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/raid/md.h>
  22#include <linux/raid/raid5.h>
  23
  24typedef raid5_conf_t raid6_conf_t; /* Same configuration */
  25
  26/* Additional compute_parity mode -- updates the parity w/o LOCKING */
  27#define UPDATE_PARITY   4
  28
  29/* We need a pre-zeroed page... if we don't want to use the kernel-provided
  30   one define it here */
  31#if RAID6_USE_EMPTY_ZERO_PAGE
  32# define raid6_empty_zero_page empty_zero_page
  33#else
  34extern const char raid6_empty_zero_page[PAGE_SIZE];
  35#endif
  36
  37#else /* ! __KERNEL__ */
  38/* Used for testing in user space */
  39
  40#include <errno.h>
  41#include <inttypes.h>
  42#include <limits.h>
  43#include <stddef.h>
  44#include <sys/mman.h>
  45#include <sys/types.h>
  46
  47/* Not standard, but glibc defines it */
  48#define BITS_PER_LONG __WORDSIZE
  49
  50typedef uint8_t  u8;
  51typedef uint16_t u16;
  52typedef uint32_t u32;
  53typedef uint64_t u64;
  54
  55#ifndef PAGE_SIZE
  56# define PAGE_SIZE 4096
  57#endif
  58extern const char raid6_empty_zero_page[PAGE_SIZE];
  59
  60#define __init
  61#define __exit
  62#define __attribute_const__ __attribute__((const))
  63#define noinline __attribute__((noinline))
  64
  65#define preempt_enable()
  66#define preempt_disable()
  67#define cpu_has_feature(x) 1
  68#define enable_kernel_altivec()
  69#define disable_kernel_altivec()
  70
  71#endif /* __KERNEL__ */
  72
  73/* Routine choices */
  74struct raid6_calls {
  75        void (*gen_syndrome)(int, size_t, void **);
  76        int  (*valid)(void);    /* Returns 1 if this routine set is usable */
  77        const char *name;       /* Name of this routine set */
  78        int prefer;             /* Has special performance attribute */
  79};
  80
  81/* Selected algorithm */
  82extern struct raid6_calls raid6_call;
  83
  84/* Algorithm list */
  85extern const struct raid6_calls * const raid6_algos[];
  86int raid6_select_algo(void);
  87
  88/* Return values from chk_syndrome */
  89#define RAID6_OK        0
  90#define RAID6_P_BAD     1
  91#define RAID6_Q_BAD     2
  92#define RAID6_PQ_BAD    3
  93
  94/* Galois field tables */
  95extern const u8 raid6_gfmul[256][256] __attribute__((aligned(256)));
  96extern const u8 raid6_gfexp[256]      __attribute__((aligned(256)));
  97extern const u8 raid6_gfinv[256]      __attribute__((aligned(256)));
  98extern const u8 raid6_gfexi[256]      __attribute__((aligned(256)));
  99
 100/* Recovery routines */
 101void raid6_2data_recov(int disks, size_t bytes, int faila, int failb, void **ptrs);
 102void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs);
 103void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, void **ptrs);
 104
 105/* Some definitions to allow code to be compiled for testing in userspace */
 106#ifndef __KERNEL__
 107
 108# define jiffies        raid6_jiffies()
 109# define printk         printf
 110# define GFP_KERNEL     0
 111# define __get_free_pages(x,y)  ((unsigned long)mmap(NULL, PAGE_SIZE << (y), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0))
 112# define free_pages(x,y)        munmap((void *)(x), (y)*PAGE_SIZE)
 113
 114static inline void cpu_relax(void)
 115{
 116        /* Nothing */
 117}
 118
 119#undef  HZ
 120#define HZ 1000
 121static inline uint32_t raid6_jiffies(void)
 122{
 123        struct timeval tv;
 124        gettimeofday(&tv, NULL);
 125        return tv.tv_sec*1000 + tv.tv_usec/1000;
 126}
 127
 128#endif /* ! __KERNEL__ */
 129
 130#endif /* LINUX_RAID_RAID6_H */
 131