linux/drivers/dma/dmatest.c
Viresh Kumar d42efe6bfb dmaengine/dmatest: Pass timeout via module params
When we try to test all channels present on our controller together, some
channels of lower priority may be very slow as compared to others. If number of
transfers is unlimited, some channels may timeout and will not finish within 3
seconds. Thus, while doing such regress testing we may need to have higher value
of timeouts. This patch adds support for passing timeout value via module
parameters. Default value is 3 msec, a negative value means max timeout
possible.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-03-22 11:12:29 -07:00

639 lines
17 KiB
C

/*
* 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/slab.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)");
static unsigned int iterations;
module_param(iterations, uint, S_IRUGO);
MODULE_PARM_DESC(iterations,
"Iterations before stopping test (default: infinite)");
static unsigned int xor_sources = 3;
module_param(xor_sources, uint, S_IRUGO);
MODULE_PARM_DESC(xor_sources,
"Number of xor source buffers (default: 3)");
static unsigned int pq_sources = 3;
module_param(pq_sources, uint, S_IRUGO);
MODULE_PARM_DESC(pq_sources,
"Number of p+q source buffers (default: 3)");
static int timeout = 3000;
module_param(timeout, uint, S_IRUGO);
MODULE_PARM_DESC(timeout, "Transfer Timeout in msec (default: 3000), \
Pass -1 for infinite timeout");
/*
* 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 **srcs;
u8 **dsts;
enum dma_transaction_type type;
};
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_srcs(u8 **bufs, unsigned int start, unsigned int len)
{
unsigned int i;
u8 *buf;
for (; (buf = *bufs); bufs++) {
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);
buf++;
}
}
static void dmatest_init_dsts(u8 **bufs, unsigned int start, unsigned int len)
{
unsigned int i;
u8 *buf;
for (; (buf = *bufs); bufs++) {
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 **bufs, unsigned int start,
unsigned int end, unsigned int counter, u8 pattern,
bool is_srcbuf)
{
unsigned int i;
unsigned int error_count = 0;
u8 actual;
u8 expected;
u8 *buf;
unsigned int counter_orig = counter;
for (; (buf = *bufs); bufs++) {
counter = counter_orig;
for (i = start; i < end; i++) {
actual = buf[i];
expected = pattern | (~counter & PATTERN_COUNT_MASK);
if (actual != expected) {
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;
}
static void dmatest_callback(void *completion)
{
complete(completion);
}
/*
* This function repeatedly tests DMA transfers of various lengths and
* offsets for a given operation type 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;
enum dma_ctrl_flags flags;
u8 pq_coefs[pq_sources + 1];
int ret;
int src_cnt;
int dst_cnt;
int i;
thread_name = current->comm;
ret = -ENOMEM;
smp_rmb();
chan = thread->chan;
if (thread->type == DMA_MEMCPY)
src_cnt = dst_cnt = 1;
else if (thread->type == DMA_XOR) {
src_cnt = xor_sources | 1; /* force odd to ensure dst = src */
dst_cnt = 1;
} else if (thread->type == DMA_PQ) {
src_cnt = pq_sources | 1; /* force odd to ensure dst = src */
dst_cnt = 2;
for (i = 0; i < src_cnt; i++)
pq_coefs[i] = 1;
} else
goto err_srcs;
thread->srcs = kcalloc(src_cnt+1, sizeof(u8 *), GFP_KERNEL);
if (!thread->srcs)
goto err_srcs;
for (i = 0; i < src_cnt; i++) {
thread->srcs[i] = kmalloc(test_buf_size, GFP_KERNEL);
if (!thread->srcs[i])
goto err_srcbuf;
}
thread->srcs[i] = NULL;
thread->dsts = kcalloc(dst_cnt+1, sizeof(u8 *), GFP_KERNEL);
if (!thread->dsts)
goto err_dsts;
for (i = 0; i < dst_cnt; i++) {
thread->dsts[i] = kmalloc(test_buf_size, GFP_KERNEL);
if (!thread->dsts[i])
goto err_dstbuf;
}
thread->dsts[i] = NULL;
set_user_nice(current, 10);
/*
* src buffers are freed by the DMAEngine code with dma_unmap_single()
* dst buffers are freed by ourselves below
*/
flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT
| DMA_COMPL_SKIP_DEST_UNMAP | DMA_COMPL_SRC_UNMAP_SINGLE;
while (!kthread_should_stop()
&& !(iterations && total_tests >= iterations)) {
struct dma_device *dev = chan->device;
struct dma_async_tx_descriptor *tx = NULL;
dma_addr_t dma_srcs[src_cnt];
dma_addr_t dma_dsts[dst_cnt];
struct completion cmp;
unsigned long tmo = msecs_to_jiffies(timeout);
u8 align = 0;
total_tests++;
/* honor alignment restrictions */
if (thread->type == DMA_MEMCPY)
align = dev->copy_align;
else if (thread->type == DMA_XOR)
align = dev->xor_align;
else if (thread->type == DMA_PQ)
align = dev->pq_align;
if (1 << align > test_buf_size) {
pr_err("%u-byte buffer too small for %d-byte alignment\n",
test_buf_size, 1 << align);
break;
}
len = dmatest_random() % test_buf_size + 1;
len = (len >> align) << align;
if (!len)
len = 1 << align;
src_off = dmatest_random() % (test_buf_size - len + 1);
dst_off = dmatest_random() % (test_buf_size - len + 1);
src_off = (src_off >> align) << align;
dst_off = (dst_off >> align) << align;
dmatest_init_srcs(thread->srcs, src_off, len);
dmatest_init_dsts(thread->dsts, dst_off, len);
for (i = 0; i < src_cnt; i++) {
u8 *buf = thread->srcs[i] + src_off;
dma_srcs[i] = dma_map_single(dev->dev, buf, len,
DMA_TO_DEVICE);
}
/* map with DMA_BIDIRECTIONAL to force writeback/invalidate */
for (i = 0; i < dst_cnt; i++) {
dma_dsts[i] = dma_map_single(dev->dev, thread->dsts[i],
test_buf_size,
DMA_BIDIRECTIONAL);
}
if (thread->type == DMA_MEMCPY)
tx = dev->device_prep_dma_memcpy(chan,
dma_dsts[0] + dst_off,
dma_srcs[0], len,
flags);
else if (thread->type == DMA_XOR)
tx = dev->device_prep_dma_xor(chan,
dma_dsts[0] + dst_off,
dma_srcs, src_cnt,
len, flags);
else if (thread->type == DMA_PQ) {
dma_addr_t dma_pq[dst_cnt];
for (i = 0; i < dst_cnt; i++)
dma_pq[i] = dma_dsts[i] + dst_off;
tx = dev->device_prep_dma_pq(chan, dma_pq, dma_srcs,
src_cnt, pq_coefs,
len, flags);
}
if (!tx) {
for (i = 0; i < src_cnt; i++)
dma_unmap_single(dev->dev, dma_srcs[i], len,
DMA_TO_DEVICE);
for (i = 0; i < dst_cnt; i++)
dma_unmap_single(dev->dev, dma_dsts[i],
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;
}
init_completion(&cmp);
tx->callback = dmatest_callback;
tx->callback_param = &cmp;
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_issue_pending(chan);
tmo = wait_for_completion_timeout(&cmp, tmo);
status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
if (tmo == 0) {
pr_warning("%s: #%u: test timed out\n",
thread_name, total_tests - 1);
failed_tests++;
continue;
} else if (status != DMA_SUCCESS) {
pr_warning("%s: #%u: got completion callback,"
" but status is \'%s\'\n",
thread_name, total_tests - 1,
status == DMA_ERROR ? "error" : "in progress");
failed_tests++;
continue;
}
/* Unmap by myself (see DMA_COMPL_SKIP_DEST_UNMAP above) */
for (i = 0; i < dst_cnt; i++)
dma_unmap_single(dev->dev, dma_dsts[i], test_buf_size,
DMA_BIDIRECTIONAL);
error_count = 0;
pr_debug("%s: verifying source buffer...\n", thread_name);
error_count += dmatest_verify(thread->srcs, 0, src_off,
0, PATTERN_SRC, true);
error_count += dmatest_verify(thread->srcs, src_off,
src_off + len, src_off,
PATTERN_SRC | PATTERN_COPY, true);
error_count += dmatest_verify(thread->srcs, 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->dsts, 0, dst_off,
0, PATTERN_DST, false);
error_count += dmatest_verify(thread->dsts, dst_off,
dst_off + len, src_off,
PATTERN_SRC | PATTERN_COPY, false);
error_count += dmatest_verify(thread->dsts, 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;
for (i = 0; thread->dsts[i]; i++)
kfree(thread->dsts[i]);
err_dstbuf:
kfree(thread->dsts);
err_dsts:
for (i = 0; thread->srcs[i]; i++)
kfree(thread->srcs[i]);
err_srcbuf:
kfree(thread->srcs);
err_srcs:
pr_notice("%s: terminating after %u tests, %u failures (status %d)\n",
thread_name, total_tests, failed_tests, ret);
if (iterations > 0)
while (!kthread_should_stop()) {
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wait_dmatest_exit);
interruptible_sleep_on(&wait_dmatest_exit);
}
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_threads(struct dmatest_chan *dtc, enum dma_transaction_type type)
{
struct dmatest_thread *thread;
struct dma_chan *chan = dtc->chan;
char *op;
unsigned int i;
if (type == DMA_MEMCPY)
op = "copy";
else if (type == DMA_XOR)
op = "xor";
else if (type == DMA_PQ)
op = "pq";
else
return -EINVAL;
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-%s%u\n",
dma_chan_name(chan), op, i);
break;
}
thread->chan = dtc->chan;
thread->type = type;
smp_wmb();
thread->task = kthread_run(dmatest_func, thread, "%s-%s%u",
dma_chan_name(chan), op, i);
if (IS_ERR(thread->task)) {
pr_warning("dmatest: Failed to run thread %s-%s%u\n",
dma_chan_name(chan), op, i);
kfree(thread);
break;
}
/* srcbuf and dstbuf are allocated by the thread itself */
list_add_tail(&thread->node, &dtc->threads);
}
return i;
}
static int dmatest_add_channel(struct dma_chan *chan)
{
struct dmatest_chan *dtc;
struct dma_device *dma_dev = chan->device;
unsigned int thread_count = 0;
int cnt;
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);
if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask)) {
cnt = dmatest_add_threads(dtc, DMA_MEMCPY);
thread_count += cnt > 0 ? cnt : 0;
}
if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
cnt = dmatest_add_threads(dtc, DMA_XOR);
thread_count += cnt > 0 ? cnt : 0;
}
if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
cnt = dmatest_add_threads(dtc, DMA_PQ);
thread_count += cnt > 0 ?: 0;
}
pr_info("dmatest: Started %u threads using %s\n",
thread_count, 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) {
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;
struct dma_chan *chan;
list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
list_del(&dtc->node);
chan = dtc->chan;
dmatest_cleanup_channel(dtc);
pr_debug("dmatest: dropped channel %s\n",
dma_chan_name(chan));
dma_release_channel(chan);
}
}
module_exit(dmatest_exit);
MODULE_AUTHOR("Haavard Skinnemoen <hskinnemoen@atmel.com>");
MODULE_LICENSE("GPL v2");