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);
288 {ICR_ASSERT_RST, "ASSERT RST"},
289 {ICR_ASSERT_ACK, "ASSERT ACK"},
290 {ICR_ASSERT_BSY, "ASSERT BSY"},
291 {ICR_ASSERT_SEL, "ASSERT SEL"},
292 {ICR_ASSERT_ATN, "ASSERT ATN"},
293 {ICR_ASSERT_DATA, "ASSERT DATA"},
297 {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
298 {MR_TARGET, "MODE TARGET"},
299 {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
300 {MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
301 {MR_ENABLE_EOP_INTR, "MODE EOP INTR"},
302 {MR_MONITOR_BSY, "MODE MONITOR BSY"},
303 {MR_DMA_MODE, "MODE DMA"},
304 {MR_ARBITRATE, "MODE ARBITRATION"},
309 * NCR5380_print - print scsi bus signals
310 * @instance: adapter state to dump
312 * Print the SCSI bus signals for debugging purposes
315 static void NCR5380_print(struct Scsi_Host *instance)
317 unsigned char status, data, basr, mr, icr, i;
319 data = NCR5380_read(CURRENT_SCSI_DATA_REG);
320 status = NCR5380_read(STATUS_REG);
321 mr = NCR5380_read(MODE_REG);
322 icr = NCR5380_read(INITIATOR_COMMAND_REG);
323 basr = NCR5380_read(BUS_AND_STATUS_REG);
325 printk("STATUS_REG: %02x ", status);
326 for (i = 0; signals[i].mask; ++i)
327 if (status & signals[i].mask)
328 printk(",%s", signals[i].name);
329 printk("\nBASR: %02x ", basr);
330 for (i = 0; basrs[i].mask; ++i)
331 if (basr & basrs[i].mask)
332 printk(",%s", basrs[i].name);
333 printk("\nICR: %02x ", icr);
334 for (i = 0; icrs[i].mask; ++i)
335 if (icr & icrs[i].mask)
336 printk(",%s", icrs[i].name);
337 printk("\nMODE: %02x ", mr);
338 for (i = 0; mrs[i].mask; ++i)
339 if (mr & mrs[i].mask)
340 printk(",%s", mrs[i].name);
348 {PHASE_DATAOUT, "DATAOUT"},
349 {PHASE_DATAIN, "DATAIN"},
350 {PHASE_CMDOUT, "CMDOUT"},
351 {PHASE_STATIN, "STATIN"},
352 {PHASE_MSGOUT, "MSGOUT"},
353 {PHASE_MSGIN, "MSGIN"},
354 {PHASE_UNKNOWN, "UNKNOWN"}
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) &&
374 (phases[i].value != (status & PHASE_MASK)); ++i)
376 shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
382 static int probe_irq __initdata;
385 * probe_intr - helper for IRQ autoprobe
386 * @irq: interrupt number
390 * Set a flag to indicate the IRQ in question was received. This is
391 * used by the IRQ probe code.
394 static irqreturn_t __init probe_intr(int irq, void *dev_id)
401 * NCR5380_probe_irq - find the IRQ of an NCR5380
402 * @instance: NCR5380 controller
403 * @possible: bitmask of ISA IRQ lines
405 * Autoprobe for the IRQ line used by the NCR5380 by triggering an IRQ
406 * and then looking to see what interrupt actually turned up.
409 static int __init __maybe_unused NCR5380_probe_irq(struct Scsi_Host *instance,
412 struct NCR5380_hostdata *hostdata = shost_priv(instance);
413 unsigned long timeout;
414 int trying_irqs, i, mask;
416 for (trying_irqs = 0, i = 1, mask = 2; i < 16; ++i, mask <<= 1)
417 if ((mask & possible) && (request_irq(i, &probe_intr, 0, "NCR-probe", NULL) == 0))
420 timeout = jiffies + msecs_to_jiffies(250);
424 * A interrupt is triggered whenever BSY = false, SEL = true
425 * and a bit set in the SELECT_ENABLE_REG is asserted on the
428 * Note that the bus is only driven when the phase control signals
429 * (I/O, C/D, and MSG) match those in the TCR, so we must reset that
433 NCR5380_write(TARGET_COMMAND_REG, 0);
434 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
435 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
436 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA | ICR_ASSERT_SEL);
438 while (probe_irq == NO_IRQ && time_before(jiffies, timeout))
439 schedule_timeout_uninterruptible(1);
441 NCR5380_write(SELECT_ENABLE_REG, 0);
442 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
444 for (i = 1, mask = 2; i < 16; ++i, mask <<= 1)
445 if (trying_irqs & mask)
452 * NCR58380_info - report driver and host information
453 * @instance: relevant scsi host instance
455 * For use as the host template info() handler.
458 static const char *NCR5380_info(struct Scsi_Host *instance)
460 struct NCR5380_hostdata *hostdata = shost_priv(instance);
462 return hostdata->info;
465 static void prepare_info(struct Scsi_Host *instance)
467 struct NCR5380_hostdata *hostdata = shost_priv(instance);
469 snprintf(hostdata->info, sizeof(hostdata->info),
470 "%s, io_port 0x%lx, n_io_port %d, "
471 "base 0x%lx, irq %d, "
472 "can_queue %d, cmd_per_lun %d, "
473 "sg_tablesize %d, this_id %d, "
476 instance->hostt->name, instance->io_port, instance->n_io_port,
477 instance->base, instance->irq,
478 instance->can_queue, instance->cmd_per_lun,
479 instance->sg_tablesize, instance->this_id,
480 hostdata->flags & FLAG_NO_DMA_FIXUP ? "NO_DMA_FIXUP " : "",
481 hostdata->flags & FLAG_NO_PSEUDO_DMA ? "NO_PSEUDO_DMA " : "",
482 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "",
505 static int __maybe_unused NCR5380_write_info(struct Scsi_Host *instance,
506 char *buffer, int length)
508 struct NCR5380_hostdata *hostdata = shost_priv(instance);
510 hostdata->spin_max_r = 0;
511 hostdata->spin_max_w = 0;
515 static int __maybe_unused NCR5380_show_info(struct seq_file *m,
516 struct Scsi_Host *instance)
518 struct NCR5380_hostdata *hostdata = shost_priv(instance);
520 seq_printf(m, "Highwater I/O busy spin counts: write %d, read %d\n",
521 hostdata->spin_max_w, hostdata->spin_max_r);
527 * NCR5380_init - initialise an NCR5380
528 * @instance: adapter to configure
529 * @flags: control flags
531 * Initializes *instance and corresponding 5380 chip,
532 * with flags OR'd into the initial flags value.
534 * Notes : I assume that the host, hostno, and id bits have been
535 * set correctly. I don't care about the irq and other fields.
537 * Returns 0 for success
540 static int NCR5380_init(struct Scsi_Host *instance, int flags)
542 struct NCR5380_hostdata *hostdata = shost_priv(instance);
544 unsigned long deadline;
546 hostdata->host = instance;
547 hostdata->id_mask = 1 << instance->this_id;
548 hostdata->id_higher_mask = 0;
549 for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
550 if (i > hostdata->id_mask)
551 hostdata->id_higher_mask |= i;
552 for (i = 0; i < 8; ++i)
553 hostdata->busy[i] = 0;
555 hostdata->dmalen = 0;
557 spin_lock_init(&hostdata->lock);
558 hostdata->connected = NULL;
559 hostdata->sensing = NULL;
560 INIT_LIST_HEAD(&hostdata->autosense);
561 INIT_LIST_HEAD(&hostdata->unissued);
562 INIT_LIST_HEAD(&hostdata->disconnected);
564 hostdata->flags = flags;
566 INIT_WORK(&hostdata->main_task, NCR5380_main);
567 hostdata->work_q = alloc_workqueue("ncr5380_%d",
568 WQ_UNBOUND | WQ_MEM_RECLAIM,
569 1, instance->host_no);
570 if (!hostdata->work_q)
573 prepare_info(instance);
575 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
576 NCR5380_write(MODE_REG, MR_BASE);
577 NCR5380_write(TARGET_COMMAND_REG, 0);
578 NCR5380_write(SELECT_ENABLE_REG, 0);
580 /* Calibrate register polling loop */
582 deadline = jiffies + 1;
585 } while (time_is_after_jiffies(deadline));
586 deadline += msecs_to_jiffies(256);
588 NCR5380_read(STATUS_REG);
591 } while (time_is_after_jiffies(deadline));
592 hostdata->accesses_per_ms = i / 256;
598 * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
599 * @instance: adapter to check
601 * If the system crashed, it may have crashed with a connected target and
602 * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
603 * currently established nexus, which we know nothing about. Failing that
606 * Note that a bus reset will cause the chip to assert IRQ.
608 * Returns 0 if successful, otherwise -ENXIO.
611 static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
613 struct NCR5380_hostdata *hostdata = shost_priv(instance);
616 for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
621 shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
622 NCR5380_poll_politely(instance,
623 STATUS_REG, SR_BSY, 0, 5 * HZ);
626 shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
630 shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
632 /* Wait after a reset; the SCSI standard calls for
633 * 250ms, we wait 500ms to be on the safe side.
634 * But some Toshiba CD-ROMs need ten times that.
636 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
642 shost_printk(KERN_ERR, instance, "bus locked solid\n");
650 * NCR5380_exit - remove an NCR5380
651 * @instance: adapter to remove
653 * Assumes that no more work can be queued (e.g. by NCR5380_intr).
656 static void NCR5380_exit(struct Scsi_Host *instance)
658 struct NCR5380_hostdata *hostdata = shost_priv(instance);
660 cancel_work_sync(&hostdata->main_task);
661 destroy_workqueue(hostdata->work_q);
665 * complete_cmd - finish processing a command and return it to the SCSI ML
666 * @instance: the host instance
667 * @cmd: command to complete
670 static void complete_cmd(struct Scsi_Host *instance,
671 struct scsi_cmnd *cmd)
673 struct NCR5380_hostdata *hostdata = shost_priv(instance);
675 dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
677 if (hostdata->sensing == cmd) {
678 /* Autosense processing ends here */
679 if ((cmd->result & 0xff) != SAM_STAT_GOOD) {
680 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
681 set_host_byte(cmd, DID_ERROR);
683 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
684 hostdata->sensing = NULL;
687 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
693 * NCR5380_queue_command - queue a command
694 * @instance: the relevant SCSI adapter
697 * cmd is added to the per-instance issue queue, with minor
698 * twiddling done to the host specific fields of cmd. If the
699 * main coroutine is not running, it is restarted.
702 static int NCR5380_queue_command(struct Scsi_Host *instance,
703 struct scsi_cmnd *cmd)
705 struct NCR5380_hostdata *hostdata = shost_priv(instance);
706 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
709 #if (NDEBUG & NDEBUG_NO_WRITE)
710 switch (cmd->cmnd[0]) {
713 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
714 cmd->result = (DID_ERROR << 16);
718 #endif /* (NDEBUG & NDEBUG_NO_WRITE) */
722 spin_lock_irqsave(&hostdata->lock, flags);
725 * Insert the cmd into the issue queue. Note that REQUEST SENSE
726 * commands are added to the head of the queue since any command will
727 * clear the contingent allegiance condition that exists and the
728 * sense data is only guaranteed to be valid while the condition exists.
731 if (cmd->cmnd[0] == REQUEST_SENSE)
732 list_add(&ncmd->list, &hostdata->unissued);
734 list_add_tail(&ncmd->list, &hostdata->unissued);
736 spin_unlock_irqrestore(&hostdata->lock, flags);
738 dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
739 cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
741 /* Kick off command processing */
742 queue_work(hostdata->work_q, &hostdata->main_task);
747 * dequeue_next_cmd - dequeue a command for processing
748 * @instance: the scsi host instance
750 * Priority is given to commands on the autosense queue. These commands
751 * need autosense because of a CHECK CONDITION result.
753 * Returns a command pointer if a command is found for a target that is
754 * not already busy. Otherwise returns NULL.
757 static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
759 struct NCR5380_hostdata *hostdata = shost_priv(instance);
760 struct NCR5380_cmd *ncmd;
761 struct scsi_cmnd *cmd;
763 if (list_empty(&hostdata->autosense)) {
764 list_for_each_entry(ncmd, &hostdata->unissued, list) {
765 cmd = NCR5380_to_scmd(ncmd);
766 dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
767 cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
769 if (!(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))) {
770 list_del(&ncmd->list);
771 dsprintk(NDEBUG_QUEUES, instance,
772 "dequeue: removed %p from issue queue\n", cmd);
777 /* Autosense processing begins here */
778 ncmd = list_first_entry(&hostdata->autosense,
779 struct NCR5380_cmd, list);
780 list_del(&ncmd->list);
781 cmd = NCR5380_to_scmd(ncmd);
782 dsprintk(NDEBUG_QUEUES, instance,
783 "dequeue: removed %p from autosense queue\n", cmd);
784 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
785 hostdata->sensing = cmd;
791 static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
793 struct NCR5380_hostdata *hostdata = shost_priv(instance);
794 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
796 if (hostdata->sensing) {
797 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
798 list_add(&ncmd->list, &hostdata->autosense);
799 hostdata->sensing = NULL;
801 list_add(&ncmd->list, &hostdata->unissued);
805 * NCR5380_main - NCR state machines
807 * NCR5380_main is a coroutine that runs as long as more work can
808 * be done on the NCR5380 host adapters in a system. Both
809 * NCR5380_queue_command() and NCR5380_intr() will try to start it
810 * in case it is not running.
813 static void NCR5380_main(struct work_struct *work)
815 struct NCR5380_hostdata *hostdata =
816 container_of(work, struct NCR5380_hostdata, main_task);
817 struct Scsi_Host *instance = hostdata->host;
818 struct scsi_cmnd *cmd;
824 spin_lock_irq(&hostdata->lock);
825 while (!hostdata->connected &&
826 (cmd = dequeue_next_cmd(instance))) {
828 dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
831 * Attempt to establish an I_T_L nexus here.
832 * On success, instance->hostdata->connected is set.
833 * On failure, we must add the command back to the
834 * issue queue so we can keep trying.
837 * REQUEST SENSE commands are issued without tagged
838 * queueing, even on SCSI-II devices because the
839 * contingent allegiance condition exists for the
843 cmd = NCR5380_select(instance, cmd);
845 dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
847 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
848 "main: select failed, returning %p to queue\n", cmd);
849 requeue_cmd(instance, cmd);
852 if (hostdata->connected
857 dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
858 NCR5380_information_transfer(instance);
861 spin_unlock_irq(&hostdata->lock);
867 #ifndef DONT_USE_INTR
870 * NCR5380_intr - generic NCR5380 irq handler
871 * @irq: interrupt number
872 * @dev_id: device info
874 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
875 * from the disconnected queue, and restarting NCR5380_main()
878 * The chip can assert IRQ in any of six different conditions. The IRQ flag
879 * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
880 * Three of these six conditions are latched in the Bus and Status Register:
881 * - End of DMA (cleared by ending DMA Mode)
882 * - Parity error (cleared by reading RPIR)
883 * - Loss of BSY (cleared by reading RPIR)
884 * Two conditions have flag bits that are not latched:
885 * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
886 * - Bus reset (non-maskable)
887 * The remaining condition has no flag bit at all:
888 * - Selection/reselection
890 * Hence, establishing the cause(s) of any interrupt is partly guesswork.
891 * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
892 * claimed that "the design of the [DP8490] interrupt logic ensures
893 * interrupts will not be lost (they can be on the DP5380)."
894 * The L5380/53C80 datasheet from LOGIC Devices has more details.
896 * Checking for bus reset by reading RST is futile because of interrupt
897 * latency, but a bus reset will reset chip logic. Checking for parity error
898 * is unnecessary because that interrupt is never enabled. A Loss of BSY
899 * condition will clear DMA Mode. We can tell when this occurs because the
900 * the Busy Monitor interrupt is enabled together with DMA Mode.
903 static irqreturn_t NCR5380_intr(int irq, void *dev_id)
905 struct Scsi_Host *instance = dev_id;
906 struct NCR5380_hostdata *hostdata = shost_priv(instance);
911 spin_lock_irqsave(&hostdata->lock, flags);
913 basr = NCR5380_read(BUS_AND_STATUS_REG);
914 if (basr & BASR_IRQ) {
915 unsigned char mr = NCR5380_read(MODE_REG);
916 unsigned char sr = NCR5380_read(STATUS_REG);
918 dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
921 #if defined(REAL_DMA)
922 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
923 /* Probably End of DMA, Phase Mismatch or Loss of BSY.
924 * We ack IRQ after clearing Mode Register. Workarounds
925 * for End of DMA errata need to happen in DMA Mode.
928 dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
932 if (!hostdata->connected)
933 panic("scsi%d : DMA interrupt with no connected cmd\n",
936 transferred = hostdata->dmalen - NCR5380_dma_residual(instance);
937 hostdata->connected->SCp.this_residual -= transferred;
938 hostdata->connected->SCp.ptr += transferred;
939 hostdata->dmalen = 0;
941 /* FIXME: we need to poll briefly then defer a workqueue task ! */
942 NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_ACK, 0, 2 * HZ);
944 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
945 NCR5380_write(MODE_REG, MR_BASE);
946 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
948 #endif /* REAL_DMA */
949 if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
950 (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
951 /* Probably reselected */
952 NCR5380_write(SELECT_ENABLE_REG, 0);
953 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
955 dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
957 if (!hostdata->connected) {
958 NCR5380_reselect(instance);
959 queue_work(hostdata->work_q, &hostdata->main_task);
961 if (!hostdata->connected)
962 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
964 /* Probably Bus Reset */
965 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
967 dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
971 shost_printk(KERN_NOTICE, instance, "interrupt without IRQ bit\n");
974 spin_unlock_irqrestore(&hostdata->lock, flags);
976 return IRQ_RETVAL(handled);
982 * Function : int NCR5380_select(struct Scsi_Host *instance,
983 * struct scsi_cmnd *cmd)
985 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
986 * including ARBITRATION, SELECTION, and initial message out for
987 * IDENTIFY and queue messages.
989 * Inputs : instance - instantiation of the 5380 driver on which this
990 * target lives, cmd - SCSI command to execute.
992 * Returns cmd if selection failed but should be retried,
993 * NULL if selection failed and should not be retried, or
994 * NULL if selection succeeded (hostdata->connected == cmd).
997 * If bus busy, arbitration failed, etc, NCR5380_select() will exit
998 * with registers as they should have been on entry - ie
999 * SELECT_ENABLE will be set appropriately, the NCR5380
1000 * will cease to drive any SCSI bus signals.
1002 * If successful : I_T_L or I_T_L_Q nexus will be established,
1003 * instance->connected will be set to cmd.
1004 * SELECT interrupt will be disabled.
1006 * If failed (no target) : cmd->scsi_done() will be called, and the
1007 * cmd->result host byte set to DID_BAD_TARGET.
1010 static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
1011 struct scsi_cmnd *cmd)
1013 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1014 unsigned char tmp[3], phase;
1015 unsigned char *data;
1019 NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1020 dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
1024 * Arbitration and selection phases are slow and involve dropping the
1025 * lock, so we have to watch out for EH. An exception handler may
1026 * change 'selecting' to NULL. This function will then return NULL
1027 * so that the caller will forget about 'cmd'. (During information
1028 * transfer phases, EH may change 'connected' to NULL.)
1030 hostdata->selecting = cmd;
1033 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1034 * data bus during SELECTION.
1037 NCR5380_write(TARGET_COMMAND_REG, 0);
1040 * Start arbitration.
1043 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1044 NCR5380_write(MODE_REG, MR_ARBITRATE);
1046 /* The chip now waits for BUS FREE phase. Then after the 800 ns
1047 * Bus Free Delay, arbitration will begin.
1050 spin_unlock_irq(&hostdata->lock);
1051 err = NCR5380_poll_politely2(instance, MODE_REG, MR_ARBITRATE, 0,
1052 INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
1053 ICR_ARBITRATION_PROGRESS, HZ);
1054 spin_lock_irq(&hostdata->lock);
1055 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
1056 /* Reselection interrupt */
1060 NCR5380_write(MODE_REG, MR_BASE);
1061 shost_printk(KERN_ERR, instance,
1062 "select: arbitration timeout\n");
1065 spin_unlock_irq(&hostdata->lock);
1067 /* The SCSI-2 arbitration delay is 2.4 us */
1070 /* Check for lost arbitration */
1071 if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1072 (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1073 (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1074 NCR5380_write(MODE_REG, MR_BASE);
1075 dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1076 spin_lock_irq(&hostdata->lock);
1080 /* After/during arbitration, BSY should be asserted.
1081 * IBM DPES-31080 Version S31Q works now
1082 * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1084 NCR5380_write(INITIATOR_COMMAND_REG,
1085 ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1088 * Again, bus clear + bus settle time is 1.2us, however, this is
1089 * a minimum so we'll udelay ceil(1.2)
1092 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1097 spin_lock_irq(&hostdata->lock);
1099 /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1100 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1103 if (!hostdata->selecting) {
1104 NCR5380_write(MODE_REG, MR_BASE);
1105 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1109 dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1112 * Now that we have won arbitration, start Selection process, asserting
1113 * the host and target ID's on the SCSI bus.
1116 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1119 * Raise ATN while SEL is true before BSY goes false from arbitration,
1120 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1121 * phase immediately after selection.
1124 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1125 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1126 NCR5380_write(MODE_REG, MR_BASE);
1129 * Reselect interrupts must be turned off prior to the dropping of BSY,
1130 * otherwise we will trigger an interrupt.
1132 NCR5380_write(SELECT_ENABLE_REG, 0);
1134 spin_unlock_irq(&hostdata->lock);
1137 * The initiator shall then wait at least two deskew delays and release
1140 udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
1143 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1144 ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1147 * Something weird happens when we cease to drive BSY - looks
1148 * like the board/chip is letting us do another read before the
1149 * appropriate propagation delay has expired, and we're confusing
1150 * a BSY signal from ourselves as the target's response to SELECTION.
1152 * A small delay (the 'C++' frontend breaks the pipeline with an
1153 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1154 * tighter 'C' code breaks and requires this) solves the problem -
1155 * the 1 us delay is arbitrary, and only used because this delay will
1156 * be the same on other platforms and since it works here, it should
1159 * wingel suggests that this could be due to failing to wait
1165 dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1168 * The SCSI specification calls for a 250 ms timeout for the actual
1172 err = NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, SR_BSY,
1173 msecs_to_jiffies(250));
1175 if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1176 spin_lock_irq(&hostdata->lock);
1177 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1178 NCR5380_reselect(instance);
1179 if (!hostdata->connected)
1180 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1181 shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1186 spin_lock_irq(&hostdata->lock);
1187 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1188 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1189 /* Can't touch cmd if it has been reclaimed by the scsi ML */
1190 if (hostdata->selecting) {
1191 cmd->result = DID_BAD_TARGET << 16;
1192 complete_cmd(instance, cmd);
1193 dsprintk(NDEBUG_SELECTION, instance, "target did not respond within 250ms\n");
1200 * No less than two deskew delays after the initiator detects the
1201 * BSY signal is true, it shall release the SEL signal and may
1202 * change the DATA BUS. -wingel
1207 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1210 * Since we followed the SCSI spec, and raised ATN while SEL
1211 * was true but before BSY was false during selection, the information
1212 * transfer phase should be a MESSAGE OUT phase so that we can send the
1215 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1216 * message (2 bytes) with a tag ID that we increment with every command
1217 * until it wraps back to 0.
1219 * XXX - it turns out that there are some broken SCSI-II devices,
1220 * which claim to support tagged queuing but fail when more than
1221 * some number of commands are issued at once.
1224 /* Wait for start of REQ/ACK handshake */
1226 err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1227 spin_lock_irq(&hostdata->lock);
1229 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1230 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1231 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1234 if (!hostdata->selecting) {
1239 dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1241 tmp[0] = IDENTIFY(((instance->irq == NO_IRQ) ? 0 : 1), cmd->device->lun);
1246 /* Send message(s) */
1248 phase = PHASE_MSGOUT;
1249 NCR5380_transfer_pio(instance, &phase, &len, &data);
1250 dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1251 /* XXX need to handle errors here */
1253 hostdata->connected = cmd;
1254 hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1256 initialize_SCp(cmd);
1261 if (!hostdata->selecting)
1263 hostdata->selecting = NULL;
1268 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1269 * unsigned char *phase, int *count, unsigned char **data)
1271 * Purpose : transfers data in given phase using polled I/O
1273 * Inputs : instance - instance of driver, *phase - pointer to
1274 * what phase is expected, *count - pointer to number of
1275 * bytes to transfer, **data - pointer to data pointer.
1277 * Returns : -1 when different phase is entered without transferring
1278 * maximum number of bytes, 0 if all bytes are transferred or exit
1281 * Also, *phase, *count, *data are modified in place.
1283 * XXX Note : handling for bus free may be useful.
1287 * Note : this code is not as quick as it could be, however it
1288 * IS 100% reliable, and for the actual data transfer where speed
1289 * counts, we will always do a pseudo DMA or DMA transfer.
1292 static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1293 unsigned char *phase, int *count,
1294 unsigned char **data)
1296 unsigned char p = *phase, tmp;
1298 unsigned char *d = *data;
1301 * The NCR5380 chip will only drive the SCSI bus when the
1302 * phase specified in the appropriate bits of the TARGET COMMAND
1303 * REGISTER match the STATUS REGISTER
1306 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1310 * Wait for assertion of REQ, after which the phase bits will be
1314 if (NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1317 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1319 /* Check for phase mismatch */
1320 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1321 dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1322 NCR5380_dprint_phase(NDEBUG_PIO, instance);
1326 /* Do actual transfer from SCSI bus to / from memory */
1328 NCR5380_write(OUTPUT_DATA_REG, *d);
1330 *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1335 * The SCSI standard suggests that in MSGOUT phase, the initiator
1336 * should drop ATN on the last byte of the message phase
1337 * after REQ has been asserted for the handshake but before
1338 * the initiator raises ACK.
1342 if (!((p & SR_MSG) && c > 1)) {
1343 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1344 NCR5380_dprint(NDEBUG_PIO, instance);
1345 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1346 ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1348 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1349 ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1350 NCR5380_dprint(NDEBUG_PIO, instance);
1351 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1352 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1355 NCR5380_dprint(NDEBUG_PIO, instance);
1356 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1359 if (NCR5380_poll_politely(instance,
1360 STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1363 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1366 * We have several special cases to consider during REQ/ACK handshaking :
1367 * 1. We were in MSGOUT phase, and we are on the last byte of the
1368 * message. ATN must be dropped as ACK is dropped.
1370 * 2. We are in a MSGIN phase, and we are on the last byte of the
1371 * message. We must exit with ACK asserted, so that the calling
1372 * code may raise ATN before dropping ACK to reject the message.
1374 * 3. ACK and ATN are clear and the target may proceed as normal.
1376 if (!(p == PHASE_MSGIN && c == 1)) {
1377 if (p == PHASE_MSGOUT && c > 1)
1378 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1380 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1384 dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1388 tmp = NCR5380_read(STATUS_REG);
1389 /* The phase read from the bus is valid if either REQ is (already)
1390 * asserted or if ACK hasn't been released yet. The latter applies if
1391 * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1393 if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1394 *phase = tmp & PHASE_MASK;
1396 *phase = PHASE_UNKNOWN;
1398 if (!c || (*phase == p))
1405 * do_reset - issue a reset command
1406 * @instance: adapter to reset
1408 * Issue a reset sequence to the NCR5380 and try and get the bus
1409 * back into sane shape.
1411 * This clears the reset interrupt flag because there may be no handler for
1412 * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1413 * been installed. And when in EH we may have released the ST DMA interrupt.
1416 static void do_reset(struct Scsi_Host *instance)
1418 unsigned long flags;
1420 local_irq_save(flags);
1421 NCR5380_write(TARGET_COMMAND_REG,
1422 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1423 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1425 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1426 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1427 local_irq_restore(flags);
1431 * do_abort - abort the currently established nexus by going to
1432 * MESSAGE OUT phase and sending an ABORT message.
1433 * @instance: relevant scsi host instance
1435 * Returns 0 on success, -1 on failure.
1438 static int do_abort(struct Scsi_Host *instance)
1440 unsigned char *msgptr, phase, tmp;
1444 /* Request message out phase */
1445 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1448 * Wait for the target to indicate a valid phase by asserting
1449 * REQ. Once this happens, we'll have either a MSGOUT phase
1450 * and can immediately send the ABORT message, or we'll have some
1451 * other phase and will have to source/sink data.
1453 * We really don't care what value was on the bus or what value
1454 * the target sees, so we just handshake.
1457 rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1461 tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1463 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1465 if (tmp != PHASE_MSGOUT) {
1466 NCR5380_write(INITIATOR_COMMAND_REG,
1467 ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1468 rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 3 * HZ);
1471 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1477 phase = PHASE_MSGOUT;
1478 NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1481 * If we got here, and the command completed successfully,
1482 * we're about to go into bus free state.
1485 return len ? -1 : 0;
1488 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1492 #if defined(REAL_DMA) || defined(PSEUDO_DMA) || defined (REAL_DMA_POLL)
1494 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1495 * unsigned char *phase, int *count, unsigned char **data)
1497 * Purpose : transfers data in given phase using either real
1500 * Inputs : instance - instance of driver, *phase - pointer to
1501 * what phase is expected, *count - pointer to number of
1502 * bytes to transfer, **data - pointer to data pointer.
1504 * Returns : -1 when different phase is entered without transferring
1505 * maximum number of bytes, 0 if all bytes or transferred or exit
1508 * Also, *phase, *count, *data are modified in place.
1512 static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1513 unsigned char *phase, int *count,
1514 unsigned char **data)
1516 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1517 register int c = *count;
1518 register unsigned char p = *phase;
1519 register unsigned char *d = *data;
1522 #if defined(REAL_DMA_POLL)
1524 unsigned char saved_data = 0, overrun = 0, residue;
1527 if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1531 #if defined(REAL_DMA) || defined(REAL_DMA_POLL)
1533 if (!(hostdata->flags & FLAG_NO_DMA_FIXUPS))
1536 hostdata->dma_len = (p & SR_IO) ? NCR5380_dma_read_setup(instance, d, c) : NCR5380_dma_write_setup(instance, d, c);
1538 dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1539 (p & SR_IO) ? "receive" : "send", c, *data);
1542 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1545 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1546 MR_ENABLE_EOP_INTR);
1547 #elif defined(REAL_DMA_POLL)
1548 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY);
1551 * Note : on my sample board, watch-dog timeouts occurred when interrupts
1552 * were not disabled for the duration of a single DMA transfer, from
1553 * before the setting of DMA mode to after transfer of the last byte.
1556 if (hostdata->flags & FLAG_NO_DMA_FIXUP)
1557 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1558 MR_ENABLE_EOP_INTR);
1560 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY);
1561 #endif /* def REAL_DMA */
1563 dprintk(NDEBUG_DMA, "scsi%d : mode reg = 0x%X\n", instance->host_no, NCR5380_read(MODE_REG));
1566 * On the PAS16 at least I/O recovery delays are not needed here.
1567 * Everyone else seems to want them.
1571 io_recovery_delay(1);
1572 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1574 io_recovery_delay(1);
1575 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1576 io_recovery_delay(1);
1577 NCR5380_write(START_DMA_SEND_REG, 0);
1578 io_recovery_delay(1);
1581 #if defined(REAL_DMA_POLL)
1583 tmp = NCR5380_read(BUS_AND_STATUS_REG);
1584 } while ((tmp & BASR_PHASE_MATCH) && !(tmp & (BASR_BUSY_ERROR | BASR_END_DMA_TRANSFER)));
1587 * At this point, either we've completed DMA, or we have a phase mismatch,
1588 * or we've unexpectedly lost BUSY (which is a real error).
1590 * For DMA sends, we want to wait until the last byte has been
1591 * transferred out over the bus before we turn off DMA mode. Alas, there
1592 * seems to be no terribly good way of doing this on a 5380 under all
1593 * conditions. For non-scatter-gather operations, we can wait until REQ
1594 * and ACK both go false, or until a phase mismatch occurs. Gather-sends
1595 * are nastier, since the device will be expecting more data than we
1596 * are prepared to send it, and REQ will remain asserted. On a 53C8[01] we
1597 * could test Last Byte Sent to assure transfer (I imagine this is precisely
1598 * why this signal was added to the newer chips) but on the older 538[01]
1599 * this signal does not exist. The workaround for this lack is a watchdog;
1600 * we bail out of the wait-loop after a modest amount of wait-time if
1601 * the usual exit conditions are not met. Not a terribly clean or
1602 * correct solution :-%
1604 * DMA receive is equally tricky due to a nasty characteristic of the NCR5380.
1605 * If the chip is in DMA receive mode, it will respond to a target's
1606 * REQ by latching the SCSI data into the INPUT DATA register and asserting
1607 * ACK, even if it has _already_ been notified by the DMA controller that
1608 * the current DMA transfer has completed! If the NCR5380 is then taken
1609 * out of DMA mode, this already-acknowledged byte is lost. This is
1610 * not a problem for "one DMA transfer per READ command", because
1611 * the situation will never arise... either all of the data is DMA'ed
1612 * properly, or the target switches to MESSAGE IN phase to signal a
1613 * disconnection (either operation bringing the DMA to a clean halt).
1614 * However, in order to handle scatter-receive, we must work around the
1615 * problem. The chosen fix is to DMA N-2 bytes, then check for the
1616 * condition before taking the NCR5380 out of DMA mode. One or two extra
1617 * bytes are transferred via PIO as necessary to fill out the original
1622 if (!(hostdata->flags & FLAG_NO_DMA_FIXUPS)) {
1624 if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
1625 (BASR_PHASE_MATCH | BASR_ACK)) {
1626 saved_data = NCR5380_read(INPUT_DATA_REGISTER);
1632 while (((tmp = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_ACK) || (NCR5380_read(STATUS_REG) & SR_REQ)) {
1633 if (!(tmp & BASR_PHASE_MATCH))
1640 dsprintk(NDEBUG_DMA, "polled DMA transfer complete, basr 0x%02x, sr 0x%02x\n",
1641 tmp, NCR5380_read(STATUS_REG));
1643 NCR5380_write(MODE_REG, MR_BASE);
1644 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1646 residue = NCR5380_dma_residual(instance);
1650 *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1652 if (!(hostdata->flags & FLAG_NO_DMA_FIXUPS) &&
1653 *phase == p && (p & SR_IO) && residue == 0) {
1655 dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
1656 **data = saved_data;
1661 printk("No overrun??\n");
1664 dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%X\n", cnt, *data);
1665 NCR5380_transfer_pio(instance, phase, &cnt, data);
1666 *count -= toPIO - cnt;
1669 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));
1672 #elif defined(REAL_DMA)
1674 #else /* defined(REAL_DMA_POLL) */
1676 foo = NCR5380_pread(instance, d,
1677 hostdata->flags & FLAG_NO_DMA_FIXUP ? c : c - 1);
1678 if (!foo && !(hostdata->flags & FLAG_NO_DMA_FIXUP)) {
1680 * We can't disable DMA mode after successfully transferring
1681 * what we plan to be the last byte, since that would open up
1682 * a race condition where if the target asserted REQ before
1683 * we got the DMA mode reset, the NCR5380 would have latched
1684 * an additional byte into the INPUT DATA register and we'd
1687 * The workaround was to transfer one fewer bytes than we
1688 * intended to with the pseudo-DMA read function, wait for
1689 * the chip to latch the last byte, read it, and then disable
1692 * After REQ is asserted, the NCR5380 asserts DRQ and ACK.
1693 * REQ is deasserted when ACK is asserted, and not reasserted
1694 * until ACK goes false. Since the NCR5380 won't lower ACK
1695 * until DACK is asserted, which won't happen unless we twiddle
1696 * the DMA port or we take the NCR5380 out of DMA mode, we
1697 * can guarantee that we won't handshake another extra
1701 if (NCR5380_poll_politely(instance, BUS_AND_STATUS_REG,
1702 BASR_DRQ, BASR_DRQ, HZ) < 0) {
1704 shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n");
1706 if (NCR5380_poll_politely(instance, STATUS_REG,
1707 SR_REQ, 0, HZ) < 0) {
1709 shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n");
1711 d[c - 1] = NCR5380_read(INPUT_DATA_REG);
1714 foo = NCR5380_pwrite(instance, d, c);
1715 if (!foo && !(hostdata->flags & FLAG_NO_DMA_FIXUP)) {
1717 * Wait for the last byte to be sent. If REQ is being asserted for
1718 * the byte we're interested, we'll ACK it and it will go false.
1720 if (NCR5380_poll_politely2(instance,
1721 BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ,
1722 BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) {
1724 shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n");
1728 NCR5380_write(MODE_REG, MR_BASE);
1729 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1730 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1733 *phase = NCR5380_read(STATUS_REG) & PHASE_MASK;
1735 #endif /* def REAL_DMA */
1737 #endif /* defined(REAL_DMA) | defined(PSEUDO_DMA) */
1740 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1742 * Purpose : run through the various SCSI phases and do as the target
1743 * directs us to. Operates on the currently connected command,
1744 * instance->connected.
1746 * Inputs : instance, instance for which we are doing commands
1748 * Side effects : SCSI things happen, the disconnected queue will be
1749 * modified if a command disconnects, *instance->connected will
1752 * XXX Note : we need to watch for bus free or a reset condition here
1753 * to recover from an unexpected bus free condition.
1756 static void NCR5380_information_transfer(struct Scsi_Host *instance)
1758 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1759 unsigned char msgout = NOP;
1762 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
1765 unsigned char *data;
1766 unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1767 struct scsi_cmnd *cmd;
1769 while ((cmd = hostdata->connected)) {
1770 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1772 tmp = NCR5380_read(STATUS_REG);
1773 /* We only have a valid SCSI phase when REQ is asserted */
1775 phase = (tmp & PHASE_MASK);
1776 if (phase != old_phase) {
1778 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1780 if (sink && (phase != PHASE_MSGOUT)) {
1781 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1783 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1785 while (NCR5380_read(STATUS_REG) & SR_REQ)
1787 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1795 #if (NDEBUG & NDEBUG_NO_DATAOUT)
1796 shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1799 cmd->result = DID_ERROR << 16;
1800 complete_cmd(instance, cmd);
1805 * If there is no room left in the current buffer in the
1806 * scatter-gather list, move onto the next one.
1809 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1811 --cmd->SCp.buffers_residual;
1812 cmd->SCp.this_residual = cmd->SCp.buffer->length;
1813 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1814 dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n",
1815 cmd->SCp.this_residual,
1816 cmd->SCp.buffers_residual);
1820 * The preferred transfer method is going to be
1821 * PSEUDO-DMA for systems that are strictly PIO,
1822 * since we can let the hardware do the handshaking.
1824 * For this to work, we need to know the transfersize
1825 * ahead of time, since the pseudo-DMA code will sit
1826 * in an unconditional loop.
1829 #if defined(PSEUDO_DMA) || defined(REAL_DMA_POLL)
1831 if (!cmd->device->borken &&
1832 !(hostdata->flags & FLAG_NO_PSEUDO_DMA))
1833 transfersize = NCR5380_dma_xfer_len(instance, cmd, phase);
1837 if (NCR5380_transfer_dma(instance, &phase,
1838 &len, (unsigned char **)&cmd->SCp.ptr)) {
1840 * If the watchdog timer fires, all future
1841 * accesses to this device will use the
1844 scmd_printk(KERN_INFO, cmd,
1845 "switching to slow handshake\n");
1846 cmd->device->borken = 1;
1849 cmd->result = DID_ERROR << 16;
1850 complete_cmd(instance, cmd);
1851 /* XXX - need to source or sink data here, as appropriate */
1853 cmd->SCp.this_residual -= transfersize - len;
1855 #endif /* defined(PSEUDO_DMA) || defined(REAL_DMA_POLL) */
1857 spin_unlock_irq(&hostdata->lock);
1858 NCR5380_transfer_pio(instance, &phase,
1859 (int *)&cmd->SCp.this_residual,
1860 (unsigned char **)&cmd->SCp.ptr);
1861 spin_lock_irq(&hostdata->lock);
1867 NCR5380_transfer_pio(instance, &phase, &len, &data);
1868 cmd->SCp.Message = tmp;
1872 case COMMAND_COMPLETE:
1873 /* Accept message by clearing ACK */
1875 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1876 dsprintk(NDEBUG_QUEUES, instance,
1877 "COMMAND COMPLETE %p target %d lun %llu\n",
1878 cmd, scmd_id(cmd), cmd->device->lun);
1880 hostdata->connected = NULL;
1882 cmd->result &= ~0xffff;
1883 cmd->result |= cmd->SCp.Status;
1884 cmd->result |= cmd->SCp.Message << 8;
1886 if (cmd->cmnd[0] == REQUEST_SENSE)
1887 complete_cmd(instance, cmd);
1889 if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
1890 cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
1891 dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
1893 list_add_tail(&ncmd->list,
1894 &hostdata->autosense);
1896 complete_cmd(instance, cmd);
1900 * Restore phase bits to 0 so an interrupted selection,
1901 * arbitration can resume.
1903 NCR5380_write(TARGET_COMMAND_REG, 0);
1905 /* Enable reselect interrupts */
1906 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1908 case MESSAGE_REJECT:
1909 /* Accept message by clearing ACK */
1910 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1911 switch (hostdata->last_message) {
1912 case HEAD_OF_QUEUE_TAG:
1913 case ORDERED_QUEUE_TAG:
1914 case SIMPLE_QUEUE_TAG:
1915 cmd->device->simple_tags = 0;
1916 hostdata->busy[cmd->device->id] |= (1 << (cmd->device->lun & 0xFF));
1923 /* Accept message by clearing ACK */
1924 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1925 hostdata->connected = NULL;
1926 list_add(&ncmd->list, &hostdata->disconnected);
1927 dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
1928 instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
1929 cmd, scmd_id(cmd), cmd->device->lun);
1932 * Restore phase bits to 0 so an interrupted selection,
1933 * arbitration can resume.
1935 NCR5380_write(TARGET_COMMAND_REG, 0);
1937 /* Enable reselect interrupts */
1938 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1941 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
1942 * operation, in violation of the SCSI spec so we can safely
1943 * ignore SAVE/RESTORE pointers calls.
1945 * Unfortunately, some disks violate the SCSI spec and
1946 * don't issue the required SAVE_POINTERS message before
1947 * disconnecting, and we have to break spec to remain
1951 case RESTORE_POINTERS:
1952 /* Accept message by clearing ACK */
1953 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1955 case EXTENDED_MESSAGE:
1957 * Start the message buffer with the EXTENDED_MESSAGE
1958 * byte, since spi_print_msg() wants the whole thing.
1960 extended_msg[0] = EXTENDED_MESSAGE;
1961 /* Accept first byte by clearing ACK */
1962 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1964 spin_unlock_irq(&hostdata->lock);
1966 dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
1969 data = extended_msg + 1;
1970 phase = PHASE_MSGIN;
1971 NCR5380_transfer_pio(instance, &phase, &len, &data);
1972 dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
1973 (int)extended_msg[1],
1974 (int)extended_msg[2]);
1976 if (!len && extended_msg[1] > 0 &&
1977 extended_msg[1] <= sizeof(extended_msg) - 2) {
1978 /* Accept third byte by clearing ACK */
1979 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1980 len = extended_msg[1] - 1;
1981 data = extended_msg + 3;
1982 phase = PHASE_MSGIN;
1984 NCR5380_transfer_pio(instance, &phase, &len, &data);
1985 dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
1988 switch (extended_msg[2]) {
1991 case EXTENDED_MODIFY_DATA_POINTER:
1992 case EXTENDED_EXTENDED_IDENTIFY:
1996 shost_printk(KERN_ERR, instance, "error receiving extended message\n");
1999 shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
2000 extended_msg[2], extended_msg[1]);
2004 spin_lock_irq(&hostdata->lock);
2005 if (!hostdata->connected)
2008 /* Fall through to reject message */
2011 * If we get something weird that we aren't expecting,
2016 shost_printk(KERN_ERR, instance, "rejecting message ");
2017 spi_print_msg(extended_msg);
2019 } else if (tmp != EXTENDED_MESSAGE)
2020 scmd_printk(KERN_INFO, cmd,
2021 "rejecting unknown message %02x\n",
2024 scmd_printk(KERN_INFO, cmd,
2025 "rejecting unknown extended message code %02x, length %d\n",
2026 extended_msg[1], extended_msg[0]);
2028 msgout = MESSAGE_REJECT;
2029 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2031 } /* switch (tmp) */
2036 hostdata->last_message = msgout;
2037 NCR5380_transfer_pio(instance, &phase, &len, &data);
2038 if (msgout == ABORT) {
2039 hostdata->connected = NULL;
2040 cmd->result = DID_ERROR << 16;
2041 complete_cmd(instance, cmd);
2042 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2051 * XXX for performance reasons, on machines with a
2052 * PSEUDO-DMA architecture we should probably
2053 * use the dma transfer function.
2055 NCR5380_transfer_pio(instance, &phase, &len, &data);
2060 NCR5380_transfer_pio(instance, &phase, &len, &data);
2061 cmd->SCp.Status = tmp;
2064 shost_printk(KERN_ERR, instance, "unknown phase\n");
2065 NCR5380_dprint(NDEBUG_ANY, instance);
2066 } /* switch(phase) */
2068 spin_unlock_irq(&hostdata->lock);
2069 NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
2070 spin_lock_irq(&hostdata->lock);
2076 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2078 * Purpose : does reselection, initializing the instance->connected
2079 * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2080 * nexus has been reestablished,
2082 * Inputs : instance - this instance of the NCR5380.
2085 static void NCR5380_reselect(struct Scsi_Host *instance)
2087 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2088 unsigned char target_mask;
2089 unsigned char lun, phase;
2091 unsigned char msg[3];
2092 unsigned char *data;
2093 struct NCR5380_cmd *ncmd;
2094 struct scsi_cmnd *tmp;
2097 * Disable arbitration, etc. since the host adapter obviously
2098 * lost, and tell an interrupted NCR5380_select() to restart.
2101 NCR5380_write(MODE_REG, MR_BASE);
2103 target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2105 dsprintk(NDEBUG_RESELECTION, instance, "reselect\n");
2108 * At this point, we have detected that our SCSI ID is on the bus,
2109 * SEL is true and BSY was false for at least one bus settle delay
2112 * We must assert BSY ourselves, until the target drops the SEL
2116 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2117 if (NCR5380_poll_politely(instance,
2118 STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2119 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2122 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2125 * Wait for target to go into MSGIN.
2128 if (NCR5380_poll_politely(instance,
2129 STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2136 phase = PHASE_MSGIN;
2137 NCR5380_transfer_pio(instance, &phase, &len, &data);
2144 if (!(msg[0] & 0x80)) {
2145 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2151 lun = msg[0] & 0x07;
2154 * We need to add code for SCSI-II to track which devices have
2155 * I_T_L_Q nexuses established, and which have simple I_T_L
2156 * nexuses so we can chose to do additional data transfer.
2160 * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
2161 * just reestablished, and remove it from the disconnected queue.
2165 list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2166 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2168 if (target_mask == (1 << scmd_id(cmd)) &&
2169 lun == (u8)cmd->device->lun) {
2170 list_del(&ncmd->list);
2177 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2178 "reselect: removed %p from disconnected queue\n", tmp);
2180 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2183 * Since we have an established nexus that we can't do anything
2184 * with, we must abort it.
2190 /* Accept message by clearing ACK */
2191 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2193 hostdata->connected = tmp;
2194 dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu, tag %d\n",
2195 scmd_id(tmp), tmp->device->lun, tmp->tag);
2199 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
2201 * Purpose : called by interrupt handler when DMA finishes or a phase
2202 * mismatch occurs (which would finish the DMA transfer).
2204 * Inputs : instance - this instance of the NCR5380.
2206 * Returns : pointer to the scsi_cmnd structure for which the I_T_L
2207 * nexus has been reestablished, on failure NULL is returned.
2211 static void NCR5380_dma_complete(NCR5380_instance * instance) {
2212 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2216 * XXX this might not be right.
2218 * Wait for final byte to transfer, ie wait for ACK to go false.
2220 * We should use the Last Byte Sent bit, unfortunately this is
2221 * not available on the 5380/5381 (only the various CMOS chips)
2223 * FIXME: timeout, and need to handle long timeout/irq case
2226 NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_ACK, 0, 5*HZ);
2228 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2231 * The only places we should see a phase mismatch and have to send
2232 * data from the same set of pointers will be the data transfer
2233 * phases. So, residual, requested length are only important here.
2236 if (!(hostdata->connected->SCp.phase & SR_CD)) {
2237 transferred = instance->dmalen - NCR5380_dma_residual();
2238 hostdata->connected->SCp.this_residual -= transferred;
2239 hostdata->connected->SCp.ptr += transferred;
2242 #endif /* def REAL_DMA */
2245 * list_find_cmd - test for presence of a command in a linked list
2246 * @haystack: list of commands
2247 * @needle: command to search for
2250 static bool list_find_cmd(struct list_head *haystack,
2251 struct scsi_cmnd *needle)
2253 struct NCR5380_cmd *ncmd;
2255 list_for_each_entry(ncmd, haystack, list)
2256 if (NCR5380_to_scmd(ncmd) == needle)
2262 * list_remove_cmd - remove a command from linked list
2263 * @haystack: list of commands
2264 * @needle: command to remove
2267 static bool list_del_cmd(struct list_head *haystack,
2268 struct scsi_cmnd *needle)
2270 if (list_find_cmd(haystack, needle)) {
2271 struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2273 list_del(&ncmd->list);
2280 * NCR5380_abort - scsi host eh_abort_handler() method
2281 * @cmd: the command to be aborted
2283 * Try to abort a given command by removing it from queues and/or sending
2284 * the target an abort message. This may not succeed in causing a target
2285 * to abort the command. Nonetheless, the low-level driver must forget about
2286 * the command because the mid-layer reclaims it and it may be re-issued.
2288 * The normal path taken by a command is as follows. For EH we trace this
2289 * same path to locate and abort the command.
2291 * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2292 * [disconnected -> connected ->]...
2293 * [autosense -> connected ->] done
2295 * If cmd is unissued then just remove it.
2296 * If cmd is disconnected, try to select the target.
2297 * If cmd is connected, try to send an abort message.
2298 * If cmd is waiting for autosense, give it a chance to complete but check
2299 * that it isn't left connected.
2300 * If cmd was not found at all then presumably it has already been completed,
2301 * in which case return SUCCESS to try to avoid further EH measures.
2302 * If the command has not completed yet, we must not fail to find it.
2305 static int NCR5380_abort(struct scsi_cmnd *cmd)
2307 struct Scsi_Host *instance = cmd->device->host;
2308 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2309 unsigned long flags;
2310 int result = SUCCESS;
2312 spin_lock_irqsave(&hostdata->lock, flags);
2314 #if (NDEBUG & NDEBUG_ANY)
2315 scmd_printk(KERN_INFO, cmd, __func__);
2317 NCR5380_dprint(NDEBUG_ANY, instance);
2318 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2320 if (list_del_cmd(&hostdata->unissued, cmd)) {
2321 dsprintk(NDEBUG_ABORT, instance,
2322 "abort: removed %p from issue queue\n", cmd);
2323 cmd->result = DID_ABORT << 16;
2324 cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2327 if (hostdata->selecting == cmd) {
2328 dsprintk(NDEBUG_ABORT, instance,
2329 "abort: cmd %p == selecting\n", cmd);
2330 hostdata->selecting = NULL;
2331 cmd->result = DID_ABORT << 16;
2332 complete_cmd(instance, cmd);
2336 if (list_del_cmd(&hostdata->disconnected, cmd)) {
2337 dsprintk(NDEBUG_ABORT, instance,
2338 "abort: removed %p from disconnected list\n", cmd);
2339 cmd->result = DID_ERROR << 16;
2340 if (!hostdata->connected)
2341 NCR5380_select(instance, cmd);
2342 if (hostdata->connected != cmd) {
2343 complete_cmd(instance, cmd);
2349 if (hostdata->connected == cmd) {
2350 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2351 hostdata->connected = NULL;
2352 if (do_abort(instance)) {
2353 set_host_byte(cmd, DID_ERROR);
2354 complete_cmd(instance, cmd);
2358 set_host_byte(cmd, DID_ABORT);
2360 hostdata->dma_len = 0;
2362 if (cmd->cmnd[0] == REQUEST_SENSE)
2363 complete_cmd(instance, cmd);
2365 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
2367 /* Perform autosense for this command */
2368 list_add(&ncmd->list, &hostdata->autosense);
2372 if (list_find_cmd(&hostdata->autosense, cmd)) {
2373 dsprintk(NDEBUG_ABORT, instance,
2374 "abort: found %p on sense queue\n", cmd);
2375 spin_unlock_irqrestore(&hostdata->lock, flags);
2376 queue_work(hostdata->work_q, &hostdata->main_task);
2378 spin_lock_irqsave(&hostdata->lock, flags);
2379 if (list_del_cmd(&hostdata->autosense, cmd)) {
2380 dsprintk(NDEBUG_ABORT, instance,
2381 "abort: removed %p from sense queue\n", cmd);
2382 set_host_byte(cmd, DID_ABORT);
2383 complete_cmd(instance, cmd);
2388 if (hostdata->connected == cmd) {
2389 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2390 hostdata->connected = NULL;
2391 if (do_abort(instance)) {
2392 set_host_byte(cmd, DID_ERROR);
2393 complete_cmd(instance, cmd);
2397 set_host_byte(cmd, DID_ABORT);
2399 hostdata->dma_len = 0;
2401 complete_cmd(instance, cmd);
2405 if (result == FAILED)
2406 dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2408 dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2410 queue_work(hostdata->work_q, &hostdata->main_task);
2411 spin_unlock_irqrestore(&hostdata->lock, flags);
2418 * NCR5380_bus_reset - reset the SCSI bus
2419 * @cmd: SCSI command undergoing EH
2424 static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
2426 struct Scsi_Host *instance = cmd->device->host;
2427 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2429 unsigned long flags;
2430 struct NCR5380_cmd *ncmd;
2432 spin_lock_irqsave(&hostdata->lock, flags);
2434 #if (NDEBUG & NDEBUG_ANY)
2435 scmd_printk(KERN_INFO, cmd, __func__);
2437 NCR5380_dprint(NDEBUG_ANY, instance);
2438 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2442 /* reset NCR registers */
2443 NCR5380_write(MODE_REG, MR_BASE);
2444 NCR5380_write(TARGET_COMMAND_REG, 0);
2445 NCR5380_write(SELECT_ENABLE_REG, 0);
2447 /* After the reset, there are no more connected or disconnected commands
2448 * and no busy units; so clear the low-level status here to avoid
2449 * conflicts when the mid-level code tries to wake up the affected
2453 hostdata->selecting = NULL;
2455 list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2456 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2458 set_host_byte(cmd, DID_RESET);
2459 cmd->scsi_done(cmd);
2462 list_for_each_entry(ncmd, &hostdata->autosense, list) {
2463 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2465 set_host_byte(cmd, DID_RESET);
2466 cmd->scsi_done(cmd);
2469 if (hostdata->connected) {
2470 set_host_byte(hostdata->connected, DID_RESET);
2471 complete_cmd(instance, hostdata->connected);
2472 hostdata->connected = NULL;
2475 if (hostdata->sensing) {
2476 set_host_byte(hostdata->connected, DID_RESET);
2477 complete_cmd(instance, hostdata->sensing);
2478 hostdata->sensing = NULL;
2481 for (i = 0; i < 8; ++i)
2482 hostdata->busy[i] = 0;
2484 hostdata->dma_len = 0;
2487 queue_work(hostdata->work_q, &hostdata->main_task);
2488 spin_unlock_irqrestore(&hostdata->lock, flags);