diff options
Diffstat (limited to 'arch/arc/lib')
| -rw-r--r-- | arch/arc/lib/memset-archs.S | 40 |
1 files changed, 32 insertions, 8 deletions
diff --git a/arch/arc/lib/memset-archs.S b/arch/arc/lib/memset-archs.S index 62ad4bcb841a..f230bb7092fd 100644 --- a/arch/arc/lib/memset-archs.S +++ b/arch/arc/lib/memset-archs.S @@ -7,11 +7,39 @@ */ #include <linux/linkage.h> +#include <asm/cache.h> -#undef PREALLOC_NOT_AVAIL +/* + * The memset implementation below is optimized to use prefetchw and prealloc + * instruction in case of CPU with 64B L1 data cache line (L1_CACHE_SHIFT == 6) + * If you want to implement optimized memset for other possible L1 data cache + * line lengths (32B and 128B) you should rewrite code carefully checking + * we don't call any prefetchw/prealloc instruction for L1 cache lines which + * don't belongs to memset area. + */ + +#if L1_CACHE_SHIFT == 6 + +.macro PREALLOC_INSTR reg, off + prealloc [\reg, \off] +.endm + +.macro PREFETCHW_INSTR reg, off + prefetchw [\reg, \off] +.endm + +#else + +.macro PREALLOC_INSTR +.endm + +.macro PREFETCHW_INSTR +.endm + +#endif ENTRY_CFI(memset) - prefetchw [r0] ; Prefetch the write location + PREFETCHW_INSTR r0, 0 ; Prefetch the first write location mov.f 0, r2 ;;; if size is zero jz.d [blink] @@ -48,11 +76,8 @@ ENTRY_CFI(memset) lpnz @.Lset64bytes ;; LOOP START -#ifdef PREALLOC_NOT_AVAIL - prefetchw [r3, 64] ;Prefetch the next write location -#else - prealloc [r3, 64] -#endif + PREALLOC_INSTR r3, 64 ; alloc next line w/o fetching + #ifdef CONFIG_ARC_HAS_LL64 std.ab r4, [r3, 8] std.ab r4, [r3, 8] @@ -85,7 +110,6 @@ ENTRY_CFI(memset) lsr.f lp_count, r2, 5 ;Last remaining max 124 bytes lpnz .Lset32bytes ;; LOOP START - prefetchw [r3, 32] ;Prefetch the next write location #ifdef CONFIG_ARC_HAS_LL64 std.ab r4, [r3, 8] std.ab r4, [r3, 8] |