LXR linux/drivers/md/raid6.h

   1/* -*- linux-c -*- ------------------------------------------------------- *
   2 *
   3 *   Copyright 2003 H. Peter Anvin - All Rights Reserved
   4 *
   5 *   This program is free software; you can redistribute it and/or modify
   6 *   it under the terms of the GNU General Public License as published by
   7 *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   8 *   Bostom MA 02111-1307, USA; either version 2 of the License, or
   9 *   (at your option) any later version; incorporated herein by reference.
  10 *
  11 * ----------------------------------------------------------------------- */
  12
  13#ifndef LINUX_RAID_RAID6_H
  14#define LINUX_RAID_RAID6_H
  15
  16#ifdef __KERNEL__
  17
  18/* Set to 1 to use kernel-wide empty_zero_page */
  19#define RAID6_USE_EMPTY_ZERO_PAGE 0
  20
  21#include <linux/module.h>
  22#include <linux/stddef.h>
  23#include <linux/compiler.h>
  24#include <linux/types.h>
  25#include <linux/kernel.h>
  26#include <linux/errno.h>
  27#include <linux/mempool.h>
  28#include <linux/list.h>
  29#include <linux/vmalloc.h>
  30#include <linux/raid/md.h>
  31#include <linux/raid/raid5.h>
  32
  33typedef raid5_conf_t raid6_conf_t; /* Same configuration */
  34
  35/* Additional compute_parity mode -- updates the parity w/o LOCKING */
  36#define UPDATE_PARITY   4
  37
  38/* We need a pre-zeroed page... if we don't want to use the kernel-provided
  39   one define it here */
  40#if RAID6_USE_EMPTY_ZERO_PAGE
  41# define raid6_empty_zero_page empty_zero_page
  42#else
  43extern const char raid6_empty_zero_page[PAGE_SIZE];
  44#endif
  45
  46#else /* ! __KERNEL__ */
  47/* Used for testing in user space */
  48
  49#include <errno.h>
  50#include <inttypes.h>
  51#include <limits.h>
  52#include <stddef.h>
  53#include <sys/mman.h>
  54#include <sys/types.h>
  55
  56/* Not standard, but glibc defines it */
  57#define BITS_PER_LONG __WORDSIZE
  58
  59typedef uint8_t  u8;
  60typedef uint16_t u16;
  61typedef uint32_t u32;
  62typedef uint64_t u64;
  63
  64#ifndef PAGE_SIZE
  65# define PAGE_SIZE 4096
  66#endif
  67extern const char raid6_empty_zero_page[PAGE_SIZE];
  68
  69#define __init
  70#define __exit
  71#define __attribute_const__ __attribute__((const))
  72
  73#define preempt_enable()
  74#define preempt_disable()
  75
  76#endif /* __KERNEL__ */
  77
  78/* Routine choices */
  79struct raid6_calls {
  80        void (*gen_syndrome)(int, size_t, void **);
  81        int  (*valid)(void);    /* Returns 1 if this routine set is usable */
  82        const char *name;       /* Name of this routine set */
  83        int prefer;             /* Has special performance attribute */
  84};
  85
  86/* Selected algorithm */
  87extern struct raid6_calls raid6_call;
  88
  89/* Algorithm list */
  90extern const struct raid6_calls * const raid6_algos[];
  91int raid6_select_algo(void);
  92
  93/* Return values from chk_syndrome */
  94#define RAID6_OK        0
  95#define RAID6_P_BAD     1
  96#define RAID6_Q_BAD     2
  97#define RAID6_PQ_BAD    3
  98
  99/* Galois field tables */
 100extern const u8 raid6_gfmul[256][256] __attribute__((aligned(256)));
 101extern const u8 raid6_gfexp[256]      __attribute__((aligned(256)));
 102extern const u8 raid6_gfinv[256]      __attribute__((aligned(256)));
 103extern const u8 raid6_gfexi[256]      __attribute__((aligned(256)));
 104
 105/* Recovery routines */
 106void raid6_2data_recov(int disks, size_t bytes, int faila, int failb, void **ptrs);
 107void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs);
 108void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, void **ptrs);
 109
 110/* Some definitions to allow code to be compiled for testing in userspace */
 111#ifndef __KERNEL__
 112
 113# define jiffies        raid6_jiffies()
 114# define printk         printf
 115# define GFP_KERNEL     0
 116# define __get_free_pages(x,y)  ((unsigned long)mmap(NULL, PAGE_SIZE << (y), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0))
 117# define free_pages(x,y)        munmap((void *)(x), (y)*PAGE_SIZE)
 118
 119static inline void cpu_relax(void)
 120{
 121        /* Nothing */
 122}
 123
 124#undef  HZ
 125#define HZ 1000
 126static inline uint32_t raid6_jiffies(void)
 127{
 128        struct timeval tv;
 129        gettimeofday(&tv, NULL);
 130        return tv.tv_sec*1000 + tv.tv_usec/1000;
 131}
 132
 133#endif /* ! __KERNEL__ */
 134
 135#endif /* LINUX_RAID_RAID6_H */
 136