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a497ee34 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
aa387cc8 MC |
2 | /* |
3 | * BSG helper library | |
4 | * | |
5 | * Copyright (C) 2008 James Smart, Emulex Corporation | |
6 | * Copyright (C) 2011 Red Hat, Inc. All rights reserved. | |
7 | * Copyright (C) 2011 Mike Christie | |
aa387cc8 | 8 | */ |
ead09dd3 | 9 | #include <linux/bsg.h> |
aa387cc8 | 10 | #include <linux/slab.h> |
cd2f076f | 11 | #include <linux/blk-mq.h> |
aa387cc8 MC |
12 | #include <linux/delay.h> |
13 | #include <linux/scatterlist.h> | |
14 | #include <linux/bsg-lib.h> | |
6adb1236 | 15 | #include <linux/export.h> |
aa387cc8 | 16 | #include <scsi/scsi_cmnd.h> |
17cb960f CH |
17 | #include <scsi/sg.h> |
18 | ||
19 | #define uptr64(val) ((void __user *)(uintptr_t)(val)) | |
20 | ||
1028e4b3 JA |
21 | struct bsg_set { |
22 | struct blk_mq_tag_set tag_set; | |
ead09dd3 | 23 | struct bsg_device *bd; |
1028e4b3 JA |
24 | bsg_job_fn *job_fn; |
25 | bsg_timeout_fn *timeout_fn; | |
26 | }; | |
27 | ||
75ca5640 CH |
28 | static int bsg_transport_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr, |
29 | fmode_t mode, unsigned int timeout) | |
17cb960f | 30 | { |
75ca5640 CH |
31 | struct bsg_job *job; |
32 | struct request *rq; | |
33 | struct bio *bio; | |
34 | int ret; | |
35 | ||
17cb960f CH |
36 | if (hdr->protocol != BSG_PROTOCOL_SCSI || |
37 | hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT) | |
38 | return -EINVAL; | |
39 | if (!capable(CAP_SYS_RAWIO)) | |
40 | return -EPERM; | |
17cb960f | 41 | |
75ca5640 CH |
42 | rq = blk_get_request(q, hdr->dout_xfer_len ? |
43 | REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0); | |
44 | if (IS_ERR(rq)) | |
45 | return PTR_ERR(rq); | |
46 | rq->timeout = timeout; | |
17cb960f | 47 | |
75ca5640 | 48 | job = blk_mq_rq_to_pdu(rq); |
17cb960f CH |
49 | job->request_len = hdr->request_len; |
50 | job->request = memdup_user(uptr64(hdr->request), hdr->request_len); | |
75ca5640 CH |
51 | if (IS_ERR(job->request)) { |
52 | ret = PTR_ERR(job->request); | |
53 | goto out_put_request; | |
54 | } | |
972248e9 CH |
55 | |
56 | if (hdr->dout_xfer_len && hdr->din_xfer_len) { | |
da6269da | 57 | job->bidi_rq = blk_get_request(rq->q, REQ_OP_DRV_IN, 0); |
972248e9 CH |
58 | if (IS_ERR(job->bidi_rq)) { |
59 | ret = PTR_ERR(job->bidi_rq); | |
75ca5640 | 60 | goto out_free_job_request; |
972248e9 CH |
61 | } |
62 | ||
63 | ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL, | |
64 | uptr64(hdr->din_xferp), hdr->din_xfer_len, | |
65 | GFP_KERNEL); | |
66 | if (ret) | |
67 | goto out_free_bidi_rq; | |
68 | ||
69 | job->bidi_bio = job->bidi_rq->bio; | |
70 | } else { | |
71 | job->bidi_rq = NULL; | |
72 | job->bidi_bio = NULL; | |
73 | } | |
47255491 | 74 | |
659a3784 | 75 | ret = 0; |
75ca5640 CH |
76 | if (hdr->dout_xfer_len) { |
77 | ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp), | |
78 | hdr->dout_xfer_len, GFP_KERNEL); | |
79 | } else if (hdr->din_xfer_len) { | |
80 | ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp), | |
81 | hdr->din_xfer_len, GFP_KERNEL); | |
82 | } | |
972248e9 | 83 | |
75ca5640 CH |
84 | if (ret) |
85 | goto out_unmap_bidi_rq; | |
17cb960f | 86 | |
75ca5640 CH |
87 | bio = rq->bio; |
88 | blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL)); | |
17cb960f CH |
89 | |
90 | /* | |
91 | * The assignments below don't make much sense, but are kept for | |
92 | * bug by bug backwards compatibility: | |
93 | */ | |
94 | hdr->device_status = job->result & 0xff; | |
95 | hdr->transport_status = host_byte(job->result); | |
54c29086 | 96 | hdr->driver_status = 0; |
17cb960f CH |
97 | hdr->info = 0; |
98 | if (hdr->device_status || hdr->transport_status || hdr->driver_status) | |
99 | hdr->info |= SG_INFO_CHECK; | |
100 | hdr->response_len = 0; | |
101 | ||
102 | if (job->result < 0) { | |
103 | /* we're only returning the result field in the reply */ | |
104 | job->reply_len = sizeof(u32); | |
105 | ret = job->result; | |
106 | } | |
107 | ||
108 | if (job->reply_len && hdr->response) { | |
109 | int len = min(hdr->max_response_len, job->reply_len); | |
110 | ||
111 | if (copy_to_user(uptr64(hdr->response), job->reply, len)) | |
112 | ret = -EFAULT; | |
113 | else | |
114 | hdr->response_len = len; | |
115 | } | |
116 | ||
117 | /* we assume all request payload was transferred, residual == 0 */ | |
118 | hdr->dout_resid = 0; | |
119 | ||
972248e9 | 120 | if (job->bidi_rq) { |
17cb960f CH |
121 | unsigned int rsp_len = job->reply_payload.payload_len; |
122 | ||
123 | if (WARN_ON(job->reply_payload_rcv_len > rsp_len)) | |
124 | hdr->din_resid = 0; | |
125 | else | |
126 | hdr->din_resid = rsp_len - job->reply_payload_rcv_len; | |
127 | } else { | |
128 | hdr->din_resid = 0; | |
129 | } | |
130 | ||
75ca5640 CH |
131 | blk_rq_unmap_user(bio); |
132 | out_unmap_bidi_rq: | |
133 | if (job->bidi_rq) | |
972248e9 | 134 | blk_rq_unmap_user(job->bidi_bio); |
75ca5640 CH |
135 | out_free_bidi_rq: |
136 | if (job->bidi_rq) | |
972248e9 | 137 | blk_put_request(job->bidi_rq); |
75ca5640 | 138 | out_free_job_request: |
17cb960f | 139 | kfree(job->request); |
75ca5640 CH |
140 | out_put_request: |
141 | blk_put_request(rq); | |
142 | return ret; | |
17cb960f CH |
143 | } |
144 | ||
aa387cc8 | 145 | /** |
50b4d485 | 146 | * bsg_teardown_job - routine to teardown a bsg job |
aa98192d | 147 | * @kref: kref inside bsg_job that is to be torn down |
aa387cc8 | 148 | */ |
50b4d485 | 149 | static void bsg_teardown_job(struct kref *kref) |
aa387cc8 | 150 | { |
bf0f2d38 | 151 | struct bsg_job *job = container_of(kref, struct bsg_job, kref); |
ef6fa64f | 152 | struct request *rq = blk_mq_rq_from_pdu(job); |
c00da4c9 | 153 | |
aa387cc8 MC |
154 | put_device(job->dev); /* release reference for the request */ |
155 | ||
156 | kfree(job->request_payload.sg_list); | |
157 | kfree(job->reply_payload.sg_list); | |
50b4d485 | 158 | |
cd2f076f | 159 | blk_mq_end_request(rq, BLK_STS_OK); |
aa387cc8 MC |
160 | } |
161 | ||
fb6f7c8d JT |
162 | void bsg_job_put(struct bsg_job *job) |
163 | { | |
50b4d485 | 164 | kref_put(&job->kref, bsg_teardown_job); |
fb6f7c8d JT |
165 | } |
166 | EXPORT_SYMBOL_GPL(bsg_job_put); | |
167 | ||
168 | int bsg_job_get(struct bsg_job *job) | |
169 | { | |
170 | return kref_get_unless_zero(&job->kref); | |
171 | } | |
172 | EXPORT_SYMBOL_GPL(bsg_job_get); | |
aa387cc8 MC |
173 | |
174 | /** | |
175 | * bsg_job_done - completion routine for bsg requests | |
176 | * @job: bsg_job that is complete | |
177 | * @result: job reply result | |
178 | * @reply_payload_rcv_len: length of payload recvd | |
179 | * | |
180 | * The LLD should call this when the bsg job has completed. | |
181 | */ | |
182 | void bsg_job_done(struct bsg_job *job, int result, | |
183 | unsigned int reply_payload_rcv_len) | |
184 | { | |
15f73f5b CH |
185 | struct request *rq = blk_mq_rq_from_pdu(job); |
186 | ||
17cb960f CH |
187 | job->result = result; |
188 | job->reply_payload_rcv_len = reply_payload_rcv_len; | |
15f73f5b CH |
189 | if (likely(!blk_should_fake_timeout(rq->q))) |
190 | blk_mq_complete_request(rq); | |
aa387cc8 MC |
191 | } |
192 | EXPORT_SYMBOL_GPL(bsg_job_done); | |
193 | ||
194 | /** | |
cd2f076f | 195 | * bsg_complete - softirq done routine for destroying the bsg requests |
aa387cc8 MC |
196 | * @rq: BSG request that holds the job to be destroyed |
197 | */ | |
cd2f076f | 198 | static void bsg_complete(struct request *rq) |
aa387cc8 | 199 | { |
50b4d485 | 200 | struct bsg_job *job = blk_mq_rq_to_pdu(rq); |
aa387cc8 | 201 | |
fb6f7c8d | 202 | bsg_job_put(job); |
aa387cc8 MC |
203 | } |
204 | ||
205 | static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req) | |
206 | { | |
207 | size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments); | |
208 | ||
209 | BUG_ON(!req->nr_phys_segments); | |
210 | ||
f952eefe | 211 | buf->sg_list = kmalloc(sz, GFP_KERNEL); |
aa387cc8 MC |
212 | if (!buf->sg_list) |
213 | return -ENOMEM; | |
214 | sg_init_table(buf->sg_list, req->nr_phys_segments); | |
215 | buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list); | |
216 | buf->payload_len = blk_rq_bytes(req); | |
217 | return 0; | |
218 | } | |
219 | ||
220 | /** | |
50b4d485 | 221 | * bsg_prepare_job - create the bsg_job structure for the bsg request |
aa387cc8 MC |
222 | * @dev: device that is being sent the bsg request |
223 | * @req: BSG request that needs a job structure | |
224 | */ | |
17cb960f | 225 | static bool bsg_prepare_job(struct device *dev, struct request *req) |
aa387cc8 | 226 | { |
50b4d485 | 227 | struct bsg_job *job = blk_mq_rq_to_pdu(req); |
aa387cc8 MC |
228 | int ret; |
229 | ||
31156ec3 | 230 | job->timeout = req->timeout; |
50b4d485 | 231 | |
aa387cc8 MC |
232 | if (req->bio) { |
233 | ret = bsg_map_buffer(&job->request_payload, req); | |
234 | if (ret) | |
235 | goto failjob_rls_job; | |
236 | } | |
972248e9 CH |
237 | if (job->bidi_rq) { |
238 | ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq); | |
aa387cc8 MC |
239 | if (ret) |
240 | goto failjob_rls_rqst_payload; | |
241 | } | |
242 | job->dev = dev; | |
243 | /* take a reference for the request */ | |
244 | get_device(job->dev); | |
bf0f2d38 | 245 | kref_init(&job->kref); |
17cb960f | 246 | return true; |
aa387cc8 MC |
247 | |
248 | failjob_rls_rqst_payload: | |
249 | kfree(job->request_payload.sg_list); | |
250 | failjob_rls_job: | |
17cb960f CH |
251 | job->result = -ENOMEM; |
252 | return false; | |
aa387cc8 MC |
253 | } |
254 | ||
aa387cc8 | 255 | /** |
cd2f076f JA |
256 | * bsg_queue_rq - generic handler for bsg requests |
257 | * @hctx: hardware queue | |
258 | * @bd: queue data | |
aa387cc8 MC |
259 | * |
260 | * On error the create_bsg_job function should return a -Exyz error value | |
17d5363b | 261 | * that will be set to ->result. |
aa387cc8 MC |
262 | * |
263 | * Drivers/subsys should pass this to the queue init function. | |
264 | */ | |
cd2f076f JA |
265 | static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx, |
266 | const struct blk_mq_queue_data *bd) | |
aa387cc8 | 267 | { |
cd2f076f | 268 | struct request_queue *q = hctx->queue; |
aa387cc8 | 269 | struct device *dev = q->queuedata; |
cd2f076f | 270 | struct request *req = bd->rq; |
1028e4b3 JA |
271 | struct bsg_set *bset = |
272 | container_of(q->tag_set, struct bsg_set, tag_set); | |
c44a4edb | 273 | blk_status_t sts = BLK_STS_IOERR; |
aa387cc8 MC |
274 | int ret; |
275 | ||
cd2f076f JA |
276 | blk_mq_start_request(req); |
277 | ||
aa387cc8 | 278 | if (!get_device(dev)) |
cd2f076f JA |
279 | return BLK_STS_IOERR; |
280 | ||
281 | if (!bsg_prepare_job(dev, req)) | |
d46fe2cb | 282 | goto out; |
cd2f076f | 283 | |
1028e4b3 | 284 | ret = bset->job_fn(blk_mq_rq_to_pdu(req)); |
d46fe2cb MW |
285 | if (!ret) |
286 | sts = BLK_STS_OK; | |
aa387cc8 | 287 | |
d46fe2cb | 288 | out: |
aa387cc8 | 289 | put_device(dev); |
d46fe2cb | 290 | return sts; |
aa387cc8 | 291 | } |
aa387cc8 | 292 | |
17cb960f | 293 | /* called right after the request is allocated for the request_queue */ |
cd2f076f JA |
294 | static int bsg_init_rq(struct blk_mq_tag_set *set, struct request *req, |
295 | unsigned int hctx_idx, unsigned int numa_node) | |
50b4d485 BB |
296 | { |
297 | struct bsg_job *job = blk_mq_rq_to_pdu(req); | |
eab40cf3 | 298 | |
cd2f076f | 299 | job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL); |
17cb960f | 300 | if (!job->reply) |
eab40cf3 | 301 | return -ENOMEM; |
eab40cf3 BB |
302 | return 0; |
303 | } | |
304 | ||
17cb960f | 305 | /* called right before the request is given to the request_queue user */ |
eab40cf3 BB |
306 | static void bsg_initialize_rq(struct request *req) |
307 | { | |
308 | struct bsg_job *job = blk_mq_rq_to_pdu(req); | |
17cb960f | 309 | void *reply = job->reply; |
eab40cf3 | 310 | |
50b4d485 | 311 | memset(job, 0, sizeof(*job)); |
17cb960f CH |
312 | job->reply = reply; |
313 | job->reply_len = SCSI_SENSE_BUFFERSIZE; | |
50b4d485 | 314 | job->dd_data = job + 1; |
50b4d485 BB |
315 | } |
316 | ||
cd2f076f JA |
317 | static void bsg_exit_rq(struct blk_mq_tag_set *set, struct request *req, |
318 | unsigned int hctx_idx) | |
50b4d485 BB |
319 | { |
320 | struct bsg_job *job = blk_mq_rq_to_pdu(req); | |
50b4d485 | 321 | |
17cb960f | 322 | kfree(job->reply); |
50b4d485 BB |
323 | } |
324 | ||
5e28b8d8 JA |
325 | void bsg_remove_queue(struct request_queue *q) |
326 | { | |
327 | if (q) { | |
1028e4b3 JA |
328 | struct bsg_set *bset = |
329 | container_of(q->tag_set, struct bsg_set, tag_set); | |
cd2f076f | 330 | |
ead09dd3 | 331 | bsg_unregister_queue(bset->bd); |
5e28b8d8 | 332 | blk_cleanup_queue(q); |
1028e4b3 JA |
333 | blk_mq_free_tag_set(&bset->tag_set); |
334 | kfree(bset); | |
5e28b8d8 JA |
335 | } |
336 | } | |
337 | EXPORT_SYMBOL_GPL(bsg_remove_queue); | |
338 | ||
cd2f076f JA |
339 | static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved) |
340 | { | |
1028e4b3 JA |
341 | struct bsg_set *bset = |
342 | container_of(rq->q->tag_set, struct bsg_set, tag_set); | |
cd2f076f | 343 | |
1028e4b3 JA |
344 | if (!bset->timeout_fn) |
345 | return BLK_EH_DONE; | |
346 | return bset->timeout_fn(rq); | |
cd2f076f JA |
347 | } |
348 | ||
349 | static const struct blk_mq_ops bsg_mq_ops = { | |
350 | .queue_rq = bsg_queue_rq, | |
351 | .init_request = bsg_init_rq, | |
352 | .exit_request = bsg_exit_rq, | |
353 | .initialize_rq_fn = bsg_initialize_rq, | |
354 | .complete = bsg_complete, | |
355 | .timeout = bsg_timeout, | |
356 | }; | |
357 | ||
aa387cc8 MC |
358 | /** |
359 | * bsg_setup_queue - Create and add the bsg hooks so we can receive requests | |
360 | * @dev: device to attach bsg device to | |
aa387cc8 MC |
361 | * @name: device to give bsg device |
362 | * @job_fn: bsg job handler | |
a0b77e36 | 363 | * @timeout: timeout handler function pointer |
aa387cc8 | 364 | * @dd_job_size: size of LLD data needed for each job |
aa387cc8 | 365 | */ |
c1225f01 | 366 | struct request_queue *bsg_setup_queue(struct device *dev, const char *name, |
1028e4b3 | 367 | bsg_job_fn *job_fn, bsg_timeout_fn *timeout, int dd_job_size) |
aa387cc8 | 368 | { |
1028e4b3 | 369 | struct bsg_set *bset; |
cd2f076f | 370 | struct blk_mq_tag_set *set; |
8ae94eb6 | 371 | struct request_queue *q; |
cd2f076f | 372 | int ret = -ENOMEM; |
aa387cc8 | 373 | |
1028e4b3 JA |
374 | bset = kzalloc(sizeof(*bset), GFP_KERNEL); |
375 | if (!bset) | |
8ae94eb6 | 376 | return ERR_PTR(-ENOMEM); |
82ed4db4 | 377 | |
1028e4b3 JA |
378 | bset->job_fn = job_fn; |
379 | bset->timeout_fn = timeout; | |
380 | ||
381 | set = &bset->tag_set; | |
03ef5941 | 382 | set->ops = &bsg_mq_ops; |
cd2f076f JA |
383 | set->nr_hw_queues = 1; |
384 | set->queue_depth = 128; | |
385 | set->numa_node = NUMA_NO_NODE; | |
386 | set->cmd_size = sizeof(struct bsg_job) + dd_job_size; | |
387 | set->flags = BLK_MQ_F_NO_SCHED | BLK_MQ_F_BLOCKING; | |
388 | if (blk_mq_alloc_tag_set(set)) | |
389 | goto out_tag_set; | |
390 | ||
391 | q = blk_mq_init_queue(set); | |
392 | if (IS_ERR(q)) { | |
393 | ret = PTR_ERR(q); | |
394 | goto out_queue; | |
395 | } | |
8ae94eb6 | 396 | |
aa387cc8 | 397 | q->queuedata = dev; |
aa387cc8 MC |
398 | blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT); |
399 | ||
75ca5640 | 400 | bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn); |
ead09dd3 CH |
401 | if (IS_ERR(bset->bd)) { |
402 | ret = PTR_ERR(bset->bd); | |
82ed4db4 | 403 | goto out_cleanup_queue; |
aa387cc8 MC |
404 | } |
405 | ||
8ae94eb6 | 406 | return q; |
82ed4db4 CH |
407 | out_cleanup_queue: |
408 | blk_cleanup_queue(q); | |
cd2f076f JA |
409 | out_queue: |
410 | blk_mq_free_tag_set(set); | |
411 | out_tag_set: | |
1028e4b3 | 412 | kfree(bset); |
82ed4db4 | 413 | return ERR_PTR(ret); |
aa387cc8 MC |
414 | } |
415 | EXPORT_SYMBOL_GPL(bsg_setup_queue); |