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