atari_NCR5380.c 91.3 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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 * 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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/* Adapted for the sun3 by Sam Creasey. */

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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
 *
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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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 * 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,
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 * which is started from a workqueue for each NCR5380 host in the
 * system.  It attempts to establish 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
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 * queue, and NCR5380_main tries to find more work.  If the target is
 * idle for too long, the system will try to sleep.
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 *
 * 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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 *
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 * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
 *	transceivers.
 *
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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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 *
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 * NCR5380_implementation_fields  - additional fields needed for this
 *      specific implementation of the NCR5380
 *
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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);
 *
 * 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,
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 * possible) function may be used.
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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)		((struct scsi_cmnd *)(cmd)->host_scribble)
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#define	SET_NEXT(cmd,next)	((cmd)->host_scribble = (void *)(next))
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#define	NEXTADDR(cmd)		((struct scsi_cmnd **)&(cmd)->host_scribble)
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#define	HOSTNO		instance->host_no
#define	H_NO(cmd)	(cmd)->device->host->host_no

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static int do_abort(struct Scsi_Host *);
static void do_reset(struct Scsi_Host *);

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#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.
 */

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static void __init init_tags(struct NCR5380_hostdata *hostdata)
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{
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	int target, lun;
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	struct tag_alloc *ta;
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	if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
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		return;

	for (target = 0; target < 8; ++target) {
		for (lun = 0; lun < 8; ++lun) {
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			ta = &hostdata->TagAlloc[target][lun];
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			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(struct scsi_cmnd *cmd, int should_be_tagged)
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{
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	u8 lun = cmd->device->lun;
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	SETUP_HOSTDATA(cmd->device->host);

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	if (hostdata->busy[cmd->device->id] & (1 << lun))
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		return 1;
	if (!should_be_tagged ||
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	    !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
	    !cmd->device->tagged_supported)
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		return 0;
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	if (hostdata->TagAlloc[scmd_id(cmd)][lun].nr_allocated >=
	    hostdata->TagAlloc[scmd_id(cmd)][lun].queue_size) {
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		dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d: no free tags\n",
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			   H_NO(cmd), cmd->device->id, lun);
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		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(struct scsi_cmnd *cmd, int should_be_tagged)
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{
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	u8 lun = cmd->device->lun;
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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 ||
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	    !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
	    !cmd->device->tagged_supported) {
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		cmd->tag = TAG_NONE;
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		hostdata->busy[cmd->device->id] |= (1 << lun);
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		dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %d now allocated by untagged "
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			   "command\n", H_NO(cmd), cmd->device->id, lun);
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	} else {
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		struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
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		cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
		set_bit(cmd->tag, ta->allocated);
		ta->nr_allocated++;
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		dprintk(NDEBUG_TAGS, "scsi%d: using tag %d for target %d lun %d "
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			   "(now %d tags in use)\n",
			   H_NO(cmd), cmd->tag, cmd->device->id,
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			   lun, ta->nr_allocated);
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	}
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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(struct scsi_cmnd *cmd)
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{
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	u8 lun = cmd->device->lun;
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	SETUP_HOSTDATA(cmd->device->host);

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


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static void free_all_tags(struct NCR5380_hostdata *hostdata)
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{
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	int target, lun;
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	struct tag_alloc *ta;
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	if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
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		return;

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

#endif /* SUPPORT_TAGS */


/*
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 * Function: void merge_contiguous_buffers( struct scsi_cmnd *cmd )
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 *
 * Purpose: Try to merge several scatter-gather requests into one DMA
 *    transfer. This is possible if the scatter buffers lie on
 *    physical contiguous addresses.
 *
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 * Parameters: struct scsi_cmnd *cmd
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 *    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(struct scsi_cmnd *cmd)
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{
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#if !defined(CONFIG_SUN3)
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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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		dprintk(NDEBUG_MERGING, "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)
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		dprintk(NDEBUG_MERGING, "merged %d buffers from %p, new length %08x\n",
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			   cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
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#endif
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#endif /* !defined(CONFIG_SUN3) */
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}

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/**
 * initialize_SCp - init the scsi pointer field
 * @cmd: command block to set up
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 *
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 * Set up the internal fields in the SCSI command.
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 */

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static inline void initialize_SCp(struct 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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}

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/**
 * NCR5380_poll_politely - wait for NCR5380 status bits
 * @instance: controller to poll
 * @reg: 5380 register to poll
 * @bit: Bitmask to check
 * @val: Value required to exit
 *
 * Polls the NCR5380 in a reasonably efficient manner waiting for
 * an event to occur, after a short quick poll we begin giving the
 * CPU back in non IRQ contexts
 *
 * Returns the value of the register or a negative error code.
 */

static int NCR5380_poll_politely(struct Scsi_Host *instance,
                                 int reg, int bit, int val, int t)
{
	int n = 500;
	unsigned long end = jiffies + t;
	int r;

	while (n-- > 0) {
		r = NCR5380_read(reg);
		if ((r & bit) == val)
			return 0;
		cpu_relax();
	}

	/* t time yet ? */
	while (time_before(jiffies, end)) {
		r = NCR5380_read(reg);
		if ((r & bit) == val)
			return 0;
		if (!in_interrupt())
			cond_resched();
		else
			cpu_relax();
	}
	return -ETIMEDOUT;
}

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#include <linux/delay.h>

#if NDEBUG
static struct {
526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546
	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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/**
 * NCR5380_print - print scsi bus signals
 * @instance: adapter state to dump
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 *
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 * Print the SCSI bus signals for debugging purposes
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 */

555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583
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 {
587 588
	unsigned char value;
	const char *name;
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} phases[] = {
590 591 592 593
	{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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/**
 * NCR5380_print_phase - show SCSI phase
 * @instance: adapter to dump
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 *
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 * Print the current SCSI phase for debugging purposes
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 *
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 * Locks: none
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 */

static void NCR5380_print_phase(struct Scsi_Host *instance)
{
606 607 608 609 610 611 612 613 614 615 616 617
	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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}

#endif

/*
 * ++roman: New scheme of calling NCR5380_main()
624
 *
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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.
 */

635
#include <linux/gfp.h>
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#include <linux/workqueue.h>
#include <linux/interrupt.h>

639
static inline void queue_main(struct NCR5380_hostdata *hostdata)
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{
641
	if (!hostdata->main_running) {
642 643 644 645
		/* 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. */
646
		schedule_work(&hostdata->main_task);
647 648 649
	}
	/* else: nothing to do: the running NCR5380_main() will pick up
	   any newly queued command. */
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}

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/**
 * NCR58380_info - report driver and host information
 * @instance: relevant scsi host instance
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 *
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 * For use as the host template info() handler.
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 *
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 * Locks: none
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 */

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static const char *NCR5380_info(struct Scsi_Host *instance)
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{
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	struct NCR5380_hostdata *hostdata = shost_priv(instance);

	return hostdata->info;
}

static void prepare_info(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);

	snprintf(hostdata->info, sizeof(hostdata->info),
	         "%s, io_port 0x%lx, n_io_port %d, "
	         "base 0x%lx, irq %d, "
	         "can_queue %d, cmd_per_lun %d, "
	         "sg_tablesize %d, this_id %d, "
677
	         "flags { %s%s}, "
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	         "options { %s} ",
	         instance->hostt->name, instance->io_port, instance->n_io_port,
	         instance->base, instance->irq,
	         instance->can_queue, instance->cmd_per_lun,
	         instance->sg_tablesize, instance->this_id,
683
	         hostdata->flags & FLAG_TAGGED_QUEUING ? "TAGGED_QUEUING " : "",
684
	         hostdata->flags & FLAG_TOSHIBA_DELAY  ? "TOSHIBA_DELAY "  : "",
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#ifdef DIFFERENTIAL
	         "DIFFERENTIAL "
#endif
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#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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	         "SUPPORT_TAGS "
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#endif
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	         "");
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}

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/**
 * NCR5380_print_status - dump controller info
 * @instance: controller to dump
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 *
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 * Print commands in the various queues, called from NCR5380_abort
 * to aid debugging.
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 */

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static void lprint_Scsi_Cmnd(struct scsi_cmnd *cmd)
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{
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	int i, s;
	unsigned char *command;
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	printk("scsi%d: destination target %d, lun %llu\n",
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		H_NO(cmd), cmd->device->id, cmd->device->lun);
	printk(KERN_CONT "        command = ");
	command = cmd->cmnd;
	printk(KERN_CONT "%2d (0x%02x)", command[0], command[0]);
	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
		printk(KERN_CONT " %02x", command[i]);
	printk("\n");
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}

722
static void __maybe_unused NCR5380_print_status(struct Scsi_Host *instance)
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{
724
	struct NCR5380_hostdata *hostdata;
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	struct scsi_cmnd *ptr;
726
	unsigned long flags;
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	NCR5380_dprint(NDEBUG_ANY, instance);
	NCR5380_dprint_phase(NDEBUG_ANY, instance);
730 731 732 733

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

	local_irq_save(flags);
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	printk("NCR5380: coroutine is%s running.\n",
735
		hostdata->main_running ? "" : "n't");
736
	if (!hostdata->connected)
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		printk("scsi%d: no currently connected command\n", HOSTNO);
738
	else
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		lprint_Scsi_Cmnd((struct scsi_cmnd *) hostdata->connected);
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	printk("scsi%d: issue_queue\n", HOSTNO);
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	for (ptr = (struct scsi_cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
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		lprint_Scsi_Cmnd(ptr);
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	printk("scsi%d: disconnected_queue\n", HOSTNO);
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	for (ptr = (struct scsi_cmnd *) hostdata->disconnected_queue; ptr;
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	     ptr = NEXT(ptr))
		lprint_Scsi_Cmnd(ptr);
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749
	local_irq_restore(flags);
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	printk("\n");
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}

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static void show_Scsi_Cmnd(struct scsi_cmnd *cmd, struct seq_file *m)
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{
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	int i, s;
	unsigned char *command;
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	seq_printf(m, "scsi%d: destination target %d, lun %llu\n",
758
		H_NO(cmd), cmd->device->id, cmd->device->lun);
759
	seq_puts(m, "        command = ");
760
	command = cmd->cmnd;
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	seq_printf(m, "%2d (0x%02x)", command[0], command[0]);
762
	for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
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		seq_printf(m, " %02x", command[i]);
764
	seq_putc(m, '\n');
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}

767 768
static int __maybe_unused NCR5380_show_info(struct seq_file *m,
                                            struct Scsi_Host *instance)
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{
	struct NCR5380_hostdata *hostdata;
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	struct scsi_cmnd *ptr;
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	unsigned long flags;

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

	local_irq_save(flags);
	seq_printf(m, "NCR5380: coroutine is%s running.\n",
778
		hostdata->main_running ? "" : "n't");
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	if (!hostdata->connected)
		seq_printf(m, "scsi%d: no currently connected command\n", HOSTNO);
	else
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		show_Scsi_Cmnd((struct scsi_cmnd *) hostdata->connected, m);
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	seq_printf(m, "scsi%d: issue_queue\n", HOSTNO);
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	for (ptr = (struct scsi_cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr))
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		show_Scsi_Cmnd(ptr, m);

	seq_printf(m, "scsi%d: disconnected_queue\n", HOSTNO);
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	for (ptr = (struct scsi_cmnd *) hostdata->disconnected_queue; ptr;
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	     ptr = NEXT(ptr))
		show_Scsi_Cmnd(ptr, m);

	local_irq_restore(flags);
	return 0;
}
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/**
 * NCR5380_init - initialise an NCR5380
 * @instance: adapter to configure
 * @flags: control flags
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 *
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 * Initializes *instance and corresponding 5380 chip,
 * with flags OR'd into the initial flags value.
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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.
806
 *
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 * Returns 0 for success
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 */

810
static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
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{
812 813 814
	int i;
	SETUP_HOSTDATA(instance);

815
	hostdata->host = instance;
816 817 818 819 820 821 822
	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
824
	init_tags(hostdata);
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#endif
#if defined (REAL_DMA)
827
	hostdata->dma_len = 0;
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#endif
829 830 831
	hostdata->connected = NULL;
	hostdata->issue_queue = NULL;
	hostdata->disconnected_queue = NULL;
832
	hostdata->flags = flags;
833

834
	INIT_WORK(&hostdata->main_task, NCR5380_main);
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	prepare_info(instance);

838 839 840 841
	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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843
	return 0;
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}

846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861
/**
 * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
 * @instance: adapter to check
 *
 * If the system crashed, it may have crashed with a connected target and
 * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
 * currently established nexus, which we know nothing about. Failing that
 * do a bus reset.
 *
 * Note that a bus reset will cause the chip to assert IRQ.
 *
 * Returns 0 if successful, otherwise -ENXIO.
 */

static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
{
862
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880
	int pass;

	for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
		switch (pass) {
		case 1:
		case 3:
		case 5:
			shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
			NCR5380_poll_politely(instance,
			                      STATUS_REG, SR_BSY, 0, 5 * HZ);
			break;
		case 2:
			shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
			do_abort(instance);
			break;
		case 4:
			shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
			do_reset(instance);
881 882 883 884 885 886 887 888
			/* Wait after a reset; the SCSI standard calls for
			 * 250ms, we wait 500ms to be on the safe side.
			 * But some Toshiba CD-ROMs need ten times that.
			 */
			if (hostdata->flags & FLAG_TOSHIBA_DELAY)
				msleep(2500);
			else
				msleep(500);
889 890 891 892 893 894 895 896 897
			break;
		case 6:
			shost_printk(KERN_ERR, instance, "bus locked solid\n");
			return -ENXIO;
		}
	}
	return 0;
}

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/**
 * NCR5380_exit - remove an NCR5380
 * @instance: adapter to remove
 *
 * Assumes that no more work can be queued (e.g. by NCR5380_intr).
 */

905 906
static void NCR5380_exit(struct Scsi_Host *instance)
{
907 908 909
	struct NCR5380_hostdata *hostdata = shost_priv(instance);

	cancel_work_sync(&hostdata->main_task);
910 911
}

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/**
 * NCR5380_queue_command - queue a command
 * @instance: the relevant SCSI adapter
 * @cmd: SCSI command
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 *
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 * cmd is added to the per instance issue_queue, with minor
 * twiddling done to the host specific fields of cmd.  If the
 * main coroutine is not running, it is restarted.
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 */

922 923
static int NCR5380_queue_command(struct Scsi_Host *instance,
                                 struct scsi_cmnd *cmd)
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{
925
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
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	struct scsi_cmnd *tmp;
927
	unsigned long flags;
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#if (NDEBUG & NDEBUG_NO_WRITE)
930 931 932 933 934 935
	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);
936
		cmd->scsi_done(cmd);
937 938
		return 0;
	}
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#endif /* (NDEBUG & NDEBUG_NO_WRITE) */

941 942 943 944 945
	/*
	 * We use the host_scribble field as a pointer to the next command
	 * in a queue
	 */

946
	SET_NEXT(cmd, NULL);
947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967
	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.
	 */

	/* ++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.
	 */
968
	if (!NCR5380_acquire_dma_irq(instance))
969 970 971 972
		return SCSI_MLQUEUE_HOST_BUSY;

	local_irq_save(flags);

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973 974 975 976 977 978 979
	/*
	 * 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.
	 */

980 981
	if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
		LIST(cmd, hostdata->issue_queue);
982
		SET_NEXT(cmd, hostdata->issue_queue);
983 984
		hostdata->issue_queue = cmd;
	} else {
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985
		for (tmp = (struct scsi_cmnd *)hostdata->issue_queue;
986 987 988
		     NEXT(tmp); tmp = NEXT(tmp))
			;
		LIST(cmd, tmp);
989
		SET_NEXT(tmp, cmd);
990 991 992
	}
	local_irq_restore(flags);

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993
	dprintk(NDEBUG_QUEUES, "scsi%d: command added to %s of queue\n", H_NO(cmd),
994 995 996 997 998 999 1000 1001 1002
		  (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.
	 */
1003
	if (in_interrupt() || irqs_disabled())
1004
		queue_main(hostdata);
1005
	else
1006
		NCR5380_main(&hostdata->main_task);
1007
	return 0;
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1008 1009
}

1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021
static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
{
	struct NCR5380_hostdata *hostdata = shost_priv(instance);

	/* Caller does the locking needed to set & test these data atomically */
	if (!hostdata->disconnected_queue &&
	    !hostdata->issue_queue &&
	    !hostdata->connected &&
	    !hostdata->retain_dma_intr)
		NCR5380_release_dma_irq(instance);
}

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1022 1023
/**
 * NCR5380_main - NCR state machines
L
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1024
 *
F
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1025 1026 1027 1028
 * 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
 * in case it is not running.
1029
 *
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1030
 * Locks: called as its own thread with no locks held.
1031 1032
 */

1033
static void NCR5380_main(struct work_struct *work)
L
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1034
{
1035 1036 1037
	struct NCR5380_hostdata *hostdata =
		container_of(work, struct NCR5380_hostdata, main_task);
	struct Scsi_Host *instance = hostdata->host;
F
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1038
	struct scsi_cmnd *tmp, *prev;
1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062
	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. */
1063
	if (hostdata->main_running)
1064
		return;
1065
	hostdata->main_running = 1;
1066 1067 1068 1069 1070 1071 1072

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

		if (!hostdata->connected) {
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			dprintk(NDEBUG_MAIN, "scsi%d: not connected\n", HOSTNO);
1074 1075 1076 1077
			/*
			 * Search through the issue_queue for a command destined
			 * for a target that's not busy.
			 */
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1078
#if (NDEBUG & NDEBUG_LISTS)
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1079
			for (tmp = (struct scsi_cmnd *) hostdata->issue_queue, prev = NULL;
1080 1081 1082 1083 1084 1085
			     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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1086
#endif
F
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1087
			for (tmp = (struct scsi_cmnd *) hostdata->issue_queue,
1088
			     prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
H
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1089
				u8 lun = tmp->device->lun;
L
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1090

1091 1092 1093 1094
				dprintk(NDEBUG_LISTS,
				        "MAIN tmp=%p target=%d busy=%d lun=%d\n",
				        tmp, scmd_id(tmp), hostdata->busy[scmd_id(tmp)],
				        lun);
1095 1096 1097
				/*  When we find one, remove it from the issue queue. */
				/* ++guenther: possible race with Falcon locking */
				if (
L
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1098
#ifdef SUPPORT_TAGS
1099
				    !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
L
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1100
#else
H
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1101
				    !(hostdata->busy[tmp->device->id] & (1 << lun))
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1102
#endif
1103 1104 1105 1106 1107
				    ) {
					/* ++guenther: just to be sure, this must be atomic */
					local_irq_disable();
					if (prev) {
						REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1108
						SET_NEXT(prev, NEXT(tmp));
1109 1110 1111 1112
					} else {
						REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
						hostdata->issue_queue = NEXT(tmp);
					}
1113
					SET_NEXT(tmp, NULL);
1114
					hostdata->retain_dma_intr++;
1115 1116 1117 1118 1119 1120 1121 1122 1123 1124

					/* 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.
					 */
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					dprintk(NDEBUG_MAIN, "scsi%d: main(): command for target %d "
1126
						    "lun %d removed from issue_queue\n",
H
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1127
						    HOSTNO, tmp->device->id, lun);
1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
					/*
					 * 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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1138
#ifdef SUPPORT_TAGS
1139
					cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
L
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1140
#endif
1141
					if (!NCR5380_select(instance, tmp)) {
1142
						/* OK or bad target */
1143
						local_irq_disable();
1144
						hostdata->retain_dma_intr--;
1145 1146
						maybe_release_dma_irq(instance);
						local_irq_restore(flags);
1147
					} else {
1148
						/* Need to retry */
1149 1150
						local_irq_disable();
						LIST(tmp, hostdata->issue_queue);
1151
						SET_NEXT(tmp, hostdata->issue_queue);
1152
						hostdata->issue_queue = tmp;
L
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1153
#ifdef SUPPORT_TAGS
1154
						cmd_free_tag(tmp);
L
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1155
#endif
1156
						hostdata->retain_dma_intr--;
1157
						local_irq_restore(flags);
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1158
						dprintk(NDEBUG_MAIN, "scsi%d: main(): select() failed, "
1159 1160
							    "returned to issue_queue\n", HOSTNO);
					}
1161 1162
					if (hostdata->connected)
						break;
1163 1164 1165 1166 1167
				} /* if target/lun/target queue is not busy */
			} /* for issue_queue */
		} /* if (!hostdata->connected) */

		if (hostdata->connected
L
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1168
#ifdef REAL_DMA
1169
		    && !hostdata->dma_len
L
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1170
#endif
1171 1172
		    ) {
			local_irq_restore(flags);
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1173
			dprintk(NDEBUG_MAIN, "scsi%d: main: performing information transfer\n",
1174 1175
				    HOSTNO);
			NCR5380_information_transfer(instance);
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1176
			dprintk(NDEBUG_MAIN, "scsi%d: main: done set false\n", HOSTNO);
1177 1178 1179
			done = 0;
		}
	} while (!done);
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1180

1181 1182 1183
	/* 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... */
1184
	hostdata->main_running = 0;
1185
	local_irq_restore(flags);
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1186 1187 1188 1189 1190 1191 1192 1193
}


#ifdef REAL_DMA
/*
 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
 *
 * Purpose : Called by interrupt handler when DMA finishes or a phase
1194
 *	mismatch occurs (which would finish the DMA transfer).
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1195 1196 1197 1198 1199
 *
 * Inputs : instance - this instance of the NCR5380.
 *
 */

1200
static void NCR5380_dma_complete(struct Scsi_Host *instance)
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1201
{
1202
	SETUP_HOSTDATA(instance);
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1203
	int transferred;
1204
	unsigned char **data;
1205
	volatile int *count;
1206 1207
	int saved_data = 0, overrun = 0;
	unsigned char p;
1208 1209 1210 1211 1212

	if (!hostdata->connected) {
		printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
		       "no connected cmd\n", HOSTNO);
		return;
L
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1213
	}
1214

1215
	if (hostdata->read_overruns) {
1216 1217 1218 1219 1220 1221 1222 1223
		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;
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1224
				dprintk(NDEBUG_DMA, "scsi%d: read overrun handled\n", HOSTNO);
1225 1226 1227 1228
			}
		}
	}

F
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1229
	dprintk(NDEBUG_DMA, "scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
1230 1231 1232
		   HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
		   NCR5380_read(STATUS_REG));

1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250
#if defined(CONFIG_SUN3)
	if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
		pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
		       instance->host_no);
		BUG();
	}

	/* make sure we're not stuck in a data phase */
	if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
	    (BASR_PHASE_MATCH | BASR_ACK)) {
		pr_err("scsi%d: BASR %02x\n", instance->host_no,
		       NCR5380_read(BUS_AND_STATUS_REG));
		pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
		       instance->host_no);
		BUG();
	}
#endif

1251 1252 1253 1254
	(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

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1255
	transferred = hostdata->dma_len - NCR5380_dma_residual(instance);
1256 1257 1258 1259
	hostdata->dma_len = 0;

	data = (unsigned char **)&hostdata->connected->SCp.ptr;
	count = &hostdata->connected->SCp.this_residual;
F
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1260 1261
	*data += transferred;
	*count -= transferred;
1262

1263
	if (hostdata->read_overruns) {
1264 1265
		int cnt, toPIO;

1266
		if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1267
			cnt = toPIO = hostdata->read_overruns;
1268
			if (overrun) {
F
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1269
				dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
1270 1271 1272 1273 1274
				*(*data)++ = saved_data;
				(*count)--;
				cnt--;
				toPIO--;
			}
F
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1275
			dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1276 1277 1278
			NCR5380_transfer_pio(instance, &p, &cnt, data);
			*count -= toPIO - cnt;
		}
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1279 1280 1281 1282 1283
	}
}
#endif /* REAL_DMA */


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1284 1285 1286 1287
/**
 * NCR5380_intr - generic NCR5380 irq handler
 * @irq: interrupt number
 * @dev_id: device info
L
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1288
 *
F
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1289 1290 1291
 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 * from the disconnected queue, and restarting NCR5380_main()
 * as required.
L
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1292 1293
 */

1294
static irqreturn_t NCR5380_intr(int irq, void *dev_id)
L
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1295
{
1296
	struct Scsi_Host *instance = dev_id;
1297 1298 1299
	int done = 1, handled = 0;
	unsigned char basr;

F
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1300
	dprintk(NDEBUG_INTR, "scsi%d: NCR5380 irq triggered\n", HOSTNO);
1301 1302 1303

	/* Look for pending interrupts */
	basr = NCR5380_read(BUS_AND_STATUS_REG);
F
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1304
	dprintk(NDEBUG_INTR, "scsi%d: BASR=%02x\n", HOSTNO, basr);
1305 1306
	/* dispatch to appropriate routine if found and done=0 */
	if (basr & BASR_IRQ) {
1307
		NCR5380_dprint(NDEBUG_INTR, instance);
1308 1309
		if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
			done = 0;
F
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1310
			dprintk(NDEBUG_INTR, "scsi%d: SEL interrupt\n", HOSTNO);
1311 1312 1313
			NCR5380_reselect(instance);
			(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
		} else if (basr & BASR_PARITY_ERROR) {
F
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1314
			dprintk(NDEBUG_INTR, "scsi%d: PARITY interrupt\n", HOSTNO);
1315 1316
			(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
		} else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
F
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1317
			dprintk(NDEBUG_INTR, "scsi%d: RESET interrupt\n", HOSTNO);
1318 1319 1320 1321 1322 1323
			(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
		} else {
			/*
			 * The rest of the interrupt conditions can occur only during a
			 * DMA transfer
			 */
L
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1324 1325

#if defined(REAL_DMA)
1326 1327 1328 1329 1330 1331 1332 1333 1334 1335
			/*
			 * 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))) {

F
Finn Thain 已提交
1336
				dprintk(NDEBUG_INTR, "scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
1337 1338 1339
				NCR5380_dma_complete( instance );
				done = 0;
			} else
L
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1340
#endif /* REAL_DMA */
1341
			{
L
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1342
/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
1343
				if (basr & BASR_PHASE_MATCH)
1344
					dprintk(NDEBUG_INTR, "scsi%d: unknown interrupt, "
1345 1346 1347 1348
					       "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);
1349 1350 1351
#ifdef SUN3_SCSI_VME
				dregs->csr |= CSR_DMA_ENABLE;
#endif
1352 1353 1354 1355 1356 1357 1358 1359
			}
		} /* 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);
1360 1361 1362
#ifdef SUN3_SCSI_VME
		dregs->csr |= CSR_DMA_ENABLE;
#endif
1363 1364 1365
	}

	if (!done) {
F
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1366
		dprintk(NDEBUG_INTR, "scsi%d: in int routine, calling main\n", HOSTNO);
1367
		/* Put a call to NCR5380_main() on the queue... */
1368
		queue_main(shost_priv(instance));
1369 1370
	}
	return IRQ_RETVAL(handled);
L
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1371 1372
}

1373
/*
F
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1374 1375
 * Function : int NCR5380_select(struct Scsi_Host *instance,
 *                               struct scsi_cmnd *cmd)
L
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1376 1377
 *
 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1378 1379
 *	including ARBITRATION, SELECTION, and initial message out for
 *	IDENTIFY and queue messages.
L
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1380
 *
1381
 * Inputs : instance - instantiation of the 5380 driver on which this
1382
 *	target lives, cmd - SCSI command to execute.
1383
 *
1384 1385 1386
 * Returns : -1 if selection failed but should be retried.
 *      0 if selection failed and should not be retried.
 *      0 if selection succeeded completely (hostdata->connected == cmd).
L
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1387
 *
1388 1389
 * Side effects :
 *	If bus busy, arbitration failed, etc, NCR5380_select() will exit
L
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1390 1391 1392 1393
 *		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.
 *
1394 1395 1396
 *	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.
L
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1397
 *
1398
 *	If failed (no target) : cmd->scsi_done() will be called, and the
L
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1399 1400 1401
 *		cmd->result host byte set to DID_BAD_TARGET.
 */

F
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1402
static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
L
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1403
{
1404 1405 1406 1407 1408 1409 1410
	SETUP_HOSTDATA(instance);
	unsigned char tmp[3], phase;
	unsigned char *data;
	int len;
	unsigned long timeout;
	unsigned long flags;

1411
	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
F
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1412
	dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO,
1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425
		   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);
L
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1426

1427 1428 1429
	/*
	 * Start arbitration.
	 */
L
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1430

1431 1432
	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
	NCR5380_write(MODE_REG, MR_ARBITRATE);
L
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1433

1434
	local_irq_restore(flags);
L
Linus Torvalds 已提交
1435

1436
	/* Wait for arbitration logic to complete */
M
Michael Schmitz 已提交
1437
#if defined(NCR_TIMEOUT)
1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450
	{
		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 */
1452 1453 1454
	while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
	       !hostdata->connected)
		;
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#endif

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	dprintk(NDEBUG_ARBITRATION, "scsi%d: arbitration complete\n", HOSTNO);
1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477

	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);
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		dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1479 1480 1481
			   HOSTNO);
		return -1;
	}
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1483 1484 1485 1486
	/* 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)
	 */
1487 1488 1489 1490 1491 1492 1493
	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);
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		dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
1495 1496 1497 1498 1499 1500 1501 1502
			   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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1504 1505 1506 1507
	if (hostdata->flags & FLAG_TOSHIBA_DELAY)
		udelay(15);
	else
		udelay(2);
1508 1509 1510 1511 1512 1513 1514

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

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	dprintk(NDEBUG_ARBITRATION, "scsi%d: won arbitration\n", HOSTNO);
1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531

	/*
	 * 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);

1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544
	/*
	 * 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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1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571
	/*
	 * 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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1573
	udelay(1);
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	dprintk(NDEBUG_SELECTION, "scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
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1577 1578 1579 1580
	/*
	 * The SCSI specification calls for a 250 ms timeout for the actual
	 * selection.
	 */
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1582
	timeout = jiffies + msecs_to_jiffies(250);
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1584 1585 1586 1587 1588
	/*
	 * 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
1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609
	/* ++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
1611 1612
	while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
		;
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#endif

1615 1616 1617 1618 1619
	/*
	 * 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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1621
	udelay(1);
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1623
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
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1625 1626 1627
	if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		cmd->result = DID_BAD_TARGET << 16;
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#ifdef SUPPORT_TAGS
1629
		cmd_free_tag(cmd);
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#endif
1631 1632
		cmd->scsi_done(cmd);
		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
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		dprintk(NDEBUG_SELECTION, "scsi%d: target did not respond within 250ms\n", HOSTNO);
1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655
		return 0;
	}

	/*
	 * 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))
		;

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	dprintk(NDEBUG_SELECTION, "scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1657 1658
		   HOSTNO, cmd->device->id);
	tmp[0] = IDENTIFY(1, cmd->device->lun);
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#ifdef SUPPORT_TAGS
1661 1662 1663 1664 1665 1666
	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
1668 1669
	len = 1;
	cmd->tag = 0;
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#endif /* SUPPORT_TAGS */

1672 1673 1674 1675
	/* Send message(s) */
	data = tmp;
	phase = PHASE_MSGOUT;
	NCR5380_transfer_pio(instance, &phase, &len, &data);
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	dprintk(NDEBUG_SELECTION, "scsi%d: nexus established.\n", HOSTNO);
1677 1678
	/* XXX need to handle errors here */
	hostdata->connected = cmd;
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#ifndef SUPPORT_TAGS
1680 1681
	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
#endif
1682 1683 1684
#ifdef SUN3_SCSI_VME
	dregs->csr |= CSR_INTR;
#endif
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1686
	initialize_SCp(cmd);
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1688
	return 0;
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}

1691 1692
/*
 * 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
 *
1697 1698
 * 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.
1700
 *
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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.
 *
1705
 *	Also, *phase, *count, *data are modified in place.
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 *
 * XXX Note : handling for bus free may be useful.
 */

/*
1711
 * 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.
 */

1716 1717 1718
static int NCR5380_transfer_pio(struct Scsi_Host *instance,
				unsigned char *phase, int *count,
				unsigned char **data)
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{
1720 1721 1722 1723 1724 1725 1726 1727
	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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	 */

1730
	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
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1732 1733 1734 1735 1736 1737 1738
	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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		dprintk(NDEBUG_HANDSHAKE, "scsi%d: REQ detected\n", HOSTNO);
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1742 1743
		/* Check for phase mismatch */
		if ((tmp & PHASE_MASK) != p) {
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			dprintk(NDEBUG_PIO, "scsi%d: phase mismatch\n", HOSTNO);
1745
			NCR5380_dprint_phase(NDEBUG_PIO, instance);
1746 1747
			break;
		}
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1749 1750 1751 1752 1753
		/* 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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1755
		++d;
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1757 1758 1759 1760 1761 1762
		/*
		 * 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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1764 1765 1766
		if (!(p & SR_IO)) {
			if (!((p & SR_MSG) && c > 1)) {
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1767
				NCR5380_dprint(NDEBUG_PIO, instance);
1768 1769 1770 1771 1772
				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);
1773
				NCR5380_dprint(NDEBUG_PIO, instance);
1774 1775 1776 1777
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
					      ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
			}
		} else {
1778
			NCR5380_dprint(NDEBUG_PIO, instance);
1779 1780
			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
		}
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1782 1783 1784
		while (NCR5380_read(STATUS_REG) & SR_REQ)
			;

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		dprintk(NDEBUG_HANDSHAKE, "scsi%d: req false, handshake complete\n", HOSTNO);
1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805

		/*
		 * 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);

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	dprintk(NDEBUG_PIO, "scsi%d: residual %d\n", HOSTNO, c);
1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823

	*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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}

1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851
/**
 * do_reset - issue a reset command
 * @instance: adapter to reset
 *
 * Issue a reset sequence to the NCR5380 and try and get the bus
 * back into sane shape.
 *
 * This clears the reset interrupt flag because there may be no handler for
 * it. When the driver is initialized, the NCR5380_intr() handler has not yet
 * been installed. And when in EH we may have released the ST DMA interrupt.
 */

static void do_reset(struct Scsi_Host *instance)
{
	unsigned long flags;

	local_irq_save(flags);
	NCR5380_write(TARGET_COMMAND_REG,
	              PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
	udelay(50);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	(void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
	local_irq_restore(flags);
}

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/*
 * Function : do_abort (Scsi_Host *host)
1854 1855 1856 1857
 *
 * 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.
 */

1861
static int do_abort(struct Scsi_Host *instance)
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{
1863 1864 1865 1866
	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);
1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878

	/*
	 * 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.
	 */

1879
	while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895
		;

	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;
1896
	NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1897 1898 1899 1900 1901 1902 1903

	/*
	 * 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)
1907 1908
/*
 * 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.
 *
1914 1915
 * 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.
1917
 *
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 * Returns : -1 when different phase is entered without transferring
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1919
 *	maximum number of bytes, 0 if all bytes or transferred or exit
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1920 1921
 *	is in same phase.
 *
1922
 *	Also, *phase, *count, *data are modified in place.
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 *
 */


1927 1928 1929
static int NCR5380_transfer_dma(struct Scsi_Host *instance,
				unsigned char *phase, int *count,
				unsigned char **data)
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{
1931 1932 1933
	SETUP_HOSTDATA(instance);
	register int c = *count;
	register unsigned char p = *phase;
1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 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 1979
	unsigned long flags;

#if defined(CONFIG_SUN3)
	/* sanity check */
	if (!sun3_dma_setup_done) {
		pr_err("scsi%d: transfer_dma without setup!\n",
		       instance->host_no);
		BUG();
	}
	hostdata->dma_len = c;

	dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
		instance->host_no, (p & SR_IO) ? "reading" : "writing",
		c, (p & SR_IO) ? "to" : "from", *data);

	/* netbsd turns off ints here, why not be safe and do it too */
	local_irq_save(flags);

	/* send start chain */
	sun3scsi_dma_start(c, *data);

	if (p & SR_IO) {
		NCR5380_write(TARGET_COMMAND_REG, 1);
		NCR5380_read(RESET_PARITY_INTERRUPT_REG);
		NCR5380_write(INITIATOR_COMMAND_REG, 0);
		NCR5380_write(MODE_REG,
			      (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
	} else {
		NCR5380_write(TARGET_COMMAND_REG, 0);
		NCR5380_read(RESET_PARITY_INTERRUPT_REG);
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_DATA);
		NCR5380_write(MODE_REG,
			      (NCR5380_read(MODE_REG) | MR_DMA_MODE | MR_ENABLE_EOP_INTR));
		NCR5380_write(START_DMA_SEND_REG, 0);
	}

#ifdef SUN3_SCSI_VME
	dregs->csr |= CSR_DMA_ENABLE;
#endif

	local_irq_restore(flags);

	sun3_dma_active = 1;

#else /* !defined(CONFIG_SUN3) */
1980 1981 1982 1983 1984 1985 1986
	register unsigned char *d = *data;
	unsigned char tmp;

	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
		*phase = tmp;
		return -1;
	}
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Linus Torvalds 已提交
1987

1988 1989
	if (hostdata->read_overruns && (p & SR_IO))
		c -= hostdata->read_overruns;
L
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1990

F
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1991
	dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1992 1993
		   HOSTNO, (p & SR_IO) ? "reading" : "writing",
		   c, (p & SR_IO) ? "to" : "from", d);
L
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1994

1995
	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
L
Linus Torvalds 已提交
1996 1997

#ifdef REAL_DMA
1998
	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
L
Linus Torvalds 已提交
1999 2000
#endif /* def REAL_DMA  */

2001
	if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
		/* 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);
	}

2019
	if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
2020 2021 2022 2023 2024 2025 2026 2027 2028
		/* 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);
	}
2029 2030
#endif /* !defined(CONFIG_SUN3) */

2031
	return 0;
L
Linus Torvalds 已提交
2032 2033 2034 2035 2036 2037
}
#endif /* defined(REAL_DMA) */

/*
 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
 *
2038 2039
 * Purpose : run through the various SCSI phases and do as the target
 *	directs us to.  Operates on the currently connected command,
L
Linus Torvalds 已提交
2040 2041 2042 2043
 *	instance->connected.
 *
 * Inputs : instance, instance for which we are doing commands
 *
2044
 * Side effects : SCSI things happen, the disconnected queue will be
L
Linus Torvalds 已提交
2045 2046 2047
 *	modified if a command disconnects, *instance->connected will
 *	change.
 *
2048 2049
 * XXX Note : we need to watch for bus free or a reset condition here
 *	to recover from an unexpected bus free condition.
L
Linus Torvalds 已提交
2050
 */
2051 2052

static void NCR5380_information_transfer(struct Scsi_Host *instance)
L
Linus Torvalds 已提交
2053
{
2054 2055 2056 2057 2058
	SETUP_HOSTDATA(instance);
	unsigned long flags;
	unsigned char msgout = NOP;
	int sink = 0;
	int len;
L
Linus Torvalds 已提交
2059
#if defined(REAL_DMA)
2060
	int transfersize;
L
Linus Torvalds 已提交
2061
#endif
2062 2063
	unsigned char *data;
	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
F
Finn Thain 已提交
2064
	struct scsi_cmnd *cmd = (struct scsi_cmnd *) hostdata->connected;
2065

2066 2067 2068 2069
#ifdef SUN3_SCSI_VME
	dregs->csr |= CSR_INTR;
#endif

2070 2071 2072 2073 2074 2075 2076
	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;
2077
				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
2078
			}
2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105
#if defined(CONFIG_SUN3)
			if (phase == PHASE_CMDOUT) {
#if defined(REAL_DMA)
				void *d;
				unsigned long count;

				if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
					count = cmd->SCp.buffer->length;
					d = sg_virt(cmd->SCp.buffer);
				} else {
					count = cmd->SCp.this_residual;
					d = cmd->SCp.ptr;
				}
				/* this command setup for dma yet? */
				if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != cmd)) {
					if (cmd->request->cmd_type == REQ_TYPE_FS) {
						sun3scsi_dma_setup(d, count,
						                   rq_data_dir(cmd->request));
						sun3_dma_setup_done = cmd;
					}
				}
#endif
#ifdef SUN3_SCSI_VME
				dregs->csr |= CSR_INTR;
#endif
			}
#endif /* CONFIG_SUN3 */
L
Linus Torvalds 已提交
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2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121
			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:
L
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2122
#if (NDEBUG & NDEBUG_NO_DATAOUT)
2123 2124 2125 2126 2127
				printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
				       "aborted\n", HOSTNO);
				sink = 1;
				do_abort(instance);
				cmd->result = DID_ERROR << 16;
2128
				cmd->scsi_done(cmd);
2129
				return;
L
Linus Torvalds 已提交
2130
#endif
2131 2132 2133 2134 2135 2136 2137 2138 2139 2140
			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;
J
Jens Axboe 已提交
2141
					cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2142 2143 2144 2145
					/* ++roman: Try to merge some scatter-buffers if
					 * they are at contiguous physical addresses.
					 */
					merge_contiguous_buffers(cmd);
F
Finn Thain 已提交
2146
					dprintk(NDEBUG_INFORMATION, "scsi%d: %d bytes and %d buffers left\n",
2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164
						   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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Linus Torvalds 已提交
2165 2166

#if defined(REAL_DMA)
2167 2168 2169 2170 2171
				if (
#if !defined(CONFIG_SUN3)
				    !cmd->device->borken &&
#endif
				    (transfersize = NCR5380_dma_xfer_len(instance, cmd, phase)) >= DMA_MIN_SIZE) {
2172 2173 2174 2175 2176 2177 2178 2179
					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. */
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Finn Thain 已提交
2180 2181
						scmd_printk(KERN_INFO, cmd,
							"switching to slow handshake\n");
2182 2183 2184 2185
						cmd->device->borken = 1;
						sink = 1;
						do_abort(instance);
						cmd->result = DID_ERROR << 16;
2186
						cmd->scsi_done(cmd);
2187 2188
						/* XXX - need to source or sink data here, as appropriate */
					} else {
L
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2189
#ifdef REAL_DMA
2190 2191 2192 2193 2194 2195 2196 2197
						/* ++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;
L
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2198
#endif
2199 2200
					}
				} else
L
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2201
#endif /* defined(REAL_DMA) */
2202 2203 2204
					NCR5380_transfer_pio(instance, &phase,
							     (int *)&cmd->SCp.this_residual,
							     (unsigned char **)&cmd->SCp.ptr);
2205 2206 2207 2208 2209
#if defined(CONFIG_SUN3) && defined(REAL_DMA)
				/* if we had intended to dma that command clear it */
				if (sun3_dma_setup_done == cmd)
					sun3_dma_setup_done = NULL;
#endif
2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228
				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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2229
#ifdef LINKED
2230 2231 2232 2233 2234
				case LINKED_CMD_COMPLETE:
				case LINKED_FLG_CMD_COMPLETE:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

H
Hannes Reinecke 已提交
2235
					dprintk(NDEBUG_LINKED, "scsi%d: target %d lun %llu linked command "
2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246
						   "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) {
H
Hannes Reinecke 已提交
2247
						 printk(KERN_NOTICE "scsi%d: target %d lun %llu "
2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259
							"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);
H
Hannes Reinecke 已提交
2260
					dprintk(NDEBUG_LINKED, "scsi%d: target %d lun %llu linked request "
2261 2262 2263 2264 2265
						   "done, calling scsi_done().\n",
						   HOSTNO, cmd->device->id, cmd->device->lun);
					cmd->scsi_done(cmd);
					cmd = hostdata->connected;
					break;
L
Linus Torvalds 已提交
2266
#endif /* def LINKED */
2267 2268 2269 2270
				case ABORT:
				case COMMAND_COMPLETE:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
H
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2271
					dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d, lun %llu "
2272
						  "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
2273 2274 2275 2276

					local_irq_save(flags);
					hostdata->retain_dma_intr++;
					hostdata->connected = NULL;
L
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2277
#ifdef SUPPORT_TAGS
2278 2279 2280 2281 2282 2283 2284 2285 2286 2287
					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. */
2288
						struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][cmd->device->lun];
H
Hannes Reinecke 已提交
2289
						dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu returned "
2290 2291 2292 2293 2294 2295
							   "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;
					}
L
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2296
#else
2297
					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
L
Linus Torvalds 已提交
2298
#endif
2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321
					/* 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);
L
Linus Torvalds 已提交
2322

2323 2324 2325 2326 2327 2328
					if ((cmd->cmnd[0] == REQUEST_SENSE) &&
						hostdata->ses.cmd_len) {
						scsi_eh_restore_cmnd(cmd, &hostdata->ses);
						hostdata->ses.cmd_len = 0 ;
					}

2329 2330
					if ((cmd->cmnd[0] != REQUEST_SENSE) &&
					    (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2331 2332
						scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);

F
Finn Thain 已提交
2333
						dprintk(NDEBUG_AUTOSENSE, "scsi%d: performing request sense\n", HOSTNO);
2334 2335

						LIST(cmd,hostdata->issue_queue);
2336
						SET_NEXT(cmd, hostdata->issue_queue);
F
Finn Thain 已提交
2337
						hostdata->issue_queue = (struct scsi_cmnd *) cmd;
F
Finn Thain 已提交
2338
						dprintk(NDEBUG_QUEUES, "scsi%d: REQUEST SENSE added to head of "
2339
							  "issue queue\n", H_NO(cmd));
2340
					} else {
2341 2342 2343
						cmd->scsi_done(cmd);
					}

2344 2345
					local_irq_restore(flags);

2346 2347 2348 2349 2350 2351 2352 2353 2354 2355
					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();

2356
					local_irq_save(flags);
2357
					hostdata->retain_dma_intr--;
2358 2359 2360 2361
					/* ++roman: For Falcon SCSI, release the lock on the
					 * ST-DMA here if no other commands are waiting on the
					 * disconnected queue.
					 */
2362 2363
					maybe_release_dma_irq(instance);
					local_irq_restore(flags);
2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382
					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;
H
Hannes Reinecke 已提交
2383
						dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu rejected "
2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395
							   "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);
2396
					SET_NEXT(cmd, hostdata->disconnected_queue);
2397 2398 2399
					hostdata->connected = NULL;
					hostdata->disconnected_queue = cmd;
					local_irq_restore(flags);
H
Hannes Reinecke 已提交
2400
					dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d lun %llu was "
2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414
						  "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();
2415 2416 2417
#ifdef SUN3_SCSI_VME
					dregs->csr |= CSR_DMA_ENABLE;
#endif
2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452
					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);

F
Finn Thain 已提交
2453
					dprintk(NDEBUG_EXTENDED, "scsi%d: receiving extended message\n", HOSTNO);
2454 2455 2456 2457 2458

					len = 2;
					data = extended_msg + 1;
					phase = PHASE_MSGIN;
					NCR5380_transfer_pio(instance, &phase, &len, &data);
F
Finn Thain 已提交
2459
					dprintk(NDEBUG_EXTENDED, "scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470
						   (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);
F
Finn Thain 已提交
2471
						dprintk(NDEBUG_EXTENDED, "scsi%d: message received, residual %d\n",
2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498
							   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) {
F
Finn Thain 已提交
2499 2500
						printk(KERN_INFO "scsi%d: rejecting message ",
						       instance->host_no);
2501 2502 2503
						spi_print_msg(extended_msg);
						printk("\n");
					} else if (tmp != EXTENDED_MESSAGE)
F
Finn Thain 已提交
2504 2505 2506
						scmd_printk(KERN_INFO, cmd,
						            "rejecting unknown message %02x\n",
						            tmp);
2507
					else
F
Finn Thain 已提交
2508 2509 2510
						scmd_printk(KERN_INFO, cmd,
						            "rejecting unknown extended message code %02x, length %d\n",
						            extended_msg[1], extended_msg[0]);
2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522

					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) {
2523
					local_irq_save(flags);
L
Linus Torvalds 已提交
2524
#ifdef SUPPORT_TAGS
2525
					cmd_free_tag(cmd);
L
Linus Torvalds 已提交
2526
#else
2527
					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
L
Linus Torvalds 已提交
2528
#endif
2529 2530 2531
					hostdata->connected = NULL;
					cmd->result = DID_ERROR << 16;
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2532 2533 2534
					maybe_release_dma_irq(instance);
					local_irq_restore(flags);
					cmd->scsi_done(cmd);
2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556
					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);
2557
				NCR5380_dprint(NDEBUG_ANY, instance);
2558 2559 2560
			} /* switch(phase) */
		} /* if (tmp * SR_REQ) */
	} /* while (1) */
L
Linus Torvalds 已提交
2561 2562 2563 2564 2565
}

/*
 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
 *
2566
 * Purpose : does reselection, initializing the instance->connected
F
Finn Thain 已提交
2567
 *	field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
L
Linus Torvalds 已提交
2568
 *	nexus has been reestablished,
2569
 *
L
Linus Torvalds 已提交
2570 2571 2572 2573 2574
 * Inputs : instance - this instance of the NCR5380.
 *
 */


2575 2576 2577
/* it might eventually prove necessary to do a dma setup on
   reselection, but it doesn't seem to be needed now -- sam */

2578
static void NCR5380_reselect(struct Scsi_Host *instance)
L
Linus Torvalds 已提交
2579
{
2580 2581
	SETUP_HOSTDATA(instance);
	unsigned char target_mask;
2582
	unsigned char lun;
L
Linus Torvalds 已提交
2583
#ifdef SUPPORT_TAGS
2584
	unsigned char tag;
L
Linus Torvalds 已提交
2585
#endif
2586
	unsigned char msg[3];
2587 2588
	int __maybe_unused len;
	unsigned char __maybe_unused *data, __maybe_unused phase;
F
Finn Thain 已提交
2589
	struct scsi_cmnd *tmp = NULL, *prev;
2590 2591 2592 2593 2594 2595 2596 2597 2598 2599

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

	NCR5380_write(MODE_REG, MR_BASE);

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

F
Finn Thain 已提交
2600
	dprintk(NDEBUG_RESELECTION, "scsi%d: reselect\n", HOSTNO);
2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623

	/*
	 * 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))
		;

2624 2625 2626 2627 2628 2629 2630
#if defined(CONFIG_SUN3) && defined(REAL_DMA)
	/* acknowledge toggle to MSGIN */
	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));

	/* peek at the byte without really hitting the bus */
	msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
#else
2631 2632 2633 2634
	len = 1;
	data = msg;
	phase = PHASE_MSGIN;
	NCR5380_transfer_pio(instance, &phase, &len, &data);
2635
#endif
2636 2637 2638 2639 2640 2641 2642 2643

	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);
L
Linus Torvalds 已提交
2644

2645
#if defined(SUPPORT_TAGS) && !defined(CONFIG_SUN3)
2646 2647 2648 2649 2650
	/* 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;
2651
	if (phase == PHASE_MSGIN && (hostdata->flags & FLAG_TAGGED_QUEUING)) {
2652 2653 2654 2655 2656 2657 2658
		/* 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];
F
Finn Thain 已提交
2659
		dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at "
2660 2661
			   "reselection\n", HOSTNO, target_mask, lun, tag);
	}
L
Linus Torvalds 已提交
2662
#endif
2663 2664 2665 2666 2667 2668

	/*
	 * 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.
	 */

F
Finn Thain 已提交
2669
	for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
2670 2671
	     tmp; prev = tmp, tmp = NEXT(tmp)) {
		if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
L
Linus Torvalds 已提交
2672
#ifdef SUPPORT_TAGS
2673
		    && (tag == tmp->tag)
L
Linus Torvalds 已提交
2674
#endif
2675 2676 2677
		    ) {
			if (prev) {
				REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2678
				SET_NEXT(prev, NEXT(tmp));
2679 2680 2681 2682
			} else {
				REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
				hostdata->disconnected_queue = NEXT(tmp);
			}
2683
			SET_NEXT(tmp, NULL);
2684 2685
			break;
		}
L
Linus Torvalds 已提交
2686
	}
2687 2688 2689

	if (!tmp) {
		printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
L
Linus Torvalds 已提交
2690
#ifdef SUPPORT_TAGS
2691
		       "tag %d "
L
Linus Torvalds 已提交
2692
#endif
2693 2694
		       "not in disconnected_queue.\n",
		       HOSTNO, target_mask, lun
L
Linus Torvalds 已提交
2695
#ifdef SUPPORT_TAGS
2696
		       , tag
L
Linus Torvalds 已提交
2697
#endif
2698 2699 2700 2701 2702 2703 2704 2705
			);
		/*
		 * Since we have an established nexus that we can't do anything
		 * with, we must abort it.
		 */
		do_abort(instance);
		return;
	}
L
Linus Torvalds 已提交
2706

2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729
#if defined(CONFIG_SUN3) && defined(REAL_DMA)
	/* engage dma setup for the command we just saw */
	{
		void *d;
		unsigned long count;

		if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
			count = tmp->SCp.buffer->length;
			d = sg_virt(tmp->SCp.buffer);
		} else {
			count = tmp->SCp.this_residual;
			d = tmp->SCp.ptr;
		}
		/* setup this command for dma if not already */
		if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != tmp)) {
			sun3scsi_dma_setup(d, count, rq_data_dir(tmp->request));
			sun3_dma_setup_done = tmp;
		}
	}

	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
#endif

2730 2731
	/* Accept message by clearing ACK */
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
L
Linus Torvalds 已提交
2732

2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751
#if defined(SUPPORT_TAGS) && defined(CONFIG_SUN3)
	/* 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];
		dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at reselection\n"
			HOSTNO, target_mask, lun, tag);
	}
#endif

2752
	hostdata->connected = tmp;
H
Hannes Reinecke 已提交
2753
	dprintk(NDEBUG_RESELECTION, "scsi%d: nexus established, target = %d, lun = %llu, tag = %d\n",
2754
		   HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
L
Linus Torvalds 已提交
2755 2756 2757 2758
}


/*
F
Finn Thain 已提交
2759
 * Function : int NCR5380_abort (struct scsi_cmnd *cmd)
L
Linus Torvalds 已提交
2760 2761 2762
 *
 * Purpose : abort a command
 *
F
Finn Thain 已提交
2763
 * Inputs : cmd - the scsi_cmnd to abort, code - code to set the
2764
 *	host byte of the result field to, if zero DID_ABORTED is
L
Linus Torvalds 已提交
2765 2766
 *	used.
 *
2767
 * Returns : SUCCESS - success, FAILED on failure.
L
Linus Torvalds 已提交
2768
 *
2769 2770
 * XXX - there is no way to abort the command that is currently
 *	 connected, you have to wait for it to complete.  If this is
L
Linus Torvalds 已提交
2771
 *	 a problem, we could implement longjmp() / setjmp(), setjmp()
2772
 *	 called where the loop started in NCR5380_main().
L
Linus Torvalds 已提交
2773 2774 2775
 */

static
F
Finn Thain 已提交
2776
int NCR5380_abort(struct scsi_cmnd *cmd)
L
Linus Torvalds 已提交
2777
{
2778 2779
	struct Scsi_Host *instance = cmd->device->host;
	SETUP_HOSTDATA(instance);
F
Finn Thain 已提交
2780
	struct scsi_cmnd *tmp, **prev;
2781
	unsigned long flags;
L
Linus Torvalds 已提交
2782

2783
	scmd_printk(KERN_NOTICE, cmd, "aborting command\n");
L
Linus Torvalds 已提交
2784

2785 2786 2787
	NCR5380_print_status(instance);

	local_irq_save(flags);
L
Linus Torvalds 已提交
2788

F
Finn Thain 已提交
2789
	dprintk(NDEBUG_ABORT, "scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2790 2791
		    NCR5380_read(BUS_AND_STATUS_REG),
		    NCR5380_read(STATUS_REG));
L
Linus Torvalds 已提交
2792 2793

#if 1
2794 2795 2796 2797 2798
	/*
	 * 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.
	 */
L
Linus Torvalds 已提交
2799

2800
	if (hostdata->connected == cmd) {
L
Linus Torvalds 已提交
2801

F
Finn Thain 已提交
2802
		dprintk(NDEBUG_ABORT, "scsi%d: aborting connected command\n", HOSTNO);
2803 2804 2805 2806
		/*
		 * We should perform BSY checking, and make sure we haven't slipped
		 * into BUS FREE.
		 */
L
Linus Torvalds 已提交
2807

2808 2809 2810 2811 2812 2813
		/*	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.
		 */
L
Linus Torvalds 已提交
2814

2815 2816 2817 2818
		/*
		 * Return control to the executing NCR drive so we can clear the
		 * aborted flag and get back into our main loop.
		 */
L
Linus Torvalds 已提交
2819

2820 2821 2822
		if (do_abort(instance) == 0) {
			hostdata->connected = NULL;
			cmd->result = DID_ABORT << 16;
L
Linus Torvalds 已提交
2823
#ifdef SUPPORT_TAGS
2824
			cmd_free_tag(cmd);
L
Linus Torvalds 已提交
2825
#else
2826
			hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
L
Linus Torvalds 已提交
2827
#endif
2828
			maybe_release_dma_irq(instance);
2829 2830
			local_irq_restore(flags);
			cmd->scsi_done(cmd);
2831
			return SUCCESS;
2832
		} else {
2833
			local_irq_restore(flags);
2834
			printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2835
			return FAILED;
2836 2837
		}
	}
L
Linus Torvalds 已提交
2838 2839
#endif

2840 2841 2842 2843
	/*
	 * Case 2 : If the command hasn't been issued yet, we simply remove it
	 *	    from the issue queue.
	 */
F
Finn Thain 已提交
2844 2845
	for (prev = (struct scsi_cmnd **)&(hostdata->issue_queue),
	     tmp = (struct scsi_cmnd *)hostdata->issue_queue;
2846 2847 2848 2849
	     tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
		if (cmd == tmp) {
			REMOVE(5, *prev, tmp, NEXT(tmp));
			(*prev) = NEXT(tmp);
2850
			SET_NEXT(tmp, NULL);
2851
			tmp->result = DID_ABORT << 16;
2852
			maybe_release_dma_irq(instance);
2853
			local_irq_restore(flags);
F
Finn Thain 已提交
2854
			dprintk(NDEBUG_ABORT, "scsi%d: abort removed command from issue queue.\n",
2855 2856 2857 2858
				    HOSTNO);
			/* Tagged queuing note: no tag to free here, hasn't been assigned
			 * yet... */
			tmp->scsi_done(tmp);
2859
			return SUCCESS;
2860
		}
L
Linus Torvalds 已提交
2861 2862
	}

2863 2864 2865 2866 2867 2868 2869 2870 2871 2872
	/*
	 * 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.
	 */
L
Linus Torvalds 已提交
2873

2874 2875
	if (hostdata->connected) {
		local_irq_restore(flags);
F
Finn Thain 已提交
2876
		dprintk(NDEBUG_ABORT, "scsi%d: abort failed, command connected.\n", HOSTNO);
2877
		return FAILED;
2878
	}
L
Linus Torvalds 已提交
2879

2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904
	/*
	 * 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.
	 */

F
Finn Thain 已提交
2905
	for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp;
2906 2907 2908
	     tmp = NEXT(tmp)) {
		if (cmd == tmp) {
			local_irq_restore(flags);
F
Finn Thain 已提交
2909
			dprintk(NDEBUG_ABORT, "scsi%d: aborting disconnected command.\n", HOSTNO);
2910

2911
			if (NCR5380_select(instance, cmd))
2912
				return FAILED;
L
Linus Torvalds 已提交
2913

F
Finn Thain 已提交
2914
			dprintk(NDEBUG_ABORT, "scsi%d: nexus reestablished.\n", HOSTNO);
2915 2916 2917 2918

			do_abort(instance);

			local_irq_save(flags);
F
Finn Thain 已提交
2919 2920
			for (prev = (struct scsi_cmnd **)&(hostdata->disconnected_queue),
			     tmp = (struct scsi_cmnd *)hostdata->disconnected_queue;
2921 2922 2923 2924
			     tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
				if (cmd == tmp) {
					REMOVE(5, *prev, tmp, NEXT(tmp));
					*prev = NEXT(tmp);
2925
					SET_NEXT(tmp, NULL);
2926 2927 2928 2929 2930
					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)
					 */
L
Linus Torvalds 已提交
2931
#ifdef SUPPORT_TAGS
2932
					cmd_free_tag(tmp);
L
Linus Torvalds 已提交
2933
#else
2934
					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
L
Linus Torvalds 已提交
2935
#endif
2936
					maybe_release_dma_irq(instance);
2937 2938
					local_irq_restore(flags);
					tmp->scsi_done(tmp);
2939
					return SUCCESS;
2940 2941
				}
			}
L
Linus Torvalds 已提交
2942 2943 2944
		}
	}

2945 2946 2947 2948 2949 2950 2951
	/* 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.
	 */
	maybe_release_dma_irq(instance);
	local_irq_restore(flags);

2952 2953 2954 2955 2956 2957 2958 2959 2960
	/*
	 * 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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2961

2962
	printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
L
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2963

2964
	return FAILED;
L
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2965 2966 2967
}


2968 2969 2970
/**
 * NCR5380_bus_reset - reset the SCSI bus
 * @cmd: SCSI command undergoing EH
L
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2971
 *
2972
 * Returns SUCCESS
2973
 */
L
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2974

F
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2975
static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
L
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2976
{
2977 2978
	struct Scsi_Host *instance = cmd->device->host;
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
2979 2980
	int i;
	unsigned long flags;
L
Linus Torvalds 已提交
2981

2982 2983 2984 2985
	local_irq_save(flags);

#if (NDEBUG & NDEBUG_ANY)
	scmd_printk(KERN_INFO, cmd, "performing bus reset\n");
2986
	NCR5380_print_status(instance);
2987 2988 2989
#endif

	do_reset(instance);
2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002

	/* reset NCR registers */
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(TARGET_COMMAND_REG, 0);
	NCR5380_write(SELECT_ENABLE_REG, 0);

	/* 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)
F
Finn Thain 已提交
3003
		dprintk(NDEBUG_ABORT, "scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
3004
	if (hostdata->connected)
F
Finn Thain 已提交
3005
		dprintk(NDEBUG_ABORT, "scsi%d: reset aborted a connected command\n", H_NO(cmd));
3006
	if (hostdata->disconnected_queue)
F
Finn Thain 已提交
3007
		dprintk(NDEBUG_ABORT, "scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
3008 3009 3010 3011

	hostdata->issue_queue = NULL;
	hostdata->connected = NULL;
	hostdata->disconnected_queue = NULL;
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3012
#ifdef SUPPORT_TAGS
3013
	free_all_tags(hostdata);
L
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3014
#endif
3015 3016
	for (i = 0; i < 8; ++i)
		hostdata->busy[i] = 0;
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3017
#ifdef REAL_DMA
3018
	hostdata->dma_len = 0;
L
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3019
#endif
3020 3021

	maybe_release_dma_irq(instance);
3022
	local_irq_restore(flags);
L
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3023

3024
	return SUCCESS;
L
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3025
}