diff options
Diffstat (limited to 'arch/arm/mm/copypage-v4wt.c')
| -rw-r--r-- | arch/arm/mm/copypage-v4wt.c | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/arm/mm/copypage-v4wt.c b/arch/arm/mm/copypage-v4wt.c new file mode 100644 index 000000000000..0f1188efae45 --- /dev/null +++ b/arch/arm/mm/copypage-v4wt.c @@ -0,0 +1,88 @@ +/* + * linux/arch/arm/mm/copypage-v4wt.S + * + * Copyright (C) 1995-1999 Russell King + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 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 __attribute__((naked)) +v4wt_copy_user_page(void *kto, const void *kfrom) +{ + asm("\ + stmfd sp!, {r4, lr} @ 2\n\ + mov r2, %0 @ 1\n\ + ldmia r1!, {r3, r4, ip, lr} @ 4\n\ +1: stmia r0!, {r3, r4, ip, lr} @ 4\n\ + ldmia r1!, {r3, r4, ip, lr} @ 4+1\n\ + stmia r0!, {r3, r4, ip, lr} @ 4\n\ + ldmia r1!, {r3, r4, ip, lr} @ 4\n\ + stmia r0!, {r3, r4, ip, lr} @ 4\n\ + ldmia r1!, {r3, r4, ip, lr} @ 4\n\ + subs r2, r2, #1 @ 1\n\ + stmia r0!, {r3, r4, ip, lr} @ 4\n\ + ldmneia r1!, {r3, r4, ip, lr} @ 4\n\ + bne 1b @ 1\n\ + mcr p15, 0, r2, c7, c7, 0 @ flush ID cache\n\ + ldmfd sp!, {r4, pc} @ 3" + : + : "I" (PAGE_SIZE / 64)); +} + +void v4wt_copy_user_highpage(struct page *to, struct page *from, + unsigned long vaddr) +{ + void *kto, *kfrom; + + kto = kmap_atomic(to, KM_USER0); + kfrom = kmap_atomic(from, KM_USER1); + v4wt_copy_user_page(kto, kfrom); + kunmap_atomic(kfrom, KM_USER1); + kunmap_atomic(kto, KM_USER0); +} + +/* + * 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, KM_USER0); + 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, KM_USER0); +} + +struct cpu_user_fns v4wt_user_fns __initdata = { + .cpu_clear_user_highpage = v4wt_clear_user_highpage, + .cpu_copy_user_highpage = v4wt_copy_user_highpage, +}; |
