1
2#include <linux/crc32.h>
3#include <crypto/internal/hash.h>
4#include <crypto/internal/simd.h>
5#include <linux/init.h>
6#include <linux/module.h>
7#include <linux/string.h>
8#include <linux/kernel.h>
9#include <linux/cpufeature.h>
10#include <asm/simd.h>
11#include <asm/switch_to.h>
12
13#define CHKSUM_BLOCK_SIZE 1
14#define CHKSUM_DIGEST_SIZE 4
15
16#define VMX_ALIGN 16
17#define VMX_ALIGN_MASK (VMX_ALIGN-1)
18
19#define VECTOR_BREAKPOINT 512
20
21u32 __crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len);
22
23static u32 crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len)
24{
25 unsigned int prealign;
26 unsigned int tail;
27
28 if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) || !crypto_simd_usable())
29 return __crc32c_le(crc, p, len);
30
31 if ((unsigned long)p & VMX_ALIGN_MASK) {
32 prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK);
33 crc = __crc32c_le(crc, p, prealign);
34 len -= prealign;
35 p += prealign;
36 }
37
38 if (len & ~VMX_ALIGN_MASK) {
39 preempt_disable();
40 pagefault_disable();
41 enable_kernel_altivec();
42 crc = __crc32c_vpmsum(crc, p, len & ~VMX_ALIGN_MASK);
43 disable_kernel_altivec();
44 pagefault_enable();
45 preempt_enable();
46 }
47
48 tail = len & VMX_ALIGN_MASK;
49 if (tail) {
50 p += len & ~VMX_ALIGN_MASK;
51 crc = __crc32c_le(crc, p, tail);
52 }
53
54 return crc;
55}
56
57static int crc32c_vpmsum_cra_init(struct crypto_tfm *tfm)
58{
59 u32 *key = crypto_tfm_ctx(tfm);
60
61 *key = ~0;
62
63 return 0;
64}
65
66
67
68
69
70
71static int crc32c_vpmsum_setkey(struct crypto_shash *hash, const u8 *key,
72 unsigned int keylen)
73{
74 u32 *mctx = crypto_shash_ctx(hash);
75
76 if (keylen != sizeof(u32))
77 return -EINVAL;
78 *mctx = le32_to_cpup((__le32 *)key);
79 return 0;
80}
81
82static int crc32c_vpmsum_init(struct shash_desc *desc)
83{
84 u32 *mctx = crypto_shash_ctx(desc->tfm);
85 u32 *crcp = shash_desc_ctx(desc);
86
87 *crcp = *mctx;
88
89 return 0;
90}
91
92static int crc32c_vpmsum_update(struct shash_desc *desc, const u8 *data,
93 unsigned int len)
94{
95 u32 *crcp = shash_desc_ctx(desc);
96
97 *crcp = crc32c_vpmsum(*crcp, data, len);
98
99 return 0;
100}
101
102static int __crc32c_vpmsum_finup(u32 *crcp, const u8 *data, unsigned int len,
103 u8 *out)
104{
105 *(__le32 *)out = ~cpu_to_le32(crc32c_vpmsum(*crcp, data, len));
106
107 return 0;
108}
109
110static int crc32c_vpmsum_finup(struct shash_desc *desc, const u8 *data,
111 unsigned int len, u8 *out)
112{
113 return __crc32c_vpmsum_finup(shash_desc_ctx(desc), data, len, out);
114}
115
116static int crc32c_vpmsum_final(struct shash_desc *desc, u8 *out)
117{
118 u32 *crcp = shash_desc_ctx(desc);
119
120 *(__le32 *)out = ~cpu_to_le32p(crcp);
121
122 return 0;
123}
124
125static int crc32c_vpmsum_digest(struct shash_desc *desc, const u8 *data,
126 unsigned int len, u8 *out)
127{
128 return __crc32c_vpmsum_finup(crypto_shash_ctx(desc->tfm), data, len,
129 out);
130}
131
132static struct shash_alg alg = {
133 .setkey = crc32c_vpmsum_setkey,
134 .init = crc32c_vpmsum_init,
135 .update = crc32c_vpmsum_update,
136 .final = crc32c_vpmsum_final,
137 .finup = crc32c_vpmsum_finup,
138 .digest = crc32c_vpmsum_digest,
139 .descsize = sizeof(u32),
140 .digestsize = CHKSUM_DIGEST_SIZE,
141 .base = {
142 .cra_name = "crc32c",
143 .cra_driver_name = "crc32c-vpmsum",
144 .cra_priority = 200,
145 .cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
146 .cra_blocksize = CHKSUM_BLOCK_SIZE,
147 .cra_ctxsize = sizeof(u32),
148 .cra_module = THIS_MODULE,
149 .cra_init = crc32c_vpmsum_cra_init,
150 }
151};
152
153static int __init crc32c_vpmsum_mod_init(void)
154{
155 if (!cpu_has_feature(CPU_FTR_ARCH_207S))
156 return -ENODEV;
157
158 return crypto_register_shash(&alg);
159}
160
161static void __exit crc32c_vpmsum_mod_fini(void)
162{
163 crypto_unregister_shash(&alg);
164}
165
166module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, crc32c_vpmsum_mod_init);
167module_exit(crc32c_vpmsum_mod_fini);
168
169MODULE_AUTHOR("Anton Blanchard <anton@samba.org>");
170MODULE_DESCRIPTION("CRC32C using vector polynomial multiply-sum instructions");
171MODULE_LICENSE("GPL");
172MODULE_ALIAS_CRYPTO("crc32c");
173MODULE_ALIAS_CRYPTO("crc32c-vpmsum");
174
