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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2006-11-30 13:00:50 -0500
committerJames Bottomley <jejb@mulgrave.il.steeleye.com>2006-12-03 10:27:33 -0500
commit26b14823441382264e6f3dfd01b8687dc18196fe (patch)
treec965c5b5967f4485f433cf80db91d3d371d9cc8c /drivers/scsi/libsrp.c
parentc603d04ef6826a29f50cb151cb992f256d0cf19d (diff)
[SCSI] scsi tgt: SCSI RDMA Protocol library functions
libsrp provides helper functions for SRP target drivers. Some SRP target drivers would be out of drivers/scsi/ so we added an entry for libsrp in drivers/scsi/Kconfig. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: Santiago Leon <santil@us.ibm.com> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/libsrp.c')
-rw-r--r--drivers/scsi/libsrp.c441
1 files changed, 441 insertions, 0 deletions
diff --git a/drivers/scsi/libsrp.c b/drivers/scsi/libsrp.c
new file mode 100644
index 000000000000..89403b00e042
--- /dev/null
+++ b/drivers/scsi/libsrp.c
@@ -0,0 +1,441 @@
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 <linux/pci.h>
26#include <scsi/scsi.h>
27#include <scsi/scsi_cmnd.h>
28#include <scsi/scsi_tcq.h>
29#include <scsi/scsi_tgt.h>
30#include <scsi/srp.h>
31#include <scsi/libsrp.h>
32
33enum srp_task_attributes {
34 SRP_SIMPLE_TASK = 0,
35 SRP_HEAD_TASK = 1,
36 SRP_ORDERED_TASK = 2,
37 SRP_ACA_TASK = 4
38};
39
40/* tmp - will replace with SCSI logging stuff */
41#define eprintk(fmt, args...) \
42do { \
43 printk("%s(%d) " fmt, __FUNCTION__, __LINE__, ##args); \
44} while (0)
45/* #define dprintk eprintk */
46#define dprintk(fmt, args...)
47
48static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
49 struct srp_buf **ring)
50{
51 int i;
52 struct iu_entry *iue;
53
54 q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
55 if (!q->pool)
56 return -ENOMEM;
57 q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
58 if (!q->items)
59 goto free_pool;
60
61 spin_lock_init(&q->lock);
62 q->queue = kfifo_init((void *) q->pool, max * sizeof(void *),
63 GFP_KERNEL, &q->lock);
64 if (IS_ERR(q->queue))
65 goto free_item;
66
67 for (i = 0, iue = q->items; i < max; i++) {
68 __kfifo_put(q->queue, (void *) &iue, sizeof(void *));
69 iue->sbuf = ring[i];
70 iue++;
71 }
72 return 0;
73
74free_item:
75 kfree(q->items);
76free_pool:
77 kfree(q->pool);
78 return -ENOMEM;
79}
80
81static void srp_iu_pool_free(struct srp_queue *q)
82{
83 kfree(q->items);
84 kfree(q->pool);
85}
86
87static struct srp_buf **srp_ring_alloc(struct device *dev,
88 size_t max, size_t size)
89{
90 int i;
91 struct srp_buf **ring;
92
93 ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
94 if (!ring)
95 return NULL;
96
97 for (i = 0; i < max; i++) {
98 ring[i] = kzalloc(sizeof(struct srp_buf), GFP_KERNEL);
99 if (!ring[i])
100 goto out;
101 ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
102 GFP_KERNEL);
103 if (!ring[i]->buf)
104 goto out;
105 }
106 return ring;
107
108out:
109 for (i = 0; i < max && ring[i]; i++) {
110 if (ring[i]->buf)
111 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
112 kfree(ring[i]);
113 }
114 kfree(ring);
115
116 return NULL;
117}
118
119static void srp_ring_free(struct device *dev, struct srp_buf **ring, size_t max,
120 size_t size)
121{
122 int i;
123
124 for (i = 0; i < max; i++) {
125 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
126 kfree(ring[i]);
127 }
128}
129
130int srp_target_alloc(struct srp_target *target, struct device *dev,
131 size_t nr, size_t iu_size)
132{
133 int err;
134
135 spin_lock_init(&target->lock);
136 INIT_LIST_HEAD(&target->cmd_queue);
137
138 target->dev = dev;
139 target->dev->driver_data = target;
140
141 target->srp_iu_size = iu_size;
142 target->rx_ring_size = nr;
143 target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
144 if (!target->rx_ring)
145 return -ENOMEM;
146 err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
147 if (err)
148 goto free_ring;
149
150 return 0;
151
152free_ring:
153 srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
154 return -ENOMEM;
155}
156EXPORT_SYMBOL_GPL(srp_target_alloc);
157
158void srp_target_free(struct srp_target *target)
159{
160 srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
161 target->srp_iu_size);
162 srp_iu_pool_free(&target->iu_queue);
163}
164EXPORT_SYMBOL_GPL(srp_target_free);
165
166struct iu_entry *srp_iu_get(struct srp_target *target)
167{
168 struct iu_entry *iue = NULL;
169
170 kfifo_get(target->iu_queue.queue, (void *) &iue, sizeof(void *));
171 if (!iue)
172 return iue;
173 iue->target = target;
174 INIT_LIST_HEAD(&iue->ilist);
175 iue->flags = 0;
176 return iue;
177}
178EXPORT_SYMBOL_GPL(srp_iu_get);
179
180void srp_iu_put(struct iu_entry *iue)
181{
182 kfifo_put(iue->target->iu_queue.queue, (void *) &iue, sizeof(void *));
183}
184EXPORT_SYMBOL_GPL(srp_iu_put);
185
186static int srp_direct_data(struct scsi_cmnd *sc, struct srp_direct_buf *md,
187 enum dma_data_direction dir, srp_rdma_t rdma_io,
188 int dma_map, int ext_desc)
189{
190 struct iu_entry *iue = NULL;
191 struct scatterlist *sg = NULL;
192 int err, nsg = 0, len;
193
194 if (dma_map) {
195 iue = (struct iu_entry *) sc->SCp.ptr;
196 sg = sc->request_buffer;
197
198 dprintk("%p %u %u %d\n", iue, sc->request_bufflen,
199 md->len, sc->use_sg);
200
201 nsg = dma_map_sg(iue->target->dev, sg, sc->use_sg,
202 DMA_BIDIRECTIONAL);
203 if (!nsg) {
204 printk("fail to map %p %d\n", iue, sc->use_sg);
205 return 0;
206 }
207 len = min(sc->request_bufflen, md->len);
208 } else
209 len = md->len;
210
211 err = rdma_io(sc, sg, nsg, md, 1, dir, len);
212
213 if (dma_map)
214 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
215
216 return err;
217}
218
219static int srp_indirect_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
220 struct srp_indirect_buf *id,
221 enum dma_data_direction dir, srp_rdma_t rdma_io,
222 int dma_map, int ext_desc)
223{
224 struct iu_entry *iue = NULL;
225 struct srp_direct_buf *md = NULL;
226 struct scatterlist dummy, *sg = NULL;
227 dma_addr_t token = 0;
228 long err;
229 unsigned int done = 0;
230 int nmd, nsg = 0, len;
231
232 if (dma_map || ext_desc) {
233 iue = (struct iu_entry *) sc->SCp.ptr;
234 sg = sc->request_buffer;
235
236 dprintk("%p %u %u %d %d\n",
237 iue, sc->request_bufflen, id->len,
238 cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
239 }
240
241 nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
242
243 if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
244 (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
245 md = &id->desc_list[0];
246 goto rdma;
247 }
248
249 if (ext_desc && dma_map) {
250 md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
251 &token, GFP_KERNEL);
252 if (!md) {
253 eprintk("Can't get dma memory %u\n", id->table_desc.len);
254 return -ENOMEM;
255 }
256
257 sg_init_one(&dummy, md, id->table_desc.len);
258 sg_dma_address(&dummy) = token;
259 err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
260 id->table_desc.len);
261 if (err < 0) {
262 eprintk("Error copying indirect table %ld\n", err);
263 goto free_mem;
264 }
265 } else {
266 eprintk("This command uses external indirect buffer\n");
267 return -EINVAL;
268 }
269
270rdma:
271 if (dma_map) {
272 nsg = dma_map_sg(iue->target->dev, sg, sc->use_sg, DMA_BIDIRECTIONAL);
273 if (!nsg) {
274 eprintk("fail to map %p %d\n", iue, sc->use_sg);
275 goto free_mem;
276 }
277 len = min(sc->request_bufflen, id->len);
278 } else
279 len = id->len;
280
281 err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
282
283 if (dma_map)
284 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
285
286free_mem:
287 if (token && dma_map)
288 dma_free_coherent(iue->target->dev, id->table_desc.len, md, token);
289
290 return done;
291}
292
293static int data_out_desc_size(struct srp_cmd *cmd)
294{
295 int size = 0;
296 u8 fmt = cmd->buf_fmt >> 4;
297
298 switch (fmt) {
299 case SRP_NO_DATA_DESC:
300 break;
301 case SRP_DATA_DESC_DIRECT:
302 size = sizeof(struct srp_direct_buf);
303 break;
304 case SRP_DATA_DESC_INDIRECT:
305 size = sizeof(struct srp_indirect_buf) +
306 sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
307 break;
308 default:
309 eprintk("client error. Invalid data_out_format %x\n", fmt);
310 break;
311 }
312 return size;
313}
314
315/*
316 * TODO: this can be called multiple times for a single command if it
317 * has very long data.
318 */
319int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
320 srp_rdma_t rdma_io, int dma_map, int ext_desc)
321{
322 struct srp_direct_buf *md;
323 struct srp_indirect_buf *id;
324 enum dma_data_direction dir;
325 int offset, err = 0;
326 u8 format;
327
328 offset = cmd->add_cdb_len * 4;
329
330 dir = srp_cmd_direction(cmd);
331 if (dir == DMA_FROM_DEVICE)
332 offset += data_out_desc_size(cmd);
333
334 if (dir == DMA_TO_DEVICE)
335 format = cmd->buf_fmt >> 4;
336 else
337 format = cmd->buf_fmt & ((1U << 4) - 1);
338
339 switch (format) {
340 case SRP_NO_DATA_DESC:
341 break;
342 case SRP_DATA_DESC_DIRECT:
343 md = (struct srp_direct_buf *)
344 (cmd->add_data + offset);
345 err = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
346 break;
347 case SRP_DATA_DESC_INDIRECT:
348 id = (struct srp_indirect_buf *)
349 (cmd->add_data + offset);
350 err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
351 ext_desc);
352 break;
353 default:
354 eprintk("Unknown format %d %x\n", dir, format);
355 break;
356 }
357
358 return err;
359}
360EXPORT_SYMBOL_GPL(srp_transfer_data);
361
362static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
363{
364 struct srp_direct_buf *md;
365 struct srp_indirect_buf *id;
366 int len = 0, offset = cmd->add_cdb_len * 4;
367 u8 fmt;
368
369 if (dir == DMA_TO_DEVICE)
370 fmt = cmd->buf_fmt >> 4;
371 else {
372 fmt = cmd->buf_fmt & ((1U << 4) - 1);
373 offset += data_out_desc_size(cmd);
374 }
375
376 switch (fmt) {
377 case SRP_NO_DATA_DESC:
378 break;
379 case SRP_DATA_DESC_DIRECT:
380 md = (struct srp_direct_buf *) (cmd->add_data + offset);
381 len = md->len;
382 break;
383 case SRP_DATA_DESC_INDIRECT:
384 id = (struct srp_indirect_buf *) (cmd->add_data + offset);
385 len = id->len;
386 break;
387 default:
388 eprintk("invalid data format %x\n", fmt);
389 break;
390 }
391 return len;
392}
393
394int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
395 u64 addr)
396{
397 enum dma_data_direction dir;
398 struct scsi_cmnd *sc;
399 int tag, len, err;
400
401 switch (cmd->task_attr) {
402 case SRP_SIMPLE_TASK:
403 tag = MSG_SIMPLE_TAG;
404 break;
405 case SRP_ORDERED_TASK:
406 tag = MSG_ORDERED_TAG;
407 break;
408 case SRP_HEAD_TASK:
409 tag = MSG_HEAD_TAG;
410 break;
411 default:
412 eprintk("Task attribute %d not supported\n", cmd->task_attr);
413 tag = MSG_ORDERED_TAG;
414 }
415
416 dir = srp_cmd_direction(cmd);
417 len = vscsis_data_length(cmd, dir);
418
419 dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
420 cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
421
422 sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
423 if (!sc)
424 return -ENOMEM;
425
426 sc->SCp.ptr = info;
427 memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
428 sc->request_bufflen = len;
429 sc->request_buffer = (void *) (unsigned long) addr;
430 sc->tag = tag;
431 err = scsi_tgt_queue_command(sc, (struct scsi_lun *) &cmd->lun, cmd->tag);
432 if (err)
433 scsi_host_put_command(shost, sc);
434
435 return err;
436}
437EXPORT_SYMBOL_GPL(srp_cmd_queue);
438
439MODULE_DESCRIPTION("SCSI RDAM Protocol lib functions");
440MODULE_AUTHOR("FUJITA Tomonori");
441MODULE_LICENSE("GPL");