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
  24 typedef 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
  34 extern 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
  50 typedef uint8_t  u8;
  51 typedef uint16_t u16;
  52 typedef uint32_t u32;
  53 typedef uint64_t u64;
  54
  55 #ifndef PAGE_SIZE
  56 # define PAGE_SIZE 4096
  57 #endif
  58 extern 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 */
  74 struct 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 */
  82 extern struct raid6_calls raid6_call;
  83
  84 /* Algorithm list */
  85 extern const struct raid6_calls * const raid6_algos[];
  86 int 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 */
  95 extern const u8 raid6_gfmul[256][256] __attribute__((aligned(256)));
  96 extern const u8 raid6_gfexp[256]      __attribute__((aligned(256)));
  97 extern const u8 raid6_gfinv[256]      __attribute__((aligned(256)));
  98 extern const u8 raid6_gfexi[256]      __attribute__((aligned(256)));
  99
 100 /* Recovery routines */
 101 void raid6_2data_recov(int disks, size_t bytes, int faila, int failb, void **ptrs);
 102 void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs);
 103 void 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
 114 static inline void cpu_relax(void)
 115 {
 116         /* Nothing */
 117 }
 118
 119 #undef  HZ
 120 #define HZ 1000
 121 static 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 */