diff options
Diffstat (limited to 'arch/x86/include/asm/io.h')
| -rw-r--r-- | arch/x86/include/asm/io.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 294cd2a40818..4b99ed326b17 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -209,6 +209,23 @@ void memset_io(volatile void __iomem *, int, size_t); #define memcpy_toio memcpy_toio #define memset_io memset_io +#ifdef CONFIG_X86_64 +/* + * Commit 0f07496144c2 ("[PATCH] Add faster __iowrite32_copy routine for + * x86_64") says that circa 2006 rep movsl is noticeably faster than a copy + * loop. + */ +static inline void __iowrite32_copy(void __iomem *to, const void *from, + size_t count) +{ + asm volatile("rep ; movsl" + : "=&c"(count), "=&D"(to), "=&S"(from) + : "0"(count), "1"(to), "2"(from) + : "memory"); +} +#define __iowrite32_copy __iowrite32_copy +#endif + /* * ISA space is 'always mapped' on a typical x86 system, no need to * explicitly ioremap() it. The fact that the ISA IO space is mapped |