| /* 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) |
