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1/*
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>
28#include <linux/export.h>
29#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 */
35static void bsg_destroy_job(struct bsg_job *job)
36{
37 put_device(job->dev); /* release reference for the request */
38
39 kfree(job->request_payload.sg_list);
40 kfree(job->reply_payload.sg_list);
41 kfree(job);
42}
43
44/**
45 * bsg_job_done - completion routine for bsg requests
46 * @job: bsg_job that is complete
47 * @result: job reply result
48 * @reply_payload_rcv_len: length of payload recvd
49 *
50 * The LLD should call this when the bsg job has completed.
51 */
52void bsg_job_done(struct bsg_job *job, int result,
53 unsigned int reply_payload_rcv_len)
54{
55 struct request *req = job->req;
56 struct request *rsp = req->next_rq;
57 int err;
58
59 err = job->req->errors = result;
60 if (err < 0)
61 /* we're only returning the result field in the reply */
62 job->req->sense_len = sizeof(u32);
63 else
64 job->req->sense_len = job->reply_len;
65 /* we assume all request payload was transferred, residual == 0 */
66 req->resid_len = 0;
67
68 if (rsp) {
69 WARN_ON(reply_payload_rcv_len > rsp->resid_len);
70
71 /* set reply (bidi) residual */
72 rsp->resid_len -= min(reply_payload_rcv_len, rsp->resid_len);
73 }
74 blk_complete_request(req);
75}
76EXPORT_SYMBOL_GPL(bsg_job_done);
77
78/**
79 * bsg_softirq_done - softirq done routine for destroying the bsg requests
80 * @rq: BSG request that holds the job to be destroyed
81 */
82static void bsg_softirq_done(struct request *rq)
83{
84 struct bsg_job *job = rq->special;
85
86 blk_end_request_all(rq, rq->errors);
87 bsg_destroy_job(job);
88}
89
90static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
91{
92 size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
93
94 BUG_ON(!req->nr_phys_segments);
95
96 buf->sg_list = kzalloc(sz, GFP_KERNEL);
97 if (!buf->sg_list)
98 return -ENOMEM;
99 sg_init_table(buf->sg_list, req->nr_phys_segments);
100 buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
101 buf->payload_len = blk_rq_bytes(req);
102 return 0;
103}
104
105/**
106 * bsg_create_job - create the bsg_job structure for the bsg request
107 * @dev: device that is being sent the bsg request
108 * @req: BSG request that needs a job structure
109 */
110static int bsg_create_job(struct device *dev, struct request *req)
111{
112 struct request *rsp = req->next_rq;
113 struct request_queue *q = req->q;
114 struct bsg_job *job;
115 int ret;
116
117 BUG_ON(req->special);
118
119 job = kzalloc(sizeof(struct bsg_job) + q->bsg_job_size, GFP_KERNEL);
120 if (!job)
121 return -ENOMEM;
122
123 req->special = job;
124 job->req = req;
125 if (q->bsg_job_size)
126 job->dd_data = (void *)&job[1];
127 job->request = req->cmd;
128 job->request_len = req->cmd_len;
129 job->reply = req->sense;
130 job->reply_len = SCSI_SENSE_BUFFERSIZE; /* Size of sense buffer
131 * allocated */
132 if (req->bio) {
133 ret = bsg_map_buffer(&job->request_payload, req);
134 if (ret)
135 goto failjob_rls_job;
136 }
137 if (rsp && rsp->bio) {
138 ret = bsg_map_buffer(&job->reply_payload, rsp);
139 if (ret)
140 goto failjob_rls_rqst_payload;
141 }
142 job->dev = dev;
143 /* take a reference for the request */
144 get_device(job->dev);
145 return 0;
146
147failjob_rls_rqst_payload:
148 kfree(job->request_payload.sg_list);
149failjob_rls_job:
150 kfree(job);
151 return -ENOMEM;
152}
153
154/**
155 * bsg_request_fn - generic handler for bsg requests
156 * @q: request queue to manage
157 *
158 * On error the create_bsg_job function should return a -Exyz error value
159 * that will be set to the req->errors.
160 *
161 * Drivers/subsys should pass this to the queue init function.
162 */
163void bsg_request_fn(struct request_queue *q)
164{
165 struct device *dev = q->queuedata;
166 struct request *req;
167 struct bsg_job *job;
168 int ret;
169
170 if (!get_device(dev))
171 return;
172
173 while (1) {
174 req = blk_fetch_request(q);
175 if (!req)
176 break;
177 spin_unlock_irq(q->queue_lock);
178
179 ret = bsg_create_job(dev, req);
180 if (ret) {
181 req->errors = ret;
182 blk_end_request_all(req, ret);
183 spin_lock_irq(q->queue_lock);
184 continue;
185 }
186
187 job = req->special;
188 ret = q->bsg_job_fn(job);
189 spin_lock_irq(q->queue_lock);
190 if (ret)
191 break;
192 }
193
194 spin_unlock_irq(q->queue_lock);
195 put_device(dev);
196 spin_lock_irq(q->queue_lock);
197}
198EXPORT_SYMBOL_GPL(bsg_request_fn);
199
200/**
201 * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
202 * @dev: device to attach bsg device to
203 * @q: request queue setup by caller
204 * @name: device to give bsg device
205 * @job_fn: bsg job handler
206 * @dd_job_size: size of LLD data needed for each job
207 *
208 * The caller should have setup the reuqest queue with bsg_request_fn
209 * as the request_fn.
210 */
211int bsg_setup_queue(struct device *dev, struct request_queue *q,
212 char *name, bsg_job_fn *job_fn, int dd_job_size)
213{
214 int ret;
215
216 q->queuedata = dev;
217 q->bsg_job_size = dd_job_size;
218 q->bsg_job_fn = job_fn;
219 queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
220 blk_queue_softirq_done(q, bsg_softirq_done);
221 blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
222
223 ret = bsg_register_queue(q, dev, name, NULL);
224 if (ret) {
225 printk(KERN_ERR "%s: bsg interface failed to "
226 "initialize - register queue\n", dev->kobj.name);
227 return ret;
228 }
229
230 return 0;
231}
232EXPORT_SYMBOL_GPL(bsg_setup_queue);
1/*
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>
28#include <linux/export.h>
29#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 */
35static void bsg_destroy_job(struct kref *kref)
36{
37 struct bsg_job *job = container_of(kref, struct bsg_job, kref);
38 struct request *rq = job->req;
39
40 blk_end_request_all(rq, rq->errors);
41
42 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
49void 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);
60
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;
74 int err;
75
76 err = job->req->errors = result;
77 if (err < 0)
78 /* we're only returning the result field in the reply */
79 job->req->sense_len = sizeof(u32);
80 else
81 job->req->sense_len = job->reply_len;
82 /* we assume all request payload was transferred, residual == 0 */
83 req->resid_len = 0;
84
85 if (rsp) {
86 WARN_ON(reply_payload_rcv_len > rsp->resid_len);
87
88 /* set reply (bidi) residual */
89 rsp->resid_len -= min(reply_payload_rcv_len, rsp->resid_len);
90 }
91 blk_complete_request(req);
92}
93EXPORT_SYMBOL_GPL(bsg_job_done);
94
95/**
96 * bsg_softirq_done - softirq done routine for destroying the bsg requests
97 * @rq: BSG request that holds the job to be destroyed
98 */
99static void bsg_softirq_done(struct request *rq)
100{
101 struct bsg_job *job = rq->special;
102
103 bsg_job_put(job);
104}
105
106static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
107{
108 size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);
109
110 BUG_ON(!req->nr_phys_segments);
111
112 buf->sg_list = kzalloc(sz, GFP_KERNEL);
113 if (!buf->sg_list)
114 return -ENOMEM;
115 sg_init_table(buf->sg_list, req->nr_phys_segments);
116 buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
117 buf->payload_len = blk_rq_bytes(req);
118 return 0;
119}
120
121/**
122 * bsg_create_job - create the bsg_job structure for the bsg request
123 * @dev: device that is being sent the bsg request
124 * @req: BSG request that needs a job structure
125 */
126static int bsg_create_job(struct device *dev, struct request *req)
127{
128 struct request *rsp = req->next_rq;
129 struct request_queue *q = req->q;
130 struct bsg_job *job;
131 int ret;
132
133 BUG_ON(req->special);
134
135 job = kzalloc(sizeof(struct bsg_job) + q->bsg_job_size, GFP_KERNEL);
136 if (!job)
137 return -ENOMEM;
138
139 req->special = job;
140 job->req = req;
141 if (q->bsg_job_size)
142 job->dd_data = (void *)&job[1];
143 job->request = req->cmd;
144 job->request_len = req->cmd_len;
145 job->reply = req->sense;
146 job->reply_len = SCSI_SENSE_BUFFERSIZE; /* Size of sense buffer
147 * allocated */
148 if (req->bio) {
149 ret = bsg_map_buffer(&job->request_payload, req);
150 if (ret)
151 goto failjob_rls_job;
152 }
153 if (rsp && rsp->bio) {
154 ret = bsg_map_buffer(&job->reply_payload, rsp);
155 if (ret)
156 goto failjob_rls_rqst_payload;
157 }
158 job->dev = dev;
159 /* take a reference for the request */
160 get_device(job->dev);
161 kref_init(&job->kref);
162 return 0;
163
164failjob_rls_rqst_payload:
165 kfree(job->request_payload.sg_list);
166failjob_rls_job:
167 kfree(job);
168 return -ENOMEM;
169}
170
171/**
172 * bsg_request_fn - generic handler for bsg requests
173 * @q: request queue to manage
174 *
175 * On error the create_bsg_job function should return a -Exyz error value
176 * that will be set to the req->errors.
177 *
178 * Drivers/subsys should pass this to the queue init function.
179 */
180void bsg_request_fn(struct request_queue *q)
181 __releases(q->queue_lock)
182 __acquires(q->queue_lock)
183{
184 struct device *dev = q->queuedata;
185 struct request *req;
186 struct bsg_job *job;
187 int ret;
188
189 if (!get_device(dev))
190 return;
191
192 while (1) {
193 req = blk_fetch_request(q);
194 if (!req)
195 break;
196 spin_unlock_irq(q->queue_lock);
197
198 ret = bsg_create_job(dev, req);
199 if (ret) {
200 req->errors = ret;
201 blk_end_request_all(req, ret);
202 spin_lock_irq(q->queue_lock);
203 continue;
204 }
205
206 job = req->special;
207 ret = q->bsg_job_fn(job);
208 spin_lock_irq(q->queue_lock);
209 if (ret)
210 break;
211 }
212
213 spin_unlock_irq(q->queue_lock);
214 put_device(dev);
215 spin_lock_irq(q->queue_lock);
216}
217EXPORT_SYMBOL_GPL(bsg_request_fn);
218
219/**
220 * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
221 * @dev: device to attach bsg device to
222 * @q: request queue setup by caller
223 * @name: device to give bsg device
224 * @job_fn: bsg job handler
225 * @dd_job_size: size of LLD data needed for each job
226 *
227 * The caller should have setup the reuqest queue with bsg_request_fn
228 * as the request_fn.
229 */
230int bsg_setup_queue(struct device *dev, struct request_queue *q,
231 char *name, bsg_job_fn *job_fn, int dd_job_size)
232{
233 int ret;
234
235 q->queuedata = dev;
236 q->bsg_job_size = dd_job_size;
237 q->bsg_job_fn = job_fn;
238 queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
239 blk_queue_softirq_done(q, bsg_softirq_done);
240 blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
241
242 ret = bsg_register_queue(q, dev, name, NULL);
243 if (ret) {
244 printk(KERN_ERR "%s: bsg interface failed to "
245 "initialize - register queue\n", dev->kobj.name);
246 return ret;
247 }
248
249 return 0;
250}
251EXPORT_SYMBOL_GPL(bsg_setup_queue);