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 EXPORT_SYMBOL_GPL(sym)
66 #define MODULE_LICENSE(licence)
67 #define MODULE_DESCRIPTION(desc)
68 #define subsys_initcall(x)
69 #define module_exit(x)
70 #endif /* __KERNEL__ */
71 
72 /* Routine choices */
73 struct raid6_calls {
74 	void (*gen_syndrome)(int, size_t, void **);
75 	int  (*valid)(void);	/* Returns 1 if this routine set is usable */
76 	const char *name;	/* Name of this routine set */
77 	int prefer;		/* Has special performance attribute */
78 };
79 
80 /* Selected algorithm */
81 extern struct raid6_calls raid6_call;
82 
83 /* Various routine sets */
84 extern const struct raid6_calls raid6_intx1;
85 extern const struct raid6_calls raid6_intx2;
86 extern const struct raid6_calls raid6_intx4;
87 extern const struct raid6_calls raid6_intx8;
88 extern const struct raid6_calls raid6_intx16;
89 extern const struct raid6_calls raid6_intx32;
90 extern const struct raid6_calls raid6_mmxx1;
91 extern const struct raid6_calls raid6_mmxx2;
92 extern const struct raid6_calls raid6_sse1x1;
93 extern const struct raid6_calls raid6_sse1x2;
94 extern const struct raid6_calls raid6_sse2x1;
95 extern const struct raid6_calls raid6_sse2x2;
96 extern const struct raid6_calls raid6_sse2x4;
97 extern const struct raid6_calls raid6_altivec1;
98 extern const struct raid6_calls raid6_altivec2;
99 extern const struct raid6_calls raid6_altivec4;
100 extern const struct raid6_calls raid6_altivec8;
101 
102 /* Algorithm list */
103 extern const struct raid6_calls * const raid6_algos[];
104 int raid6_select_algo(void);
105 
106 /* Return values from chk_syndrome */
107 #define RAID6_OK	0
108 #define RAID6_P_BAD	1
109 #define RAID6_Q_BAD	2
110 #define RAID6_PQ_BAD	3
111 
112 /* Galois field tables */
113 extern const u8 raid6_gfmul[256][256] __attribute__((aligned(256)));
114 extern const u8 raid6_gfexp[256]      __attribute__((aligned(256)));
115 extern const u8 raid6_gfinv[256]      __attribute__((aligned(256)));
116 extern const u8 raid6_gfexi[256]      __attribute__((aligned(256)));
117 
118 /* Recovery routines */
119 void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
120 		       void **ptrs);
121 void raid6_datap_recov(int disks, size_t bytes, int faila, void **ptrs);
122 void raid6_dual_recov(int disks, size_t bytes, int faila, int failb,
123 		      void **ptrs);
124 
125 /* Some definitions to allow code to be compiled for testing in userspace */
126 #ifndef __KERNEL__
127 
128 # define jiffies	raid6_jiffies()
129 # define printk 	printf
130 # define GFP_KERNEL	0
131 # define __get_free_pages(x, y)	((unsigned long)mmap(NULL, PAGE_SIZE << (y), \
132 						     PROT_READ|PROT_WRITE,   \
133 						     MAP_PRIVATE|MAP_ANONYMOUS,\
134 						     0, 0))
135 # define free_pages(x, y)	munmap((void *)(x), (y)*PAGE_SIZE)
136 
cpu_relax(void)137 static inline void cpu_relax(void)
138 {
139 	/* Nothing */
140 }
141 
142 #undef  HZ
143 #define HZ 1000
raid6_jiffies(void)144 static inline uint32_t raid6_jiffies(void)
145 {
146 	struct timeval tv;
147 	gettimeofday(&tv, NULL);
148 	return tv.tv_sec*1000 + tv.tv_usec/1000;
149 }
150 
151 #endif /* ! __KERNEL__ */
152 
153 #endif /* LINUX_RAID_RAID6_H */
154