diff options
author | Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> | 2020-03-30 22:44:43 +0300 |
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committer | Alexey Brodkin <abrodkin@synopsys.com> | 2020-03-31 18:25:16 +0300 |
commit | 7e5702282374138507ab3c08dfc1b28dd9ec2bd7 (patch) | |
tree | d9ff13574d147cf24f029bdff6bf01cad04fbec7 /arch/arc/include | |
parent | 93330d4ce416208fe202e304e5a18166c57ac569 (diff) | |
download | u-boot-7e5702282374138507ab3c08dfc1b28dd9ec2bd7.tar.xz |
ARC: IO: add volatile to accessors
We must use 'volatile' in C-version read/write IO accessors
implementation to avoid merging several reads (writes) into
one read (write), or optimizing them out by compiler.
Fixes commit 07906b3dad15 ("ARC: Switch to generic accessors")
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Diffstat (limited to 'arch/arc/include')
-rw-r--r-- | arch/arc/include/asm/io.h | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/arch/arc/include/asm/io.h b/arch/arc/include/asm/io.h index 70d050590d..1f1ae889f3 100644 --- a/arch/arc/include/asm/io.h +++ b/arch/arc/include/asm/io.h @@ -54,15 +54,21 @@ static inline void sync(void) /* Not yet implemented */ } -#define __arch_getb(a) (*(unsigned char *)(a)) -#define __arch_getw(a) (*(unsigned short *)(a)) -#define __arch_getl(a) (*(unsigned int *)(a)) -#define __arch_getq(a) (*(unsigned long long *)(a)) - -#define __arch_putb(v, a) (*(unsigned char *)(a) = (v)) -#define __arch_putw(v, a) (*(unsigned short *)(a) = (v)) -#define __arch_putl(v, a) (*(unsigned int *)(a) = (v)) -#define __arch_putq(v, a) (*(unsigned long long *)(a) = (v)) +/* + * We must use 'volatile' in C-version read/write IO accessors implementation + * to avoid merging several reads (writes) into one read (write), or optimizing + * them out by compiler. + */ +#define __arch_getb(a) (*(volatile u8 *)(a)) +#define __arch_getw(a) (*(volatile u16 *)(a)) +#define __arch_getl(a) (*(volatile u32 *)(a)) +#define __arch_getq(a) (*(volatile u64 *)(a)) + +#define __arch_putb(v, a) (*(volatile u8 *)(a) = (v)) +#define __arch_putw(v, a) (*(volatile u16 *)(a) = (v)) +#define __arch_putl(v, a) (*(volatile u32 *)(a) = (v)) +#define __arch_putq(v, a) (*(volatile u64 *)(a) = (v)) + #define __raw_writeb(v, a) __arch_putb(v, a) #define __raw_writew(v, a) __arch_putw(v, a) |