xref: /openbmc/linux/arch/sparc/crypto/crc32c_glue.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Glue code for CRC32C optimized for sparc64 crypto opcodes.
3  *
4  * This is based largely upon arch/x86/crypto/crc32c-intel.c
5  *
6  * Copyright (C) 2008 Intel Corporation
7  * Authors: Austin Zhang <austin_zhang@linux.intel.com>
8  *          Kent Liu <kent.liu@intel.com>
9  */
10 
11 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
12 
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/string.h>
16 #include <linux/kernel.h>
17 #include <linux/crc32.h>
18 
19 #include <crypto/internal/hash.h>
20 
21 #include <asm/pstate.h>
22 #include <asm/elf.h>
23 
24 #include "opcodes.h"
25 
26 /*
27  * Setting the seed allows arbitrary accumulators and flexible XOR policy
28  * If your algorithm starts with ~0, then XOR with ~0 before you set
29  * the seed.
30  */
31 static int crc32c_sparc64_setkey(struct crypto_shash *hash, const u8 *key,
32 				 unsigned int keylen)
33 {
34 	u32 *mctx = crypto_shash_ctx(hash);
35 
36 	if (keylen != sizeof(u32)) {
37 		crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
38 		return -EINVAL;
39 	}
40 	*(__le32 *)mctx = le32_to_cpup((__le32 *)key);
41 	return 0;
42 }
43 
44 static int crc32c_sparc64_init(struct shash_desc *desc)
45 {
46 	u32 *mctx = crypto_shash_ctx(desc->tfm);
47 	u32 *crcp = shash_desc_ctx(desc);
48 
49 	*crcp = *mctx;
50 
51 	return 0;
52 }
53 
54 extern void crc32c_sparc64(u32 *crcp, const u64 *data, unsigned int len);
55 
56 static void crc32c_compute(u32 *crcp, const u64 *data, unsigned int len)
57 {
58 	unsigned int asm_len;
59 
60 	asm_len = len & ~7U;
61 	if (asm_len) {
62 		crc32c_sparc64(crcp, data, asm_len);
63 		data += asm_len / 8;
64 		len -= asm_len;
65 	}
66 	if (len)
67 		*crcp = __crc32c_le(*crcp, (const unsigned char *) data, len);
68 }
69 
70 static int crc32c_sparc64_update(struct shash_desc *desc, const u8 *data,
71 				 unsigned int len)
72 {
73 	u32 *crcp = shash_desc_ctx(desc);
74 
75 	crc32c_compute(crcp, (const u64 *) data, len);
76 
77 	return 0;
78 }
79 
80 static int __crc32c_sparc64_finup(u32 *crcp, const u8 *data, unsigned int len,
81 				  u8 *out)
82 {
83 	u32 tmp = *crcp;
84 
85 	crc32c_compute(&tmp, (const u64 *) data, len);
86 
87 	*(__le32 *) out = ~cpu_to_le32(tmp);
88 	return 0;
89 }
90 
91 static int crc32c_sparc64_finup(struct shash_desc *desc, const u8 *data,
92 				unsigned int len, u8 *out)
93 {
94 	return __crc32c_sparc64_finup(shash_desc_ctx(desc), data, len, out);
95 }
96 
97 static int crc32c_sparc64_final(struct shash_desc *desc, u8 *out)
98 {
99 	u32 *crcp = shash_desc_ctx(desc);
100 
101 	*(__le32 *) out = ~cpu_to_le32p(crcp);
102 	return 0;
103 }
104 
105 static int crc32c_sparc64_digest(struct shash_desc *desc, const u8 *data,
106 				 unsigned int len, u8 *out)
107 {
108 	return __crc32c_sparc64_finup(crypto_shash_ctx(desc->tfm), data, len,
109 				      out);
110 }
111 
112 static int crc32c_sparc64_cra_init(struct crypto_tfm *tfm)
113 {
114 	u32 *key = crypto_tfm_ctx(tfm);
115 
116 	*key = ~0;
117 
118 	return 0;
119 }
120 
121 #define CHKSUM_BLOCK_SIZE	1
122 #define CHKSUM_DIGEST_SIZE	4
123 
124 static struct shash_alg alg = {
125 	.setkey			=	crc32c_sparc64_setkey,
126 	.init			=	crc32c_sparc64_init,
127 	.update			=	crc32c_sparc64_update,
128 	.final			=	crc32c_sparc64_final,
129 	.finup			=	crc32c_sparc64_finup,
130 	.digest			=	crc32c_sparc64_digest,
131 	.descsize		=	sizeof(u32),
132 	.digestsize		=	CHKSUM_DIGEST_SIZE,
133 	.base			=	{
134 		.cra_name		=	"crc32c",
135 		.cra_driver_name	=	"crc32c-sparc64",
136 		.cra_priority		=	SPARC_CR_OPCODE_PRIORITY,
137 		.cra_flags		=	CRYPTO_ALG_OPTIONAL_KEY,
138 		.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
139 		.cra_ctxsize		=	sizeof(u32),
140 		.cra_alignmask		=	7,
141 		.cra_module		=	THIS_MODULE,
142 		.cra_init		=	crc32c_sparc64_cra_init,
143 	}
144 };
145 
146 static bool __init sparc64_has_crc32c_opcode(void)
147 {
148 	unsigned long cfr;
149 
150 	if (!(sparc64_elf_hwcap & HWCAP_SPARC_CRYPTO))
151 		return false;
152 
153 	__asm__ __volatile__("rd %%asr26, %0" : "=r" (cfr));
154 	if (!(cfr & CFR_CRC32C))
155 		return false;
156 
157 	return true;
158 }
159 
160 static int __init crc32c_sparc64_mod_init(void)
161 {
162 	if (sparc64_has_crc32c_opcode()) {
163 		pr_info("Using sparc64 crc32c opcode optimized CRC32C implementation\n");
164 		return crypto_register_shash(&alg);
165 	}
166 	pr_info("sparc64 crc32c opcode not available.\n");
167 	return -ENODEV;
168 }
169 
170 static void __exit crc32c_sparc64_mod_fini(void)
171 {
172 	crypto_unregister_shash(&alg);
173 }
174 
175 module_init(crc32c_sparc64_mod_init);
176 module_exit(crc32c_sparc64_mod_fini);
177 
178 MODULE_LICENSE("GPL");
179 MODULE_DESCRIPTION("CRC32c (Castagnoli), sparc64 crc32c opcode accelerated");
180 
181 MODULE_ALIAS_CRYPTO("crc32c");
182 
183 #include "crop_devid.c"
184