18c2ecf20Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-only
28c2ecf20Sopenharmony_ci/*
38c2ecf20Sopenharmony_ci *  linux/arch/arm/mm/copypage-v4wt.S
48c2ecf20Sopenharmony_ci *
58c2ecf20Sopenharmony_ci *  Copyright (C) 1995-1999 Russell King
68c2ecf20Sopenharmony_ci *
78c2ecf20Sopenharmony_ci *  This is for CPUs with a writethrough cache and 'flush ID cache' is
88c2ecf20Sopenharmony_ci *  the only supported cache operation.
98c2ecf20Sopenharmony_ci */
108c2ecf20Sopenharmony_ci#include <linux/init.h>
118c2ecf20Sopenharmony_ci#include <linux/highmem.h>
128c2ecf20Sopenharmony_ci
138c2ecf20Sopenharmony_ci/*
148c2ecf20Sopenharmony_ci * ARMv4 optimised copy_user_highpage
158c2ecf20Sopenharmony_ci *
168c2ecf20Sopenharmony_ci * Since we have writethrough caches, we don't have to worry about
178c2ecf20Sopenharmony_ci * dirty data in the cache.  However, we do have to ensure that
188c2ecf20Sopenharmony_ci * subsequent reads are up to date.
198c2ecf20Sopenharmony_ci */
208c2ecf20Sopenharmony_cistatic void v4wt_copy_user_page(void *kto, const void *kfrom)
218c2ecf20Sopenharmony_ci{
228c2ecf20Sopenharmony_ci	int tmp;
238c2ecf20Sopenharmony_ci
248c2ecf20Sopenharmony_ci	asm volatile ("\
258c2ecf20Sopenharmony_ci	.syntax unified\n\
268c2ecf20Sopenharmony_ci	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
278c2ecf20Sopenharmony_ci1:	stmia	%0!, {r3, r4, ip, lr}		@ 4\n\
288c2ecf20Sopenharmony_ci	ldmia	%1!, {r3, r4, ip, lr}		@ 4+1\n\
298c2ecf20Sopenharmony_ci	stmia	%0!, {r3, r4, ip, lr}		@ 4\n\
308c2ecf20Sopenharmony_ci	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
318c2ecf20Sopenharmony_ci	stmia	%0!, {r3, r4, ip, lr}		@ 4\n\
328c2ecf20Sopenharmony_ci	ldmia	%1!, {r3, r4, ip, lr}		@ 4\n\
338c2ecf20Sopenharmony_ci	subs	%2, %2, #1			@ 1\n\
348c2ecf20Sopenharmony_ci	stmia	%0!, {r3, r4, ip, lr}		@ 4\n\
358c2ecf20Sopenharmony_ci	ldmiane	%1!, {r3, r4, ip, lr}		@ 4\n\
368c2ecf20Sopenharmony_ci	bne	1b				@ 1\n\
378c2ecf20Sopenharmony_ci	mcr	p15, 0, %2, c7, c7, 0		@ flush ID cache"
388c2ecf20Sopenharmony_ci	: "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
398c2ecf20Sopenharmony_ci	: "2" (PAGE_SIZE / 64)
408c2ecf20Sopenharmony_ci	: "r3", "r4", "ip", "lr");
418c2ecf20Sopenharmony_ci}
428c2ecf20Sopenharmony_ci
438c2ecf20Sopenharmony_civoid v4wt_copy_user_highpage(struct page *to, struct page *from,
448c2ecf20Sopenharmony_ci	unsigned long vaddr, struct vm_area_struct *vma)
458c2ecf20Sopenharmony_ci{
468c2ecf20Sopenharmony_ci	void *kto, *kfrom;
478c2ecf20Sopenharmony_ci
488c2ecf20Sopenharmony_ci	kto = kmap_atomic(to);
498c2ecf20Sopenharmony_ci	kfrom = kmap_atomic(from);
508c2ecf20Sopenharmony_ci	v4wt_copy_user_page(kto, kfrom);
518c2ecf20Sopenharmony_ci	kunmap_atomic(kfrom);
528c2ecf20Sopenharmony_ci	kunmap_atomic(kto);
538c2ecf20Sopenharmony_ci}
548c2ecf20Sopenharmony_ci
558c2ecf20Sopenharmony_ci/*
568c2ecf20Sopenharmony_ci * ARMv4 optimised clear_user_page
578c2ecf20Sopenharmony_ci *
588c2ecf20Sopenharmony_ci * Same story as above.
598c2ecf20Sopenharmony_ci */
608c2ecf20Sopenharmony_civoid v4wt_clear_user_highpage(struct page *page, unsigned long vaddr)
618c2ecf20Sopenharmony_ci{
628c2ecf20Sopenharmony_ci	void *ptr, *kaddr = kmap_atomic(page);
638c2ecf20Sopenharmony_ci	asm volatile("\
648c2ecf20Sopenharmony_ci	mov	r1, %2				@ 1\n\
658c2ecf20Sopenharmony_ci	mov	r2, #0				@ 1\n\
668c2ecf20Sopenharmony_ci	mov	r3, #0				@ 1\n\
678c2ecf20Sopenharmony_ci	mov	ip, #0				@ 1\n\
688c2ecf20Sopenharmony_ci	mov	lr, #0				@ 1\n\
698c2ecf20Sopenharmony_ci1:	stmia	%0!, {r2, r3, ip, lr}		@ 4\n\
708c2ecf20Sopenharmony_ci	stmia	%0!, {r2, r3, ip, lr}		@ 4\n\
718c2ecf20Sopenharmony_ci	stmia	%0!, {r2, r3, ip, lr}		@ 4\n\
728c2ecf20Sopenharmony_ci	stmia	%0!, {r2, r3, ip, lr}		@ 4\n\
738c2ecf20Sopenharmony_ci	subs	r1, r1, #1			@ 1\n\
748c2ecf20Sopenharmony_ci	bne	1b				@ 1\n\
758c2ecf20Sopenharmony_ci	mcr	p15, 0, r2, c7, c7, 0		@ flush ID cache"
768c2ecf20Sopenharmony_ci	: "=r" (ptr)
778c2ecf20Sopenharmony_ci	: "0" (kaddr), "I" (PAGE_SIZE / 64)
788c2ecf20Sopenharmony_ci	: "r1", "r2", "r3", "ip", "lr");
798c2ecf20Sopenharmony_ci	kunmap_atomic(kaddr);
808c2ecf20Sopenharmony_ci}
818c2ecf20Sopenharmony_ci
828c2ecf20Sopenharmony_cistruct cpu_user_fns v4wt_user_fns __initdata = {
838c2ecf20Sopenharmony_ci	.cpu_clear_user_highpage = v4wt_clear_user_highpage,
848c2ecf20Sopenharmony_ci	.cpu_copy_user_highpage	= v4wt_copy_user_highpage,
858c2ecf20Sopenharmony_ci};
86