linux-kernel - [PATCH 3/4] gpiolib: cdev: replace locking wrappers for config

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Message-Id: <20231220015106.16732-4-warthog618@gmail.com>
Date: Wed, 20 Dec 2023 09:51:05 +0800
From: Kent Gibson <warthog618@...il.com>
To: linux-kernel@...r.kernel.org,
	linux-gpio@...r.kernel.org,
	brgl@...ev.pl,
	linus.walleij@...aro.org,
	andy@...nel.org
Cc: Kent Gibson <warthog618@...il.com>
Subject: [PATCH 3/4] gpiolib: cdev: replace locking wrappers for config_mutex with guards

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@...il.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