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"); 580