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Diffstat (limited to 'arch/arm/mm/copypage-v4wb.S')
| -rw-r--r-- | arch/arm/mm/copypage-v4wb.S | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/arch/arm/mm/copypage-v4wb.S b/arch/arm/mm/copypage-v4wb.S new file mode 100644 index 000000000000..b94c345ceb94 --- /dev/null +++ b/arch/arm/mm/copypage-v4wb.S @@ -0,0 +1,79 @@ +/* + * 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 + + __INITDATA + + .type v4wb_user_fns, #object +ENTRY(v4wb_user_fns) + .long v4wb_clear_user_page + .long v4wb_copy_user_page + .size v4wb_user_fns, . - v4wb_user_fns |