase, int *count,
				unsigned char **data)
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{
1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
	SETUP_HOSTDATA(instance);
	register int c = *count;
	register unsigned char p = *phase;
	register unsigned char *d = *data;
	unsigned char tmp;
	unsigned long flags;

	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
		*phase = tmp;
		return -1;
	}
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1937 1938
	if (atari_read_overruns && (p & SR_IO))
		c -= atari_read_overruns;
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1940 1941 1942
	DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
		   HOSTNO, (p & SR_IO) ? "reading" : "writing",
		   c, (p & SR_IO) ? "to" : "from", d);
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1943

1944
	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
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#ifdef REAL_DMA
1947
	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
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#endif /* def REAL_DMA  */

1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978
	if (IS_A_TT()) {
		/* On the Medusa, it is a must to initialize the DMA before
		 * starting the NCR. This is also the cleaner way for the TT.
		 */
		local_irq_save(flags);
		hostdata->dma_len = (p & SR_IO) ?
			NCR5380_dma_read_setup(instance, d, c) :
			NCR5380_dma_write_setup(instance, d, c);
		local_irq_restore(flags);
	}

	if (p & SR_IO)
		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
	else {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
		NCR5380_write(START_DMA_SEND_REG, 0);
	}

	if (!IS_A_TT()) {
		/* On the Falcon, the DMA setup must be done after the last */
		/* NCR access, else the DMA setup gets trashed!
		 */
		local_irq_save(flags);
		hostdata->dma_len = (p & SR_IO) ?
			NCR5380_dma_read_setup(instance, d, c) :
			NCR5380_dma_write_setup(instance, d, c);
		local_irq_restore(flags);
	}
	return 0;
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}
#endif /* defined(REAL_DMA) */

/*
 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
 *
1985 1986
 * Purpose : run through the various SCSI phases and do as the target
 *	directs us to.  Operates on the currently connected command,
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 *	instance->connected.
 *
 * Inputs : instance, instance for which we are doing commands
 *
1991
 * Side effects : SCSI things happen, the disconnected queue will be
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 *	modified if a command disconnects, *instance->connected will
 *	change.
 *
1995 1996
 * XXX Note : we need to watch for bus free or a reset condition here
 *	to recover from an unexpected bus free condition.
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 */
1998 1999

static void NCR5380_information_transfer(struct Scsi_Host *instance)
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{
2001 2002 2003 2004 2005
	SETUP_HOSTDATA(instance);
	unsigned long flags;
	unsigned char msgout = NOP;
	int sink = 0;
	int len;
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#if defined(REAL_DMA)
2007
	int transfersize;
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#endif
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
	unsigned char *data;
	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
	Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;

	while (1) {
		tmp = NCR5380_read(STATUS_REG);
		/* We only have a valid SCSI phase when REQ is asserted */
		if (tmp & SR_REQ) {
			phase = (tmp & PHASE_MASK);
			if (phase != old_phase) {
				old_phase = phase;
				NCR_PRINT_PHASE(NDEBUG_INFORMATION);
			}
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2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037
			if (sink && (phase != PHASE_MSGOUT)) {
				NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));

				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
					      ICR_ASSERT_ACK);
				while (NCR5380_read(STATUS_REG) & SR_REQ)
					;
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
					      ICR_ASSERT_ATN);
				sink = 0;
				continue;
			}

			switch (phase) {
			case PHASE_DATAOUT:
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#if (NDEBUG & NDEBUG_NO_DATAOUT)
2039 2040 2041 2042 2043
				printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
				       "aborted\n", HOSTNO);
				sink = 1;
				do_abort(instance);
				cmd->result = DID_ERROR << 16;
2044
				cmd->scsi_done(cmd);
2045
				return;
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#endif
2047 2048 2049 2050 2051 2052 2053 2054 2055 2056
			case PHASE_DATAIN:
				/*
				 * If there is no room left in the current buffer in the
				 * scatter-gather list, move onto the next one.
				 */

				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
					++cmd->SCp.buffer;
					--cmd->SCp.buffers_residual;
					cmd->SCp.this_residual = cmd->SCp.buffer->length;
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					cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080
					/* ++roman: Try to merge some scatter-buffers if
					 * they are at contiguous physical addresses.
					 */
					merge_contiguous_buffers(cmd);
					INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
						   HOSTNO, cmd->SCp.this_residual,
						   cmd->SCp.buffers_residual);
				}

				/*
				 * The preferred transfer method is going to be
				 * PSEUDO-DMA for systems that are strictly PIO,
				 * since we can let the hardware do the handshaking.
				 *
				 * For this to work, we need to know the transfersize
				 * ahead of time, since the pseudo-DMA code will sit
				 * in an unconditional loop.
				 */

				/* ++roman: I suggest, this should be
				 *   #if def(REAL_DMA)
				 * instead of leaving REAL_DMA out.
				 */
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#if defined(REAL_DMA)
2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101
				if (!cmd->device->borken &&
				    (transfersize = NCR5380_dma_xfer_len(instance,cmd,phase)) > 31) {
					len = transfersize;
					cmd->SCp.phase = phase;
					if (NCR5380_transfer_dma(instance, &phase,
					    &len, (unsigned char **)&cmd->SCp.ptr)) {
						/*
						 * If the watchdog timer fires, all future
						 * accesses to this device will use the
						 * polled-IO. */
						printk(KERN_NOTICE "scsi%d: switching target %d "
							   "lun %d to slow handshake\n", HOSTNO,
							   cmd->device->id, cmd->device->lun);
						cmd->device->borken = 1;
						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
							ICR_ASSERT_ATN);
						sink = 1;
						do_abort(instance);
						cmd->result = DID_ERROR << 16;
2102
						cmd->scsi_done(cmd);
2103 2104
						/* XXX - need to source or sink data here, as appropriate */
					} else {
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#ifdef REAL_DMA
2106 2107 2108 2109 2110 2111 2112 2113
						/* ++roman: When using real DMA,
						 * information_transfer() should return after
						 * starting DMA since it has nothing more to
						 * do.
						 */
						return;
#else
						cmd->SCp.this_residual -= transfersize - len;
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#endif
2115 2116
					}
				} else
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#endif /* defined(REAL_DMA) */
2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139
					NCR5380_transfer_pio(instance, &phase,
							     (int *)&cmd->SCp.this_residual,
							     (unsigned char **)&cmd->SCp.ptr);
				break;
			case PHASE_MSGIN:
				len = 1;
				data = &tmp;
				NCR5380_write(SELECT_ENABLE_REG, 0);	/* disable reselects */
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				cmd->SCp.Message = tmp;

				switch (tmp) {
				/*
				 * Linking lets us reduce the time required to get the
				 * next command out to the device, hopefully this will
				 * mean we don't waste another revolution due to the delays
				 * required by ARBITRATION and another SELECTION.
				 *
				 * In the current implementation proposal, low level drivers
				 * merely have to start the next command, pointed to by
				 * next_link, done() is called as with unlinked commands.
				 */
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#ifdef LINKED
2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173
				case LINKED_CMD_COMPLETE:
				case LINKED_FLG_CMD_COMPLETE:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

					LNK_PRINTK("scsi%d: target %d lun %d linked command "
						   "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);

					/* Enable reselect interrupts */
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
					/*
					 * Sanity check : A linked command should only terminate
					 * with one of these messages if there are more linked
					 * commands available.
					 */

					if (!cmd->next_link) {
						 printk(KERN_NOTICE "scsi%d: target %d lun %d "
							"linked command complete, no next_link\n",
							HOSTNO, cmd->device->id, cmd->device->lun);
						sink = 1;
						do_abort(instance);
						return;
					}

					initialize_SCp(cmd->next_link);
					/* The next command is still part of this process; copy it
					 * and don't free it! */
					cmd->next_link->tag = cmd->tag;
					cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
					LNK_PRINTK("scsi%d: target %d lun %d linked request "
						   "done, calling scsi_done().\n",
						   HOSTNO, cmd->device->id, cmd->device->lun);
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#ifdef NCR5380_STATS
2175
					collect_stats(hostdata, cmd);
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#endif
2177 2178 2179
					cmd->scsi_done(cmd);
					cmd = hostdata->connected;
					break;
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#endif /* def LINKED */
2181 2182 2183 2184 2185 2186 2187 2188 2189
				case ABORT:
				case COMMAND_COMPLETE:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					/* ++guenther: possible race with Falcon locking */
					falcon_dont_release++;
					hostdata->connected = NULL;
					QU_PRINTK("scsi%d: command for target %d, lun %d "
						  "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
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#ifdef SUPPORT_TAGS
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					cmd_free_tag(cmd);
					if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
						/* Turn a QUEUE FULL status into BUSY, I think the
						 * mid level cannot handle QUEUE FULL :-( (The
						 * command is retried after BUSY). Also update our
						 * queue size to the number of currently issued
						 * commands now.
						 */
						/* ++Andreas: the mid level code knows about
						   QUEUE_FULL now. */
						TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
						TAG_PRINTK("scsi%d: target %d lun %d returned "
							   "QUEUE_FULL after %d commands\n",
							   HOSTNO, cmd->device->id, cmd->device->lun,
							   ta->nr_allocated);
						if (ta->queue_size > ta->nr_allocated)
							ta->nr_allocated = ta->queue_size;
					}
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#else
2210
					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
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#endif
2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234
					/* Enable reselect interrupts */
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);

					/*
					 * I'm not sure what the correct thing to do here is :
					 *
					 * If the command that just executed is NOT a request
					 * sense, the obvious thing to do is to set the result
					 * code to the values of the stored parameters.
					 *
					 * If it was a REQUEST SENSE command, we need some way to
					 * differentiate between the failure code of the original
					 * and the failure code of the REQUEST sense - the obvious
					 * case is success, where we fall through and leave the
					 * result code unchanged.
					 *
					 * The non-obvious place is where the REQUEST SENSE failed
					 */

					if (cmd->cmnd[0] != REQUEST_SENSE)
						cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
					else if (status_byte(cmd->SCp.Status) != GOOD)
						cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
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2236
#ifdef AUTOSENSE
2237 2238 2239 2240 2241 2242
					if ((cmd->cmnd[0] == REQUEST_SENSE) &&
						hostdata->ses.cmd_len) {
						scsi_eh_restore_cmnd(cmd, &hostdata->ses);
						hostdata->ses.cmd_len = 0 ;
					}

2243 2244
					if ((cmd->cmnd[0] != REQUEST_SENSE) &&
					    (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2245 2246
						scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);

2247 2248 2249 2250
						ASEN_PRINTK("scsi%d: performing request sense\n", HOSTNO);

						local_irq_save(flags);
						LIST(cmd,hostdata->issue_queue);
2251
						SET_NEXT(cmd, hostdata->issue_queue);
2252 2253 2254 2255 2256
						hostdata->issue_queue = (Scsi_Cmnd *) cmd;
						local_irq_restore(flags);
						QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
							  "issue queue\n", H_NO(cmd));
					} else
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#endif /* def AUTOSENSE */
2258
					{
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#ifdef NCR5380_STATS
2260
						collect_stats(hostdata, cmd);
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#endif
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						cmd->scsi_done(cmd);
					}

					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
					/*
					 * Restore phase bits to 0 so an interrupted selection,
					 * arbitration can resume.
					 */
					NCR5380_write(TARGET_COMMAND_REG, 0);

					while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
						barrier();

					falcon_dont_release--;
					/* ++roman: For Falcon SCSI, release the lock on the
					 * ST-DMA here if no other commands are waiting on the
					 * disconnected queue.
					 */
					falcon_release_lock_if_possible(hostdata);
					return;
				case MESSAGE_REJECT:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					/* Enable reselect interrupts */
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
					switch (hostdata->last_message) {
					case HEAD_OF_QUEUE_TAG:
					case ORDERED_QUEUE_TAG:
					case SIMPLE_QUEUE_TAG:
						/* The target obviously doesn't support tagged
						 * queuing, even though it announced this ability in
						 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
						 * clear 'tagged_supported' and lock the LUN, since
						 * the command is treated as untagged further on.
						 */
						cmd->device->tagged_supported = 0;
						hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
						cmd->tag = TAG_NONE;
						TAG_PRINTK("scsi%d: target %d lun %d rejected "
							   "QUEUE_TAG message; tagged queuing "
							   "disabled\n",
							   HOSTNO, cmd->device->id, cmd->device->lun);
						break;
					}
					break;
				case DISCONNECT:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					local_irq_save(flags);
					cmd->device->disconnect = 1;
					LIST(cmd,hostdata->disconnected_queue);
2313
					SET_NEXT(cmd, hostdata->disconnected_queue);
2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438
					hostdata->connected = NULL;
					hostdata->disconnected_queue = cmd;
					local_irq_restore(flags);
					QU_PRINTK("scsi%d: command for target %d lun %d was "
						  "moved from connected to the "
						  "disconnected_queue\n", HOSTNO,
						  cmd->device->id, cmd->device->lun);
					/*
					 * Restore phase bits to 0 so an interrupted selection,
					 * arbitration can resume.
					 */
					NCR5380_write(TARGET_COMMAND_REG, 0);

					/* Enable reselect interrupts */
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
					/* Wait for bus free to avoid nasty timeouts */
					while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
						barrier();
					return;
					/*
					 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
					 * operation, in violation of the SCSI spec so we can safely
					 * ignore SAVE/RESTORE pointers calls.
					 *
					 * Unfortunately, some disks violate the SCSI spec and
					 * don't issue the required SAVE_POINTERS message before
					 * disconnecting, and we have to break spec to remain
					 * compatible.
					 */
				case SAVE_POINTERS:
				case RESTORE_POINTERS:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					/* Enable reselect interrupts */
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
					break;
				case EXTENDED_MESSAGE:
					/*
					 * Extended messages are sent in the following format :
					 * Byte
					 * 0		EXTENDED_MESSAGE == 1
					 * 1		length (includes one byte for code, doesn't
					 *		include first two bytes)
					 * 2		code
					 * 3..length+1	arguments
					 *
					 * Start the extended message buffer with the EXTENDED_MESSAGE
					 * byte, since spi_print_msg() wants the whole thing.
					 */
					extended_msg[0] = EXTENDED_MESSAGE;
					/* Accept first byte by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

					EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);

					len = 2;
					data = extended_msg + 1;
					phase = PHASE_MSGIN;
					NCR5380_transfer_pio(instance, &phase, &len, &data);
					EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
						   (int)extended_msg[1], (int)extended_msg[2]);

					if (!len && extended_msg[1] <=
					    (sizeof(extended_msg) - 1)) {
						/* Accept third byte by clearing ACK */
						NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
						len = extended_msg[1] - 1;
						data = extended_msg + 3;
						phase = PHASE_MSGIN;

						NCR5380_transfer_pio(instance, &phase, &len, &data);
						EXT_PRINTK("scsi%d: message received, residual %d\n",
							   HOSTNO, len);

						switch (extended_msg[2]) {
						case EXTENDED_SDTR:
						case EXTENDED_WDTR:
						case EXTENDED_MODIFY_DATA_POINTER:
						case EXTENDED_EXTENDED_IDENTIFY:
							tmp = 0;
						}
					} else if (len) {
						printk(KERN_NOTICE "scsi%d: error receiving "
						       "extended message\n", HOSTNO);
						tmp = 0;
					} else {
						printk(KERN_NOTICE "scsi%d: extended message "
							   "code %02x length %d is too long\n",
							   HOSTNO, extended_msg[2], extended_msg[1]);
						tmp = 0;
					}
					/* Fall through to reject message */

					/*
					 * If we get something weird that we aren't expecting,
					 * reject it.
					 */
				default:
					if (!tmp) {
						printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
						spi_print_msg(extended_msg);
						printk("\n");
					} else if (tmp != EXTENDED_MESSAGE)
						printk(KERN_DEBUG "scsi%d: rejecting unknown "
						       "message %02x from target %d, lun %d\n",
						       HOSTNO, tmp, cmd->device->id, cmd->device->lun);
					else
						printk(KERN_DEBUG "scsi%d: rejecting unknown "
						       "extended message "
						       "code %02x, length %d from target %d, lun %d\n",
						       HOSTNO, extended_msg[1], extended_msg[0],
						       cmd->device->id, cmd->device->lun);


					msgout = MESSAGE_REJECT;
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
					break;
				} /* switch (tmp) */
				break;
			case PHASE_MSGOUT:
				len = 1;
				data = &msgout;
				hostdata->last_message = msgout;
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				if (msgout == ABORT) {
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#ifdef SUPPORT_TAGS
2440
					cmd_free_tag(cmd);
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2441
#else
2442
					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
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#endif
2444 2445
					hostdata->connected = NULL;
					cmd->result = DID_ERROR << 16;
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#ifdef NCR5380_STATS
2447
					collect_stats(hostdata, cmd);
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#endif
2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477
					cmd->scsi_done(cmd);
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
					falcon_release_lock_if_possible(hostdata);
					return;
				}
				msgout = NOP;
				break;
			case PHASE_CMDOUT:
				len = cmd->cmd_len;
				data = cmd->cmnd;
				/*
				 * XXX for performance reasons, on machines with a
				 * PSEUDO-DMA architecture we should probably
				 * use the dma transfer function.
				 */
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				break;
			case PHASE_STATIN:
				len = 1;
				data = &tmp;
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				cmd->SCp.Status = tmp;
				break;
			default:
				printk("scsi%d: unknown phase\n", HOSTNO);
				NCR_PRINT(NDEBUG_ANY);
			} /* switch(phase) */
		} /* if (tmp * SR_REQ) */
	} /* while (1) */
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}

/*
 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
 *
2483 2484
 * Purpose : does reselection, initializing the instance->connected
 *	field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
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 *	nexus has been reestablished,
2486
 *
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 * Inputs : instance - this instance of the NCR5380.
 *
 */


2492
static void NCR5380_reselect(struct Scsi_Host *instance)
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{
2494 2495 2496 2497
	SETUP_HOSTDATA(instance);
	unsigned char target_mask;
	unsigned char lun, phase;
	int len;
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#ifdef SUPPORT_TAGS
2499
	unsigned char tag;
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#endif
2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551
	unsigned char msg[3];
	unsigned char *data;
	Scsi_Cmnd *tmp = NULL, *prev;
/*	unsigned long flags; */

	/*
	 * Disable arbitration, etc. since the host adapter obviously
	 * lost, and tell an interrupted NCR5380_select() to restart.
	 */

	NCR5380_write(MODE_REG, MR_BASE);
	hostdata->restart_select = 1;

	target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);

	RSL_PRINTK("scsi%d: reselect\n", HOSTNO);

	/*
	 * At this point, we have detected that our SCSI ID is on the bus,
	 * SEL is true and BSY was false for at least one bus settle delay
	 * (400 ns).
	 *
	 * We must assert BSY ourselves, until the target drops the SEL
	 * signal.
	 */

	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);

	while (NCR5380_read(STATUS_REG) & SR_SEL)
		;
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

	/*
	 * Wait for target to go into MSGIN.
	 */

	while (!(NCR5380_read(STATUS_REG) & SR_REQ))
		;

	len = 1;
	data = msg;
	phase = PHASE_MSGIN;
	NCR5380_transfer_pio(instance, &phase, &len, &data);

	if (!(msg[0] & 0x80)) {
		printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
		spi_print_msg(msg);
		do_abort(instance);
		return;
	}
	lun = (msg[0] & 0x07);
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#ifdef SUPPORT_TAGS
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	/* If the phase is still MSGIN, the target wants to send some more
	 * messages. In case it supports tagged queuing, this is probably a
	 * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
	 */
	tag = TAG_NONE;
	if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
		/* Accept previous IDENTIFY message by clearing ACK */
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		len = 2;
		data = msg + 1;
		if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
		    msg[1] == SIMPLE_QUEUE_TAG)
			tag = msg[2];
		TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
			   "reselection\n", HOSTNO, target_mask, lun, tag);
	}
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#endif
2571 2572 2573 2574 2575 2576 2577 2578 2579

	/*
	 * Find the command corresponding to the I_T_L or I_T_L_Q  nexus we
	 * just reestablished, and remove it from the disconnected queue.
	 */

	for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL;
	     tmp; prev = tmp, tmp = NEXT(tmp)) {
		if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
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#ifdef SUPPORT_TAGS
2581
		    && (tag == tmp->tag)
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#endif
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		    ) {
			/* ++guenther: prevent race with falcon_release_lock */
			falcon_dont_release++;
			if (prev) {
				REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2588
				SET_NEXT(prev, NEXT(tmp));
2589 2590 2591 2592
			} else {
				REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
				hostdata->disconnected_queue = NEXT(tmp);
			}
2593
			SET_NEXT(tmp, NULL);
2594 2595
			break;
		}
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	}
2597 2598 2599

	if (!tmp) {
		printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
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#ifdef SUPPORT_TAGS
2601
		       "tag %d "
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#endif
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		       "not in disconnected_queue.\n",
		       HOSTNO, target_mask, lun
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#ifdef SUPPORT_TAGS
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		       , tag
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#endif
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			);
		/*
		 * Since we have an established nexus that we can't do anything
		 * with, we must abort it.
		 */
		do_abort(instance);
		return;
	}
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	/* Accept message by clearing ACK */
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
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2620 2621 2622 2623
	hostdata->connected = tmp;
	RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
		   HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
	falcon_dont_release--;
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}


/*
 * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
 *
 * Purpose : abort a command
 *
2632 2633
 * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
 *	host byte of the result field to, if zero DID_ABORTED is
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 *	used.
 *
 * Returns : 0 - success, -1 on failure.
 *
2638 2639
 * XXX - there is no way to abort the command that is currently
 *	 connected, you have to wait for it to complete.  If this is
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 *	 a problem, we could implement longjmp() / setjmp(), setjmp()
2641
 *	 called where the loop started in NCR5380_main().
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 */

static
2645
int NCR5380_abort(Scsi_Cmnd *cmd)
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{
2647 2648 2649 2650
	struct Scsi_Host *instance = cmd->device->host;
	SETUP_HOSTDATA(instance);
	Scsi_Cmnd *tmp, **prev;
	unsigned long flags;
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2652 2653
	printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
	scsi_print_command(cmd);
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2655 2656 2657
	NCR5380_print_status(instance);

	local_irq_save(flags);
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2659 2660 2661
	if (!IS_A_TT() && !falcon_got_lock)
		printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_abort\n",
		       HOSTNO);
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2663 2664 2665
	ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
		    NCR5380_read(BUS_AND_STATUS_REG),
		    NCR5380_read(STATUS_REG));
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#if 1
2668 2669 2670 2671 2672
	/*
	 * Case 1 : If the command is the currently executing command,
	 * we'll set the aborted flag and return control so that
	 * information transfer routine can exit cleanly.
	 */
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2674
	if (hostdata->connected == cmd) {
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2676 2677 2678 2679 2680
		ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
		/*
		 * We should perform BSY checking, and make sure we haven't slipped
		 * into BUS FREE.
		 */
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2682 2683 2684 2685 2686 2687
		/*	NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
		/*
		 * Since we can't change phases until we've completed the current
		 * handshake, we have to source or sink a byte of data if the current
		 * phase is not MSGOUT.
		 */
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2689 2690 2691 2692
		/*
		 * Return control to the executing NCR drive so we can clear the
		 * aborted flag and get back into our main loop.
		 */
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2694 2695 2696 2697
		if (do_abort(instance) == 0) {
			hostdata->aborted = 1;
			hostdata->connected = NULL;
			cmd->result = DID_ABORT << 16;
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#ifdef SUPPORT_TAGS
2699
			cmd_free_tag(cmd);
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#else
2701
			hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
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#endif
2703 2704 2705 2706 2707 2708 2709 2710 2711 2712
			local_irq_restore(flags);
			cmd->scsi_done(cmd);
			falcon_release_lock_if_possible(hostdata);
			return SCSI_ABORT_SUCCESS;
		} else {
/*			local_irq_restore(flags); */
			printk("scsi%d: abort of connected command failed!\n", HOSTNO);
			return SCSI_ABORT_ERROR;
		}
	}
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#endif

2715 2716 2717 2718 2719 2720 2721 2722 2723 2724
	/*
	 * Case 2 : If the command hasn't been issued yet, we simply remove it
	 *	    from the issue queue.
	 */
	for (prev = (Scsi_Cmnd **)&(hostdata->issue_queue),
	     tmp = (Scsi_Cmnd *)hostdata->issue_queue;
	     tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
		if (cmd == tmp) {
			REMOVE(5, *prev, tmp, NEXT(tmp));
			(*prev) = NEXT(tmp);
2725
			SET_NEXT(tmp, NULL);
2726 2727 2728 2729 2730 2731 2732 2733 2734 2735
			tmp->result = DID_ABORT << 16;
			local_irq_restore(flags);
			ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
				    HOSTNO);
			/* Tagged queuing note: no tag to free here, hasn't been assigned
			 * yet... */
			tmp->scsi_done(tmp);
			falcon_release_lock_if_possible(hostdata);
			return SCSI_ABORT_SUCCESS;
		}
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	}

2738 2739 2740 2741 2742 2743 2744 2745 2746 2747
	/*
	 * Case 3 : If any commands are connected, we're going to fail the abort
	 *	    and let the high level SCSI driver retry at a later time or
	 *	    issue a reset.
	 *
	 *	    Timeouts, and therefore aborted commands, will be highly unlikely
	 *          and handling them cleanly in this situation would make the common
	 *	    case of noresets less efficient, and would pollute our code.  So,
	 *	    we fail.
	 */
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2749 2750 2751 2752 2753
	if (hostdata->connected) {
		local_irq_restore(flags);
		ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
		return SCSI_ABORT_SNOOZE;
	}
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2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787
	/*
	 * Case 4: If the command is currently disconnected from the bus, and
	 *	there are no connected commands, we reconnect the I_T_L or
	 *	I_T_L_Q nexus associated with it, go into message out, and send
	 *      an abort message.
	 *
	 * This case is especially ugly. In order to reestablish the nexus, we
	 * need to call NCR5380_select().  The easiest way to implement this
	 * function was to abort if the bus was busy, and let the interrupt
	 * handler triggered on the SEL for reselect take care of lost arbitrations
	 * where necessary, meaning interrupts need to be enabled.
	 *
	 * When interrupts are enabled, the queues may change - so we
	 * can't remove it from the disconnected queue before selecting it
	 * because that could cause a failure in hashing the nexus if that
	 * device reselected.
	 *
	 * Since the queues may change, we can't use the pointers from when we
	 * first locate it.
	 *
	 * So, we must first locate the command, and if NCR5380_select()
	 * succeeds, then issue the abort, relocate the command and remove
	 * it from the disconnected queue.
	 */

	for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
	     tmp = NEXT(tmp)) {
		if (cmd == tmp) {
			local_irq_restore(flags);
			ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);

			if (NCR5380_select(instance, cmd, (int)cmd->tag))
				return SCSI_ABORT_BUSY;
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2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799
			ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);

			do_abort(instance);

			local_irq_save(flags);
			for (prev = (Scsi_Cmnd **)&(hostdata->disconnected_queue),
			     tmp = (Scsi_Cmnd *)hostdata->disconnected_queue;
			     tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
				if (cmd == tmp) {
					REMOVE(5, *prev, tmp, NEXT(tmp));
					*prev = NEXT(tmp);
2800
					SET_NEXT(tmp, NULL);
2801 2802 2803 2804 2805
					tmp->result = DID_ABORT << 16;
					/* We must unlock the tag/LUN immediately here, since the
					 * target goes to BUS FREE and doesn't send us another
					 * message (COMMAND_COMPLETE or the like)
					 */
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#ifdef SUPPORT_TAGS
2807
					cmd_free_tag(tmp);
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#else
2809
					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
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#endif
2811 2812 2813 2814 2815 2816
					local_irq_restore(flags);
					tmp->scsi_done(tmp);
					falcon_release_lock_if_possible(hostdata);
					return SCSI_ABORT_SUCCESS;
				}
			}
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		}
	}

2820 2821 2822 2823 2824 2825 2826 2827 2828
	/*
	 * Case 5 : If we reached this point, the command was not found in any of
	 *	    the queues.
	 *
	 * We probably reached this point because of an unlikely race condition
	 * between the command completing successfully and the abortion code,
	 * so we won't panic, but we will notify the user in case something really
	 * broke.
	 */
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2830
	local_irq_restore(flags);
2831
	printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
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2833 2834 2835 2836 2837
	/* Maybe it is sufficient just to release the ST-DMA lock... (if
	 * possible at all) At least, we should check if the lock could be
	 * released after the abort, in case it is kept due to some bug.
	 */
	falcon_release_lock_if_possible(hostdata);
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2839
	return SCSI_ABORT_NOT_RUNNING;
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}


2843
/*
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 * Function : int NCR5380_reset (Scsi_Cmnd *cmd)
2845
 *
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 * Purpose : reset the SCSI bus.
 *
 * Returns : SCSI_RESET_WAKEUP
 *
2850
 */
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2852
static int NCR5380_bus_reset(Scsi_Cmnd *cmd)
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{
2854 2855 2856
	SETUP_HOSTDATA(cmd->device->host);
	int i;
	unsigned long flags;
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#if 1
2858
	Scsi_Cmnd *connected, *disconnected_queue;
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#endif

2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896
	if (!IS_A_TT() && !falcon_got_lock)
		printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_reset\n",
		       H_NO(cmd));

	NCR5380_print_status(cmd->device->host);

	/* get in phase */
	NCR5380_write(TARGET_COMMAND_REG,
		      PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
	/* assert RST */
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
	udelay(40);
	/* reset NCR registers */
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(TARGET_COMMAND_REG, 0);
	NCR5380_write(SELECT_ENABLE_REG, 0);
	/* ++roman: reset interrupt condition! otherwise no interrupts don't get
	 * through anymore ... */
	(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);

#if 1	/* XXX Should now be done by midlevel code, but it's broken XXX */
	/* XXX see below                                            XXX */

	/* MSch: old-style reset: actually abort all command processing here */

	/* After the reset, there are no more connected or disconnected commands
	 * and no busy units; to avoid problems with re-inserting the commands
	 * into the issue_queue (via scsi_done()), the aborted commands are
	 * remembered in local variables first.
	 */
	local_irq_save(flags);
	connected = (Scsi_Cmnd *)hostdata->connected;
	hostdata->connected = NULL;
	disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
	hostdata->disconnected_queue = NULL;
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#ifdef SUPPORT_TAGS
2898
	free_all_tags();
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#endif
2900 2901
	for (i = 0; i < 8; ++i)
		hostdata->busy[i] = 0;
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#ifdef REAL_DMA
2903
	hostdata->dma_len = 0;
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2904
#endif
2905
	local_irq_restore(flags);
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2907 2908 2909 2910
	/* In order to tell the mid-level code which commands were aborted,
	 * set the command status to DID_RESET and call scsi_done() !!!
	 * This ultimately aborts processing of these commands in the mid-level.
	 */
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2912 2913 2914 2915 2916
	if ((cmd = connected)) {
		ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
		cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
		cmd->scsi_done(cmd);
	}
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2917

2918 2919
	for (i = 0; (cmd = disconnected_queue); ++i) {
		disconnected_queue = NEXT(cmd);
2920
		SET_NEXT(cmd, NULL);
2921 2922 2923 2924 2925
		cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
		cmd->scsi_done(cmd);
	}
	if (i > 0)
		ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);
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2926

2927 2928 2929 2930 2931 2932
	/* The Falcon lock should be released after a reset...
	 */
	/* ++guenther: moved to atari_scsi_reset(), to prevent a race between
	 * unlocking and enabling dma interrupt.
	 */
/*	falcon_release_lock_if_possible( hostdata );*/
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2933

2934 2935 2936 2937 2938
	/* since all commands have been explicitly terminated, we need to tell
	 * the midlevel code that the reset was SUCCESSFUL, and there is no
	 * need to 'wake up' the commands by a request_sense
	 */
	return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
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2939 2940
#else /* 1 */

2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974
	/* MSch: new-style reset handling: let the mid-level do what it can */

	/* ++guenther: MID-LEVEL IS STILL BROKEN.
	 * Mid-level is supposed to requeue all commands that were active on the
	 * various low-level queues. In fact it does this, but that's not enough
	 * because all these commands are subject to timeout. And if a timeout
	 * happens for any removed command, *_abort() is called but all queues
	 * are now empty. Abort then gives up the falcon lock, which is fatal,
	 * since the mid-level will queue more commands and must have the lock
	 * (it's all happening inside timer interrupt handler!!).
	 * Even worse, abort will return NOT_RUNNING for all those commands not
	 * on any queue, so they won't be retried ...
	 *
	 * Conclusion: either scsi.c disables timeout for all resetted commands
	 * immediately, or we lose!  As of linux-2.0.20 it doesn't.
	 */

	/* After the reset, there are no more connected or disconnected commands
	 * and no busy units; so clear the low-level status here to avoid
	 * conflicts when the mid-level code tries to wake up the affected
	 * commands!
	 */

	if (hostdata->issue_queue)
		ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
	if (hostdata->connected)
		ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
	if (hostdata->disconnected_queue)
		ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));

	local_irq_save(flags);
	hostdata->issue_queue = NULL;
	hostdata->connected = NULL;
	hostdata->disconnected_queue = NULL;
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2975
#ifdef SUPPORT_TAGS
2976
	free_all_tags();
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2977
#endif
2978 2979
	for (i = 0; i < 8; ++i)
		hostdata->busy[i] = 0;
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2980
#ifdef REAL_DMA
2981
	hostdata->dma_len = 0;
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2982
#endif
2983
	local_irq_restore(flags);
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2984

2985 2986
	/* we did no complete reset of all commands, so a wakeup is required */
	return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
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2987 2988
#endif /* 1 */
}