blob: 6cbb7926534cd7985e22ce280c4b29c66a900826 [file] [log] [blame]
Christoph Hellwiga497ee32019-04-30 14:42:40 -04001// SPDX-License-Identifier: GPL-2.0-or-later
Mike Christieaa387cc2011-07-31 22:05:09 +02002/*
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
Mike Christieaa387cc2011-07-31 22:05:09 +02008 */
9#include <linux/slab.h>
Jens Axboecd2f0762018-10-24 07:11:39 -060010#include <linux/blk-mq.h>
Mike Christieaa387cc2011-07-31 22:05:09 +020011#include <linux/delay.h>
12#include <linux/scatterlist.h>
13#include <linux/bsg-lib.h>
Paul Gortmaker6adb1232011-09-28 18:26:05 -040014#include <linux/export.h>
Mike Christieaa387cc2011-07-31 22:05:09 +020015#include <scsi/scsi_cmnd.h>
Christoph Hellwig17cb9602018-03-13 17:28:41 +010016#include <scsi/sg.h>
17
18#define uptr64(val) ((void __user *)(uintptr_t)(val))
19
Jens Axboe1028e4b2018-10-29 09:47:17 -060020struct bsg_set {
21 struct blk_mq_tag_set tag_set;
22 bsg_job_fn *job_fn;
23 bsg_timeout_fn *timeout_fn;
24};
25
Christoph Hellwig17cb9602018-03-13 17:28:41 +010026static 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
36static 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);
Christoph Hellwig972248e2019-01-29 09:32:03 +010040 int ret;
Christoph Hellwig17cb9602018-03-13 17:28:41 +010041
42 job->request_len = hdr->request_len;
43 job->request = memdup_user(uptr64(hdr->request), hdr->request_len);
Christoph Hellwig972248e2019-01-29 09:32:03 +010044 if (IS_ERR(job->request))
45 return PTR_ERR(job->request);
zhong jiang47255492018-08-01 00:13:14 +080046
Christoph Hellwig972248e2019-01-29 09:32:03 +010047 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 }
65
66 return 0;
67
68out_free_bidi_rq:
69 if (job->bidi_rq)
70 blk_put_request(job->bidi_rq);
71out:
72 kfree(job->request);
73 return ret;
Christoph Hellwig17cb9602018-03-13 17:28:41 +010074}
75
76static 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
Christoph Hellwig972248e2019-01-29 09:32:03 +0100111 if (job->bidi_rq) {
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100112 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
125static void bsg_transport_free_rq(struct request *rq)
126{
127 struct bsg_job *job = blk_mq_rq_to_pdu(rq);
128
Christoph Hellwig972248e2019-01-29 09:32:03 +0100129 if (job->bidi_rq) {
130 blk_rq_unmap_user(job->bidi_bio);
131 blk_put_request(job->bidi_rq);
132 }
133
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100134 kfree(job->request);
135}
136
137static 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};
Mike Christieaa387cc2011-07-31 22:05:09 +0200143
144/**
Benjamin Block50b4d482017-08-24 01:57:56 +0200145 * bsg_teardown_job - routine to teardown a bsg job
Bart Van Asscheaa981922018-01-09 10:11:00 -0800146 * @kref: kref inside bsg_job that is to be torn down
Mike Christieaa387cc2011-07-31 22:05:09 +0200147 */
Benjamin Block50b4d482017-08-24 01:57:56 +0200148static void bsg_teardown_job(struct kref *kref)
Mike Christieaa387cc2011-07-31 22:05:09 +0200149{
Johannes Thumshirnbf0f2d32016-11-17 10:31:18 +0100150 struct bsg_job *job = container_of(kref, struct bsg_job, kref);
Christoph Hellwigef6fa642018-03-13 17:28:40 +0100151 struct request *rq = blk_mq_rq_from_pdu(job);
Johannes Thumshirnc00da4c2016-11-17 10:31:20 +0100152
Mike Christieaa387cc2011-07-31 22:05:09 +0200153 put_device(job->dev); /* release reference for the request */
154
155 kfree(job->request_payload.sg_list);
156 kfree(job->reply_payload.sg_list);
Benjamin Block50b4d482017-08-24 01:57:56 +0200157
Jens Axboecd2f0762018-10-24 07:11:39 -0600158 blk_mq_end_request(rq, BLK_STS_OK);
Mike Christieaa387cc2011-07-31 22:05:09 +0200159}
160
Johannes Thumshirnfb6f7c82016-11-17 10:31:23 +0100161void bsg_job_put(struct bsg_job *job)
162{
Benjamin Block50b4d482017-08-24 01:57:56 +0200163 kref_put(&job->kref, bsg_teardown_job);
Johannes Thumshirnfb6f7c82016-11-17 10:31:23 +0100164}
165EXPORT_SYMBOL_GPL(bsg_job_put);
166
167int bsg_job_get(struct bsg_job *job)
168{
169 return kref_get_unless_zero(&job->kref);
170}
171EXPORT_SYMBOL_GPL(bsg_job_get);
Mike Christieaa387cc2011-07-31 22:05:09 +0200172
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 */
181void bsg_job_done(struct bsg_job *job, int result,
182 unsigned int reply_payload_rcv_len)
183{
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100184 job->result = result;
185 job->reply_payload_rcv_len = reply_payload_rcv_len;
Jens Axboecd2f0762018-10-24 07:11:39 -0600186 blk_mq_complete_request(blk_mq_rq_from_pdu(job));
Mike Christieaa387cc2011-07-31 22:05:09 +0200187}
188EXPORT_SYMBOL_GPL(bsg_job_done);
189
190/**
Jens Axboecd2f0762018-10-24 07:11:39 -0600191 * bsg_complete - softirq done routine for destroying the bsg requests
Mike Christieaa387cc2011-07-31 22:05:09 +0200192 * @rq: BSG request that holds the job to be destroyed
193 */
Jens Axboecd2f0762018-10-24 07:11:39 -0600194static void bsg_complete(struct request *rq)
Mike Christieaa387cc2011-07-31 22:05:09 +0200195{
Benjamin Block50b4d482017-08-24 01:57:56 +0200196 struct bsg_job *job = blk_mq_rq_to_pdu(rq);
Mike Christieaa387cc2011-07-31 22:05:09 +0200197
Johannes Thumshirnfb6f7c82016-11-17 10:31:23 +0100198 bsg_job_put(job);
Mike Christieaa387cc2011-07-31 22:05:09 +0200199}
200
201static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
202{
203 size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
204
205 BUG_ON(!req->nr_phys_segments);
206
207 buf->sg_list = kzalloc(sz, GFP_KERNEL);
208 if (!buf->sg_list)
209 return -ENOMEM;
210 sg_init_table(buf->sg_list, req->nr_phys_segments);
211 buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
212 buf->payload_len = blk_rq_bytes(req);
213 return 0;
214}
215
216/**
Benjamin Block50b4d482017-08-24 01:57:56 +0200217 * bsg_prepare_job - create the bsg_job structure for the bsg request
Mike Christieaa387cc2011-07-31 22:05:09 +0200218 * @dev: device that is being sent the bsg request
219 * @req: BSG request that needs a job structure
220 */
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100221static bool bsg_prepare_job(struct device *dev, struct request *req)
Mike Christieaa387cc2011-07-31 22:05:09 +0200222{
Benjamin Block50b4d482017-08-24 01:57:56 +0200223 struct bsg_job *job = blk_mq_rq_to_pdu(req);
Mike Christieaa387cc2011-07-31 22:05:09 +0200224 int ret;
225
Christoph Hellwig31156ec2018-03-13 17:28:39 +0100226 job->timeout = req->timeout;
Benjamin Block50b4d482017-08-24 01:57:56 +0200227
Mike Christieaa387cc2011-07-31 22:05:09 +0200228 if (req->bio) {
229 ret = bsg_map_buffer(&job->request_payload, req);
230 if (ret)
231 goto failjob_rls_job;
232 }
Christoph Hellwig972248e2019-01-29 09:32:03 +0100233 if (job->bidi_rq) {
234 ret = bsg_map_buffer(&job->reply_payload, job->bidi_rq);
Mike Christieaa387cc2011-07-31 22:05:09 +0200235 if (ret)
236 goto failjob_rls_rqst_payload;
237 }
238 job->dev = dev;
239 /* take a reference for the request */
240 get_device(job->dev);
Johannes Thumshirnbf0f2d32016-11-17 10:31:18 +0100241 kref_init(&job->kref);
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100242 return true;
Mike Christieaa387cc2011-07-31 22:05:09 +0200243
244failjob_rls_rqst_payload:
245 kfree(job->request_payload.sg_list);
246failjob_rls_job:
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100247 job->result = -ENOMEM;
248 return false;
Mike Christieaa387cc2011-07-31 22:05:09 +0200249}
250
Mike Christieaa387cc2011-07-31 22:05:09 +0200251/**
Jens Axboecd2f0762018-10-24 07:11:39 -0600252 * bsg_queue_rq - generic handler for bsg requests
253 * @hctx: hardware queue
254 * @bd: queue data
Mike Christieaa387cc2011-07-31 22:05:09 +0200255 *
256 * On error the create_bsg_job function should return a -Exyz error value
Christoph Hellwig17d53632017-04-20 16:03:01 +0200257 * that will be set to ->result.
Mike Christieaa387cc2011-07-31 22:05:09 +0200258 *
259 * Drivers/subsys should pass this to the queue init function.
260 */
Jens Axboecd2f0762018-10-24 07:11:39 -0600261static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx,
262 const struct blk_mq_queue_data *bd)
Mike Christieaa387cc2011-07-31 22:05:09 +0200263{
Jens Axboecd2f0762018-10-24 07:11:39 -0600264 struct request_queue *q = hctx->queue;
Mike Christieaa387cc2011-07-31 22:05:09 +0200265 struct device *dev = q->queuedata;
Jens Axboecd2f0762018-10-24 07:11:39 -0600266 struct request *req = bd->rq;
Jens Axboe1028e4b2018-10-29 09:47:17 -0600267 struct bsg_set *bset =
268 container_of(q->tag_set, struct bsg_set, tag_set);
Bart Van Asschec44a4ed2019-12-17 16:23:29 -0800269 blk_status_t sts = BLK_STS_IOERR;
Mike Christieaa387cc2011-07-31 22:05:09 +0200270 int ret;
271
Jens Axboecd2f0762018-10-24 07:11:39 -0600272 blk_mq_start_request(req);
273
Mike Christieaa387cc2011-07-31 22:05:09 +0200274 if (!get_device(dev))
Jens Axboecd2f0762018-10-24 07:11:39 -0600275 return BLK_STS_IOERR;
Mike Christieaa387cc2011-07-31 22:05:09 +0200276
Jens Axboecd2f0762018-10-24 07:11:39 -0600277 if (!bsg_prepare_job(dev, req))
Martin Wilckd46fe2c2019-09-23 14:02:02 +0000278 goto out;
Mike Christieaa387cc2011-07-31 22:05:09 +0200279
Jens Axboe1028e4b2018-10-29 09:47:17 -0600280 ret = bset->job_fn(blk_mq_rq_to_pdu(req));
Martin Wilckd46fe2c2019-09-23 14:02:02 +0000281 if (!ret)
282 sts = BLK_STS_OK;
Mike Christieaa387cc2011-07-31 22:05:09 +0200283
Martin Wilckd46fe2c2019-09-23 14:02:02 +0000284out:
Mike Christieaa387cc2011-07-31 22:05:09 +0200285 put_device(dev);
Martin Wilckd46fe2c2019-09-23 14:02:02 +0000286 return sts;
Mike Christieaa387cc2011-07-31 22:05:09 +0200287}
Mike Christieaa387cc2011-07-31 22:05:09 +0200288
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100289/* called right after the request is allocated for the request_queue */
Jens Axboecd2f0762018-10-24 07:11:39 -0600290static int bsg_init_rq(struct blk_mq_tag_set *set, struct request *req,
291 unsigned int hctx_idx, unsigned int numa_node)
Benjamin Block50b4d482017-08-24 01:57:56 +0200292{
293 struct bsg_job *job = blk_mq_rq_to_pdu(req);
Benjamin Block50b4d482017-08-24 01:57:56 +0200294
Jens Axboecd2f0762018-10-24 07:11:39 -0600295 job->reply = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_KERNEL);
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100296 if (!job->reply)
Benjamin Block50b4d482017-08-24 01:57:56 +0200297 return -ENOMEM;
Benjamin Blockeab40cf2017-10-03 12:48:37 +0200298 return 0;
299}
300
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100301/* called right before the request is given to the request_queue user */
Benjamin Blockeab40cf2017-10-03 12:48:37 +0200302static void bsg_initialize_rq(struct request *req)
303{
304 struct bsg_job *job = blk_mq_rq_to_pdu(req);
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100305 void *reply = job->reply;
Benjamin Blockeab40cf2017-10-03 12:48:37 +0200306
307 memset(job, 0, sizeof(*job));
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100308 job->reply = reply;
309 job->reply_len = SCSI_SENSE_BUFFERSIZE;
Benjamin Block50b4d482017-08-24 01:57:56 +0200310 job->dd_data = job + 1;
Benjamin Block50b4d482017-08-24 01:57:56 +0200311}
312
Jens Axboecd2f0762018-10-24 07:11:39 -0600313static void bsg_exit_rq(struct blk_mq_tag_set *set, struct request *req,
314 unsigned int hctx_idx)
Benjamin Block50b4d482017-08-24 01:57:56 +0200315{
316 struct bsg_job *job = blk_mq_rq_to_pdu(req);
Benjamin Block50b4d482017-08-24 01:57:56 +0200317
Christoph Hellwig17cb9602018-03-13 17:28:41 +0100318 kfree(job->reply);
Benjamin Block50b4d482017-08-24 01:57:56 +0200319}
320
Jens Axboe5e28b8d2018-10-26 11:27:02 -0600321void bsg_remove_queue(struct request_queue *q)
322{
323 if (q) {
Jens Axboe1028e4b2018-10-29 09:47:17 -0600324 struct bsg_set *bset =
325 container_of(q->tag_set, struct bsg_set, tag_set);
Jens Axboecd2f0762018-10-24 07:11:39 -0600326
Jens Axboe5e28b8d2018-10-26 11:27:02 -0600327 bsg_unregister_queue(q);
328 blk_cleanup_queue(q);
Jens Axboe1028e4b2018-10-29 09:47:17 -0600329 blk_mq_free_tag_set(&bset->tag_set);
330 kfree(bset);
Jens Axboe5e28b8d2018-10-26 11:27:02 -0600331 }
332}
333EXPORT_SYMBOL_GPL(bsg_remove_queue);
334
Jens Axboecd2f0762018-10-24 07:11:39 -0600335static enum blk_eh_timer_return bsg_timeout(struct request *rq, bool reserved)
336{
Jens Axboe1028e4b2018-10-29 09:47:17 -0600337 struct bsg_set *bset =
338 container_of(rq->q->tag_set, struct bsg_set, tag_set);
Jens Axboecd2f0762018-10-24 07:11:39 -0600339
Jens Axboe1028e4b2018-10-29 09:47:17 -0600340 if (!bset->timeout_fn)
341 return BLK_EH_DONE;
342 return bset->timeout_fn(rq);
Jens Axboecd2f0762018-10-24 07:11:39 -0600343}
344
345static const struct blk_mq_ops bsg_mq_ops = {
346 .queue_rq = bsg_queue_rq,
347 .init_request = bsg_init_rq,
348 .exit_request = bsg_exit_rq,
349 .initialize_rq_fn = bsg_initialize_rq,
350 .complete = bsg_complete,
351 .timeout = bsg_timeout,
352};
353
Mike Christieaa387cc2011-07-31 22:05:09 +0200354/**
355 * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
356 * @dev: device to attach bsg device to
Mike Christieaa387cc2011-07-31 22:05:09 +0200357 * @name: device to give bsg device
358 * @job_fn: bsg job handler
Bart Van Asschea0b77e32019-05-30 17:00:51 -0700359 * @timeout: timeout handler function pointer
Mike Christieaa387cc2011-07-31 22:05:09 +0200360 * @dd_job_size: size of LLD data needed for each job
Mike Christieaa387cc2011-07-31 22:05:09 +0200361 */
Christoph Hellwigc1225f02017-08-25 17:37:38 +0200362struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
Jens Axboe1028e4b2018-10-29 09:47:17 -0600363 bsg_job_fn *job_fn, bsg_timeout_fn *timeout, int dd_job_size)
Mike Christieaa387cc2011-07-31 22:05:09 +0200364{
Jens Axboe1028e4b2018-10-29 09:47:17 -0600365 struct bsg_set *bset;
Jens Axboecd2f0762018-10-24 07:11:39 -0600366 struct blk_mq_tag_set *set;
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300367 struct request_queue *q;
Jens Axboecd2f0762018-10-24 07:11:39 -0600368 int ret = -ENOMEM;
Mike Christieaa387cc2011-07-31 22:05:09 +0200369
Jens Axboe1028e4b2018-10-29 09:47:17 -0600370 bset = kzalloc(sizeof(*bset), GFP_KERNEL);
371 if (!bset)
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300372 return ERR_PTR(-ENOMEM);
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100373
Jens Axboe1028e4b2018-10-29 09:47:17 -0600374 bset->job_fn = job_fn;
375 bset->timeout_fn = timeout;
376
377 set = &bset->tag_set;
Jens Axboecd2f0762018-10-24 07:11:39 -0600378 set->ops = &bsg_mq_ops,
379 set->nr_hw_queues = 1;
380 set->queue_depth = 128;
381 set->numa_node = NUMA_NO_NODE;
382 set->cmd_size = sizeof(struct bsg_job) + dd_job_size;
383 set->flags = BLK_MQ_F_NO_SCHED | BLK_MQ_F_BLOCKING;
384 if (blk_mq_alloc_tag_set(set))
385 goto out_tag_set;
386
387 q = blk_mq_init_queue(set);
388 if (IS_ERR(q)) {
389 ret = PTR_ERR(q);
390 goto out_queue;
391 }
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300392
Mike Christieaa387cc2011-07-31 22:05:09 +0200393 q->queuedata = dev;
Mike Christieaa387cc2011-07-31 22:05:09 +0200394 blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
395
Christoph Hellwig5de815a2018-05-29 08:40:23 +0200396 ret = bsg_register_queue(q, dev, name, &bsg_transport_ops);
Mike Christieaa387cc2011-07-31 22:05:09 +0200397 if (ret) {
398 printk(KERN_ERR "%s: bsg interface failed to "
399 "initialize - register queue\n", dev->kobj.name);
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100400 goto out_cleanup_queue;
Mike Christieaa387cc2011-07-31 22:05:09 +0200401 }
402
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300403 return q;
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100404out_cleanup_queue:
405 blk_cleanup_queue(q);
Jens Axboecd2f0762018-10-24 07:11:39 -0600406out_queue:
407 blk_mq_free_tag_set(set);
408out_tag_set:
Jens Axboe1028e4b2018-10-29 09:47:17 -0600409 kfree(bset);
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100410 return ERR_PTR(ret);
Mike Christieaa387cc2011-07-31 22:05:09 +0200411}
412EXPORT_SYMBOL_GPL(bsg_setup_queue);