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