linux/arch/arm/include/asm/barrier.h
Will Deacon 3ea128065e ARM: barrier: allow options to be passed to memory barrier instructions
On ARMv7, the memory barrier instructions take an optional `option'
field which can be used to constrain the effects of a memory barrier
based on shareability and access type.

This patch allows the caller to pass these options if required, and
updates the smp_*() barriers to request inner-shareable barriers,
affecting only stores for the _wmb variant. wmb() is also changed to
use the -st version of dsb.

Reported-by: Albin Tonnerre <albin.tonnerre@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-08-12 12:25:44 +01:00

69 lines
2.3 KiB
C

#ifndef __ASM_BARRIER_H
#define __ASM_BARRIER_H
#ifndef __ASSEMBLY__
#include <asm/outercache.h>
#define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t");
#if __LINUX_ARM_ARCH__ >= 7 || \
(__LINUX_ARM_ARCH__ == 6 && defined(CONFIG_CPU_32v6K))
#define sev() __asm__ __volatile__ ("sev" : : : "memory")
#define wfe() __asm__ __volatile__ ("wfe" : : : "memory")
#define wfi() __asm__ __volatile__ ("wfi" : : : "memory")
#endif
#if __LINUX_ARM_ARCH__ >= 7
#define isb(option) __asm__ __volatile__ ("isb " #option : : : "memory")
#define dsb(option) __asm__ __volatile__ ("dsb " #option : : : "memory")
#define dmb(option) __asm__ __volatile__ ("dmb " #option : : : "memory")
#elif defined(CONFIG_CPU_XSC3) || __LINUX_ARM_ARCH__ == 6
#define isb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
: : "r" (0) : "memory")
#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
: : "r" (0) : "memory")
#define dmb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" \
: : "r" (0) : "memory")
#elif defined(CONFIG_CPU_FA526)
#define isb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
: : "r" (0) : "memory")
#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
: : "r" (0) : "memory")
#define dmb(x) __asm__ __volatile__ ("" : : : "memory")
#else
#define isb(x) __asm__ __volatile__ ("" : : : "memory")
#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
: : "r" (0) : "memory")
#define dmb(x) __asm__ __volatile__ ("" : : : "memory")
#endif
#ifdef CONFIG_ARCH_HAS_BARRIERS
#include <mach/barriers.h>
#elif defined(CONFIG_ARM_DMA_MEM_BUFFERABLE) || defined(CONFIG_SMP)
#define mb() do { dsb(); outer_sync(); } while (0)
#define rmb() dsb()
#define wmb() do { dsb(st); outer_sync(); } while (0)
#else
#define mb() barrier()
#define rmb() barrier()
#define wmb() barrier()
#endif
#ifndef CONFIG_SMP
#define smp_mb() barrier()
#define smp_rmb() barrier()
#define smp_wmb() barrier()
#else
#define smp_mb() dmb(ish)
#define smp_rmb() smp_mb()
#define smp_wmb() dmb(ishst)
#endif
#define read_barrier_depends() do { } while(0)
#define smp_read_barrier_depends() do { } while(0)
#define set_mb(var, value) do { var = value; smp_mb(); } while (0)
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_BARRIER_H */