/* * 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 __naked v4wt_copy_user_page(void *kto, const void *kfrom) { asm("\ stmfd sp!, {r4, lr} @ 2\n\ mov r2, %2 @ 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" : : "r" (kto), "r" (kfrom), "I" (PAGE_SIZE / 64)); } 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, 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, };