atari_NCR5380.c 83.8 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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/* Adapted for the sun3 by Sam Creasey. */

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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

/*
 * 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. [...] 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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 * 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

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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
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 * target.
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 *
 * 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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	struct Scsi_Host *instance = cmd->device->host;
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
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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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		dsprintk(NDEBUG_TAGS, instance, "target %d lun %d: no free tags\n",
		         scmd_id(cmd), 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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	struct Scsi_Host *instance = cmd->device->host;
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
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	/* 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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		dsprintk(NDEBUG_TAGS, instance, "target %d lun %d now allocated by untagged command\n",
		         scmd_id(cmd), 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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		dsprintk(NDEBUG_TAGS, instance, "using tag %d for target %d lun %d (%d tags allocated)\n",
		         cmd->tag, scmd_id(cmd), 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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	struct Scsi_Host *instance = cmd->device->host;
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
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	if (cmd->tag == TAG_NONE) {
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		hostdata->busy[cmd->device->id] &= ~(1 << lun);
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		dsprintk(NDEBUG_TAGS, instance, "target %d lun %d untagged cmd freed\n",
		         scmd_id(cmd), lun);
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	} else if (cmd->tag >= MAX_TAGS) {
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		shost_printk(KERN_NOTICE, instance,
		             "trying to free bad tag %d!\n", cmd->tag);
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	} 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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		dsprintk(NDEBUG_TAGS, instance, "freed tag %d for target %d lun %d\n",
		         cmd->tag, scmd_id(cmd), 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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/**
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 * NCR5380_poll_politely2 - wait for two chip register values
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 * @instance: controller to poll
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 * @reg1: 5380 register to poll
 * @bit1: Bitmask to check
 * @val1: Expected value
 * @reg2: Second 5380 register to poll
 * @bit2: Second bitmask to check
 * @val2: Second expected value
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 * @wait: Time-out in jiffies
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 *
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 * Polls the chip in a reasonably efficient manner waiting for an
 * event to occur. After a short quick poll we begin to yield the CPU
 * (if possible). In irq contexts the time-out is arbitrarily limited.
 * Callers may hold locks as long as they are held in irq mode.
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 *
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 * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
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 */

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static int NCR5380_poll_politely2(struct Scsi_Host *instance,
                                  int reg1, int bit1, int val1,
                                  int reg2, int bit2, int val2, int wait)
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{
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	struct NCR5380_hostdata *hostdata = shost_priv(instance);
	unsigned long deadline = jiffies + wait;
	unsigned long n;

	/* Busy-wait for up to 10 ms */
	n = min(10000U, jiffies_to_usecs(wait));
	n *= hostdata->accesses_per_ms;
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	n /= 2000;
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	do {
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		if ((NCR5380_read(reg1) & bit1) == val1)
			return 0;
		if ((NCR5380_read(reg2) & bit2) == val2)
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			return 0;
		cpu_relax();
491 492 493 494
	} while (n--);

	if (irqs_disabled() || in_interrupt())
		return -ETIMEDOUT;
495

496 497 498
	/* Repeatedly sleep for 1 ms until deadline */
	while (time_is_after_jiffies(deadline)) {
		schedule_timeout_uninterruptible(1);
499 500 501
		if ((NCR5380_read(reg1) & bit1) == val1)
			return 0;
		if ((NCR5380_read(reg2) & bit2) == val2)
502 503
			return 0;
	}
504

505 506 507
	return -ETIMEDOUT;
}

508 509 510 511 512 513 514
static inline int NCR5380_poll_politely(struct Scsi_Host *instance,
                                        int reg, int bit, int val, int wait)
{
	return NCR5380_poll_politely2(instance, reg, bit, val,
	                                        reg, bit, val, wait);
}

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#if NDEBUG
static struct {
517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537
	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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 */

546 547 548 549 550 551 552 553 554
static void NCR5380_print(struct Scsi_Host *instance)
{
	unsigned char status, data, basr, mr, icr, i;

	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);
555

556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572
	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 {
576 577
	unsigned char value;
	const char *name;
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} phases[] = {
579 580 581 582
	{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)
{
595 596 597 598 599 600 601 602 603 604 605 606
	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

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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, "
636
	         "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,
642
	         hostdata->flags & FLAG_TAGGED_QUEUING ? "TAGGED_QUEUING " : "",
643
	         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_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.
669
 *
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 * Returns 0 for success
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 */

673
static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
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{
675 676
	int i;
	SETUP_HOSTDATA(instance);
677
	unsigned long deadline;
678

679
	hostdata->host = instance;
680 681 682 683 684 685 686
	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
688
	init_tags(hostdata);
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#endif
#if defined (REAL_DMA)
691
	hostdata->dma_len = 0;
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#endif
693
	spin_lock_init(&hostdata->lock);
694 695 696
	hostdata->connected = NULL;
	hostdata->issue_queue = NULL;
	hostdata->disconnected_queue = NULL;
697
	hostdata->flags = flags;
698

699
	INIT_WORK(&hostdata->main_task, NCR5380_main);
700 701 702 703 704
	hostdata->work_q = alloc_workqueue("ncr5380_%d",
	                        WQ_UNBOUND | WQ_MEM_RECLAIM,
	                        1, instance->host_no);
	if (!hostdata->work_q)
		return -ENOMEM;
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	prepare_info(instance);

708 709 710 711
	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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	/* Calibrate register polling loop */
	i = 0;
	deadline = jiffies + 1;
	do {
		cpu_relax();
	} while (time_is_after_jiffies(deadline));
	deadline += msecs_to_jiffies(256);
	do {
		NCR5380_read(STATUS_REG);
		++i;
		cpu_relax();
	} while (time_is_after_jiffies(deadline));
	hostdata->accesses_per_ms = i / 256;

727
	return 0;
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}

730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745
/**
 * 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)
{
746
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764
	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);
765 766 767 768 769 770 771 772
			/* 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);
773 774 775 776 777 778 779 780 781
			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).
 */

789 790
static void NCR5380_exit(struct Scsi_Host *instance)
{
791 792 793
	struct NCR5380_hostdata *hostdata = shost_priv(instance);

	cancel_work_sync(&hostdata->main_task);
794
	destroy_workqueue(hostdata->work_q);
795 796
}

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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
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 * twiddling done to the host specific fields of cmd.  If the
 * main coroutine is not running, it is restarted.
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 */

807 808
static int NCR5380_queue_command(struct Scsi_Host *instance,
                                 struct scsi_cmnd *cmd)
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{
810
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
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	struct scsi_cmnd *tmp;
812
	unsigned long flags;
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#if (NDEBUG & NDEBUG_NO_WRITE)
815 816 817
	switch (cmd->cmnd[0]) {
	case WRITE_6:
	case WRITE_10:
818
		shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
819
		cmd->result = (DID_ERROR << 16);
820
		cmd->scsi_done(cmd);
821 822
		return 0;
	}
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#endif /* (NDEBUG & NDEBUG_NO_WRITE) */

825 826 827 828 829
	/*
	 * We use the host_scribble field as a pointer to the next command
	 * in a queue
	 */

830
	SET_NEXT(cmd, NULL);
831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851
	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.
	 */
852
	if (!NCR5380_acquire_dma_irq(instance))
853 854
		return SCSI_MLQUEUE_HOST_BUSY;

855
	spin_lock_irqsave(&hostdata->lock, flags);
856

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	/*
	 * 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.
	 */

864 865
	if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
		LIST(cmd, hostdata->issue_queue);
866
		SET_NEXT(cmd, hostdata->issue_queue);
867 868
		hostdata->issue_queue = cmd;
	} else {
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		for (tmp = (struct scsi_cmnd *)hostdata->issue_queue;
870 871 872
		     NEXT(tmp); tmp = NEXT(tmp))
			;
		LIST(cmd, tmp);
873
		SET_NEXT(tmp, cmd);
874
	}
875
	spin_unlock_irqrestore(&hostdata->lock, flags);
876

877 878
	dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
	         cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
879

880 881
	/* Kick off command processing */
	queue_work(hostdata->work_q, &hostdata->main_task);
882
	return 0;
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}

885 886 887 888 889 890 891 892 893 894 895 896
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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/**
 * NCR5380_main - NCR state machines
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 *
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 * 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.
904
 *
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 * Locks: called as its own thread with no locks held.
906 907
 */

908
static void NCR5380_main(struct work_struct *work)
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{
910 911 912
	struct NCR5380_hostdata *hostdata =
		container_of(work, struct NCR5380_hostdata, main_task);
	struct Scsi_Host *instance = hostdata->host;
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	struct scsi_cmnd *tmp, *prev;
914 915 916 917 918 919 920 921
	int done;

	/*
	 * ++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.
	 */

922
	spin_lock_irq(&hostdata->lock);
923 924 925 926
	do {
		done = 1;

		if (!hostdata->connected) {
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			dprintk(NDEBUG_MAIN, "scsi%d: not connected\n", HOSTNO);
928 929 930 931
			/*
			 * Search through the issue_queue for a command destined
			 * for a target that's not busy.
			 */
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#if (NDEBUG & NDEBUG_LISTS)
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			for (tmp = (struct scsi_cmnd *) hostdata->issue_queue, prev = NULL;
934 935 936 937 938 939
			     tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
				;
			/*printk("%p  ", tmp);*/
			if ((tmp == prev) && tmp)
				printk(" LOOP\n");
			/* else printk("\n"); */
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#endif
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			for (tmp = (struct scsi_cmnd *) hostdata->issue_queue,
942
			     prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
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				u8 lun = tmp->device->lun;
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945 946 947 948
				dprintk(NDEBUG_LISTS,
				        "MAIN tmp=%p target=%d busy=%d lun=%d\n",
				        tmp, scmd_id(tmp), hostdata->busy[scmd_id(tmp)],
				        lun);
949 950
				/*  When we find one, remove it from the issue queue. */
				if (
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#ifdef SUPPORT_TAGS
952
				    !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
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#else
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				    !(hostdata->busy[tmp->device->id] & (1 << lun))
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#endif
956 957 958
				    ) {
					if (prev) {
						REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
959
						SET_NEXT(prev, NEXT(tmp));
960 961 962 963
					} else {
						REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
						hostdata->issue_queue = NEXT(tmp);
					}
964
					SET_NEXT(tmp, NULL);
965
					hostdata->retain_dma_intr++;
966 967 968 969 970 971 972

					/*
					 * 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 "
974
						    "lun %d removed from issue_queue\n",
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						    HOSTNO, tmp->device->id, lun);
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					/*
					 * REQUEST SENSE commands are issued without tagged
					 * queueing, even on SCSI-II devices because the
					 * contingent allegiance condition exists for the
					 * entire unit.
					 */
					/* ++roman: ...and the standard also requires that
					 * REQUEST SENSE command are untagged.
					 */

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#ifdef SUPPORT_TAGS
987
					cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
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#endif
989
					if (!NCR5380_select(instance, tmp)) {
990
						/* OK or bad target */
991
						hostdata->retain_dma_intr--;
992
						maybe_release_dma_irq(instance);
993
					} else {
994
						/* Need to retry */
995
						LIST(tmp, hostdata->issue_queue);
996
						SET_NEXT(tmp, hostdata->issue_queue);
997
						hostdata->issue_queue = tmp;
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#ifdef SUPPORT_TAGS
999
						cmd_free_tag(tmp);
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1000
#endif
1001
						hostdata->retain_dma_intr--;
1002
						done = 0;
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						dprintk(NDEBUG_MAIN, "scsi%d: main(): select() failed, "
1004 1005
							    "returned to issue_queue\n", HOSTNO);
					}
1006 1007
					if (hostdata->connected)
						break;
1008 1009 1010 1011 1012
				} /* if target/lun/target queue is not busy */
			} /* for issue_queue */
		} /* if (!hostdata->connected) */

		if (hostdata->connected
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#ifdef REAL_DMA
1014
		    && !hostdata->dma_len
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#endif
1016
		    ) {
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			dprintk(NDEBUG_MAIN, "scsi%d: main: performing information transfer\n",
1018 1019
				    HOSTNO);
			NCR5380_information_transfer(instance);
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			dprintk(NDEBUG_MAIN, "scsi%d: main: done set false\n", HOSTNO);
1021 1022 1023
			done = 0;
		}
	} while (!done);
1024
	spin_unlock_irq(&hostdata->lock);
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}


#ifdef REAL_DMA
/*
 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
 *
 * Purpose : Called by interrupt handler when DMA finishes or a phase
1033
 *	mismatch occurs (which would finish the DMA transfer).
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 *
 * Inputs : instance - this instance of the NCR5380.
 *
 */

1039
static void NCR5380_dma_complete(struct Scsi_Host *instance)
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1040
{
1041
	SETUP_HOSTDATA(instance);
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	int transferred;
1043
	unsigned char **data;
1044
	volatile int *count;
1045 1046
	int saved_data = 0, overrun = 0;
	unsigned char p;
1047

1048
	if (hostdata->read_overruns) {
1049 1050 1051 1052 1053 1054 1055 1056
		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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				dprintk(NDEBUG_DMA, "scsi%d: read overrun handled\n", HOSTNO);
1058 1059 1060 1061
			}
		}
	}

1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079
#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

1080 1081
	NCR5380_write(MODE_REG, MR_BASE);
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1082
	NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1083

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	transferred = hostdata->dma_len - NCR5380_dma_residual(instance);
1085 1086 1087 1088
	hostdata->dma_len = 0;

	data = (unsigned char **)&hostdata->connected->SCp.ptr;
	count = &hostdata->connected->SCp.this_residual;
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1089 1090
	*data += transferred;
	*count -= transferred;
1091

1092
	if (hostdata->read_overruns) {
1093 1094
		int cnt, toPIO;

1095
		if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1096
			cnt = toPIO = hostdata->read_overruns;
1097
			if (overrun) {
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				dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
1099 1100 1101 1102 1103
				*(*data)++ = saved_data;
				(*count)--;
				cnt--;
				toPIO--;
			}
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			dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1105 1106 1107
			NCR5380_transfer_pio(instance, &p, &cnt, data);
			*count -= toPIO - cnt;
		}
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1108 1109 1110 1111 1112
	}
}
#endif /* REAL_DMA */


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/**
 * NCR5380_intr - generic NCR5380 irq handler
 * @irq: interrupt number
 * @dev_id: device info
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 *
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 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
 * from the disconnected queue, and restarting NCR5380_main()
 * as required.
1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144
 *
 * The chip can assert IRQ in any of six different conditions. The IRQ flag
 * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
 * Three of these six conditions are latched in the Bus and Status Register:
 * - End of DMA (cleared by ending DMA Mode)
 * - Parity error (cleared by reading RPIR)
 * - Loss of BSY (cleared by reading RPIR)
 * Two conditions have flag bits that are not latched:
 * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
 * - Bus reset (non-maskable)
 * The remaining condition has no flag bit at all:
 * - Selection/reselection
 *
 * Hence, establishing the cause(s) of any interrupt is partly guesswork.
 * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
 * claimed that "the design of the [DP8490] interrupt logic ensures
 * interrupts will not be lost (they can be on the DP5380)."
 * The L5380/53C80 datasheet from LOGIC Devices has more details.
 *
 * Checking for bus reset by reading RST is futile because of interrupt
 * latency, but a bus reset will reset chip logic. Checking for parity error
 * is unnecessary because that interrupt is never enabled. A Loss of BSY
 * condition will clear DMA Mode. We can tell when this occurs because the
 * the Busy Monitor interrupt is enabled together with DMA Mode.
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 */

1147
static irqreturn_t NCR5380_intr(int irq, void *dev_id)
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{
1149
	struct Scsi_Host *instance = dev_id;
1150
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
1151
	int handled = 0;
1152
	unsigned char basr;
1153 1154 1155
	unsigned long flags;

	spin_lock_irqsave(&hostdata->lock, flags);
1156 1157 1158

	basr = NCR5380_read(BUS_AND_STATUS_REG);
	if (basr & BASR_IRQ) {
1159 1160 1161 1162 1163
		unsigned char mr = NCR5380_read(MODE_REG);
		unsigned char sr = NCR5380_read(STATUS_REG);

		dprintk(NDEBUG_INTR, "scsi%d: IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
		        HOSTNO, irq, basr, sr, mr);
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#if defined(REAL_DMA)
1166 1167 1168 1169
		if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
			/* Probably End of DMA, Phase Mismatch or Loss of BSY.
			 * We ack IRQ after clearing Mode Register. Workarounds
			 * for End of DMA errata need to happen in DMA Mode.
1170 1171
			 */

1172
			dprintk(NDEBUG_INTR, "scsi%d: interrupt in DMA mode\n", HOSTNO);
1173

1174 1175 1176 1177 1178 1179 1180 1181
			if (hostdata->connected) {
				NCR5380_dma_complete(instance);
				queue_work(hostdata->work_q, &hostdata->main_task);
			} else {
				NCR5380_write(MODE_REG, MR_BASE);
				NCR5380_read(RESET_PARITY_INTERRUPT_REG);
			}
		} else
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#endif /* REAL_DMA */
1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
		if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
		    (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
			/* Probably reselected */
			NCR5380_write(SELECT_ENABLE_REG, 0);
			NCR5380_read(RESET_PARITY_INTERRUPT_REG);

			dprintk(NDEBUG_INTR, "scsi%d: interrupt with SEL and IO\n",
			        HOSTNO);

			if (!hostdata->connected) {
				NCR5380_reselect(instance);
				queue_work(hostdata->work_q, &hostdata->main_task);
			}
			if (!hostdata->connected)
				NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		} else {
			/* Probably Bus Reset */
			NCR5380_read(RESET_PARITY_INTERRUPT_REG);

			dprintk(NDEBUG_INTR, "scsi%d: unknown interrupt\n", HOSTNO);
1203
#ifdef SUN3_SCSI_VME
1204
			dregs->csr |= CSR_DMA_ENABLE;
1205
#endif
1206
		}
1207
		handled = 1;
1208 1209
	} else {
		shost_printk(KERN_NOTICE, instance, "interrupt without IRQ bit\n");
1210 1211 1212
#ifdef SUN3_SCSI_VME
		dregs->csr |= CSR_DMA_ENABLE;
#endif
1213 1214
	}

1215 1216
	spin_unlock_irqrestore(&hostdata->lock, flags);

1217
	return IRQ_RETVAL(handled);
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}

1220
/*
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 * Function : int NCR5380_select(struct Scsi_Host *instance,
 *                               struct scsi_cmnd *cmd)
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1223 1224
 *
 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1225 1226
 *	including ARBITRATION, SELECTION, and initial message out for
 *	IDENTIFY and queue messages.
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 *
1228
 * Inputs : instance - instantiation of the 5380 driver on which this
1229
 *	target lives, cmd - SCSI command to execute.
1230
 *
1231 1232 1233
 * 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).
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 *
1235 1236
 * Side effects :
 *	If bus busy, arbitration failed, etc, NCR5380_select() will exit
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 *		with registers as they should have been on entry - ie
 *		SELECT_ENABLE will be set appropriately, the NCR5380
 *		will cease to drive any SCSI bus signals.
 *
1241 1242 1243
 *	If successful : I_T_L or I_T_L_Q nexus will be established,
 *		instance->connected will be set to cmd.
 *		SELECT interrupt will be disabled.
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 *
1245
 *	If failed (no target) : cmd->scsi_done() will be called, and the
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 *		cmd->result host byte set to DID_BAD_TARGET.
 */

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static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
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{
1251 1252 1253 1254
	SETUP_HOSTDATA(instance);
	unsigned char tmp[3], phase;
	unsigned char *data;
	int len;
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	int err;
1256

1257
	NCR5380_dprint(NDEBUG_ARBITRATION, instance);
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	dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO,
1259 1260 1261 1262 1263 1264 1265 1266
		   instance->this_id);

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

	NCR5380_write(TARGET_COMMAND_REG, 0);
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1268 1269 1270
	/*
	 * Start arbitration.
	 */
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1272 1273
	NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
	NCR5380_write(MODE_REG, MR_ARBITRATE);
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1275 1276 1277
	/* The chip now waits for BUS FREE phase. Then after the 800 ns
	 * Bus Free Delay, arbitration will begin.
	 */
1278

1279
	spin_unlock_irq(&hostdata->lock);
1280 1281 1282
	err = NCR5380_poll_politely2(instance, MODE_REG, MR_ARBITRATE, 0,
	                INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
	                                       ICR_ARBITRATION_PROGRESS, HZ);
1283
	spin_lock_irq(&hostdata->lock);
1284 1285 1286 1287 1288 1289 1290 1291 1292
	if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
		/* Reselection interrupt */
		return -1;
	}
	if (err < 0) {
		NCR5380_write(MODE_REG, MR_BASE);
		shost_printk(KERN_ERR, instance,
		             "select: arbitration timeout\n");
		return -1;
1293
	}
1294
	spin_unlock_irq(&hostdata->lock);
1295

1296
	/* The SCSI-2 arbitration delay is 2.4 us */
1297 1298 1299 1300 1301
	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) ||
1302
	    (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1303
		NCR5380_write(MODE_REG, MR_BASE);
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		dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1305
			   HOSTNO);
1306
		spin_lock_irq(&hostdata->lock);
1307 1308
		return -1;
	}
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1310 1311 1312 1313
	/* 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)
	 */
1314 1315 1316 1317 1318 1319 1320
	NCR5380_write(INITIATOR_COMMAND_REG,
		      ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);

	/*
	 * 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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1321

1322 1323 1324 1325
	if (hostdata->flags & FLAG_TOSHIBA_DELAY)
		udelay(15);
	else
		udelay(2);
1326

1327 1328
	spin_lock_irq(&hostdata->lock);

1329 1330
	/* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
	if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1331 1332
		return -1;

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1333
	dprintk(NDEBUG_ARBITRATION, "scsi%d: won arbitration\n", HOSTNO);
1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349

	/*
	 * 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);

1352 1353 1354 1355 1356
	/*
	 * Reselect interrupts must be turned off prior to the dropping of BSY,
	 * otherwise we will trigger an interrupt.
	 */
	NCR5380_write(SELECT_ENABLE_REG, 0);
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1358 1359
	spin_unlock_irq(&hostdata->lock);

1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385
	/*
	 * 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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1387
	udelay(1);
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1388

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1389
	dprintk(NDEBUG_SELECTION, "scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
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1390

1391 1392 1393 1394
	/*
	 * The SCSI specification calls for a 250 ms timeout for the actual
	 * selection.
	 */
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1396 1397
	err = NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, SR_BSY,
	                            msecs_to_jiffies(250));
1398 1399

	if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1400
		spin_lock_irq(&hostdata->lock);
1401 1402
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		NCR5380_reselect(instance);
1403 1404
		if (!hostdata->connected)
			NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1405 1406 1407 1408
		printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
		       HOSTNO);
		return -1;
	}
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1410
	if (err < 0) {
1411
		spin_lock_irq(&hostdata->lock);
1412 1413
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		cmd->result = DID_BAD_TARGET << 16;
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1414
#ifdef SUPPORT_TAGS
1415
		cmd_free_tag(cmd);
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1416
#endif
1417 1418
		cmd->scsi_done(cmd);
		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
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1419
		dprintk(NDEBUG_SELECTION, "scsi%d: target did not respond within 250ms\n", HOSTNO);
1420 1421 1422
		return 0;
	}

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	/*
	 * 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
	 */

	udelay(1);

	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);

1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448
	/*
	 * 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 */
1449 1450

	err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1451
	spin_lock_irq(&hostdata->lock);
1452 1453 1454 1455 1456 1457
	if (err < 0) {
		shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
		return -1;
	}
1458

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1459
	dprintk(NDEBUG_SELECTION, "scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1460 1461
		   HOSTNO, cmd->device->id);
	tmp[0] = IDENTIFY(1, cmd->device->lun);
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1462 1463

#ifdef SUPPORT_TAGS
1464 1465 1466 1467 1468 1469
	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
1471 1472
	len = 1;
	cmd->tag = 0;
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1473 1474
#endif /* SUPPORT_TAGS */

1475 1476 1477 1478
	/* Send message(s) */
	data = tmp;
	phase = PHASE_MSGOUT;
	NCR5380_transfer_pio(instance, &phase, &len, &data);
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1479
	dprintk(NDEBUG_SELECTION, "scsi%d: nexus established.\n", HOSTNO);
1480
	/* XXX need to handle errors here */
1481

1482
	hostdata->connected = cmd;
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1483
#ifndef SUPPORT_TAGS
1484 1485
	hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
#endif
1486 1487 1488
#ifdef SUN3_SCSI_VME
	dregs->csr |= CSR_INTR;
#endif
L
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1489

1490
	initialize_SCp(cmd);
L
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1491

1492
	return 0;
L
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1493 1494
}

1495 1496
/*
 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
L
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1497 1498 1499 1500
 *      unsigned char *phase, int *count, unsigned char **data)
 *
 * Purpose : transfers data in given phase using polled I/O
 *
1501 1502
 * Inputs : instance - instance of driver, *phase - pointer to
 *	what phase is expected, *count - pointer to number of
L
Linus Torvalds 已提交
1503
 *	bytes to transfer, **data - pointer to data pointer.
1504
 *
L
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1505
 * Returns : -1 when different phase is entered without transferring
L
Lucas De Marchi 已提交
1506
 *	maximum number of bytes, 0 if all bytes are transferred or exit
L
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1507 1508
 *	is in same phase.
 *
1509
 *	Also, *phase, *count, *data are modified in place.
L
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1510 1511 1512 1513 1514
 *
 * XXX Note : handling for bus free may be useful.
 */

/*
1515
 * Note : this code is not as quick as it could be, however it
L
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1516 1517 1518 1519
 * IS 100% reliable, and for the actual data transfer where speed
 * counts, we will always do a pseudo DMA or DMA transfer.
 */

1520 1521 1522
static int NCR5380_transfer_pio(struct Scsi_Host *instance,
				unsigned char *phase, int *count,
				unsigned char **data)
L
Linus Torvalds 已提交
1523
{
1524 1525 1526 1527 1528 1529 1530 1531
	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
L
Linus Torvalds 已提交
1532 1533
	 */

1534
	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
L
Linus Torvalds 已提交
1535

1536 1537 1538 1539 1540
	do {
		/*
		 * Wait for assertion of REQ, after which the phase bits will be
		 * valid
		 */
1541 1542 1543

		if (NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
			break;
L
Linus Torvalds 已提交
1544

F
Finn Thain 已提交
1545
		dprintk(NDEBUG_HANDSHAKE, "scsi%d: REQ detected\n", HOSTNO);
L
Linus Torvalds 已提交
1546

1547
		/* Check for phase mismatch */
1548
		if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
F
Finn Thain 已提交
1549
			dprintk(NDEBUG_PIO, "scsi%d: phase mismatch\n", HOSTNO);
1550
			NCR5380_dprint_phase(NDEBUG_PIO, instance);
1551 1552
			break;
		}
L
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1553

1554 1555 1556 1557 1558
		/* 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);
L
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1559

1560
		++d;
L
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1561

1562 1563 1564 1565 1566 1567
		/*
		 * 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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1568

1569 1570 1571
		if (!(p & SR_IO)) {
			if (!((p & SR_MSG) && c > 1)) {
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1572
				NCR5380_dprint(NDEBUG_PIO, instance);
1573 1574 1575 1576 1577
				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);
1578
				NCR5380_dprint(NDEBUG_PIO, instance);
1579 1580 1581 1582
				NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
					      ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
			}
		} else {
1583
			NCR5380_dprint(NDEBUG_PIO, instance);
1584 1585
			NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
		}
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Linus Torvalds 已提交
1586

1587 1588 1589
		if (NCR5380_poll_politely(instance,
		                          STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
			break;
1590

F
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1591
		dprintk(NDEBUG_HANDSHAKE, "scsi%d: req false, handshake complete\n", HOSTNO);
1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611

		/*
		 * 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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1612
	dprintk(NDEBUG_PIO, "scsi%d: residual %d\n", HOSTNO, c);
1613 1614 1615 1616 1617

	*count = c;
	*data = d;
	tmp = NCR5380_read(STATUS_REG);
	/* The phase read from the bus is valid if either REQ is (already)
1618 1619
	 * asserted or if ACK hasn't been released yet. The latter applies if
	 * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1620
	 */
1621
	if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1622 1623 1624 1625 1626 1627 1628 1629
		*phase = tmp & PHASE_MASK;
	else
		*phase = PHASE_UNKNOWN;

	if (!c || (*phase == p))
		return 0;
	else
		return -1;
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1630 1631
}

1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657
/**
 * 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);
}

1658 1659 1660 1661
/**
 * do_abort - abort the currently established nexus by going to
 * MESSAGE OUT phase and sending an ABORT message.
 * @instance: relevant scsi host instance
1662
 *
1663
 * Returns 0 on success, -1 on failure.
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1664 1665
 */

1666
static int do_abort(struct Scsi_Host *instance)
L
Linus Torvalds 已提交
1667
{
1668 1669
	unsigned char tmp, *msgptr, phase;
	int len;
1670
	int rc;
1671 1672

	/* Request message out phase */
L
Linus Torvalds 已提交
1673
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684

	/*
	 * 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.
	 */

1685 1686 1687 1688 1689
	rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
	if (rc < 0)
		goto timeout;

	tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1690 1691 1692

	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));

1693 1694 1695 1696 1697 1698
	if (tmp != PHASE_MSGOUT) {
		NCR5380_write(INITIATOR_COMMAND_REG,
		              ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
		rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 3 * HZ);
		if (rc < 0)
			goto timeout;
1699 1700 1701 1702 1703 1704 1705
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
	}

	tmp = ABORT;
	msgptr = &tmp;
	len = 1;
	phase = PHASE_MSGOUT;
1706
	NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1707 1708 1709 1710 1711 1712 1713

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

	return len ? -1 : 0;
1714 1715 1716 1717

timeout:
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
	return -1;
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1718 1719 1720
}

#if defined(REAL_DMA)
1721 1722
/*
 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
L
Linus Torvalds 已提交
1723 1724 1725 1726 1727
 *      unsigned char *phase, int *count, unsigned char **data)
 *
 * Purpose : transfers data in given phase using either real
 *	or pseudo DMA.
 *
1728 1729
 * Inputs : instance - instance of driver, *phase - pointer to
 *	what phase is expected, *count - pointer to number of
L
Linus Torvalds 已提交
1730
 *	bytes to transfer, **data - pointer to data pointer.
1731
 *
L
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1732
 * Returns : -1 when different phase is entered without transferring
L
Lucas De Marchi 已提交
1733
 *	maximum number of bytes, 0 if all bytes or transferred or exit
L
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1734 1735
 *	is in same phase.
 *
1736
 *	Also, *phase, *count, *data are modified in place.
L
Linus Torvalds 已提交
1737 1738 1739 1740
 *
 */


1741 1742 1743
static int NCR5380_transfer_dma(struct Scsi_Host *instance,
				unsigned char *phase, int *count,
				unsigned char **data)
L
Linus Torvalds 已提交
1744
{
1745 1746 1747
	SETUP_HOSTDATA(instance);
	register int c = *count;
	register unsigned char p = *phase;
1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766

#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 */

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

1767 1768 1769
	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
	                        MR_ENABLE_EOP_INTR);
1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784
	if (p & SR_IO) {
		NCR5380_write(INITIATOR_COMMAND_REG, 0);
		NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
	} else {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_DATA);
		NCR5380_write(START_DMA_SEND_REG, 0);
	}

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

	sun3_dma_active = 1;

#else /* !defined(CONFIG_SUN3) */
1785 1786 1787 1788 1789 1790 1791
	register unsigned char *d = *data;
	unsigned char tmp;

	if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
		*phase = tmp;
		return -1;
	}
L
Linus Torvalds 已提交
1792

1793 1794
	if (hostdata->read_overruns && (p & SR_IO))
		c -= hostdata->read_overruns;
L
Linus Torvalds 已提交
1795

F
Finn Thain 已提交
1796
	dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1797 1798
		   HOSTNO, (p & SR_IO) ? "reading" : "writing",
		   c, (p & SR_IO) ? "to" : "from", d);
L
Linus Torvalds 已提交
1799

1800
	NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1801 1802
	NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
	                        MR_ENABLE_EOP_INTR);
L
Linus Torvalds 已提交
1803

1804
	if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819
		/* On the Medusa, it is a must to initialize the DMA before
		 * starting the NCR. This is also the cleaner way for the TT.
		 */
		hostdata->dma_len = (p & SR_IO) ?
			NCR5380_dma_read_setup(instance, d, c) :
			NCR5380_dma_write_setup(instance, d, c);
	}

	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);
	}

1820
	if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1821 1822 1823 1824 1825 1826 1827
		/* On the Falcon, the DMA setup must be done after the last */
		/* NCR access, else the DMA setup gets trashed!
		 */
		hostdata->dma_len = (p & SR_IO) ?
			NCR5380_dma_read_setup(instance, d, c) :
			NCR5380_dma_write_setup(instance, d, c);
	}
1828 1829
#endif /* !defined(CONFIG_SUN3) */

1830
	return 0;
L
Linus Torvalds 已提交
1831 1832 1833 1834 1835 1836
}
#endif /* defined(REAL_DMA) */

/*
 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
 *
1837 1838
 * 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
1839 1840 1841 1842
 *	instance->connected.
 *
 * Inputs : instance, instance for which we are doing commands
 *
1843
 * Side effects : SCSI things happen, the disconnected queue will be
L
Linus Torvalds 已提交
1844 1845 1846
 *	modified if a command disconnects, *instance->connected will
 *	change.
 *
1847 1848
 * 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
1849
 */
1850 1851

static void NCR5380_information_transfer(struct Scsi_Host *instance)
L
Linus Torvalds 已提交
1852
{
1853 1854 1855 1856
	SETUP_HOSTDATA(instance);
	unsigned char msgout = NOP;
	int sink = 0;
	int len;
L
Linus Torvalds 已提交
1857
#if defined(REAL_DMA)
1858
	int transfersize;
L
Linus Torvalds 已提交
1859
#endif
1860 1861
	unsigned char *data;
	unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1862
	struct scsi_cmnd *cmd;
1863

1864 1865 1866 1867
#ifdef SUN3_SCSI_VME
	dregs->csr |= CSR_INTR;
#endif

1868
	while ((cmd = hostdata->connected)) {
1869 1870 1871 1872 1873 1874
		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;
1875
				NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1876
			}
1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903
#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
1904

1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919
			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
Linus Torvalds 已提交
1920
#if (NDEBUG & NDEBUG_NO_DATAOUT)
1921 1922 1923 1924 1925
				printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
				       "aborted\n", HOSTNO);
				sink = 1;
				do_abort(instance);
				cmd->result = DID_ERROR << 16;
1926
				cmd->scsi_done(cmd);
1927
				return;
L
Linus Torvalds 已提交
1928
#endif
1929 1930 1931 1932 1933 1934 1935 1936 1937 1938
			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
1939
					cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1940 1941 1942 1943
					/* ++roman: Try to merge some scatter-buffers if
					 * they are at contiguous physical addresses.
					 */
					merge_contiguous_buffers(cmd);
F
Finn Thain 已提交
1944
					dprintk(NDEBUG_INFORMATION, "scsi%d: %d bytes and %d buffers left\n",
1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962
						   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.
				 */
L
Linus Torvalds 已提交
1963 1964

#if defined(REAL_DMA)
1965
#if !defined(CONFIG_SUN3)
1966 1967
				transfersize = 0;
				if (!cmd->device->borken)
1968
#endif
1969 1970 1971
					transfersize = NCR5380_dma_xfer_len(instance, cmd, phase);

				if (transfersize >= DMA_MIN_SIZE) {
1972 1973 1974 1975 1976 1977 1978 1979
					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. */
F
Finn Thain 已提交
1980 1981
						scmd_printk(KERN_INFO, cmd,
							"switching to slow handshake\n");
1982 1983 1984 1985
						cmd->device->borken = 1;
						sink = 1;
						do_abort(instance);
						cmd->result = DID_ERROR << 16;
1986
						cmd->scsi_done(cmd);
1987 1988
						/* XXX - need to source or sink data here, as appropriate */
					} else {
L
Linus Torvalds 已提交
1989
#ifdef REAL_DMA
1990 1991 1992 1993 1994 1995 1996 1997
						/* ++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
Linus Torvalds 已提交
1998
#endif
1999 2000
					}
				} else
L
Linus Torvalds 已提交
2001
#endif /* defined(REAL_DMA) */
2002 2003
				{
					spin_unlock_irq(&hostdata->lock);
2004 2005 2006
					NCR5380_transfer_pio(instance, &phase,
							     (int *)&cmd->SCp.this_residual,
							     (unsigned char **)&cmd->SCp.ptr);
2007 2008
					spin_lock_irq(&hostdata->lock);
				}
2009 2010 2011 2012 2013
#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
2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
				break;
			case PHASE_MSGIN:
				len = 1;
				data = &tmp;
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				cmd->SCp.Message = tmp;

				switch (tmp) {
				case ABORT:
				case COMMAND_COMPLETE:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
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					dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d, lun %llu "
2027
						  "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
2028 2029

					hostdata->connected = NULL;
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#ifdef SUPPORT_TAGS
2031 2032
					cmd_free_tag(cmd);
					if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2033
						struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][cmd->device->lun];
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						dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu returned "
2035 2036 2037 2038
							   "QUEUE_FULL after %d commands\n",
							   HOSTNO, cmd->device->id, cmd->device->lun,
							   ta->nr_allocated);
						if (ta->queue_size > ta->nr_allocated)
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							ta->queue_size = ta->nr_allocated;
2040
					}
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#else
2042
					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
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#endif
2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064

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

					if (cmd->cmnd[0] != REQUEST_SENSE)
						cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
					else if (status_byte(cmd->SCp.Status) != GOOD)
						cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
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2066 2067 2068 2069 2070 2071
					if ((cmd->cmnd[0] == REQUEST_SENSE) &&
						hostdata->ses.cmd_len) {
						scsi_eh_restore_cmnd(cmd, &hostdata->ses);
						hostdata->ses.cmd_len = 0 ;
					}

2072 2073
					if ((cmd->cmnd[0] != REQUEST_SENSE) &&
					    (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2074 2075
						scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);

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						dprintk(NDEBUG_AUTOSENSE, "scsi%d: performing request sense\n", HOSTNO);
2077 2078

						LIST(cmd,hostdata->issue_queue);
2079
						SET_NEXT(cmd, hostdata->issue_queue);
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						hostdata->issue_queue = (struct scsi_cmnd *) cmd;
2081 2082 2083
						dsprintk(NDEBUG_QUEUES, instance,
						         "REQUEST SENSE cmd %p added to head of issue queue\n",
						         cmd);
2084
					} else {
2085 2086 2087 2088 2089 2090 2091 2092 2093
						cmd->scsi_done(cmd);
					}

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

2094 2095 2096
					/* Enable reselect interrupts */
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);

2097 2098 2099 2100
					/* ++roman: For Falcon SCSI, release the lock on the
					 * ST-DMA here if no other commands are waiting on the
					 * disconnected queue.
					 */
2101
					maybe_release_dma_irq(instance);
2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118
					return;
				case MESSAGE_REJECT:
					/* Accept message by clearing ACK */
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
					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;
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						dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu rejected "
2120 2121 2122 2123 2124 2125 2126 2127 2128 2129
							   "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);
					LIST(cmd,hostdata->disconnected_queue);
2130
					SET_NEXT(cmd, hostdata->disconnected_queue);
2131 2132
					hostdata->connected = NULL;
					hostdata->disconnected_queue = cmd;
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					dprintk(NDEBUG_QUEUES, "scsi%d: command for target %d lun %llu was "
2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144
						  "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);
2145 2146 2147
#ifdef SUN3_SCSI_VME
					dregs->csr |= CSR_DMA_ENABLE;
#endif
2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180
					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);
					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);

2181 2182
					spin_unlock_irq(&hostdata->lock);

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					dprintk(NDEBUG_EXTENDED, "scsi%d: receiving extended message\n", HOSTNO);
2184 2185 2186 2187 2188

					len = 2;
					data = extended_msg + 1;
					phase = PHASE_MSGIN;
					NCR5380_transfer_pio(instance, &phase, &len, &data);
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					dprintk(NDEBUG_EXTENDED, "scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2190 2191
						   (int)extended_msg[1], (int)extended_msg[2]);

2192 2193
					if (!len && extended_msg[1] > 0 &&
					    extended_msg[1] <= sizeof(extended_msg) - 2) {
2194 2195 2196 2197 2198 2199 2200
						/* 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);
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						dprintk(NDEBUG_EXTENDED, "scsi%d: message received, residual %d\n",
2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220
							   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;
					}
2221 2222 2223 2224 2225

					spin_lock_irq(&hostdata->lock);
					if (!hostdata->connected)
						return;

2226 2227 2228 2229 2230 2231 2232 2233
					/* Fall through to reject message */

					/*
					 * If we get something weird that we aren't expecting,
					 * reject it.
					 */
				default:
					if (!tmp) {
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						printk(KERN_INFO "scsi%d: rejecting message ",
						       instance->host_no);
2236 2237 2238
						spi_print_msg(extended_msg);
						printk("\n");
					} else if (tmp != EXTENDED_MESSAGE)
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						scmd_printk(KERN_INFO, cmd,
						            "rejecting unknown message %02x\n",
						            tmp);
2242
					else
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						scmd_printk(KERN_INFO, cmd,
						            "rejecting unknown extended message code %02x, length %d\n",
						            extended_msg[1], extended_msg[0]);
2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257

					msgout = MESSAGE_REJECT;
					NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
					break;
				} /* switch (tmp) */
				break;
			case PHASE_MSGOUT:
				len = 1;
				data = &msgout;
				hostdata->last_message = msgout;
				NCR5380_transfer_pio(instance, &phase, &len, &data);
				if (msgout == ABORT) {
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#ifdef SUPPORT_TAGS
2259
					cmd_free_tag(cmd);
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#else
2261
					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
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#endif
2263 2264
					hostdata->connected = NULL;
					cmd->result = DID_ERROR << 16;
2265 2266
					maybe_release_dma_irq(instance);
					cmd->scsi_done(cmd);
2267
					NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289
					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);
2290
				NCR5380_dprint(NDEBUG_ANY, instance);
2291
			} /* switch(phase) */
2292
		} else {
2293
			spin_unlock_irq(&hostdata->lock);
2294
			NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
2295
			spin_lock_irq(&hostdata->lock);
2296
		}
2297
	}
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}

/*
 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
 *
2303
 * Purpose : does reselection, initializing the instance->connected
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 *	field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
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 *	nexus has been reestablished,
2306
 *
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 * Inputs : instance - this instance of the NCR5380.
 *
 */


2312 2313 2314
/* it might eventually prove necessary to do a dma setup on
   reselection, but it doesn't seem to be needed now -- sam */

2315
static void NCR5380_reselect(struct Scsi_Host *instance)
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{
2317 2318
	SETUP_HOSTDATA(instance);
	unsigned char target_mask;
2319
	unsigned char lun;
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#ifdef SUPPORT_TAGS
2321
	unsigned char tag;
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#endif
2323
	unsigned char msg[3];
2324 2325
	int __maybe_unused len;
	unsigned char __maybe_unused *data, __maybe_unused phase;
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	struct scsi_cmnd *tmp = NULL, *prev;
2327 2328 2329 2330 2331 2332 2333 2334 2335 2336

	/*
	 * 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);

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	dprintk(NDEBUG_RESELECTION, "scsi%d: reselect\n", HOSTNO);
2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348

	/*
	 * 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);
2349 2350 2351 2352 2353
	if (NCR5380_poll_politely(instance,
	                          STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
		NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
		return;
	}
2354 2355 2356 2357 2358 2359
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);

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

2360 2361 2362 2363 2364
	if (NCR5380_poll_politely(instance,
	                          STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
		do_abort(instance);
		return;
	}
2365

2366 2367 2368 2369 2370 2371 2372
#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
2373 2374 2375 2376
	len = 1;
	data = msg;
	phase = PHASE_MSGIN;
	NCR5380_transfer_pio(instance, &phase, &len, &data);
2377 2378 2379 2380 2381

	if (len) {
		do_abort(instance);
		return;
	}
2382
#endif
2383 2384

	if (!(msg[0] & 0x80)) {
2385
		shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2386
		spi_print_msg(msg);
2387
		printk("\n");
2388 2389 2390
		do_abort(instance);
		return;
	}
2391
	lun = msg[0] & 0x07;
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2393
#if defined(SUPPORT_TAGS) && !defined(CONFIG_SUN3)
2394 2395 2396 2397 2398
	/* 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;
2399
	if (phase == PHASE_MSGIN && (hostdata->flags & FLAG_TAGGED_QUEUING)) {
2400 2401 2402 2403 2404 2405 2406
		/* 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];
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		dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at "
2408 2409
			   "reselection\n", HOSTNO, target_mask, lun, tag);
	}
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#endif
2411 2412 2413 2414 2415 2416

	/*
	 * 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.
	 */

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	for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
2418
	     tmp; prev = tmp, tmp = NEXT(tmp)) {
2419
		if ((target_mask == (1 << tmp->device->id)) && (lun == (u8)tmp->device->lun)
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2420
#ifdef SUPPORT_TAGS
2421
		    && (tag == tmp->tag)
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#endif
2423 2424 2425
		    ) {
			if (prev) {
				REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2426
				SET_NEXT(prev, NEXT(tmp));
2427 2428 2429 2430
			} else {
				REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
				hostdata->disconnected_queue = NEXT(tmp);
			}
2431
			SET_NEXT(tmp, NULL);
2432 2433
			break;
		}
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2434
	}
2435 2436

	if (!tmp) {
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#ifdef SUPPORT_TAGS
2438 2439 2440 2441 2442
		shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d tag %d not in disconnected queue.\n",
		             target_mask, lun, tag);
#else
		shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
		             target_mask, lun);
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#endif
2444 2445 2446 2447 2448 2449 2450
		/*
		 * Since we have an established nexus that we can't do anything
		 * with, we must abort it.
		 */
		do_abort(instance);
		return;
	}
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2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474
#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

2475 2476
	/* Accept message by clearing ACK */
	NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
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2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496
#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

2497
	hostdata->connected = tmp;
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	dprintk(NDEBUG_RESELECTION, "scsi%d: nexus established, target = %d, lun = %llu, tag = %d\n",
2499
		   HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
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}


/*
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2504
 * Function : int NCR5380_abort (struct scsi_cmnd *cmd)
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2505 2506 2507
 *
 * Purpose : abort a command
 *
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2508
 * Inputs : cmd - the scsi_cmnd to abort, code - code to set the
2509
 *	host byte of the result field to, if zero DID_ABORTED is
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2510 2511
 *	used.
 *
2512
 * Returns : SUCCESS - success, FAILED on failure.
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2513
 *
2514 2515
 * XXX - there is no way to abort the command that is currently
 *	 connected, you have to wait for it to complete.  If this is
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2516
 *	 a problem, we could implement longjmp() / setjmp(), setjmp()
2517
 *	 called where the loop started in NCR5380_main().
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2518 2519 2520
 */

static
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2521
int NCR5380_abort(struct scsi_cmnd *cmd)
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2522
{
2523 2524
	struct Scsi_Host *instance = cmd->device->host;
	SETUP_HOSTDATA(instance);
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2525
	struct scsi_cmnd *tmp, **prev;
2526
	unsigned long flags;
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2527

2528
	scmd_printk(KERN_NOTICE, cmd, "aborting command\n");
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2529

2530
	spin_lock_irqsave(&hostdata->lock, flags);
2531

2532 2533
	NCR5380_dprint(NDEBUG_ANY, instance);
	NCR5380_dprint_phase(NDEBUG_ANY, instance);
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2534

F
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2535
	dprintk(NDEBUG_ABORT, "scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2536 2537
		    NCR5380_read(BUS_AND_STATUS_REG),
		    NCR5380_read(STATUS_REG));
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2538 2539

#if 1
2540 2541 2542 2543 2544
	/*
	 * Case 1 : If the command is the currently executing command,
	 * we'll set the aborted flag and return control so that
	 * information transfer routine can exit cleanly.
	 */
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2545

2546
	if (hostdata->connected == cmd) {
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2547

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2548
		dprintk(NDEBUG_ABORT, "scsi%d: aborting connected command\n", HOSTNO);
2549 2550 2551 2552
		/*
		 * We should perform BSY checking, and make sure we haven't slipped
		 * into BUS FREE.
		 */
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2553

2554 2555 2556 2557 2558 2559
		/*	NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
		/*
		 * Since we can't change phases until we've completed the current
		 * handshake, we have to source or sink a byte of data if the current
		 * phase is not MSGOUT.
		 */
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2560

2561 2562 2563 2564
		/*
		 * Return control to the executing NCR drive so we can clear the
		 * aborted flag and get back into our main loop.
		 */
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2565

2566 2567 2568
		if (do_abort(instance) == 0) {
			hostdata->connected = NULL;
			cmd->result = DID_ABORT << 16;
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2569
#ifdef SUPPORT_TAGS
2570
			cmd_free_tag(cmd);
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2571
#else
2572
			hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
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2573
#endif
2574
			maybe_release_dma_irq(instance);
2575
			spin_unlock_irqrestore(&hostdata->lock, flags);
2576
			cmd->scsi_done(cmd);
2577
			return SUCCESS;
2578
		} else {
2579
			spin_unlock_irqrestore(&hostdata->lock, flags);
2580
			printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2581
			return FAILED;
2582 2583
		}
	}
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2584 2585
#endif

2586 2587 2588 2589
	/*
	 * Case 2 : If the command hasn't been issued yet, we simply remove it
	 *	    from the issue queue.
	 */
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2590 2591
	for (prev = (struct scsi_cmnd **)&(hostdata->issue_queue),
	     tmp = (struct scsi_cmnd *)hostdata->issue_queue;
2592 2593 2594 2595
	     tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
		if (cmd == tmp) {
			REMOVE(5, *prev, tmp, NEXT(tmp));
			(*prev) = NEXT(tmp);
2596
			SET_NEXT(tmp, NULL);
2597
			tmp->result = DID_ABORT << 16;
2598
			maybe_release_dma_irq(instance);
2599
			spin_unlock_irqrestore(&hostdata->lock, flags);
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2600
			dprintk(NDEBUG_ABORT, "scsi%d: abort removed command from issue queue.\n",
2601 2602 2603 2604
				    HOSTNO);
			/* Tagged queuing note: no tag to free here, hasn't been assigned
			 * yet... */
			tmp->scsi_done(tmp);
2605
			return SUCCESS;
2606
		}
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2607 2608
	}

2609 2610 2611 2612 2613 2614 2615 2616 2617 2618
	/*
	 * Case 3 : If any commands are connected, we're going to fail the abort
	 *	    and let the high level SCSI driver retry at a later time or
	 *	    issue a reset.
	 *
	 *	    Timeouts, and therefore aborted commands, will be highly unlikely
	 *          and handling them cleanly in this situation would make the common
	 *	    case of noresets less efficient, and would pollute our code.  So,
	 *	    we fail.
	 */
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2619

2620
	if (hostdata->connected) {
2621
		spin_unlock_irqrestore(&hostdata->lock, flags);
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2622
		dprintk(NDEBUG_ABORT, "scsi%d: abort failed, command connected.\n", HOSTNO);
2623
		return FAILED;
2624
	}
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2625

2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650
	/*
	 * 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.
	 */

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2651
	for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp;
2652 2653
	     tmp = NEXT(tmp)) {
		if (cmd == tmp) {
F
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2654
			dprintk(NDEBUG_ABORT, "scsi%d: aborting disconnected command.\n", HOSTNO);
2655

2656 2657
			if (NCR5380_select(instance, cmd)) {
				spin_unlock_irq(&hostdata->lock);
2658
				return FAILED;
2659
			}
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2660
			dprintk(NDEBUG_ABORT, "scsi%d: nexus reestablished.\n", HOSTNO);
2661 2662 2663

			do_abort(instance);

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2664 2665
			for (prev = (struct scsi_cmnd **)&(hostdata->disconnected_queue),
			     tmp = (struct scsi_cmnd *)hostdata->disconnected_queue;
2666 2667 2668 2669
			     tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
				if (cmd == tmp) {
					REMOVE(5, *prev, tmp, NEXT(tmp));
					*prev = NEXT(tmp);
2670
					SET_NEXT(tmp, NULL);
2671 2672 2673 2674 2675
					tmp->result = DID_ABORT << 16;
					/* We must unlock the tag/LUN immediately here, since the
					 * target goes to BUS FREE and doesn't send us another
					 * message (COMMAND_COMPLETE or the like)
					 */
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2676
#ifdef SUPPORT_TAGS
2677
					cmd_free_tag(tmp);
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2678
#else
2679
					hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
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2680
#endif
2681
					maybe_release_dma_irq(instance);
2682
					spin_unlock_irqrestore(&hostdata->lock, flags);
2683
					tmp->scsi_done(tmp);
2684
					return SUCCESS;
2685 2686
				}
			}
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2687 2688 2689
		}
	}

2690 2691 2692 2693 2694
	/* 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);
2695
	spin_unlock_irqrestore(&hostdata->lock, flags);
2696

2697 2698 2699 2700 2701 2702 2703 2704 2705
	/*
	 * 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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2706

2707
	printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
L
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2708

2709
	return FAILED;
L
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2710 2711 2712
}


2713 2714 2715
/**
 * NCR5380_bus_reset - reset the SCSI bus
 * @cmd: SCSI command undergoing EH
L
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2716
 *
2717
 * Returns SUCCESS
2718
 */
L
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2719

F
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2720
static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
L
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2721
{
2722 2723
	struct Scsi_Host *instance = cmd->device->host;
	struct NCR5380_hostdata *hostdata = shost_priv(instance);
2724 2725
	int i;
	unsigned long flags;
L
Linus Torvalds 已提交
2726

2727
	spin_lock_irqsave(&hostdata->lock, flags);
2728 2729 2730 2731

#if (NDEBUG & NDEBUG_ANY)
	scmd_printk(KERN_INFO, cmd, "performing bus reset\n");
#endif
2732 2733
	NCR5380_dprint(NDEBUG_ANY, instance);
	NCR5380_dprint_phase(NDEBUG_ANY, instance);
2734 2735

	do_reset(instance);
2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748

	/* 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)
2749
		dsprintk(NDEBUG_ABORT, instance, "reset aborted issued command(s)\n");
2750
	if (hostdata->connected)
2751
		dsprintk(NDEBUG_ABORT, instance, "reset aborted a connected command\n");
2752
	if (hostdata->disconnected_queue)
2753
		dsprintk(NDEBUG_ABORT, instance, "reset aborted disconnected command(s)\n");
2754 2755 2756 2757

	hostdata->issue_queue = NULL;
	hostdata->connected = NULL;
	hostdata->disconnected_queue = NULL;
L
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2758
#ifdef SUPPORT_TAGS
2759
	free_all_tags(hostdata);
L
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2760
#endif
2761 2762
	for (i = 0; i < 8; ++i)
		hostdata->busy[i] = 0;
L
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2763
#ifdef REAL_DMA
2764
	hostdata->dma_len = 0;
L
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2765
#endif
2766 2767

	maybe_release_dma_irq(instance);
2768
	spin_unlock_irqrestore(&hostdata->lock, flags);
L
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2769

2770
	return SUCCESS;
L
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2771
}