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Mike Christieaa387cc2011-07-31 22:05:09 +02001/*
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>
24#include <linux/blkdev.h>
25#include <linux/delay.h>
26#include <linux/scatterlist.h>
27#include <linux/bsg-lib.h>
Paul Gortmaker6adb1232011-09-28 18:26:05 -040028#include <linux/export.h>
Mike Christieaa387cc2011-07-31 22:05:09 +020029#include <scsi/scsi_cmnd.h>
30
31/**
32 * bsg_destroy_job - routine to teardown/delete a bsg job
33 * @job: bsg_job that is to be torn down
34 */
Johannes Thumshirnfb6f7c82016-11-17 10:31:23 +010035static void bsg_destroy_job(struct kref *kref)
Mike Christieaa387cc2011-07-31 22:05:09 +020036{
Johannes Thumshirnbf0f2d32016-11-17 10:31:18 +010037 struct bsg_job *job = container_of(kref, struct bsg_job, kref);
Johannes Thumshirnc00da4c2016-11-17 10:31:20 +010038 struct request *rq = job->req;
39
40 blk_end_request_all(rq, rq->errors);
Johannes Thumshirnbf0f2d32016-11-17 10:31:18 +010041
Mike Christieaa387cc2011-07-31 22:05:09 +020042 put_device(job->dev); /* release reference for the request */
43
44 kfree(job->request_payload.sg_list);
45 kfree(job->reply_payload.sg_list);
46 kfree(job);
47}
48
Johannes Thumshirnfb6f7c82016-11-17 10:31:23 +010049void bsg_job_put(struct bsg_job *job)
50{
51 kref_put(&job->kref, bsg_destroy_job);
52}
53EXPORT_SYMBOL_GPL(bsg_job_put);
54
55int bsg_job_get(struct bsg_job *job)
56{
57 return kref_get_unless_zero(&job->kref);
58}
59EXPORT_SYMBOL_GPL(bsg_job_get);
Mike Christieaa387cc2011-07-31 22:05:09 +020060
61/**
62 * bsg_job_done - completion routine for bsg requests
63 * @job: bsg_job that is complete
64 * @result: job reply result
65 * @reply_payload_rcv_len: length of payload recvd
66 *
67 * The LLD should call this when the bsg job has completed.
68 */
69void bsg_job_done(struct bsg_job *job, int result,
70 unsigned int reply_payload_rcv_len)
71{
72 struct request *req = job->req;
73 struct request *rsp = req->next_rq;
Christoph Hellwig82ed4db2017-01-27 09:46:29 +010074 struct scsi_request *rq = scsi_req(req);
Mike Christieaa387cc2011-07-31 22:05:09 +020075 int err;
76
77 err = job->req->errors = result;
78 if (err < 0)
79 /* we're only returning the result field in the reply */
Christoph Hellwig82ed4db2017-01-27 09:46:29 +010080 rq->sense_len = sizeof(u32);
Mike Christieaa387cc2011-07-31 22:05:09 +020081 else
Christoph Hellwig82ed4db2017-01-27 09:46:29 +010082 rq->sense_len = job->reply_len;
Mike Christieaa387cc2011-07-31 22:05:09 +020083 /* we assume all request payload was transferred, residual == 0 */
Christoph Hellwig82ed4db2017-01-27 09:46:29 +010084 rq->resid_len = 0;
Mike Christieaa387cc2011-07-31 22:05:09 +020085
86 if (rsp) {
Christoph Hellwig82ed4db2017-01-27 09:46:29 +010087 WARN_ON(reply_payload_rcv_len > scsi_req(rsp)->resid_len);
Mike Christieaa387cc2011-07-31 22:05:09 +020088
89 /* set reply (bidi) residual */
Christoph Hellwig82ed4db2017-01-27 09:46:29 +010090 scsi_req(rsp)->resid_len -=
91 min(reply_payload_rcv_len, scsi_req(rsp)->resid_len);
Mike Christieaa387cc2011-07-31 22:05:09 +020092 }
93 blk_complete_request(req);
94}
95EXPORT_SYMBOL_GPL(bsg_job_done);
96
97/**
98 * bsg_softirq_done - softirq done routine for destroying the bsg requests
99 * @rq: BSG request that holds the job to be destroyed
100 */
101static void bsg_softirq_done(struct request *rq)
102{
103 struct bsg_job *job = rq->special;
104
Johannes Thumshirnfb6f7c82016-11-17 10:31:23 +0100105 bsg_job_put(job);
Mike Christieaa387cc2011-07-31 22:05:09 +0200106}
107
108static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
109{
110 size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
111
112 BUG_ON(!req->nr_phys_segments);
113
114 buf->sg_list = kzalloc(sz, GFP_KERNEL);
115 if (!buf->sg_list)
116 return -ENOMEM;
117 sg_init_table(buf->sg_list, req->nr_phys_segments);
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100118 scsi_req(req)->resid_len = blk_rq_bytes(req);
Mike Christieaa387cc2011-07-31 22:05:09 +0200119 buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
120 buf->payload_len = blk_rq_bytes(req);
121 return 0;
122}
123
124/**
125 * bsg_create_job - create the bsg_job structure for the bsg request
126 * @dev: device that is being sent the bsg request
127 * @req: BSG request that needs a job structure
128 */
129static int bsg_create_job(struct device *dev, struct request *req)
130{
131 struct request *rsp = req->next_rq;
132 struct request_queue *q = req->q;
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100133 struct scsi_request *rq = scsi_req(req);
Mike Christieaa387cc2011-07-31 22:05:09 +0200134 struct bsg_job *job;
135 int ret;
136
137 BUG_ON(req->special);
138
139 job = kzalloc(sizeof(struct bsg_job) + q->bsg_job_size, GFP_KERNEL);
140 if (!job)
141 return -ENOMEM;
142
143 req->special = job;
144 job->req = req;
145 if (q->bsg_job_size)
146 job->dd_data = (void *)&job[1];
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100147 job->request = rq->cmd;
148 job->request_len = rq->cmd_len;
149 job->reply = rq->sense;
Mike Christieaa387cc2011-07-31 22:05:09 +0200150 job->reply_len = SCSI_SENSE_BUFFERSIZE; /* Size of sense buffer
151 * allocated */
152 if (req->bio) {
153 ret = bsg_map_buffer(&job->request_payload, req);
154 if (ret)
155 goto failjob_rls_job;
156 }
157 if (rsp && rsp->bio) {
158 ret = bsg_map_buffer(&job->reply_payload, rsp);
159 if (ret)
160 goto failjob_rls_rqst_payload;
161 }
162 job->dev = dev;
163 /* take a reference for the request */
164 get_device(job->dev);
Johannes Thumshirnbf0f2d32016-11-17 10:31:18 +0100165 kref_init(&job->kref);
Mike Christieaa387cc2011-07-31 22:05:09 +0200166 return 0;
167
168failjob_rls_rqst_payload:
169 kfree(job->request_payload.sg_list);
170failjob_rls_job:
171 kfree(job);
172 return -ENOMEM;
173}
174
Mike Christieaa387cc2011-07-31 22:05:09 +0200175/**
176 * bsg_request_fn - generic handler for bsg requests
177 * @q: request queue to manage
178 *
179 * On error the create_bsg_job function should return a -Exyz error value
180 * that will be set to the req->errors.
181 *
182 * Drivers/subsys should pass this to the queue init function.
183 */
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300184static void bsg_request_fn(struct request_queue *q)
Bart Van Asschedbb3ab02016-09-25 19:54:38 -0700185 __releases(q->queue_lock)
186 __acquires(q->queue_lock)
Mike Christieaa387cc2011-07-31 22:05:09 +0200187{
188 struct device *dev = q->queuedata;
189 struct request *req;
190 struct bsg_job *job;
191 int ret;
192
193 if (!get_device(dev))
194 return;
195
196 while (1) {
197 req = blk_fetch_request(q);
198 if (!req)
199 break;
200 spin_unlock_irq(q->queue_lock);
201
202 ret = bsg_create_job(dev, req);
203 if (ret) {
204 req->errors = ret;
205 blk_end_request_all(req, ret);
206 spin_lock_irq(q->queue_lock);
207 continue;
208 }
209
210 job = req->special;
211 ret = q->bsg_job_fn(job);
212 spin_lock_irq(q->queue_lock);
213 if (ret)
214 break;
215 }
216
217 spin_unlock_irq(q->queue_lock);
218 put_device(dev);
219 spin_lock_irq(q->queue_lock);
220}
Mike Christieaa387cc2011-07-31 22:05:09 +0200221
222/**
223 * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
224 * @dev: device to attach bsg device to
Mike Christieaa387cc2011-07-31 22:05:09 +0200225 * @name: device to give bsg device
226 * @job_fn: bsg job handler
227 * @dd_job_size: size of LLD data needed for each job
Mike Christieaa387cc2011-07-31 22:05:09 +0200228 */
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300229struct request_queue *bsg_setup_queue(struct device *dev, char *name,
230 bsg_job_fn *job_fn, int dd_job_size)
Mike Christieaa387cc2011-07-31 22:05:09 +0200231{
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300232 struct request_queue *q;
Mike Christieaa387cc2011-07-31 22:05:09 +0200233 int ret;
234
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100235 q = blk_alloc_queue(GFP_KERNEL);
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300236 if (!q)
237 return ERR_PTR(-ENOMEM);
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100238 q->cmd_size = sizeof(struct scsi_request);
239 q->request_fn = bsg_request_fn;
240
241 ret = blk_init_allocated_queue(q);
242 if (ret)
243 goto out_cleanup_queue;
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300244
Mike Christieaa387cc2011-07-31 22:05:09 +0200245 q->queuedata = dev;
246 q->bsg_job_size = dd_job_size;
247 q->bsg_job_fn = job_fn;
248 queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
249 blk_queue_softirq_done(q, bsg_softirq_done);
250 blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
251
252 ret = bsg_register_queue(q, dev, name, NULL);
253 if (ret) {
254 printk(KERN_ERR "%s: bsg interface failed to "
255 "initialize - register queue\n", dev->kobj.name);
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100256 goto out_cleanup_queue;
Mike Christieaa387cc2011-07-31 22:05:09 +0200257 }
258
Christoph Hellwig8ae94eb2017-01-03 15:25:02 +0300259 return q;
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100260out_cleanup_queue:
261 blk_cleanup_queue(q);
262 return ERR_PTR(ret);
Mike Christieaa387cc2011-07-31 22:05:09 +0200263}
264EXPORT_SYMBOL_GPL(bsg_setup_queue);