arch/x86/crypto/sha256_ssse3_glue.c - linux - Git at Google

 /*
  * Cryptographic API.
  *
  * Glue code for the SHA256 Secure Hash Algorithm assembler
  * implementation using supplemental SSE3 / AVX / AVX2 instructions.
  *
  * This file is based on sha256_generic.c
  *
  * Copyright (C) 2013 Intel Corporation.
  *
  * Author:
  *     Tim Chen <tim.c.chen@linux.intel.com>
  *
  * 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.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  */


 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

 #include <crypto/internal/hash.h>
 #include <crypto/internal/simd.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/types.h>
 #include <crypto/sha2.h>
 #include <crypto/sha256_base.h>
 #include <linux/string.h>
 #include <asm/simd.h>

 asmlinkage void sha256_transform_ssse3(struct sha256_state *state,
 				       const u8 *data, int blocks);

 static int _sha256_update(struct shash_desc *desc, const u8 *data,
 			  unsigned int len, sha256_block_fn *sha256_xform)
 {
 	struct sha256_state *sctx = shash_desc_ctx(desc);

 	if (!crypto_simd_usable() ||
 	    (sctx->count % SHA256_BLOCK_SIZE) + len < SHA256_BLOCK_SIZE)
 		return crypto_sha256_update(desc, data, len);

 	/*
 	 * Make sure struct sha256_state begins directly with the SHA256
 	 * 256-bit internal state, as this is what the asm functions expect.
 	 */
 	BUILD_BUG_ON(offsetof(struct sha256_state, state) != 0);

 	kernel_fpu_begin();
 	sha256_base_do_update(desc, data, len, sha256_xform);
 	kernel_fpu_end();

 	return 0;
 }

 static int sha256_finup(struct shash_desc *desc, const u8 *data,
 	      unsigned int len, u8 *out, sha256_block_fn *sha256_xform)
 {
 	if (!crypto_simd_usable())
 		return crypto_sha256_finup(desc, data, len, out);

 	kernel_fpu_begin();
 	if (len)
 		sha256_base_do_update(desc, data, len, sha256_xform);
 	sha256_base_do_finalize(desc, sha256_xform);
 	kernel_fpu_end();

 	return sha256_base_finish(desc, out);
 }

 static int sha256_ssse3_update(struct shash_desc *desc, const u8 *data,
 			 unsigned int len)
 {
 	return _sha256_update(desc, data, len, sha256_transform_ssse3);
 }

 static int sha256_ssse3_finup(struct shash_desc *desc, const u8 *data,
 	      unsigned int len, u8 *out)
 {
 	return sha256_finup(desc, data, len, out, sha256_transform_ssse3);
 }

 /* Add padding and return the message digest. */
 static int sha256_ssse3_final(struct shash_desc *desc, u8 *out)
 {
 	return sha256_ssse3_finup(desc, NULL, 0, out);
 }

 static struct shash_alg sha256_ssse3_algs[] = { {
 	.digestsize	=	SHA256_DIGEST_SIZE,
 	.init		=	sha256_base_init,
 	.update		=	sha256_ssse3_update,
 	.final		=	sha256_ssse3_final,
 	.finup		=	sha256_ssse3_finup,
 	.descsize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha256",
 		.cra_driver_name =	"sha256-ssse3",
 		.cra_priority	=	150,
 		.cra_blocksize	=	SHA256_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 }, {
 	.digestsize	=	SHA224_DIGEST_SIZE,
 	.init		=	sha224_base_init,
 	.update		=	sha256_ssse3_update,
 	.final		=	sha256_ssse3_final,
 	.finup		=	sha256_ssse3_finup,
 	.descsize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha224",
 		.cra_driver_name =	"sha224-ssse3",
 		.cra_priority	=	150,
 		.cra_blocksize	=	SHA224_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 } };

 static int register_sha256_ssse3(void)
 {
 	if (boot_cpu_has(X86_FEATURE_SSSE3))
 		return crypto_register_shashes(sha256_ssse3_algs,
 				ARRAY_SIZE(sha256_ssse3_algs));
 	return 0;
 }

 static void unregister_sha256_ssse3(void)
 {
 	if (boot_cpu_has(X86_FEATURE_SSSE3))
 		crypto_unregister_shashes(sha256_ssse3_algs,
 				ARRAY_SIZE(sha256_ssse3_algs));
 }

 asmlinkage void sha256_transform_avx(struct sha256_state *state,
 				     const u8 *data, int blocks);

 static int sha256_avx_update(struct shash_desc *desc, const u8 *data,
 			 unsigned int len)
 {
 	return _sha256_update(desc, data, len, sha256_transform_avx);
 }

 static int sha256_avx_finup(struct shash_desc *desc, const u8 *data,
 		      unsigned int len, u8 *out)
 {
 	return sha256_finup(desc, data, len, out, sha256_transform_avx);
 }

 static int sha256_avx_final(struct shash_desc *desc, u8 *out)
 {
 	return sha256_avx_finup(desc, NULL, 0, out);
 }

 static struct shash_alg sha256_avx_algs[] = { {
 	.digestsize	=	SHA256_DIGEST_SIZE,
 	.init		=	sha256_base_init,
 	.update		=	sha256_avx_update,
 	.final		=	sha256_avx_final,
 	.finup		=	sha256_avx_finup,
 	.descsize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha256",
 		.cra_driver_name =	"sha256-avx",
 		.cra_priority	=	160,
 		.cra_blocksize	=	SHA256_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 }, {
 	.digestsize	=	SHA224_DIGEST_SIZE,
 	.init		=	sha224_base_init,
 	.update		=	sha256_avx_update,
 	.final		=	sha256_avx_final,
 	.finup		=	sha256_avx_finup,
 	.descsize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha224",
 		.cra_driver_name =	"sha224-avx",
 		.cra_priority	=	160,
 		.cra_blocksize	=	SHA224_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 } };

 static bool avx_usable(void)
 {
 	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL)) {
 		if (boot_cpu_has(X86_FEATURE_AVX))
 			pr_info("AVX detected but unusable.\n");
 		return false;
 	}

 	return true;
 }

 static int register_sha256_avx(void)
 {
 	if (avx_usable())
 		return crypto_register_shashes(sha256_avx_algs,
 				ARRAY_SIZE(sha256_avx_algs));
 	return 0;
 }

 static void unregister_sha256_avx(void)
 {
 	if (avx_usable())
 		crypto_unregister_shashes(sha256_avx_algs,
 				ARRAY_SIZE(sha256_avx_algs));
 }

 asmlinkage void sha256_transform_rorx(struct sha256_state *state,
 				      const u8 *data, int blocks);

 static int sha256_avx2_update(struct shash_desc *desc, const u8 *data,
 			 unsigned int len)
 {
 	return _sha256_update(desc, data, len, sha256_transform_rorx);
 }

 static int sha256_avx2_finup(struct shash_desc *desc, const u8 *data,
 		      unsigned int len, u8 *out)
 {
 	return sha256_finup(desc, data, len, out, sha256_transform_rorx);
 }

 static int sha256_avx2_final(struct shash_desc *desc, u8 *out)
 {
 	return sha256_avx2_finup(desc, NULL, 0, out);
 }

 static struct shash_alg sha256_avx2_algs[] = { {
 	.digestsize	=	SHA256_DIGEST_SIZE,
 	.init		=	sha256_base_init,
 	.update		=	sha256_avx2_update,
 	.final		=	sha256_avx2_final,
 	.finup		=	sha256_avx2_finup,
 	.descsize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha256",
 		.cra_driver_name =	"sha256-avx2",
 		.cra_priority	=	170,
 		.cra_blocksize	=	SHA256_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 }, {
 	.digestsize	=	SHA224_DIGEST_SIZE,
 	.init		=	sha224_base_init,
 	.update		=	sha256_avx2_update,
 	.final		=	sha256_avx2_final,
 	.finup		=	sha256_avx2_finup,
 	.descsize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha224",
 		.cra_driver_name =	"sha224-avx2",
 		.cra_priority	=	170,
 		.cra_blocksize	=	SHA224_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 } };

 static bool avx2_usable(void)
 {
 	if (avx_usable() && boot_cpu_has(X86_FEATURE_AVX2) &&
 		    boot_cpu_has(X86_FEATURE_BMI2))
 		return true;

 	return false;
 }

 static int register_sha256_avx2(void)
 {
 	if (avx2_usable())
 		return crypto_register_shashes(sha256_avx2_algs,
 				ARRAY_SIZE(sha256_avx2_algs));
 	return 0;
 }

 static void unregister_sha256_avx2(void)
 {
 	if (avx2_usable())
 		crypto_unregister_shashes(sha256_avx2_algs,
 				ARRAY_SIZE(sha256_avx2_algs));
 }

 #ifdef CONFIG_AS_SHA256_NI
 asmlinkage void sha256_ni_transform(struct sha256_state *digest,
 				    const u8 *data, int rounds);

 static int sha256_ni_update(struct shash_desc *desc, const u8 *data,
 			 unsigned int len)
 {
 	return _sha256_update(desc, data, len, sha256_ni_transform);
 }

 static int sha256_ni_finup(struct shash_desc *desc, const u8 *data,
 		      unsigned int len, u8 *out)
 {
 	return sha256_finup(desc, data, len, out, sha256_ni_transform);
 }

 static int sha256_ni_final(struct shash_desc *desc, u8 *out)
 {
 	return sha256_ni_finup(desc, NULL, 0, out);
 }

 static struct shash_alg sha256_ni_algs[] = { {
 	.digestsize	=	SHA256_DIGEST_SIZE,
 	.init		=	sha256_base_init,
 	.update		=	sha256_ni_update,
 	.final		=	sha256_ni_final,
 	.finup		=	sha256_ni_finup,
 	.descsize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha256",
 		.cra_driver_name =	"sha256-ni",
 		.cra_priority	=	250,
 		.cra_blocksize	=	SHA256_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 }, {
 	.digestsize	=	SHA224_DIGEST_SIZE,
 	.init		=	sha224_base_init,
 	.update		=	sha256_ni_update,
 	.final		=	sha256_ni_final,
 	.finup		=	sha256_ni_finup,
 	.descsize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha224",
 		.cra_driver_name =	"sha224-ni",
 		.cra_priority	=	250,
 		.cra_blocksize	=	SHA224_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 } };

 static int register_sha256_ni(void)
 {
 	if (boot_cpu_has(X86_FEATURE_SHA_NI))
 		return crypto_register_shashes(sha256_ni_algs,
 				ARRAY_SIZE(sha256_ni_algs));
 	return 0;
 }

 static void unregister_sha256_ni(void)
 {
 	if (boot_cpu_has(X86_FEATURE_SHA_NI))
 		crypto_unregister_shashes(sha256_ni_algs,
 				ARRAY_SIZE(sha256_ni_algs));
 }

 #else
 static inline int register_sha256_ni(void) { return 0; }
 static inline void unregister_sha256_ni(void) { }
 #endif

 static int __init sha256_ssse3_mod_init(void)
 {
 	if (register_sha256_ssse3())
 		goto fail;

 	if (register_sha256_avx()) {
 		unregister_sha256_ssse3();
 		goto fail;
 	}

 	if (register_sha256_avx2()) {
 		unregister_sha256_avx();
 		unregister_sha256_ssse3();
 		goto fail;
 	}

 	if (register_sha256_ni()) {
 		unregister_sha256_avx2();
 		unregister_sha256_avx();
 		unregister_sha256_ssse3();
 		goto fail;
 	}

 	return 0;
 fail:
 	return -ENODEV;
 }

 static void __exit sha256_ssse3_mod_fini(void)
 {
 	unregister_sha256_ni();
 	unregister_sha256_avx2();
 	unregister_sha256_avx();
 	unregister_sha256_ssse3();
 }

 module_init(sha256_ssse3_mod_init);
 module_exit(sha256_ssse3_mod_fini);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("SHA256 Secure Hash Algorithm, Supplemental SSE3 accelerated");

 MODULE_ALIAS_CRYPTO("sha256");
 MODULE_ALIAS_CRYPTO("sha256-ssse3");
 MODULE_ALIAS_CRYPTO("sha256-avx");
 MODULE_ALIAS_CRYPTO("sha256-avx2");
 MODULE_ALIAS_CRYPTO("sha224");
 MODULE_ALIAS_CRYPTO("sha224-ssse3");
 MODULE_ALIAS_CRYPTO("sha224-avx");
 MODULE_ALIAS_CRYPTO("sha224-avx2");
 #ifdef CONFIG_AS_SHA256_NI
 MODULE_ALIAS_CRYPTO("sha256-ni");
 MODULE_ALIAS_CRYPTO("sha224-ni");
 #endif
	/*
	* Cryptographic API.
	*
	* Glue code for the SHA256 Secure Hash Algorithm assembler
	* implementation using supplemental SSE3 / AVX / AVX2 instructions.
	*
	* This file is based on sha256_generic.c
	*
	* Copyright (C) 2013 Intel Corporation.
	*
	* Author:
	* Tim Chen <tim.c.chen@linux.intel.com>
	*
	* 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.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	* SOFTWARE.
	*/


	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <crypto/internal/hash.h>
	#include <crypto/internal/simd.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/mm.h>
	#include <linux/types.h>
	#include <crypto/sha2.h>
	#include <crypto/sha256_base.h>
	#include <linux/string.h>
	#include <asm/simd.h>

	asmlinkage void sha256_transform_ssse3(struct sha256_state *state,
	const u8 *data, int blocks);

	static int _sha256_update(struct shash_desc desc, const u8 data,
	unsigned int len, sha256_block_fn *sha256_xform)
	{
	struct sha256_state *sctx = shash_desc_ctx(desc);

	if (!crypto_simd_usable() \|\|
	(sctx->count % SHA256_BLOCK_SIZE) + len < SHA256_BLOCK_SIZE)
	return crypto_sha256_update(desc, data, len);

	/*
	* Make sure struct sha256_state begins directly with the SHA256
	* 256-bit internal state, as this is what the asm functions expect.
	*/
	BUILD_BUG_ON(offsetof(struct sha256_state, state) != 0);

	kernel_fpu_begin();
	sha256_base_do_update(desc, data, len, sha256_xform);
	kernel_fpu_end();

	return 0;
	}

	static int sha256_finup(struct shash_desc desc, const u8 data,
	unsigned int len, u8 out, sha256_block_fn sha256_xform)
	{
	if (!crypto_simd_usable())
	return crypto_sha256_finup(desc, data, len, out);

	kernel_fpu_begin();
	if (len)
	sha256_base_do_update(desc, data, len, sha256_xform);
	sha256_base_do_finalize(desc, sha256_xform);
	kernel_fpu_end();

	return sha256_base_finish(desc, out);
	}

	static int sha256_ssse3_update(struct shash_desc desc, const u8 data,
	unsigned int len)
	{
	return _sha256_update(desc, data, len, sha256_transform_ssse3);
	}

	static int sha256_ssse3_finup(struct shash_desc desc, const u8 data,
	unsigned int len, u8 *out)
	{
	return sha256_finup(desc, data, len, out, sha256_transform_ssse3);
	}

	/* Add padding and return the message digest. */
	static int sha256_ssse3_final(struct shash_desc desc, u8 out)
	{
	return sha256_ssse3_finup(desc, NULL, 0, out);
	}

	static struct shash_alg sha256_ssse3_algs[] = { {
	.digestsize = SHA256_DIGEST_SIZE,
	.init = sha256_base_init,
	.update = sha256_ssse3_update,
	.final = sha256_ssse3_final,
	.finup = sha256_ssse3_finup,
	.descsize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha256",
	.cra_driver_name = "sha256-ssse3",
	.cra_priority = 150,
	.cra_blocksize = SHA256_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	}, {
	.digestsize = SHA224_DIGEST_SIZE,
	.init = sha224_base_init,
	.update = sha256_ssse3_update,
	.final = sha256_ssse3_final,
	.finup = sha256_ssse3_finup,
	.descsize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha224",
	.cra_driver_name = "sha224-ssse3",
	.cra_priority = 150,
	.cra_blocksize = SHA224_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	} };

	static int register_sha256_ssse3(void)
	{
	if (boot_cpu_has(X86_FEATURE_SSSE3))
	return crypto_register_shashes(sha256_ssse3_algs,
	ARRAY_SIZE(sha256_ssse3_algs));
	return 0;
	}

	static void unregister_sha256_ssse3(void)
	{
	if (boot_cpu_has(X86_FEATURE_SSSE3))
	crypto_unregister_shashes(sha256_ssse3_algs,
	ARRAY_SIZE(sha256_ssse3_algs));
	}

	asmlinkage void sha256_transform_avx(struct sha256_state *state,
	const u8 *data, int blocks);

	static int sha256_avx_update(struct shash_desc desc, const u8 data,
	unsigned int len)
	{
	return _sha256_update(desc, data, len, sha256_transform_avx);
	}

	static int sha256_avx_finup(struct shash_desc desc, const u8 data,
	unsigned int len, u8 *out)
	{
	return sha256_finup(desc, data, len, out, sha256_transform_avx);
	}

	static int sha256_avx_final(struct shash_desc desc, u8 out)
	{
	return sha256_avx_finup(desc, NULL, 0, out);
	}

	static struct shash_alg sha256_avx_algs[] = { {
	.digestsize = SHA256_DIGEST_SIZE,
	.init = sha256_base_init,
	.update = sha256_avx_update,
	.final = sha256_avx_final,
	.finup = sha256_avx_finup,
	.descsize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha256",
	.cra_driver_name = "sha256-avx",
	.cra_priority = 160,
	.cra_blocksize = SHA256_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	}, {
	.digestsize = SHA224_DIGEST_SIZE,
	.init = sha224_base_init,
	.update = sha256_avx_update,
	.final = sha256_avx_final,
	.finup = sha256_avx_finup,
	.descsize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha224",
	.cra_driver_name = "sha224-avx",
	.cra_priority = 160,
	.cra_blocksize = SHA224_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	} };

	static bool avx_usable(void)
	{
	if (!cpu_has_xfeatures(XFEATURE_MASK_SSE \| XFEATURE_MASK_YMM, NULL)) {
	if (boot_cpu_has(X86_FEATURE_AVX))
	pr_info("AVX detected but unusable.\n");
	return false;
	}

	return true;
	}

	static int register_sha256_avx(void)
	{
	if (avx_usable())
	return crypto_register_shashes(sha256_avx_algs,
	ARRAY_SIZE(sha256_avx_algs));
	return 0;
	}

	static void unregister_sha256_avx(void)
	{
	if (avx_usable())
	crypto_unregister_shashes(sha256_avx_algs,
	ARRAY_SIZE(sha256_avx_algs));
	}

	asmlinkage void sha256_transform_rorx(struct sha256_state *state,
	const u8 *data, int blocks);

	static int sha256_avx2_update(struct shash_desc desc, const u8 data,
	unsigned int len)
	{
	return _sha256_update(desc, data, len, sha256_transform_rorx);
	}

	static int sha256_avx2_finup(struct shash_desc desc, const u8 data,
	unsigned int len, u8 *out)
	{
	return sha256_finup(desc, data, len, out, sha256_transform_rorx);
	}

	static int sha256_avx2_final(struct shash_desc desc, u8 out)
	{
	return sha256_avx2_finup(desc, NULL, 0, out);
	}

	static struct shash_alg sha256_avx2_algs[] = { {
	.digestsize = SHA256_DIGEST_SIZE,
	.init = sha256_base_init,
	.update = sha256_avx2_update,
	.final = sha256_avx2_final,
	.finup = sha256_avx2_finup,
	.descsize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha256",
	.cra_driver_name = "sha256-avx2",
	.cra_priority = 170,
	.cra_blocksize = SHA256_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	}, {
	.digestsize = SHA224_DIGEST_SIZE,
	.init = sha224_base_init,
	.update = sha256_avx2_update,
	.final = sha256_avx2_final,
	.finup = sha256_avx2_finup,
	.descsize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha224",
	.cra_driver_name = "sha224-avx2",
	.cra_priority = 170,
	.cra_blocksize = SHA224_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	} };

	static bool avx2_usable(void)
	{
	if (avx_usable() && boot_cpu_has(X86_FEATURE_AVX2) &&
	boot_cpu_has(X86_FEATURE_BMI2))
	return true;

	return false;
	}

	static int register_sha256_avx2(void)
	{
	if (avx2_usable())
	return crypto_register_shashes(sha256_avx2_algs,
	ARRAY_SIZE(sha256_avx2_algs));
	return 0;
	}

	static void unregister_sha256_avx2(void)
	{
	if (avx2_usable())
	crypto_unregister_shashes(sha256_avx2_algs,
	ARRAY_SIZE(sha256_avx2_algs));
	}

	#ifdef CONFIG_AS_SHA256_NI
	asmlinkage void sha256_ni_transform(struct sha256_state *digest,
	const u8 *data, int rounds);

	static int sha256_ni_update(struct shash_desc desc, const u8 data,
	unsigned int len)
	{
	return _sha256_update(desc, data, len, sha256_ni_transform);
	}

	static int sha256_ni_finup(struct shash_desc desc, const u8 data,
	unsigned int len, u8 *out)
	{
	return sha256_finup(desc, data, len, out, sha256_ni_transform);
	}

	static int sha256_ni_final(struct shash_desc desc, u8 out)
	{
	return sha256_ni_finup(desc, NULL, 0, out);
	}

	static struct shash_alg sha256_ni_algs[] = { {
	.digestsize = SHA256_DIGEST_SIZE,
	.init = sha256_base_init,
	.update = sha256_ni_update,
	.final = sha256_ni_final,
	.finup = sha256_ni_finup,
	.descsize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha256",
	.cra_driver_name = "sha256-ni",
	.cra_priority = 250,
	.cra_blocksize = SHA256_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	}, {
	.digestsize = SHA224_DIGEST_SIZE,
	.init = sha224_base_init,
	.update = sha256_ni_update,
	.final = sha256_ni_final,
	.finup = sha256_ni_finup,
	.descsize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha224",
	.cra_driver_name = "sha224-ni",
	.cra_priority = 250,
	.cra_blocksize = SHA224_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	} };

	static int register_sha256_ni(void)
	{
	if (boot_cpu_has(X86_FEATURE_SHA_NI))
	return crypto_register_shashes(sha256_ni_algs,
	ARRAY_SIZE(sha256_ni_algs));
	return 0;
	}

	static void unregister_sha256_ni(void)
	{
	if (boot_cpu_has(X86_FEATURE_SHA_NI))
	crypto_unregister_shashes(sha256_ni_algs,
	ARRAY_SIZE(sha256_ni_algs));
	}

	#else
	static inline int register_sha256_ni(void) { return 0; }
	static inline void unregister_sha256_ni(void) { }
	#endif

	static int __init sha256_ssse3_mod_init(void)
	{
	if (register_sha256_ssse3())
	goto fail;

	if (register_sha256_avx()) {
	unregister_sha256_ssse3();
	goto fail;
	}

	if (register_sha256_avx2()) {
	unregister_sha256_avx();
	unregister_sha256_ssse3();
	goto fail;
	}

	if (register_sha256_ni()) {
	unregister_sha256_avx2();
	unregister_sha256_avx();
	unregister_sha256_ssse3();
	goto fail;
	}

	return 0;
	fail:
	return -ENODEV;
	}

	static void __exit sha256_ssse3_mod_fini(void)
	{
	unregister_sha256_ni();
	unregister_sha256_avx2();
	unregister_sha256_avx();
	unregister_sha256_ssse3();
	}

	module_init(sha256_ssse3_mod_init);
	module_exit(sha256_ssse3_mod_fini);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("SHA256 Secure Hash Algorithm, Supplemental SSE3 accelerated");

	MODULE_ALIAS_CRYPTO("sha256");
	MODULE_ALIAS_CRYPTO("sha256-ssse3");
	MODULE_ALIAS_CRYPTO("sha256-avx");
	MODULE_ALIAS_CRYPTO("sha256-avx2");
	MODULE_ALIAS_CRYPTO("sha224");
	MODULE_ALIAS_CRYPTO("sha224-ssse3");
	MODULE_ALIAS_CRYPTO("sha224-avx");
	MODULE_ALIAS_CRYPTO("sha224-avx2");
	#ifdef CONFIG_AS_SHA256_NI
	MODULE_ALIAS_CRYPTO("sha256-ni");
	MODULE_ALIAS_CRYPTO("sha224-ni");
	#endif