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1/*
2 * NCR 5380 generic driver routines. These should make it *trivial*
3 * to implement 5380 SCSI drivers under Linux with a non-trantor
4 * architecture.
5 *
6 * Note that these routines also work with NR53c400 family chips.
7 *
8 * Copyright 1993, Drew Eckhardt
9 * Visionary Computing
10 * (Unix and Linux consulting and custom programming)
11 * drew@colorado.edu
12 * +1 (303) 666-5836
13 *
14 * DISTRIBUTION RELEASE 6.
15 *
16 * For more information, please consult
17 *
18 * NCR 5380 Family
19 * SCSI Protocol Controller
20 * Databook
21 *
22 * NCR Microelectronics
23 * 1635 Aeroplaza Drive
24 * Colorado Springs, CO 80916
25 * 1+ (719) 578-3400
26 * 1+ (800) 334-5454
27 */
28
29/*
30 * ++roman: To port the 5380 driver to the Atari, I had to do some changes in
31 * this file, too:
32 *
33 * - Some of the debug statements were incorrect (undefined variables and the
34 * like). I fixed that.
35 *
36 * - In information_transfer(), I think a #ifdef was wrong. Looking at the
37 * possible DMA transfer size should also happen for REAL_DMA. I added this
38 * in the #if statement.
39 *
40 * - When using real DMA, information_transfer() should return in a DATAOUT
41 * phase after starting the DMA. It has nothing more to do.
42 *
43 * - The interrupt service routine should run main after end of DMA, too (not
44 * only after RESELECTION interrupts). Additionally, it should _not_ test
45 * for more interrupts after running main, since a DMA process may have
46 * been started and interrupts are turned on now. The new int could happen
47 * inside the execution of NCR5380_intr(), leading to recursive
48 * calls.
49 *
50 * - I've added a function merge_contiguous_buffers() that tries to
51 * merge scatter-gather buffers that are located at contiguous
52 * physical addresses and can be processed with the same DMA setup.
53 * Since most scatter-gather operations work on a page (4K) of
54 * 4 buffers (1K), in more than 90% of all cases three interrupts and
55 * DMA setup actions are saved.
56 *
57 * - I've deleted all the stuff for AUTOPROBE_IRQ, REAL_DMA_POLL, PSEUDO_DMA
58 * and USLEEP, because these were messing up readability and will never be
59 * needed for Atari SCSI.
60 *
61 * - I've revised the NCR5380_main() calling scheme (relax the 'main_running'
62 * stuff), and 'main' is executed in a bottom half if awoken by an
63 * interrupt.
64 *
65 * - The code was quite cluttered up by "#if (NDEBUG & NDEBUG_*) printk..."
66 * constructs. In my eyes, this made the source rather unreadable, so I
67 * finally replaced that by the *_PRINTK() macros.
68 *
69 */
70
71/*
72 * Further development / testing that should be done :
73 * 1. Test linked command handling code after Eric is ready with
74 * the high level code.
75 */
76#include <scsi/scsi_dbg.h>
77#include <scsi/scsi_transport_spi.h>
78
79#if (NDEBUG & NDEBUG_LISTS)
80#define LIST(x, y) \
81 do { \
82 printk("LINE:%d Adding %p to %p\n", \
83 __LINE__, (void*)(x), (void*)(y)); \
84 if ((x) == (y)) \
85 udelay(5); \
86 } while (0)
87#define REMOVE(w, x, y, z) \
88 do { \
89 printk("LINE:%d Removing: %p->%p %p->%p \n", \
90 __LINE__, (void*)(w), (void*)(x), \
91 (void*)(y), (void*)(z)); \
92 if ((x) == (y)) \
93 udelay(5); \
94 } while (0)
95#else
96#define LIST(x,y)
97#define REMOVE(w,x,y,z)
98#endif
99
100#ifndef notyet
101#undef LINKED
102#endif
103
104/*
105 * Design
106 * Issues :
107 *
108 * The other Linux SCSI drivers were written when Linux was Intel PC-only,
109 * and specifically for each board rather than each chip. This makes their
110 * adaptation to platforms like the Mac (Some of which use NCR5380's)
111 * more difficult than it has to be.
112 *
113 * Also, many of the SCSI drivers were written before the command queuing
114 * routines were implemented, meaning their implementations of queued
115 * commands were hacked on rather than designed in from the start.
116 *
117 * When I designed the Linux SCSI drivers I figured that
118 * while having two different SCSI boards in a system might be useful
119 * for debugging things, two of the same type wouldn't be used.
120 * Well, I was wrong and a number of users have mailed me about running
121 * multiple high-performance SCSI boards in a server.
122 *
123 * Finally, when I get questions from users, I have no idea what
124 * revision of my driver they are running.
125 *
126 * This driver attempts to address these problems :
127 * This is a generic 5380 driver. To use it on a different platform,
128 * one simply writes appropriate system specific macros (ie, data
129 * transfer - some PC's will use the I/O bus, 68K's must use
130 * memory mapped) and drops this file in their 'C' wrapper.
131 *
132 * As far as command queueing, two queues are maintained for
133 * each 5380 in the system - commands that haven't been issued yet,
134 * and commands that are currently executing. This means that an
135 * unlimited number of commands may be queued, letting
136 * more commands propagate from the higher driver levels giving higher
137 * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
138 * allowing multiple commands to propagate all the way to a SCSI-II device
139 * while a command is already executing.
140 *
141 * To solve the multiple-boards-in-the-same-system problem,
142 * there is a separate instance structure for each instance
143 * of a 5380 in the system. So, multiple NCR5380 drivers will
144 * be able to coexist with appropriate changes to the high level
145 * SCSI code.
146 *
147 * A NCR5380_PUBLIC_REVISION macro is provided, with the release
148 * number (updated for each public release) printed by the
149 * NCR5380_print_options command, which should be called from the
150 * wrapper detect function, so that I know what release of the driver
151 * users are using.
152 *
153 * Issues specific to the NCR5380 :
154 *
155 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
156 * piece of hardware that requires you to sit in a loop polling for
157 * the REQ signal as long as you are connected. Some devices are
158 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
159 * while doing long seek operations.
160 *
161 * The workaround for this is to keep track of devices that have
162 * disconnected. If the device hasn't disconnected, for commands that
163 * should disconnect, we do something like
164 *
165 * while (!REQ is asserted) { sleep for N usecs; poll for M usecs }
166 *
167 * Some tweaking of N and M needs to be done. An algorithm based
168 * on "time to data" would give the best results as long as short time
169 * to datas (ie, on the same track) were considered, however these
170 * broken devices are the exception rather than the rule and I'd rather
171 * spend my time optimizing for the normal case.
172 *
173 * Architecture :
174 *
175 * At the heart of the design is a coroutine, NCR5380_main,
176 * which is started when not running by the interrupt handler,
177 * timer, and queue command function. It attempts to establish
178 * I_T_L or I_T_L_Q nexuses by removing the commands from the
179 * issue queue and calling NCR5380_select() if a nexus
180 * is not established.
181 *
182 * Once a nexus is established, the NCR5380_information_transfer()
183 * phase goes through the various phases as instructed by the target.
184 * if the target goes into MSG IN and sends a DISCONNECT message,
185 * the command structure is placed into the per instance disconnected
186 * queue, and NCR5380_main tries to find more work. If USLEEP
187 * was defined, and the target is idle for too long, the system
188 * will try to sleep.
189 *
190 * If a command has disconnected, eventually an interrupt will trigger,
191 * calling NCR5380_intr() which will in turn call NCR5380_reselect
192 * to reestablish a nexus. This will run main if necessary.
193 *
194 * On command termination, the done function will be called as
195 * appropriate.
196 *
197 * SCSI pointers are maintained in the SCp field of SCSI command
198 * structures, being initialized after the command is connected
199 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
200 * Note that in violation of the standard, an implicit SAVE POINTERS operation
201 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
202 */
203
204/*
205 * Using this file :
206 * This file a skeleton Linux SCSI driver for the NCR 5380 series
207 * of chips. To use it, you write an architecture specific functions
208 * and macros and include this file in your driver.
209 *
210 * These macros control options :
211 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
212 * for commands that return with a CHECK CONDITION status.
213 *
214 * LINKED - if defined, linked commands are supported.
215 *
216 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
217 *
218 * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
219 *
220 * These macros MUST be defined :
221 *
222 * NCR5380_read(register) - read from the specified register
223 *
224 * NCR5380_write(register, value) - write to the specific register
225 *
226 * Either real DMA *or* pseudo DMA may be implemented
227 * REAL functions :
228 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
229 * Note that the DMA setup functions should return the number of bytes
230 * that they were able to program the controller for.
231 *
232 * Also note that generic i386/PC versions of these macros are
233 * available as NCR5380_i386_dma_write_setup,
234 * NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
235 *
236 * NCR5380_dma_write_setup(instance, src, count) - initialize
237 * NCR5380_dma_read_setup(instance, dst, count) - initialize
238 * NCR5380_dma_residual(instance); - residual count
239 *
240 * PSEUDO functions :
241 * NCR5380_pwrite(instance, src, count)
242 * NCR5380_pread(instance, dst, count);
243 *
244 * If nothing specific to this implementation needs doing (ie, with external
245 * hardware), you must also define
246 *
247 * NCR5380_queue_command
248 * NCR5380_reset
249 * NCR5380_abort
250 * NCR5380_proc_info
251 *
252 * to be the global entry points into the specific driver, ie
253 * #define NCR5380_queue_command t128_queue_command.
254 *
255 * If this is not done, the routines will be defined as static functions
256 * with the NCR5380* names and the user must provide a globally
257 * accessible wrapper function.
258 *
259 * The generic driver is initialized by calling NCR5380_init(instance),
260 * after setting the appropriate host specific fields and ID. If the
261 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
262 * possible) function may be used. Before the specific driver initialization
263 * code finishes, NCR5380_print_options should be called.
264 */
265
266static struct Scsi_Host *first_instance = NULL;
267static struct scsi_host_template *the_template = NULL;
268
269/* Macros ease life... :-) */
270#define SETUP_HOSTDATA(in) \
271 struct NCR5380_hostdata *hostdata = \
272 (struct NCR5380_hostdata *)(in)->hostdata
273#define HOSTDATA(in) ((struct NCR5380_hostdata *)(in)->hostdata)
274
275#define NEXT(cmd) ((Scsi_Cmnd *)(cmd)->host_scribble)
276#define SET_NEXT(cmd,next) ((cmd)->host_scribble = (void *)(next))
277#define NEXTADDR(cmd) ((Scsi_Cmnd **)&(cmd)->host_scribble)
278
279#define HOSTNO instance->host_no
280#define H_NO(cmd) (cmd)->device->host->host_no
281
282#ifdef SUPPORT_TAGS
283
284/*
285 * Functions for handling tagged queuing
286 * =====================================
287 *
288 * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
289 *
290 * Using consecutive numbers for the tags is no good idea in my eyes. There
291 * could be wrong re-usings if the counter (8 bit!) wraps and some early
292 * command has been preempted for a long time. My solution: a bitfield for
293 * remembering used tags.
294 *
295 * There's also the problem that each target has a certain queue size, but we
296 * cannot know it in advance :-( We just see a QUEUE_FULL status being
297 * returned. So, in this case, the driver internal queue size assumption is
298 * reduced to the number of active tags if QUEUE_FULL is returned by the
299 * target. The command is returned to the mid-level, but with status changed
300 * to BUSY, since --as I've seen-- the mid-level can't handle QUEUE_FULL
301 * correctly.
302 *
303 * We're also not allowed running tagged commands as long as an untagged
304 * command is active. And REQUEST SENSE commands after a contingent allegiance
305 * condition _must_ be untagged. To keep track whether an untagged command has
306 * been issued, the host->busy array is still employed, as it is without
307 * support for tagged queuing.
308 *
309 * One could suspect that there are possible race conditions between
310 * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
311 * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
312 * which already guaranteed to be running at most once. It is also the only
313 * place where tags/LUNs are allocated. So no other allocation can slip
314 * between that pair, there could only happen a reselection, which can free a
315 * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
316 * important: the tag bit must be cleared before 'nr_allocated' is decreased.
317 */
318
319/* -1 for TAG_NONE is not possible with unsigned char cmd->tag */
320#undef TAG_NONE
321#define TAG_NONE 0xff
322
323typedef struct {
324 DECLARE_BITMAP(allocated, MAX_TAGS);
325 int nr_allocated;
326 int queue_size;
327} TAG_ALLOC;
328
329static TAG_ALLOC TagAlloc[8][8]; /* 8 targets and 8 LUNs */
330
331
332static void __init init_tags(void)
333{
334 int target, lun;
335 TAG_ALLOC *ta;
336
337 if (!setup_use_tagged_queuing)
338 return;
339
340 for (target = 0; target < 8; ++target) {
341 for (lun = 0; lun < 8; ++lun) {
342 ta = &TagAlloc[target][lun];
343 bitmap_zero(ta->allocated, MAX_TAGS);
344 ta->nr_allocated = 0;
345 /* At the beginning, assume the maximum queue size we could
346 * support (MAX_TAGS). This value will be decreased if the target
347 * returns QUEUE_FULL status.
348 */
349 ta->queue_size = MAX_TAGS;
350 }
351 }
352}
353
354
355/* Check if we can issue a command to this LUN: First see if the LUN is marked
356 * busy by an untagged command. If the command should use tagged queuing, also
357 * check that there is a free tag and the target's queue won't overflow. This
358 * function should be called with interrupts disabled to avoid race
359 * conditions.
360 */
361
362static int is_lun_busy(Scsi_Cmnd *cmd, int should_be_tagged)
363{
364 SETUP_HOSTDATA(cmd->device->host);
365
366 if (hostdata->busy[cmd->device->id] & (1 << cmd->device->lun))
367 return 1;
368 if (!should_be_tagged ||
369 !setup_use_tagged_queuing || !cmd->device->tagged_supported)
370 return 0;
371 if (TagAlloc[cmd->device->id][cmd->device->lun].nr_allocated >=
372 TagAlloc[cmd->device->id][cmd->device->lun].queue_size) {
373 TAG_PRINTK("scsi%d: target %d lun %d: no free tags\n",
374 H_NO(cmd), cmd->device->id, cmd->device->lun);
375 return 1;
376 }
377 return 0;
378}
379
380
381/* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
382 * must be called before!), or reserve the LUN in 'busy' if the command is
383 * untagged.
384 */
385
386static void cmd_get_tag(Scsi_Cmnd *cmd, int should_be_tagged)
387{
388 SETUP_HOSTDATA(cmd->device->host);
389
390 /* If we or the target don't support tagged queuing, allocate the LUN for
391 * an untagged command.
392 */
393 if (!should_be_tagged ||
394 !setup_use_tagged_queuing || !cmd->device->tagged_supported) {
395 cmd->tag = TAG_NONE;
396 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
397 TAG_PRINTK("scsi%d: target %d lun %d now allocated by untagged "
398 "command\n", H_NO(cmd), cmd->device->id, cmd->device->lun);
399 } else {
400 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
401
402 cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
403 set_bit(cmd->tag, ta->allocated);
404 ta->nr_allocated++;
405 TAG_PRINTK("scsi%d: using tag %d for target %d lun %d "
406 "(now %d tags in use)\n",
407 H_NO(cmd), cmd->tag, cmd->device->id,
408 cmd->device->lun, ta->nr_allocated);
409 }
410}
411
412
413/* Mark the tag of command 'cmd' as free, or in case of an untagged command,
414 * unlock the LUN.
415 */
416
417static void cmd_free_tag(Scsi_Cmnd *cmd)
418{
419 SETUP_HOSTDATA(cmd->device->host);
420
421 if (cmd->tag == TAG_NONE) {
422 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
423 TAG_PRINTK("scsi%d: target %d lun %d untagged cmd finished\n",
424 H_NO(cmd), cmd->device->id, cmd->device->lun);
425 } else if (cmd->tag >= MAX_TAGS) {
426 printk(KERN_NOTICE "scsi%d: trying to free bad tag %d!\n",
427 H_NO(cmd), cmd->tag);
428 } else {
429 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
430 clear_bit(cmd->tag, ta->allocated);
431 ta->nr_allocated--;
432 TAG_PRINTK("scsi%d: freed tag %d for target %d lun %d\n",
433 H_NO(cmd), cmd->tag, cmd->device->id, cmd->device->lun);
434 }
435}
436
437
438static void free_all_tags(void)
439{
440 int target, lun;
441 TAG_ALLOC *ta;
442
443 if (!setup_use_tagged_queuing)
444 return;
445
446 for (target = 0; target < 8; ++target) {
447 for (lun = 0; lun < 8; ++lun) {
448 ta = &TagAlloc[target][lun];
449 bitmap_zero(ta->allocated, MAX_TAGS);
450 ta->nr_allocated = 0;
451 }
452 }
453}
454
455#endif /* SUPPORT_TAGS */
456
457
458/*
459 * Function: void merge_contiguous_buffers( Scsi_Cmnd *cmd )
460 *
461 * Purpose: Try to merge several scatter-gather requests into one DMA
462 * transfer. This is possible if the scatter buffers lie on
463 * physical contiguous addresses.
464 *
465 * Parameters: Scsi_Cmnd *cmd
466 * The command to work on. The first scatter buffer's data are
467 * assumed to be already transferred into ptr/this_residual.
468 */
469
470static void merge_contiguous_buffers(Scsi_Cmnd *cmd)
471{
472 unsigned long endaddr;
473#if (NDEBUG & NDEBUG_MERGING)
474 unsigned long oldlen = cmd->SCp.this_residual;
475 int cnt = 1;
476#endif
477
478 for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
479 cmd->SCp.buffers_residual &&
480 virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
481 MER_PRINTK("VTOP(%p) == %08lx -> merging\n",
482 page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
483#if (NDEBUG & NDEBUG_MERGING)
484 ++cnt;
485#endif
486 ++cmd->SCp.buffer;
487 --cmd->SCp.buffers_residual;
488 cmd->SCp.this_residual += cmd->SCp.buffer->length;
489 endaddr += cmd->SCp.buffer->length;
490 }
491#if (NDEBUG & NDEBUG_MERGING)
492 if (oldlen != cmd->SCp.this_residual)
493 MER_PRINTK("merged %d buffers from %p, new length %08x\n",
494 cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
495#endif
496}
497
498/*
499 * Function : void initialize_SCp(Scsi_Cmnd *cmd)
500 *
501 * Purpose : initialize the saved data pointers for cmd to point to the
502 * start of the buffer.
503 *
504 * Inputs : cmd - Scsi_Cmnd structure to have pointers reset.
505 */
506
507static inline void initialize_SCp(Scsi_Cmnd *cmd)
508{
509 /*
510 * Initialize the Scsi Pointer field so that all of the commands in the
511 * various queues are valid.
512 */
513
514 if (scsi_bufflen(cmd)) {
515 cmd->SCp.buffer = scsi_sglist(cmd);
516 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
517 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
518 cmd->SCp.this_residual = cmd->SCp.buffer->length;
519 /* ++roman: Try to merge some scatter-buffers if they are at
520 * contiguous physical addresses.
521 */
522 merge_contiguous_buffers(cmd);
523 } else {
524 cmd->SCp.buffer = NULL;
525 cmd->SCp.buffers_residual = 0;
526 cmd->SCp.ptr = NULL;
527 cmd->SCp.this_residual = 0;
528 }
529}
530
531#include <linux/delay.h>
532
533#if NDEBUG
534static struct {
535 unsigned char mask;
536 const char *name;
537} signals[] = {
538 { SR_DBP, "PARITY"}, { SR_RST, "RST" }, { SR_BSY, "BSY" },
539 { SR_REQ, "REQ" }, { SR_MSG, "MSG" }, { SR_CD, "CD" }, { SR_IO, "IO" },
540 { SR_SEL, "SEL" }, {0, NULL}
541}, basrs[] = {
542 {BASR_ATN, "ATN"}, {BASR_ACK, "ACK"}, {0, NULL}
543}, icrs[] = {
544 {ICR_ASSERT_RST, "ASSERT RST"},{ICR_ASSERT_ACK, "ASSERT ACK"},
545 {ICR_ASSERT_BSY, "ASSERT BSY"}, {ICR_ASSERT_SEL, "ASSERT SEL"},
546 {ICR_ASSERT_ATN, "ASSERT ATN"}, {ICR_ASSERT_DATA, "ASSERT DATA"},
547 {0, NULL}
548}, mrs[] = {
549 {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"}, {MR_TARGET, "MODE TARGET"},
550 {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"}, {MR_ENABLE_PAR_INTR,
551 "MODE PARITY INTR"}, {MR_ENABLE_EOP_INTR,"MODE EOP INTR"},
552 {MR_MONITOR_BSY, "MODE MONITOR BSY"},
553 {MR_DMA_MODE, "MODE DMA"}, {MR_ARBITRATE, "MODE ARBITRATION"},
554 {0, NULL}
555};
556
557/*
558 * Function : void NCR5380_print(struct Scsi_Host *instance)
559 *
560 * Purpose : print the SCSI bus signals for debugging purposes
561 *
562 * Input : instance - which NCR5380
563 */
564
565static void NCR5380_print(struct Scsi_Host *instance)
566{
567 unsigned char status, data, basr, mr, icr, i;
568 unsigned long flags;
569
570 local_irq_save(flags);
571 data = NCR5380_read(CURRENT_SCSI_DATA_REG);
572 status = NCR5380_read(STATUS_REG);
573 mr = NCR5380_read(MODE_REG);
574 icr = NCR5380_read(INITIATOR_COMMAND_REG);
575 basr = NCR5380_read(BUS_AND_STATUS_REG);
576 local_irq_restore(flags);
577 printk("STATUS_REG: %02x ", status);
578 for (i = 0; signals[i].mask; ++i)
579 if (status & signals[i].mask)
580 printk(",%s", signals[i].name);
581 printk("\nBASR: %02x ", basr);
582 for (i = 0; basrs[i].mask; ++i)
583 if (basr & basrs[i].mask)
584 printk(",%s", basrs[i].name);
585 printk("\nICR: %02x ", icr);
586 for (i = 0; icrs[i].mask; ++i)
587 if (icr & icrs[i].mask)
588 printk(",%s", icrs[i].name);
589 printk("\nMODE: %02x ", mr);
590 for (i = 0; mrs[i].mask; ++i)
591 if (mr & mrs[i].mask)
592 printk(",%s", mrs[i].name);
593 printk("\n");
594}
595
596static struct {
597 unsigned char value;
598 const char *name;
599} phases[] = {
600 {PHASE_DATAOUT, "DATAOUT"}, {PHASE_DATAIN, "DATAIN"}, {PHASE_CMDOUT, "CMDOUT"},
601 {PHASE_STATIN, "STATIN"}, {PHASE_MSGOUT, "MSGOUT"}, {PHASE_MSGIN, "MSGIN"},
602 {PHASE_UNKNOWN, "UNKNOWN"}
603};
604
605/*
606 * Function : void NCR5380_print_phase(struct Scsi_Host *instance)
607 *
608 * Purpose : print the current SCSI phase for debugging purposes
609 *
610 * Input : instance - which NCR5380
611 */
612
613static void NCR5380_print_phase(struct Scsi_Host *instance)
614{
615 unsigned char status;
616 int i;
617
618 status = NCR5380_read(STATUS_REG);
619 if (!(status & SR_REQ))
620 printk(KERN_DEBUG "scsi%d: REQ not asserted, phase unknown.\n", HOSTNO);
621 else {
622 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
623 (phases[i].value != (status & PHASE_MASK)); ++i)
624 ;
625 printk(KERN_DEBUG "scsi%d: phase %s\n", HOSTNO, phases[i].name);
626 }
627}
628
629#else /* !NDEBUG */
630
631/* dummies... */
632static inline void NCR5380_print(struct Scsi_Host *instance)
633{
634};
635static inline void NCR5380_print_phase(struct Scsi_Host *instance)
636{
637};
638
639#endif
640
641/*
642 * ++roman: New scheme of calling NCR5380_main()
643 *
644 * If we're not in an interrupt, we can call our main directly, it cannot be
645 * already running. Else, we queue it on a task queue, if not 'main_running'
646 * tells us that a lower level is already executing it. This way,
647 * 'main_running' needs not be protected in a special way.
648 *
649 * queue_main() is a utility function for putting our main onto the task
650 * queue, if main_running is false. It should be called only from a
651 * interrupt or bottom half.
652 */
653
654#include <linux/gfp.h>
655#include <linux/workqueue.h>
656#include <linux/interrupt.h>
657
658static volatile int main_running;
659static DECLARE_WORK(NCR5380_tqueue, NCR5380_main);
660
661static inline void queue_main(void)
662{
663 if (!main_running) {
664 /* If in interrupt and NCR5380_main() not already running,
665 queue it on the 'immediate' task queue, to be processed
666 immediately after the current interrupt processing has
667 finished. */
668 schedule_work(&NCR5380_tqueue);
669 }
670 /* else: nothing to do: the running NCR5380_main() will pick up
671 any newly queued command. */
672}
673
674
675static inline void NCR5380_all_init(void)
676{
677 static int done = 0;
678 if (!done) {
679 INI_PRINTK("scsi : NCR5380_all_init()\n");
680 done = 1;
681 }
682}
683
684
685/*
686 * Function : void NCR58380_print_options (struct Scsi_Host *instance)
687 *
688 * Purpose : called by probe code indicating the NCR5380 driver
689 * options that were selected.
690 *
691 * Inputs : instance, pointer to this instance. Unused.
692 */
693
694static void __init NCR5380_print_options(struct Scsi_Host *instance)
695{
696 printk(" generic options"
697#ifdef AUTOSENSE
698 " AUTOSENSE"
699#endif
700#ifdef REAL_DMA
701 " REAL DMA"
702#endif
703#ifdef PARITY
704 " PARITY"
705#endif
706#ifdef SUPPORT_TAGS
707 " SCSI-2 TAGGED QUEUING"
708#endif
709 );
710 printk(" generic release=%d", NCR5380_PUBLIC_RELEASE);
711}
712
713/*
714 * Function : void NCR5380_print_status (struct Scsi_Host *instance)
715 *
716 * Purpose : print commands in the various queues, called from
717 * NCR5380_abort and NCR5380_debug to aid debugging.
718 *
719 * Inputs : instance, pointer to this instance.
720 */
721
722static void NCR5380_print_status(struct Scsi_Host *instance)
723{
724 char *pr_bfr;
725 char *start;
726 int len;
727
728 NCR_PRINT(NDEBUG_ANY);
729 NCR_PRINT_PHASE(NDEBUG_ANY);
730
731 pr_bfr = (char *)__get_free_page(GFP_ATOMIC);
732 if (!pr_bfr) {
733 printk("NCR5380_print_status: no memory for print buffer\n");
734 return;
735 }
736 len = NCR5380_proc_info(instance, pr_bfr, &start, 0, PAGE_SIZE, 0);
737 pr_bfr[len] = 0;
738 printk("\n%s\n", pr_bfr);
739 free_page((unsigned long)pr_bfr);
740}
741
742
743/******************************************/
744/*
745 * /proc/scsi/[dtc pas16 t128 generic]/[0-ASC_NUM_BOARD_SUPPORTED]
746 *
747 * *buffer: I/O buffer
748 * **start: if inout == FALSE pointer into buffer where user read should start
749 * offset: current offset
750 * length: length of buffer
751 * hostno: Scsi_Host host_no
752 * inout: TRUE - user is writing; FALSE - user is reading
753 *
754 * Return the number of bytes read from or written
755*/
756
757#undef SPRINTF
758#define SPRINTF(fmt,args...) \
759 do { \
760 if (pos + strlen(fmt) + 20 /* slop */ < buffer + length) \
761 pos += sprintf(pos, fmt , ## args); \
762 } while(0)
763static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length);
764
765static int NCR5380_proc_info(struct Scsi_Host *instance, char *buffer,
766 char **start, off_t offset, int length, int inout)
767{
768 char *pos = buffer;
769 struct NCR5380_hostdata *hostdata;
770 Scsi_Cmnd *ptr;
771 unsigned long flags;
772 off_t begin = 0;
773#define check_offset() \
774 do { \
775 if (pos - buffer < offset - begin) { \
776 begin += pos - buffer; \
777 pos = buffer; \
778 } \
779 } while (0)
780
781 hostdata = (struct NCR5380_hostdata *)instance->hostdata;
782
783 if (inout) /* Has data been written to the file ? */
784 return -ENOSYS; /* Currently this is a no-op */
785 SPRINTF("NCR5380 core release=%d.\n", NCR5380_PUBLIC_RELEASE);
786 check_offset();
787 local_irq_save(flags);
788 SPRINTF("NCR5380: coroutine is%s running.\n",
789 main_running ? "" : "n't");
790 check_offset();
791 if (!hostdata->connected)
792 SPRINTF("scsi%d: no currently connected command\n", HOSTNO);
793 else
794 pos = lprint_Scsi_Cmnd((Scsi_Cmnd *) hostdata->connected,
795 pos, buffer, length);
796 SPRINTF("scsi%d: issue_queue\n", HOSTNO);
797 check_offset();
798 for (ptr = (Scsi_Cmnd *)hostdata->issue_queue; ptr; ptr = NEXT(ptr)) {
799 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
800 check_offset();
801 }
802
803 SPRINTF("scsi%d: disconnected_queue\n", HOSTNO);
804 check_offset();
805 for (ptr = (Scsi_Cmnd *) hostdata->disconnected_queue; ptr;
806 ptr = NEXT(ptr)) {
807 pos = lprint_Scsi_Cmnd(ptr, pos, buffer, length);
808 check_offset();
809 }
810
811 local_irq_restore(flags);
812 *start = buffer + (offset - begin);
813 if (pos - buffer < offset - begin)
814 return 0;
815 else if (pos - buffer - (offset - begin) < length)
816 return pos - buffer - (offset - begin);
817 return length;
818}
819
820static char *lprint_Scsi_Cmnd(Scsi_Cmnd *cmd, char *pos, char *buffer, int length)
821{
822 int i, s;
823 unsigned char *command;
824 SPRINTF("scsi%d: destination target %d, lun %d\n",
825 H_NO(cmd), cmd->device->id, cmd->device->lun);
826 SPRINTF(" command = ");
827 command = cmd->cmnd;
828 SPRINTF("%2d (0x%02x)", command[0], command[0]);
829 for (i = 1, s = COMMAND_SIZE(command[0]); i < s; ++i)
830 SPRINTF(" %02x", command[i]);
831 SPRINTF("\n");
832 return pos;
833}
834
835
836/*
837 * Function : void NCR5380_init (struct Scsi_Host *instance)
838 *
839 * Purpose : initializes *instance and corresponding 5380 chip.
840 *
841 * Inputs : instance - instantiation of the 5380 driver.
842 *
843 * Notes : I assume that the host, hostno, and id bits have been
844 * set correctly. I don't care about the irq and other fields.
845 *
846 */
847
848static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
849{
850 int i;
851 SETUP_HOSTDATA(instance);
852
853 NCR5380_all_init();
854
855 hostdata->aborted = 0;
856 hostdata->id_mask = 1 << instance->this_id;
857 hostdata->id_higher_mask = 0;
858 for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
859 if (i > hostdata->id_mask)
860 hostdata->id_higher_mask |= i;
861 for (i = 0; i < 8; ++i)
862 hostdata->busy[i] = 0;
863#ifdef SUPPORT_TAGS
864 init_tags();
865#endif
866#if defined (REAL_DMA)
867 hostdata->dma_len = 0;
868#endif
869 hostdata->targets_present = 0;
870 hostdata->connected = NULL;
871 hostdata->issue_queue = NULL;
872 hostdata->disconnected_queue = NULL;
873 hostdata->flags = FLAG_CHECK_LAST_BYTE_SENT;
874
875 if (!the_template) {
876 the_template = instance->hostt;
877 first_instance = instance;
878 }
879
880#ifndef AUTOSENSE
881 if ((instance->cmd_per_lun > 1) || (instance->can_queue > 1))
882 printk("scsi%d: WARNING : support for multiple outstanding commands enabled\n"
883 " without AUTOSENSE option, contingent allegiance conditions may\n"
884 " be incorrectly cleared.\n", HOSTNO);
885#endif /* def AUTOSENSE */
886
887 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
888 NCR5380_write(MODE_REG, MR_BASE);
889 NCR5380_write(TARGET_COMMAND_REG, 0);
890 NCR5380_write(SELECT_ENABLE_REG, 0);
891
892 return 0;
893}
894
895static void NCR5380_exit(struct Scsi_Host *instance)
896{
897 /* Empty, as we didn't schedule any delayed work */
898}
899
900/*
901 * Function : int NCR5380_queue_command (Scsi_Cmnd *cmd,
902 * void (*done)(Scsi_Cmnd *))
903 *
904 * Purpose : enqueues a SCSI command
905 *
906 * Inputs : cmd - SCSI command, done - function called on completion, with
907 * a pointer to the command descriptor.
908 *
909 * Returns : 0
910 *
911 * Side effects :
912 * cmd is added to the per instance issue_queue, with minor
913 * twiddling done to the host specific fields of cmd. If the
914 * main coroutine is not running, it is restarted.
915 *
916 */
917
918static int NCR5380_queue_command_lck(Scsi_Cmnd *cmd, void (*done)(Scsi_Cmnd *))
919{
920 SETUP_HOSTDATA(cmd->device->host);
921 Scsi_Cmnd *tmp;
922 unsigned long flags;
923
924#if (NDEBUG & NDEBUG_NO_WRITE)
925 switch (cmd->cmnd[0]) {
926 case WRITE_6:
927 case WRITE_10:
928 printk(KERN_NOTICE "scsi%d: WRITE attempted with NO_WRITE debugging flag set\n",
929 H_NO(cmd));
930 cmd->result = (DID_ERROR << 16);
931 done(cmd);
932 return 0;
933 }
934#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
935
936#ifdef NCR5380_STATS
937# if 0
938 if (!hostdata->connected && !hostdata->issue_queue &&
939 !hostdata->disconnected_queue) {
940 hostdata->timebase = jiffies;
941 }
942# endif
943# ifdef NCR5380_STAT_LIMIT
944 if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
945# endif
946 switch (cmd->cmnd[0]) {
947 case WRITE:
948 case WRITE_6:
949 case WRITE_10:
950 hostdata->time_write[cmd->device->id] -= (jiffies - hostdata->timebase);
951 hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);
952 hostdata->pendingw++;
953 break;
954 case READ:
955 case READ_6:
956 case READ_10:
957 hostdata->time_read[cmd->device->id] -= (jiffies - hostdata->timebase);
958 hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);
959 hostdata->pendingr++;
960 break;
961 }
962#endif
963
964 /*
965 * We use the host_scribble field as a pointer to the next command
966 * in a queue
967 */
968
969 SET_NEXT(cmd, NULL);
970 cmd->scsi_done = done;
971
972 cmd->result = 0;
973
974 /*
975 * Insert the cmd into the issue queue. Note that REQUEST SENSE
976 * commands are added to the head of the queue since any command will
977 * clear the contingent allegiance condition that exists and the
978 * sense data is only guaranteed to be valid while the condition exists.
979 */
980
981 local_irq_save(flags);
982 /* ++guenther: now that the issue queue is being set up, we can lock ST-DMA.
983 * Otherwise a running NCR5380_main may steal the lock.
984 * Lock before actually inserting due to fairness reasons explained in
985 * atari_scsi.c. If we insert first, then it's impossible for this driver
986 * to release the lock.
987 * Stop timer for this command while waiting for the lock, or timeouts
988 * may happen (and they really do), and it's no good if the command doesn't
989 * appear in any of the queues.
990 * ++roman: Just disabling the NCR interrupt isn't sufficient here,
991 * because also a timer int can trigger an abort or reset, which would
992 * alter queues and touch the lock.
993 */
994 if (!IS_A_TT()) {
995 /* perhaps stop command timer here */
996 falcon_get_lock();
997 /* perhaps restart command timer here */
998 }
999 if (!(hostdata->issue_queue) || (cmd->cmnd[0] == REQUEST_SENSE)) {
1000 LIST(cmd, hostdata->issue_queue);
1001 SET_NEXT(cmd, hostdata->issue_queue);
1002 hostdata->issue_queue = cmd;
1003 } else {
1004 for (tmp = (Scsi_Cmnd *)hostdata->issue_queue;
1005 NEXT(tmp); tmp = NEXT(tmp))
1006 ;
1007 LIST(cmd, tmp);
1008 SET_NEXT(tmp, cmd);
1009 }
1010 local_irq_restore(flags);
1011
1012 QU_PRINTK("scsi%d: command added to %s of queue\n", H_NO(cmd),
1013 (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
1014
1015 /* If queue_command() is called from an interrupt (real one or bottom
1016 * half), we let queue_main() do the job of taking care about main. If it
1017 * is already running, this is a no-op, else main will be queued.
1018 *
1019 * If we're not in an interrupt, we can call NCR5380_main()
1020 * unconditionally, because it cannot be already running.
1021 */
1022 if (in_interrupt() || ((flags >> 8) & 7) >= 6)
1023 queue_main();
1024 else
1025 NCR5380_main(NULL);
1026 return 0;
1027}
1028
1029static DEF_SCSI_QCMD(NCR5380_queue_command)
1030
1031/*
1032 * Function : NCR5380_main (void)
1033 *
1034 * Purpose : NCR5380_main is a coroutine that runs as long as more work can
1035 * be done on the NCR5380 host adapters in a system. Both
1036 * NCR5380_queue_command() and NCR5380_intr() will try to start it
1037 * in case it is not running.
1038 *
1039 * NOTE : NCR5380_main exits with interrupts *disabled*, the caller should
1040 * reenable them. This prevents reentrancy and kernel stack overflow.
1041 */
1042
1043static void NCR5380_main(struct work_struct *work)
1044{
1045 Scsi_Cmnd *tmp, *prev;
1046 struct Scsi_Host *instance = first_instance;
1047 struct NCR5380_hostdata *hostdata = HOSTDATA(instance);
1048 int done;
1049 unsigned long flags;
1050
1051 /*
1052 * We run (with interrupts disabled) until we're sure that none of
1053 * the host adapters have anything that can be done, at which point
1054 * we set main_running to 0 and exit.
1055 *
1056 * Interrupts are enabled before doing various other internal
1057 * instructions, after we've decided that we need to run through
1058 * the loop again.
1059 *
1060 * this should prevent any race conditions.
1061 *
1062 * ++roman: Just disabling the NCR interrupt isn't sufficient here,
1063 * because also a timer int can trigger an abort or reset, which can
1064 * alter queues and touch the Falcon lock.
1065 */
1066
1067 /* Tell int handlers main() is now already executing. Note that
1068 no races are possible here. If an int comes in before
1069 'main_running' is set here, and queues/executes main via the
1070 task queue, it doesn't do any harm, just this instance of main
1071 won't find any work left to do. */
1072 if (main_running)
1073 return;
1074 main_running = 1;
1075
1076 local_save_flags(flags);
1077 do {
1078 local_irq_disable(); /* Freeze request queues */
1079 done = 1;
1080
1081 if (!hostdata->connected) {
1082 MAIN_PRINTK("scsi%d: not connected\n", HOSTNO);
1083 /*
1084 * Search through the issue_queue for a command destined
1085 * for a target that's not busy.
1086 */
1087#if (NDEBUG & NDEBUG_LISTS)
1088 for (tmp = (Scsi_Cmnd *) hostdata->issue_queue, prev = NULL;
1089 tmp && (tmp != prev); prev = tmp, tmp = NEXT(tmp))
1090 ;
1091 /*printk("%p ", tmp);*/
1092 if ((tmp == prev) && tmp)
1093 printk(" LOOP\n");
1094 /* else printk("\n"); */
1095#endif
1096 for (tmp = (Scsi_Cmnd *) hostdata->issue_queue,
1097 prev = NULL; tmp; prev = tmp, tmp = NEXT(tmp)) {
1098
1099#if (NDEBUG & NDEBUG_LISTS)
1100 if (prev != tmp)
1101 printk("MAIN tmp=%p target=%d busy=%d lun=%d\n",
1102 tmp, tmp->device->id, hostdata->busy[tmp->device->id],
1103 tmp->device->lun);
1104#endif
1105 /* When we find one, remove it from the issue queue. */
1106 /* ++guenther: possible race with Falcon locking */
1107 if (
1108#ifdef SUPPORT_TAGS
1109 !is_lun_busy( tmp, tmp->cmnd[0] != REQUEST_SENSE)
1110#else
1111 !(hostdata->busy[tmp->device->id] & (1 << tmp->device->lun))
1112#endif
1113 ) {
1114 /* ++guenther: just to be sure, this must be atomic */
1115 local_irq_disable();
1116 if (prev) {
1117 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
1118 SET_NEXT(prev, NEXT(tmp));
1119 } else {
1120 REMOVE(-1, hostdata->issue_queue, tmp, NEXT(tmp));
1121 hostdata->issue_queue = NEXT(tmp);
1122 }
1123 SET_NEXT(tmp, NULL);
1124 falcon_dont_release++;
1125
1126 /* reenable interrupts after finding one */
1127 local_irq_restore(flags);
1128
1129 /*
1130 * Attempt to establish an I_T_L nexus here.
1131 * On success, instance->hostdata->connected is set.
1132 * On failure, we must add the command back to the
1133 * issue queue so we can keep trying.
1134 */
1135 MAIN_PRINTK("scsi%d: main(): command for target %d "
1136 "lun %d removed from issue_queue\n",
1137 HOSTNO, tmp->device->id, tmp->device->lun);
1138 /*
1139 * REQUEST SENSE commands are issued without tagged
1140 * queueing, even on SCSI-II devices because the
1141 * contingent allegiance condition exists for the
1142 * entire unit.
1143 */
1144 /* ++roman: ...and the standard also requires that
1145 * REQUEST SENSE command are untagged.
1146 */
1147
1148#ifdef SUPPORT_TAGS
1149 cmd_get_tag(tmp, tmp->cmnd[0] != REQUEST_SENSE);
1150#endif
1151 if (!NCR5380_select(instance, tmp,
1152 (tmp->cmnd[0] == REQUEST_SENSE) ? TAG_NONE :
1153 TAG_NEXT)) {
1154 falcon_dont_release--;
1155 /* release if target did not response! */
1156 falcon_release_lock_if_possible(hostdata);
1157 break;
1158 } else {
1159 local_irq_disable();
1160 LIST(tmp, hostdata->issue_queue);
1161 SET_NEXT(tmp, hostdata->issue_queue);
1162 hostdata->issue_queue = tmp;
1163#ifdef SUPPORT_TAGS
1164 cmd_free_tag(tmp);
1165#endif
1166 falcon_dont_release--;
1167 local_irq_restore(flags);
1168 MAIN_PRINTK("scsi%d: main(): select() failed, "
1169 "returned to issue_queue\n", HOSTNO);
1170 if (hostdata->connected)
1171 break;
1172 }
1173 } /* if target/lun/target queue is not busy */
1174 } /* for issue_queue */
1175 } /* if (!hostdata->connected) */
1176
1177 if (hostdata->connected
1178#ifdef REAL_DMA
1179 && !hostdata->dma_len
1180#endif
1181 ) {
1182 local_irq_restore(flags);
1183 MAIN_PRINTK("scsi%d: main: performing information transfer\n",
1184 HOSTNO);
1185 NCR5380_information_transfer(instance);
1186 MAIN_PRINTK("scsi%d: main: done set false\n", HOSTNO);
1187 done = 0;
1188 }
1189 } while (!done);
1190
1191 /* Better allow ints _after_ 'main_running' has been cleared, else
1192 an interrupt could believe we'll pick up the work it left for
1193 us, but we won't see it anymore here... */
1194 main_running = 0;
1195 local_irq_restore(flags);
1196}
1197
1198
1199#ifdef REAL_DMA
1200/*
1201 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
1202 *
1203 * Purpose : Called by interrupt handler when DMA finishes or a phase
1204 * mismatch occurs (which would finish the DMA transfer).
1205 *
1206 * Inputs : instance - this instance of the NCR5380.
1207 *
1208 */
1209
1210static void NCR5380_dma_complete(struct Scsi_Host *instance)
1211{
1212 SETUP_HOSTDATA(instance);
1213 int transfered, saved_data = 0, overrun = 0, cnt, toPIO;
1214 unsigned char **data, p;
1215 volatile int *count;
1216
1217 if (!hostdata->connected) {
1218 printk(KERN_WARNING "scsi%d: received end of DMA interrupt with "
1219 "no connected cmd\n", HOSTNO);
1220 return;
1221 }
1222
1223 if (atari_read_overruns) {
1224 p = hostdata->connected->SCp.phase;
1225 if (p & SR_IO) {
1226 udelay(10);
1227 if ((NCR5380_read(BUS_AND_STATUS_REG) &
1228 (BASR_PHASE_MATCH|BASR_ACK)) ==
1229 (BASR_PHASE_MATCH|BASR_ACK)) {
1230 saved_data = NCR5380_read(INPUT_DATA_REG);
1231 overrun = 1;
1232 DMA_PRINTK("scsi%d: read overrun handled\n", HOSTNO);
1233 }
1234 }
1235 }
1236
1237 DMA_PRINTK("scsi%d: real DMA transfer complete, basr 0x%X, sr 0x%X\n",
1238 HOSTNO, NCR5380_read(BUS_AND_STATUS_REG),
1239 NCR5380_read(STATUS_REG));
1240
1241 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1242 NCR5380_write(MODE_REG, MR_BASE);
1243 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1244
1245 transfered = hostdata->dma_len - NCR5380_dma_residual(instance);
1246 hostdata->dma_len = 0;
1247
1248 data = (unsigned char **)&hostdata->connected->SCp.ptr;
1249 count = &hostdata->connected->SCp.this_residual;
1250 *data += transfered;
1251 *count -= transfered;
1252
1253 if (atari_read_overruns) {
1254 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1255 cnt = toPIO = atari_read_overruns;
1256 if (overrun) {
1257 DMA_PRINTK("Got an input overrun, using saved byte\n");
1258 *(*data)++ = saved_data;
1259 (*count)--;
1260 cnt--;
1261 toPIO--;
1262 }
1263 DMA_PRINTK("Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1264 NCR5380_transfer_pio(instance, &p, &cnt, data);
1265 *count -= toPIO - cnt;
1266 }
1267 }
1268}
1269#endif /* REAL_DMA */
1270
1271
1272/*
1273 * Function : void NCR5380_intr (int irq)
1274 *
1275 * Purpose : handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1276 * from the disconnected queue, and restarting NCR5380_main()
1277 * as required.
1278 *
1279 * Inputs : int irq, irq that caused this interrupt.
1280 *
1281 */
1282
1283static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1284{
1285 struct Scsi_Host *instance = first_instance;
1286 int done = 1, handled = 0;
1287 unsigned char basr;
1288
1289 INT_PRINTK("scsi%d: NCR5380 irq triggered\n", HOSTNO);
1290
1291 /* Look for pending interrupts */
1292 basr = NCR5380_read(BUS_AND_STATUS_REG);
1293 INT_PRINTK("scsi%d: BASR=%02x\n", HOSTNO, basr);
1294 /* dispatch to appropriate routine if found and done=0 */
1295 if (basr & BASR_IRQ) {
1296 NCR_PRINT(NDEBUG_INTR);
1297 if ((NCR5380_read(STATUS_REG) & (SR_SEL|SR_IO)) == (SR_SEL|SR_IO)) {
1298 done = 0;
1299 ENABLE_IRQ();
1300 INT_PRINTK("scsi%d: SEL interrupt\n", HOSTNO);
1301 NCR5380_reselect(instance);
1302 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1303 } else if (basr & BASR_PARITY_ERROR) {
1304 INT_PRINTK("scsi%d: PARITY interrupt\n", HOSTNO);
1305 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1306 } else if ((NCR5380_read(STATUS_REG) & SR_RST) == SR_RST) {
1307 INT_PRINTK("scsi%d: RESET interrupt\n", HOSTNO);
1308 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1309 } else {
1310 /*
1311 * The rest of the interrupt conditions can occur only during a
1312 * DMA transfer
1313 */
1314
1315#if defined(REAL_DMA)
1316 /*
1317 * We should only get PHASE MISMATCH and EOP interrupts if we have
1318 * DMA enabled, so do a sanity check based on the current setting
1319 * of the MODE register.
1320 */
1321
1322 if ((NCR5380_read(MODE_REG) & MR_DMA_MODE) &&
1323 ((basr & BASR_END_DMA_TRANSFER) ||
1324 !(basr & BASR_PHASE_MATCH))) {
1325
1326 INT_PRINTK("scsi%d: PHASE MISM or EOP interrupt\n", HOSTNO);
1327 NCR5380_dma_complete( instance );
1328 done = 0;
1329 ENABLE_IRQ();
1330 } else
1331#endif /* REAL_DMA */
1332 {
1333/* MS: Ignore unknown phase mismatch interrupts (caused by EOP interrupt) */
1334 if (basr & BASR_PHASE_MATCH)
1335 printk(KERN_NOTICE "scsi%d: unknown interrupt, "
1336 "BASR 0x%x, MR 0x%x, SR 0x%x\n",
1337 HOSTNO, basr, NCR5380_read(MODE_REG),
1338 NCR5380_read(STATUS_REG));
1339 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1340 }
1341 } /* if !(SELECTION || PARITY) */
1342 handled = 1;
1343 } /* BASR & IRQ */ else {
1344 printk(KERN_NOTICE "scsi%d: interrupt without IRQ bit set in BASR, "
1345 "BASR 0x%X, MR 0x%X, SR 0x%x\n", HOSTNO, basr,
1346 NCR5380_read(MODE_REG), NCR5380_read(STATUS_REG));
1347 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1348 }
1349
1350 if (!done) {
1351 INT_PRINTK("scsi%d: in int routine, calling main\n", HOSTNO);
1352 /* Put a call to NCR5380_main() on the queue... */
1353 queue_main();
1354 }
1355 return IRQ_RETVAL(handled);
1356}
1357
1358#ifdef NCR5380_STATS
1359static void collect_stats(struct NCR5380_hostdata* hostdata, Scsi_Cmnd *cmd)
1360{
1361# ifdef NCR5380_STAT_LIMIT
1362 if (scsi_bufflen(cmd) > NCR5380_STAT_LIMIT)
1363# endif
1364 switch (cmd->cmnd[0]) {
1365 case WRITE:
1366 case WRITE_6:
1367 case WRITE_10:
1368 hostdata->time_write[cmd->device->id] += (jiffies - hostdata->timebase);
1369 /*hostdata->bytes_write[cmd->device->id] += scsi_bufflen(cmd);*/
1370 hostdata->pendingw--;
1371 break;
1372 case READ:
1373 case READ_6:
1374 case READ_10:
1375 hostdata->time_read[cmd->device->id] += (jiffies - hostdata->timebase);
1376 /*hostdata->bytes_read[cmd->device->id] += scsi_bufflen(cmd);*/
1377 hostdata->pendingr--;
1378 break;
1379 }
1380}
1381#endif
1382
1383/*
1384 * Function : int NCR5380_select (struct Scsi_Host *instance, Scsi_Cmnd *cmd,
1385 * int tag);
1386 *
1387 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1388 * including ARBITRATION, SELECTION, and initial message out for
1389 * IDENTIFY and queue messages.
1390 *
1391 * Inputs : instance - instantiation of the 5380 driver on which this
1392 * target lives, cmd - SCSI command to execute, tag - set to TAG_NEXT for
1393 * new tag, TAG_NONE for untagged queueing, otherwise set to the tag for
1394 * the command that is presently connected.
1395 *
1396 * Returns : -1 if selection could not execute for some reason,
1397 * 0 if selection succeeded or failed because the target
1398 * did not respond.
1399 *
1400 * Side effects :
1401 * If bus busy, arbitration failed, etc, NCR5380_select() will exit
1402 * with registers as they should have been on entry - ie
1403 * SELECT_ENABLE will be set appropriately, the NCR5380
1404 * will cease to drive any SCSI bus signals.
1405 *
1406 * If successful : I_T_L or I_T_L_Q nexus will be established,
1407 * instance->connected will be set to cmd.
1408 * SELECT interrupt will be disabled.
1409 *
1410 * If failed (no target) : cmd->scsi_done() will be called, and the
1411 * cmd->result host byte set to DID_BAD_TARGET.
1412 */
1413
1414static int NCR5380_select(struct Scsi_Host *instance, Scsi_Cmnd *cmd, int tag)
1415{
1416 SETUP_HOSTDATA(instance);
1417 unsigned char tmp[3], phase;
1418 unsigned char *data;
1419 int len;
1420 unsigned long timeout;
1421 unsigned long flags;
1422
1423 hostdata->restart_select = 0;
1424 NCR_PRINT(NDEBUG_ARBITRATION);
1425 ARB_PRINTK("scsi%d: starting arbitration, id = %d\n", HOSTNO,
1426 instance->this_id);
1427
1428 /*
1429 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1430 * data bus during SELECTION.
1431 */
1432
1433 local_irq_save(flags);
1434 if (hostdata->connected) {
1435 local_irq_restore(flags);
1436 return -1;
1437 }
1438 NCR5380_write(TARGET_COMMAND_REG, 0);
1439
1440 /*
1441 * Start arbitration.
1442 */
1443
1444 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1445 NCR5380_write(MODE_REG, MR_ARBITRATE);
1446
1447 local_irq_restore(flags);
1448
1449 /* Wait for arbitration logic to complete */
1450#if defined(NCR_TIMEOUT)
1451 {
1452 unsigned long timeout = jiffies + 2*NCR_TIMEOUT;
1453
1454 while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1455 time_before(jiffies, timeout) && !hostdata->connected)
1456 ;
1457 if (time_after_eq(jiffies, timeout)) {
1458 printk("scsi : arbitration timeout at %d\n", __LINE__);
1459 NCR5380_write(MODE_REG, MR_BASE);
1460 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1461 return -1;
1462 }
1463 }
1464#else /* NCR_TIMEOUT */
1465 while (!(NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_PROGRESS) &&
1466 !hostdata->connected)
1467 ;
1468#endif
1469
1470 ARB_PRINTK("scsi%d: arbitration complete\n", HOSTNO);
1471
1472 if (hostdata->connected) {
1473 NCR5380_write(MODE_REG, MR_BASE);
1474 return -1;
1475 }
1476 /*
1477 * The arbitration delay is 2.2us, but this is a minimum and there is
1478 * no maximum so we can safely sleep for ceil(2.2) usecs to accommodate
1479 * the integral nature of udelay().
1480 *
1481 */
1482
1483 udelay(3);
1484
1485 /* Check for lost arbitration */
1486 if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1487 (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1488 (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1489 hostdata->connected) {
1490 NCR5380_write(MODE_REG, MR_BASE);
1491 ARB_PRINTK("scsi%d: lost arbitration, deasserting MR_ARBITRATE\n",
1492 HOSTNO);
1493 return -1;
1494 }
1495
1496 /* after/during arbitration, BSY should be asserted.
1497 IBM DPES-31080 Version S31Q works now */
1498 /* Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman) */
1499 NCR5380_write(INITIATOR_COMMAND_REG,
1500 ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1501
1502 if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1503 hostdata->connected) {
1504 NCR5380_write(MODE_REG, MR_BASE);
1505 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1506 ARB_PRINTK("scsi%d: lost arbitration, deasserting ICR_ASSERT_SEL\n",
1507 HOSTNO);
1508 return -1;
1509 }
1510
1511 /*
1512 * Again, bus clear + bus settle time is 1.2us, however, this is
1513 * a minimum so we'll udelay ceil(1.2)
1514 */
1515
1516#ifdef CONFIG_ATARI_SCSI_TOSHIBA_DELAY
1517 /* ++roman: But some targets (see above :-) seem to need a bit more... */
1518 udelay(15);
1519#else
1520 udelay(2);
1521#endif
1522
1523 if (hostdata->connected) {
1524 NCR5380_write(MODE_REG, MR_BASE);
1525 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1526 return -1;
1527 }
1528
1529 ARB_PRINTK("scsi%d: won arbitration\n", HOSTNO);
1530
1531 /*
1532 * Now that we have won arbitration, start Selection process, asserting
1533 * the host and target ID's on the SCSI bus.
1534 */
1535
1536 NCR5380_write(OUTPUT_DATA_REG, (hostdata->id_mask | (1 << cmd->device->id)));
1537
1538 /*
1539 * Raise ATN while SEL is true before BSY goes false from arbitration,
1540 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1541 * phase immediately after selection.
1542 */
1543
1544 NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_BSY |
1545 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL ));
1546 NCR5380_write(MODE_REG, MR_BASE);
1547
1548 /*
1549 * Reselect interrupts must be turned off prior to the dropping of BSY,
1550 * otherwise we will trigger an interrupt.
1551 */
1552
1553 if (hostdata->connected) {
1554 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1555 return -1;
1556 }
1557
1558 NCR5380_write(SELECT_ENABLE_REG, 0);
1559
1560 /*
1561 * The initiator shall then wait at least two deskew delays and release
1562 * the BSY signal.
1563 */
1564 udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
1565
1566 /* Reset BSY */
1567 NCR5380_write(INITIATOR_COMMAND_REG, (ICR_BASE | ICR_ASSERT_DATA |
1568 ICR_ASSERT_ATN | ICR_ASSERT_SEL));
1569
1570 /*
1571 * Something weird happens when we cease to drive BSY - looks
1572 * like the board/chip is letting us do another read before the
1573 * appropriate propagation delay has expired, and we're confusing
1574 * a BSY signal from ourselves as the target's response to SELECTION.
1575 *
1576 * A small delay (the 'C++' frontend breaks the pipeline with an
1577 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1578 * tighter 'C' code breaks and requires this) solves the problem -
1579 * the 1 us delay is arbitrary, and only used because this delay will
1580 * be the same on other platforms and since it works here, it should
1581 * work there.
1582 *
1583 * wingel suggests that this could be due to failing to wait
1584 * one deskew delay.
1585 */
1586
1587 udelay(1);
1588
1589 SEL_PRINTK("scsi%d: selecting target %d\n", HOSTNO, cmd->device->id);
1590
1591 /*
1592 * The SCSI specification calls for a 250 ms timeout for the actual
1593 * selection.
1594 */
1595
1596 timeout = jiffies + 25;
1597
1598 /*
1599 * XXX very interesting - we're seeing a bounce where the BSY we
1600 * asserted is being reflected / still asserted (propagation delay?)
1601 * and it's detecting as true. Sigh.
1602 */
1603
1604#if 0
1605 /* ++roman: If a target conformed to the SCSI standard, it wouldn't assert
1606 * IO while SEL is true. But again, there are some disks out the in the
1607 * world that do that nevertheless. (Somebody claimed that this announces
1608 * reselection capability of the target.) So we better skip that test and
1609 * only wait for BSY... (Famous german words: Der Klügere gibt nach :-)
1610 */
1611
1612 while (time_before(jiffies, timeout) &&
1613 !(NCR5380_read(STATUS_REG) & (SR_BSY | SR_IO)))
1614 ;
1615
1616 if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1617 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1618 NCR5380_reselect(instance);
1619 printk(KERN_ERR "scsi%d: reselection after won arbitration?\n",
1620 HOSTNO);
1621 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1622 return -1;
1623 }
1624#else
1625 while (time_before(jiffies, timeout) && !(NCR5380_read(STATUS_REG) & SR_BSY))
1626 ;
1627#endif
1628
1629 /*
1630 * No less than two deskew delays after the initiator detects the
1631 * BSY signal is true, it shall release the SEL signal and may
1632 * change the DATA BUS. -wingel
1633 */
1634
1635 udelay(1);
1636
1637 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1638
1639 if (!(NCR5380_read(STATUS_REG) & SR_BSY)) {
1640 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1641 if (hostdata->targets_present & (1 << cmd->device->id)) {
1642 printk(KERN_ERR "scsi%d: weirdness\n", HOSTNO);
1643 if (hostdata->restart_select)
1644 printk(KERN_NOTICE "\trestart select\n");
1645 NCR_PRINT(NDEBUG_ANY);
1646 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1647 return -1;
1648 }
1649 cmd->result = DID_BAD_TARGET << 16;
1650#ifdef NCR5380_STATS
1651 collect_stats(hostdata, cmd);
1652#endif
1653#ifdef SUPPORT_TAGS
1654 cmd_free_tag(cmd);
1655#endif
1656 cmd->scsi_done(cmd);
1657 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1658 SEL_PRINTK("scsi%d: target did not respond within 250ms\n", HOSTNO);
1659 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1660 return 0;
1661 }
1662
1663 hostdata->targets_present |= (1 << cmd->device->id);
1664
1665 /*
1666 * Since we followed the SCSI spec, and raised ATN while SEL
1667 * was true but before BSY was false during selection, the information
1668 * transfer phase should be a MESSAGE OUT phase so that we can send the
1669 * IDENTIFY message.
1670 *
1671 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1672 * message (2 bytes) with a tag ID that we increment with every command
1673 * until it wraps back to 0.
1674 *
1675 * XXX - it turns out that there are some broken SCSI-II devices,
1676 * which claim to support tagged queuing but fail when more than
1677 * some number of commands are issued at once.
1678 */
1679
1680 /* Wait for start of REQ/ACK handshake */
1681 while (!(NCR5380_read(STATUS_REG) & SR_REQ))
1682 ;
1683
1684 SEL_PRINTK("scsi%d: target %d selected, going into MESSAGE OUT phase.\n",
1685 HOSTNO, cmd->device->id);
1686 tmp[0] = IDENTIFY(1, cmd->device->lun);
1687
1688#ifdef SUPPORT_TAGS
1689 if (cmd->tag != TAG_NONE) {
1690 tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1691 tmp[2] = cmd->tag;
1692 len = 3;
1693 } else
1694 len = 1;
1695#else
1696 len = 1;
1697 cmd->tag = 0;
1698#endif /* SUPPORT_TAGS */
1699
1700 /* Send message(s) */
1701 data = tmp;
1702 phase = PHASE_MSGOUT;
1703 NCR5380_transfer_pio(instance, &phase, &len, &data);
1704 SEL_PRINTK("scsi%d: nexus established.\n", HOSTNO);
1705 /* XXX need to handle errors here */
1706 hostdata->connected = cmd;
1707#ifndef SUPPORT_TAGS
1708 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
1709#endif
1710
1711 initialize_SCp(cmd);
1712
1713 return 0;
1714}
1715
1716/*
1717 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1718 * unsigned char *phase, int *count, unsigned char **data)
1719 *
1720 * Purpose : transfers data in given phase using polled I/O
1721 *
1722 * Inputs : instance - instance of driver, *phase - pointer to
1723 * what phase is expected, *count - pointer to number of
1724 * bytes to transfer, **data - pointer to data pointer.
1725 *
1726 * Returns : -1 when different phase is entered without transferring
1727 * maximum number of bytes, 0 if all bytes are transferred or exit
1728 * is in same phase.
1729 *
1730 * Also, *phase, *count, *data are modified in place.
1731 *
1732 * XXX Note : handling for bus free may be useful.
1733 */
1734
1735/*
1736 * Note : this code is not as quick as it could be, however it
1737 * IS 100% reliable, and for the actual data transfer where speed
1738 * counts, we will always do a pseudo DMA or DMA transfer.
1739 */
1740
1741static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1742 unsigned char *phase, int *count,
1743 unsigned char **data)
1744{
1745 register unsigned char p = *phase, tmp;
1746 register int c = *count;
1747 register unsigned char *d = *data;
1748
1749 /*
1750 * The NCR5380 chip will only drive the SCSI bus when the
1751 * phase specified in the appropriate bits of the TARGET COMMAND
1752 * REGISTER match the STATUS REGISTER
1753 */
1754
1755 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1756
1757 do {
1758 /*
1759 * Wait for assertion of REQ, after which the phase bits will be
1760 * valid
1761 */
1762 while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1763 ;
1764
1765 HSH_PRINTK("scsi%d: REQ detected\n", HOSTNO);
1766
1767 /* Check for phase mismatch */
1768 if ((tmp & PHASE_MASK) != p) {
1769 PIO_PRINTK("scsi%d: phase mismatch\n", HOSTNO);
1770 NCR_PRINT_PHASE(NDEBUG_PIO);
1771 break;
1772 }
1773
1774 /* Do actual transfer from SCSI bus to / from memory */
1775 if (!(p & SR_IO))
1776 NCR5380_write(OUTPUT_DATA_REG, *d);
1777 else
1778 *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1779
1780 ++d;
1781
1782 /*
1783 * The SCSI standard suggests that in MSGOUT phase, the initiator
1784 * should drop ATN on the last byte of the message phase
1785 * after REQ has been asserted for the handshake but before
1786 * the initiator raises ACK.
1787 */
1788
1789 if (!(p & SR_IO)) {
1790 if (!((p & SR_MSG) && c > 1)) {
1791 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1792 NCR_PRINT(NDEBUG_PIO);
1793 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1794 ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1795 } else {
1796 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1797 ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1798 NCR_PRINT(NDEBUG_PIO);
1799 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1800 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1801 }
1802 } else {
1803 NCR_PRINT(NDEBUG_PIO);
1804 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1805 }
1806
1807 while (NCR5380_read(STATUS_REG) & SR_REQ)
1808 ;
1809
1810 HSH_PRINTK("scsi%d: req false, handshake complete\n", HOSTNO);
1811
1812 /*
1813 * We have several special cases to consider during REQ/ACK handshaking :
1814 * 1. We were in MSGOUT phase, and we are on the last byte of the
1815 * message. ATN must be dropped as ACK is dropped.
1816 *
1817 * 2. We are in a MSGIN phase, and we are on the last byte of the
1818 * message. We must exit with ACK asserted, so that the calling
1819 * code may raise ATN before dropping ACK to reject the message.
1820 *
1821 * 3. ACK and ATN are clear and the target may proceed as normal.
1822 */
1823 if (!(p == PHASE_MSGIN && c == 1)) {
1824 if (p == PHASE_MSGOUT && c > 1)
1825 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1826 else
1827 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1828 }
1829 } while (--c);
1830
1831 PIO_PRINTK("scsi%d: residual %d\n", HOSTNO, c);
1832
1833 *count = c;
1834 *data = d;
1835 tmp = NCR5380_read(STATUS_REG);
1836 /* The phase read from the bus is valid if either REQ is (already)
1837 * asserted or if ACK hasn't been released yet. The latter is the case if
1838 * we're in MSGIN and all wanted bytes have been received.
1839 */
1840 if ((tmp & SR_REQ) || (p == PHASE_MSGIN && c == 0))
1841 *phase = tmp & PHASE_MASK;
1842 else
1843 *phase = PHASE_UNKNOWN;
1844
1845 if (!c || (*phase == p))
1846 return 0;
1847 else
1848 return -1;
1849}
1850
1851/*
1852 * Function : do_abort (Scsi_Host *host)
1853 *
1854 * Purpose : abort the currently established nexus. Should only be
1855 * called from a routine which can drop into a
1856 *
1857 * Returns : 0 on success, -1 on failure.
1858 */
1859
1860static int do_abort(struct Scsi_Host *host)
1861{
1862 unsigned char tmp, *msgptr, phase;
1863 int len;
1864
1865 /* Request message out phase */
1866 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1867
1868 /*
1869 * Wait for the target to indicate a valid phase by asserting
1870 * REQ. Once this happens, we'll have either a MSGOUT phase
1871 * and can immediately send the ABORT message, or we'll have some
1872 * other phase and will have to source/sink data.
1873 *
1874 * We really don't care what value was on the bus or what value
1875 * the target sees, so we just handshake.
1876 */
1877
1878 while (!((tmp = NCR5380_read(STATUS_REG)) & SR_REQ))
1879 ;
1880
1881 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1882
1883 if ((tmp & PHASE_MASK) != PHASE_MSGOUT) {
1884 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1885 ICR_ASSERT_ACK);
1886 while (NCR5380_read(STATUS_REG) & SR_REQ)
1887 ;
1888 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1889 }
1890
1891 tmp = ABORT;
1892 msgptr = &tmp;
1893 len = 1;
1894 phase = PHASE_MSGOUT;
1895 NCR5380_transfer_pio(host, &phase, &len, &msgptr);
1896
1897 /*
1898 * If we got here, and the command completed successfully,
1899 * we're about to go into bus free state.
1900 */
1901
1902 return len ? -1 : 0;
1903}
1904
1905#if defined(REAL_DMA)
1906/*
1907 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1908 * unsigned char *phase, int *count, unsigned char **data)
1909 *
1910 * Purpose : transfers data in given phase using either real
1911 * or pseudo DMA.
1912 *
1913 * Inputs : instance - instance of driver, *phase - pointer to
1914 * what phase is expected, *count - pointer to number of
1915 * bytes to transfer, **data - pointer to data pointer.
1916 *
1917 * Returns : -1 when different phase is entered without transferring
1918 * maximum number of bytes, 0 if all bytes or transferred or exit
1919 * is in same phase.
1920 *
1921 * Also, *phase, *count, *data are modified in place.
1922 *
1923 */
1924
1925
1926static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1927 unsigned char *phase, int *count,
1928 unsigned char **data)
1929{
1930 SETUP_HOSTDATA(instance);
1931 register int c = *count;
1932 register unsigned char p = *phase;
1933 register unsigned char *d = *data;
1934 unsigned char tmp;
1935 unsigned long flags;
1936
1937 if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1938 *phase = tmp;
1939 return -1;
1940 }
1941
1942 if (atari_read_overruns && (p & SR_IO))
1943 c -= atari_read_overruns;
1944
1945 DMA_PRINTK("scsi%d: initializing DMA for %s, %d bytes %s %p\n",
1946 HOSTNO, (p & SR_IO) ? "reading" : "writing",
1947 c, (p & SR_IO) ? "to" : "from", d);
1948
1949 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1950
1951#ifdef REAL_DMA
1952 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_ENABLE_EOP_INTR | MR_MONITOR_BSY);
1953#endif /* def REAL_DMA */
1954
1955 if (IS_A_TT()) {
1956 /* On the Medusa, it is a must to initialize the DMA before
1957 * starting the NCR. This is also the cleaner way for the TT.
1958 */
1959 local_irq_save(flags);
1960 hostdata->dma_len = (p & SR_IO) ?
1961 NCR5380_dma_read_setup(instance, d, c) :
1962 NCR5380_dma_write_setup(instance, d, c);
1963 local_irq_restore(flags);
1964 }
1965
1966 if (p & SR_IO)
1967 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1968 else {
1969 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1970 NCR5380_write(START_DMA_SEND_REG, 0);
1971 }
1972
1973 if (!IS_A_TT()) {
1974 /* On the Falcon, the DMA setup must be done after the last */
1975 /* NCR access, else the DMA setup gets trashed!
1976 */
1977 local_irq_save(flags);
1978 hostdata->dma_len = (p & SR_IO) ?
1979 NCR5380_dma_read_setup(instance, d, c) :
1980 NCR5380_dma_write_setup(instance, d, c);
1981 local_irq_restore(flags);
1982 }
1983 return 0;
1984}
1985#endif /* defined(REAL_DMA) */
1986
1987/*
1988 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1989 *
1990 * Purpose : run through the various SCSI phases and do as the target
1991 * directs us to. Operates on the currently connected command,
1992 * instance->connected.
1993 *
1994 * Inputs : instance, instance for which we are doing commands
1995 *
1996 * Side effects : SCSI things happen, the disconnected queue will be
1997 * modified if a command disconnects, *instance->connected will
1998 * change.
1999 *
2000 * XXX Note : we need to watch for bus free or a reset condition here
2001 * to recover from an unexpected bus free condition.
2002 */
2003
2004static void NCR5380_information_transfer(struct Scsi_Host *instance)
2005{
2006 SETUP_HOSTDATA(instance);
2007 unsigned long flags;
2008 unsigned char msgout = NOP;
2009 int sink = 0;
2010 int len;
2011#if defined(REAL_DMA)
2012 int transfersize;
2013#endif
2014 unsigned char *data;
2015 unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
2016 Scsi_Cmnd *cmd = (Scsi_Cmnd *) hostdata->connected;
2017
2018 while (1) {
2019 tmp = NCR5380_read(STATUS_REG);
2020 /* We only have a valid SCSI phase when REQ is asserted */
2021 if (tmp & SR_REQ) {
2022 phase = (tmp & PHASE_MASK);
2023 if (phase != old_phase) {
2024 old_phase = phase;
2025 NCR_PRINT_PHASE(NDEBUG_INFORMATION);
2026 }
2027
2028 if (sink && (phase != PHASE_MSGOUT)) {
2029 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
2030
2031 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
2032 ICR_ASSERT_ACK);
2033 while (NCR5380_read(STATUS_REG) & SR_REQ)
2034 ;
2035 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2036 ICR_ASSERT_ATN);
2037 sink = 0;
2038 continue;
2039 }
2040
2041 switch (phase) {
2042 case PHASE_DATAOUT:
2043#if (NDEBUG & NDEBUG_NO_DATAOUT)
2044 printk("scsi%d: NDEBUG_NO_DATAOUT set, attempted DATAOUT "
2045 "aborted\n", HOSTNO);
2046 sink = 1;
2047 do_abort(instance);
2048 cmd->result = DID_ERROR << 16;
2049 cmd->scsi_done(cmd);
2050 return;
2051#endif
2052 case PHASE_DATAIN:
2053 /*
2054 * If there is no room left in the current buffer in the
2055 * scatter-gather list, move onto the next one.
2056 */
2057
2058 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
2059 ++cmd->SCp.buffer;
2060 --cmd->SCp.buffers_residual;
2061 cmd->SCp.this_residual = cmd->SCp.buffer->length;
2062 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
2063 /* ++roman: Try to merge some scatter-buffers if
2064 * they are at contiguous physical addresses.
2065 */
2066 merge_contiguous_buffers(cmd);
2067 INF_PRINTK("scsi%d: %d bytes and %d buffers left\n",
2068 HOSTNO, cmd->SCp.this_residual,
2069 cmd->SCp.buffers_residual);
2070 }
2071
2072 /*
2073 * The preferred transfer method is going to be
2074 * PSEUDO-DMA for systems that are strictly PIO,
2075 * since we can let the hardware do the handshaking.
2076 *
2077 * For this to work, we need to know the transfersize
2078 * ahead of time, since the pseudo-DMA code will sit
2079 * in an unconditional loop.
2080 */
2081
2082 /* ++roman: I suggest, this should be
2083 * #if def(REAL_DMA)
2084 * instead of leaving REAL_DMA out.
2085 */
2086
2087#if defined(REAL_DMA)
2088 if (!cmd->device->borken &&
2089 (transfersize = NCR5380_dma_xfer_len(instance,cmd,phase)) > 31) {
2090 len = transfersize;
2091 cmd->SCp.phase = phase;
2092 if (NCR5380_transfer_dma(instance, &phase,
2093 &len, (unsigned char **)&cmd->SCp.ptr)) {
2094 /*
2095 * If the watchdog timer fires, all future
2096 * accesses to this device will use the
2097 * polled-IO. */
2098 printk(KERN_NOTICE "scsi%d: switching target %d "
2099 "lun %d to slow handshake\n", HOSTNO,
2100 cmd->device->id, cmd->device->lun);
2101 cmd->device->borken = 1;
2102 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
2103 ICR_ASSERT_ATN);
2104 sink = 1;
2105 do_abort(instance);
2106 cmd->result = DID_ERROR << 16;
2107 cmd->scsi_done(cmd);
2108 /* XXX - need to source or sink data here, as appropriate */
2109 } else {
2110#ifdef REAL_DMA
2111 /* ++roman: When using real DMA,
2112 * information_transfer() should return after
2113 * starting DMA since it has nothing more to
2114 * do.
2115 */
2116 return;
2117#else
2118 cmd->SCp.this_residual -= transfersize - len;
2119#endif
2120 }
2121 } else
2122#endif /* defined(REAL_DMA) */
2123 NCR5380_transfer_pio(instance, &phase,
2124 (int *)&cmd->SCp.this_residual,
2125 (unsigned char **)&cmd->SCp.ptr);
2126 break;
2127 case PHASE_MSGIN:
2128 len = 1;
2129 data = &tmp;
2130 NCR5380_write(SELECT_ENABLE_REG, 0); /* disable reselects */
2131 NCR5380_transfer_pio(instance, &phase, &len, &data);
2132 cmd->SCp.Message = tmp;
2133
2134 switch (tmp) {
2135 /*
2136 * Linking lets us reduce the time required to get the
2137 * next command out to the device, hopefully this will
2138 * mean we don't waste another revolution due to the delays
2139 * required by ARBITRATION and another SELECTION.
2140 *
2141 * In the current implementation proposal, low level drivers
2142 * merely have to start the next command, pointed to by
2143 * next_link, done() is called as with unlinked commands.
2144 */
2145#ifdef LINKED
2146 case LINKED_CMD_COMPLETE:
2147 case LINKED_FLG_CMD_COMPLETE:
2148 /* Accept message by clearing ACK */
2149 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2150
2151 LNK_PRINTK("scsi%d: target %d lun %d linked command "
2152 "complete.\n", HOSTNO, cmd->device->id, cmd->device->lun);
2153
2154 /* Enable reselect interrupts */
2155 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2156 /*
2157 * Sanity check : A linked command should only terminate
2158 * with one of these messages if there are more linked
2159 * commands available.
2160 */
2161
2162 if (!cmd->next_link) {
2163 printk(KERN_NOTICE "scsi%d: target %d lun %d "
2164 "linked command complete, no next_link\n",
2165 HOSTNO, cmd->device->id, cmd->device->lun);
2166 sink = 1;
2167 do_abort(instance);
2168 return;
2169 }
2170
2171 initialize_SCp(cmd->next_link);
2172 /* The next command is still part of this process; copy it
2173 * and don't free it! */
2174 cmd->next_link->tag = cmd->tag;
2175 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2176 LNK_PRINTK("scsi%d: target %d lun %d linked request "
2177 "done, calling scsi_done().\n",
2178 HOSTNO, cmd->device->id, cmd->device->lun);
2179#ifdef NCR5380_STATS
2180 collect_stats(hostdata, cmd);
2181#endif
2182 cmd->scsi_done(cmd);
2183 cmd = hostdata->connected;
2184 break;
2185#endif /* def LINKED */
2186 case ABORT:
2187 case COMMAND_COMPLETE:
2188 /* Accept message by clearing ACK */
2189 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2190 /* ++guenther: possible race with Falcon locking */
2191 falcon_dont_release++;
2192 hostdata->connected = NULL;
2193 QU_PRINTK("scsi%d: command for target %d, lun %d "
2194 "completed\n", HOSTNO, cmd->device->id, cmd->device->lun);
2195#ifdef SUPPORT_TAGS
2196 cmd_free_tag(cmd);
2197 if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2198 /* Turn a QUEUE FULL status into BUSY, I think the
2199 * mid level cannot handle QUEUE FULL :-( (The
2200 * command is retried after BUSY). Also update our
2201 * queue size to the number of currently issued
2202 * commands now.
2203 */
2204 /* ++Andreas: the mid level code knows about
2205 QUEUE_FULL now. */
2206 TAG_ALLOC *ta = &TagAlloc[cmd->device->id][cmd->device->lun];
2207 TAG_PRINTK("scsi%d: target %d lun %d returned "
2208 "QUEUE_FULL after %d commands\n",
2209 HOSTNO, cmd->device->id, cmd->device->lun,
2210 ta->nr_allocated);
2211 if (ta->queue_size > ta->nr_allocated)
2212 ta->nr_allocated = ta->queue_size;
2213 }
2214#else
2215 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2216#endif
2217 /* Enable reselect interrupts */
2218 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2219
2220 /*
2221 * I'm not sure what the correct thing to do here is :
2222 *
2223 * If the command that just executed is NOT a request
2224 * sense, the obvious thing to do is to set the result
2225 * code to the values of the stored parameters.
2226 *
2227 * If it was a REQUEST SENSE command, we need some way to
2228 * differentiate between the failure code of the original
2229 * and the failure code of the REQUEST sense - the obvious
2230 * case is success, where we fall through and leave the
2231 * result code unchanged.
2232 *
2233 * The non-obvious place is where the REQUEST SENSE failed
2234 */
2235
2236 if (cmd->cmnd[0] != REQUEST_SENSE)
2237 cmd->result = cmd->SCp.Status | (cmd->SCp.Message << 8);
2238 else if (status_byte(cmd->SCp.Status) != GOOD)
2239 cmd->result = (cmd->result & 0x00ffff) | (DID_ERROR << 16);
2240
2241#ifdef AUTOSENSE
2242 if ((cmd->cmnd[0] == REQUEST_SENSE) &&
2243 hostdata->ses.cmd_len) {
2244 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
2245 hostdata->ses.cmd_len = 0 ;
2246 }
2247
2248 if ((cmd->cmnd[0] != REQUEST_SENSE) &&
2249 (status_byte(cmd->SCp.Status) == CHECK_CONDITION)) {
2250 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
2251
2252 ASEN_PRINTK("scsi%d: performing request sense\n", HOSTNO);
2253
2254 local_irq_save(flags);
2255 LIST(cmd,hostdata->issue_queue);
2256 SET_NEXT(cmd, hostdata->issue_queue);
2257 hostdata->issue_queue = (Scsi_Cmnd *) cmd;
2258 local_irq_restore(flags);
2259 QU_PRINTK("scsi%d: REQUEST SENSE added to head of "
2260 "issue queue\n", H_NO(cmd));
2261 } else
2262#endif /* def AUTOSENSE */
2263 {
2264#ifdef NCR5380_STATS
2265 collect_stats(hostdata, cmd);
2266#endif
2267 cmd->scsi_done(cmd);
2268 }
2269
2270 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2271 /*
2272 * Restore phase bits to 0 so an interrupted selection,
2273 * arbitration can resume.
2274 */
2275 NCR5380_write(TARGET_COMMAND_REG, 0);
2276
2277 while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2278 barrier();
2279
2280 falcon_dont_release--;
2281 /* ++roman: For Falcon SCSI, release the lock on the
2282 * ST-DMA here if no other commands are waiting on the
2283 * disconnected queue.
2284 */
2285 falcon_release_lock_if_possible(hostdata);
2286 return;
2287 case MESSAGE_REJECT:
2288 /* Accept message by clearing ACK */
2289 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2290 /* Enable reselect interrupts */
2291 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2292 switch (hostdata->last_message) {
2293 case HEAD_OF_QUEUE_TAG:
2294 case ORDERED_QUEUE_TAG:
2295 case SIMPLE_QUEUE_TAG:
2296 /* The target obviously doesn't support tagged
2297 * queuing, even though it announced this ability in
2298 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2299 * clear 'tagged_supported' and lock the LUN, since
2300 * the command is treated as untagged further on.
2301 */
2302 cmd->device->tagged_supported = 0;
2303 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2304 cmd->tag = TAG_NONE;
2305 TAG_PRINTK("scsi%d: target %d lun %d rejected "
2306 "QUEUE_TAG message; tagged queuing "
2307 "disabled\n",
2308 HOSTNO, cmd->device->id, cmd->device->lun);
2309 break;
2310 }
2311 break;
2312 case DISCONNECT:
2313 /* Accept message by clearing ACK */
2314 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2315 local_irq_save(flags);
2316 cmd->device->disconnect = 1;
2317 LIST(cmd,hostdata->disconnected_queue);
2318 SET_NEXT(cmd, hostdata->disconnected_queue);
2319 hostdata->connected = NULL;
2320 hostdata->disconnected_queue = cmd;
2321 local_irq_restore(flags);
2322 QU_PRINTK("scsi%d: command for target %d lun %d was "
2323 "moved from connected to the "
2324 "disconnected_queue\n", HOSTNO,
2325 cmd->device->id, cmd->device->lun);
2326 /*
2327 * Restore phase bits to 0 so an interrupted selection,
2328 * arbitration can resume.
2329 */
2330 NCR5380_write(TARGET_COMMAND_REG, 0);
2331
2332 /* Enable reselect interrupts */
2333 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2334 /* Wait for bus free to avoid nasty timeouts */
2335 while ((NCR5380_read(STATUS_REG) & SR_BSY) && !hostdata->connected)
2336 barrier();
2337 return;
2338 /*
2339 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2340 * operation, in violation of the SCSI spec so we can safely
2341 * ignore SAVE/RESTORE pointers calls.
2342 *
2343 * Unfortunately, some disks violate the SCSI spec and
2344 * don't issue the required SAVE_POINTERS message before
2345 * disconnecting, and we have to break spec to remain
2346 * compatible.
2347 */
2348 case SAVE_POINTERS:
2349 case RESTORE_POINTERS:
2350 /* Accept message by clearing ACK */
2351 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2352 /* Enable reselect interrupts */
2353 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2354 break;
2355 case EXTENDED_MESSAGE:
2356 /*
2357 * Extended messages are sent in the following format :
2358 * Byte
2359 * 0 EXTENDED_MESSAGE == 1
2360 * 1 length (includes one byte for code, doesn't
2361 * include first two bytes)
2362 * 2 code
2363 * 3..length+1 arguments
2364 *
2365 * Start the extended message buffer with the EXTENDED_MESSAGE
2366 * byte, since spi_print_msg() wants the whole thing.
2367 */
2368 extended_msg[0] = EXTENDED_MESSAGE;
2369 /* Accept first byte by clearing ACK */
2370 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2371
2372 EXT_PRINTK("scsi%d: receiving extended message\n", HOSTNO);
2373
2374 len = 2;
2375 data = extended_msg + 1;
2376 phase = PHASE_MSGIN;
2377 NCR5380_transfer_pio(instance, &phase, &len, &data);
2378 EXT_PRINTK("scsi%d: length=%d, code=0x%02x\n", HOSTNO,
2379 (int)extended_msg[1], (int)extended_msg[2]);
2380
2381 if (!len && extended_msg[1] <=
2382 (sizeof(extended_msg) - 1)) {
2383 /* Accept third byte by clearing ACK */
2384 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2385 len = extended_msg[1] - 1;
2386 data = extended_msg + 3;
2387 phase = PHASE_MSGIN;
2388
2389 NCR5380_transfer_pio(instance, &phase, &len, &data);
2390 EXT_PRINTK("scsi%d: message received, residual %d\n",
2391 HOSTNO, len);
2392
2393 switch (extended_msg[2]) {
2394 case EXTENDED_SDTR:
2395 case EXTENDED_WDTR:
2396 case EXTENDED_MODIFY_DATA_POINTER:
2397 case EXTENDED_EXTENDED_IDENTIFY:
2398 tmp = 0;
2399 }
2400 } else if (len) {
2401 printk(KERN_NOTICE "scsi%d: error receiving "
2402 "extended message\n", HOSTNO);
2403 tmp = 0;
2404 } else {
2405 printk(KERN_NOTICE "scsi%d: extended message "
2406 "code %02x length %d is too long\n",
2407 HOSTNO, extended_msg[2], extended_msg[1]);
2408 tmp = 0;
2409 }
2410 /* Fall through to reject message */
2411
2412 /*
2413 * If we get something weird that we aren't expecting,
2414 * reject it.
2415 */
2416 default:
2417 if (!tmp) {
2418 printk(KERN_DEBUG "scsi%d: rejecting message ", HOSTNO);
2419 spi_print_msg(extended_msg);
2420 printk("\n");
2421 } else if (tmp != EXTENDED_MESSAGE)
2422 printk(KERN_DEBUG "scsi%d: rejecting unknown "
2423 "message %02x from target %d, lun %d\n",
2424 HOSTNO, tmp, cmd->device->id, cmd->device->lun);
2425 else
2426 printk(KERN_DEBUG "scsi%d: rejecting unknown "
2427 "extended message "
2428 "code %02x, length %d from target %d, lun %d\n",
2429 HOSTNO, extended_msg[1], extended_msg[0],
2430 cmd->device->id, cmd->device->lun);
2431
2432
2433 msgout = MESSAGE_REJECT;
2434 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2435 break;
2436 } /* switch (tmp) */
2437 break;
2438 case PHASE_MSGOUT:
2439 len = 1;
2440 data = &msgout;
2441 hostdata->last_message = msgout;
2442 NCR5380_transfer_pio(instance, &phase, &len, &data);
2443 if (msgout == ABORT) {
2444#ifdef SUPPORT_TAGS
2445 cmd_free_tag(cmd);
2446#else
2447 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2448#endif
2449 hostdata->connected = NULL;
2450 cmd->result = DID_ERROR << 16;
2451#ifdef NCR5380_STATS
2452 collect_stats(hostdata, cmd);
2453#endif
2454 cmd->scsi_done(cmd);
2455 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2456 falcon_release_lock_if_possible(hostdata);
2457 return;
2458 }
2459 msgout = NOP;
2460 break;
2461 case PHASE_CMDOUT:
2462 len = cmd->cmd_len;
2463 data = cmd->cmnd;
2464 /*
2465 * XXX for performance reasons, on machines with a
2466 * PSEUDO-DMA architecture we should probably
2467 * use the dma transfer function.
2468 */
2469 NCR5380_transfer_pio(instance, &phase, &len, &data);
2470 break;
2471 case PHASE_STATIN:
2472 len = 1;
2473 data = &tmp;
2474 NCR5380_transfer_pio(instance, &phase, &len, &data);
2475 cmd->SCp.Status = tmp;
2476 break;
2477 default:
2478 printk("scsi%d: unknown phase\n", HOSTNO);
2479 NCR_PRINT(NDEBUG_ANY);
2480 } /* switch(phase) */
2481 } /* if (tmp * SR_REQ) */
2482 } /* while (1) */
2483}
2484
2485/*
2486 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2487 *
2488 * Purpose : does reselection, initializing the instance->connected
2489 * field to point to the Scsi_Cmnd for which the I_T_L or I_T_L_Q
2490 * nexus has been reestablished,
2491 *
2492 * Inputs : instance - this instance of the NCR5380.
2493 *
2494 */
2495
2496
2497static void NCR5380_reselect(struct Scsi_Host *instance)
2498{
2499 SETUP_HOSTDATA(instance);
2500 unsigned char target_mask;
2501 unsigned char lun, phase;
2502 int len;
2503#ifdef SUPPORT_TAGS
2504 unsigned char tag;
2505#endif
2506 unsigned char msg[3];
2507 unsigned char *data;
2508 Scsi_Cmnd *tmp = NULL, *prev;
2509/* unsigned long flags; */
2510
2511 /*
2512 * Disable arbitration, etc. since the host adapter obviously
2513 * lost, and tell an interrupted NCR5380_select() to restart.
2514 */
2515
2516 NCR5380_write(MODE_REG, MR_BASE);
2517 hostdata->restart_select = 1;
2518
2519 target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2520
2521 RSL_PRINTK("scsi%d: reselect\n", HOSTNO);
2522
2523 /*
2524 * At this point, we have detected that our SCSI ID is on the bus,
2525 * SEL is true and BSY was false for at least one bus settle delay
2526 * (400 ns).
2527 *
2528 * We must assert BSY ourselves, until the target drops the SEL
2529 * signal.
2530 */
2531
2532 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2533
2534 while (NCR5380_read(STATUS_REG) & SR_SEL)
2535 ;
2536 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2537
2538 /*
2539 * Wait for target to go into MSGIN.
2540 */
2541
2542 while (!(NCR5380_read(STATUS_REG) & SR_REQ))
2543 ;
2544
2545 len = 1;
2546 data = msg;
2547 phase = PHASE_MSGIN;
2548 NCR5380_transfer_pio(instance, &phase, &len, &data);
2549
2550 if (!(msg[0] & 0x80)) {
2551 printk(KERN_DEBUG "scsi%d: expecting IDENTIFY message, got ", HOSTNO);
2552 spi_print_msg(msg);
2553 do_abort(instance);
2554 return;
2555 }
2556 lun = (msg[0] & 0x07);
2557
2558#ifdef SUPPORT_TAGS
2559 /* If the phase is still MSGIN, the target wants to send some more
2560 * messages. In case it supports tagged queuing, this is probably a
2561 * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2562 */
2563 tag = TAG_NONE;
2564 if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2565 /* Accept previous IDENTIFY message by clearing ACK */
2566 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2567 len = 2;
2568 data = msg + 1;
2569 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2570 msg[1] == SIMPLE_QUEUE_TAG)
2571 tag = msg[2];
2572 TAG_PRINTK("scsi%d: target mask %02x, lun %d sent tag %d at "
2573 "reselection\n", HOSTNO, target_mask, lun, tag);
2574 }
2575#endif
2576
2577 /*
2578 * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
2579 * just reestablished, and remove it from the disconnected queue.
2580 */
2581
2582 for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue, prev = NULL;
2583 tmp; prev = tmp, tmp = NEXT(tmp)) {
2584 if ((target_mask == (1 << tmp->device->id)) && (lun == tmp->device->lun)
2585#ifdef SUPPORT_TAGS
2586 && (tag == tmp->tag)
2587#endif
2588 ) {
2589 /* ++guenther: prevent race with falcon_release_lock */
2590 falcon_dont_release++;
2591 if (prev) {
2592 REMOVE(prev, NEXT(prev), tmp, NEXT(tmp));
2593 SET_NEXT(prev, NEXT(tmp));
2594 } else {
2595 REMOVE(-1, hostdata->disconnected_queue, tmp, NEXT(tmp));
2596 hostdata->disconnected_queue = NEXT(tmp);
2597 }
2598 SET_NEXT(tmp, NULL);
2599 break;
2600 }
2601 }
2602
2603 if (!tmp) {
2604 printk(KERN_WARNING "scsi%d: warning: target bitmask %02x lun %d "
2605#ifdef SUPPORT_TAGS
2606 "tag %d "
2607#endif
2608 "not in disconnected_queue.\n",
2609 HOSTNO, target_mask, lun
2610#ifdef SUPPORT_TAGS
2611 , tag
2612#endif
2613 );
2614 /*
2615 * Since we have an established nexus that we can't do anything
2616 * with, we must abort it.
2617 */
2618 do_abort(instance);
2619 return;
2620 }
2621
2622 /* Accept message by clearing ACK */
2623 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2624
2625 hostdata->connected = tmp;
2626 RSL_PRINTK("scsi%d: nexus established, target = %d, lun = %d, tag = %d\n",
2627 HOSTNO, tmp->device->id, tmp->device->lun, tmp->tag);
2628 falcon_dont_release--;
2629}
2630
2631
2632/*
2633 * Function : int NCR5380_abort (Scsi_Cmnd *cmd)
2634 *
2635 * Purpose : abort a command
2636 *
2637 * Inputs : cmd - the Scsi_Cmnd to abort, code - code to set the
2638 * host byte of the result field to, if zero DID_ABORTED is
2639 * used.
2640 *
2641 * Returns : 0 - success, -1 on failure.
2642 *
2643 * XXX - there is no way to abort the command that is currently
2644 * connected, you have to wait for it to complete. If this is
2645 * a problem, we could implement longjmp() / setjmp(), setjmp()
2646 * called where the loop started in NCR5380_main().
2647 */
2648
2649static
2650int NCR5380_abort(Scsi_Cmnd *cmd)
2651{
2652 struct Scsi_Host *instance = cmd->device->host;
2653 SETUP_HOSTDATA(instance);
2654 Scsi_Cmnd *tmp, **prev;
2655 unsigned long flags;
2656
2657 printk(KERN_NOTICE "scsi%d: aborting command\n", HOSTNO);
2658 scsi_print_command(cmd);
2659
2660 NCR5380_print_status(instance);
2661
2662 local_irq_save(flags);
2663
2664 if (!IS_A_TT() && !falcon_got_lock)
2665 printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_abort\n",
2666 HOSTNO);
2667
2668 ABRT_PRINTK("scsi%d: abort called basr 0x%02x, sr 0x%02x\n", HOSTNO,
2669 NCR5380_read(BUS_AND_STATUS_REG),
2670 NCR5380_read(STATUS_REG));
2671
2672#if 1
2673 /*
2674 * Case 1 : If the command is the currently executing command,
2675 * we'll set the aborted flag and return control so that
2676 * information transfer routine can exit cleanly.
2677 */
2678
2679 if (hostdata->connected == cmd) {
2680
2681 ABRT_PRINTK("scsi%d: aborting connected command\n", HOSTNO);
2682 /*
2683 * We should perform BSY checking, and make sure we haven't slipped
2684 * into BUS FREE.
2685 */
2686
2687 /* NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_ATN); */
2688 /*
2689 * Since we can't change phases until we've completed the current
2690 * handshake, we have to source or sink a byte of data if the current
2691 * phase is not MSGOUT.
2692 */
2693
2694 /*
2695 * Return control to the executing NCR drive so we can clear the
2696 * aborted flag and get back into our main loop.
2697 */
2698
2699 if (do_abort(instance) == 0) {
2700 hostdata->aborted = 1;
2701 hostdata->connected = NULL;
2702 cmd->result = DID_ABORT << 16;
2703#ifdef SUPPORT_TAGS
2704 cmd_free_tag(cmd);
2705#else
2706 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2707#endif
2708 local_irq_restore(flags);
2709 cmd->scsi_done(cmd);
2710 falcon_release_lock_if_possible(hostdata);
2711 return SCSI_ABORT_SUCCESS;
2712 } else {
2713/* local_irq_restore(flags); */
2714 printk("scsi%d: abort of connected command failed!\n", HOSTNO);
2715 return SCSI_ABORT_ERROR;
2716 }
2717 }
2718#endif
2719
2720 /*
2721 * Case 2 : If the command hasn't been issued yet, we simply remove it
2722 * from the issue queue.
2723 */
2724 for (prev = (Scsi_Cmnd **)&(hostdata->issue_queue),
2725 tmp = (Scsi_Cmnd *)hostdata->issue_queue;
2726 tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2727 if (cmd == tmp) {
2728 REMOVE(5, *prev, tmp, NEXT(tmp));
2729 (*prev) = NEXT(tmp);
2730 SET_NEXT(tmp, NULL);
2731 tmp->result = DID_ABORT << 16;
2732 local_irq_restore(flags);
2733 ABRT_PRINTK("scsi%d: abort removed command from issue queue.\n",
2734 HOSTNO);
2735 /* Tagged queuing note: no tag to free here, hasn't been assigned
2736 * yet... */
2737 tmp->scsi_done(tmp);
2738 falcon_release_lock_if_possible(hostdata);
2739 return SCSI_ABORT_SUCCESS;
2740 }
2741 }
2742
2743 /*
2744 * Case 3 : If any commands are connected, we're going to fail the abort
2745 * and let the high level SCSI driver retry at a later time or
2746 * issue a reset.
2747 *
2748 * Timeouts, and therefore aborted commands, will be highly unlikely
2749 * and handling them cleanly in this situation would make the common
2750 * case of noresets less efficient, and would pollute our code. So,
2751 * we fail.
2752 */
2753
2754 if (hostdata->connected) {
2755 local_irq_restore(flags);
2756 ABRT_PRINTK("scsi%d: abort failed, command connected.\n", HOSTNO);
2757 return SCSI_ABORT_SNOOZE;
2758 }
2759
2760 /*
2761 * Case 4: If the command is currently disconnected from the bus, and
2762 * there are no connected commands, we reconnect the I_T_L or
2763 * I_T_L_Q nexus associated with it, go into message out, and send
2764 * an abort message.
2765 *
2766 * This case is especially ugly. In order to reestablish the nexus, we
2767 * need to call NCR5380_select(). The easiest way to implement this
2768 * function was to abort if the bus was busy, and let the interrupt
2769 * handler triggered on the SEL for reselect take care of lost arbitrations
2770 * where necessary, meaning interrupts need to be enabled.
2771 *
2772 * When interrupts are enabled, the queues may change - so we
2773 * can't remove it from the disconnected queue before selecting it
2774 * because that could cause a failure in hashing the nexus if that
2775 * device reselected.
2776 *
2777 * Since the queues may change, we can't use the pointers from when we
2778 * first locate it.
2779 *
2780 * So, we must first locate the command, and if NCR5380_select()
2781 * succeeds, then issue the abort, relocate the command and remove
2782 * it from the disconnected queue.
2783 */
2784
2785 for (tmp = (Scsi_Cmnd *) hostdata->disconnected_queue; tmp;
2786 tmp = NEXT(tmp)) {
2787 if (cmd == tmp) {
2788 local_irq_restore(flags);
2789 ABRT_PRINTK("scsi%d: aborting disconnected command.\n", HOSTNO);
2790
2791 if (NCR5380_select(instance, cmd, (int)cmd->tag))
2792 return SCSI_ABORT_BUSY;
2793
2794 ABRT_PRINTK("scsi%d: nexus reestablished.\n", HOSTNO);
2795
2796 do_abort(instance);
2797
2798 local_irq_save(flags);
2799 for (prev = (Scsi_Cmnd **)&(hostdata->disconnected_queue),
2800 tmp = (Scsi_Cmnd *)hostdata->disconnected_queue;
2801 tmp; prev = NEXTADDR(tmp), tmp = NEXT(tmp)) {
2802 if (cmd == tmp) {
2803 REMOVE(5, *prev, tmp, NEXT(tmp));
2804 *prev = NEXT(tmp);
2805 SET_NEXT(tmp, NULL);
2806 tmp->result = DID_ABORT << 16;
2807 /* We must unlock the tag/LUN immediately here, since the
2808 * target goes to BUS FREE and doesn't send us another
2809 * message (COMMAND_COMPLETE or the like)
2810 */
2811#ifdef SUPPORT_TAGS
2812 cmd_free_tag(tmp);
2813#else
2814 hostdata->busy[cmd->device->id] &= ~(1 << cmd->device->lun);
2815#endif
2816 local_irq_restore(flags);
2817 tmp->scsi_done(tmp);
2818 falcon_release_lock_if_possible(hostdata);
2819 return SCSI_ABORT_SUCCESS;
2820 }
2821 }
2822 }
2823 }
2824
2825 /*
2826 * Case 5 : If we reached this point, the command was not found in any of
2827 * the queues.
2828 *
2829 * We probably reached this point because of an unlikely race condition
2830 * between the command completing successfully and the abortion code,
2831 * so we won't panic, but we will notify the user in case something really
2832 * broke.
2833 */
2834
2835 local_irq_restore(flags);
2836 printk(KERN_INFO "scsi%d: warning : SCSI command probably completed successfully before abortion\n", HOSTNO);
2837
2838 /* Maybe it is sufficient just to release the ST-DMA lock... (if
2839 * possible at all) At least, we should check if the lock could be
2840 * released after the abort, in case it is kept due to some bug.
2841 */
2842 falcon_release_lock_if_possible(hostdata);
2843
2844 return SCSI_ABORT_NOT_RUNNING;
2845}
2846
2847
2848/*
2849 * Function : int NCR5380_reset (Scsi_Cmnd *cmd)
2850 *
2851 * Purpose : reset the SCSI bus.
2852 *
2853 * Returns : SCSI_RESET_WAKEUP
2854 *
2855 */
2856
2857static int NCR5380_bus_reset(Scsi_Cmnd *cmd)
2858{
2859 SETUP_HOSTDATA(cmd->device->host);
2860 int i;
2861 unsigned long flags;
2862#if 1
2863 Scsi_Cmnd *connected, *disconnected_queue;
2864#endif
2865
2866 if (!IS_A_TT() && !falcon_got_lock)
2867 printk(KERN_ERR "scsi%d: !!BINGO!! Falcon has no lock in NCR5380_reset\n",
2868 H_NO(cmd));
2869
2870 NCR5380_print_status(cmd->device->host);
2871
2872 /* get in phase */
2873 NCR5380_write(TARGET_COMMAND_REG,
2874 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG)));
2875 /* assert RST */
2876 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
2877 udelay(40);
2878 /* reset NCR registers */
2879 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2880 NCR5380_write(MODE_REG, MR_BASE);
2881 NCR5380_write(TARGET_COMMAND_REG, 0);
2882 NCR5380_write(SELECT_ENABLE_REG, 0);
2883 /* ++roman: reset interrupt condition! otherwise no interrupts don't get
2884 * through anymore ... */
2885 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
2886
2887#if 1 /* XXX Should now be done by midlevel code, but it's broken XXX */
2888 /* XXX see below XXX */
2889
2890 /* MSch: old-style reset: actually abort all command processing here */
2891
2892 /* After the reset, there are no more connected or disconnected commands
2893 * and no busy units; to avoid problems with re-inserting the commands
2894 * into the issue_queue (via scsi_done()), the aborted commands are
2895 * remembered in local variables first.
2896 */
2897 local_irq_save(flags);
2898 connected = (Scsi_Cmnd *)hostdata->connected;
2899 hostdata->connected = NULL;
2900 disconnected_queue = (Scsi_Cmnd *)hostdata->disconnected_queue;
2901 hostdata->disconnected_queue = NULL;
2902#ifdef SUPPORT_TAGS
2903 free_all_tags();
2904#endif
2905 for (i = 0; i < 8; ++i)
2906 hostdata->busy[i] = 0;
2907#ifdef REAL_DMA
2908 hostdata->dma_len = 0;
2909#endif
2910 local_irq_restore(flags);
2911
2912 /* In order to tell the mid-level code which commands were aborted,
2913 * set the command status to DID_RESET and call scsi_done() !!!
2914 * This ultimately aborts processing of these commands in the mid-level.
2915 */
2916
2917 if ((cmd = connected)) {
2918 ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2919 cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2920 cmd->scsi_done(cmd);
2921 }
2922
2923 for (i = 0; (cmd = disconnected_queue); ++i) {
2924 disconnected_queue = NEXT(cmd);
2925 SET_NEXT(cmd, NULL);
2926 cmd->result = (cmd->result & 0xffff) | (DID_RESET << 16);
2927 cmd->scsi_done(cmd);
2928 }
2929 if (i > 0)
2930 ABRT_PRINTK("scsi: reset aborted %d disconnected command(s)\n", i);
2931
2932 /* The Falcon lock should be released after a reset...
2933 */
2934 /* ++guenther: moved to atari_scsi_reset(), to prevent a race between
2935 * unlocking and enabling dma interrupt.
2936 */
2937/* falcon_release_lock_if_possible( hostdata );*/
2938
2939 /* since all commands have been explicitly terminated, we need to tell
2940 * the midlevel code that the reset was SUCCESSFUL, and there is no
2941 * need to 'wake up' the commands by a request_sense
2942 */
2943 return SCSI_RESET_SUCCESS | SCSI_RESET_BUS_RESET;
2944#else /* 1 */
2945
2946 /* MSch: new-style reset handling: let the mid-level do what it can */
2947
2948 /* ++guenther: MID-LEVEL IS STILL BROKEN.
2949 * Mid-level is supposed to requeue all commands that were active on the
2950 * various low-level queues. In fact it does this, but that's not enough
2951 * because all these commands are subject to timeout. And if a timeout
2952 * happens for any removed command, *_abort() is called but all queues
2953 * are now empty. Abort then gives up the falcon lock, which is fatal,
2954 * since the mid-level will queue more commands and must have the lock
2955 * (it's all happening inside timer interrupt handler!!).
2956 * Even worse, abort will return NOT_RUNNING for all those commands not
2957 * on any queue, so they won't be retried ...
2958 *
2959 * Conclusion: either scsi.c disables timeout for all resetted commands
2960 * immediately, or we lose! As of linux-2.0.20 it doesn't.
2961 */
2962
2963 /* After the reset, there are no more connected or disconnected commands
2964 * and no busy units; so clear the low-level status here to avoid
2965 * conflicts when the mid-level code tries to wake up the affected
2966 * commands!
2967 */
2968
2969 if (hostdata->issue_queue)
2970 ABRT_PRINTK("scsi%d: reset aborted issued command(s)\n", H_NO(cmd));
2971 if (hostdata->connected)
2972 ABRT_PRINTK("scsi%d: reset aborted a connected command\n", H_NO(cmd));
2973 if (hostdata->disconnected_queue)
2974 ABRT_PRINTK("scsi%d: reset aborted disconnected command(s)\n", H_NO(cmd));
2975
2976 local_irq_save(flags);
2977 hostdata->issue_queue = NULL;
2978 hostdata->connected = NULL;
2979 hostdata->disconnected_queue = NULL;
2980#ifdef SUPPORT_TAGS
2981 free_all_tags();
2982#endif
2983 for (i = 0; i < 8; ++i)
2984 hostdata->busy[i] = 0;
2985#ifdef REAL_DMA
2986 hostdata->dma_len = 0;
2987#endif
2988 local_irq_restore(flags);
2989
2990 /* we did no complete reset of all commands, so a wakeup is required */
2991 return SCSI_RESET_WAKEUP | SCSI_RESET_BUS_RESET;
2992#endif /* 1 */
2993}
1/*
2 * NCR 5380 generic driver routines. These should make it *trivial*
3 * to implement 5380 SCSI drivers under Linux with a non-trantor
4 * architecture.
5 *
6 * Note that these routines also work with NR53c400 family chips.
7 *
8 * Copyright 1993, Drew Eckhardt
9 * Visionary Computing
10 * (Unix and Linux consulting and custom programming)
11 * drew@colorado.edu
12 * +1 (303) 666-5836
13 *
14 * For more information, please consult
15 *
16 * NCR 5380 Family
17 * SCSI Protocol Controller
18 * Databook
19 *
20 * NCR Microelectronics
21 * 1635 Aeroplaza Drive
22 * Colorado Springs, CO 80916
23 * 1+ (719) 578-3400
24 * 1+ (800) 334-5454
25 */
26
27/* Ported to Atari by Roman Hodek and others. */
28
29/* Adapted for the sun3 by Sam Creasey. */
30
31/*
32 * Design
33 *
34 * This is a generic 5380 driver. To use it on a different platform,
35 * one simply writes appropriate system specific macros (ie, data
36 * transfer - some PC's will use the I/O bus, 68K's must use
37 * memory mapped) and drops this file in their 'C' wrapper.
38 *
39 * As far as command queueing, two queues are maintained for
40 * each 5380 in the system - commands that haven't been issued yet,
41 * and commands that are currently executing. This means that an
42 * unlimited number of commands may be queued, letting
43 * more commands propagate from the higher driver levels giving higher
44 * throughput. Note that both I_T_L and I_T_L_Q nexuses are supported,
45 * allowing multiple commands to propagate all the way to a SCSI-II device
46 * while a command is already executing.
47 *
48 *
49 * Issues specific to the NCR5380 :
50 *
51 * When used in a PIO or pseudo-dma mode, the NCR5380 is a braindead
52 * piece of hardware that requires you to sit in a loop polling for
53 * the REQ signal as long as you are connected. Some devices are
54 * brain dead (ie, many TEXEL CD ROM drives) and won't disconnect
55 * while doing long seek operations. [...] These
56 * broken devices are the exception rather than the rule and I'd rather
57 * spend my time optimizing for the normal case.
58 *
59 * Architecture :
60 *
61 * At the heart of the design is a coroutine, NCR5380_main,
62 * which is started from a workqueue for each NCR5380 host in the
63 * system. It attempts to establish I_T_L or I_T_L_Q nexuses by
64 * removing the commands from the issue queue and calling
65 * NCR5380_select() if a nexus is not established.
66 *
67 * Once a nexus is established, the NCR5380_information_transfer()
68 * phase goes through the various phases as instructed by the target.
69 * if the target goes into MSG IN and sends a DISCONNECT message,
70 * the command structure is placed into the per instance disconnected
71 * queue, and NCR5380_main tries to find more work. If the target is
72 * idle for too long, the system will try to sleep.
73 *
74 * If a command has disconnected, eventually an interrupt will trigger,
75 * calling NCR5380_intr() which will in turn call NCR5380_reselect
76 * to reestablish a nexus. This will run main if necessary.
77 *
78 * On command termination, the done function will be called as
79 * appropriate.
80 *
81 * SCSI pointers are maintained in the SCp field of SCSI command
82 * structures, being initialized after the command is connected
83 * in NCR5380_select, and set as appropriate in NCR5380_information_transfer.
84 * Note that in violation of the standard, an implicit SAVE POINTERS operation
85 * is done, since some BROKEN disks fail to issue an explicit SAVE POINTERS.
86 */
87
88/*
89 * Using this file :
90 * This file a skeleton Linux SCSI driver for the NCR 5380 series
91 * of chips. To use it, you write an architecture specific functions
92 * and macros and include this file in your driver.
93 *
94 * These macros control options :
95 * AUTOSENSE - if defined, REQUEST SENSE will be performed automatically
96 * for commands that return with a CHECK CONDITION status.
97 *
98 * DIFFERENTIAL - if defined, NCR53c81 chips will use external differential
99 * transceivers.
100 *
101 * REAL_DMA - if defined, REAL DMA is used during the data transfer phases.
102 *
103 * SUPPORT_TAGS - if defined, SCSI-2 tagged queuing is used where possible
104 *
105 * These macros MUST be defined :
106 *
107 * NCR5380_read(register) - read from the specified register
108 *
109 * NCR5380_write(register, value) - write to the specific register
110 *
111 * NCR5380_implementation_fields - additional fields needed for this
112 * specific implementation of the NCR5380
113 *
114 * Either real DMA *or* pseudo DMA may be implemented
115 * REAL functions :
116 * NCR5380_REAL_DMA should be defined if real DMA is to be used.
117 * Note that the DMA setup functions should return the number of bytes
118 * that they were able to program the controller for.
119 *
120 * Also note that generic i386/PC versions of these macros are
121 * available as NCR5380_i386_dma_write_setup,
122 * NCR5380_i386_dma_read_setup, and NCR5380_i386_dma_residual.
123 *
124 * NCR5380_dma_write_setup(instance, src, count) - initialize
125 * NCR5380_dma_read_setup(instance, dst, count) - initialize
126 * NCR5380_dma_residual(instance); - residual count
127 *
128 * PSEUDO functions :
129 * NCR5380_pwrite(instance, src, count)
130 * NCR5380_pread(instance, dst, count);
131 *
132 * The generic driver is initialized by calling NCR5380_init(instance),
133 * after setting the appropriate host specific fields and ID. If the
134 * driver wishes to autoprobe for an IRQ line, the NCR5380_probe_irq(instance,
135 * possible) function may be used.
136 */
137
138static int do_abort(struct Scsi_Host *);
139static void do_reset(struct Scsi_Host *);
140
141#ifdef SUPPORT_TAGS
142
143/*
144 * Functions for handling tagged queuing
145 * =====================================
146 *
147 * ++roman (01/96): Now I've implemented SCSI-2 tagged queuing. Some notes:
148 *
149 * Using consecutive numbers for the tags is no good idea in my eyes. There
150 * could be wrong re-usings if the counter (8 bit!) wraps and some early
151 * command has been preempted for a long time. My solution: a bitfield for
152 * remembering used tags.
153 *
154 * There's also the problem that each target has a certain queue size, but we
155 * cannot know it in advance :-( We just see a QUEUE_FULL status being
156 * returned. So, in this case, the driver internal queue size assumption is
157 * reduced to the number of active tags if QUEUE_FULL is returned by the
158 * target.
159 *
160 * We're also not allowed running tagged commands as long as an untagged
161 * command is active. And REQUEST SENSE commands after a contingent allegiance
162 * condition _must_ be untagged. To keep track whether an untagged command has
163 * been issued, the host->busy array is still employed, as it is without
164 * support for tagged queuing.
165 *
166 * One could suspect that there are possible race conditions between
167 * is_lun_busy(), cmd_get_tag() and cmd_free_tag(). But I think this isn't the
168 * case: is_lun_busy() and cmd_get_tag() are both called from NCR5380_main(),
169 * which already guaranteed to be running at most once. It is also the only
170 * place where tags/LUNs are allocated. So no other allocation can slip
171 * between that pair, there could only happen a reselection, which can free a
172 * tag, but that doesn't hurt. Only the sequence in cmd_free_tag() becomes
173 * important: the tag bit must be cleared before 'nr_allocated' is decreased.
174 */
175
176static void __init init_tags(struct NCR5380_hostdata *hostdata)
177{
178 int target, lun;
179 struct tag_alloc *ta;
180
181 if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
182 return;
183
184 for (target = 0; target < 8; ++target) {
185 for (lun = 0; lun < 8; ++lun) {
186 ta = &hostdata->TagAlloc[target][lun];
187 bitmap_zero(ta->allocated, MAX_TAGS);
188 ta->nr_allocated = 0;
189 /* At the beginning, assume the maximum queue size we could
190 * support (MAX_TAGS). This value will be decreased if the target
191 * returns QUEUE_FULL status.
192 */
193 ta->queue_size = MAX_TAGS;
194 }
195 }
196}
197
198
199/* Check if we can issue a command to this LUN: First see if the LUN is marked
200 * busy by an untagged command. If the command should use tagged queuing, also
201 * check that there is a free tag and the target's queue won't overflow. This
202 * function should be called with interrupts disabled to avoid race
203 * conditions.
204 */
205
206static int is_lun_busy(struct scsi_cmnd *cmd, int should_be_tagged)
207{
208 u8 lun = cmd->device->lun;
209 struct Scsi_Host *instance = cmd->device->host;
210 struct NCR5380_hostdata *hostdata = shost_priv(instance);
211
212 if (hostdata->busy[cmd->device->id] & (1 << lun))
213 return 1;
214 if (!should_be_tagged ||
215 !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
216 !cmd->device->tagged_supported)
217 return 0;
218 if (hostdata->TagAlloc[scmd_id(cmd)][lun].nr_allocated >=
219 hostdata->TagAlloc[scmd_id(cmd)][lun].queue_size) {
220 dsprintk(NDEBUG_TAGS, instance, "target %d lun %d: no free tags\n",
221 scmd_id(cmd), lun);
222 return 1;
223 }
224 return 0;
225}
226
227
228/* Allocate a tag for a command (there are no checks anymore, check_lun_busy()
229 * must be called before!), or reserve the LUN in 'busy' if the command is
230 * untagged.
231 */
232
233static void cmd_get_tag(struct scsi_cmnd *cmd, int should_be_tagged)
234{
235 u8 lun = cmd->device->lun;
236 struct Scsi_Host *instance = cmd->device->host;
237 struct NCR5380_hostdata *hostdata = shost_priv(instance);
238
239 /* If we or the target don't support tagged queuing, allocate the LUN for
240 * an untagged command.
241 */
242 if (!should_be_tagged ||
243 !(hostdata->flags & FLAG_TAGGED_QUEUING) ||
244 !cmd->device->tagged_supported) {
245 cmd->tag = TAG_NONE;
246 hostdata->busy[cmd->device->id] |= (1 << lun);
247 dsprintk(NDEBUG_TAGS, instance, "target %d lun %d now allocated by untagged command\n",
248 scmd_id(cmd), lun);
249 } else {
250 struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
251
252 cmd->tag = find_first_zero_bit(ta->allocated, MAX_TAGS);
253 set_bit(cmd->tag, ta->allocated);
254 ta->nr_allocated++;
255 dsprintk(NDEBUG_TAGS, instance, "using tag %d for target %d lun %d (%d tags allocated)\n",
256 cmd->tag, scmd_id(cmd), lun, ta->nr_allocated);
257 }
258}
259
260
261/* Mark the tag of command 'cmd' as free, or in case of an untagged command,
262 * unlock the LUN.
263 */
264
265static void cmd_free_tag(struct scsi_cmnd *cmd)
266{
267 u8 lun = cmd->device->lun;
268 struct Scsi_Host *instance = cmd->device->host;
269 struct NCR5380_hostdata *hostdata = shost_priv(instance);
270
271 if (cmd->tag == TAG_NONE) {
272 hostdata->busy[cmd->device->id] &= ~(1 << lun);
273 dsprintk(NDEBUG_TAGS, instance, "target %d lun %d untagged cmd freed\n",
274 scmd_id(cmd), lun);
275 } else if (cmd->tag >= MAX_TAGS) {
276 shost_printk(KERN_NOTICE, instance,
277 "trying to free bad tag %d!\n", cmd->tag);
278 } else {
279 struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
280 clear_bit(cmd->tag, ta->allocated);
281 ta->nr_allocated--;
282 dsprintk(NDEBUG_TAGS, instance, "freed tag %d for target %d lun %d\n",
283 cmd->tag, scmd_id(cmd), lun);
284 }
285}
286
287
288static void free_all_tags(struct NCR5380_hostdata *hostdata)
289{
290 int target, lun;
291 struct tag_alloc *ta;
292
293 if (!(hostdata->flags & FLAG_TAGGED_QUEUING))
294 return;
295
296 for (target = 0; target < 8; ++target) {
297 for (lun = 0; lun < 8; ++lun) {
298 ta = &hostdata->TagAlloc[target][lun];
299 bitmap_zero(ta->allocated, MAX_TAGS);
300 ta->nr_allocated = 0;
301 }
302 }
303}
304
305#endif /* SUPPORT_TAGS */
306
307/**
308 * merge_contiguous_buffers - coalesce scatter-gather list entries
309 * @cmd: command requesting IO
310 *
311 * Try to merge several scatter-gather buffers into one DMA transfer.
312 * This is possible if the scatter buffers lie on physically
313 * contiguous addresses. The first scatter-gather buffer's data are
314 * assumed to be already transferred into cmd->SCp.this_residual.
315 * Every buffer merged avoids an interrupt and a DMA setup operation.
316 */
317
318static void merge_contiguous_buffers(struct scsi_cmnd *cmd)
319{
320#if !defined(CONFIG_SUN3)
321 unsigned long endaddr;
322#if (NDEBUG & NDEBUG_MERGING)
323 unsigned long oldlen = cmd->SCp.this_residual;
324 int cnt = 1;
325#endif
326
327 for (endaddr = virt_to_phys(cmd->SCp.ptr + cmd->SCp.this_residual - 1) + 1;
328 cmd->SCp.buffers_residual &&
329 virt_to_phys(sg_virt(&cmd->SCp.buffer[1])) == endaddr;) {
330 dprintk(NDEBUG_MERGING, "VTOP(%p) == %08lx -> merging\n",
331 page_address(sg_page(&cmd->SCp.buffer[1])), endaddr);
332#if (NDEBUG & NDEBUG_MERGING)
333 ++cnt;
334#endif
335 ++cmd->SCp.buffer;
336 --cmd->SCp.buffers_residual;
337 cmd->SCp.this_residual += cmd->SCp.buffer->length;
338 endaddr += cmd->SCp.buffer->length;
339 }
340#if (NDEBUG & NDEBUG_MERGING)
341 if (oldlen != cmd->SCp.this_residual)
342 dprintk(NDEBUG_MERGING, "merged %d buffers from %p, new length %08x\n",
343 cnt, cmd->SCp.ptr, cmd->SCp.this_residual);
344#endif
345#endif /* !defined(CONFIG_SUN3) */
346}
347
348/**
349 * initialize_SCp - init the scsi pointer field
350 * @cmd: command block to set up
351 *
352 * Set up the internal fields in the SCSI command.
353 */
354
355static inline void initialize_SCp(struct scsi_cmnd *cmd)
356{
357 /*
358 * Initialize the Scsi Pointer field so that all of the commands in the
359 * various queues are valid.
360 */
361
362 if (scsi_bufflen(cmd)) {
363 cmd->SCp.buffer = scsi_sglist(cmd);
364 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
365 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
366 cmd->SCp.this_residual = cmd->SCp.buffer->length;
367
368 merge_contiguous_buffers(cmd);
369 } else {
370 cmd->SCp.buffer = NULL;
371 cmd->SCp.buffers_residual = 0;
372 cmd->SCp.ptr = NULL;
373 cmd->SCp.this_residual = 0;
374 }
375
376 cmd->SCp.Status = 0;
377 cmd->SCp.Message = 0;
378}
379
380/**
381 * NCR5380_poll_politely2 - wait for two chip register values
382 * @instance: controller to poll
383 * @reg1: 5380 register to poll
384 * @bit1: Bitmask to check
385 * @val1: Expected value
386 * @reg2: Second 5380 register to poll
387 * @bit2: Second bitmask to check
388 * @val2: Second expected value
389 * @wait: Time-out in jiffies
390 *
391 * Polls the chip in a reasonably efficient manner waiting for an
392 * event to occur. After a short quick poll we begin to yield the CPU
393 * (if possible). In irq contexts the time-out is arbitrarily limited.
394 * Callers may hold locks as long as they are held in irq mode.
395 *
396 * Returns 0 if either or both event(s) occurred otherwise -ETIMEDOUT.
397 */
398
399static int NCR5380_poll_politely2(struct Scsi_Host *instance,
400 int reg1, int bit1, int val1,
401 int reg2, int bit2, int val2, int wait)
402{
403 struct NCR5380_hostdata *hostdata = shost_priv(instance);
404 unsigned long deadline = jiffies + wait;
405 unsigned long n;
406
407 /* Busy-wait for up to 10 ms */
408 n = min(10000U, jiffies_to_usecs(wait));
409 n *= hostdata->accesses_per_ms;
410 n /= 2000;
411 do {
412 if ((NCR5380_read(reg1) & bit1) == val1)
413 return 0;
414 if ((NCR5380_read(reg2) & bit2) == val2)
415 return 0;
416 cpu_relax();
417 } while (n--);
418
419 if (irqs_disabled() || in_interrupt())
420 return -ETIMEDOUT;
421
422 /* Repeatedly sleep for 1 ms until deadline */
423 while (time_is_after_jiffies(deadline)) {
424 schedule_timeout_uninterruptible(1);
425 if ((NCR5380_read(reg1) & bit1) == val1)
426 return 0;
427 if ((NCR5380_read(reg2) & bit2) == val2)
428 return 0;
429 }
430
431 return -ETIMEDOUT;
432}
433
434static inline int NCR5380_poll_politely(struct Scsi_Host *instance,
435 int reg, int bit, int val, int wait)
436{
437 return NCR5380_poll_politely2(instance, reg, bit, val,
438 reg, bit, val, wait);
439}
440
441#if NDEBUG
442static struct {
443 unsigned char mask;
444 const char *name;
445} signals[] = {
446 {SR_DBP, "PARITY"},
447 {SR_RST, "RST"},
448 {SR_BSY, "BSY"},
449 {SR_REQ, "REQ"},
450 {SR_MSG, "MSG"},
451 {SR_CD, "CD"},
452 {SR_IO, "IO"},
453 {SR_SEL, "SEL"},
454 {0, NULL}
455},
456basrs[] = {
457 {BASR_ATN, "ATN"},
458 {BASR_ACK, "ACK"},
459 {0, NULL}
460},
461icrs[] = {
462 {ICR_ASSERT_RST, "ASSERT RST"},
463 {ICR_ASSERT_ACK, "ASSERT ACK"},
464 {ICR_ASSERT_BSY, "ASSERT BSY"},
465 {ICR_ASSERT_SEL, "ASSERT SEL"},
466 {ICR_ASSERT_ATN, "ASSERT ATN"},
467 {ICR_ASSERT_DATA, "ASSERT DATA"},
468 {0, NULL}
469},
470mrs[] = {
471 {MR_BLOCK_DMA_MODE, "MODE BLOCK DMA"},
472 {MR_TARGET, "MODE TARGET"},
473 {MR_ENABLE_PAR_CHECK, "MODE PARITY CHECK"},
474 {MR_ENABLE_PAR_INTR, "MODE PARITY INTR"},
475 {MR_ENABLE_EOP_INTR, "MODE EOP INTR"},
476 {MR_MONITOR_BSY, "MODE MONITOR BSY"},
477 {MR_DMA_MODE, "MODE DMA"},
478 {MR_ARBITRATE, "MODE ARBITRATION"},
479 {0, NULL}
480};
481
482/**
483 * NCR5380_print - print scsi bus signals
484 * @instance: adapter state to dump
485 *
486 * Print the SCSI bus signals for debugging purposes
487 */
488
489static void NCR5380_print(struct Scsi_Host *instance)
490{
491 unsigned char status, data, basr, mr, icr, i;
492
493 data = NCR5380_read(CURRENT_SCSI_DATA_REG);
494 status = NCR5380_read(STATUS_REG);
495 mr = NCR5380_read(MODE_REG);
496 icr = NCR5380_read(INITIATOR_COMMAND_REG);
497 basr = NCR5380_read(BUS_AND_STATUS_REG);
498
499 printk("STATUS_REG: %02x ", status);
500 for (i = 0; signals[i].mask; ++i)
501 if (status & signals[i].mask)
502 printk(",%s", signals[i].name);
503 printk("\nBASR: %02x ", basr);
504 for (i = 0; basrs[i].mask; ++i)
505 if (basr & basrs[i].mask)
506 printk(",%s", basrs[i].name);
507 printk("\nICR: %02x ", icr);
508 for (i = 0; icrs[i].mask; ++i)
509 if (icr & icrs[i].mask)
510 printk(",%s", icrs[i].name);
511 printk("\nMODE: %02x ", mr);
512 for (i = 0; mrs[i].mask; ++i)
513 if (mr & mrs[i].mask)
514 printk(",%s", mrs[i].name);
515 printk("\n");
516}
517
518static struct {
519 unsigned char value;
520 const char *name;
521} phases[] = {
522 {PHASE_DATAOUT, "DATAOUT"},
523 {PHASE_DATAIN, "DATAIN"},
524 {PHASE_CMDOUT, "CMDOUT"},
525 {PHASE_STATIN, "STATIN"},
526 {PHASE_MSGOUT, "MSGOUT"},
527 {PHASE_MSGIN, "MSGIN"},
528 {PHASE_UNKNOWN, "UNKNOWN"}
529};
530
531/**
532 * NCR5380_print_phase - show SCSI phase
533 * @instance: adapter to dump
534 *
535 * Print the current SCSI phase for debugging purposes
536 */
537
538static void NCR5380_print_phase(struct Scsi_Host *instance)
539{
540 unsigned char status;
541 int i;
542
543 status = NCR5380_read(STATUS_REG);
544 if (!(status & SR_REQ))
545 shost_printk(KERN_DEBUG, instance, "REQ not asserted, phase unknown.\n");
546 else {
547 for (i = 0; (phases[i].value != PHASE_UNKNOWN) &&
548 (phases[i].value != (status & PHASE_MASK)); ++i)
549 ;
550 shost_printk(KERN_DEBUG, instance, "phase %s\n", phases[i].name);
551 }
552}
553#endif
554
555/**
556 * NCR58380_info - report driver and host information
557 * @instance: relevant scsi host instance
558 *
559 * For use as the host template info() handler.
560 */
561
562static const char *NCR5380_info(struct Scsi_Host *instance)
563{
564 struct NCR5380_hostdata *hostdata = shost_priv(instance);
565
566 return hostdata->info;
567}
568
569static void prepare_info(struct Scsi_Host *instance)
570{
571 struct NCR5380_hostdata *hostdata = shost_priv(instance);
572
573 snprintf(hostdata->info, sizeof(hostdata->info),
574 "%s, io_port 0x%lx, n_io_port %d, "
575 "base 0x%lx, irq %d, "
576 "can_queue %d, cmd_per_lun %d, "
577 "sg_tablesize %d, this_id %d, "
578 "flags { %s%s}, "
579 "options { %s} ",
580 instance->hostt->name, instance->io_port, instance->n_io_port,
581 instance->base, instance->irq,
582 instance->can_queue, instance->cmd_per_lun,
583 instance->sg_tablesize, instance->this_id,
584 hostdata->flags & FLAG_TAGGED_QUEUING ? "TAGGED_QUEUING " : "",
585 hostdata->flags & FLAG_TOSHIBA_DELAY ? "TOSHIBA_DELAY " : "",
586#ifdef DIFFERENTIAL
587 "DIFFERENTIAL "
588#endif
589#ifdef REAL_DMA
590 "REAL_DMA "
591#endif
592#ifdef PARITY
593 "PARITY "
594#endif
595#ifdef SUPPORT_TAGS
596 "SUPPORT_TAGS "
597#endif
598 "");
599}
600
601/**
602 * NCR5380_init - initialise an NCR5380
603 * @instance: adapter to configure
604 * @flags: control flags
605 *
606 * Initializes *instance and corresponding 5380 chip,
607 * with flags OR'd into the initial flags value.
608 *
609 * Notes : I assume that the host, hostno, and id bits have been
610 * set correctly. I don't care about the irq and other fields.
611 *
612 * Returns 0 for success
613 */
614
615static int __init NCR5380_init(struct Scsi_Host *instance, int flags)
616{
617 struct NCR5380_hostdata *hostdata = shost_priv(instance);
618 int i;
619 unsigned long deadline;
620
621 hostdata->host = instance;
622 hostdata->id_mask = 1 << instance->this_id;
623 hostdata->id_higher_mask = 0;
624 for (i = hostdata->id_mask; i <= 0x80; i <<= 1)
625 if (i > hostdata->id_mask)
626 hostdata->id_higher_mask |= i;
627 for (i = 0; i < 8; ++i)
628 hostdata->busy[i] = 0;
629#ifdef SUPPORT_TAGS
630 init_tags(hostdata);
631#endif
632#if defined (REAL_DMA)
633 hostdata->dma_len = 0;
634#endif
635 spin_lock_init(&hostdata->lock);
636 hostdata->connected = NULL;
637 hostdata->sensing = NULL;
638 INIT_LIST_HEAD(&hostdata->autosense);
639 INIT_LIST_HEAD(&hostdata->unissued);
640 INIT_LIST_HEAD(&hostdata->disconnected);
641
642 hostdata->flags = flags;
643
644 INIT_WORK(&hostdata->main_task, NCR5380_main);
645 hostdata->work_q = alloc_workqueue("ncr5380_%d",
646 WQ_UNBOUND | WQ_MEM_RECLAIM,
647 1, instance->host_no);
648 if (!hostdata->work_q)
649 return -ENOMEM;
650
651 prepare_info(instance);
652
653 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
654 NCR5380_write(MODE_REG, MR_BASE);
655 NCR5380_write(TARGET_COMMAND_REG, 0);
656 NCR5380_write(SELECT_ENABLE_REG, 0);
657
658 /* Calibrate register polling loop */
659 i = 0;
660 deadline = jiffies + 1;
661 do {
662 cpu_relax();
663 } while (time_is_after_jiffies(deadline));
664 deadline += msecs_to_jiffies(256);
665 do {
666 NCR5380_read(STATUS_REG);
667 ++i;
668 cpu_relax();
669 } while (time_is_after_jiffies(deadline));
670 hostdata->accesses_per_ms = i / 256;
671
672 return 0;
673}
674
675/**
676 * NCR5380_maybe_reset_bus - Detect and correct bus wedge problems.
677 * @instance: adapter to check
678 *
679 * If the system crashed, it may have crashed with a connected target and
680 * the SCSI bus busy. Check for BUS FREE phase. If not, try to abort the
681 * currently established nexus, which we know nothing about. Failing that
682 * do a bus reset.
683 *
684 * Note that a bus reset will cause the chip to assert IRQ.
685 *
686 * Returns 0 if successful, otherwise -ENXIO.
687 */
688
689static int NCR5380_maybe_reset_bus(struct Scsi_Host *instance)
690{
691 struct NCR5380_hostdata *hostdata = shost_priv(instance);
692 int pass;
693
694 for (pass = 1; (NCR5380_read(STATUS_REG) & SR_BSY) && pass <= 6; ++pass) {
695 switch (pass) {
696 case 1:
697 case 3:
698 case 5:
699 shost_printk(KERN_ERR, instance, "SCSI bus busy, waiting up to five seconds\n");
700 NCR5380_poll_politely(instance,
701 STATUS_REG, SR_BSY, 0, 5 * HZ);
702 break;
703 case 2:
704 shost_printk(KERN_ERR, instance, "bus busy, attempting abort\n");
705 do_abort(instance);
706 break;
707 case 4:
708 shost_printk(KERN_ERR, instance, "bus busy, attempting reset\n");
709 do_reset(instance);
710 /* Wait after a reset; the SCSI standard calls for
711 * 250ms, we wait 500ms to be on the safe side.
712 * But some Toshiba CD-ROMs need ten times that.
713 */
714 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
715 msleep(2500);
716 else
717 msleep(500);
718 break;
719 case 6:
720 shost_printk(KERN_ERR, instance, "bus locked solid\n");
721 return -ENXIO;
722 }
723 }
724 return 0;
725}
726
727/**
728 * NCR5380_exit - remove an NCR5380
729 * @instance: adapter to remove
730 *
731 * Assumes that no more work can be queued (e.g. by NCR5380_intr).
732 */
733
734static void NCR5380_exit(struct Scsi_Host *instance)
735{
736 struct NCR5380_hostdata *hostdata = shost_priv(instance);
737
738 cancel_work_sync(&hostdata->main_task);
739 destroy_workqueue(hostdata->work_q);
740}
741
742/**
743 * complete_cmd - finish processing a command and return it to the SCSI ML
744 * @instance: the host instance
745 * @cmd: command to complete
746 */
747
748static void complete_cmd(struct Scsi_Host *instance,
749 struct scsi_cmnd *cmd)
750{
751 struct NCR5380_hostdata *hostdata = shost_priv(instance);
752
753 dsprintk(NDEBUG_QUEUES, instance, "complete_cmd: cmd %p\n", cmd);
754
755 if (hostdata->sensing == cmd) {
756 /* Autosense processing ends here */
757 if ((cmd->result & 0xff) != SAM_STAT_GOOD) {
758 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
759 set_host_byte(cmd, DID_ERROR);
760 } else
761 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
762 hostdata->sensing = NULL;
763 }
764
765#ifdef SUPPORT_TAGS
766 cmd_free_tag(cmd);
767#else
768 hostdata->busy[scmd_id(cmd)] &= ~(1 << cmd->device->lun);
769#endif
770 cmd->scsi_done(cmd);
771}
772
773/**
774 * NCR5380_queue_command - queue a command
775 * @instance: the relevant SCSI adapter
776 * @cmd: SCSI command
777 *
778 * cmd is added to the per-instance issue queue, with minor
779 * twiddling done to the host specific fields of cmd. If the
780 * main coroutine is not running, it is restarted.
781 */
782
783static int NCR5380_queue_command(struct Scsi_Host *instance,
784 struct scsi_cmnd *cmd)
785{
786 struct NCR5380_hostdata *hostdata = shost_priv(instance);
787 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
788 unsigned long flags;
789
790#if (NDEBUG & NDEBUG_NO_WRITE)
791 switch (cmd->cmnd[0]) {
792 case WRITE_6:
793 case WRITE_10:
794 shost_printk(KERN_DEBUG, instance, "WRITE attempted with NDEBUG_NO_WRITE set\n");
795 cmd->result = (DID_ERROR << 16);
796 cmd->scsi_done(cmd);
797 return 0;
798 }
799#endif /* (NDEBUG & NDEBUG_NO_WRITE) */
800
801 cmd->result = 0;
802
803 /*
804 * ++roman: Just disabling the NCR interrupt isn't sufficient here,
805 * because also a timer int can trigger an abort or reset, which would
806 * alter queues and touch the lock.
807 */
808 if (!NCR5380_acquire_dma_irq(instance))
809 return SCSI_MLQUEUE_HOST_BUSY;
810
811 spin_lock_irqsave(&hostdata->lock, flags);
812
813 /*
814 * Insert the cmd into the issue queue. Note that REQUEST SENSE
815 * commands are added to the head of the queue since any command will
816 * clear the contingent allegiance condition that exists and the
817 * sense data is only guaranteed to be valid while the condition exists.
818 */
819
820 if (cmd->cmnd[0] == REQUEST_SENSE)
821 list_add(&ncmd->list, &hostdata->unissued);
822 else
823 list_add_tail(&ncmd->list, &hostdata->unissued);
824
825 spin_unlock_irqrestore(&hostdata->lock, flags);
826
827 dsprintk(NDEBUG_QUEUES, instance, "command %p added to %s of queue\n",
828 cmd, (cmd->cmnd[0] == REQUEST_SENSE) ? "head" : "tail");
829
830 /* Kick off command processing */
831 queue_work(hostdata->work_q, &hostdata->main_task);
832 return 0;
833}
834
835static inline void maybe_release_dma_irq(struct Scsi_Host *instance)
836{
837 struct NCR5380_hostdata *hostdata = shost_priv(instance);
838
839 /* Caller does the locking needed to set & test these data atomically */
840 if (list_empty(&hostdata->disconnected) &&
841 list_empty(&hostdata->unissued) &&
842 list_empty(&hostdata->autosense) &&
843 !hostdata->connected &&
844 !hostdata->selecting)
845 NCR5380_release_dma_irq(instance);
846}
847
848/**
849 * dequeue_next_cmd - dequeue a command for processing
850 * @instance: the scsi host instance
851 *
852 * Priority is given to commands on the autosense queue. These commands
853 * need autosense because of a CHECK CONDITION result.
854 *
855 * Returns a command pointer if a command is found for a target that is
856 * not already busy. Otherwise returns NULL.
857 */
858
859static struct scsi_cmnd *dequeue_next_cmd(struct Scsi_Host *instance)
860{
861 struct NCR5380_hostdata *hostdata = shost_priv(instance);
862 struct NCR5380_cmd *ncmd;
863 struct scsi_cmnd *cmd;
864
865 if (hostdata->sensing || list_empty(&hostdata->autosense)) {
866 list_for_each_entry(ncmd, &hostdata->unissued, list) {
867 cmd = NCR5380_to_scmd(ncmd);
868 dsprintk(NDEBUG_QUEUES, instance, "dequeue: cmd=%p target=%d busy=0x%02x lun=%llu\n",
869 cmd, scmd_id(cmd), hostdata->busy[scmd_id(cmd)], cmd->device->lun);
870
871 if (
872#ifdef SUPPORT_TAGS
873 !is_lun_busy(cmd, 1)
874#else
875 !(hostdata->busy[scmd_id(cmd)] & (1 << cmd->device->lun))
876#endif
877 ) {
878 list_del(&ncmd->list);
879 dsprintk(NDEBUG_QUEUES, instance,
880 "dequeue: removed %p from issue queue\n", cmd);
881 return cmd;
882 }
883 }
884 } else {
885 /* Autosense processing begins here */
886 ncmd = list_first_entry(&hostdata->autosense,
887 struct NCR5380_cmd, list);
888 list_del(&ncmd->list);
889 cmd = NCR5380_to_scmd(ncmd);
890 dsprintk(NDEBUG_QUEUES, instance,
891 "dequeue: removed %p from autosense queue\n", cmd);
892 scsi_eh_prep_cmnd(cmd, &hostdata->ses, NULL, 0, ~0);
893 hostdata->sensing = cmd;
894 return cmd;
895 }
896 return NULL;
897}
898
899static void requeue_cmd(struct Scsi_Host *instance, struct scsi_cmnd *cmd)
900{
901 struct NCR5380_hostdata *hostdata = shost_priv(instance);
902 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
903
904 if (hostdata->sensing == cmd) {
905 scsi_eh_restore_cmnd(cmd, &hostdata->ses);
906 list_add(&ncmd->list, &hostdata->autosense);
907 hostdata->sensing = NULL;
908 } else
909 list_add(&ncmd->list, &hostdata->unissued);
910}
911
912/**
913 * NCR5380_main - NCR state machines
914 *
915 * NCR5380_main is a coroutine that runs as long as more work can
916 * be done on the NCR5380 host adapters in a system. Both
917 * NCR5380_queue_command() and NCR5380_intr() will try to start it
918 * in case it is not running.
919 */
920
921static void NCR5380_main(struct work_struct *work)
922{
923 struct NCR5380_hostdata *hostdata =
924 container_of(work, struct NCR5380_hostdata, main_task);
925 struct Scsi_Host *instance = hostdata->host;
926 int done;
927
928 /*
929 * ++roman: Just disabling the NCR interrupt isn't sufficient here,
930 * because also a timer int can trigger an abort or reset, which can
931 * alter queues and touch the Falcon lock.
932 */
933
934 do {
935 done = 1;
936
937 spin_lock_irq(&hostdata->lock);
938 while (!hostdata->connected && !hostdata->selecting) {
939 struct scsi_cmnd *cmd = dequeue_next_cmd(instance);
940
941 if (!cmd)
942 break;
943
944 dsprintk(NDEBUG_MAIN, instance, "main: dequeued %p\n", cmd);
945
946 /*
947 * Attempt to establish an I_T_L nexus here.
948 * On success, instance->hostdata->connected is set.
949 * On failure, we must add the command back to the
950 * issue queue so we can keep trying.
951 */
952 /*
953 * REQUEST SENSE commands are issued without tagged
954 * queueing, even on SCSI-II devices because the
955 * contingent allegiance condition exists for the
956 * entire unit.
957 */
958 /* ++roman: ...and the standard also requires that
959 * REQUEST SENSE command are untagged.
960 */
961
962#ifdef SUPPORT_TAGS
963 cmd_get_tag(cmd, cmd->cmnd[0] != REQUEST_SENSE);
964#endif
965 if (!NCR5380_select(instance, cmd)) {
966 dsprintk(NDEBUG_MAIN, instance, "main: select complete\n");
967 maybe_release_dma_irq(instance);
968 } else {
969 dsprintk(NDEBUG_MAIN | NDEBUG_QUEUES, instance,
970 "main: select failed, returning %p to queue\n", cmd);
971 requeue_cmd(instance, cmd);
972#ifdef SUPPORT_TAGS
973 cmd_free_tag(cmd);
974#endif
975 }
976 }
977 if (hostdata->connected
978#ifdef REAL_DMA
979 && !hostdata->dma_len
980#endif
981 ) {
982 dsprintk(NDEBUG_MAIN, instance, "main: performing information transfer\n");
983 NCR5380_information_transfer(instance);
984 done = 0;
985 }
986 spin_unlock_irq(&hostdata->lock);
987 if (!done)
988 cond_resched();
989 } while (!done);
990}
991
992
993#ifdef REAL_DMA
994/*
995 * Function : void NCR5380_dma_complete (struct Scsi_Host *instance)
996 *
997 * Purpose : Called by interrupt handler when DMA finishes or a phase
998 * mismatch occurs (which would finish the DMA transfer).
999 *
1000 * Inputs : instance - this instance of the NCR5380.
1001 */
1002
1003static void NCR5380_dma_complete(struct Scsi_Host *instance)
1004{
1005 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1006 int transferred;
1007 unsigned char **data;
1008 int *count;
1009 int saved_data = 0, overrun = 0;
1010 unsigned char p;
1011
1012 if (hostdata->read_overruns) {
1013 p = hostdata->connected->SCp.phase;
1014 if (p & SR_IO) {
1015 udelay(10);
1016 if ((NCR5380_read(BUS_AND_STATUS_REG) &
1017 (BASR_PHASE_MATCH|BASR_ACK)) ==
1018 (BASR_PHASE_MATCH|BASR_ACK)) {
1019 saved_data = NCR5380_read(INPUT_DATA_REG);
1020 overrun = 1;
1021 dsprintk(NDEBUG_DMA, instance, "read overrun handled\n");
1022 }
1023 }
1024 }
1025
1026#if defined(CONFIG_SUN3)
1027 if ((sun3scsi_dma_finish(rq_data_dir(hostdata->connected->request)))) {
1028 pr_err("scsi%d: overrun in UDC counter -- not prepared to deal with this!\n",
1029 instance->host_no);
1030 BUG();
1031 }
1032
1033 /* make sure we're not stuck in a data phase */
1034 if ((NCR5380_read(BUS_AND_STATUS_REG) & (BASR_PHASE_MATCH | BASR_ACK)) ==
1035 (BASR_PHASE_MATCH | BASR_ACK)) {
1036 pr_err("scsi%d: BASR %02x\n", instance->host_no,
1037 NCR5380_read(BUS_AND_STATUS_REG));
1038 pr_err("scsi%d: bus stuck in data phase -- probably a single byte overrun!\n",
1039 instance->host_no);
1040 BUG();
1041 }
1042#endif
1043
1044 NCR5380_write(MODE_REG, MR_BASE);
1045 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1046 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1047
1048 transferred = hostdata->dma_len - NCR5380_dma_residual(instance);
1049 hostdata->dma_len = 0;
1050
1051 data = (unsigned char **)&hostdata->connected->SCp.ptr;
1052 count = &hostdata->connected->SCp.this_residual;
1053 *data += transferred;
1054 *count -= transferred;
1055
1056 if (hostdata->read_overruns) {
1057 int cnt, toPIO;
1058
1059 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) == p && (p & SR_IO)) {
1060 cnt = toPIO = hostdata->read_overruns;
1061 if (overrun) {
1062 dprintk(NDEBUG_DMA, "Got an input overrun, using saved byte\n");
1063 *(*data)++ = saved_data;
1064 (*count)--;
1065 cnt--;
1066 toPIO--;
1067 }
1068 dprintk(NDEBUG_DMA, "Doing %d-byte PIO to 0x%08lx\n", cnt, (long)*data);
1069 NCR5380_transfer_pio(instance, &p, &cnt, data);
1070 *count -= toPIO - cnt;
1071 }
1072 }
1073}
1074#endif /* REAL_DMA */
1075
1076
1077/**
1078 * NCR5380_intr - generic NCR5380 irq handler
1079 * @irq: interrupt number
1080 * @dev_id: device info
1081 *
1082 * Handle interrupts, reestablishing I_T_L or I_T_L_Q nexuses
1083 * from the disconnected queue, and restarting NCR5380_main()
1084 * as required.
1085 *
1086 * The chip can assert IRQ in any of six different conditions. The IRQ flag
1087 * is then cleared by reading the Reset Parity/Interrupt Register (RPIR).
1088 * Three of these six conditions are latched in the Bus and Status Register:
1089 * - End of DMA (cleared by ending DMA Mode)
1090 * - Parity error (cleared by reading RPIR)
1091 * - Loss of BSY (cleared by reading RPIR)
1092 * Two conditions have flag bits that are not latched:
1093 * - Bus phase mismatch (non-maskable in DMA Mode, cleared by ending DMA Mode)
1094 * - Bus reset (non-maskable)
1095 * The remaining condition has no flag bit at all:
1096 * - Selection/reselection
1097 *
1098 * Hence, establishing the cause(s) of any interrupt is partly guesswork.
1099 * In "The DP8490 and DP5380 Comparison Guide", National Semiconductor
1100 * claimed that "the design of the [DP8490] interrupt logic ensures
1101 * interrupts will not be lost (they can be on the DP5380)."
1102 * The L5380/53C80 datasheet from LOGIC Devices has more details.
1103 *
1104 * Checking for bus reset by reading RST is futile because of interrupt
1105 * latency, but a bus reset will reset chip logic. Checking for parity error
1106 * is unnecessary because that interrupt is never enabled. A Loss of BSY
1107 * condition will clear DMA Mode. We can tell when this occurs because the
1108 * the Busy Monitor interrupt is enabled together with DMA Mode.
1109 */
1110
1111static irqreturn_t NCR5380_intr(int irq, void *dev_id)
1112{
1113 struct Scsi_Host *instance = dev_id;
1114 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1115 int handled = 0;
1116 unsigned char basr;
1117 unsigned long flags;
1118
1119 spin_lock_irqsave(&hostdata->lock, flags);
1120
1121 basr = NCR5380_read(BUS_AND_STATUS_REG);
1122 if (basr & BASR_IRQ) {
1123 unsigned char mr = NCR5380_read(MODE_REG);
1124 unsigned char sr = NCR5380_read(STATUS_REG);
1125
1126 dsprintk(NDEBUG_INTR, instance, "IRQ %d, BASR 0x%02x, SR 0x%02x, MR 0x%02x\n",
1127 irq, basr, sr, mr);
1128
1129#if defined(REAL_DMA)
1130 if ((mr & MR_DMA_MODE) || (mr & MR_MONITOR_BSY)) {
1131 /* Probably End of DMA, Phase Mismatch or Loss of BSY.
1132 * We ack IRQ after clearing Mode Register. Workarounds
1133 * for End of DMA errata need to happen in DMA Mode.
1134 */
1135
1136 dsprintk(NDEBUG_INTR, instance, "interrupt in DMA mode\n");
1137
1138 if (hostdata->connected) {
1139 NCR5380_dma_complete(instance);
1140 queue_work(hostdata->work_q, &hostdata->main_task);
1141 } else {
1142 NCR5380_write(MODE_REG, MR_BASE);
1143 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1144 }
1145 } else
1146#endif /* REAL_DMA */
1147 if ((NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_mask) &&
1148 (sr & (SR_SEL | SR_IO | SR_BSY | SR_RST)) == (SR_SEL | SR_IO)) {
1149 /* Probably reselected */
1150 NCR5380_write(SELECT_ENABLE_REG, 0);
1151 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1152
1153 dsprintk(NDEBUG_INTR, instance, "interrupt with SEL and IO\n");
1154
1155 if (!hostdata->connected) {
1156 NCR5380_reselect(instance);
1157 queue_work(hostdata->work_q, &hostdata->main_task);
1158 }
1159 if (!hostdata->connected)
1160 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1161 } else {
1162 /* Probably Bus Reset */
1163 NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1164
1165 dsprintk(NDEBUG_INTR, instance, "unknown interrupt\n");
1166#ifdef SUN3_SCSI_VME
1167 dregs->csr |= CSR_DMA_ENABLE;
1168#endif
1169 }
1170 handled = 1;
1171 } else {
1172 shost_printk(KERN_NOTICE, instance, "interrupt without IRQ bit\n");
1173#ifdef SUN3_SCSI_VME
1174 dregs->csr |= CSR_DMA_ENABLE;
1175#endif
1176 }
1177
1178 spin_unlock_irqrestore(&hostdata->lock, flags);
1179
1180 return IRQ_RETVAL(handled);
1181}
1182
1183/*
1184 * Function : int NCR5380_select(struct Scsi_Host *instance,
1185 * struct scsi_cmnd *cmd)
1186 *
1187 * Purpose : establishes I_T_L or I_T_L_Q nexus for new or existing command,
1188 * including ARBITRATION, SELECTION, and initial message out for
1189 * IDENTIFY and queue messages.
1190 *
1191 * Inputs : instance - instantiation of the 5380 driver on which this
1192 * target lives, cmd - SCSI command to execute.
1193 *
1194 * Returns cmd if selection failed but should be retried,
1195 * NULL if selection failed and should not be retried, or
1196 * NULL if selection succeeded (hostdata->connected == cmd).
1197 *
1198 * Side effects :
1199 * If bus busy, arbitration failed, etc, NCR5380_select() will exit
1200 * with registers as they should have been on entry - ie
1201 * SELECT_ENABLE will be set appropriately, the NCR5380
1202 * will cease to drive any SCSI bus signals.
1203 *
1204 * If successful : I_T_L or I_T_L_Q nexus will be established,
1205 * instance->connected will be set to cmd.
1206 * SELECT interrupt will be disabled.
1207 *
1208 * If failed (no target) : cmd->scsi_done() will be called, and the
1209 * cmd->result host byte set to DID_BAD_TARGET.
1210 */
1211
1212static struct scsi_cmnd *NCR5380_select(struct Scsi_Host *instance,
1213 struct scsi_cmnd *cmd)
1214{
1215 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1216 unsigned char tmp[3], phase;
1217 unsigned char *data;
1218 int len;
1219 int err;
1220
1221 NCR5380_dprint(NDEBUG_ARBITRATION, instance);
1222 dsprintk(NDEBUG_ARBITRATION, instance, "starting arbitration, id = %d\n",
1223 instance->this_id);
1224
1225 /*
1226 * Arbitration and selection phases are slow and involve dropping the
1227 * lock, so we have to watch out for EH. An exception handler may
1228 * change 'selecting' to NULL. This function will then return NULL
1229 * so that the caller will forget about 'cmd'. (During information
1230 * transfer phases, EH may change 'connected' to NULL.)
1231 */
1232 hostdata->selecting = cmd;
1233
1234 /*
1235 * Set the phase bits to 0, otherwise the NCR5380 won't drive the
1236 * data bus during SELECTION.
1237 */
1238
1239 NCR5380_write(TARGET_COMMAND_REG, 0);
1240
1241 /*
1242 * Start arbitration.
1243 */
1244
1245 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask);
1246 NCR5380_write(MODE_REG, MR_ARBITRATE);
1247
1248 /* The chip now waits for BUS FREE phase. Then after the 800 ns
1249 * Bus Free Delay, arbitration will begin.
1250 */
1251
1252 spin_unlock_irq(&hostdata->lock);
1253 err = NCR5380_poll_politely2(instance, MODE_REG, MR_ARBITRATE, 0,
1254 INITIATOR_COMMAND_REG, ICR_ARBITRATION_PROGRESS,
1255 ICR_ARBITRATION_PROGRESS, HZ);
1256 spin_lock_irq(&hostdata->lock);
1257 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE)) {
1258 /* Reselection interrupt */
1259 goto out;
1260 }
1261 if (!hostdata->selecting) {
1262 /* Command was aborted */
1263 NCR5380_write(MODE_REG, MR_BASE);
1264 goto out;
1265 }
1266 if (err < 0) {
1267 NCR5380_write(MODE_REG, MR_BASE);
1268 shost_printk(KERN_ERR, instance,
1269 "select: arbitration timeout\n");
1270 goto out;
1271 }
1272 spin_unlock_irq(&hostdata->lock);
1273
1274 /* The SCSI-2 arbitration delay is 2.4 us */
1275 udelay(3);
1276
1277 /* Check for lost arbitration */
1278 if ((NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST) ||
1279 (NCR5380_read(CURRENT_SCSI_DATA_REG) & hostdata->id_higher_mask) ||
1280 (NCR5380_read(INITIATOR_COMMAND_REG) & ICR_ARBITRATION_LOST)) {
1281 NCR5380_write(MODE_REG, MR_BASE);
1282 dsprintk(NDEBUG_ARBITRATION, instance, "lost arbitration, deasserting MR_ARBITRATE\n");
1283 spin_lock_irq(&hostdata->lock);
1284 goto out;
1285 }
1286
1287 /* After/during arbitration, BSY should be asserted.
1288 * IBM DPES-31080 Version S31Q works now
1289 * Tnx to Thomas_Roesch@m2.maus.de for finding this! (Roman)
1290 */
1291 NCR5380_write(INITIATOR_COMMAND_REG,
1292 ICR_BASE | ICR_ASSERT_SEL | ICR_ASSERT_BSY);
1293
1294 /*
1295 * Again, bus clear + bus settle time is 1.2us, however, this is
1296 * a minimum so we'll udelay ceil(1.2)
1297 */
1298
1299 if (hostdata->flags & FLAG_TOSHIBA_DELAY)
1300 udelay(15);
1301 else
1302 udelay(2);
1303
1304 spin_lock_irq(&hostdata->lock);
1305
1306 /* NCR5380_reselect() clears MODE_REG after a reselection interrupt */
1307 if (!(NCR5380_read(MODE_REG) & MR_ARBITRATE))
1308 goto out;
1309
1310 if (!hostdata->selecting) {
1311 NCR5380_write(MODE_REG, MR_BASE);
1312 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1313 goto out;
1314 }
1315
1316 dsprintk(NDEBUG_ARBITRATION, instance, "won arbitration\n");
1317
1318 /*
1319 * Now that we have won arbitration, start Selection process, asserting
1320 * the host and target ID's on the SCSI bus.
1321 */
1322
1323 NCR5380_write(OUTPUT_DATA_REG, hostdata->id_mask | (1 << scmd_id(cmd)));
1324
1325 /*
1326 * Raise ATN while SEL is true before BSY goes false from arbitration,
1327 * since this is the only way to guarantee that we'll get a MESSAGE OUT
1328 * phase immediately after selection.
1329 */
1330
1331 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY |
1332 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1333 NCR5380_write(MODE_REG, MR_BASE);
1334
1335 /*
1336 * Reselect interrupts must be turned off prior to the dropping of BSY,
1337 * otherwise we will trigger an interrupt.
1338 */
1339 NCR5380_write(SELECT_ENABLE_REG, 0);
1340
1341 spin_unlock_irq(&hostdata->lock);
1342
1343 /*
1344 * The initiator shall then wait at least two deskew delays and release
1345 * the BSY signal.
1346 */
1347 udelay(1); /* wingel -- wait two bus deskew delay >2*45ns */
1348
1349 /* Reset BSY */
1350 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA |
1351 ICR_ASSERT_ATN | ICR_ASSERT_SEL);
1352
1353 /*
1354 * Something weird happens when we cease to drive BSY - looks
1355 * like the board/chip is letting us do another read before the
1356 * appropriate propagation delay has expired, and we're confusing
1357 * a BSY signal from ourselves as the target's response to SELECTION.
1358 *
1359 * A small delay (the 'C++' frontend breaks the pipeline with an
1360 * unnecessary jump, making it work on my 386-33/Trantor T128, the
1361 * tighter 'C' code breaks and requires this) solves the problem -
1362 * the 1 us delay is arbitrary, and only used because this delay will
1363 * be the same on other platforms and since it works here, it should
1364 * work there.
1365 *
1366 * wingel suggests that this could be due to failing to wait
1367 * one deskew delay.
1368 */
1369
1370 udelay(1);
1371
1372 dsprintk(NDEBUG_SELECTION, instance, "selecting target %d\n", scmd_id(cmd));
1373
1374 /*
1375 * The SCSI specification calls for a 250 ms timeout for the actual
1376 * selection.
1377 */
1378
1379 err = NCR5380_poll_politely(instance, STATUS_REG, SR_BSY, SR_BSY,
1380 msecs_to_jiffies(250));
1381
1382 if ((NCR5380_read(STATUS_REG) & (SR_SEL | SR_IO)) == (SR_SEL | SR_IO)) {
1383 spin_lock_irq(&hostdata->lock);
1384 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1385 NCR5380_reselect(instance);
1386 if (!hostdata->connected)
1387 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1388 shost_printk(KERN_ERR, instance, "reselection after won arbitration?\n");
1389 goto out;
1390 }
1391
1392 if (err < 0) {
1393 spin_lock_irq(&hostdata->lock);
1394 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1395 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1396 /* Can't touch cmd if it has been reclaimed by the scsi ML */
1397 if (hostdata->selecting) {
1398 cmd->result = DID_BAD_TARGET << 16;
1399 complete_cmd(instance, cmd);
1400 dsprintk(NDEBUG_SELECTION, instance, "target did not respond within 250ms\n");
1401 cmd = NULL;
1402 }
1403 goto out;
1404 }
1405
1406 /*
1407 * No less than two deskew delays after the initiator detects the
1408 * BSY signal is true, it shall release the SEL signal and may
1409 * change the DATA BUS. -wingel
1410 */
1411
1412 udelay(1);
1413
1414 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1415
1416 /*
1417 * Since we followed the SCSI spec, and raised ATN while SEL
1418 * was true but before BSY was false during selection, the information
1419 * transfer phase should be a MESSAGE OUT phase so that we can send the
1420 * IDENTIFY message.
1421 *
1422 * If SCSI-II tagged queuing is enabled, we also send a SIMPLE_QUEUE_TAG
1423 * message (2 bytes) with a tag ID that we increment with every command
1424 * until it wraps back to 0.
1425 *
1426 * XXX - it turns out that there are some broken SCSI-II devices,
1427 * which claim to support tagged queuing but fail when more than
1428 * some number of commands are issued at once.
1429 */
1430
1431 /* Wait for start of REQ/ACK handshake */
1432
1433 err = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
1434 spin_lock_irq(&hostdata->lock);
1435 if (err < 0) {
1436 shost_printk(KERN_ERR, instance, "select: REQ timeout\n");
1437 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1438 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
1439 goto out;
1440 }
1441 if (!hostdata->selecting) {
1442 do_abort(instance);
1443 goto out;
1444 }
1445
1446 dsprintk(NDEBUG_SELECTION, instance, "target %d selected, going into MESSAGE OUT phase.\n",
1447 scmd_id(cmd));
1448 tmp[0] = IDENTIFY(1, cmd->device->lun);
1449
1450#ifdef SUPPORT_TAGS
1451 if (cmd->tag != TAG_NONE) {
1452 tmp[1] = hostdata->last_message = SIMPLE_QUEUE_TAG;
1453 tmp[2] = cmd->tag;
1454 len = 3;
1455 } else
1456 len = 1;
1457#else
1458 len = 1;
1459 cmd->tag = 0;
1460#endif /* SUPPORT_TAGS */
1461
1462 /* Send message(s) */
1463 data = tmp;
1464 phase = PHASE_MSGOUT;
1465 NCR5380_transfer_pio(instance, &phase, &len, &data);
1466 dsprintk(NDEBUG_SELECTION, instance, "nexus established.\n");
1467 /* XXX need to handle errors here */
1468
1469 hostdata->connected = cmd;
1470#ifndef SUPPORT_TAGS
1471 hostdata->busy[cmd->device->id] |= 1 << cmd->device->lun;
1472#endif
1473#ifdef SUN3_SCSI_VME
1474 dregs->csr |= CSR_INTR;
1475#endif
1476
1477 initialize_SCp(cmd);
1478
1479 cmd = NULL;
1480
1481out:
1482 if (!hostdata->selecting)
1483 return NULL;
1484 hostdata->selecting = NULL;
1485 return cmd;
1486}
1487
1488/*
1489 * Function : int NCR5380_transfer_pio (struct Scsi_Host *instance,
1490 * unsigned char *phase, int *count, unsigned char **data)
1491 *
1492 * Purpose : transfers data in given phase using polled I/O
1493 *
1494 * Inputs : instance - instance of driver, *phase - pointer to
1495 * what phase is expected, *count - pointer to number of
1496 * bytes to transfer, **data - pointer to data pointer.
1497 *
1498 * Returns : -1 when different phase is entered without transferring
1499 * maximum number of bytes, 0 if all bytes are transferred or exit
1500 * is in same phase.
1501 *
1502 * Also, *phase, *count, *data are modified in place.
1503 *
1504 * XXX Note : handling for bus free may be useful.
1505 */
1506
1507/*
1508 * Note : this code is not as quick as it could be, however it
1509 * IS 100% reliable, and for the actual data transfer where speed
1510 * counts, we will always do a pseudo DMA or DMA transfer.
1511 */
1512
1513static int NCR5380_transfer_pio(struct Scsi_Host *instance,
1514 unsigned char *phase, int *count,
1515 unsigned char **data)
1516{
1517 unsigned char p = *phase, tmp;
1518 int c = *count;
1519 unsigned char *d = *data;
1520
1521 /*
1522 * The NCR5380 chip will only drive the SCSI bus when the
1523 * phase specified in the appropriate bits of the TARGET COMMAND
1524 * REGISTER match the STATUS REGISTER
1525 */
1526
1527 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1528
1529 do {
1530 /*
1531 * Wait for assertion of REQ, after which the phase bits will be
1532 * valid
1533 */
1534
1535 if (NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ) < 0)
1536 break;
1537
1538 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ asserted\n");
1539
1540 /* Check for phase mismatch */
1541 if ((NCR5380_read(STATUS_REG) & PHASE_MASK) != p) {
1542 dsprintk(NDEBUG_PIO, instance, "phase mismatch\n");
1543 NCR5380_dprint_phase(NDEBUG_PIO, instance);
1544 break;
1545 }
1546
1547 /* Do actual transfer from SCSI bus to / from memory */
1548 if (!(p & SR_IO))
1549 NCR5380_write(OUTPUT_DATA_REG, *d);
1550 else
1551 *d = NCR5380_read(CURRENT_SCSI_DATA_REG);
1552
1553 ++d;
1554
1555 /*
1556 * The SCSI standard suggests that in MSGOUT phase, the initiator
1557 * should drop ATN on the last byte of the message phase
1558 * after REQ has been asserted for the handshake but before
1559 * the initiator raises ACK.
1560 */
1561
1562 if (!(p & SR_IO)) {
1563 if (!((p & SR_MSG) && c > 1)) {
1564 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1565 NCR5380_dprint(NDEBUG_PIO, instance);
1566 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1567 ICR_ASSERT_DATA | ICR_ASSERT_ACK);
1568 } else {
1569 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1570 ICR_ASSERT_DATA | ICR_ASSERT_ATN);
1571 NCR5380_dprint(NDEBUG_PIO, instance);
1572 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1573 ICR_ASSERT_DATA | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1574 }
1575 } else {
1576 NCR5380_dprint(NDEBUG_PIO, instance);
1577 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
1578 }
1579
1580 if (NCR5380_poll_politely(instance,
1581 STATUS_REG, SR_REQ, 0, 5 * HZ) < 0)
1582 break;
1583
1584 dsprintk(NDEBUG_HANDSHAKE, instance, "REQ negated, handshake complete\n");
1585
1586/*
1587 * We have several special cases to consider during REQ/ACK handshaking :
1588 * 1. We were in MSGOUT phase, and we are on the last byte of the
1589 * message. ATN must be dropped as ACK is dropped.
1590 *
1591 * 2. We are in a MSGIN phase, and we are on the last byte of the
1592 * message. We must exit with ACK asserted, so that the calling
1593 * code may raise ATN before dropping ACK to reject the message.
1594 *
1595 * 3. ACK and ATN are clear and the target may proceed as normal.
1596 */
1597 if (!(p == PHASE_MSGIN && c == 1)) {
1598 if (p == PHASE_MSGOUT && c > 1)
1599 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1600 else
1601 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1602 }
1603 } while (--c);
1604
1605 dsprintk(NDEBUG_PIO, instance, "residual %d\n", c);
1606
1607 *count = c;
1608 *data = d;
1609 tmp = NCR5380_read(STATUS_REG);
1610 /* The phase read from the bus is valid if either REQ is (already)
1611 * asserted or if ACK hasn't been released yet. The latter applies if
1612 * we're in MSG IN, DATA IN or STATUS and all bytes have been received.
1613 */
1614 if ((tmp & SR_REQ) || ((tmp & SR_IO) && c == 0))
1615 *phase = tmp & PHASE_MASK;
1616 else
1617 *phase = PHASE_UNKNOWN;
1618
1619 if (!c || (*phase == p))
1620 return 0;
1621 else
1622 return -1;
1623}
1624
1625/**
1626 * do_reset - issue a reset command
1627 * @instance: adapter to reset
1628 *
1629 * Issue a reset sequence to the NCR5380 and try and get the bus
1630 * back into sane shape.
1631 *
1632 * This clears the reset interrupt flag because there may be no handler for
1633 * it. When the driver is initialized, the NCR5380_intr() handler has not yet
1634 * been installed. And when in EH we may have released the ST DMA interrupt.
1635 */
1636
1637static void do_reset(struct Scsi_Host *instance)
1638{
1639 unsigned long flags;
1640
1641 local_irq_save(flags);
1642 NCR5380_write(TARGET_COMMAND_REG,
1643 PHASE_SR_TO_TCR(NCR5380_read(STATUS_REG) & PHASE_MASK));
1644 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST);
1645 udelay(50);
1646 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1647 (void)NCR5380_read(RESET_PARITY_INTERRUPT_REG);
1648 local_irq_restore(flags);
1649}
1650
1651/**
1652 * do_abort - abort the currently established nexus by going to
1653 * MESSAGE OUT phase and sending an ABORT message.
1654 * @instance: relevant scsi host instance
1655 *
1656 * Returns 0 on success, -1 on failure.
1657 */
1658
1659static int do_abort(struct Scsi_Host *instance)
1660{
1661 unsigned char *msgptr, phase, tmp;
1662 int len;
1663 int rc;
1664
1665 /* Request message out phase */
1666 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1667
1668 /*
1669 * Wait for the target to indicate a valid phase by asserting
1670 * REQ. Once this happens, we'll have either a MSGOUT phase
1671 * and can immediately send the ABORT message, or we'll have some
1672 * other phase and will have to source/sink data.
1673 *
1674 * We really don't care what value was on the bus or what value
1675 * the target sees, so we just handshake.
1676 */
1677
1678 rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, 10 * HZ);
1679 if (rc < 0)
1680 goto timeout;
1681
1682 tmp = NCR5380_read(STATUS_REG) & PHASE_MASK;
1683
1684 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1685
1686 if (tmp != PHASE_MSGOUT) {
1687 NCR5380_write(INITIATOR_COMMAND_REG,
1688 ICR_BASE | ICR_ASSERT_ATN | ICR_ASSERT_ACK);
1689 rc = NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, 3 * HZ);
1690 if (rc < 0)
1691 goto timeout;
1692 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
1693 }
1694
1695 tmp = ABORT;
1696 msgptr = &tmp;
1697 len = 1;
1698 phase = PHASE_MSGOUT;
1699 NCR5380_transfer_pio(instance, &phase, &len, &msgptr);
1700
1701 /*
1702 * If we got here, and the command completed successfully,
1703 * we're about to go into bus free state.
1704 */
1705
1706 return len ? -1 : 0;
1707
1708timeout:
1709 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
1710 return -1;
1711}
1712
1713#if defined(REAL_DMA)
1714/*
1715 * Function : int NCR5380_transfer_dma (struct Scsi_Host *instance,
1716 * unsigned char *phase, int *count, unsigned char **data)
1717 *
1718 * Purpose : transfers data in given phase using either real
1719 * or pseudo DMA.
1720 *
1721 * Inputs : instance - instance of driver, *phase - pointer to
1722 * what phase is expected, *count - pointer to number of
1723 * bytes to transfer, **data - pointer to data pointer.
1724 *
1725 * Returns : -1 when different phase is entered without transferring
1726 * maximum number of bytes, 0 if all bytes or transferred or exit
1727 * is in same phase.
1728 *
1729 * Also, *phase, *count, *data are modified in place.
1730 */
1731
1732
1733static int NCR5380_transfer_dma(struct Scsi_Host *instance,
1734 unsigned char *phase, int *count,
1735 unsigned char **data)
1736{
1737 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1738 register int c = *count;
1739 register unsigned char p = *phase;
1740
1741#if defined(CONFIG_SUN3)
1742 /* sanity check */
1743 if (!sun3_dma_setup_done) {
1744 pr_err("scsi%d: transfer_dma without setup!\n",
1745 instance->host_no);
1746 BUG();
1747 }
1748 hostdata->dma_len = c;
1749
1750 dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1751 (p & SR_IO) ? "receive" : "send", c, *data);
1752
1753 /* netbsd turns off ints here, why not be safe and do it too */
1754
1755 /* send start chain */
1756 sun3scsi_dma_start(c, *data);
1757
1758 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1759 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1760 MR_ENABLE_EOP_INTR);
1761 if (p & SR_IO) {
1762 NCR5380_write(INITIATOR_COMMAND_REG, 0);
1763 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1764 } else {
1765 NCR5380_write(INITIATOR_COMMAND_REG, ICR_ASSERT_DATA);
1766 NCR5380_write(START_DMA_SEND_REG, 0);
1767 }
1768
1769#ifdef SUN3_SCSI_VME
1770 dregs->csr |= CSR_DMA_ENABLE;
1771#endif
1772
1773 sun3_dma_active = 1;
1774
1775#else /* !defined(CONFIG_SUN3) */
1776 register unsigned char *d = *data;
1777 unsigned char tmp;
1778
1779 if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) {
1780 *phase = tmp;
1781 return -1;
1782 }
1783
1784 if (hostdata->read_overruns && (p & SR_IO))
1785 c -= hostdata->read_overruns;
1786
1787 dsprintk(NDEBUG_DMA, instance, "initializing DMA %s: length %d, address %p\n",
1788 (p & SR_IO) ? "receive" : "send", c, d);
1789
1790 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(p));
1791 NCR5380_write(MODE_REG, MR_BASE | MR_DMA_MODE | MR_MONITOR_BSY |
1792 MR_ENABLE_EOP_INTR);
1793
1794 if (!(hostdata->flags & FLAG_LATE_DMA_SETUP)) {
1795 /* On the Medusa, it is a must to initialize the DMA before
1796 * starting the NCR. This is also the cleaner way for the TT.
1797 */
1798 hostdata->dma_len = (p & SR_IO) ?
1799 NCR5380_dma_read_setup(instance, d, c) :
1800 NCR5380_dma_write_setup(instance, d, c);
1801 }
1802
1803 if (p & SR_IO)
1804 NCR5380_write(START_DMA_INITIATOR_RECEIVE_REG, 0);
1805 else {
1806 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_DATA);
1807 NCR5380_write(START_DMA_SEND_REG, 0);
1808 }
1809
1810 if (hostdata->flags & FLAG_LATE_DMA_SETUP) {
1811 /* On the Falcon, the DMA setup must be done after the last */
1812 /* NCR access, else the DMA setup gets trashed!
1813 */
1814 hostdata->dma_len = (p & SR_IO) ?
1815 NCR5380_dma_read_setup(instance, d, c) :
1816 NCR5380_dma_write_setup(instance, d, c);
1817 }
1818#endif /* !defined(CONFIG_SUN3) */
1819
1820 return 0;
1821}
1822#endif /* defined(REAL_DMA) */
1823
1824/*
1825 * Function : NCR5380_information_transfer (struct Scsi_Host *instance)
1826 *
1827 * Purpose : run through the various SCSI phases and do as the target
1828 * directs us to. Operates on the currently connected command,
1829 * instance->connected.
1830 *
1831 * Inputs : instance, instance for which we are doing commands
1832 *
1833 * Side effects : SCSI things happen, the disconnected queue will be
1834 * modified if a command disconnects, *instance->connected will
1835 * change.
1836 *
1837 * XXX Note : we need to watch for bus free or a reset condition here
1838 * to recover from an unexpected bus free condition.
1839 */
1840
1841static void NCR5380_information_transfer(struct Scsi_Host *instance)
1842{
1843 struct NCR5380_hostdata *hostdata = shost_priv(instance);
1844 unsigned char msgout = NOP;
1845 int sink = 0;
1846 int len;
1847 int transfersize;
1848 unsigned char *data;
1849 unsigned char phase, tmp, extended_msg[10], old_phase = 0xff;
1850 struct scsi_cmnd *cmd;
1851
1852#ifdef SUN3_SCSI_VME
1853 dregs->csr |= CSR_INTR;
1854#endif
1855
1856 while ((cmd = hostdata->connected)) {
1857 struct NCR5380_cmd *ncmd = scsi_cmd_priv(cmd);
1858
1859 tmp = NCR5380_read(STATUS_REG);
1860 /* We only have a valid SCSI phase when REQ is asserted */
1861 if (tmp & SR_REQ) {
1862 phase = (tmp & PHASE_MASK);
1863 if (phase != old_phase) {
1864 old_phase = phase;
1865 NCR5380_dprint_phase(NDEBUG_INFORMATION, instance);
1866 }
1867#if defined(CONFIG_SUN3)
1868 if (phase == PHASE_CMDOUT) {
1869#if defined(REAL_DMA)
1870 void *d;
1871 unsigned long count;
1872
1873 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1874 count = cmd->SCp.buffer->length;
1875 d = sg_virt(cmd->SCp.buffer);
1876 } else {
1877 count = cmd->SCp.this_residual;
1878 d = cmd->SCp.ptr;
1879 }
1880 /* this command setup for dma yet? */
1881 if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != cmd)) {
1882 if (cmd->request->cmd_type == REQ_TYPE_FS) {
1883 sun3scsi_dma_setup(instance, d, count,
1884 rq_data_dir(cmd->request));
1885 sun3_dma_setup_done = cmd;
1886 }
1887 }
1888#endif
1889#ifdef SUN3_SCSI_VME
1890 dregs->csr |= CSR_INTR;
1891#endif
1892 }
1893#endif /* CONFIG_SUN3 */
1894
1895 if (sink && (phase != PHASE_MSGOUT)) {
1896 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(tmp));
1897
1898 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN |
1899 ICR_ASSERT_ACK);
1900 while (NCR5380_read(STATUS_REG) & SR_REQ)
1901 ;
1902 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE |
1903 ICR_ASSERT_ATN);
1904 sink = 0;
1905 continue;
1906 }
1907
1908 switch (phase) {
1909 case PHASE_DATAOUT:
1910#if (NDEBUG & NDEBUG_NO_DATAOUT)
1911 shost_printk(KERN_DEBUG, instance, "NDEBUG_NO_DATAOUT set, attempted DATAOUT aborted\n");
1912 sink = 1;
1913 do_abort(instance);
1914 cmd->result = DID_ERROR << 16;
1915 complete_cmd(instance, cmd);
1916 hostdata->connected = NULL;
1917 return;
1918#endif
1919 case PHASE_DATAIN:
1920 /*
1921 * If there is no room left in the current buffer in the
1922 * scatter-gather list, move onto the next one.
1923 */
1924
1925 if (!cmd->SCp.this_residual && cmd->SCp.buffers_residual) {
1926 ++cmd->SCp.buffer;
1927 --cmd->SCp.buffers_residual;
1928 cmd->SCp.this_residual = cmd->SCp.buffer->length;
1929 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
1930 merge_contiguous_buffers(cmd);
1931 dsprintk(NDEBUG_INFORMATION, instance, "%d bytes and %d buffers left\n",
1932 cmd->SCp.this_residual,
1933 cmd->SCp.buffers_residual);
1934 }
1935
1936 /*
1937 * The preferred transfer method is going to be
1938 * PSEUDO-DMA for systems that are strictly PIO,
1939 * since we can let the hardware do the handshaking.
1940 *
1941 * For this to work, we need to know the transfersize
1942 * ahead of time, since the pseudo-DMA code will sit
1943 * in an unconditional loop.
1944 */
1945
1946 /* ++roman: I suggest, this should be
1947 * #if def(REAL_DMA)
1948 * instead of leaving REAL_DMA out.
1949 */
1950
1951#if defined(REAL_DMA)
1952#if !defined(CONFIG_SUN3)
1953 transfersize = 0;
1954 if (!cmd->device->borken)
1955#endif
1956 transfersize = NCR5380_dma_xfer_len(instance, cmd, phase);
1957
1958 if (transfersize >= DMA_MIN_SIZE) {
1959 len = transfersize;
1960 cmd->SCp.phase = phase;
1961 if (NCR5380_transfer_dma(instance, &phase,
1962 &len, (unsigned char **)&cmd->SCp.ptr)) {
1963 /*
1964 * If the watchdog timer fires, all future
1965 * accesses to this device will use the
1966 * polled-IO.
1967 */
1968 scmd_printk(KERN_INFO, cmd,
1969 "switching to slow handshake\n");
1970 cmd->device->borken = 1;
1971 sink = 1;
1972 do_abort(instance);
1973 cmd->result = DID_ERROR << 16;
1974 /* XXX - need to source or sink data here, as appropriate */
1975 } else {
1976#ifdef REAL_DMA
1977 /* ++roman: When using real DMA,
1978 * information_transfer() should return after
1979 * starting DMA since it has nothing more to
1980 * do.
1981 */
1982 return;
1983#else
1984 cmd->SCp.this_residual -= transfersize - len;
1985#endif
1986 }
1987 } else
1988#endif /* defined(REAL_DMA) */
1989 {
1990 /* Break up transfer into 3 ms chunks,
1991 * presuming 6 accesses per handshake.
1992 */
1993 transfersize = min((unsigned long)cmd->SCp.this_residual,
1994 hostdata->accesses_per_ms / 2);
1995 len = transfersize;
1996 NCR5380_transfer_pio(instance, &phase, &len,
1997 (unsigned char **)&cmd->SCp.ptr);
1998 cmd->SCp.this_residual -= transfersize - len;
1999 }
2000#if defined(CONFIG_SUN3) && defined(REAL_DMA)
2001 /* if we had intended to dma that command clear it */
2002 if (sun3_dma_setup_done == cmd)
2003 sun3_dma_setup_done = NULL;
2004#endif
2005 return;
2006 case PHASE_MSGIN:
2007 len = 1;
2008 data = &tmp;
2009 NCR5380_transfer_pio(instance, &phase, &len, &data);
2010 cmd->SCp.Message = tmp;
2011
2012 switch (tmp) {
2013 case ABORT:
2014 case COMMAND_COMPLETE:
2015 /* Accept message by clearing ACK */
2016 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2017 dsprintk(NDEBUG_QUEUES, instance,
2018 "COMMAND COMPLETE %p target %d lun %llu\n",
2019 cmd, scmd_id(cmd), cmd->device->lun);
2020
2021 hostdata->connected = NULL;
2022#ifdef SUPPORT_TAGS
2023 cmd_free_tag(cmd);
2024 if (status_byte(cmd->SCp.Status) == QUEUE_FULL) {
2025 u8 lun = cmd->device->lun;
2026 struct tag_alloc *ta = &hostdata->TagAlloc[scmd_id(cmd)][lun];
2027
2028 dsprintk(NDEBUG_TAGS, instance,
2029 "QUEUE_FULL %p target %d lun %d nr_allocated %d\n",
2030 cmd, scmd_id(cmd), lun, ta->nr_allocated);
2031 if (ta->queue_size > ta->nr_allocated)
2032 ta->queue_size = ta->nr_allocated;
2033 }
2034#endif
2035
2036 cmd->result &= ~0xffff;
2037 cmd->result |= cmd->SCp.Status;
2038 cmd->result |= cmd->SCp.Message << 8;
2039
2040 if (cmd->cmnd[0] == REQUEST_SENSE)
2041 complete_cmd(instance, cmd);
2042 else {
2043 if (cmd->SCp.Status == SAM_STAT_CHECK_CONDITION ||
2044 cmd->SCp.Status == SAM_STAT_COMMAND_TERMINATED) {
2045 dsprintk(NDEBUG_QUEUES, instance, "autosense: adding cmd %p to tail of autosense queue\n",
2046 cmd);
2047 list_add_tail(&ncmd->list,
2048 &hostdata->autosense);
2049 } else
2050 complete_cmd(instance, cmd);
2051 }
2052
2053 /*
2054 * Restore phase bits to 0 so an interrupted selection,
2055 * arbitration can resume.
2056 */
2057 NCR5380_write(TARGET_COMMAND_REG, 0);
2058
2059 /* Enable reselect interrupts */
2060 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2061
2062 maybe_release_dma_irq(instance);
2063 return;
2064 case MESSAGE_REJECT:
2065 /* Accept message by clearing ACK */
2066 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2067 switch (hostdata->last_message) {
2068 case HEAD_OF_QUEUE_TAG:
2069 case ORDERED_QUEUE_TAG:
2070 case SIMPLE_QUEUE_TAG:
2071 /* The target obviously doesn't support tagged
2072 * queuing, even though it announced this ability in
2073 * its INQUIRY data ?!? (maybe only this LUN?) Ok,
2074 * clear 'tagged_supported' and lock the LUN, since
2075 * the command is treated as untagged further on.
2076 */
2077 cmd->device->tagged_supported = 0;
2078 hostdata->busy[cmd->device->id] |= (1 << cmd->device->lun);
2079 cmd->tag = TAG_NONE;
2080 dsprintk(NDEBUG_TAGS, instance, "target %d lun %llu rejected QUEUE_TAG message; tagged queuing disabled\n",
2081 scmd_id(cmd), cmd->device->lun);
2082 break;
2083 }
2084 break;
2085 case DISCONNECT:
2086 /* Accept message by clearing ACK */
2087 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2088 hostdata->connected = NULL;
2089 list_add(&ncmd->list, &hostdata->disconnected);
2090 dsprintk(NDEBUG_INFORMATION | NDEBUG_QUEUES,
2091 instance, "connected command %p for target %d lun %llu moved to disconnected queue\n",
2092 cmd, scmd_id(cmd), cmd->device->lun);
2093
2094 /*
2095 * Restore phase bits to 0 so an interrupted selection,
2096 * arbitration can resume.
2097 */
2098 NCR5380_write(TARGET_COMMAND_REG, 0);
2099
2100 /* Enable reselect interrupts */
2101 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2102#ifdef SUN3_SCSI_VME
2103 dregs->csr |= CSR_DMA_ENABLE;
2104#endif
2105 return;
2106 /*
2107 * The SCSI data pointer is *IMPLICITLY* saved on a disconnect
2108 * operation, in violation of the SCSI spec so we can safely
2109 * ignore SAVE/RESTORE pointers calls.
2110 *
2111 * Unfortunately, some disks violate the SCSI spec and
2112 * don't issue the required SAVE_POINTERS message before
2113 * disconnecting, and we have to break spec to remain
2114 * compatible.
2115 */
2116 case SAVE_POINTERS:
2117 case RESTORE_POINTERS:
2118 /* Accept message by clearing ACK */
2119 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2120 break;
2121 case EXTENDED_MESSAGE:
2122 /*
2123 * Start the message buffer with the EXTENDED_MESSAGE
2124 * byte, since spi_print_msg() wants the whole thing.
2125 */
2126 extended_msg[0] = EXTENDED_MESSAGE;
2127 /* Accept first byte by clearing ACK */
2128 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2129
2130 spin_unlock_irq(&hostdata->lock);
2131
2132 dsprintk(NDEBUG_EXTENDED, instance, "receiving extended message\n");
2133
2134 len = 2;
2135 data = extended_msg + 1;
2136 phase = PHASE_MSGIN;
2137 NCR5380_transfer_pio(instance, &phase, &len, &data);
2138 dsprintk(NDEBUG_EXTENDED, instance, "length %d, code 0x%02x\n",
2139 (int)extended_msg[1],
2140 (int)extended_msg[2]);
2141
2142 if (!len && extended_msg[1] > 0 &&
2143 extended_msg[1] <= sizeof(extended_msg) - 2) {
2144 /* Accept third byte by clearing ACK */
2145 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2146 len = extended_msg[1] - 1;
2147 data = extended_msg + 3;
2148 phase = PHASE_MSGIN;
2149
2150 NCR5380_transfer_pio(instance, &phase, &len, &data);
2151 dsprintk(NDEBUG_EXTENDED, instance, "message received, residual %d\n",
2152 len);
2153
2154 switch (extended_msg[2]) {
2155 case EXTENDED_SDTR:
2156 case EXTENDED_WDTR:
2157 case EXTENDED_MODIFY_DATA_POINTER:
2158 case EXTENDED_EXTENDED_IDENTIFY:
2159 tmp = 0;
2160 }
2161 } else if (len) {
2162 shost_printk(KERN_ERR, instance, "error receiving extended message\n");
2163 tmp = 0;
2164 } else {
2165 shost_printk(KERN_NOTICE, instance, "extended message code %02x length %d is too long\n",
2166 extended_msg[2], extended_msg[1]);
2167 tmp = 0;
2168 }
2169
2170 spin_lock_irq(&hostdata->lock);
2171 if (!hostdata->connected)
2172 return;
2173
2174 /* Fall through to reject message */
2175
2176 /*
2177 * If we get something weird that we aren't expecting,
2178 * reject it.
2179 */
2180 default:
2181 if (!tmp) {
2182 shost_printk(KERN_ERR, instance, "rejecting message ");
2183 spi_print_msg(extended_msg);
2184 printk("\n");
2185 } else if (tmp != EXTENDED_MESSAGE)
2186 scmd_printk(KERN_INFO, cmd,
2187 "rejecting unknown message %02x\n",
2188 tmp);
2189 else
2190 scmd_printk(KERN_INFO, cmd,
2191 "rejecting unknown extended message code %02x, length %d\n",
2192 extended_msg[1], extended_msg[0]);
2193
2194 msgout = MESSAGE_REJECT;
2195 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ATN);
2196 break;
2197 } /* switch (tmp) */
2198 break;
2199 case PHASE_MSGOUT:
2200 len = 1;
2201 data = &msgout;
2202 hostdata->last_message = msgout;
2203 NCR5380_transfer_pio(instance, &phase, &len, &data);
2204 if (msgout == ABORT) {
2205 hostdata->connected = NULL;
2206 cmd->result = DID_ERROR << 16;
2207 complete_cmd(instance, cmd);
2208 maybe_release_dma_irq(instance);
2209 NCR5380_write(SELECT_ENABLE_REG, hostdata->id_mask);
2210 return;
2211 }
2212 msgout = NOP;
2213 break;
2214 case PHASE_CMDOUT:
2215 len = cmd->cmd_len;
2216 data = cmd->cmnd;
2217 /*
2218 * XXX for performance reasons, on machines with a
2219 * PSEUDO-DMA architecture we should probably
2220 * use the dma transfer function.
2221 */
2222 NCR5380_transfer_pio(instance, &phase, &len, &data);
2223 break;
2224 case PHASE_STATIN:
2225 len = 1;
2226 data = &tmp;
2227 NCR5380_transfer_pio(instance, &phase, &len, &data);
2228 cmd->SCp.Status = tmp;
2229 break;
2230 default:
2231 shost_printk(KERN_ERR, instance, "unknown phase\n");
2232 NCR5380_dprint(NDEBUG_ANY, instance);
2233 } /* switch(phase) */
2234 } else {
2235 spin_unlock_irq(&hostdata->lock);
2236 NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, SR_REQ, HZ);
2237 spin_lock_irq(&hostdata->lock);
2238 }
2239 }
2240}
2241
2242/*
2243 * Function : void NCR5380_reselect (struct Scsi_Host *instance)
2244 *
2245 * Purpose : does reselection, initializing the instance->connected
2246 * field to point to the scsi_cmnd for which the I_T_L or I_T_L_Q
2247 * nexus has been reestablished,
2248 *
2249 * Inputs : instance - this instance of the NCR5380.
2250 */
2251
2252
2253/* it might eventually prove necessary to do a dma setup on
2254 reselection, but it doesn't seem to be needed now -- sam */
2255
2256static void NCR5380_reselect(struct Scsi_Host *instance)
2257{
2258 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2259 unsigned char target_mask;
2260 unsigned char lun;
2261#ifdef SUPPORT_TAGS
2262 unsigned char tag;
2263#endif
2264 unsigned char msg[3];
2265 int __maybe_unused len;
2266 unsigned char __maybe_unused *data, __maybe_unused phase;
2267 struct NCR5380_cmd *ncmd;
2268 struct scsi_cmnd *tmp;
2269
2270 /*
2271 * Disable arbitration, etc. since the host adapter obviously
2272 * lost, and tell an interrupted NCR5380_select() to restart.
2273 */
2274
2275 NCR5380_write(MODE_REG, MR_BASE);
2276
2277 target_mask = NCR5380_read(CURRENT_SCSI_DATA_REG) & ~(hostdata->id_mask);
2278
2279 dsprintk(NDEBUG_RESELECTION, instance, "reselect\n");
2280
2281 /*
2282 * At this point, we have detected that our SCSI ID is on the bus,
2283 * SEL is true and BSY was false for at least one bus settle delay
2284 * (400 ns).
2285 *
2286 * We must assert BSY ourselves, until the target drops the SEL
2287 * signal.
2288 */
2289
2290 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_BSY);
2291 if (NCR5380_poll_politely(instance,
2292 STATUS_REG, SR_SEL, 0, 2 * HZ) < 0) {
2293 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2294 return;
2295 }
2296 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2297
2298 /*
2299 * Wait for target to go into MSGIN.
2300 */
2301
2302 if (NCR5380_poll_politely(instance,
2303 STATUS_REG, SR_REQ, SR_REQ, 2 * HZ) < 0) {
2304 do_abort(instance);
2305 return;
2306 }
2307
2308#if defined(CONFIG_SUN3) && defined(REAL_DMA)
2309 /* acknowledge toggle to MSGIN */
2310 NCR5380_write(TARGET_COMMAND_REG, PHASE_SR_TO_TCR(PHASE_MSGIN));
2311
2312 /* peek at the byte without really hitting the bus */
2313 msg[0] = NCR5380_read(CURRENT_SCSI_DATA_REG);
2314#else
2315 len = 1;
2316 data = msg;
2317 phase = PHASE_MSGIN;
2318 NCR5380_transfer_pio(instance, &phase, &len, &data);
2319
2320 if (len) {
2321 do_abort(instance);
2322 return;
2323 }
2324#endif
2325
2326 if (!(msg[0] & 0x80)) {
2327 shost_printk(KERN_ERR, instance, "expecting IDENTIFY message, got ");
2328 spi_print_msg(msg);
2329 printk("\n");
2330 do_abort(instance);
2331 return;
2332 }
2333 lun = msg[0] & 0x07;
2334
2335#if defined(SUPPORT_TAGS) && !defined(CONFIG_SUN3)
2336 /* If the phase is still MSGIN, the target wants to send some more
2337 * messages. In case it supports tagged queuing, this is probably a
2338 * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2339 */
2340 tag = TAG_NONE;
2341 if (phase == PHASE_MSGIN && (hostdata->flags & FLAG_TAGGED_QUEUING)) {
2342 /* Accept previous IDENTIFY message by clearing ACK */
2343 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2344 len = 2;
2345 data = msg + 1;
2346 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2347 msg[1] == SIMPLE_QUEUE_TAG)
2348 tag = msg[2];
2349 dsprintk(NDEBUG_TAGS, instance, "reselect: target mask %02x, lun %d sent tag %d\n",
2350 target_mask, lun, tag);
2351 }
2352#endif
2353
2354 /*
2355 * Find the command corresponding to the I_T_L or I_T_L_Q nexus we
2356 * just reestablished, and remove it from the disconnected queue.
2357 */
2358
2359 tmp = NULL;
2360 list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2361 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2362
2363 if (target_mask == (1 << scmd_id(cmd)) &&
2364 lun == (u8)cmd->device->lun
2365#ifdef SUPPORT_TAGS
2366 && (tag == cmd->tag)
2367#endif
2368 ) {
2369 list_del(&ncmd->list);
2370 tmp = cmd;
2371 break;
2372 }
2373 }
2374
2375 if (tmp) {
2376 dsprintk(NDEBUG_RESELECTION | NDEBUG_QUEUES, instance,
2377 "reselect: removed %p from disconnected queue\n", tmp);
2378 } else {
2379
2380#ifdef SUPPORT_TAGS
2381 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d tag %d not in disconnected queue.\n",
2382 target_mask, lun, tag);
2383#else
2384 shost_printk(KERN_ERR, instance, "target bitmask 0x%02x lun %d not in disconnected queue.\n",
2385 target_mask, lun);
2386#endif
2387 /*
2388 * Since we have an established nexus that we can't do anything
2389 * with, we must abort it.
2390 */
2391 do_abort(instance);
2392 return;
2393 }
2394
2395#if defined(CONFIG_SUN3) && defined(REAL_DMA)
2396 /* engage dma setup for the command we just saw */
2397 {
2398 void *d;
2399 unsigned long count;
2400
2401 if (!tmp->SCp.this_residual && tmp->SCp.buffers_residual) {
2402 count = tmp->SCp.buffer->length;
2403 d = sg_virt(tmp->SCp.buffer);
2404 } else {
2405 count = tmp->SCp.this_residual;
2406 d = tmp->SCp.ptr;
2407 }
2408 /* setup this command for dma if not already */
2409 if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != tmp)) {
2410 sun3scsi_dma_setup(instance, d, count,
2411 rq_data_dir(tmp->request));
2412 sun3_dma_setup_done = tmp;
2413 }
2414 }
2415
2416 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_ACK);
2417#endif
2418
2419 /* Accept message by clearing ACK */
2420 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2421
2422#if defined(SUPPORT_TAGS) && defined(CONFIG_SUN3)
2423 /* If the phase is still MSGIN, the target wants to send some more
2424 * messages. In case it supports tagged queuing, this is probably a
2425 * SIMPLE_QUEUE_TAG for the I_T_L_Q nexus.
2426 */
2427 tag = TAG_NONE;
2428 if (phase == PHASE_MSGIN && setup_use_tagged_queuing) {
2429 /* Accept previous IDENTIFY message by clearing ACK */
2430 NCR5380_write(INITIATOR_COMMAND_REG, ICR_BASE);
2431 len = 2;
2432 data = msg + 1;
2433 if (!NCR5380_transfer_pio(instance, &phase, &len, &data) &&
2434 msg[1] == SIMPLE_QUEUE_TAG)
2435 tag = msg[2];
2436 dsprintk(NDEBUG_TAGS, instance, "reselect: target mask %02x, lun %d sent tag %d\n"
2437 target_mask, lun, tag);
2438 }
2439#endif
2440
2441 hostdata->connected = tmp;
2442 dsprintk(NDEBUG_RESELECTION, instance, "nexus established, target %d, lun %llu, tag %d\n",
2443 scmd_id(tmp), tmp->device->lun, tmp->tag);
2444}
2445
2446
2447/**
2448 * list_find_cmd - test for presence of a command in a linked list
2449 * @haystack: list of commands
2450 * @needle: command to search for
2451 */
2452
2453static bool list_find_cmd(struct list_head *haystack,
2454 struct scsi_cmnd *needle)
2455{
2456 struct NCR5380_cmd *ncmd;
2457
2458 list_for_each_entry(ncmd, haystack, list)
2459 if (NCR5380_to_scmd(ncmd) == needle)
2460 return true;
2461 return false;
2462}
2463
2464/**
2465 * list_remove_cmd - remove a command from linked list
2466 * @haystack: list of commands
2467 * @needle: command to remove
2468 */
2469
2470static bool list_del_cmd(struct list_head *haystack,
2471 struct scsi_cmnd *needle)
2472{
2473 if (list_find_cmd(haystack, needle)) {
2474 struct NCR5380_cmd *ncmd = scsi_cmd_priv(needle);
2475
2476 list_del(&ncmd->list);
2477 return true;
2478 }
2479 return false;
2480}
2481
2482/**
2483 * NCR5380_abort - scsi host eh_abort_handler() method
2484 * @cmd: the command to be aborted
2485 *
2486 * Try to abort a given command by removing it from queues and/or sending
2487 * the target an abort message. This may not succeed in causing a target
2488 * to abort the command. Nonetheless, the low-level driver must forget about
2489 * the command because the mid-layer reclaims it and it may be re-issued.
2490 *
2491 * The normal path taken by a command is as follows. For EH we trace this
2492 * same path to locate and abort the command.
2493 *
2494 * unissued -> selecting -> [unissued -> selecting ->]... connected ->
2495 * [disconnected -> connected ->]...
2496 * [autosense -> connected ->] done
2497 *
2498 * If cmd was not found at all then presumably it has already been completed,
2499 * in which case return SUCCESS to try to avoid further EH measures.
2500 *
2501 * If the command has not completed yet, we must not fail to find it.
2502 * We have no option but to forget the aborted command (even if it still
2503 * lacks sense data). The mid-layer may re-issue a command that is in error
2504 * recovery (see scsi_send_eh_cmnd), but the logic and data structures in
2505 * this driver are such that a command can appear on one queue only.
2506 *
2507 * The lock protects driver data structures, but EH handlers also use it
2508 * to serialize their own execution and prevent their own re-entry.
2509 */
2510
2511static int NCR5380_abort(struct scsi_cmnd *cmd)
2512{
2513 struct Scsi_Host *instance = cmd->device->host;
2514 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2515 unsigned long flags;
2516 int result = SUCCESS;
2517
2518 spin_lock_irqsave(&hostdata->lock, flags);
2519
2520#if (NDEBUG & NDEBUG_ANY)
2521 scmd_printk(KERN_INFO, cmd, __func__);
2522#endif
2523 NCR5380_dprint(NDEBUG_ANY, instance);
2524 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2525
2526 if (list_del_cmd(&hostdata->unissued, cmd)) {
2527 dsprintk(NDEBUG_ABORT, instance,
2528 "abort: removed %p from issue queue\n", cmd);
2529 cmd->result = DID_ABORT << 16;
2530 cmd->scsi_done(cmd); /* No tag or busy flag to worry about */
2531 goto out;
2532 }
2533
2534 if (hostdata->selecting == cmd) {
2535 dsprintk(NDEBUG_ABORT, instance,
2536 "abort: cmd %p == selecting\n", cmd);
2537 hostdata->selecting = NULL;
2538 cmd->result = DID_ABORT << 16;
2539 complete_cmd(instance, cmd);
2540 goto out;
2541 }
2542
2543 if (list_del_cmd(&hostdata->disconnected, cmd)) {
2544 dsprintk(NDEBUG_ABORT, instance,
2545 "abort: removed %p from disconnected list\n", cmd);
2546 /* Can't call NCR5380_select() and send ABORT because that
2547 * means releasing the lock. Need a bus reset.
2548 */
2549 set_host_byte(cmd, DID_ERROR);
2550 complete_cmd(instance, cmd);
2551 result = FAILED;
2552 goto out;
2553 }
2554
2555 if (hostdata->connected == cmd) {
2556 dsprintk(NDEBUG_ABORT, instance, "abort: cmd %p is connected\n", cmd);
2557 hostdata->connected = NULL;
2558#ifdef REAL_DMA
2559 hostdata->dma_len = 0;
2560#endif
2561 if (do_abort(instance)) {
2562 set_host_byte(cmd, DID_ERROR);
2563 complete_cmd(instance, cmd);
2564 result = FAILED;
2565 goto out;
2566 }
2567 set_host_byte(cmd, DID_ABORT);
2568 complete_cmd(instance, cmd);
2569 goto out;
2570 }
2571
2572 if (list_del_cmd(&hostdata->autosense, cmd)) {
2573 dsprintk(NDEBUG_ABORT, instance,
2574 "abort: removed %p from sense queue\n", cmd);
2575 set_host_byte(cmd, DID_ERROR);
2576 complete_cmd(instance, cmd);
2577 }
2578
2579out:
2580 if (result == FAILED)
2581 dsprintk(NDEBUG_ABORT, instance, "abort: failed to abort %p\n", cmd);
2582 else
2583 dsprintk(NDEBUG_ABORT, instance, "abort: successfully aborted %p\n", cmd);
2584
2585 queue_work(hostdata->work_q, &hostdata->main_task);
2586 maybe_release_dma_irq(instance);
2587 spin_unlock_irqrestore(&hostdata->lock, flags);
2588
2589 return result;
2590}
2591
2592
2593/**
2594 * NCR5380_bus_reset - reset the SCSI bus
2595 * @cmd: SCSI command undergoing EH
2596 *
2597 * Returns SUCCESS
2598 */
2599
2600static int NCR5380_bus_reset(struct scsi_cmnd *cmd)
2601{
2602 struct Scsi_Host *instance = cmd->device->host;
2603 struct NCR5380_hostdata *hostdata = shost_priv(instance);
2604 int i;
2605 unsigned long flags;
2606 struct NCR5380_cmd *ncmd;
2607
2608 spin_lock_irqsave(&hostdata->lock, flags);
2609
2610#if (NDEBUG & NDEBUG_ANY)
2611 scmd_printk(KERN_INFO, cmd, __func__);
2612#endif
2613 NCR5380_dprint(NDEBUG_ANY, instance);
2614 NCR5380_dprint_phase(NDEBUG_ANY, instance);
2615
2616 do_reset(instance);
2617
2618 /* reset NCR registers */
2619 NCR5380_write(MODE_REG, MR_BASE);
2620 NCR5380_write(TARGET_COMMAND_REG, 0);
2621 NCR5380_write(SELECT_ENABLE_REG, 0);
2622
2623 /* After the reset, there are no more connected or disconnected commands
2624 * and no busy units; so clear the low-level status here to avoid
2625 * conflicts when the mid-level code tries to wake up the affected
2626 * commands!
2627 */
2628
2629 if (list_del_cmd(&hostdata->unissued, cmd)) {
2630 cmd->result = DID_RESET << 16;
2631 cmd->scsi_done(cmd);
2632 }
2633
2634 if (hostdata->selecting) {
2635 hostdata->selecting->result = DID_RESET << 16;
2636 complete_cmd(instance, hostdata->selecting);
2637 hostdata->selecting = NULL;
2638 }
2639
2640 list_for_each_entry(ncmd, &hostdata->disconnected, list) {
2641 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2642
2643 set_host_byte(cmd, DID_RESET);
2644 cmd->scsi_done(cmd);
2645 }
2646 INIT_LIST_HEAD(&hostdata->disconnected);
2647
2648 list_for_each_entry(ncmd, &hostdata->autosense, list) {
2649 struct scsi_cmnd *cmd = NCR5380_to_scmd(ncmd);
2650
2651 set_host_byte(cmd, DID_RESET);
2652 cmd->scsi_done(cmd);
2653 }
2654 INIT_LIST_HEAD(&hostdata->autosense);
2655
2656 if (hostdata->connected) {
2657 set_host_byte(hostdata->connected, DID_RESET);
2658 complete_cmd(instance, hostdata->connected);
2659 hostdata->connected = NULL;
2660 }
2661
2662#ifdef SUPPORT_TAGS
2663 free_all_tags(hostdata);
2664#endif
2665 for (i = 0; i < 8; ++i)
2666 hostdata->busy[i] = 0;
2667#ifdef REAL_DMA
2668 hostdata->dma_len = 0;
2669#endif
2670
2671 queue_work(hostdata->work_q, &hostdata->main_task);
2672 maybe_release_dma_irq(instance);
2673 spin_unlock_irqrestore(&hostdata->lock, flags);
2674
2675 return SUCCESS;
2676}