[PATCH 3/4] gpiolib: cdev: replace locking wrappers for config_mutex with guards

Kent Gibson
2023-12-20T01:51:56Z

After the adoption of guard(), the locking wrappers that hold the
config_mutex for linereq_set_values() and linereq_set_config() no
longer add value, so combine them into the functions they wrap.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
drivers/gpio/gpiolib-cdev.c | 63 ++++++++++++++-----------------------
1 file changed, 24 insertions(+), 39 deletions(-)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 6fec793f5513..5b07578e3bfa 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -1454,14 +1454,19 @@ static long linereq_get_values(struct linereq *lr, void __user *ip)
return 0;
}

-static long linereq_set_values_unlocked(struct linereq *lr,
- struct gpio_v2_line_values *lv)
+static long linereq_set_values(struct linereq *lr, void __user *ip)
{
DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX);
+ struct gpio_v2_line_values lv;
struct gpio_desc **descs;
unsigned int i, didx, num_set;
int ret;

+ if (copy_from_user(&lv, ip, sizeof(lv)))
+ return -EFAULT;
+
+ guard(mutex)(&lr->config_mutex);
+
/*
* gpiod_set_array_value_complex() requires compacted desc and val
* arrays, rather than the sparse ones in lv.
@@ -1472,12 +1477,12 @@ static long linereq_set_values_unlocked(struct linereq *lr,
bitmap_zero(vals, GPIO_V2_LINES_MAX);
/* scan requested lines to determine the subset to be set */
for (num_set = 0, i = 0; i < lr->num_lines; i++) {
- if (lv->mask & BIT_ULL(i)) {
+ if (lv.mask & BIT_ULL(i)) {
/* setting inputs is not allowed */
if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags))
return -EPERM;
/* add to compacted values */
- if (lv->bits & BIT_ULL(i))
+ if (lv.bits & BIT_ULL(i))
__set_bit(num_set, vals);
num_set++;
/* capture desc for the num_set == 1 case */
@@ -1493,7 +1498,7 @@ static long linereq_set_values_unlocked(struct linereq *lr,
if (!descs)
return -ENOMEM;
for (didx = 0, i = 0; i < lr->num_lines; i++) {
- if (lv->mask & BIT_ULL(i)) {
+ if (lv.mask & BIT_ULL(i)) {
descs[didx] = lr->lines[i].desc;
didx++;
}
@@ -1507,31 +1512,28 @@ static long linereq_set_values_unlocked(struct linereq *lr,
return ret;
}

-static long linereq_set_values(struct linereq *lr, void __user *ip)
-{
- struct gpio_v2_line_values lv;
-
- if (copy_from_user(&lv, ip, sizeof(lv)))
- return -EFAULT;
-
- guard(mutex)(&lr->config_mutex);
-
- return linereq_set_values_unlocked(lr, &lv);
-}
-
-static long linereq_set_config_unlocked(struct linereq *lr,
- struct gpio_v2_line_config *lc)
+static long linereq_set_config(struct linereq *lr, void __user *ip)
{
+ struct gpio_v2_line_config lc;
struct gpio_desc *desc;
struct line *line;
unsigned int i;
u64 flags, edflags;
int ret;

+ if (copy_from_user(&lc, ip, sizeof(lc)))
+ return -EFAULT;
+
+ ret = gpio_v2_line_config_validate(&lc, lr->num_lines);
+ if (ret)
+ return ret;
+
+ guard(mutex)(&lr->config_mutex);
+
for (i = 0; i < lr->num_lines; i++) {
line = &lr->lines[i];
desc = lr->lines[i].desc;
- flags = gpio_v2_line_config_flags(lc, i);
+ flags = gpio_v2_line_config_flags(&lc, i);
gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags);
edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS;
/*
@@ -1539,7 +1541,7 @@ static long linereq_set_config_unlocked(struct linereq *lr,
* or output, else the line will be treated "as is".
*/
if (flags & GPIO_V2_LINE_FLAG_OUTPUT) {
- int val = gpio_v2_line_config_output_value(lc, i);
+ int val = gpio_v2_line_config_output_value(&lc, i);

edge_detector_stop(line);
ret = gpiod_direction_output(desc, val);
@@ -1550,7 +1552,7 @@ static long linereq_set_config_unlocked(struct linereq *lr,
if (ret)
return ret;

- ret = edge_detector_update(line, lc, i, edflags);
+ ret = edge_detector_update(line, &lc, i, edflags);
if (ret)
return ret;
}
@@ -1562,23 +1564,6 @@ static long linereq_set_config_unlocked(struct linereq *lr,
return 0;
}

-static long linereq_set_config(struct linereq *lr, void __user *ip)
-{
- struct gpio_v2_line_config lc;
- int ret;
-
- if (copy_from_user(&lc, ip, sizeof(lc)))
- return -EFAULT;
-
- ret = gpio_v2_line_config_validate(&lc, lr->num_lines);
- if (ret)
- return ret;
-
- guard(mutex)(&lr->config_mutex);
-
- return linereq_set_config_unlocked(lr, &lc);
-}
-
static long linereq_ioctl_unlocked(struct file *file, unsigned int cmd,
unsigned long arg)
{
--
2.39.2