crypto: sha512-mb - SHA512 multibuffer job manager and glue code

This patch introduces the multi-buffer job manager which is responsible
for submitting scatter-gather buffers from several SHA512 jobs to the
multi-buffer algorithm. It also contains the flush routine that's called
by the crypto daemon to complete the job when no new jobs arrive before
the deadline of maximum latency of a SHA512 crypto job.

The SHA512 multi-buffer crypto algorithm is defined and initialized in this
patch.
Signed-off-by: Megha Dey <megha.dey@linux.intel.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/x86/crypto/Makefile

@@ -51,6 +51,7 @@ ifeq ($(avx2_supported),yes)
 	obj-$(CONFIG_CRYPTO_SERPENT_AVX2_X86_64) += serpent-avx2.o
 	obj-$(CONFIG_CRYPTO_SHA1_MB) += sha1-mb/
 	obj-$(CONFIG_CRYPTO_SHA256_MB) += sha256-mb/
+	obj-$(CONFIG_CRYPTO_SHA512_MB) += sha512-mb/
 endif
 
 aes-i586-y := aes-i586-asm_32.o aes_glue.o

arch/x86/crypto/sha512-mb/Makefile

+#
+# Arch-specific CryptoAPI modules.
+#
+
+avx2_supported := $(call as-instr,vpgatherdd %ymm0$(comma)(%eax$(comma)%ymm1\
+                                $(comma)4)$(comma)%ymm2,yes,no)
+ifeq ($(avx2_supported),yes)
+	obj-$(CONFIG_CRYPTO_SHA512_MB) += sha512-mb.o
+	sha512-mb-y := sha512_mb.o sha512_mb_mgr_flush_avx2.o \
+	     sha512_mb_mgr_init_avx2.o sha512_mb_mgr_submit_avx2.o sha512_x4_avx2.o
+endif

arch/x86/crypto/sha512-mb/sha512_mb.c

+/*
+ * Multi buffer SHA512 algorithm Glue Code
+ *
+ * This file is provided under a dual BSD/GPLv2 license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2016 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * Contact Information:
+ *	Megha Dey <megha.dey@linux.intel.com>
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2016 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <crypto/internal/hash.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/cryptohash.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <crypto/scatterwalk.h>
+#include <crypto/sha.h>
+#include <crypto/mcryptd.h>
+#include <crypto/crypto_wq.h>
+#include <asm/byteorder.h>
+#include <linux/hardirq.h>
+#include <asm/fpu/api.h>
+#include "sha512_mb_ctx.h"
+
+#define FLUSH_INTERVAL 1000 /* in usec */
+
+static struct mcryptd_alg_state sha512_mb_alg_state;
+
+struct sha512_mb_ctx {
+	struct mcryptd_ahash *mcryptd_tfm;
+};
+
+static inline struct mcryptd_hash_request_ctx
+		*cast_hash_to_mcryptd_ctx(struct sha512_hash_ctx *hash_ctx)
+{
+	struct ahash_request *areq;
+
+	areq = container_of((void *) hash_ctx, struct ahash_request, __ctx);
+	return container_of(areq, struct mcryptd_hash_request_ctx, areq);
+}
+
+static inline struct ahash_request
+		*cast_mcryptd_ctx_to_req(struct mcryptd_hash_request_ctx *ctx)
+{
+	return container_of((void *) ctx, struct ahash_request, __ctx);
+}
+
+static void req_ctx_init(struct mcryptd_hash_request_ctx *rctx,
+				struct ahash_request *areq)
+{
+	rctx->flag = HASH_UPDATE;
+}
+
+static asmlinkage void (*sha512_job_mgr_init)(struct sha512_mb_mgr *state);
+static asmlinkage struct job_sha512* (*sha512_job_mgr_submit)
+						(struct sha512_mb_mgr *state,
+						struct job_sha512 *job);
+static asmlinkage struct job_sha512* (*sha512_job_mgr_flush)
+						(struct sha512_mb_mgr *state);
+static asmlinkage struct job_sha512* (*sha512_job_mgr_get_comp_job)
+						(struct sha512_mb_mgr *state);
+
+inline void sha512_init_digest(uint64_t *digest)
+{
+	static const uint64_t initial_digest[SHA512_DIGEST_LENGTH] = {
+					SHA512_H0, SHA512_H1, SHA512_H2,
+					SHA512_H3, SHA512_H4, SHA512_H5,
+					SHA512_H6, SHA512_H7 };
+	memcpy(digest, initial_digest, sizeof(initial_digest));
+}
+
+inline uint32_t sha512_pad(uint8_t padblock[SHA512_BLOCK_SIZE * 2],
+			 uint32_t total_len)
+{
+	uint32_t i = total_len & (SHA512_BLOCK_SIZE - 1);
+
+	memset(&padblock[i], 0, SHA512_BLOCK_SIZE);
+	padblock[i] = 0x80;
+
+	i += ((SHA512_BLOCK_SIZE - 1) &
+	      (0 - (total_len + SHA512_PADLENGTHFIELD_SIZE + 1)))
+	     + 1 + SHA512_PADLENGTHFIELD_SIZE;
+
+#if SHA512_PADLENGTHFIELD_SIZE == 16
+	*((uint64_t *) &padblock[i - 16]) = 0;
+#endif
+
+	*((uint64_t *) &padblock[i - 8]) = cpu_to_be64(total_len << 3);
+
+	/* Number of extra blocks to hash */
+	return i >> SHA512_LOG2_BLOCK_SIZE;
+}
+
+static struct sha512_hash_ctx *sha512_ctx_mgr_resubmit
+		(struct sha512_ctx_mgr *mgr, struct sha512_hash_ctx *ctx)
+{
+	while (ctx) {
+		if (ctx->status & HASH_CTX_STS_COMPLETE) {
+			/* Clear PROCESSING bit */
+			ctx->status = HASH_CTX_STS_COMPLETE;
+			return ctx;
+		}
+
+		/*
+		 * If the extra blocks are empty, begin hashing what remains
+		 * in the user's buffer.
+		 */
+		if (ctx->partial_block_buffer_length == 0 &&
+		    ctx->incoming_buffer_length) {
+
+			const void *buffer = ctx->incoming_buffer;
+			uint32_t len = ctx->incoming_buffer_length;
+			uint32_t copy_len;
+
+			/*
+			 * Only entire blocks can be hashed.
+			 * Copy remainder to extra blocks buffer.
+			 */
+			copy_len = len & (SHA512_BLOCK_SIZE-1);
+
+			if (copy_len) {
+				len -= copy_len;
+				memcpy(ctx->partial_block_buffer,
+				       ((const char *) buffer + len),
+				       copy_len);
+				ctx->partial_block_buffer_length = copy_len;
+			}
+
+			ctx->incoming_buffer_length = 0;
+
+			/* len should be a multiple of the block size now */
+			assert((len % SHA512_BLOCK_SIZE) == 0);
+
+			/* Set len to the number of blocks to be hashed */
+			len >>= SHA512_LOG2_BLOCK_SIZE;
+
+			if (len) {
+
+				ctx->job.buffer = (uint8_t *) buffer;
+				ctx->job.len = len;
+				ctx = (struct sha512_hash_ctx *)
+					sha512_job_mgr_submit(&mgr->mgr,
+					&ctx->job);
+				continue;
+			}
+		}
+
+		/*
+		 * If the extra blocks are not empty, then we are
+		 * either on the last block(s) or we need more
+		 * user input before continuing.
+		 */
+		if (ctx->status & HASH_CTX_STS_LAST) {
+
+			uint8_t *buf = ctx->partial_block_buffer;
+			uint32_t n_extra_blocks =
+					sha512_pad(buf, ctx->total_length);
+
+			ctx->status = (HASH_CTX_STS_PROCESSING |
+				       HASH_CTX_STS_COMPLETE);
+			ctx->job.buffer = buf;
+			ctx->job.len = (uint32_t) n_extra_blocks;
+			ctx = (struct sha512_hash_ctx *)
+				sha512_job_mgr_submit(&mgr->mgr, &ctx->job);
+			continue;
+		}
+
+		if (ctx)
+			ctx->status = HASH_CTX_STS_IDLE;
+		return ctx;
+	}
+
+	return NULL;
+}
+
+static struct sha512_hash_ctx
+		*sha512_ctx_mgr_get_comp_ctx(struct sha512_ctx_mgr *mgr)
+{
+	/*
+	 * If get_comp_job returns NULL, there are no jobs complete.
+	 * If get_comp_job returns a job, verify that it is safe to return to
+	 * the user.
+	 * If it is not ready, resubmit the job to finish processing.
+	 * If sha512_ctx_mgr_resubmit returned a job, it is ready to be
+	 * returned.
+	 * Otherwise, all jobs currently being managed by the hash_ctx_mgr
+	 * still need processing.
+	 */
+	struct sha512_hash_ctx *ctx;
+
+	ctx = (struct sha512_hash_ctx *)
+				sha512_job_mgr_get_comp_job(&mgr->mgr);
+	return sha512_ctx_mgr_resubmit(mgr, ctx);
+}
+
+static void sha512_ctx_mgr_init(struct sha512_ctx_mgr *mgr)
+{
+	sha512_job_mgr_init(&mgr->mgr);
+}
+
+static struct sha512_hash_ctx
+			*sha512_ctx_mgr_submit(struct sha512_ctx_mgr *mgr,
+					  struct sha512_hash_ctx *ctx,
+					  const void *buffer,
+					  uint32_t len,
+					  int flags)
+{
+	if (flags & (~HASH_ENTIRE)) {
+		/* User should not pass anything other than FIRST, UPDATE, or
+		 * LAST
+		 */
+		ctx->error = HASH_CTX_ERROR_INVALID_FLAGS;
+		return ctx;
+	}
+
+	if (ctx->status & HASH_CTX_STS_PROCESSING) {
+		/* Cannot submit to a currently processing job. */
+		ctx->error = HASH_CTX_ERROR_ALREADY_PROCESSING;
+		return ctx;
+	}
+
+	if ((ctx->status & HASH_CTX_STS_COMPLETE) && !(flags & HASH_FIRST)) {
+		/* Cannot update a finished job. */
+		ctx->error = HASH_CTX_ERROR_ALREADY_COMPLETED;
+		return ctx;
+	}
+
+
+	if (flags & HASH_FIRST) {
+		/* Init digest */
+		sha512_init_digest(ctx->job.result_digest);
+
+		/* Reset byte counter */
+		ctx->total_length = 0;
+
+		/* Clear extra blocks */
+		ctx->partial_block_buffer_length = 0;
+	}
+
+	/* If we made it here, there were no errors during this call to
+	 * submit
+	 */
+	ctx->error = HASH_CTX_ERROR_NONE;
+
+	/* Store buffer ptr info from user */
+	ctx->incoming_buffer = buffer;
+	ctx->incoming_buffer_length = len;
+
+	/* Store the user's request flags and mark this ctx as currently being
+	 * processed.
+	 */
+	ctx->status = (flags & HASH_LAST) ?
+			(HASH_CTX_STS_PROCESSING | HASH_CTX_STS_LAST) :
+			HASH_CTX_STS_PROCESSING;
+
+	/* Advance byte counter */
+	ctx->total_length += len;
+
+	/*
+	 * If there is anything currently buffered in the extra blocks,
+	 * append to it until it contains a whole block.
+	 * Or if the user's buffer contains less than a whole block,
+	 * append as much as possible to the extra block.
+	 */
+	if ((ctx->partial_block_buffer_length) | (len < SHA512_BLOCK_SIZE)) {
+		/* Compute how many bytes to copy from user buffer into extra
+		 * block
+		 */
+		uint32_t copy_len = SHA512_BLOCK_SIZE -
+					ctx->partial_block_buffer_length;
+		if (len < copy_len)
+			copy_len = len;
+
+		if (copy_len) {
+			/* Copy and update relevant pointers and counters */
+			memcpy
+		(&ctx->partial_block_buffer[ctx->partial_block_buffer_length],
+				buffer, copy_len);
+
+			ctx->partial_block_buffer_length += copy_len;
+			ctx->incoming_buffer = (const void *)
+					((const char *)buffer + copy_len);
+			ctx->incoming_buffer_length = len - copy_len;
+		}
+
+		/* The extra block should never contain more than 1 block
+		 * here
+		 */
+		assert(ctx->partial_block_buffer_length <= SHA512_BLOCK_SIZE);
+
+		/* If the extra block buffer contains exactly 1 block, it can
+		 * be hashed.
+		 */
+		if (ctx->partial_block_buffer_length >= SHA512_BLOCK_SIZE) {
+			ctx->partial_block_buffer_length = 0;
+
+			ctx->job.buffer = ctx->partial_block_buffer;
+			ctx->job.len = 1;
+			ctx = (struct sha512_hash_ctx *)
+				sha512_job_mgr_submit(&mgr->mgr, &ctx->job);
+		}
+	}
+
+	return sha512_ctx_mgr_resubmit(mgr, ctx);
+}
+
+static struct sha512_hash_ctx *sha512_ctx_mgr_flush(struct sha512_ctx_mgr *mgr)
+{
+	struct sha512_hash_ctx *ctx;
+
+	while (1) {
+		ctx = (struct sha512_hash_ctx *)
+					sha512_job_mgr_flush(&mgr->mgr);
+
+		/* If flush returned 0, there are no more jobs in flight. */
+		if (!ctx)
+			return NULL;
+
+		/*
+		 * If flush returned a job, resubmit the job to finish
+		 * processing.
+		 */
+		ctx = sha512_ctx_mgr_resubmit(mgr, ctx);
+
+		/*
+		 * If sha512_ctx_mgr_resubmit returned a job, it is ready to
+		 * be returned. Otherwise, all jobs currently being managed by
+		 * the sha512_ctx_mgr still need processing. Loop.
+		 */
+		if (ctx)
+			return ctx;
+	}
+}
+
+static int sha512_mb_init(struct ahash_request *areq)
+{
+	struct sha512_hash_ctx *sctx = ahash_request_ctx(areq);
+
+	hash_ctx_init(sctx);
+	sctx->job.result_digest[0] = SHA512_H0;
+	sctx->job.result_digest[1] = SHA512_H1;
+	sctx->job.result_digest[2] = SHA512_H2;
+	sctx->job.result_digest[3] = SHA512_H3;
+	sctx->job.result_digest[4] = SHA512_H4;
+	sctx->job.result_digest[5] = SHA512_H5;
+	sctx->job.result_digest[6] = SHA512_H6;
+	sctx->job.result_digest[7] = SHA512_H7;
+	sctx->total_length = 0;
+	sctx->partial_block_buffer_length = 0;
+	sctx->status = HASH_CTX_STS_IDLE;
+
+	return 0;
+}
+
+static int sha512_mb_set_results(struct mcryptd_hash_request_ctx *rctx)
+{
+	int	i;
+	struct	sha512_hash_ctx *sctx = ahash_request_ctx(&rctx->areq);
+	__be64	*dst = (__be64 *) rctx->out;
+
+	for (i = 0; i < 8; ++i)
+		dst[i] = cpu_to_be64(sctx->job.result_digest[i]);
+
+	return 0;
+}
+
+static int sha_finish_walk(struct mcryptd_hash_request_ctx **ret_rctx,
+			struct mcryptd_alg_cstate *cstate, bool flush)
+{
+	int	flag = HASH_UPDATE;
+	int	nbytes, err = 0;
+	struct mcryptd_hash_request_ctx *rctx = *ret_rctx;
+	struct sha512_hash_ctx *sha_ctx;
+
+	/* more work ? */
+	while (!(rctx->flag & HASH_DONE)) {
+		nbytes = crypto_ahash_walk_done(&rctx->walk, 0);
+		if (nbytes < 0) {
+			err = nbytes;
+			goto out;
+		}
+		/* check if the walk is done */
+		if (crypto_ahash_walk_last(&rctx->walk)) {
+			rctx->flag |= HASH_DONE;
+			if (rctx->flag & HASH_FINAL)
+				flag |= HASH_LAST;
+
+		}
+		sha_ctx = (struct sha512_hash_ctx *)
+						ahash_request_ctx(&rctx->areq);
+		kernel_fpu_begin();
+		sha_ctx = sha512_ctx_mgr_submit(cstate->mgr, sha_ctx,
+						rctx->walk.data, nbytes, flag);
+		if (!sha_ctx) {
+			if (flush)
+				sha_ctx = sha512_ctx_mgr_flush(cstate->mgr);
+		}
+		kernel_fpu_end();
+		if (sha_ctx)
+			rctx = cast_hash_to_mcryptd_ctx(sha_ctx);
+		else {
+			rctx = NULL;
+			goto out;
+		}
+	}
+
+	/* copy the results */
+	if (rctx->flag & HASH_FINAL)
+		sha512_mb_set_results(rctx);
+
+out:
+	*ret_rctx = rctx;
+	return err;
+}
+
+static int sha_complete_job(struct mcryptd_hash_request_ctx *rctx,
+			    struct mcryptd_alg_cstate *cstate,
+			    int err)
+{
+	struct ahash_request *req = cast_mcryptd_ctx_to_req(rctx);
+	struct sha512_hash_ctx *sha_ctx;
+	struct mcryptd_hash_request_ctx *req_ctx;
+	int ret;
+
+	/* remove from work list */
+	spin_lock(&cstate->work_lock);
+	list_del(&rctx->waiter);
+	spin_unlock(&cstate->work_lock);
+
+	if (irqs_disabled())
+		rctx->complete(&req->base, err);
+	else {
+		local_bh_disable();
+		rctx->complete(&req->base, err);
+		local_bh_enable();
+	}
+
+	/* check to see if there are other jobs that are done */
+	sha_ctx = sha512_ctx_mgr_get_comp_ctx(cstate->mgr);
+	while (sha_ctx) {
+		req_ctx = cast_hash_to_mcryptd_ctx(sha_ctx);
+		ret = sha_finish_walk(&req_ctx, cstate, false);
+		if (req_ctx) {
+			spin_lock(&cstate->work_lock);
+			list_del(&req_ctx->waiter);
+			spin_unlock(&cstate->work_lock);
+
+			req = cast_mcryptd_ctx_to_req(req_ctx);
+			if (irqs_disabled())
+				rctx->complete(&req->base, ret);
+			else {
+				local_bh_disable();
+				rctx->complete(&req->base, ret);
+				local_bh_enable();
+			}
+		}
+		sha_ctx = sha512_ctx_mgr_get_comp_ctx(cstate->mgr);
+	}
+
+	return 0;
+}
+
+static void sha512_mb_add_list(struct mcryptd_hash_request_ctx *rctx,
+			     struct mcryptd_alg_cstate *cstate)
+{
+	unsigned long next_flush;
+	unsigned long delay = usecs_to_jiffies(FLUSH_INTERVAL);
+
+	/* initialize tag */
+	rctx->tag.arrival = jiffies;    /* tag the arrival time */
+	rctx->tag.seq_num = cstate->next_seq_num++;
+	next_flush = rctx->tag.arrival + delay;
+	rctx->tag.expire = next_flush;
+
+	spin_lock(&cstate->work_lock);
+	list_add_tail(&rctx->waiter, &cstate->work_list);
+	spin_unlock(&cstate->work_lock);
+
+	mcryptd_arm_flusher(cstate, delay);
+}
+
+static int sha512_mb_update(struct ahash_request *areq)
+{
+	struct mcryptd_hash_request_ctx *rctx =
+			container_of(areq, struct mcryptd_hash_request_ctx,
+									areq);
+	struct mcryptd_alg_cstate *cstate =
+				this_cpu_ptr(sha512_mb_alg_state.alg_cstate);
+
+	struct ahash_request *req = cast_mcryptd_ctx_to_req(rctx);
+	struct sha512_hash_ctx *sha_ctx;
+	int ret = 0, nbytes;
+
+
+	/* sanity check */
+	if (rctx->tag.cpu != smp_processor_id()) {
+		pr_err("mcryptd error: cpu clash\n");
+		goto done;
+	}
+
+	/* need to init context */
+	req_ctx_init(rctx, areq);
+
+	nbytes = crypto_ahash_walk_first(req, &rctx->walk);
+
+	if (nbytes < 0) {
+		ret = nbytes;
+		goto done;
+	}
+
+	if (crypto_ahash_walk_last(&rctx->walk))
+		rctx->flag |= HASH_DONE;
+
+	/* submit */
+	sha_ctx = (struct sha512_hash_ctx *) ahash_request_ctx(areq);
+	sha512_mb_add_list(rctx, cstate);
+	kernel_fpu_begin();
+	sha_ctx = sha512_ctx_mgr_submit(cstate->mgr, sha_ctx, rctx->walk.data,
+							nbytes, HASH_UPDATE);
+	kernel_fpu_end();
+
+	/* check if anything is returned */
+	if (!sha_ctx)
+		return -EINPROGRESS;
+
+	if (sha_ctx->error) {
+		ret = sha_ctx->error;
+		rctx = cast_hash_to_mcryptd_ctx(sha_ctx);
+		goto done;
+	}
+
+	rctx = cast_hash_to_mcryptd_ctx(sha_ctx);
+	ret = sha_finish_walk(&rctx, cstate, false);
+
+	if (!rctx)
+		return -EINPROGRESS;
+done:
+	sha_complete_job(rctx, cstate, ret);
+	return ret;
+}
+
+static int sha512_mb_finup(struct ahash_request *areq)
+{
+	struct mcryptd_hash_request_ctx *rctx =
+			container_of(areq, struct mcryptd_hash_request_ctx,
+									areq);
+	struct mcryptd_alg_cstate *cstate =
+				this_cpu_ptr(sha512_mb_alg_state.alg_cstate);
+
+	struct ahash_request *req = cast_mcryptd_ctx_to_req(rctx);
+	struct sha512_hash_ctx *sha_ctx;
+	int ret = 0, flag = HASH_UPDATE, nbytes;
+
+	/* sanity check */
+	if (rctx->tag.cpu != smp_processor_id()) {
+		pr_err("mcryptd error: cpu clash\n");
+		goto done;
+	}
+
+	/* need to init context */
+	req_ctx_init(rctx, areq);
+
+	nbytes = crypto_ahash_walk_first(req, &rctx->walk);
+
+	if (nbytes < 0) {
+		ret = nbytes;
+		goto done;
+	}
+
+	if (crypto_ahash_walk_last(&rctx->walk)) {
+		rctx->flag |= HASH_DONE;
+		flag = HASH_LAST;
+	}
+
+	/* submit */
+	rctx->flag |= HASH_FINAL;
+	sha_ctx = (struct sha512_hash_ctx *) ahash_request_ctx(areq);
+	sha512_mb_add_list(rctx, cstate);
+
+	kernel_fpu_begin();
+	sha_ctx = sha512_ctx_mgr_submit(cstate->mgr, sha_ctx, rctx->walk.data,
+								nbytes, flag);
+	kernel_fpu_end();
+
+	/* check if anything is returned */
+	if (!sha_ctx)
+		return -EINPROGRESS;
+
+	if (sha_ctx->error) {
+		ret = sha_ctx->error;
+		goto done;
+	}
+
+	rctx = cast_hash_to_mcryptd_ctx(sha_ctx);
+	ret = sha_finish_walk(&rctx, cstate, false);
+	if (!rctx)
+		return -EINPROGRESS;
+done:
+	sha_complete_job(rctx, cstate, ret);
+	return ret;
+}
+
+static int sha512_mb_final(struct ahash_request *areq)
+{
+	struct mcryptd_hash_request_ctx *rctx =
+			container_of(areq, struct mcryptd_hash_request_ctx,
+									areq);
+	struct mcryptd_alg_cstate *cstate =
+				this_cpu_ptr(sha512_mb_alg_state.alg_cstate);
+
+	struct sha512_hash_ctx *sha_ctx;
+	int ret = 0;
+	u8 data;
+
+	/* sanity check */
+	if (rctx->tag.cpu != smp_processor_id()) {
+		pr_err("mcryptd error: cpu clash\n");
+		goto done;
+	}
+
+	/* need to init context */
+	req_ctx_init(rctx, areq);
+
+	rctx->flag |= HASH_DONE | HASH_FINAL;
+
+	sha_ctx = (struct sha512_hash_ctx *) ahash_request_ctx(areq);
+	/* flag HASH_FINAL and 0 data size */
+	sha512_mb_add_list(rctx, cstate);
+	kernel_fpu_begin();
+	sha_ctx = sha512_ctx_mgr_submit(cstate->mgr, sha_ctx, &data, 0,
+								HASH_LAST);
+	kernel_fpu_end();
+
+	/* check if anything is returned */
+	if (!sha_ctx)
+		return -EINPROGRESS;
+
+	if (sha_ctx->error) {
+		ret = sha_ctx->error;
+		rctx = cast_hash_to_mcryptd_ctx(sha_ctx);
+		goto done;
+	}
+
+	rctx = cast_hash_to_mcryptd_ctx(sha_ctx);
+	ret = sha_finish_walk(&rctx, cstate, false);
+	if (!rctx)
+		return -EINPROGRESS;
+done:
+	sha_complete_job(rctx, cstate, ret);
+	return ret;
+}
+
+static int sha512_mb_export(struct ahash_request *areq, void *out)
+{
+	struct sha512_hash_ctx *sctx = ahash_request_ctx(areq);
+
+	memcpy(out, sctx, sizeof(*sctx));
+
+	return 0;
+}
+
+static int sha512_mb_import(struct ahash_request *areq, const void *in)
+{
+	struct sha512_hash_ctx *sctx = ahash_request_ctx(areq);
+
+	memcpy(sctx, in, sizeof(*sctx));
+
+	return 0;
+}
+
+static int sha512_mb_async_init_tfm(struct crypto_tfm *tfm)
+{
+	struct mcryptd_ahash *mcryptd_tfm;
+	struct sha512_mb_ctx *ctx = crypto_tfm_ctx(tfm);
+	struct mcryptd_hash_ctx *mctx;
+
+	mcryptd_tfm = mcryptd_alloc_ahash("__intel_sha512-mb",
+						CRYPTO_ALG_INTERNAL,
+						CRYPTO_ALG_INTERNAL);
+	if (IS_ERR(mcryptd_tfm))
+		return PTR_ERR(mcryptd_tfm);
+	mctx = crypto_ahash_ctx(&mcryptd_tfm->base);
+	mctx->alg_state = &sha512_mb_alg_state;
+	ctx->mcryptd_tfm = mcryptd_tfm;
+	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
+				sizeof(struct ahash_request) +
+				crypto_ahash_reqsize(&mcryptd_tfm->base));
+
+	return 0;
+}
+
+static void sha512_mb_async_exit_tfm(struct crypto_tfm *tfm)
+{
+	struct sha512_mb_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	mcryptd_free_ahash(ctx->mcryptd_tfm);
+}
+
+static int sha512_mb_areq_init_tfm(struct crypto_tfm *tfm)
+{
+	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
+				sizeof(struct ahash_request) +
+				sizeof(struct sha512_hash_ctx));
+
+	return 0;
+}
+
+static void sha512_mb_areq_exit_tfm(struct crypto_tfm *tfm)
+{
+	struct sha512_mb_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	mcryptd_free_ahash(ctx->mcryptd_tfm);
+}
+
+static struct ahash_alg sha512_mb_areq_alg = {
+	.init		=	sha512_mb_init,
+	.update		=	sha512_mb_update,
+	.final		=	sha512_mb_final,
+	.finup		=	sha512_mb_finup,
+	.export		=	sha512_mb_export,
+	.import		=	sha512_mb_import,
+	.halg		=	{
+	.digestsize	=	SHA512_DIGEST_SIZE,
+	.statesize	=	sizeof(struct sha512_hash_ctx),
+	.base		=	{
+			.cra_name	 = "__sha512-mb",
+			.cra_driver_name = "__intel_sha512-mb",
+			.cra_priority	 = 100,
+			/*
+			 * use ASYNC flag as some buffers in multi-buffer
+			 * algo may not have completed before hashing thread
+			 * sleep
+			 */
+			.cra_flags	= CRYPTO_ALG_TYPE_AHASH |
+						CRYPTO_ALG_ASYNC |
+						CRYPTO_ALG_INTERNAL,
+			.cra_blocksize	= SHA512_BLOCK_SIZE,
+			.cra_module	= THIS_MODULE,
+			.cra_list	= LIST_HEAD_INIT
+					(sha512_mb_areq_alg.halg.base.cra_list),
+			.cra_init	= sha512_mb_areq_init_tfm,
+			.cra_exit	= sha512_mb_areq_exit_tfm,
+			.cra_ctxsize	= sizeof(struct sha512_hash_ctx),
+		}
+	}
+};
+
+static int sha512_mb_async_init(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct sha512_mb_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct ahash_request *mcryptd_req = ahash_request_ctx(req);
+	struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
+
+	memcpy(mcryptd_req, req, sizeof(*req));
+	ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
+	return crypto_ahash_init(mcryptd_req);
+}
+
+static int sha512_mb_async_update(struct ahash_request *req)
+{
+	struct ahash_request *mcryptd_req = ahash_request_ctx(req);
+
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct sha512_mb_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
+
+	memcpy(mcryptd_req, req, sizeof(*req));
+	ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
+	return crypto_ahash_update(mcryptd_req);
+}
+
+static int sha512_mb_async_finup(struct ahash_request *req)
+{
+	struct ahash_request *mcryptd_req = ahash_request_ctx(req);
+
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct sha512_mb_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
+
+	memcpy(mcryptd_req, req, sizeof(*req));
+	ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
+	return crypto_ahash_finup(mcryptd_req);
+}
+
+static int sha512_mb_async_final(struct ahash_request *req)
+{
+	struct ahash_request *mcryptd_req = ahash_request_ctx(req);
+
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct sha512_mb_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
+
+	memcpy(mcryptd_req, req, sizeof(*req));
+	ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
+	return crypto_ahash_final(mcryptd_req);
+}
+
+static int sha512_mb_async_digest(struct ahash_request *req)
+{
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct sha512_mb_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct ahash_request *mcryptd_req = ahash_request_ctx(req);
+	struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
+
+	memcpy(mcryptd_req, req, sizeof(*req));
+	ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
+	return crypto_ahash_digest(mcryptd_req);
+}
+
+static int sha512_mb_async_export(struct ahash_request *req, void *out)
+{
+	struct ahash_request *mcryptd_req = ahash_request_ctx(req);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct sha512_mb_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
+
+	memcpy(mcryptd_req, req, sizeof(*req));
+	ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
+	return crypto_ahash_export(mcryptd_req, out);
+}
+
+static int sha512_mb_async_import(struct ahash_request *req, const void *in)
+{
+	struct ahash_request *mcryptd_req = ahash_request_ctx(req);
+	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
+	struct sha512_mb_ctx *ctx = crypto_ahash_ctx(tfm);
+	struct mcryptd_ahash *mcryptd_tfm = ctx->mcryptd_tfm;
+	struct crypto_ahash *child = mcryptd_ahash_child(mcryptd_tfm);
+	struct mcryptd_hash_request_ctx *rctx;
+	struct ahash_request *areq;
+
+	memcpy(mcryptd_req, req, sizeof(*req));
+	ahash_request_set_tfm(mcryptd_req, &mcryptd_tfm->base);
+	rctx = ahash_request_ctx(mcryptd_req);
+
+	areq = &rctx->areq;
+
+	ahash_request_set_tfm(areq, child);
+	ahash_request_set_callback(areq, CRYPTO_TFM_REQ_MAY_SLEEP,
+					rctx->complete, req);
+
+	return crypto_ahash_import(mcryptd_req, in);
+}
+
+static struct ahash_alg sha512_mb_async_alg = {
+	.init           = sha512_mb_async_init,
+	.update         = sha512_mb_async_update,
+	.final          = sha512_mb_async_final,
+	.finup          = sha512_mb_async_finup,
+	.digest         = sha512_mb_async_digest,
+	.export		= sha512_mb_async_export,
+	.import		= sha512_mb_async_import,
+	.halg = {
+		.digestsize     = SHA512_DIGEST_SIZE,
+		.statesize      = sizeof(struct sha512_hash_ctx),
+		.base = {
+			.cra_name               = "sha512",
+			.cra_driver_name        = "sha512_mb",
+			.cra_priority           = 200,
+			.cra_flags              = CRYPTO_ALG_TYPE_AHASH |
+							CRYPTO_ALG_ASYNC,
+			.cra_blocksize          = SHA512_BLOCK_SIZE,
+			.cra_type               = &crypto_ahash_type,
+			.cra_module             = THIS_MODULE,
+			.cra_list               = LIST_HEAD_INIT
+				(sha512_mb_async_alg.halg.base.cra_list),
+			.cra_init               = sha512_mb_async_init_tfm,
+			.cra_exit               = sha512_mb_async_exit_tfm,
+			.cra_ctxsize		= sizeof(struct sha512_mb_ctx),
+			.cra_alignmask		= 0,
+		},
+	},
+};
+
+static unsigned long sha512_mb_flusher(struct mcryptd_alg_cstate *cstate)
+{
+	struct mcryptd_hash_request_ctx *rctx;
+	unsigned long cur_time;
+	unsigned long next_flush = 0;
+	struct sha512_hash_ctx *sha_ctx;
+
+
+	cur_time = jiffies;
+
+	while (!list_empty(&cstate->work_list)) {
+		rctx = list_entry(cstate->work_list.next,
+				struct mcryptd_hash_request_ctx, waiter);
+		if time_before(cur_time, rctx->tag.expire)
+			break;
+		kernel_fpu_begin();
+		sha_ctx = (struct sha512_hash_ctx *)
+					sha512_ctx_mgr_flush(cstate->mgr);
+		kernel_fpu_end();
+		if (!sha_ctx) {
+			pr_err("sha512_mb error: nothing got flushed for"
+							" non-empty list\n");
+			break;
+		}
+		rctx = cast_hash_to_mcryptd_ctx(sha_ctx);
+		sha_finish_walk(&rctx, cstate, true);
+		sha_complete_job(rctx, cstate, 0);
+	}
+
+	if (!list_empty(&cstate->work_list)) {
+		rctx = list_entry(cstate->work_list.next,
+				struct mcryptd_hash_request_ctx, waiter);
+		/* get the hash context and then flush time */
+		next_flush = rctx->tag.expire;
+		mcryptd_arm_flusher(cstate, get_delay(next_flush));
+	}
+	return next_flush;
+}
+
+static int __init sha512_mb_mod_init(void)
+{
+
+	int cpu;
+	int err;
+	struct mcryptd_alg_cstate *cpu_state;
+
+	/* check for dependent cpu features */
+	if (!boot_cpu_has(X86_FEATURE_AVX2) ||
+	    !boot_cpu_has(X86_FEATURE_BMI2))
+		return -ENODEV;
+
+	/* initialize multibuffer structures */
+	sha512_mb_alg_state.alg_cstate =
+				alloc_percpu(struct mcryptd_alg_cstate);
+
+	sha512_job_mgr_init = sha512_mb_mgr_init_avx2;
+	sha512_job_mgr_submit = sha512_mb_mgr_submit_avx2;
+	sha512_job_mgr_flush = sha512_mb_mgr_flush_avx2;
+	sha512_job_mgr_get_comp_job = sha512_mb_mgr_get_comp_job_avx2;
+
+	if (!sha512_mb_alg_state.alg_cstate)
+		return -ENOMEM;
+	for_each_possible_cpu(cpu) {
+		cpu_state = per_cpu_ptr(sha512_mb_alg_state.alg_cstate, cpu);
+		cpu_state->next_flush = 0;
+		cpu_state->next_seq_num = 0;
+		cpu_state->flusher_engaged = false;
+		INIT_DELAYED_WORK(&cpu_state->flush, mcryptd_flusher);
+		cpu_state->cpu = cpu;
+		cpu_state->alg_state = &sha512_mb_alg_state;
+		cpu_state->mgr = kzalloc(sizeof(struct sha512_ctx_mgr),
+								GFP_KERNEL);
+		if (!cpu_state->mgr)
+			goto err2;
+		sha512_ctx_mgr_init(cpu_state->mgr);
+		INIT_LIST_HEAD(&cpu_state->work_list);
+		spin_lock_init(&cpu_state->work_lock);
+	}
+	sha512_mb_alg_state.flusher = &sha512_mb_flusher;
+
+	err = crypto_register_ahash(&sha512_mb_areq_alg);
+	if (err)
+		goto err2;
+	err = crypto_register_ahash(&sha512_mb_async_alg);
+	if (err)
+		goto err1;
+
+
+	return 0;
+err1:
+	crypto_unregister_ahash(&sha512_mb_areq_alg);
+err2:
+	for_each_possible_cpu(cpu) {
+		cpu_state = per_cpu_ptr(sha512_mb_alg_state.alg_cstate, cpu);
+		kfree(cpu_state->mgr);
+	}
+	free_percpu(sha512_mb_alg_state.alg_cstate);
+	return -ENODEV;
+}
+
+static void __exit sha512_mb_mod_fini(void)
+{
+	int cpu;
+	struct mcryptd_alg_cstate *cpu_state;
+
+	crypto_unregister_ahash(&sha512_mb_async_alg);
+	crypto_unregister_ahash(&sha512_mb_areq_alg);
+	for_each_possible_cpu(cpu) {
+		cpu_state = per_cpu_ptr(sha512_mb_alg_state.alg_cstate, cpu);
+		kfree(cpu_state->mgr);
+	}
+	free_percpu(sha512_mb_alg_state.alg_cstate);
+}
+
+module_init(sha512_mb_mod_init);
+module_exit(sha512_mb_mod_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SHA512 Secure Hash Algorithm, multi buffer accelerated");
+
+MODULE_ALIAS("sha512");