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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
33
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, scsi_req(rq)->result);
41
42 put_device(job->dev);
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
63
64
65
66
67
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 struct scsi_request *rq = scsi_req(req);
75 int err;
76
77 err = scsi_req(job->req)->result = result;
78 if (err < 0)
79
80 rq->sense_len = sizeof(u32);
81 else
82 rq->sense_len = job->reply_len;
83
84 rq->resid_len = 0;
85
86 if (rsp) {
87 WARN_ON(reply_payload_rcv_len > scsi_req(rsp)->resid_len);
88
89
90 scsi_req(rsp)->resid_len -=
91 min(reply_payload_rcv_len, scsi_req(rsp)->resid_len);
92 }
93 blk_complete_request(req);
94}
95EXPORT_SYMBOL_GPL(bsg_job_done);
96
97
98
99
100
101static void bsg_softirq_done(struct request *rq)
102{
103 struct bsg_job *job = rq->special;
104
105 bsg_job_put(job);
106}
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);
118 scsi_req(req)->resid_len = blk_rq_bytes(req);
119 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
126
127
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;
133 struct scsi_request *rq = scsi_req(req);
134 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];
147 job->request = rq->cmd;
148 job->request_len = rq->cmd_len;
149 job->reply = rq->sense;
150 job->reply_len = SCSI_SENSE_BUFFERSIZE;
151
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
164 get_device(job->dev);
165 kref_init(&job->kref);
166 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
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178
179
180
181
182
183
184static void bsg_request_fn(struct request_queue *q)
185 __releases(q->queue_lock)
186 __acquires(q->queue_lock)
187{
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 scsi_req(req)->result = 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}
221
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223
224
225
226
227
228
229struct request_queue *bsg_setup_queue(struct device *dev, char *name,
230 bsg_job_fn *job_fn, int dd_job_size)
231{
232 struct request_queue *q;
233 int ret;
234
235 q = blk_alloc_queue(GFP_KERNEL);
236 if (!q)
237 return ERR_PTR(-ENOMEM);
238 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;
244
245 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);
256 goto out_cleanup_queue;
257 }
258
259 return q;
260out_cleanup_queue:
261 blk_cleanup_queue(q);
262 return ERR_PTR(ret);
263}
264EXPORT_SYMBOL_GPL(bsg_setup_queue);
265