2 * NCR 5380 generic driver routines. These should make it *trivial*
3 * to implement 5380 SCSI drivers under Linux with a non-trantor
6 * Note that these routines also work with NR53c400 family chips.
8 * Copyright 1993, Drew Eckhardt
10 * (Unix and Linux consulting and custom programming)
14 * For more information, please consult
17 * SCSI Protocol Controller
20 * NCR Microelectronics
21 * 1635 Aeroplaza Drive
22 * Colorado Springs, CO 80916
28 * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
31 * - Some of the debug statements were incorrect (undefined variables and the
32 * like). I fixed that.
34 * - In information_transfer(), I think a #ifdef was wrong. Looking at the
35 * possible DMA transfer size should also happen for REAL_DMA. I added this
36 * in the #if statement.
38 * - When using real DMA, information_transfer() should return in a DATAOUT
39 * phase after starting the DMA. It has nothing more to do.
41 * - The interrupt service routine should run main after end of DMA, too (not
42 * only after RESELECTION interrupts). Additionally, it should _not_ test
43 * for more interrupts after running main, since a DMA process may have
44 * been started and interrupts are turned on now. The new int could happen
45 * inside the execution of NCR5380_intr(), leading to recursive
48 * - I've added a function merge_contiguous_buffers() that tries to
49 * merge scatter-gather buffers that are located at contiguous
50 * physical addresses and can be processed with the same DMA setup.
51 * Since most scatter-gather operations work on a page (4K) of
52 * 4 buffers (1K), in more than 90% of all cases three interrupts and
53 * DMA setup actions are saved.
55 * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
56 * and USLEEP, because these were messing up readability and will never be
57 * needed for Atari SCSI.
59 * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
60 * stuff), and 'main' is executed in a bottom half if awoken by an
63 * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
64 * constructs. In my eyes, this made the source rather unreadable, so I
65 * finally replaced that by the *_PRINTK() macros.
69 /* Adapted for the sun3 by Sam Creasey. */
74 * This is a generic 5380 driver. To use it on a different platform,
75 * one simply writes appropriate system specific macros (ie, data
76 * transfer - some PC's will use the I/O bus, 68K's must use
77 * memory mapped) and drops this file in their 'C' wrapper.
79 * As far as command queueing, two queues are maintained for
80 * each 5380 in the system - commands that haven't been issued yet,
81 * and commands that are currently executing. This means that an
82 * unlimited number of commands may be queued, letting
83 * more commands propagate from the higher driver levels giving higher
84 * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
85 * allowing multiple commands to propagate all the way to a SCSI-II device
86 * while a command is already executing.
89 * Issues specific to the NCR5380 :
91 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
92 * piece of hardware that requires you to sit in a loop polling for
93 * the REQ signal as long as you are connected. Some devices are
94 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
95 * while doing long seek operations. [...] These
96 * broken devices are the exception rather than the rule and I'd rather
97 * spend my time optimizing for the normal case.
101 * At the heart of the design is a coroutine, NCR5380_main,
102 * which is started from a workqueue for each NCR5380 host in the
103 * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
104 * removing the commands from the issue queue and calling
105 * NCR5380_select() if a nexus is not established.
107 * Once a nexus is established, the NCR5380_information_transfer()
108 * phase goes through the various phases as instructed by the target.
109 * if the target goes into MSG IN and sends a DISCONNECT message,
110 * the command structure is placed into the per instance disconnected
111 * queue, and NCR5380_main tries to find more work. If the target is
112 * idle for too long, the system will try to sleep.
114 * If a command has disconnected, eventually an interrupt will trigger,
115 * calling NCR5380_intr() which will in turn call NCR5380_reselect
116 * to reestablish a nexus. This will run main if necessary.
118 * On command termination, the done function will be called as
121 * SCSI pointers are maintained in the SCp field of SCSI command
122 * structures, being initialized after the command is connected
123 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
124 * Note that in violation of the standard, an implicit SAVE POINTERS operation
125 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
130 * This file a skeleton Linux SCSI driver for the NCR 5380 series
131 * of chips. To use it, you write an architecture specific functions
132 * and macros and include this file in your driver.
134 * These macros control options :
135 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
136 * for commands that return with a CHECK CONDITION status.
138 * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
141 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
143 * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
145 * These macros MUST be defined :
147 * NCR5380_read(register) - read from the specified register
149 * NCR5380_write(register, value) - write to the specific register
151 * NCR5380_implementation_fields - additional fields needed for this
152 * specific implementation of the NCR5380
154 * Either real DMA *or* pseudo DMA may be implemented
156 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
157 * Note that the DMA setup functions should return the number of bytes
158 * that they were able to program the controller for.
160 * Also note that generic i386/PC versions of these macros are
161 * available as NCR5380_i386_dma_write_setup,
162 * NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
164 * NCR5380_dma_write_setup(instance, src, count) - initialize
165 * NCR5380_dma_read_setup(instance, dst, count) - initialize
166 * NCR5380_dma_residual(instance); - residual count
169 * NCR5380_pwrite(instance, src, count)
170 * NCR5380_pread(instance, dst, count);
172 * The generic driver is initialized by calling NCR5380_init(instance),
173 * after setting the appropriate host specific fields and ID. If the
174 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
175 * possible) function may be used.
178 #define NEXT(cmd) ((struct scsi_cmnd *)(cmd)->host_scribble)
179 #define SET_NEXT(cmd,next) ((cmd)->host_scribble = (void *)(next))
180 #define NEXTADDR(cmd) ((struct scsi_cmnd **)&(cmd)->host_scribble)
182 #define HOSTNO instance->host_no
184 static int do_abort(struct Scsi_Host *);
185 static void do_reset(struct Scsi_Host *);
190 * Functions for handling tagged queuing
191 * =====================================
193 * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
195 * Using consecutive numbers for the tags is no good idea in my eyes. There
196 * could be wrong re-usings if the counter (8 bit!) wraps and some early
197 * command has been preempted for a long time. My solution: a bitfield for
198 * remembering used tags.
200 * There's also the problem that each target has a certain queue size, but we
201 * cannot know it in advance :-( We just see a QUEUE_FULL status being
202 * returned. So, in this case, the driver internal queue size assumption is
203 * reduced to the number of active tags if QUEUE_FULL is returned by the
206 * We're also not allowed running tagged commands as long as an untagged
207 * command is active. And REQUEST SENSE commands after a contingent allegiance
208 * condition _must_ be untagged. To keep track whether an untagged command has
209 * been issued, the host->busy array is still employed, as it is without
210 * support for tagged queuing.
212 * One could suspect that there are possible race conditions between
213 * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
214 * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
215 * which already guaranteed to be running at most once. It is also the only
216 * place where tags/LUNs are allocated. So no other allocation can slip
217 * between that pair, there could only happen a reselection, which can free a
218 * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
219 * important: the tag bit must be cleared before 'nr_allocated' is decreased.
222 static void __init init_tags(struct NCR5380_hostdata *hostdata)
225 struct tag_alloc *ta;
227 if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
230 for (target = 0; target < 8; ++target) {
231 for (lun = 0; lun < 8; ++lun) {
232 ta = &hostdata->TagAlloc[target][lun];
233 bitmap_zero(ta->allocated, MAX_TAGS);
234 ta->nr_allocated = 0;
235 /* At the beginning, assume the maximum queue size we could
236 * support (MAX_TAGS). This value will be decreased if the target
237 * returns QUEUE_FULL status.
239 ta->queue_size = MAX_TAGS;
245 /* Check if we can issue a command to this LUN: First see if the LUN is marked
246 * busy by an untagged command. If the command should use tagged queuing, also
247 * check that there is a free tag and the target's queue won't overflow. This
248 * function should be called with interrupts disabled to avoid race
252 static int is_lun_busy(struct scsi_cmnd *cmd, int should_be_tagged)
254 u8 lun = cmd->device->lun;
255 struct Scsi_Host *instance = cmd->device->host;
256 struct NCR5380_hostdata *hostdata = shost_priv(instance);
258 if (hostdata->busy[cmd->device->id] & (1 << lun))
260 if (!should_be_tagged ||
261 !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
262 !cmd->device->tagged_supported)
264 if (hostdata->TagAlloc[scmd_id(cmd)][lun].nr_allocated >=
265 hostdata->TagAlloc[scmd_id(cmd)][lun].queue_size) {
266 dsprintk(NDEBUG_TAGS, instance, "target %d lun %d: no free tags\n",
274 /* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
275 * must be called before!), or reserve the LUN in 'busy' if the command is
279 static void cmd_get_tag(struct scsi_cmnd *cmd, int should_be_tagged)
281 u8 lun = cmd->device->lun;
282 struct Scsi_Host *instance = cmd->device->host;
283 struct NCR5380_hostdata *hostdata = shost_priv(instance);
285 /* If we or the target don't support tagged queuing, allocate the LUN for
286 * an untagged command.
288 if (!should_be_tagged ||
289 !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
290 !cmd->device->tagged_supported) {
292 hostdata->busy[cmd->device->id] |= (1 << lun);
293 dsprintk(NDEBUG_TAGS, instance, "target %d lun %d now allocated by untagged command\n",
296 struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
298 cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
299 set_bit(cmd->tag, ta->allocated);
301 dsprintk(NDEBUG_TAGS, instance, "using tag %d for target %d lun %d (%d tags allocated)\n",
302 cmd->tag, scmd_id(cmd), lun, ta->nr_allocated);
307 /* Mark the tag of command 'cmd' as free, or in case of an untagged command,
311 static void cmd_free_tag(struct scsi_cmnd *cmd)
313 u8 lun = cmd->device->lun;
314 struct Scsi_Host *instance = cmd->device->host;
315 struct NCR5380_hostdata *hostdata = shost_priv(instance);
317 if (cmd->tag == TAG_NONE) {
318 hostdata->busy[cmd->device->id] &= ~(1 << lun);
319 dsprintk(NDEBUG_TAGS, instance, "target %d lun %d untagged cmd freed\n",
321 } else if (cmd->tag >= MAX_TAGS) {
322 shost_printk(KERN_NOTICE, instance,
323 "trying to free bad tag %d!\n", cmd->tag);
325 struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
326 clear_bit(cmd->tag, ta->allocated);
328 dsprintk(NDEBUG_TAGS, instance, "freed tag %d for target %d lun %d\n",
329 cmd->tag, scmd_id(cmd), lun);
334 static void free_all_tags(struct NCR5380_hostdata *hostdata)
337 struct tag_alloc *ta;
339 if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
342 for (target = 0; target < 8; ++target) {
343 for (lun = 0; lun < 8; ++lun) {
344 ta = &hostdata->TagAlloc[target][lun];
345 bitmap_zero(ta->allocated, MAX_TAGS);
346 ta->nr_allocated = 0;
351 #endif /* SUPPORT_TAGS */
355 * Function: void merge_contiguous_buffers( struct scsi_cmnd *cmd )
357 * Purpose: Try to merge several scatter-gather requests into one DMA
358 * transfer. This is possible if the scatter buffers lie on
359 * physical contiguous addresses.
361 * Parameters: struct scsi_cmnd *cmd
362 * The command to work on. The first scatter buffer's data are
363 * assumed to be already transferred into ptr/this_residual.
366 static void merge_contiguous_buffers(struct scsi_cmnd *cmd)
368 #if !defined(CONFIG_SUN3)
369 unsigned long endaddr;
370 #if (NDEBUG & NDEBUG_MERGING)
371 unsigned long oldlen = cmd->SCp.this_residual;
375 for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
376 cmd->SCp.buffers_residual &&
377 virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
378 dprintk(NDEBUG_MERGING, "VTOP(%p) == %08lx -> merging\n",
379 page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
380 #if (NDEBUG & NDEBUG_MERGING)
384 --cmd->SCp.buffers_residual;
385 cmd->SCp.this_residual += cmd->SCp.buffer->length;
386 endaddr += cmd->SCp.buffer->length;
388 #if (NDEBUG & NDEBUG_MERGING)
389 if (oldlen != cmd->SCp.this_residual)
390 dprintk(NDEBUG_MERGING, "merged %d buffers from %p, new length %08x\n",
391 cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
393 #endif /* !defined(CONFIG_SUN3) */
397 * initialize_SCp - init the scsi pointer field
398 * @cmd: command block to set up
400 * Set up the internal fields in the SCSI command.
403 static inline void initialize_SCp(struct scsi_cmnd *cmd)
406 * Initialize the Scsi Pointer field so that all of the commands in the
407 * various queues are valid.
410 if (scsi_bufflen(cmd)) {
411 cmd->SCp.buffer = scsi_sglist(cmd);
412 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
413 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
414 cmd->SCp.this_residual = cmd->SCp.buffer->length;
415 /* ++roman: Try to merge some scatter-buffers if they are at
416 * contiguous physical addresses.
418 merge_contiguous_buffers(cmd);
420 cmd->SCp.buffer = NULL;
421 cmd->SCp.buffers_residual = 0;
423 cmd->SCp.this_residual = 0;
428 * NCR5380_poll_politely2 - wait for two chip register values
429 * @instance: controller to poll
430 * @reg1: 5380 register to poll
431 * @bit1: Bitmask to check
432 * @val1: Expected value
433 * @reg2: Second 5380 register to poll
434 * @bit2: Second bitmask to check
435 * @val2: Second expected value
436 * @wait: Time-out in jiffies
438 * Polls the chip in a reasonably efficient manner waiting for an
439 * event to occur. After a short quick poll we begin to yield the CPU
440 * (if possible). In irq contexts the time-out is arbitrarily limited.
441 * Callers may hold locks as long as they are held in irq mode.
443 * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
446 static int NCR5380_poll_politely2(struct Scsi_Host *instance,
447 int reg1, int bit1, int val1,
448 int reg2, int bit2, int val2, int wait)
450 struct NCR5380_hostdata *hostdata = shost_priv(instance);
451 unsigned long deadline = jiffies + wait;
454 /* Busy-wait for up to 10 ms */
455 n = min(10000U, jiffies_to_usecs(wait));
456 n *= hostdata->accesses_per_ms;
459 if ((NCR5380_read(reg1) & bit1) == val1)
461 if ((NCR5380_read(reg2) & bit2) == val2)
466 if (irqs_disabled() || in_interrupt())
469 /* Repeatedly sleep for 1 ms until deadline */
470 while (time_is_after_jiffies(deadline)) {
471 schedule_timeout_uninterruptible(1);
472 if ((NCR5380_read(reg1) & bit1) == val1)
474 if ((NCR5380_read(reg2) & bit2) == val2)
481 static inline int NCR5380_poll_politely(struct Scsi_Host *instance,
482 int reg, int bit, int val, int wait)
484 return NCR5380_poll_politely2(instance, reg, bit, val,
485 reg, bit, val, wait);
493 { SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
494 { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD, "CD" }, { SR_IO, "IO" },
495 { SR_SEL, "SEL" }, {0, NULL}
497 {BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
499 {ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
500 {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
501 {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
504 {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
505 {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
506 "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
507 {MR_MONITOR_BSY, "MODE MONITOR BSY"},
508 {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
513 * NCR5380_print - print scsi bus signals
514 * @instance: adapter state to dump
516 * Print the SCSI bus signals for debugging purposes
519 static void NCR5380_print(struct Scsi_Host *instance)
521 unsigned char status, data, basr, mr, icr, i;
523 data = NCR5380_read(CURRENT_SCSI_DATA_REG);
524 status = NCR5380_read(STATUS_REG);
525 mr = NCR5380_read(MODE_REG);
526 icr = NCR5380_read(INITIATOR_COMMAND_REG);
527 basr = NCR5380_read(BUS_AND_STATUS_REG);
529 printk("STATUS_REG: %02x ", status);
530 for (i = 0; signals[i].mask; ++i)
531 if (status & signals[i].mask)
532 printk(",%s", signals[i].name);
533 printk("\nBASR: %02x ", basr);
534 for (i = 0; basrs[i].mask; ++i)
535 if (basr & basrs[i].mask)
536 printk(",%s", basrs[i].name);
537 printk("\nICR: %02x ", icr);
538 for (i = 0; icrs[i].mask; ++i)
539 if (icr & icrs[i].mask)
540 printk(",%s", icrs[i].name);
541 printk("\nMODE: %02x ", mr);
542 for (i = 0; mrs[i].mask; ++i)
543 if (mr & mrs[i].mask)
544 printk(",%s", mrs[i].name);
552 {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
553 {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
554 {PHASE_UNKNOWN, "UNKNOWN"}
558 * NCR5380_print_phase - show SCSI phase
559 * @instance: adapter to dump
561 * Print the current SCSI phase for debugging purposes
566 static void NCR5380_print_phase(struct Scsi_Host *instance)
568 unsigned char status;
571 status = NCR5380_read(STATUS_REG);
572 if (!(status & SR_REQ))
573 printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
575 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
576 (phases[i].value != (status & PHASE_MASK)); ++i)
578 printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
585 * NCR58380_info - report driver and host information
586 * @instance: relevant scsi host instance
588 * For use as the host template info() handler.
593 static const char *NCR5380_info(struct Scsi_Host *instance)
595 struct NCR5380_hostdata *hostdata = shost_priv(instance);
597 return hostdata->info;
600 static void prepare_info(struct Scsi_Host *instance)
602 struct NCR5380_hostdata *hostdata = shost_priv(instance);
604 snprintf(hostdata->info, sizeof(hostdata->info),
605 "%s, io_port 0x%lx, n_io_port %d, "
606 "base 0x%lx, irq %d, "
607 "can_queue %d, cmd_per_lun %d, "
608 "sg_tablesize %d, this_id %d, "
611 instance->hostt->name, instance->io_port, instance->n_io_port,
612 instance->base, instance->irq,
613 instance->can_queue, instance->cmd_per_lun,
614 instance->sg_tablesize, instance->this_id,
615 hostdata->flags & FLAG_TAGGED_QUEUING ? "TAGGED_QUEUING " : "",
616 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "",
633 * NCR5380_init - initialise an NCR5380
634 * @instance: adapter to configure
635 * @flags: control flags
637 * Initializes *instance and corresponding 5380 chip,
638 * with flags OR'd into the initial flags value.
640 * Notes : I assume that the host, hostno, and id bits have been
641 * set correctly. I don't care about the irq and other fields.
643 * Returns 0 for success
646 static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
648 struct NCR5380_hostdata *hostdata = shost_priv(instance);
650 unsigned long deadline;
652 hostdata->host = instance;
653 hostdata->id_mask = 1 << instance->this_id;
654 hostdata->id_higher_mask = 0;
655 for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
656 if (i > hostdata->id_mask)
657 hostdata->id_higher_mask |= i;
658 for (i = 0; i < 8; ++i)
659 hostdata->busy[i] = 0;
663 #if defined (REAL_DMA)
664 hostdata->dma_len = 0;
666 spin_lock_init(&hostdata->lock);
667 hostdata->connected = NULL;
668 hostdata->issue_queue = NULL;
669 hostdata->disconnected_queue = NULL;
670 hostdata->flags = flags;
672 INIT_WORK(&hostdata->main_task, NCR5380_main);
673 hostdata->work_q = alloc_workqueue("ncr5380_%d",
674 WQ_UNBOUND | WQ_MEM_RECLAIM,
675 1, instance->host_no);
676 if (!hostdata->work_q)
679 prepare_info(instance);
681 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
682 NCR5380_write(MODE_REG, MR_BASE);
683 NCR5380_write(TARGET_COMMAND_REG, 0);
684 NCR5380_write(SELECT_ENABLE_REG, 0);
686 /* Calibrate register polling loop */
688 deadline = jiffies + 1;
691 } while (time_is_after_jiffies(deadline));
692 deadline += msecs_to_jiffies(256);
694 NCR5380_read(STATUS_REG);
697 } while (time_is_after_jiffies(deadline));
698 hostdata->accesses_per_ms = i / 256;
704 * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
705 * @instance: adapter to check
707 * If the system crashed, it may have crashed with a connected target and
708 * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
709 * currently established nexus, which we know nothing about. Failing that
712 * Note that a bus reset will cause the chip to assert IRQ.
714 * Returns 0 if successful, otherwise -ENXIO.
717 static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
719 struct NCR5380_hostdata *hostdata = shost_priv(instance);
722 for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
727 shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
728 NCR5380_poll_politely(instance,
729 STATUS_REG, SR_BSY, 0, 5 * HZ);
732 shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
736 shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
738 /* Wait after a reset; the SCSI standard calls for
739 * 250ms, we wait 500ms to be on the safe side.
740 * But some Toshiba CD-ROMs need ten times that.
742 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
748 shost_printk(KERN_ERR, instance, "bus locked solid\n");
756 * NCR5380_exit - remove an NCR5380
757 * @instance: adapter to remove
759 * Assumes that no more work can be queued (e.g. by NCR5380_intr).
762 static void NCR5380_exit(struct Scsi_Host *instance)
764 struct NCR5380_hostdata *hostdata = shost_priv(instance);
766 cancel_work_sync(&hostdata->main_task);
767 destroy_workqueue(hostdata->work_q);
771 * NCR5380_queue_command - queue a command
772 * @instance: the relevant SCSI adapter
775 * cmd is added to the per-instance issue queue, with minor
776 * twiddling done to the host specific fields of cmd. If the
777 * main coroutine is not running, it is restarted.
780 static int NCR5380_queue_command(struct Scsi_Host *instance,
781 struct scsi_cmnd *cmd)
783 struct NCR5380_hostdata *hostdata = shost_priv(instance);
784 struct scsi_cmnd *tmp;
787 #if (NDEBUG & NDEBUG_NO_WRITE)
788 switch (cmd->cmnd[0]) {
791 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
792 cmd->result = (DID_ERROR << 16);
796 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
799 * We use the host_scribble field as a pointer to the next command
807 * Insert the cmd into the issue queue. Note that REQUEST SENSE
808 * commands are added to the head of the queue since any command will
809 * clear the contingent allegiance condition that exists and the
810 * sense data is only guaranteed to be valid while the condition exists.
813 /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
814 * Otherwise a running NCR5380_main may steal the lock.
815 * Lock before actually inserting due to fairness reasons explained in
816 * atari_scsi.c. If we insert first, then it's impossible for this driver
817 * to release the lock.
818 * Stop timer for this command while waiting for the lock, or timeouts
819 * may happen (and they really do), and it's no good if the command doesn't
820 * appear in any of the queues.
821 * ++roman: Just disabling the NCR interrupt isn't sufficient here,
822 * because also a timer int can trigger an abort or reset, which would
823 * alter queues and touch the lock.
825 if (!NCR5380_acquire_dma_irq(instance))
826 return SCSI_MLQUEUE_HOST_BUSY;
828 spin_lock_irqsave(&hostdata->lock, flags);
831 * Insert the cmd into the issue queue. Note that REQUEST SENSE
832 * commands are added to the head of the queue since any command will
833 * clear the contingent allegiance condition that exists and the
834 * sense data is only guaranteed to be valid while the condition exists.
837 if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
838 SET_NEXT(cmd, hostdata->issue_queue);
839 hostdata->issue_queue = cmd;
841 for (tmp = (struct scsi_cmnd *)hostdata->issue_queue;
842 NEXT(tmp); tmp = NEXT(tmp))
846 spin_unlock_irqrestore(&hostdata->lock, flags);
848 dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
849 cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
851 /* Kick off command processing */
852 queue_work(hostdata->work_q, &hostdata->main_task);
856 static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
858 struct NCR5380_hostdata *hostdata = shost_priv(instance);
860 /* Caller does the locking needed to set & test these data atomically */
861 if (!hostdata->disconnected_queue &&
862 !hostdata->issue_queue &&
863 !hostdata->connected &&
864 !hostdata->retain_dma_intr)
865 NCR5380_release_dma_irq(instance);
869 * NCR5380_main - NCR state machines
871 * NCR5380_main is a coroutine that runs as long as more work can
872 * be done on the NCR5380 host adapters in a system. Both
873 * NCR5380_queue_command() and NCR5380_intr() will try to start it
874 * in case it is not running.
876 * Locks: called as its own thread with no locks held.
879 static void NCR5380_main(struct work_struct *work)
881 struct NCR5380_hostdata *hostdata =
882 container_of(work, struct NCR5380_hostdata, main_task);
883 struct Scsi_Host *instance = hostdata->host;
884 struct scsi_cmnd *tmp, *prev;
888 * ++roman: Just disabling the NCR interrupt isn't sufficient here,
889 * because also a timer int can trigger an abort or reset, which can
890 * alter queues and touch the Falcon lock.
893 spin_lock_irq(&hostdata->lock);
897 if (!hostdata->connected) {
898 dprintk(NDEBUG_MAIN, "scsi%d: not connected\n", HOSTNO);
900 * Search through the issue_queue for a command destined
901 * for a target that's not busy.
903 #if (NDEBUG & NDEBUG_LISTS)
904 for (tmp = (struct scsi_cmnd *) hostdata->issue_queue, prev = NULL;
905 tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
907 /*printk("%p ", tmp);*/
908 if ((tmp == prev) && tmp)
910 /* else printk("\n"); */
912 for (tmp = (struct scsi_cmnd *) hostdata->issue_queue,
913 prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
914 u8 lun = tmp->device->lun;
916 dsprintk(NDEBUG_QUEUES, instance, "main: tmp=%p target=%d busy=%d lun=%d\n",
917 tmp, scmd_id(tmp), hostdata->busy[scmd_id(tmp)], lun);
918 /* When we find one, remove it from the issue queue. */
921 !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
923 !(hostdata->busy[tmp->device->id] & (1 << lun))
927 SET_NEXT(prev, NEXT(tmp));
929 hostdata->issue_queue = NEXT(tmp);
932 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES,
933 instance, "main: removed %p from issue queue %p\n",
936 hostdata->retain_dma_intr++;
939 * Attempt to establish an I_T_L nexus here.
940 * On success, instance->hostdata->connected is set.
941 * On failure, we must add the command back to the
942 * issue queue so we can keep trying.
945 * REQUEST SENSE commands are issued without tagged
946 * queueing, even on SCSI-II devices because the
947 * contingent allegiance condition exists for the
950 /* ++roman: ...and the standard also requires that
951 * REQUEST SENSE command are untagged.
955 cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
957 if (!NCR5380_select(instance, tmp)) {
958 /* OK or bad target */
959 hostdata->retain_dma_intr--;
960 maybe_release_dma_irq(instance);
963 SET_NEXT(tmp, hostdata->issue_queue);
964 hostdata->issue_queue = tmp;
965 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES,
966 instance, "main: select() failed, %p returned to issue queue\n",
971 hostdata->retain_dma_intr--;
974 if (hostdata->connected)
976 } /* if target/lun/target queue is not busy */
977 } /* for issue_queue */
978 } /* if (!hostdata->connected) */
980 if (hostdata->connected
982 && !hostdata->dma_len
985 dprintk(NDEBUG_MAIN, "scsi%d: main: performing information transfer\n",
987 NCR5380_information_transfer(instance);
988 dprintk(NDEBUG_MAIN, "scsi%d: main: done set false\n", HOSTNO);
992 spin_unlock_irq(&hostdata->lock);
998 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
1000 * Purpose : Called by interrupt handler when DMA finishes or a phase
1001 * mismatch occurs (which would finish the DMA transfer).
1003 * Inputs : instance - this instance of the NCR5380.
1007 static void NCR5380_dma_complete(struct Scsi_Host *instance)
1009 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1011 unsigned char **data;
1012 volatile int *count;
1013 int saved_data = 0, overrun = 0;
1016 if (hostdata->read_overruns) {
1017 p = hostdata->connected->SCp.phase;
1020 if ((NCR5380_read(BUS_AND_STATUS_REG) &
1021 (BASR_PHASE_MATCH|BASR_ACK)) ==
1022 (BASR_PHASE_MATCH|BASR_ACK)) {
1023 saved_data = NCR5380_read(INPUT_DATA_REG);
1025 dprintk(NDEBUG_DMA, "scsi%d: read overrun handled\n", HOSTNO);
1030 #if defined(CONFIG_SUN3)
1031 if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
1032 pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
1037 /* make sure we're not stuck in a data phase */
1038 if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
1039 (BASR_PHASE_MATCH | BASR_ACK)) {
1040 pr_err("scsi%d: BASR %02x\n", instance->host_no,
1041 NCR5380_read(BUS_AND_STATUS_REG));
1042 pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
1048 NCR5380_write(MODE_REG, MR_BASE);
1049 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1050 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1052 transferred = hostdata->dma_len - NCR5380_dma_residual(instance);
1053 hostdata->dma_len = 0;
1055 data = (unsigned char **)&hostdata->connected->SCp.ptr;
1056 count = &hostdata->connected->SCp.this_residual;
1057 *data += transferred;
1058 *count -= transferred;
1060 if (hostdata->read_overruns) {
1063 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1064 cnt = toPIO = hostdata->read_overruns;
1066 dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
1067 *(*data)++ = saved_data;
1072 dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1073 NCR5380_transfer_pio(instance, &p, &cnt, data);
1074 *count -= toPIO - cnt;
1078 #endif /* REAL_DMA */
1082 * NCR5380_intr - generic NCR5380 irq handler
1083 * @irq: interrupt number
1084 * @dev_id: device info
1086 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1087 * from the disconnected queue, and restarting NCR5380_main()
1090 * The chip can assert IRQ in any of six different conditions. The IRQ flag
1091 * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
1092 * Three of these six conditions are latched in the Bus and Status Register:
1093 * - End of DMA (cleared by ending DMA Mode)
1094 * - Parity error (cleared by reading RPIR)
1095 * - Loss of BSY (cleared by reading RPIR)
1096 * Two conditions have flag bits that are not latched:
1097 * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
1098 * - Bus reset (non-maskable)
1099 * The remaining condition has no flag bit at all:
1100 * - Selection/reselection
1102 * Hence, establishing the cause(s) of any interrupt is partly guesswork.
1103 * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
1104 * claimed that "the design of the [DP8490] interrupt logic ensures
1105 * interrupts will not be lost (they can be on the DP5380)."
1106 * The L5380/53C80 datasheet from LOGIC Devices has more details.
1108 * Checking for bus reset by reading RST is futile because of interrupt
1109 * latency, but a bus reset will reset chip logic. Checking for parity error
1110 * is unnecessary because that interrupt is never enabled. A Loss of BSY
1111 * condition will clear DMA Mode. We can tell when this occurs because the
1112 * the Busy Monitor interrupt is enabled together with DMA Mode.
1115 static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1117 struct Scsi_Host *instance = dev_id;
1118 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1121 unsigned long flags;
1123 spin_lock_irqsave(&hostdata->lock, flags);
1125 basr = NCR5380_read(BUS_AND_STATUS_REG);
1126 if (basr & BASR_IRQ) {
1127 unsigned char mr = NCR5380_read(MODE_REG);
1128 unsigned char sr = NCR5380_read(STATUS_REG);
1130 dprintk(NDEBUG_INTR, "scsi%d: IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
1131 HOSTNO, irq, basr, sr, mr);
1133 #if defined(REAL_DMA)
1134 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
1135 /* Probably End of DMA, Phase Mismatch or Loss of BSY.
1136 * We ack IRQ after clearing Mode Register. Workarounds
1137 * for End of DMA errata need to happen in DMA Mode.
1140 dprintk(NDEBUG_INTR, "scsi%d: interrupt in DMA mode\n", HOSTNO);
1142 if (hostdata->connected) {
1143 NCR5380_dma_complete(instance);
1144 queue_work(hostdata->work_q, &hostdata->main_task);
1146 NCR5380_write(MODE_REG, MR_BASE);
1147 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1150 #endif /* REAL_DMA */
1151 if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
1152 (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
1153 /* Probably reselected */
1154 NCR5380_write(SELECT_ENABLE_REG, 0);
1155 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1157 dprintk(NDEBUG_INTR, "scsi%d: interrupt with SEL and IO\n",
1160 if (!hostdata->connected) {
1161 NCR5380_reselect(instance);
1162 queue_work(hostdata->work_q, &hostdata->main_task);
1164 if (!hostdata->connected)
1165 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1167 /* Probably Bus Reset */
1168 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1170 dprintk(NDEBUG_INTR, "scsi%d: unknown interrupt\n", HOSTNO);
1171 #ifdef SUN3_SCSI_VME
1172 dregs->csr |= CSR_DMA_ENABLE;
1177 shost_printk(KERN_NOTICE, instance, "interrupt without IRQ bit\n");
1178 #ifdef SUN3_SCSI_VME
1179 dregs->csr |= CSR_DMA_ENABLE;
1183 spin_unlock_irqrestore(&hostdata->lock, flags);
1185 return IRQ_RETVAL(handled);
1189 * Function : int NCR5380_select(struct Scsi_Host *instance,
1190 * struct scsi_cmnd *cmd)
1192 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1193 * including ARBITRATION, SELECTION, and initial message out for
1194 * IDENTIFY and queue messages.
1196 * Inputs : instance - instantiation of the 5380 driver on which this
1197 * target lives, cmd - SCSI command to execute.
1199 * Returns : -1 if selection failed but should be retried.
1200 * 0 if selection failed and should not be retried.
1201 * 0 if selection succeeded completely (hostdata->connected == cmd).
1204 * If bus busy, arbitration failed, etc, NCR5380_select() will exit
1205 * with registers as they should have been on entry - ie
1206 * SELECT_ENABLE will be set appropriately, the NCR5380
1207 * will cease to drive any SCSI bus signals.
1209 * If successful : I_T_L or I_T_L_Q nexus will be established,
1210 * instance->connected will be set to cmd.
1211 * SELECT interrupt will be disabled.
1213 * If failed (no target) : cmd->scsi_done() will be called, and the
1214 * cmd->result host byte set to DID_BAD_TARGET.
1217 static int NCR5380_select(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
1219 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1220 unsigned char tmp[3], phase;
1221 unsigned char *data;
1225 NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1226 dprintk(NDEBUG_ARBITRATION, "scsi%d: starting arbitration, id = %d\n", HOSTNO,
1230 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1231 * data bus during SELECTION.
1234 NCR5380_write(TARGET_COMMAND_REG, 0);
1237 * Start arbitration.
1240 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1241 NCR5380_write(MODE_REG, MR_ARBITRATE);
1243 /* The chip now waits for BUS FREE phase. Then after the 800 ns
1244 * Bus Free Delay, arbitration will begin.
1247 spin_unlock_irq(&hostdata->lock);
1248 err = NCR5380_poll_politely2(instance, MODE_REG, MR_ARBITRATE, 0,
1249 INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
1250 ICR_ARBITRATION_PROGRESS, HZ);
1251 spin_lock_irq(&hostdata->lock);
1252 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
1253 /* Reselection interrupt */
1257 NCR5380_write(MODE_REG, MR_BASE);
1258 shost_printk(KERN_ERR, instance,
1259 "select: arbitration timeout\n");
1262 spin_unlock_irq(&hostdata->lock);
1264 /* The SCSI-2 arbitration delay is 2.4 us */
1267 /* Check for lost arbitration */
1268 if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1269 (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1270 (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1271 NCR5380_write(MODE_REG, MR_BASE);
1272 dprintk(NDEBUG_ARBITRATION, "scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1274 spin_lock_irq(&hostdata->lock);
1278 /* After/during arbitration, BSY should be asserted.
1279 * IBM DPES-31080 Version S31Q works now
1280 * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1282 NCR5380_write(INITIATOR_COMMAND_REG,
1283 ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1286 * Again, bus clear + bus settle time is 1.2us, however, this is
1287 * a minimum so we'll udelay ceil(1.2)
1290 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1295 spin_lock_irq(&hostdata->lock);
1297 /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1298 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1301 dprintk(NDEBUG_ARBITRATION, "scsi%d: won arbitration\n", HOSTNO);
1304 * Now that we have won arbitration, start Selection process, asserting
1305 * the host and target ID's on the SCSI bus.
1308 NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
1311 * Raise ATN while SEL is true before BSY goes false from arbitration,
1312 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1313 * phase immediately after selection.
1316 NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
1317 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
1318 NCR5380_write(MODE_REG, MR_BASE);
1321 * Reselect interrupts must be turned off prior to the dropping of BSY,
1322 * otherwise we will trigger an interrupt.
1324 NCR5380_write(SELECT_ENABLE_REG, 0);
1326 spin_unlock_irq(&hostdata->lock);
1329 * The initiator shall then wait at least two deskew delays and release
1332 udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
1335 NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
1336 ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1339 * Something weird happens when we cease to drive BSY - looks
1340 * like the board/chip is letting us do another read before the
1341 * appropriate propagation delay has expired, and we're confusing
1342 * a BSY signal from ourselves as the target's response to SELECTION.
1344 * A small delay (the 'C++' frontend breaks the pipeline with an
1345 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1346 * tighter 'C' code breaks and requires this) solves the problem -
1347 * the 1 us delay is arbitrary, and only used because this delay will
1348 * be the same on other platforms and since it works here, it should
1351 * wingel suggests that this could be due to failing to wait
1357 dprintk(NDEBUG_SELECTION, "scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
1360 * The SCSI specification calls for a 250 ms timeout for the actual
1364 err = NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, SR_BSY,
1365 msecs_to_jiffies(250));
1367 if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1368 spin_lock_irq(&hostdata->lock);
1369 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1370 NCR5380_reselect(instance);
1371 if (!hostdata->connected)
1372 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1373 printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
1379 spin_lock_irq(&hostdata->lock);
1380 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1381 cmd->result = DID_BAD_TARGET << 16;
1385 cmd->scsi_done(cmd);
1386 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1387 dprintk(NDEBUG_SELECTION, "scsi%d: target did not respond within 250ms\n", HOSTNO);
1392 * No less than two deskew delays after the initiator detects the
1393 * BSY signal is true, it shall release the SEL signal and may
1394 * change the DATA BUS. -wingel
1399 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1402 * Since we followed the SCSI spec, and raised ATN while SEL
1403 * was true but before BSY was false during selection, the information
1404 * transfer phase should be a MESSAGE OUT phase so that we can send the
1407 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1408 * message (2 bytes) with a tag ID that we increment with every command
1409 * until it wraps back to 0.
1411 * XXX - it turns out that there are some broken SCSI-II devices,
1412 * which claim to support tagged queuing but fail when more than
1413 * some number of commands are issued at once.
1416 /* Wait for start of REQ/ACK handshake */
1418 err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1419 spin_lock_irq(&hostdata->lock);
1421 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1422 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1423 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1427 dprintk(NDEBUG_SELECTION, "scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1428 HOSTNO, cmd->device->id);
1429 tmp[0] = IDENTIFY(1, cmd->device->lun);
1432 if (cmd->tag != TAG_NONE) {
1433 tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1441 #endif /* SUPPORT_TAGS */
1443 /* Send message(s) */
1445 phase = PHASE_MSGOUT;
1446 NCR5380_transfer_pio(instance, &phase, &len, &data);
1447 dprintk(NDEBUG_SELECTION, "scsi%d: nexus established.\n", HOSTNO);
1448 /* XXX need to handle errors here */
1450 hostdata->connected = cmd;
1451 #ifndef SUPPORT_TAGS
1452 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1454 #ifdef SUN3_SCSI_VME
1455 dregs->csr |= CSR_INTR;
1458 initialize_SCp(cmd);
1464 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1465 * unsigned char *phase, int *count, unsigned char **data)
1467 * Purpose : transfers data in given phase using polled I/O
1469 * Inputs : instance - instance of driver, *phase - pointer to
1470 * what phase is expected, *count - pointer to number of
1471 * bytes to transfer, **data - pointer to data pointer.
1473 * Returns : -1 when different phase is entered without transferring
1474 * maximum number of bytes, 0 if all bytes are transferred or exit
1477 * Also, *phase, *count, *data are modified in place.
1479 * XXX Note : handling for bus free may be useful.
1483 * Note : this code is not as quick as it could be, however it
1484 * IS 100% reliable, and for the actual data transfer where speed
1485 * counts, we will always do a pseudo DMA or DMA transfer.
1488 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1489 unsigned char *phase, int *count,
1490 unsigned char **data)
1492 register unsigned char p = *phase, tmp;
1493 register int c = *count;
1494 register unsigned char *d = *data;
1497 * The NCR5380 chip will only drive the SCSI bus when the
1498 * phase specified in the appropriate bits of the TARGET COMMAND
1499 * REGISTER match the STATUS REGISTER
1502 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1506 * Wait for assertion of REQ, after which the phase bits will be
1510 if (NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1513 dprintk(NDEBUG_HANDSHAKE, "scsi%d: REQ detected\n", HOSTNO);
1515 /* Check for phase mismatch */
1516 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1517 dprintk(NDEBUG_PIO, "scsi%d: phase mismatch\n", HOSTNO);
1518 NCR5380_dprint_phase(NDEBUG_PIO, instance);
1522 /* Do actual transfer from SCSI bus to / from memory */
1524 NCR5380_write(OUTPUT_DATA_REG, *d);
1526 *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1531 * The SCSI standard suggests that in MSGOUT phase, the initiator
1532 * should drop ATN on the last byte of the message phase
1533 * after REQ has been asserted for the handshake but before
1534 * the initiator raises ACK.
1538 if (!((p & SR_MSG) && c > 1)) {
1539 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1540 NCR5380_dprint(NDEBUG_PIO, instance);
1541 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1542 ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1544 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1545 ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1546 NCR5380_dprint(NDEBUG_PIO, instance);
1547 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1548 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1551 NCR5380_dprint(NDEBUG_PIO, instance);
1552 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1555 if (NCR5380_poll_politely(instance,
1556 STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1559 dprintk(NDEBUG_HANDSHAKE, "scsi%d: req false, handshake complete\n", HOSTNO);
1562 * We have several special cases to consider during REQ/ACK handshaking :
1563 * 1. We were in MSGOUT phase, and we are on the last byte of the
1564 * message. ATN must be dropped as ACK is dropped.
1566 * 2. We are in a MSGIN phase, and we are on the last byte of the
1567 * message. We must exit with ACK asserted, so that the calling
1568 * code may raise ATN before dropping ACK to reject the message.
1570 * 3. ACK and ATN are clear and the target may proceed as normal.
1572 if (!(p == PHASE_MSGIN && c == 1)) {
1573 if (p == PHASE_MSGOUT && c > 1)
1574 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1576 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1580 dprintk(NDEBUG_PIO, "scsi%d: residual %d\n", HOSTNO, c);
1584 tmp = NCR5380_read(STATUS_REG);
1585 /* The phase read from the bus is valid if either REQ is (already)
1586 * asserted or if ACK hasn't been released yet. The latter applies if
1587 * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1589 if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1590 *phase = tmp & PHASE_MASK;
1592 *phase = PHASE_UNKNOWN;
1594 if (!c || (*phase == p))
1601 * do_reset - issue a reset command
1602 * @instance: adapter to reset
1604 * Issue a reset sequence to the NCR5380 and try and get the bus
1605 * back into sane shape.
1607 * This clears the reset interrupt flag because there may be no handler for
1608 * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1609 * been installed. And when in EH we may have released the ST DMA interrupt.
1612 static void do_reset(struct Scsi_Host *instance)
1614 unsigned long flags;
1616 local_irq_save(flags);
1617 NCR5380_write(TARGET_COMMAND_REG,
1618 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1619 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1621 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1622 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1623 local_irq_restore(flags);
1627 * do_abort - abort the currently established nexus by going to
1628 * MESSAGE OUT phase and sending an ABORT message.
1629 * @instance: relevant scsi host instance
1631 * Returns 0 on success, -1 on failure.
1634 static int do_abort(struct Scsi_Host *instance)
1636 unsigned char tmp, *msgptr, phase;
1640 /* Request message out phase */
1641 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1644 * Wait for the target to indicate a valid phase by asserting
1645 * REQ. Once this happens, we'll have either a MSGOUT phase
1646 * and can immediately send the ABORT message, or we'll have some
1647 * other phase and will have to source/sink data.
1649 * We really don't care what value was on the bus or what value
1650 * the target sees, so we just handshake.
1653 rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1657 tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1659 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1661 if (tmp != PHASE_MSGOUT) {
1662 NCR5380_write(INITIATOR_COMMAND_REG,
1663 ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1664 rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 3 * HZ);
1667 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1673 phase = PHASE_MSGOUT;
1674 NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1677 * If we got here, and the command completed successfully,
1678 * we're about to go into bus free state.
1681 return len ? -1 : 0;
1684 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1688 #if defined(REAL_DMA)
1690 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1691 * unsigned char *phase, int *count, unsigned char **data)
1693 * Purpose : transfers data in given phase using either real
1696 * Inputs : instance - instance of driver, *phase - pointer to
1697 * what phase is expected, *count - pointer to number of
1698 * bytes to transfer, **data - pointer to data pointer.
1700 * Returns : -1 when different phase is entered without transferring
1701 * maximum number of bytes, 0 if all bytes or transferred or exit
1704 * Also, *phase, *count, *data are modified in place.
1709 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1710 unsigned char *phase, int *count,
1711 unsigned char **data)
1713 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1714 register int c = *count;
1715 register unsigned char p = *phase;
1717 #if defined(CONFIG_SUN3)
1719 if (!sun3_dma_setup_done) {
1720 pr_err("scsi%d: transfer_dma without setup!\n",
1724 hostdata->dma_len = c;
1726 dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1727 instance->host_no, (p & SR_IO) ? "reading" : "writing",
1728 c, (p & SR_IO) ? "to" : "from", *data);
1730 /* netbsd turns off ints here, why not be safe and do it too */
1732 /* send start chain */
1733 sun3scsi_dma_start(c, *data);
1735 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1736 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1737 MR_ENABLE_EOP_INTR);
1739 NCR5380_write(INITIATOR_COMMAND_REG, 0);
1740 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1742 NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_DATA);
1743 NCR5380_write(START_DMA_SEND_REG, 0);
1746 #ifdef SUN3_SCSI_VME
1747 dregs->csr |= CSR_DMA_ENABLE;
1750 sun3_dma_active = 1;
1752 #else /* !defined(CONFIG_SUN3) */
1753 register unsigned char *d = *data;
1756 if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1761 if (hostdata->read_overruns && (p & SR_IO))
1762 c -= hostdata->read_overruns;
1764 dprintk(NDEBUG_DMA, "scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1765 HOSTNO, (p & SR_IO) ? "reading" : "writing",
1766 c, (p & SR_IO) ? "to" : "from", d);
1768 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1769 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1770 MR_ENABLE_EOP_INTR);
1772 if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1773 /* On the Medusa, it is a must to initialize the DMA before
1774 * starting the NCR. This is also the cleaner way for the TT.
1776 hostdata->dma_len = (p & SR_IO) ?
1777 NCR5380_dma_read_setup(instance, d, c) :
1778 NCR5380_dma_write_setup(instance, d, c);
1782 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1784 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1785 NCR5380_write(START_DMA_SEND_REG, 0);
1788 if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1789 /* On the Falcon, the DMA setup must be done after the last */
1790 /* NCR access, else the DMA setup gets trashed!
1792 hostdata->dma_len = (p & SR_IO) ?
1793 NCR5380_dma_read_setup(instance, d, c) :
1794 NCR5380_dma_write_setup(instance, d, c);
1796 #endif /* !defined(CONFIG_SUN3) */
1800 #endif /* defined(REAL_DMA) */
1803 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1805 * Purpose : run through the various SCSI phases and do as the target
1806 * directs us to. Operates on the currently connected command,
1807 * instance->connected.
1809 * Inputs : instance, instance for which we are doing commands
1811 * Side effects : SCSI things happen, the disconnected queue will be
1812 * modified if a command disconnects, *instance->connected will
1815 * XXX Note : we need to watch for bus free or a reset condition here
1816 * to recover from an unexpected bus free condition.
1819 static void NCR5380_information_transfer(struct Scsi_Host *instance)
1821 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1822 unsigned char msgout = NOP;
1825 #if defined(REAL_DMA)
1828 unsigned char *data;
1829 unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1830 struct scsi_cmnd *cmd;
1832 #ifdef SUN3_SCSI_VME
1833 dregs->csr |= CSR_INTR;
1836 while ((cmd = hostdata->connected)) {
1837 tmp = NCR5380_read(STATUS_REG);
1838 /* We only have a valid SCSI phase when REQ is asserted */
1840 phase = (tmp & PHASE_MASK);
1841 if (phase != old_phase) {
1843 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1845 #if defined(CONFIG_SUN3)
1846 if (phase == PHASE_CMDOUT) {
1847 #if defined(REAL_DMA)
1849 unsigned long count;
1851 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1852 count = cmd->SCp.buffer->length;
1853 d = sg_virt(cmd->SCp.buffer);
1855 count = cmd->SCp.this_residual;
1858 /* this command setup for dma yet? */
1859 if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != cmd)) {
1860 if (cmd->request->cmd_type == REQ_TYPE_FS) {
1861 sun3scsi_dma_setup(d, count,
1862 rq_data_dir(cmd->request));
1863 sun3_dma_setup_done = cmd;
1867 #ifdef SUN3_SCSI_VME
1868 dregs->csr |= CSR_INTR;
1871 #endif /* CONFIG_SUN3 */
1873 if (sink && (phase != PHASE_MSGOUT)) {
1874 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1876 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1878 while (NCR5380_read(STATUS_REG) & SR_REQ)
1880 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1888 #if (NDEBUG & NDEBUG_NO_DATAOUT)
1889 printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
1890 "aborted\n", HOSTNO);
1893 cmd->result = DID_ERROR << 16;
1894 cmd->scsi_done(cmd);
1899 * If there is no room left in the current buffer in the
1900 * scatter-gather list, move onto the next one.
1903 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1905 --cmd->SCp.buffers_residual;
1906 cmd->SCp.this_residual = cmd->SCp.buffer->length;
1907 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1908 /* ++roman: Try to merge some scatter-buffers if
1909 * they are at contiguous physical addresses.
1911 merge_contiguous_buffers(cmd);
1912 dprintk(NDEBUG_INFORMATION, "scsi%d: %d bytes and %d buffers left\n",
1913 HOSTNO, cmd->SCp.this_residual,
1914 cmd->SCp.buffers_residual);
1918 * The preferred transfer method is going to be
1919 * PSEUDO-DMA for systems that are strictly PIO,
1920 * since we can let the hardware do the handshaking.
1922 * For this to work, we need to know the transfersize
1923 * ahead of time, since the pseudo-DMA code will sit
1924 * in an unconditional loop.
1927 /* ++roman: I suggest, this should be
1929 * instead of leaving REAL_DMA out.
1932 #if defined(REAL_DMA)
1933 #if !defined(CONFIG_SUN3)
1935 if (!cmd->device->borken)
1937 transfersize = NCR5380_dma_xfer_len(instance, cmd, phase);
1939 if (transfersize >= DMA_MIN_SIZE) {
1941 cmd->SCp.phase = phase;
1942 if (NCR5380_transfer_dma(instance, &phase,
1943 &len, (unsigned char **)&cmd->SCp.ptr)) {
1945 * If the watchdog timer fires, all future
1946 * accesses to this device will use the
1948 scmd_printk(KERN_INFO, cmd,
1949 "switching to slow handshake\n");
1950 cmd->device->borken = 1;
1953 cmd->result = DID_ERROR << 16;
1954 cmd->scsi_done(cmd);
1955 /* XXX - need to source or sink data here, as appropriate */
1958 /* ++roman: When using real DMA,
1959 * information_transfer() should return after
1960 * starting DMA since it has nothing more to
1965 cmd->SCp.this_residual -= transfersize - len;
1969 #endif /* defined(REAL_DMA) */
1971 spin_unlock_irq(&hostdata->lock);
1972 NCR5380_transfer_pio(instance, &phase,
1973 (int *)&cmd->SCp.this_residual,
1974 (unsigned char **)&cmd->SCp.ptr);
1975 spin_lock_irq(&hostdata->lock);
1977 #if defined(CONFIG_SUN3) && defined(REAL_DMA)
1978 /* if we had intended to dma that command clear it */
1979 if (sun3_dma_setup_done == cmd)
1980 sun3_dma_setup_done = NULL;
1986 NCR5380_transfer_pio(instance, &phase, &len, &data);
1987 cmd->SCp.Message = tmp;
1991 case COMMAND_COMPLETE:
1992 /* Accept message by clearing ACK */
1993 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1994 dsprintk(NDEBUG_QUEUES, instance,
1995 "COMMAND COMPLETE %p target %d lun %llu\n",
1996 cmd, scmd_id(cmd), cmd->device->lun);
1998 hostdata->connected = NULL;
2001 if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2002 struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][cmd->device->lun];
2003 dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu returned "
2004 "QUEUE_FULL after %d commands\n",
2005 HOSTNO, cmd->device->id, cmd->device->lun,
2007 if (ta->queue_size > ta->nr_allocated)
2008 ta->queue_size = ta->nr_allocated;
2011 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2015 * I'm not sure what the correct thing to do here is :
2017 * If the command that just executed is NOT a request
2018 * sense, the obvious thing to do is to set the result
2019 * code to the values of the stored parameters.
2021 * If it was a REQUEST SENSE command, we need some way to
2022 * differentiate between the failure code of the original
2023 * and the failure code of the REQUEST sense - the obvious
2024 * case is success, where we fall through and leave the
2025 * result code unchanged.
2027 * The non-obvious place is where the REQUEST SENSE failed
2030 if (cmd->cmnd[0] != REQUEST_SENSE)
2031 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2032 else if (status_byte(cmd->SCp.Status) != GOOD)
2033 cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2035 if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2036 hostdata->ses.cmd_len) {
2037 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2038 hostdata->ses.cmd_len = 0 ;
2041 if ((cmd->cmnd[0] != REQUEST_SENSE) &&
2042 (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2043 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2045 SET_NEXT(cmd, hostdata->issue_queue);
2046 hostdata->issue_queue = (struct scsi_cmnd *) cmd;
2047 dsprintk(NDEBUG_AUTOSENSE | NDEBUG_QUEUES,
2048 instance, "REQUEST SENSE cmd %p added to head of issue queue\n",
2051 cmd->scsi_done(cmd);
2055 * Restore phase bits to 0 so an interrupted selection,
2056 * arbitration can resume.
2058 NCR5380_write(TARGET_COMMAND_REG, 0);
2060 /* Enable reselect interrupts */
2061 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2063 /* ++roman: For Falcon SCSI, release the lock on the
2064 * ST-DMA here if no other commands are waiting on the
2065 * disconnected queue.
2067 maybe_release_dma_irq(instance);
2069 case MESSAGE_REJECT:
2070 /* Accept message by clearing ACK */
2071 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2072 switch (hostdata->last_message) {
2073 case HEAD_OF_QUEUE_TAG:
2074 case ORDERED_QUEUE_TAG:
2075 case SIMPLE_QUEUE_TAG:
2076 /* The target obviously doesn't support tagged
2077 * queuing, even though it announced this ability in
2078 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2079 * clear 'tagged_supported' and lock the LUN, since
2080 * the command is treated as untagged further on.
2082 cmd->device->tagged_supported = 0;
2083 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2084 cmd->tag = TAG_NONE;
2085 dprintk(NDEBUG_TAGS, "scsi%d: target %d lun %llu rejected "
2086 "QUEUE_TAG message; tagged queuing "
2088 HOSTNO, cmd->device->id, cmd->device->lun);
2093 /* Accept message by clearing ACK */
2094 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2095 SET_NEXT(cmd, hostdata->disconnected_queue);
2096 hostdata->connected = NULL;
2097 hostdata->disconnected_queue = cmd;
2098 dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
2099 instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
2100 cmd, scmd_id(cmd), cmd->device->lun);
2103 * Restore phase bits to 0 so an interrupted selection,
2104 * arbitration can resume.
2106 NCR5380_write(TARGET_COMMAND_REG, 0);
2108 /* Enable reselect interrupts */
2109 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2110 #ifdef SUN3_SCSI_VME
2111 dregs->csr |= CSR_DMA_ENABLE;
2115 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2116 * operation, in violation of the SCSI spec so we can safely
2117 * ignore SAVE/RESTORE pointers calls.
2119 * Unfortunately, some disks violate the SCSI spec and
2120 * don't issue the required SAVE_POINTERS message before
2121 * disconnecting, and we have to break spec to remain
2125 case RESTORE_POINTERS:
2126 /* Accept message by clearing ACK */
2127 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2129 case EXTENDED_MESSAGE:
2131 * Extended messages are sent in the following format :
2133 * 0 EXTENDED_MESSAGE == 1
2134 * 1 length (includes one byte for code, doesn't
2135 * include first two bytes)
2137 * 3..length+1 arguments
2139 * Start the extended message buffer with the EXTENDED_MESSAGE
2140 * byte, since spi_print_msg() wants the whole thing.
2142 extended_msg[0] = EXTENDED_MESSAGE;
2143 /* Accept first byte by clearing ACK */
2144 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2146 spin_unlock_irq(&hostdata->lock);
2148 dprintk(NDEBUG_EXTENDED, "scsi%d: receiving extended message\n", HOSTNO);
2151 data = extended_msg + 1;
2152 phase = PHASE_MSGIN;
2153 NCR5380_transfer_pio(instance, &phase, &len, &data);
2154 dprintk(NDEBUG_EXTENDED, "scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2155 (int)extended_msg[1], (int)extended_msg[2]);
2157 if (!len && extended_msg[1] > 0 &&
2158 extended_msg[1] <= sizeof(extended_msg) - 2) {
2159 /* Accept third byte by clearing ACK */
2160 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2161 len = extended_msg[1] - 1;
2162 data = extended_msg + 3;
2163 phase = PHASE_MSGIN;
2165 NCR5380_transfer_pio(instance, &phase, &len, &data);
2166 dprintk(NDEBUG_EXTENDED, "scsi%d: message received, residual %d\n",
2169 switch (extended_msg[2]) {
2172 case EXTENDED_MODIFY_DATA_POINTER:
2173 case EXTENDED_EXTENDED_IDENTIFY:
2177 printk(KERN_NOTICE "scsi%d: error receiving "
2178 "extended message\n", HOSTNO);
2181 printk(KERN_NOTICE "scsi%d: extended message "
2182 "code %02x length %d is too long\n",
2183 HOSTNO, extended_msg[2], extended_msg[1]);
2187 spin_lock_irq(&hostdata->lock);
2188 if (!hostdata->connected)
2191 /* Fall through to reject message */
2194 * If we get something weird that we aren't expecting,
2199 printk(KERN_INFO "scsi%d: rejecting message ",
2201 spi_print_msg(extended_msg);
2203 } else if (tmp != EXTENDED_MESSAGE)
2204 scmd_printk(KERN_INFO, cmd,
2205 "rejecting unknown message %02x\n",
2208 scmd_printk(KERN_INFO, cmd,
2209 "rejecting unknown extended message code %02x, length %d\n",
2210 extended_msg[1], extended_msg[0]);
2212 msgout = MESSAGE_REJECT;
2213 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2215 } /* switch (tmp) */
2220 hostdata->last_message = msgout;
2221 NCR5380_transfer_pio(instance, &phase, &len, &data);
2222 if (msgout == ABORT) {
2226 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2228 hostdata->connected = NULL;
2229 cmd->result = DID_ERROR << 16;
2230 maybe_release_dma_irq(instance);
2231 cmd->scsi_done(cmd);
2232 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2241 * XXX for performance reasons, on machines with a
2242 * PSEUDO-DMA architecture we should probably
2243 * use the dma transfer function.
2245 NCR5380_transfer_pio(instance, &phase, &len, &data);
2250 NCR5380_transfer_pio(instance, &phase, &len, &data);
2251 cmd->SCp.Status = tmp;
2254 printk("scsi%d: unknown phase\n", HOSTNO);
2255 NCR5380_dprint(NDEBUG_ANY, instance);
2256 } /* switch(phase) */
2258 spin_unlock_irq(&hostdata->lock);
2259 NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
2260 spin_lock_irq(&hostdata->lock);
2266 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2268 * Purpose : does reselection, initializing the instance->connected
2269 * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2270 * nexus has been reestablished,
2272 * Inputs : instance - this instance of the NCR5380.
2277 /* it might eventually prove necessary to do a dma setup on
2278 reselection, but it doesn't seem to be needed now -- sam */
2280 static void NCR5380_reselect(struct Scsi_Host *instance)
2282 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2283 unsigned char target_mask;
2288 unsigned char msg[3];
2289 int __maybe_unused len;
2290 unsigned char __maybe_unused *data, __maybe_unused phase;
2291 struct scsi_cmnd *tmp = NULL, *prev;
2294 * Disable arbitration, etc. since the host adapter obviously
2295 * lost, and tell an interrupted NCR5380_select() to restart.
2298 NCR5380_write(MODE_REG, MR_BASE);
2300 target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2302 dprintk(NDEBUG_RESELECTION, "scsi%d: reselect\n", HOSTNO);
2305 * At this point, we have detected that our SCSI ID is on the bus,
2306 * SEL is true and BSY was false for at least one bus settle delay
2309 * We must assert BSY ourselves, until the target drops the SEL
2313 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2314 if (NCR5380_poll_politely(instance,
2315 STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2316 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2319 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2322 * Wait for target to go into MSGIN.
2325 if (NCR5380_poll_politely(instance,
2326 STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2331 #if defined(CONFIG_SUN3) && defined(REAL_DMA)
2332 /* acknowledge toggle to MSGIN */
2333 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2335 /* peek at the byte without really hitting the bus */
2336 msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2340 phase = PHASE_MSGIN;
2341 NCR5380_transfer_pio(instance, &phase, &len, &data);
2349 if (!(msg[0] & 0x80)) {
2350 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2356 lun = msg[0] & 0x07;
2358 #if defined(SUPPORT_TAGS) && !defined(CONFIG_SUN3)
2359 /* If the phase is still MSGIN, the target wants to send some more
2360 * messages. In case it supports tagged queuing, this is probably a
2361 * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2364 if (phase == PHASE_MSGIN && (hostdata->flags & FLAG_TAGGED_QUEUING)) {
2365 /* Accept previous IDENTIFY message by clearing ACK */
2366 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2369 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2370 msg[1] == SIMPLE_QUEUE_TAG)
2372 dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at "
2373 "reselection\n", HOSTNO, target_mask, lun, tag);
2378 * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
2379 * just reestablished, and remove it from the disconnected queue.
2382 for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue, prev = NULL;
2383 tmp; prev = tmp, tmp = NEXT(tmp)) {
2384 if ((target_mask == (1 << tmp->device->id)) && (lun == (u8)tmp->device->lun)
2386 && (tag == tmp->tag)
2390 SET_NEXT(prev, NEXT(tmp));
2392 hostdata->disconnected_queue = NEXT(tmp);
2394 SET_NEXT(tmp, NULL);
2400 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2401 "reselect: removed %p from disconnected queue\n", tmp);
2405 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d tag %d not in disconnected queue.\n",
2406 target_mask, lun, tag);
2408 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2412 * Since we have an established nexus that we can't do anything
2413 * with, we must abort it.
2419 #if defined(CONFIG_SUN3) && defined(REAL_DMA)
2420 /* engage dma setup for the command we just saw */
2423 unsigned long count;
2425 if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
2426 count = tmp->SCp.buffer->length;
2427 d = sg_virt(tmp->SCp.buffer);
2429 count = tmp->SCp.this_residual;
2432 /* setup this command for dma if not already */
2433 if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != tmp)) {
2434 sun3scsi_dma_setup(d, count, rq_data_dir(tmp->request));
2435 sun3_dma_setup_done = tmp;
2439 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2442 /* Accept message by clearing ACK */
2443 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2445 #if defined(SUPPORT_TAGS) && defined(CONFIG_SUN3)
2446 /* If the phase is still MSGIN, the target wants to send some more
2447 * messages. In case it supports tagged queuing, this is probably a
2448 * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2451 if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2452 /* Accept previous IDENTIFY message by clearing ACK */
2453 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2456 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2457 msg[1] == SIMPLE_QUEUE_TAG)
2459 dprintk(NDEBUG_TAGS, "scsi%d: target mask %02x, lun %d sent tag %d at reselection\n"
2460 HOSTNO, target_mask, lun, tag);
2464 hostdata->connected = tmp;
2465 dprintk(NDEBUG_RESELECTION, "scsi%d: nexus established, target = %d, lun = %llu, tag = %d\n",
2466 HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
2471 * Function : int NCR5380_abort (struct scsi_cmnd *cmd)
2473 * Purpose : abort a command
2475 * Inputs : cmd - the scsi_cmnd to abort, code - code to set the
2476 * host byte of the result field to, if zero DID_ABORTED is
2479 * Returns : SUCCESS - success, FAILED on failure.
2481 * XXX - there is no way to abort the command that is currently
2482 * connected, you have to wait for it to complete. If this is
2483 * a problem, we could implement longjmp() / setjmp(), setjmp()
2484 * called where the loop started in NCR5380_main().
2488 int NCR5380_abort(struct scsi_cmnd *cmd)
2490 struct Scsi_Host *instance = cmd->device->host;
2491 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2492 struct scsi_cmnd *tmp, **prev;
2493 unsigned long flags;
2495 scmd_printk(KERN_NOTICE, cmd, "aborting command\n");
2497 spin_lock_irqsave(&hostdata->lock, flags);
2499 NCR5380_dprint(NDEBUG_ANY, instance);
2500 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2502 dprintk(NDEBUG_ABORT, "scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2503 NCR5380_read(BUS_AND_STATUS_REG),
2504 NCR5380_read(STATUS_REG));
2508 * Case 1 : If the command is the currently executing command,
2509 * we'll set the aborted flag and return control so that
2510 * information transfer routine can exit cleanly.
2513 if (hostdata->connected == cmd) {
2515 dprintk(NDEBUG_ABORT, "scsi%d: aborting connected command\n", HOSTNO);
2517 * We should perform BSY checking, and make sure we haven't slipped
2521 /* NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
2523 * Since we can't change phases until we've completed the current
2524 * handshake, we have to source or sink a byte of data if the current
2525 * phase is not MSGOUT.
2529 * Return control to the executing NCR drive so we can clear the
2530 * aborted flag and get back into our main loop.
2533 if (do_abort(instance) == 0) {
2534 hostdata->connected = NULL;
2535 cmd->result = DID_ABORT << 16;
2539 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2541 maybe_release_dma_irq(instance);
2542 spin_unlock_irqrestore(&hostdata->lock, flags);
2543 cmd->scsi_done(cmd);
2546 spin_unlock_irqrestore(&hostdata->lock, flags);
2547 printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2554 * Case 2 : If the command hasn't been issued yet, we simply remove it
2555 * from the issue queue.
2557 for (prev = (struct scsi_cmnd **)&(hostdata->issue_queue),
2558 tmp = (struct scsi_cmnd *)hostdata->issue_queue;
2559 tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2561 (*prev) = NEXT(tmp);
2562 SET_NEXT(tmp, NULL);
2563 tmp->result = DID_ABORT << 16;
2564 maybe_release_dma_irq(instance);
2565 spin_unlock_irqrestore(&hostdata->lock, flags);
2566 dprintk(NDEBUG_ABORT, "scsi%d: abort removed command from issue queue.\n",
2568 /* Tagged queuing note: no tag to free here, hasn't been assigned
2570 tmp->scsi_done(tmp);
2576 * Case 3 : If any commands are connected, we're going to fail the abort
2577 * and let the high level SCSI driver retry at a later time or
2580 * Timeouts, and therefore aborted commands, will be highly unlikely
2581 * and handling them cleanly in this situation would make the common
2582 * case of noresets less efficient, and would pollute our code. So,
2586 if (hostdata->connected) {
2587 spin_unlock_irqrestore(&hostdata->lock, flags);
2588 dprintk(NDEBUG_ABORT, "scsi%d: abort failed, command connected.\n", HOSTNO);
2593 * Case 4: If the command is currently disconnected from the bus, and
2594 * there are no connected commands, we reconnect the I_T_L or
2595 * I_T_L_Q nexus associated with it, go into message out, and send
2598 * This case is especially ugly. In order to reestablish the nexus, we
2599 * need to call NCR5380_select(). The easiest way to implement this
2600 * function was to abort if the bus was busy, and let the interrupt
2601 * handler triggered on the SEL for reselect take care of lost arbitrations
2602 * where necessary, meaning interrupts need to be enabled.
2604 * When interrupts are enabled, the queues may change - so we
2605 * can't remove it from the disconnected queue before selecting it
2606 * because that could cause a failure in hashing the nexus if that
2607 * device reselected.
2609 * Since the queues may change, we can't use the pointers from when we
2612 * So, we must first locate the command, and if NCR5380_select()
2613 * succeeds, then issue the abort, relocate the command and remove
2614 * it from the disconnected queue.
2617 for (tmp = (struct scsi_cmnd *) hostdata->disconnected_queue; tmp;
2620 dprintk(NDEBUG_ABORT, "scsi%d: aborting disconnected command.\n", HOSTNO);
2622 if (NCR5380_select(instance, cmd)) {
2623 spin_unlock_irq(&hostdata->lock);
2626 dprintk(NDEBUG_ABORT, "scsi%d: nexus reestablished.\n", HOSTNO);
2630 for (prev = (struct scsi_cmnd **)&(hostdata->disconnected_queue),
2631 tmp = (struct scsi_cmnd *)hostdata->disconnected_queue;
2632 tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2635 SET_NEXT(tmp, NULL);
2636 tmp->result = DID_ABORT << 16;
2637 /* We must unlock the tag/LUN immediately here, since the
2638 * target goes to BUS FREE and doesn't send us another
2639 * message (COMMAND_COMPLETE or the like)
2644 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2646 maybe_release_dma_irq(instance);
2647 spin_unlock_irqrestore(&hostdata->lock, flags);
2648 tmp->scsi_done(tmp);
2655 /* Maybe it is sufficient just to release the ST-DMA lock... (if
2656 * possible at all) At least, we should check if the lock could be
2657 * released after the abort, in case it is kept due to some bug.
2659 maybe_release_dma_irq(instance);
2660 spin_unlock_irqrestore(&hostdata->lock, flags);
2663 * Case 5 : If we reached this point, the command was not found in any of
2666 * We probably reached this point because of an unlikely race condition
2667 * between the command completing successfully and the abortion code,
2668 * so we won't panic, but we will notify the user in case something really
2672 printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
2679 * NCR5380_bus_reset - reset the SCSI bus
2680 * @cmd: SCSI command undergoing EH
2685 static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
2687 struct Scsi_Host *instance = cmd->device->host;
2688 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2690 unsigned long flags;
2692 spin_lock_irqsave(&hostdata->lock, flags);
2694 #if (NDEBUG & NDEBUG_ANY)
2695 scmd_printk(KERN_INFO, cmd, "performing bus reset\n");
2697 NCR5380_dprint(NDEBUG_ANY, instance);
2698 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2702 /* reset NCR registers */
2703 NCR5380_write(MODE_REG, MR_BASE);
2704 NCR5380_write(TARGET_COMMAND_REG, 0);
2705 NCR5380_write(SELECT_ENABLE_REG, 0);
2707 /* After the reset, there are no more connected or disconnected commands
2708 * and no busy units; so clear the low-level status here to avoid
2709 * conflicts when the mid-level code tries to wake up the affected
2713 if (hostdata->issue_queue)
2714 dsprintk(NDEBUG_ABORT, instance, "reset aborted issued command(s)\n");
2715 if (hostdata->connected)
2716 dsprintk(NDEBUG_ABORT, instance, "reset aborted a connected command\n");
2717 if (hostdata->disconnected_queue)
2718 dsprintk(NDEBUG_ABORT, instance, "reset aborted disconnected command(s)\n");
2720 hostdata->issue_queue = NULL;
2721 hostdata->connected = NULL;
2722 hostdata->disconnected_queue = NULL;
2724 free_all_tags(hostdata);
2726 for (i = 0; i < 8; ++i)
2727 hostdata->busy[i] = 0;
2729 hostdata->dma_len = 0;
2732 maybe_release_dma_irq(instance);
2733 spin_unlock_irqrestore(&hostdata->lock, flags);