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Message-ID: <20260116081036.352286-23-tzungbi@kernel.org>
Date: Fri, 16 Jan 2026 08:10:35 +0000
From: Tzung-Bi Shih <tzungbi@...nel.org>
To: Benson Leung <bleung@...omium.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
"Rafael J . Wysocki" <rafael@...nel.org>,
Danilo Krummrich <dakr@...nel.org>,
Bartosz Golaszewski <brgl@...ev.pl>,
Linus Walleij <linusw@...nel.org>
Cc: Jonathan Corbet <corbet@....net>,
Shuah Khan <shuah@...nel.org>,
linux-doc@...r.kernel.org,
linux-kernel@...r.kernel.org,
chrome-platform@...ts.linux.dev,
linux-kselftest@...r.kernel.org,
tzungbi@...nel.org,
Laurent Pinchart <laurent.pinchart@...asonboard.com>,
Wolfram Sang <wsa+renesas@...g-engineering.com>,
Simona Vetter <simona.vetter@...ll.ch>,
Dan Williams <dan.j.williams@...el.com>,
Jason Gunthorpe <jgg@...dia.com>,
linux-gpio@...r.kernel.org
Subject: [PATCH 22/23] gpiolib: Leverage revocable for other independent lifecycle instances
There are independent lifecycle instances (e.g., other drivers) can save
a raw pointer to the struct gpio_device (e.g., via gpio_device_find())
or struct gpio_desc (e.g., via gpio_to_desc()). In some operations,
they have to access the underlying struct gpio_chip.
Leverage revocable for them so that they don't need to handle the
synchronization by accessing the SRCU explicitly.
Signed-off-by: Tzung-Bi Shih <tzungbi@...nel.org>
---
drivers/gpio/gpiolib-cdev.c | 10 +-
drivers/gpio/gpiolib-sysfs.c | 35 +++--
drivers/gpio/gpiolib.c | 241 ++++++++++++++++++++---------------
drivers/gpio/gpiolib.h | 21 ---
4 files changed, 163 insertions(+), 144 deletions(-)
diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 1a4dde56dc0c..ecb1472b5c8f 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -2252,9 +2252,11 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
u32 debounce_period_us;
unsigned long dflags;
const char *label;
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return;
memset(info, 0, sizeof(*info));
@@ -2288,10 +2290,10 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
test_bit(GPIOD_FLAG_IS_HOGGED, &dflags) ||
test_bit(GPIOD_FLAG_EXPORT, &dflags) ||
test_bit(GPIOD_FLAG_SYSFS, &dflags) ||
- !gpiochip_line_is_valid(guard.gc, info->offset)) {
+ !gpiochip_line_is_valid(gc, info->offset)) {
info->flags |= GPIO_V2_LINE_FLAG_USED;
} else if (!atomic) {
- if (!pinctrl_gpio_can_use_line(guard.gc, info->offset))
+ if (!pinctrl_gpio_can_use_line(gc, info->offset))
info->flags |= GPIO_V2_LINE_FLAG_USED;
}
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index a4427a5cfa85..bc8d4af73cc3 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -215,9 +215,11 @@ static int gpio_sysfs_request_irq(struct gpiod_data *data, unsigned char flags)
struct gpio_desc *desc = data->desc;
unsigned long irq_flags;
int ret;
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
data->irq = gpiod_to_irq(desc);
@@ -244,7 +246,7 @@ static int gpio_sysfs_request_irq(struct gpiod_data *data, unsigned char flags)
* Remove this redundant call (along with the corresponding unlock)
* when those drivers have been fixed.
*/
- ret = gpiochip_lock_as_irq(guard.gc, gpiod_hwgpio(desc));
+ ret = gpiochip_lock_as_irq(gc, gpiod_hwgpio(desc));
if (ret < 0)
goto err_clr_bits;
@@ -258,7 +260,7 @@ static int gpio_sysfs_request_irq(struct gpiod_data *data, unsigned char flags)
return 0;
err_unlock:
- gpiochip_unlock_as_irq(guard.gc, gpiod_hwgpio(desc));
+ gpiochip_unlock_as_irq(gc, gpiod_hwgpio(desc));
err_clr_bits:
clear_bit(GPIOD_FLAG_EDGE_RISING, &desc->flags);
clear_bit(GPIOD_FLAG_EDGE_FALLING, &desc->flags);
@@ -273,14 +275,16 @@ static int gpio_sysfs_request_irq(struct gpiod_data *data, unsigned char flags)
static void gpio_sysfs_free_irq(struct gpiod_data *data)
{
struct gpio_desc *desc = data->desc;
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return;
data->irq_flags = 0;
free_irq(data->irq, data);
- gpiochip_unlock_as_irq(guard.gc, gpiod_hwgpio(desc));
+ gpiochip_unlock_as_irq(gc, gpiod_hwgpio(desc));
clear_bit(GPIOD_FLAG_EDGE_RISING, &desc->flags);
clear_bit(GPIOD_FLAG_EDGE_FALLING, &desc->flags);
}
@@ -473,13 +477,15 @@ static DEVICE_ATTR_RO(ngpio);
static int export_gpio_desc(struct gpio_desc *desc)
{
int offset, ret;
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
offset = gpiod_hwgpio(desc);
- if (!gpiochip_line_is_valid(guard.gc, offset)) {
+ if (!gpiochip_line_is_valid(gc, offset)) {
pr_debug_ratelimited("%s: GPIO %d masked\n", __func__,
gpiod_hwgpio(desc));
return -EINVAL;
@@ -732,6 +738,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
struct gpio_device *gdev;
struct attribute **attrs;
int status;
+ struct gpio_chip *gc;
/* can't export until sysfs is available ... */
if (!class_is_registered(&gpio_class)) {
@@ -744,8 +751,10 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
return -EINVAL;
}
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
if (test_and_set_bit(GPIOD_FLAG_EXPORT, &desc->flags))
@@ -769,7 +778,7 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
desc_data->desc = desc;
mutex_init(&desc_data->mutex);
- if (guard.gc->direction_input && guard.gc->direction_output)
+ if (gc->direction_input && gc->direction_output)
desc_data->direction_can_change = direction_may_change;
else
desc_data->direction_can_change = false;
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index cd18ff42b610..44915c8b6131 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -338,7 +338,11 @@ EXPORT_SYMBOL(gpio_device_get_label);
*/
struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev)
{
- return rcu_dereference_check(gdev->chip, 1);
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ return gc;
}
EXPORT_SYMBOL_GPL(gpio_device_get_chip);
@@ -449,13 +453,16 @@ int gpiod_get_direction(struct gpio_desc *desc)
unsigned long flags;
unsigned int offset;
int ret;
+ struct gpio_chip *gc;
ret = validate_desc(desc, __func__);
if (ret <= 0)
return -EINVAL;
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
offset = gpiod_hwgpio(desc);
@@ -469,7 +476,7 @@ int gpiod_get_direction(struct gpio_desc *desc)
test_bit(GPIOD_FLAG_IS_OUT, &flags))
return 0;
- ret = gpiochip_get_direction(guard.gc, offset);
+ ret = gpiochip_get_direction(gc, offset);
if (ret < 0)
return ret;
@@ -557,9 +564,9 @@ static struct gpio_desc *gpio_name_to_desc(const char * const name)
list_for_each_entry_srcu(gdev, &gpio_devices, list,
srcu_read_lock_held(&gpio_devices_srcu)) {
- guard(srcu)(&gdev->srcu);
+ DEFINE_REVOCABLE(rev, gdev->chip_rp);
- gc = srcu_dereference(gdev->chip, &gdev->srcu);
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
if (!gc)
continue;
@@ -971,9 +978,9 @@ static void gpiochip_setup_devs(void)
list_for_each_entry_srcu(gdev, &gpio_devices, list,
srcu_read_lock_held(&gpio_devices_srcu)) {
- guard(srcu)(&gdev->srcu);
+ DEFINE_REVOCABLE(rev, gdev->chip_rp);
- gc = srcu_dereference(gdev->chip, &gdev->srcu);
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
if (!gc) {
dev_err(&gdev->dev, "Underlying GPIO chip is gone\n");
continue;
@@ -1386,11 +1393,13 @@ struct gpio_device *gpio_device_find(const void *data,
if (!device_is_registered(&gdev->dev))
continue;
- guard(srcu)(&gdev->srcu);
+ DEFINE_REVOCABLE(rev, gdev->chip_rp);
- gc = srcu_dereference(gdev->chip, &gdev->srcu);
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
+ continue;
- if (gc && match(gc, data))
+ if (match(gc, data))
return gpio_device_get(gdev);
}
@@ -2482,31 +2491,33 @@ static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
{
unsigned int offset;
int ret;
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
if (test_and_set_bit(GPIOD_FLAG_REQUESTED, &desc->flags))
return -EBUSY;
offset = gpiod_hwgpio(desc);
- if (!gpiochip_line_is_valid(guard.gc, offset))
+ if (!gpiochip_line_is_valid(gc, offset))
return -EINVAL;
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
*/
- if (guard.gc->request) {
- ret = guard.gc->request(guard.gc, offset);
+ if (gc->request) {
+ ret = gc->request(gc, offset);
if (ret > 0)
ret = -EBADE;
if (ret)
goto out_clear_bit;
}
- if (guard.gc->get_direction)
+ if (gc->get_direction)
gpiod_get_direction(desc);
ret = desc_set_label(desc, label ? : "?");
@@ -2543,16 +2554,21 @@ int gpiod_request(struct gpio_desc *desc, const char *label)
static void gpiod_free_commit(struct gpio_desc *desc)
{
unsigned long flags;
+ struct gpio_chip *gc;
might_sleep();
- CLASS(gpio_chip_guard, guard)(desc);
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
+ return;
flags = READ_ONCE(desc->flags);
- if (guard.gc && test_bit(GPIOD_FLAG_REQUESTED, &flags)) {
- if (guard.gc->free)
- guard.gc->free(guard.gc, gpiod_hwgpio(desc));
+ if (gc && test_bit(GPIOD_FLAG_REQUESTED, &flags)) {
+ if (gc->free)
+ gc->free(gc, gpiod_hwgpio(desc));
clear_bit(GPIOD_FLAG_ACTIVE_LOW, &flags);
clear_bit(GPIOD_FLAG_REQUESTED, &flags);
@@ -2704,15 +2720,17 @@ EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
int gpio_do_set_config(struct gpio_desc *desc, unsigned long config)
{
int ret;
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
- if (!guard.gc->set_config)
+ if (!gc->set_config)
return -ENOTSUPP;
- ret = guard.gc->set_config(guard.gc, gpiod_hwgpio(desc), config);
+ ret = gc->set_config(gc, gpiod_hwgpio(desc), config);
if (ret > 0)
ret = -EBADE;
@@ -2881,9 +2899,11 @@ EXPORT_SYMBOL_GPL(gpiod_direction_input);
int gpiod_direction_input_nonotify(struct gpio_desc *desc)
{
int ret = 0, dir;
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
/*
@@ -2891,7 +2911,7 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc)
* the chip is output-only, but you can't specify .direction_input()
* and not support the .get() operation, that doesn't make sense.
*/
- if (!guard.gc->get && guard.gc->direction_input) {
+ if (!gc->get && gc->direction_input) {
gpiod_warn(desc,
"%s: missing get() but have direction_input()\n",
__func__);
@@ -2904,11 +2924,10 @@ int gpiod_direction_input_nonotify(struct gpio_desc *desc)
* direction (if .get_direction() is supported) else we silently
* assume we are in input mode after this.
*/
- if (guard.gc->direction_input) {
- ret = gpiochip_direction_input(guard.gc,
- gpiod_hwgpio(desc));
- } else if (guard.gc->get_direction) {
- dir = gpiochip_get_direction(guard.gc, gpiod_hwgpio(desc));
+ if (gc->direction_input) {
+ ret = gpiochip_direction_input(gc, gpiod_hwgpio(desc));
+ } else if (gc->get_direction) {
+ dir = gpiochip_get_direction(gc, gpiod_hwgpio(desc));
if (dir < 0)
return dir;
@@ -2948,9 +2967,11 @@ static int gpiochip_set(struct gpio_chip *gc, unsigned int offset, int value)
static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
{
int val = !!value, ret = 0, dir;
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
/*
@@ -2958,21 +2979,19 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
* output-only, but if there is then not even a .set() operation it
* is pretty tricky to drive the output line.
*/
- if (!guard.gc->set && !guard.gc->direction_output) {
+ if (!gc->set && !gc->direction_output) {
gpiod_warn(desc,
"%s: missing set() and direction_output() operations\n",
__func__);
return -EIO;
}
- if (guard.gc->direction_output) {
- ret = gpiochip_direction_output(guard.gc,
- gpiod_hwgpio(desc), val);
+ if (gc->direction_output) {
+ ret = gpiochip_direction_output(gc, gpiod_hwgpio(desc), val);
} else {
/* Check that we are in output mode if we can */
- if (guard.gc->get_direction) {
- dir = gpiochip_get_direction(guard.gc,
- gpiod_hwgpio(desc));
+ if (gc->get_direction) {
+ dir = gpiochip_get_direction(gc, gpiod_hwgpio(desc));
if (dir < 0)
return dir;
@@ -2987,7 +3006,7 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
* If we can't actively set the direction, we are some
* output-only chip, so just drive the output as desired.
*/
- ret = gpiochip_set(guard.gc, gpiod_hwgpio(desc), val);
+ ret = gpiochip_set(gc, gpiod_hwgpio(desc), val);
if (ret)
return ret;
}
@@ -3125,20 +3144,22 @@ int gpiod_direction_output_nonotify(struct gpio_desc *desc, int value)
int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
{
int ret;
+ struct gpio_chip *gc;
VALIDATE_DESC(desc);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
- if (!guard.gc->en_hw_timestamp) {
+ if (!gc->en_hw_timestamp) {
gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
return -ENOTSUPP;
}
- ret = guard.gc->en_hw_timestamp(guard.gc,
- gpiod_hwgpio(desc), flags);
+ ret = gc->en_hw_timestamp(gc, gpiod_hwgpio(desc), flags);
if (ret)
gpiod_warn(desc, "%s: hw ts request failed\n", __func__);
@@ -3158,20 +3179,22 @@ EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
{
int ret;
+ struct gpio_chip *gc;
VALIDATE_DESC(desc);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
- if (!guard.gc->dis_hw_timestamp) {
+ if (!gc->dis_hw_timestamp) {
gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
return -ENOTSUPP;
}
- ret = guard.gc->dis_hw_timestamp(guard.gc, gpiod_hwgpio(desc),
- flags);
+ ret = gc->dis_hw_timestamp(gc, gpiod_hwgpio(desc), flags);
if (ret)
gpiod_warn(desc, "%s: hw ts release failed\n", __func__);
@@ -3328,16 +3351,11 @@ static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *des
static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
{
- struct gpio_device *gdev;
struct gpio_chip *gc;
int value;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- /* FIXME Unable to use gpio_chip_guard due to const desc. */
- gdev = desc->gdev;
-
- guard(srcu)(&gdev->srcu);
-
- gc = srcu_dereference(gdev->chip, &gdev->srcu);
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
if (!gc)
return -ENODEV;
@@ -3378,9 +3396,11 @@ static int gpio_chip_get_multiple(struct gpio_chip *gc,
/* The 'other' chip must be protected with its GPIO device's SRCU. */
static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc)
{
- guard(srcu)(&gdev->srcu);
+ struct gpio_chip *chip;
+ DEFINE_REVOCABLE(rev, gdev->chip_rp);
- return gc == srcu_dereference(gdev->chip, &gdev->srcu);
+ REVOCABLE_TRY_ACCESS_WITH(rev, chip);
+ return chip ? chip == gc : false;
}
int gpiod_get_array_value_complex(bool raw, bool can_sleep,
@@ -3403,9 +3423,9 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep,
if (!can_sleep)
WARN_ON(array_info->gdev->can_sleep);
- guard(srcu)(&array_info->gdev->srcu);
- gc = srcu_dereference(array_info->gdev->chip,
- &array_info->gdev->srcu);
+ DEFINE_REVOCABLE(rev, array_info->gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
if (!gc)
return -ENODEV;
@@ -3430,32 +3450,33 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep,
DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
unsigned long *mask, *bits;
int first, j;
+ DEFINE_REVOCABLE(rev, desc_array[i]->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc_array[i]);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
- if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
+ if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
mask = fastpath_mask;
bits = fastpath_bits;
} else {
gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
- mask = bitmap_alloc(guard.gc->ngpio, flags);
+ mask = bitmap_alloc(gc->ngpio, flags);
if (!mask)
return -ENOMEM;
- bits = bitmap_alloc(guard.gc->ngpio, flags);
+ bits = bitmap_alloc(gc->ngpio, flags);
if (!bits) {
bitmap_free(mask);
return -ENOMEM;
}
}
- bitmap_zero(mask, guard.gc->ngpio);
+ bitmap_zero(mask, gc->ngpio);
if (!can_sleep)
- WARN_ON(guard.gc->can_sleep);
+ WARN_ON(gc->can_sleep);
/* collect all inputs belonging to the same chip */
first = i;
@@ -3470,9 +3491,9 @@ int gpiod_get_array_value_complex(bool raw, bool can_sleep,
i = find_next_zero_bit(array_info->get_mask,
array_size, i);
} while ((i < array_size) &&
- gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
+ gpio_device_chip_cmp(desc_array[i]->gdev, gc));
- ret = gpio_chip_get_multiple(guard.gc, mask, bits);
+ ret = gpio_chip_get_multiple(gc, mask, bits);
if (ret) {
if (mask != fastpath_mask)
bitmap_free(mask);
@@ -3621,15 +3642,17 @@ EXPORT_SYMBOL_GPL(gpiod_get_array_value);
static int gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
{
int ret = 0, offset = gpiod_hwgpio(desc);
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
if (value) {
- ret = gpiochip_direction_input(guard.gc, offset);
+ ret = gpiochip_direction_input(gc, offset);
} else {
- ret = gpiochip_direction_output(guard.gc, offset, 0);
+ ret = gpiochip_direction_output(gc, offset, 0);
if (!ret)
set_bit(GPIOD_FLAG_IS_OUT, &desc->flags);
}
@@ -3650,17 +3673,19 @@ static int gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
static int gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
{
int ret = 0, offset = gpiod_hwgpio(desc);
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
if (value) {
- ret = gpiochip_direction_output(guard.gc, offset, 1);
+ ret = gpiochip_direction_output(gc, offset, 1);
if (!ret)
set_bit(GPIOD_FLAG_IS_OUT, &desc->flags);
} else {
- ret = gpiochip_direction_input(guard.gc, offset);
+ ret = gpiochip_direction_input(gc, offset);
}
trace_gpio_direction(desc_to_gpio(desc), !value, ret);
if (ret < 0)
@@ -3673,15 +3698,19 @@ static int gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
static int gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
{
+ struct gpio_chip *gc;
+
if (unlikely(!test_bit(GPIOD_FLAG_IS_OUT, &desc->flags)))
return -EPERM;
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
trace_gpio_value(desc_to_gpio(desc), 0, value);
- return gpiochip_set(guard.gc, gpiod_hwgpio(desc), value);
+ return gpiochip_set(gc, gpiod_hwgpio(desc), value);
}
/*
@@ -3748,9 +3777,9 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep,
return -EPERM;
}
- guard(srcu)(&array_info->gdev->srcu);
- gc = srcu_dereference(array_info->gdev->chip,
- &array_info->gdev->srcu);
+ DEFINE_REVOCABLE(rev, array_info->gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
if (!gc)
return -ENODEV;
@@ -3775,32 +3804,33 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep,
DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
unsigned long *mask, *bits;
int count = 0;
+ DEFINE_REVOCABLE(rev, desc_array[i]->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc_array[i]);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
- if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
+ if (likely(gc->ngpio <= FASTPATH_NGPIO)) {
mask = fastpath_mask;
bits = fastpath_bits;
} else {
gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
- mask = bitmap_alloc(guard.gc->ngpio, flags);
+ mask = bitmap_alloc(gc->ngpio, flags);
if (!mask)
return -ENOMEM;
- bits = bitmap_alloc(guard.gc->ngpio, flags);
+ bits = bitmap_alloc(gc->ngpio, flags);
if (!bits) {
bitmap_free(mask);
return -ENOMEM;
}
}
- bitmap_zero(mask, guard.gc->ngpio);
+ bitmap_zero(mask, gc->ngpio);
if (!can_sleep)
- WARN_ON(guard.gc->can_sleep);
+ WARN_ON(gc->can_sleep);
do {
struct gpio_desc *desc = desc_array[i];
@@ -3839,10 +3869,10 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep,
i = find_next_zero_bit(array_info->set_mask,
array_size, i);
} while ((i < array_size) &&
- gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
+ gpio_device_chip_cmp(desc_array[i]->gdev, gc));
/* push collected bits to outputs */
if (count != 0) {
- ret = gpiochip_set_multiple(guard.gc, mask, bits);
+ ret = gpiochip_set_multiple(gc, mask, bits);
if (ret)
return ret;
}
@@ -4048,7 +4078,6 @@ EXPORT_SYMBOL_GPL(gpiod_is_shared);
*/
int gpiod_to_irq(const struct gpio_desc *desc)
{
- struct gpio_device *gdev;
struct gpio_chip *gc;
int offset;
int ret;
@@ -4057,10 +4086,9 @@ int gpiod_to_irq(const struct gpio_desc *desc)
if (ret <= 0)
return -EINVAL;
- gdev = desc->gdev;
- /* FIXME Cannot use gpio_chip_guard due to const desc. */
- guard(srcu)(&gdev->srcu);
- gc = srcu_dereference(gdev->chip, &gdev->srcu);
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
+
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
if (!gc)
return -ENODEV;
@@ -5058,9 +5086,11 @@ int gpiod_hog(struct gpio_desc *desc, const char *name,
struct gpio_desc *local_desc;
int hwnum;
int ret;
+ struct gpio_chip *gc;
+ DEFINE_REVOCABLE(rev, desc->gdev->chip_rp);
- CLASS(gpio_chip_guard, guard)(desc);
- if (!guard.gc)
+ REVOCABLE_TRY_ACCESS_WITH(rev, gc);
+ if (!gc)
return -ENODEV;
if (test_and_set_bit(GPIOD_FLAG_IS_HOGGED, &desc->flags))
@@ -5068,8 +5098,7 @@ int gpiod_hog(struct gpio_desc *desc, const char *name,
hwnum = gpiod_hwgpio(desc);
- local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name,
- lflags, dflags);
+ local_desc = gpiochip_request_own_desc(gc, hwnum, name, lflags, dflags);
if (IS_ERR(local_desc)) {
clear_bit(GPIOD_FLAG_IS_HOGGED, &desc->flags);
ret = PTR_ERR(local_desc);
diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h
index e61db3a75e84..00aa354950c9 100644
--- a/drivers/gpio/gpiolib.h
+++ b/drivers/gpio/gpiolib.h
@@ -224,27 +224,6 @@ struct gpio_desc {
#define gpiod_not_found(desc) (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
-struct gpio_chip_guard {
- struct gpio_device *gdev;
- struct gpio_chip *gc;
- int idx;
-};
-
-DEFINE_CLASS(gpio_chip_guard,
- struct gpio_chip_guard,
- srcu_read_unlock(&_T.gdev->srcu, _T.idx),
- ({
- struct gpio_chip_guard _guard;
-
- _guard.gdev = desc->gdev;
- _guard.idx = srcu_read_lock(&_guard.gdev->srcu);
- _guard.gc = srcu_dereference(_guard.gdev->chip,
- &_guard.gdev->srcu);
-
- _guard;
- }),
- struct gpio_desc *desc)
-
int gpiod_request(struct gpio_desc *desc, const char *label);
void gpiod_free(struct gpio_desc *desc);
--
2.52.0.457.g6b5491de43-goog
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