diff options
Diffstat (limited to 'arch/arm64/lib/clear_page.S')
| -rw-r--r-- | arch/arm64/lib/clear_page.S | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/arm64/lib/clear_page.S b/arch/arm64/lib/clear_page.S new file mode 100644 index 000000000..1fd5d790a --- /dev/null +++ b/arch/arm64/lib/clear_page.S @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012 ARM Ltd. + */ + +#include <linux/linkage.h> +#include <linux/const.h> +#include <asm/assembler.h> +#include <asm/page.h> + +/* + * Clear page @dest + * + * Parameters: + * x0 - dest + */ +SYM_FUNC_START_PI(clear_page) + mrs x1, dczid_el0 + tbnz x1, #4, 2f /* Branch if DC ZVA is prohibited */ + and w1, w1, #0xf + mov x2, #4 + lsl x1, x2, x1 + +1: dc zva, x0 + add x0, x0, x1 + tst x0, #(PAGE_SIZE - 1) + b.ne 1b + ret + +2: stnp xzr, xzr, [x0] + stnp xzr, xzr, [x0, #16] + stnp xzr, xzr, [x0, #32] + stnp xzr, xzr, [x0, #48] + add x0, x0, #64 + tst x0, #(PAGE_SIZE - 1) + b.ne 2b + ret +SYM_FUNC_END_PI(clear_page) +EXPORT_SYMBOL(clear_page) |