mcryptd.c 18 KB
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727
/*
 * Software multibuffer async crypto daemon.
 *
 * Copyright (c) 2014 Tim Chen <tim.c.chen@linux.intel.com>
 *
 * Adapted from crypto daemon.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/algapi.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/aead.h>
#include <crypto/mcryptd.h>
#include <crypto/crypto_wq.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/hardirq.h>

#define MCRYPTD_MAX_CPU_QLEN 100
#define MCRYPTD_BATCH 9

static void *mcryptd_alloc_instance(struct crypto_alg *alg, unsigned int head,
				   unsigned int tail);

struct mcryptd_flush_list {
	struct list_head list;
	struct mutex lock;
};

static struct mcryptd_flush_list __percpu *mcryptd_flist;

struct hashd_instance_ctx {
	struct crypto_shash_spawn spawn;
	struct mcryptd_queue *queue;
};

static void mcryptd_queue_worker(struct work_struct *work);

void mcryptd_arm_flusher(struct mcryptd_alg_cstate *cstate, unsigned long delay)
{
	struct mcryptd_flush_list *flist;

	if (!cstate->flusher_engaged) {
		/* put the flusher on the flush list */
		flist = per_cpu_ptr(mcryptd_flist, smp_processor_id());
		mutex_lock(&flist->lock);
		list_add_tail(&cstate->flush_list, &flist->list);
		cstate->flusher_engaged = true;
		cstate->next_flush = jiffies + delay;
		queue_delayed_work_on(smp_processor_id(), kcrypto_wq,
			&cstate->flush, delay);
		mutex_unlock(&flist->lock);
	}
}
EXPORT_SYMBOL(mcryptd_arm_flusher);

static int mcryptd_init_queue(struct mcryptd_queue *queue,
			     unsigned int max_cpu_qlen)
{
	int cpu;
	struct mcryptd_cpu_queue *cpu_queue;

	queue->cpu_queue = alloc_percpu(struct mcryptd_cpu_queue);
	pr_debug("mqueue:%p mcryptd_cpu_queue %p\n", queue, queue->cpu_queue);
	if (!queue->cpu_queue)
		return -ENOMEM;
	for_each_possible_cpu(cpu) {
		cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
		pr_debug("cpu_queue #%d %p\n", cpu, queue->cpu_queue);
		crypto_init_queue(&cpu_queue->queue, max_cpu_qlen);
		INIT_WORK(&cpu_queue->work, mcryptd_queue_worker);
	}
	return 0;
}

static void mcryptd_fini_queue(struct mcryptd_queue *queue)
{
	int cpu;
	struct mcryptd_cpu_queue *cpu_queue;

	for_each_possible_cpu(cpu) {
		cpu_queue = per_cpu_ptr(queue->cpu_queue, cpu);
		BUG_ON(cpu_queue->queue.qlen);
	}
	free_percpu(queue->cpu_queue);
}

static int mcryptd_enqueue_request(struct mcryptd_queue *queue,
				  struct crypto_async_request *request,
				  struct mcryptd_hash_request_ctx *rctx)
{
	int cpu, err;
	struct mcryptd_cpu_queue *cpu_queue;

	cpu = get_cpu();
	cpu_queue = this_cpu_ptr(queue->cpu_queue);
	rctx->tag.cpu = cpu;

	err = crypto_enqueue_request(&cpu_queue->queue, request);
	pr_debug("enqueue request: cpu %d cpu_queue %p request %p\n",
		 cpu, cpu_queue, request);
	queue_work_on(cpu, kcrypto_wq, &cpu_queue->work);
	put_cpu();

	return err;
}

/*
 * Try to opportunisticlly flush the partially completed jobs if
 * crypto daemon is the only task running.
 */
static void mcryptd_opportunistic_flush(void)
{
	struct mcryptd_flush_list *flist;
	struct mcryptd_alg_cstate *cstate;

	flist = per_cpu_ptr(mcryptd_flist, smp_processor_id());
	while (single_task_running()) {
		mutex_lock(&flist->lock);
		if (list_empty(&flist->list)) {
			mutex_unlock(&flist->lock);
			return;
		}
		cstate = list_entry(flist->list.next,
				struct mcryptd_alg_cstate, flush_list);
		if (!cstate->flusher_engaged) {
			mutex_unlock(&flist->lock);
			return;
		}
		list_del(&cstate->flush_list);
		cstate->flusher_engaged = false;
		mutex_unlock(&flist->lock);
		cstate->alg_state->flusher(cstate);
	}
}

/*
 * Called in workqueue context, do one real cryption work (via
 * req->complete) and reschedule itself if there are more work to
 * do.
 */
static void mcryptd_queue_worker(struct work_struct *work)
{
	struct mcryptd_cpu_queue *cpu_queue;
	struct crypto_async_request *req, *backlog;
	int i;

	/*
	 * Need to loop through more than once for multi-buffer to
	 * be effective.
	 */

	cpu_queue = container_of(work, struct mcryptd_cpu_queue, work);
	i = 0;
	while (i < MCRYPTD_BATCH || single_task_running()) {
		/*
		 * preempt_disable/enable is used to prevent
		 * being preempted by mcryptd_enqueue_request()
		 */
		local_bh_disable();
		preempt_disable();
		backlog = crypto_get_backlog(&cpu_queue->queue);
		req = crypto_dequeue_request(&cpu_queue->queue);
		preempt_enable();
		local_bh_enable();

		if (!req) {
			mcryptd_opportunistic_flush();
			return;
		}

		if (backlog)
			backlog->complete(backlog, -EINPROGRESS);
		req->complete(req, 0);
		if (!cpu_queue->queue.qlen)
			return;
		++i;
	}
	if (cpu_queue->queue.qlen)
		queue_work(kcrypto_wq, &cpu_queue->work);
}

void mcryptd_flusher(struct work_struct *__work)
{
	struct	mcryptd_alg_cstate	*alg_cpu_state;
	struct	mcryptd_alg_state	*alg_state;
	struct	mcryptd_flush_list	*flist;
	int	cpu;

	cpu = smp_processor_id();
	alg_cpu_state = container_of(to_delayed_work(__work),
				     struct mcryptd_alg_cstate, flush);
	alg_state = alg_cpu_state->alg_state;
	if (alg_cpu_state->cpu != cpu)
		pr_debug("mcryptd error: work on cpu %d, should be cpu %d\n",
				cpu, alg_cpu_state->cpu);

	if (alg_cpu_state->flusher_engaged) {
		flist = per_cpu_ptr(mcryptd_flist, cpu);
		mutex_lock(&flist->lock);
		list_del(&alg_cpu_state->flush_list);
		alg_cpu_state->flusher_engaged = false;
		mutex_unlock(&flist->lock);
		alg_state->flusher(alg_cpu_state);
	}
}
EXPORT_SYMBOL_GPL(mcryptd_flusher);

static inline struct mcryptd_queue *mcryptd_get_queue(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
	struct mcryptd_instance_ctx *ictx = crypto_instance_ctx(inst);

	return ictx->queue;
}

static void *mcryptd_alloc_instance(struct crypto_alg *alg, unsigned int head,
				   unsigned int tail)
{
	char *p;
	struct crypto_instance *inst;
	int err;

	p = kzalloc(head + sizeof(*inst) + tail, GFP_KERNEL);
	if (!p)
		return ERR_PTR(-ENOMEM);

	inst = (void *)(p + head);

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		    "mcryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
		goto out_free_inst;

	memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);

	inst->alg.cra_priority = alg->cra_priority + 50;
	inst->alg.cra_blocksize = alg->cra_blocksize;
	inst->alg.cra_alignmask = alg->cra_alignmask;

out:
	return p;

out_free_inst:
	kfree(p);
	p = ERR_PTR(err);
	goto out;
}

static inline void mcryptd_check_internal(struct rtattr **tb, u32 *type,
					  u32 *mask)
{
	struct crypto_attr_type *algt;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return;
	if ((algt->type & CRYPTO_ALG_INTERNAL))
		*type |= CRYPTO_ALG_INTERNAL;
	if ((algt->mask & CRYPTO_ALG_INTERNAL))
		*mask |= CRYPTO_ALG_INTERNAL;
}

static int mcryptd_hash_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
	struct hashd_instance_ctx *ictx = crypto_instance_ctx(inst);
	struct crypto_shash_spawn *spawn = &ictx->spawn;
	struct mcryptd_hash_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_shash *hash;

	hash = crypto_spawn_shash(spawn);
	if (IS_ERR(hash))
		return PTR_ERR(hash);

	ctx->child = hash;
	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
				 sizeof(struct mcryptd_hash_request_ctx) +
				 crypto_shash_descsize(hash));
	return 0;
}

static void mcryptd_hash_exit_tfm(struct crypto_tfm *tfm)
{
	struct mcryptd_hash_ctx *ctx = crypto_tfm_ctx(tfm);

	crypto_free_shash(ctx->child);
}

static int mcryptd_hash_setkey(struct crypto_ahash *parent,
				   const u8 *key, unsigned int keylen)
{
	struct mcryptd_hash_ctx *ctx   = crypto_ahash_ctx(parent);
	struct crypto_shash *child = ctx->child;
	int err;

	crypto_shash_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_shash_set_flags(child, crypto_ahash_get_flags(parent) &
				      CRYPTO_TFM_REQ_MASK);
	err = crypto_shash_setkey(child, key, keylen);
	crypto_ahash_set_flags(parent, crypto_shash_get_flags(child) &
				       CRYPTO_TFM_RES_MASK);
	return err;
}

static int mcryptd_hash_enqueue(struct ahash_request *req,
				crypto_completion_t complete)
{
	int ret;

	struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
	struct mcryptd_queue *queue =
		mcryptd_get_queue(crypto_ahash_tfm(tfm));

	rctx->complete = req->base.complete;
	req->base.complete = complete;

	ret = mcryptd_enqueue_request(queue, &req->base, rctx);

	return ret;
}

static void mcryptd_hash_init(struct crypto_async_request *req_async, int err)
{
	struct mcryptd_hash_ctx *ctx = crypto_tfm_ctx(req_async->tfm);
	struct crypto_shash *child = ctx->child;
	struct ahash_request *req = ahash_request_cast(req_async);
	struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
	struct shash_desc *desc = &rctx->desc;

	if (unlikely(err == -EINPROGRESS))
		goto out;

	desc->tfm = child;
	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;

	err = crypto_shash_init(desc);

	req->base.complete = rctx->complete;

out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int mcryptd_hash_init_enqueue(struct ahash_request *req)
{
	return mcryptd_hash_enqueue(req, mcryptd_hash_init);
}

static void mcryptd_hash_update(struct crypto_async_request *req_async, int err)
{
	struct ahash_request *req = ahash_request_cast(req_async);
	struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

	if (unlikely(err == -EINPROGRESS))
		goto out;

	err = shash_ahash_mcryptd_update(req, &rctx->desc);
	if (err) {
		req->base.complete = rctx->complete;
		goto out;
	}

	return;
out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int mcryptd_hash_update_enqueue(struct ahash_request *req)
{
	return mcryptd_hash_enqueue(req, mcryptd_hash_update);
}

static void mcryptd_hash_final(struct crypto_async_request *req_async, int err)
{
	struct ahash_request *req = ahash_request_cast(req_async);
	struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

	if (unlikely(err == -EINPROGRESS))
		goto out;

	err = shash_ahash_mcryptd_final(req, &rctx->desc);
	if (err) {
		req->base.complete = rctx->complete;
		goto out;
	}

	return;
out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int mcryptd_hash_final_enqueue(struct ahash_request *req)
{
	return mcryptd_hash_enqueue(req, mcryptd_hash_final);
}

static void mcryptd_hash_finup(struct crypto_async_request *req_async, int err)
{
	struct ahash_request *req = ahash_request_cast(req_async);
	struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

	if (unlikely(err == -EINPROGRESS))
		goto out;

	err = shash_ahash_mcryptd_finup(req, &rctx->desc);

	if (err) {
		req->base.complete = rctx->complete;
		goto out;
	}

	return;
out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int mcryptd_hash_finup_enqueue(struct ahash_request *req)
{
	return mcryptd_hash_enqueue(req, mcryptd_hash_finup);
}

static void mcryptd_hash_digest(struct crypto_async_request *req_async, int err)
{
	struct mcryptd_hash_ctx *ctx = crypto_tfm_ctx(req_async->tfm);
	struct crypto_shash *child = ctx->child;
	struct ahash_request *req = ahash_request_cast(req_async);
	struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
	struct shash_desc *desc = &rctx->desc;

	if (unlikely(err == -EINPROGRESS))
		goto out;

	desc->tfm = child;
	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;  /* check this again */

	err = shash_ahash_mcryptd_digest(req, desc);

	if (err) {
		req->base.complete = rctx->complete;
		goto out;
	}

	return;
out:
	local_bh_disable();
	rctx->complete(&req->base, err);
	local_bh_enable();
}

static int mcryptd_hash_digest_enqueue(struct ahash_request *req)
{
	return mcryptd_hash_enqueue(req, mcryptd_hash_digest);
}

static int mcryptd_hash_export(struct ahash_request *req, void *out)
{
	struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

	return crypto_shash_export(&rctx->desc, out);
}

static int mcryptd_hash_import(struct ahash_request *req, const void *in)
{
	struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);

	return crypto_shash_import(&rctx->desc, in);
}

static int mcryptd_create_hash(struct crypto_template *tmpl, struct rtattr **tb,
			      struct mcryptd_queue *queue)
{
	struct hashd_instance_ctx *ctx;
	struct ahash_instance *inst;
	struct shash_alg *salg;
	struct crypto_alg *alg;
	u32 type = 0;
	u32 mask = 0;
	int err;

	mcryptd_check_internal(tb, &type, &mask);

	salg = shash_attr_alg(tb[1], type, mask);
	if (IS_ERR(salg))
		return PTR_ERR(salg);

	alg = &salg->base;
	pr_debug("crypto: mcryptd hash alg: %s\n", alg->cra_name);
	inst = mcryptd_alloc_instance(alg, ahash_instance_headroom(),
					sizeof(*ctx));
	err = PTR_ERR(inst);
	if (IS_ERR(inst))
		goto out_put_alg;

	ctx = ahash_instance_ctx(inst);
	ctx->queue = queue;

	err = crypto_init_shash_spawn(&ctx->spawn, salg,
				      ahash_crypto_instance(inst));
	if (err)
		goto out_free_inst;

	type = CRYPTO_ALG_ASYNC;
	if (alg->cra_flags & CRYPTO_ALG_INTERNAL)
		type |= CRYPTO_ALG_INTERNAL;
	inst->alg.halg.base.cra_flags = type;

	inst->alg.halg.digestsize = salg->digestsize;
	inst->alg.halg.base.cra_ctxsize = sizeof(struct mcryptd_hash_ctx);

	inst->alg.halg.base.cra_init = mcryptd_hash_init_tfm;
	inst->alg.halg.base.cra_exit = mcryptd_hash_exit_tfm;

	inst->alg.init   = mcryptd_hash_init_enqueue;
	inst->alg.update = mcryptd_hash_update_enqueue;
	inst->alg.final  = mcryptd_hash_final_enqueue;
	inst->alg.finup  = mcryptd_hash_finup_enqueue;
	inst->alg.export = mcryptd_hash_export;
	inst->alg.import = mcryptd_hash_import;
	inst->alg.setkey = mcryptd_hash_setkey;
	inst->alg.digest = mcryptd_hash_digest_enqueue;

	err = ahash_register_instance(tmpl, inst);
	if (err) {
		crypto_drop_shash(&ctx->spawn);
out_free_inst:
		kfree(inst);
	}

out_put_alg:
	crypto_mod_put(alg);
	return err;
}

static struct mcryptd_queue mqueue;

static int mcryptd_create(struct crypto_template *tmpl, struct rtattr **tb)
{
	struct crypto_attr_type *algt;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
	case CRYPTO_ALG_TYPE_DIGEST:
		return mcryptd_create_hash(tmpl, tb, &mqueue);
	break;
	}

	return -EINVAL;
}

static void mcryptd_free(struct crypto_instance *inst)
{
	struct mcryptd_instance_ctx *ctx = crypto_instance_ctx(inst);
	struct hashd_instance_ctx *hctx = crypto_instance_ctx(inst);

	switch (inst->alg.cra_flags & CRYPTO_ALG_TYPE_MASK) {
	case CRYPTO_ALG_TYPE_AHASH:
		crypto_drop_shash(&hctx->spawn);
		kfree(ahash_instance(inst));
		return;
	default:
		crypto_drop_spawn(&ctx->spawn);
		kfree(inst);
	}
}

static struct crypto_template mcryptd_tmpl = {
	.name = "mcryptd",
	.create = mcryptd_create,
	.free = mcryptd_free,
	.module = THIS_MODULE,
};

struct mcryptd_ahash *mcryptd_alloc_ahash(const char *alg_name,
					u32 type, u32 mask)
{
	char mcryptd_alg_name[CRYPTO_MAX_ALG_NAME];
	struct crypto_ahash *tfm;

	if (snprintf(mcryptd_alg_name, CRYPTO_MAX_ALG_NAME,
		     "mcryptd(%s)", alg_name) >= CRYPTO_MAX_ALG_NAME)
		return ERR_PTR(-EINVAL);
	tfm = crypto_alloc_ahash(mcryptd_alg_name, type, mask);
	if (IS_ERR(tfm))
		return ERR_CAST(tfm);
	if (tfm->base.__crt_alg->cra_module != THIS_MODULE) {
		crypto_free_ahash(tfm);
		return ERR_PTR(-EINVAL);
	}

	return __mcryptd_ahash_cast(tfm);
}
EXPORT_SYMBOL_GPL(mcryptd_alloc_ahash);

int shash_ahash_mcryptd_digest(struct ahash_request *req,
			       struct shash_desc *desc)
{
	int err;

	err = crypto_shash_init(desc) ?:
	      shash_ahash_mcryptd_finup(req, desc);

	return err;
}
EXPORT_SYMBOL_GPL(shash_ahash_mcryptd_digest);

int shash_ahash_mcryptd_update(struct ahash_request *req,
			       struct shash_desc *desc)
{
	struct crypto_shash *tfm = desc->tfm;
	struct shash_alg *shash = crypto_shash_alg(tfm);

	/* alignment is to be done by multi-buffer crypto algorithm if needed */

	return shash->update(desc, NULL, 0);
}
EXPORT_SYMBOL_GPL(shash_ahash_mcryptd_update);

int shash_ahash_mcryptd_finup(struct ahash_request *req,
			      struct shash_desc *desc)
{
	struct crypto_shash *tfm = desc->tfm;
	struct shash_alg *shash = crypto_shash_alg(tfm);

	/* alignment is to be done by multi-buffer crypto algorithm if needed */

	return shash->finup(desc, NULL, 0, req->result);
}
EXPORT_SYMBOL_GPL(shash_ahash_mcryptd_finup);

int shash_ahash_mcryptd_final(struct ahash_request *req,
			      struct shash_desc *desc)
{
	struct crypto_shash *tfm = desc->tfm;
	struct shash_alg *shash = crypto_shash_alg(tfm);

	/* alignment is to be done by multi-buffer crypto algorithm if needed */

	return shash->final(desc, req->result);
}
EXPORT_SYMBOL_GPL(shash_ahash_mcryptd_final);

struct crypto_shash *mcryptd_ahash_child(struct mcryptd_ahash *tfm)
{
	struct mcryptd_hash_ctx *ctx = crypto_ahash_ctx(&tfm->base);

	return ctx->child;
}
EXPORT_SYMBOL_GPL(mcryptd_ahash_child);

struct shash_desc *mcryptd_shash_desc(struct ahash_request *req)
{
	struct mcryptd_hash_request_ctx *rctx = ahash_request_ctx(req);
	return &rctx->desc;
}
EXPORT_SYMBOL_GPL(mcryptd_shash_desc);

void mcryptd_free_ahash(struct mcryptd_ahash *tfm)
{
	crypto_free_ahash(&tfm->base);
}
EXPORT_SYMBOL_GPL(mcryptd_free_ahash);


static int __init mcryptd_init(void)
{
	int err, cpu;
	struct mcryptd_flush_list *flist;

	mcryptd_flist = alloc_percpu(struct mcryptd_flush_list);
	for_each_possible_cpu(cpu) {
		flist = per_cpu_ptr(mcryptd_flist, cpu);
		INIT_LIST_HEAD(&flist->list);
		mutex_init(&flist->lock);
	}

	err = mcryptd_init_queue(&mqueue, MCRYPTD_MAX_CPU_QLEN);
	if (err) {
		free_percpu(mcryptd_flist);
		return err;
	}

	err = crypto_register_template(&mcryptd_tmpl);
	if (err) {
		mcryptd_fini_queue(&mqueue);
		free_percpu(mcryptd_flist);
	}

	return err;
}

static void __exit mcryptd_exit(void)
{
	mcryptd_fini_queue(&mqueue);
	crypto_unregister_template(&mcryptd_tmpl);
	free_percpu(mcryptd_flist);
}

subsys_initcall(mcryptd_init);
module_exit(mcryptd_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Software async multibuffer crypto daemon");
MODULE_ALIAS_CRYPTO("mcryptd");