1 files changed, 255 insertions, 2 deletions

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index c6e5d8331c66..fc31542e7200 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -2,6 +2,7 @@
  * 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
@@ -18,6 +19,10 @@
 #include <linux/random.h>
 #include <linux/slab.h>
 #include <linux/wait.h>
+#include <linux/ctype.h>
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/seq_file.h>
 
 static unsigned int test_buf_size = 16384;
 module_param(test_buf_size, uint, S_IRUGO);
@@ -123,6 +128,7 @@ struct dmatest_params {
 /**
  * struct dmatest_info - test information.
  * @params:		test parameters
+ * @lock:		access protection to the fields of this structure
  */
 struct dmatest_info {
 	/* Test parameters */
@@ -131,6 +137,11 @@ struct dmatest_info {
 	/* Internal state */
 	struct list_head	channels;
 	unsigned int		nr_channels;
+	struct mutex		lock;
+
+	/* debugfs related stuff */
+	struct dentry		*root;
+	struct dmatest_params	dbgfs_params;
 };
 
 static struct dmatest_info test_info;
@@ -718,7 +729,7 @@ static bool filter(struct dma_chan *chan, void *param)
 		return true;
 }
 
-static int run_threaded_test(struct dmatest_info *info)
+static int __run_threaded_test(struct dmatest_info *info)
 {
 	dma_cap_mask_t mask;
 	struct dma_chan *chan;
@@ -744,7 +755,19 @@ static int run_threaded_test(struct dmatest_info *info)
 	return err;
 }
 
-static void stop_threaded_test(struct dmatest_info *info)
+#ifndef MODULE
+static int run_threaded_test(struct dmatest_info *info)
+{
+	int ret;
+
+	mutex_lock(&info->lock);
+	ret = __run_threaded_test(info);
+	mutex_unlock(&info->lock);
+	return ret;
+}
+#endif
+
+static void __stop_threaded_test(struct dmatest_info *info)
 {
 	struct dmatest_chan *dtc, *_dtc;
 	struct dma_chan *chan;
@@ -760,13 +783,234 @@ static void stop_threaded_test(struct dmatest_info *info)
 	info->nr_channels = 0;
 }
 
+static void stop_threaded_test(struct dmatest_info *info)
+{
+	mutex_lock(&info->lock);
+	__stop_threaded_test(info);
+	mutex_unlock(&info->lock);
+}
+
+static int __restart_threaded_test(struct dmatest_info *info, bool run)
+{
+	struct dmatest_params *params = &info->params;
+	int ret;
+
+	/* Stop any running test first */
+	__stop_threaded_test(info);
+
+	if (run == false)
+		return 0;
+
+	/* Copy test parameters */
+	memcpy(params, &info->dbgfs_params, sizeof(*params));
+
+	/* Run test with new parameters */
+	ret = __run_threaded_test(info);
+	if (ret) {
+		__stop_threaded_test(info);
+		pr_err("dmatest: Can't run test\n");
+	}
+
+	return ret;
+}
+
+static ssize_t dtf_write_string(void *to, size_t available, loff_t *ppos,
+		const void __user *from, size_t count)
+{
+	char tmp[20];
+	ssize_t len;
+
+	len = simple_write_to_buffer(tmp, sizeof(tmp) - 1, ppos, from, count);
+	if (len >= 0) {
+		tmp[len] = '\0';
+		strlcpy(to, strim(tmp), available);
+	}
+
+	return len;
+}
+
+static ssize_t dtf_read_channel(struct file *file, char __user *buf,
+		size_t count, loff_t *ppos)
+{
+	struct dmatest_info *info = file->private_data;
+	return simple_read_from_buffer(buf, count, ppos,
+			info->dbgfs_params.channel,
+			strlen(info->dbgfs_params.channel));
+}
+
+static ssize_t dtf_write_channel(struct file *file, const char __user *buf,
+		size_t size, loff_t *ppos)
+{
+	struct dmatest_info *info = file->private_data;
+	return dtf_write_string(info->dbgfs_params.channel,
+				sizeof(info->dbgfs_params.channel),
+				ppos, buf, size);
+}
+
+static const struct file_operations dtf_channel_fops = {
+	.read	= dtf_read_channel,
+	.write	= dtf_write_channel,
+	.open	= simple_open,
+	.llseek	= default_llseek,
+};
+
+static ssize_t dtf_read_device(struct file *file, char __user *buf,
+		size_t count, loff_t *ppos)
+{
+	struct dmatest_info *info = file->private_data;
+	return simple_read_from_buffer(buf, count, ppos,
+			info->dbgfs_params.device,
+			strlen(info->dbgfs_params.device));
+}
+
+static ssize_t dtf_write_device(struct file *file, const char __user *buf,
+		size_t size, loff_t *ppos)
+{
+	struct dmatest_info *info = file->private_data;
+	return dtf_write_string(info->dbgfs_params.device,
+				sizeof(info->dbgfs_params.device),
+				ppos, buf, size);
+}
+
+static const struct file_operations dtf_device_fops = {
+	.read	= dtf_read_device,
+	.write	= dtf_write_device,
+	.open	= simple_open,
+	.llseek	= default_llseek,
+};
+
+static ssize_t dtf_read_run(struct file *file, char __user *user_buf,
+		size_t count, loff_t *ppos)
+{
+	struct dmatest_info *info = file->private_data;
+	char buf[3];
+
+	mutex_lock(&info->lock);
+	if (info->nr_channels)
+		buf[0] = 'Y';
+	else
+		buf[0] = 'N';
+	mutex_unlock(&info->lock);
+	buf[1] = '\n';
+	buf[2] = 0x00;
+	return simple_read_from_buffer(user_buf, count, ppos, buf, 2);
+}
+
+static ssize_t dtf_write_run(struct file *file, const char __user *user_buf,
+		size_t count, loff_t *ppos)
+{
+	struct dmatest_info *info = file->private_data;
+	char buf[16];
+	bool bv;
+	int ret = 0;
+
+	if (copy_from_user(buf, user_buf, min(count, (sizeof(buf) - 1))))
+		return -EFAULT;
+
+	if (strtobool(buf, &bv) == 0) {
+		mutex_lock(&info->lock);
+		ret = __restart_threaded_test(info, bv);
+		mutex_unlock(&info->lock);
+	}
+
+	return ret ? ret : count;
+}
+
+static const struct file_operations dtf_run_fops = {
+	.read	= dtf_read_run,
+	.write	= dtf_write_run,
+	.open	= simple_open,
+	.llseek	= default_llseek,
+};
+
+static int dmatest_register_dbgfs(struct dmatest_info *info)
+{
+	struct dentry *d;
+	struct dmatest_params *params = &info->dbgfs_params;
+	int ret = -ENOMEM;
+
+	d = debugfs_create_dir("dmatest", NULL);
+	if (IS_ERR(d))
+		return PTR_ERR(d);
+	if (!d)
+		goto err_root;
+
+	info->root = d;
+
+	/* Copy initial values */
+	memcpy(params, &info->params, sizeof(*params));
+
+	/* Test parameters */
+
+	d = debugfs_create_u32("test_buf_size", S_IWUSR | S_IRUGO, info->root,
+			       (u32 *)&params->buf_size);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	d = debugfs_create_file("channel", S_IRUGO | S_IWUSR, info->root,
+				info, &dtf_channel_fops);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	d = debugfs_create_file("device", S_IRUGO | S_IWUSR, info->root,
+				info, &dtf_device_fops);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	d = debugfs_create_u32("threads_per_chan", S_IWUSR | S_IRUGO, info->root,
+			       (u32 *)&params->threads_per_chan);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	d = debugfs_create_u32("max_channels", S_IWUSR | S_IRUGO, info->root,
+			       (u32 *)&params->max_channels);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	d = debugfs_create_u32("iterations", S_IWUSR | S_IRUGO, info->root,
+			       (u32 *)&params->iterations);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	d = debugfs_create_u32("xor_sources", S_IWUSR | S_IRUGO, info->root,
+			       (u32 *)&params->xor_sources);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	d = debugfs_create_u32("pq_sources", S_IWUSR | S_IRUGO, info->root,
+			       (u32 *)&params->pq_sources);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	d = debugfs_create_u32("timeout", S_IWUSR | S_IRUGO, info->root,
+			       (u32 *)&params->timeout);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	/* Run or stop threaded test */
+	d = debugfs_create_file("run", S_IWUSR | S_IRUGO, info->root,
+				info, &dtf_run_fops);
+	if (IS_ERR_OR_NULL(d))
+		goto err_node;
+
+	return 0;
+
+err_node:
+	debugfs_remove_recursive(info->root);
+err_root:
+	pr_err("dmatest: Failed to initialize debugfs\n");
+	return ret;
+}
+
 static int __init dmatest_init(void)
 {
 	struct dmatest_info *info = &test_info;
 	struct dmatest_params *params = &info->params;
+	int ret;
 
 	memset(info, 0, sizeof(*info));
 
+	mutex_init(&info->lock);
 	INIT_LIST_HEAD(&info->channels);
 
 	/* Set default parameters */
@@ -780,7 +1024,15 @@ static int __init dmatest_init(void)
 	params->pq_sources = pq_sources;
 	params->timeout = timeout;
 
+	ret = dmatest_register_dbgfs(info);
+	if (ret)
+		return ret;
+
+#ifdef MODULE
+	return 0;
+#else
 	return run_threaded_test(info);
+#endif
 }
 /* when compiled-in wait for drivers to load first */
 late_initcall(dmatest_init);
@@ -789,6 +1041,7 @@ static void __exit dmatest_exit(void)
 {
 	struct dmatest_info *info = &test_info;
 
+	debugfs_remove_recursive(info->root);
 	stop_threaded_test(info);
 }
 module_exit(dmatest_exit);