Commands needing to be retried require a complete re-initialization.
[linux-2.6] / drivers / scsi / ide-scsi.c
1 /*
2  * Copyright (C) 1996-1999  Gadi Oxman <gadio@netvision.net.il>
3  * Copyright (C) 2004-2005  Bartlomiej Zolnierkiewicz
4  */
5
6 /*
7  * Emulation of a SCSI host adapter for IDE ATAPI devices.
8  *
9  * With this driver, one can use the Linux SCSI drivers instead of the
10  * native IDE ATAPI drivers.
11  *
12  * Ver 0.1   Dec  3 96   Initial version.
13  * Ver 0.2   Jan 26 97   Fixed bug in cleanup_module() and added emulation
14  *                        of MODE_SENSE_6/MODE_SELECT_6 for cdroms. Thanks
15  *                        to Janos Farkas for pointing this out.
16  *                       Avoid using bitfields in structures for m68k.
17  *                       Added Scatter/Gather and DMA support.
18  * Ver 0.4   Dec  7 97   Add support for ATAPI PD/CD drives.
19  *                       Use variable timeout for each command.
20  * Ver 0.5   Jan  2 98   Fix previous PD/CD support.
21  *                       Allow disabling of SCSI-6 to SCSI-10 transformation.
22  * Ver 0.6   Jan 27 98   Allow disabling of SCSI command translation layer
23  *                        for access through /dev/sg.
24  *                       Fix MODE_SENSE_6/MODE_SELECT_6/INQUIRY translation.
25  * Ver 0.7   Dec 04 98   Ignore commands where lun != 0 to avoid multiple
26  *                        detection of devices with CONFIG_SCSI_MULTI_LUN
27  * Ver 0.8   Feb 05 99   Optical media need translation too. Reverse 0.7.
28  * Ver 0.9   Jul 04 99   Fix a bug in SG_SET_TRANSFORM.
29  * Ver 0.91  Jun 10 02   Fix "off by one" error in transforms
30  * Ver 0.92  Dec 31 02   Implement new SCSI mid level API
31  */
32
33 #define IDESCSI_VERSION "0.92"
34
35 #include <linux/module.h>
36 #include <linux/types.h>
37 #include <linux/string.h>
38 #include <linux/kernel.h>
39 #include <linux/mm.h>
40 #include <linux/ioport.h>
41 #include <linux/blkdev.h>
42 #include <linux/errno.h>
43 #include <linux/slab.h>
44 #include <linux/ide.h>
45 #include <linux/scatterlist.h>
46 #include <linux/delay.h>
47 #include <linux/mutex.h>
48 #include <linux/bitops.h>
49
50 #include <asm/io.h>
51 #include <asm/uaccess.h>
52
53 #include <scsi/scsi.h>
54 #include <scsi/scsi_cmnd.h>
55 #include <scsi/scsi_device.h>
56 #include <scsi/scsi_host.h>
57 #include <scsi/scsi_tcq.h>
58 #include <scsi/sg.h>
59
60 #define IDESCSI_DEBUG_LOG               0
61
62 #if IDESCSI_DEBUG_LOG
63 #define debug_log(fmt, args...) \
64         printk(KERN_INFO "ide-scsi: " fmt, ## args)
65 #else
66 #define debug_log(fmt, args...) do {} while (0)
67 #endif
68
69 /*
70  *      SCSI command transformation layer
71  */
72 #define IDESCSI_SG_TRANSFORM            1       /* /dev/sg transformation */
73
74 /*
75  *      Log flags
76  */
77 #define IDESCSI_LOG_CMD                 0       /* Log SCSI commands */
78
79 typedef struct ide_scsi_obj {
80         ide_drive_t             *drive;
81         ide_driver_t            *driver;
82         struct gendisk          *disk;
83         struct Scsi_Host        *host;
84
85         unsigned long transform;                /* SCSI cmd translation layer */
86         unsigned long log;                      /* log flags */
87 } idescsi_scsi_t;
88
89 static DEFINE_MUTEX(idescsi_ref_mutex);
90 /* Set by module param to skip cd */
91 static int idescsi_nocd;
92
93 #define ide_scsi_g(disk) \
94         container_of((disk)->private_data, struct ide_scsi_obj, driver)
95
96 static struct ide_scsi_obj *ide_scsi_get(struct gendisk *disk)
97 {
98         struct ide_scsi_obj *scsi = NULL;
99
100         mutex_lock(&idescsi_ref_mutex);
101         scsi = ide_scsi_g(disk);
102         if (scsi) {
103                 if (ide_device_get(scsi->drive))
104                         scsi = NULL;
105                 else
106                         scsi_host_get(scsi->host);
107         }
108         mutex_unlock(&idescsi_ref_mutex);
109         return scsi;
110 }
111
112 static void ide_scsi_put(struct ide_scsi_obj *scsi)
113 {
114         ide_drive_t *drive = scsi->drive;
115
116         mutex_lock(&idescsi_ref_mutex);
117         scsi_host_put(scsi->host);
118         ide_device_put(drive);
119         mutex_unlock(&idescsi_ref_mutex);
120 }
121
122 static inline idescsi_scsi_t *scsihost_to_idescsi(struct Scsi_Host *host)
123 {
124         return (idescsi_scsi_t*) (&host[1]);
125 }
126
127 static inline idescsi_scsi_t *drive_to_idescsi(ide_drive_t *ide_drive)
128 {
129         return scsihost_to_idescsi(ide_drive->driver_data);
130 }
131
132 static void ide_scsi_hex_dump(u8 *data, int len)
133 {
134         print_hex_dump(KERN_CONT, "", DUMP_PREFIX_NONE, 16, 1, data, len, 0);
135 }
136
137 static int idescsi_end_request(ide_drive_t *, int, int);
138
139 static void ide_scsi_callback(ide_drive_t *drive, int dsc)
140 {
141         idescsi_scsi_t *scsi = drive_to_idescsi(drive);
142         struct ide_atapi_pc *pc = drive->pc;
143
144         if (pc->flags & PC_FLAG_TIMEDOUT)
145                 debug_log("%s: got timed out packet %lu at %lu\n", __func__,
146                           pc->scsi_cmd->serial_number, jiffies);
147                 /* end this request now - scsi should retry it*/
148         else if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
149                 printk(KERN_INFO "Packet command completed, %d bytes"
150                                  " transferred\n", pc->xferred);
151
152         idescsi_end_request(drive, 1, 0);
153 }
154
155 static int idescsi_check_condition(ide_drive_t *drive,
156                 struct request *failed_cmd)
157 {
158         idescsi_scsi_t *scsi = drive_to_idescsi(drive);
159         struct ide_atapi_pc   *pc;
160         struct request *rq;
161         u8             *buf;
162
163         /* stuff a sense request in front of our current request */
164         pc = kzalloc(sizeof(struct ide_atapi_pc), GFP_ATOMIC);
165         rq = blk_get_request(drive->queue, READ, GFP_ATOMIC);
166         buf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_ATOMIC);
167         if (!pc || !rq || !buf) {
168                 kfree(buf);
169                 if (rq)
170                         blk_put_request(rq);
171                 kfree(pc);
172                 return -ENOMEM;
173         }
174         rq->special = (char *) pc;
175         pc->rq = rq;
176         pc->buf = buf;
177         pc->c[0] = REQUEST_SENSE;
178         pc->c[4] = pc->req_xfer = pc->buf_size = SCSI_SENSE_BUFFERSIZE;
179         rq->cmd_type = REQ_TYPE_SENSE;
180         rq->cmd_flags |= REQ_PREEMPT;
181         pc->timeout = jiffies + WAIT_READY;
182         /* NOTE! Save the failed packet command in "rq->buffer" */
183         rq->buffer = (void *) failed_cmd->special;
184         pc->scsi_cmd = ((struct ide_atapi_pc *) failed_cmd->special)->scsi_cmd;
185         if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
186                 printk ("ide-scsi: %s: queue cmd = ", drive->name);
187                 ide_scsi_hex_dump(pc->c, 6);
188         }
189         rq->rq_disk = scsi->disk;
190         rq->ref_count++;
191         memcpy(rq->cmd, pc->c, 12);
192         ide_do_drive_cmd(drive, rq);
193         return 0;
194 }
195
196 static ide_startstop_t
197 idescsi_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
198 {
199         ide_hwif_t *hwif = drive->hwif;
200
201         if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
202                 /* force an abort */
203                 hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE);
204
205         rq->errors++;
206
207         idescsi_end_request(drive, 0, 0);
208
209         return ide_stopped;
210 }
211
212 static int idescsi_end_request (ide_drive_t *drive, int uptodate, int nrsecs)
213 {
214         idescsi_scsi_t *scsi = drive_to_idescsi(drive);
215         struct request *rq = HWGROUP(drive)->rq;
216         struct ide_atapi_pc *pc = (struct ide_atapi_pc *) rq->special;
217         int log = test_bit(IDESCSI_LOG_CMD, &scsi->log);
218         struct Scsi_Host *host;
219         int errors = rq->errors;
220         unsigned long flags;
221
222         if (!blk_special_request(rq) && !blk_sense_request(rq)) {
223                 ide_end_request(drive, uptodate, nrsecs);
224                 return 0;
225         }
226         ide_end_drive_cmd (drive, 0, 0);
227         if (blk_sense_request(rq)) {
228                 struct ide_atapi_pc *opc = (struct ide_atapi_pc *) rq->buffer;
229                 if (log) {
230                         printk ("ide-scsi: %s: wrap up check %lu, rst = ", drive->name, opc->scsi_cmd->serial_number);
231                         ide_scsi_hex_dump(pc->buf, 16);
232                 }
233                 memcpy((void *) opc->scsi_cmd->sense_buffer, pc->buf,
234                         SCSI_SENSE_BUFFERSIZE);
235                 kfree(pc->buf);
236                 kfree(pc);
237                 blk_put_request(rq);
238                 pc = opc;
239                 rq = pc->rq;
240                 pc->scsi_cmd->result = (CHECK_CONDITION << 1) |
241                                 (((pc->flags & PC_FLAG_TIMEDOUT) ?
242                                   DID_TIME_OUT :
243                                   DID_OK) << 16);
244         } else if (pc->flags & PC_FLAG_TIMEDOUT) {
245                 if (log)
246                         printk (KERN_WARNING "ide-scsi: %s: timed out for %lu\n",
247                                         drive->name, pc->scsi_cmd->serial_number);
248                 pc->scsi_cmd->result = DID_TIME_OUT << 16;
249         } else if (errors >= ERROR_MAX) {
250                 pc->scsi_cmd->result = DID_ERROR << 16;
251                 if (log)
252                         printk ("ide-scsi: %s: I/O error for %lu\n", drive->name, pc->scsi_cmd->serial_number);
253         } else if (errors) {
254                 if (log)
255                         printk ("ide-scsi: %s: check condition for %lu\n", drive->name, pc->scsi_cmd->serial_number);
256                 if (!idescsi_check_condition(drive, rq))
257                         /* we started a request sense, so we'll be back, exit for now */
258                         return 0;
259                 pc->scsi_cmd->result = (CHECK_CONDITION << 1) | (DID_OK << 16);
260         } else {
261                 pc->scsi_cmd->result = DID_OK << 16;
262         }
263         host = pc->scsi_cmd->device->host;
264         spin_lock_irqsave(host->host_lock, flags);
265         pc->done(pc->scsi_cmd);
266         spin_unlock_irqrestore(host->host_lock, flags);
267         kfree(pc);
268         blk_put_request(rq);
269         drive->pc = NULL;
270         return 0;
271 }
272
273 static inline int idescsi_set_direction(struct ide_atapi_pc *pc)
274 {
275         switch (pc->c[0]) {
276                 case READ_6: case READ_10: case READ_12:
277                         pc->flags &= ~PC_FLAG_WRITING;
278                         return 0;
279                 case WRITE_6: case WRITE_10: case WRITE_12:
280                         pc->flags |= PC_FLAG_WRITING;
281                         return 0;
282                 default:
283                         return 1;
284         }
285 }
286
287 static int idescsi_map_sg(ide_drive_t *drive, struct ide_atapi_pc *pc)
288 {
289         ide_hwif_t *hwif = drive->hwif;
290         struct scatterlist *sg, *scsi_sg;
291         int segments;
292
293         if (!pc->req_xfer || pc->req_xfer % 1024)
294                 return 1;
295
296         if (idescsi_set_direction(pc))
297                 return 1;
298
299         sg = hwif->sg_table;
300         scsi_sg = scsi_sglist(pc->scsi_cmd);
301         segments = scsi_sg_count(pc->scsi_cmd);
302
303         if (segments > hwif->sg_max_nents)
304                 return 1;
305
306         hwif->sg_nents = segments;
307         memcpy(sg, scsi_sg, sizeof(*sg) * segments);
308
309         return 0;
310 }
311
312 static ide_startstop_t idescsi_issue_pc(ide_drive_t *drive,
313                 struct ide_atapi_pc *pc)
314 {
315         /* Set the current packet command */
316         drive->pc = pc;
317
318         return ide_issue_pc(drive, ide_scsi_get_timeout(pc), ide_scsi_expiry);
319 }
320
321 /*
322  *      idescsi_do_request is our request handling function.
323  */
324 static ide_startstop_t idescsi_do_request (ide_drive_t *drive, struct request *rq, sector_t block)
325 {
326         debug_log("dev: %s, cmd: %x, errors: %d\n", rq->rq_disk->disk_name,
327                   rq->cmd[0], rq->errors);
328         debug_log("sector: %ld, nr_sectors: %ld, current_nr_sectors: %d\n",
329                   rq->sector, rq->nr_sectors, rq->current_nr_sectors);
330
331         if (blk_sense_request(rq) || blk_special_request(rq)) {
332                 struct ide_atapi_pc *pc = (struct ide_atapi_pc *)rq->special;
333
334                 if ((drive->dev_flags & IDE_DFLAG_USING_DMA) &&
335                     idescsi_map_sg(drive, pc) == 0)
336                         pc->flags |= PC_FLAG_DMA_OK;
337
338                 return idescsi_issue_pc(drive, pc);
339         }
340         blk_dump_rq_flags(rq, "ide-scsi: unsup command");
341         idescsi_end_request (drive, 0, 0);
342         return ide_stopped;
343 }
344
345 #ifdef CONFIG_IDE_PROC_FS
346 static ide_proc_entry_t idescsi_proc[] = {
347         { "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL },
348         { NULL, 0, NULL, NULL }
349 };
350
351 #define ide_scsi_devset_get(name, field) \
352 static int get_##name(ide_drive_t *drive) \
353 { \
354         idescsi_scsi_t *scsi = drive_to_idescsi(drive); \
355         return scsi->field; \
356 }
357
358 #define ide_scsi_devset_set(name, field) \
359 static int set_##name(ide_drive_t *drive, int arg) \
360 { \
361         idescsi_scsi_t *scsi = drive_to_idescsi(drive); \
362         scsi->field = arg; \
363         return 0; \
364 }
365
366 #define ide_scsi_devset_rw_field(_name, _field) \
367 ide_scsi_devset_get(_name, _field); \
368 ide_scsi_devset_set(_name, _field); \
369 IDE_DEVSET(_name, DS_SYNC, get_##_name, set_##_name);
370
371 ide_devset_rw_field(bios_cyl, bios_cyl);
372 ide_devset_rw_field(bios_head, bios_head);
373 ide_devset_rw_field(bios_sect, bios_sect);
374
375 ide_scsi_devset_rw_field(transform, transform);
376 ide_scsi_devset_rw_field(log, log);
377
378 static const struct ide_proc_devset idescsi_settings[] = {
379         IDE_PROC_DEVSET(bios_cyl,  0, 1023),
380         IDE_PROC_DEVSET(bios_head, 0,  255),
381         IDE_PROC_DEVSET(bios_sect, 0,   63),
382         IDE_PROC_DEVSET(log,       0,    1),
383         IDE_PROC_DEVSET(transform, 0,    3),
384         { 0 },
385 };
386
387 static ide_proc_entry_t *ide_scsi_proc_entries(ide_drive_t *drive)
388 {
389         return idescsi_proc;
390 }
391
392 static const struct ide_proc_devset *ide_scsi_proc_devsets(ide_drive_t *drive)
393 {
394         return idescsi_settings;
395 }
396 #endif
397
398 /*
399  *      Driver initialization.
400  */
401 static void idescsi_setup (ide_drive_t *drive, idescsi_scsi_t *scsi)
402 {
403         clear_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
404 #if IDESCSI_DEBUG_LOG
405         set_bit(IDESCSI_LOG_CMD, &scsi->log);
406 #endif /* IDESCSI_DEBUG_LOG */
407
408         drive->pc_callback       = ide_scsi_callback;
409         drive->pc_update_buffers = NULL;
410         drive->pc_io_buffers     = ide_io_buffers;
411
412         ide_proc_register_driver(drive, scsi->driver);
413 }
414
415 static void ide_scsi_remove(ide_drive_t *drive)
416 {
417         struct Scsi_Host *scsihost = drive->driver_data;
418         struct ide_scsi_obj *scsi = scsihost_to_idescsi(scsihost);
419         struct gendisk *g = scsi->disk;
420
421         scsi_remove_host(scsihost);
422         ide_proc_unregister_driver(drive, scsi->driver);
423
424         ide_unregister_region(g);
425
426         drive->driver_data = NULL;
427         g->private_data = NULL;
428         put_disk(g);
429
430         ide_scsi_put(scsi);
431
432         drive->dev_flags &= ~IDE_DFLAG_SCSI;
433 }
434
435 static int ide_scsi_probe(ide_drive_t *);
436
437 static ide_driver_t idescsi_driver = {
438         .gen_driver = {
439                 .owner          = THIS_MODULE,
440                 .name           = "ide-scsi",
441                 .bus            = &ide_bus_type,
442         },
443         .probe                  = ide_scsi_probe,
444         .remove                 = ide_scsi_remove,
445         .version                = IDESCSI_VERSION,
446         .do_request             = idescsi_do_request,
447         .end_request            = idescsi_end_request,
448         .error                  = idescsi_atapi_error,
449 #ifdef CONFIG_IDE_PROC_FS
450         .proc_entries           = ide_scsi_proc_entries,
451         .proc_devsets           = ide_scsi_proc_devsets,
452 #endif
453 };
454
455 static int idescsi_ide_open(struct block_device *bdev, fmode_t mode)
456 {
457         struct ide_scsi_obj *scsi = ide_scsi_get(bdev->bd_disk);
458
459         if (!scsi)
460                 return -ENXIO;
461
462         return 0;
463 }
464
465 static int idescsi_ide_release(struct gendisk *disk, fmode_t mode)
466 {
467         ide_scsi_put(ide_scsi_g(disk));
468         return 0;
469 }
470
471 static int idescsi_ide_ioctl(struct block_device *bdev, fmode_t mode,
472                         unsigned int cmd, unsigned long arg)
473 {
474         struct ide_scsi_obj *scsi = ide_scsi_g(bdev->bd_disk);
475         return generic_ide_ioctl(scsi->drive, bdev, cmd, arg);
476 }
477
478 static struct block_device_operations idescsi_ops = {
479         .owner          = THIS_MODULE,
480         .open           = idescsi_ide_open,
481         .release        = idescsi_ide_release,
482         .locked_ioctl   = idescsi_ide_ioctl,
483 };
484
485 static int idescsi_slave_configure(struct scsi_device * sdp)
486 {
487         /* Configure detected device */
488         sdp->use_10_for_rw = 1;
489         sdp->use_10_for_ms = 1;
490         scsi_adjust_queue_depth(sdp, MSG_SIMPLE_TAG, sdp->host->cmd_per_lun);
491         return 0;
492 }
493
494 static const char *idescsi_info (struct Scsi_Host *host)
495 {
496         return "SCSI host adapter emulation for IDE ATAPI devices";
497 }
498
499 static int idescsi_ioctl (struct scsi_device *dev, int cmd, void __user *arg)
500 {
501         idescsi_scsi_t *scsi = scsihost_to_idescsi(dev->host);
502
503         if (cmd == SG_SET_TRANSFORM) {
504                 if (arg)
505                         set_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
506                 else
507                         clear_bit(IDESCSI_SG_TRANSFORM, &scsi->transform);
508                 return 0;
509         } else if (cmd == SG_GET_TRANSFORM)
510                 return put_user(test_bit(IDESCSI_SG_TRANSFORM, &scsi->transform), (int __user *) arg);
511         return -EINVAL;
512 }
513
514 static int idescsi_queue (struct scsi_cmnd *cmd,
515                 void (*done)(struct scsi_cmnd *))
516 {
517         struct Scsi_Host *host = cmd->device->host;
518         idescsi_scsi_t *scsi = scsihost_to_idescsi(host);
519         ide_drive_t *drive = scsi->drive;
520         struct request *rq = NULL;
521         struct ide_atapi_pc *pc = NULL;
522         int write = cmd->sc_data_direction == DMA_TO_DEVICE;
523
524         if (!drive) {
525                 scmd_printk (KERN_ERR, cmd, "drive not present\n");
526                 goto abort;
527         }
528         scsi = drive_to_idescsi(drive);
529         pc = kmalloc(sizeof(struct ide_atapi_pc), GFP_ATOMIC);
530         rq = blk_get_request(drive->queue, write, GFP_ATOMIC);
531         if (rq == NULL || pc == NULL) {
532                 printk (KERN_ERR "ide-scsi: %s: out of memory\n", drive->name);
533                 goto abort;
534         }
535
536         memset (pc->c, 0, 12);
537         pc->flags = 0;
538         if (cmd->sc_data_direction == DMA_TO_DEVICE)
539                 pc->flags |= PC_FLAG_WRITING;
540         pc->rq = rq;
541         memcpy (pc->c, cmd->cmnd, cmd->cmd_len);
542         pc->buf = NULL;
543         pc->sg = scsi_sglist(cmd);
544         pc->sg_cnt = scsi_sg_count(cmd);
545         pc->b_count = 0;
546         pc->req_xfer = pc->buf_size = scsi_bufflen(cmd);
547         pc->scsi_cmd = cmd;
548         pc->done = done;
549         pc->timeout = jiffies + cmd->request->timeout;
550
551         if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
552                 printk ("ide-scsi: %s: que %lu, cmd = ", drive->name, cmd->serial_number);
553                 ide_scsi_hex_dump(cmd->cmnd, cmd->cmd_len);
554                 if (memcmp(pc->c, cmd->cmnd, cmd->cmd_len)) {
555                         printk ("ide-scsi: %s: que %lu, tsl = ", drive->name, cmd->serial_number);
556                         ide_scsi_hex_dump(pc->c, 12);
557                 }
558         }
559
560         rq->special = (char *) pc;
561         rq->cmd_type = REQ_TYPE_SPECIAL;
562         spin_unlock_irq(host->host_lock);
563         rq->ref_count++;
564         memcpy(rq->cmd, pc->c, 12);
565         blk_execute_rq_nowait(drive->queue, scsi->disk, rq, 0, NULL);
566         spin_lock_irq(host->host_lock);
567         return 0;
568 abort:
569         kfree (pc);
570         if (rq)
571                 blk_put_request(rq);
572         cmd->result = DID_ERROR << 16;
573         done(cmd);
574         return 0;
575 }
576
577 static int idescsi_eh_abort (struct scsi_cmnd *cmd)
578 {
579         idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
580         ide_drive_t    *drive = scsi->drive;
581         int             busy;
582         int             ret   = FAILED;
583
584         struct ide_atapi_pc *pc;
585
586         /* In idescsi_eh_abort we try to gently pry our command from the ide subsystem */
587
588         if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
589                 printk (KERN_WARNING "ide-scsi: abort called for %lu\n", cmd->serial_number);
590
591         if (!drive) {
592                 printk (KERN_WARNING "ide-scsi: Drive not set in idescsi_eh_abort\n");
593                 WARN_ON(1);
594                 goto no_drive;
595         }
596
597         /* First give it some more time, how much is "right" is hard to say :-( */
598
599         busy = ide_wait_not_busy(HWIF(drive), 100);     /* FIXME - uses mdelay which causes latency? */
600         if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
601                 printk (KERN_WARNING "ide-scsi: drive did%s become ready\n", busy?" not":"");
602
603         spin_lock_irq(&ide_lock);
604
605         /* If there is no pc running we're done (our interrupt took care of it) */
606         pc = drive->pc;
607         if (pc == NULL) {
608                 ret = SUCCESS;
609                 goto ide_unlock;
610         }
611
612         /* It's somewhere in flight. Does ide subsystem agree? */
613         if (pc->scsi_cmd->serial_number == cmd->serial_number && !busy &&
614             elv_queue_empty(drive->queue) && HWGROUP(drive)->rq != pc->rq) {
615                 /*
616                  * FIXME - not sure this condition can ever occur
617                  */
618                 printk (KERN_ERR "ide-scsi: cmd aborted!\n");
619
620                 if (blk_sense_request(pc->rq))
621                         kfree(pc->buf);
622                 /* we need to call blk_put_request twice. */
623                 blk_put_request(pc->rq);
624                 blk_put_request(pc->rq);
625                 kfree(pc);
626                 drive->pc = NULL;
627
628                 ret = SUCCESS;
629         }
630
631 ide_unlock:
632         spin_unlock_irq(&ide_lock);
633 no_drive:
634         if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
635                 printk (KERN_WARNING "ide-scsi: abort returns %s\n", ret == SUCCESS?"success":"failed");
636
637         return ret;
638 }
639
640 static int idescsi_eh_reset (struct scsi_cmnd *cmd)
641 {
642         struct request *req;
643         idescsi_scsi_t *scsi  = scsihost_to_idescsi(cmd->device->host);
644         ide_drive_t    *drive = scsi->drive;
645         int             ready = 0;
646         int             ret   = SUCCESS;
647
648         struct ide_atapi_pc *pc;
649
650         /* In idescsi_eh_reset we forcefully remove the command from the ide subsystem and reset the device. */
651
652         if (test_bit(IDESCSI_LOG_CMD, &scsi->log))
653                 printk (KERN_WARNING "ide-scsi: reset called for %lu\n", cmd->serial_number);
654
655         if (!drive) {
656                 printk (KERN_WARNING "ide-scsi: Drive not set in idescsi_eh_reset\n");
657                 WARN_ON(1);
658                 return FAILED;
659         }
660
661         spin_lock_irq(cmd->device->host->host_lock);
662         spin_lock(&ide_lock);
663
664         pc = drive->pc;
665
666         if (pc == NULL || (req = pc->rq) != HWGROUP(drive)->rq || !HWGROUP(drive)->handler) {
667                 printk (KERN_WARNING "ide-scsi: No active request in idescsi_eh_reset\n");
668                 spin_unlock(&ide_lock);
669                 spin_unlock_irq(cmd->device->host->host_lock);
670                 return FAILED;
671         }
672
673         /* kill current request */
674         if (__blk_end_request(req, -EIO, 0))
675                 BUG();
676         if (blk_sense_request(req))
677                 kfree(pc->buf);
678         kfree(pc);
679         drive->pc = NULL;
680         blk_put_request(req);
681
682         /* now nuke the drive queue */
683         while ((req = elv_next_request(drive->queue))) {
684                 if (__blk_end_request(req, -EIO, 0))
685                         BUG();
686         }
687
688         HWGROUP(drive)->rq = NULL;
689         HWGROUP(drive)->handler = NULL;
690         HWGROUP(drive)->busy = 1;               /* will set this to zero when ide reset finished */
691         spin_unlock(&ide_lock);
692
693         ide_do_reset(drive);
694
695         /* ide_do_reset starts a polling handler which restarts itself every 50ms until the reset finishes */
696
697         do {
698                 spin_unlock_irq(cmd->device->host->host_lock);
699                 msleep(50);
700                 spin_lock_irq(cmd->device->host->host_lock);
701         } while ( HWGROUP(drive)->handler );
702
703         ready = drive_is_ready(drive);
704         HWGROUP(drive)->busy--;
705         if (!ready) {
706                 printk (KERN_ERR "ide-scsi: reset failed!\n");
707                 ret = FAILED;
708         }
709
710         spin_unlock_irq(cmd->device->host->host_lock);
711         return ret;
712 }
713
714 static int idescsi_bios(struct scsi_device *sdev, struct block_device *bdev,
715                 sector_t capacity, int *parm)
716 {
717         idescsi_scsi_t *idescsi = scsihost_to_idescsi(sdev->host);
718         ide_drive_t *drive = idescsi->drive;
719
720         if (drive->bios_cyl && drive->bios_head && drive->bios_sect) {
721                 parm[0] = drive->bios_head;
722                 parm[1] = drive->bios_sect;
723                 parm[2] = drive->bios_cyl;
724         }
725         return 0;
726 }
727
728 static struct scsi_host_template idescsi_template = {
729         .module                 = THIS_MODULE,
730         .name                   = "idescsi",
731         .info                   = idescsi_info,
732         .slave_configure        = idescsi_slave_configure,
733         .ioctl                  = idescsi_ioctl,
734         .queuecommand           = idescsi_queue,
735         .eh_abort_handler       = idescsi_eh_abort,
736         .eh_host_reset_handler  = idescsi_eh_reset,
737         .bios_param             = idescsi_bios,
738         .can_queue              = 40,
739         .this_id                = -1,
740         .sg_tablesize           = 256,
741         .cmd_per_lun            = 5,
742         .max_sectors            = 128,
743         .use_clustering         = DISABLE_CLUSTERING,
744         .emulated               = 1,
745         .proc_name              = "ide-scsi",
746 };
747
748 static int ide_scsi_probe(ide_drive_t *drive)
749 {
750         idescsi_scsi_t *idescsi;
751         struct Scsi_Host *host;
752         struct gendisk *g;
753         static int warned;
754         int err = -ENOMEM;
755         u16 last_lun;
756
757         if (!warned && drive->media == ide_cdrom) {
758                 printk(KERN_WARNING "ide-scsi is deprecated for cd burning! Use ide-cd and give dev=/dev/hdX as device\n");
759                 warned = 1;
760         }
761
762         if (idescsi_nocd && drive->media == ide_cdrom)
763                 return -ENODEV;
764
765         if (!strstr("ide-scsi", drive->driver_req) ||
766             drive->media == ide_disk ||
767             !(host = scsi_host_alloc(&idescsi_template,sizeof(idescsi_scsi_t))))
768                 return -ENODEV;
769
770         drive->dev_flags |= IDE_DFLAG_SCSI;
771
772         g = alloc_disk(1 << PARTN_BITS);
773         if (!g)
774                 goto out_host_put;
775
776         ide_init_disk(g, drive);
777
778         host->max_id = 1;
779
780         last_lun = drive->id[ATA_ID_LAST_LUN];
781         if (last_lun)
782                 debug_log("%s: last_lun=%u\n", drive->name, last_lun);
783
784         if ((last_lun & 7) != 7)
785                 host->max_lun = (last_lun & 7) + 1;
786         else
787                 host->max_lun = 1;
788
789         drive->driver_data = host;
790         idescsi = scsihost_to_idescsi(host);
791         idescsi->drive = drive;
792         idescsi->driver = &idescsi_driver;
793         idescsi->host = host;
794         idescsi->disk = g;
795         g->private_data = &idescsi->driver;
796         err = 0;
797         idescsi_setup(drive, idescsi);
798         g->fops = &idescsi_ops;
799         ide_register_region(g);
800         err = scsi_add_host(host, &drive->gendev);
801         if (!err) {
802                 scsi_scan_host(host);
803                 return 0;
804         }
805         /* fall through on error */
806         ide_unregister_region(g);
807         ide_proc_unregister_driver(drive, &idescsi_driver);
808
809         put_disk(g);
810 out_host_put:
811         drive->dev_flags &= ~IDE_DFLAG_SCSI;
812         scsi_host_put(host);
813         return err;
814 }
815
816 static int __init init_idescsi_module(void)
817 {
818         return driver_register(&idescsi_driver.gen_driver);
819 }
820
821 static void __exit exit_idescsi_module(void)
822 {
823         driver_unregister(&idescsi_driver.gen_driver);
824 }
825
826 module_param(idescsi_nocd, int, 0600);
827 MODULE_PARM_DESC(idescsi_nocd, "Disable handling of CD-ROMs so they may be driven by ide-cd");
828 module_init(init_idescsi_module);
829 module_exit(exit_idescsi_module);
830 MODULE_LICENSE("GPL");