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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 MC |
8 | */ |
9 | #include <linux/slab.h> | |
cd2f076f | 10 | #include <linux/blk-mq.h> |
aa387cc8 MC |
11 | #include <linux/delay.h> |
12 | #include <linux/scatterlist.h> | |
13 | #include <linux/bsg-lib.h> | |
6adb1236 | 14 | #include <linux/export.h> |
aa387cc8 | 15 | #include <scsi/scsi_cmnd.h> |
17cb960f CH |
16 | #include <scsi/sg.h> |
17 | ||
18 | #define uptr64(val) ((void __user *)(uintptr_t)(val)) | |
19 | ||
1028e4b3 JA |
20 | struct bsg_set { |
21 | struct blk_mq_tag_set tag_set; | |
22 | bsg_job_fn *job_fn; | |
23 | bsg_timeout_fn *timeout_fn; | |
24 | }; | |
25 | ||
17cb960f CH |
26 | static int bsg_transport_check_proto(struct sg_io_v4 *hdr) |
27 | { | |
28 | if (hdr->protocol != BSG_PROTOCOL_SCSI || | |
29 | hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT) | |
30 | return -EINVAL; | |
31 | if (!capable(CAP_SYS_RAWIO)) | |
32 | return -EPERM; | |
33 | return 0; | |
34 | } | |
35 | ||
36 | static int bsg_transport_fill_hdr(struct request *rq, struct sg_io_v4 *hdr, | |
37 | fmode_t mode) | |
38 | { | |
39 | struct bsg_job *job = blk_mq_rq_to_pdu(rq); | |
972248e9 | 40 | int ret; |
17cb960f CH |
41 | |
42 | job->request_len = hdr->request_len; | |
43 | job->request = memdup_user(uptr64(hdr->request), hdr->request_len); | |
972248e9 CH |
44 | if (IS_ERR(job->request)) |
45 | return PTR_ERR(job->request); | |
46 | ||
47 | if (hdr->dout_xfer_len && hdr->din_xfer_len) { | |
48 | job->bidi_rq = blk_get_request(rq->q, REQ_OP_SCSI_IN, 0); | |
49 | if (IS_ERR(job->bidi_rq)) { | |
50 | ret = PTR_ERR(job->bidi_rq); | |
51 | goto out; | |
52 | } | |
53 | ||
54 | ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL, | |
55 | uptr64(hdr->din_xferp), hdr->din_xfer_len, | |
56 | GFP_KERNEL); | |
57 | if (ret) | |
58 | goto out_free_bidi_rq; | |
59 | ||
60 | job->bidi_bio = job->bidi_rq->bio; | |
61 | } else { | |
62 | job->bidi_rq = NULL; | |
63 | job->bidi_bio = NULL; | |
64 | } | |
47255491 | 65 | |
972248e9 CH |
66 | return 0; |
67 | ||
68 | out_free_bidi_rq: | |
69 | if (job->bidi_rq) | |
70 | blk_put_request(job->bidi_rq); | |
71 | out: | |
72 | kfree(job->request); | |
73 | return ret; | |
17cb960f CH |
74 | } |
75 | ||
76 | static int bsg_transport_complete_rq(struct request *rq, struct sg_io_v4 *hdr) | |
77 | { | |
78 | struct bsg_job *job = blk_mq_rq_to_pdu(rq); | |
79 | int ret = 0; | |
80 | ||
81 | /* | |
82 | * The assignments below don't make much sense, but are kept for | |
83 | * bug by bug backwards compatibility: | |
84 | */ | |
85 | hdr->device_status = job->result & 0xff; | |
86 | hdr->transport_status = host_byte(job->result); | |
87 | hdr->driver_status = driver_byte(job->result); | |
88 | hdr->info = 0; | |
89 | if (hdr->device_status || hdr->transport_status || hdr->driver_status) | |
90 | hdr->info |= SG_INFO_CHECK; | |
91 | hdr->response_len = 0; | |
92 | ||
93 | if (job->result < 0) { | |
94 | /* we're only returning the result field in the reply */ | |
95 | job->reply_len = sizeof(u32); | |
96 | ret = job->result; | |
97 | } | |
98 | ||
99 | if (job->reply_len && hdr->response) { | |
100 | int len = min(hdr->max_response_len, job->reply_len); | |
101 | ||
102 | if (copy_to_user(uptr64(hdr->response), job->reply, len)) | |
103 | ret = -EFAULT; | |
104 | else | |
105 | hdr->response_len = len; | |
106 | } | |
107 | ||
108 | /* we assume all request payload was transferred, residual == 0 */ | |
109 | hdr->dout_resid = 0; | |
110 | ||
972248e9 | 111 | if (job->bidi_rq) { |
17cb960f CH |
112 | unsigned int rsp_len = job->reply_payload.payload_len; |
113 | ||
114 | if (WARN_ON(job->reply_payload_rcv_len > rsp_len)) | |
115 | hdr->din_resid = 0; | |
116 | else | |
117 | hdr->din_resid = rsp_len - job->reply_payload_rcv_len; | |
118 | } else { | |
119 | hdr->din_resid = 0; | |
120 | } | |
121 | ||
122 | return ret; | |
123 | } | |
124 | ||
125 | static void bsg_transport_free_rq(struct request *rq) | |
126 | { | |
127 | struct bsg_job *job = blk_mq_rq_to_pdu(rq); | |
128 | ||
972248e9 CH |
129 | if (job->bidi_rq) { |
130 | blk_rq_unmap_user(job->bidi_bio); | |
131 | blk_put_request(job->bidi_rq); | |
132 | } | |
133 | ||
17cb960f CH |
134 | kfree(job->request); |
135 | } | |
136 | ||
137 | static const struct bsg_ops bsg_transport_ops = { | |
138 | .check_proto = bsg_transport_check_proto, | |
139 | .fill_hdr = bsg_transport_fill_hdr, | |
140 | .complete_rq = bsg_transport_complete_rq, | |
141 | .free_rq = bsg_transport_free_rq, | |
142 | }; | |
aa387cc8 MC |
143 | |
144 | /** | |
50b4d485 | 145 | * bsg_teardown_job - routine to teardown a bsg job |
aa98192d | 146 | * @kref: kref inside bsg_job that is to be torn down |
aa387cc8 | 147 | */ |
50b4d485 | 148 | static void bsg_teardown_job(struct kref *kref) |
aa387cc8 | 149 | { |
bf0f2d38 | 150 | struct bsg_job *job = container_of(kref, struct bsg_job, kref); |
ef6fa64f | 151 | struct request *rq = blk_mq_rq_from_pdu(job); |
c00da4c9 | 152 | |
aa387cc8 MC |
153 | put_device(job->dev); /* release reference for the request */ |
154 | ||
155 | kfree(job->request_payload.sg_list); | |
156 | kfree(job->reply_payload.sg_list); | |
50b4d485 | 157 | |
cd2f076f | 158 | blk_mq_end_request(rq, BLK_STS_OK); |
aa387cc8 MC |
159 | } |
160 | ||
fb6f7c8d JT |
161 | void bsg_job_put(struct bsg_job *job) |
162 | { | |
50b4d485 | 163 | kref_put(&job->kref, bsg_teardown_job); |
fb6f7c8d JT |
164 | } |
165 | EXPORT_SYMBOL_GPL(bsg_job_put); | |
166 | ||
167 | int bsg_job_get(struct bsg_job *job) | |
168 | { | |
169 | return kref_get_unless_zero(&job->kref); | |
170 | } | |
171 | EXPORT_SYMBOL_GPL(bsg_job_get); | |
aa387cc8 MC |
172 | |
173 | /** | |
174 | * bsg_job_done - completion routine for bsg requests | |
175 | * @job: bsg_job that is complete | |
176 | * @result: job reply result | |
177 | * @reply_payload_rcv_len: length of payload recvd | |
178 | * | |
179 | * The LLD should call this when the bsg job has completed. | |
180 | */ | |
181 | void bsg_job_done(struct bsg_job *job, int result, | |
182 | unsigned int reply_payload_rcv_len) | |
183 | { | |
15f73f5b CH |
184 | struct request *rq = blk_mq_rq_from_pdu(job); |
185 | ||
17cb960f CH |
186 | job->result = result; |
187 | job->reply_payload_rcv_len = reply_payload_rcv_len; | |
15f73f5b CH |
188 | if (likely(!blk_should_fake_timeout(rq->q))) |
189 | blk_mq_complete_request(rq); | |
aa387cc8 MC |
190 | } |
191 | EXPORT_SYMBOL_GPL(bsg_job_done); | |
192 | ||
193 | /** | |
cd2f076f | 194 | * bsg_complete - softirq done routine for destroying the bsg requests |
aa387cc8 MC |
195 | * @rq: BSG request that holds the job to be destroyed |
196 | */ | |
cd2f076f | 197 | static void bsg_complete(struct request *rq) |
aa387cc8 | 198 | { |
50b4d485 | 199 | struct bsg_job *job = blk_mq_rq_to_pdu(rq); |
aa387cc8 | 200 | |
fb6f7c8d | 201 | bsg_job_put(job); |
aa387cc8 MC |
202 | } |
203 | ||
204 | static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req) | |
205 | { | |
206 | size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments); | |
207 | ||
208 | BUG_ON(!req->nr_phys_segments); | |
209 | ||
210 | buf->sg_list = kzalloc(sz, GFP_KERNEL); | |
211 | if (!buf->sg_list) | |
212 | return -ENOMEM; | |
213 | sg_init_table(buf->sg_list, req->nr_phys_segments); | |
214 | buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list); | |
215 | buf->payload_len = blk_rq_bytes(req); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | /** | |
50b4d485 | 220 | * bsg_prepare_job - create the bsg_job structure for the bsg request |
aa387cc8 MC |
221 | * @dev: device that is being sent the bsg request |
222 | * @req: BSG request that needs a job structure | |
223 | */ | |
17cb960f | 224 | static bool bsg_prepare_job(struct device *dev, struct request *req) |
aa387cc8 | 225 | { |
50b4d485 | 226 | struct bsg_job *job = blk_mq_rq_to_pdu(req); |
aa387cc8 MC |
227 | int ret; |
228 | ||
31156ec3 | 229 | job->timeout = req->timeout; |
50b4d485 | 230 | |
aa387cc8 MC |
231 | if (req->bio) { |
232 | ret = bsg_map_buffer(&job->request_payload, req); | |
233 | if (ret) | |
234 | goto failjob_rls_job; | |
235 | } | |
972248e9 CH |
236 | if (job->bidi_rq) { |
237 | ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq); | |
aa387cc8 MC |
238 | if (ret) |
239 | goto failjob_rls_rqst_payload; | |
240 | } | |
241 | job->dev = dev; | |
242 | /* take a reference for the request */ | |
243 | get_device(job->dev); | |
bf0f2d38 | 244 | kref_init(&job->kref); |
17cb960f | 245 | return true; |
aa387cc8 MC |
246 | |
247 | failjob_rls_rqst_payload: | |
248 | kfree(job->request_payload.sg_list); | |
249 | failjob_rls_job: | |
17cb960f CH |
250 | job->result = -ENOMEM; |
251 | return false; | |
aa387cc8 MC |
252 | } |
253 | ||
aa387cc8 | 254 | /** |
cd2f076f JA |
255 | * bsg_queue_rq - generic handler for bsg requests |
256 | * @hctx: hardware queue | |
257 | * @bd: queue data | |
aa387cc8 MC |
258 | * |
259 | * On error the create_bsg_job function should return a -Exyz error value | |
17d5363b | 260 | * that will be set to ->result. |
aa387cc8 MC |
261 | * |
262 | * Drivers/subsys should pass this to the queue init function. | |
263 | */ | |
cd2f076f JA |
264 | static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx, |
265 | const struct blk_mq_queue_data *bd) | |
aa387cc8 | 266 | { |
cd2f076f | 267 | struct request_queue *q = hctx->queue; |
aa387cc8 | 268 | struct device *dev = q->queuedata; |
cd2f076f | 269 | struct request *req = bd->rq; |
1028e4b3 JA |
270 | struct bsg_set *bset = |
271 | container_of(q->tag_set, struct bsg_set, tag_set); | |
c44a4edb | 272 | blk_status_t sts = BLK_STS_IOERR; |
aa387cc8 MC |
273 | int ret; |
274 | ||
cd2f076f JA |
275 | blk_mq_start_request(req); |
276 | ||
aa387cc8 | 277 | if (!get_device(dev)) |
cd2f076f JA |
278 | return BLK_STS_IOERR; |
279 | ||
280 | if (!bsg_prepare_job(dev, req)) | |
d46fe2cb | 281 | goto out; |
cd2f076f | 282 | |
1028e4b3 | 283 | ret = bset->job_fn(blk_mq_rq_to_pdu(req)); |
d46fe2cb MW |
284 | if (!ret) |
285 | sts = BLK_STS_OK; | |
aa387cc8 | 286 | |
d46fe2cb | 287 | out: |
aa387cc8 | 288 | put_device(dev); |
d46fe2cb | 289 | return sts; |
aa387cc8 | 290 | } |
aa387cc8 | 291 | |
17cb960f | 292 | /* called right after the request is allocated for the request_queue */ |
cd2f076f JA |
293 | static int bsg_init_rq(struct blk_mq_tag_set *set, struct request *req, |
294 | unsigned int hctx_idx, unsigned int numa_node) | |
50b4d485 BB |
295 | { |
296 | struct bsg_job *job = blk_mq_rq_to_pdu(req); | |
eab40cf3 | 297 | |
cd2f076f | 298 | job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL); |
17cb960f | 299 | if (!job->reply) |
eab40cf3 | 300 | return -ENOMEM; |
eab40cf3 BB |
301 | return 0; |
302 | } | |
303 | ||
17cb960f | 304 | /* called right before the request is given to the request_queue user */ |
eab40cf3 BB |
305 | static void bsg_initialize_rq(struct request *req) |
306 | { | |
307 | struct bsg_job *job = blk_mq_rq_to_pdu(req); | |
17cb960f | 308 | void *reply = job->reply; |
eab40cf3 | 309 | |
50b4d485 | 310 | memset(job, 0, sizeof(*job)); |
17cb960f CH |
311 | job->reply = reply; |
312 | job->reply_len = SCSI_SENSE_BUFFERSIZE; | |
50b4d485 | 313 | job->dd_data = job + 1; |
50b4d485 BB |
314 | } |
315 | ||
cd2f076f JA |
316 | static void bsg_exit_rq(struct blk_mq_tag_set *set, struct request *req, |
317 | unsigned int hctx_idx) | |
50b4d485 BB |
318 | { |
319 | struct bsg_job *job = blk_mq_rq_to_pdu(req); | |
50b4d485 | 320 | |
17cb960f | 321 | kfree(job->reply); |
50b4d485 BB |
322 | } |
323 | ||
5e28b8d8 JA |
324 | void bsg_remove_queue(struct request_queue *q) |
325 | { | |
326 | if (q) { | |
1028e4b3 JA |
327 | struct bsg_set *bset = |
328 | container_of(q->tag_set, struct bsg_set, tag_set); | |
cd2f076f | 329 | |
5e28b8d8 JA |
330 | bsg_unregister_queue(q); |
331 | blk_cleanup_queue(q); | |
1028e4b3 JA |
332 | blk_mq_free_tag_set(&bset->tag_set); |
333 | kfree(bset); | |
5e28b8d8 JA |
334 | } |
335 | } | |
336 | EXPORT_SYMBOL_GPL(bsg_remove_queue); | |
337 | ||
cd2f076f JA |
338 | static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved) |
339 | { | |
1028e4b3 JA |
340 | struct bsg_set *bset = |
341 | container_of(rq->q->tag_set, struct bsg_set, tag_set); | |
cd2f076f | 342 | |
1028e4b3 JA |
343 | if (!bset->timeout_fn) |
344 | return BLK_EH_DONE; | |
345 | return bset->timeout_fn(rq); | |
cd2f076f JA |
346 | } |
347 | ||
348 | static const struct blk_mq_ops bsg_mq_ops = { | |
349 | .queue_rq = bsg_queue_rq, | |
350 | .init_request = bsg_init_rq, | |
351 | .exit_request = bsg_exit_rq, | |
352 | .initialize_rq_fn = bsg_initialize_rq, | |
353 | .complete = bsg_complete, | |
354 | .timeout = bsg_timeout, | |
355 | }; | |
356 | ||
aa387cc8 MC |
357 | /** |
358 | * bsg_setup_queue - Create and add the bsg hooks so we can receive requests | |
359 | * @dev: device to attach bsg device to | |
aa387cc8 MC |
360 | * @name: device to give bsg device |
361 | * @job_fn: bsg job handler | |
a0b77e36 | 362 | * @timeout: timeout handler function pointer |
aa387cc8 | 363 | * @dd_job_size: size of LLD data needed for each job |
aa387cc8 | 364 | */ |
c1225f01 | 365 | struct request_queue *bsg_setup_queue(struct device *dev, const char *name, |
1028e4b3 | 366 | bsg_job_fn *job_fn, bsg_timeout_fn *timeout, int dd_job_size) |
aa387cc8 | 367 | { |
1028e4b3 | 368 | struct bsg_set *bset; |
cd2f076f | 369 | struct blk_mq_tag_set *set; |
8ae94eb6 | 370 | struct request_queue *q; |
cd2f076f | 371 | int ret = -ENOMEM; |
aa387cc8 | 372 | |
1028e4b3 JA |
373 | bset = kzalloc(sizeof(*bset), GFP_KERNEL); |
374 | if (!bset) | |
8ae94eb6 | 375 | return ERR_PTR(-ENOMEM); |
82ed4db4 | 376 | |
1028e4b3 JA |
377 | bset->job_fn = job_fn; |
378 | bset->timeout_fn = timeout; | |
379 | ||
380 | set = &bset->tag_set; | |
03ef5941 | 381 | set->ops = &bsg_mq_ops; |
cd2f076f JA |
382 | set->nr_hw_queues = 1; |
383 | set->queue_depth = 128; | |
384 | set->numa_node = NUMA_NO_NODE; | |
385 | set->cmd_size = sizeof(struct bsg_job) + dd_job_size; | |
386 | set->flags = BLK_MQ_F_NO_SCHED | BLK_MQ_F_BLOCKING; | |
387 | if (blk_mq_alloc_tag_set(set)) | |
388 | goto out_tag_set; | |
389 | ||
390 | q = blk_mq_init_queue(set); | |
391 | if (IS_ERR(q)) { | |
392 | ret = PTR_ERR(q); | |
393 | goto out_queue; | |
394 | } | |
8ae94eb6 | 395 | |
aa387cc8 | 396 | q->queuedata = dev; |
aa387cc8 MC |
397 | blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT); |
398 | ||
5de815a7 | 399 | ret = bsg_register_queue(q, dev, name, &bsg_transport_ops); |
aa387cc8 MC |
400 | if (ret) { |
401 | printk(KERN_ERR "%s: bsg interface failed to " | |
402 | "initialize - register queue\n", dev->kobj.name); | |
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); |