3 files changed, 452 insertions, 0 deletions

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 5af8b1cfc1e9..4b6bd3d099cf 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -72,4 +72,11 @@ config NET_DMA
           Say Y here if you enabled INTEL_IOATDMA or FSL_DMA, otherwise
           say N.
 
+config DMATEST
+        tristate "DMA Test client"
+        depends on DMA_ENGINE
+        help
+          Simple DMA test client. Say N unless you're debugging a
+          DMA Device driver.
+
 endif
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index ee272fd329c9..181e3646fbfe 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -1,5 +1,6 @@
 obj-$(CONFIG_DMA_ENGINE) += dmaengine.o
 obj-$(CONFIG_NET_DMA) += iovlock.o
+obj-$(CONFIG_DMATEST) += dmatest.o
 obj-$(CONFIG_INTEL_IOATDMA) += ioatdma.o
 ioatdma-objs := ioat.o ioat_dma.o ioat_dca.o
 obj-$(CONFIG_INTEL_IOP_ADMA) += iop-adma.o
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
new file mode 100644
index 000000000000..a08d19704743
--- /dev/null
+++ b/drivers/dma/dmatest.c
@@ -0,0 +1,444 @@
+/*
+ * 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");