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Message-ID: <7F38996F7185A24AB9071ED4950AD8C101C21EB2@swsmsx413.ger.corp.intel.com>
Date: Tue, 1 Jul 2008 14:43:10 +0100
From: "Sosnowski, Maciej" <maciej.sosnowski@...el.com>
To: <haavard.skinnemoen@...el.com>
Cc: "Williams, Dan J" <dan.j.williams@...el.com>,
"lkml" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] dmatest: Simple DMA memcpy test client
> ---------- Original message ----------
> From: Haavard Skinnemoen <haavard.skinnemoen@...el.com>
> Date: Jun 25, 2008 2:19 PM
> Subject: [PATCH] dmatest: Simple DMA memcpy test client
> To: Dan Williams <dan.j.williams@...el.com>
> Cc: linux-kernel@...r.kernel.org, Haavard Skinnemoen
<hskinnemoen@...el.com>
>
>
> From: Haavard Skinnemoen <hskinnemoen@...el.com>
>
> This client tests DMA memcpy using various lengths and various offsets
> into the source and destination buffers. It will initialize both
> buffers with a repeatable pattern and verify that the DMA engine
copies
> the requested region and nothing more. It will also verify that the
> bytes aren't swapped around, and that the source buffer isn't
modified.
>
> The dmatest module can be configured to test a specific device, a
> specific channel. It can also test multiple channels at the same time,
> and it can start multiple threads competing for the same channel.
>
> Signed-off-by: Haavard Skinnemoen <hskinnemoen@...el.com>
>
> Changes since v2:
> * Support testing multiple channels at the same time
> * Support testing with multiple threads competing for the same
channel
> * Use counting test patterns in order to catch byte ordering issues
>
> Changes since v1:
> * Remove extra dashes around "help"
> * Remove "default n" from Kconfig
> * Turn TEST_BUF_SIZE into a module parameter
> * Return DMA_NAK instead of DMA_DUP
> * Print unhandled events
> * Support testing specific channels and devices
> * Move to the end of the Makefile
With one comment below the patch looks fine to me.
Acked-by: Maciej Sosnowski <maciej.sosnowski@...el.com>
> ---
> drivers/dma/Kconfig | 7 +
> drivers/dma/Makefile | 1 +
> drivers/dma/dmatest.c | 444
> +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed,
452
> insertions(+), 0 deletions(-) create mode 100644
drivers/dma/dmatest.c
>
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index 6239c3d..18f6ef3 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -61,4 +61,11 @@ config NET_DMA
> Since this is the main user of the DMA engine, it should be
enabled;
> say Y here.
>
> +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 c8036d9..2ff6d7f 100644
> --- a/drivers/dma/Makefile
> +++ b/drivers/dma/Makefile
> @@ -4,3 +4,4 @@ obj-$(CONFIG_INTEL_IOATDMA) += ioatdma.o
> ioatdma-objs := ioat.o ioat_dma.o ioat_dca.o
> obj-$(CONFIG_INTEL_IOP_ADMA) += iop-adma.o
> obj-$(CONFIG_FSL_DMA) += fsldma.o
> +obj-$(CONFIG_DMATEST) += dmatest.o
> diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
> new file mode 100644
> index 0000000..5c9fd10
> --- /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)
> + && (!max_channels
> + || nr_channels <
max_channels))
> + ack = dmatest_add_channel(chan);
> + else
> + ack = DMA_DUP;
> + break;
In case when nr_channels exceeds max_channels
ack should be rather set to DMA_NAK than DMA_DUP.
> +
> + 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@...el.com>");
> +MODULE_LICENSE("GPL v2");
> --
> 1.5.5.4
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