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/*
* 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 (Atmel)");
MODULE_LICENSE("GPL v2");
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