Commit | Line | Data |
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aa387cc8 MC |
1 | /* |
2 | * BSG helper library | |
3 | * | |
4 | * Copyright (C) 2008 James Smart, Emulex Corporation | |
5 | * Copyright (C) 2011 Red Hat, Inc. All rights reserved. | |
6 | * Copyright (C) 2011 Mike Christie | |
7 | * | |
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. | |
12 | * | |
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. | |
17 | * | |
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 | |
21 | * | |
22 | */ | |
23 | #include <linux/slab.h> | |
cd2f076f | 24 | #include <linux/blk-mq.h> |
aa387cc8 MC |
25 | #include <linux/delay.h> |
26 | #include <linux/scatterlist.h> | |
27 | #include <linux/bsg-lib.h> | |
6adb1236 | 28 | #include <linux/export.h> |
aa387cc8 | 29 | #include <scsi/scsi_cmnd.h> |
17cb960f CH |
30 | #include <scsi/sg.h> |
31 | ||
32 | #define uptr64(val) ((void __user *)(uintptr_t)(val)) | |
33 | ||
1028e4b3 JA |
34 | struct bsg_set { |
35 | struct blk_mq_tag_set tag_set; | |
36 | bsg_job_fn *job_fn; | |
37 | bsg_timeout_fn *timeout_fn; | |
38 | }; | |
39 | ||
17cb960f CH |
40 | static int bsg_transport_check_proto(struct sg_io_v4 *hdr) |
41 | { | |
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; | |
48 | } | |
49 | ||
50 | static int bsg_transport_fill_hdr(struct request *rq, struct sg_io_v4 *hdr, | |
51 | fmode_t mode) | |
52 | { | |
53 | struct bsg_job *job = blk_mq_rq_to_pdu(rq); | |
972248e9 | 54 | int ret; |
17cb960f CH |
55 | |
56 | job->request_len = hdr->request_len; | |
57 | job->request = memdup_user(uptr64(hdr->request), hdr->request_len); | |
972248e9 CH |
58 | if (IS_ERR(job->request)) |
59 | return PTR_ERR(job->request); | |
60 | ||
61 | if (hdr->dout_xfer_len && hdr->din_xfer_len) { | |
62 | job->bidi_rq = blk_get_request(rq->q, REQ_OP_SCSI_IN, 0); | |
63 | if (IS_ERR(job->bidi_rq)) { | |
64 | ret = PTR_ERR(job->bidi_rq); | |
65 | goto out; | |
66 | } | |
67 | ||
68 | ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL, | |
69 | uptr64(hdr->din_xferp), hdr->din_xfer_len, | |
70 | GFP_KERNEL); | |
71 | if (ret) | |
72 | goto out_free_bidi_rq; | |
73 | ||
74 | job->bidi_bio = job->bidi_rq->bio; | |
75 | } else { | |
76 | job->bidi_rq = NULL; | |
77 | job->bidi_bio = NULL; | |
78 | } | |
47255491 | 79 | |
972248e9 CH |
80 | return 0; |
81 | ||
82 | out_free_bidi_rq: | |
83 | if (job->bidi_rq) | |
84 | blk_put_request(job->bidi_rq); | |
85 | out: | |
86 | kfree(job->request); | |
87 | return ret; | |
17cb960f CH |
88 | } |
89 | ||
90 | static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr) | |
91 | { | |
92 | struct bsg_job *job = blk_mq_rq_to_pdu(rq); | |
93 | int ret = 0; | |
94 | ||
95 | /* | |
96 | * The assignments below don't make much sense, but are kept for | |
97 | * bug by bug backwards compatibility: | |
98 | */ | |
99 | hdr->device_status = job->result & 0xff; | |
100 | hdr->transport_status = host_byte(job->result); | |
101 | hdr->driver_status = driver_byte(job->result); | |
102 | hdr->info = 0; | |
103 | if (hdr->device_status || hdr->transport_status || hdr->driver_status) | |
104 | hdr->info |= SG_INFO_CHECK; | |
105 | hdr->response_len = 0; | |
106 | ||
107 | if (job->result < 0) { | |
108 | /* we're only returning the result field in the reply */ | |
109 | job->reply_len = sizeof(u32); | |
110 | ret = job->result; | |
111 | } | |
112 | ||
113 | if (job->reply_len && hdr->response) { | |
114 | int len = min(hdr->max_response_len, job->reply_len); | |
115 | ||
116 | if (copy_to_user(uptr64(hdr->response), job->reply, len)) | |
117 | ret = -EFAULT; | |
118 | else | |
119 | hdr->response_len = len; | |
120 | } | |
121 | ||
122 | /* we assume all request payload was transferred, residual == 0 */ | |
123 | hdr->dout_resid = 0; | |
124 | ||
972248e9 | 125 | if (job->bidi_rq) { |
17cb960f CH |
126 | unsigned int rsp_len = job->reply_payload.payload_len; |
127 | ||
128 | if (WARN_ON(job->reply_payload_rcv_len > rsp_len)) | |
129 | hdr->din_resid = 0; | |
130 | else | |
131 | hdr->din_resid = rsp_len - job->reply_payload_rcv_len; | |
132 | } else { | |
133 | hdr->din_resid = 0; | |
134 | } | |
135 | ||
136 | return ret; | |
137 | } | |
138 | ||
139 | static void bsg_transport_free_rq(struct request *rq) | |
140 | { | |
141 | struct bsg_job *job = blk_mq_rq_to_pdu(rq); | |
142 | ||
972248e9 CH |
143 | if (job->bidi_rq) { |
144 | blk_rq_unmap_user(job->bidi_bio); | |
145 | blk_put_request(job->bidi_rq); | |
146 | } | |
147 | ||
17cb960f CH |
148 | kfree(job->request); |
149 | } | |
150 | ||
151 | static const struct bsg_ops bsg_transport_ops = { | |
152 | .check_proto = bsg_transport_check_proto, | |
153 | .fill_hdr = bsg_transport_fill_hdr, | |
154 | .complete_rq = bsg_transport_complete_rq, | |
155 | .free_rq = bsg_transport_free_rq, | |
156 | }; | |
aa387cc8 MC |
157 | |
158 | /** | |
50b4d485 | 159 | * bsg_teardown_job - routine to teardown a bsg job |
aa98192d | 160 | * @kref: kref inside bsg_job that is to be torn down |
aa387cc8 | 161 | */ |
50b4d485 | 162 | static void bsg_teardown_job(struct kref *kref) |
aa387cc8 | 163 | { |
bf0f2d38 | 164 | struct bsg_job *job = container_of(kref, struct bsg_job, kref); |
ef6fa64f | 165 | struct request *rq = blk_mq_rq_from_pdu(job); |
c00da4c9 | 166 | |
aa387cc8 MC |
167 | put_device(job->dev); /* release reference for the request */ |
168 | ||
169 | kfree(job->request_payload.sg_list); | |
170 | kfree(job->reply_payload.sg_list); | |
50b4d485 | 171 | |
cd2f076f | 172 | blk_mq_end_request(rq, BLK_STS_OK); |
aa387cc8 MC |
173 | } |
174 | ||
fb6f7c8d JT |
175 | void bsg_job_put(struct bsg_job *job) |
176 | { | |
50b4d485 | 177 | kref_put(&job->kref, bsg_teardown_job); |
fb6f7c8d JT |
178 | } |
179 | EXPORT_SYMBOL_GPL(bsg_job_put); | |
180 | ||
181 | int bsg_job_get(struct bsg_job *job) | |
182 | { | |
183 | return kref_get_unless_zero(&job->kref); | |
184 | } | |
185 | EXPORT_SYMBOL_GPL(bsg_job_get); | |
aa387cc8 MC |
186 | |
187 | /** | |
188 | * bsg_job_done - completion routine for bsg requests | |
189 | * @job: bsg_job that is complete | |
190 | * @result: job reply result | |
191 | * @reply_payload_rcv_len: length of payload recvd | |
192 | * | |
193 | * The LLD should call this when the bsg job has completed. | |
194 | */ | |
195 | void bsg_job_done(struct bsg_job *job, int result, | |
196 | unsigned int reply_payload_rcv_len) | |
197 | { | |
17cb960f CH |
198 | job->result = result; |
199 | job->reply_payload_rcv_len = reply_payload_rcv_len; | |
cd2f076f | 200 | blk_mq_complete_request(blk_mq_rq_from_pdu(job)); |
aa387cc8 MC |
201 | } |
202 | EXPORT_SYMBOL_GPL(bsg_job_done); | |
203 | ||
204 | /** | |
cd2f076f | 205 | * bsg_complete - softirq done routine for destroying the bsg requests |
aa387cc8 MC |
206 | * @rq: BSG request that holds the job to be destroyed |
207 | */ | |
cd2f076f | 208 | static void bsg_complete(struct request *rq) |
aa387cc8 | 209 | { |
50b4d485 | 210 | struct bsg_job *job = blk_mq_rq_to_pdu(rq); |
aa387cc8 | 211 | |
fb6f7c8d | 212 | bsg_job_put(job); |
aa387cc8 MC |
213 | } |
214 | ||
215 | static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req) | |
216 | { | |
217 | size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments); | |
218 | ||
219 | BUG_ON(!req->nr_phys_segments); | |
220 | ||
221 | buf->sg_list = kzalloc(sz, GFP_KERNEL); | |
222 | if (!buf->sg_list) | |
223 | return -ENOMEM; | |
224 | sg_init_table(buf->sg_list, req->nr_phys_segments); | |
225 | buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list); | |
226 | buf->payload_len = blk_rq_bytes(req); | |
227 | return 0; | |
228 | } | |
229 | ||
230 | /** | |
50b4d485 | 231 | * bsg_prepare_job - create the bsg_job structure for the bsg request |
aa387cc8 MC |
232 | * @dev: device that is being sent the bsg request |
233 | * @req: BSG request that needs a job structure | |
234 | */ | |
17cb960f | 235 | static bool bsg_prepare_job(struct device *dev, struct request *req) |
aa387cc8 | 236 | { |
50b4d485 | 237 | struct bsg_job *job = blk_mq_rq_to_pdu(req); |
aa387cc8 MC |
238 | int ret; |
239 | ||
31156ec3 | 240 | job->timeout = req->timeout; |
50b4d485 | 241 | |
aa387cc8 MC |
242 | if (req->bio) { |
243 | ret = bsg_map_buffer(&job->request_payload, req); | |
244 | if (ret) | |
245 | goto failjob_rls_job; | |
246 | } | |
972248e9 CH |
247 | if (job->bidi_rq) { |
248 | ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq); | |
aa387cc8 MC |
249 | if (ret) |
250 | goto failjob_rls_rqst_payload; | |
251 | } | |
252 | job->dev = dev; | |
253 | /* take a reference for the request */ | |
254 | get_device(job->dev); | |
bf0f2d38 | 255 | kref_init(&job->kref); |
17cb960f | 256 | return true; |
aa387cc8 MC |
257 | |
258 | failjob_rls_rqst_payload: | |
259 | kfree(job->request_payload.sg_list); | |
260 | failjob_rls_job: | |
17cb960f CH |
261 | job->result = -ENOMEM; |
262 | return false; | |
aa387cc8 MC |
263 | } |
264 | ||
aa387cc8 | 265 | /** |
cd2f076f JA |
266 | * bsg_queue_rq - generic handler for bsg requests |
267 | * @hctx: hardware queue | |
268 | * @bd: queue data | |
aa387cc8 MC |
269 | * |
270 | * On error the create_bsg_job function should return a -Exyz error value | |
17d5363b | 271 | * that will be set to ->result. |
aa387cc8 MC |
272 | * |
273 | * Drivers/subsys should pass this to the queue init function. | |
274 | */ | |
cd2f076f JA |
275 | static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx, |
276 | const struct blk_mq_queue_data *bd) | |
aa387cc8 | 277 | { |
cd2f076f | 278 | struct request_queue *q = hctx->queue; |
aa387cc8 | 279 | struct device *dev = q->queuedata; |
cd2f076f | 280 | struct request *req = bd->rq; |
1028e4b3 JA |
281 | struct bsg_set *bset = |
282 | container_of(q->tag_set, struct bsg_set, tag_set); | |
aa387cc8 MC |
283 | int ret; |
284 | ||
cd2f076f JA |
285 | blk_mq_start_request(req); |
286 | ||
aa387cc8 | 287 | if (!get_device(dev)) |
cd2f076f JA |
288 | return BLK_STS_IOERR; |
289 | ||
290 | if (!bsg_prepare_job(dev, req)) | |
291 | return BLK_STS_IOERR; | |
292 | ||
1028e4b3 | 293 | ret = bset->job_fn(blk_mq_rq_to_pdu(req)); |
cd2f076f JA |
294 | if (ret) |
295 | return BLK_STS_IOERR; | |
aa387cc8 | 296 | |
aa387cc8 | 297 | put_device(dev); |
cd2f076f | 298 | return BLK_STS_OK; |
aa387cc8 | 299 | } |
aa387cc8 | 300 | |
17cb960f | 301 | /* called right after the request is allocated for the request_queue */ |
cd2f076f JA |
302 | static int bsg_init_rq(struct blk_mq_tag_set *set, struct request *req, |
303 | unsigned int hctx_idx, unsigned int numa_node) | |
50b4d485 BB |
304 | { |
305 | struct bsg_job *job = blk_mq_rq_to_pdu(req); | |
eab40cf3 | 306 | |
cd2f076f | 307 | job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL); |
17cb960f | 308 | if (!job->reply) |
eab40cf3 | 309 | return -ENOMEM; |
eab40cf3 BB |
310 | return 0; |
311 | } | |
312 | ||
17cb960f | 313 | /* called right before the request is given to the request_queue user */ |
eab40cf3 BB |
314 | static void bsg_initialize_rq(struct request *req) |
315 | { | |
316 | struct bsg_job *job = blk_mq_rq_to_pdu(req); | |
17cb960f | 317 | void *reply = job->reply; |
eab40cf3 | 318 | |
50b4d485 | 319 | memset(job, 0, sizeof(*job)); |
17cb960f CH |
320 | job->reply = reply; |
321 | job->reply_len = SCSI_SENSE_BUFFERSIZE; | |
50b4d485 | 322 | job->dd_data = job + 1; |
50b4d485 BB |
323 | } |
324 | ||
cd2f076f JA |
325 | static void bsg_exit_rq(struct blk_mq_tag_set *set, struct request *req, |
326 | unsigned int hctx_idx) | |
50b4d485 BB |
327 | { |
328 | struct bsg_job *job = blk_mq_rq_to_pdu(req); | |
50b4d485 | 329 | |
17cb960f | 330 | kfree(job->reply); |
50b4d485 BB |
331 | } |
332 | ||
5e28b8d8 JA |
333 | void bsg_remove_queue(struct request_queue *q) |
334 | { | |
335 | if (q) { | |
1028e4b3 JA |
336 | struct bsg_set *bset = |
337 | container_of(q->tag_set, struct bsg_set, tag_set); | |
cd2f076f | 338 | |
5e28b8d8 JA |
339 | bsg_unregister_queue(q); |
340 | blk_cleanup_queue(q); | |
1028e4b3 JA |
341 | blk_mq_free_tag_set(&bset->tag_set); |
342 | kfree(bset); | |
5e28b8d8 JA |
343 | } |
344 | } | |
345 | EXPORT_SYMBOL_GPL(bsg_remove_queue); | |
346 | ||
cd2f076f JA |
347 | static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved) |
348 | { | |
1028e4b3 JA |
349 | struct bsg_set *bset = |
350 | container_of(rq->q->tag_set, struct bsg_set, tag_set); | |
cd2f076f | 351 | |
1028e4b3 JA |
352 | if (!bset->timeout_fn) |
353 | return BLK_EH_DONE; | |
354 | return bset->timeout_fn(rq); | |
cd2f076f JA |
355 | } |
356 | ||
357 | static const struct blk_mq_ops bsg_mq_ops = { | |
358 | .queue_rq = bsg_queue_rq, | |
359 | .init_request = bsg_init_rq, | |
360 | .exit_request = bsg_exit_rq, | |
361 | .initialize_rq_fn = bsg_initialize_rq, | |
362 | .complete = bsg_complete, | |
363 | .timeout = bsg_timeout, | |
364 | }; | |
365 | ||
aa387cc8 MC |
366 | /** |
367 | * bsg_setup_queue - Create and add the bsg hooks so we can receive requests | |
368 | * @dev: device to attach bsg device to | |
aa387cc8 MC |
369 | * @name: device to give bsg device |
370 | * @job_fn: bsg job handler | |
371 | * @dd_job_size: size of LLD data needed for each job | |
aa387cc8 | 372 | */ |
c1225f01 | 373 | struct request_queue *bsg_setup_queue(struct device *dev, const char *name, |
1028e4b3 | 374 | bsg_job_fn *job_fn, bsg_timeout_fn *timeout, int dd_job_size) |
aa387cc8 | 375 | { |
1028e4b3 | 376 | struct bsg_set *bset; |
cd2f076f | 377 | struct blk_mq_tag_set *set; |
8ae94eb6 | 378 | struct request_queue *q; |
cd2f076f | 379 | int ret = -ENOMEM; |
aa387cc8 | 380 | |
1028e4b3 JA |
381 | bset = kzalloc(sizeof(*bset), GFP_KERNEL); |
382 | if (!bset) | |
8ae94eb6 | 383 | return ERR_PTR(-ENOMEM); |
82ed4db4 | 384 | |
1028e4b3 JA |
385 | bset->job_fn = job_fn; |
386 | bset->timeout_fn = timeout; | |
387 | ||
388 | set = &bset->tag_set; | |
cd2f076f JA |
389 | set->ops = &bsg_mq_ops, |
390 | set->nr_hw_queues = 1; | |
391 | set->queue_depth = 128; | |
392 | set->numa_node = NUMA_NO_NODE; | |
393 | set->cmd_size = sizeof(struct bsg_job) + dd_job_size; | |
394 | set->flags = BLK_MQ_F_NO_SCHED | BLK_MQ_F_BLOCKING; | |
395 | if (blk_mq_alloc_tag_set(set)) | |
396 | goto out_tag_set; | |
397 | ||
398 | q = blk_mq_init_queue(set); | |
399 | if (IS_ERR(q)) { | |
400 | ret = PTR_ERR(q); | |
401 | goto out_queue; | |
402 | } | |
8ae94eb6 | 403 | |
aa387cc8 | 404 | q->queuedata = dev; |
aa387cc8 MC |
405 | blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT); |
406 | ||
5de815a7 | 407 | ret = bsg_register_queue(q, dev, name, &bsg_transport_ops); |
aa387cc8 MC |
408 | if (ret) { |
409 | printk(KERN_ERR "%s: bsg interface failed to " | |
410 | "initialize - register queue\n", dev->kobj.name); | |
82ed4db4 | 411 | goto out_cleanup_queue; |
aa387cc8 MC |
412 | } |
413 | ||
8ae94eb6 | 414 | return q; |
82ed4db4 CH |
415 | out_cleanup_queue: |
416 | blk_cleanup_queue(q); | |
cd2f076f JA |
417 | out_queue: |
418 | blk_mq_free_tag_set(set); | |
419 | out_tag_set: | |
1028e4b3 | 420 | kfree(bset); |
82ed4db4 | 421 | return ERR_PTR(ret); |
aa387cc8 MC |
422 | } |
423 | EXPORT_SYMBOL_GPL(bsg_setup_queue); |