1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0-only */ 2*4882a593Smuzhiyun#include <linux/linkage.h> 3*4882a593Smuzhiyun#include <asm/export.h> 4*4882a593Smuzhiyun 5*4882a593Smuzhiyun/* 6*4882a593Smuzhiyun * Most CPUs support enhanced REP MOVSB/STOSB instructions. It is 7*4882a593Smuzhiyun * recommended to use this when possible and we do use them by default. 8*4882a593Smuzhiyun * If enhanced REP MOVSB/STOSB is not available, try to use fast string. 9*4882a593Smuzhiyun * Otherwise, use original. 10*4882a593Smuzhiyun */ 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun/* 13*4882a593Smuzhiyun * Zero a page. 14*4882a593Smuzhiyun * %rdi - page 15*4882a593Smuzhiyun */ 16*4882a593SmuzhiyunSYM_FUNC_START(clear_page_rep) 17*4882a593Smuzhiyun movl $4096/8,%ecx 18*4882a593Smuzhiyun xorl %eax,%eax 19*4882a593Smuzhiyun rep stosq 20*4882a593Smuzhiyun RET 21*4882a593SmuzhiyunSYM_FUNC_END(clear_page_rep) 22*4882a593SmuzhiyunEXPORT_SYMBOL_GPL(clear_page_rep) 23*4882a593Smuzhiyun 24*4882a593SmuzhiyunSYM_FUNC_START(clear_page_orig) 25*4882a593Smuzhiyun xorl %eax,%eax 26*4882a593Smuzhiyun movl $4096/64,%ecx 27*4882a593Smuzhiyun .p2align 4 28*4882a593Smuzhiyun.Lloop: 29*4882a593Smuzhiyun decl %ecx 30*4882a593Smuzhiyun#define PUT(x) movq %rax,x*8(%rdi) 31*4882a593Smuzhiyun movq %rax,(%rdi) 32*4882a593Smuzhiyun PUT(1) 33*4882a593Smuzhiyun PUT(2) 34*4882a593Smuzhiyun PUT(3) 35*4882a593Smuzhiyun PUT(4) 36*4882a593Smuzhiyun PUT(5) 37*4882a593Smuzhiyun PUT(6) 38*4882a593Smuzhiyun PUT(7) 39*4882a593Smuzhiyun leaq 64(%rdi),%rdi 40*4882a593Smuzhiyun jnz .Lloop 41*4882a593Smuzhiyun nop 42*4882a593Smuzhiyun RET 43*4882a593SmuzhiyunSYM_FUNC_END(clear_page_orig) 44*4882a593SmuzhiyunEXPORT_SYMBOL_GPL(clear_page_orig) 45*4882a593Smuzhiyun 46*4882a593SmuzhiyunSYM_FUNC_START(clear_page_erms) 47*4882a593Smuzhiyun movl $4096,%ecx 48*4882a593Smuzhiyun xorl %eax,%eax 49*4882a593Smuzhiyun rep stosb 50*4882a593Smuzhiyun RET 51*4882a593SmuzhiyunSYM_FUNC_END(clear_page_erms) 52*4882a593SmuzhiyunEXPORT_SYMBOL_GPL(clear_page_erms) 53