1/* SPDX-License-Identifier: GPL-2.0-only */ 2/* 3 * Copyright (c) 2023 Ventana Micro Systems Inc. 4 */ 5 6#include <linux/linkage.h> 7#include <linux/export.h> 8#include <asm/asm.h> 9#include <asm/alternative-macros.h> 10#include <asm/hwcap.h> 11#include <asm/insn-def.h> 12#include <asm/page.h> 13 14#define CBOZ_ALT(order, old, new) \ 15 ALTERNATIVE(old, new, 0, \ 16 ((order) << 16) | RISCV_ISA_EXT_ZICBOZ, \ 17 CONFIG_RISCV_ISA_ZICBOZ) 18 19/* void clear_page(void *page) */ 20SYM_FUNC_START(clear_page) 21 li a2, PAGE_SIZE 22 23 /* 24 * If Zicboz isn't present, or somehow has a block 25 * size larger than 4K, then fallback to memset. 26 */ 27 CBOZ_ALT(12, "j .Lno_zicboz", "nop") 28 29 lw a1, riscv_cboz_block_size 30 add a2, a0, a2 31.Lzero_loop: 32 CBO_ZERO(a0) 33 add a0, a0, a1 34 CBOZ_ALT(11, "bltu a0, a2, .Lzero_loop; ret", "nop; nop") 35 CBO_ZERO(a0) 36 add a0, a0, a1 37 CBOZ_ALT(10, "bltu a0, a2, .Lzero_loop; ret", "nop; nop") 38 CBO_ZERO(a0) 39 add a0, a0, a1 40 CBO_ZERO(a0) 41 add a0, a0, a1 42 CBOZ_ALT(9, "bltu a0, a2, .Lzero_loop; ret", "nop; nop") 43 CBO_ZERO(a0) 44 add a0, a0, a1 45 CBO_ZERO(a0) 46 add a0, a0, a1 47 CBO_ZERO(a0) 48 add a0, a0, a1 49 CBO_ZERO(a0) 50 add a0, a0, a1 51 CBOZ_ALT(8, "bltu a0, a2, .Lzero_loop; ret", "nop; nop") 52 CBO_ZERO(a0) 53 add a0, a0, a1 54 CBO_ZERO(a0) 55 add a0, a0, a1 56 CBO_ZERO(a0) 57 add a0, a0, a1 58 CBO_ZERO(a0) 59 add a0, a0, a1 60 CBO_ZERO(a0) 61 add a0, a0, a1 62 CBO_ZERO(a0) 63 add a0, a0, a1 64 CBO_ZERO(a0) 65 add a0, a0, a1 66 CBO_ZERO(a0) 67 add a0, a0, a1 68 bltu a0, a2, .Lzero_loop 69 ret 70.Lno_zicboz: 71 li a1, 0 72 tail __memset 73SYM_FUNC_END(clear_page) 74EXPORT_SYMBOL(clear_page) 75