| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * Accelerated CRC32(C) using AArch64 CRC instructions |
| * |
| * Copyright (C) 2016 - 2018 Linaro Ltd <ard.biesheuvel@linaro.org> |
| */ |
| |
| #include <linux/linkage.h> |
| #include <asm/alternative.h> |
| #include <asm/assembler.h> |
| |
| .arch armv8-a+crc |
| |
| .macro __crc32, c |
| cmp x2, #16 |
| b.lt 8f // less than 16 bytes |
| |
| and x7, x2, #0x1f |
| and x2, x2, #~0x1f |
| cbz x7, 32f // multiple of 32 bytes |
| |
| and x8, x7, #0xf |
| ldp x3, x4, [x1] |
| add x8, x8, x1 |
| add x1, x1, x7 |
| ldp x5, x6, [x8] |
| CPU_BE( rev x3, x3 ) |
| CPU_BE( rev x4, x4 ) |
| CPU_BE( rev x5, x5 ) |
| CPU_BE( rev x6, x6 ) |
| |
| tst x7, #8 |
| crc32\c\()x w8, w0, x3 |
| csel x3, x3, x4, eq |
| csel w0, w0, w8, eq |
| tst x7, #4 |
| lsr x4, x3, #32 |
| crc32\c\()w w8, w0, w3 |
| csel x3, x3, x4, eq |
| csel w0, w0, w8, eq |
| tst x7, #2 |
| lsr w4, w3, #16 |
| crc32\c\()h w8, w0, w3 |
| csel w3, w3, w4, eq |
| csel w0, w0, w8, eq |
| tst x7, #1 |
| crc32\c\()b w8, w0, w3 |
| csel w0, w0, w8, eq |
| tst x7, #16 |
| crc32\c\()x w8, w0, x5 |
| crc32\c\()x w8, w8, x6 |
| csel w0, w0, w8, eq |
| cbz x2, 0f |
| |
| 32: ldp x3, x4, [x1], #32 |
| sub x2, x2, #32 |
| ldp x5, x6, [x1, #-16] |
| CPU_BE( rev x3, x3 ) |
| CPU_BE( rev x4, x4 ) |
| CPU_BE( rev x5, x5 ) |
| CPU_BE( rev x6, x6 ) |
| crc32\c\()x w0, w0, x3 |
| crc32\c\()x w0, w0, x4 |
| crc32\c\()x w0, w0, x5 |
| crc32\c\()x w0, w0, x6 |
| cbnz x2, 32b |
| 0: ret |
| |
| 8: tbz x2, #3, 4f |
| ldr x3, [x1], #8 |
| CPU_BE( rev x3, x3 ) |
| crc32\c\()x w0, w0, x3 |
| 4: tbz x2, #2, 2f |
| ldr w3, [x1], #4 |
| CPU_BE( rev w3, w3 ) |
| crc32\c\()w w0, w0, w3 |
| 2: tbz x2, #1, 1f |
| ldrh w3, [x1], #2 |
| CPU_BE( rev16 w3, w3 ) |
| crc32\c\()h w0, w0, w3 |
| 1: tbz x2, #0, 0f |
| ldrb w3, [x1] |
| crc32\c\()b w0, w0, w3 |
| 0: ret |
| .endm |
| |
| .align 5 |
| SYM_FUNC_START(crc32_le) |
| alternative_if_not ARM64_HAS_CRC32 |
| b crc32_le_base |
| alternative_else_nop_endif |
| __crc32 |
| SYM_FUNC_END(crc32_le) |
| |
| .align 5 |
| SYM_FUNC_START(__crc32c_le) |
| alternative_if_not ARM64_HAS_CRC32 |
| b __crc32c_le_base |
| alternative_else_nop_endif |
| __crc32 c |
| SYM_FUNC_END(__crc32c_le) |
