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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* -*- 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 */