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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * GHASH routines supporting VMX instructions on the Power 8
4 *
5 * Copyright (C) 2015, 2019 International Business Machines Inc.
6 *
7 * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
8 *
9 * Extended by Daniel Axtens <dja@axtens.net> to replace the fallback
10 * mechanism. The new approach is based on arm64 code, which is:
11 * Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org>
12 */
13
14#include <linux/types.h>
15#include <linux/err.h>
16#include <linux/crypto.h>
17#include <linux/delay.h>
18#include <asm/simd.h>
19#include <asm/switch_to.h>
20#include <crypto/aes.h>
21#include <crypto/ghash.h>
22#include <crypto/scatterwalk.h>
23#include <crypto/internal/hash.h>
24#include <crypto/internal/simd.h>
25#include <crypto/b128ops.h>
26#include "aesp8-ppc.h"
27
28void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
29void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
30void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
31 const u8 *in, size_t len);
32
33struct p8_ghash_ctx {
34 /* key used by vector asm */
35 u128 htable[16];
36 /* key used by software fallback */
37 be128 key;
38};
39
40struct p8_ghash_desc_ctx {
41 u64 shash[2];
42 u8 buffer[GHASH_DIGEST_SIZE];
43 int bytes;
44};
45
46static int p8_ghash_init(struct shash_desc *desc)
47{
48 struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
49
50 dctx->bytes = 0;
51 memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
52 return 0;
53}
54
55static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
56 unsigned int keylen)
57{
58 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));
59
60 if (keylen != GHASH_BLOCK_SIZE)
61 return -EINVAL;
62
63 preempt_disable();
64 pagefault_disable();
65 enable_kernel_vsx();
66 gcm_init_p8(ctx->htable, (const u64 *) key);
67 disable_kernel_vsx();
68 pagefault_enable();
69 preempt_enable();
70
71 memcpy(&ctx->key, key, GHASH_BLOCK_SIZE);
72
73 return 0;
74}
75
76static inline void __ghash_block(struct p8_ghash_ctx *ctx,
77 struct p8_ghash_desc_ctx *dctx)
78{
79 if (crypto_simd_usable()) {
80 preempt_disable();
81 pagefault_disable();
82 enable_kernel_vsx();
83 gcm_ghash_p8(dctx->shash, ctx->htable,
84 dctx->buffer, GHASH_DIGEST_SIZE);
85 disable_kernel_vsx();
86 pagefault_enable();
87 preempt_enable();
88 } else {
89 crypto_xor((u8 *)dctx->shash, dctx->buffer, GHASH_BLOCK_SIZE);
90 gf128mul_lle((be128 *)dctx->shash, &ctx->key);
91 }
92}
93
94static inline void __ghash_blocks(struct p8_ghash_ctx *ctx,
95 struct p8_ghash_desc_ctx *dctx,
96 const u8 *src, unsigned int srclen)
97{
98 if (crypto_simd_usable()) {
99 preempt_disable();
100 pagefault_disable();
101 enable_kernel_vsx();
102 gcm_ghash_p8(dctx->shash, ctx->htable,
103 src, srclen);
104 disable_kernel_vsx();
105 pagefault_enable();
106 preempt_enable();
107 } else {
108 while (srclen >= GHASH_BLOCK_SIZE) {
109 crypto_xor((u8 *)dctx->shash, src, GHASH_BLOCK_SIZE);
110 gf128mul_lle((be128 *)dctx->shash, &ctx->key);
111 srclen -= GHASH_BLOCK_SIZE;
112 src += GHASH_BLOCK_SIZE;
113 }
114 }
115}
116
117static int p8_ghash_update(struct shash_desc *desc,
118 const u8 *src, unsigned int srclen)
119{
120 unsigned int len;
121 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
122 struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
123
124 if (dctx->bytes) {
125 if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
126 memcpy(dctx->buffer + dctx->bytes, src,
127 srclen);
128 dctx->bytes += srclen;
129 return 0;
130 }
131 memcpy(dctx->buffer + dctx->bytes, src,
132 GHASH_DIGEST_SIZE - dctx->bytes);
133
134 __ghash_block(ctx, dctx);
135
136 src += GHASH_DIGEST_SIZE - dctx->bytes;
137 srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
138 dctx->bytes = 0;
139 }
140 len = srclen & ~(GHASH_DIGEST_SIZE - 1);
141 if (len) {
142 __ghash_blocks(ctx, dctx, src, len);
143 src += len;
144 srclen -= len;
145 }
146 if (srclen) {
147 memcpy(dctx->buffer, src, srclen);
148 dctx->bytes = srclen;
149 }
150 return 0;
151}
152
153static int p8_ghash_final(struct shash_desc *desc, u8 *out)
154{
155 int i;
156 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
157 struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
158
159 if (dctx->bytes) {
160 for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
161 dctx->buffer[i] = 0;
162 __ghash_block(ctx, dctx);
163 dctx->bytes = 0;
164 }
165 memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
166 return 0;
167}
168
169struct shash_alg p8_ghash_alg = {
170 .digestsize = GHASH_DIGEST_SIZE,
171 .init = p8_ghash_init,
172 .update = p8_ghash_update,
173 .final = p8_ghash_final,
174 .setkey = p8_ghash_setkey,
175 .descsize = sizeof(struct p8_ghash_desc_ctx)
176 + sizeof(struct ghash_desc_ctx),
177 .base = {
178 .cra_name = "ghash",
179 .cra_driver_name = "p8_ghash",
180 .cra_priority = 1000,
181 .cra_blocksize = GHASH_BLOCK_SIZE,
182 .cra_ctxsize = sizeof(struct p8_ghash_ctx),
183 .cra_module = THIS_MODULE,
184 },
185};
1/**
2 * GHASH routines supporting VMX instructions on the Power 8
3 *
4 * Copyright (C) 2015 International Business Machines Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 only.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 *
19 * Author: Marcelo Henrique Cerri <mhcerri@br.ibm.com>
20 */
21
22#include <linux/types.h>
23#include <linux/err.h>
24#include <linux/crypto.h>
25#include <linux/delay.h>
26#include <linux/hardirq.h>
27#include <asm/switch_to.h>
28#include <crypto/aes.h>
29#include <crypto/ghash.h>
30#include <crypto/scatterwalk.h>
31#include <crypto/internal/hash.h>
32#include <crypto/b128ops.h>
33
34#define IN_INTERRUPT in_interrupt()
35
36void gcm_init_p8(u128 htable[16], const u64 Xi[2]);
37void gcm_gmult_p8(u64 Xi[2], const u128 htable[16]);
38void gcm_ghash_p8(u64 Xi[2], const u128 htable[16],
39 const u8 *in, size_t len);
40
41struct p8_ghash_ctx {
42 u128 htable[16];
43 struct crypto_shash *fallback;
44};
45
46struct p8_ghash_desc_ctx {
47 u64 shash[2];
48 u8 buffer[GHASH_DIGEST_SIZE];
49 int bytes;
50 struct shash_desc fallback_desc;
51};
52
53static int p8_ghash_init_tfm(struct crypto_tfm *tfm)
54{
55 const char *alg = "ghash-generic";
56 struct crypto_shash *fallback;
57 struct crypto_shash *shash_tfm = __crypto_shash_cast(tfm);
58 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
59
60 fallback = crypto_alloc_shash(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
61 if (IS_ERR(fallback)) {
62 printk(KERN_ERR
63 "Failed to allocate transformation for '%s': %ld\n",
64 alg, PTR_ERR(fallback));
65 return PTR_ERR(fallback);
66 }
67 printk(KERN_INFO "Using '%s' as fallback implementation.\n",
68 crypto_tfm_alg_driver_name(crypto_shash_tfm(fallback)));
69
70 crypto_shash_set_flags(fallback,
71 crypto_shash_get_flags((struct crypto_shash
72 *) tfm));
73
74 /* Check if the descsize defined in the algorithm is still enough. */
75 if (shash_tfm->descsize < sizeof(struct p8_ghash_desc_ctx)
76 + crypto_shash_descsize(fallback)) {
77 printk(KERN_ERR
78 "Desc size of the fallback implementation (%s) does not match the expected value: %lu vs %u\n",
79 alg,
80 shash_tfm->descsize - sizeof(struct p8_ghash_desc_ctx),
81 crypto_shash_descsize(fallback));
82 return -EINVAL;
83 }
84 ctx->fallback = fallback;
85
86 return 0;
87}
88
89static void p8_ghash_exit_tfm(struct crypto_tfm *tfm)
90{
91 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(tfm);
92
93 if (ctx->fallback) {
94 crypto_free_shash(ctx->fallback);
95 ctx->fallback = NULL;
96 }
97}
98
99static int p8_ghash_init(struct shash_desc *desc)
100{
101 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
102 struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
103
104 dctx->bytes = 0;
105 memset(dctx->shash, 0, GHASH_DIGEST_SIZE);
106 dctx->fallback_desc.tfm = ctx->fallback;
107 dctx->fallback_desc.flags = desc->flags;
108 return crypto_shash_init(&dctx->fallback_desc);
109}
110
111static int p8_ghash_setkey(struct crypto_shash *tfm, const u8 *key,
112 unsigned int keylen)
113{
114 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(tfm));
115
116 if (keylen != GHASH_BLOCK_SIZE)
117 return -EINVAL;
118
119 preempt_disable();
120 pagefault_disable();
121 enable_kernel_vsx();
122 gcm_init_p8(ctx->htable, (const u64 *) key);
123 disable_kernel_vsx();
124 pagefault_enable();
125 preempt_enable();
126 return crypto_shash_setkey(ctx->fallback, key, keylen);
127}
128
129static int p8_ghash_update(struct shash_desc *desc,
130 const u8 *src, unsigned int srclen)
131{
132 unsigned int len;
133 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
134 struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
135
136 if (IN_INTERRUPT) {
137 return crypto_shash_update(&dctx->fallback_desc, src,
138 srclen);
139 } else {
140 if (dctx->bytes) {
141 if (dctx->bytes + srclen < GHASH_DIGEST_SIZE) {
142 memcpy(dctx->buffer + dctx->bytes, src,
143 srclen);
144 dctx->bytes += srclen;
145 return 0;
146 }
147 memcpy(dctx->buffer + dctx->bytes, src,
148 GHASH_DIGEST_SIZE - dctx->bytes);
149 preempt_disable();
150 pagefault_disable();
151 enable_kernel_vsx();
152 gcm_ghash_p8(dctx->shash, ctx->htable,
153 dctx->buffer, GHASH_DIGEST_SIZE);
154 disable_kernel_vsx();
155 pagefault_enable();
156 preempt_enable();
157 src += GHASH_DIGEST_SIZE - dctx->bytes;
158 srclen -= GHASH_DIGEST_SIZE - dctx->bytes;
159 dctx->bytes = 0;
160 }
161 len = srclen & ~(GHASH_DIGEST_SIZE - 1);
162 if (len) {
163 preempt_disable();
164 pagefault_disable();
165 enable_kernel_vsx();
166 gcm_ghash_p8(dctx->shash, ctx->htable, src, len);
167 disable_kernel_vsx();
168 pagefault_enable();
169 preempt_enable();
170 src += len;
171 srclen -= len;
172 }
173 if (srclen) {
174 memcpy(dctx->buffer, src, srclen);
175 dctx->bytes = srclen;
176 }
177 return 0;
178 }
179}
180
181static int p8_ghash_final(struct shash_desc *desc, u8 *out)
182{
183 int i;
184 struct p8_ghash_ctx *ctx = crypto_tfm_ctx(crypto_shash_tfm(desc->tfm));
185 struct p8_ghash_desc_ctx *dctx = shash_desc_ctx(desc);
186
187 if (IN_INTERRUPT) {
188 return crypto_shash_final(&dctx->fallback_desc, out);
189 } else {
190 if (dctx->bytes) {
191 for (i = dctx->bytes; i < GHASH_DIGEST_SIZE; i++)
192 dctx->buffer[i] = 0;
193 preempt_disable();
194 pagefault_disable();
195 enable_kernel_vsx();
196 gcm_ghash_p8(dctx->shash, ctx->htable,
197 dctx->buffer, GHASH_DIGEST_SIZE);
198 disable_kernel_vsx();
199 pagefault_enable();
200 preempt_enable();
201 dctx->bytes = 0;
202 }
203 memcpy(out, dctx->shash, GHASH_DIGEST_SIZE);
204 return 0;
205 }
206}
207
208struct shash_alg p8_ghash_alg = {
209 .digestsize = GHASH_DIGEST_SIZE,
210 .init = p8_ghash_init,
211 .update = p8_ghash_update,
212 .final = p8_ghash_final,
213 .setkey = p8_ghash_setkey,
214 .descsize = sizeof(struct p8_ghash_desc_ctx)
215 + sizeof(struct ghash_desc_ctx),
216 .base = {
217 .cra_name = "ghash",
218 .cra_driver_name = "p8_ghash",
219 .cra_priority = 1000,
220 .cra_flags = CRYPTO_ALG_TYPE_SHASH | CRYPTO_ALG_NEED_FALLBACK,
221 .cra_blocksize = GHASH_BLOCK_SIZE,
222 .cra_ctxsize = sizeof(struct p8_ghash_ctx),
223 .cra_module = THIS_MODULE,
224 .cra_init = p8_ghash_init_tfm,
225 .cra_exit = p8_ghash_exit_tfm,
226 },
227};