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

/*
 * Cryptographic API.
 *
 * Support for ATMEL AES 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 driver.
 */


#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/aes.h>
#include <crypto/hash.h>
#include <crypto/internal/hash.h>
#include <linux/platform_data/atmel-aes.h>
#include "atmel-aes-regs.h"

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

/* AES flags */
#define AES_FLAGS_MODE_MASK	0x01ff
#define AES_FLAGS_ENCRYPT	BIT(0)
#define AES_FLAGS_CBC		BIT(1)
#define AES_FLAGS_CFB		BIT(2)
#define AES_FLAGS_CFB8		BIT(3)
#define AES_FLAGS_CFB16		BIT(4)
#define AES_FLAGS_CFB32		BIT(5)
#define AES_FLAGS_CFB64		BIT(6)
#define AES_FLAGS_OFB		BIT(7)
#define AES_FLAGS_CTR		BIT(8)

#define AES_FLAGS_INIT		BIT(16)
#define AES_FLAGS_DMA		BIT(17)
#define AES_FLAGS_BUSY		BIT(18)

#define AES_FLAGS_DUALBUFF	BIT(24)

#define ATMEL_AES_QUEUE_LENGTH	1
#define ATMEL_AES_CACHE_SIZE	0

#define ATMEL_AES_DMA_THRESHOLD		16


struct atmel_aes_dev;

struct atmel_aes_ctx {
	struct atmel_aes_dev *dd;

	int		keylen;
	u32		key[AES_KEYSIZE_256 / sizeof(u32)];
};

struct atmel_aes_reqctx {
	unsigned long mode;
};

struct atmel_aes_dma {
	struct dma_chan			*chan;
	struct dma_slave_config dma_conf;
};

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

	struct atmel_aes_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;
	unsigned int		nb_in_sg;

	struct scatterlist	*out_sg;
	unsigned int		nb_out_sg;

	size_t	bufcnt;

	u8	buf_in[ATMEL_AES_DMA_THRESHOLD] __aligned(sizeof(u32));
	int	dma_in;
	struct atmel_aes_dma	dma_lch_in;

	u8	buf_out[ATMEL_AES_DMA_THRESHOLD] __aligned(sizeof(u32));
	int	dma_out;
	struct atmel_aes_dma	dma_lch_out;

	u32	hw_version;
};

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

static struct atmel_aes_drv atmel_aes = {
	.dev_list = LIST_HEAD_INIT(atmel_aes.dev_list),
	.lock = __SPIN_LOCK_UNLOCKED(atmel_aes.lock),
};

static int atmel_aes_sg_length(struct ablkcipher_request *req,
			struct scatterlist *sg)
{
	unsigned int total = req->nbytes;
	int sg_nb;
	unsigned int len;
	struct scatterlist *sg_list;

	sg_nb = 0;
	sg_list = sg;
	total = req->nbytes;

	while (total) {
		len = min(sg_list->length, total);

		sg_nb++;
		total -= len;

		sg_list = sg_next(sg_list);
		if (!sg_list)
			total = 0;
	}

	return sg_nb;
}

static inline u32 atmel_aes_read(struct atmel_aes_dev *dd, u32 offset)
{
	return readl_relaxed(dd->io_base + offset);
}

static inline void atmel_aes_write(struct atmel_aes_dev *dd,
					u32 offset, u32 value)
{
	writel_relaxed(value, dd->io_base + offset);
}

static void atmel_aes_read_n(struct atmel_aes_dev *dd, u32 offset,
					u32 *value, int count)
{
	for (; count