LXR linux/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
  27extern 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
  43typedef uint8_t  u8;
  44typedef uint16_t u16;
  45typedef uint32_t u32;
  46typedef uint64_t u64;
  47
  48#ifndef PAGE_SIZE
  49# define PAGE_SIZE 4096
  50#endif
  51extern 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 */
  71struct 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 */
  79extern struct raid6_calls raid6_call;
  80
  81/* Algorithm list */
  82extern const struct raid6_calls * const raid6_algos[];
  83int 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 */
  92extern const u8 raid6_gfmul[256][256] __attribute__((aligned(256)));
  93extern const u8 raid6_gfexp[256]      __attribute__((aligned(256)));
  94extern const u8 raid6_gfinv[256]      __attribute__((aligned(256)));
  95extern const u8 raid6_gfexi[256]      __attribute__((aligned(256)));
  96
  97/* Recovery routines */
  98void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
  99                       void **ptrs);
 100void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs);
 101void 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
 116static inline void cpu_relax(void)
 117{
 118        /* Nothing */
 119}
 120
 121#undef  HZ
 122#define HZ 1000
 123static 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 */
 133