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 * With contributions from Ray Van Tassle, Ingmar Baumgart,
29 * Ronald van Cuijlenborg, Alan Cox and others.
33 * Further development / testing that should be done :
34 * 1. Cleanup the NCR5380_transfer_dma function and DMA operation complete
35 * code so that everything does the same thing that's done at the
36 * end of a pseudo-DMA read operation.
38 * 2. Fix REAL_DMA (interrupt driven, polled works fine) -
39 * basically, transfer size needs to be reduced by one
40 * and the last byte read as is done with PSEUDO_DMA.
42 * 4. Test SCSI-II tagged queueing (I have no devices which support
50 #ifdef BOARD_REQUIRES_NO_DELAY
51 #define io_recovery_delay(x)
53 #define io_recovery_delay(x) udelay(x)
59 * This is a generic 5380 driver. To use it on a different platform,
60 * one simply writes appropriate system specific macros (ie, data
61 * transfer - some PC's will use the I/O bus, 68K's must use
62 * memory mapped) and drops this file in their 'C' wrapper.
64 * As far as command queueing, two queues are maintained for
65 * each 5380 in the system - commands that haven't been issued yet,
66 * and commands that are currently executing. This means that an
67 * unlimited number of commands may be queued, letting
68 * more commands propagate from the higher driver levels giving higher
69 * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
70 * allowing multiple commands to propagate all the way to a SCSI-II device
71 * while a command is already executing.
74 * Issues specific to the NCR5380 :
76 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
77 * piece of hardware that requires you to sit in a loop polling for
78 * the REQ signal as long as you are connected. Some devices are
79 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
80 * while doing long seek operations. [...] These
81 * broken devices are the exception rather than the rule and I'd rather
82 * spend my time optimizing for the normal case.
86 * At the heart of the design is a coroutine, NCR5380_main,
87 * which is started from a workqueue for each NCR5380 host in the
88 * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
89 * removing the commands from the issue queue and calling
90 * NCR5380_select() if a nexus is not established.
92 * Once a nexus is established, the NCR5380_information_transfer()
93 * phase goes through the various phases as instructed by the target.
94 * if the target goes into MSG IN and sends a DISCONNECT message,
95 * the command structure is placed into the per instance disconnected
96 * queue, and NCR5380_main tries to find more work. If the target is
97 * idle for too long, the system will try to sleep.
99 * If a command has disconnected, eventually an interrupt will trigger,
100 * calling NCR5380_intr() which will in turn call NCR5380_reselect
101 * to reestablish a nexus. This will run main if necessary.
103 * On command termination, the done function will be called as
106 * SCSI pointers are maintained in the SCp field of SCSI command
107 * structures, being initialized after the command is connected
108 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
109 * Note that in violation of the standard, an implicit SAVE POINTERS operation
110 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
115 * This file a skeleton Linux SCSI driver for the NCR 5380 series
116 * of chips. To use it, you write an architecture specific functions
117 * and macros and include this file in your driver.
119 * These macros control options :
120 * AUTOPROBE_IRQ - if defined, the NCR5380_probe_irq() function will be
123 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
124 * for commands that return with a CHECK CONDITION status.
126 * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
129 * DONT_USE_INTR - if defined, never use interrupts, even if we probe or
130 * override-configure an IRQ.
132 * PSEUDO_DMA - if defined, PSEUDO DMA is used during the data transfer phases.
134 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
136 * REAL_DMA_POLL - if defined, REAL DMA is used but the driver doesn't
137 * rely on phase mismatch and EOP interrupts to determine end
140 * These macros MUST be defined :
142 * NCR5380_read(register) - read from the specified register
144 * NCR5380_write(register, value) - write to the specific register
146 * NCR5380_implementation_fields - additional fields needed for this
147 * specific implementation of the NCR5380
149 * Either real DMA *or* pseudo DMA may be implemented
151 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
152 * Note that the DMA setup functions should return the number of bytes
153 * that they were able to program the controller for.
155 * Also note that generic i386/PC versions of these macros are
156 * available as NCR5380_i386_dma_write_setup,
157 * NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
159 * NCR5380_dma_write_setup(instance, src, count) - initialize
160 * NCR5380_dma_read_setup(instance, dst, count) - initialize
161 * NCR5380_dma_residual(instance); - residual count
164 * NCR5380_pwrite(instance, src, count)
165 * NCR5380_pread(instance, dst, count);
167 * The generic driver is initialized by calling NCR5380_init(instance),
168 * after setting the appropriate host specific fields and ID. If the
169 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
170 * possible) function may be used.
173 static int do_abort(struct Scsi_Host *);
174 static void do_reset(struct Scsi_Host *);
177 * initialize_SCp - init the scsi pointer field
178 * @cmd: command block to set up
180 * Set up the internal fields in the SCSI command.
183 static inline void initialize_SCp(struct scsi_cmnd *cmd)
186 * Initialize the Scsi Pointer field so that all of the commands in the
187 * various queues are valid.
190 if (scsi_bufflen(cmd)) {
191 cmd->SCp.buffer = scsi_sglist(cmd);
192 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
193 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
194 cmd->SCp.this_residual = cmd->SCp.buffer->length;
196 cmd->SCp.buffer = NULL;
197 cmd->SCp.buffers_residual = 0;
199 cmd->SCp.this_residual = 0;
203 cmd->SCp.Message = 0;
207 * NCR5380_poll_politely2 - wait for two chip register values
208 * @instance: controller to poll
209 * @reg1: 5380 register to poll
210 * @bit1: Bitmask to check
211 * @val1: Expected value
212 * @reg2: Second 5380 register to poll
213 * @bit2: Second bitmask to check
214 * @val2: Second expected value
215 * @wait: Time-out in jiffies
217 * Polls the chip in a reasonably efficient manner waiting for an
218 * event to occur. After a short quick poll we begin to yield the CPU
219 * (if possible). In irq contexts the time-out is arbitrarily limited.
220 * Callers may hold locks as long as they are held in irq mode.
222 * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
225 static int NCR5380_poll_politely2(struct Scsi_Host *instance,
226 int reg1, int bit1, int val1,
227 int reg2, int bit2, int val2, int wait)
229 struct NCR5380_hostdata *hostdata = shost_priv(instance);
230 unsigned long deadline = jiffies + wait;
233 /* Busy-wait for up to 10 ms */
234 n = min(10000U, jiffies_to_usecs(wait));
235 n *= hostdata->accesses_per_ms;
238 if ((NCR5380_read(reg1) & bit1) == val1)
240 if ((NCR5380_read(reg2) & bit2) == val2)
245 if (irqs_disabled() || in_interrupt())
248 /* Repeatedly sleep for 1 ms until deadline */
249 while (time_is_after_jiffies(deadline)) {
250 schedule_timeout_uninterruptible(1);
251 if ((NCR5380_read(reg1) & bit1) == val1)
253 if ((NCR5380_read(reg2) & bit2) == val2)
260 static inline int NCR5380_poll_politely(struct Scsi_Host *instance,
261 int reg, int bit, int val, int wait)
263 return NCR5380_poll_politely2(instance, reg, bit, val,
264 reg, bit, val, wait);
270 } phases[] __maybe_unused = {
271 {PHASE_DATAOUT, "DATAOUT"},
272 {PHASE_DATAIN, "DATAIN"},
273 {PHASE_CMDOUT, "CMDOUT"},
274 {PHASE_STATIN, "STATIN"},
275 {PHASE_MSGOUT, "MSGOUT"},
276 {PHASE_MSGIN, "MSGIN"},
277 {PHASE_UNKNOWN, "UNKNOWN"}
301 {ICR_ASSERT_RST, "ASSERT RST"},
302 {ICR_ASSERT_ACK, "ASSERT ACK"},
303 {ICR_ASSERT_BSY, "ASSERT BSY"},
304 {ICR_ASSERT_SEL, "ASSERT SEL"},
305 {ICR_ASSERT_ATN, "ASSERT ATN"},
306 {ICR_ASSERT_DATA, "ASSERT DATA"},
310 {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
311 {MR_TARGET, "MODE TARGET"},
312 {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
313 {MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
314 {MR_MONITOR_BSY, "MODE MONITOR BSY"},
315 {MR_DMA_MODE, "MODE DMA"},
316 {MR_ARBITRATE, "MODE ARBITRATION"},
321 * NCR5380_print - print scsi bus signals
322 * @instance: adapter state to dump
324 * Print the SCSI bus signals for debugging purposes
327 static void NCR5380_print(struct Scsi_Host *instance)
329 unsigned char status, data, basr, mr, icr, i;
331 data = NCR5380_read(CURRENT_SCSI_DATA_REG);
332 status = NCR5380_read(STATUS_REG);
333 mr = NCR5380_read(MODE_REG);
334 icr = NCR5380_read(INITIATOR_COMMAND_REG);
335 basr = NCR5380_read(BUS_AND_STATUS_REG);
337 printk("STATUS_REG: %02x ", status);
338 for (i = 0; signals[i].mask; ++i)
339 if (status & signals[i].mask)
340 printk(",%s", signals[i].name);
341 printk("\nBASR: %02x ", basr);
342 for (i = 0; basrs[i].mask; ++i)
343 if (basr & basrs[i].mask)
344 printk(",%s", basrs[i].name);
345 printk("\nICR: %02x ", icr);
346 for (i = 0; icrs[i].mask; ++i)
347 if (icr & icrs[i].mask)
348 printk(",%s", icrs[i].name);
349 printk("\nMODE: %02x ", mr);
350 for (i = 0; mrs[i].mask; ++i)
351 if (mr & mrs[i].mask)
352 printk(",%s", mrs[i].name);
358 * NCR5380_print_phase - show SCSI phase
359 * @instance: adapter to dump
361 * Print the current SCSI phase for debugging purposes
364 static void NCR5380_print_phase(struct Scsi_Host *instance)
366 unsigned char status;
369 status = NCR5380_read(STATUS_REG);
370 if (!(status & SR_REQ))
371 shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
373 for (i = 0; (phases[i].value != PHASE_UNKNOWN) && (phases[i].value != (status & PHASE_MASK)); ++i);
374 shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
380 static int probe_irq __initdata;
383 * probe_intr - helper for IRQ autoprobe
384 * @irq: interrupt number
388 * Set a flag to indicate the IRQ in question was received. This is
389 * used by the IRQ probe code.
392 static irqreturn_t __init probe_intr(int irq, void *dev_id)
399 * NCR5380_probe_irq - find the IRQ of an NCR5380
400 * @instance: NCR5380 controller
401 * @possible: bitmask of ISA IRQ lines
403 * Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
404 * and then looking to see what interrupt actually turned up.
407 static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
410 struct NCR5380_hostdata *hostdata = shost_priv(instance);
411 unsigned long timeout;
412 int trying_irqs, i, mask;
414 for (trying_irqs = 0, i = 1, mask = 2; i < 16; ++i, mask <<= 1)
415 if ((mask & possible) && (request_irq(i, &probe_intr, 0, "NCR-probe", NULL) == 0))
418 timeout = jiffies + msecs_to_jiffies(250);
422 * A interrupt is triggered whenever BSY = false, SEL = true
423 * and a bit set in the SELECT_ENABLE_REG is asserted on the
426 * Note that the bus is only driven when the phase control signals
427 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
431 NCR5380_write(TARGET_COMMAND_REG, 0);
432 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
433 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
434 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
436 while (probe_irq == NO_IRQ && time_before(jiffies, timeout))
437 schedule_timeout_uninterruptible(1);
439 NCR5380_write(SELECT_ENABLE_REG, 0);
440 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
442 for (i = 1, mask = 2; i < 16; ++i, mask <<= 1)
443 if (trying_irqs & mask)
450 * NCR58380_info - report driver and host information
451 * @instance: relevant scsi host instance
453 * For use as the host template info() handler.
456 static const char *NCR5380_info(struct Scsi_Host *instance)
458 struct NCR5380_hostdata *hostdata = shost_priv(instance);
460 return hostdata->info;
463 static void prepare_info(struct Scsi_Host *instance)
465 struct NCR5380_hostdata *hostdata = shost_priv(instance);
467 snprintf(hostdata->info, sizeof(hostdata->info),
468 "%s, io_port 0x%lx, n_io_port %d, "
469 "base 0x%lx, irq %d, "
470 "can_queue %d, cmd_per_lun %d, "
471 "sg_tablesize %d, this_id %d, "
474 instance->hostt->name, instance->io_port, instance->n_io_port,
475 instance->base, instance->irq,
476 instance->can_queue, instance->cmd_per_lun,
477 instance->sg_tablesize, instance->this_id,
478 hostdata->flags & FLAG_NO_DMA_FIXUP ? "NO_DMA_FIXUP " : "",
479 hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
480 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "",
503 static int __maybe_unused NCR5380_write_info(struct Scsi_Host *instance,
504 char *buffer, int length)
506 struct NCR5380_hostdata *hostdata = shost_priv(instance);
508 hostdata->spin_max_r = 0;
509 hostdata->spin_max_w = 0;
513 static int __maybe_unused NCR5380_show_info(struct seq_file *m,
514 struct Scsi_Host *instance)
516 struct NCR5380_hostdata *hostdata = shost_priv(instance);
518 seq_printf(m, "Highwater I/O busy spin counts: write %d, read %d\n",
519 hostdata->spin_max_w, hostdata->spin_max_r);
525 * NCR5380_init - initialise an NCR5380
526 * @instance: adapter to configure
527 * @flags: control flags
529 * Initializes *instance and corresponding 5380 chip,
530 * with flags OR'd into the initial flags value.
532 * Notes : I assume that the host, hostno, and id bits have been
533 * set correctly. I don't care about the irq and other fields.
535 * Returns 0 for success
538 static int NCR5380_init(struct Scsi_Host *instance, int flags)
540 struct NCR5380_hostdata *hostdata = shost_priv(instance);
542 unsigned long deadline;
545 printk(KERN_ERR "NCR5380_init called with interrupts off!\n");
547 hostdata->id_mask = 1 << instance->this_id;
548 for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
549 if (i > hostdata->id_mask)
550 hostdata->id_higher_mask |= i;
551 for (i = 0; i < 8; ++i)
552 hostdata->busy[i] = 0;
554 hostdata->dmalen = 0;
556 spin_lock_init(&hostdata->lock);
557 hostdata->connected = NULL;
558 hostdata->sensing = NULL;
559 INIT_LIST_HEAD(&hostdata->autosense);
560 INIT_LIST_HEAD(&hostdata->unissued);
561 INIT_LIST_HEAD(&hostdata->disconnected);
563 hostdata->flags = flags;
565 INIT_WORK(&hostdata->main_task, NCR5380_main);
566 hostdata->work_q = alloc_workqueue("ncr5380_%d",
567 WQ_UNBOUND | WQ_MEM_RECLAIM,
568 1, instance->host_no);
569 if (!hostdata->work_q)
572 hostdata->host = instance;
574 prepare_info(instance);
576 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
577 NCR5380_write(MODE_REG, MR_BASE);
578 NCR5380_write(TARGET_COMMAND_REG, 0);
579 NCR5380_write(SELECT_ENABLE_REG, 0);
581 /* Calibrate register polling loop */
583 deadline = jiffies + 1;
586 } while (time_is_after_jiffies(deadline));
587 deadline += msecs_to_jiffies(256);
589 NCR5380_read(STATUS_REG);
592 } while (time_is_after_jiffies(deadline));
593 hostdata->accesses_per_ms = i / 256;
599 * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
600 * @instance: adapter to check
602 * If the system crashed, it may have crashed with a connected target and
603 * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
604 * currently established nexus, which we know nothing about. Failing that
607 * Note that a bus reset will cause the chip to assert IRQ.
609 * Returns 0 if successful, otherwise -ENXIO.
612 static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
614 struct NCR5380_hostdata *hostdata = shost_priv(instance);
617 for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
622 shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
623 NCR5380_poll_politely(instance,
624 STATUS_REG, SR_BSY, 0, 5 * HZ);
627 shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
631 shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
633 /* Wait after a reset; the SCSI standard calls for
634 * 250ms, we wait 500ms to be on the safe side.
635 * But some Toshiba CD-ROMs need ten times that.
637 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
643 shost_printk(KERN_ERR, instance, "bus locked solid\n");
651 * NCR5380_exit - remove an NCR5380
652 * @instance: adapter to remove
655 static void NCR5380_exit(struct Scsi_Host *instance)
657 struct NCR5380_hostdata *hostdata = shost_priv(instance);
659 cancel_work_sync(&hostdata->main_task);
660 destroy_workqueue(hostdata->work_q);
664 * complete_cmd - finish processing a command and return it to the SCSI ML
665 * @instance: the host instance
666 * @cmd: command to complete
669 static void complete_cmd(struct Scsi_Host *instance,
670 struct scsi_cmnd *cmd)
672 struct NCR5380_hostdata *hostdata = shost_priv(instance);
674 dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
676 if (hostdata->sensing == cmd) {
677 /* Autosense processing ends here */
678 if ((cmd->result & 0xff) != SAM_STAT_GOOD) {
679 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
680 set_host_byte(cmd, DID_ERROR);
682 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
683 hostdata->sensing = NULL;
686 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
692 * NCR5380_queue_command - queue a command
693 * @instance: the relevant SCSI adapter
696 * cmd is added to the per-instance issue queue, with minor
697 * twiddling done to the host specific fields of cmd. If the
698 * main coroutine is not running, it is restarted.
701 static int NCR5380_queue_command(struct Scsi_Host *instance,
702 struct scsi_cmnd *cmd)
704 struct NCR5380_hostdata *hostdata = shost_priv(instance);
705 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
708 #if (NDEBUG & NDEBUG_NO_WRITE)
709 switch (cmd->cmnd[0]) {
712 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
713 cmd->result = (DID_ERROR << 16);
717 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
721 spin_lock_irqsave(&hostdata->lock, flags);
724 * Insert the cmd into the issue queue. Note that REQUEST SENSE
725 * commands are added to the head of the queue since any command will
726 * clear the contingent allegiance condition that exists and the
727 * sense data is only guaranteed to be valid while the condition exists.
730 if (cmd->cmnd[0] == REQUEST_SENSE)
731 list_add(&ncmd->list, &hostdata->unissued);
733 list_add_tail(&ncmd->list, &hostdata->unissued);
735 spin_unlock_irqrestore(&hostdata->lock, flags);
737 dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
738 cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
740 /* Kick off command processing */
741 queue_work(hostdata->work_q, &hostdata->main_task);
746 * dequeue_next_cmd - dequeue a command for processing
747 * @instance: the scsi host instance
749 * Priority is given to commands on the autosense queue. These commands
750 * need autosense because of a CHECK CONDITION result.
752 * Returns a command pointer if a command is found for a target that is
753 * not already busy. Otherwise returns NULL.
756 static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
758 struct NCR5380_hostdata *hostdata = shost_priv(instance);
759 struct NCR5380_cmd *ncmd;
760 struct scsi_cmnd *cmd;
762 if (list_empty(&hostdata->autosense)) {
763 list_for_each_entry(ncmd, &hostdata->unissued, list) {
764 cmd = NCR5380_to_scmd(ncmd);
765 dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
766 cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
768 if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
769 list_del(&ncmd->list);
770 dsprintk(NDEBUG_QUEUES, instance,
771 "dequeue: removed %p from issue queue\n", cmd);
776 /* Autosense processing begins here */
777 ncmd = list_first_entry(&hostdata->autosense,
778 struct NCR5380_cmd, list);
779 list_del(&ncmd->list);
780 cmd = NCR5380_to_scmd(ncmd);
781 dsprintk(NDEBUG_QUEUES, instance,
782 "dequeue: removed %p from autosense queue\n", cmd);
783 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
784 hostdata->sensing = cmd;
790 static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
792 struct NCR5380_hostdata *hostdata = shost_priv(instance);
793 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
795 if (hostdata->sensing) {
796 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
797 list_add(&ncmd->list, &hostdata->autosense);
798 hostdata->sensing = NULL;
800 list_add(&ncmd->list, &hostdata->unissued);
804 * NCR5380_main - NCR state machines
806 * NCR5380_main is a coroutine that runs as long as more work can
807 * be done on the NCR5380 host adapters in a system. Both
808 * NCR5380_queue_command() and NCR5380_intr() will try to start it
809 * in case it is not running.
812 static void NCR5380_main(struct work_struct *work)
814 struct NCR5380_hostdata *hostdata =
815 container_of(work, struct NCR5380_hostdata, main_task);
816 struct Scsi_Host *instance = hostdata->host;
817 struct scsi_cmnd *cmd;
823 spin_lock_irq(&hostdata->lock);
824 while (!hostdata->connected &&
825 (cmd = dequeue_next_cmd(instance))) {
827 dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
830 * Attempt to establish an I_T_L nexus here.
831 * On success, instance->hostdata->connected is set.
832 * On failure, we must add the command back to the
833 * issue queue so we can keep trying.
836 * REQUEST SENSE commands are issued without tagged
837 * queueing, even on SCSI-II devices because the
838 * contingent allegiance condition exists for the
842 cmd = NCR5380_select(instance, cmd);
844 dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
846 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
847 "main: select failed, returning %p to queue\n", cmd);
848 requeue_cmd(instance, cmd);
851 if (hostdata->connected
856 dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
857 NCR5380_information_transfer(instance);
860 spin_unlock_irq(&hostdata->lock);
866 #ifndef DONT_USE_INTR
869 * NCR5380_intr - generic NCR5380 irq handler
870 * @irq: interrupt number
871 * @dev_id: device info
873 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
874 * from the disconnected queue, and restarting NCR5380_main()
877 * The chip can assert IRQ in any of six different conditions. The IRQ flag
878 * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
879 * Three of these six conditions are latched in the Bus and Status Register:
880 * - End of DMA (cleared by ending DMA Mode)
881 * - Parity error (cleared by reading RPIR)
882 * - Loss of BSY (cleared by reading RPIR)
883 * Two conditions have flag bits that are not latched:
884 * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
885 * - Bus reset (non-maskable)
886 * The remaining condition has no flag bit at all:
887 * - Selection/reselection
889 * Hence, establishing the cause(s) of any interrupt is partly guesswork.
890 * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
891 * claimed that "the design of the [DP8490] interrupt logic ensures
892 * interrupts will not be lost (they can be on the DP5380)."
893 * The L5380/53C80 datasheet from LOGIC Devices has more details.
895 * Checking for bus reset by reading RST is futile because of interrupt
896 * latency, but a bus reset will reset chip logic. Checking for parity error
897 * is unnecessary because that interrupt is never enabled. A Loss of BSY
898 * condition will clear DMA Mode. We can tell when this occurs because the
899 * the Busy Monitor interrupt is enabled together with DMA Mode.
902 static irqreturn_t NCR5380_intr(int irq, void *dev_id)
904 struct Scsi_Host *instance = dev_id;
905 struct NCR5380_hostdata *hostdata = shost_priv(instance);
910 spin_lock_irqsave(&hostdata->lock, flags);
912 basr = NCR5380_read(BUS_AND_STATUS_REG);
913 if (basr & BASR_IRQ) {
914 unsigned char mr = NCR5380_read(MODE_REG);
915 unsigned char sr = NCR5380_read(STATUS_REG);
917 dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
920 #if defined(REAL_DMA)
921 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
922 /* Probably End of DMA, Phase Mismatch or Loss of BSY.
923 * We ack IRQ after clearing Mode Register. Workarounds
924 * for End of DMA errata need to happen in DMA Mode.
927 dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
931 if (!hostdata->connected)
932 panic("scsi%d : DMA interrupt with no connected cmd\n",
935 transferred = hostdata->dmalen - NCR5380_dma_residual(instance);
936 hostdata->connected->SCp.this_residual -= transferred;
937 hostdata->connected->SCp.ptr += transferred;
938 hostdata->dmalen = 0;
940 /* FIXME: we need to poll briefly then defer a workqueue task ! */
941 NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2 * HZ);
943 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
944 NCR5380_write(MODE_REG, MR_BASE);
945 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
947 #endif /* REAL_DMA */
948 if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
949 (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
950 /* Probably reselected */
951 NCR5380_write(SELECT_ENABLE_REG, 0);
952 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
954 dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
956 if (!hostdata->connected) {
957 NCR5380_reselect(instance);
958 queue_work(hostdata->work_q, &hostdata->main_task);
960 if (!hostdata->connected)
961 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
963 /* Probably Bus Reset */
964 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
966 dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
970 shost_printk(KERN_NOTICE, instance, "interrupt without IRQ bit\n");
973 spin_unlock_irqrestore(&hostdata->lock, flags);
975 return IRQ_RETVAL(handled);
981 * Function : int NCR5380_select(struct Scsi_Host *instance,
982 * struct scsi_cmnd *cmd)
984 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
985 * including ARBITRATION, SELECTION, and initial message out for
986 * IDENTIFY and queue messages.
988 * Inputs : instance - instantiation of the 5380 driver on which this
989 * target lives, cmd - SCSI command to execute.
991 * Returns cmd if selection failed but should be retried,
992 * NULL if selection failed and should not be retried, or
993 * NULL if selection succeeded (hostdata->connected == cmd).
996 * If bus busy, arbitration failed, etc, NCR5380_select() will exit
997 * with registers as they should have been on entry - ie
998 * SELECT_ENABLE will be set appropriately, the NCR5380
999 * will cease to drive any SCSI bus signals.
1001 * If successful : I_T_L or I_T_L_Q nexus will be established,
1002 * instance->connected will be set to cmd.
1003 * SELECT interrupt will be disabled.
1005 * If failed (no target) : cmd->scsi_done() will be called, and the
1006 * cmd->result host byte set to DID_BAD_TARGET.
1009 static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
1010 struct scsi_cmnd *cmd)
1012 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1013 unsigned char tmp[3], phase;
1014 unsigned char *data;
1018 NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1019 dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
1023 * Arbitration and selection phases are slow and involve dropping the
1024 * lock, so we have to watch out for EH. An exception handler may
1025 * change 'selecting' to NULL. This function will then return NULL
1026 * so that the caller will forget about 'cmd'. (During information
1027 * transfer phases, EH may change 'connected' to NULL.)
1029 hostdata->selecting = cmd;
1032 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1033 * data bus during SELECTION.
1036 NCR5380_write(TARGET_COMMAND_REG, 0);
1039 * Start arbitration.
1042 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1043 NCR5380_write(MODE_REG, MR_ARBITRATE);
1045 /* The chip now waits for BUS FREE phase. Then after the 800 ns
1046 * Bus Free Delay, arbitration will begin.
1049 spin_unlock_irq(&hostdata->lock);
1050 err = NCR5380_poll_politely2(instance, MODE_REG, MR_ARBITRATE, 0,
1051 INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
1052 ICR_ARBITRATION_PROGRESS, HZ);
1053 spin_lock_irq(&hostdata->lock);
1054 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
1055 /* Reselection interrupt */
1059 NCR5380_write(MODE_REG, MR_BASE);
1060 shost_printk(KERN_ERR, instance,
1061 "select: arbitration timeout\n");
1064 spin_unlock_irq(&hostdata->lock);
1066 /* The SCSI-2 arbitration delay is 2.4 us */
1069 /* Check for lost arbitration */
1070 if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) || (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) || (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1071 NCR5380_write(MODE_REG, MR_BASE);
1072 dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1073 spin_lock_irq(&hostdata->lock);
1077 /* After/during arbitration, BSY should be asserted.
1078 * IBM DPES-31080 Version S31Q works now
1079 * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1081 NCR5380_write(INITIATOR_COMMAND_REG,
1082 ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1085 * Again, bus clear + bus settle time is 1.2us, however, this is
1086 * a minimum so we'll udelay ceil(1.2)
1089 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1094 spin_lock_irq(&hostdata->lock);
1096 /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1097 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1100 if (!hostdata->selecting) {
1101 NCR5380_write(MODE_REG, MR_BASE);
1102 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1106 dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1109 * Now that we have won arbitration, start Selection process, asserting
1110 * the host and target ID's on the SCSI bus.
1113 NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << scmd_id(cmd))));
1116 * Raise ATN while SEL is true before BSY goes false from arbitration,
1117 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1118 * phase immediately after selection.
1121 NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1122 NCR5380_write(MODE_REG, MR_BASE);
1125 * Reselect interrupts must be turned off prior to the dropping of BSY,
1126 * otherwise we will trigger an interrupt.
1128 NCR5380_write(SELECT_ENABLE_REG, 0);
1130 spin_unlock_irq(&hostdata->lock);
1133 * The initiator shall then wait at least two deskew delays and release
1136 udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
1139 NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1142 * Something weird happens when we cease to drive BSY - looks
1143 * like the board/chip is letting us do another read before the
1144 * appropriate propagation delay has expired, and we're confusing
1145 * a BSY signal from ourselves as the target's response to SELECTION.
1147 * A small delay (the 'C++' frontend breaks the pipeline with an
1148 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1149 * tighter 'C' code breaks and requires this) solves the problem -
1150 * the 1 us delay is arbitrary, and only used because this delay will
1151 * be the same on other platforms and since it works here, it should
1154 * wingel suggests that this could be due to failing to wait
1160 dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1163 * The SCSI specification calls for a 250 ms timeout for the actual
1167 err = NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, SR_BSY,
1168 msecs_to_jiffies(250));
1170 if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1171 spin_lock_irq(&hostdata->lock);
1172 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1173 NCR5380_reselect(instance);
1174 if (!hostdata->connected)
1175 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1176 shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1181 spin_lock_irq(&hostdata->lock);
1182 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1183 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1184 /* Can't touch cmd if it has been reclaimed by the scsi ML */
1185 if (hostdata->selecting) {
1186 cmd->result = DID_BAD_TARGET << 16;
1187 complete_cmd(instance, cmd);
1188 dsprintk(NDEBUG_SELECTION, instance, "target did not respond within 250ms\n");
1195 * No less than two deskew delays after the initiator detects the
1196 * BSY signal is true, it shall release the SEL signal and may
1197 * change the DATA BUS. -wingel
1202 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1205 * Since we followed the SCSI spec, and raised ATN while SEL
1206 * was true but before BSY was false during selection, the information
1207 * transfer phase should be a MESSAGE OUT phase so that we can send the
1210 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1211 * message (2 bytes) with a tag ID that we increment with every command
1212 * until it wraps back to 0.
1214 * XXX - it turns out that there are some broken SCSI-II devices,
1215 * which claim to support tagged queuing but fail when more than
1216 * some number of commands are issued at once.
1219 /* Wait for start of REQ/ACK handshake */
1221 err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1222 spin_lock_irq(&hostdata->lock);
1224 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1225 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1226 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1229 if (!hostdata->selecting) {
1234 dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1236 tmp[0] = IDENTIFY(((instance->irq == NO_IRQ) ? 0 : 1), cmd->device->lun);
1241 /* Send message(s) */
1243 phase = PHASE_MSGOUT;
1244 NCR5380_transfer_pio(instance, &phase, &len, &data);
1245 dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1246 /* XXX need to handle errors here */
1248 hostdata->connected = cmd;
1249 hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1251 initialize_SCp(cmd);
1256 if (!hostdata->selecting)
1258 hostdata->selecting = NULL;
1263 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1264 * unsigned char *phase, int *count, unsigned char **data)
1266 * Purpose : transfers data in given phase using polled I/O
1268 * Inputs : instance - instance of driver, *phase - pointer to
1269 * what phase is expected, *count - pointer to number of
1270 * bytes to transfer, **data - pointer to data pointer.
1272 * Returns : -1 when different phase is entered without transferring
1273 * maximum number of bytes, 0 if all bytes or transferred or exit
1276 * Also, *phase, *count, *data are modified in place.
1278 * XXX Note : handling for bus free may be useful.
1282 * Note : this code is not as quick as it could be, however it
1283 * IS 100% reliable, and for the actual data transfer where speed
1284 * counts, we will always do a pseudo DMA or DMA transfer.
1287 static int NCR5380_transfer_pio(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1288 unsigned char p = *phase, tmp;
1290 unsigned char *d = *data;
1293 * The NCR5380 chip will only drive the SCSI bus when the
1294 * phase specified in the appropriate bits of the TARGET COMMAND
1295 * REGISTER match the STATUS REGISTER
1298 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1302 * Wait for assertion of REQ, after which the phase bits will be
1306 if (NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1309 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1311 /* Check for phase mismatch */
1312 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1313 dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1314 NCR5380_dprint_phase(NDEBUG_PIO, instance);
1317 /* Do actual transfer from SCSI bus to / from memory */
1319 NCR5380_write(OUTPUT_DATA_REG, *d);
1321 *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1326 * The SCSI standard suggests that in MSGOUT phase, the initiator
1327 * should drop ATN on the last byte of the message phase
1328 * after REQ has been asserted for the handshake but before
1329 * the initiator raises ACK.
1333 if (!((p & SR_MSG) && c > 1)) {
1334 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1335 NCR5380_dprint(NDEBUG_PIO, instance);
1336 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1338 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1339 NCR5380_dprint(NDEBUG_PIO, instance);
1340 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1343 NCR5380_dprint(NDEBUG_PIO, instance);
1344 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1347 if (NCR5380_poll_politely(instance,
1348 STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1351 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1354 * We have several special cases to consider during REQ/ACK handshaking :
1355 * 1. We were in MSGOUT phase, and we are on the last byte of the
1356 * message. ATN must be dropped as ACK is dropped.
1358 * 2. We are in a MSGIN phase, and we are on the last byte of the
1359 * message. We must exit with ACK asserted, so that the calling
1360 * code may raise ATN before dropping ACK to reject the message.
1362 * 3. ACK and ATN are clear and the target may proceed as normal.
1364 if (!(p == PHASE_MSGIN && c == 1)) {
1365 if (p == PHASE_MSGOUT && c > 1)
1366 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1368 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1372 dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1376 tmp = NCR5380_read(STATUS_REG);
1377 /* The phase read from the bus is valid if either REQ is (already)
1378 * asserted or if ACK hasn't been released yet. The latter applies if
1379 * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1381 if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1382 *phase = tmp & PHASE_MASK;
1384 *phase = PHASE_UNKNOWN;
1386 if (!c || (*phase == p))
1393 * do_reset - issue a reset command
1394 * @instance: adapter to reset
1396 * Issue a reset sequence to the NCR5380 and try and get the bus
1397 * back into sane shape.
1399 * This clears the reset interrupt flag because there may be no handler for
1400 * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1401 * been installed. And when in EH we may have released the ST DMA interrupt.
1404 static void do_reset(struct Scsi_Host *instance)
1406 unsigned long flags;
1408 local_irq_save(flags);
1409 NCR5380_write(TARGET_COMMAND_REG,
1410 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1411 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1413 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1414 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1415 local_irq_restore(flags);
1419 * do_abort - abort the currently established nexus by going to
1420 * MESSAGE OUT phase and sending an ABORT message.
1421 * @instance: relevant scsi host instance
1423 * Returns 0 on success, -1 on failure.
1426 static int do_abort(struct Scsi_Host *instance)
1428 unsigned char *msgptr, phase, tmp;
1432 /* Request message out phase */
1433 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1436 * Wait for the target to indicate a valid phase by asserting
1437 * REQ. Once this happens, we'll have either a MSGOUT phase
1438 * and can immediately send the ABORT message, or we'll have some
1439 * other phase and will have to source/sink data.
1441 * We really don't care what value was on the bus or what value
1442 * the target sees, so we just handshake.
1445 rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1449 tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1451 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1453 if (tmp != PHASE_MSGOUT) {
1454 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1455 rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 3 * HZ);
1458 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1463 phase = PHASE_MSGOUT;
1464 NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1467 * If we got here, and the command completed successfully,
1468 * we're about to go into bus free state.
1471 return len ? -1 : 0;
1474 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1478 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1480 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1481 * unsigned char *phase, int *count, unsigned char **data)
1483 * Purpose : transfers data in given phase using either real
1486 * Inputs : instance - instance of driver, *phase - pointer to
1487 * what phase is expected, *count - pointer to number of
1488 * bytes to transfer, **data - pointer to data pointer.
1490 * Returns : -1 when different phase is entered without transferring
1491 * maximum number of bytes, 0 if all bytes or transferred or exit
1494 * Also, *phase, *count, *data are modified in place.
1498 static int NCR5380_transfer_dma(struct Scsi_Host *instance, unsigned char *phase, int *count, unsigned char **data) {
1499 register int c = *count;
1500 register unsigned char p = *phase;
1501 register unsigned char *d = *data;
1504 #if defined(REAL_DMA_POLL)
1506 unsigned char saved_data = 0, overrun = 0, residue;
1509 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1511 if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1515 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1517 if (!(hostdata->flags & FLAG_NO_DMA_FIXUPS))
1520 hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1522 dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1523 (p & SR_IO) ? "receive" : "send", c, *data);
1526 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1529 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1530 MR_ENABLE_EOP_INTR);
1531 #elif defined(REAL_DMA_POLL)
1532 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY);
1535 * Note : on my sample board, watch-dog timeouts occurred when interrupts
1536 * were not disabled for the duration of a single DMA transfer, from
1537 * before the setting of DMA mode to after transfer of the last byte.
1540 if (hostdata->flags & FLAG_NO_DMA_FIXUP)
1541 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1542 MR_ENABLE_EOP_INTR);
1544 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY);
1545 #endif /* def REAL_DMA */
1547 dprintk(NDEBUG_DMA, "scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG));
1550 * On the PAS16 at least I/O recovery delays are not needed here.
1551 * Everyone else seems to want them.
1555 io_recovery_delay(1);
1556 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1558 io_recovery_delay(1);
1559 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1560 io_recovery_delay(1);
1561 NCR5380_write(START_DMA_SEND_REG, 0);
1562 io_recovery_delay(1);
1565 #if defined(REAL_DMA_POLL)
1567 tmp = NCR5380_read(BUS_AND_STATUS_REG);
1568 } while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1571 * At this point, either we've completed DMA, or we have a phase mismatch,
1572 * or we've unexpectedly lost BUSY (which is a real error).
1574 * For DMA sends, we want to wait until the last byte has been
1575 * transferred out over the bus before we turn off DMA mode. Alas, there
1576 * seems to be no terribly good way of doing this on a 5380 under all
1577 * conditions. For non-scatter-gather operations, we can wait until REQ
1578 * and ACK both go false, or until a phase mismatch occurs. Gather-sends
1579 * are nastier, since the device will be expecting more data than we
1580 * are prepared to send it, and REQ will remain asserted. On a 53C8[01] we
1581 * could test Last Byte Sent to assure transfer (I imagine this is precisely
1582 * why this signal was added to the newer chips) but on the older 538[01]
1583 * this signal does not exist. The workaround for this lack is a watchdog;
1584 * we bail out of the wait-loop after a modest amount of wait-time if
1585 * the usual exit conditions are not met. Not a terribly clean or
1586 * correct solution :-%
1588 * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1589 * If the chip is in DMA receive mode, it will respond to a target's
1590 * REQ by latching the SCSI data into the INPUT DATA register and asserting
1591 * ACK, even if it has _already_ been notified by the DMA controller that
1592 * the current DMA transfer has completed! If the NCR5380 is then taken
1593 * out of DMA mode, this already-acknowledged byte is lost. This is
1594 * not a problem for "one DMA transfer per READ command", because
1595 * the situation will never arise... either all of the data is DMA'ed
1596 * properly, or the target switches to MESSAGE IN phase to signal a
1597 * disconnection (either operation bringing the DMA to a clean halt).
1598 * However, in order to handle scatter-receive, we must work around the
1599 * problem. The chosen fix is to DMA N-2 bytes, then check for the
1600 * condition before taking the NCR5380 out of DMA mode. One or two extra
1601 * bytes are transferred via PIO as necessary to fill out the original
1606 if (!(hostdata->flags & FLAG_NO_DMA_FIXUPS)) {
1608 if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
1609 (BASR_PHASE_MATCH | BASR_ACK)) {
1610 saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1616 while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1617 if (!(tmp & BASR_PHASE_MATCH))
1624 dsprintk(NDEBUG_DMA, "polled DMA transfer complete, basr 0x%02x, sr 0x%02x\n",
1625 tmp, NCR5380_read(STATUS_REG));
1627 NCR5380_write(MODE_REG, MR_BASE);
1628 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1630 residue = NCR5380_dma_residual(instance);
1634 *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1636 if (!(hostdata->flags & FLAG_NO_DMA_FIXUPS) &&
1637 *phase == p && (p & SR_IO) && residue == 0) {
1639 dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
1640 **data = saved_data;
1645 printk("No overrun??\n");
1648 dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%X\n", cnt, *data);
1649 NCR5380_transfer_pio(instance, phase, &cnt, data);
1650 *count -= toPIO - cnt;
1653 dprintk(NDEBUG_DMA, "Return with data ptr = 0x%X, count %d, last 0x%X, next 0x%X\n", *data, *count, *(*data + *count - 1), *(*data + *count));
1656 #elif defined(REAL_DMA)
1658 #else /* defined(REAL_DMA_POLL) */
1660 foo = NCR5380_pread(instance, d,
1661 hostdata->flags & FLAG_NO_DMA_FIXUP ? c : c - 1);
1662 if (!foo && !(hostdata->flags & FLAG_NO_DMA_FIXUP)) {
1664 * We can't disable DMA mode after successfully transferring
1665 * what we plan to be the last byte, since that would open up
1666 * a race condition where if the target asserted REQ before
1667 * we got the DMA mode reset, the NCR5380 would have latched
1668 * an additional byte into the INPUT DATA register and we'd
1671 * The workaround was to transfer one fewer bytes than we
1672 * intended to with the pseudo-DMA read function, wait for
1673 * the chip to latch the last byte, read it, and then disable
1676 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1677 * REQ is deasserted when ACK is asserted, and not reasserted
1678 * until ACK goes false. Since the NCR5380 won't lower ACK
1679 * until DACK is asserted, which won't happen unless we twiddle
1680 * the DMA port or we take the NCR5380 out of DMA mode, we
1681 * can guarantee that we won't handshake another extra
1685 if (NCR5380_poll_politely(instance, BUS_AND_STATUS_REG,
1686 BASR_DRQ, BASR_DRQ, HZ) < 0) {
1688 shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1690 if (NCR5380_poll_politely(instance, STATUS_REG,
1691 SR_REQ, 0, HZ) < 0) {
1693 shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1695 d[c - 1] = NCR5380_read(INPUT_DATA_REG);
1698 foo = NCR5380_pwrite(instance, d, c);
1699 if (!foo && !(hostdata->flags & FLAG_NO_DMA_FIXUP)) {
1701 * Wait for the last byte to be sent. If REQ is being asserted for
1702 * the byte we're interested, we'll ACK it and it will go false.
1704 if (NCR5380_poll_politely2(instance,
1705 BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1706 BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
1708 shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1712 NCR5380_write(MODE_REG, MR_BASE);
1713 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1714 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1717 *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1719 #endif /* def REAL_DMA */
1721 #endif /* defined(REAL_DMA) | defined(PSEUDO_DMA) */
1724 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1726 * Purpose : run through the various SCSI phases and do as the target
1727 * directs us to. Operates on the currently connected command,
1728 * instance->connected.
1730 * Inputs : instance, instance for which we are doing commands
1732 * Side effects : SCSI things happen, the disconnected queue will be
1733 * modified if a command disconnects, *instance->connected will
1736 * XXX Note : we need to watch for bus free or a reset condition here
1737 * to recover from an unexpected bus free condition.
1740 static void NCR5380_information_transfer(struct Scsi_Host *instance) {
1741 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1742 unsigned char msgout = NOP;
1745 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
1748 unsigned char *data;
1749 unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1750 struct scsi_cmnd *cmd;
1752 while ((cmd = hostdata->connected)) {
1753 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1755 tmp = NCR5380_read(STATUS_REG);
1756 /* We only have a valid SCSI phase when REQ is asserted */
1758 phase = (tmp & PHASE_MASK);
1759 if (phase != old_phase) {
1761 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1763 if (sink && (phase != PHASE_MSGOUT)) {
1764 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1766 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1767 while (NCR5380_read(STATUS_REG) & SR_REQ);
1768 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1774 #if (NDEBUG & NDEBUG_NO_DATAOUT)
1775 shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1778 cmd->result = DID_ERROR << 16;
1779 complete_cmd(instance, cmd);
1784 * If there is no room left in the current buffer in the
1785 * scatter-gather list, move onto the next one.
1788 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1790 --cmd->SCp.buffers_residual;
1791 cmd->SCp.this_residual = cmd->SCp.buffer->length;
1792 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1793 dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n",
1794 cmd->SCp.this_residual,
1795 cmd->SCp.buffers_residual);
1798 * The preferred transfer method is going to be
1799 * PSEUDO-DMA for systems that are strictly PIO,
1800 * since we can let the hardware do the handshaking.
1802 * For this to work, we need to know the transfersize
1803 * ahead of time, since the pseudo-DMA code will sit
1804 * in an unconditional loop.
1807 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
1809 if (!cmd->device->borken &&
1810 !(hostdata->flags & FLAG_NO_PSEUDO_DMA))
1811 transfersize = NCR5380_dma_xfer_len(instance, cmd, phase);
1815 if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **) &cmd->SCp.ptr)) {
1817 * If the watchdog timer fires, all future accesses to this
1818 * device will use the polled-IO.
1820 scmd_printk(KERN_INFO, cmd,
1821 "switching to slow handshake\n");
1822 cmd->device->borken = 1;
1825 cmd->result = DID_ERROR << 16;
1826 complete_cmd(instance, cmd);
1827 /* XXX - need to source or sink data here, as appropriate */
1829 cmd->SCp.this_residual -= transfersize - len;
1831 #endif /* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
1833 spin_unlock_irq(&hostdata->lock);
1834 NCR5380_transfer_pio(instance, &phase, (int *) &cmd->SCp.this_residual, (unsigned char **)
1836 spin_lock_irq(&hostdata->lock);
1842 NCR5380_transfer_pio(instance, &phase, &len, &data);
1843 cmd->SCp.Message = tmp;
1847 case COMMAND_COMPLETE:
1848 /* Accept message by clearing ACK */
1850 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1851 dsprintk(NDEBUG_QUEUES, instance,
1852 "COMMAND COMPLETE %p target %d lun %llu\n",
1853 cmd, scmd_id(cmd), cmd->device->lun);
1855 hostdata->connected = NULL;
1857 cmd->result &= ~0xffff;
1858 cmd->result |= cmd->SCp.Status;
1859 cmd->result |= cmd->SCp.Message << 8;
1861 if (cmd->cmnd[0] == REQUEST_SENSE)
1862 complete_cmd(instance, cmd);
1864 if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
1865 cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
1866 dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1868 list_add_tail(&ncmd->list,
1869 &hostdata->autosense);
1871 complete_cmd(instance, cmd);
1875 * Restore phase bits to 0 so an interrupted selection,
1876 * arbitration can resume.
1878 NCR5380_write(TARGET_COMMAND_REG, 0);
1880 /* Enable reselect interrupts */
1881 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1883 case MESSAGE_REJECT:
1884 /* Accept message by clearing ACK */
1885 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1886 switch (hostdata->last_message) {
1887 case HEAD_OF_QUEUE_TAG:
1888 case ORDERED_QUEUE_TAG:
1889 case SIMPLE_QUEUE_TAG:
1890 cmd->device->simple_tags = 0;
1891 hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1898 /* Accept message by clearing ACK */
1899 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1900 hostdata->connected = NULL;
1901 list_add(&ncmd->list, &hostdata->disconnected);
1902 dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1903 instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1904 cmd, scmd_id(cmd), cmd->device->lun);
1907 * Restore phase bits to 0 so an interrupted selection,
1908 * arbitration can resume.
1910 NCR5380_write(TARGET_COMMAND_REG, 0);
1912 /* Enable reselect interrupts */
1913 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1917 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
1918 * operation, in violation of the SCSI spec so we can safely
1919 * ignore SAVE/RESTORE pointers calls.
1921 * Unfortunately, some disks violate the SCSI spec and
1922 * don't issue the required SAVE_POINTERS message before
1923 * disconnecting, and we have to break spec to remain
1927 case RESTORE_POINTERS:
1928 /* Accept message by clearing ACK */
1929 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1931 case EXTENDED_MESSAGE:
1933 * Start the message buffer with the EXTENDED_MESSAGE
1934 * byte, since spi_print_msg() wants the whole thing.
1936 extended_msg[0] = EXTENDED_MESSAGE;
1937 /* Accept first byte by clearing ACK */
1938 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1940 spin_unlock_irq(&hostdata->lock);
1942 dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
1945 data = extended_msg + 1;
1946 phase = PHASE_MSGIN;
1947 NCR5380_transfer_pio(instance, &phase, &len, &data);
1948 dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
1949 (int)extended_msg[1],
1950 (int)extended_msg[2]);
1952 if (!len && extended_msg[1] > 0 &&
1953 extended_msg[1] <= sizeof(extended_msg) - 2) {
1954 /* Accept third byte by clearing ACK */
1955 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1956 len = extended_msg[1] - 1;
1957 data = extended_msg + 3;
1958 phase = PHASE_MSGIN;
1960 NCR5380_transfer_pio(instance, &phase, &len, &data);
1961 dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
1964 switch (extended_msg[2]) {
1967 case EXTENDED_MODIFY_DATA_POINTER:
1968 case EXTENDED_EXTENDED_IDENTIFY:
1972 shost_printk(KERN_ERR, instance, "error receiving extended message\n");
1975 shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
1976 extended_msg[2], extended_msg[1]);
1980 spin_lock_irq(&hostdata->lock);
1981 if (!hostdata->connected)
1984 /* Fall through to reject message */
1987 * If we get something weird that we aren't expecting,
1992 shost_printk(KERN_ERR, instance, "rejecting message ");
1993 spi_print_msg(extended_msg);
1995 } else if (tmp != EXTENDED_MESSAGE)
1996 scmd_printk(KERN_INFO, cmd,
1997 "rejecting unknown message %02x\n",tmp);
1999 scmd_printk(KERN_INFO, cmd,
2000 "rejecting unknown extended message code %02x, length %d\n", extended_msg[1], extended_msg[0]);
2002 msgout = MESSAGE_REJECT;
2003 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2005 } /* switch (tmp) */
2010 hostdata->last_message = msgout;
2011 NCR5380_transfer_pio(instance, &phase, &len, &data);
2012 if (msgout == ABORT) {
2013 hostdata->connected = NULL;
2014 cmd->result = DID_ERROR << 16;
2015 complete_cmd(instance, cmd);
2016 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2025 * XXX for performance reasons, on machines with a
2026 * PSEUDO-DMA architecture we should probably
2027 * use the dma transfer function.
2029 NCR5380_transfer_pio(instance, &phase, &len, &data);
2034 NCR5380_transfer_pio(instance, &phase, &len, &data);
2035 cmd->SCp.Status = tmp;
2038 shost_printk(KERN_ERR, instance, "unknown phase\n");
2039 NCR5380_dprint(NDEBUG_ANY, instance);
2040 } /* switch(phase) */
2042 spin_unlock_irq(&hostdata->lock);
2043 NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
2044 spin_lock_irq(&hostdata->lock);
2050 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2052 * Purpose : does reselection, initializing the instance->connected
2053 * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2054 * nexus has been reestablished,
2056 * Inputs : instance - this instance of the NCR5380.
2059 static void NCR5380_reselect(struct Scsi_Host *instance) {
2060 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2061 unsigned char target_mask;
2062 unsigned char lun, phase;
2064 unsigned char msg[3];
2065 unsigned char *data;
2066 struct NCR5380_cmd *ncmd;
2067 struct scsi_cmnd *tmp;
2070 * Disable arbitration, etc. since the host adapter obviously
2071 * lost, and tell an interrupted NCR5380_select() to restart.
2074 NCR5380_write(MODE_REG, MR_BASE);
2076 target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2078 dsprintk(NDEBUG_RESELECTION, instance, "reselect\n");
2081 * At this point, we have detected that our SCSI ID is on the bus,
2082 * SEL is true and BSY was false for at least one bus settle delay
2085 * We must assert BSY ourselves, until the target drops the SEL
2089 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2090 if (NCR5380_poll_politely(instance,
2091 STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2092 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2095 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2098 * Wait for target to go into MSGIN.
2101 if (NCR5380_poll_politely(instance,
2102 STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2109 phase = PHASE_MSGIN;
2110 NCR5380_transfer_pio(instance, &phase, &len, &data);
2117 if (!(msg[0] & 0x80)) {
2118 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2124 lun = msg[0] & 0x07;
2127 * We need to add code for SCSI-II to track which devices have
2128 * I_T_L_Q nexuses established, and which have simple I_T_L
2129 * nexuses so we can chose to do additional data transfer.
2133 * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
2134 * just reestablished, and remove it from the disconnected queue.
2138 list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2139 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2141 if (target_mask == (1 << scmd_id(cmd)) &&
2142 lun == (u8)cmd->device->lun) {
2143 list_del(&ncmd->list);
2150 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2151 "reselect: removed %p from disconnected queue\n", tmp);
2153 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2156 * Since we have an established nexus that we can't do anything with,
2163 /* Accept message by clearing ACK */
2164 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2166 hostdata->connected = tmp;
2167 dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu, tag %d\n",
2168 scmd_id(tmp), tmp->device->lun, tmp->tag);
2172 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2174 * Purpose : called by interrupt handler when DMA finishes or a phase
2175 * mismatch occurs (which would finish the DMA transfer).
2177 * Inputs : instance - this instance of the NCR5380.
2179 * Returns : pointer to the scsi_cmnd structure for which the I_T_L
2180 * nexus has been reestablished, on failure NULL is returned.
2184 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2185 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2189 * XXX this might not be right.
2191 * Wait for final byte to transfer, ie wait for ACK to go false.
2193 * We should use the Last Byte Sent bit, unfortunately this is
2194 * not available on the 5380/5381 (only the various CMOS chips)
2196 * FIXME: timeout, and need to handle long timeout/irq case
2199 NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2201 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2204 * The only places we should see a phase mismatch and have to send
2205 * data from the same set of pointers will be the data transfer
2206 * phases. So, residual, requested length are only important here.
2209 if (!(hostdata->connected->SCp.phase & SR_CD)) {
2210 transferred = instance->dmalen - NCR5380_dma_residual();
2211 hostdata->connected->SCp.this_residual -= transferred;
2212 hostdata->connected->SCp.ptr += transferred;
2215 #endif /* def REAL_DMA */
2218 * list_find_cmd - test for presence of a command in a linked list
2219 * @haystack: list of commands
2220 * @needle: command to search for
2223 static bool list_find_cmd(struct list_head *haystack,
2224 struct scsi_cmnd *needle)
2226 struct NCR5380_cmd *ncmd;
2228 list_for_each_entry(ncmd, haystack, list)
2229 if (NCR5380_to_scmd(ncmd) == needle)
2235 * list_remove_cmd - remove a command from linked list
2236 * @haystack: list of commands
2237 * @needle: command to remove
2240 static bool list_del_cmd(struct list_head *haystack,
2241 struct scsi_cmnd *needle)
2243 if (list_find_cmd(haystack, needle)) {
2244 struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2246 list_del(&ncmd->list);
2253 * NCR5380_abort - scsi host eh_abort_handler() method
2254 * @cmd: the command to be aborted
2256 * Try to abort a given command by removing it from queues and/or sending
2257 * the target an abort message. This may not succeed in causing a target
2258 * to abort the command. Nonetheless, the low-level driver must forget about
2259 * the command because the mid-layer reclaims it and it may be re-issued.
2261 * The normal path taken by a command is as follows. For EH we trace this
2262 * same path to locate and abort the command.
2264 * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2265 * [disconnected -> connected ->]...
2266 * [autosense -> connected ->] done
2268 * If cmd is unissued then just remove it.
2269 * If cmd is disconnected, try to select the target.
2270 * If cmd is connected, try to send an abort message.
2271 * If cmd is waiting for autosense, give it a chance to complete but check
2272 * that it isn't left connected.
2273 * If cmd was not found at all then presumably it has already been completed,
2274 * in which case return SUCCESS to try to avoid further EH measures.
2275 * If the command has not completed yet, we must not fail to find it.
2278 static int NCR5380_abort(struct scsi_cmnd *cmd)
2280 struct Scsi_Host *instance = cmd->device->host;
2281 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2282 unsigned long flags;
2283 int result = SUCCESS;
2285 spin_lock_irqsave(&hostdata->lock, flags);
2287 #if (NDEBUG & NDEBUG_ANY)
2288 scmd_printk(KERN_INFO, cmd, __func__);
2290 NCR5380_dprint(NDEBUG_ANY, instance);
2291 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2293 if (list_del_cmd(&hostdata->unissued, cmd)) {
2294 dsprintk(NDEBUG_ABORT, instance,
2295 "abort: removed %p from issue queue\n", cmd);
2296 cmd->result = DID_ABORT << 16;
2297 cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2300 if (hostdata->selecting == cmd) {
2301 dsprintk(NDEBUG_ABORT, instance,
2302 "abort: cmd %p == selecting\n", cmd);
2303 hostdata->selecting = NULL;
2304 cmd->result = DID_ABORT << 16;
2305 complete_cmd(instance, cmd);
2309 if (list_del_cmd(&hostdata->disconnected, cmd)) {
2310 dsprintk(NDEBUG_ABORT, instance,
2311 "abort: removed %p from disconnected list\n", cmd);
2312 cmd->result = DID_ERROR << 16;
2313 if (!hostdata->connected)
2314 NCR5380_select(instance, cmd);
2315 if (hostdata->connected != cmd) {
2316 complete_cmd(instance, cmd);
2322 if (hostdata->connected == cmd) {
2323 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2324 hostdata->connected = NULL;
2325 if (do_abort(instance)) {
2326 set_host_byte(cmd, DID_ERROR);
2327 complete_cmd(instance, cmd);
2331 set_host_byte(cmd, DID_ABORT);
2333 hostdata->dma_len = 0;
2335 if (cmd->cmnd[0] == REQUEST_SENSE)
2336 complete_cmd(instance, cmd);
2338 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
2340 /* Perform autosense for this command */
2341 list_add(&ncmd->list, &hostdata->autosense);
2345 if (list_find_cmd(&hostdata->autosense, cmd)) {
2346 dsprintk(NDEBUG_ABORT, instance,
2347 "abort: found %p on sense queue\n", cmd);
2348 spin_unlock_irqrestore(&hostdata->lock, flags);
2349 queue_work(hostdata->work_q, &hostdata->main_task);
2351 spin_lock_irqsave(&hostdata->lock, flags);
2352 if (list_del_cmd(&hostdata->autosense, cmd)) {
2353 dsprintk(NDEBUG_ABORT, instance,
2354 "abort: removed %p from sense queue\n", cmd);
2355 set_host_byte(cmd, DID_ABORT);
2356 complete_cmd(instance, cmd);
2361 if (hostdata->connected == cmd) {
2362 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2363 hostdata->connected = NULL;
2364 if (do_abort(instance)) {
2365 set_host_byte(cmd, DID_ERROR);
2366 complete_cmd(instance, cmd);
2370 set_host_byte(cmd, DID_ABORT);
2372 hostdata->dma_len = 0;
2374 complete_cmd(instance, cmd);
2378 if (result == FAILED)
2379 dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2381 dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2383 queue_work(hostdata->work_q, &hostdata->main_task);
2384 spin_unlock_irqrestore(&hostdata->lock, flags);
2391 * NCR5380_bus_reset - reset the SCSI bus
2392 * @cmd: SCSI command undergoing EH
2397 static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
2399 struct Scsi_Host *instance = cmd->device->host;
2400 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2402 unsigned long flags;
2403 struct NCR5380_cmd *ncmd;
2405 spin_lock_irqsave(&hostdata->lock, flags);
2407 #if (NDEBUG & NDEBUG_ANY)
2408 scmd_printk(KERN_INFO, cmd, __func__);
2410 NCR5380_dprint(NDEBUG_ANY, instance);
2411 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2415 /* reset NCR registers */
2416 NCR5380_write(MODE_REG, MR_BASE);
2417 NCR5380_write(TARGET_COMMAND_REG, 0);
2418 NCR5380_write(SELECT_ENABLE_REG, 0);
2420 /* After the reset, there are no more connected or disconnected commands
2421 * and no busy units; so clear the low-level status here to avoid
2422 * conflicts when the mid-level code tries to wake up the affected
2426 hostdata->selecting = NULL;
2428 list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2429 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2431 set_host_byte(cmd, DID_RESET);
2432 cmd->scsi_done(cmd);
2435 list_for_each_entry(ncmd, &hostdata->autosense, list) {
2436 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2438 set_host_byte(cmd, DID_RESET);
2439 cmd->scsi_done(cmd);
2442 if (hostdata->connected) {
2443 set_host_byte(hostdata->connected, DID_RESET);
2444 complete_cmd(instance, hostdata->connected);
2445 hostdata->connected = NULL;
2448 if (hostdata->sensing) {
2449 set_host_byte(hostdata->connected, DID_RESET);
2450 complete_cmd(instance, hostdata->sensing);
2451 hostdata->sensing = NULL;
2454 for (i = 0; i < 8; ++i)
2455 hostdata->busy[i] = 0;
2457 hostdata->dma_len = 0;
2460 queue_work(hostdata->work_q, &hostdata->main_task);
2461 spin_unlock_irqrestore(&hostdata->lock, flags);