GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / x86 / crypto / crc32c-intel_glue.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/cpufeatures.h>
34 #include <asm/cpu_device_id.h>
35 #include <asm/fpu/internal.h>
36
37 #define CHKSUM_BLOCK_SIZE       1
38 #define CHKSUM_DIGEST_SIZE      4
39
40 #define SCALE_F sizeof(unsigned long)
41
42 #ifdef CONFIG_X86_64
43 #define REX_PRE "0x48, "
44 #else
45 #define REX_PRE
46 #endif
47
48 #ifdef CONFIG_X86_64
49 /*
50  * use carryless multiply version of crc32c when buffer
51  * size is >= 512 to account
52  * for fpu state save/restore overhead.
53  */
54 #define CRC32C_PCL_BREAKEVEN    512
55
56 asmlinkage unsigned int crc_pcl(const u8 *buffer, int len,
57                                 unsigned int crc_init);
58 #endif /* CONFIG_X86_64 */
59
60 static u32 crc32c_intel_le_hw_byte(u32 crc, unsigned char const *data, size_t length)
61 {
62         while (length--) {
63                 __asm__ __volatile__(
64                         ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1"
65                         :"=S"(crc)
66                         :"0"(crc), "c"(*data)
67                 );
68                 data++;
69         }
70
71         return crc;
72 }
73
74 static u32 __pure crc32c_intel_le_hw(u32 crc, unsigned char const *p, size_t len)
75 {
76         unsigned int iquotient = len / SCALE_F;
77         unsigned int iremainder = len % SCALE_F;
78         unsigned long *ptmp = (unsigned long *)p;
79
80         while (iquotient--) {
81                 __asm__ __volatile__(
82                         ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
83                         :"=S"(crc)
84                         :"0"(crc), "c"(*ptmp)
85                 );
86                 ptmp++;
87         }
88
89         if (iremainder)
90                 crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp,
91                                  iremainder);
92
93         return crc;
94 }
95
96 /*
97  * Setting the seed allows arbitrary accumulators and flexible XOR policy
98  * If your algorithm starts with ~0, then XOR with ~0 before you set
99  * the seed.
100  */
101 static int crc32c_intel_setkey(struct crypto_shash *hash, const u8 *key,
102                         unsigned int keylen)
103 {
104         u32 *mctx = crypto_shash_ctx(hash);
105
106         if (keylen != sizeof(u32)) {
107                 crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
108                 return -EINVAL;
109         }
110         *mctx = le32_to_cpup((__le32 *)key);
111         return 0;
112 }
113
114 static int crc32c_intel_init(struct shash_desc *desc)
115 {
116         u32 *mctx = crypto_shash_ctx(desc->tfm);
117         u32 *crcp = shash_desc_ctx(desc);
118
119         *crcp = *mctx;
120
121         return 0;
122 }
123
124 static int crc32c_intel_update(struct shash_desc *desc, const u8 *data,
125                                unsigned int len)
126 {
127         u32 *crcp = shash_desc_ctx(desc);
128
129         *crcp = crc32c_intel_le_hw(*crcp, data, len);
130         return 0;
131 }
132
133 static int __crc32c_intel_finup(u32 *crcp, const u8 *data, unsigned int len,
134                                 u8 *out)
135 {
136         *(__le32 *)out = ~cpu_to_le32(crc32c_intel_le_hw(*crcp, data, len));
137         return 0;
138 }
139
140 static int crc32c_intel_finup(struct shash_desc *desc, const u8 *data,
141                               unsigned int len, u8 *out)
142 {
143         return __crc32c_intel_finup(shash_desc_ctx(desc), data, len, out);
144 }
145
146 static int crc32c_intel_final(struct shash_desc *desc, u8 *out)
147 {
148         u32 *crcp = shash_desc_ctx(desc);
149
150         *(__le32 *)out = ~cpu_to_le32p(crcp);
151         return 0;
152 }
153
154 static int crc32c_intel_digest(struct shash_desc *desc, const u8 *data,
155                                unsigned int len, u8 *out)
156 {
157         return __crc32c_intel_finup(crypto_shash_ctx(desc->tfm), data, len,
158                                     out);
159 }
160
161 static int crc32c_intel_cra_init(struct crypto_tfm *tfm)
162 {
163         u32 *key = crypto_tfm_ctx(tfm);
164
165         *key = ~0;
166
167         return 0;
168 }
169
170 #ifdef CONFIG_X86_64
171 static int crc32c_pcl_intel_update(struct shash_desc *desc, const u8 *data,
172                                unsigned int len)
173 {
174         u32 *crcp = shash_desc_ctx(desc);
175
176         /*
177          * use faster PCL version if datasize is large enough to
178          * overcome kernel fpu state save/restore overhead
179          */
180         if (len >= CRC32C_PCL_BREAKEVEN && irq_fpu_usable()) {
181                 kernel_fpu_begin();
182                 *crcp = crc_pcl(data, len, *crcp);
183                 kernel_fpu_end();
184         } else
185                 *crcp = crc32c_intel_le_hw(*crcp, data, len);
186         return 0;
187 }
188
189 static int __crc32c_pcl_intel_finup(u32 *crcp, const u8 *data, unsigned int len,
190                                 u8 *out)
191 {
192         if (len >= CRC32C_PCL_BREAKEVEN && irq_fpu_usable()) {
193                 kernel_fpu_begin();
194                 *(__le32 *)out = ~cpu_to_le32(crc_pcl(data, len, *crcp));
195                 kernel_fpu_end();
196         } else
197                 *(__le32 *)out =
198                         ~cpu_to_le32(crc32c_intel_le_hw(*crcp, data, len));
199         return 0;
200 }
201
202 static int crc32c_pcl_intel_finup(struct shash_desc *desc, const u8 *data,
203                               unsigned int len, u8 *out)
204 {
205         return __crc32c_pcl_intel_finup(shash_desc_ctx(desc), data, len, out);
206 }
207
208 static int crc32c_pcl_intel_digest(struct shash_desc *desc, const u8 *data,
209                                unsigned int len, u8 *out)
210 {
211         return __crc32c_pcl_intel_finup(crypto_shash_ctx(desc->tfm), data, len,
212                                     out);
213 }
214 #endif /* CONFIG_X86_64 */
215
216 static struct shash_alg alg = {
217         .setkey                 =       crc32c_intel_setkey,
218         .init                   =       crc32c_intel_init,
219         .update                 =       crc32c_intel_update,
220         .final                  =       crc32c_intel_final,
221         .finup                  =       crc32c_intel_finup,
222         .digest                 =       crc32c_intel_digest,
223         .descsize               =       sizeof(u32),
224         .digestsize             =       CHKSUM_DIGEST_SIZE,
225         .base                   =       {
226                 .cra_name               =       "crc32c",
227                 .cra_driver_name        =       "crc32c-intel",
228                 .cra_priority           =       200,
229                 .cra_flags              =       CRYPTO_ALG_OPTIONAL_KEY,
230                 .cra_blocksize          =       CHKSUM_BLOCK_SIZE,
231                 .cra_ctxsize            =       sizeof(u32),
232                 .cra_module             =       THIS_MODULE,
233                 .cra_init               =       crc32c_intel_cra_init,
234         }
235 };
236
237 static const struct x86_cpu_id crc32c_cpu_id[] = {
238         X86_FEATURE_MATCH(X86_FEATURE_XMM4_2),
239         {}
240 };
241 MODULE_DEVICE_TABLE(x86cpu, crc32c_cpu_id);
242
243 static int __init crc32c_intel_mod_init(void)
244 {
245         if (!x86_match_cpu(crc32c_cpu_id))
246                 return -ENODEV;
247 #ifdef CONFIG_X86_64
248         if (boot_cpu_has(X86_FEATURE_PCLMULQDQ)) {
249                 alg.update = crc32c_pcl_intel_update;
250                 alg.finup = crc32c_pcl_intel_finup;
251                 alg.digest = crc32c_pcl_intel_digest;
252         }
253 #endif
254         return crypto_register_shash(&alg);
255 }
256
257 static void __exit crc32c_intel_mod_fini(void)
258 {
259         crypto_unregister_shash(&alg);
260 }
261
262 module_init(crc32c_intel_mod_init);
263 module_exit(crc32c_intel_mod_fini);
264
265 MODULE_AUTHOR("Austin Zhang <austin.zhang@intel.com>, Kent Liu <kent.liu@intel.com>");
266 MODULE_DESCRIPTION("CRC32c (Castagnoli) optimization using Intel Hardware.");
267 MODULE_LICENSE("GPL");
268
269 MODULE_ALIAS_CRYPTO("crc32c");
270 MODULE_ALIAS_CRYPTO("crc32c-intel");