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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
32enum 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
40#define eprintk(fmt, args...) \
41do { \
42 printk("%s(%d) " fmt, __func__, __LINE__, ##args); \
43} while (0)
44
45#define dprintk(fmt, args...)
46
47static 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
73free_item:
74 kfree(q->items);
75free_pool:
76 kfree(q->pool);
77 return -ENOMEM;
78}
79
80static void srp_iu_pool_free(struct srp_queue *q)
81{
82 kfree(q->items);
83 kfree(q->pool);
84}
85
86static 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
107out:
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
118static 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 kfree(ring);
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 dev_set_drvdata(target->dev, 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 = scsi_sglist(sc);
197
198 dprintk("%p %u %u %d\n", iue, scsi_bufflen(sc),
199 md->len, scsi_sg_count(sc));
200
201 nsg = dma_map_sg(iue->target->dev, sg, scsi_sg_count(sc),
202 DMA_BIDIRECTIONAL);
203 if (!nsg) {
204 printk("fail to map %p %d\n", iue, scsi_sg_count(sc));
205 return 0;
206 }
207 len = min(scsi_bufflen(sc), 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 int err = 0;
229 int nmd, nsg = 0, len;
230
231 if (dma_map || ext_desc) {
232 iue = (struct iu_entry *) sc->SCp.ptr;
233 sg = scsi_sglist(sc);
234
235 dprintk("%p %u %u %d %d\n",
236 iue, scsi_bufflen(sc), id->len,
237 cmd->data_in_desc_cnt, cmd->data_out_desc_cnt);
238 }
239
240 nmd = id->table_desc.len / sizeof(struct srp_direct_buf);
241
242 if ((dir == DMA_FROM_DEVICE && nmd == cmd->data_in_desc_cnt) ||
243 (dir == DMA_TO_DEVICE && nmd == cmd->data_out_desc_cnt)) {
244 md = &id->desc_list[0];
245 goto rdma;
246 }
247
248 if (ext_desc && dma_map) {
249 md = dma_alloc_coherent(iue->target->dev, id->table_desc.len,
250 &token, GFP_KERNEL);
251 if (!md) {
252 eprintk("Can't get dma memory %u\n", id->table_desc.len);
253 return -ENOMEM;
254 }
255
256 sg_init_one(&dummy, md, id->table_desc.len);
257 sg_dma_address(&dummy) = token;
258 sg_dma_len(&dummy) = id->table_desc.len;
259 err = rdma_io(sc, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
260 id->table_desc.len);
261 if (err) {
262 eprintk("Error copying indirect table %d\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, scsi_sg_count(sc),
273 DMA_BIDIRECTIONAL);
274 if (!nsg) {
275 eprintk("fail to map %p %d\n", iue, scsi_sg_count(sc));
276 err = -EIO;
277 goto free_mem;
278 }
279 len = min(scsi_bufflen(sc), id->len);
280 } else
281 len = id->len;
282
283 err = rdma_io(sc, sg, nsg, md, nmd, dir, len);
284
285 if (dma_map)
286 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
287
288free_mem:
289 if (token && dma_map)
290 dma_free_coherent(iue->target->dev, id->table_desc.len, md, token);
291
292 return err;
293}
294
295static int data_out_desc_size(struct srp_cmd *cmd)
296{
297 int size = 0;
298 u8 fmt = cmd->buf_fmt >> 4;
299
300 switch (fmt) {
301 case SRP_NO_DATA_DESC:
302 break;
303 case SRP_DATA_DESC_DIRECT:
304 size = sizeof(struct srp_direct_buf);
305 break;
306 case SRP_DATA_DESC_INDIRECT:
307 size = sizeof(struct srp_indirect_buf) +
308 sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
309 break;
310 default:
311 eprintk("client error. Invalid data_out_format %x\n", fmt);
312 break;
313 }
314 return size;
315}
316
317
318
319
320
321int srp_transfer_data(struct scsi_cmnd *sc, struct srp_cmd *cmd,
322 srp_rdma_t rdma_io, int dma_map, int ext_desc)
323{
324 struct srp_direct_buf *md;
325 struct srp_indirect_buf *id;
326 enum dma_data_direction dir;
327 int offset, err = 0;
328 u8 format;
329
330 offset = cmd->add_cdb_len * 4;
331
332 dir = srp_cmd_direction(cmd);
333 if (dir == DMA_FROM_DEVICE)
334 offset += data_out_desc_size(cmd);
335
336 if (dir == DMA_TO_DEVICE)
337 format = cmd->buf_fmt >> 4;
338 else
339 format = cmd->buf_fmt & ((1U << 4) - 1);
340
341 switch (format) {
342 case SRP_NO_DATA_DESC:
343 break;
344 case SRP_DATA_DESC_DIRECT:
345 md = (struct srp_direct_buf *)
346 (cmd->add_data + offset);
347 err = srp_direct_data(sc, md, dir, rdma_io, dma_map, ext_desc);
348 break;
349 case SRP_DATA_DESC_INDIRECT:
350 id = (struct srp_indirect_buf *)
351 (cmd->add_data + offset);
352 err = srp_indirect_data(sc, cmd, id, dir, rdma_io, dma_map,
353 ext_desc);
354 break;
355 default:
356 eprintk("Unknown format %d %x\n", dir, format);
357 err = -EINVAL;
358 }
359
360 return err;
361}
362EXPORT_SYMBOL_GPL(srp_transfer_data);
363
364static int vscsis_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
365{
366 struct srp_direct_buf *md;
367 struct srp_indirect_buf *id;
368 int len = 0, offset = cmd->add_cdb_len * 4;
369 u8 fmt;
370
371 if (dir == DMA_TO_DEVICE)
372 fmt = cmd->buf_fmt >> 4;
373 else {
374 fmt = cmd->buf_fmt & ((1U << 4) - 1);
375 offset += data_out_desc_size(cmd);
376 }
377
378 switch (fmt) {
379 case SRP_NO_DATA_DESC:
380 break;
381 case SRP_DATA_DESC_DIRECT:
382 md = (struct srp_direct_buf *) (cmd->add_data + offset);
383 len = md->len;
384 break;
385 case SRP_DATA_DESC_INDIRECT:
386 id = (struct srp_indirect_buf *) (cmd->add_data + offset);
387 len = id->len;
388 break;
389 default:
390 eprintk("invalid data format %x\n", fmt);
391 break;
392 }
393 return len;
394}
395
396int srp_cmd_queue(struct Scsi_Host *shost, struct srp_cmd *cmd, void *info,
397 u64 itn_id, u64 addr)
398{
399 enum dma_data_direction dir;
400 struct scsi_cmnd *sc;
401 int tag, len, err;
402
403 switch (cmd->task_attr) {
404 case SRP_SIMPLE_TASK:
405 tag = MSG_SIMPLE_TAG;
406 break;
407 case SRP_ORDERED_TASK:
408 tag = MSG_ORDERED_TAG;
409 break;
410 case SRP_HEAD_TASK:
411 tag = MSG_HEAD_TAG;
412 break;
413 default:
414 eprintk("Task attribute %d not supported\n", cmd->task_attr);
415 tag = MSG_ORDERED_TAG;
416 }
417
418 dir = srp_cmd_direction(cmd);
419 len = vscsis_data_length(cmd, dir);
420
421 dprintk("%p %x %lx %d %d %d %llx\n", info, cmd->cdb[0],
422 cmd->lun, dir, len, tag, (unsigned long long) cmd->tag);
423
424 sc = scsi_host_get_command(shost, dir, GFP_KERNEL);
425 if (!sc)
426 return -ENOMEM;
427
428 sc->SCp.ptr = info;
429 memcpy(sc->cmnd, cmd->cdb, MAX_COMMAND_SIZE);
430 sc->sdb.length = len;
431 sc->sdb.table.sgl = (void *) (unsigned long) addr;
432 sc->tag = tag;
433 err = scsi_tgt_queue_command(sc, itn_id, (struct scsi_lun *)&cmd->lun,
434 cmd->tag);
435 if (err)
436 scsi_host_put_command(shost, sc);
437
438 return err;
439}
440EXPORT_SYMBOL_GPL(srp_cmd_queue);
441
442MODULE_DESCRIPTION("SCSI RDAM Protocol lib functions");
443MODULE_AUTHOR("FUJITA Tomonori");
444MODULE_LICENSE("GPL");
445
