linux-kernel - [PATCH 10/10] gpiolib: remove gpiochip_is

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20231129142411.76863-11-brgl@bgdev.pl>
Date:   Wed, 29 Nov 2023 15:24:11 +0100
From:   Bartosz Golaszewski <brgl@...ev.pl>
To:     Linus Walleij <linus.walleij@...aro.org>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc:     linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: [PATCH 10/10] gpiolib: remove gpiochip_is_requested()

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

We have no external users of gpiochip_is_requested(). Let's remove it
and replace its internal calls with direct testing of the REQUESTED flag.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
---
 drivers/gpio/gpiolib.c      | 46 ++++++++++---------------------------
 include/linux/gpio/driver.h |  1 -
 2 files changed, 12 insertions(+), 35 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 8e932e6a6a8d..3070a4f7bbb1 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1085,7 +1085,7 @@ void gpiochip_remove(struct gpio_chip *gc)
 
 	spin_lock_irqsave(&gpio_lock, flags);
 	for (i = 0; i < gdev->ngpio; i++) {
-		if (gpiochip_is_requested(gc, i))
+		if (test_bit(FLAG_REQUESTED, &gdev->descs[i].flags))
 			break;
 	}
 	spin_unlock_irqrestore(&gpio_lock, flags);
@@ -2373,33 +2373,6 @@ void gpiod_free(struct gpio_desc *desc)
 	gpio_device_put(desc->gdev);
 }
 
-/**
- * gpiochip_is_requested - return string iff signal was requested
- * @gc: controller managing the signal
- * @offset: of signal within controller's 0..(ngpio - 1) range
- *
- * Returns NULL if the GPIO is not currently requested, else a string.
- * The string returned is the label passed to gpio_request(); if none has been
- * passed it is a meaningless, non-NULL constant.
- *
- * This function is for use by GPIO controller drivers.  The label can
- * help with diagnostics, and knowing that the signal is used as a GPIO
- * can help avoid accidentally multiplexing it to another controller.
- */
-const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset)
-{
-	struct gpio_desc *desc;
-
-	desc = gpiochip_get_desc(gc, offset);
-	if (IS_ERR(desc))
-		return NULL;
-
-	if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
-		return NULL;
-	return desc->label;
-}
-EXPORT_SYMBOL_GPL(gpiochip_is_requested);
-
 /**
  * gpiochip_dup_line_label - Get a copy of the consumer label.
  * @gc: GPIO chip controlling this line.
@@ -2414,16 +2387,21 @@ EXPORT_SYMBOL_GPL(gpiochip_is_requested);
  */
 char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)
 {
-	const char *label;
+	struct gpio_desc *desc;
 	char *cpy;
 
-	label = gpiochip_is_requested(gc, offset);
-	if (!label)
+	desc = gpiochip_get_desc(gc, offset);
+	if (IS_ERR(desc))
 		return NULL;
 
-	cpy = kstrdup(label, GFP_KERNEL);
-	if (!cpy)
-		return ERR_PTR(-ENOMEM);
+	scoped_guard(spinlock_irqsave, &gpio_lock) {
+		if (!test_bit(FLAG_REQUESTED, &desc->flags))
+			return NULL;
+
+		cpy = kstrdup(desc->label, GFP_KERNEL);
+		if (!cpy)
+			return ERR_PTR(-ENOMEM);
+	}
 
 	return cpy;
 }
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 6405f6d454af..1679e6fa5469 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -531,7 +531,6 @@ struct gpio_chip {
 #endif /* CONFIG_OF_GPIO */
 };
 
-const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset);
 char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset);
 
 /**
-- 
2.40.1