path: root/drivers/crypto/atmel-tdes.c

/*
 * Cryptographic API.
 *
 * Support for ATMEL DES/TDES HW acceleration.
 *
 * Copyright (c) 2012 Eukréa Electromatique - ATMEL
 * Author: Nicolas Royer <nicolas@eukrea.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * Some ideas are from omap-aes.c drivers.
 */


#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/hw_random.h>
#include <linux/platform_device.h>

#include <linux/device.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <linux/crypto.h>
#include <linux/cryptohash.h>
#include <crypto/scatterwalk.h>
#include <crypto/algapi.h>
#include <crypto/des.h>
#include <crypto/hash.h>
#include <crypto/internal/hash.h>
#include "atmel-tdes-regs.h"

/* TDES flags  */
#define TDES_FLAGS_MODE_MASK		0x007f
#define TDES_FLAGS_ENCRYPT	BIT(0)
#define TDES_FLAGS_CBC		BIT(1)
#define TDES_FLAGS_CFB		BIT(2)
#define TDES_FLAGS_CFB8		BIT(3)
#define TDES_FLAGS_CFB16	BIT(4)
#define TDES_FLAGS_CFB32	BIT(5)
#define TDES_FLAGS_OFB		BIT(6)

#define TDES_FLAGS_INIT		BIT(16)
#define TDES_FLAGS_FAST		BIT(17)
#define TDES_FLAGS_BUSY		BIT(18)

#define ATMEL_TDES_QUEUE_LENGTH	1

#define CFB8_BLOCK_SIZE		1
#define CFB16_BLOCK_SIZE	2
#define CFB32_BLOCK_SIZE	4
#define CFB64_BLOCK_SIZE	8


struct atmel_tdes_dev;

struct atmel_tdes_ctx {
	struct atmel_tdes_dev *dd;

	int		keylen;
	u32		key[3*DES_KEY_SIZE / sizeof(u32)];
	unsigned long	flags;
};

struct atmel_tdes_reqctx {
	unsigned long mode;
};

struct atmel_tdes_dev {
	struct list_head	list;
	unsigned long		phys_base;
	void __iomem		*io_base;

	struct atmel_tdes_ctx	*ctx;
	struct device		*dev;
	struct clk			*iclk;
	int					irq;

	unsigned long		flags;
	int			err;

	spinlock_t		lock;
	struct crypto_queue	queue;

	struct tasklet_struct	done_task;
	struct tasklet_struct	queue_task;

	struct ablkcipher_request	*req;
	size_t				total;

	struct scatterlist	*in_sg;
	size_t				in_offset;
	struct scatterlist	*out_sg;
	size_t				out_offset;

	size_t	buflen;
	size_t	dma_size;

	void	*buf_in;
	int		dma_in;
	dma_addr_t	dma_addr_in;

	void	*buf_out;
	int		dma_out;
	dma_addr_t	dma_addr_out;
};

struct atmel_tdes_drv {
	struct list_head	dev_list;
	spinlock_t		lock;
};

static struct atmel_tdes_drv atmel_tdes = {
	.dev_list = LIST_HEAD_INIT(atmel_tdes.dev_list),
	.lock = __SPIN_LOCK_UNLOCKED(atmel_tdes.lock),
};

static int atmel_tdes_sg_copy(struct scatterlist **sg, size_t *offset,
			void *buf, size_t buflen, size_t total, int out)
{
	unsigned int count, off = 0;

	while (buflen && total) {
		count = min((*sg)->length - *offset, total);
		count = min(count, buflen);

		if (!count)
			return off;

		scatterwalk_map_and_copy(buf + off, *sg, *offset, count, out);