273 lines
6.3 KiB
C
273 lines
6.3 KiB
C
|
/* -*- 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.
|
||
|
|
*
|
||
|
|
* ----------------------------------------------------------------------- */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* raid6/algos.c
|
||
|
|
*
|
||
|
|
* Algorithm list and algorithm selection for RAID-6
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/raid/pq.h>
|
||
|
|
#ifndef __KERNEL__
|
||
|
|
#include <sys/mman.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
#else
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <linux/gfp.h>
|
||
|
|
#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);
|
||
|
|
|
||
|
|
const struct raid6_calls * const raid6_algos[] = {
|
||
|
|
#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,
|
||
|
|
#ifdef CONFIG_AS_AVX2
|
||
|
|
&raid6_avx2x1,
|
||
|
|
&raid6_avx2x2,
|
||
|
|
#endif
|
||
|
|
#ifdef CONFIG_AS_AVX512
|
||
|
|
&raid6_avx512x1,
|
||
|
|
&raid6_avx512x2,
|
||
|
|
#endif
|
||
|
|
#endif
|
||
|
|
#if defined(__x86_64__) && !defined(__arch_um__)
|
||
|
|
&raid6_sse2x1,
|
||
|
|
&raid6_sse2x2,
|
||
|
|
&raid6_sse2x4,
|
||
|
|
#ifdef CONFIG_AS_AVX2
|
||
|
|
&raid6_avx2x1,
|
||
|
|
&raid6_avx2x2,
|
||
|
|
&raid6_avx2x4,
|
||
|
|
#endif
|
||
|
|
#ifdef CONFIG_AS_AVX512
|
||
|
|
&raid6_avx512x1,
|
||
|
|
&raid6_avx512x2,
|
||
|
|
&raid6_avx512x4,
|
||
|
|
#endif
|
||
|
|
#endif
|
||
|
|
#ifdef CONFIG_ALTIVEC
|
||
|
|
&raid6_altivec1,
|
||
|
|
&raid6_altivec2,
|
||
|
|
&raid6_altivec4,
|
||
|
|
&raid6_altivec8,
|
||
|
|
&raid6_vpermxor1,
|
||
|
|
&raid6_vpermxor2,
|
||
|
|
&raid6_vpermxor4,
|
||
|
|
&raid6_vpermxor8,
|
||
|
|
#endif
|
||
|
|
#if defined(CONFIG_S390)
|
||
|
|
&raid6_s390vx8,
|
||
|
|
#endif
|
||
|
|
&raid6_intx1,
|
||
|
|
&raid6_intx2,
|
||
|
|
&raid6_intx4,
|
||
|
|
&raid6_intx8,
|
||
|
|
#ifdef CONFIG_KERNEL_MODE_NEON
|
||
|
|
&raid6_neonx1,
|
||
|
|
&raid6_neonx2,
|
||
|
|
&raid6_neonx4,
|
||
|
|
&raid6_neonx8,
|
||
|
|
#endif
|
||
|
|
NULL
|
||
|
|
};
|
||
|
|
|
||
|
|
void (*raid6_2data_recov)(int, size_t, int, int, void **);
|
||
|
|
EXPORT_SYMBOL_GPL(raid6_2data_recov);
|
||
|
|
|
||
|
|
void (*raid6_datap_recov)(int, size_t, int, void **);
|
||
|
|
EXPORT_SYMBOL_GPL(raid6_datap_recov);
|
||
|
|
|
||
|
|
const struct raid6_recov_calls *const raid6_recov_algos[] = {
|
||
|
|
#ifdef CONFIG_AS_AVX512
|
||
|
|
&raid6_recov_avx512,
|
||
|
|
#endif
|
||
|
|
#ifdef CONFIG_AS_AVX2
|
||
|
|
&raid6_recov_avx2,
|
||
|
|
#endif
|
||
|
|
#ifdef CONFIG_AS_SSSE3
|
||
|
|
&raid6_recov_ssse3,
|
||
|
|
#endif
|
||
|
|
#ifdef CONFIG_S390
|
||
|
|
&raid6_recov_s390xc,
|
||
|
|
#endif
|
||
|
|
#if defined(CONFIG_KERNEL_MODE_NEON)
|
||
|
|
&raid6_recov_neon,
|
||
|
|
#endif
|
||
|
|
&raid6_recov_intx1,
|
||
|
|
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
|
||
|
|
|
||
|
|
static inline const struct raid6_recov_calls *raid6_choose_recov(void)
|
||
|
|
{
|
||
|
|
const struct raid6_recov_calls *const *algo;
|
||
|
|
const struct raid6_recov_calls *best;
|
||
|
|
|
||
|
|
for (best = NULL, algo = raid6_recov_algos; *algo; algo++)
|
||
|
|
if (!best || (*algo)->priority > best->priority)
|
||
|
|
if (!(*algo)->valid || (*algo)->valid())
|
||
|
|
best = *algo;
|
||
|
|
|
||
|
|
if (best) {
|
||
|
|
raid6_2data_recov = best->data2;
|
||
|
|
raid6_datap_recov = best->datap;
|
||
|
|
|
||
|
|
pr_info("raid6: using %s recovery algorithm\n", best->name);
|
||
|
|
} else
|
||
|
|
pr_err("raid6: Yikes! No recovery algorithm found!\n");
|
||
|
|
|
||
|
|
return best;
|
||
|
|
}
|
||
|
|
|
||
|
|
static inline const struct raid6_calls *raid6_choose_gen(
|
||
|
|
void *(*const dptrs)[(65536/PAGE_SIZE)+2], const int disks)
|
||
|
|
{
|
||
|
|
unsigned long perf, bestgenperf, bestxorperf, j0, j1;
|
||
|
|
int start = (disks>>1)-1, stop = disks-3; /* work on the second half of the disks */
|
||
|
|
const struct raid6_calls *const *algo;
|
||
|
|
const struct raid6_calls *best;
|
||
|
|
|
||
|
|
for (bestgenperf = 0, bestxorperf = 0, best = NULL, algo = raid6_algos; *algo; algo++) {
|
||
|
|
if (!best || (*algo)->prefer >= best->prefer) {
|
||
|
|
if ((*algo)->valid && !(*algo)->valid())
|
||
|
|
continue;
|
||
|
|
|
||
|
|
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 (perf > bestgenperf) {
|
||
|
|
bestgenperf = perf;
|
||
|
|
best = *algo;
|
||
|
|
}
|
||
|
|
pr_info("raid6: %-8s gen() %5ld MB/s\n", (*algo)->name,
|
||
|
|
(perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2));
|
||
|
|
|
||
|
|
if (!(*algo)->xor_syndrome)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
perf = 0;
|
||
|
|
|
||
|
|
preempt_disable();
|
||
|
|
j0 = jiffies;
|
||
|
|
while ((j1 = jiffies) == j0)
|
||
|
|
cpu_relax();
|
||
|
|
while (time_before(jiffies,
|
||
|
|
j1 + (1<<RAID6_TIME_JIFFIES_LG2))) {
|
||
|
|
(*algo)->xor_syndrome(disks, start, stop,
|
||
|
|
PAGE_SIZE, *dptrs);
|
||
|
|
perf++;
|
||
|
|
}
|
||
|
|
preempt_enable();
|
||
|
|
|
||
|
|
if (best == *algo)
|
||
|
|
bestxorperf = perf;
|
||
|
|
|
||
|
|
pr_info("raid6: %-8s xor() %5ld MB/s\n", (*algo)->name,
|
||
|
|
(perf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (best) {
|
||
|
|
pr_info("raid6: using algorithm %s gen() %ld MB/s\n",
|
||
|
|
best->name,
|
||
|
|
(bestgenperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2));
|
||
|
|
if (best->xor_syndrome)
|
||
|
|
pr_info("raid6: .... xor() %ld MB/s, rmw enabled\n",
|
||
|
|
(bestxorperf*HZ) >> (20-16+RAID6_TIME_JIFFIES_LG2+1));
|
||
|
|
raid6_call = *best;
|
||
|
|
} else
|
||
|
|
pr_err("raid6: Yikes! No algorithm found!\n");
|
||
|
|
|
||
|
|
return best;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/* 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 int disks = (65536/PAGE_SIZE)+2;
|
||
|
|
|
||
|
|
const struct raid6_calls *gen_best;
|
||
|
|
const struct raid6_recov_calls *rec_best;
|
||
|
|
char *syndromes;
|
||
|
|
void *dptrs[(65536/PAGE_SIZE)+2];
|
||
|
|
int i;
|
||
|
|
|
||
|
|
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) {
|
||
|
|
pr_err("raid6: Yikes! No memory available.\n");
|
||
|
|
return -ENOMEM;
|
||
|
|
}
|
||
|
|
|
||
|
|
dptrs[disks-2] = syndromes;
|
||
|
|
dptrs[disks-1] = syndromes + PAGE_SIZE;
|
||
|
|
|
||
|
|
/* select raid gen_syndrome function */
|
||
|
|
gen_best = raid6_choose_gen(&dptrs, disks);
|
||
|
|
|
||
|
|
/* select raid recover functions */
|
||
|
|
rec_best = raid6_choose_recov();
|
||
|
|
|
||
|
|
free_pages((unsigned long)syndromes, 1);
|
||
|
|
|
||
|
|
return gen_best && rec_best ? 0 : -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void raid6_exit(void)
|
||
|
|
{
|
||
|
|
do { } while (0);
|
||
|
|
}
|
||
|
|
|
||
|
|
subsys_initcall(raid6_select_algo);
|
||
|
|
module_exit(raid6_exit);
|
||
|
|
MODULE_LICENSE("GPL");
|
||
|
|
MODULE_DESCRIPTION("RAID6 Q-syndrome calculations");
|