x86, acpi/irq: Handle isa irqs that are not identity mapped to gsi's.
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / block / bsg.c
blob82d58829ba591eeef13a3ed4eca96b8a019c4d85
1 /*
2 * bsg.c - block layer implementation of the sg v4 interface
4 * Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs
5 * Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License version 2. See the file "COPYING" in the main directory of this
9 * archive for more details.
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/file.h>
15 #include <linux/blkdev.h>
16 #include <linux/poll.h>
17 #include <linux/cdev.h>
18 #include <linux/jiffies.h>
19 #include <linux/percpu.h>
20 #include <linux/uio.h>
21 #include <linux/idr.h>
22 #include <linux/bsg.h>
23 #include <linux/smp_lock.h>
24 #include <linux/slab.h>
26 #include <scsi/scsi.h>
27 #include <scsi/scsi_ioctl.h>
28 #include <scsi/scsi_cmnd.h>
29 #include <scsi/scsi_device.h>
30 #include <scsi/scsi_driver.h>
31 #include <scsi/sg.h>
33 #define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
34 #define BSG_VERSION "0.4"
36 struct bsg_device {
37 struct request_queue *queue;
38 spinlock_t lock;
39 struct list_head busy_list;
40 struct list_head done_list;
41 struct hlist_node dev_list;
42 atomic_t ref_count;
43 int queued_cmds;
44 int done_cmds;
45 wait_queue_head_t wq_done;
46 wait_queue_head_t wq_free;
47 char name[20];
48 int max_queue;
49 unsigned long flags;
52 enum {
53 BSG_F_BLOCK = 1,
56 #define BSG_DEFAULT_CMDS 64
57 #define BSG_MAX_DEVS 32768
59 #undef BSG_DEBUG
61 #ifdef BSG_DEBUG
62 #define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args)
63 #else
64 #define dprintk(fmt, args...)
65 #endif
67 static DEFINE_MUTEX(bsg_mutex);
68 static DEFINE_IDR(bsg_minor_idr);
70 #define BSG_LIST_ARRAY_SIZE 8
71 static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
73 static struct class *bsg_class;
74 static int bsg_major;
76 static struct kmem_cache *bsg_cmd_cachep;
79 * our internal command type
81 struct bsg_command {
82 struct bsg_device *bd;
83 struct list_head list;
84 struct request *rq;
85 struct bio *bio;
86 struct bio *bidi_bio;
87 int err;
88 struct sg_io_v4 hdr;
89 char sense[SCSI_SENSE_BUFFERSIZE];
92 static void bsg_free_command(struct bsg_command *bc)
94 struct bsg_device *bd = bc->bd;
95 unsigned long flags;
97 kmem_cache_free(bsg_cmd_cachep, bc);
99 spin_lock_irqsave(&bd->lock, flags);
100 bd->queued_cmds--;
101 spin_unlock_irqrestore(&bd->lock, flags);
103 wake_up(&bd->wq_free);
106 static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
108 struct bsg_command *bc = ERR_PTR(-EINVAL);
110 spin_lock_irq(&bd->lock);
112 if (bd->queued_cmds >= bd->max_queue)
113 goto out;
115 bd->queued_cmds++;
116 spin_unlock_irq(&bd->lock);
118 bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
119 if (unlikely(!bc)) {
120 spin_lock_irq(&bd->lock);
121 bd->queued_cmds--;
122 bc = ERR_PTR(-ENOMEM);
123 goto out;
126 bc->bd = bd;
127 INIT_LIST_HEAD(&bc->list);
128 dprintk("%s: returning free cmd %p\n", bd->name, bc);
129 return bc;
130 out:
131 spin_unlock_irq(&bd->lock);
132 return bc;
135 static inline struct hlist_head *bsg_dev_idx_hash(int index)
137 return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
140 static int bsg_io_schedule(struct bsg_device *bd)
142 DEFINE_WAIT(wait);
143 int ret = 0;
145 spin_lock_irq(&bd->lock);
147 BUG_ON(bd->done_cmds > bd->queued_cmds);
150 * -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no
151 * work to do", even though we return -ENOSPC after this same test
152 * during bsg_write() -- there, it means our buffer can't have more
153 * bsg_commands added to it, thus has no space left.
155 if (bd->done_cmds == bd->queued_cmds) {
156 ret = -ENODATA;
157 goto unlock;
160 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
161 ret = -EAGAIN;
162 goto unlock;
165 prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
166 spin_unlock_irq(&bd->lock);
167 io_schedule();
168 finish_wait(&bd->wq_done, &wait);
170 return ret;
171 unlock:
172 spin_unlock_irq(&bd->lock);
173 return ret;
176 static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
177 struct sg_io_v4 *hdr, struct bsg_device *bd,
178 fmode_t has_write_perm)
180 if (hdr->request_len > BLK_MAX_CDB) {
181 rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
182 if (!rq->cmd)
183 return -ENOMEM;
186 if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request,
187 hdr->request_len))
188 return -EFAULT;
190 if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
191 if (blk_verify_command(rq->cmd, has_write_perm))
192 return -EPERM;
193 } else if (!capable(CAP_SYS_RAWIO))
194 return -EPERM;
197 * fill in request structure
199 rq->cmd_len = hdr->request_len;
200 rq->cmd_type = REQ_TYPE_BLOCK_PC;
202 rq->timeout = msecs_to_jiffies(hdr->timeout);
203 if (!rq->timeout)
204 rq->timeout = q->sg_timeout;
205 if (!rq->timeout)
206 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
207 if (rq->timeout < BLK_MIN_SG_TIMEOUT)
208 rq->timeout = BLK_MIN_SG_TIMEOUT;
210 return 0;
214 * Check if sg_io_v4 from user is allowed and valid
216 static int
217 bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
219 int ret = 0;
221 if (hdr->guard != 'Q')
222 return -EINVAL;
224 switch (hdr->protocol) {
225 case BSG_PROTOCOL_SCSI:
226 switch (hdr->subprotocol) {
227 case BSG_SUB_PROTOCOL_SCSI_CMD:
228 case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
229 break;
230 default:
231 ret = -EINVAL;
233 break;
234 default:
235 ret = -EINVAL;
238 *rw = hdr->dout_xfer_len ? WRITE : READ;
239 return ret;
243 * map sg_io_v4 to a request.
245 static struct request *
246 bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
247 u8 *sense)
249 struct request_queue *q = bd->queue;
250 struct request *rq, *next_rq = NULL;
251 int ret, rw;
252 unsigned int dxfer_len;
253 void *dxferp = NULL;
255 dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
256 hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
257 hdr->din_xfer_len);
259 ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
260 if (ret)
261 return ERR_PTR(ret);
264 * map scatter-gather elements separately and string them to request
266 rq = blk_get_request(q, rw, GFP_KERNEL);
267 if (!rq)
268 return ERR_PTR(-ENOMEM);
269 ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
270 if (ret)
271 goto out;
273 if (rw == WRITE && hdr->din_xfer_len) {
274 if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
275 ret = -EOPNOTSUPP;
276 goto out;
279 next_rq = blk_get_request(q, READ, GFP_KERNEL);
280 if (!next_rq) {
281 ret = -ENOMEM;
282 goto out;
284 rq->next_rq = next_rq;
285 next_rq->cmd_type = rq->cmd_type;
287 dxferp = (void*)(unsigned long)hdr->din_xferp;
288 ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
289 hdr->din_xfer_len, GFP_KERNEL);
290 if (ret)
291 goto out;
294 if (hdr->dout_xfer_len) {
295 dxfer_len = hdr->dout_xfer_len;
296 dxferp = (void*)(unsigned long)hdr->dout_xferp;
297 } else if (hdr->din_xfer_len) {
298 dxfer_len = hdr->din_xfer_len;
299 dxferp = (void*)(unsigned long)hdr->din_xferp;
300 } else
301 dxfer_len = 0;
303 if (dxfer_len) {
304 ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
305 GFP_KERNEL);
306 if (ret)
307 goto out;
310 rq->sense = sense;
311 rq->sense_len = 0;
313 return rq;
314 out:
315 if (rq->cmd != rq->__cmd)
316 kfree(rq->cmd);
317 blk_put_request(rq);
318 if (next_rq) {
319 blk_rq_unmap_user(next_rq->bio);
320 blk_put_request(next_rq);
322 return ERR_PTR(ret);
326 * async completion call-back from the block layer, when scsi/ide/whatever
327 * calls end_that_request_last() on a request
329 static void bsg_rq_end_io(struct request *rq, int uptodate)
331 struct bsg_command *bc = rq->end_io_data;
332 struct bsg_device *bd = bc->bd;
333 unsigned long flags;
335 dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
336 bd->name, rq, bc, bc->bio, uptodate);
338 bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
340 spin_lock_irqsave(&bd->lock, flags);
341 list_move_tail(&bc->list, &bd->done_list);
342 bd->done_cmds++;
343 spin_unlock_irqrestore(&bd->lock, flags);
345 wake_up(&bd->wq_done);
349 * do final setup of a 'bc' and submit the matching 'rq' to the block
350 * layer for io
352 static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
353 struct bsg_command *bc, struct request *rq)
355 int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
358 * add bc command to busy queue and submit rq for io
360 bc->rq = rq;
361 bc->bio = rq->bio;
362 if (rq->next_rq)
363 bc->bidi_bio = rq->next_rq->bio;
364 bc->hdr.duration = jiffies;
365 spin_lock_irq(&bd->lock);
366 list_add_tail(&bc->list, &bd->busy_list);
367 spin_unlock_irq(&bd->lock);
369 dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
371 rq->end_io_data = bc;
372 blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
375 static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
377 struct bsg_command *bc = NULL;
379 spin_lock_irq(&bd->lock);
380 if (bd->done_cmds) {
381 bc = list_first_entry(&bd->done_list, struct bsg_command, list);
382 list_del(&bc->list);
383 bd->done_cmds--;
385 spin_unlock_irq(&bd->lock);
387 return bc;
391 * Get a finished command from the done list
393 static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
395 struct bsg_command *bc;
396 int ret;
398 do {
399 bc = bsg_next_done_cmd(bd);
400 if (bc)
401 break;
403 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
404 bc = ERR_PTR(-EAGAIN);
405 break;
408 ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
409 if (ret) {
410 bc = ERR_PTR(-ERESTARTSYS);
411 break;
413 } while (1);
415 dprintk("%s: returning done %p\n", bd->name, bc);
417 return bc;
420 static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
421 struct bio *bio, struct bio *bidi_bio)
423 int ret = 0;
425 dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
427 * fill in all the output members
429 hdr->device_status = status_byte(rq->errors);
430 hdr->transport_status = host_byte(rq->errors);
431 hdr->driver_status = driver_byte(rq->errors);
432 hdr->info = 0;
433 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
434 hdr->info |= SG_INFO_CHECK;
435 hdr->response_len = 0;
437 if (rq->sense_len && hdr->response) {
438 int len = min_t(unsigned int, hdr->max_response_len,
439 rq->sense_len);
441 ret = copy_to_user((void*)(unsigned long)hdr->response,
442 rq->sense, len);
443 if (!ret)
444 hdr->response_len = len;
445 else
446 ret = -EFAULT;
449 if (rq->next_rq) {
450 hdr->dout_resid = rq->resid_len;
451 hdr->din_resid = rq->next_rq->resid_len;
452 blk_rq_unmap_user(bidi_bio);
453 blk_put_request(rq->next_rq);
454 } else if (rq_data_dir(rq) == READ)
455 hdr->din_resid = rq->resid_len;
456 else
457 hdr->dout_resid = rq->resid_len;
460 * If the request generated a negative error number, return it
461 * (providing we aren't already returning an error); if it's
462 * just a protocol response (i.e. non negative), that gets
463 * processed above.
465 if (!ret && rq->errors < 0)
466 ret = rq->errors;
468 blk_rq_unmap_user(bio);
469 if (rq->cmd != rq->__cmd)
470 kfree(rq->cmd);
471 blk_put_request(rq);
473 return ret;
476 static int bsg_complete_all_commands(struct bsg_device *bd)
478 struct bsg_command *bc;
479 int ret, tret;
481 dprintk("%s: entered\n", bd->name);
484 * wait for all commands to complete
486 ret = 0;
487 do {
488 ret = bsg_io_schedule(bd);
490 * look for -ENODATA specifically -- we'll sometimes get
491 * -ERESTARTSYS when we've taken a signal, but we can't
492 * return until we're done freeing the queue, so ignore
493 * it. The signal will get handled when we're done freeing
494 * the bsg_device.
496 } while (ret != -ENODATA);
499 * discard done commands
501 ret = 0;
502 do {
503 spin_lock_irq(&bd->lock);
504 if (!bd->queued_cmds) {
505 spin_unlock_irq(&bd->lock);
506 break;
508 spin_unlock_irq(&bd->lock);
510 bc = bsg_get_done_cmd(bd);
511 if (IS_ERR(bc))
512 break;
514 tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
515 bc->bidi_bio);
516 if (!ret)
517 ret = tret;
519 bsg_free_command(bc);
520 } while (1);
522 return ret;
525 static int
526 __bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
527 const struct iovec *iov, ssize_t *bytes_read)
529 struct bsg_command *bc;
530 int nr_commands, ret;
532 if (count % sizeof(struct sg_io_v4))
533 return -EINVAL;
535 ret = 0;
536 nr_commands = count / sizeof(struct sg_io_v4);
537 while (nr_commands) {
538 bc = bsg_get_done_cmd(bd);
539 if (IS_ERR(bc)) {
540 ret = PTR_ERR(bc);
541 break;
545 * this is the only case where we need to copy data back
546 * after completing the request. so do that here,
547 * bsg_complete_work() cannot do that for us
549 ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
550 bc->bidi_bio);
552 if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
553 ret = -EFAULT;
555 bsg_free_command(bc);
557 if (ret)
558 break;
560 buf += sizeof(struct sg_io_v4);
561 *bytes_read += sizeof(struct sg_io_v4);
562 nr_commands--;
565 return ret;
568 static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
570 if (file->f_flags & O_NONBLOCK)
571 clear_bit(BSG_F_BLOCK, &bd->flags);
572 else
573 set_bit(BSG_F_BLOCK, &bd->flags);
577 * Check if the error is a "real" error that we should return.
579 static inline int err_block_err(int ret)
581 if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
582 return 1;
584 return 0;
587 static ssize_t
588 bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
590 struct bsg_device *bd = file->private_data;
591 int ret;
592 ssize_t bytes_read;
594 dprintk("%s: read %Zd bytes\n", bd->name, count);
596 bsg_set_block(bd, file);
598 bytes_read = 0;
599 ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
600 *ppos = bytes_read;
602 if (!bytes_read || (bytes_read && err_block_err(ret)))
603 bytes_read = ret;
605 return bytes_read;
608 static int __bsg_write(struct bsg_device *bd, const char __user *buf,
609 size_t count, ssize_t *bytes_written,
610 fmode_t has_write_perm)
612 struct bsg_command *bc;
613 struct request *rq;
614 int ret, nr_commands;
616 if (count % sizeof(struct sg_io_v4))
617 return -EINVAL;
619 nr_commands = count / sizeof(struct sg_io_v4);
620 rq = NULL;
621 bc = NULL;
622 ret = 0;
623 while (nr_commands) {
624 struct request_queue *q = bd->queue;
626 bc = bsg_alloc_command(bd);
627 if (IS_ERR(bc)) {
628 ret = PTR_ERR(bc);
629 bc = NULL;
630 break;
633 if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
634 ret = -EFAULT;
635 break;
639 * get a request, fill in the blanks, and add to request queue
641 rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense);
642 if (IS_ERR(rq)) {
643 ret = PTR_ERR(rq);
644 rq = NULL;
645 break;
648 bsg_add_command(bd, q, bc, rq);
649 bc = NULL;
650 rq = NULL;
651 nr_commands--;
652 buf += sizeof(struct sg_io_v4);
653 *bytes_written += sizeof(struct sg_io_v4);
656 if (bc)
657 bsg_free_command(bc);
659 return ret;
662 static ssize_t
663 bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
665 struct bsg_device *bd = file->private_data;
666 ssize_t bytes_written;
667 int ret;
669 dprintk("%s: write %Zd bytes\n", bd->name, count);
671 bsg_set_block(bd, file);
673 bytes_written = 0;
674 ret = __bsg_write(bd, buf, count, &bytes_written,
675 file->f_mode & FMODE_WRITE);
677 *ppos = bytes_written;
680 * return bytes written on non-fatal errors
682 if (!bytes_written || (bytes_written && err_block_err(ret)))
683 bytes_written = ret;
685 dprintk("%s: returning %Zd\n", bd->name, bytes_written);
686 return bytes_written;
689 static struct bsg_device *bsg_alloc_device(void)
691 struct bsg_device *bd;
693 bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
694 if (unlikely(!bd))
695 return NULL;
697 spin_lock_init(&bd->lock);
699 bd->max_queue = BSG_DEFAULT_CMDS;
701 INIT_LIST_HEAD(&bd->busy_list);
702 INIT_LIST_HEAD(&bd->done_list);
703 INIT_HLIST_NODE(&bd->dev_list);
705 init_waitqueue_head(&bd->wq_free);
706 init_waitqueue_head(&bd->wq_done);
707 return bd;
710 static void bsg_kref_release_function(struct kref *kref)
712 struct bsg_class_device *bcd =
713 container_of(kref, struct bsg_class_device, ref);
714 struct device *parent = bcd->parent;
716 if (bcd->release)
717 bcd->release(bcd->parent);
719 put_device(parent);
722 static int bsg_put_device(struct bsg_device *bd)
724 int ret = 0, do_free;
725 struct request_queue *q = bd->queue;
727 mutex_lock(&bsg_mutex);
729 do_free = atomic_dec_and_test(&bd->ref_count);
730 if (!do_free) {
731 mutex_unlock(&bsg_mutex);
732 goto out;
735 hlist_del(&bd->dev_list);
736 mutex_unlock(&bsg_mutex);
738 dprintk("%s: tearing down\n", bd->name);
741 * close can always block
743 set_bit(BSG_F_BLOCK, &bd->flags);
746 * correct error detection baddies here again. it's the responsibility
747 * of the app to properly reap commands before close() if it wants
748 * fool-proof error detection
750 ret = bsg_complete_all_commands(bd);
752 kfree(bd);
753 out:
754 kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
755 if (do_free)
756 blk_put_queue(q);
757 return ret;
760 static struct bsg_device *bsg_add_device(struct inode *inode,
761 struct request_queue *rq,
762 struct file *file)
764 struct bsg_device *bd;
765 int ret;
766 #ifdef BSG_DEBUG
767 unsigned char buf[32];
768 #endif
769 ret = blk_get_queue(rq);
770 if (ret)
771 return ERR_PTR(-ENXIO);
773 bd = bsg_alloc_device();
774 if (!bd) {
775 blk_put_queue(rq);
776 return ERR_PTR(-ENOMEM);
779 bd->queue = rq;
781 bsg_set_block(bd, file);
783 atomic_set(&bd->ref_count, 1);
784 mutex_lock(&bsg_mutex);
785 hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
787 strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
788 dprintk("bound to <%s>, max queue %d\n",
789 format_dev_t(buf, inode->i_rdev), bd->max_queue);
791 mutex_unlock(&bsg_mutex);
792 return bd;
795 static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
797 struct bsg_device *bd;
798 struct hlist_node *entry;
800 mutex_lock(&bsg_mutex);
802 hlist_for_each_entry(bd, entry, bsg_dev_idx_hash(minor), dev_list) {
803 if (bd->queue == q) {
804 atomic_inc(&bd->ref_count);
805 goto found;
808 bd = NULL;
809 found:
810 mutex_unlock(&bsg_mutex);
811 return bd;
814 static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
816 struct bsg_device *bd;
817 struct bsg_class_device *bcd;
820 * find the class device
822 mutex_lock(&bsg_mutex);
823 bcd = idr_find(&bsg_minor_idr, iminor(inode));
824 if (bcd)
825 kref_get(&bcd->ref);
826 mutex_unlock(&bsg_mutex);
828 if (!bcd)
829 return ERR_PTR(-ENODEV);
831 bd = __bsg_get_device(iminor(inode), bcd->queue);
832 if (bd)
833 return bd;
835 bd = bsg_add_device(inode, bcd->queue, file);
836 if (IS_ERR(bd))
837 kref_put(&bcd->ref, bsg_kref_release_function);
839 return bd;
842 static int bsg_open(struct inode *inode, struct file *file)
844 struct bsg_device *bd;
846 lock_kernel();
847 bd = bsg_get_device(inode, file);
848 unlock_kernel();
850 if (IS_ERR(bd))
851 return PTR_ERR(bd);
853 file->private_data = bd;
854 return 0;
857 static int bsg_release(struct inode *inode, struct file *file)
859 struct bsg_device *bd = file->private_data;
861 file->private_data = NULL;
862 return bsg_put_device(bd);
865 static unsigned int bsg_poll(struct file *file, poll_table *wait)
867 struct bsg_device *bd = file->private_data;
868 unsigned int mask = 0;
870 poll_wait(file, &bd->wq_done, wait);
871 poll_wait(file, &bd->wq_free, wait);
873 spin_lock_irq(&bd->lock);
874 if (!list_empty(&bd->done_list))
875 mask |= POLLIN | POLLRDNORM;
876 if (bd->queued_cmds >= bd->max_queue)
877 mask |= POLLOUT;
878 spin_unlock_irq(&bd->lock);
880 return mask;
883 static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
885 struct bsg_device *bd = file->private_data;
886 int __user *uarg = (int __user *) arg;
887 int ret;
889 switch (cmd) {
891 * our own ioctls
893 case SG_GET_COMMAND_Q:
894 return put_user(bd->max_queue, uarg);
895 case SG_SET_COMMAND_Q: {
896 int queue;
898 if (get_user(queue, uarg))
899 return -EFAULT;
900 if (queue < 1)
901 return -EINVAL;
903 spin_lock_irq(&bd->lock);
904 bd->max_queue = queue;
905 spin_unlock_irq(&bd->lock);
906 return 0;
910 * SCSI/sg ioctls
912 case SG_GET_VERSION_NUM:
913 case SCSI_IOCTL_GET_IDLUN:
914 case SCSI_IOCTL_GET_BUS_NUMBER:
915 case SG_SET_TIMEOUT:
916 case SG_GET_TIMEOUT:
917 case SG_GET_RESERVED_SIZE:
918 case SG_SET_RESERVED_SIZE:
919 case SG_EMULATED_HOST:
920 case SCSI_IOCTL_SEND_COMMAND: {
921 void __user *uarg = (void __user *) arg;
922 return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
924 case SG_IO: {
925 struct request *rq;
926 struct bio *bio, *bidi_bio = NULL;
927 struct sg_io_v4 hdr;
928 int at_head;
929 u8 sense[SCSI_SENSE_BUFFERSIZE];
931 if (copy_from_user(&hdr, uarg, sizeof(hdr)))
932 return -EFAULT;
934 rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense);
935 if (IS_ERR(rq))
936 return PTR_ERR(rq);
938 bio = rq->bio;
939 if (rq->next_rq)
940 bidi_bio = rq->next_rq->bio;
942 at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
943 blk_execute_rq(bd->queue, NULL, rq, at_head);
944 ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
946 if (copy_to_user(uarg, &hdr, sizeof(hdr)))
947 return -EFAULT;
949 return ret;
952 * block device ioctls
954 default:
955 #if 0
956 return ioctl_by_bdev(bd->bdev, cmd, arg);
957 #else
958 return -ENOTTY;
959 #endif
963 static const struct file_operations bsg_fops = {
964 .read = bsg_read,
965 .write = bsg_write,
966 .poll = bsg_poll,
967 .open = bsg_open,
968 .release = bsg_release,
969 .unlocked_ioctl = bsg_ioctl,
970 .owner = THIS_MODULE,
973 void bsg_unregister_queue(struct request_queue *q)
975 struct bsg_class_device *bcd = &q->bsg_dev;
977 if (!bcd->class_dev)
978 return;
980 mutex_lock(&bsg_mutex);
981 idr_remove(&bsg_minor_idr, bcd->minor);
982 sysfs_remove_link(&q->kobj, "bsg");
983 device_unregister(bcd->class_dev);
984 bcd->class_dev = NULL;
985 kref_put(&bcd->ref, bsg_kref_release_function);
986 mutex_unlock(&bsg_mutex);
988 EXPORT_SYMBOL_GPL(bsg_unregister_queue);
990 int bsg_register_queue(struct request_queue *q, struct device *parent,
991 const char *name, void (*release)(struct device *))
993 struct bsg_class_device *bcd;
994 dev_t dev;
995 int ret, minor;
996 struct device *class_dev = NULL;
997 const char *devname;
999 if (name)
1000 devname = name;
1001 else
1002 devname = dev_name(parent);
1005 * we need a proper transport to send commands, not a stacked device
1007 if (!q->request_fn)
1008 return 0;
1010 bcd = &q->bsg_dev;
1011 memset(bcd, 0, sizeof(*bcd));
1013 mutex_lock(&bsg_mutex);
1015 ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL);
1016 if (!ret) {
1017 ret = -ENOMEM;
1018 goto unlock;
1021 ret = idr_get_new(&bsg_minor_idr, bcd, &minor);
1022 if (ret < 0)
1023 goto unlock;
1025 if (minor >= BSG_MAX_DEVS) {
1026 printk(KERN_ERR "bsg: too many bsg devices\n");
1027 ret = -EINVAL;
1028 goto remove_idr;
1031 bcd->minor = minor;
1032 bcd->queue = q;
1033 bcd->parent = get_device(parent);
1034 bcd->release = release;
1035 kref_init(&bcd->ref);
1036 dev = MKDEV(bsg_major, bcd->minor);
1037 class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
1038 if (IS_ERR(class_dev)) {
1039 ret = PTR_ERR(class_dev);
1040 goto put_dev;
1042 bcd->class_dev = class_dev;
1044 if (q->kobj.sd) {
1045 ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
1046 if (ret)
1047 goto unregister_class_dev;
1050 mutex_unlock(&bsg_mutex);
1051 return 0;
1053 unregister_class_dev:
1054 device_unregister(class_dev);
1055 put_dev:
1056 put_device(parent);
1057 remove_idr:
1058 idr_remove(&bsg_minor_idr, minor);
1059 unlock:
1060 mutex_unlock(&bsg_mutex);
1061 return ret;
1063 EXPORT_SYMBOL_GPL(bsg_register_queue);
1065 static struct cdev bsg_cdev;
1067 static char *bsg_devnode(struct device *dev, mode_t *mode)
1069 return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
1072 static int __init bsg_init(void)
1074 int ret, i;
1075 dev_t devid;
1077 bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
1078 sizeof(struct bsg_command), 0, 0, NULL);
1079 if (!bsg_cmd_cachep) {
1080 printk(KERN_ERR "bsg: failed creating slab cache\n");
1081 return -ENOMEM;
1084 for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
1085 INIT_HLIST_HEAD(&bsg_device_list[i]);
1087 bsg_class = class_create(THIS_MODULE, "bsg");
1088 if (IS_ERR(bsg_class)) {
1089 ret = PTR_ERR(bsg_class);
1090 goto destroy_kmemcache;
1092 bsg_class->devnode = bsg_devnode;
1094 ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
1095 if (ret)
1096 goto destroy_bsg_class;
1098 bsg_major = MAJOR(devid);
1100 cdev_init(&bsg_cdev, &bsg_fops);
1101 ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1102 if (ret)
1103 goto unregister_chrdev;
1105 printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
1106 " loaded (major %d)\n", bsg_major);
1107 return 0;
1108 unregister_chrdev:
1109 unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1110 destroy_bsg_class:
1111 class_destroy(bsg_class);
1112 destroy_kmemcache:
1113 kmem_cache_destroy(bsg_cmd_cachep);
1114 return ret;
1117 MODULE_AUTHOR("Jens Axboe");
1118 MODULE_DESCRIPTION(BSG_DESCRIPTION);
1119 MODULE_LICENSE("GPL");
1121 device_initcall(bsg_init);