diff options
author | David Woodhouse <dwmw2@tylersburg.infradead.org> | 2009-07-13 11:35:12 +0100 |
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committer | David Woodhouse <David.Woodhouse@intel.com> | 2009-10-29 14:38:47 +0000 |
commit | f5e70d0fe3ea990cfb3fc8d7f76a719adcb1e0b5 (patch) | |
tree | 1794eb51814228ff76f672a541100ad62dd791c9 /drivers/md/raid6algos.c | |
parent | 17d857be649a21ca90008c6dc425d849fa83db5c (diff) |
md: Factor out RAID6 algorithms into lib/
We'll want to use these in btrfs too.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/md/raid6algos.c')
-rw-r--r-- | drivers/md/raid6algos.c | 171 |
1 files changed, 0 insertions, 171 deletions
diff --git a/drivers/md/raid6algos.c b/drivers/md/raid6algos.c deleted file mode 100644 index 866215ac7f25..000000000000 --- a/drivers/md/raid6algos.c +++ /dev/null @@ -1,171 +0,0 @@ -/* -*- linux-c -*- ------------------------------------------------------- * - * - * Copyright 2002 H. Peter Anvin - All Rights Reserved - * - * 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, Inc., 53 Temple Place Ste 330, - * Boston MA 02111-1307, USA; either version 2 of the License, or - * (at your option) any later version; incorporated herein by reference. - * - * ----------------------------------------------------------------------- */ - -/* - * raid6algos.c - * - * Algorithm list and algorithm selection for RAID-6 - */ - -#include <linux/raid/pq.h> -#ifndef __KERNEL__ -#include <sys/mman.h> -#include <stdio.h> -#else -#if !RAID6_USE_EMPTY_ZERO_PAGE -/* In .bss so it's zeroed */ -const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); -EXPORT_SYMBOL(raid6_empty_zero_page); -#endif -#endif - -struct raid6_calls raid6_call; -EXPORT_SYMBOL_GPL(raid6_call); - -/* Various routine sets */ -extern const struct raid6_calls raid6_intx1; -extern const struct raid6_calls raid6_intx2; -extern const struct raid6_calls raid6_intx4; -extern const struct raid6_calls raid6_intx8; -extern const struct raid6_calls raid6_intx16; -extern const struct raid6_calls raid6_intx32; -extern const struct raid6_calls raid6_mmxx1; -extern const struct raid6_calls raid6_mmxx2; -extern const struct raid6_calls raid6_sse1x1; -extern const struct raid6_calls raid6_sse1x2; -extern const struct raid6_calls raid6_sse2x1; -extern const struct raid6_calls raid6_sse2x2; -extern const struct raid6_calls raid6_sse2x4; -extern const struct raid6_calls raid6_altivec1; -extern const struct raid6_calls raid6_altivec2; -extern const struct raid6_calls raid6_altivec4; -extern const struct raid6_calls raid6_altivec8; - -const struct raid6_calls * const raid6_algos[] = { - &raid6_intx1, - &raid6_intx2, - &raid6_intx4, - &raid6_intx8, -#if defined(__ia64__) - &raid6_intx16, - &raid6_intx32, -#endif -#if defined(__i386__) && !defined(__arch_um__) - &raid6_mmxx1, - &raid6_mmxx2, - &raid6_sse1x1, - &raid6_sse1x2, - &raid6_sse2x1, - &raid6_sse2x2, -#endif -#if defined(__x86_64__) && !defined(__arch_um__) - &raid6_sse2x1, - &raid6_sse2x2, - &raid6_sse2x4, -#endif -#ifdef CONFIG_ALTIVEC - &raid6_altivec1, - &raid6_altivec2, - &raid6_altivec4, - &raid6_altivec8, -#endif - NULL -}; - -#ifdef __KERNEL__ -#define RAID6_TIME_JIFFIES_LG2 4 -#else -/* Need more time to be stable in userspace */ -#define RAID6_TIME_JIFFIES_LG2 9 -#define time_before(x, y) ((x) < (y)) -#endif - -/* Try to pick the best algorithm */ -/* This code uses the gfmul table as convenient data set to abuse */ - -int __init raid6_select_algo(void) -{ - const struct raid6_calls * const * algo; - const struct raid6_calls * best; - char *syndromes; - void *dptrs[(65536/PAGE_SIZE)+2]; - int i, disks; - unsigned long perf, bestperf; - int bestprefer; - unsigned long j0, j1; - - disks = (65536/PAGE_SIZE)+2; - for ( i = 0 ; i < disks-2 ; i++ ) { - dptrs[i] = ((char *)raid6_gfmul) + PAGE_SIZE*i; - } - - /* Normal code - use a 2-page allocation to avoid D$ conflict */ - syndromes = (void *) __get_free_pages(GFP_KERNEL, 1); - - if ( !syndromes ) { - printk("raid6: Yikes! No memory available.\n"); - return -ENOMEM; - } - - dptrs[disks-2] = syndromes; - dptrs[disks-1] = syndromes + PAGE_SIZE; - - bestperf = 0; bestprefer = 0; best = NULL; - - for ( algo = raid6_algos ; *algo ; algo++ ) { - if ( !(*algo)->valid || (*algo)->valid() ) { - perf = 0; - - preempt_disable(); - j0 = jiffies; - while ( (j1 = jiffies) == j0 ) - cpu_relax(); - while (time_before(jiffies, - j1 + (1<<RAID6_TIME_JIFFIES_LG2))) { - (*algo)->gen_syndrome(disks, PAGE_SIZE, dptrs); - perf++; - } - preempt_enable(); - - if ( (*algo)->prefer > bestprefer || - ((*algo)->prefer == bestprefer && - perf > bestperf) ) { - best = *algo; - bestprefer = best->prefer; - bestperf = perf; - } - printk("raid6: %-8s %5ld MB/s\n", (*algo)->name, - (perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); - } - } - - if (best) { - printk("raid6: using algorithm %s (%ld MB/s)\n", - best->name, - (bestperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2)); - raid6_call = *best; - } else - printk("raid6: Yikes! No algorithm found!\n"); - - free_pages((unsigned long)syndromes, 1); - - return best ? 0 : -EINVAL; -} - -static void raid6_exit(void) -{ - do { } while (0); -} - -subsys_initcall(raid6_select_algo); -module_exit(raid6_exit); -MODULE_LICENSE("GPL"); |