diff options
Diffstat (limited to 'arch/um/sys-ppc/misc.S')
| -rw-r--r-- | arch/um/sys-ppc/misc.S | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/um/sys-ppc/misc.S b/arch/um/sys-ppc/misc.S new file mode 100644 index 0000000..11b7bd7 --- /dev/null +++ b/arch/um/sys-ppc/misc.S @@ -0,0 +1,116 @@ +/* + * This file contains miscellaneous low-level functions. + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Largely rewritten by Cort Dougan (cort@cs.nmt.edu) + * and Paul Mackerras. + * + * A couple of functions stolen from arch/ppc/kernel/misc.S for UML + * by Chris Emerson. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ + +#include <linux/config.h> +#include <asm/processor.h> +#include "ppc_asm.h" + +#if defined(CONFIG_4xx) || defined(CONFIG_8xx) +#define CACHE_LINE_SIZE 16 +#define LG_CACHE_LINE_SIZE 4 +#define MAX_COPY_PREFETCH 1 +#elif !defined(CONFIG_PPC64BRIDGE) +#define CACHE_LINE_SIZE 32 +#define LG_CACHE_LINE_SIZE 5 +#define MAX_COPY_PREFETCH 4 +#else +#define CACHE_LINE_SIZE 128 +#define LG_CACHE_LINE_SIZE 7 +#define MAX_COPY_PREFETCH 1 +#endif /* CONFIG_4xx || CONFIG_8xx */ + + .text + +/* + * Clear a page using the dcbz instruction, which doesn't cause any + * memory traffic (except to write out any cache lines which get + * displaced). This only works on cacheable memory. + */ +_GLOBAL(clear_page) + li r0,4096/CACHE_LINE_SIZE + mtctr r0 +#ifdef CONFIG_8xx + li r4, 0 +1: stw r4, 0(r3) + stw r4, 4(r3) + stw r4, 8(r3) + stw r4, 12(r3) +#else +1: dcbz 0,r3 +#endif + addi r3,r3,CACHE_LINE_SIZE + bdnz 1b + blr + +/* + * Copy a whole page. We use the dcbz instruction on the destination + * to reduce memory traffic (it eliminates the unnecessary reads of + * the destination into cache). This requires that the destination + * is cacheable. + */ +#define COPY_16_BYTES \ + lwz r6,4(r4); \ + lwz r7,8(r4); \ + lwz r8,12(r4); \ + lwzu r9,16(r4); \ + stw r6,4(r3); \ + stw r7,8(r3); \ + stw r8,12(r3); \ + stwu r9,16(r3) + +_GLOBAL(copy_page) + addi r3,r3,-4 + addi r4,r4,-4 + li r5,4 + +#ifndef CONFIG_8xx +#if MAX_COPY_PREFETCH > 1 + li r0,MAX_COPY_PREFETCH + li r11,4 + mtctr r0 +11: dcbt r11,r4 + addi r11,r11,CACHE_LINE_SIZE + bdnz 11b +#else /* MAX_COPY_PREFETCH == 1 */ + dcbt r5,r4 + li r11,CACHE_LINE_SIZE+4 +#endif /* MAX_COPY_PREFETCH */ +#endif /* CONFIG_8xx */ + + li r0,4096/CACHE_LINE_SIZE + mtctr r0 +1: +#ifndef CONFIG_8xx + dcbt r11,r4 + dcbz r5,r3 +#endif + COPY_16_BYTES +#if CACHE_LINE_SIZE >= 32 + COPY_16_BYTES +#if CACHE_LINE_SIZE >= 64 + COPY_16_BYTES + COPY_16_BYTES +#if CACHE_LINE_SIZE >= 128 + COPY_16_BYTES + COPY_16_BYTES + COPY_16_BYTES + COPY_16_BYTES +#endif +#endif +#endif + bdnz 1b + blr |
