Commit b7adfb60 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski
Browse files

gpio: cdev: update flags at once when reconfiguring from user-space 



Make updating the descriptor flags when reconfiguring from user-space
consistent with the rest of the codebase: read the current state
atomically, update it according to user's instructions and write it back
atomically as well.

Reviewed-by: default avatarKent Gibson <warthog618@gmail.com>
Link: https://lore.kernel.org/r/20241004-gpio-notify-in-kernel-events-v1-3-8ac29e1df4fe@linaro.org


Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent fa17f749

drivers/gpio/gpiolib-cdev.c

+44 −36
Original line number Diff line number Diff line
@@ -143,18 +143,22 @@ static int linehandle_validate_flags(u32 flags) 


static void linehandle_flags_to_desc_flags(u32 lflags, unsigned long *flagsp)

{

	assign_bit(FLAG_ACTIVE_LOW, flagsp,

	unsigned long flags = READ_ONCE(*flagsp);



	assign_bit(FLAG_ACTIVE_LOW, &flags,

		   lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW);

	assign_bit(FLAG_OPEN_DRAIN, flagsp,

	assign_bit(FLAG_OPEN_DRAIN, &flags,

		   lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN);

	assign_bit(FLAG_OPEN_SOURCE, flagsp,

	assign_bit(FLAG_OPEN_SOURCE, &flags,

		   lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE);

	assign_bit(FLAG_PULL_UP, flagsp,

	assign_bit(FLAG_PULL_UP, &flags,

		   lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP);

	assign_bit(FLAG_PULL_DOWN, flagsp,

	assign_bit(FLAG_PULL_DOWN, &flags,

		   lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN);

	assign_bit(FLAG_BIAS_DISABLE, flagsp,

	assign_bit(FLAG_BIAS_DISABLE, &flags,

		   lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE);



	WRITE_ONCE(*flagsp, flags);

}



static long linehandle_set_config(struct linehandle_state *lh,
@@ -1348,38 +1352,42 @@ static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc, 
	return 0;

}



static void gpio_v2_line_config_flags_to_desc_flags(u64 flags,

static void gpio_v2_line_config_flags_to_desc_flags(u64 lflags,

						    unsigned long *flagsp)

{

	assign_bit(FLAG_ACTIVE_LOW, flagsp,

		   flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW);



	if (flags & GPIO_V2_LINE_FLAG_OUTPUT)

		set_bit(FLAG_IS_OUT, flagsp);

	else if (flags & GPIO_V2_LINE_FLAG_INPUT)

		clear_bit(FLAG_IS_OUT, flagsp);



	assign_bit(FLAG_EDGE_RISING, flagsp,

		   flags & GPIO_V2_LINE_FLAG_EDGE_RISING);

	assign_bit(FLAG_EDGE_FALLING, flagsp,

		   flags & GPIO_V2_LINE_FLAG_EDGE_FALLING);



	assign_bit(FLAG_OPEN_DRAIN, flagsp,

		   flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN);

	assign_bit(FLAG_OPEN_SOURCE, flagsp,

		   flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE);



	assign_bit(FLAG_PULL_UP, flagsp,

		   flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP);

	assign_bit(FLAG_PULL_DOWN, flagsp,

		   flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN);

	assign_bit(FLAG_BIAS_DISABLE, flagsp,

		   flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED);



	assign_bit(FLAG_EVENT_CLOCK_REALTIME, flagsp,

		   flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME);

	assign_bit(FLAG_EVENT_CLOCK_HTE, flagsp,

		   flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE);

	unsigned long flags = READ_ONCE(*flagsp);



	assign_bit(FLAG_ACTIVE_LOW, &flags,

		   lflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW);



	if (lflags & GPIO_V2_LINE_FLAG_OUTPUT)

		set_bit(FLAG_IS_OUT, &flags);

	else if (lflags & GPIO_V2_LINE_FLAG_INPUT)

		clear_bit(FLAG_IS_OUT, &flags);



	assign_bit(FLAG_EDGE_RISING, &flags,

		   lflags & GPIO_V2_LINE_FLAG_EDGE_RISING);

	assign_bit(FLAG_EDGE_FALLING, &flags,

		   lflags & GPIO_V2_LINE_FLAG_EDGE_FALLING);



	assign_bit(FLAG_OPEN_DRAIN, &flags,

		   lflags & GPIO_V2_LINE_FLAG_OPEN_DRAIN);

	assign_bit(FLAG_OPEN_SOURCE, &flags,

		   lflags & GPIO_V2_LINE_FLAG_OPEN_SOURCE);



	assign_bit(FLAG_PULL_UP, &flags,

		   lflags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP);

	assign_bit(FLAG_PULL_DOWN, &flags,

		   lflags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN);

	assign_bit(FLAG_BIAS_DISABLE, &flags,

		   lflags & GPIO_V2_LINE_FLAG_BIAS_DISABLED);



	assign_bit(FLAG_EVENT_CLOCK_REALTIME, &flags,

		   lflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME);

	assign_bit(FLAG_EVENT_CLOCK_HTE, &flags,

		   lflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE);



	WRITE_ONCE(*flagsp, flags);

}



static long linereq_get_values(struct linereq *lr, void __user *ip)