1 // SPDX-License-Identifier: GPL-2.0-or-later
5 * Copyright (C) 2008 James Smart, Emulex Corporation
6 * Copyright (C) 2011 Red Hat, Inc. All rights reserved.
7 * Copyright (C) 2011 Mike Christie
10 #include <linux/slab.h>
11 #include <linux/blk-mq.h>
12 #include <linux/delay.h>
13 #include <linux/scatterlist.h>
14 #include <linux/bsg-lib.h>
15 #include <linux/export.h>
16 #include <scsi/scsi_cmnd.h>
19 #define uptr64(val) ((void __user *)(uintptr_t)(val))
22 struct blk_mq_tag_set tag_set;
23 struct bsg_device *bd;
25 bsg_timeout_fn *timeout_fn;
28 static int bsg_transport_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr,
29 fmode_t mode, unsigned int timeout)
36 if (hdr->protocol != BSG_PROTOCOL_SCSI ||
37 hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_TRANSPORT)
39 if (!capable(CAP_SYS_RAWIO))
42 rq = blk_get_request(q, hdr->dout_xfer_len ?
43 REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0);
46 rq->timeout = timeout;
48 job = blk_mq_rq_to_pdu(rq);
49 job->request_len = hdr->request_len;
50 job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
51 if (IS_ERR(job->request)) {
52 ret = PTR_ERR(job->request);
56 if (hdr->dout_xfer_len && hdr->din_xfer_len) {
57 job->bidi_rq = blk_get_request(rq->q, REQ_OP_DRV_IN, 0);
58 if (IS_ERR(job->bidi_rq)) {
59 ret = PTR_ERR(job->bidi_rq);
60 goto out_free_job_request;
63 ret = blk_rq_map_user(rq->q, job->bidi_rq, NULL,
64 uptr64(hdr->din_xferp), hdr->din_xfer_len,
67 goto out_free_bidi_rq;
69 job->bidi_bio = job->bidi_rq->bio;
75 if (hdr->dout_xfer_len) {
76 ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp),
77 hdr->dout_xfer_len, GFP_KERNEL);
78 } else if (hdr->din_xfer_len) {
79 ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp),
80 hdr->din_xfer_len, GFP_KERNEL);
84 goto out_unmap_bidi_rq;
87 blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL));
90 * The assignments below don't make much sense, but are kept for
91 * bug by bug backwards compatibility:
93 hdr->device_status = job->result & 0xff;
94 hdr->transport_status = host_byte(job->result);
95 hdr->driver_status = 0;
97 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
98 hdr->info |= SG_INFO_CHECK;
99 hdr->response_len = 0;
101 if (job->result < 0) {
102 /* we're only returning the result field in the reply */
103 job->reply_len = sizeof(u32);
107 if (job->reply_len && hdr->response) {
108 int len = min(hdr->max_response_len, job->reply_len);
110 if (copy_to_user(uptr64(hdr->response), job->reply, len))
113 hdr->response_len = len;
116 /* we assume all request payload was transferred, residual == 0 */
120 unsigned int rsp_len = job->reply_payload.payload_len;
122 if (WARN_ON(job->reply_payload_rcv_len > rsp_len))
125 hdr->din_resid = rsp_len - job->reply_payload_rcv_len;
130 blk_rq_unmap_user(bio);
133 blk_rq_unmap_user(job->bidi_bio);
136 blk_put_request(job->bidi_rq);
137 out_free_job_request:
145 * bsg_teardown_job - routine to teardown a bsg job
146 * @kref: kref inside bsg_job that is to be torn down
148 static void bsg_teardown_job(struct kref *kref)
150 struct bsg_job *job = container_of(kref, struct bsg_job, kref);
151 struct request *rq = blk_mq_rq_from_pdu(job);
153 put_device(job->dev); /* release reference for the request */
155 kfree(job->request_payload.sg_list);
156 kfree(job->reply_payload.sg_list);
158 blk_mq_end_request(rq, BLK_STS_OK);
161 void bsg_job_put(struct bsg_job *job)
163 kref_put(&job->kref, bsg_teardown_job);
165 EXPORT_SYMBOL_GPL(bsg_job_put);
167 int bsg_job_get(struct bsg_job *job)
169 return kref_get_unless_zero(&job->kref);
171 EXPORT_SYMBOL_GPL(bsg_job_get);
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
179 * The LLD should call this when the bsg job has completed.
181 void bsg_job_done(struct bsg_job *job, int result,
182 unsigned int reply_payload_rcv_len)
184 struct request *rq = blk_mq_rq_from_pdu(job);
186 job->result = result;
187 job->reply_payload_rcv_len = reply_payload_rcv_len;
188 if (likely(!blk_should_fake_timeout(rq->q)))
189 blk_mq_complete_request(rq);
191 EXPORT_SYMBOL_GPL(bsg_job_done);
194 * bsg_complete - softirq done routine for destroying the bsg requests
195 * @rq: BSG request that holds the job to be destroyed
197 static void bsg_complete(struct request *rq)
199 struct bsg_job *job = blk_mq_rq_to_pdu(rq);
204 static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
206 size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
208 BUG_ON(!req->nr_phys_segments);
210 buf->sg_list = kmalloc(sz, GFP_KERNEL);
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);
220 * bsg_prepare_job - create the bsg_job structure for the bsg request
221 * @dev: device that is being sent the bsg request
222 * @req: BSG request that needs a job structure
224 static bool bsg_prepare_job(struct device *dev, struct request *req)
226 struct bsg_job *job = blk_mq_rq_to_pdu(req);
229 job->timeout = req->timeout;
232 ret = bsg_map_buffer(&job->request_payload, req);
234 goto failjob_rls_job;
237 ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq);
239 goto failjob_rls_rqst_payload;
242 /* take a reference for the request */
243 get_device(job->dev);
244 kref_init(&job->kref);
247 failjob_rls_rqst_payload:
248 kfree(job->request_payload.sg_list);
250 job->result = -ENOMEM;
255 * bsg_queue_rq - generic handler for bsg requests
256 * @hctx: hardware queue
259 * On error the create_bsg_job function should return a -Exyz error value
260 * that will be set to ->result.
262 * Drivers/subsys should pass this to the queue init function.
264 static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx,
265 const struct blk_mq_queue_data *bd)
267 struct request_queue *q = hctx->queue;
268 struct device *dev = q->queuedata;
269 struct request *req = bd->rq;
270 struct bsg_set *bset =
271 container_of(q->tag_set, struct bsg_set, tag_set);
272 blk_status_t sts = BLK_STS_IOERR;
275 blk_mq_start_request(req);
277 if (!get_device(dev))
278 return BLK_STS_IOERR;
280 if (!bsg_prepare_job(dev, req))
283 ret = bset->job_fn(blk_mq_rq_to_pdu(req));
292 /* called right after the request is allocated for the request_queue */
293 static int bsg_init_rq(struct blk_mq_tag_set *set, struct request *req,
294 unsigned int hctx_idx, unsigned int numa_node)
296 struct bsg_job *job = blk_mq_rq_to_pdu(req);
298 job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
304 /* called right before the request is given to the request_queue user */
305 static void bsg_initialize_rq(struct request *req)
307 struct bsg_job *job = blk_mq_rq_to_pdu(req);
308 void *reply = job->reply;
310 memset(job, 0, sizeof(*job));
312 job->reply_len = SCSI_SENSE_BUFFERSIZE;
313 job->dd_data = job + 1;
316 static void bsg_exit_rq(struct blk_mq_tag_set *set, struct request *req,
317 unsigned int hctx_idx)
319 struct bsg_job *job = blk_mq_rq_to_pdu(req);
324 void bsg_remove_queue(struct request_queue *q)
327 struct bsg_set *bset =
328 container_of(q->tag_set, struct bsg_set, tag_set);
330 bsg_unregister_queue(bset->bd);
331 blk_cleanup_queue(q);
332 blk_mq_free_tag_set(&bset->tag_set);
336 EXPORT_SYMBOL_GPL(bsg_remove_queue);
338 static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved)
340 struct bsg_set *bset =
341 container_of(rq->q->tag_set, struct bsg_set, tag_set);
343 if (!bset->timeout_fn)
345 return bset->timeout_fn(rq);
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,
358 * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
359 * @dev: device to attach bsg device to
360 * @name: device to give bsg device
361 * @job_fn: bsg job handler
362 * @timeout: timeout handler function pointer
363 * @dd_job_size: size of LLD data needed for each job
365 struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
366 bsg_job_fn *job_fn, bsg_timeout_fn *timeout, int dd_job_size)
368 struct bsg_set *bset;
369 struct blk_mq_tag_set *set;
370 struct request_queue *q;
373 bset = kzalloc(sizeof(*bset), GFP_KERNEL);
375 return ERR_PTR(-ENOMEM);
377 bset->job_fn = job_fn;
378 bset->timeout_fn = timeout;
380 set = &bset->tag_set;
381 set->ops = &bsg_mq_ops;
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))
390 q = blk_mq_init_queue(set);
397 blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
399 bset->bd = bsg_register_queue(q, dev, name, bsg_transport_sg_io_fn);
400 if (IS_ERR(bset->bd)) {
401 ret = PTR_ERR(bset->bd);
402 goto out_cleanup_queue;
407 blk_cleanup_queue(q);
409 blk_mq_free_tag_set(set);
414 EXPORT_SYMBOL_GPL(bsg_setup_queue);