Pileus Git - ~andy/linux/blob - drivers/dma/dmatest.c

   1 /*
   2  * DMA Engine test module
   3  *
   4  * Copyright (C) 2007 Atmel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #include <linux/delay.h>
  11 #include <linux/dma-mapping.h>
  12 #include <linux/dmaengine.h>
  13 #include <linux/freezer.h>
  14 #include <linux/init.h>
  15 #include <linux/kthread.h>
  16 #include <linux/module.h>
  17 #include <linux/moduleparam.h>
  18 #include <linux/random.h>
  19 #include <linux/slab.h>
  20 #include <linux/wait.h>
  21
  22 static unsigned int test_buf_size = 16384;
  23 module_param(test_buf_size, uint, S_IRUGO);
  24 MODULE_PARM_DESC(test_buf_size, "Size of the memcpy test buffer");
  25
  26 static char test_channel[20];
  27 module_param_string(channel, test_channel, sizeof(test_channel), S_IRUGO);
  28 MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)");
  29
  30 static char test_device[20];
  31 module_param_string(device, test_device, sizeof(test_device), S_IRUGO);
  32 MODULE_PARM_DESC(device, "Bus ID of the DMA Engine to test (default: any)");
  33
  34 static unsigned int threads_per_chan = 1;
  35 module_param(threads_per_chan, uint, S_IRUGO);
  36 MODULE_PARM_DESC(threads_per_chan,
  37                 "Number of threads to start per channel (default: 1)");
  38
  39 static unsigned int max_channels;
  40 module_param(max_channels, uint, S_IRUGO);
  41 MODULE_PARM_DESC(max_channels,
  42                 "Maximum number of channels to use (default: all)");
  43
  44 static unsigned int iterations;
  45 module_param(iterations, uint, S_IRUGO);
  46 MODULE_PARM_DESC(iterations,
  47                 "Iterations before stopping test (default: infinite)");
  48
  49 static unsigned int xor_sources = 3;
  50 module_param(xor_sources, uint, S_IRUGO);
  51 MODULE_PARM_DESC(xor_sources,
  52                 "Number of xor source buffers (default: 3)");
  53
  54 static unsigned int pq_sources = 3;
  55 module_param(pq_sources, uint, S_IRUGO);
  56 MODULE_PARM_DESC(pq_sources,
  57                 "Number of p+q source buffers (default: 3)");
  58
  59 static int timeout = 3000;
  60 module_param(timeout, uint, S_IRUGO);
  61 MODULE_PARM_DESC(timeout, "Transfer Timeout in msec (default: 3000), "
  62                  "Pass -1 for infinite timeout");
  63
  64 /*
  65  * Initialization patterns. All bytes in the source buffer has bit 7
  66  * set, all bytes in the destination buffer has bit 7 cleared.
  67  *
  68  * Bit 6 is set for all bytes which are to be copied by the DMA
  69  * engine. Bit 5 is set for all bytes which are to be overwritten by
  70  * the DMA engine.
  71  *
  72  * The remaining bits are the inverse of a counter which increments by
  73  * one for each byte address.
  74  */
  75 #define PATTERN_SRC             0x80
  76 #define PATTERN_DST             0x00
  77 #define PATTERN_COPY            0x40
  78 #define PATTERN_OVERWRITE       0x20
  79 #define PATTERN_COUNT_MASK      0x1f
  80
  81 struct dmatest_thread {
  82         struct list_head        node;
  83         struct task_struct      *task;
  84         struct dma_chan         *chan;
  85         u8                      **srcs;
  86         u8                      **dsts;
  87         enum dma_transaction_type type;
  88 };
  89
  90 struct dmatest_chan {
  91         struct list_head        node;
  92         struct dma_chan         *chan;
  93         struct list_head        threads;
  94 };
  95
  96 /*
  97  * These are protected by dma_list_mutex since they're only used by
  98  * the DMA filter function callback
  99  */
 100 static LIST_HEAD(dmatest_channels);
 101 static unsigned int nr_channels;
 102
 103 static bool dmatest_match_channel(struct dma_chan *chan)
 104 {
 105         if (test_channel[0] == '\0')
 106                 return true;
 107         return strcmp(dma_chan_name(chan), test_channel) == 0;
 108 }
 109
 110 static bool dmatest_match_device(struct dma_device *device)
 111 {
 112         if (test_device[0] == '\0')
 113                 return true;
 114         return strcmp(dev_name(device->dev), test_device) == 0;
 115 }
 116
 117 static unsigned long dmatest_random(void)
 118 {
 119         unsigned long buf;
 120
 121         get_random_bytes(&buf, sizeof(buf));
 122         return buf;
 123 }
 124
 125 static void dmatest_init_srcs(u8 **bufs, unsigned int start, unsigned int len)
 126 {
 127         unsigned int i;
 128         u8 *buf;
 129
 130         for (; (buf = *bufs); bufs++) {
 131                 for (i = 0; i < start; i++)
 132                         buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
 133                 for ( ; i < start + len; i++)
 134                         buf[i] = PATTERN_SRC | PATTERN_COPY
 135                                 | (~i & PATTERN_COUNT_MASK);
 136                 for ( ; i < test_buf_size; i++)
 137                         buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
 138                 buf++;
 139         }
 140 }
 141
 142 static void dmatest_init_dsts(u8 **bufs, unsigned int start, unsigned int len)
 143 {
 144         unsigned int i;
 145         u8 *buf;
 146
 147         for (; (buf = *bufs); bufs++) {
 148                 for (i = 0; i < start; i++)
 149                         buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
 150                 for ( ; i < start + len; i++)
 151                         buf[i] = PATTERN_DST | PATTERN_OVERWRITE
 152                                 | (~i & PATTERN_COUNT_MASK);
 153                 for ( ; i < test_buf_size; i++)
 154                         buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
 155         }
 156 }
 157
 158 static void dmatest_mismatch(u8 actual, u8 pattern, unsigned int index,
 159                 unsigned int counter, bool is_srcbuf)
 160 {
 161         u8              diff = actual ^ pattern;
 162         u8              expected = pattern | (~counter & PATTERN_COUNT_MASK);
 163         const char      *thread_name = current->comm;
 164
 165         if (is_srcbuf)
 166                 pr_warning("%s: srcbuf[0x%x] overwritten!"
 167                                 " Expected %02x, got %02x\n",
 168                                 thread_name, index, expected, actual);
 169         else if ((pattern & PATTERN_COPY)
 170                         && (diff & (PATTERN_COPY | PATTERN_OVERWRITE)))
 171                 pr_warning("%s: dstbuf[0x%x] not copied!"
 172                                 " Expected %02x, got %02x\n",
 173                                 thread_name, index, expected, actual);
 174         else if (diff & PATTERN_SRC)
 175                 pr_warning("%s: dstbuf[0x%x] was copied!"
 176                                 " Expected %02x, got %02x\n",
 177                                 thread_name, index, expected, actual);
 178         else
 179                 pr_warning("%s: dstbuf[0x%x] mismatch!"
 180                                 " Expected %02x, got %02x\n",
 181                                 thread_name, index, expected, actual);
 182 }
 183
 184 static unsigned int dmatest_verify(u8 **bufs, unsigned int start,
 185                 unsigned int end, unsigned int counter, u8 pattern,
 186                 bool is_srcbuf)
 187 {
 188         unsigned int i;
 189         unsigned int error_count = 0;
 190         u8 actual;
 191         u8 expected;
 192         u8 *buf;
 193         unsigned int counter_orig = counter;
 194
 195         for (; (buf = *bufs); bufs++) {
 196                 counter = counter_orig;
 197                 for (i = start; i < end; i++) {
 198                         actual = buf[i];
 199                         expected = pattern | (~counter & PATTERN_COUNT_MASK);
 200                         if (actual != expected) {
 201                                 if (error_count < 32)
 202                                         dmatest_mismatch(actual, pattern, i,
 203                                                          counter, is_srcbuf);
 204                                 error_count++;
 205                         }
 206                         counter++;
 207                 }
 208         }
 209
 210         if (error_count > 32)
 211                 pr_warning("%s: %u errors suppressed\n",
 212                         current->comm, error_count - 32);
 213
 214         return error_count;
 215 }
 216
 217 /* poor man's completion - we want to use wait_event_freezable() on it */
 218 struct dmatest_done {
 219         bool                    done;
 220         wait_queue_head_t       *wait;
 221 };
 222
 223 static void dmatest_callback(void *arg)
 224 {
 225         struct dmatest_done *done = arg;
 226
 227         done->done = true;
 228         wake_up_all(done->wait);
 229 }
 230
 231 static inline void unmap_src(struct device *dev, dma_addr_t *addr, size_t len,
 232                              unsigned int count)
 233 {
 234         while (count--)
 235                 dma_unmap_single(dev, addr[count], len, DMA_TO_DEVICE);
 236 }
 237
 238 static inline void unmap_dst(struct device *dev, dma_addr_t *addr, size_t len,
 239                              unsigned int count)
 240 {
 241         while (count--)
 242                 dma_unmap_single(dev, addr[count], len, DMA_BIDIRECTIONAL);
 243 }
 244
 245 /*
 246  * This function repeatedly tests DMA transfers of various lengths and
 247  * offsets for a given operation type until it is told to exit by
 248  * kthread_stop(). There may be multiple threads running this function
 249  * in parallel for a single channel, and there may be multiple channels
 250  * being tested in parallel.
 251  *
 252  * Before each test, the source and destination buffer is initialized
 253  * with a known pattern. This pattern is different depending on
 254  * whether it's in an area which is supposed to be copied or
 255  * overwritten, and different in the source and destination buffers.
 256  * So if the DMA engine doesn't copy exactly what we tell it to copy,
 257  * we'll notice.
 258  */
 259 static int dmatest_func(void *data)
 260 {
 261         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(done_wait);
 262         struct dmatest_thread   *thread = data;
 263         struct dmatest_done     done = { .wait = &done_wait };
 264         struct dma_chan         *chan;
 265         const char              *thread_name;
 266         unsigned int            src_off, dst_off, len;
 267         unsigned int            error_count;
 268         unsigned int            failed_tests = 0;
 269         unsigned int            total_tests = 0;
 270         dma_cookie_t            cookie;
 271         enum dma_status         status;
 272         enum dma_ctrl_flags     flags;
 273         u8                      pq_coefs[pq_sources + 1];
 274         int                     ret;
 275         int                     src_cnt;
 276         int                     dst_cnt;
 277         int                     i;
 278
 279         thread_name = current->comm;
 280         set_freezable();
 281
 282         ret = -ENOMEM;
 283
 284         smp_rmb();
 285         chan = thread->chan;
 286         if (thread->type == DMA_MEMCPY)
 287                 src_cnt = dst_cnt = 1;
 288         else if (thread->type == DMA_XOR) {
 289                 src_cnt = xor_sources | 1; /* force odd to ensure dst = src */
 290                 dst_cnt = 1;
 291         } else if (thread->type == DMA_PQ) {
 292                 src_cnt = pq_sources | 1; /* force odd to ensure dst = src */
 293                 dst_cnt = 2;
 294                 for (i = 0; i < src_cnt; i++)
 295                         pq_coefs[i] = 1;
 296         } else
 297                 goto err_srcs;
 298
 299         thread->srcs = kcalloc(src_cnt+1, sizeof(u8 *), GFP_KERNEL);
 300         if (!thread->srcs)
 301                 goto err_srcs;
 302         for (i = 0; i < src_cnt; i++) {
 303                 thread->srcs[i] = kmalloc(test_buf_size, GFP_KERNEL);
 304                 if (!thread->srcs[i])
 305                         goto err_srcbuf;
 306         }
 307         thread->srcs[i] = NULL;
 308
 309         thread->dsts = kcalloc(dst_cnt+1, sizeof(u8 *), GFP_KERNEL);
 310         if (!thread->dsts)
 311                 goto err_dsts;
 312         for (i = 0; i < dst_cnt; i++) {
 313                 thread->dsts[i] = kmalloc(test_buf_size, GFP_KERNEL);
 314                 if (!thread->dsts[i])
 315                         goto err_dstbuf;
 316         }
 317         thread->dsts[i] = NULL;
 318
 319         set_user_nice(current, 10);
 320
 321         /*
 322          * src buffers are freed by the DMAEngine code with dma_unmap_single()
 323          * dst buffers are freed by ourselves below
 324          */
 325         flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT
 326               | DMA_COMPL_SKIP_DEST_UNMAP | DMA_COMPL_SRC_UNMAP_SINGLE;
 327
 328         while (!kthread_should_stop()
 329                && !(iterations && total_tests >= iterations)) {
 330                 struct dma_device *dev = chan->device;
 331                 struct dma_async_tx_descriptor *tx = NULL;
 332                 dma_addr_t dma_srcs[src_cnt];
 333                 dma_addr_t dma_dsts[dst_cnt];
 334                 u8 align = 0;
 335
 336                 total_tests++;
 337
 338                 /* honor alignment restrictions */
 339                 if (thread->type == DMA_MEMCPY)
 340                         align = dev->copy_align;
 341                 else if (thread->type == DMA_XOR)
 342                         align = dev->xor_align;
 343                 else if (thread->type == DMA_PQ)
 344                         align = dev->pq_align;
 345
 346                 if (1 << align > test_buf_size) {
 347                         pr_err("%u-byte buffer too small for %d-byte alignment\n",
 348                                test_buf_size, 1 << align);
 349                         break;
 350                 }
 351
 352                 len = dmatest_random() % test_buf_size + 1;
 353                 len = (len >> align) << align;
 354                 if (!len)
 355                         len = 1 << align;
 356                 src_off = dmatest_random() % (test_buf_size - len + 1);
 357                 dst_off = dmatest_random() % (test_buf_size - len + 1);
 358
 359                 src_off = (src_off >> align) << align;
 360                 dst_off = (dst_off >> align) << align;
 361
 362                 dmatest_init_srcs(thread->srcs, src_off, len);
 363                 dmatest_init_dsts(thread->dsts, dst_off, len);
 364
 365                 for (i = 0; i < src_cnt; i++) {
 366                         u8 *buf = thread->srcs[i] + src_off;
 367
 368                         dma_srcs[i] = dma_map_single(dev->dev, buf, len,
 369                                                      DMA_TO_DEVICE);
 370                         ret = dma_mapping_error(dev->dev, dma_srcs[i]);
 371                         if (ret) {
 372                                 unmap_src(dev->dev, dma_srcs, len, i);
 373                                 pr_warn("%s: #%u: mapping error %d with "
 374                                         "src_off=0x%x len=0x%x\n",
 375                                         thread_name, total_tests - 1, ret,
 376                                         src_off, len);
 377                                 failed_tests++;
 378                                 continue;
 379                         }
 380                 }
 381                 /* map with DMA_BIDIRECTIONAL to force writeback/invalidate */
 382                 for (i = 0; i < dst_cnt; i++) {
 383                         dma_dsts[i] = dma_map_single(dev->dev, thread->dsts[i],
 384                                                      test_buf_size,
 385                                                      DMA_BIDIRECTIONAL);
 386                         ret = dma_mapping_error(dev->dev, dma_dsts[i]);
 387                         if (ret) {
 388                                 unmap_src(dev->dev, dma_srcs, len, src_cnt);
 389                                 unmap_dst(dev->dev, dma_dsts, test_buf_size, i);
 390                                 pr_warn("%s: #%u: mapping error %d with "
 391                                         "dst_off=0x%x len=0x%x\n",
 392                                         thread_name, total_tests - 1, ret,
 393                                         dst_off, test_buf_size);
 394                                 failed_tests++;
 395                                 continue;
 396                         }
 397                 }
 398
 399                 if (thread->type == DMA_MEMCPY)
 400                         tx = dev->device_prep_dma_memcpy(chan,
 401                                                          dma_dsts[0] + dst_off,
 402                                                          dma_srcs[0], len,
 403                                                          flags);
 404                 else if (thread->type == DMA_XOR)
 405                         tx = dev->device_prep_dma_xor(chan,
 406                                                       dma_dsts[0] + dst_off,
 407                                                       dma_srcs, src_cnt,
 408                                                       len, flags);
 409                 else if (thread->type == DMA_PQ) {
 410                         dma_addr_t dma_pq[dst_cnt];
 411
 412                         for (i = 0; i < dst_cnt; i++)
 413                                 dma_pq[i] = dma_dsts[i] + dst_off;
 414                         tx = dev->device_prep_dma_pq(chan, dma_pq, dma_srcs,
 415                                                      src_cnt, pq_coefs,
 416                                                      len, flags);
 417                 }
 418
 419                 if (!tx) {
 420                         unmap_src(dev->dev, dma_srcs, len, src_cnt);
 421                         unmap_dst(dev->dev, dma_dsts, test_buf_size, dst_cnt);
 422                         pr_warning("%s: #%u: prep error with src_off=0x%x "
 423                                         "dst_off=0x%x len=0x%x\n",
 424                                         thread_name, total_tests - 1,
 425                                         src_off, dst_off, len);
 426                         msleep(100);
 427                         failed_tests++;
 428                         continue;
 429                 }
 430
 431                 done.done = false;
 432                 tx->callback = dmatest_callback;
 433                 tx->callback_param = &done;
 434                 cookie = tx->tx_submit(tx);
 435
 436                 if (dma_submit_error(cookie)) {
 437                         pr_warning("%s: #%u: submit error %d with src_off=0x%x "
 438                                         "dst_off=0x%x len=0x%x\n",
 439                                         thread_name, total_tests - 1, cookie,
 440                                         src_off, dst_off, len);
 441                         msleep(100);
 442                         failed_tests++;
 443                         continue;
 444                 }
 445                 dma_async_issue_pending(chan);
 446
 447                 wait_event_freezable_timeout(done_wait, done.done,
 448                                              msecs_to_jiffies(timeout));
 449
 450                 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
 451
 452                 if (!done.done) {
 453                         /*
 454                          * We're leaving the timed out dma operation with
 455                          * dangling pointer to done_wait.  To make this
 456                          * correct, we'll need to allocate wait_done for
 457                          * each test iteration and perform "who's gonna
 458                          * free it this time?" dancing.  For now, just
 459                          * leave it dangling.
 460                          */
 461                         pr_warning("%s: #%u: test timed out\n",
 462                                    thread_name, total_tests - 1);
 463                         failed_tests++;
 464                         continue;
 465                 } else if (status != DMA_SUCCESS) {
 466                         pr_warning("%s: #%u: got completion callback,"
 467                                    " but status is \'%s\'\n",
 468                                    thread_name, total_tests - 1,
 469                                    status == DMA_ERROR ? "error" : "in progress");
 470                         failed_tests++;
 471                         continue;
 472                 }
 473
 474                 /* Unmap by myself (see DMA_COMPL_SKIP_DEST_UNMAP above) */
 475                 unmap_dst(dev->dev, dma_dsts, test_buf_size, dst_cnt);
 476
 477                 error_count = 0;
 478
 479                 pr_debug("%s: verifying source buffer...\n", thread_name);
 480                 error_count += dmatest_verify(thread->srcs, 0, src_off,
 481                                 0, PATTERN_SRC, true);
 482                 error_count += dmatest_verify(thread->srcs, src_off,
 483                                 src_off + len, src_off,
 484                                 PATTERN_SRC | PATTERN_COPY, true);
 485                 error_count += dmatest_verify(thread->srcs, src_off + len,
 486                                 test_buf_size, src_off + len,
 487                                 PATTERN_SRC, true);
 488
 489                 pr_debug("%s: verifying dest buffer...\n",
 490                                 thread->task->comm);
 491                 error_count += dmatest_verify(thread->dsts, 0, dst_off,
 492                                 0, PATTERN_DST, false);
 493                 error_count += dmatest_verify(thread->dsts, dst_off,
 494                                 dst_off + len, src_off,
 495                                 PATTERN_SRC | PATTERN_COPY, false);
 496                 error_count += dmatest_verify(thread->dsts, dst_off + len,
 497                                 test_buf_size, dst_off + len,
 498                                 PATTERN_DST, false);
 499
 500                 if (error_count) {
 501                         pr_warning("%s: #%u: %u errors with "
 502                                 "src_off=0x%x dst_off=0x%x len=0x%x\n",
 503                                 thread_name, total_tests - 1, error_count,
 504                                 src_off, dst_off, len);
 505                         failed_tests++;
 506                 } else {
 507                         pr_debug("%s: #%u: No errors with "
 508                                 "src_off=0x%x dst_off=0x%x len=0x%x\n",
 509                                 thread_name, total_tests - 1,
 510                                 src_off, dst_off, len);
 511                 }
 512         }
 513
 514         ret = 0;
 515         for (i = 0; thread->dsts[i]; i++)
 516                 kfree(thread->dsts[i]);
 517 err_dstbuf:
 518         kfree(thread->dsts);
 519 err_dsts:
 520         for (i = 0; thread->srcs[i]; i++)
 521                 kfree(thread->srcs[i]);
 522 err_srcbuf:
 523         kfree(thread->srcs);
 524 err_srcs:
 525         pr_notice("%s: terminating after %u tests, %u failures (status %d)\n",
 526                         thread_name, total_tests, failed_tests, ret);
 527
 528         /* terminate all transfers on specified channels */
 529         chan->device->device_control(chan, DMA_TERMINATE_ALL, 0);
 530         if (iterations > 0)
 531                 while (!kthread_should_stop()) {
 532                         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wait_dmatest_exit);
 533                         interruptible_sleep_on(&wait_dmatest_exit);
 534                 }
 535
 536         return ret;
 537 }
 538
 539 static void dmatest_cleanup_channel(struct dmatest_chan *dtc)
 540 {
 541         struct dmatest_thread   *thread;
 542         struct dmatest_thread   *_thread;
 543         int                     ret;
 544
 545         list_for_each_entry_safe(thread, _thread, &dtc->threads, node) {
 546                 ret = kthread_stop(thread->task);
 547                 pr_debug("dmatest: thread %s exited with status %d\n",
 548                                 thread->task->comm, ret);
 549                 list_del(&thread->node);
 550                 kfree(thread);
 551         }
 552
 553         /* terminate all transfers on specified channels */
 554         dtc->chan->device->device_control(dtc->chan, DMA_TERMINATE_ALL, 0);
 555
 556         kfree(dtc);
 557 }
 558
 559 static int dmatest_add_threads(struct dmatest_chan *dtc, enum dma_transaction_type type)
 560 {
 561         struct dmatest_thread *thread;
 562         struct dma_chan *chan = dtc->chan;
 563         char *op;
 564         unsigned int i;
 565
 566         if (type == DMA_MEMCPY)
 567                 op = "copy";
 568         else if (type == DMA_XOR)
 569                 op = "xor";
 570         else if (type == DMA_PQ)
 571                 op = "pq";
 572         else
 573                 return -EINVAL;
 574
 575         for (i = 0; i < threads_per_chan; i++) {
 576                 thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);
 577                 if (!thread) {
 578                         pr_warning("dmatest: No memory for %s-%s%u\n",
 579                                    dma_chan_name(chan), op, i);
 580
 581                         break;
 582                 }
 583                 thread->chan = dtc->chan;
 584                 thread->type = type;
 585                 smp_wmb();
 586                 thread->task = kthread_run(dmatest_func, thread, "%s-%s%u",
 587                                 dma_chan_name(chan), op, i);
 588                 if (IS_ERR(thread->task)) {
 589                         pr_warning("dmatest: Failed to run thread %s-%s%u\n",
 590                                         dma_chan_name(chan), op, i);
 591                         kfree(thread);
 592                         break;
 593                 }
 594
 595                 /* srcbuf and dstbuf are allocated by the thread itself */
 596
 597                 list_add_tail(&thread->node, &dtc->threads);
 598         }
 599
 600         return i;
 601 }
 602
 603 static int dmatest_add_channel(struct dma_chan *chan)
 604 {
 605         struct dmatest_chan     *dtc;
 606         struct dma_device       *dma_dev = chan->device;
 607         unsigned int            thread_count = 0;
 608         int cnt;
 609
 610         dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);
 611         if (!dtc) {
 612                 pr_warning("dmatest: No memory for %s\n", dma_chan_name(chan));
 613                 return -ENOMEM;
 614         }
 615
 616         dtc->chan = chan;
 617         INIT_LIST_HEAD(&dtc->threads);
 618
 619         if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) {
 620                 cnt = dmatest_add_threads(dtc, DMA_MEMCPY);
 621                 thread_count += cnt > 0 ? cnt : 0;
 622         }
 623         if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
 624                 cnt = dmatest_add_threads(dtc, DMA_XOR);
 625                 thread_count += cnt > 0 ? cnt : 0;
 626         }
 627         if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
 628                 cnt = dmatest_add_threads(dtc, DMA_PQ);
 629                 thread_count += cnt > 0 ? cnt : 0;
 630         }
 631
 632         pr_info("dmatest: Started %u threads using %s\n",
 633                 thread_count, dma_chan_name(chan));
 634
 635         list_add_tail(&dtc->node, &dmatest_channels);
 636         nr_channels++;
 637
 638         return 0;
 639 }
 640
 641 static bool filter(struct dma_chan *chan, void *param)
 642 {
 643         if (!dmatest_match_channel(chan) || !dmatest_match_device(chan->device))
 644                 return false;
 645         else
 646                 return true;
 647 }
 648
 649 static int __init dmatest_init(void)
 650 {
 651         dma_cap_mask_t mask;
 652         struct dma_chan *chan;
 653         int err = 0;
 654
 655         dma_cap_zero(mask);
 656         dma_cap_set(DMA_MEMCPY, mask);
 657         for (;;) {
 658                 chan = dma_request_channel(mask, filter, NULL);
 659                 if (chan) {
 660                         err = dmatest_add_channel(chan);
 661                         if (err) {
 662                                 dma_release_channel(chan);
 663                                 break; /* add_channel failed, punt */
 664                         }
 665                 } else
 666                         break; /* no more channels available */
 667                 if (max_channels && nr_channels >= max_channels)
 668                         break; /* we have all we need */
 669         }
 670
 671         return err;
 672 }
 673 /* when compiled-in wait for drivers to load first */
 674 late_initcall(dmatest_init);
 675
 676 static void __exit dmatest_exit(void)
 677 {
 678         struct dmatest_chan *dtc, *_dtc;
 679         struct dma_chan *chan;
 680
 681         list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
 682                 list_del(&dtc->node);
 683                 chan = dtc->chan;
 684                 dmatest_cleanup_channel(dtc);
 685                 pr_debug("dmatest: dropped channel %s\n",
 686                          dma_chan_name(chan));
 687                 dma_release_channel(chan);
 688         }
 689 }
 690 module_exit(dmatest_exit);
 691
 692 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
 693 MODULE_LICENSE("GPL v2");