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19#define pr_fmt(fmt) "libsrp: " fmt
20
21#include <linux/printk.h>
22#include <linux/err.h>
23#include <linux/slab.h>
24#include <linux/kfifo.h>
25#include <linux/scatterlist.h>
26#include <linux/dma-mapping.h>
27#include <linux/module.h>
28#include <scsi/srp.h>
29#include <target/target_core_base.h>
30#include "libsrp.h"
31#include "ibmvscsi_tgt.h"
32
33static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
34 struct srp_buf **ring)
35{
36 struct iu_entry *iue;
37 int i;
38
39 q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
40 if (!q->pool)
41 return -ENOMEM;
42 q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
43 if (!q->items)
44 goto free_pool;
45
46 spin_lock_init(&q->lock);
47 kfifo_init(&q->queue, (void *)q->pool, max * sizeof(void *));
48
49 for (i = 0, iue = q->items; i < max; i++) {
50 kfifo_in(&q->queue, (void *)&iue, sizeof(void *));
51 iue->sbuf = ring[i];
52 iue++;
53 }
54 return 0;
55
56free_pool:
57 kfree(q->pool);
58 return -ENOMEM;
59}
60
61static void srp_iu_pool_free(struct srp_queue *q)
62{
63 kfree(q->items);
64 kfree(q->pool);
65}
66
67static struct srp_buf **srp_ring_alloc(struct device *dev,
68 size_t max, size_t size)
69{
70 struct srp_buf **ring;
71 int i;
72
73 ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
74 if (!ring)
75 return NULL;
76
77 for (i = 0; i < max; i++) {
78 ring[i] = kzalloc(sizeof(*ring[i]), GFP_KERNEL);
79 if (!ring[i])
80 goto out;
81 ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
82 GFP_KERNEL);
83 if (!ring[i]->buf)
84 goto out;
85 }
86 return ring;
87
88out:
89 for (i = 0; i < max && ring[i]; i++) {
90 if (ring[i]->buf) {
91 dma_free_coherent(dev, size, ring[i]->buf,
92 ring[i]->dma);
93 }
94 kfree(ring[i]);
95 }
96 kfree(ring);
97
98 return NULL;
99}
100
101static void srp_ring_free(struct device *dev, struct srp_buf **ring,
102 size_t max, size_t size)
103{
104 int i;
105
106 for (i = 0; i < max; i++) {
107 dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
108 kfree(ring[i]);
109 }
110 kfree(ring);
111}
112
113int srp_target_alloc(struct srp_target *target, struct device *dev,
114 size_t nr, size_t iu_size)
115{
116 int err;
117
118 spin_lock_init(&target->lock);
119
120 target->dev = dev;
121
122 target->srp_iu_size = iu_size;
123 target->rx_ring_size = nr;
124 target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
125 if (!target->rx_ring)
126 return -ENOMEM;
127 err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
128 if (err)
129 goto free_ring;
130
131 dev_set_drvdata(target->dev, target);
132 return 0;
133
134free_ring:
135 srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
136 return -ENOMEM;
137}
138
139void srp_target_free(struct srp_target *target)
140{
141 dev_set_drvdata(target->dev, NULL);
142 srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
143 target->srp_iu_size);
144 srp_iu_pool_free(&target->iu_queue);
145}
146
147struct iu_entry *srp_iu_get(struct srp_target *target)
148{
149 struct iu_entry *iue = NULL;
150
151 if (kfifo_out_locked(&target->iu_queue.queue, (void *)&iue,
152 sizeof(void *),
153 &target->iu_queue.lock) != sizeof(void *)) {
154 WARN_ONCE(1, "unexpected fifo state");
155 return NULL;
156 }
157 if (!iue)
158 return iue;
159 iue->target = target;
160 iue->flags = 0;
161 return iue;
162}
163
164void srp_iu_put(struct iu_entry *iue)
165{
166 kfifo_in_locked(&iue->target->iu_queue.queue, (void *)&iue,
167 sizeof(void *), &iue->target->iu_queue.lock);
168}
169
170static int srp_direct_data(struct ibmvscsis_cmd *cmd, struct srp_direct_buf *md,
171 enum dma_data_direction dir, srp_rdma_t rdma_io,
172 int dma_map, int ext_desc)
173{
174 struct iu_entry *iue = NULL;
175 struct scatterlist *sg = NULL;
176 int err, nsg = 0, len;
177
178 if (dma_map) {
179 iue = cmd->iue;
180 sg = cmd->se_cmd.t_data_sg;
181 nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents,
182 DMA_BIDIRECTIONAL);
183 if (!nsg) {
184 pr_err("fail to map %p %d\n", iue,
185 cmd->se_cmd.t_data_nents);
186 return 0;
187 }
188 len = min(cmd->se_cmd.data_length, be32_to_cpu(md->len));
189 } else {
190 len = be32_to_cpu(md->len);
191 }
192
193 err = rdma_io(cmd, sg, nsg, md, 1, dir, len);
194
195 if (dma_map)
196 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
197
198 return err;
199}
200
201static int srp_indirect_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd,
202 struct srp_indirect_buf *id,
203 enum dma_data_direction dir, srp_rdma_t rdma_io,
204 int dma_map, int ext_desc)
205{
206 struct iu_entry *iue = NULL;
207 struct srp_direct_buf *md = NULL;
208 struct scatterlist dummy, *sg = NULL;
209 dma_addr_t token = 0;
210 int err = 0;
211 int nmd, nsg = 0, len;
212
213 if (dma_map || ext_desc) {
214 iue = cmd->iue;
215 sg = cmd->se_cmd.t_data_sg;
216 }
217
218 nmd = be32_to_cpu(id->table_desc.len) / sizeof(struct srp_direct_buf);
219
220 if ((dir == DMA_FROM_DEVICE && nmd == srp_cmd->data_in_desc_cnt) ||
221 (dir == DMA_TO_DEVICE && nmd == srp_cmd->data_out_desc_cnt)) {
222 md = &id->desc_list[0];
223 goto rdma;
224 }
225
226 if (ext_desc && dma_map) {
227 md = dma_alloc_coherent(iue->target->dev,
228 be32_to_cpu(id->table_desc.len),
229 &token, GFP_KERNEL);
230 if (!md) {
231 pr_err("Can't get dma memory %u\n",
232 be32_to_cpu(id->table_desc.len));
233 return -ENOMEM;
234 }
235
236 sg_init_one(&dummy, md, be32_to_cpu(id->table_desc.len));
237 sg_dma_address(&dummy) = token;
238 sg_dma_len(&dummy) = be32_to_cpu(id->table_desc.len);
239 err = rdma_io(cmd, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
240 be32_to_cpu(id->table_desc.len));
241 if (err) {
242 pr_err("Error copying indirect table %d\n", err);
243 goto free_mem;
244 }
245 } else {
246 pr_err("This command uses external indirect buffer\n");
247 return -EINVAL;
248 }
249
250rdma:
251 if (dma_map) {
252 nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents,
253 DMA_BIDIRECTIONAL);
254 if (!nsg) {
255 pr_err("fail to map %p %d\n", iue,
256 cmd->se_cmd.t_data_nents);
257 err = -EIO;
258 goto free_mem;
259 }
260 len = min(cmd->se_cmd.data_length, be32_to_cpu(id->len));
261 } else {
262 len = be32_to_cpu(id->len);
263 }
264
265 err = rdma_io(cmd, sg, nsg, md, nmd, dir, len);
266
267 if (dma_map)
268 dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
269
270free_mem:
271 if (token && dma_map) {
272 dma_free_coherent(iue->target->dev,
273 be32_to_cpu(id->table_desc.len), md, token);
274 }
275 return err;
276}
277
278static int data_out_desc_size(struct srp_cmd *cmd)
279{
280 int size = 0;
281 u8 fmt = cmd->buf_fmt >> 4;
282
283 switch (fmt) {
284 case SRP_NO_DATA_DESC:
285 break;
286 case SRP_DATA_DESC_DIRECT:
287 size = sizeof(struct srp_direct_buf);
288 break;
289 case SRP_DATA_DESC_INDIRECT:
290 size = sizeof(struct srp_indirect_buf) +
291 sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
292 break;
293 default:
294 pr_err("client error. Invalid data_out_format %x\n", fmt);
295 break;
296 }
297 return size;
298}
299
300
301
302
303
304int srp_transfer_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd,
305 srp_rdma_t rdma_io, int dma_map, int ext_desc)
306{
307 struct srp_direct_buf *md;
308 struct srp_indirect_buf *id;
309 enum dma_data_direction dir;
310 int offset, err = 0;
311 u8 format;
312
313 if (!cmd->se_cmd.t_data_nents)
314 return 0;
315
316 offset = srp_cmd->add_cdb_len & ~3;
317
318 dir = srp_cmd_direction(srp_cmd);
319 if (dir == DMA_FROM_DEVICE)
320 offset += data_out_desc_size(srp_cmd);
321
322 if (dir == DMA_TO_DEVICE)
323 format = srp_cmd->buf_fmt >> 4;
324 else
325 format = srp_cmd->buf_fmt & ((1U << 4) - 1);
326
327 switch (format) {
328 case SRP_NO_DATA_DESC:
329 break;
330 case SRP_DATA_DESC_DIRECT:
331 md = (struct srp_direct_buf *)(srp_cmd->add_data + offset);
332 err = srp_direct_data(cmd, md, dir, rdma_io, dma_map, ext_desc);
333 break;
334 case SRP_DATA_DESC_INDIRECT:
335 id = (struct srp_indirect_buf *)(srp_cmd->add_data + offset);
336 err = srp_indirect_data(cmd, srp_cmd, id, dir, rdma_io, dma_map,
337 ext_desc);
338 break;
339 default:
340 pr_err("Unknown format %d %x\n", dir, format);
341 err = -EINVAL;
342 }
343
344 return err;
345}
346
347u64 srp_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
348{
349 struct srp_direct_buf *md;
350 struct srp_indirect_buf *id;
351 u64 len = 0;
352 uint offset = cmd->add_cdb_len & ~3;
353 u8 fmt;
354
355 if (dir == DMA_TO_DEVICE) {
356 fmt = cmd->buf_fmt >> 4;
357 } else {
358 fmt = cmd->buf_fmt & ((1U << 4) - 1);
359 offset += data_out_desc_size(cmd);
360 }
361
362 switch (fmt) {
363 case SRP_NO_DATA_DESC:
364 break;
365 case SRP_DATA_DESC_DIRECT:
366 md = (struct srp_direct_buf *)(cmd->add_data + offset);
367 len = be32_to_cpu(md->len);
368 break;
369 case SRP_DATA_DESC_INDIRECT:
370 id = (struct srp_indirect_buf *)(cmd->add_data + offset);
371 len = be32_to_cpu(id->len);
372 break;
373 default:
374 pr_err("invalid data format %x\n", fmt);
375 break;
376 }
377 return len;
378}
379
380int srp_get_desc_table(struct srp_cmd *srp_cmd, enum dma_data_direction *dir,
381 u64 *data_len)
382{
383 struct srp_indirect_buf *idb;
384 struct srp_direct_buf *db;
385 uint add_cdb_offset;
386 int rc;
387
388
389
390
391
392
393 BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0)
394 && !__same_type(srp_cmd->add_data[0], (u8)0));
395
396 BUG_ON(!dir);
397 BUG_ON(!data_len);
398
399 rc = 0;
400 *data_len = 0;
401
402 *dir = DMA_NONE;
403
404 if (srp_cmd->buf_fmt & 0xf)
405 *dir = DMA_FROM_DEVICE;
406 else if (srp_cmd->buf_fmt >> 4)
407 *dir = DMA_TO_DEVICE;
408
409 add_cdb_offset = srp_cmd->add_cdb_len & ~3;
410 if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
411 ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
412 db = (struct srp_direct_buf *)(srp_cmd->add_data
413 + add_cdb_offset);
414 *data_len = be32_to_cpu(db->len);
415 } else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
416 ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
417 idb = (struct srp_indirect_buf *)(srp_cmd->add_data
418 + add_cdb_offset);
419
420 *data_len = be32_to_cpu(idb->len);
421 }
422 return rc;
423}
424
425MODULE_DESCRIPTION("SCSI RDMA Protocol lib functions");
426MODULE_AUTHOR("FUJITA Tomonori");
427MODULE_LICENSE("GPL");
428
