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 <linux/export.h>
29 #include <scsi/scsi_cmnd.h>
32 * bsg_destroy_job - routine to teardown/delete a bsg job
33 * @job: bsg_job that is to be torn down
35 static void bsg_destroy_job(struct bsg_job
*job
)
37 put_device(job
->dev
); /* release reference for the request */
39 kfree(job
->request_payload
.sg_list
);
40 kfree(job
->reply_payload
.sg_list
);
45 * bsg_job_done - completion routine for bsg requests
46 * @job: bsg_job that is complete
47 * @result: job reply result
48 * @reply_payload_rcv_len: length of payload recvd
50 * The LLD should call this when the bsg job has completed.
52 void bsg_job_done(struct bsg_job
*job
, int result
,
53 unsigned int reply_payload_rcv_len
)
55 struct request
*req
= job
->req
;
56 struct request
*rsp
= req
->next_rq
;
59 err
= job
->req
->errors
= result
;
61 /* we're only returning the result field in the reply */
62 job
->req
->sense_len
= sizeof(u32
);
64 job
->req
->sense_len
= job
->reply_len
;
65 /* we assume all request payload was transferred, residual == 0 */
69 WARN_ON(reply_payload_rcv_len
> rsp
->resid_len
);
71 /* set reply (bidi) residual */
72 rsp
->resid_len
-= min(reply_payload_rcv_len
, rsp
->resid_len
);
74 blk_complete_request(req
);
76 EXPORT_SYMBOL_GPL(bsg_job_done
);
79 * bsg_softirq_done - softirq done routine for destroying the bsg requests
80 * @rq: BSG request that holds the job to be destroyed
82 static void bsg_softirq_done(struct request
*rq
)
84 struct bsg_job
*job
= rq
->special
;
86 blk_end_request_all(rq
, rq
->errors
);
90 static int bsg_map_buffer(struct bsg_buffer
*buf
, struct request
*req
)
92 size_t sz
= (sizeof(struct scatterlist
) * req
->nr_phys_segments
);
94 BUG_ON(!req
->nr_phys_segments
);
96 buf
->sg_list
= kzalloc(sz
, GFP_KERNEL
);
99 sg_init_table(buf
->sg_list
, req
->nr_phys_segments
);
100 buf
->sg_cnt
= blk_rq_map_sg(req
->q
, req
, buf
->sg_list
);
101 buf
->payload_len
= blk_rq_bytes(req
);
106 * bsg_create_job - create the bsg_job structure for the bsg request
107 * @dev: device that is being sent the bsg request
108 * @req: BSG request that needs a job structure
110 static int bsg_create_job(struct device
*dev
, struct request
*req
)
112 struct request
*rsp
= req
->next_rq
;
113 struct request_queue
*q
= req
->q
;
117 BUG_ON(req
->special
);
119 job
= kzalloc(sizeof(struct bsg_job
) + q
->bsg_job_size
, GFP_KERNEL
);
126 job
->dd_data
= (void *)&job
[1];
127 job
->request
= req
->cmd
;
128 job
->request_len
= req
->cmd_len
;
129 job
->reply
= req
->sense
;
130 job
->reply_len
= SCSI_SENSE_BUFFERSIZE
; /* Size of sense buffer
133 ret
= bsg_map_buffer(&job
->request_payload
, req
);
135 goto failjob_rls_job
;
137 if (rsp
&& rsp
->bio
) {
138 ret
= bsg_map_buffer(&job
->reply_payload
, rsp
);
140 goto failjob_rls_rqst_payload
;
143 /* take a reference for the request */
144 get_device(job
->dev
);
147 failjob_rls_rqst_payload
:
148 kfree(job
->request_payload
.sg_list
);
155 * bsg_goose_queue - restart queue in case it was stopped
156 * @q: request q to be restarted
158 void bsg_goose_queue(struct request_queue
*q
)
163 blk_run_queue_async(q
);
165 EXPORT_SYMBOL_GPL(bsg_goose_queue
);
168 * bsg_request_fn - generic handler for bsg requests
169 * @q: request queue to manage
171 * On error the create_bsg_job function should return a -Exyz error value
172 * that will be set to the req->errors.
174 * Drivers/subsys should pass this to the queue init function.
176 void bsg_request_fn(struct request_queue
*q
)
178 struct device
*dev
= q
->queuedata
;
183 if (!get_device(dev
))
187 req
= blk_fetch_request(q
);
190 spin_unlock_irq(q
->queue_lock
);
192 ret
= bsg_create_job(dev
, req
);
195 blk_end_request_all(req
, ret
);
196 spin_lock_irq(q
->queue_lock
);
201 ret
= q
->bsg_job_fn(job
);
202 spin_lock_irq(q
->queue_lock
);
207 spin_unlock_irq(q
->queue_lock
);
209 spin_lock_irq(q
->queue_lock
);
211 EXPORT_SYMBOL_GPL(bsg_request_fn
);
214 * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
215 * @dev: device to attach bsg device to
216 * @q: request queue setup by caller
217 * @name: device to give bsg device
218 * @job_fn: bsg job handler
219 * @dd_job_size: size of LLD data needed for each job
221 * The caller should have setup the reuqest queue with bsg_request_fn
224 int bsg_setup_queue(struct device
*dev
, struct request_queue
*q
,
225 char *name
, bsg_job_fn
*job_fn
, int dd_job_size
)
230 q
->bsg_job_size
= dd_job_size
;
231 q
->bsg_job_fn
= job_fn
;
232 queue_flag_set_unlocked(QUEUE_FLAG_BIDI
, q
);
233 blk_queue_softirq_done(q
, bsg_softirq_done
);
234 blk_queue_rq_timeout(q
, BLK_DEFAULT_SG_TIMEOUT
);
236 ret
= bsg_register_queue(q
, dev
, name
, NULL
);
238 printk(KERN_ERR
"%s: bsg interface failed to "
239 "initialize - register queue\n", dev
->kobj
.name
);
245 EXPORT_SYMBOL_GPL(bsg_setup_queue
);
248 * bsg_remove_queue - Deletes the bsg dev from the q
249 * @q: the request_queue that is to be torn down.
252 * Before unregistering the queue empty any requests that are blocked
254 void bsg_remove_queue(struct request_queue
*q
)
256 struct request
*req
; /* block request */
257 int counts
; /* totals for request_list count and starved */
262 /* Stop taking in new requests */
263 spin_lock_irq(q
->queue_lock
);
266 /* drain all requests in the queue */
268 /* need the lock to fetch a request
269 * this may fetch the same reqeust as the previous pass
271 req
= blk_fetch_request(q
);
272 /* save requests in use and starved */
273 counts
= q
->rq
.count
[0] + q
->rq
.count
[1] +
274 q
->rq
.starved
[0] + q
->rq
.starved
[1];
275 spin_unlock_irq(q
->queue_lock
);
276 /* any requests still outstanding? */
280 /* This may be the same req as the previous iteration,
281 * always send the blk_end_request_all after a prefetch.
282 * It is not okay to not end the request because the
283 * prefetch started the request.
286 /* return -ENXIO to indicate that this queue is
289 req
->errors
= -ENXIO
;
290 blk_end_request_all(req
, -ENXIO
);
293 msleep(200); /* allow bsg to possibly finish */
294 spin_lock_irq(q
->queue_lock
);
296 bsg_unregister_queue(q
);
298 EXPORT_SYMBOL_GPL(bsg_remove_queue
);
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