Initial import

1 files changed, 987 insertions, 0 deletions

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
new file mode 100644
index 000000000..220ee4963
--- /dev/null
+++ b/drivers/dma/dmatest.c
@@ -0,0 +1,987 @@
+/*
+ * DMA Engine test module
+ *
+ * Copyright (C) 2007 Atmel Corporation
+ * Copyright (C) 2013 Intel 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.
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/freezer.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 | S_IWUSR);
+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 | S_IWUSR);
+MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)");
+
+static char test_device[32];
+module_param_string(device, test_device, sizeof(test_device),
+		S_IRUGO | S_IWUSR);
+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 | S_IWUSR);
+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 | S_IWUSR);
+MODULE_PARM_DESC(max_channels,
+		"Maximum number of channels to use (default: all)");
+
+static unsigned int iterations;
+module_param(iterations, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(iterations,
+		"Iterations before stopping test (default: infinite)");
+
+static unsigned int xor_sources = 3;
+module_param(xor_sources, uint, S_IRUGO | S_IWUSR);
+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 | S_IWUSR);
+MODULE_PARM_DESC(pq_sources,
+		"Number of p+q source buffers (default: 3)");
+
+static int timeout = 3000;
+module_param(timeout, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(timeout, "Transfer Timeout in msec (default: 3000), "
+		 "Pass -1 for infinite timeout");
+
+static bool noverify;
+module_param(noverify, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(noverify, "Disable random data setup and verification");
+
+static bool verbose;
+module_param(verbose, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(verbose, "Enable \"success\" result messages (default: off)");
+
+/**
+ * struct dmatest_params - test parameters.
+ * @buf_size:		size of the memcpy test buffer
+ * @channel:		bus ID of the channel to test
+ * @device:		bus ID of the DMA Engine to test
+ * @threads_per_chan:	number of threads to start per channel
+ * @max_channels:	maximum number of channels to use
+ * @iterations:		iterations before stopping test
+ * @xor_sources:	number of xor source buffers
+ * @pq_sources:		number of p+q source buffers
+ * @timeout:		transfer timeout in msec, -1 for infinite timeout
+ */
+struct dmatest_params {
+	unsigned int	buf_size;
+	char		channel[20];
+	char		device[32];
+	unsigned int	threads_per_chan;
+	unsigned int	max_channels;
+	unsigned int	iterations;
+	unsigned int	xor_sources;
+	unsigned int	pq_sources;
+	int		timeout;
+	bool		noverify;
+};
+
+/**
+ * struct dmatest_info - test information.
+ * @params:		test parameters
+ * @lock:		access protection to the fields of this structure
+ */
+static struct dmatest_info {
+	/* Test parameters */
+	struct dmatest_params	params;
+
+	/* Internal state */
+	struct list_head	channels;
+	unsigned int		nr_channels;
+	struct mutex		lock;
+	bool			did_init;
+} test_info = {
+	.channels = LIST_HEAD_INIT(test_info.channels),
+	.lock = __MUTEX_INITIALIZER(test_info.lock),
+};
+
+static int dmatest_run_set(const char *val, const struct kernel_param *kp);
+static int dmatest_run_get(char *val, const struct kernel_param *kp);
+static struct kernel_param_ops run_ops = {
+	.set = dmatest_run_set,
+	.get = dmatest_run_get,
+};
+static bool dmatest_run;
+module_param_cb(run, &run_ops, &dmatest_run, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(run, "Run the test (default: false)");
+
+/* Maximum amount of mismatched bytes in buffer to print */
+#define MAX_ERROR_COUNT		32
+
+/*
+ * 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 dmatest_info	*info;
+	struct task_struct	*task;
+	struct dma_chan		*chan;
+	u8			**srcs;
+	u8			**dsts;
+	enum dma_transaction_type type;
+	bool			done;
+};
+
+struct dmatest_chan {
+	struct list_head	node;
+	struct dma_chan		*chan;
+	struct list_head	threads;
+};
+
+static DECLARE_WAIT_QUEUE_HEAD(thread_wait);
+static bool wait;
+
+static bool is_threaded_test_run(struct dmatest_info *info)
+{
+	struct dmatest_chan *dtc;
+
+	list_for_each_entry(dtc, &info->channels, node) {
+		struct dmatest_thread *thread;
+
+		list_for_each_entry(thread, &dtc->threads, node) {
+			if (!thread->done)
+				return true;
+		}
+	}
+
+	return false;
+}
+
+static int dmatest_wait_get(char *val, const struct kernel_param *kp)
+{
+	struct dmatest_info *info = &test_info;
+	struct dmatest_params *params = &info->params;
+
+	if (params->iterations)
+		wait_event(thread_wait, !is_threaded_test_run(info));
+	wait = true;
+	return param_get_bool(val, kp);
+}
+
+static struct kernel_param_ops wait_ops = {
+	.get = dmatest_wait_get,
+	.set = param_set_bool,
+};
+module_param_cb(wait, &wait_ops, &wait, S_IRUGO);
+MODULE_PARM_DESC(wait, "Wait for tests to complete (default: false)");
+
+static bool dmatest_match_channel(struct dmatest_params *params,
+		struct dma_chan *chan)
+{
+	if (params->channel[0] == '\0')
+		return true;
+	return strcmp(dma_chan_name(chan), params->channel) == 0;
+}
+
+static bool dmatest_match_device(struct dmatest_params *params,
+		struct dma_device *device)
+{
+	if (params->device[0] == '\0')
+		return true;
+	return strcmp(dev_name(device->dev), params->device) == 0;
+}
+
+static unsigned long dmatest_random(void)
+{
+	unsigned long buf;
+
+	prandom_bytes(&buf, sizeof(buf));
+	return buf;
+}
+
+static void dmatest_init_srcs(u8 **bufs, unsigned int start, unsigned int len,
+		unsigned int buf_size)
+{
+	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 < 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 buf_size)
+{
+	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 < 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_warn("%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_warn("%s: dstbuf[0x%x] not copied! Expected %02x, got %02x\n",
+			thread_name, index, expected, actual);
+	else if (diff & PATTERN_SRC)
+		pr_warn("%s: dstbuf[0x%x] was copied! Expected %02x, got %02x\n",
+			thread_name, index, expected, actual);
+	else
+		pr_warn("%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 < MAX_ERROR_COUNT)
+					dmatest_mismatch(actual, pattern, i,
+							 counter, is_srcbuf);
+				error_count++;
+			}
+			counter++;
+		}
+	}
+
+	if (error_count > MAX_ERROR_COUNT)
+		pr_warn("%s: %u errors suppressed\n",
+			current->comm, error_count - MAX_ERROR_COUNT);
+
+	return error_count;
+}
+
+/* poor man's completion - we want to use wait_event_freezable() on it */
+struct dmatest_done {
+	bool			done;
+	wait_queue_head_t	*wait;
+};
+
+static void dmatest_callback(void *arg)
+{
+	struct dmatest_done *done = arg;
+
+	done->done = true;
+	wake_up_all(done->wait);
+}
+
+static unsigned int min_odd(unsigned int x, unsigned int y)
+{
+	unsigned int val = min(x, y);
+
+	return val % 2 ? val : val - 1;
+}
+
+static void result(const char *err, unsigned int n, unsigned int src_off,
+		   unsigned int dst_off, unsigned int len, unsigned long data)
+{
+	pr_info("%s: result #%u: '%s' with src_off=0x%x dst_off=0x%x len=0x%x (%lu)\n",
+		current->comm, n, err, src_off, dst_off, len, data);
+}
+
+static void dbg_result(const char *err, unsigned int n, unsigned int src_off,
+		       unsigned int dst_off, unsigned int len,
+		       unsigned long data)
+{
+	pr_debug("%s: result #%u: '%s' with src_off=0x%x dst_off=0x%x len=0x%x (%lu)\n",
+		 current->comm, n, err, src_off, dst_off, len, data);
+}
+
+#define verbose_result(err, n, src_off, dst_off, len, data) ({	\
+	if (verbose)						\
+		result(err, n, src_off, dst_off, len, data);	\
+	else							\
+		dbg_result(err, n, src_off, dst_off, len, data);\
+})
+
+static unsigned long long dmatest_persec(s64 runtime, unsigned int val)
+{
+	unsigned long long per_sec = 1000000;
+
+	if (runtime <= 0)
+		return 0;
+
+	/* drop precision until runtime is 32-bits */
+	while (runtime > UINT_MAX) {
+		runtime >>= 1;
+		per_sec <<= 1;
+	}
+
+	per_sec *= val;
+	do_div(per_sec, runtime);
+	return per_sec;
+}
+
+static unsigned long long dmatest_KBs(s64 runtime, unsigned long long len)
+{
+	return dmatest_persec(runtime, len >> 10);
+}
+
+/*
+ * 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)
+{
+	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(done_wait);
+	struct dmatest_thread	*thread = data;
+	struct dmatest_done	done = { .wait = &done_wait };
+	struct dmatest_info	*info;
+	struct dmatest_params	*params;
+	struct dma_chan		*chan;
+	struct dma_device	*dev;
+	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 = NULL;
+	int			ret;
+	int			src_cnt;
+	int			dst_cnt;
+	int			i;
+	ktime_t			ktime;
+	s64			runtime = 0;
+	unsigned long long	total_len = 0;
+
+	set_freezable();
+
+	ret = -ENOMEM;
+
+	smp_rmb();
+	info = thread->info;
+	params = &info->params;
+	chan = thread->chan;
+	dev = chan->device;
+	if (thread->type == DMA_MEMCPY)
+		src_cnt = dst_cnt = 1;
+	else if (thread->type == DMA_XOR) {
+		/* force odd to ensure dst = src */
+		src_cnt = min_odd(params->xor_sources | 1, dev->max_xor);
+		dst_cnt = 1;
+	} else if (thread->type == DMA_PQ) {
+		/* force odd to ensure dst = src */
+		src_cnt = min_odd(params->pq_sources | 1, dma_maxpq(dev, 0));
+		dst_cnt = 2;
+
+		pq_coefs = kmalloc(params->pq_sources+1, GFP_KERNEL);
+		if (!pq_coefs)
+			goto err_thread_type;
+
+		for (i = 0; i < src_cnt; i++)
+			pq_coefs[i] = 1;
+	} else
+		goto err_thread_type;
+
+	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(params->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(params->buf_size, GFP_KERNEL);
+		if (!thread->dsts[i])
+			goto err_dstbuf;
+	}
+	thread->dsts[i] = NULL;
+
+	set_user_nice(current, 10);
+
+	/*
+	 * src and dst buffers are freed by ourselves below
+	 */
+	flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
+
+	ktime = ktime_get();
+	while (!kthread_should_stop()
+	       && !(params->iterations && total_tests >= params->iterations)) {
+		struct dma_async_tx_descriptor *tx = NULL;
+		struct dmaengine_unmap_data *um;
+		dma_addr_t srcs[src_cnt];
+		dma_addr_t *dsts;
+		unsigned int src_off, dst_off, len;
+		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 > params->buf_size) {
+			pr_err("%u-byte buffer too small for %d-byte alignment\n",
+			       params->buf_size, 1 << align);
+			break;
+		}
+
+		if (params->noverify)
+			len = params->buf_size;
+		else
+			len = dmatest_random() % params->buf_size + 1;
+
+		len = (len >> align) << align;
+		if (!len)
+			len = 1 << align;
+
+		total_len += len;
+
+		if (params->noverify) {
+			src_off = 0;
+			dst_off = 0;
+		} else {
+			src_off = dmatest_random() % (params->buf_size - len + 1);
+			dst_off = dmatest_random() % (params->buf_size - len + 1);
+
+			src_off = (src_off >> align) << align;
+			dst_off = (dst_off >> align) << align;
+
+			dmatest_init_srcs(thread->srcs, src_off, len,
+					  params->buf_size);
+			dmatest_init_dsts(thread->dsts, dst_off, len,
+					  params->buf_size);
+		}
+
+		um = dmaengine_get_unmap_data(dev->dev, src_cnt+dst_cnt,
+					      GFP_KERNEL);
+		if (!um) {
+			failed_tests++;
+			result("unmap data NULL", total_tests,
+			       src_off, dst_off, len, ret);
+			continue;
+		}
+
+		um->len = params->buf_size;
+		for (i = 0; i < src_cnt; i++) {
+			void *buf = thread->srcs[i];
+			struct page *pg = virt_to_page(buf);
+			unsigned pg_off = (unsigned long) buf & ~PAGE_MASK;
+
+			um->addr[i] = dma_map_page(dev->dev, pg, pg_off,
+						   um->len, DMA_TO_DEVICE);
+			srcs[i] = um->addr[i] + src_off;
+			ret = dma_mapping_error(dev->dev, um->addr[i]);
+			if (ret) {
+				dmaengine_unmap_put(um);
+				result("src mapping error", total_tests,
+				       src_off, dst_off, len, ret);
+				failed_tests++;
+				continue;
+			}
+			um->to_cnt++;
+		}
+		/* map with DMA_BIDIRECTIONAL to force writeback/invalidate */
+		dsts = &um->addr[src_cnt];
+		for (i = 0; i < dst_cnt; i++) {
+			void *buf = thread->dsts[i];
+			struct page *pg = virt_to_page(buf);
+			unsigned pg_off = (unsigned long) buf & ~PAGE_MASK;
+
+			dsts[i] = dma_map_page(dev->dev, pg, pg_off, um->len,
+					       DMA_BIDIRECTIONAL);
+			ret = dma_mapping_error(dev->dev, dsts[i]);
+			if (ret) {
+				dmaengine_unmap_put(um);
+				result("dst mapping error", total_tests,
+				       src_off, dst_off, len, ret);
+				failed_tests++;
+				continue;
+			}
+			um->bidi_cnt++;
+		}
+
+		if (thread->type == DMA_MEMCPY)
+			tx = dev->device_prep_dma_memcpy(chan,
+							 dsts[0] + dst_off,
+							 srcs[0], len, flags);
+		else if (thread->type == DMA_XOR)
+			tx = dev->device_prep_dma_xor(chan,
+						      dsts[0] + dst_off,
+						      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] = dsts[i] + dst_off;
+			tx = dev->device_prep_dma_pq(chan, dma_pq, srcs,
+						     src_cnt, pq_coefs,
+						     len, flags);
+		}
+
+		if (!tx) {
+			dmaengine_unmap_put(um);
+			result("prep error", total_tests, src_off,
+			       dst_off, len, ret);
+			msleep(100);
+			failed_tests++;
+			continue;
+		}
+
+		done.done = false;
+		tx->callback = dmatest_callback;
+		tx->callback_param = &done;
+		cookie = tx->tx_submit(tx);
+
+		if (dma_submit_error(cookie)) {
+			dmaengine_unmap_put(um);
+			result("submit error", total_tests, src_off,
+			       dst_off, len, ret);
+			msleep(100);
+			failed_tests++;
+			continue;
+		}
+		dma_async_issue_pending(chan);
+
+		wait_event_freezable_timeout(done_wait, done.done,
+					     msecs_to_jiffies(params->timeout));
+
+		status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
+
+		if (!done.done) {
+			/*
+			 * We're leaving the timed out dma operation with
+			 * dangling pointer to done_wait.  To make this
+			 * correct, we'll need to allocate wait_done for
+			 * each test iteration and perform "who's gonna
+			 * free it this time?" dancing.  For now, just
+			 * leave it dangling.
+			 */
+			dmaengine_unmap_put(um);
+			result("test timed out", total_tests, src_off, dst_off,
+			       len, 0);
+			failed_tests++;
+			continue;
+		} else if (status != DMA_COMPLETE) {
+			dmaengine_unmap_put(um);
+			result(status == DMA_ERROR ?
+			       "completion error status" :
+			       "completion busy status", total_tests, src_off,
+			       dst_off, len, ret);
+			failed_tests++;
+			continue;
+		}
+
+		dmaengine_unmap_put(um);
+
+		if (params->noverify) {
+			verbose_result("test passed", total_tests, src_off,
+				       dst_off, len, 0);
+			continue;
+		}
+
+		pr_debug("%s: verifying source buffer...\n", current->comm);
+		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,
+				params->buf_size, src_off + len,
+				PATTERN_SRC, true);
+
+		pr_debug("%s: verifying dest buffer...\n", current->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,
+				params->buf_size, dst_off + len,
+				PATTERN_DST, false);
+
+		if (error_count) {
+			result("data error", total_tests, src_off, dst_off,
+			       len, error_count);
+			failed_tests++;
+		} else {
+			verbose_result("test passed", total_tests, src_off,
+				       dst_off, len, 0);
+		}
+	}
+	runtime = ktime_us_delta(ktime_get(), ktime);
+
+	ret = 0;
+err_dstbuf:
+	for (i = 0; thread->dsts[i]; i++)
+		kfree(thread->dsts[i]);
+	kfree(thread->dsts);
+err_dsts:
+err_srcbuf:
+	for (i = 0; thread->srcs[i]; i++)
+		kfree(thread->srcs[i]);
+	kfree(thread->srcs);
+err_srcs:
+	kfree(pq_coefs);
+err_thread_type:
+	pr_info("%s: summary %u tests, %u failures %llu iops %llu KB/s (%d)\n",
+		current->comm, total_tests, failed_tests,
+		dmatest_persec(runtime, total_tests),
+		dmatest_KBs(runtime, total_len), ret);
+
+	/* terminate all transfers on specified channels */
+	if (ret)
+		dmaengine_terminate_all(chan);
+
+	thread->done = true;
+	wake_up(&thread_wait);
+
+	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("thread %s exited with status %d\n",
+			 thread->task->comm, ret);
+		list_del(&thread->node);
+		put_task_struct(thread->task);
+		kfree(thread);
+	}
+
+	/* terminate all transfers on specified channels */
+	dmaengine_terminate_all(dtc->chan);
+
+	kfree(dtc);
+}
+
+static int dmatest_add_threads(struct dmatest_info *info,
+		struct dmatest_chan *dtc, enum dma_transaction_type type)
+{
+	struct dmatest_params *params = &info->params;
+	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 < params->threads_per_chan; i++) {
+		thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);
+		if (!thread) {
+			pr_warn("No memory for %s-%s%u\n",
+				dma_chan_name(chan), op, i);
+			break;
+		}
+		thread->info = info;
+		thread->chan = dtc->chan;
+		thread->type = type;
+		smp_wmb();
+		thread->task = kthread_create(dmatest_func, thread, "%s-%s%u",
+				dma_chan_name(chan), op, i);
+		if (IS_ERR(thread->task)) {
+			pr_warn("Failed to create thread %s-%s%u\n",
+				dma_chan_name(chan), op, i);
+			kfree(thread);
+			break;
+		}
+
+		/* srcbuf and dstbuf are allocated by the thread itself */
+		get_task_struct(thread->task);
+		list_add_tail(&thread->node, &dtc->threads);
+		wake_up_process(thread->task);
+	}
+
+	return i;
+}
+
+static int dmatest_add_channel(struct dmatest_info *info,
+		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_warn("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(info, dtc, DMA_MEMCPY);
+		thread_count += cnt > 0 ? cnt : 0;
+	}
+	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
+		cnt = dmatest_add_threads(info, dtc, DMA_XOR);
+		thread_count += cnt > 0 ? cnt : 0;
+	}
+	if (dma_has_cap(DMA_PQ, dma_dev->cap_mask)) {
+		cnt = dmatest_add_threads(info, dtc, DMA_PQ);
+		thread_count += cnt > 0 ? cnt : 0;
+	}
+
+	pr_info("Started %u threads using %s\n",
+		thread_count, dma_chan_name(chan));
+
+	list_add_tail(&dtc->node, &info->channels);
+	info->nr_channels++;
+
+	return 0;
+}
+
+static bool filter(struct dma_chan *chan, void *param)
+{
+	struct dmatest_params *params = param;
+
+	if (!dmatest_match_channel(params, chan) ||
+	    !dmatest_match_device(params, chan->device))
+		return false;
+	else
+		return true;
+}
+
+static void request_channels(struct dmatest_info *info,
+			     enum dma_transaction_type type)
+{
+	dma_cap_mask_t mask;
+
+	dma_cap_zero(mask);
+	dma_cap_set(type, mask);
+	for (;;) {
+		struct dmatest_params *params = &info->params;
+		struct dma_chan *chan;
+
+		chan = dma_request_channel(mask, filter, params);
+		if (chan) {
+			if (dmatest_add_channel(info, chan)) {
+				dma_release_channel(chan);
+				break; /* add_channel failed, punt */
+			}
+		} else
+			break; /* no more channels available */
+		if (params->max_channels &&
+		    info->nr_channels >= params->max_channels)
+			break; /* we have all we need */
+	}
+}
+
+static void run_threaded_test(struct dmatest_info *info)
+{
+	struct dmatest_params *params = &info->params;
+
+	/* Copy test parameters */
+	params->buf_size = test_buf_size;
+	strlcpy(params->channel, strim(test_channel), sizeof(params->channel));
+	strlcpy(params->device, strim(test_device), sizeof(params->device));
+	params->threads_per_chan = threads_per_chan;
+	params->max_channels = max_channels;
+	params->iterations = iterations;
+	params->xor_sources = xor_sources;
+	params->pq_sources = pq_sources;
+	params->timeout = timeout;
+	params->noverify = noverify;
+
+	request_channels(info, DMA_MEMCPY);
+	request_channels(info, DMA_XOR);
+	request_channels(info, DMA_PQ);
+}
+
+static void stop_threaded_test(struct dmatest_info *info)
+{
+	struct dmatest_chan *dtc, *_dtc;
+	struct dma_chan *chan;
+
+	list_for_each_entry_safe(dtc, _dtc, &info->channels, node) {
+		list_del(&dtc->node);
+		chan = dtc->chan;
+		dmatest_cleanup_channel(dtc);
+		pr_debug("dropped channel %s\n", dma_chan_name(chan));
+		dma_release_channel(chan);
+	}
+
+	info->nr_channels = 0;
+}
+
+static void restart_threaded_test(struct dmatest_info *info, bool run)
+{
+	/* we might be called early to set run=, defer running until all
+	 * parameters have been evaluated
+	 */
+	if (!info->did_init)
+		return;
+
+	/* Stop any running test first */
+	stop_threaded_test(info);
+
+	/* Run test with new parameters */
+	run_threaded_test(info);
+}
+
+static int dmatest_run_get(char *val, const struct kernel_param *kp)
+{
+	struct dmatest_info *info = &test_info;
+
+	mutex_lock(&info->lock);
+	if (is_threaded_test_run(info)) {
+		dmatest_run = true;
+	} else {
+		stop_threaded_test(info);
+		dmatest_run = false;
+	}
+	mutex_unlock(&info->lock);
+
+	return param_get_bool(val, kp);
+}
+
+static int dmatest_run_set(const char *val, const struct kernel_param *kp)
+{
+	struct dmatest_info *info = &test_info;
+	int ret;
+
+	mutex_lock(&info->lock);
+	ret = param_set_bool(val, kp);
+	if (ret) {
+		mutex_unlock(&info->lock);
+		return ret;
+	}
+
+	if (is_threaded_test_run(info))
+		ret = -EBUSY;
+	else if (dmatest_run)
+		restart_threaded_test(info, dmatest_run);
+
+	mutex_unlock(&info->lock);
+
+	return ret;
+}
+
+static int __init dmatest_init(void)
+{
+	struct dmatest_info *info = &test_info;
+	struct dmatest_params *params = &info->params;
+
+	if (dmatest_run) {
+		mutex_lock(&info->lock);
+		run_threaded_test(info);
+		mutex_unlock(&info->lock);
+	}
+
+	if (params->iterations && wait)
+		wait_event(thread_wait, !is_threaded_test_run(info));
+
+	/* module parameters are stable, inittime tests are started,
+	 * let userspace take over 'run' control
+	 */
+	info->did_init = true;
+
+	return 0;
+}
+/* when compiled-in wait for drivers to load first */
+late_initcall(dmatest_init);
+
+static void __exit dmatest_exit(void)
+{
+	struct dmatest_info *info = &test_info;
+
+	mutex_lock(&info->lock);
+	stop_threaded_test(info);
+	mutex_unlock(&info->lock);
+}
+module_exit(dmatest_exit);
+
+MODULE_AUTHOR("Haavard Skinnemoen (Atmel)");
+MODULE_LICENSE("GPL v2");