/*
   * 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/sha.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.
  ");

  		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