xref: /linux/arch/arm64/lib/clear_page.S (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
1/*
2 * Copyright (C) 2012 ARM Ltd.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15 */
16
17#include <linux/linkage.h>
18#include <linux/const.h>
19#include <asm/assembler.h>
20#include <asm/page.h>
21
22/*
23 * Clear page @dest
24 *
25 * Parameters:
26 *	x0 - dest
27 */
28ENTRY(clear_page)
29	mrs	x1, dczid_el0
30	and	w1, w1, #0xf
31	mov	x2, #4
32	lsl	x1, x2, x1
33
341:	dc	zva, x0
35	add	x0, x0, x1
36	tst	x0, #(PAGE_SIZE - 1)
37	b.ne	1b
38	ret
39ENDPROC(clear_page)
40EXPORT_SYMBOL(clear_page)
41