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 <[email protected]> --- 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
