--- /dev/null
+/*
+ * 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");
projects / linux-2.6 / commitdiff