Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[linux/fpc-iii.git] / block / bsg-lib.c
blob1921298563429a8165838e6c9dad6f0e9e6cb28d
1 /*
2 * BSG helper library
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/blk-mq.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>
30 #include <scsi/sg.h>
32 #define uptr64(val) ((void __user *)(uintptr_t)(val))
34 struct bsg_set {
35 struct blk_mq_tag_set tag_set;
36 bsg_job_fn *job_fn;
37 bsg_timeout_fn *timeout_fn;
40 static int bsg_transport_check_proto(struct sg_io_v4 *hdr)
42 if (hdr->protocol != BSG_PROTOCOL_SCSI ||
43 hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT)
44 return -EINVAL;
45 if (!capable(CAP_SYS_RAWIO))
46 return -EPERM;
47 return 0;
50 static int bsg_transport_fill_hdr(struct request *rq, struct sg_io_v4 *hdr,
51 fmode_t mode)
53 struct bsg_job *job = blk_mq_rq_to_pdu(rq);
55 job->request_len = hdr->request_len;
56 job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
58 return PTR_ERR_OR_ZERO(job->request);
61 static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr)
63 struct bsg_job *job = blk_mq_rq_to_pdu(rq);
64 int ret = 0;
67 * The assignments below don't make much sense, but are kept for
68 * bug by bug backwards compatibility:
70 hdr->device_status = job->result & 0xff;
71 hdr->transport_status = host_byte(job->result);
72 hdr->driver_status = driver_byte(job->result);
73 hdr->info = 0;
74 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
75 hdr->info |= SG_INFO_CHECK;
76 hdr->response_len = 0;
78 if (job->result < 0) {
79 /* we're only returning the result field in the reply */
80 job->reply_len = sizeof(u32);
81 ret = job->result;
84 if (job->reply_len && hdr->response) {
85 int len = min(hdr->max_response_len, job->reply_len);
87 if (copy_to_user(uptr64(hdr->response), job->reply, len))
88 ret = -EFAULT;
89 else
90 hdr->response_len = len;
93 /* we assume all request payload was transferred, residual == 0 */
94 hdr->dout_resid = 0;
96 if (rq->next_rq) {
97 unsigned int rsp_len = job->reply_payload.payload_len;
99 if (WARN_ON(job->reply_payload_rcv_len > rsp_len))
100 hdr->din_resid = 0;
101 else
102 hdr->din_resid = rsp_len - job->reply_payload_rcv_len;
103 } else {
104 hdr->din_resid = 0;
107 return ret;
110 static void bsg_transport_free_rq(struct request *rq)
112 struct bsg_job *job = blk_mq_rq_to_pdu(rq);
114 kfree(job->request);
117 static const struct bsg_ops bsg_transport_ops = {
118 .check_proto = bsg_transport_check_proto,
119 .fill_hdr = bsg_transport_fill_hdr,
120 .complete_rq = bsg_transport_complete_rq,
121 .free_rq = bsg_transport_free_rq,
125 * bsg_teardown_job - routine to teardown a bsg job
126 * @kref: kref inside bsg_job that is to be torn down
128 static void bsg_teardown_job(struct kref *kref)
130 struct bsg_job *job = container_of(kref, struct bsg_job, kref);
131 struct request *rq = blk_mq_rq_from_pdu(job);
133 put_device(job->dev); /* release reference for the request */
135 kfree(job->request_payload.sg_list);
136 kfree(job->reply_payload.sg_list);
138 blk_mq_end_request(rq, BLK_STS_OK);
141 void bsg_job_put(struct bsg_job *job)
143 kref_put(&job->kref, bsg_teardown_job);
145 EXPORT_SYMBOL_GPL(bsg_job_put);
147 int bsg_job_get(struct bsg_job *job)
149 return kref_get_unless_zero(&job->kref);
151 EXPORT_SYMBOL_GPL(bsg_job_get);
154 * bsg_job_done - completion routine for bsg requests
155 * @job: bsg_job that is complete
156 * @result: job reply result
157 * @reply_payload_rcv_len: length of payload recvd
159 * The LLD should call this when the bsg job has completed.
161 void bsg_job_done(struct bsg_job *job, int result,
162 unsigned int reply_payload_rcv_len)
164 job->result = result;
165 job->reply_payload_rcv_len = reply_payload_rcv_len;
166 blk_mq_complete_request(blk_mq_rq_from_pdu(job));
168 EXPORT_SYMBOL_GPL(bsg_job_done);
171 * bsg_complete - softirq done routine for destroying the bsg requests
172 * @rq: BSG request that holds the job to be destroyed
174 static void bsg_complete(struct request *rq)
176 struct bsg_job *job = blk_mq_rq_to_pdu(rq);
178 bsg_job_put(job);
181 static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
183 size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
185 BUG_ON(!req->nr_phys_segments);
187 buf->sg_list = kzalloc(sz, GFP_KERNEL);
188 if (!buf->sg_list)
189 return -ENOMEM;
190 sg_init_table(buf->sg_list, req->nr_phys_segments);
191 buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
192 buf->payload_len = blk_rq_bytes(req);
193 return 0;
197 * bsg_prepare_job - create the bsg_job structure for the bsg request
198 * @dev: device that is being sent the bsg request
199 * @req: BSG request that needs a job structure
201 static bool bsg_prepare_job(struct device *dev, struct request *req)
203 struct request *rsp = req->next_rq;
204 struct bsg_job *job = blk_mq_rq_to_pdu(req);
205 int ret;
207 job->timeout = req->timeout;
209 if (req->bio) {
210 ret = bsg_map_buffer(&job->request_payload, req);
211 if (ret)
212 goto failjob_rls_job;
214 if (rsp && rsp->bio) {
215 ret = bsg_map_buffer(&job->reply_payload, rsp);
216 if (ret)
217 goto failjob_rls_rqst_payload;
219 job->dev = dev;
220 /* take a reference for the request */
221 get_device(job->dev);
222 kref_init(&job->kref);
223 return true;
225 failjob_rls_rqst_payload:
226 kfree(job->request_payload.sg_list);
227 failjob_rls_job:
228 job->result = -ENOMEM;
229 return false;
233 * bsg_queue_rq - generic handler for bsg requests
234 * @hctx: hardware queue
235 * @bd: queue data
237 * On error the create_bsg_job function should return a -Exyz error value
238 * that will be set to ->result.
240 * Drivers/subsys should pass this to the queue init function.
242 static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx,
243 const struct blk_mq_queue_data *bd)
245 struct request_queue *q = hctx->queue;
246 struct device *dev = q->queuedata;
247 struct request *req = bd->rq;
248 struct bsg_set *bset =
249 container_of(q->tag_set, struct bsg_set, tag_set);
250 int ret;
252 blk_mq_start_request(req);
254 if (!get_device(dev))
255 return BLK_STS_IOERR;
257 if (!bsg_prepare_job(dev, req))
258 return BLK_STS_IOERR;
260 ret = bset->job_fn(blk_mq_rq_to_pdu(req));
261 if (ret)
262 return BLK_STS_IOERR;
264 put_device(dev);
265 return BLK_STS_OK;
268 /* called right after the request is allocated for the request_queue */
269 static int bsg_init_rq(struct blk_mq_tag_set *set, struct request *req,
270 unsigned int hctx_idx, unsigned int numa_node)
272 struct bsg_job *job = blk_mq_rq_to_pdu(req);
274 job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
275 if (!job->reply)
276 return -ENOMEM;
277 return 0;
280 /* called right before the request is given to the request_queue user */
281 static void bsg_initialize_rq(struct request *req)
283 struct bsg_job *job = blk_mq_rq_to_pdu(req);
284 void *reply = job->reply;
286 memset(job, 0, sizeof(*job));
287 job->reply = reply;
288 job->reply_len = SCSI_SENSE_BUFFERSIZE;
289 job->dd_data = job + 1;
292 static void bsg_exit_rq(struct blk_mq_tag_set *set, struct request *req,
293 unsigned int hctx_idx)
295 struct bsg_job *job = blk_mq_rq_to_pdu(req);
297 kfree(job->reply);
300 void bsg_remove_queue(struct request_queue *q)
302 if (q) {
303 struct bsg_set *bset =
304 container_of(q->tag_set, struct bsg_set, tag_set);
306 bsg_unregister_queue(q);
307 blk_cleanup_queue(q);
308 blk_mq_free_tag_set(&bset->tag_set);
309 kfree(bset);
312 EXPORT_SYMBOL_GPL(bsg_remove_queue);
314 static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved)
316 struct bsg_set *bset =
317 container_of(rq->q->tag_set, struct bsg_set, tag_set);
319 if (!bset->timeout_fn)
320 return BLK_EH_DONE;
321 return bset->timeout_fn(rq);
324 static const struct blk_mq_ops bsg_mq_ops = {
325 .queue_rq = bsg_queue_rq,
326 .init_request = bsg_init_rq,
327 .exit_request = bsg_exit_rq,
328 .initialize_rq_fn = bsg_initialize_rq,
329 .complete = bsg_complete,
330 .timeout = bsg_timeout,
334 * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
335 * @dev: device to attach bsg device to
336 * @name: device to give bsg device
337 * @job_fn: bsg job handler
338 * @dd_job_size: size of LLD data needed for each job
340 struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
341 bsg_job_fn *job_fn, bsg_timeout_fn *timeout, int dd_job_size)
343 struct bsg_set *bset;
344 struct blk_mq_tag_set *set;
345 struct request_queue *q;
346 int ret = -ENOMEM;
348 bset = kzalloc(sizeof(*bset), GFP_KERNEL);
349 if (!bset)
350 return ERR_PTR(-ENOMEM);
352 bset->job_fn = job_fn;
353 bset->timeout_fn = timeout;
355 set = &bset->tag_set;
356 set->ops = &bsg_mq_ops,
357 set->nr_hw_queues = 1;
358 set->queue_depth = 128;
359 set->numa_node = NUMA_NO_NODE;
360 set->cmd_size = sizeof(struct bsg_job) + dd_job_size;
361 set->flags = BLK_MQ_F_NO_SCHED | BLK_MQ_F_BLOCKING;
362 if (blk_mq_alloc_tag_set(set))
363 goto out_tag_set;
365 q = blk_mq_init_queue(set);
366 if (IS_ERR(q)) {
367 ret = PTR_ERR(q);
368 goto out_queue;
371 q->queuedata = dev;
372 blk_queue_flag_set(QUEUE_FLAG_BIDI, q);
373 blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
375 ret = bsg_register_queue(q, dev, name, &bsg_transport_ops);
376 if (ret) {
377 printk(KERN_ERR "%s: bsg interface failed to "
378 "initialize - register queue\n", dev->kobj.name);
379 goto out_cleanup_queue;
382 return q;
383 out_cleanup_queue:
384 blk_cleanup_queue(q);
385 out_queue:
386 blk_mq_free_tag_set(set);
387 out_tag_set:
388 kfree(bset);
389 return ERR_PTR(ret);
391 EXPORT_SYMBOL_GPL(bsg_setup_queue);