[18/22] gpio: add the can_sleep flag to struct gpio_device

Message ID	20240130124828.14678-19-brgl@bgdev.pl
State	Superseded
Headers	show Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AA28786AE1 for <linux-gpio@vger.kernel.org>; Tue, 30 Jan 2024 12:48:57 +0000 (UTC) From: Bartosz Golaszewski <brgl@bgdev.pl> To: Linus Walleij <linus.walleij@linaro.org>, Kent Gibson <warthog618@gmail.com>, Alex Elder <elder@linaro.org>, Geert Uytterhoeven <geert+renesas@glider.be>, "Paul E . McKenney" <paulmck@kernel.org>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, Wolfram Sang <wsa@the-dreams.de> Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Subject: [PATCH 18/22] gpio: add the can_sleep flag to struct gpio_device Date: Tue, 30 Jan 2024 13:48:24 +0100 Message-Id: <20240130124828.14678-19-brgl@bgdev.pl> In-Reply-To: <20240130124828.14678-1-brgl@bgdev.pl> References: <20240130124828.14678-1-brgl@bgdev.pl> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	gpio: rework locking and object life-time control \| expand [00/22] gpio: rework locking and object life-time control [01/22] gpio: protect the list of GPIO devices with SRCU [02/22] gpio: of: assign and read the hog pointer atomically [03/22] gpio: remove unused logging helpers [04/22] gpio: provide and use gpiod_get_label() [05/22] gpio: don't set label from irq helpers [06/22] gpio: add SRCU infrastructure to struct gpio_desc [07/22] gpio: protect the descriptor label with SRCU [08/22] gpio: sysfs: use gpio_device_find() to iterate over existing devices [09/22] gpio: remove gpio_lock [10/22] gpio: reinforce desc->flags handling [11/22] gpio: remove unneeded code from gpio_device_get_desc() [12/22] gpio: sysfs: extend the critical section for unregistering sysfs devices [13/22] gpio: sysfs: pass the GPIO device - not chip - to sysfs callbacks [14/22] gpio: cdev: replace gpiochip_get_desc() with gpio_device_get_desc() [15/22] gpio: cdev: don't access gdev->chip if it's not needed [16/22] gpio: reduce the functionality of validate_desc() [17/22] gpio: remove unnecessary checks from gpiod_to_chip() [18/22] gpio: add the can_sleep flag to struct gpio_device [19/22] gpio: add SRCU infrastructure to struct gpio_device [20/22] gpio: protect the pointer to gpio_chip in gpio_device with SRCU [21/22] gpio: remove the RW semaphore from the GPIO device [22/22] gpio: mark unsafe gpio_chip manipulators as deprecated

Message ID

20240130124828.14678-19-brgl@bgdev.pl

State

Superseded

Headers

From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Linus Walleij <linus.walleij@linaro.org>,
	Kent Gibson <warthog618@gmail.com>,
	Alex Elder <elder@linaro.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Wolfram Sang <wsa@the-dreams.de>
Cc: linux-gpio@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Subject: [PATCH 18/22] gpio: add the can_sleep flag to struct gpio_device
Date: Tue, 30 Jan 2024 13:48:24 +0100
Message-Id: <20240130124828.14678-19-brgl@bgdev.pl>
In-Reply-To: <20240130124828.14678-1-brgl@bgdev.pl>
References: <20240130124828.14678-1-brgl@bgdev.pl>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

Series

gpio: rework locking and object life-time control | expand

Commit Message

Bartosz Golaszewski Jan. 30, 2024, 12:48 p.m. UTC

From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Duplicating the can_sleep value in GPIO device will allow us to not
needlessly dereference the chip pointer in several places and reduce the
number of SRCU read-only critical sections.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/gpio/gpiolib.c | 11 ++++++-----
 drivers/gpio/gpiolib.h |  3 +++
 2 files changed, 9 insertions(+), 5 deletions(-)

Comments

Linus Walleij Jan. 31, 2024, 8:17 p.m. UTC | #1

On Tue, Jan 30, 2024 at 1:48 PM Bartosz Golaszewski <brgl@bgdev.pl> wrote:

> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
>
> Duplicating the can_sleep value in GPIO device will allow us to not
> needlessly dereference the chip pointer in several places and reduce the
> number of SRCU read-only critical sections.
>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index e6b9f1c82a7d..9548c9e53197 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -893,6 +893,7 @@  int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
 	}
 
 	gdev->ngpio = gc->ngpio;
+	gdev->can_sleep = gc->can_sleep;
 
 	scoped_guard(mutex, &gpio_devices_lock) {
 		/*
@@ -3063,7 +3064,7 @@  int gpiod_get_raw_value(const struct gpio_desc *desc)
 {
 	VALIDATE_DESC(desc);
 	/* Should be using gpiod_get_raw_value_cansleep() */
-	WARN_ON(desc->gdev->chip->can_sleep);
+	WARN_ON(desc->gdev->can_sleep);
 	return gpiod_get_raw_value_commit(desc);
 }
 EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
@@ -3084,7 +3085,7 @@  int gpiod_get_value(const struct gpio_desc *desc)
 
 	VALIDATE_DESC(desc);
 	/* Should be using gpiod_get_value_cansleep() */
-	WARN_ON(desc->gdev->chip->can_sleep);
+	WARN_ON(desc->gdev->can_sleep);
 
 	value = gpiod_get_raw_value_commit(desc);
 	if (value < 0)
@@ -3357,7 +3358,7 @@  void gpiod_set_raw_value(struct gpio_desc *desc, int value)
 {
 	VALIDATE_DESC_VOID(desc);
 	/* Should be using gpiod_set_raw_value_cansleep() */
-	WARN_ON(desc->gdev->chip->can_sleep);
+	WARN_ON(desc->gdev->can_sleep);
 	gpiod_set_raw_value_commit(desc, value);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
@@ -3398,7 +3399,7 @@  void gpiod_set_value(struct gpio_desc *desc, int value)
 {
 	VALIDATE_DESC_VOID(desc);
 	/* Should be using gpiod_set_value_cansleep() */
-	WARN_ON(desc->gdev->chip->can_sleep);
+	WARN_ON(desc->gdev->can_sleep);
 	gpiod_set_value_nocheck(desc, value);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_value);
@@ -3462,7 +3463,7 @@  EXPORT_SYMBOL_GPL(gpiod_set_array_value);
 int gpiod_cansleep(const struct gpio_desc *desc)
 {
 	VALIDATE_DESC(desc);
-	return desc->gdev->chip->can_sleep;
+	return desc->gdev->can_sleep;
 }
 EXPORT_SYMBOL_GPL(gpiod_cansleep);
 
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index 9b7afe87f1bd..43ff4931e2c3 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -34,6 +34,8 @@ 
  * @descs: array of ngpio descriptors.
  * @ngpio: the number of GPIO lines on this GPIO device, equal to the size
  * of the @descs array.
+ * @can_sleep: indicate whether the GPIO chip driver's callbacks can sleep
+ * implying that they cannot be used from atomic context
  * @base: GPIO base in the DEPRECATED global Linux GPIO numberspace, assigned
  * at device creation time.
  * @label: a descriptive name for the GPIO device, such as the part number
@@ -64,6 +66,7 @@  struct gpio_device {
 	struct gpio_desc	*descs;
 	int			base;
 	u16			ngpio;
+	bool			can_sleep;
 	const char		*label;
 	void			*data;
 	struct list_head        list;

[18/22] gpio: add the can_sleep flag to struct gpio_device

Commit Message

Comments

Patch