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/export.h> 12#include <asm/regdef.h> 13 14#define EX(insn,reg,addr,handler) \ 159: insn reg, addr; \ 16 .section __ex_table,"a"; \ 17 PTR 9b, handler; \ 18 .previous 19 20/* 21 * Return the size of a string including the ending NUL character up to a 22 * maximum of a1 or 0 in case of error. 23 * 24 * Note: for performance reasons we deliberately accept that a user may 25 * make strlen_user and strnlen_user access the first few KSEG0 26 * bytes. There's nothing secret there. On 64-bit accessing beyond 27 * the maximum is a tad hairier ... 28 */ 29 .macro __BUILD_STRNLEN_ASM func 30LEAF(__strnlen_\func\()_asm) 31 LONG_L v0, TI_ADDR_LIMIT($28) # pointer ok? 32 and v0, a0 33 bnez v0, .Lfault\@ 34 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 .set __strnlen_user_asm, __strnlen_kernel_asm 71EXPORT_SYMBOL(__strnlen_user_asm) 72#endif 73 74__BUILD_STRNLEN_ASM kernel 75EXPORT_SYMBOL(__strnlen_kernel_asm) 76 77#ifdef CONFIG_EVA 78 79 .set push 80 .set eva 81__BUILD_STRNLEN_ASM user 82 .set pop 83EXPORT_SYMBOL(__strnlen_user_asm) 84#endif 85