include/linux/raid/pq.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  *   Boston 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 #include <linux/blkdev.h>
  21
  22 /* We need a pre-zeroed page... if we don't want to use the kernel-provided
  23    one define it here */
  24 #if RAID6_USE_EMPTY_ZERO_PAGE
  25 # define raid6_empty_zero_page empty_zero_page
  26 #else
  27 extern const char raid6_empty_zero_page[PAGE_SIZE];
  28 #endif
  29
  30 #else /* ! __KERNEL__ */
  31 /* Used for testing in user space */
  32
  33 #include <errno.h>
  34 #include <inttypes.h>
  35 #include <limits.h>
  36 #include <stddef.h>
  37 #include <sys/mman.h>
  38 #include <sys/types.h>
  39
  40 /* Not standard, but glibc defines it */
  41 #define BITS_PER_LONG __WORDSIZE
  42
  43 typedef uint8_t  u8;
  44 typedef uint16_t u16;
  45 typedef uint32_t u32;
  46 typedef uint64_t u64;
  47
  48 #ifndef PAGE_SIZE
  49 # define PAGE_SIZE 4096
  50 #endif
  51 extern const char raid6_empty_zero_page[PAGE_SIZE];
  52
  53 #define __init
  54 #define __exit
  55 #define __attribute_const__ __attribute__((const))
  56 #define noinline __attribute__((noinline))
  57
  58 #define preempt_enable()
  59 #define preempt_disable()
  60 #define cpu_has_feature(x) 1
  61 #define enable_kernel_altivec()
  62 #define disable_kernel_altivec()
  63
  64 #define EXPORT_SYMBOL(sym)
  65 #define MODULE_LICENSE(licence)
  66 #define subsys_initcall(x)
  67 #define module_exit(x)
  68 #endif /* __KERNEL__ */
  69
  70 /* Routine choices */
  71 struct raid6_calls {
  72         void (*gen_syndrome)(int, size_t, void **);
  73         int  (*valid)(void);    /* Returns 1 if this routine set is usable */
  74         const char *name;       /* Name of this routine set */
  75         int prefer;             /* Has special performance attribute */
  76 };
  77
  78 /* Selected algorithm */
  79 extern struct raid6_calls raid6_call;
  80
  81 /* Algorithm list */
  82 extern const struct raid6_calls * const raid6_algos[];
  83 int raid6_select_algo(void);
  84
  85 /* Return values from chk_syndrome */
  86 #define RAID6_OK        0
  87 #define RAID6_P_BAD     1
  88 #define RAID6_Q_BAD     2
  89 #define RAID6_PQ_BAD    3
  90
  91 /* Galois field tables */
  92 extern const u8 raid6_gfmul[256][256] __attribute__((aligned(256)));
  93 extern const u8 raid6_gfexp[256]      __attribute__((aligned(256)));
  94 extern const u8 raid6_gfinv[256]      __attribute__((aligned(256)));
  95 extern const u8 raid6_gfexi[256]      __attribute__((aligned(256)));
  96
  97 /* Recovery routines */
  98 void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
  99                        void **ptrs);
 100 void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs);
 101 void raid6_dual_recov(int disks, size_t bytes, int faila, int failb,
 102                       void **ptrs);
 103
 104 /* Some definitions to allow code to be compiled for testing in userspace */
 105 #ifndef __KERNEL__
 106
 107 # define jiffies        raid6_jiffies()
 108 # define printk         printf
 109 # define GFP_KERNEL     0
 110 # define __get_free_pages(x, y) ((unsigned long)mmap(NULL, PAGE_SIZE << (y), \
 111                                                      PROT_READ|PROT_WRITE,   \
 112                                                      MAP_PRIVATE|MAP_ANONYMOUS,\
 113                                                      0, 0))
 114 # define free_pages(x, y)       munmap((void *)(x), (y)*PAGE_SIZE)
 115
 116 static inline void cpu_relax(void)
 117 {
 118         /* Nothing */
 119 }
 120
 121 #undef  HZ
 122 #define HZ 1000
 123 static inline uint32_t raid6_jiffies(void)
 124 {
 125         struct timeval tv;
 126         gettimeofday(&tv, NULL);
 127         return tv.tv_sec*1000 + tv.tv_usec/1000;
 128 }
 129
 130 #endif /* ! __KERNEL__ */
 131
 132 #endif /* LINUX_RAID_RAID6_H */