1/* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Copyright (c) 1996, 1998, 1999, 2004 by Ralf Baechle 7 * Copyright (c) 1999 Silicon Graphics, Inc. 8 */ 9#include <asm/asm.h> 10#include <asm/asm-offsets.h> 11#include <asm/regdef.h> 12 13#define EX(insn,reg,addr,handler) \ 149: insn reg, addr; \ 15 .section __ex_table,"a"; \ 16 PTR 9b, handler; \ 17 .previous 18 19/* 20 * Return the size of a string including the ending NUL character up to a 21 * maximum of a1 or 0 in case of error. 22 * 23 * Note: for performance reasons we deliberately accept that a user may 24 * make strlen_user and strnlen_user access the first few KSEG0 25 * bytes. There's nothing secret there. On 64-bit accessing beyond 26 * the maximum is a tad hairier ... 27 */ 28 .macro __BUILD_STRNLEN_ASM func 29LEAF(__strnlen_\func\()_asm) 30 LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok? 31 and v0, a0 32 bnez v0, .Lfault\@ 33 34FEXPORT(__strnlen_\func\()_nocheck_asm) 35 move v0, a0 36 PTR_ADDU a1, a0 # stop pointer 371: 38#ifdef CONFIG_CPU_DADDI_WORKAROUNDS 39 .set noat 40 li AT, 1 41#endif 42 beq v0, a1, 1f # limit reached? 43.ifeqs "\func", "kernel" 44 EX(lb, t0, (v0), .Lfault\@) 45.else 46 EX(lbe, t0, (v0), .Lfault\@) 47.endif 48 .set noreorder 49 bnez t0, 1b 501: 51#ifndef CONFIG_CPU_DADDI_WORKAROUNDS 52 PTR_ADDIU v0, 1 53#else 54 PTR_ADDU v0, AT 55 .set at 56#endif 57 .set reorder 58 PTR_SUBU v0, a0 59 jr ra 60 END(__strnlen_\func\()_asm) 61 62.Lfault\@: 63 move v0, zero 64 jr ra 65 .endm 66 67#ifndef CONFIG_EVA 68 /* Set aliases */ 69 .global __strnlen_user_asm 70 .global __strnlen_user_nocheck_asm 71 .set __strnlen_user_asm, __strnlen_kernel_asm 72 .set __strnlen_user_nocheck_asm, __strnlen_kernel_nocheck_asm 73#endif 74 75__BUILD_STRNLEN_ASM kernel 76 77#ifdef CONFIG_EVA 78 79 .set push 80 .set eva 81__BUILD_STRNLEN_ASM user 82 .set pop 83#endif 84