| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 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) \ |
| 15 | 9: 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 |
| 30 | LEAF(__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 |
| 37 | 1: |
| 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 |
| 50 | 1: |
| 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 |
| 71 | EXPORT_SYMBOL(__strnlen_user_asm) |
| 72 | #endif |
| 73 | |
| 74 | __BUILD_STRNLEN_ASM kernel |
| 75 | EXPORT_SYMBOL(__strnlen_kernel_asm) |
| 76 | |
| 77 | #ifdef CONFIG_EVA |
| 78 | |
| 79 | .set push |
| 80 | .set eva |
| 81 | __BUILD_STRNLEN_ASM user |
| 82 | .set pop |
| 83 | EXPORT_SYMBOL(__strnlen_user_asm) |
| 84 | #endif |