Merge branch 'samsung/exynos5' into next/soc2
[linux-2.6.git] / arch / x86 / crypto / crc32c-intel.c
1 /*
2  * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal.
3  * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE)
4  * CRC32 is a new instruction in Intel SSE4.2, the reference can be found at:
5  * http://www.intel.com/products/processor/manuals/
6  * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
7  * Volume 2A: Instruction Set Reference, A-M
8  *
9  * Copyright (C) 2008 Intel Corporation
10  * Authors: Austin Zhang <austin_zhang@linux.intel.com>
11  *          Kent Liu <kent.liu@intel.com>
12  *
13  * This program is free software; you can redistribute it and/or modify it
14  * under the terms and conditions of the GNU General Public License,
15  * version 2, as published by the Free Software Foundation.
16  *
17  * This program is distributed in the hope it will be useful, but WITHOUT
18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
20  * more details.
21  *
22  * You should have received a copy of the GNU General Public License along with
23  * this program; if not, write to the Free Software Foundation, Inc.,
24  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
25  *
26  */
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/string.h>
30 #include <linux/kernel.h>
31 #include <crypto/internal/hash.h>
32
33 #include <asm/cpufeature.h>
34 #include <asm/cpu_device_id.h>
35
36 #define CHKSUM_BLOCK_SIZE       1
37 #define CHKSUM_DIGEST_SIZE      4
38
39 #define SCALE_F sizeof(unsigned long)
40
41 #ifdef CONFIG_X86_64
42 #define REX_PRE "0x48, "
43 #else
44 #define REX_PRE
45 #endif
46
47 static u32 crc32c_intel_le_hw_byte(u32 crc, unsigned char const *data, size_t length)
48 {
49         while (length--) {
50                 __asm__ __volatile__(
51                         ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1"
52                         :"=S"(crc)
53                         :"0"(crc), "c"(*data)
54                 );
55                 data++;
56         }
57
58         return crc;
59 }
60
61 static u32 __pure crc32c_intel_le_hw(u32 crc, unsigned char const *p, size_t len)
62 {
63         unsigned int iquotient = len / SCALE_F;
64         unsigned int iremainder = len % SCALE_F;
65         unsigned long *ptmp = (unsigned long *)p;
66
67         while (iquotient--) {
68                 __asm__ __volatile__(
69                         ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
70                         :"=S"(crc)
71                         :"0"(crc), "c"(*ptmp)
72                 );
73                 ptmp++;
74         }
75
76         if (iremainder)
77                 crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp,
78                                  iremainder);
79
80         return crc;
81 }
82
83 /*
84  * Setting the seed allows arbitrary accumulators and flexible XOR policy
85  * If your algorithm starts with ~0, then XOR with ~0 before you set
86  * the seed.
87  */
88 static int crc32c_intel_setkey(struct crypto_shash *hash, const u8 *key,
89                         unsigned int keylen)
90 {
91         u32 *mctx = crypto_shash_ctx(hash);
92
93         if (keylen != sizeof(u32)) {
94                 crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
95                 return -EINVAL;
96         }
97         *mctx = le32_to_cpup((__le32 *)key);
98         return 0;
99 }
100
101 static int crc32c_intel_init(struct shash_desc *desc)
102 {
103         u32 *mctx = crypto_shash_ctx(desc->tfm);
104         u32 *crcp = shash_desc_ctx(desc);
105
106         *crcp = *mctx;
107
108         return 0;
109 }
110
111 static int crc32c_intel_update(struct shash_desc *desc, const u8 *data,
112                                unsigned int len)
113 {
114         u32 *crcp = shash_desc_ctx(desc);
115
116         *crcp = crc32c_intel_le_hw(*crcp, data, len);
117         return 0;
118 }
119
120 static int __crc32c_intel_finup(u32 *crcp, const u8 *data, unsigned int len,
121                                 u8 *out)
122 {
123         *(__le32 *)out = ~cpu_to_le32(crc32c_intel_le_hw(*crcp, data, len));
124         return 0;
125 }
126
127 static int crc32c_intel_finup(struct shash_desc *desc, const u8 *data,
128                               unsigned int len, u8 *out)
129 {
130         return __crc32c_intel_finup(shash_desc_ctx(desc), data, len, out);
131 }
132
133 static int crc32c_intel_final(struct shash_desc *desc, u8 *out)
134 {
135         u32 *crcp = shash_desc_ctx(desc);
136
137         *(__le32 *)out = ~cpu_to_le32p(crcp);
138         return 0;
139 }
140
141 static int crc32c_intel_digest(struct shash_desc *desc, const u8 *data,
142                                unsigned int len, u8 *out)
143 {
144         return __crc32c_intel_finup(crypto_shash_ctx(desc->tfm), data, len,
145                                     out);
146 }
147
148 static int crc32c_intel_cra_init(struct crypto_tfm *tfm)
149 {
150         u32 *key = crypto_tfm_ctx(tfm);
151
152         *key = ~0;
153
154         return 0;
155 }
156
157 static struct shash_alg alg = {
158         .setkey                 =       crc32c_intel_setkey,
159         .init                   =       crc32c_intel_init,
160         .update                 =       crc32c_intel_update,
161         .final                  =       crc32c_intel_final,
162         .finup                  =       crc32c_intel_finup,
163         .digest                 =       crc32c_intel_digest,
164         .descsize               =       sizeof(u32),
165         .digestsize             =       CHKSUM_DIGEST_SIZE,
166         .base                   =       {
167                 .cra_name               =       "crc32c",
168                 .cra_driver_name        =       "crc32c-intel",
169                 .cra_priority           =       200,
170                 .cra_blocksize          =       CHKSUM_BLOCK_SIZE,
171                 .cra_ctxsize            =       sizeof(u32),
172                 .cra_module             =       THIS_MODULE,
173                 .cra_init               =       crc32c_intel_cra_init,
174         }
175 };
176
177 static const struct x86_cpu_id crc32c_cpu_id[] = {
178         X86_FEATURE_MATCH(X86_FEATURE_XMM4_2),
179         {}
180 };
181 MODULE_DEVICE_TABLE(x86cpu, crc32c_cpu_id);
182
183 static int __init crc32c_intel_mod_init(void)
184 {
185         if (!x86_match_cpu(crc32c_cpu_id))
186                 return -ENODEV;
187         return crypto_register_shash(&alg);
188 }
189
190 static void __exit crc32c_intel_mod_fini(void)
191 {
192         crypto_unregister_shash(&alg);
193 }
194
195 module_init(crc32c_intel_mod_init);
196 module_exit(crc32c_intel_mod_fini);
197
198 MODULE_AUTHOR("Austin Zhang <austin.zhang@intel.com>, Kent Liu <kent.liu@intel.com>");
199 MODULE_DESCRIPTION("CRC32c (Castagnoli) optimization using Intel Hardware.");
200 MODULE_LICENSE("GPL");
201
202 MODULE_ALIAS("crc32c");
203 MODULE_ALIAS("crc32c-intel");