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