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/* * linux/arch/arm/lib/copypage.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. * * ASM optimised string functions */ #include <linux/linkage.h> #include <linux/init.h> #include <asm/constants.h> .text .align 5 /* * ARMv4 optimised copy_user_page * * We flush the destination cache lines just before we write the data into the * corresponding address. Since the Dcache is read-allocate, this removes the * Dcache aliasing issue. The writes will be forwarded to the write buffer, * and merged as appropriate. * * Note: We rely on all ARMv4 processors implementing the "invalidate D line" * instruction. If your processor does not supply this, you have to write your * own copy_user_page that does the right thing. */ ENTRY(v4wb_copy_user_page) stmfd sp!, {r4, lr} @ 2 mov r2, #PAGE_SZ/64 @ 1 ldmia r1!, {r3, r4, ip, lr} @ 4 1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line stmia r0!, {r3, r4, ip, lr} @ 4 ldmia r1!, {r3, r4, ip, lr} @ 4+1 stmia r0!, {r3, r4, ip, lr} @ 4 ldmia r1!, {r3, r4, ip, lr} @ 4 mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line stmia r0!, {r3, r4, ip, lr} @ 4 ldmia r1!, {r3, r4, ip, lr} @ 4 subs r2, r2, #1 @ 1 stmia r0!, {r3, r4, ip, lr} @ 4 ldmneia r1!, {r3, r4, ip, lr} @ 4 bne 1b @ 1 mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB ldmfd sp!, {r4, pc} @ 3 .align 5 /* * ARMv4 optimised clear_user_page * * Same story as above. */ ENTRY(v4wb_clear_user_page) str lr, [sp, #-4]! mov r1, #PAGE_SZ/64 @ 1 mov r2, #0 @ 1 mov r3, #0 @ 1 mov ip, #0 @ 1 mov lr, #0 @ 1 1: mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line stmia r0!, {r2, r3, ip, lr} @ 4 stmia r0!, {r2, r3, ip, lr} @ 4 mcr p15, 0, r0, c7, c6, 1 @ 1 invalidate D line stmia r0!, {r2, r3, ip, lr} @ 4 stmia r0!, {r2, r3, ip, lr} @ 4 subs r1, r1, #1 @ 1 bne 1b @ 1 mcr p15, 0, r1, c7, c10, 4 @ 1 drain WB ldr pc, [sp], #4 __INIT ENTRY(v4wb_user_fns) .long v4wb_clear_user_page .long v4wb_copy_user_page |