/*
 * Cryptographic API.
 *
 * Support for Infineon DEU hardware crypto engine.
 *
 * Copyright (c) 2005  Johannes Doering <info@com-style.de>, INFINEON
 *
 * modified from crypto/sha1.c
 *
 * ---------------------------------------------------------------------------
 * Cryptographic API.
 *
 * SHA1 Secure Hash Algorithm.
 *
 * Derived from cryptoapi implementation, adapted for in-place
 * scatterlist interface.
 *
 * Copyright (c) Alan Smithee.
 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
 * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
 *
 * 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.
 *
 * ---------------------------------------------------------------------------
 ** HISTORY
 ** $Date        $Author  	$Comment
 * ---------------------------------------------------------------------------
 */

/**
  \addtogroup AMAZON_S_DEU
  \ingroup AMAZON_S_BSP
  \brief amazon_s deu driver module
*/

/*!
  \file amazon_s_deu_sha1_hmac.c
  \ingroup AMAZON_S_DEU
  \brief sha1 hmac driver file
*/

/*!
  \addtogroup AMAZON_S_DEU_FUNCTIONS
  \ingroup AMAZON_S_DEU
  \brief amazon_s deu driver functions
*/

#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/crypto.h>
#include <linux/cryptohash.h>
#include <linux/types.h>
#include <asm/scatterlist.h>
#include <asm/byteorder.h>
#include <amazon_s_deu.h>

#define SHA1_DIGEST_SIZE	20
#define SHA1_HMAC_BLOCK_SIZE	64

#define SHA1_HMAC_DBN_TEMP_SIZE	1024 // size in dword, needed for dbn workaround

#if 0
     #define CRTCL_SECT_INIT
     #define CRTCL_SECT_START       local_irq_save(flag)
     #define CRTCL_SECT_END         local_irq_restore(flag)
#else
     static spinlock_t lock;
     #define CRTCL_SECT_INIT        spin_lock_init(&lock)
     #define CRTCL_SECT_START       spin_lock_irqsave(&lock, flag)
     #define CRTCL_SECT_END         spin_unlock_irqrestore(&lock, flag)
#endif

//#define CRYPTO_DEBUG
#ifdef CRYPTO_DEBUG
extern char debug_level;
#define DPRINTF(level, format, args...)	if (level < debug_level) printk(KERN_INFO "[%s %s %d]: " format, __FILE__, __func__, __LINE__, ##args);
#else
#define DPRINTF(level, format, args...)
#endif

#ifdef CONFIG_CRYPTO_DEV_AMAZON_S_SHA1_HMAC
#include <amazon_s.h>
#include <amazon_s_deu_structs.h>
#define HASH_START   AMAZON_S_HASH_CON
#endif
#ifdef CONFIG_CRYPTO_DEV_AMAZON_S_DMA
#include <amazon_s_deu_dma.h>
#include <amazon_s_dma.h>
#include <irq.h>
#endif

struct sha1_hmac_ctx {
        u64 count;
        u32 state[5];
        u8 buffer[64];
	u32 dbn;
	u32 temp[SHA1_HMAC_DBN_TEMP_SIZE];
};

extern int disable_deudma;
//static spinlock_t lock;

/*! \fn static void sha1_hmac_transform(struct crypto_tfm *tfm, u32 const *in)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief save input block to context
    \param tfm linux crypto algo transform
    \param in 64-byte block of input
*/
static void sha1_hmac_transform(struct crypto_tfm *tfm, u32 const *in)
{
	struct sha1_hmac_ctx *sctx = crypto_tfm_ctx(tfm);

	memcpy(&sctx->temp[sctx->dbn<<4], in, 64); //dbn workaround
        sctx->dbn += 1;

	if ( (sctx->dbn<<4) > SHA1_HMAC_DBN_TEMP_SIZE )
	{
	    printk("SHA1_HMAC_DBN_TEMP_SIZE exceeded\n");
	}

}

/*! \fn int sha1_hmac_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief sets sha1 hmac key
    \param tfm linux crypto algo transform
    \param key input key
    \param keylen key length greater than 64 bytes IS NOT SUPPORTED
*/
int sha1_hmac_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
{
    volatile struct deu_hash_t *hash = (struct deu_hash_t *) HASH_START;
    int i, j;
    u32 *in_key = (u32 *)key;

    //hash->controlr.NDC = 1;
    //hash->controlr.ENDI = 1;

    hash->KIDX = 0x80000000; // reset all 16 words of the key to '0'
    asm("sync");

    j = 0;
    for (i = 0; i < keylen; i+=4)
    {
         hash->KIDX = j;
         asm("sync");
         hash->KEY = *((u32 *) in_key + j);
         j++;
    }

    return 0;
}

/*! \fn void sha1_hmac_init(struct crypto_tfm *tfm)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief initialize sha1 hmac context
    \param tfm linux crypto algo transform
*/
void sha1_hmac_init(struct crypto_tfm *tfm)
{
	struct sha1_hmac_ctx *sctx = crypto_tfm_ctx(tfm);

        memset(sctx, 0, sizeof(struct sha1_hmac_ctx));
	sctx->dbn = 0; //dbn workaround
}

/*! \fn static void sha1_hmac_update(struct crypto_tfm *tfm, const u8 *data, unsigned int len)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief on-the-fly sha1 hmac computation
    \param tfm linux crypto algo transform
    \param data input data
    \param len size of input data
*/
static void sha1_hmac_update(struct crypto_tfm *tfm, const u8 *data,
			unsigned int len)
{
	struct sha1_hmac_ctx *sctx = crypto_tfm_ctx(tfm);
	unsigned int i, j;

	j = (sctx->count >> 3) & 0x3f;
	sctx->count += len << 3;
	//printk("sctx->count = %d\n", (sctx->count >> 3));

	if ((j + len) > 63) {
		memcpy (&sctx->buffer[j], data, (i = 64 - j));
		sha1_hmac_transform (tfm, (const u32 *)sctx->buffer);
		for (; i + 63 < len; i += 64) {
			sha1_hmac_transform (tfm, (const u32 *)&data[i]);
		}

		j = 0;
	}
	else
		i = 0;

	memcpy (&sctx->buffer[j], &data[i], len - i);
}

/*! \fn static void sha1_hmac_final(struct crypto_tfm *tfm, u8 *out)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief ompute final sha1 hmac value
    \param tfm linux crypto algo transform
    \param out final sha1 hmac output value
*/
static void sha1_hmac_final(struct crypto_tfm *tfm, u8 *out)
{
        struct sha1_hmac_ctx *sctx = crypto_tfm_ctx(tfm);
	u32 index, padlen;
	u64 t;
	u8 bits[8] = { 0, };
	static const u8 padding[64] = { 0x80, };
	volatile struct deu_hash_t *hashs = (struct deu_hash_t *) HASH_START;
	unsigned long flag;

	int i = 0;
    int dbn;
    u32 *in;

	t = sctx->count + 512; // need to add 512 bit of the IPAD operation
	bits[7] = 0xff & t;
	t >>= 8;
	bits[6] = 0xff & t;
	t >>= 8;
	bits[5] = 0xff & t;
	t >>= 8;
	bits[4] = 0xff & t;
	t >>= 8;
	bits[3] = 0xff & t;
	t >>= 8;
	bits[2] = 0xff & t;
	t >>= 8;
	bits[1] = 0xff & t;
	t >>= 8;
	bits[0] = 0xff & t;

	/* Pad out to 56 mod 64 */
	index = (sctx->count >> 3) & 0x3f;
	padlen = (index < 56) ? (56 - index) : ((64 + 56) - index);
	sha1_hmac_update (tfm, padding, padlen);

	/* Append length */
	sha1_hmac_update (tfm, bits, sizeof bits);

    in = &sctx->temp[0];

    CRTCL_SECT_START;

#if 0
    printk("dummy dbn = %d\n", 0xffff);
    hashs->DBN = 0xffff;
#else
    printk("dbn = %d\n", sctx->dbn);
    hashs->DBN = sctx->dbn;
#endif

    *AMAZON_S_HASH_CON = 0x0700002C; //khs, go, init, kyue, hmen, sha1

    //wait for processing
    while (hashs->controlr.BSY) {
        // this will not take long
    }

for (dbn = 0; dbn < sctx->dbn; dbn++)
{
#if 0
    if (dbn == (sctx->dbn - 1))
    {
         printk("dbn = %d\n", sctx->dbn);
         hashs->DBN = sctx->dbn;
    }
#endif

    for (i = 0; i < 16; i++) {
	    //printk("in[%d] = %08x\n", i, in[i]);
            hashs->MR = in[i];
    };

    hashs->controlr.GO = 1;
    asm("sync");

    //wait for processing
    while (hashs->controlr.BSY) {
            // this will not take long
    }

    in += 16;
}


#if 1
    //wait for digest ready
    while (! hashs->controlr.DGRY) {
        // this will not take long
    }
#endif

    *((u32 *) out + 0) = hashs->D1R;
    *((u32 *) out + 1) = hashs->D2R;
    *((u32 *) out + 2) = hashs->D3R;
    *((u32 *) out + 3) = hashs->D4R;
    *((u32 *) out + 4) = hashs->D5R;

    CRTCL_SECT_END;
}

struct crypto_alg ifxdeu_sha1_hmac_alg = {
        .cra_name       =       "hmac(sha1)",
        .cra_driver_name=       "ifxdeu-sha1_hmac",
        .cra_flags      =       CRYPTO_ALG_TYPE_DIGEST,
        .cra_blocksize  =       SHA1_HMAC_BLOCK_SIZE,
        .cra_ctxsize    =       sizeof(struct sha1_hmac_ctx),
        .cra_module   =         THIS_MODULE,
        .cra_alignmask  =       3,
        .cra_list       =       LIST_HEAD_INIT(ifxdeu_sha1_hmac_alg.cra_list),
        .cra_u          =       { .digest = {
        .dia_digestsize =       SHA1_DIGEST_SIZE,
        .dia_setkey     =       sha1_hmac_setkey,
        .dia_init       =       sha1_hmac_init,
        .dia_update     =       sha1_hmac_update,
        .dia_final      =       sha1_hmac_final } }
};


/*! \fn int __init ifxdeu_init_sha1_hmac (void)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief initialize sha1 hmac driver
*/
int __init ifxdeu_init_sha1_hmac (void)
{
	int ret;

	if ((ret = crypto_register_alg(&ifxdeu_sha1_hmac_alg)))
		goto sha1_err;

	CRTCL_SECT_INIT;

	printk (KERN_NOTICE "IFX DEU SHA1_HMAC initialized%s.\n", disable_deudma ? "" : " (DMA)");
	return ret;

sha1_err:
	printk(KERN_ERR "IFX DEU SHA1_HMAC initialization failed!\n");
	return ret;
}

/*! \fn void __exit ifxdeu_fini_sha1_hmac (void)
    \ingroup AMAZON_S_DEU_FUNCTIONS
    \brief unregister sha1 hmac driver
*/
void __exit ifxdeu_fini_sha1_hmac (void)
{
	crypto_unregister_alg (&ifxdeu_sha1_hmac_alg);
}