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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2023 Ventana Micro Systems Inc.
*/
#include <linux/linkage.h>
#include <asm/asm.h>
#include <asm/alternative-macros.h>
#include <asm-generic/export.h>
#include <asm/hwcap.h>
#include <asm/insn-def.h>
#include <asm/page.h>
#define CBOZ_ALT(order, old, new) \
ALTERNATIVE(old, new, 0, \
((order) << 16) | RISCV_ISA_EXT_ZICBOZ, \
CONFIG_RISCV_ISA_ZICBOZ)
/* void clear_page(void *page) */
SYM_FUNC_START(clear_page)
li a2, PAGE_SIZE
/*
* If Zicboz isn't present, or somehow has a block
* size larger than 4K, then fallback to memset.
*/
CBOZ_ALT(12, "j .Lno_zicboz", "nop")
lw a1, riscv_cboz_block_size
add a2, a0, a2
.Lzero_loop:
CBO_zero(a0)
add a0, a0, a1
CBOZ_ALT(11, "bltu a0, a2, .Lzero_loop; ret", "nop; nop")
CBO_zero(a0)
add a0, a0, a1
CBOZ_ALT(10, "bltu a0, a2, .Lzero_loop; ret", "nop; nop")
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBOZ_ALT(9, "bltu a0, a2, .Lzero_loop; ret", "nop; nop")
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBOZ_ALT(8, "bltu a0, a2, .Lzero_loop; ret", "nop; nop")
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
CBO_zero(a0)
add a0, a0, a1
bltu a0, a2, .Lzero_loop
ret
.Lno_zicboz:
li a1, 0
tail __memset
SYM_FUNC_END(clear_page)
EXPORT_SYMBOL(clear_page)
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