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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Shared crypto simd helpers
4 *
5 * Copyright (c) 2012 Jussi Kivilinna <[email protected]>
6 * Copyright (c) 2016 Herbert Xu <[email protected]>
7 * Copyright (c) 2019 Google LLC
8 *
9 * Based on aesni-intel_glue.c by:
10 * Copyright (C) 2008, Intel Corp.
11 * Author: Huang Ying <[email protected]>
12 */
13
14/*
15 * Shared crypto SIMD helpers. These functions dynamically create and register
16 * an AEAD algorithm that wraps another, internal algorithm. The wrapper
17 * ensures that the internal algorithm is only executed in a context where SIMD
18 * instructions are usable, i.e. where may_use_simd() returns true. If SIMD is
19 * already usable, the wrapper directly calls the internal algorithm. Otherwise
20 * it defers execution to a workqueue via cryptd.
21 *
22 * This is an alternative to the internal algorithm implementing a fallback for
23 * the !may_use_simd() case itself.
24 *
25 * Note that the wrapper algorithm is asynchronous, i.e. it has the
26 * CRYPTO_ALG_ASYNC flag set. Therefore it won't be found by users who
27 * explicitly allocate a synchronous algorithm.
28 */
29
30#include <crypto/cryptd.h>
31#include <crypto/internal/aead.h>
32#include <crypto/internal/simd.h>
33#include <linux/kernel.h>
34#include <linux/module.h>
35#include <linux/preempt.h>
36#include <asm/simd.h>
37
38struct simd_aead_alg {
39 const char *ialg_name;
40 struct aead_alg alg;
41};
42
43struct simd_aead_ctx {
44 struct cryptd_aead *cryptd_tfm;
45};
46
47static int simd_aead_setkey(struct crypto_aead *tfm, const u8 *key,
48 unsigned int key_len)
49{
50 struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
51 struct crypto_aead *child = &ctx->cryptd_tfm->base;
52
53 crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
54 crypto_aead_set_flags(child, crypto_aead_get_flags(tfm) &
55 CRYPTO_TFM_REQ_MASK);
56 return crypto_aead_setkey(child, key, key_len);
57}
58
59static int simd_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
60{
61 struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
62 struct crypto_aead *child = &ctx->cryptd_tfm->base;
63
64 return crypto_aead_setauthsize(child, authsize);
65}
66
67static int simd_aead_encrypt(struct aead_request *req)
68{
69 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
70 struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
71 struct aead_request *subreq;
72 struct crypto_aead *child;
73
74 subreq = aead_request_ctx(req);
75 *subreq = *req;
76
77 if (!crypto_simd_usable() ||
78 (in_atomic() && cryptd_aead_queued(ctx->cryptd_tfm)))
79 child = &ctx->cryptd_tfm->base;
80 else
81 child = cryptd_aead_child(ctx->cryptd_tfm);
82
83 aead_request_set_tfm(subreq, child);
84
85 return crypto_aead_encrypt(subreq);
86}
87
88static int simd_aead_decrypt(struct aead_request *req)
89{
90 struct crypto_aead *tfm = crypto_aead_reqtfm(req);
91 struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
92 struct aead_request *subreq;
93 struct crypto_aead *child;
94
95 subreq = aead_request_ctx(req);
96 *subreq = *req;
97
98 if (!crypto_simd_usable() ||
99 (in_atomic() && cryptd_aead_queued(ctx->cryptd_tfm)))
100 child = &ctx->cryptd_tfm->base;
101 else
102 child = cryptd_aead_child(ctx->cryptd_tfm);
103
104 aead_request_set_tfm(subreq, child);
105
106 return crypto_aead_decrypt(subreq);
107}
108
109static void simd_aead_exit(struct crypto_aead *tfm)
110{
111 struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
112
113 cryptd_free_aead(ctx->cryptd_tfm);
114}
115
116static int simd_aead_init(struct crypto_aead *tfm)
117{
118 struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
119 struct cryptd_aead *cryptd_tfm;
120 struct simd_aead_alg *salg;
121 struct aead_alg *alg;
122 unsigned reqsize;
123
124 alg = crypto_aead_alg(tfm);
125 salg = container_of(alg, struct simd_aead_alg, alg);
126
127 cryptd_tfm = cryptd_alloc_aead(salg->ialg_name, CRYPTO_ALG_INTERNAL,
128 CRYPTO_ALG_INTERNAL);
129 if (IS_ERR(cryptd_tfm))
130 return PTR_ERR(cryptd_tfm);
131
132 ctx->cryptd_tfm = cryptd_tfm;
133
134 reqsize = max(crypto_aead_reqsize(cryptd_aead_child(cryptd_tfm)),
135 crypto_aead_reqsize(&cryptd_tfm->base));
136 reqsize += sizeof(struct aead_request);
137
138 crypto_aead_set_reqsize(tfm, reqsize);
139
140 return 0;
141}
142
143static struct simd_aead_alg *simd_aead_create_compat(struct aead_alg *ialg,
144 const char *algname,
145 const char *drvname,
146 const char *basename)
147{
148 struct simd_aead_alg *salg;
149 struct aead_alg *alg;
150 int err;
151
152 salg = kzalloc_obj(*salg);
153 if (!salg) {
154 salg = ERR_PTR(-ENOMEM);
155 goto out;
156 }
157
158 salg->ialg_name = basename;
159 alg = &salg->alg;
160
161 err = -ENAMETOOLONG;
162 if (snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", algname) >=
163 CRYPTO_MAX_ALG_NAME)
164 goto out_free_salg;
165
166 if (snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
167 drvname) >= CRYPTO_MAX_ALG_NAME)
168 goto out_free_salg;
169
170 alg->base.cra_flags = CRYPTO_ALG_ASYNC |
171 (ialg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS);
172 alg->base.cra_priority = ialg->base.cra_priority;
173 alg->base.cra_blocksize = ialg->base.cra_blocksize;
174 alg->base.cra_alignmask = ialg->base.cra_alignmask;
175 alg->base.cra_module = ialg->base.cra_module;
176 alg->base.cra_ctxsize = sizeof(struct simd_aead_ctx);
177
178 alg->ivsize = ialg->ivsize;
179 alg->maxauthsize = ialg->maxauthsize;
180 alg->chunksize = ialg->chunksize;
181
182 alg->init = simd_aead_init;
183 alg->exit = simd_aead_exit;
184
185 alg->setkey = simd_aead_setkey;
186 alg->setauthsize = simd_aead_setauthsize;
187 alg->encrypt = simd_aead_encrypt;
188 alg->decrypt = simd_aead_decrypt;
189
190 err = crypto_register_aead(alg);
191 if (err)
192 goto out_free_salg;
193
194out:
195 return salg;
196
197out_free_salg:
198 kfree(salg);
199 salg = ERR_PTR(err);
200 goto out;
201}
202
203static void simd_aead_free(struct simd_aead_alg *salg)
204{
205 crypto_unregister_aead(&salg->alg);
206 kfree(salg);
207}
208
209int simd_register_aeads_compat(struct aead_alg *algs, int count,
210 struct simd_aead_alg **simd_algs)
211{
212 int err;
213 int i;
214 const char *algname;
215 const char *drvname;
216 const char *basename;
217 struct simd_aead_alg *simd;
218
219 for (i = 0; i < count; i++) {
220 if (WARN_ON(strncmp(algs[i].base.cra_name, "__", 2) ||
221 strncmp(algs[i].base.cra_driver_name, "__", 2)))
222 return -EINVAL;
223 }
224
225 err = crypto_register_aeads(algs, count);
226 if (err)
227 return err;
228
229 for (i = 0; i < count; i++) {
230 algname = algs[i].base.cra_name + 2;
231 drvname = algs[i].base.cra_driver_name + 2;
232 basename = algs[i].base.cra_driver_name;
233 simd = simd_aead_create_compat(algs + i, algname, drvname, basename);
234 err = PTR_ERR(simd);
235 if (IS_ERR(simd))
236 goto err_unregister;
237 simd_algs[i] = simd;
238 }
239 return 0;
240
241err_unregister:
242 simd_unregister_aeads(algs, count, simd_algs);
243 return err;
244}
245EXPORT_SYMBOL_GPL(simd_register_aeads_compat);
246
247void simd_unregister_aeads(struct aead_alg *algs, int count,
248 struct simd_aead_alg **simd_algs)
249{
250 int i;
251
252 crypto_unregister_aeads(algs, count);
253
254 for (i = 0; i < count; i++) {
255 if (simd_algs[i]) {
256 simd_aead_free(simd_algs[i]);
257 simd_algs[i] = NULL;
258 }
259 }
260}
261EXPORT_SYMBOL_GPL(simd_unregister_aeads);
262
263MODULE_DESCRIPTION("Shared crypto SIMD helpers");
264MODULE_LICENSE("GPL");