xref: /openbmc/linux/crypto/pcrypt.c (revision 2c684d89)
1 /*
2  * pcrypt - Parallel crypto wrapper.
3  *
4  * Copyright (C) 2009 secunet Security Networks AG
5  * Copyright (C) 2009 Steffen Klassert <steffen.klassert@secunet.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20 
21 #include <crypto/algapi.h>
22 #include <crypto/internal/aead.h>
23 #include <linux/atomic.h>
24 #include <linux/err.h>
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/notifier.h>
29 #include <linux/kobject.h>
30 #include <linux/cpu.h>
31 #include <crypto/pcrypt.h>
32 
33 struct padata_pcrypt {
34 	struct padata_instance *pinst;
35 	struct workqueue_struct *wq;
36 
37 	/*
38 	 * Cpumask for callback CPUs. It should be
39 	 * equal to serial cpumask of corresponding padata instance,
40 	 * so it is updated when padata notifies us about serial
41 	 * cpumask change.
42 	 *
43 	 * cb_cpumask is protected by RCU. This fact prevents us from
44 	 * using cpumask_var_t directly because the actual type of
45 	 * cpumsak_var_t depends on kernel configuration(particularly on
46 	 * CONFIG_CPUMASK_OFFSTACK macro). Depending on the configuration
47 	 * cpumask_var_t may be either a pointer to the struct cpumask
48 	 * or a variable allocated on the stack. Thus we can not safely use
49 	 * cpumask_var_t with RCU operations such as rcu_assign_pointer or
50 	 * rcu_dereference. So cpumask_var_t is wrapped with struct
51 	 * pcrypt_cpumask which makes possible to use it with RCU.
52 	 */
53 	struct pcrypt_cpumask {
54 		cpumask_var_t mask;
55 	} *cb_cpumask;
56 	struct notifier_block nblock;
57 };
58 
59 static struct padata_pcrypt pencrypt;
60 static struct padata_pcrypt pdecrypt;
61 static struct kset           *pcrypt_kset;
62 
63 struct pcrypt_instance_ctx {
64 	struct crypto_aead_spawn spawn;
65 	atomic_t tfm_count;
66 };
67 
68 struct pcrypt_aead_ctx {
69 	struct crypto_aead *child;
70 	unsigned int cb_cpu;
71 };
72 
73 static int pcrypt_do_parallel(struct padata_priv *padata, unsigned int *cb_cpu,
74 			      struct padata_pcrypt *pcrypt)
75 {
76 	unsigned int cpu_index, cpu, i;
77 	struct pcrypt_cpumask *cpumask;
78 
79 	cpu = *cb_cpu;
80 
81 	rcu_read_lock_bh();
82 	cpumask = rcu_dereference_bh(pcrypt->cb_cpumask);
83 	if (cpumask_test_cpu(cpu, cpumask->mask))
84 			goto out;
85 
86 	if (!cpumask_weight(cpumask->mask))
87 			goto out;
88 
89 	cpu_index = cpu % cpumask_weight(cpumask->mask);
90 
91 	cpu = cpumask_first(cpumask->mask);
92 	for (i = 0; i < cpu_index; i++)
93 		cpu = cpumask_next(cpu, cpumask->mask);
94 
95 	*cb_cpu = cpu;
96 
97 out:
98 	rcu_read_unlock_bh();
99 	return padata_do_parallel(pcrypt->pinst, padata, cpu);
100 }
101 
102 static int pcrypt_aead_setkey(struct crypto_aead *parent,
103 			      const u8 *key, unsigned int keylen)
104 {
105 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
106 
107 	return crypto_aead_setkey(ctx->child, key, keylen);
108 }
109 
110 static int pcrypt_aead_setauthsize(struct crypto_aead *parent,
111 				   unsigned int authsize)
112 {
113 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(parent);
114 
115 	return crypto_aead_setauthsize(ctx->child, authsize);
116 }
117 
118 static void pcrypt_aead_serial(struct padata_priv *padata)
119 {
120 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
121 	struct aead_request *req = pcrypt_request_ctx(preq);
122 
123 	aead_request_complete(req->base.data, padata->info);
124 }
125 
126 static void pcrypt_aead_done(struct crypto_async_request *areq, int err)
127 {
128 	struct aead_request *req = areq->data;
129 	struct pcrypt_request *preq = aead_request_ctx(req);
130 	struct padata_priv *padata = pcrypt_request_padata(preq);
131 
132 	padata->info = err;
133 	req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
134 
135 	padata_do_serial(padata);
136 }
137 
138 static void pcrypt_aead_enc(struct padata_priv *padata)
139 {
140 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
141 	struct aead_request *req = pcrypt_request_ctx(preq);
142 
143 	padata->info = crypto_aead_encrypt(req);
144 
145 	if (padata->info == -EINPROGRESS)
146 		return;
147 
148 	padata_do_serial(padata);
149 }
150 
151 static int pcrypt_aead_encrypt(struct aead_request *req)
152 {
153 	int err;
154 	struct pcrypt_request *preq = aead_request_ctx(req);
155 	struct aead_request *creq = pcrypt_request_ctx(preq);
156 	struct padata_priv *padata = pcrypt_request_padata(preq);
157 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
158 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
159 	u32 flags = aead_request_flags(req);
160 
161 	memset(padata, 0, sizeof(struct padata_priv));
162 
163 	padata->parallel = pcrypt_aead_enc;
164 	padata->serial = pcrypt_aead_serial;
165 
166 	aead_request_set_tfm(creq, ctx->child);
167 	aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
168 				  pcrypt_aead_done, req);
169 	aead_request_set_crypt(creq, req->src, req->dst,
170 			       req->cryptlen, req->iv);
171 	aead_request_set_ad(creq, req->assoclen);
172 
173 	err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pencrypt);
174 	if (!err)
175 		return -EINPROGRESS;
176 
177 	return err;
178 }
179 
180 static void pcrypt_aead_dec(struct padata_priv *padata)
181 {
182 	struct pcrypt_request *preq = pcrypt_padata_request(padata);
183 	struct aead_request *req = pcrypt_request_ctx(preq);
184 
185 	padata->info = crypto_aead_decrypt(req);
186 
187 	if (padata->info == -EINPROGRESS)
188 		return;
189 
190 	padata_do_serial(padata);
191 }
192 
193 static int pcrypt_aead_decrypt(struct aead_request *req)
194 {
195 	int err;
196 	struct pcrypt_request *preq = aead_request_ctx(req);
197 	struct aead_request *creq = pcrypt_request_ctx(preq);
198 	struct padata_priv *padata = pcrypt_request_padata(preq);
199 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
200 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(aead);
201 	u32 flags = aead_request_flags(req);
202 
203 	memset(padata, 0, sizeof(struct padata_priv));
204 
205 	padata->parallel = pcrypt_aead_dec;
206 	padata->serial = pcrypt_aead_serial;
207 
208 	aead_request_set_tfm(creq, ctx->child);
209 	aead_request_set_callback(creq, flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
210 				  pcrypt_aead_done, req);
211 	aead_request_set_crypt(creq, req->src, req->dst,
212 			       req->cryptlen, req->iv);
213 	aead_request_set_ad(creq, req->assoclen);
214 
215 	err = pcrypt_do_parallel(padata, &ctx->cb_cpu, &pdecrypt);
216 	if (!err)
217 		return -EINPROGRESS;
218 
219 	return err;
220 }
221 
222 static int pcrypt_aead_init_tfm(struct crypto_aead *tfm)
223 {
224 	int cpu, cpu_index;
225 	struct aead_instance *inst = aead_alg_instance(tfm);
226 	struct pcrypt_instance_ctx *ictx = aead_instance_ctx(inst);
227 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
228 	struct crypto_aead *cipher;
229 
230 	cpu_index = (unsigned int)atomic_inc_return(&ictx->tfm_count) %
231 		    cpumask_weight(cpu_online_mask);
232 
233 	ctx->cb_cpu = cpumask_first(cpu_online_mask);
234 	for (cpu = 0; cpu < cpu_index; cpu++)
235 		ctx->cb_cpu = cpumask_next(ctx->cb_cpu, cpu_online_mask);
236 
237 	cipher = crypto_spawn_aead(&ictx->spawn);
238 
239 	if (IS_ERR(cipher))
240 		return PTR_ERR(cipher);
241 
242 	ctx->child = cipher;
243 	crypto_aead_set_reqsize(tfm, sizeof(struct pcrypt_request) +
244 				     sizeof(struct aead_request) +
245 				     crypto_aead_reqsize(cipher));
246 
247 	return 0;
248 }
249 
250 static void pcrypt_aead_exit_tfm(struct crypto_aead *tfm)
251 {
252 	struct pcrypt_aead_ctx *ctx = crypto_aead_ctx(tfm);
253 
254 	crypto_free_aead(ctx->child);
255 }
256 
257 static int pcrypt_init_instance(struct crypto_instance *inst,
258 				struct crypto_alg *alg)
259 {
260 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
261 		     "pcrypt(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
262 		return -ENAMETOOLONG;
263 
264 	memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
265 
266 	inst->alg.cra_priority = alg->cra_priority + 100;
267 	inst->alg.cra_blocksize = alg->cra_blocksize;
268 	inst->alg.cra_alignmask = alg->cra_alignmask;
269 
270 	return 0;
271 }
272 
273 static int pcrypt_create_aead(struct crypto_template *tmpl, struct rtattr **tb,
274 			      u32 type, u32 mask)
275 {
276 	struct pcrypt_instance_ctx *ctx;
277 	struct crypto_attr_type *algt;
278 	struct aead_instance *inst;
279 	struct aead_alg *alg;
280 	const char *name;
281 	int err;
282 
283 	algt = crypto_get_attr_type(tb);
284 	if (IS_ERR(algt))
285 		return PTR_ERR(algt);
286 
287 	name = crypto_attr_alg_name(tb[1]);
288 	if (IS_ERR(name))
289 		return PTR_ERR(name);
290 
291 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
292 	if (!inst)
293 		return -ENOMEM;
294 
295 	ctx = aead_instance_ctx(inst);
296 	crypto_set_aead_spawn(&ctx->spawn, aead_crypto_instance(inst));
297 
298 	err = crypto_grab_aead(&ctx->spawn, name, 0, 0);
299 	if (err)
300 		goto out_free_inst;
301 
302 	alg = crypto_spawn_aead_alg(&ctx->spawn);
303 	err = pcrypt_init_instance(aead_crypto_instance(inst), &alg->base);
304 	if (err)
305 		goto out_drop_aead;
306 
307 	inst->alg.base.cra_flags = CRYPTO_ALG_ASYNC;
308 
309 	inst->alg.ivsize = crypto_aead_alg_ivsize(alg);
310 	inst->alg.maxauthsize = crypto_aead_alg_maxauthsize(alg);
311 
312 	inst->alg.base.cra_ctxsize = sizeof(struct pcrypt_aead_ctx);
313 
314 	inst->alg.init = pcrypt_aead_init_tfm;
315 	inst->alg.exit = pcrypt_aead_exit_tfm;
316 
317 	inst->alg.setkey = pcrypt_aead_setkey;
318 	inst->alg.setauthsize = pcrypt_aead_setauthsize;
319 	inst->alg.encrypt = pcrypt_aead_encrypt;
320 	inst->alg.decrypt = pcrypt_aead_decrypt;
321 
322 	err = aead_register_instance(tmpl, inst);
323 	if (err)
324 		goto out_drop_aead;
325 
326 out:
327 	return err;
328 
329 out_drop_aead:
330 	crypto_drop_aead(&ctx->spawn);
331 out_free_inst:
332 	kfree(inst);
333 	goto out;
334 }
335 
336 static int pcrypt_create(struct crypto_template *tmpl, struct rtattr **tb)
337 {
338 	struct crypto_attr_type *algt;
339 
340 	algt = crypto_get_attr_type(tb);
341 	if (IS_ERR(algt))
342 		return PTR_ERR(algt);
343 
344 	switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
345 	case CRYPTO_ALG_TYPE_AEAD:
346 		return pcrypt_create_aead(tmpl, tb, algt->type, algt->mask);
347 	}
348 
349 	return -EINVAL;
350 }
351 
352 static void pcrypt_free(struct crypto_instance *inst)
353 {
354 	struct pcrypt_instance_ctx *ctx = crypto_instance_ctx(inst);
355 
356 	crypto_drop_aead(&ctx->spawn);
357 	kfree(inst);
358 }
359 
360 static int pcrypt_cpumask_change_notify(struct notifier_block *self,
361 					unsigned long val, void *data)
362 {
363 	struct padata_pcrypt *pcrypt;
364 	struct pcrypt_cpumask *new_mask, *old_mask;
365 	struct padata_cpumask *cpumask = (struct padata_cpumask *)data;
366 
367 	if (!(val & PADATA_CPU_SERIAL))
368 		return 0;
369 
370 	pcrypt = container_of(self, struct padata_pcrypt, nblock);
371 	new_mask = kmalloc(sizeof(*new_mask), GFP_KERNEL);
372 	if (!new_mask)
373 		return -ENOMEM;
374 	if (!alloc_cpumask_var(&new_mask->mask, GFP_KERNEL)) {
375 		kfree(new_mask);
376 		return -ENOMEM;
377 	}
378 
379 	old_mask = pcrypt->cb_cpumask;
380 
381 	cpumask_copy(new_mask->mask, cpumask->cbcpu);
382 	rcu_assign_pointer(pcrypt->cb_cpumask, new_mask);
383 	synchronize_rcu_bh();
384 
385 	free_cpumask_var(old_mask->mask);
386 	kfree(old_mask);
387 	return 0;
388 }
389 
390 static int pcrypt_sysfs_add(struct padata_instance *pinst, const char *name)
391 {
392 	int ret;
393 
394 	pinst->kobj.kset = pcrypt_kset;
395 	ret = kobject_add(&pinst->kobj, NULL, name);
396 	if (!ret)
397 		kobject_uevent(&pinst->kobj, KOBJ_ADD);
398 
399 	return ret;
400 }
401 
402 static int pcrypt_init_padata(struct padata_pcrypt *pcrypt,
403 			      const char *name)
404 {
405 	int ret = -ENOMEM;
406 	struct pcrypt_cpumask *mask;
407 
408 	get_online_cpus();
409 
410 	pcrypt->wq = alloc_workqueue("%s", WQ_MEM_RECLAIM | WQ_CPU_INTENSIVE,
411 				     1, name);
412 	if (!pcrypt->wq)
413 		goto err;
414 
415 	pcrypt->pinst = padata_alloc_possible(pcrypt->wq);
416 	if (!pcrypt->pinst)
417 		goto err_destroy_workqueue;
418 
419 	mask = kmalloc(sizeof(*mask), GFP_KERNEL);
420 	if (!mask)
421 		goto err_free_padata;
422 	if (!alloc_cpumask_var(&mask->mask, GFP_KERNEL)) {
423 		kfree(mask);
424 		goto err_free_padata;
425 	}
426 
427 	cpumask_and(mask->mask, cpu_possible_mask, cpu_online_mask);
428 	rcu_assign_pointer(pcrypt->cb_cpumask, mask);
429 
430 	pcrypt->nblock.notifier_call = pcrypt_cpumask_change_notify;
431 	ret = padata_register_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
432 	if (ret)
433 		goto err_free_cpumask;
434 
435 	ret = pcrypt_sysfs_add(pcrypt->pinst, name);
436 	if (ret)
437 		goto err_unregister_notifier;
438 
439 	put_online_cpus();
440 
441 	return ret;
442 
443 err_unregister_notifier:
444 	padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
445 err_free_cpumask:
446 	free_cpumask_var(mask->mask);
447 	kfree(mask);
448 err_free_padata:
449 	padata_free(pcrypt->pinst);
450 err_destroy_workqueue:
451 	destroy_workqueue(pcrypt->wq);
452 err:
453 	put_online_cpus();
454 
455 	return ret;
456 }
457 
458 static void pcrypt_fini_padata(struct padata_pcrypt *pcrypt)
459 {
460 	free_cpumask_var(pcrypt->cb_cpumask->mask);
461 	kfree(pcrypt->cb_cpumask);
462 
463 	padata_stop(pcrypt->pinst);
464 	padata_unregister_cpumask_notifier(pcrypt->pinst, &pcrypt->nblock);
465 	destroy_workqueue(pcrypt->wq);
466 	padata_free(pcrypt->pinst);
467 }
468 
469 static struct crypto_template pcrypt_tmpl = {
470 	.name = "pcrypt",
471 	.create = pcrypt_create,
472 	.free = pcrypt_free,
473 	.module = THIS_MODULE,
474 };
475 
476 static int __init pcrypt_init(void)
477 {
478 	int err = -ENOMEM;
479 
480 	pcrypt_kset = kset_create_and_add("pcrypt", NULL, kernel_kobj);
481 	if (!pcrypt_kset)
482 		goto err;
483 
484 	err = pcrypt_init_padata(&pencrypt, "pencrypt");
485 	if (err)
486 		goto err_unreg_kset;
487 
488 	err = pcrypt_init_padata(&pdecrypt, "pdecrypt");
489 	if (err)
490 		goto err_deinit_pencrypt;
491 
492 	padata_start(pencrypt.pinst);
493 	padata_start(pdecrypt.pinst);
494 
495 	return crypto_register_template(&pcrypt_tmpl);
496 
497 err_deinit_pencrypt:
498 	pcrypt_fini_padata(&pencrypt);
499 err_unreg_kset:
500 	kset_unregister(pcrypt_kset);
501 err:
502 	return err;
503 }
504 
505 static void __exit pcrypt_exit(void)
506 {
507 	pcrypt_fini_padata(&pencrypt);
508 	pcrypt_fini_padata(&pdecrypt);
509 
510 	kset_unregister(pcrypt_kset);
511 	crypto_unregister_template(&pcrypt_tmpl);
512 }
513 
514 module_init(pcrypt_init);
515 module_exit(pcrypt_exit);
516 
517 MODULE_LICENSE("GPL");
518 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
519 MODULE_DESCRIPTION("Parallel crypto wrapper");
520 MODULE_ALIAS_CRYPTO("pcrypt");
521