ReactOS 0.4.15-dev-8127-g6338913
galois.c File Reference
#include "btrfs_drv.h"
Include dependency graph for galois.c:

Go to the source code of this file.


void galois_divpower (uint8_t *data, uint8_t div, uint32_t len)
uint8_t gpow2 (uint8_t e)
uint8_t gmul (uint8_t a, uint8_t b)
uint8_t gdiv (uint8_t a, uint8_t b)
static __inline uint32_t galois_double_mask32 (uint32_t v)
void galois_double (uint8_t *data, uint32_t len)


static const uint8_t glog []
static const uint8_t gilog []

Function Documentation

◆ galois_divpower()

void galois_divpower ( uint8_t data,
uint8_t  div,
uint32_t  len 

Definition at line 55 of file galois.c.

55 {
56 while (len > 0) {
57 if (data[0] != 0) {
58 if (gilog[data[0]] <= div)
59 data[0] = glog[(gilog[data[0]] + (255 - div)) % 255];
60 else
61 data[0] = glog[(gilog[data[0]] - div) % 255];
62 }
64 data++;
65 len--;
66 }
_STLP_VENDOR_CSTD::ldiv_t div(long __x, long __y)
Definition: _cstdlib.h:137
static const uint8_t glog[]
Definition: galois.c:20
static const uint8_t gilog[]
Definition: galois.c:37
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: gl.h:1950
GLenum GLsizei len
Definition: glext.h:6722

Referenced by raid6_recover2(), and scrub_raid6_stripe().

◆ galois_double()

void galois_double ( uint8_t data,
uint32_t  len 

Definition at line 109 of file galois.c.

109 {
110 // FIXME - SIMD?
112#if defined(_AMD64_) || defined(_ARM64_)
113 while (len > sizeof(uint64_t)) {
114 uint64_t v = *((uint64_t*)data), vv;
116 vv = (v << 1) & 0xfefefefefefefefe;
117 vv ^= galois_double_mask64(v) & 0x1d1d1d1d1d1d1d1d;
118 *((uint64_t*)data) = vv;
120 data += sizeof(uint64_t);
121 len -= sizeof(uint64_t);
122 }
124 while (len > sizeof(uint32_t)) {
125 uint32_t v = *((uint32_t*)data), vv;
127 vv = (v << 1) & 0xfefefefe;
128 vv ^= galois_double_mask32(v) & 0x1d1d1d1d;
129 *((uint32_t*)data) = vv;
131 data += sizeof(uint32_t);
132 len -= sizeof(uint32_t);
133 }
136 while (len > 0) {
137 data[0] = (data[0] << 1) ^ ((data[0] & 0x80) ? 0x1d : 0);
138 data++;
139 len--;
140 }
UINT32 uint32_t
Definition: types.h:75
UINT64 uint64_t
Definition: types.h:77
static __inline uint32_t galois_double_mask32(uint32_t v)
Definition: galois.c:103
const GLdouble * v
Definition: gl.h:2040
#define uint32_t
Definition: nsiface.idl:61
#define uint64_t
Definition: nsiface.idl:62

Referenced by flush_partial_stripe(), raid6_recover2(), and scrub_raid6_stripe().

◆ galois_double_mask32()

static __inline uint32_t galois_double_mask32 ( uint32_t  v)

Definition at line 103 of file galois.c.

103 {
104 v &= 0x80808080;
105 return (v << 1) - (v >> 7);

Referenced by galois_double().

◆ gdiv()

uint8_t gdiv ( uint8_t  a,
uint8_t  b 

Definition at line 80 of file galois.c.

80 {
81 if (b == 0) {
82 return 0xff; // shouldn't happen
83 } else if (a == 0) {
84 return 0;
85 } else {
86 if (gilog[a] >= gilog[b])
87 return glog[(gilog[a] - gilog[b]) % 255];
88 else
89 return glog[255-((gilog[b] - gilog[a]) % 255)];
90 }
GLboolean GLboolean GLboolean b
Definition: glext.h:6204
GLboolean GLboolean GLboolean GLboolean a
Definition: glext.h:6204
#define a
Definition: ke_i.h:78
#define b
Definition: ke_i.h:79

Referenced by raid6_recover2(), and scrub_raid6_stripe().

◆ gmul()

uint8_t gmul ( uint8_t  a,
uint8_t  b 

Definition at line 73 of file galois.c.

73 {
74 if (a == 0 || b == 0)
75 return 0;
76 else
77 return glog[(gilog[a] + gilog[b]) % 255];

Referenced by raid6_recover2(), and scrub_raid6_stripe().

◆ gpow2()

uint8_t gpow2 ( uint8_t  e)

Definition at line 69 of file galois.c.

69 {
70 return glog[e%255];
#define e
Definition: ke_i.h:82

Referenced by raid6_recover2(), and scrub_raid6_stripe().

Variable Documentation

◆ gilog

const uint8_t gilog[]
Initial value:
= {0x00, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b,
0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71,
0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21, 0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45,
0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9, 0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6,
0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd, 0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88,
0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd, 0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40,
0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e, 0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3d,
0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b, 0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57,
0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d, 0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18,
0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c, 0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e,
0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd, 0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61,
0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e, 0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2,
0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76, 0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6,
0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa, 0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a,
0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51, 0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7,
0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8, 0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf}

Definition at line 37 of file galois.c.

Referenced by galois_divpower(), gdiv(), and gmul().

◆ glog

const uint8_t glog[]
Initial value:
= {0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26,
0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9, 0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0,
0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35, 0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23,
0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0, 0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1,
0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc, 0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0,
0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f, 0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2,
0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88, 0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce,
0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93, 0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc,
0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9, 0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54,
0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa, 0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73,
0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e, 0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff,
0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4, 0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41,
0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e, 0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6,
0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef, 0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09,
0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5, 0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16,
0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x01}

Definition at line 20 of file galois.c.

Referenced by galois_divpower(), gdiv(), gmul(), and gpow2().