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1/*
2 * SCSI RDMA 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/slab.h>
23#include <linux/kfifo.h>
24#include <linux/scatterlist.h>
25#include <linux/dma-mapping.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, __func__, __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 kfifo_init(&q->queue, (void *) q->pool, max * sizeof(void *));
63
64 for (i = 0, iue = q->items; i < max; i++) {
65 kfifo_in(&q->queue, (void *) &iue, sizeof(void *));
66 iue->sbuf = ring[i];
67 iue++;
68 }
69 return 0;
70
71 kfree(q->items);
72free_pool:
73 kfree(q->pool);
74 return -ENOMEM;
75}
76
77static void srp_iu_pool_free(struct srp_queue *q)
78{
79 kfree(q->items);
80 kfree(q->pool);
81}
82
83static struct srp_buf **srp_ring_alloc(struct device *dev,
84 size_t max, size_t size)
85{
86 int i;
87 struct srp_buf **ring;
88
89 ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
90 if (!ring)
91 return NULL;
92
93 for (i = 0; i < max; i++) {
94 ring[i] = kzalloc(sizeof(struct srp_buf), GFP_KERNEL);
95 if (!ring[i])
96 goto out;
97 ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
98 GFP_KERNEL);
99 if (!ring[i]->buf)
100 goto out;
101 }
102 return ring;
103
104out:
105 for (i = 0; i < max && ring[i]; i++) {
106 if (ring[i]->buf)
107 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
108 kfree(ring[i]);
109 }
110 kfree(ring);
111
112 return NULL;
113}
114
115static void srp_ring_free(struct device *dev, struct srp_buf **ring, size_t max,
116 size_t size)
117{
118 int i;
119
120 for (i = 0; i < max; i++) {
121 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
122 kfree(ring[i]);
123 }
124 kfree(ring);
125}
126
127int srp_target_alloc(struct srp_target *target, struct device *dev,
128 size_t nr, size_t iu_size)
129{
130 int err;
131
132 spin_lock_init(&target->lock);
133 INIT_LIST_HEAD(&target->cmd_queue);
134
135 target->dev = dev;
136 dev_set_drvdata(target->dev, target);
137
138 target->srp_iu_size = iu_size;
139 target->rx_ring_size = nr;
140 target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
141 if (!target->rx_ring)
142 return -ENOMEM;
143 err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
144 if (err)
145 goto free_ring;
146
147 return 0;
148
149free_ring:
150 srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
151 return -ENOMEM;
152}
153EXPORT_SYMBOL_GPL(srp_target_alloc);
154
155void srp_target_free(struct srp_target *target)
156{
157 srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
158 target->srp_iu_size);
159 srp_iu_pool_free(&target->iu_queue);
160}
161EXPORT_SYMBOL_GPL(srp_target_free);
162
163struct iu_entry *srp_iu_get(struct srp_target *target)
164{
165 struct iu_entry *iue = NULL;
166
167 if (kfifo_out_locked(&target->iu_queue.queue, (void *) &iue,
168 sizeof(void *), &target->iu_queue.lock) != sizeof(void *)) {
169 WARN_ONCE(1, "unexpected fifo state");
170 return NULL;
171 }
172 if (!iue)
173 return iue;
174 iue->target = target;
175 INIT_LIST_HEAD(&iue->ilist);
176 iue->flags = 0;
177 return iue;
178}
179EXPORT_SYMBOL_GPL(srp_iu_get);
180
181void srp_iu_put(struct iu_entry *iue)
182{
183 kfifo_in_locked(&iue->target->iu_queue.queue, (void *) &iue,
184 sizeof(void *), &iue->target->iu_queue.lock);
185}
186EXPORT_SYMBOL_GPL(srp_iu_put);
187
188static int srp_direct_data(struct scsi_cmnd *sc, struct srp_direct_buf *md,
189 enum dma_data_direction dir, srp_rdma_t rdma_io,
190 int dma_map, int ext_desc)
191{
192 struct iu_entry *iue = NULL;
193 struct scatterlist *sg = NULL;
194 int err, nsg = 0, len;
195
196 if (dma_map) {
197 iue = (struct iu_entry *) sc->SCp.ptr;
198 sg = scsi_sglist(sc);
199
200 dprintk("%p %u %u %d\n", iue, scsi_bufflen(sc),
201 md->len, scsi_sg_count(sc));
202
203 nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
204 DMA_BIDIRECTIONAL);
205 if (!nsg) {
206 printk("fail to map %p %d\n", iue, scsi_sg_count(sc));
207 return 0;
208 }
209 len = min(scsi_bufflen(sc), md->len);
210 } else
211 len = md->len;
212
213 err = rdma_io(sc, sg, nsg, md, 1, dir, len);
214
215 if (dma_map)
216 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
217
218 return err;
219}
220
221static int srp_indirect_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
222 struct srp_indirect_buf *id,
223 enum dma_data_direction dir, srp_rdma_t rdma_io,
224 int dma_map, int ext_desc)
225{
226 struct iu_entry *iue = NULL;
227 struct srp_direct_buf *md = NULL;
228 struct scatterlist dummy, *sg = NULL;
229 dma_addr_t token = 0;
230 int err = 0;
231 int nmd, nsg = 0, len;
232
233 if (dma_map || ext_desc) {
234 iue = (struct iu_entry *) sc->SCp.ptr;
235 sg = scsi_sglist(sc);
236
237 dprintk("%p %u %u %d %d\n",
238 iue, scsi_bufflen(sc), id->len,
239 cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
240 }
241
242 nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
243
244 if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
245 (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
246 md = &id->desc_list[0];
247 goto rdma;
248 }
249
250 if (ext_desc && dma_map) {
251 md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
252 &token, GFP_KERNEL);
253 if (!md) {
254 eprintk("Can't get dma memory %u\n", id->table_desc.len);
255 return -ENOMEM;
256 }
257
258 sg_init_one(&dummy, md, id->table_desc.len);
259 sg_dma_address(&dummy) = token;
260 sg_dma_len(&dummy) = id->table_desc.len;
261 err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
262 id->table_desc.len);
263 if (err) {
264 eprintk("Error copying indirect table %d\n", err);
265 goto free_mem;
266 }
267 } else {
268 eprintk("This command uses external indirect buffer\n");
269 return -EINVAL;
270 }
271
272rdma:
273 if (dma_map) {
274 nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
275 DMA_BIDIRECTIONAL);
276 if (!nsg) {
277 eprintk("fail to map %p %d\n", iue, scsi_sg_count(sc));
278 err = -EIO;
279 goto free_mem;
280 }
281 len = min(scsi_bufflen(sc), id->len);
282 } else
283 len = id->len;
284
285 err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
286
287 if (dma_map)
288 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
289
290free_mem:
291 if (token && dma_map)
292 dma_free_coherent(iue->target->dev, id->table_desc.len, md, token);
293
294 return err;
295}
296
297static int data_out_desc_size(struct srp_cmd *cmd)
298{
299 int size = 0;
300 u8 fmt = cmd->buf_fmt >> 4;
301
302 switch (fmt) {
303 case SRP_NO_DATA_DESC:
304 break;
305 case SRP_DATA_DESC_DIRECT:
306 size = sizeof(struct srp_direct_buf);
307 break;
308 case SRP_DATA_DESC_INDIRECT:
309 size = sizeof(struct srp_indirect_buf) +
310 sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
311 break;
312 default:
313 eprintk("client error. Invalid data_out_format %x\n", fmt);
314 break;
315 }
316 return size;
317}
318
319/*
320 * TODO: this can be called multiple times for a single command if it
321 * has very long data.
322 */
323int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
324 srp_rdma_t rdma_io, int dma_map, int ext_desc)
325{
326 struct srp_direct_buf *md;
327 struct srp_indirect_buf *id;
328 enum dma_data_direction dir;
329 int offset, err = 0;
330 u8 format;
331
332 offset = cmd->add_cdb_len & ~3;
333
334 dir = srp_cmd_direction(cmd);
335 if (dir == DMA_FROM_DEVICE)
336 offset += data_out_desc_size(cmd);
337
338 if (dir == DMA_TO_DEVICE)
339 format = cmd->buf_fmt >> 4;
340 else
341 format = cmd->buf_fmt & ((1U << 4) - 1);
342
343 switch (format) {
344 case SRP_NO_DATA_DESC:
345 break;
346 case SRP_DATA_DESC_DIRECT:
347 md = (struct srp_direct_buf *)
348 (cmd->add_data + offset);
349 err = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
350 break;
351 case SRP_DATA_DESC_INDIRECT:
352 id = (struct srp_indirect_buf *)
353 (cmd->add_data + offset);
354 err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
355 ext_desc);
356 break;
357 default:
358 eprintk("Unknown format %d %x\n", dir, format);
359 err = -EINVAL;
360 }
361
362 return err;
363}
364EXPORT_SYMBOL_GPL(srp_transfer_data);
365
366static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
367{
368 struct srp_direct_buf *md;
369 struct srp_indirect_buf *id;
370 int len = 0, offset = cmd->add_cdb_len & ~3;
371 u8 fmt;
372
373 if (dir == DMA_TO_DEVICE)
374 fmt = cmd->buf_fmt >> 4;
375 else {
376 fmt = cmd->buf_fmt & ((1U << 4) - 1);
377 offset += data_out_desc_size(cmd);
378 }
379
380 switch (fmt) {
381 case SRP_NO_DATA_DESC:
382 break;
383 case SRP_DATA_DESC_DIRECT:
384 md = (struct srp_direct_buf *) (cmd->add_data + offset);
385 len = md->len;
386 break;
387 case SRP_DATA_DESC_INDIRECT:
388 id = (struct srp_indirect_buf *) (cmd->add_data + offset);
389 len = id->len;
390 break;
391 default:
392 eprintk("invalid data format %x\n", fmt);
393 break;
394 }
395 return len;
396}
397
398int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
399 u64 itn_id, u64 addr)
400{
401 enum dma_data_direction dir;
402 struct scsi_cmnd *sc;
403 int tag, len, err;
404
405 switch (cmd->task_attr) {
406 case SRP_SIMPLE_TASK:
407 tag = MSG_SIMPLE_TAG;
408 break;
409 case SRP_ORDERED_TASK:
410 tag = MSG_ORDERED_TAG;
411 break;
412 case SRP_HEAD_TASK:
413 tag = MSG_HEAD_TAG;
414 break;
415 default:
416 eprintk("Task attribute %d not supported\n", cmd->task_attr);
417 tag = MSG_ORDERED_TAG;
418 }
419
420 dir = srp_cmd_direction(cmd);
421 len = vscsis_data_length(cmd, dir);
422
423 dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
424 cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
425
426 sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
427 if (!sc)
428 return -ENOMEM;
429
430 sc->SCp.ptr = info;
431 memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
432 sc->sdb.length = len;
433 sc->sdb.table.sgl = (void *) (unsigned long) addr;
434 sc->tag = tag;
435 err = scsi_tgt_queue_command(sc, itn_id, (struct scsi_lun *)&cmd->lun,
436 cmd->tag);
437 if (err)
438 scsi_host_put_command(shost, sc);
439
440 return err;
441}
442EXPORT_SYMBOL_GPL(srp_cmd_queue);
443
444MODULE_DESCRIPTION("SCSI RDMA Protocol lib functions");
445MODULE_AUTHOR("FUJITA Tomonori");
446MODULE_LICENSE("GPL");