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| // SPDX-License-Identifier: GPL-2.0-only
| /*
| * linux/arch/arm/mm/copypage-v4wt.S
| *
| * Copyright (C) 1995-1999 Russell King
| *
| * This is for CPUs with a writethrough cache and 'flush ID cache' is
| * the only supported cache operation.
| */
| #include <linux/init.h>
| #include <linux/highmem.h>
|
| /*
| * ARMv4 optimised copy_user_highpage
| *
| * Since we have writethrough caches, we don't have to worry about
| * dirty data in the cache. However, we do have to ensure that
| * subsequent reads are up to date.
| */
| static void v4wt_copy_user_page(void *kto, const void *kfrom)
| {
| int tmp;
|
| asm volatile ("\
| .syntax unified\n\
| ldmia %1!, {r3, r4, ip, lr} @ 4\n\
| 1: stmia %0!, {r3, r4, ip, lr} @ 4\n\
| ldmia %1!, {r3, r4, ip, lr} @ 4+1\n\
| stmia %0!, {r3, r4, ip, lr} @ 4\n\
| ldmia %1!, {r3, r4, ip, lr} @ 4\n\
| stmia %0!, {r3, r4, ip, lr} @ 4\n\
| ldmia %1!, {r3, r4, ip, lr} @ 4\n\
| subs %2, %2, #1 @ 1\n\
| stmia %0!, {r3, r4, ip, lr} @ 4\n\
| ldmiane %1!, {r3, r4, ip, lr} @ 4\n\
| bne 1b @ 1\n\
| mcr p15, 0, %2, c7, c7, 0 @ flush ID cache"
| : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
| : "2" (PAGE_SIZE / 64)
| : "r3", "r4", "ip", "lr");
| }
|
| void v4wt_copy_user_highpage(struct page *to, struct page *from,
| unsigned long vaddr, struct vm_area_struct *vma)
| {
| void *kto, *kfrom;
|
| kto = kmap_atomic(to);
| kfrom = kmap_atomic(from);
| v4wt_copy_user_page(kto, kfrom);
| kunmap_atomic(kfrom);
| kunmap_atomic(kto);
| }
|
| /*
| * ARMv4 optimised clear_user_page
| *
| * Same story as above.
| */
| void v4wt_clear_user_highpage(struct page *page, unsigned long vaddr)
| {
| void *ptr, *kaddr = kmap_atomic(page);
| asm volatile("\
| mov r1, %2 @ 1\n\
| mov r2, #0 @ 1\n\
| mov r3, #0 @ 1\n\
| mov ip, #0 @ 1\n\
| mov lr, #0 @ 1\n\
| 1: stmia %0!, {r2, r3, ip, lr} @ 4\n\
| stmia %0!, {r2, r3, ip, lr} @ 4\n\
| stmia %0!, {r2, r3, ip, lr} @ 4\n\
| stmia %0!, {r2, r3, ip, lr} @ 4\n\
| subs r1, r1, #1 @ 1\n\
| bne 1b @ 1\n\
| mcr p15, 0, r2, c7, c7, 0 @ flush ID cache"
| : "=r" (ptr)
| : "0" (kaddr), "I" (PAGE_SIZE / 64)
| : "r1", "r2", "r3", "ip", "lr");
| kunmap_atomic(kaddr);
| }
|
| struct cpu_user_fns v4wt_user_fns __initdata = {
| .cpu_clear_user_highpage = v4wt_clear_user_highpage,
| .cpu_copy_user_highpage = v4wt_copy_user_highpage,
| };
|
|
