1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0-only */ 2*4882a593Smuzhiyun/* 3*4882a593Smuzhiyun * Copyright (C) 2012 ARM Ltd. 4*4882a593Smuzhiyun */ 5*4882a593Smuzhiyun 6*4882a593Smuzhiyun#include <linux/linkage.h> 7*4882a593Smuzhiyun#include <linux/const.h> 8*4882a593Smuzhiyun#include <asm/assembler.h> 9*4882a593Smuzhiyun#include <asm/page.h> 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun/* 12*4882a593Smuzhiyun * Clear page @dest 13*4882a593Smuzhiyun * 14*4882a593Smuzhiyun * Parameters: 15*4882a593Smuzhiyun * x0 - dest 16*4882a593Smuzhiyun */ 17*4882a593SmuzhiyunSYM_FUNC_START_PI(clear_page) 18*4882a593Smuzhiyun mrs x1, dczid_el0 19*4882a593Smuzhiyun tbnz x1, #4, 2f /* Branch if DC ZVA is prohibited */ 20*4882a593Smuzhiyun and w1, w1, #0xf 21*4882a593Smuzhiyun mov x2, #4 22*4882a593Smuzhiyun lsl x1, x2, x1 23*4882a593Smuzhiyun 24*4882a593Smuzhiyun1: dc zva, x0 25*4882a593Smuzhiyun add x0, x0, x1 26*4882a593Smuzhiyun tst x0, #(PAGE_SIZE - 1) 27*4882a593Smuzhiyun b.ne 1b 28*4882a593Smuzhiyun ret 29*4882a593Smuzhiyun 30*4882a593Smuzhiyun2: stnp xzr, xzr, [x0] 31*4882a593Smuzhiyun stnp xzr, xzr, [x0, #16] 32*4882a593Smuzhiyun stnp xzr, xzr, [x0, #32] 33*4882a593Smuzhiyun stnp xzr, xzr, [x0, #48] 34*4882a593Smuzhiyun add x0, x0, #64 35*4882a593Smuzhiyun tst x0, #(PAGE_SIZE - 1) 36*4882a593Smuzhiyun b.ne 2b 37*4882a593Smuzhiyun ret 38*4882a593SmuzhiyunSYM_FUNC_END_PI(clear_page) 39*4882a593SmuzhiyunEXPORT_SYMBOL(clear_page) 40