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Initial commit
[wrt350n-kernel.git] / drivers / infiniband / ulp / iser / iser_memory.c
blob4a17743a639f2ae884f4cbe122e8e68f1a6f12b9
1 /*
2 * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 * $Id: iser_memory.c 6964 2006-05-07 11:11:43Z ogerlitz $
33 */
34 #include <linux/module.h>
35 #include <linux/kernel.h>
36 #include <linux/slab.h>
37 #include <linux/mm.h>
38 #include <linux/highmem.h>
39 #include <linux/scatterlist.h>
40
41 #include "iscsi_iser.h"
42
43 #define ISER_KMALLOC_THRESHOLD 0x20000 /* 128K - kmalloc limit */
44
45 /**
46 * Decrements the reference count for the
47 * registered buffer & releases it
48 *
49 * returns 0 if released, 1 if deferred
50 */
51 int iser_regd_buff_release(struct iser_regd_buf *regd_buf)
52 {
53 struct ib_device *dev;
54
55 if ((atomic_read(&regd_buf->ref_count) == 0) ||
56 atomic_dec_and_test(&regd_buf->ref_count)) {
57 /* if we used the dma mr, unreg is just NOP */
58 if (regd_buf->reg.is_fmr)
59 iser_unreg_mem(&regd_buf->reg);
60
61 if (regd_buf->dma_addr) {
62 dev = regd_buf->device->ib_device;
63 ib_dma_unmap_single(dev,
64 regd_buf->dma_addr,
65 regd_buf->data_size,
66 regd_buf->direction);
67 }
68 /* else this regd buf is associated with task which we */
69 /* dma_unmap_single/sg later */
70 return 0;
71 } else {
72 iser_dbg("Release deferred, regd.buff: 0x%p\n", regd_buf);
73 return 1;
74 }
75 }
76
77 /**
78 * iser_reg_single - fills registered buffer descriptor with
79 * registration information
80 */
81 void iser_reg_single(struct iser_device *device,
82 struct iser_regd_buf *regd_buf,
83 enum dma_data_direction direction)
84 {
85 u64 dma_addr;
86
87 dma_addr = ib_dma_map_single(device->ib_device,
88 regd_buf->virt_addr,
89 regd_buf->data_size, direction);
90 BUG_ON(ib_dma_mapping_error(device->ib_device, dma_addr));
91
92 regd_buf->reg.lkey = device->mr->lkey;
93 regd_buf->reg.len = regd_buf->data_size;
94 regd_buf->reg.va = dma_addr;
95 regd_buf->reg.is_fmr = 0;
96
97 regd_buf->dma_addr = dma_addr;
98 regd_buf->direction = direction;
99 }
100
101 /**
102 * iser_start_rdma_unaligned_sg
103 */
104 static int iser_start_rdma_unaligned_sg(struct iscsi_iser_cmd_task *iser_ctask,
105 enum iser_data_dir cmd_dir)
106 {
107 int dma_nents;
108 struct ib_device *dev;
109 char *mem = NULL;
110 struct iser_data_buf *data = &iser_ctask->data[cmd_dir];
111 unsigned long cmd_data_len = data->data_len;
112
113 if (cmd_data_len > ISER_KMALLOC_THRESHOLD)
114 mem = (void *)__get_free_pages(GFP_NOIO,
115 ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT);
116 else
117 mem = kmalloc(cmd_data_len, GFP_NOIO);
118
119 if (mem == NULL) {
120 iser_err("Failed to allocate mem size %d %d for copying sglist\n",
121 data->size,(int)cmd_data_len);
122 return -ENOMEM;
123 }
124
125 if (cmd_dir == ISER_DIR_OUT) {
126 /* copy the unaligned sg the buffer which is used for RDMA */
127 struct scatterlist *sgl = (struct scatterlist *)data->buf;
128 struct scatterlist *sg;
129 int i;
130 char *p, *from;
131
132 p = mem;
133 for_each_sg(sgl, sg, data->size, i) {
134 from = kmap_atomic(sg_page(sg), KM_USER0);
135 memcpy(p,
136 from + sg->offset,
137 sg->length);
138 kunmap_atomic(from, KM_USER0);
139 p += sg->length;
140 }
141 }
142
143 sg_init_one(&iser_ctask->data_copy[cmd_dir].sg_single, mem, cmd_data_len);
144 iser_ctask->data_copy[cmd_dir].buf =
145 &iser_ctask->data_copy[cmd_dir].sg_single;
146 iser_ctask->data_copy[cmd_dir].size = 1;
147
148 iser_ctask->data_copy[cmd_dir].copy_buf = mem;
149
150 dev = iser_ctask->iser_conn->ib_conn->device->ib_device;
151 dma_nents = ib_dma_map_sg(dev,
152 &iser_ctask->data_copy[cmd_dir].sg_single,
153 1,
154 (cmd_dir == ISER_DIR_OUT) ?
155 DMA_TO_DEVICE : DMA_FROM_DEVICE);
156 BUG_ON(dma_nents == 0);
157
158 iser_ctask->data_copy[cmd_dir].dma_nents = dma_nents;
159 return 0;
160 }
161
162 /**
163 * iser_finalize_rdma_unaligned_sg
164 */
165 void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_cmd_task *iser_ctask,
166 enum iser_data_dir cmd_dir)
167 {
168 struct ib_device *dev;
169 struct iser_data_buf *mem_copy;
170 unsigned long cmd_data_len;
171
172 dev = iser_ctask->iser_conn->ib_conn->device->ib_device;
173 mem_copy = &iser_ctask->data_copy[cmd_dir];
174
175 ib_dma_unmap_sg(dev, &mem_copy->sg_single, 1,
176 (cmd_dir == ISER_DIR_OUT) ?
177 DMA_TO_DEVICE : DMA_FROM_DEVICE);
178
179 if (cmd_dir == ISER_DIR_IN) {
180 char *mem;
181 struct scatterlist *sgl, *sg;
182 unsigned char *p, *to;
183 unsigned int sg_size;
184 int i;
185
186 /* copy back read RDMA to unaligned sg */
187 mem = mem_copy->copy_buf;
188
189 sgl = (struct scatterlist *)iser_ctask->data[ISER_DIR_IN].buf;
190 sg_size = iser_ctask->data[ISER_DIR_IN].size;
191
192 p = mem;
193 for_each_sg(sgl, sg, sg_size, i) {
194 to = kmap_atomic(sg_page(sg), KM_SOFTIRQ0);
195 memcpy(to + sg->offset,
196 p,
197 sg->length);
198 kunmap_atomic(to, KM_SOFTIRQ0);
199 p += sg->length;
200 }
201 }
202
203 cmd_data_len = iser_ctask->data[cmd_dir].data_len;
204
205 if (cmd_data_len > ISER_KMALLOC_THRESHOLD)
206 free_pages((unsigned long)mem_copy->copy_buf,
207 ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT);
208 else
209 kfree(mem_copy->copy_buf);
210
211 mem_copy->copy_buf = NULL;
212 }
213
214 /**
215 * iser_sg_to_page_vec - Translates scatterlist entries to physical addresses
216 * and returns the length of resulting physical address array (may be less than
217 * the original due to possible compaction).
218 *
219 * we build a "page vec" under the assumption that the SG meets the RDMA
220 * alignment requirements. Other then the first and last SG elements, all
221 * the "internal" elements can be compacted into a list whose elements are
222 * dma addresses of physical pages. The code supports also the weird case
223 * where --few fragments of the same page-- are present in the SG as
224 * consecutive elements. Also, it handles one entry SG.
225 */
226 static int iser_sg_to_page_vec(struct iser_data_buf *data,
227 struct iser_page_vec *page_vec,
228 struct ib_device *ibdev)
229 {
230 struct scatterlist *sgl = (struct scatterlist *)data->buf;
231 struct scatterlist *sg;
232 u64 first_addr, last_addr, page;
233 int end_aligned;
234 unsigned int cur_page = 0;
235 unsigned long total_sz = 0;
236 int i;
237
238 /* compute the offset of first element */
239 page_vec->offset = (u64) sgl[0].offset & ~MASK_4K;
240
241 for_each_sg(sgl, sg, data->dma_nents, i) {
242 unsigned int dma_len = ib_sg_dma_len(ibdev, sg);
243
244 total_sz += dma_len;
245
246 first_addr = ib_sg_dma_address(ibdev, sg);
247 last_addr = first_addr + dma_len;
248
249 end_aligned = !(last_addr & ~MASK_4K);
250
251 /* continue to collect page fragments till aligned or SG ends */
252 while (!end_aligned && (i + 1 < data->dma_nents)) {
253 sg = sg_next(sg);
254 i++;
255 dma_len = ib_sg_dma_len(ibdev, sg);
256 total_sz += dma_len;
257 last_addr = ib_sg_dma_address(ibdev, sg) + dma_len;
258 end_aligned = !(last_addr & ~MASK_4K);
259 }
260
261 /* handle the 1st page in the 1st DMA element */
262 if (cur_page == 0) {
263 page = first_addr & MASK_4K;
264 page_vec->pages[cur_page] = page;
265 cur_page++;
266 page += SIZE_4K;
267 } else
268 page = first_addr;
269
270 for (; page < last_addr; page += SIZE_4K) {
271 page_vec->pages[cur_page] = page;
272 cur_page++;
273 }
274
275 }
276 page_vec->data_size = total_sz;
277 iser_dbg("page_vec->data_size:%d cur_page %d\n", page_vec->data_size,cur_page);
278 return cur_page;
279 }
280
281 #define IS_4K_ALIGNED(addr) ((((unsigned long)addr) & ~MASK_4K) == 0)
282
283 /**
284 * iser_data_buf_aligned_len - Tries to determine the maximal correctly aligned
285 * for RDMA sub-list of a scatter-gather list of memory buffers, and returns
286 * the number of entries which are aligned correctly. Supports the case where
287 * consecutive SG elements are actually fragments of the same physcial page.
288 */
289 static unsigned int iser_data_buf_aligned_len(struct iser_data_buf *data,
290 struct ib_device *ibdev)
291 {
292 struct scatterlist *sgl, *sg;
293 u64 end_addr, next_addr;
294 int i, cnt;
295 unsigned int ret_len = 0;
296
297 sgl = (struct scatterlist *)data->buf;
298
299 cnt = 0;
300 for_each_sg(sgl, sg, data->dma_nents, i) {
301 /* iser_dbg("Checking sg iobuf [%d]: phys=0x%08lX "
302 "offset: %ld sz: %ld\n", i,
303 (unsigned long)sg_phys(sg),
304 (unsigned long)sg->offset,
305 (unsigned long)sg->length); */
306 end_addr = ib_sg_dma_address(ibdev, sg) +
307 ib_sg_dma_len(ibdev, sg);
308 /* iser_dbg("Checking sg iobuf end address "
309 "0x%08lX\n", end_addr); */
310 if (i + 1 < data->dma_nents) {
311 next_addr = ib_sg_dma_address(ibdev, sg_next(sg));
312 /* are i, i+1 fragments of the same page? */
313 if (end_addr == next_addr) {
314 cnt++;
315 continue;
316 } else if (!IS_4K_ALIGNED(end_addr)) {
317 ret_len = cnt + 1;
318 break;
319 }
320 }
321 cnt++;
322 }
323 if (i == data->dma_nents)
324 ret_len = cnt; /* loop ended */
325 iser_dbg("Found %d aligned entries out of %d in sg:0x%p\n",
326 ret_len, data->dma_nents, data);
327 return ret_len;
328 }
329
330 static void iser_data_buf_dump(struct iser_data_buf *data,
331 struct ib_device *ibdev)
332 {
333 struct scatterlist *sgl = (struct scatterlist *)data->buf;
334 struct scatterlist *sg;
335 int i;
336
337 for_each_sg(sgl, sg, data->dma_nents, i)
338 iser_err("sg[%d] dma_addr:0x%lX page:0x%p "
339 "off:0x%x sz:0x%x dma_len:0x%x\n",
340 i, (unsigned long)ib_sg_dma_address(ibdev, sg),
341 sg_page(sg), sg->offset,
342 sg->length, ib_sg_dma_len(ibdev, sg));
343 }
344
345 static void iser_dump_page_vec(struct iser_page_vec *page_vec)
346 {
347 int i;
348
349 iser_err("page vec length %d data size %d\n",
350 page_vec->length, page_vec->data_size);
351 for (i = 0; i < page_vec->length; i++)
352 iser_err("%d %lx\n",i,(unsigned long)page_vec->pages[i]);
353 }
354
355 static void iser_page_vec_build(struct iser_data_buf *data,
356 struct iser_page_vec *page_vec,
357 struct ib_device *ibdev)
358 {
359 int page_vec_len = 0;
360
361 page_vec->length = 0;
362 page_vec->offset = 0;
363
364 iser_dbg("Translating sg sz: %d\n", data->dma_nents);
365 page_vec_len = iser_sg_to_page_vec(data, page_vec, ibdev);
366 iser_dbg("sg len %d page_vec_len %d\n", data->dma_nents,page_vec_len);
367
368 page_vec->length = page_vec_len;
369
370 if (page_vec_len * SIZE_4K < page_vec->data_size) {
371 iser_err("page_vec too short to hold this SG\n");
372 iser_data_buf_dump(data, ibdev);
373 iser_dump_page_vec(page_vec);
374 BUG();
375 }
376 }
377
378 int iser_dma_map_task_data(struct iscsi_iser_cmd_task *iser_ctask,
379 struct iser_data_buf *data,
380 enum iser_data_dir iser_dir,
381 enum dma_data_direction dma_dir)
382 {
383 struct ib_device *dev;
384
385 iser_ctask->dir[iser_dir] = 1;
386 dev = iser_ctask->iser_conn->ib_conn->device->ib_device;
387
388 data->dma_nents = ib_dma_map_sg(dev, data->buf, data->size, dma_dir);
389 if (data->dma_nents == 0) {
390 iser_err("dma_map_sg failed!!!\n");
391 return -EINVAL;
392 }
393 return 0;
394 }
395
396 void iser_dma_unmap_task_data(struct iscsi_iser_cmd_task *iser_ctask)
397 {
398 struct ib_device *dev;
399 struct iser_data_buf *data;
400
401 dev = iser_ctask->iser_conn->ib_conn->device->ib_device;
402
403 if (iser_ctask->dir[ISER_DIR_IN]) {
404 data = &iser_ctask->data[ISER_DIR_IN];
405 ib_dma_unmap_sg(dev, data->buf, data->size, DMA_FROM_DEVICE);
406 }
407
408 if (iser_ctask->dir[ISER_DIR_OUT]) {
409 data = &iser_ctask->data[ISER_DIR_OUT];
410 ib_dma_unmap_sg(dev, data->buf, data->size, DMA_TO_DEVICE);
411 }
412 }
413
414 /**
415 * iser_reg_rdma_mem - Registers memory intended for RDMA,
416 * obtaining rkey and va
417 *
418 * returns 0 on success, errno code on failure
419 */
420 int iser_reg_rdma_mem(struct iscsi_iser_cmd_task *iser_ctask,
421 enum iser_data_dir cmd_dir)
422 {
423 struct iser_conn *ib_conn = iser_ctask->iser_conn->ib_conn;
424 struct iser_device *device = ib_conn->device;
425 struct ib_device *ibdev = device->ib_device;
426 struct iser_data_buf *mem = &iser_ctask->data[cmd_dir];
427 struct iser_regd_buf *regd_buf;
428 int aligned_len;
429 int err;
430 int i;
431 struct scatterlist *sg;
432
433 regd_buf = &iser_ctask->rdma_regd[cmd_dir];
434
435 aligned_len = iser_data_buf_aligned_len(mem, ibdev);
436 if (aligned_len != mem->dma_nents) {
437 iser_err("rdma alignment violation %d/%d aligned\n",
438 aligned_len, mem->size);
439 iser_data_buf_dump(mem, ibdev);
440
441 /* unmap the command data before accessing it */
442 iser_dma_unmap_task_data(iser_ctask);
443
444 /* allocate copy buf, if we are writing, copy the */
445 /* unaligned scatterlist, dma map the copy */
446 if (iser_start_rdma_unaligned_sg(iser_ctask, cmd_dir) != 0)
447 return -ENOMEM;
448 mem = &iser_ctask->data_copy[cmd_dir];
449 }
450
451 /* if there a single dma entry, FMR is not needed */
452 if (mem->dma_nents == 1) {
453 sg = (struct scatterlist *)mem->buf;
454
455 regd_buf->reg.lkey = device->mr->lkey;
456 regd_buf->reg.rkey = device->mr->rkey;
457 regd_buf->reg.len = ib_sg_dma_len(ibdev, &sg[0]);
458 regd_buf->reg.va = ib_sg_dma_address(ibdev, &sg[0]);
459 regd_buf->reg.is_fmr = 0;
460
461 iser_dbg("PHYSICAL Mem.register: lkey: 0x%08X rkey: 0x%08X "
462 "va: 0x%08lX sz: %ld]\n",
463 (unsigned int)regd_buf->reg.lkey,
464 (unsigned int)regd_buf->reg.rkey,
465 (unsigned long)regd_buf->reg.va,
466 (unsigned long)regd_buf->reg.len);
467 } else { /* use FMR for multiple dma entries */
468 iser_page_vec_build(mem, ib_conn->page_vec, ibdev);
469 err = iser_reg_page_vec(ib_conn, ib_conn->page_vec, &regd_buf->reg);
470 if (err) {
471 iser_data_buf_dump(mem, ibdev);
472 iser_err("mem->dma_nents = %d (dlength = 0x%x)\n", mem->dma_nents,
473 ntoh24(iser_ctask->desc.iscsi_header.dlength));
474 iser_err("page_vec: data_size = 0x%x, length = %d, offset = 0x%x\n",
475 ib_conn->page_vec->data_size, ib_conn->page_vec->length,
476 ib_conn->page_vec->offset);
477 for (i=0 ; i<ib_conn->page_vec->length ; i++)
478 iser_err("page_vec[%d] = 0x%llx\n", i,
479 (unsigned long long) ib_conn->page_vec->pages[i]);
480 return err;
481 }
482 }
483
484 /* take a reference on this regd buf such that it will not be released *
485 * (eg in send dto completion) before we get the scsi response */
486 atomic_inc(&regd_buf->ref_count);
487 return 0;
488 }
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