1 /*
2 * SCSI RDAM Protocol lib functions
3 *
4 * Copyright (C) 2006 FUJITA Tomonori <tomof@acm.org>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation; either version 2 of the
9 * License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19 * 02110-1301 USA
20 */
21 #include <linux/err.h>
22 #include <linux/kfifo.h>
23 #include <linux/scatterlist.h>
24 #include <linux/dma-mapping.h>
25 #include <scsi/scsi.h>
26 #include <scsi/scsi_cmnd.h>
27 #include <scsi/scsi_tcq.h>
28 #include <scsi/scsi_tgt.h>
29 #include <scsi/srp.h>
30 #include <scsi/libsrp.h>
31
32 enum srp_task_attributes {
33 SRP_SIMPLE_TASK = 0,
34 SRP_HEAD_TASK = 1,
35 SRP_ORDERED_TASK = 2,
36 SRP_ACA_TASK = 4
37 };
38
39 /* tmp - will replace with SCSI logging stuff */
40 #define eprintk(fmt, args...) \
41 do { \
42 printk("%s(%d) " fmt, __func__, __LINE__, ##args); \
43 } while (0)
44 /* #define dprintk eprintk */
45 #define dprintk(fmt, args...)
46
srp_iu_pool_alloc(struct srp_queue * q,size_t max,struct srp_buf ** ring)47 static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
48 struct srp_buf **ring)
49 {
50 int i;
51 struct iu_entry *iue;
52
53 q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
54 if (!q->pool)
55 return -ENOMEM;
56 q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
57 if (!q->items)
58 goto free_pool;
59
60 spin_lock_init(&q->lock);
61 q->queue = kfifo_init((void *) q->pool, max * sizeof(void *),
62 GFP_KERNEL, &q->lock);
63 if (IS_ERR(q->queue))
64 goto free_item;
65
66 for (i = 0, iue = q->items; i < max; i++) {
67 __kfifo_put(q->queue, (void *) &iue, sizeof(void *));
68 iue->sbuf = ring[i];
69 iue++;
70 }
71 return 0;
72
73 free_item:
74 kfree(q->items);
75 free_pool:
76 kfree(q->pool);
77 return -ENOMEM;
78 }
79
srp_iu_pool_free(struct srp_queue * q)80 static void srp_iu_pool_free(struct srp_queue *q)
81 {
82 kfree(q->items);
83 kfree(q->pool);
84 }
85
srp_ring_alloc(struct device * dev,size_t max,size_t size)86 static struct srp_buf **srp_ring_alloc(struct device *dev,
87 size_t max, size_t size)
88 {
89 int i;
90 struct srp_buf **ring;
91
92 ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
93 if (!ring)
94 return NULL;
95
96 for (i = 0; i < max; i++) {
97 ring[i] = kzalloc(sizeof(struct srp_buf), GFP_KERNEL);
98 if (!ring[i])
99 goto out;
100 ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
101 GFP_KERNEL);
102 if (!ring[i]->buf)
103 goto out;
104 }
105 return ring;
106
107 out:
108 for (i = 0; i < max && ring[i]; i++) {
109 if (ring[i]->buf)
110 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
111 kfree(ring[i]);
112 }
113 kfree(ring);
114
115 return NULL;
116 }
117
srp_ring_free(struct device * dev,struct srp_buf ** ring,size_t max,size_t size)118 static void srp_ring_free(struct device *dev, struct srp_buf **ring, size_t max,
119 size_t size)
120 {
121 int i;
122
123 for (i = 0; i < max; i++) {
124 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
125 kfree(ring[i]);
126 }
127 }
128
srp_target_alloc(struct srp_target * target,struct device * dev,size_t nr,size_t iu_size)129 int srp_target_alloc(struct srp_target *target, struct device *dev,
130 size_t nr, size_t iu_size)
131 {
132 int err;
133
134 spin_lock_init(&target->lock);
135 INIT_LIST_HEAD(&target->cmd_queue);
136
137 target->dev = dev;
138 target->dev->driver_data = target;
139
140 target->srp_iu_size = iu_size;
141 target->rx_ring_size = nr;
142 target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
143 if (!target->rx_ring)
144 return -ENOMEM;
145 err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
146 if (err)
147 goto free_ring;
148
149 return 0;
150
151 free_ring:
152 srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
153 return -ENOMEM;
154 }
155 EXPORT_SYMBOL_GPL(srp_target_alloc);
156
srp_target_free(struct srp_target * target)157 void srp_target_free(struct srp_target *target)
158 {
159 srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
160 target->srp_iu_size);
161 srp_iu_pool_free(&target->iu_queue);
162 }
163 EXPORT_SYMBOL_GPL(srp_target_free);
164
srp_iu_get(struct srp_target * target)165 struct iu_entry *srp_iu_get(struct srp_target *target)
166 {
167 struct iu_entry *iue = NULL;
168
169 kfifo_get(target->iu_queue.queue, (void *) &iue, sizeof(void *));
170 if (!iue)
171 return iue;
172 iue->target = target;
173 INIT_LIST_HEAD(&iue->ilist);
174 iue->flags = 0;
175 return iue;
176 }
177 EXPORT_SYMBOL_GPL(srp_iu_get);
178
srp_iu_put(struct iu_entry * iue)179 void srp_iu_put(struct iu_entry *iue)
180 {
181 kfifo_put(iue->target->iu_queue.queue, (void *) &iue, sizeof(void *));
182 }
183 EXPORT_SYMBOL_GPL(srp_iu_put);
184
srp_direct_data(struct scsi_cmnd * sc,struct srp_direct_buf * md,enum dma_data_direction dir,srp_rdma_t rdma_io,int dma_map,int ext_desc)185 static int srp_direct_data(struct scsi_cmnd *sc, struct srp_direct_buf *md,
186 enum dma_data_direction dir, srp_rdma_t rdma_io,
187 int dma_map, int ext_desc)
188 {
189 struct iu_entry *iue = NULL;
190 struct scatterlist *sg = NULL;
191 int err, nsg = 0, len;
192
193 if (dma_map) {
194 iue = (struct iu_entry *) sc->SCp.ptr;
195 sg = scsi_sglist(sc);
196
197 dprintk("%p %u %u %d\n", iue, scsi_bufflen(sc),
198 md->len, scsi_sg_count(sc));
199
200 nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
201 DMA_BIDIRECTIONAL);
202 if (!nsg) {
203 printk("fail to map %p %d\n", iue, scsi_sg_count(sc));
204 return 0;
205 }
206 len = min(scsi_bufflen(sc), md->len);
207 } else
208 len = md->len;
209
210 err = rdma_io(sc, sg, nsg, md, 1, dir, len);
211
212 if (dma_map)
213 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
214
215 return err;
216 }
217
srp_indirect_data(struct scsi_cmnd * sc,struct srp_cmd * cmd,struct srp_indirect_buf * id,enum dma_data_direction dir,srp_rdma_t rdma_io,int dma_map,int ext_desc)218 static int srp_indirect_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
219 struct srp_indirect_buf *id,
220 enum dma_data_direction dir, srp_rdma_t rdma_io,
221 int dma_map, int ext_desc)
222 {
223 struct iu_entry *iue = NULL;
224 struct srp_direct_buf *md = NULL;
225 struct scatterlist dummy, *sg = NULL;
226 dma_addr_t token = 0;
227 int err = 0;
228 int nmd, nsg = 0, len;
229
230 if (dma_map || ext_desc) {
231 iue = (struct iu_entry *) sc->SCp.ptr;
232 sg = scsi_sglist(sc);
233
234 dprintk("%p %u %u %d %d\n",
235 iue, scsi_bufflen(sc), id->len,
236 cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
237 }
238
239 nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
240
241 if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
242 (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
243 md = &id->desc_list[0];
244 goto rdma;
245 }
246
247 if (ext_desc && dma_map) {
248 md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
249 &token, GFP_KERNEL);
250 if (!md) {
251 eprintk("Can't get dma memory %u\n", id->table_desc.len);
252 return -ENOMEM;
253 }
254
255 sg_init_one(&dummy, md, id->table_desc.len);
256 sg_dma_address(&dummy) = token;
257 sg_dma_len(&dummy) = id->table_desc.len;
258 err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
259 id->table_desc.len);
260 if (err) {
261 eprintk("Error copying indirect table %d\n", err);
262 goto free_mem;
263 }
264 } else {
265 eprintk("This command uses external indirect buffer\n");
266 return -EINVAL;
267 }
268
269 rdma:
270 if (dma_map) {
271 nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
272 DMA_BIDIRECTIONAL);
273 if (!nsg) {
274 eprintk("fail to map %p %d\n", iue, scsi_sg_count(sc));
275 err = -EIO;
276 goto free_mem;
277 }
278 len = min(scsi_bufflen(sc), id->len);
279 } else
280 len = id->len;
281
282 err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
283
284 if (dma_map)
285 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
286
287 free_mem:
288 if (token && dma_map)
289 dma_free_coherent(iue->target->dev, id->table_desc.len, md, token);
290
291 return err;
292 }
293
data_out_desc_size(struct srp_cmd * cmd)294 static int data_out_desc_size(struct srp_cmd *cmd)
295 {
296 int size = 0;
297 u8 fmt = cmd->buf_fmt >> 4;
298
299 switch (fmt) {
300 case SRP_NO_DATA_DESC:
301 break;
302 case SRP_DATA_DESC_DIRECT:
303 size = sizeof(struct srp_direct_buf);
304 break;
305 case SRP_DATA_DESC_INDIRECT:
306 size = sizeof(struct srp_indirect_buf) +
307 sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
308 break;
309 default:
310 eprintk("client error. Invalid data_out_format %x\n", fmt);
311 break;
312 }
313 return size;
314 }
315
316 /*
317 * TODO: this can be called multiple times for a single command if it
318 * has very long data.
319 */
srp_transfer_data(struct scsi_cmnd * sc,struct srp_cmd * cmd,srp_rdma_t rdma_io,int dma_map,int ext_desc)320 int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
321 srp_rdma_t rdma_io, int dma_map, int ext_desc)
322 {
323 struct srp_direct_buf *md;
324 struct srp_indirect_buf *id;
325 enum dma_data_direction dir;
326 int offset, err = 0;
327 u8 format;
328
329 offset = cmd->add_cdb_len * 4;
330
331 dir = srp_cmd_direction(cmd);
332 if (dir == DMA_FROM_DEVICE)
333 offset += data_out_desc_size(cmd);
334
335 if (dir == DMA_TO_DEVICE)
336 format = cmd->buf_fmt >> 4;
337 else
338 format = cmd->buf_fmt & ((1U << 4) - 1);
339
340 switch (format) {
341 case SRP_NO_DATA_DESC:
342 break;
343 case SRP_DATA_DESC_DIRECT:
344 md = (struct srp_direct_buf *)
345 (cmd->add_data + offset);
346 err = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
347 break;
348 case SRP_DATA_DESC_INDIRECT:
349 id = (struct srp_indirect_buf *)
350 (cmd->add_data + offset);
351 err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
352 ext_desc);
353 break;
354 default:
355 eprintk("Unknown format %d %x\n", dir, format);
356 err = -EINVAL;
357 }
358
359 return err;
360 }
361 EXPORT_SYMBOL_GPL(srp_transfer_data);
362
vscsis_data_length(struct srp_cmd * cmd,enum dma_data_direction dir)363 static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
364 {
365 struct srp_direct_buf *md;
366 struct srp_indirect_buf *id;
367 int len = 0, offset = cmd->add_cdb_len * 4;
368 u8 fmt;
369
370 if (dir == DMA_TO_DEVICE)
371 fmt = cmd->buf_fmt >> 4;
372 else {
373 fmt = cmd->buf_fmt & ((1U << 4) - 1);
374 offset += data_out_desc_size(cmd);
375 }
376
377 switch (fmt) {
378 case SRP_NO_DATA_DESC:
379 break;
380 case SRP_DATA_DESC_DIRECT:
381 md = (struct srp_direct_buf *) (cmd->add_data + offset);
382 len = md->len;
383 break;
384 case SRP_DATA_DESC_INDIRECT:
385 id = (struct srp_indirect_buf *) (cmd->add_data + offset);
386 len = id->len;
387 break;
388 default:
389 eprintk("invalid data format %x\n", fmt);
390 break;
391 }
392 return len;
393 }
394
srp_cmd_queue(struct Scsi_Host * shost,struct srp_cmd * cmd,void * info,u64 itn_id,u64 addr)395 int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
396 u64 itn_id, u64 addr)
397 {
398 enum dma_data_direction dir;
399 struct scsi_cmnd *sc;
400 int tag, len, err;
401
402 switch (cmd->task_attr) {
403 case SRP_SIMPLE_TASK:
404 tag = MSG_SIMPLE_TAG;
405 break;
406 case SRP_ORDERED_TASK:
407 tag = MSG_ORDERED_TAG;
408 break;
409 case SRP_HEAD_TASK:
410 tag = MSG_HEAD_TAG;
411 break;
412 default:
413 eprintk("Task attribute %d not supported\n", cmd->task_attr);
414 tag = MSG_ORDERED_TAG;
415 }
416
417 dir = srp_cmd_direction(cmd);
418 len = vscsis_data_length(cmd, dir);
419
420 dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
421 cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
422
423 sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
424 if (!sc)
425 return -ENOMEM;
426
427 sc->SCp.ptr = info;
428 memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
429 sc->sdb.length = len;
430 sc->sdb.table.sgl = (void *) (unsigned long) addr;
431 sc->tag = tag;
432 err = scsi_tgt_queue_command(sc, itn_id, (struct scsi_lun *)&cmd->lun,
433 cmd->tag);
434 if (err)
435 scsi_host_put_command(shost, sc);
436
437 return err;
438 }
439 EXPORT_SYMBOL_GPL(srp_cmd_queue);
440
441 MODULE_DESCRIPTION("SCSI RDAM Protocol lib functions");
442 MODULE_AUTHOR("FUJITA Tomonori");
443 MODULE_LICENSE("GPL");
444