[PATCH] mmc_test: move files from sysfs to debugfs

From: Andy Shevchenko
Date: Fri Sep 10 2010 - 03:11:06 EST


As proposed by Greg the more logically is to keep files for mmc_test driver
under debugfs.

Additionally this patch brings seq_file API for show() method. It allows to
write unlimited data to the file.

Example of usage:
# mount -t debugfs none /sys/kernel/debug
# modprobe mmc_test
[ 581.395843] mmc_test mmc0:0001: Card claimed for testing.
# echo 25 > /sys/kernel/debug/mmc0/mmc0\:0001/test
[ 604.568542] mmc0: Starting tests of card mmc0:0001...
[ 604.582733] mmc0: Test case 25. Best-case read performance into scattered pages...
[ 604.923553] mmc0: Transfer of 8192 sectors (4096 KiB) took 0.124664314 seconds (33644 kB/s, 32856 KiB/s)
[ 604.933227] mmc0: Result: OK
[ 604.936248] mmc0: Tests completed.
# cat /sys/kernel/debug/mmc0/mmc0\:0001/test
Test 25: 0
1 8192 0.124664314 33644784

Signed-off-by: Andy Shevchenko <ext-andriy.shevchenko@xxxxxxxxx>
---
drivers/mmc/card/mmc_test.c | 138 ++++++++++++++++++++++++++++++++-----------
1 files changed, 103 insertions(+), 35 deletions(-)

diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
index 58d746b..e59bb02 100644
--- a/drivers/mmc/card/mmc_test.c
+++ b/drivers/mmc/card/mmc_test.c
@@ -19,6 +19,10 @@
#include <linux/swap.h> /* For nr_free_buffer_pages() */
#include <linux/list.h>

+#include <linux/debugfs.h>
+#include <asm/uaccess.h>
+#include <linux/seq_file.h>
+
#define RESULT_OK 0
#define RESULT_FAIL 1
#define RESULT_UNSUP_HOST 2
@@ -106,6 +110,18 @@ struct mmc_test_general_result {
};

/**
+ * struct mmc_test_dbgfs_file - debugfs related file.
+ * @link: double-linked list
+ * @card: card under test
+ * @file: file created under debugfs
+ */
+struct mmc_test_dbgfs_file {
+ struct list_head link;
+ struct mmc_card *card;
+ struct dentry *file;
+};
+
+/**
* struct mmc_test_card - test information.
* @card: card under test
* @scratch: transfer buffer
@@ -2037,14 +2053,12 @@ static void mmc_test_free_result(struct mmc_card *card)
mutex_unlock(&mmc_test_lock);
}

-static ssize_t mmc_test_show(struct device *dev,
- struct device_attribute *attr, char *buf)
+static LIST_HEAD(mmc_test_file_test);
+
+static int mtf_test_show(struct seq_file *sf, void *data)
{
- struct mmc_card *card = mmc_dev_to_card(dev);
+ struct mmc_card *card = (struct mmc_card *)sf->private;
struct mmc_test_general_result *gr;
- char *p = buf;
- size_t len = PAGE_SIZE;
- int ret;

mutex_lock(&mmc_test_lock);

@@ -2054,49 +2068,44 @@ static ssize_t mmc_test_show(struct device *dev,
if (gr->card != card)
continue;

- ret = snprintf(p, len, "Test %d: %d\n", gr->testcase + 1,
- gr->result);
- if (ret < 0)
- goto err;
- if (ret >= len) {
- ret = -ENOBUFS;
- goto err;
- }
- p += ret;
- len -= ret;
+ seq_printf(sf, "Test %d: %d\n", gr->testcase + 1, gr->result);

list_for_each_entry(tr, &gr->tr_lst, link) {
- ret = snprintf(p, len, "%u %d %lu.%09lu %u\n",
+ seq_printf(sf, "%u %d %lu.%09lu %u\n",
tr->count, tr->sectors,
(unsigned long)tr->ts.tv_sec,
(unsigned long)tr->ts.tv_nsec,
tr->rate);
- if (ret < 0)
- goto err;
- if (ret >= len) {
- ret = -ENOBUFS;
- goto err;
- }
- p += ret;
- len -= ret;
}
}

- ret = PAGE_SIZE - len;
-err:
mutex_unlock(&mmc_test_lock);

- return ret;
+ return 0;
}

-static ssize_t mmc_test_store(struct device *dev,
- struct device_attribute *attr, const char *buf, size_t count)
+static int mtf_test_open(struct inode *inode, struct file *file)
{
- struct mmc_card *card = mmc_dev_to_card(dev);
+ return single_open(file, mtf_test_show, inode->i_private);
+}
+
+static ssize_t mtf_test_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct seq_file *sf = (struct seq_file *)file->private_data;
+ struct mmc_card *card = (struct mmc_card *)sf->private;
struct mmc_test_card *test;
+ char lbuf[12];
long testcase;

- if (strict_strtol(buf, 10, &testcase))
+ if (count >= sizeof(lbuf))
+ return -EINVAL;
+
+ if (copy_from_user(lbuf, buf, count))
+ return -EFAULT;
+ lbuf[count] = '\0';
+
+ if (strict_strtol(lbuf, 10, &testcase))
return -EINVAL;

test = kzalloc(sizeof(struct mmc_test_card), GFP_KERNEL);
@@ -2135,7 +2144,65 @@ static ssize_t mmc_test_store(struct device *dev,
return count;
}

-static DEVICE_ATTR(test, S_IWUSR | S_IRUGO, mmc_test_show, mmc_test_store);
+static const struct file_operations mmc_test_fops_test = {
+ .open = mtf_test_open,
+ .read = seq_read,
+ .write = mtf_test_write,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static void mmc_test_free_file_test(struct mmc_card *card)
+{
+ struct mmc_test_dbgfs_file *df, *dfs;
+
+ mutex_lock(&mmc_test_lock);
+
+ list_for_each_entry_safe(df, dfs, &mmc_test_file_test, link) {
+ if (card && df->card != card)
+ continue;
+ debugfs_remove(df->file);
+ list_del(&df->link);
+ kfree(df);
+ }
+
+ mutex_unlock(&mmc_test_lock);
+}
+
+static int mmc_test_register_file_test(struct mmc_card *card)
+{
+ struct dentry *file = NULL;
+ struct mmc_test_dbgfs_file *df;
+ int ret = 0;
+
+ mutex_lock(&mmc_test_lock);
+
+ if (card->debugfs_root)
+ file = debugfs_create_file("test", S_IWUSR, card->debugfs_root,
+ card, &mmc_test_fops_test);
+
+ if (IS_ERR_OR_NULL(file)) {
+ ret = -ENODEV;
+ goto err;
+ }
+
+ df = kmalloc(sizeof(struct mmc_test_dbgfs_file), GFP_KERNEL);
+ if (!df) {
+ debugfs_remove(file);
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ df->card = card;
+ df->file = file;
+
+ list_add(&df->link, &mmc_test_file_test);
+
+err:
+ mutex_unlock(&mmc_test_lock);
+
+ return ret;
+}

static int mmc_test_probe(struct mmc_card *card)
{
@@ -2144,7 +2211,7 @@ static int mmc_test_probe(struct mmc_card *card)
if (!mmc_card_mmc(card) && !mmc_card_sd(card))
return -ENODEV;

- ret = device_create_file(&card->dev, &dev_attr_test);
+ ret = mmc_test_register_file_test(card);
if (ret)
return ret;

@@ -2156,7 +2223,7 @@ static int mmc_test_probe(struct mmc_card *card)
static void mmc_test_remove(struct mmc_card *card)
{
mmc_test_free_result(card);
- device_remove_file(&card->dev, &dev_attr_test);
+ mmc_test_free_file_test(card);
}

static struct mmc_driver mmc_driver = {
@@ -2176,6 +2243,7 @@ static void __exit mmc_test_exit(void)
{
/* Clear stalled data if card is still plugged */
mmc_test_free_result(NULL);
+ mmc_test_free_file_test(NULL);

mmc_unregister_driver(&mmc_driver);
}
--
1.6.3.3

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