1 // SPDX-License-Identifier: GPL-2.0-only
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
21 u32 __crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len);
22
crc32c_vpmsum(u32 crc,unsigned char const * p,size_t len)23 static 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
crc32c_vpmsum_cra_init(struct crypto_tfm * tfm)57 static 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 * Setting the seed allows arbitrary accumulators and flexible XOR policy
68 * If your algorithm starts with ~0, then XOR with ~0 before you set
69 * the seed.
70 */
crc32c_vpmsum_setkey(struct crypto_shash * hash,const u8 * key,unsigned int keylen)71 static 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 crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
78 return -EINVAL;
79 }
80 *mctx = le32_to_cpup((__le32 *)key);
81 return 0;
82 }
83
crc32c_vpmsum_init(struct shash_desc * desc)84 static int crc32c_vpmsum_init(struct shash_desc *desc)
85 {
86 u32 *mctx = crypto_shash_ctx(desc->tfm);
87 u32 *crcp = shash_desc_ctx(desc);
88
89 *crcp = *mctx;
90
91 return 0;
92 }
93
crc32c_vpmsum_update(struct shash_desc * desc,const u8 * data,unsigned int len)94 static int crc32c_vpmsum_update(struct shash_desc *desc, const u8 *data,
95 unsigned int len)
96 {
97 u32 *crcp = shash_desc_ctx(desc);
98
99 *crcp = crc32c_vpmsum(*crcp, data, len);
100
101 return 0;
102 }
103
__crc32c_vpmsum_finup(u32 * crcp,const u8 * data,unsigned int len,u8 * out)104 static int __crc32c_vpmsum_finup(u32 *crcp, const u8 *data, unsigned int len,
105 u8 *out)
106 {
107 *(__le32 *)out = ~cpu_to_le32(crc32c_vpmsum(*crcp, data, len));
108
109 return 0;
110 }
111
crc32c_vpmsum_finup(struct shash_desc * desc,const u8 * data,unsigned int len,u8 * out)112 static int crc32c_vpmsum_finup(struct shash_desc *desc, const u8 *data,
113 unsigned int len, u8 *out)
114 {
115 return __crc32c_vpmsum_finup(shash_desc_ctx(desc), data, len, out);
116 }
117
crc32c_vpmsum_final(struct shash_desc * desc,u8 * out)118 static int crc32c_vpmsum_final(struct shash_desc *desc, u8 *out)
119 {
120 u32 *crcp = shash_desc_ctx(desc);
121
122 *(__le32 *)out = ~cpu_to_le32p(crcp);
123
124 return 0;
125 }
126
crc32c_vpmsum_digest(struct shash_desc * desc,const u8 * data,unsigned int len,u8 * out)127 static int crc32c_vpmsum_digest(struct shash_desc *desc, const u8 *data,
128 unsigned int len, u8 *out)
129 {
130 return __crc32c_vpmsum_finup(crypto_shash_ctx(desc->tfm), data, len,
131 out);
132 }
133
134 static struct shash_alg alg = {
135 .setkey = crc32c_vpmsum_setkey,
136 .init = crc32c_vpmsum_init,
137 .update = crc32c_vpmsum_update,
138 .final = crc32c_vpmsum_final,
139 .finup = crc32c_vpmsum_finup,
140 .digest = crc32c_vpmsum_digest,
141 .descsize = sizeof(u32),
142 .digestsize = CHKSUM_DIGEST_SIZE,
143 .base = {
144 .cra_name = "crc32c",
145 .cra_driver_name = "crc32c-vpmsum",
146 .cra_priority = 200,
147 .cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
148 .cra_blocksize = CHKSUM_BLOCK_SIZE,
149 .cra_ctxsize = sizeof(u32),
150 .cra_module = THIS_MODULE,
151 .cra_init = crc32c_vpmsum_cra_init,
152 }
153 };
154
crc32c_vpmsum_mod_init(void)155 static int __init crc32c_vpmsum_mod_init(void)
156 {
157 if (!cpu_has_feature(CPU_FTR_ARCH_207S))
158 return -ENODEV;
159
160 return crypto_register_shash(&alg);
161 }
162
crc32c_vpmsum_mod_fini(void)163 static void __exit crc32c_vpmsum_mod_fini(void)
164 {
165 crypto_unregister_shash(&alg);
166 }
167
168 module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, crc32c_vpmsum_mod_init);
169 module_exit(crc32c_vpmsum_mod_fini);
170
171 MODULE_AUTHOR("Anton Blanchard <anton@samba.org>");
172 MODULE_DESCRIPTION("CRC32C using vector polynomial multiply-sum instructions");
173 MODULE_LICENSE("GPL");
174 MODULE_ALIAS_CRYPTO("crc32c");
175 MODULE_ALIAS_CRYPTO("crc32c-vpmsum");
176