// SPDX-License-Identifier: GPL-2.0
//
// Cryptographic API.
//
// Support for Samsung S5PV210 and Exynos HW acceleration.
//
// Copyright (C) 2011 NetUP Inc. All rights reserved.
// Copyright (c) 2017 Samsung Electronics Co., Ltd. All rights reserved.
//
// Hash part based on omap-sham.c driver.

#include <crypto/aes.h>
#include <crypto/ctr.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/skcipher.h>
#include <crypto/md5.h>
#include <crypto/scatterwalk.h>
#include <crypto/sha1.h>
#include <crypto/sha2.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>

#define _SBF(s, v)                      ((v) << (s))

/* Feed control registers */
#define SSS_REG_FCINTSTAT               0x0000
#define SSS_FCINTSTAT_HPARTINT          BIT(7)
#define SSS_FCINTSTAT_HDONEINT          BIT(5)
#define SSS_FCINTSTAT_BRDMAINT          BIT(3)
#define SSS_FCINTSTAT_BTDMAINT          BIT(2)
#define SSS_FCINTSTAT_HRDMAINT          BIT(1)
#define SSS_FCINTSTAT_PKDMAINT          BIT(0)

#define SSS_REG_FCINTENSET              0x0004
#define SSS_FCINTENSET_HPARTINTENSET    BIT(7)
#define SSS_FCINTENSET_HDONEINTENSET    BIT(5)
#define SSS_FCINTENSET_BRDMAINTENSET    BIT(3)
#define SSS_FCINTENSET_BTDMAINTENSET    BIT(2)
#define SSS_FCINTENSET_HRDMAINTENSET    BIT(1)
#define SSS_FCINTENSET_PKDMAINTENSET    BIT(0)

#define SSS_REG_FCINTENCLR              0x0008
#define SSS_FCINTENCLR_HPARTINTENCLR    BIT(7)
#define SSS_FCINTENCLR_HDONEINTENCLR    BIT(5)
#define SSS_FCINTENCLR_BRDMAINTENCLR    BIT(3)
#define SSS_FCINTENCLR_BTDMAINTENCLR    BIT(2)
#define SSS_FCINTENCLR_HRDMAINTENCLR    BIT(1)
#define SSS_FCINTENCLR_PKDMAINTENCLR    BIT(0)

#define SSS_REG_FCINTPEND               0x000C
#define SSS_FCINTPEND_HPARTINTP         BIT(7)
#define SSS_FCINTPEND_HDONEINTP         BIT(5)
#define SSS_FCINTPEND_BRDMAINTP         BIT(3)
#define SSS_FCINTPEND_BTDMAINTP         BIT(2)
#define SSS_FCINTPEND_HRDMAINTP         BIT(1)
#define SSS_FCINTPEND_PKDMAINTP         BIT(0)

#define SSS_REG_FCFIFOSTAT              0x0010
#define SSS_FCFIFOSTAT_BRFIFOFUL        BIT(7)
#define SSS_FCFIFOSTAT_BRFIFOEMP        BIT(6)
#define SSS_FCFIFOSTAT_BTFIFOFUL        BIT(5)
#define SSS_FCFIFOSTAT_BTFIFOEMP        BIT(4)
#define SSS_FCFIFOSTAT_HRFIFOFUL        BIT(3)
#define SSS_FCFIFOSTAT_HRFIFOEMP        BIT(2)
#define SSS_FCFIFOSTAT_PKFIFOFUL        BIT(1)
#define SSS_FCFIFOSTAT_PKFIFOEMP        BIT(0)

#define SSS_REG_FCFIFOCTRL              0x0014
#define SSS_FCFIFOCTRL_DESSEL           BIT(2)
#define SSS_HASHIN_INDEPENDENT          _SBF(0, 0x00)
#define SSS_HASHIN_CIPHER_INPUT         _SBF(0, 0x01)
#define SSS_HASHIN_CIPHER_OUTPUT        _SBF(0, 0x02)
#define SSS_HASHIN_MASK                 _SBF(0, 0x03)

#define SSS_REG_FCBRDMAS                0x0020
#define SSS_REG_FCBRDMAL                0x0024
#define SSS_REG_FCBRDMAC                0x0028
#define SSS_FCBRDMAC_BYTESWAP           BIT(1)
#define SSS_FCBRDMAC_FLUSH              BIT(0)

#define SSS_REG_FCBTDMAS                0x0030
#define SSS_REG_FCBTDMAL                0x0034
#define SSS_REG_FCBTDMAC                0x0038
#define SSS_FCBTDMAC_BYTESWAP           BIT(1)
#define SSS_FCBTDMAC_FLUSH              BIT(0)

#define SSS_REG_FCHRDMAS                0x0040
#define SSS_REG_FCHRDMAL                0x0044
#define SSS_REG_FCHRDMAC                0x0048
#define SSS_FCHRDMAC_BYTESWAP           BIT(1)
#define SSS_FCHRDMAC_FLUSH              BIT(0)

#define SSS_REG_FCPKDMAS                0x0050
#define SSS_REG_FCPKDMAL                0x0054
#define SSS_REG_FCPKDMAC                0x0058
#define SSS_FCPKDMAC_BYTESWAP           BIT(3)
#define SSS_FCPKDMAC_DESCEND            BIT(2)
#define SSS_FCPKDMAC_TRANSMIT           BIT(1)
#define SSS_FCPKDMAC_FLUSH              BIT(0)

#define SSS_REG_FCPKDMAO                0x005C

/* AES registers */
#define SSS_REG_AES_CONTROL             0x00
#define SSS_AES_BYTESWAP_DI             BIT(11)
#define SSS_AES_BYTESWAP_DO             BIT(10)
#define SSS_AES_BYTESWAP_IV             BIT(9)
#define SSS_AES_BYTESWAP_CNT            BIT(8)
#define SSS_AES_BYTESWAP_KEY            BIT(7)
#define SSS_AES_KEY_CHANGE_MODE         BIT(6)
#define SSS_AES_KEY_SIZE_128            _SBF(4, 0x00)
#define SSS_AES_KEY_SIZE_192            _SBF(4, 0x01)
#define SSS_AES_KEY_SIZE_256            _SBF(4, 0x02)
#define SSS_AES_FIFO_MODE               BIT(3)
#define SSS_AES_CHAIN_MODE_ECB          _SBF(1, 0x00)
#define SSS_AES_CHAIN_MODE_CBC          _SBF(1, 0x01)
#define SSS_AES_CHAIN_MODE_CTR          _SBF(1, 0x02)
#define SSS_AES_MODE_DECRYPT            BIT(0)

#define SSS_REG_AES_STATUS              0x04
#define SSS_AES_BUSY                    BIT(2)
#define SSS_AES_INPUT_READY             BIT(1)
#define SSS_AES_OUTPUT_READY            BIT(0)

#define SSS_REG_AES_IN_DATA(s)          (0x10 + (s << 2))
#define SSS_REG_AES_OUT_DATA(s)         (0x20 + (s << 2))
#define SSS_REG_AES_IV_DATA(s)          (0x30 + (s << 2))
#define SSS_REG_AES_CNT_DATA(s)         (0x40 + (s << 2))
#define SSS_REG_AES_KEY_DATA(s)         (0x80 + (s << 2))

#define SSS_REG(dev, reg)               ((dev)->ioaddr + (SSS_REG_##reg))
#define SSS_READ(dev, reg)              __raw_readl(SSS_REG(dev, reg))
#define SSS_WRITE(dev, reg, val)        __raw_writel((val), SSS_REG(dev, reg))

#define SSS_AES_REG(dev, reg)           ((dev)->aes_ioaddr + SSS_REG_##reg)
#define SSS_AES_WRITE(dev, reg, val)    __raw_writel((val), \
                                                SSS_AES_REG(dev, reg))

/* HW engine modes */
#define FLAGS_AES_DECRYPT               BIT(0)
#define FLAGS_AES_MODE_MASK             _SBF(1, 0x03)
#define FLAGS_AES_CBC                   _SBF(1, 0x01)
#define FLAGS_AES_CTR                   _SBF(1, 0x02)

#define AES_KEY_LEN                     16
#define CRYPTO_QUEUE_LEN                1

/* HASH registers */
#define SSS_REG_HASH_CTRL               0x00

#define SSS_HASH_USER_IV_EN             BIT(5)
#define SSS_HASH_INIT_BIT               BIT(4)
#define SSS_HASH_ENGINE_SHA1            _SBF(1, 0x00)
#define SSS_HASH_ENGINE_MD5             _SBF(1, 0x01)
#define SSS_HASH_ENGINE_SHA256          _SBF(1, 0x02)

#define SSS_HASH_ENGINE_MASK            _SBF(1, 0x03)

#define SSS_REG_HASH_CTRL_PAUSE         0x04

#define SSS_HASH_PAUSE                  BIT(0)

#define SSS_REG_HASH_CTRL_FIFO          0x08

#define SSS_HASH_FIFO_MODE_DMA          BIT(0)
#define SSS_HASH_FIFO_MODE_CPU          0

#define SSS_REG_HASH_CTRL_SWAP          0x0C

#define SSS_HASH_BYTESWAP_DI            BIT(3)
#define SSS_HASH_BYTESWAP_DO            BIT(2)
#define SSS_HASH_BYTESWAP_IV            BIT(1)
#define SSS_HASH_BYTESWAP_KEY           BIT(0)

#define SSS_REG_HASH_STATUS             0x10

#define SSS_HASH_STATUS_MSG_DONE        BIT(6)
#define SSS_HASH_STATUS_PARTIAL_DONE    BIT(4)
#define SSS_HASH_STATUS_BUFFER_READY    BIT(0)

#define SSS_REG_HASH_MSG_SIZE_LOW       0x20
#define SSS_REG_HASH_MSG_SIZE_HIGH      0x24

#define SSS_REG_HASH_PRE_MSG_SIZE_LOW   0x28
#define SSS_REG_HASH_PRE_MSG_SIZE_HIGH  0x2C

#define SSS_REG_HASH_IV(s)              (0xB0 + ((s) << 2))
#define SSS_REG_HASH_OUT(s)             (0x100 + ((s) << 2))

#define HASH_BLOCK_SIZE                 64
#define HASH_REG_SIZEOF                 4
#define HASH_MD5_MAX_REG                (MD5_DIGEST_SIZE / HASH_REG_SIZEOF)
#define HASH_SHA1_MAX_REG               (SHA1_DIGEST_SIZE / HASH_REG_SIZEOF)
#define HASH_SHA256_MAX_REG             (SHA256_DIGEST_SIZE / HASH_REG_SIZEOF)

/*
 * HASH bit numbers, used by device, setting in dev->hash_flags with
 * functions set_bit(), clear_bit() or tested with test_bit() or BIT(),
 * to keep HASH state BUSY or FREE, or to signal state from irq_handler
 * to hash_tasklet. SGS keep track of allocated memory for scatterlist
 */
#define HASH_FLAGS_BUSY         0
#define HASH_FLAGS_FINAL        1
#define HASH_FLAGS_DMA_ACTIVE   2
#define HASH_FLAGS_OUTPUT_READY 3
#define HASH_FLAGS_DMA_READY    4
#define HASH_FLAGS_SGS_COPIED   5
#define HASH_FLAGS_SGS_ALLOCED  6

/* HASH HW constants */
#define BUFLEN                  HASH_BLOCK_SIZE

#define SSS_HASH_QUEUE_LENGTH   10

/**
 * struct samsung_aes_variant - platform specific SSS driver data
 * @aes_offset: AES register offset from SSS module's base.
 * @hash_offset: HASH register offset from SSS module's base.
 * @clk_names: names of clocks needed to run SSS IP
 *
 * Specifies platform specific configuration of SSS module.
 * Note: A structure for driver specific platform data is used for future
 * expansion of its usage.
 */
struct samsung_aes_variant {
        unsigned int                    aes_offset;
        unsigned int                    hash_offset;
        const char                      *clk_names[2];
};

struct s5p_aes_reqctx {
        unsigned long                   mode;
};

struct s5p_aes_ctx {
        struct s5p_aes_dev              *dev;

        u8                              aes_key[AES_MAX_KEY_SIZE];
        u8                              nonce[CTR_RFC3686_NONCE_SIZE];
        int                             keylen;
};

/**
 * struct s5p_aes_dev - Crypto device state container
 * @dev:        Associated device
 * @clk:        Clock for accessing hardware
 * @pclk:       APB bus clock necessary to access the hardware
 * @ioaddr:     Mapped IO memory region
 * @aes_ioaddr: Per-varian offset for AES block IO memory
 * @irq_fc:     Feed control interrupt line
 * @req:        Crypto request currently handled by the device
 * @ctx:        Configuration for currently handled crypto request
 * @sg_src:     Scatter list with source data for currently handled block
 *              in device.  This is DMA-mapped into device.
 * @sg_dst:     Scatter list with destination data for currently handled block
 *              in device. This is DMA-mapped into device.
 * @sg_src_cpy: In case of unaligned access, copied scatter list
 *              with source data.
 * @sg_dst_cpy: In case of unaligned access, copied scatter list
 *              with destination data.
 * @tasklet:    New request scheduling jib
 * @queue:      Crypto queue
 * @busy:       Indicates whether the device is currently handling some request
 *              thus it uses some of the fields from this state, like:
 *              req, ctx, sg_src/dst (and copies).  This essentially
 *              protects against concurrent access to these fields.
 * @lock:       Lock for protecting both access to device hardware registers
 *              and fields related to current request (including the busy field).
 * @res:        Resources for hash.
 * @io_hash_base: Per-variant offset for HASH block IO memory.
 * @hash_lock:  Lock for protecting hash_req, hash_queue and hash_flags
 *              variable.
 * @hash_flags: Flags for current HASH op.
 * @hash_queue: Async hash queue.
 * @hash_tasklet: New HASH request scheduling job.
 * @xmit_buf:   Buffer for current HASH request transfer into SSS block.
 * @hash_req:   Current request sending to SSS HASH block.
 * @hash_sg_iter: Scatterlist transferred through DMA into SSS HASH block.
 * @hash_sg_cnt: Counter for hash_sg_iter.
 *
 * @use_hash:   true if HASH algs enabled
 */
struct s5p_aes_dev {
        struct device                   *dev;
        struct clk                      *clk;
        struct clk                      *pclk;
        void __iomem                    *ioaddr;
        void __iomem                    *aes_ioaddr;
        int                             irq_fc;

        struct skcipher_request         *req;
        struct s5p_aes_ctx              *ctx;
        struct scatterlist              *sg_src;
        struct scatterlist              *sg_dst;

        struct scatterlist              *sg_src_cpy;
        struct scatterlist              *sg_dst_cpy;

        struct tasklet_struct           tasklet;
        struct crypto_queue             queue;
        bool                            busy;
        spinlock_t                      lock;

        struct resource                 *res;
        void __iomem                    *io_hash_base;

        spinlock_t                      hash_lock; /* protect hash_ vars */
        unsigned long                   hash_flags;
        struct crypto_queue             hash_queue;
        struct tasklet_struct           hash_tasklet;

        u8                              xmit_buf[BUFLEN];
        struct ahash_request            *hash_req;
        struct scatterlist              *hash_sg_iter;
        unsigned int                    hash_sg_cnt;

        bool                            use_hash;
};

/**
 * struct s5p_hash_reqctx - HASH request context
 * @dd:         Associated device
 * @op_update:  Current request operation (OP_UPDATE or OP_FINAL)
 * @digcnt:     Number of bytes processed by HW (without buffer[] ones)
 * @digest:     Digest message or IV for partial result
 * @nregs:      Number of HW registers for digest or IV read/write
 * @engine:     Bits for selecting type of HASH in SSS block
 * @sg:         sg for DMA transfer
 * @sg_len:     Length of sg for DMA transfer
 * @sgl:        sg for joining buffer and req->src scatterlist
 * @skip:       Skip offset in req->src for current op
 * @total:      Total number of bytes for current request
 * @finup:      Keep state for finup or final.
 * @error:      Keep track of error.
 * @bufcnt:     Number of bytes holded in buffer[]
 * @buffer:     For byte(s) from end of req->src in UPDATE op
 */
struct s5p_hash_reqctx {
        struct s5p_aes_dev      *dd;
        bool                    op_update;

        u64                     digcnt;
        u8                      digest[SHA256_DIGEST_SIZE];

        unsigned int            nregs; /* digest_size / sizeof(reg) */
        u32                     engine;

        struct scatterlist      *sg;
        unsigned int            sg_len;
        struct scatterlist      sgl[2];
        unsigned int            skip;
        unsigned int            total;
        bool                    finup;
        bool                    error;

        u32                     bufcnt;
        u8                      buffer[];
};

/**
 * struct s5p_hash_ctx - HASH transformation context
 * @dd:         Associated device
 * @flags:      Bits for algorithm HASH.
 * @fallback:   Software transformation for zero message or size < BUFLEN.
 */
struct s5p_hash_ctx {
        struct s5p_aes_dev      *dd;
        unsigned long           flags;
        struct crypto_shash     *fallback;
};

static const struct samsung_aes_variant s5p_aes_data = {
        .aes_offset     = 0x4000,
        .hash_offset    = 0x6000,
        .clk_names      = { "secss", },
};

static const struct samsung_aes_variant exynos_aes_data = {
        .aes_offset     = 0x200,
        .hash_offset    = 0x400,
        .clk_names      = { "secss", },
};

static const struct samsung_aes_variant exynos5433_slim_aes_data = {
        .aes_offset     = 0x400,
        .hash_offset    = 0x800,
        .clk_names      = { "aclk", "pclk", },
};

static const struct of_device_id s5p_sss_dt_match[] = {
        {
                .compatible = "samsung,s5pv210-secss",
                .data = &s5p_aes_data,
        },
        {
                .compatible = "samsung,exynos4210-secss",
                .data = &exynos_aes_data,
        },
        {
                .compatible = "samsung,exynos5433-slim-sss",
                .data = &exynos5433_slim_aes_data,
        },
        { },
};
MODULE_DEVICE_TABLE(of, s5p_sss_dt_match);

static inline const struct samsung_aes_variant *find_s5p_sss_version
                                   (const struct platform_device *pdev)
{
        if (IS_ENABLED(CONFIG_OF) && (pdev->dev.of_node))
                return of_device_get_match_data(&pdev->dev);

        return (const struct samsung_aes_variant *)
                        platform_get_device_id(pdev)->driver_data;
}

static struct s5p_aes_dev *s5p_dev;

static void s5p_set_dma_indata(struct s5p_aes_dev *dev,
                               const struct scatterlist *sg)
{
        SSS_WRITE(dev, FCBRDMAS, sg_dma_address(sg));
        SSS_WRITE(dev, FCBRDMAL, sg_dma_len(sg));
}

static void s5p_set_dma_outdata(struct s5p_aes_dev *dev,
                                const struct scatterlist *sg)
{
        SSS_WRITE(dev, FCBTDMAS, sg_dma_address(sg));
        SSS_WRITE(dev, FCBTDMAL, sg_dma_len(sg));
}

static void s5p_free_sg_cpy(struct s5p_aes_dev *dev, struct scatterlist **sg)
{
        int len;

        if (!*sg)
                return;

        len = ALIGN(dev->req->cryptlen, AES_BLOCK_SIZE);
        free_pages((unsigned long)sg_virt(*sg), get_order(len));

        kfree(*sg);
        *sg = NULL;
}

static void s5p_sg_done(struct s5p_aes_dev *dev)
{
        struct skcipher_request *req = dev->req;
        struct s5p_aes_reqctx *reqctx = skcipher_request_ctx(req);

        if (dev->sg_dst_cpy) {
                dev_dbg(dev->dev,
                        "Copying %d bytes of output data back to original place\n",
                        dev->req->cryptlen);
                memcpy_to_sglist(dev->req->dst, 0, sg_virt(dev->sg_dst_cpy),
                                 dev->req->cryptlen);
        }
        s5p_free_sg_cpy(dev, &dev->sg_src_cpy);
        s5p_free_sg_cpy(dev, &dev->sg_dst_cpy);
        if (reqctx->mode & FLAGS_AES_CBC)
                memcpy_fromio(req->iv, dev->aes_ioaddr + SSS_REG_AES_IV_DATA(0), AES_BLOCK_SIZE);

        else if (reqctx->mode & FLAGS_AES_CTR)
                memcpy_fromio(req->iv, dev->aes_ioaddr + SSS_REG_AES_CNT_DATA(0), AES_BLOCK_SIZE);
}

/* Calls the completion. Cannot be called with dev->lock hold. */
static void s5p_aes_complete(struct skcipher_request *req, int err)
{
        skcipher_request_complete(req, err);
}

static void s5p_unset_outdata(struct s5p_aes_dev *dev)
{
        dma_unmap_sg(dev->dev, dev->sg_dst, 1, DMA_FROM_DEVICE);
}

static void s5p_unset_indata(struct s5p_aes_dev *dev)
{
        dma_unmap_sg(dev->dev, dev->sg_src, 1, DMA_TO_DEVICE);
}

static int s5p_make_sg_cpy(struct s5p_aes_dev *dev, struct scatterlist *src,
                           struct scatterlist **dst)
{
        void *pages;
        int len;

        *dst = kmalloc_obj(**dst, GFP_ATOMIC);
        if (!*dst)
                return -ENOMEM;

        len = ALIGN(dev->req->cryptlen, AES_BLOCK_SIZE);
        pages = (void *)__get_free_pages(GFP_ATOMIC, get_order(len));
        if (!pages) {
                kfree(*dst);
                *dst = NULL;
                return -ENOMEM;
        }

        memcpy_from_sglist(pages, src, 0, dev->req->cryptlen);

        sg_init_table(*dst, 1);
        sg_set_buf(*dst, pages, len);

        return 0;
}

static int s5p_set_outdata(struct s5p_aes_dev *dev, struct scatterlist *sg)
{
        if (!sg->length)
                return -EINVAL;

        if (!dma_map_sg(dev->dev, sg, 1, DMA_FROM_DEVICE))
                return -ENOMEM;

        dev->sg_dst = sg;

        return 0;
}

static int s5p_set_indata(struct s5p_aes_dev *dev, struct scatterlist *sg)
{
        if (!sg->length)
                return -EINVAL;

        if (!dma_map_sg(dev->dev, sg, 1, DMA_TO_DEVICE))
                return -ENOMEM;

        dev->sg_src = sg;

        return 0;
}

/*
 * Returns -ERRNO on error (mapping of new data failed).
 * On success returns:
 *  - 0 if there is no more data,
 *  - 1 if new transmitting (output) data is ready and its address+length
 *     have to be written to device (by calling s5p_set_dma_outdata()).
 */
static int s5p_aes_tx(struct s5p_aes_dev *dev)
{
        int ret = 0;

        s5p_unset_outdata(dev);

        if (!sg_is_last(dev->sg_dst)) {
                ret = s5p_set_outdata(dev, sg_next(dev->sg_dst));
                if (!ret)
                        ret = 1;
        }

        return ret;
}

/*
 * Returns -ERRNO on error (mapping of new data failed).
 * On success returns:
 *  - 0 if there is no more data,
 *  - 1 if new receiving (input) data is ready and its address+length
 *     have to be written to device (by calling s5p_set_dma_indata()).
 */
static int s5p_aes_rx(struct s5p_aes_dev *dev/*, bool *set_dma*/)
{
        int ret = 0;

        s5p_unset_indata(dev);

        if (!sg_is_last(dev->sg_src)) {
                ret = s5p_set_indata(dev, sg_next(dev->sg_src));
                if (!ret)
                        ret = 1;
        }

        return ret;
}

static inline u32 s5p_hash_read(struct s5p_aes_dev *dd, u32 offset)
{
        return __raw_readl(dd->io_hash_base + offset);
}

static inline void s5p_hash_write(struct s5p_aes_dev *dd,
                                  u32 offset, u32 value)
{
        __raw_writel(value, dd->io_hash_base + offset);
}

/**
 * s5p_set_dma_hashdata() - start DMA with sg
 * @dev:        device
 * @sg:         scatterlist ready to DMA transmit
 */
static void s5p_set_dma_hashdata(struct s5p_aes_dev *dev,
                                 const struct scatterlist *sg)
{
        dev->hash_sg_cnt--;
        SSS_WRITE(dev, FCHRDMAS, sg_dma_address(sg));
        SSS_WRITE(dev, FCHRDMAL, sg_dma_len(sg)); /* DMA starts */
}

/**
 * s5p_hash_rx() - get next hash_sg_iter
 * @dev:        device
 *
 * Return:
 * 2    if there is no more data and it is UPDATE op
 * 1    if new receiving (input) data is ready and can be written to device
 * 0    if there is no more data and it is FINAL op
 */
static int s5p_hash_rx(struct s5p_aes_dev *dev)
{
        if (dev->hash_sg_cnt > 0) {
                dev->hash_sg_iter = sg_next(dev->hash_sg_iter);
                return 1;
        }

        set_bit(HASH_FLAGS_DMA_READY, &dev->hash_flags);
        if (test_bit(HASH_FLAGS_FINAL, &dev->hash_flags))
                return 0;

        return 2;
}

static irqreturn_t s5p_aes_interrupt(int irq, void *dev_id)
{
        struct platform_device *pdev = dev_id;
        struct s5p_aes_dev *dev = platform_get_drvdata(pdev);
        struct skcipher_request *req;
        int err_dma_tx = 0;
        int err_dma_rx = 0;
        int err_dma_hx = 0;
        bool tx_end = false;
        bool hx_end = false;
        unsigned long flags;
        u32 status, st_bits;
        int err;

        spin_lock_irqsave(&dev->lock, flags);

        /*
         * Handle rx or tx interrupt. If there is still data (scatterlist did not
         * reach end), then map next scatterlist entry.
         * In case of such mapping error, s5p_aes_complete() should be called.
         *
         * If there is no more data in tx scatter list, call s5p_aes_complete()
         * and schedule new tasklet.
         *
         * Handle hx interrupt. If there is still data map next entry.
         */
        status = SSS_READ(dev, FCINTSTAT);
        if (status & SSS_FCINTSTAT_BRDMAINT)
                err_dma_rx = s5p_aes_rx(dev);

        if (status & SSS_FCINTSTAT_BTDMAINT) {
                if (sg_is_last(dev->sg_dst))
                        tx_end = true;
                err_dma_tx = s5p_aes_tx(dev);
        }

        if (status & SSS_FCINTSTAT_HRDMAINT)
                err_dma_hx = s5p_hash_rx(dev);

        st_bits = status & (SSS_FCINTSTAT_BRDMAINT | SSS_FCINTSTAT_BTDMAINT |
                                SSS_FCINTSTAT_HRDMAINT);
        /* clear DMA bits */
        SSS_WRITE(dev, FCINTPEND, st_bits);

        /* clear HASH irq bits */
        if (status & (SSS_FCINTSTAT_HDONEINT | SSS_FCINTSTAT_HPARTINT)) {
                /* cannot have both HPART and HDONE */
                if (status & SSS_FCINTSTAT_HPARTINT)
                        st_bits = SSS_HASH_STATUS_PARTIAL_DONE;

                if (status & SSS_FCINTSTAT_HDONEINT)
                        st_bits = SSS_HASH_STATUS_MSG_DONE;

                set_bit(HASH_FLAGS_OUTPUT_READY, &dev->hash_flags);
                s5p_hash_write(dev, SSS_REG_HASH_STATUS, st_bits);
                hx_end = true;
                /* when DONE or PART, do not handle HASH DMA */
                err_dma_hx = 0;
        }

        if (err_dma_rx < 0) {
                err = err_dma_rx;
                goto error;
        }
        if (err_dma_tx < 0) {
                err = err_dma_tx;
                goto error;
        }

        if (tx_end) {
                s5p_sg_done(dev);
                if (err_dma_hx == 1)
                        s5p_set_dma_hashdata(dev, dev->hash_sg_iter);

                spin_unlock_irqrestore(&dev->lock, flags);

                s5p_aes_complete(dev->req, 0);
                /* Device is still busy */
                tasklet_schedule(&dev->tasklet);
        } else {
                /*
                 * Writing length of DMA block (either receiving or
                 * transmitting) will start the operation immediately, so this
                 * should be done at the end (even after clearing pending
                 * interrupts to not miss the interrupt).
                 */
                if (err_dma_tx == 1)
                        s5p_set_dma_outdata(dev, dev->sg_dst);
                if (err_dma_rx == 1)
                        s5p_set_dma_indata(dev, dev->sg_src);
                if (err_dma_hx == 1)
                        s5p_set_dma_hashdata(dev, dev->hash_sg_iter);

                spin_unlock_irqrestore(&dev->lock, flags);
        }

        goto hash_irq_end;

error:
        s5p_sg_done(dev);
        dev->busy = false;
        req = dev->req;
        if (err_dma_hx == 1)
                s5p_set_dma_hashdata(dev, dev->hash_sg_iter);

        spin_unlock_irqrestore(&dev->lock, flags);
        s5p_aes_complete(req, err);

hash_irq_end:
        /*
         * Note about else if:
         *   when hash_sg_iter reaches end and its UPDATE op,
         *   issue SSS_HASH_PAUSE and wait for HPART irq
         */
        if (hx_end)
                tasklet_schedule(&dev->hash_tasklet);
        else if (err_dma_hx == 2)
                s5p_hash_write(dev, SSS_REG_HASH_CTRL_PAUSE,
                               SSS_HASH_PAUSE);

        return IRQ_HANDLED;
}

/**
 * s5p_hash_read_msg() - read message or IV from HW
 * @req:        AHASH request
 */
static void s5p_hash_read_msg(struct ahash_request *req)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
        struct s5p_aes_dev *dd = ctx->dd;
        u32 *hash = (u32 *)ctx->digest;
        unsigned int i;

        for (i = 0; i < ctx->nregs; i++)
                hash[i] = s5p_hash_read(dd, SSS_REG_HASH_OUT(i));
}

/**
 * s5p_hash_write_ctx_iv() - write IV for next partial/finup op.
 * @dd:         device
 * @ctx:        request context
 */
static void s5p_hash_write_ctx_iv(struct s5p_aes_dev *dd,
                                  const struct s5p_hash_reqctx *ctx)
{
        const u32 *hash = (const u32 *)ctx->digest;
        unsigned int i;

        for (i = 0; i < ctx->nregs; i++)
                s5p_hash_write(dd, SSS_REG_HASH_IV(i), hash[i]);
}

/**
 * s5p_hash_write_iv() - write IV for next partial/finup op.
 * @req:        AHASH request
 */
static void s5p_hash_write_iv(struct ahash_request *req)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);

        s5p_hash_write_ctx_iv(ctx->dd, ctx);
}

/**
 * s5p_hash_copy_result() - copy digest into req->result
 * @req:        AHASH request
 */
static void s5p_hash_copy_result(struct ahash_request *req)
{
        const struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);

        if (!req->result)
                return;

        memcpy(req->result, ctx->digest, ctx->nregs * HASH_REG_SIZEOF);
}

/**
 * s5p_hash_dma_flush() - flush HASH DMA
 * @dev:        secss device
 */
static void s5p_hash_dma_flush(struct s5p_aes_dev *dev)
{
        SSS_WRITE(dev, FCHRDMAC, SSS_FCHRDMAC_FLUSH);
}

/**
 * s5p_hash_dma_enable() - enable DMA mode for HASH
 * @dev:        secss device
 *
 * enable DMA mode for HASH
 */
static void s5p_hash_dma_enable(struct s5p_aes_dev *dev)
{
        s5p_hash_write(dev, SSS_REG_HASH_CTRL_FIFO, SSS_HASH_FIFO_MODE_DMA);
}

/**
 * s5p_hash_irq_disable() - disable irq HASH signals
 * @dev:        secss device
 * @flags:      bitfield with irq's to be disabled
 */
static void s5p_hash_irq_disable(struct s5p_aes_dev *dev, u32 flags)
{
        SSS_WRITE(dev, FCINTENCLR, flags);
}

/**
 * s5p_hash_irq_enable() - enable irq signals
 * @dev:        secss device
 * @flags:      bitfield with irq's to be enabled
 */
static void s5p_hash_irq_enable(struct s5p_aes_dev *dev, int flags)
{
        SSS_WRITE(dev, FCINTENSET, flags);
}

/**
 * s5p_hash_set_flow() - set flow inside SecSS AES/DES with/without HASH
 * @dev:        secss device
 * @hashflow:   HASH stream flow with/without crypto AES/DES
 */
static void s5p_hash_set_flow(struct s5p_aes_dev *dev, u32 hashflow)
{
        unsigned long flags;
        u32 flow;

        spin_lock_irqsave(&dev->lock, flags);

        flow = SSS_READ(dev, FCFIFOCTRL);
        flow &= ~SSS_HASHIN_MASK;
        flow |= hashflow;
        SSS_WRITE(dev, FCFIFOCTRL, flow);

        spin_unlock_irqrestore(&dev->lock, flags);
}

/**
 * s5p_ahash_dma_init() - enable DMA and set HASH flow inside SecSS
 * @dev:        secss device
 * @hashflow:   HASH stream flow with/without AES/DES
 *
 * flush HASH DMA and enable DMA, set HASH stream flow inside SecSS HW,
 * enable HASH irq's HRDMA, HDONE, HPART
 */
static void s5p_ahash_dma_init(struct s5p_aes_dev *dev, u32 hashflow)
{
        s5p_hash_irq_disable(dev, SSS_FCINTENCLR_HRDMAINTENCLR |
                             SSS_FCINTENCLR_HDONEINTENCLR |
                             SSS_FCINTENCLR_HPARTINTENCLR);
        s5p_hash_dma_flush(dev);

        s5p_hash_dma_enable(dev);
        s5p_hash_set_flow(dev, hashflow & SSS_HASHIN_MASK);
        s5p_hash_irq_enable(dev, SSS_FCINTENSET_HRDMAINTENSET |
                            SSS_FCINTENSET_HDONEINTENSET |
                            SSS_FCINTENSET_HPARTINTENSET);
}

/**
 * s5p_hash_write_ctrl() - prepare HASH block in SecSS for processing
 * @dd:         secss device
 * @length:     length for request
 * @final:      true if final op
 *
 * Prepare SSS HASH block for processing bytes in DMA mode. If it is called
 * after previous updates, fill up IV words. For final, calculate and set
 * lengths for HASH so SecSS can finalize hash. For partial, set SSS HASH
 * length as 2^63 so it will be never reached and set to zero prelow and
 * prehigh.
 *
 * This function does not start DMA transfer.
 */
static void s5p_hash_write_ctrl(struct s5p_aes_dev *dd, size_t length,
                                bool final)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(dd->hash_req);
        u32 prelow, prehigh, low, high;
        u32 configflags, swapflags;
        u64 tmplen;

        configflags = ctx->engine | SSS_HASH_INIT_BIT;

        if (likely(ctx->digcnt)) {
                s5p_hash_write_ctx_iv(dd, ctx);
                configflags |= SSS_HASH_USER_IV_EN;
        }

        if (final) {
                /* number of bytes for last part */
                low = length;
                high = 0;
                /* total number of bits prev hashed */
                tmplen = ctx->digcnt * 8;
                prelow = (u32)tmplen;
                prehigh = (u32)(tmplen >> 32);
        } else {
                prelow = 0;
                prehigh = 0;
                low = 0;
                high = BIT(31);
        }

        swapflags = SSS_HASH_BYTESWAP_DI | SSS_HASH_BYTESWAP_DO |
                    SSS_HASH_BYTESWAP_IV | SSS_HASH_BYTESWAP_KEY;

        s5p_hash_write(dd, SSS_REG_HASH_MSG_SIZE_LOW, low);
        s5p_hash_write(dd, SSS_REG_HASH_MSG_SIZE_HIGH, high);
        s5p_hash_write(dd, SSS_REG_HASH_PRE_MSG_SIZE_LOW, prelow);
        s5p_hash_write(dd, SSS_REG_HASH_PRE_MSG_SIZE_HIGH, prehigh);

        s5p_hash_write(dd, SSS_REG_HASH_CTRL_SWAP, swapflags);
        s5p_hash_write(dd, SSS_REG_HASH_CTRL, configflags);
}

/**
 * s5p_hash_xmit_dma() - start DMA hash processing
 * @dd:         secss device
 * @length:     length for request
 * @final:      true if final op
 *
 * Update digcnt here, as it is needed for finup/final op.
 */
static int s5p_hash_xmit_dma(struct s5p_aes_dev *dd, size_t length,
                             bool final)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(dd->hash_req);
        unsigned int cnt;

        cnt = dma_map_sg(dd->dev, ctx->sg, ctx->sg_len, DMA_TO_DEVICE);
        if (!cnt) {
                dev_err(dd->dev, "dma_map_sg error\n");
                ctx->error = true;
                return -EINVAL;
        }

        set_bit(HASH_FLAGS_DMA_ACTIVE, &dd->hash_flags);
        dd->hash_sg_iter = ctx->sg;
        dd->hash_sg_cnt = cnt;
        s5p_hash_write_ctrl(dd, length, final);
        ctx->digcnt += length;
        ctx->total -= length;

        /* catch last interrupt */
        if (final)
                set_bit(HASH_FLAGS_FINAL, &dd->hash_flags);

        s5p_set_dma_hashdata(dd, dd->hash_sg_iter); /* DMA starts */

        return -EINPROGRESS;
}

/**
 * s5p_hash_copy_sgs() - copy request's bytes into new buffer
 * @ctx:        request context
 * @sg:         source scatterlist request
 * @new_len:    number of bytes to process from sg
 *
 * Allocate new buffer, copy data for HASH into it. If there was xmit_buf
 * filled, copy it first, then copy data from sg into it. Prepare one sgl[0]
 * with allocated buffer.
 *
 * Set bit in dd->hash_flag so we can free it after irq ends processing.
 */
static int s5p_hash_copy_sgs(struct s5p_hash_reqctx *ctx,
                             struct scatterlist *sg, unsigned int new_len)
{
        unsigned int pages, len;
        void *buf;

        len = new_len + ctx->bufcnt;
        pages = get_order(len);

        buf = (void *)__get_free_pages(GFP_ATOMIC, pages);
        if (!buf) {
                dev_err(ctx->dd->dev, "alloc pages for unaligned case.\n");
                ctx->error = true;
                return -ENOMEM;
        }

        if (ctx->bufcnt)
                memcpy(buf, ctx->dd->xmit_buf, ctx->bufcnt);

        memcpy_from_sglist(buf + ctx->bufcnt, sg, ctx->skip, new_len);
        sg_init_table(ctx->sgl, 1);
        sg_set_buf(ctx->sgl, buf, len);
        ctx->sg = ctx->sgl;
        ctx->sg_len = 1;
        ctx->bufcnt = 0;
        ctx->skip = 0;
        set_bit(HASH_FLAGS_SGS_COPIED, &ctx->dd->hash_flags);

        return 0;
}

/**
 * s5p_hash_copy_sg_lists() - copy sg list and make fixes in copy
 * @ctx:        request context
 * @sg:         source scatterlist request
 * @new_len:    number of bytes to process from sg
 *
 * Allocate new scatterlist table, copy data for HASH into it. If there was
 * xmit_buf filled, prepare it first, then copy page, length and offset from
 * source sg into it, adjusting begin and/or end for skip offset and
 * hash_later value.
 *
 * Resulting sg table will be assigned to ctx->sg. Set flag so we can free
 * it after irq ends processing.
 */
static int s5p_hash_copy_sg_lists(struct s5p_hash_reqctx *ctx,
                                  struct scatterlist *sg, unsigned int new_len)
{
        unsigned int skip = ctx->skip, n = sg_nents(sg);
        struct scatterlist *tmp;
        unsigned int len;

        if (ctx->bufcnt)
                n++;

        ctx->sg = kmalloc_objs(*sg, n);
        if (!ctx->sg) {
                ctx->error = true;
                return -ENOMEM;
        }

        sg_init_table(ctx->sg, n);

        tmp = ctx->sg;

        ctx->sg_len = 0;

        if (ctx->bufcnt) {
                sg_set_buf(tmp, ctx->dd->xmit_buf, ctx->bufcnt);
                tmp = sg_next(tmp);
                ctx->sg_len++;
        }

        while (sg && skip >= sg->length) {
                skip -= sg->length;
                sg = sg_next(sg);
        }

        while (sg && new_len) {
                len = sg->length - skip;
                if (new_len < len)
                        len = new_len;

                new_len -= len;
                sg_set_page(tmp, sg_page(sg), len, sg->offset + skip);
                skip = 0;
                if (new_len <= 0)
                        sg_mark_end(tmp);

                tmp = sg_next(tmp);
                ctx->sg_len++;
                sg = sg_next(sg);
        }

        set_bit(HASH_FLAGS_SGS_ALLOCED, &ctx->dd->hash_flags);

        return 0;
}

/**
 * s5p_hash_prepare_sgs() - prepare sg for processing
 * @ctx:        request context
 * @sg:         source scatterlist request
 * @new_len:    number of bytes to process from sg
 * @final:      final flag
 *
 * Check two conditions: (1) if buffers in sg have len aligned data, and (2)
 * sg table have good aligned elements (list_ok). If one of this checks fails,
 * then either (1) allocates new buffer for data with s5p_hash_copy_sgs, copy
 * data into this buffer and prepare request in sgl, or (2) allocates new sg
 * table and prepare sg elements.
 *
 * For digest or finup all conditions can be good, and we may not need any
 * fixes.
 */
static int s5p_hash_prepare_sgs(struct s5p_hash_reqctx *ctx,
                                struct scatterlist *sg,
                                unsigned int new_len, bool final)
{
        unsigned int skip = ctx->skip, nbytes = new_len, n = 0;
        bool aligned = true, list_ok = true;
        struct scatterlist *sg_tmp = sg;

        if (!sg || !sg->length || !new_len)
                return 0;

        if (skip || !final)
                list_ok = false;

        while (nbytes > 0 && sg_tmp) {
                n++;
                if (skip >= sg_tmp->length) {
                        skip -= sg_tmp->length;
                        if (!sg_tmp->length) {
                                aligned = false;
                                break;
                        }
                } else {
                        if (!IS_ALIGNED(sg_tmp->length - skip, BUFLEN)) {
                                aligned = false;
                                break;
                        }

                        if (nbytes < sg_tmp->length - skip) {
                                list_ok = false;
                                break;
                        }

                        nbytes -= sg_tmp->length - skip;
                        skip = 0;
                }

                sg_tmp = sg_next(sg_tmp);
        }

        if (!aligned)
                return s5p_hash_copy_sgs(ctx, sg, new_len);
        else if (!list_ok)
                return s5p_hash_copy_sg_lists(ctx, sg, new_len);

        /*
         * Have aligned data from previous operation and/or current
         * Note: will enter here only if (digest or finup) and aligned
         */
        if (ctx->bufcnt) {
                ctx->sg_len = n;
                sg_init_table(ctx->sgl, 2);
                sg_set_buf(ctx->sgl, ctx->dd->xmit_buf, ctx->bufcnt);
                sg_chain(ctx->sgl, 2, sg);
                ctx->sg = ctx->sgl;
                ctx->sg_len++;
        } else {
                ctx->sg = sg;
                ctx->sg_len = n;
        }

        return 0;
}

/**
 * s5p_hash_prepare_request() - prepare request for processing
 * @req:        AHASH request
 * @update:     true if UPDATE op
 *
 * Note 1: we can have update flag _and_ final flag at the same time.
 * Note 2: we enter here when digcnt > BUFLEN (=HASH_BLOCK_SIZE) or
 *         either req->nbytes or ctx->bufcnt + req->nbytes is > BUFLEN or
 *         we have final op
 */
static int s5p_hash_prepare_request(struct ahash_request *req, bool update)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
        bool final = ctx->finup;
        int xmit_len, hash_later, nbytes;
        int ret;

        if (update)
                nbytes = req->nbytes;
        else
                nbytes = 0;

        ctx->total = nbytes + ctx->bufcnt;
        if (!ctx->total)
                return 0;

        if (nbytes && (!IS_ALIGNED(ctx->bufcnt, BUFLEN))) {
                /* bytes left from previous request, so fill up to BUFLEN */
                int len = BUFLEN - ctx->bufcnt % BUFLEN;

                if (len > nbytes)
                        len = nbytes;

                memcpy_from_sglist(ctx->buffer + ctx->bufcnt, req->src, 0, len);
                ctx->bufcnt += len;
                nbytes -= len;
                ctx->skip = len;
        } else {
                ctx->skip = 0;
        }

        if (ctx->bufcnt)
                memcpy(ctx->dd->xmit_buf, ctx->buffer, ctx->bufcnt);

        xmit_len = ctx->total;
        if (final) {
                hash_later = 0;
        } else {
                if (IS_ALIGNED(xmit_len, BUFLEN))
                        xmit_len -= BUFLEN;
                else
                        xmit_len -= xmit_len & (BUFLEN - 1);

                hash_later = ctx->total - xmit_len;
                /* copy hash_later bytes from end of req->src */
                /* previous bytes are in xmit_buf, so no overwrite */
                memcpy_from_sglist(ctx->buffer, req->src,
                                   req->nbytes - hash_later, hash_later);
        }

        if (xmit_len > BUFLEN) {
                ret = s5p_hash_prepare_sgs(ctx, req->src, nbytes - hash_later,
                                           final);
                if (ret)
                        return ret;
        } else {
                /* have buffered data only */
                if (unlikely(!ctx->bufcnt)) {
                        /* first update didn't fill up buffer */
                        memcpy_from_sglist(ctx->dd->xmit_buf, req->src,
                                           0, xmit_len);
                }

                sg_init_table(ctx->sgl, 1);
                sg_set_buf(ctx->sgl, ctx->dd->xmit_buf, xmit_len);

                ctx->sg = ctx->sgl;
                ctx->sg_len = 1;
        }

        ctx->bufcnt = hash_later;
        if (!final)
                ctx->total = xmit_len;

        return 0;
}

/**
 * s5p_hash_update_dma_stop() - unmap DMA
 * @dd:         secss device
 *
 * Unmap scatterlist ctx->sg.
 */
static void s5p_hash_update_dma_stop(struct s5p_aes_dev *dd)
{
        const struct s5p_hash_reqctx *ctx = ahash_request_ctx(dd->hash_req);

        dma_unmap_sg(dd->dev, ctx->sg, ctx->sg_len, DMA_TO_DEVICE);
        clear_bit(HASH_FLAGS_DMA_ACTIVE, &dd->hash_flags);
}

/**
 * s5p_hash_finish() - copy calculated digest to crypto layer
 * @req:        AHASH request
 */
static void s5p_hash_finish(struct ahash_request *req)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
        struct s5p_aes_dev *dd = ctx->dd;

        if (ctx->digcnt)
                s5p_hash_copy_result(req);

        dev_dbg(dd->dev, "hash_finish digcnt: %lld\n", ctx->digcnt);
}

/**
 * s5p_hash_finish_req() - finish request
 * @req:        AHASH request
 * @err:        error
 */
static void s5p_hash_finish_req(struct ahash_request *req, int err)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
        struct s5p_aes_dev *dd = ctx->dd;
        unsigned long flags;

        if (test_bit(HASH_FLAGS_SGS_COPIED, &dd->hash_flags))
                free_pages((unsigned long)sg_virt(ctx->sg),
                           get_order(ctx->sg->length));

        if (test_bit(HASH_FLAGS_SGS_ALLOCED, &dd->hash_flags))
                kfree(ctx->sg);

        ctx->sg = NULL;
        dd->hash_flags &= ~(BIT(HASH_FLAGS_SGS_ALLOCED) |
                            BIT(HASH_FLAGS_SGS_COPIED));

        if (!err && !ctx->error) {
                s5p_hash_read_msg(req);
                if (test_bit(HASH_FLAGS_FINAL, &dd->hash_flags))
                        s5p_hash_finish(req);
        } else {
                ctx->error = true;
        }

        spin_lock_irqsave(&dd->hash_lock, flags);
        dd->hash_flags &= ~(BIT(HASH_FLAGS_BUSY) | BIT(HASH_FLAGS_FINAL) |
                            BIT(HASH_FLAGS_DMA_READY) |
                            BIT(HASH_FLAGS_OUTPUT_READY));
        spin_unlock_irqrestore(&dd->hash_lock, flags);

        if (req->base.complete)
                ahash_request_complete(req, err);
}

/**
 * s5p_hash_handle_queue() - handle hash queue
 * @dd:         device s5p_aes_dev
 * @req:        AHASH request
 *
 * If req!=NULL enqueue it on dd->queue, if FLAGS_BUSY is not set on the
 * device then processes the first request from the dd->queue
 *
 * Returns: see s5p_hash_final below.
 */
static int s5p_hash_handle_queue(struct s5p_aes_dev *dd,
                                 struct ahash_request *req)
{
        struct crypto_async_request *async_req, *backlog;
        struct s5p_hash_reqctx *ctx;
        unsigned long flags;
        int err = 0, ret = 0;

retry:
        spin_lock_irqsave(&dd->hash_lock, flags);
        if (req)
                ret = ahash_enqueue_request(&dd->hash_queue, req);

        if (test_bit(HASH_FLAGS_BUSY, &dd->hash_flags)) {
                spin_unlock_irqrestore(&dd->hash_lock, flags);
                return ret;
        }

        backlog = crypto_get_backlog(&dd->hash_queue);
        async_req = crypto_dequeue_request(&dd->hash_queue);
        if (async_req)
                set_bit(HASH_FLAGS_BUSY, &dd->hash_flags);

        spin_unlock_irqrestore(&dd->hash_lock, flags);

        if (!async_req)
                return ret;

        if (backlog)
                crypto_request_complete(backlog, -EINPROGRESS);

        req = ahash_request_cast(async_req);
        dd->hash_req = req;
        ctx = ahash_request_ctx(req);

        err = s5p_hash_prepare_request(req, ctx->op_update);
        if (err || !ctx->total)
                goto out;

        dev_dbg(dd->dev, "handling new req, op_update: %u, nbytes: %d\n",
                ctx->op_update, req->nbytes);

        s5p_ahash_dma_init(dd, SSS_HASHIN_INDEPENDENT);
        if (ctx->digcnt)
                s5p_hash_write_iv(req); /* restore hash IV */

        if (ctx->op_update) { /* HASH_OP_UPDATE */
                err = s5p_hash_xmit_dma(dd, ctx->total, ctx->finup);
                if (err != -EINPROGRESS && ctx->finup && !ctx->error)
                        /* no final() after finup() */
                        err = s5p_hash_xmit_dma(dd, ctx->total, true);
        } else { /* HASH_OP_FINAL */
                err = s5p_hash_xmit_dma(dd, ctx->total, true);
        }
out:
        if (err != -EINPROGRESS) {
                /* hash_tasklet_cb will not finish it, so do it here */
                s5p_hash_finish_req(req, err);
                req = NULL;

                /*
                 * Execute next request immediately if there is anything
                 * in queue.
                 */
                goto retry;
        }

        return ret;
}

/**
 * s5p_hash_tasklet_cb() - hash tasklet
 * @data:       ptr to s5p_aes_dev
 */
static void s5p_hash_tasklet_cb(unsigned long data)
{
        struct s5p_aes_dev *dd = (struct s5p_aes_dev *)data;

        if (!test_bit(HASH_FLAGS_BUSY, &dd->hash_flags)) {
                s5p_hash_handle_queue(dd, NULL);
                return;
        }

        if (test_bit(HASH_FLAGS_DMA_READY, &dd->hash_flags)) {
                if (test_and_clear_bit(HASH_FLAGS_DMA_ACTIVE,
                                       &dd->hash_flags)) {
                        s5p_hash_update_dma_stop(dd);
                }

                if (test_and_clear_bit(HASH_FLAGS_OUTPUT_READY,
                                       &dd->hash_flags)) {
                        /* hash or semi-hash ready */
                        clear_bit(HASH_FLAGS_DMA_READY, &dd->hash_flags);
                        goto finish;
                }
        }

        return;

finish:
        /* finish curent request */
        s5p_hash_finish_req(dd->hash_req, 0);

        /* If we are not busy, process next req */
        if (!test_bit(HASH_FLAGS_BUSY, &dd->hash_flags))
                s5p_hash_handle_queue(dd, NULL);
}

/**
 * s5p_hash_enqueue() - enqueue request
 * @req:        AHASH request
 * @op:         operation UPDATE (true) or FINAL (false)
 *
 * Returns: see s5p_hash_final below.
 */
static int s5p_hash_enqueue(struct ahash_request *req, bool op)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
        struct s5p_hash_ctx *tctx = crypto_tfm_ctx(req->base.tfm);

        ctx->op_update = op;

        return s5p_hash_handle_queue(tctx->dd, req);
}

/**
 * s5p_hash_update() - process the hash input data
 * @req:        AHASH request
 *
 * If request will fit in buffer, copy it and return immediately
 * else enqueue it with OP_UPDATE.
 *
 * Returns: see s5p_hash_final below.
 */
static int s5p_hash_update(struct ahash_request *req)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);

        if (!req->nbytes)
                return 0;

        if (ctx->bufcnt + req->nbytes <= BUFLEN) {
                memcpy_from_sglist(ctx->buffer + ctx->bufcnt, req->src,
                                   0, req->nbytes);
                ctx->bufcnt += req->nbytes;
                return 0;
        }

        return s5p_hash_enqueue(req, true); /* HASH_OP_UPDATE */
}

/**
 * s5p_hash_final() - close up hash and calculate digest
 * @req:        AHASH request
 *
 * Note: in final req->src do not have any data, and req->nbytes can be
 * non-zero.
 *
 * If there were no input data processed yet and the buffered hash data is
 * less than BUFLEN (64) then calculate the final hash immediately by using
 * SW algorithm fallback.
 *
 * Otherwise enqueues the current AHASH request with OP_FINAL operation op
 * and finalize hash message in HW. Note that if digcnt!=0 then there were
 * previous update op, so there are always some buffered bytes in ctx->buffer,
 * which means that ctx->bufcnt!=0
 *
 * Returns:
 * 0 if the request has been processed immediately,
 * -EINPROGRESS if the operation has been queued for later execution or is set
 *              to processing by HW,
 * -EBUSY if queue is full and request should be resubmitted later,
 * other negative values denotes an error.
 */
static int s5p_hash_final(struct ahash_request *req)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);

        ctx->finup = true;
        if (ctx->error)
                return -EINVAL; /* uncompleted hash is not needed */

        if (!ctx->digcnt && ctx->bufcnt < BUFLEN) {
                struct s5p_hash_ctx *tctx = crypto_tfm_ctx(req->base.tfm);

                return crypto_shash_tfm_digest(tctx->fallback, ctx->buffer,
                                               ctx->bufcnt, req->result);
        }

        return s5p_hash_enqueue(req, false); /* HASH_OP_FINAL */
}

/**
 * s5p_hash_finup() - process last req->src and calculate digest
 * @req:        AHASH request containing the last update data
 *
 * Return values: see s5p_hash_final above.
 */
static int s5p_hash_finup(struct ahash_request *req)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
        int err1, err2;

        ctx->finup = true;

        err1 = s5p_hash_update(req);
        if (err1 == -EINPROGRESS || err1 == -EBUSY)
                return err1;

        /*
         * final() has to be always called to cleanup resources even if
         * update() failed, except EINPROGRESS or calculate digest for small
         * size
         */
        err2 = s5p_hash_final(req);

        return err1 ?: err2;
}

/**
 * s5p_hash_init() - initialize AHASH request contex
 * @req:        AHASH request
 *
 * Init async hash request context.
 */
static int s5p_hash_init(struct ahash_request *req)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct s5p_hash_ctx *tctx = crypto_ahash_ctx(tfm);

        ctx->dd = tctx->dd;
        ctx->error = false;
        ctx->finup = false;
        ctx->bufcnt = 0;
        ctx->digcnt = 0;
        ctx->total = 0;
        ctx->skip = 0;

        dev_dbg(tctx->dd->dev, "init: digest size: %d\n",
                crypto_ahash_digestsize(tfm));

        switch (crypto_ahash_digestsize(tfm)) {
        case MD5_DIGEST_SIZE:
                ctx->engine = SSS_HASH_ENGINE_MD5;
                ctx->nregs = HASH_MD5_MAX_REG;
                break;
        case SHA1_DIGEST_SIZE:
                ctx->engine = SSS_HASH_ENGINE_SHA1;
                ctx->nregs = HASH_SHA1_MAX_REG;
                break;
        case SHA256_DIGEST_SIZE:
                ctx->engine = SSS_HASH_ENGINE_SHA256;
                ctx->nregs = HASH_SHA256_MAX_REG;
                break;
        default:
                ctx->error = true;
                return -EINVAL;
        }

        return 0;
}

/**
 * s5p_hash_digest - calculate digest from req->src
 * @req:        AHASH request
 *
 * Return values: see s5p_hash_final above.
 */
static int s5p_hash_digest(struct ahash_request *req)
{
        return s5p_hash_init(req) ?: s5p_hash_finup(req);
}

/**
 * s5p_hash_cra_init_alg - init crypto alg transformation
 * @tfm:        crypto transformation
 */
static int s5p_hash_cra_init_alg(struct crypto_tfm *tfm)
{
        struct s5p_hash_ctx *tctx = crypto_tfm_ctx(tfm);
        const char *alg_name = crypto_tfm_alg_name(tfm);

        tctx->dd = s5p_dev;
        /* Allocate a fallback and abort if it failed. */
        tctx->fallback = crypto_alloc_shash(alg_name, 0,
                                            CRYPTO_ALG_NEED_FALLBACK);
        if (IS_ERR(tctx->fallback)) {
                pr_err("fallback alloc fails for '%s'\n", alg_name);
                return PTR_ERR(tctx->fallback);
        }

        crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
                                 sizeof(struct s5p_hash_reqctx) + BUFLEN);

        return 0;
}

/**
 * s5p_hash_cra_init - init crypto tfm
 * @tfm:        crypto transformation
 */
static int s5p_hash_cra_init(struct crypto_tfm *tfm)
{
        return s5p_hash_cra_init_alg(tfm);
}

/**
 * s5p_hash_cra_exit - exit crypto tfm
 * @tfm:        crypto transformation
 *
 * free allocated fallback
 */
static void s5p_hash_cra_exit(struct crypto_tfm *tfm)
{
        struct s5p_hash_ctx *tctx = crypto_tfm_ctx(tfm);

        crypto_free_shash(tctx->fallback);
        tctx->fallback = NULL;
}

/**
 * s5p_hash_export - export hash state
 * @req:        AHASH request
 * @out:        buffer for exported state
 */
static int s5p_hash_export(struct ahash_request *req, void *out)
{
        const struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);

        memcpy(out, ctx, sizeof(*ctx) + ctx->bufcnt);

        return 0;
}

/**
 * s5p_hash_import - import hash state
 * @req:        AHASH request
 * @in:         buffer with state to be imported from
 */
static int s5p_hash_import(struct ahash_request *req, const void *in)
{
        struct s5p_hash_reqctx *ctx = ahash_request_ctx(req);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct s5p_hash_ctx *tctx = crypto_ahash_ctx(tfm);
        const struct s5p_hash_reqctx *ctx_in = in;

        memcpy(ctx, in, sizeof(*ctx) + BUFLEN);
        if (ctx_in->bufcnt > BUFLEN) {
                ctx->error = true;
                return -EINVAL;
        }

        ctx->dd = tctx->dd;
        ctx->error = false;

        return 0;
}

static struct ahash_alg algs_sha1_md5_sha256[] = {
{
        .init           = s5p_hash_init,
        .update         = s5p_hash_update,
        .final          = s5p_hash_final,
        .finup          = s5p_hash_finup,
        .digest         = s5p_hash_digest,
        .export         = s5p_hash_export,
        .import         = s5p_hash_import,
        .halg.statesize = sizeof(struct s5p_hash_reqctx) + BUFLEN,
        .halg.digestsize        = SHA1_DIGEST_SIZE,
        .halg.base      = {
                .cra_name               = "sha1",
                .cra_driver_name        = "exynos-sha1",
                .cra_priority           = 100,
                .cra_flags              = CRYPTO_ALG_KERN_DRIVER_ONLY |
                                          CRYPTO_ALG_ASYNC |
                                          CRYPTO_ALG_NEED_FALLBACK,
                .cra_blocksize          = HASH_BLOCK_SIZE,
                .cra_ctxsize            = sizeof(struct s5p_hash_ctx),
                .cra_module             = THIS_MODULE,
                .cra_init               = s5p_hash_cra_init,
                .cra_exit               = s5p_hash_cra_exit,
        }
},
{
        .init           = s5p_hash_init,
        .update         = s5p_hash_update,
        .final          = s5p_hash_final,
        .finup          = s5p_hash_finup,
        .digest         = s5p_hash_digest,
        .export         = s5p_hash_export,
        .import         = s5p_hash_import,
        .halg.statesize = sizeof(struct s5p_hash_reqctx) + BUFLEN,
        .halg.digestsize        = MD5_DIGEST_SIZE,
        .halg.base      = {
                .cra_name               = "md5",
                .cra_driver_name        = "exynos-md5",
                .cra_priority           = 100,
                .cra_flags              = CRYPTO_ALG_KERN_DRIVER_ONLY |
                                          CRYPTO_ALG_ASYNC |
                                          CRYPTO_ALG_NEED_FALLBACK,
                .cra_blocksize          = HASH_BLOCK_SIZE,
                .cra_ctxsize            = sizeof(struct s5p_hash_ctx),
                .cra_module             = THIS_MODULE,
                .cra_init               = s5p_hash_cra_init,
                .cra_exit               = s5p_hash_cra_exit,
        }
},
{
        .init           = s5p_hash_init,
        .update         = s5p_hash_update,
        .final          = s5p_hash_final,
        .finup          = s5p_hash_finup,
        .digest         = s5p_hash_digest,
        .export         = s5p_hash_export,
        .import         = s5p_hash_import,
        .halg.statesize = sizeof(struct s5p_hash_reqctx) + BUFLEN,
        .halg.digestsize        = SHA256_DIGEST_SIZE,
        .halg.base      = {
                .cra_name               = "sha256",
                .cra_driver_name        = "exynos-sha256",
                .cra_priority           = 100,
                .cra_flags              = CRYPTO_ALG_KERN_DRIVER_ONLY |
                                          CRYPTO_ALG_ASYNC |
                                          CRYPTO_ALG_NEED_FALLBACK,
                .cra_blocksize          = HASH_BLOCK_SIZE,
                .cra_ctxsize            = sizeof(struct s5p_hash_ctx),
                .cra_module             = THIS_MODULE,
                .cra_init               = s5p_hash_cra_init,
                .cra_exit               = s5p_hash_cra_exit,
        }
}

};

static void s5p_set_aes(struct s5p_aes_dev *dev,
                        const u8 *key, const u8 *iv, const u8 *ctr,
                        unsigned int keylen)
{
        void __iomem *keystart;

        if (iv)
                memcpy_toio(dev->aes_ioaddr + SSS_REG_AES_IV_DATA(0), iv,
                            AES_BLOCK_SIZE);

        if (ctr)
                memcpy_toio(dev->aes_ioaddr + SSS_REG_AES_CNT_DATA(0), ctr,
                            AES_BLOCK_SIZE);

        if (keylen == AES_KEYSIZE_256)
                keystart = dev->aes_ioaddr + SSS_REG_AES_KEY_DATA(0);
        else if (keylen == AES_KEYSIZE_192)
                keystart = dev->aes_ioaddr + SSS_REG_AES_KEY_DATA(2);
        else
                keystart = dev->aes_ioaddr + SSS_REG_AES_KEY_DATA(4);

        memcpy_toio(keystart, key, keylen);
}

static bool s5p_is_sg_aligned(struct scatterlist *sg)
{
        while (sg) {
                if (!IS_ALIGNED(sg->length, AES_BLOCK_SIZE))
                        return false;
                sg = sg_next(sg);
        }

        return true;
}

static int s5p_set_indata_start(struct s5p_aes_dev *dev,
                                struct skcipher_request *req)
{
        struct scatterlist *sg;
        int err;

        dev->sg_src_cpy = NULL;
        sg = req->src;
        if (!s5p_is_sg_aligned(sg)) {
                dev_dbg(dev->dev,
                        "At least one unaligned source scatter list, making a copy\n");
                err = s5p_make_sg_cpy(dev, sg, &dev->sg_src_cpy);
                if (err)
                        return err;

                sg = dev->sg_src_cpy;
        }

        err = s5p_set_indata(dev, sg);
        if (err) {
                s5p_free_sg_cpy(dev, &dev->sg_src_cpy);
                return err;
        }

        return 0;
}

static int s5p_set_outdata_start(struct s5p_aes_dev *dev,
                                 struct skcipher_request *req)
{
        struct scatterlist *sg;
        int err;

        dev->sg_dst_cpy = NULL;
        sg = req->dst;
        if (!s5p_is_sg_aligned(sg)) {
                dev_dbg(dev->dev,
                        "At least one unaligned dest scatter list, making a copy\n");
                err = s5p_make_sg_cpy(dev, sg, &dev->sg_dst_cpy);
                if (err)
                        return err;

                sg = dev->sg_dst_cpy;
        }

        err = s5p_set_outdata(dev, sg);
        if (err) {
                s5p_free_sg_cpy(dev, &dev->sg_dst_cpy);
                return err;
        }

        return 0;
}

static void s5p_aes_crypt_start(struct s5p_aes_dev *dev, unsigned long mode)
{
        struct skcipher_request *req = dev->req;
        u32 aes_control;
        unsigned long flags;
        int err;
        u8 *iv, *ctr;

        /* This sets bit [13:12] to 00, which selects 128-bit counter */
        aes_control = SSS_AES_KEY_CHANGE_MODE;
        if (mode & FLAGS_AES_DECRYPT)
                aes_control |= SSS_AES_MODE_DECRYPT;

        if ((mode & FLAGS_AES_MODE_MASK) == FLAGS_AES_CBC) {
                aes_control |= SSS_AES_CHAIN_MODE_CBC;
                iv = req->iv;
                ctr = NULL;
        } else if ((mode & FLAGS_AES_MODE_MASK) == FLAGS_AES_CTR) {
                aes_control |= SSS_AES_CHAIN_MODE_CTR;
                iv = NULL;
                ctr = req->iv;
        } else {
                iv = NULL; /* AES_ECB */
                ctr = NULL;
        }

        if (dev->ctx->keylen == AES_KEYSIZE_192)
                aes_control |= SSS_AES_KEY_SIZE_192;
        else if (dev->ctx->keylen == AES_KEYSIZE_256)
                aes_control |= SSS_AES_KEY_SIZE_256;

        aes_control |= SSS_AES_FIFO_MODE;

        /* as a variant it is possible to use byte swapping on DMA side */
        aes_control |= SSS_AES_BYTESWAP_DI
                    |  SSS_AES_BYTESWAP_DO
                    |  SSS_AES_BYTESWAP_IV
                    |  SSS_AES_BYTESWAP_KEY
                    |  SSS_AES_BYTESWAP_CNT;

        spin_lock_irqsave(&dev->lock, flags);

        SSS_WRITE(dev, FCINTENCLR,
                  SSS_FCINTENCLR_BTDMAINTENCLR | SSS_FCINTENCLR_BRDMAINTENCLR);
        SSS_WRITE(dev, FCFIFOCTRL, 0x00);

        err = s5p_set_indata_start(dev, req);
        if (err)
                goto indata_error;

        err = s5p_set_outdata_start(dev, req);
        if (err)
                goto outdata_error;

        SSS_AES_WRITE(dev, AES_CONTROL, aes_control);
        s5p_set_aes(dev, dev->ctx->aes_key, iv, ctr, dev->ctx->keylen);

        s5p_set_dma_indata(dev,  dev->sg_src);
        s5p_set_dma_outdata(dev, dev->sg_dst);

        SSS_WRITE(dev, FCINTENSET,
                  SSS_FCINTENSET_BTDMAINTENSET | SSS_FCINTENSET_BRDMAINTENSET);

        spin_unlock_irqrestore(&dev->lock, flags);

        return;

outdata_error:
        s5p_unset_indata(dev);

indata_error:
        s5p_sg_done(dev);
        dev->busy = false;
        spin_unlock_irqrestore(&dev->lock, flags);
        s5p_aes_complete(req, err);
}

static void s5p_tasklet_cb(unsigned long data)
{
        struct s5p_aes_dev *dev = (struct s5p_aes_dev *)data;
        struct crypto_async_request *async_req, *backlog;
        struct s5p_aes_reqctx *reqctx;
        unsigned long flags;

        spin_lock_irqsave(&dev->lock, flags);
        backlog   = crypto_get_backlog(&dev->queue);
        async_req = crypto_dequeue_request(&dev->queue);

        if (!async_req) {
                dev->busy = false;
                spin_unlock_irqrestore(&dev->lock, flags);
                return;
        }
        spin_unlock_irqrestore(&dev->lock, flags);

        if (backlog)
                crypto_request_complete(backlog, -EINPROGRESS);

        dev->req = skcipher_request_cast(async_req);
        dev->ctx = crypto_tfm_ctx(dev->req->base.tfm);
        reqctx   = skcipher_request_ctx(dev->req);

        s5p_aes_crypt_start(dev, reqctx->mode);
}

static int s5p_aes_handle_req(struct s5p_aes_dev *dev,
                              struct skcipher_request *req)
{
        unsigned long flags;
        int err;

        spin_lock_irqsave(&dev->lock, flags);
        err = crypto_enqueue_request(&dev->queue, &req->base);
        if (dev->busy) {
                spin_unlock_irqrestore(&dev->lock, flags);
                return err;
        }
        dev->busy = true;

        spin_unlock_irqrestore(&dev->lock, flags);

        tasklet_schedule(&dev->tasklet);

        return err;
}

static int s5p_aes_crypt(struct skcipher_request *req, unsigned long mode)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct s5p_aes_reqctx *reqctx = skcipher_request_ctx(req);
        struct s5p_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct s5p_aes_dev *dev = ctx->dev;

        if (!req->cryptlen)
                return 0;

        if (!IS_ALIGNED(req->cryptlen, AES_BLOCK_SIZE) &&
                        ((mode & FLAGS_AES_MODE_MASK) != FLAGS_AES_CTR)) {
                dev_dbg(dev->dev, "request size is not exact amount of AES blocks\n");
                return -EINVAL;
        }

        reqctx->mode = mode;

        return s5p_aes_handle_req(dev, req);
}

static int s5p_aes_setkey(struct crypto_skcipher *cipher,
                          const u8 *key, unsigned int keylen)
{
        struct crypto_tfm *tfm = crypto_skcipher_tfm(cipher);
        struct s5p_aes_ctx *ctx = crypto_tfm_ctx(tfm);

        if (keylen != AES_KEYSIZE_128 &&
            keylen != AES_KEYSIZE_192 &&
            keylen != AES_KEYSIZE_256)
                return -EINVAL;

        memcpy(ctx->aes_key, key, keylen);
        ctx->keylen = keylen;

        return 0;
}

static int s5p_aes_ecb_encrypt(struct skcipher_request *req)
{
        return s5p_aes_crypt(req, 0);
}

static int s5p_aes_ecb_decrypt(struct skcipher_request *req)
{
        return s5p_aes_crypt(req, FLAGS_AES_DECRYPT);
}

static int s5p_aes_cbc_encrypt(struct skcipher_request *req)
{
        return s5p_aes_crypt(req, FLAGS_AES_CBC);
}

static int s5p_aes_cbc_decrypt(struct skcipher_request *req)
{
        return s5p_aes_crypt(req, FLAGS_AES_DECRYPT | FLAGS_AES_CBC);
}

static int s5p_aes_ctr_crypt(struct skcipher_request *req)
{
        return s5p_aes_crypt(req, FLAGS_AES_CTR);
}

static int s5p_aes_init_tfm(struct crypto_skcipher *tfm)
{
        struct s5p_aes_ctx *ctx = crypto_skcipher_ctx(tfm);

        ctx->dev = s5p_dev;
        crypto_skcipher_set_reqsize(tfm, sizeof(struct s5p_aes_reqctx));

        return 0;
}

static struct skcipher_alg algs[] = {
        {
                .base.cra_name          = "ecb(aes)",
                .base.cra_driver_name   = "ecb-aes-s5p",
                .base.cra_priority      = 100,
                .base.cra_flags         = CRYPTO_ALG_ASYNC |
                                          CRYPTO_ALG_KERN_DRIVER_ONLY,
                .base.cra_blocksize     = AES_BLOCK_SIZE,
                .base.cra_ctxsize       = sizeof(struct s5p_aes_ctx),
                .base.cra_alignmask     = 0x0f,
                .base.cra_module        = THIS_MODULE,

                .min_keysize            = AES_MIN_KEY_SIZE,
                .max_keysize            = AES_MAX_KEY_SIZE,
                .setkey                 = s5p_aes_setkey,
                .encrypt                = s5p_aes_ecb_encrypt,
                .decrypt                = s5p_aes_ecb_decrypt,
                .init                   = s5p_aes_init_tfm,
        },
        {
                .base.cra_name          = "cbc(aes)",
                .base.cra_driver_name   = "cbc-aes-s5p",
                .base.cra_priority      = 100,
                .base.cra_flags         = CRYPTO_ALG_ASYNC |
                                          CRYPTO_ALG_KERN_DRIVER_ONLY,
                .base.cra_blocksize     = AES_BLOCK_SIZE,
                .base.cra_ctxsize       = sizeof(struct s5p_aes_ctx),
                .base.cra_alignmask     = 0x0f,
                .base.cra_module        = THIS_MODULE,

                .min_keysize            = AES_MIN_KEY_SIZE,
                .max_keysize            = AES_MAX_KEY_SIZE,
                .ivsize                 = AES_BLOCK_SIZE,
                .setkey                 = s5p_aes_setkey,
                .encrypt                = s5p_aes_cbc_encrypt,
                .decrypt                = s5p_aes_cbc_decrypt,
                .init                   = s5p_aes_init_tfm,
        },
        {
                .base.cra_name          = "ctr(aes)",
                .base.cra_driver_name   = "ctr-aes-s5p",
                .base.cra_priority      = 100,
                .base.cra_flags         = CRYPTO_ALG_ASYNC |
                                          CRYPTO_ALG_KERN_DRIVER_ONLY,
                .base.cra_blocksize     = 1,
                .base.cra_ctxsize       = sizeof(struct s5p_aes_ctx),
                .base.cra_alignmask     = 0x0f,
                .base.cra_module        = THIS_MODULE,

                .min_keysize            = AES_MIN_KEY_SIZE,
                .max_keysize            = AES_MAX_KEY_SIZE,
                .ivsize                 = AES_BLOCK_SIZE,
                .setkey                 = s5p_aes_setkey,
                .encrypt                = s5p_aes_ctr_crypt,
                .decrypt                = s5p_aes_ctr_crypt,
                .init                   = s5p_aes_init_tfm,
        },
};

static int s5p_aes_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        int i, j, err;
        const struct samsung_aes_variant *variant;
        struct s5p_aes_dev *pdata;
        struct resource *res;
        unsigned int hash_i;

        if (s5p_dev)
                return -EEXIST;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return -ENOMEM;

        variant = find_s5p_sss_version(pdev);
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -EINVAL;

        /*
         * Note: HASH and PRNG uses the same registers in secss, avoid
         * overwrite each other. This will drop HASH when CONFIG_EXYNOS_RNG
         * is enabled in config. We need larger size for HASH registers in
         * secss, current describe only AES/DES
         */
        if (IS_ENABLED(CONFIG_CRYPTO_DEV_EXYNOS_HASH)) {
                if (variant == &exynos_aes_data) {
                        res->end += 0x300;
                        pdata->use_hash = true;
                }
        }

        pdata->res = res;
        pdata->ioaddr = devm_ioremap_resource(dev, res);
        if (IS_ERR(pdata->ioaddr)) {
                if (!pdata->use_hash)
                        return PTR_ERR(pdata->ioaddr);
                /* try AES without HASH */
                res->end -= 0x300;
                pdata->use_hash = false;
                pdata->ioaddr = devm_ioremap_resource(dev, res);
                if (IS_ERR(pdata->ioaddr))
                        return PTR_ERR(pdata->ioaddr);
        }

        pdata->clk = devm_clk_get(dev, variant->clk_names[0]);
        if (IS_ERR(pdata->clk))
                return dev_err_probe(dev, PTR_ERR(pdata->clk),
                                     "failed to find secss clock %s\n",
                                     variant->clk_names[0]);

        err = clk_prepare_enable(pdata->clk);
        if (err < 0) {
                dev_err(dev, "Enabling clock %s failed, err %d\n",
                        variant->clk_names[0], err);
                return err;
        }

        if (variant->clk_names[1]) {
                pdata->pclk = devm_clk_get(dev, variant->clk_names[1]);
                if (IS_ERR(pdata->pclk)) {
                        err = dev_err_probe(dev, PTR_ERR(pdata->pclk),
                                            "failed to find clock %s\n",
                                            variant->clk_names[1]);
                        goto err_clk;
                }

                err = clk_prepare_enable(pdata->pclk);
                if (err < 0) {
                        dev_err(dev, "Enabling clock %s failed, err %d\n",
                                variant->clk_names[0], err);
                        goto err_clk;
                }
        } else {
                pdata->pclk = NULL;
        }

        spin_lock_init(&pdata->lock);
        spin_lock_init(&pdata->hash_lock);

        pdata->aes_ioaddr = pdata->ioaddr + variant->aes_offset;
        pdata->io_hash_base = pdata->ioaddr + variant->hash_offset;

        pdata->irq_fc = platform_get_irq(pdev, 0);
        if (pdata->irq_fc < 0) {
                err = pdata->irq_fc;
                dev_warn(dev, "feed control interrupt is not available.\n");
                goto err_irq;
        }
        err = devm_request_threaded_irq(dev, pdata->irq_fc, NULL,
                                        s5p_aes_interrupt, IRQF_ONESHOT,
                                        pdev->name, pdev);
        if (err < 0) {
                dev_warn(dev, "feed control interrupt is not available.\n");
                goto err_irq;
        }

        pdata->busy = false;
        pdata->dev = dev;
        platform_set_drvdata(pdev, pdata);
        s5p_dev = pdata;

        tasklet_init(&pdata->tasklet, s5p_tasklet_cb, (unsigned long)pdata);
        crypto_init_queue(&pdata->queue, CRYPTO_QUEUE_LEN);

        for (i = 0; i < ARRAY_SIZE(algs); i++) {
                err = crypto_register_skcipher(&algs[i]);
                if (err)
                        goto err_algs;
        }

        if (pdata->use_hash) {
                tasklet_init(&pdata->hash_tasklet, s5p_hash_tasklet_cb,
                             (unsigned long)pdata);
                crypto_init_queue(&pdata->hash_queue, SSS_HASH_QUEUE_LENGTH);

                for (hash_i = 0; hash_i < ARRAY_SIZE(algs_sha1_md5_sha256);
                     hash_i++) {
                        struct ahash_alg *alg;

                        alg = &algs_sha1_md5_sha256[hash_i];
                        err = crypto_register_ahash(alg);
                        if (err) {
                                dev_err(dev, "can't register '%s': %d\n",
                                        alg->halg.base.cra_driver_name, err);
                                goto err_hash;
                        }
                }
        }

        dev_info(dev, "s5p-sss driver registered\n");

        return 0;

err_hash:
        for (j = hash_i - 1; j >= 0; j--)
                crypto_unregister_ahash(&algs_sha1_md5_sha256[j]);

        tasklet_kill(&pdata->hash_tasklet);
        res->end -= 0x300;

err_algs:
        if (i < ARRAY_SIZE(algs))
                dev_err(dev, "can't register '%s': %d\n", algs[i].base.cra_name,
                        err);

        for (j = 0; j < i; j++)
                crypto_unregister_skcipher(&algs[j]);

        tasklet_kill(&pdata->tasklet);

err_irq:
        clk_disable_unprepare(pdata->pclk);

err_clk:
        clk_disable_unprepare(pdata->clk);
        s5p_dev = NULL;

        return err;
}

static void s5p_aes_remove(struct platform_device *pdev)
{
        struct s5p_aes_dev *pdata = platform_get_drvdata(pdev);
        int i;

        for (i = 0; i < ARRAY_SIZE(algs); i++)
                crypto_unregister_skcipher(&algs[i]);

        tasklet_kill(&pdata->tasklet);
        if (pdata->use_hash) {
                for (i = ARRAY_SIZE(algs_sha1_md5_sha256) - 1; i >= 0; i--)
                        crypto_unregister_ahash(&algs_sha1_md5_sha256[i]);

                pdata->res->end -= 0x300;
                tasklet_kill(&pdata->hash_tasklet);
                pdata->use_hash = false;
        }

        clk_disable_unprepare(pdata->pclk);

        clk_disable_unprepare(pdata->clk);
        s5p_dev = NULL;
}

static struct platform_driver s5p_aes_crypto = {
        .probe  = s5p_aes_probe,
        .remove = s5p_aes_remove,
        .driver = {
                .name   = "s5p-secss",
                .of_match_table = s5p_sss_dt_match,
        },
};

module_platform_driver(s5p_aes_crypto);

MODULE_DESCRIPTION("S5PV210 AES hw acceleration support.");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Vladimir Zapolskiy <vzapolskiy@gmail.com>");
MODULE_AUTHOR("Kamil Konieczny <k.konieczny@partner.samsung.com>");