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gpio: xilinx: Convert gpio_lock to raw spinlock
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irq_chip functions may be called in raw spinlock context. Therefore, we
must also use a raw spinlock for our own internal locking.

This fixes the following lockdep splat:

[    5.349336] =============================
[    5.353349] [ BUG: Invalid wait context ]
[    5.357361] 6.13.0-rc5+ #69 Tainted: G        W
[    5.363031] -----------------------------
[    5.367045] kworker/u17:1/44 is trying to lock:
[    5.371587] ffffff88018b02c0 (&chip->gpio_lock){....}-{3:3}, at: xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.380079] other info that might help us debug this:
[    5.385138] context-{5:5}
[    5.387762] 5 locks held by kworker/u17:1/44:
[    5.392123] #0: ffffff8800014958 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3204)
[    5.402260] #1: ffffffc082fcbdd8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3205)
[    5.411528] #2: ffffff880172c900 (&dev->mutex){....}-{4:4}, at: __device_attach (drivers/base/dd.c:1006)
[    5.419929] #3: ffffff88039c8268 (request_class#2){+.+.}-{4:4}, at: __setup_irq (kernel/irq/internals.h:156 kernel/irq/manage.c:1596)
[    5.428331] #4: ffffff88039c80c8 (lock_class#2){....}-{2:2}, at: __setup_irq (kernel/irq/manage.c:1614)
[    5.436472] stack backtrace:
[    5.439359] CPU: 2 UID: 0 PID: 44 Comm: kworker/u17:1 Tainted: G        W          6.13.0-rc5+ #69
[    5.448690] Tainted: [W]=WARN
[    5.451656] Hardware name: xlnx,zynqmp (DT)
[    5.455845] Workqueue: events_unbound deferred_probe_work_func
[    5.461699] Call trace:
[    5.464147] show_stack+0x18/0x24 C
[    5.467821] dump_stack_lvl (lib/dump_stack.c:123)
[    5.471501] dump_stack (lib/dump_stack.c:130)
[    5.474824] __lock_acquire (kernel/locking/lockdep.c:4828 kernel/locking/lockdep.c:4898 kernel/locking/lockdep.c:5176)
[    5.478758] lock_acquire (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851 kernel/locking/lockdep.c:5814)
[    5.482429] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162)
[    5.486797] xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8))
[    5.490737] irq_enable (kernel/irq/internals.h:236 kernel/irq/chip.c:170 kernel/irq/chip.c:439 kernel/irq/chip.c:432 kernel/irq/chip.c:345)
[    5.494060] __irq_startup (kernel/irq/internals.h:241 kernel/irq/chip.c:180 kernel/irq/chip.c:250)
[    5.497645] irq_startup (kernel/irq/chip.c:270)
[    5.501143] __setup_irq (kernel/irq/manage.c:1807)
[    5.504728] request_threaded_irq (kernel/irq/manage.c:2208)

Fixes: a32c7ca ("gpio: gpio-xilinx: Add interrupt support")
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250110163354.2012654-1-sean.anderson@linux.dev
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
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Sean Anderson authored and Bartosz Golaszewski committed Jan 14, 2025
1 parent 5bc55a3 commit 9860370
Showing 1 changed file with 16 additions and 16 deletions.
32 changes: 16 additions & 16 deletions drivers/gpio/gpio-xilinx.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,7 @@ struct xgpio_instance {
DECLARE_BITMAP(state, 64);
DECLARE_BITMAP(last_irq_read, 64);
DECLARE_BITMAP(dir, 64);
spinlock_t gpio_lock; /* For serializing operations */
raw_spinlock_t gpio_lock; /* For serializing operations */
int irq;
DECLARE_BITMAP(enable, 64);
DECLARE_BITMAP(rising_edge, 64);
Expand Down Expand Up @@ -179,14 +179,14 @@ static void xgpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
struct xgpio_instance *chip = gpiochip_get_data(gc);
int bit = xgpio_to_bit(chip, gpio);

spin_lock_irqsave(&chip->gpio_lock, flags);
raw_spin_lock_irqsave(&chip->gpio_lock, flags);

/* Write to GPIO signal and set its direction to output */
__assign_bit(bit, chip->state, val);

xgpio_write_ch(chip, XGPIO_DATA_OFFSET, bit, chip->state);

spin_unlock_irqrestore(&chip->gpio_lock, flags);
raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
}

/**
Expand All @@ -210,15 +210,15 @@ static void xgpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
bitmap_remap(hw_mask, mask, chip->sw_map, chip->hw_map, 64);
bitmap_remap(hw_bits, bits, chip->sw_map, chip->hw_map, 64);

spin_lock_irqsave(&chip->gpio_lock, flags);
raw_spin_lock_irqsave(&chip->gpio_lock, flags);

bitmap_replace(state, chip->state, hw_bits, hw_mask, 64);

xgpio_write_ch_all(chip, XGPIO_DATA_OFFSET, state);

bitmap_copy(chip->state, state, 64);

spin_unlock_irqrestore(&chip->gpio_lock, flags);
raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
}

/**
Expand All @@ -236,13 +236,13 @@ static int xgpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
struct xgpio_instance *chip = gpiochip_get_data(gc);
int bit = xgpio_to_bit(chip, gpio);

spin_lock_irqsave(&chip->gpio_lock, flags);
raw_spin_lock_irqsave(&chip->gpio_lock, flags);

/* Set the GPIO bit in shadow register and set direction as input */
__set_bit(bit, chip->dir);
xgpio_write_ch(chip, XGPIO_TRI_OFFSET, bit, chip->dir);

spin_unlock_irqrestore(&chip->gpio_lock, flags);
raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);

return 0;
}
Expand All @@ -265,7 +265,7 @@ static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
struct xgpio_instance *chip = gpiochip_get_data(gc);
int bit = xgpio_to_bit(chip, gpio);

spin_lock_irqsave(&chip->gpio_lock, flags);
raw_spin_lock_irqsave(&chip->gpio_lock, flags);

/* Write state of GPIO signal */
__assign_bit(bit, chip->state, val);
Expand All @@ -275,7 +275,7 @@ static int xgpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
__clear_bit(bit, chip->dir);
xgpio_write_ch(chip, XGPIO_TRI_OFFSET, bit, chip->dir);

spin_unlock_irqrestore(&chip->gpio_lock, flags);
raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);

return 0;
}
Expand Down Expand Up @@ -398,7 +398,7 @@ static void xgpio_irq_mask(struct irq_data *irq_data)
int bit = xgpio_to_bit(chip, irq_offset);
u32 mask = BIT(bit / 32), temp;

spin_lock_irqsave(&chip->gpio_lock, flags);
raw_spin_lock_irqsave(&chip->gpio_lock, flags);

__clear_bit(bit, chip->enable);

Expand All @@ -408,7 +408,7 @@ static void xgpio_irq_mask(struct irq_data *irq_data)
temp &= ~mask;
xgpio_writereg(chip->regs + XGPIO_IPIER_OFFSET, temp);
}
spin_unlock_irqrestore(&chip->gpio_lock, flags);
raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);

gpiochip_disable_irq(&chip->gc, irq_offset);
}
Expand All @@ -428,7 +428,7 @@ static void xgpio_irq_unmask(struct irq_data *irq_data)

gpiochip_enable_irq(&chip->gc, irq_offset);

spin_lock_irqsave(&chip->gpio_lock, flags);
raw_spin_lock_irqsave(&chip->gpio_lock, flags);

__set_bit(bit, chip->enable);

Expand All @@ -447,7 +447,7 @@ static void xgpio_irq_unmask(struct irq_data *irq_data)
xgpio_writereg(chip->regs + XGPIO_IPIER_OFFSET, val);
}

spin_unlock_irqrestore(&chip->gpio_lock, flags);
raw_spin_unlock_irqrestore(&chip->gpio_lock, flags);
}

/**
Expand Down Expand Up @@ -512,7 +512,7 @@ static void xgpio_irqhandler(struct irq_desc *desc)

chained_irq_enter(irqchip, desc);

spin_lock(&chip->gpio_lock);
raw_spin_lock(&chip->gpio_lock);

xgpio_read_ch_all(chip, XGPIO_DATA_OFFSET, all);

Expand All @@ -529,7 +529,7 @@ static void xgpio_irqhandler(struct irq_desc *desc)
bitmap_copy(chip->last_irq_read, all, 64);
bitmap_or(all, rising, falling, 64);

spin_unlock(&chip->gpio_lock);
raw_spin_unlock(&chip->gpio_lock);

dev_dbg(gc->parent, "IRQ rising %*pb falling %*pb\n", 64, rising, 64, falling);

Expand Down Expand Up @@ -620,7 +620,7 @@ static int xgpio_probe(struct platform_device *pdev)
bitmap_set(chip->hw_map, 0, width[0]);
bitmap_set(chip->hw_map, 32, width[1]);

spin_lock_init(&chip->gpio_lock);
raw_spin_lock_init(&chip->gpio_lock);

chip->gc.base = -1;
chip->gc.ngpio = bitmap_weight(chip->hw_map, 64);
Expand Down

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