/*
* 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[20];
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[20];
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(max_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 filter function 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(dma_chan_name(chan), test_channel) == 0;
}
static bool dmatest_match_device(struct dma_device *device)
{
if (test_device[0] == '\0')
return true;
return strcmp(dev_name(device->dev), 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;
while (!kthread_should_stop()) {
struct dma_device *dev = chan->device;
struct dma_async_tx_descriptor *tx;
dma_addr_t dma_src, dma_dest;
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);
dma_src = dma_map_single(dev->dev, thread->srcbuf + src_off,
len, DMA_TO_DEVICE);
/* map with DMA_BIDIRECTIONAL to force writeback/invalidate */
dma_dest = dma_map_single(dev->dev, thread->dstbuf,
test_buf_size, DMA_BIDIRECTIONAL);
tx = dev->device_prep_dma_memcpy(chan, dma_dest + dst_off,
dma_src, len,
DMA_CTRL_ACK | DMA_COMPL_SKIP_DEST_UNMAP);
if (!tx) {
dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
dma_unmap_single(dev->dev, dma_dest,
test_buf_size, DMA_BIDIRECTIONAL);
pr_warning("%s: #%u: prep error with src_off=0x%x "
"dst_off=0x%x len=0x%x\n",
thread_name, total_tests - 1,
src_off, dst_off, len);
msleep(100);
failed_tests++;
continue;
}
tx->callback = NULL;
cookie = tx->tx_submit(tx);
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;
}
/* Unmap by myself (see DMA_COMPL_SKIP_DEST_UNMAP above) */
dma_unmap_single(dev->dev, dma_dest,
test_buf_size, DMA_BIDIRECTIONAL);
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;
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 int 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_KERNEL);
if (!dtc) {
pr_warning("dmatest: No memory for %s\n", dma_chan_name(chan));
return -ENOMEM;
}
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",
dma_chan_name(chan), i);
break;
}
thread->chan = dtc->chan;
smp_wmb();
thread->task = kthread_run(dmatest_func, thread, "%s-test%u",
dma_chan_name(chan), i);
if (IS_ERR(thread->task)) {
pr_warning("dmatest: Failed to run thread %s-test%u\n",
dma_chan_name(chan), 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, dma_chan_name(chan));
list_add_tail(&dtc->node, &dmatest_channels);
nr_channels++;
return 0;
}
static bool filter(struct dma_chan *chan, void *param)
{
if (!dmatest_match_channel(chan) || !dmatest_match_device(chan->device))
return false;
else
return true;
}
static int __init dmatest_init(void)
{
dma_cap_mask_t mask;
struct dma_chan *chan;
int err = 0;
dma_cap_zero(mask);
dma_cap_set(DMA_MEMCPY, mask);
for (;;) {
chan = dma_request_channel(mask, filter, NULL);
if (chan) {
err = dmatest_add_channel(chan);
if (err == 0)
continue;
else {
dma_release_channel(chan);
break; /* add_channel failed, punt */
}
} else
break; /* no more channels available */
if (max_channels && nr_channels >= max_channels)
break; /* we have all we need */
}
return err;
}
/* when compiled-in wait for drivers to load first */
late_initcall(dmatest_init);
static void __exit dmatest_exit(void)
{
struct dmatest_chan *dtc, *_dtc;
list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
list_del(&dtc->node);
dmatest_cleanup_channel(dtc);
pr_debug("dmatest: dropped channel %s\n",
dma_chan_name(dtc->chan));
dma_release_channel(dtc->chan);
}
}
module_exit(dmatest_exit);
MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
MODULE_LICENSE("GPL v2");
