aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/md/raid6.h
blob: f80ee6350edf1dce079af9e680ec12740229b3f2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright 2003 H. Peter Anvin - All Rights Reserved
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
 *   Bostom MA 02111-1307, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

#ifndef LINUX_RAID_RAID6_H
#define LINUX_RAID_RAID6_H

#ifdef __KERNEL__

/* Set to 1 to use kernel-wide empty_zero_page */
#define RAID6_USE_EMPTY_ZERO_PAGE 0

#include <linux/module.h>
#include <linux/stddef.h>
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/mempool.h>
#include <linux/list.h>
#include <linux/vmalloc.h>
#include <linux/raid/md.h>
#include <linux/raid/raid5.h>

typedef raid5_conf_t raid6_conf_t; /* Same configuration */

/* Additional compute_parity mode -- updates the parity w/o LOCKING */
#define UPDATE_PARITY	4

/* We need a pre-zeroed page... if we don't want to use the kernel-provided
   one define it here */
#if RAID6_USE_EMPTY_ZERO_PAGE
# define raid6_empty_zero_page empty_zero_page
#else
extern const char raid6_empty_zero_page[PAGE_SIZE];
#endif

#else /* ! __KERNEL__ */
/* Used for testing in user space */

#include <errno.h>
#include <inttypes.h>
#include <limits.h>
#include <stddef.h>
#include <sys/mman.h>
#include <sys/types.h>

/* Not standard, but glibc defines it */
#define BITS_PER_LONG __WORDSIZE

typedef uint8_t  u8;
typedef uint16_t u16;
typedef uint32_t u32;
typedef uint64_t u64;

#ifndef PAGE_SIZE
# define PAGE_SIZE 4096
#endif
extern const char raid6_empty_zero_page[PAGE_SIZE];

#define __init
#define __exit
#define __attribute_const__ __attribute__((const))

#define preempt_enable()
#define preempt_disable()

#endif /* __KERNEL__ */

/* Routine choices */
struct raid6_calls {
	void (*gen_syndrome)(int, size_t, void **);
	int  (*valid)(void);	/* Returns 1 if this routine set is usable */
	const char *name;	/* Name of this routine set */
	int prefer;		/* Has special performance attribute */
};

/* Selected algorithm */
extern struct raid6_calls raid6_call;

/* Algorithm list */
extern const struct raid6_calls * const raid6_algos[];
int raid6_select_algo(void);

/* Return values from chk_syndrome */
#define RAID6_OK	0
#define RAID6_P_BAD	1
#define RAID6_Q_BAD	2
#define RAID6_PQ_BAD	3

/* Galois field tables */
extern const u8 raid6_gfmul[256][256] __attribute__((aligned(256)));
extern const u8 raid6_gfexp[256]      __attribute__((aligned(256)));
extern const u8 raid6_gfinv[256]      __attribute__((aligned(256)));
extern const u8 raid6_gfexi[256]      __attribute__((aligned(256)));

/* Recovery routines */
void raid6_2data_recov(int disks, size_t bytes, int faila, int failb, void **ptrs);
void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs);
void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, void **ptrs);

/* Some definitions to allow code to be compiled for testing in userspace */
#ifndef __KERNEL__

# define jiffies	raid6_jiffies()
# define printk 	printf
# define GFP_KERNEL	0
# define __get_free_pages(x,y)	((unsigned long)mmap(NULL, PAGE_SIZE << (y), PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0))
# define free_pages(x,y)	munmap((void *)(x), (y)*PAGE_SIZE)

static inline void cpu_relax(void)
{
	/* Nothing */
}

#undef  HZ
#define HZ 1000
static inline uint32_t raid6_jiffies(void)
{
	struct timeval tv;
	gettimeofday(&tv, NULL);
	return tv.tv_sec*1000 + tv.tv_usec/1000;
}

#endif /* ! __KERNEL__ */

#endif /* LINUX_RAID_RAID6_H */