/* * DMA Engine test module * * Copyright (C) 2007 Atmel Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/delay.h> #include <linux/dmaengine.h> #include <linux/init.h> #include <linux/kthread.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/random.h> #include <linux/wait.h> static unsigned int test_buf_size = 16384; module_param(test_buf_size, uint, S_IRUGO); MODULE_PARM_DESC(test_buf_size, "Size of the memcpy test buffer"); static char test_channel[BUS_ID_SIZE]; module_param_string(channel, test_channel, sizeof(test_channel), S_IRUGO); MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)"); static char test_device[BUS_ID_SIZE]; module_param_string(device, test_device, sizeof(test_device), S_IRUGO); MODULE_PARM_DESC(device, "Bus ID of the DMA Engine to test (default: any)"); static unsigned int threads_per_chan = 1; module_param(threads_per_chan, uint, S_IRUGO); MODULE_PARM_DESC(threads_per_chan, "Number of threads to start per channel (default: 1)"); static unsigned int max_channels; module_param(max_channels, uint, S_IRUGO); MODULE_PARM_DESC(nr_channels, "Maximum number of channels to use (default: all)"); /* * Initialization patterns. All bytes in the source buffer has bit 7 * set, all bytes in the destination buffer has bit 7 cleared. * * Bit 6 is set for all bytes which are to be copied by the DMA * engine. Bit 5 is set for all bytes which are to be overwritten by * the DMA engine. * * The remaining bits are the inverse of a counter which increments by * one for each byte address. */ #define PATTERN_SRC 0x80 #define PATTERN_DST 0x00 #define PATTERN_COPY 0x40 #define PATTERN_OVERWRITE 0x20 #define PATTERN_COUNT_MASK 0x1f struct dmatest_thread { struct list_head node; struct task_struct *task; struct dma_chan *chan; u8 *srcbuf; u8 *dstbuf; }; struct dmatest_chan { struct list_head node; struct dma_chan *chan; struct list_head threads; }; /* * These are protected by dma_list_mutex since they're only used by * the DMA client event callback */ static LIST_HEAD(dmatest_channels); static unsigned int nr_channels; static bool dmatest_match_channel(struct dma_chan *chan) { if (test_channel[0] == '\0') return true; return strcmp(chan->dev.bus_id, test_channel) == 0; } static bool dmatest_match_device(struct dma_device *device) { if (test_device[0] == '\0') return true; return strcmp(device->dev->bus_id, test_device) == 0; } static unsigned long dmatest_random(void) { unsigned long buf; get_random_bytes(&buf, sizeof(buf)); return buf; } static void dmatest_init_srcbuf(u8 *buf, unsigned int start, unsigned int len) { unsigned int i; for (i = 0; i < start; i++) buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK); for ( ; i < start + len; i++) buf[i] = PATTERN_SRC | PATTERN_COPY | (~i & PATTERN_COUNT_MASK);; for ( ; i < test_buf_size; i++) buf[i] = PATTERN_SRC | (~i & PATTERN_COUNT_MASK); } static void dmatest_init_dstbuf(u8 *buf, unsigned int start, unsigned int len) { unsigned int i; for (i = 0; i < start; i++) buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK); for ( ; i < start + len; i++) buf[i] = PATTERN_DST | PATTERN_OVERWRITE | (~i & PATTERN_COUNT_MASK); for ( ; i < test_buf_size; i++) buf[i] = PATTERN_DST | (~i & PATTERN_COUNT_MASK); } static void dmatest_mismatch(u8 actual, u8 pattern, unsigned int index, unsigned int counter, bool is_srcbuf) { u8 diff = actual ^ pattern; u8 expected = pattern | (~counter & PATTERN_COUNT_MASK); const char *thread_name = current->comm; if (is_srcbuf) pr_warning("%s: srcbuf[0x%x] overwritten!" " Expected %02x, got %02x\n", thread_name, index, expected, actual); else if ((pattern & PATTERN_COPY) && (diff & (PATTERN_COPY | PATTERN_OVERWRITE))) pr_warning("%s: dstbuf[0x%x] not copied!" " Expected %02x, got %02x\n", thread_name, index, expected, actual); else if (diff & PATTERN_SRC) pr_warning("%s: dstbuf[0x%x] was copied!" " Expected %02x, got %02x\n", thread_name, index, expected, actual); else pr_warning("%s: dstbuf[0x%x] mismatch!" " Expected %02x, got %02x\n", thread_name, index, expected, actual); } static unsigned int dmatest_verify(u8 *buf, unsigned int start, unsigned int end, unsigned int counter, u8 pattern, bool is_srcbuf) { unsigned int i; unsigned int error_count = 0; u8 actual; for (i = start; i < end; i++) { actual = buf[i]; if (actual != (pattern | (~counter & PATTERN_COUNT_MASK))) { if (error_count < 32) dmatest_mismatch(actual, pattern, i, counter, is_srcbuf); error_count++; } counter++; } if (error_count > 32) pr_warning("%s: %u errors suppressed\n", current->comm, error_count - 32); return error_count; } /* * This function repeatedly tests DMA transfers of various lengths and * offsets until it is told to exit by kthread_stop(). There may be * multiple threads running this function in parallel for a single * channel, and there may be multiple channels being tested in * parallel. * * Before each test, the source and destination buffer is initialized * with a known pattern. This pattern is different depending on * whether it's in an area which is supposed to be copied or * overwritten, and different in the source and destination buffers. * So if the DMA engine doesn't copy exactly what we tell it to copy, * we'll notice. */ static int dmatest_func(void *data) { struct dmatest_thread *thread = data; struct dma_chan *chan; const char *thread_name; unsigned int src_off, dst_off, len; unsigned int error_count; unsigned int failed_tests = 0; unsigned int total_tests = 0; dma_cookie_t cookie; enum dma_status status; int ret; thread_name = current->comm; ret = -ENOMEM; thread->srcbuf = kmalloc(test_buf_size, GFP_KERNEL); if (!thread->srcbuf) goto err_srcbuf; thread->dstbuf = kmalloc(test_buf_size, GFP_KERNEL); if (!thread->dstbuf) goto err_dstbuf; smp_rmb(); chan = thread->chan; dma_chan_get(chan); while (!kthread_should_stop()) { total_tests++; len = dmatest_random() % test_buf_size + 1; src_off = dmatest_random() % (test_buf_size - len + 1); dst_off = dmatest_random() % (test_buf_size - len + 1); dmatest_init_srcbuf(thread->srcbuf, src_off, len); dmatest_init_dstbuf(thread->dstbuf, dst_off, len); cookie = dma_async_memcpy_buf_to_buf(chan, thread->dstbuf + dst_off, thread->srcbuf + src_off, len); if (dma_submit_error(cookie)) { pr_warning("%s: #%u: submit error %d with src_off=0x%x " "dst_off=0x%x len=0x%x\n", thread_name, total_tests - 1, cookie, src_off, dst_off, len); msleep(100); failed_tests++; continue; } dma_async_memcpy_issue_pending(chan); do { msleep(1); status = dma_async_memcpy_complete( chan, cookie, NULL, NULL); } while (status == DMA_IN_PROGRESS); if (status == DMA_ERROR) { pr_warning("%s: #%u: error during copy\n", thread_name, total_tests - 1); failed_tests++; continue; } error_count = 0; pr_debug("%s: verifying source buffer...\n", thread_name); error_count += dmatest_verify(thread->srcbuf, 0, src_off, 0, PATTERN_SRC, true); error_count += dmatest_verify(thread->srcbuf, src_off, src_off + len, src_off, PATTERN_SRC | PATTERN_COPY, true); error_count += dmatest_verify(thread->srcbuf, src_off + len, test_buf_size, src_off + len, PATTERN_SRC, true); pr_debug("%s: verifying dest buffer...\n", thread->task->comm); error_count += dmatest_verify(thread->dstbuf, 0, dst_off, 0, PATTERN_DST, false); error_count += dmatest_verify(thread->dstbuf, dst_off, dst_off + len, src_off, PATTERN_SRC | PATTERN_COPY, false); error_count += dmatest_verify(thread->dstbuf, dst_off + len, test_buf_size, dst_off + len, PATTERN_DST, false); if (error_count) { pr_warning("%s: #%u: %u errors with " "src_off=0x%x dst_off=0x%x len=0x%x\n", thread_name, total_tests - 1, error_count, src_off, dst_off, len); failed_tests++; } else { pr_debug("%s: #%u: No errors with " "src_off=0x%x dst_off=0x%x len=0x%x\n", thread_name, total_tests - 1, src_off, dst_off, len); } } ret = 0; dma_chan_put(chan); kfree(thread->dstbuf); err_dstbuf: kfree(thread->srcbuf); err_srcbuf: pr_notice("%s: terminating after %u tests, %u failures (status %d)\n", thread_name, total_tests, failed_tests, ret); return ret; } static void dmatest_cleanup_channel(struct dmatest_chan *dtc) { struct dmatest_thread *thread; struct dmatest_thread *_thread; int ret; list_for_each_entry_safe(thread, _thread, &dtc->threads, node) { ret = kthread_stop(thread->task); pr_debug("dmatest: thread %s exited with status %d\n", thread->task->comm, ret); list_del(&thread->node); kfree(thread); } kfree(dtc); } static enum dma_state_client dmatest_add_channel(struct dma_chan *chan) { struct dmatest_chan *dtc; struct dmatest_thread *thread; unsigned int i; dtc = kmalloc(sizeof(struct dmatest_chan), GFP_ATOMIC); if (!dtc) { pr_warning("dmatest: No memory for %s\n", chan->dev.bus_id); return DMA_NAK; } dtc->chan = chan; INIT_LIST_HEAD(&dtc->threads); for (i = 0; i < threads_per_chan; i++) { thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL); if (!thread) { pr_warning("dmatest: No memory for %s-test%u\n", chan->dev.bus_id, i); break; } thread->chan = dtc->chan; smp_wmb(); thread->task = kthread_run(dmatest_func, thread, "%s-test%u", chan->dev.bus_id, i); if (IS_ERR(thread->task)) { pr_warning("dmatest: Failed to run thread %s-test%u\n", chan->dev.bus_id, i); kfree(thread); break; } /* srcbuf and dstbuf are allocated by the thread itself */ list_add_tail(&thread->node, &dtc->threads); } pr_info("dmatest: Started %u threads using %s\n", i, chan->dev.bus_id); list_add_tail(&dtc->node, &dmatest_channels); nr_channels++; return DMA_ACK; } static enum dma_state_client dmatest_remove_channel(struct dma_chan *chan) { struct dmatest_chan *dtc, *_dtc; list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) { if (dtc->chan == chan) { list_del(&dtc->node); dmatest_cleanup_channel(dtc); pr_debug("dmatest: lost channel %s\n", chan->dev.bus_id); return DMA_ACK; } } return DMA_DUP; } /* * Start testing threads as new channels are assigned to us, and kill * them when the channels go away. * * When we unregister the client, all channels are removed so this * will also take care of cleaning things up when the module is * unloaded. */ static enum dma_state_client dmatest_event(struct dma_client *client, struct dma_chan *chan, enum dma_state state) { enum dma_state_client ack = DMA_NAK; switch (state) { case DMA_RESOURCE_AVAILABLE: if (!dmatest_match_channel(chan) || !dmatest_match_device(chan->device)) ack = DMA_DUP; else if (max_channels && nr_channels >= max_channels) ack = DMA_NAK; else ack = dmatest_add_channel(chan); break; case DMA_RESOURCE_REMOVED: ack = dmatest_remove_channel(chan); break; default: pr_info("dmatest: Unhandled event %u (%s)\n", state, chan->dev.bus_id); break; } return ack; } static struct dma_client dmatest_client = { .event_callback = dmatest_event, }; static int __init dmatest_init(void) { dma_cap_set(DMA_MEMCPY, dmatest_client.cap_mask); dma_async_client_register(&dmatest_client); dma_async_client_chan_request(&dmatest_client); return 0; } module_init(dmatest_init); static void __exit dmatest_exit(void) { dma_async_client_unregister(&dmatest_client); } module_exit(dmatest_exit); MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>"); MODULE_LICENSE("GPL v2");