arch/powerpc/crypto/sha256-spe-glue.c - third_party/linux - Git at Google

 /*
  * Glue code for SHA-256 implementation for SPE instructions (PPC)
  *
  * Based on generic implementation. The assembler module takes care
  * about the SPE registers so it can run from interrupt context.
  *
  * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
  *
  * 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/internal/hash.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/cryptohash.h>
 #include <linux/types.h>
 #include <crypto/sha.h>
 #include <asm/byteorder.h>
 #include <asm/switch_to.h>
 #include <linux/hardirq.h>

 /*
  * MAX_BYTES defines the number of bytes that are allowed to be processed
  * between preempt_disable() and preempt_enable(). SHA256 takes ~2,000
  * operations per 64 bytes. e500 cores can issue two arithmetic instructions
  * per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2).
  * Thus 1KB of input data will need an estimated maximum of 18,000 cycles.
  * Headroom for cache misses included. Even with the low end model clocked
  * at 667 MHz this equals to a critical time window of less than 27us.
  *
  */
 #define MAX_BYTES 1024

 extern void ppc_spe_sha256_transform(u32 *state, const u8 *src, u32 blocks);

 static void spe_begin(void)
 {
 	/* We just start SPE operations and will save SPE registers later. */
 	preempt_disable();
 	enable_kernel_spe();
 }

 static void spe_end(void)
 {
 	disable_kernel_spe();
 	/* reenable preemption */
 	preempt_enable();
 }

 static inline void ppc_sha256_clear_context(struct sha256_state *sctx)
 {
 	int count = sizeof(struct sha256_state) >> 2;
 	u32 *ptr = (u32 *)sctx;

 	/* make sure we can clear the fast way */
 	BUILD_BUG_ON(sizeof(struct sha256_state) % 4);
 	do { *ptr++ = 0; } while (--count);
 }

 static int ppc_spe_sha256_init(struct shash_desc *desc)
 {
 	struct sha256_state *sctx = shash_desc_ctx(desc);

 	sctx->state[0] = SHA256_H0;
 	sctx->state[1] = SHA256_H1;
 	sctx->state[2] = SHA256_H2;
 	sctx->state[3] = SHA256_H3;
 	sctx->state[4] = SHA256_H4;
 	sctx->state[5] = SHA256_H5;
 	sctx->state[6] = SHA256_H6;
 	sctx->state[7] = SHA256_H7;
 	sctx->count = 0;

 	return 0;
 }

 static int ppc_spe_sha224_init(struct shash_desc *desc)
 {
 	struct sha256_state *sctx = shash_desc_ctx(desc);

 	sctx->state[0] = SHA224_H0;
 	sctx->state[1] = SHA224_H1;
 	sctx->state[2] = SHA224_H2;
 	sctx->state[3] = SHA224_H3;
 	sctx->state[4] = SHA224_H4;
 	sctx->state[5] = SHA224_H5;
 	sctx->state[6] = SHA224_H6;
 	sctx->state[7] = SHA224_H7;
 	sctx->count = 0;

 	return 0;
 }

 static int ppc_spe_sha256_update(struct shash_desc *desc, const u8 *data,
 			unsigned int len)
 {
 	struct sha256_state *sctx = shash_desc_ctx(desc);
 	const unsigned int offset = sctx->count & 0x3f;
 	const unsigned int avail = 64 - offset;
 	unsigned int bytes;
 	const u8 *src = data;

 	if (avail > len) {
 		sctx->count += len;
 		memcpy((char *)sctx->buf + offset, src, len);
 		return 0;
 	}

 	sctx->count += len;

 	if (offset) {
 		memcpy((char *)sctx->buf + offset, src, avail);

 		spe_begin();
 		ppc_spe_sha256_transform(sctx->state, (const u8 *)sctx->buf, 1);
 		spe_end();

 		len -= avail;
 		src += avail;
 	}

 	while (len > 63) {
 		/* cut input data into smaller blocks */
 		bytes = (len > MAX_BYTES) ? MAX_BYTES : len;
 		bytes = bytes & ~0x3f;

 		spe_begin();
 		ppc_spe_sha256_transform(sctx->state, src, bytes >> 6);
 		spe_end();

 		src += bytes;
 		len -= bytes;
 	};

 	memcpy((char *)sctx->buf, src, len);
 	return 0;
 }

 static int ppc_spe_sha256_final(struct shash_desc *desc, u8 *out)
 {
 	struct sha256_state *sctx = shash_desc_ctx(desc);
 	const unsigned int offset = sctx->count & 0x3f;
 	char *p = (char *)sctx->buf + offset;
 	int padlen;
 	__be64 *pbits = (__be64 *)(((char *)&sctx->buf) + 56);
 	__be32 *dst = (__be32 *)out;

 	padlen = 55 - offset;
 	*p++ = 0x80;

 	spe_begin();

 	if (padlen < 0) {
 		memset(p, 0x00, padlen + sizeof (u64));
 		ppc_spe_sha256_transform(sctx->state, sctx->buf, 1);
 		p = (char *)sctx->buf;
 		padlen = 56;
 	}

 	memset(p, 0, padlen);
 	*pbits = cpu_to_be64(sctx->count << 3);
 	ppc_spe_sha256_transform(sctx->state, sctx->buf, 1);

 	spe_end();

 	dst[0] = cpu_to_be32(sctx->state[0]);
 	dst[1] = cpu_to_be32(sctx->state[1]);
 	dst[2] = cpu_to_be32(sctx->state[2]);
 	dst[3] = cpu_to_be32(sctx->state[3]);
 	dst[4] = cpu_to_be32(sctx->state[4]);
 	dst[5] = cpu_to_be32(sctx->state[5]);
 	dst[6] = cpu_to_be32(sctx->state[6]);
 	dst[7] = cpu_to_be32(sctx->state[7]);

 	ppc_sha256_clear_context(sctx);
 	return 0;
 }

 static int ppc_spe_sha224_final(struct shash_desc *desc, u8 *out)
 {
 	u32 D[SHA256_DIGEST_SIZE >> 2];
 	__be32 *dst = (__be32 *)out;

 	ppc_spe_sha256_final(desc, (u8 *)D);

 	/* avoid bytewise memcpy */
 	dst[0] = D[0];
 	dst[1] = D[1];
 	dst[2] = D[2];
 	dst[3] = D[3];
 	dst[4] = D[4];
 	dst[5] = D[5];
 	dst[6] = D[6];

 	/* clear sensitive data */
 	memzero_explicit(D, SHA256_DIGEST_SIZE);
 	return 0;
 }

 static int ppc_spe_sha256_export(struct shash_desc *desc, void *out)
 {
 	struct sha256_state *sctx = shash_desc_ctx(desc);

 	memcpy(out, sctx, sizeof(*sctx));
 	return 0;
 }

 static int ppc_spe_sha256_import(struct shash_desc *desc, const void *in)
 {
 	struct sha256_state *sctx = shash_desc_ctx(desc);

 	memcpy(sctx, in, sizeof(*sctx));
 	return 0;
 }

 static struct shash_alg algs[2] = { {
 	.digestsize	=	SHA256_DIGEST_SIZE,
 	.init		=	ppc_spe_sha256_init,
 	.update		=	ppc_spe_sha256_update,
 	.final		=	ppc_spe_sha256_final,
 	.export		=	ppc_spe_sha256_export,
 	.import		=	ppc_spe_sha256_import,
 	.descsize	=	sizeof(struct sha256_state),
 	.statesize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha256",
 		.cra_driver_name=	"sha256-ppc-spe",
 		.cra_priority	=	300,
 		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
 		.cra_blocksize	=	SHA256_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 }, {
 	.digestsize	=	SHA224_DIGEST_SIZE,
 	.init		=	ppc_spe_sha224_init,
 	.update		=	ppc_spe_sha256_update,
 	.final		=	ppc_spe_sha224_final,
 	.export		=	ppc_spe_sha256_export,
 	.import		=	ppc_spe_sha256_import,
 	.descsize	=	sizeof(struct sha256_state),
 	.statesize	=	sizeof(struct sha256_state),
 	.base		=	{
 		.cra_name	=	"sha224",
 		.cra_driver_name=	"sha224-ppc-spe",
 		.cra_priority	=	300,
 		.cra_flags	=	CRYPTO_ALG_TYPE_SHASH,
 		.cra_blocksize	=	SHA224_BLOCK_SIZE,
 		.cra_module	=	THIS_MODULE,
 	}
 } };

 static int __init ppc_spe_sha256_mod_init(void)
 {
 	return crypto_register_shashes(algs, ARRAY_SIZE(algs));
 }

 static void __exit ppc_spe_sha256_mod_fini(void)
 {
 	crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
 }

 module_init(ppc_spe_sha256_mod_init);
 module_exit(ppc_spe_sha256_mod_fini);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("SHA-224 and SHA-256 Secure Hash Algorithm, SPE optimized");

 MODULE_ALIAS_CRYPTO("sha224");
 MODULE_ALIAS_CRYPTO("sha224-ppc-spe");
 MODULE_ALIAS_CRYPTO("sha256");
 MODULE_ALIAS_CRYPTO("sha256-ppc-spe");
	/*
	* Glue code for SHA-256 implementation for SPE instructions (PPC)
	*
	* Based on generic implementation. The assembler module takes care
	* about the SPE registers so it can run from interrupt context.
	*
	* Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
	*
	* 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/internal/hash.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/mm.h>
	#include <linux/cryptohash.h>
	#include <linux/types.h>
	#include <crypto/sha.h>
	#include <asm/byteorder.h>
	#include <asm/switch_to.h>
	#include <linux/hardirq.h>

	/*
	* MAX_BYTES defines the number of bytes that are allowed to be processed
	* between preempt_disable() and preempt_enable(). SHA256 takes ~2,000
	* operations per 64 bytes. e500 cores can issue two arithmetic instructions
	* per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2).
	* Thus 1KB of input data will need an estimated maximum of 18,000 cycles.
	* Headroom for cache misses included. Even with the low end model clocked
	* at 667 MHz this equals to a critical time window of less than 27us.
	*
	*/
	#define MAX_BYTES 1024

	extern void ppc_spe_sha256_transform(u32 state, const u8 src, u32 blocks);

	static void spe_begin(void)
	{
	/* We just start SPE operations and will save SPE registers later. */
	preempt_disable();
	enable_kernel_spe();
	}

	static void spe_end(void)
	{
	disable_kernel_spe();
	/* reenable preemption */
	preempt_enable();
	}

	static inline void ppc_sha256_clear_context(struct sha256_state *sctx)
	{
	int count = sizeof(struct sha256_state) >> 2;
	u32 ptr = (u32 )sctx;

	/* make sure we can clear the fast way */
	BUILD_BUG_ON(sizeof(struct sha256_state) % 4);
	do { *ptr++ = 0; } while (--count);
	}

	static int ppc_spe_sha256_init(struct shash_desc *desc)
	{
	struct sha256_state *sctx = shash_desc_ctx(desc);

	sctx->state[0] = SHA256_H0;
	sctx->state[1] = SHA256_H1;
	sctx->state[2] = SHA256_H2;
	sctx->state[3] = SHA256_H3;
	sctx->state[4] = SHA256_H4;
	sctx->state[5] = SHA256_H5;
	sctx->state[6] = SHA256_H6;
	sctx->state[7] = SHA256_H7;
	sctx->count = 0;

	return 0;
	}

	static int ppc_spe_sha224_init(struct shash_desc *desc)
	{
	struct sha256_state *sctx = shash_desc_ctx(desc);

	sctx->state[0] = SHA224_H0;
	sctx->state[1] = SHA224_H1;
	sctx->state[2] = SHA224_H2;
	sctx->state[3] = SHA224_H3;
	sctx->state[4] = SHA224_H4;
	sctx->state[5] = SHA224_H5;
	sctx->state[6] = SHA224_H6;
	sctx->state[7] = SHA224_H7;
	sctx->count = 0;

	return 0;
	}

	static int ppc_spe_sha256_update(struct shash_desc desc, const u8 data,
	unsigned int len)
	{
	struct sha256_state *sctx = shash_desc_ctx(desc);
	const unsigned int offset = sctx->count & 0x3f;
	const unsigned int avail = 64 - offset;
	unsigned int bytes;
	const u8 *src = data;

	if (avail > len) {
	sctx->count += len;
	memcpy((char *)sctx->buf + offset, src, len);
	return 0;
	}

	sctx->count += len;

	if (offset) {
	memcpy((char *)sctx->buf + offset, src, avail);

	spe_begin();
	ppc_spe_sha256_transform(sctx->state, (const u8 *)sctx->buf, 1);
	spe_end();

	len -= avail;
	src += avail;
	}

	while (len > 63) {
	/* cut input data into smaller blocks */
	bytes = (len > MAX_BYTES) ? MAX_BYTES : len;
	bytes = bytes & ~0x3f;

	spe_begin();
	ppc_spe_sha256_transform(sctx->state, src, bytes >> 6);
	spe_end();

	src += bytes;
	len -= bytes;
	};

	memcpy((char *)sctx->buf, src, len);
	return 0;
	}

	static int ppc_spe_sha256_final(struct shash_desc desc, u8 out)
	{
	struct sha256_state *sctx = shash_desc_ctx(desc);
	const unsigned int offset = sctx->count & 0x3f;
	char p = (char )sctx->buf + offset;
	int padlen;
	__be64 pbits = (__be64 )(((char *)&sctx->buf) + 56);
	__be32 dst = (__be32 )out;

	padlen = 55 - offset;
	*p++ = 0x80;

	spe_begin();

	if (padlen < 0) {
	memset(p, 0x00, padlen + sizeof (u64));
	ppc_spe_sha256_transform(sctx->state, sctx->buf, 1);
	p = (char *)sctx->buf;
	padlen = 56;
	}

	memset(p, 0, padlen);
	*pbits = cpu_to_be64(sctx->count << 3);
	ppc_spe_sha256_transform(sctx->state, sctx->buf, 1);

	spe_end();

	dst[0] = cpu_to_be32(sctx->state[0]);
	dst[1] = cpu_to_be32(sctx->state[1]);
	dst[2] = cpu_to_be32(sctx->state[2]);
	dst[3] = cpu_to_be32(sctx->state[3]);
	dst[4] = cpu_to_be32(sctx->state[4]);
	dst[5] = cpu_to_be32(sctx->state[5]);
	dst[6] = cpu_to_be32(sctx->state[6]);
	dst[7] = cpu_to_be32(sctx->state[7]);

	ppc_sha256_clear_context(sctx);
	return 0;
	}

	static int ppc_spe_sha224_final(struct shash_desc desc, u8 out)
	{
	u32 D[SHA256_DIGEST_SIZE >> 2];
	__be32 dst = (__be32 )out;

	ppc_spe_sha256_final(desc, (u8 *)D);

	/* avoid bytewise memcpy */
	dst[0] = D[0];
	dst[1] = D[1];
	dst[2] = D[2];
	dst[3] = D[3];
	dst[4] = D[4];
	dst[5] = D[5];
	dst[6] = D[6];

	/* clear sensitive data */
	memzero_explicit(D, SHA256_DIGEST_SIZE);
	return 0;
	}

	static int ppc_spe_sha256_export(struct shash_desc desc, void out)
	{
	struct sha256_state *sctx = shash_desc_ctx(desc);

	memcpy(out, sctx, sizeof(*sctx));
	return 0;
	}

	static int ppc_spe_sha256_import(struct shash_desc desc, const void in)
	{
	struct sha256_state *sctx = shash_desc_ctx(desc);

	memcpy(sctx, in, sizeof(*sctx));
	return 0;
	}

	static struct shash_alg algs[2] = { {
	.digestsize = SHA256_DIGEST_SIZE,
	.init = ppc_spe_sha256_init,
	.update = ppc_spe_sha256_update,
	.final = ppc_spe_sha256_final,
	.export = ppc_spe_sha256_export,
	.import = ppc_spe_sha256_import,
	.descsize = sizeof(struct sha256_state),
	.statesize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha256",
	.cra_driver_name= "sha256-ppc-spe",
	.cra_priority = 300,
	.cra_flags = CRYPTO_ALG_TYPE_SHASH,
	.cra_blocksize = SHA256_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	}, {
	.digestsize = SHA224_DIGEST_SIZE,
	.init = ppc_spe_sha224_init,
	.update = ppc_spe_sha256_update,
	.final = ppc_spe_sha224_final,
	.export = ppc_spe_sha256_export,
	.import = ppc_spe_sha256_import,
	.descsize = sizeof(struct sha256_state),
	.statesize = sizeof(struct sha256_state),
	.base = {
	.cra_name = "sha224",
	.cra_driver_name= "sha224-ppc-spe",
	.cra_priority = 300,
	.cra_flags = CRYPTO_ALG_TYPE_SHASH,
	.cra_blocksize = SHA224_BLOCK_SIZE,
	.cra_module = THIS_MODULE,
	}
	} };

	static int __init ppc_spe_sha256_mod_init(void)
	{
	return crypto_register_shashes(algs, ARRAY_SIZE(algs));
	}

	static void __exit ppc_spe_sha256_mod_fini(void)
	{
	crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
	}

	module_init(ppc_spe_sha256_mod_init);
	module_exit(ppc_spe_sha256_mod_fini);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION("SHA-224 and SHA-256 Secure Hash Algorithm, SPE optimized");

	MODULE_ALIAS_CRYPTO("sha224");
	MODULE_ALIAS_CRYPTO("sha224-ppc-spe");
	MODULE_ALIAS_CRYPTO("sha256");
	MODULE_ALIAS_CRYPTO("sha256-ppc-spe");