dmatest: replace stored results mechanism, with uniform messages

	Part 2 - When dmatest is built as a module...

After mounting debugfs and loading the module, the /sys/kernel/debug/dmatest

folder with nodes will be created. There are two important files located. First

is the 'run' node that controls run and stop phases of the test, and the second

one, 'results', is used to get the test case results.

folder with a file named 'run' nodes will be created.  'run' controls run and

stop phases of the test.

Note that in this case test will not run on load automatically.

command:

	% ls -1 /sys/class/dma/

After a while you will start to get messages about current status or error like

in the original code.

Once started a message like "dmatest: Started 1 threads using dma0chan0" is

emitted.  After that only test failure messages are reported until the test

stops.

Note that running a new test will not stop any in progress test.

	Part 4 - Gathering the test results

The module provides a storage for the test results in the memory. The gathered

data could be used after test is done.

Test results are printed to the kernel log buffer with the format:

The special file 'results' in the debugfs represents gathered data of the in

progress test. The messages collected are printed to the kernel log as well.

"dmatest: result <channel>: <test id>: '<error msg>' with src_off=<val> dst_off=<val> len=<val> (<err code>)"

Example of output:

	% cat /sys/kernel/debug/dmatest/results

	dma0chan0-copy0: #1: No errors with src_off=0x7bf dst_off=0x8ad len=0x3fea (0)

	% dmesg | tail -n 1

	dmatest: result dma0chan0-copy0: #1: No errors with src_off=0x7bf dst_off=0x8ad len=0x3fea (0)

The message format is unified across the different types of errors. A number in

the parens represents additional information, e.g. error code, error counter,

or status.

or status.  A test thread also emits a summary line at completion listing the

number of tests executed, number that failed, and a result code.

Note that the buffer comparison is done in the old way, i.e. data is not

collected and just printed out.

The details of a data miscompare error are also emitted, but do not follow the

above format.

 * 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>

#define PATTERN_OVERWRITE	0x20

#define PATTERN_COUNT_MASK	0x1f

enum dmatest_error_type {

	DMATEST_ET_OK,

	DMATEST_ET_MAP_SRC,

	DMATEST_ET_MAP_DST,

	DMATEST_ET_PREP,

	DMATEST_ET_SUBMIT,

	DMATEST_ET_TIMEOUT,

	DMATEST_ET_DMA_ERROR,

	DMATEST_ET_DMA_IN_PROGRESS,

	DMATEST_ET_VERIFY,

};

struct dmatest_thread_result {

	struct list_head	node;

	unsigned int		n;

	unsigned int		src_off;

	unsigned int		dst_off;

	unsigned int		len;

	enum dmatest_error_type	type;

	union {

		unsigned long		data;

		dma_cookie_t		cookie;

		enum dma_status		status;

		int			error;

	};

};

struct dmatest_result {

	struct list_head	node;

	char			*name;

	struct list_head	results;

};

struct dmatest_info;

struct dmatest_thread {

	/* debugfs related stuff */

	struct dentry		*root;

	/* Test results */

	struct list_head	results;

	struct mutex		results_lock;

};

static struct dmatest_info test_info;

	return val % 2 ? val : val - 1;

}

static char *thread_result_get(const char *name,

		struct dmatest_thread_result *tr)

static void result(const char *err, unsigned int n, unsigned int src_off,

		   unsigned int dst_off, unsigned int len, unsigned long data)

{

	static const char * const messages[] = {

		[DMATEST_ET_OK]			= "No errors",

		[DMATEST_ET_MAP_SRC]		= "src mapping error",

		[DMATEST_ET_MAP_DST]		= "dst mapping error",

		[DMATEST_ET_PREP]		= "prep error",

		[DMATEST_ET_SUBMIT]		= "submit error",

		[DMATEST_ET_TIMEOUT]		= "test timed out",

		[DMATEST_ET_DMA_ERROR]		=

			"got completion callback (DMA_ERROR)",

		[DMATEST_ET_DMA_IN_PROGRESS]	=

			"got completion callback (DMA_IN_PROGRESS)",

		[DMATEST_ET_VERIFY]		= "errors",

	};

	static char buf[512];

	snprintf(buf, sizeof(buf) - 1,

		 "%s: #%u: %s with src_off=0x%x ""dst_off=0x%x len=0x%x (%lu)",

		 name, tr->n, messages[tr->type], tr->src_off, tr->dst_off,

		 tr->len, tr->data);

	return buf;

	pr_info("%s: result #%u: '%s' with src_off=0x%x ""dst_off=0x%x len=0x%x (%lu)",

		current->comm, n, err, src_off, dst_off, len, data);

}

static int thread_result_add(struct dmatest_info *info,

		struct dmatest_result *r, enum dmatest_error_type type,

		unsigned int n, unsigned int src_off, unsigned int dst_off,

		unsigned int len, unsigned long 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)

{

	struct dmatest_thread_result *tr;

	tr = kzalloc(sizeof(*tr), GFP_KERNEL);

	if (!tr)

		return -ENOMEM;

	tr->type = type;

	tr->n = n;

	tr->src_off = src_off;

	tr->dst_off = dst_off;

	tr->len = len;

	tr->data = data;

	mutex_lock(&info->results_lock);

	list_add_tail(&tr->node, &r->results);

	mutex_unlock(&info->results_lock);

	if (tr->type == DMATEST_ET_OK)

		pr_debug("%s\n", thread_result_get(r->name, tr));

	else

		pr_warn("%s\n", thread_result_get(r->name, tr));

	return 0;

}

static void result_free(struct dmatest_info *info, const char *name)

{

	struct dmatest_result *r, *_r;

	mutex_lock(&info->results_lock);

	list_for_each_entry_safe(r, _r, &info->results, node) {

		struct dmatest_thread_result *tr, *_tr;

		if (name && strcmp(r->name, name))

			continue;

		list_for_each_entry_safe(tr, _tr, &r->results, node) {

			list_del(&tr->node);

			kfree(tr);

		}

		kfree(r->name);

		list_del(&r->node);

		kfree(r);

	}

	mutex_unlock(&info->results_lock);

}

static struct dmatest_result *result_init(struct dmatest_info *info,

		const char *name)

{

	struct dmatest_result *r;

	r = kzalloc(sizeof(*r), GFP_KERNEL);

	if (r) {

		r->name = kstrdup(name, GFP_KERNEL);

		INIT_LIST_HEAD(&r->results);

		mutex_lock(&info->results_lock);

		list_add_tail(&r->node, &info->results);

		mutex_unlock(&info->results_lock);

	}

	return r;

	pr_debug("%s: result #%u: '%s' with src_off=0x%x ""dst_off=0x%x len=0x%x (%lu)",

		 current->comm, n, err, src_off, dst_off, len, data);

}

/*

	struct dmatest_params	*params;

	struct dma_chan		*chan;

	struct dma_device	*dev;

	const char		*thread_name;

	unsigned int		src_off, dst_off, len;

	unsigned int		error_count;

	unsigned int		failed_tests = 0;

	int			src_cnt;

	int			dst_cnt;

	int			i;

	struct dmatest_result	*result;

	thread_name = current->comm;

	set_freezable();

	ret = -ENOMEM;

	} else

		goto err_thread_type;

	result = result_init(info, thread_name);

	if (!result)

		goto err_srcs;

	thread->srcs = kcalloc(src_cnt+1, sizeof(u8 *), GFP_KERNEL);

	if (!thread->srcs)

		goto err_srcs;

			ret = dma_mapping_error(dev->dev, dma_srcs[i]);

			if (ret) {

				unmap_src(dev->dev, dma_srcs, len, i);

				thread_result_add(info, result,

						  DMATEST_ET_MAP_SRC,

						  total_tests, src_off, dst_off,

						  len, ret);

				result("src mapping error", total_tests,

				       src_off, dst_off, len, ret);

				failed_tests++;

				continue;

			}

				unmap_src(dev->dev, dma_srcs, len, src_cnt);

				unmap_dst(dev->dev, dma_dsts, params->buf_size,

					  i);

				thread_result_add(info, result,

						  DMATEST_ET_MAP_DST,

						  total_tests, src_off, dst_off,

						  len, ret);

				result("dst mapping error", total_tests,

				       src_off, dst_off, len, ret);

				failed_tests++;

				continue;

			}

			unmap_src(dev->dev, dma_srcs, len, src_cnt);

			unmap_dst(dev->dev, dma_dsts, params->buf_size,

				  dst_cnt);

			thread_result_add(info, result, DMATEST_ET_PREP,

					  total_tests, src_off, dst_off,

					  len, 0);

			result("prep error", total_tests, src_off,

			       dst_off, len, ret);

			msleep(100);

			failed_tests++;

			continue;

		cookie = tx->tx_submit(tx);

		if (dma_submit_error(cookie)) {

			thread_result_add(info, result, DMATEST_ET_SUBMIT,

					  total_tests, src_off, dst_off,

					  len, cookie);

			result("submit error", total_tests, src_off,

			       dst_off, len, ret);

			msleep(100);

			failed_tests++;

			continue;

			 * free it this time?" dancing.  For now, just

			 * leave it dangling.

			 */

			thread_result_add(info, result, DMATEST_ET_TIMEOUT,

					  total_tests, src_off, dst_off,

			result("test timed out", total_tests, src_off, dst_off,

			       len, 0);

			failed_tests++;

			continue;

		} else if (status != DMA_SUCCESS) {

			enum dmatest_error_type type = (status == DMA_ERROR) ?

				DMATEST_ET_DMA_ERROR : DMATEST_ET_DMA_IN_PROGRESS;

			thread_result_add(info, result, type,

					  total_tests, src_off, dst_off,

					  len, status);

			result(status == DMA_ERROR ?

			       "completion error status" :

			       "completion busy status", total_tests, src_off,

			       dst_off, len, ret);

			failed_tests++;

			continue;

		}

		error_count = 0;

		pr_debug("%s: verifying source buffer...\n", thread_name);

		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,

				params->buf_size, src_off + len,

				PATTERN_SRC, true);

		pr_debug("%s: verifying dest buffer...\n",

				thread->task->comm);

		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,

				PATTERN_DST, false);

		if (error_count) {

			thread_result_add(info, result, DMATEST_ET_VERIFY,

					  total_tests, src_off, dst_off,

			result("data error", total_tests, src_off, dst_off,

			       len, error_count);

			failed_tests++;

		} else {

			thread_result_add(info, result, DMATEST_ET_OK,

					  total_tests, src_off, dst_off,

			dbg_result("test passed", total_tests, src_off, dst_off,

				   len, 0);

		}

	}

err_srcs:

	kfree(pq_coefs);

err_thread_type:

	pr_notice("%s: terminating after %u tests, %u failures (status %d)\n",

			thread_name, total_tests, failed_tests, ret);

	pr_info("%s: terminating after %u tests, %u failures (status %d)\n",

		current->comm, total_tests, failed_tests, ret);

	/* terminate all transfers on specified channels */

	if (ret)

	if (run == false)

		return 0;

	/* Clear results from previous run */

	result_free(info, NULL);

	/* Copy test parameters */

	params->buf_size = test_buf_size;

	strlcpy(params->channel, strim(test_channel), sizeof(params->channel));

	.llseek	= default_llseek,

};

static int dtf_results_show(struct seq_file *sf, void *data)

{

	struct dmatest_info *info = sf->private;

	struct dmatest_result *result;

	struct dmatest_thread_result *tr;

	mutex_lock(&info->results_lock);

	list_for_each_entry(result, &info->results, node) {

		list_for_each_entry(tr, &result->results, node)

			seq_printf(sf, "%s\n",

				thread_result_get(result->name, tr));

	}

	mutex_unlock(&info->results_lock);

	return 0;

}

static int dtf_results_open(struct inode *inode, struct file *file)

{

	return single_open(file, dtf_results_show, inode->i_private);

}

static const struct file_operations dtf_results_fops = {

	.open		= dtf_results_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= single_release,

};

static int dmatest_register_dbgfs(struct dmatest_info *info)

{

	struct dentry *d;

	debugfs_create_file("run", S_IWUSR | S_IRUGO, info->root, info,

			    &dtf_run_fops);

	/* Results of test in progress */

	debugfs_create_file("results", S_IRUGO, info->root, info,

			    &dtf_results_fops);

	return 0;

err_root:

	mutex_init(&info->lock);

	INIT_LIST_HEAD(&info->channels);

	mutex_init(&info->results_lock);

	INIT_LIST_HEAD(&info->results);

	ret = dmatest_register_dbgfs(info);

	if (ret)

		return ret;

	debugfs_remove_recursive(info->root);

	stop_threaded_test(info);

	result_free(info, NULL);

}

module_exit(dmatest_exit);