#ifndef _ASM_GENERIC_GPIO_H #define _ASM_GENERIC_GPIO_H #include #include #include #include #ifdef CONFIG_GPIOLIB #include #include #include /* Platforms may implement their GPIO interface with library code, * at a small performance cost for non-inlined operations and some * extra memory (for code and for per-GPIO table entries). * * While the GPIO programming interface defines valid GPIO numbers * to be in the range 0..MAX_INT, this library restricts them to the * smaller range 0..ARCH_NR_GPIOS-1. * * ARCH_NR_GPIOS is somewhat arbitrary; it usually reflects the sum of * builtin/SoC GPIOs plus a number of GPIOs on expanders; the latter is * actually an estimate of a board-specific value. */ #ifndef ARCH_NR_GPIOS #if defined(CONFIG_ARCH_NR_GPIO) && CONFIG_ARCH_NR_GPIO > 0 #define ARCH_NR_GPIOS CONFIG_ARCH_NR_GPIO #else #define ARCH_NR_GPIOS 512 #endif #endif /* * "valid" GPIO numbers are nonnegative and may be passed to * setup routines like gpio_request(). only some valid numbers * can successfully be requested and used. * * Invalid GPIO numbers are useful for indicating no-such-GPIO in * platform data and other tables. */ static inline bool gpio_is_valid(int number) { return number >= 0 && number < ARCH_NR_GPIOS; } struct device; struct gpio; struct seq_file; struct module; struct device_node; struct gpio_desc; /* caller holds gpio_lock *OR* gpio is marked as requested */ static inline struct gpio_chip *gpio_to_chip(unsigned gpio) { return gpiod_to_chip(gpio_to_desc(gpio)); } /* Always use the library code for GPIO management calls, * or when sleeping may be involved. */ extern int gpio_request(unsigned gpio, const char *label); extern void gpio_free(unsigned gpio); static inline int gpio_direction_input(unsigned gpio) { return gpiod_direction_input(gpio_to_desc(gpio)); } static inline int gpio_direction_output(unsigned gpio, int value) { return gpiod_direction_output_raw(gpio_to_desc(gpio), value); } static inline int gpio_set_debounce(unsigned gpio, unsigned debounce) { return gpiod_set_debounce(gpio_to_desc(gpio), debounce); } static inline int gpio_get_value_cansleep(unsigned gpio) { return gpiod_get_raw_value_cansleep(gpio_to_desc(gpio)); } static inline void gpio_set_value_cansleep(unsigned gpio, int value) { return gpiod_set_raw_value_cansleep(gpio_to_desc(gpio), value); } /* A platform's code may want to inline the I/O calls when * the GPIO is constant and refers to some always-present controller, * giving direct access to chip registers and tight bitbanging loops. */ static inline int __gpio_get_value(unsigned gpio) { return gpiod_get_raw_value(gpio_to_desc(gpio)); } static inline void __gpio_set_value(unsigned gpio, int value) { return gpiod_set_raw_value(gpio_to_desc(gpio), value); } static inline int __gpio_cansleep(unsigned gpio) { return gpiod_cansleep(gpio_to_desc(gpio)); } static inline int __gpio_to_irq(unsigned gpio) { return gpiod_to_irq(gpio_to_desc(gpio)); } extern int gpio_request_one(unsigned gpio, unsigned long flags, const char *label); extern int gpio_request_array(const struct gpio *array, size_t num); extern void gpio_free_array(const struct gpio *array, size_t num); /* * A sysfs interface can be exported by individual drivers if they want, * but more typically is configured entirely from userspace. */ static inline int gpio_export(unsigned gpio, bool direction_may_change) { return gpiod_export(gpio_to_desc(gpio), direction_may_change); } static inline int gpio_export_link(struct device *dev, const char *name, unsigned gpio) { return gpiod_export_link(dev, name, gpio_to_desc(gpio)); } static inline void gpio_unexport(unsigned gpio) { gpiod_unexport(gpio_to_desc(gpio)); } #else /* !CONFIG_GPIOLIB */ static inline bool gpio_is_valid(int number) { /* only non-negative numbers are valid */ return number >= 0; } /* platforms that don't directly support access to GPIOs through I2C, SPI, * or other blocking infrastructure can use these wrappers. */ static inline int gpio_cansleep(unsigned gpio) { return 0; } static inline int gpio_get_value_cansleep(unsigned gpio) { might_sleep(); return __gpio_get_value(gpio); } static inline void gpio_set_value_cansleep(unsigned gpio, int value) { might_sleep(); __gpio_set_value(gpio, value); } #endif /* !CONFIG_GPIOLIB */ #endif /* _ASM_GENERIC_GPIO_H */ cted'>unified
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-02-01 17:45:02 +0000
committerIngo Molnar <mingo@kernel.org>2017-02-01 21:17:49 +0100
commitc8f325a59cfc718d13a50fbc746ed9b415c25e92 (patch)
treed53fbdac9d0781e39a13b2ac6b2bd258cf3b4140 /include/trace/events/page_isolation.h
parentbf29bddf0417a4783da3b24e8c9e017ac649326f (diff)
efi/fdt: Avoid FDT manipulation after ExitBootServices()
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/trace/events/page_isolation.h')