diff options
Diffstat (limited to 'arch/arc/lib/memset-archs.S')
| -rw-r--r-- | arch/arc/lib/memset-archs.S | 46 |
1 files changed, 34 insertions, 12 deletions
diff --git a/arch/arc/lib/memset-archs.S b/arch/arc/lib/memset-archs.S index 62ad4bcb841a..d0a5cec4cdca 100644 --- a/arch/arc/lib/memset-archs.S +++ b/arch/arc/lib/memset-archs.S @@ -1,22 +1,48 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com) - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. */ #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 reg, off +.endm + +.macro PREFETCHW_INSTR reg, off +.endm + +#endif ENTRY_CFI(memset) - prefetchw [r0] ; Prefetch the write location mov.f 0, r2 ;;; if size is zero jz.d [blink] mov r3, r0 ; don't clobber ret val + PREFETCHW_INSTR r0, 0 ; Prefetch the first write location + ;;; if length < 8 brls.d.nt r2, 8, .Lsmallchunk mov.f lp_count,r2 @@ -48,11 +74,8 @@ 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 +108,6 @@ 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] |