summaryrefslogtreecommitdiffstats
path: root/drivers/crypto/vmx/ghash.c
blob: 77eca20bc7ac6190c60963c26a250932d4623738 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
// SPDX-License-Identifier: GPL-2.0
/*
 * GHASH routines supporting VMX instructions on the Power 8
 *
 * Copyright (C) 2015, 2019 International Business Machines Inc.
 *
 * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
 *
 * Extended by Daniel Axtens <dja@axtens.net> to replace the fallback
 * mechanism. The new approach is based on arm64 code, which is:
 *   Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
 */

#include <linux/types.h>
#include <linux/err.h>
#include <linux/crypto.h>
#include <linux/delay.h>
#include <asm/simd.h>
#include <asm/switch_to.h>
#include <crypto/aes.h>
#include <crypto/ghash.h>
#include <crypto/scatterwalk.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/simd.h>
#include <crypto/b128ops.h>
#include "aesp8-ppc.h"

void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
		  const u8 *in, size_t len);

struct p8_ghash_ctx {
	/* key used by vector asm */
	u128 htable[16];
	/* key used by software fallback */
	be128 key;
};

struct p8_ghash_desc_ctx {
	u64 shash[2];
	u8 buffer[GHASH_DIGEST_SIZE];
	int bytes;
};

static int p8_ghash_init(struct shash_desc *desc)
{
	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);

	dctx->bytes = 0;
	memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
	return 0;
}

static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
			   unsigned int keylen)
{
	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));

	if (keylen != GHASH_BLOCK_SIZE)
		return -EINVAL;

	preempt_disable();
	pagefault_disable();
	enable_kernel_vsx();
	gcm_init_p8(ctx->htable, (const u64 *) key);
	disable_kernel_vsx();
	pagefault_enable();
	preempt_enable();

	memcpy(&ctx->key, key, GHASH_BLOCK_SIZE);

	return 0;
}

static inline void __ghash_block(struct p8_ghash_ctx *ctx,
				 struct p8_ghash_desc_ctx *dctx)
{
	if (crypto_simd_usable()) {
		preempt_disable();
		pagefault_disable();
		enable_kernel_vsx();
		gcm_ghash_p8(dctx->shash, ctx->htable,
				dctx->buffer, GHASH_DIGEST_SIZE);
		disable_kernel_vsx();
		pagefault_enable();
		preempt_enable();
	} else {
		crypto_xor((u8 *)dctx->shash, dctx->buffer, GHASH_BLOCK_SIZE);
		gf128mul_lle((be128 *)dctx->shash, &ctx->key);
	}
}

static inline void __ghash_blocks(struct p8_ghash_ctx *ctx,
				  struct p8_ghash_desc_ctx *dctx,
				  const u8 *src, unsigned int srclen)
{
	if (crypto_simd_usable()) {
		preempt_disable();
		pagefault_disable();
		enable_kernel_vsx();
		gcm_ghash_p8(dctx->shash, ctx->htable,
				src, srclen);
		disable_kernel_vsx();
		pagefault_enable();
		preempt_enable();
	} else {
		while (srclen >= GHASH_BLOCK_SIZE) {
			crypto_xor((u8 *)dctx->shash, src, GHASH_BLOCK_SIZE);
			gf128mul_lle((be128 *)dctx->shash, &ctx->key);
			srclen -= GHASH_BLOCK_SIZE;
			src += GHASH_BLOCK_SIZE;
		}
	}
}

static int p8_ghash_update(struct shash_desc *desc,
			   const u8 *src, unsigned int srclen)
{
	unsigned int len;
	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);

	if (dctx->bytes) {
		if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
			memcpy(dctx->buffer + dctx->bytes, src,
				srclen);
			dctx->bytes += srclen;
			return 0;
		}
		memcpy(dctx->buffer + dctx->bytes, src,
			GHASH_DIGEST_SIZE - dctx->bytes);

		__ghash_block(ctx, dctx);

		src += GHASH_DIGEST_SIZE - dctx->bytes;
		srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
		dctx->bytes = 0;
	}
	len = srclen & ~(GHASH_DIGEST_SIZE - 1);
	if (len) {
		__ghash_blocks(ctx, dctx, src, len);
		src += len;
		srclen -= len;
	}
	if (srclen) {
		memcpy(dctx->buffer, src, srclen);
		dctx->bytes = srclen;
	}
	return 0;
}

static int p8_ghash_final(struct shash_desc *desc, u8 *out)
{
	int i;
	struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
	struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);

	if (dctx->bytes) {
		for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
			dctx->buffer[i] = 0;
		__ghash_block(ctx, dctx);
		dctx->bytes = 0;
	}
	memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
	return 0;
}

struct shash_alg p8_ghash_alg = {
	.digestsize = GHASH_DIGEST_SIZE,
	.init = p8_ghash_init,
	.update = p8_ghash_update,
	.final = p8_ghash_final,
	.setkey = p8_ghash_setkey,
	.descsize = sizeof(struct p8_ghash_desc_ctx)
		+ sizeof(struct ghash_desc_ctx),
	.base = {
		 .cra_name = "ghash",
		 .cra_driver_name = "p8_ghash",
		 .cra_priority = 1000,
		 .cra_blocksize = GHASH_BLOCK_SIZE,
		 .cra_ctxsize = sizeof(struct p8_ghash_ctx),
		 .cra_module = THIS_MODULE,
	},
};