1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /******************************************************************************* |
3 | * SCSI RDMA Protocol lib functions |
4 | * |
5 | * Copyright (C) 2006 FUJITA Tomonori <tomof@acm.org> |
6 | * Copyright (C) 2016 Bryant G. Ly <bryantly@linux.vnet.ibm.com> IBM Corp. |
7 | * |
8 | ***********************************************************************/ |
9 | |
10 | #define pr_fmt(fmt) "libsrp: " fmt |
11 | |
12 | #include <linux/printk.h> |
13 | #include <linux/err.h> |
14 | #include <linux/slab.h> |
15 | #include <linux/kfifo.h> |
16 | #include <linux/scatterlist.h> |
17 | #include <linux/dma-mapping.h> |
18 | #include <linux/module.h> |
19 | #include <scsi/srp.h> |
20 | #include <target/target_core_base.h> |
21 | #include "libsrp.h" |
22 | #include "ibmvscsi_tgt.h" |
23 | |
24 | static int srp_iu_pool_alloc(struct srp_queue *q, size_t max, |
25 | struct srp_buf **ring) |
26 | { |
27 | struct iu_entry *iue; |
28 | int i; |
29 | |
30 | q->pool = kcalloc(n: max, size: sizeof(struct iu_entry *), GFP_KERNEL); |
31 | if (!q->pool) |
32 | return -ENOMEM; |
33 | q->items = kcalloc(n: max, size: sizeof(struct iu_entry), GFP_KERNEL); |
34 | if (!q->items) |
35 | goto free_pool; |
36 | |
37 | spin_lock_init(&q->lock); |
38 | kfifo_init(&q->queue, (void *)q->pool, max * sizeof(void *)); |
39 | |
40 | for (i = 0, iue = q->items; i < max; i++) { |
41 | kfifo_in(&q->queue, (void *)&iue, sizeof(void *)); |
42 | iue->sbuf = ring[i]; |
43 | iue++; |
44 | } |
45 | return 0; |
46 | |
47 | free_pool: |
48 | kfree(objp: q->pool); |
49 | return -ENOMEM; |
50 | } |
51 | |
52 | static void srp_iu_pool_free(struct srp_queue *q) |
53 | { |
54 | kfree(objp: q->items); |
55 | kfree(objp: q->pool); |
56 | } |
57 | |
58 | static struct srp_buf **srp_ring_alloc(struct device *dev, |
59 | size_t max, size_t size) |
60 | { |
61 | struct srp_buf **ring; |
62 | int i; |
63 | |
64 | ring = kcalloc(n: max, size: sizeof(struct srp_buf *), GFP_KERNEL); |
65 | if (!ring) |
66 | return NULL; |
67 | |
68 | for (i = 0; i < max; i++) { |
69 | ring[i] = kzalloc(size: sizeof(*ring[i]), GFP_KERNEL); |
70 | if (!ring[i]) |
71 | goto out; |
72 | ring[i]->buf = dma_alloc_coherent(dev, size, dma_handle: &ring[i]->dma, |
73 | GFP_KERNEL); |
74 | if (!ring[i]->buf) |
75 | goto out; |
76 | } |
77 | return ring; |
78 | |
79 | out: |
80 | for (i = 0; i < max && ring[i]; i++) { |
81 | if (ring[i]->buf) { |
82 | dma_free_coherent(dev, size, cpu_addr: ring[i]->buf, |
83 | dma_handle: ring[i]->dma); |
84 | } |
85 | kfree(objp: ring[i]); |
86 | } |
87 | kfree(objp: ring); |
88 | |
89 | return NULL; |
90 | } |
91 | |
92 | static void srp_ring_free(struct device *dev, struct srp_buf **ring, |
93 | size_t max, size_t size) |
94 | { |
95 | int i; |
96 | |
97 | for (i = 0; i < max; i++) { |
98 | dma_free_coherent(dev, size, cpu_addr: ring[i]->buf, dma_handle: ring[i]->dma); |
99 | kfree(objp: ring[i]); |
100 | } |
101 | kfree(objp: ring); |
102 | } |
103 | |
104 | int srp_target_alloc(struct srp_target *target, struct device *dev, |
105 | size_t nr, size_t iu_size) |
106 | { |
107 | int err; |
108 | |
109 | spin_lock_init(&target->lock); |
110 | |
111 | target->dev = dev; |
112 | |
113 | target->srp_iu_size = iu_size; |
114 | target->rx_ring_size = nr; |
115 | target->rx_ring = srp_ring_alloc(dev: target->dev, max: nr, size: iu_size); |
116 | if (!target->rx_ring) |
117 | return -ENOMEM; |
118 | err = srp_iu_pool_alloc(q: &target->iu_queue, max: nr, ring: target->rx_ring); |
119 | if (err) |
120 | goto free_ring; |
121 | |
122 | dev_set_drvdata(dev: target->dev, data: target); |
123 | return 0; |
124 | |
125 | free_ring: |
126 | srp_ring_free(dev: target->dev, ring: target->rx_ring, max: nr, size: iu_size); |
127 | return -ENOMEM; |
128 | } |
129 | |
130 | void srp_target_free(struct srp_target *target) |
131 | { |
132 | dev_set_drvdata(dev: target->dev, NULL); |
133 | srp_ring_free(dev: target->dev, ring: target->rx_ring, max: target->rx_ring_size, |
134 | size: target->srp_iu_size); |
135 | srp_iu_pool_free(q: &target->iu_queue); |
136 | } |
137 | |
138 | struct iu_entry *srp_iu_get(struct srp_target *target) |
139 | { |
140 | struct iu_entry *iue = NULL; |
141 | |
142 | if (kfifo_out_locked(&target->iu_queue.queue, (void *)&iue, |
143 | sizeof(void *), |
144 | &target->iu_queue.lock) != sizeof(void *)) { |
145 | WARN_ONCE(1, "unexpected fifo state" ); |
146 | return NULL; |
147 | } |
148 | if (!iue) |
149 | return iue; |
150 | iue->target = target; |
151 | iue->flags = 0; |
152 | return iue; |
153 | } |
154 | |
155 | void srp_iu_put(struct iu_entry *iue) |
156 | { |
157 | kfifo_in_locked(&iue->target->iu_queue.queue, (void *)&iue, |
158 | sizeof(void *), &iue->target->iu_queue.lock); |
159 | } |
160 | |
161 | static int srp_direct_data(struct ibmvscsis_cmd *cmd, struct srp_direct_buf *md, |
162 | enum dma_data_direction dir, srp_rdma_t rdma_io, |
163 | int dma_map, int ext_desc) |
164 | { |
165 | struct iu_entry *iue = NULL; |
166 | struct scatterlist *sg = NULL; |
167 | int err, nsg = 0, len; |
168 | |
169 | if (dma_map) { |
170 | iue = cmd->iue; |
171 | sg = cmd->se_cmd.t_data_sg; |
172 | nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents, |
173 | DMA_BIDIRECTIONAL); |
174 | if (!nsg) { |
175 | pr_err("fail to map %p %d\n" , iue, |
176 | cmd->se_cmd.t_data_nents); |
177 | return 0; |
178 | } |
179 | len = min(cmd->se_cmd.data_length, be32_to_cpu(md->len)); |
180 | } else { |
181 | len = be32_to_cpu(md->len); |
182 | } |
183 | |
184 | err = rdma_io(cmd, sg, nsg, md, 1, dir, len); |
185 | |
186 | if (dma_map) |
187 | dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL); |
188 | |
189 | return err; |
190 | } |
191 | |
192 | static int srp_indirect_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd, |
193 | struct srp_indirect_buf *id, |
194 | enum dma_data_direction dir, srp_rdma_t rdma_io, |
195 | int dma_map, int ext_desc) |
196 | { |
197 | struct iu_entry *iue = NULL; |
198 | struct srp_direct_buf *md = NULL; |
199 | struct scatterlist dummy, *sg = NULL; |
200 | dma_addr_t token = 0; |
201 | int err = 0; |
202 | int nmd, nsg = 0, len; |
203 | |
204 | if (dma_map || ext_desc) { |
205 | iue = cmd->iue; |
206 | sg = cmd->se_cmd.t_data_sg; |
207 | } |
208 | |
209 | nmd = be32_to_cpu(id->table_desc.len) / sizeof(struct srp_direct_buf); |
210 | |
211 | if ((dir == DMA_FROM_DEVICE && nmd == srp_cmd->data_in_desc_cnt) || |
212 | (dir == DMA_TO_DEVICE && nmd == srp_cmd->data_out_desc_cnt)) { |
213 | md = &id->desc_list[0]; |
214 | goto rdma; |
215 | } |
216 | |
217 | if (ext_desc && dma_map) { |
218 | md = dma_alloc_coherent(dev: iue->target->dev, |
219 | be32_to_cpu(id->table_desc.len), |
220 | dma_handle: &token, GFP_KERNEL); |
221 | if (!md) { |
222 | pr_err("Can't get dma memory %u\n" , |
223 | be32_to_cpu(id->table_desc.len)); |
224 | return -ENOMEM; |
225 | } |
226 | |
227 | sg_init_one(&dummy, md, be32_to_cpu(id->table_desc.len)); |
228 | sg_dma_address(&dummy) = token; |
229 | sg_dma_len(&dummy) = be32_to_cpu(id->table_desc.len); |
230 | err = rdma_io(cmd, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE, |
231 | be32_to_cpu(id->table_desc.len)); |
232 | if (err) { |
233 | pr_err("Error copying indirect table %d\n" , err); |
234 | goto free_mem; |
235 | } |
236 | } else { |
237 | pr_err("This command uses external indirect buffer\n" ); |
238 | return -EINVAL; |
239 | } |
240 | |
241 | rdma: |
242 | if (dma_map) { |
243 | nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents, |
244 | DMA_BIDIRECTIONAL); |
245 | if (!nsg) { |
246 | pr_err("fail to map %p %d\n" , iue, |
247 | cmd->se_cmd.t_data_nents); |
248 | err = -EIO; |
249 | goto free_mem; |
250 | } |
251 | len = min(cmd->se_cmd.data_length, be32_to_cpu(id->len)); |
252 | } else { |
253 | len = be32_to_cpu(id->len); |
254 | } |
255 | |
256 | err = rdma_io(cmd, sg, nsg, md, nmd, dir, len); |
257 | |
258 | if (dma_map) |
259 | dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL); |
260 | |
261 | free_mem: |
262 | if (token && dma_map) { |
263 | dma_free_coherent(dev: iue->target->dev, |
264 | be32_to_cpu(id->table_desc.len), cpu_addr: md, dma_handle: token); |
265 | } |
266 | return err; |
267 | } |
268 | |
269 | static int data_out_desc_size(struct srp_cmd *cmd) |
270 | { |
271 | int size = 0; |
272 | u8 fmt = cmd->buf_fmt >> 4; |
273 | |
274 | switch (fmt) { |
275 | case SRP_NO_DATA_DESC: |
276 | break; |
277 | case SRP_DATA_DESC_DIRECT: |
278 | size = sizeof(struct srp_direct_buf); |
279 | break; |
280 | case SRP_DATA_DESC_INDIRECT: |
281 | size = sizeof(struct srp_indirect_buf) + |
282 | sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt; |
283 | break; |
284 | default: |
285 | pr_err("client error. Invalid data_out_format %x\n" , fmt); |
286 | break; |
287 | } |
288 | return size; |
289 | } |
290 | |
291 | /* |
292 | * TODO: this can be called multiple times for a single command if it |
293 | * has very long data. |
294 | */ |
295 | int srp_transfer_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd, |
296 | srp_rdma_t rdma_io, int dma_map, int ext_desc) |
297 | { |
298 | struct srp_direct_buf *md; |
299 | struct srp_indirect_buf *id; |
300 | enum dma_data_direction dir; |
301 | int offset, err = 0; |
302 | u8 format; |
303 | |
304 | if (!cmd->se_cmd.t_data_nents) |
305 | return 0; |
306 | |
307 | offset = srp_cmd->add_cdb_len & ~3; |
308 | |
309 | dir = srp_cmd_direction(cmd: srp_cmd); |
310 | if (dir == DMA_FROM_DEVICE) |
311 | offset += data_out_desc_size(cmd: srp_cmd); |
312 | |
313 | if (dir == DMA_TO_DEVICE) |
314 | format = srp_cmd->buf_fmt >> 4; |
315 | else |
316 | format = srp_cmd->buf_fmt & ((1U << 4) - 1); |
317 | |
318 | switch (format) { |
319 | case SRP_NO_DATA_DESC: |
320 | break; |
321 | case SRP_DATA_DESC_DIRECT: |
322 | md = (struct srp_direct_buf *)(srp_cmd->add_data + offset); |
323 | err = srp_direct_data(cmd, md, dir, rdma_io, dma_map, ext_desc); |
324 | break; |
325 | case SRP_DATA_DESC_INDIRECT: |
326 | id = (struct srp_indirect_buf *)(srp_cmd->add_data + offset); |
327 | err = srp_indirect_data(cmd, srp_cmd, id, dir, rdma_io, dma_map, |
328 | ext_desc); |
329 | break; |
330 | default: |
331 | pr_err("Unknown format %d %x\n" , dir, format); |
332 | err = -EINVAL; |
333 | } |
334 | |
335 | return err; |
336 | } |
337 | |
338 | u64 srp_data_length(struct srp_cmd *cmd, enum dma_data_direction dir) |
339 | { |
340 | struct srp_direct_buf *md; |
341 | struct srp_indirect_buf *id; |
342 | u64 len = 0; |
343 | uint offset = cmd->add_cdb_len & ~3; |
344 | u8 fmt; |
345 | |
346 | if (dir == DMA_TO_DEVICE) { |
347 | fmt = cmd->buf_fmt >> 4; |
348 | } else { |
349 | fmt = cmd->buf_fmt & ((1U << 4) - 1); |
350 | offset += data_out_desc_size(cmd); |
351 | } |
352 | |
353 | switch (fmt) { |
354 | case SRP_NO_DATA_DESC: |
355 | break; |
356 | case SRP_DATA_DESC_DIRECT: |
357 | md = (struct srp_direct_buf *)(cmd->add_data + offset); |
358 | len = be32_to_cpu(md->len); |
359 | break; |
360 | case SRP_DATA_DESC_INDIRECT: |
361 | id = (struct srp_indirect_buf *)(cmd->add_data + offset); |
362 | len = be32_to_cpu(id->len); |
363 | break; |
364 | default: |
365 | pr_err("invalid data format %x\n" , fmt); |
366 | break; |
367 | } |
368 | return len; |
369 | } |
370 | |
371 | int srp_get_desc_table(struct srp_cmd *srp_cmd, enum dma_data_direction *dir, |
372 | u64 *data_len) |
373 | { |
374 | struct srp_indirect_buf *idb; |
375 | struct srp_direct_buf *db; |
376 | uint add_cdb_offset; |
377 | int rc; |
378 | |
379 | /* |
380 | * The pointer computations below will only be compiled correctly |
381 | * if srp_cmd::add_data is declared as s8*, u8*, s8[] or u8[], so check |
382 | * whether srp_cmd::add_data has been declared as a byte pointer. |
383 | */ |
384 | BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0) |
385 | && !__same_type(srp_cmd->add_data[0], (u8)0)); |
386 | |
387 | BUG_ON(!dir); |
388 | BUG_ON(!data_len); |
389 | |
390 | rc = 0; |
391 | *data_len = 0; |
392 | |
393 | *dir = DMA_NONE; |
394 | |
395 | if (srp_cmd->buf_fmt & 0xf) |
396 | *dir = DMA_FROM_DEVICE; |
397 | else if (srp_cmd->buf_fmt >> 4) |
398 | *dir = DMA_TO_DEVICE; |
399 | |
400 | add_cdb_offset = srp_cmd->add_cdb_len & ~3; |
401 | if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) || |
402 | ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) { |
403 | db = (struct srp_direct_buf *)(srp_cmd->add_data |
404 | + add_cdb_offset); |
405 | *data_len = be32_to_cpu(db->len); |
406 | } else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) || |
407 | ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) { |
408 | idb = (struct srp_indirect_buf *)(srp_cmd->add_data |
409 | + add_cdb_offset); |
410 | |
411 | *data_len = be32_to_cpu(idb->len); |
412 | } |
413 | return rc; |
414 | } |
415 | |
416 | MODULE_DESCRIPTION("SCSI RDMA Protocol lib functions" ); |
417 | MODULE_AUTHOR("FUJITA Tomonori" ); |
418 | MODULE_LICENSE("GPL" ); |
419 | |