1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
2 | /* |
3 | * Copyright (C) 2012 ARM Ltd. |
4 | */ |
5 | |
6 | #include <linux/linkage.h> |
7 | #include <linux/const.h> |
8 | #include <asm/assembler.h> |
9 | #include <asm/page.h> |
10 | |
11 | /* |
12 | * Clear page @dest |
13 | * |
14 | * Parameters: |
15 | * x0 - dest |
16 | */ |
17 | SYM_FUNC_START(__pi_clear_page) |
18 | mrs x1, dczid_el0 |
19 | tbnz x1, #4, 2f /* Branch if DC ZVA is prohibited */ |
20 | and w1, w1, #0xf |
21 | mov x2, #4 |
22 | lsl x1, x2, x1 |
23 | |
24 | 1: dc zva, x0 |
25 | add x0, x0, x1 |
26 | tst x0, #(PAGE_SIZE - 1) |
27 | b.ne 1b |
28 | ret |
29 | |
30 | 2: stnp xzr, xzr, [x0] |
31 | stnp xzr, xzr, [x0, #16] |
32 | stnp xzr, xzr, [x0, #32] |
33 | stnp xzr, xzr, [x0, #48] |
34 | add x0, x0, #64 |
35 | tst x0, #(PAGE_SIZE - 1) |
36 | b.ne 2b |
37 | ret |
38 | SYM_FUNC_END(__pi_clear_page) |
39 | SYM_FUNC_ALIAS(clear_page, __pi_clear_page) |
40 | EXPORT_SYMBOL(clear_page) |
41 | |