diff options
Diffstat (limited to 'arch/powerpc/lib/memcmp_64.S')
| -rw-r--r-- | arch/powerpc/lib/memcmp_64.S | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/arch/powerpc/lib/memcmp_64.S b/arch/powerpc/lib/memcmp_64.S index 844d8e774492..142c666d3897 100644 --- a/arch/powerpc/lib/memcmp_64.S +++ b/arch/powerpc/lib/memcmp_64.S @@ -1,14 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Author: Anton Blanchard <anton@au.ibm.com> * Copyright 2015 IBM Corporation. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. */ +#include <linux/export.h> #include <asm/ppc_asm.h> -#include <asm/export.h> #include <asm/ppc-opcode.h> #define off8 r6 @@ -48,7 +44,7 @@ std r5,-STACKFRAMESIZE+STK_REG(R29)(r1); \ std r0,16(r1); \ stdu r1,-STACKFRAMESIZE(r1); \ - bl enter_vmx_ops; \ + bl CFUNC(enter_vmx_ops); \ cmpwi cr1,r3,0; \ ld r0,STACKFRAMESIZE+16(r1); \ ld r3,STK_REG(R31)(r1); \ @@ -64,7 +60,7 @@ std r5,-STACKFRAMESIZE+STK_REG(R29)(r1); \ std r0,16(r1); \ stdu r1,-STACKFRAMESIZE(r1); \ - bl exit_vmx_ops; \ + bl CFUNC(exit_vmx_ops); \ ld r0,STACKFRAMESIZE+16(r1); \ ld r3,STK_REG(R31)(r1); \ ld r4,STK_REG(R30)(r1); \ @@ -215,11 +211,20 @@ _GLOBAL_TOC(memcmp) beq .Lzero .Lcmp_rest_lt8bytes: - /* Here we have only less than 8 bytes to compare with. at least s1 - * Address is aligned with 8 bytes. - * The next double words are load and shift right with appropriate - * bits. + /* + * Here we have less than 8 bytes to compare. At least s1 is aligned to + * 8 bytes, but s2 may not be. We must make sure s2 + 7 doesn't cross a + * page boundary, otherwise we might read past the end of the buffer and + * trigger a page fault. We use 4K as the conservative minimum page + * size. If we detect that case we go to the byte-by-byte loop. + * + * Otherwise the next double word is loaded from s1 and s2, and shifted + * right to compare the appropriate bits. */ + clrldi r6,r4,(64-12) // r6 = r4 & 0xfff + cmpdi r6,0xff8 + bgt .Lshort + subfic r6,r5,8 slwi r6,r6,3 LD rA,0,r3 |