linux/drivers/dma/dmatest.c
<<
>>
Prefs
   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
  19static unsigned int test_buf_size = 16384;
  20module_param(test_buf_size, uint, S_IRUGO);
  21MODULE_PARM_DESC(test_buf_size, "Size of the memcpy test buffer");
  22
  23static char test_channel[20];
  24module_param_string(channel, test_channel, sizeof(test_channel), S_IRUGO);
  25MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)");
  26
  27static char test_device[20];
  28module_param_string(device, test_device, sizeof(test_device), S_IRUGO);
  29MODULE_PARM_DESC(device, "Bus ID of the DMA Engine to test (default: any)");
  30
  31static unsigned int threads_per_chan = 1;
  32module_param(threads_per_chan, uint, S_IRUGO);
  33MODULE_PARM_DESC(threads_per_chan,
  34                "Number of threads to start per channel (default: 1)");
  35
  36static unsigned int max_channels;
  37module_param(max_channels, uint, S_IRUGO);
  38MODULE_PARM_DESC(max_channels,
  39                "Maximum number of channels to use (default: all)");
  40
  41static unsigned int iterations;
  42module_param(iterations, uint, S_IRUGO);
  43MODULE_PARM_DESC(iterations,
  44                "Iterations before stopping test (default: infinite)");
  45
  46static unsigned int xor_sources = 3;
  47module_param(xor_sources, uint, S_IRUGO);
  48MODULE_PARM_DESC(xor_sources,
  49                "Number of xor source buffers (default: 3)");
  50
  51static unsigned int pq_sources = 3;
  52module_param(pq_sources, uint, S_IRUGO);
  53MODULE_PARM_DESC(pq_sources,
  54                "Number of p+q source buffers (default: 3)");
  55
  56/*
  57 * Initialization patterns. All bytes in the source buffer has bit 7
  58 * set, all bytes in the destination buffer has bit 7 cleared.
  59 *
  60 * Bit 6 is set for all bytes which are to be copied by the DMA
  61 * engine. Bit 5 is set for all bytes which are to be overwritten by
  62 * the DMA engine.
  63 *
  64 * The remaining bits are the inverse of a counter which increments by
  65 * one for each byte address.
  66 */
  67#define PATTERN_SRC             0x80
  68#define PATTERN_DST             0x00
  69#define PATTERN_COPY            0x40
  70#define PATTERN_OVERWRITE       0x20
  71#define PATTERN_COUNT_MASK      0x1f
  72
  73struct dmatest_thread {
  74        struct list_head        node;
  75        struct task_struct      *task;
  76        struct dma_chan         *chan;
  77        u8                      **srcs;
  78        u8                      **dsts;
  79        enum dma_transaction_type type;
  80};
  81
  82struct dmatest_chan {
  83        struct list_head        node;
  84        struct dma_chan         *chan;
  85        struct list_head        threads;
  86};
  87
  88/*
  89 * These are protected by dma_list_mutex since they're only used by
  90 * the DMA filter function callback
  91 */
  92static LIST_HEAD(dmatest_channels);
  93static unsigned int nr_channels;
  94
  95static bool dmatest_match_channel(struct dma_chan *chan)
  96{
  97        if (test_channel[0] == '\0')
  98                return true;
  99        return strcmp(dma_chan_name(chan), test_channel) == 0;
 100}
 101
 102static bool dmatest_match_device(struct dma_device *device)
 103{
 104        if (test_device[0] == '\0')
 105                return true;
 106        return strcmp(dev_name(device->dev), test_device) == 0;
 107}
 108
 109static unsigned long dmatest_random(void)
 110{
 111        unsigned long buf;
 112
 113        get_random_bytes(&buf, sizeof(buf));
 114        return buf;
 115}
 116
 117static void dmatest_init_srcs(u8 **bufs, unsigned int start, unsigned int len)
 118{
 119        unsigned int i;
 120        u8 *buf;
 121
 122        for (; (buf = *bufs); bufs++) {
 123                for (i = 0; i < start; i++)
 124                        buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
 125                for ( ; i < start + len; i++)
 126                        buf[i] = PATTERN_SRC | PATTERN_COPY
 127                                | (~i & PATTERN_COUNT_MASK);
 128                for ( ; i < test_buf_size; i++)
 129                        buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK);
 130                buf++;
 131        }
 132}
 133
 134static void dmatest_init_dsts(u8 **bufs, unsigned int start, unsigned int len)
 135{
 136        unsigned int i;
 137        u8 *buf;
 138
 139        for (; (buf = *bufs); bufs++) {
 140                for (i = 0; i < start; i++)
 141                        buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
 142                for ( ; i < start + len; i++)
 143                        buf[i] = PATTERN_DST | PATTERN_OVERWRITE
 144                                | (~i & PATTERN_COUNT_MASK);
 145                for ( ; i < test_buf_size; i++)
 146                        buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK);
 147        }
 148}
 149
 150static void dmatest_mismatch(u8 actual, u8 pattern, unsigned int index,
 151                unsigned int counter, bool is_srcbuf)
 152{
 153        u8              diff = actual ^ pattern;
 154        u8              expected = pattern | (~counter & PATTERN_COUNT_MASK);
 155        const char      *thread_name = current->comm;
 156
 157        if (is_srcbuf)
 158                pr_warning("%s: srcbuf[0x%x] overwritten!"
 159                                " Expected %02x, got %02x\n",
 160                                thread_name, index, expected, actual);
 161        else if ((pattern & PATTERN_COPY)
 162                        && (diff & (PATTERN_COPY | PATTERN_OVERWRITE)))
 163                pr_warning("%s: dstbuf[0x%x] not copied!"
 164                                " Expected %02x, got %02x\n",
 165                                thread_name, index, expected, actual);
 166        else if (diff & PATTERN_SRC)
 167                pr_warning("%s: dstbuf[0x%x] was copied!"
 168                                " Expected %02x, got %02x\n",
 169                                thread_name, index, expected, actual);
 170        else
 171                pr_warning("%s: dstbuf[0x%x] mismatch!"
 172                                " Expected %02x, got %02x\n",
 173                                thread_name, index, expected, actual);
 174}
 175
 176static unsigned int dmatest_verify(u8 **bufs, unsigned int start,
 177                unsigned int end, unsigned int counter, u8 pattern,
 178                bool is_srcbuf)
 179{
 180        unsigned int i;
 181        unsigned int error_count = 0;
 182        u8 actual;
 183        u8 expected;
 184        u8 *buf;
 185        unsigned int counter_orig = counter;
 186
 187        for (; (buf = *bufs); bufs++) {
 188                counter = counter_orig;
 189                for (i = start; i < end; i++) {
 190                        actual = buf[i];
 191                        expected = pattern | (~counter & PATTERN_COUNT_MASK);
 192                        if (actual != expected) {
 193                                if (error_count < 32)
 194                                        dmatest_mismatch(actual, pattern, i,
 195                                                         counter, is_srcbuf);
 196                                error_count++;
 197                        }
 198                        counter++;
 199                }
 200        }
 201
 202        if (error_count > 32)
 203                pr_warning("%s: %u errors suppressed\n",
 204                        current->comm, error_count - 32);
 205
 206        return error_count;
 207}
 208
 209static void dmatest_callback(void *completion)
 210{
 211        complete(completion);
 212}
 213
 214/*
 215 * This function repeatedly tests DMA transfers of various lengths and
 216 * offsets for a given operation type until it is told to exit by
 217 * kthread_stop(). There may be multiple threads running this function
 218 * in parallel for a single channel, and there may be multiple channels
 219 * being tested in parallel.
 220 *
 221 * Before each test, the source and destination buffer is initialized
 222 * with a known pattern. This pattern is different depending on
 223 * whether it's in an area which is supposed to be copied or
 224 * overwritten, and different in the source and destination buffers.
 225 * So if the DMA engine doesn't copy exactly what we tell it to copy,
 226 * we'll notice.
 227 */
 228static int dmatest_func(void *data)
 229{
 230        struct dmatest_thread   *thread = data;
 231        struct dma_chan         *chan;
 232        const char              *thread_name;
 233        unsigned int            src_off, dst_off, len;
 234        unsigned int            error_count;
 235        unsigned int            failed_tests = 0;
 236        unsigned int            total_tests = 0;
 237        dma_cookie_t            cookie;
 238        enum dma_status         status;
 239        enum dma_ctrl_flags     flags;
 240        u8                      pq_coefs[pq_sources];
 241        int                     ret;
 242        int                     src_cnt;
 243        int                     dst_cnt;
 244        int                     i;
 245
 246        thread_name = current->comm;
 247
 248        ret = -ENOMEM;
 249
 250        smp_rmb();
 251        chan = thread->chan;
 252        if (thread->type == DMA_MEMCPY)
 253                src_cnt = dst_cnt = 1;
 254        else if (thread->type == DMA_XOR) {
 255                src_cnt = xor_sources | 1; /* force odd to ensure dst = src */
 256                dst_cnt = 1;
 257        } else if (thread->type == DMA_PQ) {
 258                src_cnt = pq_sources | 1; /* force odd to ensure dst = src */
 259                dst_cnt = 2;
 260                for (i = 0; i < pq_sources; i++)
 261                        pq_coefs[i] = 1;
 262        } else
 263                goto err_srcs;
 264
 265        thread->srcs = kcalloc(src_cnt+1, sizeof(u8 *), GFP_KERNEL);
 266        if (!thread->srcs)
 267                goto err_srcs;
 268        for (i = 0; i < src_cnt; i++) {
 269                thread->srcs[i] = kmalloc(test_buf_size, GFP_KERNEL);
 270                if (!thread->srcs[i])
 271                        goto err_srcbuf;
 272        }
 273        thread->srcs[i] = NULL;
 274
 275        thread->dsts = kcalloc(dst_cnt+1, sizeof(u8 *), GFP_KERNEL);
 276        if (!thread->dsts)
 277                goto err_dsts;
 278        for (i = 0; i < dst_cnt; i++) {
 279                thread->dsts[i] = kmalloc(test_buf_size, GFP_KERNEL);
 280                if (!thread->dsts[i])
 281                        goto err_dstbuf;
 282        }
 283        thread->dsts[i] = NULL;
 284
 285        set_user_nice(current, 10);
 286
 287        flags = DMA_CTRL_ACK | DMA_COMPL_SKIP_DEST_UNMAP | DMA_PREP_INTERRUPT;
 288
 289        while (!kthread_should_stop()
 290               && !(iterations && total_tests >= iterations)) {
 291                struct dma_device *dev = chan->device;
 292                struct dma_async_tx_descriptor *tx = NULL;
 293                dma_addr_t dma_srcs[src_cnt];
 294                dma_addr_t dma_dsts[dst_cnt];
 295                struct completion cmp;
 296                unsigned long tmo = msecs_to_jiffies(3000);
 297                u8 align = 0;
 298
 299                total_tests++;
 300
 301                len = dmatest_random() % test_buf_size + 1;
 302                src_off = dmatest_random() % (test_buf_size - len + 1);
 303                dst_off = dmatest_random() % (test_buf_size - len + 1);
 304
 305                /* honor alignment restrictions */
 306                if (thread->type == DMA_MEMCPY)
 307                        align = dev->copy_align;
 308                else if (thread->type == DMA_XOR)
 309                        align = dev->xor_align;
 310                else if (thread->type == DMA_PQ)
 311                        align = dev->pq_align;
 312
 313                len = (len >> align) << align;
 314                src_off = (src_off >> align) << align;
 315                dst_off = (dst_off >> align) << align;
 316
 317                dmatest_init_srcs(thread->srcs, src_off, len);
 318                dmatest_init_dsts(thread->dsts, dst_off, len);
 319
 320                for (i = 0; i < src_cnt; i++) {
 321                        u8 *buf = thread->srcs[i] + src_off;
 322
 323                        dma_srcs[i] = dma_map_single(dev->dev, buf, len,
 324                                                     DMA_TO_DEVICE);
 325                }
 326                /* map with DMA_BIDIRECTIONAL to force writeback/invalidate */
 327                for (i = 0; i < dst_cnt; i++) {
 328                        dma_dsts[i] = dma_map_single(dev->dev, thread->dsts[i],
 329                                                     test_buf_size,
 330                                                     DMA_BIDIRECTIONAL);
 331                }
 332
 333
 334                if (thread->type == DMA_MEMCPY)
 335                        tx = dev->device_prep_dma_memcpy(chan,
 336                                                         dma_dsts[0] + dst_off,
 337                                                         dma_srcs[0], len,
 338                                                         flags);
 339                else if (thread->type == DMA_XOR)
 340                        tx = dev->device_prep_dma_xor(chan,
 341                                                      dma_dsts[0] + dst_off,
 342                                                      dma_srcs, xor_sources,
 343                                                      len, flags);
 344                else if (thread->type == DMA_PQ) {
 345                        dma_addr_t dma_pq[dst_cnt];
 346
 347                        for (i = 0; i < dst_cnt; i++)
 348                                dma_pq[i] = dma_dsts[i] + dst_off;
 349                        tx = dev->device_prep_dma_pq(chan, dma_pq, dma_srcs,
 350                                                     pq_sources, pq_coefs,
 351                                                     len, flags);
 352                }
 353
 354                if (!tx) {
 355                        for (i = 0; i < src_cnt; i++)
 356                                dma_unmap_single(dev->dev, dma_srcs[i], len,
 357                                                 DMA_TO_DEVICE);
 358                        for (i = 0; i < dst_cnt; i++)
 359                                dma_unmap_single(dev->dev, dma_dsts[i],
 360                                                 test_buf_size,
 361                                                 DMA_BIDIRECTIONAL);
 362                        pr_warning("%s: #%u: prep error with src_off=0x%x "
 363                                        "dst_off=0x%x len=0x%x\n",
 364                                        thread_name, total_tests - 1,
 365                                        src_off, dst_off, len);
 366                        msleep(100);
 367                        failed_tests++;
 368                        continue;
 369                }
 370
 371                init_completion(&cmp);
 372                tx->callback = dmatest_callback;
 373                tx->callback_param = &cmp;
 374                cookie = tx->tx_submit(tx);
 375
 376                if (dma_submit_error(cookie)) {
 377                        pr_warning("%s: #%u: submit error %d with src_off=0x%x "
 378                                        "dst_off=0x%x len=0x%x\n",
 379                                        thread_name, total_tests - 1, cookie,
 380                                        src_off, dst_off, len);
 381                        msleep(100);
 382                        failed_tests++;
 383                        continue;
 384                }
 385                dma_async_issue_pending(chan);
 386
 387                tmo = wait_for_completion_timeout(&cmp, tmo);
 388                status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
 389
 390                if (tmo == 0) {
 391                        pr_warning("%s: #%u: test timed out\n",
 392                                   thread_name, total_tests - 1);
 393                        failed_tests++;
 394                        continue;
 395                } else if (status != DMA_SUCCESS) {
 396                        pr_warning("%s: #%u: got completion callback,"
 397                                   " but status is \'%s\'\n",
 398                                   thread_name, total_tests - 1,
 399                                   status == DMA_ERROR ? "error" : "in progress");
 400                        failed_tests++;
 401                        continue;
 402                }
 403
 404                /* Unmap by myself (see DMA_COMPL_SKIP_DEST_UNMAP above) */
 405                for (i = 0; i < dst_cnt; i++)
 406                        dma_unmap_single(dev->dev, dma_dsts[i], test_buf_size,
 407                                         DMA_BIDIRECTIONAL);
 408
 409                error_count = 0;
 410
 411                pr_debug("%s: verifying source buffer...\n", thread_name);
 412                error_count += dmatest_verify(thread->srcs, 0, src_off,
 413                                0, PATTERN_SRC, true);
 414                error_count += dmatest_verify(thread->srcs, src_off,
 415                                src_off + len, src_off,
 416                                PATTERN_SRC | PATTERN_COPY, true);
 417                error_count += dmatest_verify(thread->srcs, src_off + len,
 418                                test_buf_size, src_off + len,
 419                                PATTERN_SRC, true);
 420
 421                pr_debug("%s: verifying dest buffer...\n",
 422                                thread->task->comm);
 423                error_count += dmatest_verify(thread->dsts, 0, dst_off,
 424                                0, PATTERN_DST, false);
 425                error_count += dmatest_verify(thread->dsts, dst_off,
 426                                dst_off + len, src_off,
 427                                PATTERN_SRC | PATTERN_COPY, false);
 428                error_count += dmatest_verify(thread->dsts, dst_off + len,
 429                                test_buf_size, dst_off + len,
 430                                PATTERN_DST, false);
 431
 432                if (error_count) {
 433                        pr_warning("%s: #%u: %u errors with "
 434                                "src_off=0x%x dst_off=0x%x len=0x%x\n",
 435                                thread_name, total_tests - 1, error_count,
 436                                src_off, dst_off, len);
 437                        failed_tests++;
 438                } else {
 439                        pr_debug("%s: #%u: No errors with "
 440                                "src_off=0x%x dst_off=0x%x len=0x%x\n",
 441                                thread_name, total_tests - 1,
 442                                src_off, dst_off, len);
 443                }
 444        }
 445
 446        ret = 0;
 447        for (i = 0; thread->dsts[i]; i++)
 448                kfree(thread->dsts[i]);
 449err_dstbuf:
 450        kfree(thread->dsts);
 451err_dsts:
 452        for (i = 0; thread->srcs[i]; i++)
 453                kfree(thread->srcs[i]);
 454err_srcbuf:
 455        kfree(thread->srcs);
 456err_srcs:
 457        pr_notice("%s: terminating after %u tests, %u failures (status %d)\n",
 458                        thread_name, total_tests, failed_tests, ret);
 459
 460        if (iterations > 0)
 461                while (!kthread_should_stop()) {
 462                        DECLARE_WAIT_QUEUE_HEAD(wait_dmatest_exit);
 463                        interruptible_sleep_on(&wait_dmatest_exit);
 464                }
 465
 466        return ret;
 467}
 468
 469static void dmatest_cleanup_channel(struct dmatest_chan *dtc)
 470{
 471        struct dmatest_thread   *thread;
 472        struct dmatest_thread   *_thread;
 473        int                     ret;
 474
 475        list_for_each_entry_safe(thread, _thread, &dtc->threads, node) {
 476                ret = kthread_stop(thread->task);
 477                pr_debug("dmatest: thread %s exited with status %d\n",
 478                                thread->task->comm, ret);
 479                list_del(&thread->node);
 480                kfree(thread);
 481        }
 482        kfree(dtc);
 483}
 484
 485static int dmatest_add_threads(struct dmatest_chan *dtc, enum dma_transaction_type type)
 486{
 487        struct dmatest_thread *thread;
 488        struct dma_chan *chan = dtc->chan;
 489        char *op;
 490        unsigned int i;
 491
 492        if (type == DMA_MEMCPY)
 493                op = "copy";
 494        else if (type == DMA_XOR)
 495                op = "xor";
 496        else if (type == DMA_PQ)
 497                op = "pq";
 498        else
 499                return -EINVAL;
 500
 501        for (i = 0; i < threads_per_chan; i++) {
 502                thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);
 503                if (!thread) {
 504                        pr_warning("dmatest: No memory for %s-%s%u\n",
 505                                   dma_chan_name(chan), op, i);
 506
 507                        break;
 508                }
 509                thread->chan = dtc->chan;
 510                thread->type = type;
 511                smp_wmb();
 512                thread->task = kthread_run(dmatest_func, thread, "%s-%s%u",
 513                                dma_chan_name(chan), op, i);
 514                if (IS_ERR(thread->task)) {
 515                        pr_warning("dmatest: Failed to run thread %s-%s%u\n",
 516                                        dma_chan_name(chan), op, i);
 517                        kfree(thread);
 518                        break;
 519                }
 520
 521                /* srcbuf and dstbuf are allocated by the thread itself */
 522
 523                list_add_tail(&thread->node, &dtc->threads);
 524        }
 525
 526        return i;
 527}
 528
 529static int dmatest_add_channel(struct dma_chan *chan)
 530{
 531        struct dmatest_chan     *dtc;
 532        struct dma_device       *dma_dev = chan->device;
 533        unsigned int            thread_count = 0;
 534        unsigned int            cnt;
 535
 536        dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);
 537        if (!dtc) {
 538                pr_warning("dmatest: No memory for %s\n", dma_chan_name(chan));
 539                return -ENOMEM;
 540        }
 541
 542        dtc->chan = chan;
 543        INIT_LIST_HEAD(&dtc->threads);
 544
 545        if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) {
 546                cnt = dmatest_add_threads(dtc, DMA_MEMCPY);
 547                thread_count += cnt > 0 ? cnt : 0;
 548        }
 549        if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
 550                cnt = dmatest_add_threads(dtc, DMA_XOR);
 551                thread_count += cnt > 0 ? cnt : 0;
 552        }
 553        if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
 554                cnt = dmatest_add_threads(dtc, DMA_PQ);
 555                thread_count += cnt > 0 ?: 0;
 556        }
 557
 558        pr_info("dmatest: Started %u threads using %s\n",
 559                thread_count, dma_chan_name(chan));
 560
 561        list_add_tail(&dtc->node, &dmatest_channels);
 562        nr_channels++;
 563
 564        return 0;
 565}
 566
 567static bool filter(struct dma_chan *chan, void *param)
 568{
 569        if (!dmatest_match_channel(chan) || !dmatest_match_device(chan->device))
 570                return false;
 571        else
 572                return true;
 573}
 574
 575static int __init dmatest_init(void)
 576{
 577        dma_cap_mask_t mask;
 578        struct dma_chan *chan;
 579        int err = 0;
 580
 581        dma_cap_zero(mask);
 582        dma_cap_set(DMA_MEMCPY, mask);
 583        for (;;) {
 584                chan = dma_request_channel(mask, filter, NULL);
 585                if (chan) {
 586                        err = dmatest_add_channel(chan);
 587                        if (err) {
 588                                dma_release_channel(chan);
 589                                break; /* add_channel failed, punt */
 590                        }
 591                } else
 592                        break; /* no more channels available */
 593                if (max_channels && nr_channels >= max_channels)
 594                        break; /* we have all we need */
 595        }
 596
 597        return err;
 598}
 599/* when compiled-in wait for drivers to load first */
 600late_initcall(dmatest_init);
 601
 602static void __exit dmatest_exit(void)
 603{
 604        struct dmatest_chan *dtc, *_dtc;
 605        struct dma_chan *chan;
 606
 607        list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
 608                list_del(&dtc->node);
 609                chan = dtc->chan;
 610                dmatest_cleanup_channel(dtc);
 611                pr_debug("dmatest: dropped channel %s\n",
 612                         dma_chan_name(chan));
 613                dma_release_channel(chan);
 614        }
 615}
 616module_exit(dmatest_exit);
 617
 618MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
 619MODULE_LICENSE("GPL v2");
 620
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.