diff options
Diffstat (limited to 'arch/x86/lib/iomem.c')
| -rw-r--r-- | arch/x86/lib/iomem.c | 33 |
1 files changed, 30 insertions, 3 deletions
diff --git a/arch/x86/lib/iomem.c b/arch/x86/lib/iomem.c index 66894675f3c8..df50451d94ef 100644 --- a/arch/x86/lib/iomem.c +++ b/arch/x86/lib/iomem.c @@ -2,8 +2,11 @@ #include <linux/module.h> #include <linux/io.h> +#define movs(type,to,from) \ + asm volatile("movs" type:"=&D" (to), "=&S" (from):"0" (to), "1" (from):"memory") + /* Originally from i386/string.h */ -static __always_inline void __iomem_memcpy(void *to, const void *from, size_t n) +static __always_inline void rep_movs(void *to, const void *from, size_t n) { unsigned long d0, d1, d2; asm volatile("rep ; movsl\n\t" @@ -21,13 +24,37 @@ static __always_inline void __iomem_memcpy(void *to, const void *from, size_t n) void memcpy_fromio(void *to, const volatile void __iomem *from, size_t n) { - __iomem_memcpy(to, (const void *)from, n); + if (unlikely(!n)) + return; + + /* Align any unaligned source IO */ + if (unlikely(1 & (unsigned long)from)) { + movs("b", to, from); + n--; + } + if (n > 1 && unlikely(2 & (unsigned long)from)) { + movs("w", to, from); + n-=2; + } + rep_movs(to, (const void *)from, n); } EXPORT_SYMBOL(memcpy_fromio); void memcpy_toio(volatile void __iomem *to, const void *from, size_t n) { - __iomem_memcpy((void *)to, (const void *) from, n); + if (unlikely(!n)) + return; + + /* Align any unaligned destination IO */ + if (unlikely(1 & (unsigned long)to)) { + movs("b", to, from); + n--; + } + if (n > 1 && unlikely(2 & (unsigned long)to)) { + movs("w", to, from); + n-=2; + } + rep_movs((void *)to, (const void *) from, n); } EXPORT_SYMBOL(memcpy_toio); |