ACPI: kill acpi_get_pci_id
[linux-2.6/linux-acpi-2.6.git] / block / bsg.c
blobdd81be455e00b3c258357cd2537d200d06455e27
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/percpu.h>
19 #include <linux/uio.h>
20 #include <linux/idr.h>
21 #include <linux/bsg.h>
22 #include <linux/smp_lock.h>
24 #include <scsi/scsi.h>
25 #include <scsi/scsi_ioctl.h>
26 #include <scsi/scsi_cmnd.h>
27 #include <scsi/scsi_device.h>
28 #include <scsi/scsi_driver.h>
29 #include <scsi/sg.h>
31 #define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
32 #define BSG_VERSION "0.4"
34 struct bsg_device {
35 struct request_queue *queue;
36 spinlock_t lock;
37 struct list_head busy_list;
38 struct list_head done_list;
39 struct hlist_node dev_list;
40 atomic_t ref_count;
41 int queued_cmds;
42 int done_cmds;
43 wait_queue_head_t wq_done;
44 wait_queue_head_t wq_free;
45 char name[20];
46 int max_queue;
47 unsigned long flags;
50 enum {
51 BSG_F_BLOCK = 1,
54 #define BSG_DEFAULT_CMDS 64
55 #define BSG_MAX_DEVS 32768
57 #undef BSG_DEBUG
59 #ifdef BSG_DEBUG
60 #define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args)
61 #else
62 #define dprintk(fmt, args...)
63 #endif
65 static DEFINE_MUTEX(bsg_mutex);
66 static DEFINE_IDR(bsg_minor_idr);
68 #define BSG_LIST_ARRAY_SIZE 8
69 static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
71 static struct class *bsg_class;
72 static int bsg_major;
74 static struct kmem_cache *bsg_cmd_cachep;
77 * our internal command type
79 struct bsg_command {
80 struct bsg_device *bd;
81 struct list_head list;
82 struct request *rq;
83 struct bio *bio;
84 struct bio *bidi_bio;
85 int err;
86 struct sg_io_v4 hdr;
87 char sense[SCSI_SENSE_BUFFERSIZE];
90 static void bsg_free_command(struct bsg_command *bc)
92 struct bsg_device *bd = bc->bd;
93 unsigned long flags;
95 kmem_cache_free(bsg_cmd_cachep, bc);
97 spin_lock_irqsave(&bd->lock, flags);
98 bd->queued_cmds--;
99 spin_unlock_irqrestore(&bd->lock, flags);
101 wake_up(&bd->wq_free);
104 static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
106 struct bsg_command *bc = ERR_PTR(-EINVAL);
108 spin_lock_irq(&bd->lock);
110 if (bd->queued_cmds >= bd->max_queue)
111 goto out;
113 bd->queued_cmds++;
114 spin_unlock_irq(&bd->lock);
116 bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
117 if (unlikely(!bc)) {
118 spin_lock_irq(&bd->lock);
119 bd->queued_cmds--;
120 bc = ERR_PTR(-ENOMEM);
121 goto out;
124 bc->bd = bd;
125 INIT_LIST_HEAD(&bc->list);
126 dprintk("%s: returning free cmd %p\n", bd->name, bc);
127 return bc;
128 out:
129 spin_unlock_irq(&bd->lock);
130 return bc;
133 static inline struct hlist_head *bsg_dev_idx_hash(int index)
135 return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
138 static int bsg_io_schedule(struct bsg_device *bd)
140 DEFINE_WAIT(wait);
141 int ret = 0;
143 spin_lock_irq(&bd->lock);
145 BUG_ON(bd->done_cmds > bd->queued_cmds);
148 * -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no
149 * work to do", even though we return -ENOSPC after this same test
150 * during bsg_write() -- there, it means our buffer can't have more
151 * bsg_commands added to it, thus has no space left.
153 if (bd->done_cmds == bd->queued_cmds) {
154 ret = -ENODATA;
155 goto unlock;
158 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
159 ret = -EAGAIN;
160 goto unlock;
163 prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
164 spin_unlock_irq(&bd->lock);
165 io_schedule();
166 finish_wait(&bd->wq_done, &wait);
168 return ret;
169 unlock:
170 spin_unlock_irq(&bd->lock);
171 return ret;
174 static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
175 struct sg_io_v4 *hdr, struct bsg_device *bd,
176 fmode_t has_write_perm)
178 if (hdr->request_len > BLK_MAX_CDB) {
179 rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
180 if (!rq->cmd)
181 return -ENOMEM;
184 if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request,
185 hdr->request_len))
186 return -EFAULT;
188 if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
189 if (blk_verify_command(&q->cmd_filter, rq->cmd, has_write_perm))
190 return -EPERM;
191 } else if (!capable(CAP_SYS_RAWIO))
192 return -EPERM;
195 * fill in request structure
197 rq->cmd_len = hdr->request_len;
198 rq->cmd_type = REQ_TYPE_BLOCK_PC;
200 rq->timeout = (hdr->timeout * HZ) / 1000;
201 if (!rq->timeout)
202 rq->timeout = q->sg_timeout;
203 if (!rq->timeout)
204 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
205 if (rq->timeout < BLK_MIN_SG_TIMEOUT)
206 rq->timeout = BLK_MIN_SG_TIMEOUT;
208 return 0;
212 * Check if sg_io_v4 from user is allowed and valid
214 static int
215 bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
217 int ret = 0;
219 if (hdr->guard != 'Q')
220 return -EINVAL;
222 switch (hdr->protocol) {
223 case BSG_PROTOCOL_SCSI:
224 switch (hdr->subprotocol) {
225 case BSG_SUB_PROTOCOL_SCSI_CMD:
226 case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
227 break;
228 default:
229 ret = -EINVAL;
231 break;
232 default:
233 ret = -EINVAL;
236 *rw = hdr->dout_xfer_len ? WRITE : READ;
237 return ret;
241 * map sg_io_v4 to a request.
243 static struct request *
244 bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
245 u8 *sense)
247 struct request_queue *q = bd->queue;
248 struct request *rq, *next_rq = NULL;
249 int ret, rw;
250 unsigned int dxfer_len;
251 void *dxferp = NULL;
253 dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
254 hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
255 hdr->din_xfer_len);
257 ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
258 if (ret)
259 return ERR_PTR(ret);
262 * map scatter-gather elements seperately and string them to request
264 rq = blk_get_request(q, rw, GFP_KERNEL);
265 if (!rq)
266 return ERR_PTR(-ENOMEM);
267 ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
268 if (ret)
269 goto out;
271 if (rw == WRITE && hdr->din_xfer_len) {
272 if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
273 ret = -EOPNOTSUPP;
274 goto out;
277 next_rq = blk_get_request(q, READ, GFP_KERNEL);
278 if (!next_rq) {
279 ret = -ENOMEM;
280 goto out;
282 rq->next_rq = next_rq;
283 next_rq->cmd_type = rq->cmd_type;
285 dxferp = (void*)(unsigned long)hdr->din_xferp;
286 ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
287 hdr->din_xfer_len, GFP_KERNEL);
288 if (ret)
289 goto out;
292 if (hdr->dout_xfer_len) {
293 dxfer_len = hdr->dout_xfer_len;
294 dxferp = (void*)(unsigned long)hdr->dout_xferp;
295 } else if (hdr->din_xfer_len) {
296 dxfer_len = hdr->din_xfer_len;
297 dxferp = (void*)(unsigned long)hdr->din_xferp;
298 } else
299 dxfer_len = 0;
301 if (dxfer_len) {
302 ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
303 GFP_KERNEL);
304 if (ret)
305 goto out;
308 rq->sense = sense;
309 rq->sense_len = 0;
311 return rq;
312 out:
313 if (rq->cmd != rq->__cmd)
314 kfree(rq->cmd);
315 blk_put_request(rq);
316 if (next_rq) {
317 blk_rq_unmap_user(next_rq->bio);
318 next_rq->bio = NULL;
319 blk_put_request(next_rq);
321 return ERR_PTR(ret);
325 * async completion call-back from the block layer, when scsi/ide/whatever
326 * calls end_that_request_last() on a request
328 static void bsg_rq_end_io(struct request *rq, int uptodate)
330 struct bsg_command *bc = rq->end_io_data;
331 struct bsg_device *bd = bc->bd;
332 unsigned long flags;
334 dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
335 bd->name, rq, bc, bc->bio, uptodate);
337 bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
339 spin_lock_irqsave(&bd->lock, flags);
340 list_move_tail(&bc->list, &bd->done_list);
341 bd->done_cmds++;
342 spin_unlock_irqrestore(&bd->lock, flags);
344 wake_up(&bd->wq_done);
348 * do final setup of a 'bc' and submit the matching 'rq' to the block
349 * layer for io
351 static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
352 struct bsg_command *bc, struct request *rq)
354 int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
357 * add bc command to busy queue and submit rq for io
359 bc->rq = rq;
360 bc->bio = rq->bio;
361 if (rq->next_rq)
362 bc->bidi_bio = rq->next_rq->bio;
363 bc->hdr.duration = jiffies;
364 spin_lock_irq(&bd->lock);
365 list_add_tail(&bc->list, &bd->busy_list);
366 spin_unlock_irq(&bd->lock);
368 dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
370 rq->end_io_data = bc;
371 blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
374 static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
376 struct bsg_command *bc = NULL;
378 spin_lock_irq(&bd->lock);
379 if (bd->done_cmds) {
380 bc = list_first_entry(&bd->done_list, struct bsg_command, list);
381 list_del(&bc->list);
382 bd->done_cmds--;
384 spin_unlock_irq(&bd->lock);
386 return bc;
390 * Get a finished command from the done list
392 static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
394 struct bsg_command *bc;
395 int ret;
397 do {
398 bc = bsg_next_done_cmd(bd);
399 if (bc)
400 break;
402 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
403 bc = ERR_PTR(-EAGAIN);
404 break;
407 ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
408 if (ret) {
409 bc = ERR_PTR(-ERESTARTSYS);
410 break;
412 } while (1);
414 dprintk("%s: returning done %p\n", bd->name, bc);
416 return bc;
419 static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
420 struct bio *bio, struct bio *bidi_bio)
422 int ret = 0;
424 dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
426 * fill in all the output members
428 hdr->device_status = status_byte(rq->errors);
429 hdr->transport_status = host_byte(rq->errors);
430 hdr->driver_status = driver_byte(rq->errors);
431 hdr->info = 0;
432 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
433 hdr->info |= SG_INFO_CHECK;
434 hdr->response_len = 0;
436 if (rq->sense_len && hdr->response) {
437 int len = min_t(unsigned int, hdr->max_response_len,
438 rq->sense_len);
440 ret = copy_to_user((void*)(unsigned long)hdr->response,
441 rq->sense, len);
442 if (!ret)
443 hdr->response_len = len;
444 else
445 ret = -EFAULT;
448 if (rq->next_rq) {
449 hdr->dout_resid = rq->data_len;
450 hdr->din_resid = rq->next_rq->data_len;
451 blk_rq_unmap_user(bidi_bio);
452 rq->next_rq->bio = NULL;
453 blk_put_request(rq->next_rq);
454 } else if (rq_data_dir(rq) == READ)
455 hdr->din_resid = rq->data_len;
456 else
457 hdr->dout_resid = rq->data_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 rq->bio = NULL;
472 blk_put_request(rq);
474 return ret;
477 static int bsg_complete_all_commands(struct bsg_device *bd)
479 struct bsg_command *bc;
480 int ret, tret;
482 dprintk("%s: entered\n", bd->name);
485 * wait for all commands to complete
487 ret = 0;
488 do {
489 ret = bsg_io_schedule(bd);
491 * look for -ENODATA specifically -- we'll sometimes get
492 * -ERESTARTSYS when we've taken a signal, but we can't
493 * return until we're done freeing the queue, so ignore
494 * it. The signal will get handled when we're done freeing
495 * the bsg_device.
497 } while (ret != -ENODATA);
500 * discard done commands
502 ret = 0;
503 do {
504 spin_lock_irq(&bd->lock);
505 if (!bd->queued_cmds) {
506 spin_unlock_irq(&bd->lock);
507 break;
509 spin_unlock_irq(&bd->lock);
511 bc = bsg_get_done_cmd(bd);
512 if (IS_ERR(bc))
513 break;
515 tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
516 bc->bidi_bio);
517 if (!ret)
518 ret = tret;
520 bsg_free_command(bc);
521 } while (1);
523 return ret;
526 static int
527 __bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
528 const struct iovec *iov, ssize_t *bytes_read)
530 struct bsg_command *bc;
531 int nr_commands, ret;
533 if (count % sizeof(struct sg_io_v4))
534 return -EINVAL;
536 ret = 0;
537 nr_commands = count / sizeof(struct sg_io_v4);
538 while (nr_commands) {
539 bc = bsg_get_done_cmd(bd);
540 if (IS_ERR(bc)) {
541 ret = PTR_ERR(bc);
542 break;
546 * this is the only case where we need to copy data back
547 * after completing the request. so do that here,
548 * bsg_complete_work() cannot do that for us
550 ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
551 bc->bidi_bio);
553 if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
554 ret = -EFAULT;
556 bsg_free_command(bc);
558 if (ret)
559 break;
561 buf += sizeof(struct sg_io_v4);
562 *bytes_read += sizeof(struct sg_io_v4);
563 nr_commands--;
566 return ret;
569 static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
571 if (file->f_flags & O_NONBLOCK)
572 clear_bit(BSG_F_BLOCK, &bd->flags);
573 else
574 set_bit(BSG_F_BLOCK, &bd->flags);
578 * Check if the error is a "real" error that we should return.
580 static inline int err_block_err(int ret)
582 if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
583 return 1;
585 return 0;
588 static ssize_t
589 bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
591 struct bsg_device *bd = file->private_data;
592 int ret;
593 ssize_t bytes_read;
595 dprintk("%s: read %Zd bytes\n", bd->name, count);
597 bsg_set_block(bd, file);
599 bytes_read = 0;
600 ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
601 *ppos = bytes_read;
603 if (!bytes_read || (bytes_read && err_block_err(ret)))
604 bytes_read = ret;
606 return bytes_read;
609 static int __bsg_write(struct bsg_device *bd, const char __user *buf,
610 size_t count, ssize_t *bytes_written,
611 fmode_t has_write_perm)
613 struct bsg_command *bc;
614 struct request *rq;
615 int ret, nr_commands;
617 if (count % sizeof(struct sg_io_v4))
618 return -EINVAL;
620 nr_commands = count / sizeof(struct sg_io_v4);
621 rq = NULL;
622 bc = NULL;
623 ret = 0;
624 while (nr_commands) {
625 struct request_queue *q = bd->queue;
627 bc = bsg_alloc_command(bd);
628 if (IS_ERR(bc)) {
629 ret = PTR_ERR(bc);
630 bc = NULL;
631 break;
634 if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
635 ret = -EFAULT;
636 break;
640 * get a request, fill in the blanks, and add to request queue
642 rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense);
643 if (IS_ERR(rq)) {
644 ret = PTR_ERR(rq);
645 rq = NULL;
646 break;
649 bsg_add_command(bd, q, bc, rq);
650 bc = NULL;
651 rq = NULL;
652 nr_commands--;
653 buf += sizeof(struct sg_io_v4);
654 *bytes_written += sizeof(struct sg_io_v4);
657 if (bc)
658 bsg_free_command(bc);
660 return ret;
663 static ssize_t
664 bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
666 struct bsg_device *bd = file->private_data;
667 ssize_t bytes_written;
668 int ret;
670 dprintk("%s: write %Zd bytes\n", bd->name, count);
672 bsg_set_block(bd, file);
674 bytes_written = 0;
675 ret = __bsg_write(bd, buf, count, &bytes_written,
676 file->f_mode & FMODE_WRITE);
678 *ppos = bytes_written;
681 * return bytes written on non-fatal errors
683 if (!bytes_written || (bytes_written && err_block_err(ret)))
684 bytes_written = ret;
686 dprintk("%s: returning %Zd\n", bd->name, bytes_written);
687 return bytes_written;
690 static struct bsg_device *bsg_alloc_device(void)
692 struct bsg_device *bd;
694 bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
695 if (unlikely(!bd))
696 return NULL;
698 spin_lock_init(&bd->lock);
700 bd->max_queue = BSG_DEFAULT_CMDS;
702 INIT_LIST_HEAD(&bd->busy_list);
703 INIT_LIST_HEAD(&bd->done_list);
704 INIT_HLIST_NODE(&bd->dev_list);
706 init_waitqueue_head(&bd->wq_free);
707 init_waitqueue_head(&bd->wq_done);
708 return bd;
711 static void bsg_kref_release_function(struct kref *kref)
713 struct bsg_class_device *bcd =
714 container_of(kref, struct bsg_class_device, ref);
715 struct device *parent = bcd->parent;
717 if (bcd->release)
718 bcd->release(bcd->parent);
720 put_device(parent);
723 static int bsg_put_device(struct bsg_device *bd)
725 int ret = 0, do_free;
726 struct request_queue *q = bd->queue;
728 mutex_lock(&bsg_mutex);
730 do_free = atomic_dec_and_test(&bd->ref_count);
731 if (!do_free) {
732 mutex_unlock(&bsg_mutex);
733 goto out;
736 hlist_del(&bd->dev_list);
737 mutex_unlock(&bsg_mutex);
739 dprintk("%s: tearing down\n", bd->name);
742 * close can always block
744 set_bit(BSG_F_BLOCK, &bd->flags);
747 * correct error detection baddies here again. it's the responsibility
748 * of the app to properly reap commands before close() if it wants
749 * fool-proof error detection
751 ret = bsg_complete_all_commands(bd);
753 kfree(bd);
754 out:
755 kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
756 if (do_free)
757 blk_put_queue(q);
758 return ret;
761 static struct bsg_device *bsg_add_device(struct inode *inode,
762 struct request_queue *rq,
763 struct file *file)
765 struct bsg_device *bd;
766 int ret;
767 #ifdef BSG_DEBUG
768 unsigned char buf[32];
769 #endif
770 ret = blk_get_queue(rq);
771 if (ret)
772 return ERR_PTR(-ENXIO);
774 bd = bsg_alloc_device();
775 if (!bd) {
776 blk_put_queue(rq);
777 return ERR_PTR(-ENOMEM);
780 bd->queue = rq;
782 bsg_set_block(bd, file);
784 atomic_set(&bd->ref_count, 1);
785 mutex_lock(&bsg_mutex);
786 hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
788 strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
789 dprintk("bound to <%s>, max queue %d\n",
790 format_dev_t(buf, inode->i_rdev), bd->max_queue);
792 mutex_unlock(&bsg_mutex);
793 return bd;
796 static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
798 struct bsg_device *bd;
799 struct hlist_node *entry;
801 mutex_lock(&bsg_mutex);
803 hlist_for_each_entry(bd, entry, bsg_dev_idx_hash(minor), dev_list) {
804 if (bd->queue == q) {
805 atomic_inc(&bd->ref_count);
806 goto found;
809 bd = NULL;
810 found:
811 mutex_unlock(&bsg_mutex);
812 return bd;
815 static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
817 struct bsg_device *bd;
818 struct bsg_class_device *bcd;
821 * find the class device
823 mutex_lock(&bsg_mutex);
824 bcd = idr_find(&bsg_minor_idr, iminor(inode));
825 if (bcd)
826 kref_get(&bcd->ref);
827 mutex_unlock(&bsg_mutex);
829 if (!bcd)
830 return ERR_PTR(-ENODEV);
832 bd = __bsg_get_device(iminor(inode), bcd->queue);
833 if (bd)
834 return bd;
836 bd = bsg_add_device(inode, bcd->queue, file);
837 if (IS_ERR(bd))
838 kref_put(&bcd->ref, bsg_kref_release_function);
840 return bd;
843 static int bsg_open(struct inode *inode, struct file *file)
845 struct bsg_device *bd;
847 lock_kernel();
848 bd = bsg_get_device(inode, file);
849 unlock_kernel();
851 if (IS_ERR(bd))
852 return PTR_ERR(bd);
854 file->private_data = bd;
855 return 0;
858 static int bsg_release(struct inode *inode, struct file *file)
860 struct bsg_device *bd = file->private_data;
862 file->private_data = NULL;
863 return bsg_put_device(bd);
866 static unsigned int bsg_poll(struct file *file, poll_table *wait)
868 struct bsg_device *bd = file->private_data;
869 unsigned int mask = 0;
871 poll_wait(file, &bd->wq_done, wait);
872 poll_wait(file, &bd->wq_free, wait);
874 spin_lock_irq(&bd->lock);
875 if (!list_empty(&bd->done_list))
876 mask |= POLLIN | POLLRDNORM;
877 if (bd->queued_cmds >= bd->max_queue)
878 mask |= POLLOUT;
879 spin_unlock_irq(&bd->lock);
881 return mask;
884 static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
886 struct bsg_device *bd = file->private_data;
887 int __user *uarg = (int __user *) arg;
888 int ret;
890 switch (cmd) {
892 * our own ioctls
894 case SG_GET_COMMAND_Q:
895 return put_user(bd->max_queue, uarg);
896 case SG_SET_COMMAND_Q: {
897 int queue;
899 if (get_user(queue, uarg))
900 return -EFAULT;
901 if (queue < 1)
902 return -EINVAL;
904 spin_lock_irq(&bd->lock);
905 bd->max_queue = queue;
906 spin_unlock_irq(&bd->lock);
907 return 0;
911 * SCSI/sg ioctls
913 case SG_GET_VERSION_NUM:
914 case SCSI_IOCTL_GET_IDLUN:
915 case SCSI_IOCTL_GET_BUS_NUMBER:
916 case SG_SET_TIMEOUT:
917 case SG_GET_TIMEOUT:
918 case SG_GET_RESERVED_SIZE:
919 case SG_SET_RESERVED_SIZE:
920 case SG_EMULATED_HOST:
921 case SCSI_IOCTL_SEND_COMMAND: {
922 void __user *uarg = (void __user *) arg;
923 return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
925 case SG_IO: {
926 struct request *rq;
927 struct bio *bio, *bidi_bio = NULL;
928 struct sg_io_v4 hdr;
929 int at_head;
930 u8 sense[SCSI_SENSE_BUFFERSIZE];
932 if (copy_from_user(&hdr, uarg, sizeof(hdr)))
933 return -EFAULT;
935 rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense);
936 if (IS_ERR(rq))
937 return PTR_ERR(rq);
939 bio = rq->bio;
940 if (rq->next_rq)
941 bidi_bio = rq->next_rq->bio;
943 at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
944 blk_execute_rq(bd->queue, NULL, rq, at_head);
945 ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
947 if (copy_to_user(uarg, &hdr, sizeof(hdr)))
948 return -EFAULT;
950 return ret;
953 * block device ioctls
955 default:
956 #if 0
957 return ioctl_by_bdev(bd->bdev, cmd, arg);
958 #else
959 return -ENOTTY;
960 #endif
964 static const struct file_operations bsg_fops = {
965 .read = bsg_read,
966 .write = bsg_write,
967 .poll = bsg_poll,
968 .open = bsg_open,
969 .release = bsg_release,
970 .unlocked_ioctl = bsg_ioctl,
971 .owner = THIS_MODULE,
974 void bsg_unregister_queue(struct request_queue *q)
976 struct bsg_class_device *bcd = &q->bsg_dev;
978 if (!bcd->class_dev)
979 return;
981 mutex_lock(&bsg_mutex);
982 idr_remove(&bsg_minor_idr, bcd->minor);
983 sysfs_remove_link(&q->kobj, "bsg");
984 device_unregister(bcd->class_dev);
985 bcd->class_dev = NULL;
986 kref_put(&bcd->ref, bsg_kref_release_function);
987 mutex_unlock(&bsg_mutex);
989 EXPORT_SYMBOL_GPL(bsg_unregister_queue);
991 int bsg_register_queue(struct request_queue *q, struct device *parent,
992 const char *name, void (*release)(struct device *))
994 struct bsg_class_device *bcd;
995 dev_t dev;
996 int ret, minor;
997 struct device *class_dev = NULL;
998 const char *devname;
1000 if (name)
1001 devname = name;
1002 else
1003 devname = dev_name(parent);
1006 * we need a proper transport to send commands, not a stacked device
1008 if (!q->request_fn)
1009 return 0;
1011 bcd = &q->bsg_dev;
1012 memset(bcd, 0, sizeof(*bcd));
1014 mutex_lock(&bsg_mutex);
1016 ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL);
1017 if (!ret) {
1018 ret = -ENOMEM;
1019 goto unlock;
1022 ret = idr_get_new(&bsg_minor_idr, bcd, &minor);
1023 if (ret < 0)
1024 goto unlock;
1026 if (minor >= BSG_MAX_DEVS) {
1027 printk(KERN_ERR "bsg: too many bsg devices\n");
1028 ret = -EINVAL;
1029 goto remove_idr;
1032 bcd->minor = minor;
1033 bcd->queue = q;
1034 bcd->parent = get_device(parent);
1035 bcd->release = release;
1036 kref_init(&bcd->ref);
1037 dev = MKDEV(bsg_major, bcd->minor);
1038 class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
1039 if (IS_ERR(class_dev)) {
1040 ret = PTR_ERR(class_dev);
1041 goto put_dev;
1043 bcd->class_dev = class_dev;
1045 if (q->kobj.sd) {
1046 ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
1047 if (ret)
1048 goto unregister_class_dev;
1051 mutex_unlock(&bsg_mutex);
1052 return 0;
1054 unregister_class_dev:
1055 device_unregister(class_dev);
1056 put_dev:
1057 put_device(parent);
1058 remove_idr:
1059 idr_remove(&bsg_minor_idr, minor);
1060 unlock:
1061 mutex_unlock(&bsg_mutex);
1062 return ret;
1064 EXPORT_SYMBOL_GPL(bsg_register_queue);
1066 static struct cdev bsg_cdev;
1068 static int __init bsg_init(void)
1070 int ret, i;
1071 dev_t devid;
1073 bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
1074 sizeof(struct bsg_command), 0, 0, NULL);
1075 if (!bsg_cmd_cachep) {
1076 printk(KERN_ERR "bsg: failed creating slab cache\n");
1077 return -ENOMEM;
1080 for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
1081 INIT_HLIST_HEAD(&bsg_device_list[i]);
1083 bsg_class = class_create(THIS_MODULE, "bsg");
1084 if (IS_ERR(bsg_class)) {
1085 ret = PTR_ERR(bsg_class);
1086 goto destroy_kmemcache;
1089 ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
1090 if (ret)
1091 goto destroy_bsg_class;
1093 bsg_major = MAJOR(devid);
1095 cdev_init(&bsg_cdev, &bsg_fops);
1096 ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1097 if (ret)
1098 goto unregister_chrdev;
1100 printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
1101 " loaded (major %d)\n", bsg_major);
1102 return 0;
1103 unregister_chrdev:
1104 unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1105 destroy_bsg_class:
1106 class_destroy(bsg_class);
1107 destroy_kmemcache:
1108 kmem_cache_destroy(bsg_cmd_cachep);
1109 return ret;
1112 MODULE_AUTHOR("Jens Axboe");
1113 MODULE_DESCRIPTION(BSG_DESCRIPTION);
1114 MODULE_LICENSE("GPL");
1116 device_initcall(bsg_init);