4 * Copyright (C) 2008 James Smart, Emulex Corporation
5 * Copyright (C) 2011 Red Hat, Inc. All rights reserved.
6 * Copyright (C) 2011 Mike Christie
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/slab.h>
24 #include <linux/blkdev.h>
25 #include <linux/delay.h>
26 #include <linux/scatterlist.h>
27 #include <linux/bsg-lib.h>
28 #include <scsi/scsi_cmnd.h>
31 * bsg_destroy_job - routine to teardown/delete a bsg job
32 * @job: bsg_job that is to be torn down
34 static void bsg_destroy_job(struct bsg_job
*job
)
36 put_device(job
->dev
); /* release reference for the request */
38 kfree(job
->request_payload
.sg_list
);
39 kfree(job
->reply_payload
.sg_list
);
44 * bsg_job_done - completion routine for bsg requests
45 * @job: bsg_job that is complete
46 * @result: job reply result
47 * @reply_payload_rcv_len: length of payload recvd
49 * The LLD should call this when the bsg job has completed.
51 void bsg_job_done(struct bsg_job
*job
, int result
,
52 unsigned int reply_payload_rcv_len
)
54 struct request
*req
= job
->req
;
55 struct request
*rsp
= req
->next_rq
;
58 err
= job
->req
->errors
= result
;
60 /* we're only returning the result field in the reply */
61 job
->req
->sense_len
= sizeof(u32
);
63 job
->req
->sense_len
= job
->reply_len
;
64 /* we assume all request payload was transferred, residual == 0 */
68 WARN_ON(reply_payload_rcv_len
> rsp
->resid_len
);
70 /* set reply (bidi) residual */
71 rsp
->resid_len
-= min(reply_payload_rcv_len
, rsp
->resid_len
);
73 blk_complete_request(req
);
75 EXPORT_SYMBOL_GPL(bsg_job_done
);
78 * bsg_softirq_done - softirq done routine for destroying the bsg requests
79 * @rq: BSG request that holds the job to be destroyed
81 static void bsg_softirq_done(struct request
*rq
)
83 struct bsg_job
*job
= rq
->special
;
85 blk_end_request_all(rq
, rq
->errors
);
89 static int bsg_map_buffer(struct bsg_buffer
*buf
, struct request
*req
)
91 size_t sz
= (sizeof(struct scatterlist
) * req
->nr_phys_segments
);
93 BUG_ON(!req
->nr_phys_segments
);
95 buf
->sg_list
= kzalloc(sz
, GFP_KERNEL
);
98 sg_init_table(buf
->sg_list
, req
->nr_phys_segments
);
99 buf
->sg_cnt
= blk_rq_map_sg(req
->q
, req
, buf
->sg_list
);
100 buf
->payload_len
= blk_rq_bytes(req
);
105 * bsg_create_job - create the bsg_job structure for the bsg request
106 * @dev: device that is being sent the bsg request
107 * @req: BSG request that needs a job structure
109 static int bsg_create_job(struct device
*dev
, struct request
*req
)
111 struct request
*rsp
= req
->next_rq
;
112 struct request_queue
*q
= req
->q
;
116 BUG_ON(req
->special
);
118 job
= kzalloc(sizeof(struct bsg_job
) + q
->bsg_job_size
, GFP_KERNEL
);
125 job
->dd_data
= (void *)&job
[1];
126 job
->request
= req
->cmd
;
127 job
->request_len
= req
->cmd_len
;
128 job
->reply
= req
->sense
;
129 job
->reply_len
= SCSI_SENSE_BUFFERSIZE
; /* Size of sense buffer
132 ret
= bsg_map_buffer(&job
->request_payload
, req
);
134 goto failjob_rls_job
;
136 if (rsp
&& rsp
->bio
) {
137 ret
= bsg_map_buffer(&job
->reply_payload
, rsp
);
139 goto failjob_rls_rqst_payload
;
142 /* take a reference for the request */
143 get_device(job
->dev
);
146 failjob_rls_rqst_payload
:
147 kfree(job
->request_payload
.sg_list
);
154 * bsg_goose_queue - restart queue in case it was stopped
155 * @q: request q to be restarted
157 void bsg_goose_queue(struct request_queue
*q
)
162 blk_run_queue_async(q
);
164 EXPORT_SYMBOL_GPL(bsg_goose_queue
);
167 * bsg_request_fn - generic handler for bsg requests
168 * @q: request queue to manage
170 * On error the create_bsg_job function should return a -Exyz error value
171 * that will be set to the req->errors.
173 * Drivers/subsys should pass this to the queue init function.
175 void bsg_request_fn(struct request_queue
*q
)
177 struct device
*dev
= q
->queuedata
;
182 if (!get_device(dev
))
186 req
= blk_fetch_request(q
);
189 spin_unlock_irq(q
->queue_lock
);
191 ret
= bsg_create_job(dev
, req
);
194 blk_end_request_all(req
, ret
);
195 spin_lock_irq(q
->queue_lock
);
200 ret
= q
->bsg_job_fn(job
);
201 spin_lock_irq(q
->queue_lock
);
206 spin_unlock_irq(q
->queue_lock
);
208 spin_lock_irq(q
->queue_lock
);
210 EXPORT_SYMBOL_GPL(bsg_request_fn
);
213 * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
214 * @dev: device to attach bsg device to
215 * @q: request queue setup by caller
216 * @name: device to give bsg device
217 * @job_fn: bsg job handler
218 * @dd_job_size: size of LLD data needed for each job
220 * The caller should have setup the reuqest queue with bsg_request_fn
223 int bsg_setup_queue(struct device
*dev
, struct request_queue
*q
,
224 char *name
, bsg_job_fn
*job_fn
, int dd_job_size
)
229 q
->bsg_job_size
= dd_job_size
;
230 q
->bsg_job_fn
= job_fn
;
231 queue_flag_set_unlocked(QUEUE_FLAG_BIDI
, q
);
232 blk_queue_softirq_done(q
, bsg_softirq_done
);
233 blk_queue_rq_timeout(q
, BLK_DEFAULT_SG_TIMEOUT
);
235 ret
= bsg_register_queue(q
, dev
, name
, NULL
);
237 printk(KERN_ERR
"%s: bsg interface failed to "
238 "initialize - register queue\n", dev
->kobj
.name
);
244 EXPORT_SYMBOL_GPL(bsg_setup_queue
);
247 * bsg_remove_queue - Deletes the bsg dev from the q
248 * @q: the request_queue that is to be torn down.
251 * Before unregistering the queue empty any requests that are blocked
253 void bsg_remove_queue(struct request_queue
*q
)
255 struct request
*req
; /* block request */
256 int counts
; /* totals for request_list count and starved */
261 /* Stop taking in new requests */
262 spin_lock_irq(q
->queue_lock
);
265 /* drain all requests in the queue */
267 /* need the lock to fetch a request
268 * this may fetch the same reqeust as the previous pass
270 req
= blk_fetch_request(q
);
271 /* save requests in use and starved */
272 counts
= q
->rq
.count
[0] + q
->rq
.count
[1] +
273 q
->rq
.starved
[0] + q
->rq
.starved
[1];
274 spin_unlock_irq(q
->queue_lock
);
275 /* any requests still outstanding? */
279 /* This may be the same req as the previous iteration,
280 * always send the blk_end_request_all after a prefetch.
281 * It is not okay to not end the request because the
282 * prefetch started the request.
285 /* return -ENXIO to indicate that this queue is
288 req
->errors
= -ENXIO
;
289 blk_end_request_all(req
, -ENXIO
);
292 msleep(200); /* allow bsg to possibly finish */
293 spin_lock_irq(q
->queue_lock
);
295 bsg_unregister_queue(q
);
297 EXPORT_SYMBOL_GPL(bsg_remove_queue
);