// SPDX-License-Identifier: GPL-2.0
/*
 * Cryptographic API.
 *
 * Support for ATMEL AES HW acceleration.
 *
 * Copyright (c) 2012 Eukréa Electromatique - ATMEL
 * Author: Nicolas Royer <nicolas@eukrea.com>
 *
 * 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/dmaengine.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/of_device.h>
#include <linux/delay.h>
#include <linux/crypto.h>
#include <crypto/scatterwalk.h>
#include <crypto/algapi.h>
#include <crypto/aes.h>
#include <crypto/gcm.h>
#include <crypto/xts.h>
#include <crypto/internal/aead.h>
#include <crypto/internal/skcipher.h>
#include "atmel-aes-regs.h"
#include "atmel-authenc.h"

#define ATMEL_AES_PRIORITY      300

#define ATMEL_AES_BUFFER_ORDER  2
#define ATMEL_AES_BUFFER_SIZE   (PAGE_SIZE << ATMEL_AES_BUFFER_ORDER)

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

#define SIZE_IN_WORDS(x)        ((x) >> 2)

/* AES flags */
/* Reserve bits [18:16] [14:12] [1:0] for mode (same as for AES_MR) */
#define AES_FLAGS_ENCRYPT       AES_MR_CYPHER_ENC
#define AES_FLAGS_GTAGEN        AES_MR_GTAGEN
#define AES_FLAGS_OPMODE_MASK   (AES_MR_OPMOD_MASK | AES_MR_CFBS_MASK)
#define AES_FLAGS_ECB           AES_MR_OPMOD_ECB
#define AES_FLAGS_CBC           AES_MR_OPMOD_CBC
#define AES_FLAGS_OFB           AES_MR_OPMOD_OFB
#define AES_FLAGS_CFB128        (AES_MR_OPMOD_CFB | AES_MR_CFBS_128b)
#define AES_FLAGS_CFB64         (AES_MR_OPMOD_CFB | AES_MR_CFBS_64b)
#define AES_FLAGS_CFB32         (AES_MR_OPMOD_CFB | AES_MR_CFBS_32b)
#define AES_FLAGS_CFB16         (AES_MR_OPMOD_CFB | AES_MR_CFBS_16b)
#define AES_FLAGS_CFB8          (AES_MR_OPMOD_CFB | AES_MR_CFBS_8b)
#define AES_FLAGS_CTR           AES_MR_OPMOD_CTR
#define AES_FLAGS_GCM           AES_MR_OPMOD_GCM
#define AES_FLAGS_XTS           AES_MR_OPMOD_XTS

#define AES_FLAGS_MODE_MASK     (AES_FLAGS_OPMODE_MASK |        \
                                 AES_FLAGS_ENCRYPT |            \
                                 AES_FLAGS_GTAGEN)

#define AES_FLAGS_BUSY          BIT(3)
#define AES_FLAGS_DUMP_REG      BIT(4)
#define AES_FLAGS_OWN_SHA       BIT(5)

#define AES_FLAGS_PERSISTENT    AES_FLAGS_BUSY

#define ATMEL_AES_QUEUE_LENGTH  50

#define ATMEL_AES_DMA_THRESHOLD         256


struct atmel_aes_caps {
        bool                    has_dualbuff;
        bool                    has_cfb64;
        bool                    has_gcm;
        bool                    has_xts;
        bool                    has_authenc;
        u32                     max_burst_size;
};

struct atmel_aes_dev;


typedef int (*atmel_aes_fn_t)(struct atmel_aes_dev *);


struct atmel_aes_base_ctx {
        struct atmel_aes_dev    *dd;
        atmel_aes_fn_t          start;
        int                     keylen;
        u32                     key[AES_KEYSIZE_256 / sizeof(u32)];
        u16                     block_size;
        bool                    is_aead;
};

struct atmel_aes_ctx {
        struct atmel_aes_base_ctx       base;
};

struct atmel_aes_ctr_ctx {
        struct atmel_aes_base_ctx       base;

        __be32                  iv[AES_BLOCK_SIZE / sizeof(u32)];
        size_t                  offset;
        struct scatterlist      src[2];
        struct scatterlist      dst[2];
        u32                     blocks;
};

struct atmel_aes_gcm_ctx {
        struct atmel_aes_base_ctx       base;

        struct scatterlist      src[2];
        struct scatterlist      dst[2];

        __be32                  j0[AES_BLOCK_SIZE / sizeof(u32)];
        u32                     tag[AES_BLOCK_SIZE / sizeof(u32)];
        __be32                  ghash[AES_BLOCK_SIZE / sizeof(u32)];
        size_t                  textlen;

        const __be32            *ghash_in;
        __be32                  *ghash_out;
        atmel_aes_fn_t          ghash_resume;
};

struct atmel_aes_xts_ctx {
        struct atmel_aes_base_ctx       base;

        u32                     key2[AES_KEYSIZE_256 / sizeof(u32)];
};

#if IS_ENABLED(CONFIG_CRYPTO_DEV_ATMEL_AUTHENC)
struct atmel_aes_authenc_ctx {
        struct atmel_aes_base_ctx       base;
        struct atmel_sha_authenc_ctx    *auth;
};
#endif

struct atmel_aes_reqctx {
        unsigned long           mode;
        u8                      lastc[AES_BLOCK_SIZE];
};

#if IS_ENABLED(CONFIG_CRYPTO_DEV_ATMEL_AUTHENC)
struct atmel_aes_authenc_reqctx {
        struct atmel_aes_reqctx base;

        struct scatterlist      src[2];
        struct scatterlist      dst[2];
        size_t                  textlen;
        u32                     digest[SHA512_DIGEST_SIZE / sizeof(u32)];

        /* auth_req MUST be place last. */
        struct ahash_request    auth_req;
};
#endif

struct atmel_aes_dma {
        struct dma_chan         *chan;
        struct scatterlist      *sg;
        int                     nents;
        unsigned int            remainder;
        unsigned int            sg_len;
};

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

        struct crypto_async_request     *areq;
        struct atmel_aes_base_ctx       *ctx;

        bool                    is_async;
        atmel_aes_fn_t          resume;
        atmel_aes_fn_t          cpu_transfer_complete;

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

        unsigned long           flags;

        spinlock_t              lock;
        struct crypto_queue     queue;

        struct tasklet_struct   done_task;
        struct tasklet_struct   queue_task;

        size_t                  total;
        size_t                  datalen;
        u32                     *data;

        struct atmel_aes_dma    src;
        struct atmel_aes_dma    dst;

        size_t                  buflen;
        void                    *buf;
        struct scatterlist      aligned_sg;
        struct scatterlist      *real_dst;

        struct atmel_aes_caps   caps;

        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),
};

#ifdef VERBOSE_DEBUG
static const char *atmel_aes_reg_name(u32 offset, char *tmp, size_t sz)
{
        switch (offset) {
        case AES_CR:
                return "CR";

        case AES_MR:
                return "MR";

        case AES_ISR:
                return "ISR";

        case AES_IMR:
                return "IMR";

        case AES_IER:
                return "IER";

        case AES_IDR:
                return "IDR";

        case AES_KEYWR(0):
        case AES_KEYWR(1):
        case AES_KEYWR(2):
        case AES_KEYWR(3):
        case AES_KEYWR(4):
        case AES_KEYWR(5):
        case AES_KEYWR(6):
        case AES_KEYWR(7):
                snprintf(tmp, sz, "KEYWR[%u]", (offset - AES_KEYWR(0)) >> 2);
                break;

        case AES_IDATAR(0):
        case AES_IDATAR(1):
        case AES_IDATAR(2):
        case AES_IDATAR(3):
                snprintf(tmp, sz, "IDATAR[%u]", (offset - AES_IDATAR(0)) >> 2);
                break;

        case AES_ODATAR(0):
        case AES_ODATAR(1):
        case AES_ODATAR(2):
        case AES_ODATAR(3):
                snprintf(tmp, sz, "ODATAR[%u]", (offset - AES_ODATAR(0)) >> 2);
                break;

        case AES_IVR(0):
        case AES_IVR(1):
        case AES_IVR(2):
        case AES_IVR(3):
                snprintf(tmp, sz, "IVR[%u]", (offset - AES_IVR(0)) >> 2);
                break;

        case AES_AADLENR:
                return "AADLENR";

        case AES_CLENR:
                return "CLENR";

        case AES_GHASHR(0):
        case AES_GHASHR(1):
        case AES_GHASHR(2):
        case AES_GHASHR(3):
                snprintf(tmp, sz, "GHASHR[%u]", (offset - AES_GHASHR(0)) >> 2);
                break;

        case AES_TAGR(0):
        case AES_TAGR(1):
        case AES_TAGR(2):
        case AES_TAGR(3):
                snprintf(tmp, sz, "TAGR[%u]", (offset - AES_TAGR(0)) >> 2);
                break;

        case AES_CTRR:
                return "CTRR";

        case AES_GCMHR(0):
        case AES_GCMHR(1):
        case AES_GCMHR(2):
        case AES_GCMHR(3):
                snprintf(tmp, sz, "GCMHR[%u]", (offset - AES_GCMHR(0)) >> 2);
                break;

        case AES_EMR:
                return "EMR";

        case AES_TWR(0):
        case AES_TWR(1):
        case AES_TWR(2):
        case AES_TWR(3):
                snprintf(tmp, sz, "TWR[%u]", (offset - AES_TWR(0)) >> 2);
                break;

        case AES_ALPHAR(0):
        case AES_ALPHAR(1):
        case AES_ALPHAR(2):
        case AES_ALPHAR(3):
                snprintf(tmp, sz, "ALPHAR[%u]", (offset - AES_ALPHAR(0)) >> 2);
                break;

        default:
                snprintf(tmp, sz, "0x%02x", offset);
                break;
        }

        return tmp;
}
#endif /* VERBOSE_DEBUG */

/* Shared functions */

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

#ifdef VERBOSE_DEBUG
        if (dd->flags & AES_FLAGS_DUMP_REG) {
                char tmp[16];

                dev_vdbg(dd->dev, "read 0x%08x from %s\n", value,
                         atmel_aes_reg_name(offset, tmp, sizeof(tmp)));
        }
#endif /* VERBOSE_DEBUG */

        return value;
}

static inline void atmel_aes_write(struct atmel_aes_dev *dd,
                                        u32 offset, u32 value)
{
#ifdef VERBOSE_DEBUG
        if (dd->flags & AES_FLAGS_DUMP_REG) {
                char tmp[16];

                dev_vdbg(dd->dev, "write 0x%08x into %s\n", value,
                         atmel_aes_reg_name(offset, tmp, sizeof(tmp)));
        }
#endif /* VERBOSE_DEBUG */

        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--; value++, offset += 4)
                *value = atmel_aes_read(dd, offset);
}

static void atmel_aes_write_n(struct atmel_aes_dev *dd, u32 offset,
                              const u32 *value, int count)
{
        for (; count--; value++, offset += 4)
                atmel_aes_write(dd, offset, *value);
}

static inline void atmel_aes_read_block(struct atmel_aes_dev *dd, u32 offset,
                                        void *value)
{
        atmel_aes_read_n(dd, offset, value, SIZE_IN_WORDS(AES_BLOCK_SIZE));
}

static inline void atmel_aes_write_block(struct atmel_aes_dev *dd, u32 offset,
                                         const void *value)
{
        atmel_aes_write_n(dd, offset, value, SIZE_IN_WORDS(AES_BLOCK_SIZE));
}

static inline int atmel_aes_wait_for_data_ready(struct atmel_aes_dev *dd,
                                                atmel_aes_fn_t resume)
{
        u32 isr = atmel_aes_read(dd, AES_ISR);

        if (unlikely(isr & AES_INT_DATARDY))
                return resume(dd);

        dd->resume = resume;
        atmel_aes_write(dd, AES_IER, AES_INT_DATARDY);
        return -EINPROGRESS;
}

static inline size_t atmel_aes_padlen(size_t len, size_t block_size)
{
        len &= block_size - 1;
        return len ? block_size - len : 0;
}

static struct atmel_aes_dev *atmel_aes_find_dev(struct atmel_aes_base_ctx *ctx)
{
        struct atmel_aes_dev *aes_dd = NULL;
        struct atmel_aes_dev *tmp;

        spin_lock_bh(&atmel_aes.lock);
        if (!ctx->dd) {
                list_for_each_entry(tmp, &atmel_aes.dev_list, list) {
                        aes_dd = tmp;
                        break;
                }
                ctx->dd = aes_dd;
        } else {
                aes_dd = ctx->dd;
        }

        spin_unlock_bh(&atmel_aes.lock);

        return aes_dd;
}

static int atmel_aes_hw_init(struct atmel_aes_dev *dd)
{
        int err;

        err = clk_enable(dd->iclk);
        if (err)
                return err;

        atmel_aes_write(dd, AES_CR, AES_CR_SWRST);
        atmel_aes_write(dd, AES_MR, 0xE << AES_MR_CKEY_OFFSET);

        return 0;
}

static inline unsigned int atmel_aes_get_version(struct atmel_aes_dev *dd)
{
        return atmel_aes_read(dd, AES_HW_VERSION) & 0x00000fff;
}

static int atmel_aes_hw_version_init(struct atmel_aes_dev *dd)
{
        int err;

        err = atmel_aes_hw_init(dd);
        if (err)
                return err;

        dd->hw_version = atmel_aes_get_version(dd);

        dev_info(dd->dev, "version: 0x%x\n", dd->hw_version);

        clk_disable(dd->iclk);
        return 0;
}

static inline void atmel_aes_set_mode(struct atmel_aes_dev *dd,
                                      const struct atmel_aes_reqctx *rctx)
{
        /* Clear all but persistent flags and set request flags. */
        dd->flags = (dd->flags & AES_FLAGS_PERSISTENT) | rctx->mode;
}

static inline bool atmel_aes_is_encrypt(const struct atmel_aes_dev *dd)
{
        return (dd->flags & AES_FLAGS_ENCRYPT);
}

#if IS_ENABLED(CONFIG_CRYPTO_DEV_ATMEL_AUTHENC)
static void atmel_aes_authenc_complete(struct atmel_aes_dev *dd, int err);
#endif

static void atmel_aes_set_iv_as_last_ciphertext_block(struct atmel_aes_dev *dd)
{
        struct skcipher_request *req = skcipher_request_cast(dd->areq);
        struct atmel_aes_reqctx *rctx = skcipher_request_ctx(req);
        struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
        unsigned int ivsize = crypto_skcipher_ivsize(skcipher);

        if (req->cryptlen < ivsize)
                return;

        if (rctx->mode & AES_FLAGS_ENCRYPT) {
                scatterwalk_map_and_copy(req->iv, req->dst,
                                         req->cryptlen - ivsize, ivsize, 0);
        } else {
                if (req->src == req->dst)
                        memcpy(req->iv, rctx->lastc, ivsize);
                else
                        scatterwalk_map_and_copy(req->iv, req->src,
                                                 req->cryptlen - ivsize,
                                                 ivsize, 0);
        }
}

static inline struct atmel_aes_ctr_ctx *
atmel_aes_ctr_ctx_cast(struct atmel_aes_base_ctx *ctx)
{
        return container_of(ctx, struct atmel_aes_ctr_ctx, base);
}

static void atmel_aes_ctr_update_req_iv(struct atmel_aes_dev *dd)
{
        struct atmel_aes_ctr_ctx *ctx = atmel_aes_ctr_ctx_cast(dd->ctx);
        struct skcipher_request *req = skcipher_request_cast(dd->areq);
        struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
        unsigned int ivsize = crypto_skcipher_ivsize(skcipher);
        int i;

        /*
         * The CTR transfer works in fragments of data of maximum 1 MByte
         * because of the 16 bit CTR counter embedded in the IP. When reaching
         * here, ctx->blocks contains the number of blocks of the last fragment
         * processed, there is no need to explicit cast it to u16.
         */
        for (i = 0; i < ctx->blocks; i++)
                crypto_inc((u8 *)ctx->iv, AES_BLOCK_SIZE);

        memcpy(req->iv, ctx->iv, ivsize);
}

static inline int atmel_aes_complete(struct atmel_aes_dev *dd, int err)
{
        struct skcipher_request *req = skcipher_request_cast(dd->areq);
        struct atmel_aes_reqctx *rctx = skcipher_request_ctx(req);

#if IS_ENABLED(CONFIG_CRYPTO_DEV_ATMEL_AUTHENC)
        if (dd->ctx->is_aead)
                atmel_aes_authenc_complete(dd, err);
#endif

        clk_disable(dd->iclk);
        dd->flags &= ~AES_FLAGS_BUSY;

        if (!err && !dd->ctx->is_aead &&
            (rctx->mode & AES_FLAGS_OPMODE_MASK) != AES_FLAGS_ECB) {
                if ((rctx->mode & AES_FLAGS_OPMODE_MASK) != AES_FLAGS_CTR)
                        atmel_aes_set_iv_as_last_ciphertext_block(dd);
                else
                        atmel_aes_ctr_update_req_iv(dd);
        }

        if (dd->is_async)
                dd->areq->complete(dd->areq, err);

        tasklet_schedule(&dd->queue_task);

        return err;
}

static void atmel_aes_write_ctrl_key(struct atmel_aes_dev *dd, bool use_dma,
                                     const __be32 *iv, const u32 *key, int keylen)
{
        u32 valmr = 0;

        /* MR register must be set before IV registers */
        if (keylen == AES_KEYSIZE_128)
                valmr |= AES_MR_KEYSIZE_128;
        else if (keylen == AES_KEYSIZE_192)
                valmr |= AES_MR_KEYSIZE_192;
        else
                valmr |= AES_MR_KEYSIZE_256;

        valmr |= dd->flags & AES_FLAGS_MODE_MASK;

        if (use_dma) {
                valmr |= AES_MR_SMOD_IDATAR0;
                if (dd->caps.has_dualbuff)
                        valmr |= AES_MR_DUALBUFF;
        } else {
                valmr |= AES_MR_SMOD_AUTO;
        }

        atmel_aes_write(dd, AES_MR, valmr);

        atmel_aes_write_n(dd, AES_KEYWR(0), key, SIZE_IN_WORDS(keylen));

        if (iv && (valmr & AES_MR_OPMOD_MASK) != AES_MR_OPMOD_ECB)
                atmel_aes_write_block(dd, AES_IVR(0), iv);
}

static inline void atmel_aes_write_ctrl(struct atmel_aes_dev *dd, bool use_dma,
                                        const __be32 *iv)

{
        atmel_aes_write_ctrl_key(dd, use_dma, iv,
                                 dd->ctx->key, dd->ctx->keylen);
}

/* CPU transfer */

static int atmel_aes_cpu_transfer(struct atmel_aes_dev *dd)
{
        int err = 0;
        u32 isr;

        for (;;) {
                atmel_aes_read_block(dd, AES_ODATAR(0), dd->data);
                dd->data += 4;
                dd->datalen -= AES_BLOCK_SIZE;

                if (dd->datalen < AES_BLOCK_SIZE)
                        break;

                atmel_aes_write_block(dd, AES_IDATAR(0), dd->data);

                isr = atmel_aes_read(dd, AES_ISR);
                if (!(isr & AES_INT_DATARDY)) {
                        dd->resume = atmel_aes_cpu_transfer;
                        atmel_aes_write(dd, AES_IER, AES_INT_DATARDY);
                        return -EINPROGRESS;
                }
        }

        if (!sg_copy_from_buffer(dd->real_dst, sg_nents(dd->real_dst),
                                 dd->buf, dd->total))
                err = -EINVAL;

        if (err)
                return atmel_aes_complete(dd, err);

        return dd->cpu_transfer_complete(dd);
}

static int atmel_aes_cpu_start(struct atmel_aes_dev *dd,
                               struct scatterlist *src,
                               struct scatterlist *dst,
                               size_t len,
                               atmel_aes_fn_t resume)
{
        size_t padlen = atmel_aes_padlen(len, AES_BLOCK_SIZE);

        if (unlikely(len == 0))
                return -EINVAL;

        sg_copy_to_buffer(src, sg_nents(src), dd->buf, len);

        dd->total = len;
        dd->real_dst = dst;
        dd->cpu_transfer_complete = resume;
        dd->datalen = len + padlen;
        dd->data = (u32 *)dd->buf;
        atmel_aes_write_block(dd, AES_IDATAR(0), dd->data);
        return atmel_aes_wait_for_data_ready(dd, atmel_aes_cpu_transfer);
}


/* DMA transfer */

static void atmel_aes_dma_callback(void *data);

static bool atmel_aes_check_aligned(struct atmel_aes_dev *dd,
                                    struct scatterlist *sg,
                                    size_t len,
                                    struct atmel_aes_dma *dma)
{
        int nents;

        if (!IS_ALIGNED(len, dd->ctx->block_size))
                return false;

        for (nents = 0; sg; sg = sg_next(sg), ++nents) {
                if (!IS_ALIGNED(sg->offset, sizeof(u32)))
                        return false;

                if (len <= sg->length) {
                        if (!IS_ALIGNED(len, dd->ctx->block_size))
                                return false;

                        dma->nents = nents+1;
                        dma->remainder = sg->length - len;
                        sg->length = len;
                        return true;
                }

                if (!IS_ALIGNED(sg->length, dd->ctx->block_size))
                        return false;

                len -= sg->length;
        }

        return false;
}

static inline void atmel_aes_restore_sg(const struct atmel_aes_dma *dma)
{
        struct scatterlist *sg = dma->sg;
        int nents = dma->nents;

        if (!dma->remainder)
                return;

        while (--nents > 0 && sg)
                sg = sg_next(sg);

        if (!sg)
                return;

        sg->length += dma->remainder;
}

static int atmel_aes_map(struct atmel_aes_dev *dd,
                         struct scatterlist *src,
                         struct scatterlist *dst,
                         size_t len)
{
        bool src_aligned, dst_aligned;
        size_t padlen;

        dd->total = len;
        dd->src.sg = src;
        dd->dst.sg = dst;
        dd->real_dst = dst;

        src_aligned = atmel_aes_check_aligned(dd, src, len, &dd->src);
        if (src == dst)
                dst_aligned = src_aligned;
        else
                dst_aligned = atmel_aes_check_aligned(dd, dst, len, &dd->dst);
        if (!src_aligned || !dst_aligned) {
                padlen = atmel_aes_padlen(len, dd->ctx->block_size);

                if (dd->buflen < len + padlen)
                        return -ENOMEM;

                if (!src_aligned) {
                        sg_copy_to_buffer(src, sg_nents(src), dd->buf, len);
                        dd->src.sg = &dd->aligned_sg;
                        dd->src.nents = 1;
                        dd->src.remainder = 0;
                }

                if (!dst_aligned) {
                        dd->dst.sg = &dd->aligned_sg;
                        dd->dst.nents = 1;
                        dd->dst.remainder = 0;
                }

                sg_init_table(&dd->aligned_sg, 1);
                sg_set_buf(&dd->aligned_sg, dd->buf, len + padlen);
        }

        if (dd->src.sg == dd->dst.sg) {
                dd->src.sg_len = dma_map_sg(dd->dev, dd->src.sg, dd->src.nents,
                                            DMA_BIDIRECTIONAL);
                dd->dst.sg_len = dd->src.sg_len;
                if (!dd->src.sg_len)
                        return -EFAULT;
        } else {
                dd->src.sg_len = dma_map_sg(dd->dev, dd->src.sg, dd->src.nents,
                                            DMA_TO_DEVICE);
                if (!dd->src.sg_len)
                        return -EFAULT;

                dd->dst.sg_len = dma_map_sg(dd->dev, dd->dst.sg, dd->dst.nents,
                                            DMA_FROM_DEVICE);
                if (!dd->dst.sg_len) {
                        dma_unmap_sg(dd->dev, dd->src.sg, dd->src.nents,
                                     DMA_TO_DEVICE);
                        return -EFAULT;
                }
        }

        return 0;
}

static void atmel_aes_unmap(struct atmel_aes_dev *dd)
{
        if (dd->src.sg == dd->dst.sg) {
                dma_unmap_sg(dd->dev, dd->src.sg, dd->src.nents,
                             DMA_BIDIRECTIONAL);

                if (dd->src.sg != &dd->aligned_sg)
                        atmel_aes_restore_sg(&dd->src);
        } else {
                dma_unmap_sg(dd->dev, dd->dst.sg, dd->dst.nents,
                             DMA_FROM_DEVICE);

                if (dd->dst.sg != &dd->aligned_sg)
                        atmel_aes_restore_sg(&dd->dst);

                dma_unmap_sg(dd->dev, dd->src.sg, dd->src.nents,
                             DMA_TO_DEVICE);

                if (dd->src.sg != &dd->aligned_sg)
                        atmel_aes_restore_sg(&dd->src);
        }

        if (dd->dst.sg == &dd->aligned_sg)
                sg_copy_from_buffer(dd->real_dst, sg_nents(dd->real_dst),
                                    dd->buf, dd->total);
}

static int atmel_aes_dma_transfer_start(struct atmel_aes_dev *dd,
                                        enum dma_slave_buswidth addr_width,
                                        enum dma_transfer_direction dir,
                                        u32 maxburst)
{
        struct dma_async_tx_descriptor *desc;
        struct dma_slave_config config;
        dma_async_tx_callback callback;
        struct atmel_aes_dma *dma;
        int err;

        memset(&config, 0, sizeof(config));
        config.src_addr_width = addr_width;
        config.dst_addr_width = addr_width;
        config.src_maxburst = maxburst;
        config.dst_maxburst = maxburst;

        switch (dir) {
        case DMA_MEM_TO_DEV:
                dma = &dd->src;
                callback = NULL;
                config.dst_addr = dd->phys_base + AES_IDATAR(0);
                break;

        case DMA_DEV_TO_MEM:
                dma = &dd->dst;
                callback = atmel_aes_dma_callback;
                config.src_addr = dd->phys_base + AES_ODATAR(0);
                break;

        default:
                return -EINVAL;
        }

        err = dmaengine_slave_config(dma->chan, &config);
        if (err)
                return err;

        desc = dmaengine_prep_slave_sg(dma->chan, dma->sg, dma->sg_len, dir,
                                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!desc)
                return -ENOMEM;

        desc->callback = callback;
        desc->callback_param = dd;
        dmaengine_submit(desc);
        dma_async_issue_pending(dma->chan);

        return 0;
}

static int atmel_aes_dma_start(struct atmel_aes_dev *dd,
                               struct scatterlist *src,
                               struct scatterlist *dst,
                               size_t len,
                               atmel_aes_fn_t resume)
{
        enum dma_slave_buswidth addr_width;
        u32 maxburst;
        int err;

        switch (dd->ctx->block_size) {
        case CFB8_BLOCK_SIZE:
                addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
                maxburst = 1;
                break;

        case CFB16_BLOCK_SIZE:
                addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
                maxburst = 1;
                break;

        case CFB32_BLOCK_SIZE:
        case CFB64_BLOCK_SIZE:
                addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
                maxburst = 1;
                break;

        case AES_BLOCK_SIZE:
                addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
                maxburst = dd->caps.max_burst_size;
                break;

        default:
                err = -EINVAL;
                goto exit;
        }

        err = atmel_aes_map(dd, src, dst, len);
        if (err)
                goto exit;

        dd->resume = resume;

        /* Set output DMA transfer first */
        err = atmel_aes_dma_transfer_start(dd, addr_width, DMA_DEV_TO_MEM,
                                           maxburst);
        if (err)
                goto unmap;

        /* Then set input DMA transfer */
        err = atmel_aes_dma_transfer_start(dd, addr_width, DMA_MEM_TO_DEV,
                                           maxburst);
        if (err)
                goto output_transfer_stop;

        return -EINPROGRESS;

output_transfer_stop:
        dmaengine_terminate_sync(dd->dst.chan);
unmap:
        atmel_aes_unmap(dd);
exit:
        return atmel_aes_complete(dd, err);
}

static void atmel_aes_dma_callback(void *data)
{
        struct atmel_aes_dev *dd = data;

        atmel_aes_unmap(dd);
        dd->is_async = true;
        (void)dd->resume(dd);
}

static int atmel_aes_handle_queue(struct atmel_aes_dev *dd,
                                  struct crypto_async_request *new_areq)
{
        struct crypto_async_request *areq, *backlog;
        struct atmel_aes_base_ctx *ctx;
        unsigned long flags;
        bool start_async;
        int err, ret = 0;

        spin_lock_irqsave(&dd->lock, flags);
        if (new_areq)
                ret = crypto_enqueue_request(&dd->queue, new_areq);
        if (dd->flags & AES_FLAGS_BUSY) {
                spin_unlock_irqrestore(&dd->lock, flags);
                return ret;
        }
        backlog = crypto_get_backlog(&dd->queue);
        areq = crypto_dequeue_request(&dd->queue);
        if (areq)
                dd->flags |= AES_FLAGS_BUSY;
        spin_unlock_irqrestore(&dd->lock, flags);

        if (!areq)
                return ret;

        if (backlog)
                backlog->complete(backlog, -EINPROGRESS);

        ctx = crypto_tfm_ctx(areq->tfm);

        dd->areq = areq;
        dd->ctx = ctx;
        start_async = (areq != new_areq);
        dd->is_async = start_async;

        /* WARNING: ctx->start() MAY change dd->is_async. */
        err = ctx->start(dd);
        return (start_async) ? ret : err;
}


/* AES async block ciphers */

static int atmel_aes_transfer_complete(struct atmel_aes_dev *dd)
{
        return atmel_aes_complete(dd, 0);
}

static int atmel_aes_start(struct atmel_aes_dev *dd)
{
        struct skcipher_request *req = skcipher_request_cast(dd->areq);
        struct atmel_aes_reqctx *rctx = skcipher_request_ctx(req);
        bool use_dma = (req->cryptlen >= ATMEL_AES_DMA_THRESHOLD ||
                        dd->ctx->block_size != AES_BLOCK_SIZE);
        int err;

        atmel_aes_set_mode(dd, rctx);

        err = atmel_aes_hw_init(dd);
        if (err)
                return atmel_aes_complete(dd, err);

        atmel_aes_write_ctrl(dd, use_dma, (void *)req->iv);
        if (use_dma)
                return atmel_aes_dma_start(dd, req->src, req->dst,
                                           req->cryptlen,
                                           atmel_aes_transfer_complete);

        return atmel_aes_cpu_start(dd, req->src, req->dst, req->cryptlen,
                                   atmel_aes_transfer_complete);
}

static int atmel_aes_ctr_transfer(struct atmel_aes_dev *dd)
{
        struct atmel_aes_ctr_ctx *ctx = atmel_aes_ctr_ctx_cast(dd->ctx);
        struct skcipher_request *req = skcipher_request_cast(dd->areq);
        struct scatterlist *src, *dst;
        size_t datalen;
        u32 ctr;
        u16 start, end;
        bool use_dma, fragmented = false;

        /* Check for transfer completion. */
        ctx->offset += dd->total;
        if (ctx->offset >= req->cryptlen)
                return atmel_aes_transfer_complete(dd);

        /* Compute data length. */
        datalen = req->cryptlen - ctx->offset;
        ctx->blocks = DIV_ROUND_UP(datalen, AES_BLOCK_SIZE);
        ctr = be32_to_cpu(ctx->iv[3]);

        /* Check 16bit counter overflow. */
        start = ctr & 0xffff;
        end = start + ctx->blocks - 1;

        if (ctx->blocks >> 16 || end < start) {
                ctr |= 0xffff;
                datalen = AES_BLOCK_SIZE * (0x10000 - start);
                fragmented = true;
        }

        use_dma = (datalen >= ATMEL_AES_DMA_THRESHOLD);

        /* Jump to offset. */
        src = scatterwalk_ffwd(ctx->src, req->src, ctx->offset);
        dst = ((req->src == req->dst) ? src :
               scatterwalk_ffwd(ctx->dst, req->dst, ctx->offset));

        /* Configure hardware. */
        atmel_aes_write_ctrl(dd, use_dma, ctx->iv);
        if (unlikely(fragmented)) {
                /*
                 * Increment the counter manually to cope with the hardware
                 * counter overflow.
                 */
                ctx->iv[3] = cpu_to_be32(ctr);
                crypto_inc((u8 *)ctx->iv, AES_BLOCK_SIZE);
        }

        if (use_dma)
                return atmel_aes_dma_start(dd, src, dst, datalen,
                                           atmel_aes_ctr_transfer);

        return atmel_aes_cpu_start(dd, src, dst, datalen,
                                   atmel_aes_ctr_transfer);
}

static int atmel_aes_ctr_start(struct atmel_aes_dev *dd)
{
        struct atmel_aes_ctr_ctx *ctx = atmel_aes_ctr_ctx_cast(dd->ctx);
        struct skcipher_request *req = skcipher_request_cast(dd->areq);
        struct atmel_aes_reqctx *rctx = skcipher_request_ctx(req);
        int err;

        atmel_aes_set_mode(dd, rctx);

        err = atmel_aes_hw_init(dd);
        if (err)
                return atmel_aes_complete(dd, err);

        memcpy(ctx->iv, req->iv, AES_BLOCK_SIZE);
        ctx->offset = 0;
        dd->total = 0;
        return atmel_aes_ctr_transfer(dd);
}

static int atmel_aes_crypt(struct skcipher_request *req, unsigned long mode)
{
        struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
        struct atmel_aes_base_ctx *ctx = crypto_skcipher_ctx(skcipher);
        struct atmel_aes_reqctx *rctx;
        struct atmel_aes_dev *dd;

        switch (mode & AES_FLAGS_OPMODE_MASK) {
        case AES_FLAGS_CFB8:
                ctx->block_size = CFB8_BLOCK_SIZE;
                break;

        case AES_FLAGS_CFB16:
                ctx->block_size = CFB16_BLOCK_SIZE;
                break;

        case AES_FLAGS_CFB32:
                ctx->block_size = CFB32_BLOCK_SIZE;
                break;

        case AES_FLAGS_CFB64:
                ctx->block_size = CFB64_BLOCK_SIZE;
                break;

        default:
                ctx->block_size = AES_BLOCK_SIZE;
                break;
        }
        ctx->is_aead = false;

        dd = atmel_aes_find_dev(ctx);
        if (!dd)
                return -ENODEV;

        rctx = skcipher_request_ctx(req);
        rctx->mode = mode;

        if ((mode & AES_FLAGS_OPMODE_MASK) != AES_FLAGS_ECB &&
            !(mode & AES_FLAGS_ENCRYPT) && req->src == req->dst) {
                unsigned int ivsize = crypto_skcipher_ivsize(skcipher);

                if (req->cryptlen >= ivsize)
                        scatterwalk_map_and_copy(rctx->lastc, req->src,
                                                 req->cryptlen - ivsize,
                                                 ivsize, 0);
        }

        return atmel_aes_handle_queue(dd, &req->base);
}

static int atmel_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
                           unsigned int keylen)
{
        struct atmel_aes_base_ctx *ctx = crypto_skcipher_ctx(tfm);

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

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

        return 0;
}

static int atmel_aes_ecb_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_ECB | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_ecb_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_ECB);
}

static int atmel_aes_cbc_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CBC | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_cbc_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CBC);
}

static int atmel_aes_ofb_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_OFB | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_ofb_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_OFB);
}

static int atmel_aes_cfb_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB128 | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_cfb_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB128);
}

static int atmel_aes_cfb64_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB64 | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_cfb64_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB64);
}

static int atmel_aes_cfb32_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB32 | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_cfb32_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB32);
}

static int atmel_aes_cfb16_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB16 | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_cfb16_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB16);
}

static int atmel_aes_cfb8_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB8 | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_cfb8_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CFB8);
}

static int atmel_aes_ctr_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CTR | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_ctr_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_CTR);
}

static int atmel_aes_init_tfm(struct crypto_skcipher *tfm)
{
        struct atmel_aes_ctx *ctx = crypto_skcipher_ctx(tfm);

        crypto_skcipher_set_reqsize(tfm, sizeof(struct atmel_aes_reqctx));
        ctx->base.start = atmel_aes_start;

        return 0;
}

static int atmel_aes_ctr_init_tfm(struct crypto_skcipher *tfm)
{
        struct atmel_aes_ctx *ctx = crypto_skcipher_ctx(tfm);

        crypto_skcipher_set_reqsize(tfm, sizeof(struct atmel_aes_reqctx));
        ctx->base.start = atmel_aes_ctr_start;

        return 0;
}

static struct skcipher_alg aes_algs[] = {
{
        .base.cra_name          = "ecb(aes)",
        .base.cra_driver_name   = "atmel-ecb-aes",
        .base.cra_blocksize     = AES_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_ctx),

        .init                   = atmel_aes_init_tfm,
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
        .setkey                 = atmel_aes_setkey,
        .encrypt                = atmel_aes_ecb_encrypt,
        .decrypt                = atmel_aes_ecb_decrypt,
},
{
        .base.cra_name          = "cbc(aes)",
        .base.cra_driver_name   = "atmel-cbc-aes",
        .base.cra_blocksize     = AES_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_ctx),

        .init                   = atmel_aes_init_tfm,
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
        .setkey                 = atmel_aes_setkey,
        .encrypt                = atmel_aes_cbc_encrypt,
        .decrypt                = atmel_aes_cbc_decrypt,
        .ivsize                 = AES_BLOCK_SIZE,
},
{
        .base.cra_name          = "ofb(aes)",
        .base.cra_driver_name   = "atmel-ofb-aes",
        .base.cra_blocksize     = AES_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_ctx),

        .init                   = atmel_aes_init_tfm,
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
        .setkey                 = atmel_aes_setkey,
        .encrypt                = atmel_aes_ofb_encrypt,
        .decrypt                = atmel_aes_ofb_decrypt,
        .ivsize                 = AES_BLOCK_SIZE,
},
{
        .base.cra_name          = "cfb(aes)",
        .base.cra_driver_name   = "atmel-cfb-aes",
        .base.cra_blocksize     = AES_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_ctx),

        .init                   = atmel_aes_init_tfm,
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
        .setkey                 = atmel_aes_setkey,
        .encrypt                = atmel_aes_cfb_encrypt,
        .decrypt                = atmel_aes_cfb_decrypt,
        .ivsize                 = AES_BLOCK_SIZE,
},
{
        .base.cra_name          = "cfb32(aes)",
        .base.cra_driver_name   = "atmel-cfb32-aes",
        .base.cra_blocksize     = CFB32_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_ctx),

        .init                   = atmel_aes_init_tfm,
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
        .setkey                 = atmel_aes_setkey,
        .encrypt                = atmel_aes_cfb32_encrypt,
        .decrypt                = atmel_aes_cfb32_decrypt,
        .ivsize                 = AES_BLOCK_SIZE,
},
{
        .base.cra_name          = "cfb16(aes)",
        .base.cra_driver_name   = "atmel-cfb16-aes",
        .base.cra_blocksize     = CFB16_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_ctx),

        .init                   = atmel_aes_init_tfm,
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
        .setkey                 = atmel_aes_setkey,
        .encrypt                = atmel_aes_cfb16_encrypt,
        .decrypt                = atmel_aes_cfb16_decrypt,
        .ivsize                 = AES_BLOCK_SIZE,
},
{
        .base.cra_name          = "cfb8(aes)",
        .base.cra_driver_name   = "atmel-cfb8-aes",
        .base.cra_blocksize     = CFB8_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_ctx),

        .init                   = atmel_aes_init_tfm,
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
        .setkey                 = atmel_aes_setkey,
        .encrypt                = atmel_aes_cfb8_encrypt,
        .decrypt                = atmel_aes_cfb8_decrypt,
        .ivsize                 = AES_BLOCK_SIZE,
},
{
        .base.cra_name          = "ctr(aes)",
        .base.cra_driver_name   = "atmel-ctr-aes",
        .base.cra_blocksize     = 1,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_ctr_ctx),

        .init                   = atmel_aes_ctr_init_tfm,
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
        .setkey                 = atmel_aes_setkey,
        .encrypt                = atmel_aes_ctr_encrypt,
        .decrypt                = atmel_aes_ctr_decrypt,
        .ivsize                 = AES_BLOCK_SIZE,
},
};

static struct skcipher_alg aes_cfb64_alg = {
        .base.cra_name          = "cfb64(aes)",
        .base.cra_driver_name   = "atmel-cfb64-aes",
        .base.cra_blocksize     = CFB64_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_ctx),

        .init                   = atmel_aes_init_tfm,
        .min_keysize            = AES_MIN_KEY_SIZE,
        .max_keysize            = AES_MAX_KEY_SIZE,
        .setkey                 = atmel_aes_setkey,
        .encrypt                = atmel_aes_cfb64_encrypt,
        .decrypt                = atmel_aes_cfb64_decrypt,
        .ivsize                 = AES_BLOCK_SIZE,
};


/* gcm aead functions */

static int atmel_aes_gcm_ghash(struct atmel_aes_dev *dd,
                               const u32 *data, size_t datalen,
                               const __be32 *ghash_in, __be32 *ghash_out,
                               atmel_aes_fn_t resume);
static int atmel_aes_gcm_ghash_init(struct atmel_aes_dev *dd);
static int atmel_aes_gcm_ghash_finalize(struct atmel_aes_dev *dd);

static int atmel_aes_gcm_start(struct atmel_aes_dev *dd);
static int atmel_aes_gcm_process(struct atmel_aes_dev *dd);
static int atmel_aes_gcm_length(struct atmel_aes_dev *dd);
static int atmel_aes_gcm_data(struct atmel_aes_dev *dd);
static int atmel_aes_gcm_tag_init(struct atmel_aes_dev *dd);
static int atmel_aes_gcm_tag(struct atmel_aes_dev *dd);
static int atmel_aes_gcm_finalize(struct atmel_aes_dev *dd);

static inline struct atmel_aes_gcm_ctx *
atmel_aes_gcm_ctx_cast(struct atmel_aes_base_ctx *ctx)
{
        return container_of(ctx, struct atmel_aes_gcm_ctx, base);
}

static int atmel_aes_gcm_ghash(struct atmel_aes_dev *dd,
                               const u32 *data, size_t datalen,
                               const __be32 *ghash_in, __be32 *ghash_out,
                               atmel_aes_fn_t resume)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);

        dd->data = (u32 *)data;
        dd->datalen = datalen;
        ctx->ghash_in = ghash_in;
        ctx->ghash_out = ghash_out;
        ctx->ghash_resume = resume;

        atmel_aes_write_ctrl(dd, false, NULL);
        return atmel_aes_wait_for_data_ready(dd, atmel_aes_gcm_ghash_init);
}

static int atmel_aes_gcm_ghash_init(struct atmel_aes_dev *dd)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);

        /* Set the data length. */
        atmel_aes_write(dd, AES_AADLENR, dd->total);
        atmel_aes_write(dd, AES_CLENR, 0);

        /* If needed, overwrite the GCM Intermediate Hash Word Registers */
        if (ctx->ghash_in)
                atmel_aes_write_block(dd, AES_GHASHR(0), ctx->ghash_in);

        return atmel_aes_gcm_ghash_finalize(dd);
}

static int atmel_aes_gcm_ghash_finalize(struct atmel_aes_dev *dd)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);
        u32 isr;

        /* Write data into the Input Data Registers. */
        while (dd->datalen > 0) {
                atmel_aes_write_block(dd, AES_IDATAR(0), dd->data);
                dd->data += 4;
                dd->datalen -= AES_BLOCK_SIZE;

                isr = atmel_aes_read(dd, AES_ISR);
                if (!(isr & AES_INT_DATARDY)) {
                        dd->resume = atmel_aes_gcm_ghash_finalize;
                        atmel_aes_write(dd, AES_IER, AES_INT_DATARDY);
                        return -EINPROGRESS;
                }
        }

        /* Read the computed hash from GHASHRx. */
        atmel_aes_read_block(dd, AES_GHASHR(0), ctx->ghash_out);

        return ctx->ghash_resume(dd);
}


static int atmel_aes_gcm_start(struct atmel_aes_dev *dd)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);
        struct aead_request *req = aead_request_cast(dd->areq);
        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
        struct atmel_aes_reqctx *rctx = aead_request_ctx(req);
        size_t ivsize = crypto_aead_ivsize(tfm);
        size_t datalen, padlen;
        const void *iv = req->iv;
        u8 *data = dd->buf;
        int err;

        atmel_aes_set_mode(dd, rctx);

        err = atmel_aes_hw_init(dd);
        if (err)
                return atmel_aes_complete(dd, err);

        if (likely(ivsize == GCM_AES_IV_SIZE)) {
                memcpy(ctx->j0, iv, ivsize);
                ctx->j0[3] = cpu_to_be32(1);
                return atmel_aes_gcm_process(dd);
        }

        padlen = atmel_aes_padlen(ivsize, AES_BLOCK_SIZE);
        datalen = ivsize + padlen + AES_BLOCK_SIZE;
        if (datalen > dd->buflen)
                return atmel_aes_complete(dd, -EINVAL);

        memcpy(data, iv, ivsize);
        memset(data + ivsize, 0, padlen + sizeof(u64));
        ((__be64 *)(data + datalen))[-1] = cpu_to_be64(ivsize * 8);

        return atmel_aes_gcm_ghash(dd, (const u32 *)data, datalen,
                                   NULL, ctx->j0, atmel_aes_gcm_process);
}

static int atmel_aes_gcm_process(struct atmel_aes_dev *dd)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);
        struct aead_request *req = aead_request_cast(dd->areq);
        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
        bool enc = atmel_aes_is_encrypt(dd);
        u32 authsize;

        /* Compute text length. */
        authsize = crypto_aead_authsize(tfm);
        ctx->textlen = req->cryptlen - (enc ? 0 : authsize);

        /*
         * According to tcrypt test suite, the GCM Automatic Tag Generation
         * fails when both the message and its associated data are empty.
         */
        if (likely(req->assoclen != 0 || ctx->textlen != 0))
                dd->flags |= AES_FLAGS_GTAGEN;

        atmel_aes_write_ctrl(dd, false, NULL);
        return atmel_aes_wait_for_data_ready(dd, atmel_aes_gcm_length);
}

static int atmel_aes_gcm_length(struct atmel_aes_dev *dd)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);
        struct aead_request *req = aead_request_cast(dd->areq);
        __be32 j0_lsw, *j0 = ctx->j0;
        size_t padlen;

        /* Write incr32(J0) into IV. */
        j0_lsw = j0[3];
        j0[3] = cpu_to_be32(be32_to_cpu(j0[3]) + 1);
        atmel_aes_write_block(dd, AES_IVR(0), j0);
        j0[3] = j0_lsw;

        /* Set aad and text lengths. */
        atmel_aes_write(dd, AES_AADLENR, req->assoclen);
        atmel_aes_write(dd, AES_CLENR, ctx->textlen);

        /* Check whether AAD are present. */
        if (unlikely(req->assoclen == 0)) {
                dd->datalen = 0;
                return atmel_aes_gcm_data(dd);
        }

        /* Copy assoc data and add padding. */
        padlen = atmel_aes_padlen(req->assoclen, AES_BLOCK_SIZE);
        if (unlikely(req->assoclen + padlen > dd->buflen))
                return atmel_aes_complete(dd, -EINVAL);
        sg_copy_to_buffer(req->src, sg_nents(req->src), dd->buf, req->assoclen);

        /* Write assoc data into the Input Data register. */
        dd->data = (u32 *)dd->buf;
        dd->datalen = req->assoclen + padlen;
        return atmel_aes_gcm_data(dd);
}

static int atmel_aes_gcm_data(struct atmel_aes_dev *dd)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);
        struct aead_request *req = aead_request_cast(dd->areq);
        bool use_dma = (ctx->textlen >= ATMEL_AES_DMA_THRESHOLD);
        struct scatterlist *src, *dst;
        u32 isr, mr;

        /* Write AAD first. */
        while (dd->datalen > 0) {
                atmel_aes_write_block(dd, AES_IDATAR(0), dd->data);
                dd->data += 4;
                dd->datalen -= AES_BLOCK_SIZE;

                isr = atmel_aes_read(dd, AES_ISR);
                if (!(isr & AES_INT_DATARDY)) {
                        dd->resume = atmel_aes_gcm_data;
                        atmel_aes_write(dd, AES_IER, AES_INT_DATARDY);
                        return -EINPROGRESS;
                }
        }

        /* GMAC only. */
        if (unlikely(ctx->textlen == 0))
                return atmel_aes_gcm_tag_init(dd);

        /* Prepare src and dst scatter lists to transfer cipher/plain texts */
        src = scatterwalk_ffwd(ctx->src, req->src, req->assoclen);
        dst = ((req->src == req->dst) ? src :
               scatterwalk_ffwd(ctx->dst, req->dst, req->assoclen));

        if (use_dma) {
                /* Update the Mode Register for DMA transfers. */
                mr = atmel_aes_read(dd, AES_MR);
                mr &= ~(AES_MR_SMOD_MASK | AES_MR_DUALBUFF);
                mr |= AES_MR_SMOD_IDATAR0;
                if (dd->caps.has_dualbuff)
                        mr |= AES_MR_DUALBUFF;
                atmel_aes_write(dd, AES_MR, mr);

                return atmel_aes_dma_start(dd, src, dst, ctx->textlen,
                                           atmel_aes_gcm_tag_init);
        }

        return atmel_aes_cpu_start(dd, src, dst, ctx->textlen,
                                   atmel_aes_gcm_tag_init);
}

static int atmel_aes_gcm_tag_init(struct atmel_aes_dev *dd)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);
        struct aead_request *req = aead_request_cast(dd->areq);
        __be64 *data = dd->buf;

        if (likely(dd->flags & AES_FLAGS_GTAGEN)) {
                if (!(atmel_aes_read(dd, AES_ISR) & AES_INT_TAGRDY)) {
                        dd->resume = atmel_aes_gcm_tag_init;
                        atmel_aes_write(dd, AES_IER, AES_INT_TAGRDY);
                        return -EINPROGRESS;
                }

                return atmel_aes_gcm_finalize(dd);
        }

        /* Read the GCM Intermediate Hash Word Registers. */
        atmel_aes_read_block(dd, AES_GHASHR(0), ctx->ghash);

        data[0] = cpu_to_be64(req->assoclen * 8);
        data[1] = cpu_to_be64(ctx->textlen * 8);

        return atmel_aes_gcm_ghash(dd, (const u32 *)data, AES_BLOCK_SIZE,
                                   ctx->ghash, ctx->ghash, atmel_aes_gcm_tag);
}

static int atmel_aes_gcm_tag(struct atmel_aes_dev *dd)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);
        unsigned long flags;

        /*
         * Change mode to CTR to complete the tag generation.
         * Use J0 as Initialization Vector.
         */
        flags = dd->flags;
        dd->flags &= ~(AES_FLAGS_OPMODE_MASK | AES_FLAGS_GTAGEN);
        dd->flags |= AES_FLAGS_CTR;
        atmel_aes_write_ctrl(dd, false, ctx->j0);
        dd->flags = flags;

        atmel_aes_write_block(dd, AES_IDATAR(0), ctx->ghash);
        return atmel_aes_wait_for_data_ready(dd, atmel_aes_gcm_finalize);
}

static int atmel_aes_gcm_finalize(struct atmel_aes_dev *dd)
{
        struct atmel_aes_gcm_ctx *ctx = atmel_aes_gcm_ctx_cast(dd->ctx);
        struct aead_request *req = aead_request_cast(dd->areq);
        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
        bool enc = atmel_aes_is_encrypt(dd);
        u32 offset, authsize, itag[4], *otag = ctx->tag;
        int err;

        /* Read the computed tag. */
        if (likely(dd->flags & AES_FLAGS_GTAGEN))
                atmel_aes_read_block(dd, AES_TAGR(0), ctx->tag);
        else
                atmel_aes_read_block(dd, AES_ODATAR(0), ctx->tag);

        offset = req->assoclen + ctx->textlen;
        authsize = crypto_aead_authsize(tfm);
        if (enc) {
                scatterwalk_map_and_copy(otag, req->dst, offset, authsize, 1);
                err = 0;
        } else {
                scatterwalk_map_and_copy(itag, req->src, offset, authsize, 0);
                err = crypto_memneq(itag, otag, authsize) ? -EBADMSG : 0;
        }

        return atmel_aes_complete(dd, err);
}

static int atmel_aes_gcm_crypt(struct aead_request *req,
                               unsigned long mode)
{
        struct atmel_aes_base_ctx *ctx;
        struct atmel_aes_reqctx *rctx;
        struct atmel_aes_dev *dd;

        ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
        ctx->block_size = AES_BLOCK_SIZE;
        ctx->is_aead = true;

        dd = atmel_aes_find_dev(ctx);
        if (!dd)
                return -ENODEV;

        rctx = aead_request_ctx(req);
        rctx->mode = AES_FLAGS_GCM | mode;

        return atmel_aes_handle_queue(dd, &req->base);
}

static int atmel_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
                                unsigned int keylen)
{
        struct atmel_aes_base_ctx *ctx = crypto_aead_ctx(tfm);

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

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

        return 0;
}

static int atmel_aes_gcm_setauthsize(struct crypto_aead *tfm,
                                     unsigned int authsize)
{
        return crypto_gcm_check_authsize(authsize);
}

static int atmel_aes_gcm_encrypt(struct aead_request *req)
{
        return atmel_aes_gcm_crypt(req, AES_FLAGS_ENCRYPT);
}

static int atmel_aes_gcm_decrypt(struct aead_request *req)
{
        return atmel_aes_gcm_crypt(req, 0);
}

static int atmel_aes_gcm_init(struct crypto_aead *tfm)
{
        struct atmel_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm);

        crypto_aead_set_reqsize(tfm, sizeof(struct atmel_aes_reqctx));
        ctx->base.start = atmel_aes_gcm_start;

        return 0;
}

static struct aead_alg aes_gcm_alg = {
        .setkey         = atmel_aes_gcm_setkey,
        .setauthsize    = atmel_aes_gcm_setauthsize,
        .encrypt        = atmel_aes_gcm_encrypt,
        .decrypt        = atmel_aes_gcm_decrypt,
        .init           = atmel_aes_gcm_init,
        .ivsize         = GCM_AES_IV_SIZE,
        .maxauthsize    = AES_BLOCK_SIZE,

        .base = {
                .cra_name               = "gcm(aes)",
                .cra_driver_name        = "atmel-gcm-aes",
                .cra_blocksize          = 1,
                .cra_ctxsize            = sizeof(struct atmel_aes_gcm_ctx),
        },
};


/* xts functions */

static inline struct atmel_aes_xts_ctx *
atmel_aes_xts_ctx_cast(struct atmel_aes_base_ctx *ctx)
{
        return container_of(ctx, struct atmel_aes_xts_ctx, base);
}

static int atmel_aes_xts_process_data(struct atmel_aes_dev *dd);

static int atmel_aes_xts_start(struct atmel_aes_dev *dd)
{
        struct atmel_aes_xts_ctx *ctx = atmel_aes_xts_ctx_cast(dd->ctx);
        struct skcipher_request *req = skcipher_request_cast(dd->areq);
        struct atmel_aes_reqctx *rctx = skcipher_request_ctx(req);
        unsigned long flags;
        int err;

        atmel_aes_set_mode(dd, rctx);

        err = atmel_aes_hw_init(dd);
        if (err)
                return atmel_aes_complete(dd, err);

        /* Compute the tweak value from req->iv with ecb(aes). */
        flags = dd->flags;
        dd->flags &= ~AES_FLAGS_MODE_MASK;
        dd->flags |= (AES_FLAGS_ECB | AES_FLAGS_ENCRYPT);
        atmel_aes_write_ctrl_key(dd, false, NULL,
                                 ctx->key2, ctx->base.keylen);
        dd->flags = flags;

        atmel_aes_write_block(dd, AES_IDATAR(0), req->iv);
        return atmel_aes_wait_for_data_ready(dd, atmel_aes_xts_process_data);
}

static int atmel_aes_xts_process_data(struct atmel_aes_dev *dd)
{
        struct skcipher_request *req = skcipher_request_cast(dd->areq);
        bool use_dma = (req->cryptlen >= ATMEL_AES_DMA_THRESHOLD);
        u32 tweak[AES_BLOCK_SIZE / sizeof(u32)];
        static const __le32 one[AES_BLOCK_SIZE / sizeof(u32)] = {cpu_to_le32(1), };
        u8 *tweak_bytes = (u8 *)tweak;
        int i;

        /* Read the computed ciphered tweak value. */
        atmel_aes_read_block(dd, AES_ODATAR(0), tweak);
        /*
         * Hardware quirk:
         * the order of the ciphered tweak bytes need to be reversed before
         * writing them into the ODATARx registers.
         */
        for (i = 0; i < AES_BLOCK_SIZE/2; ++i) {
                u8 tmp = tweak_bytes[AES_BLOCK_SIZE - 1 - i];

                tweak_bytes[AES_BLOCK_SIZE - 1 - i] = tweak_bytes[i];
                tweak_bytes[i] = tmp;
        }

        /* Process the data. */
        atmel_aes_write_ctrl(dd, use_dma, NULL);
        atmel_aes_write_block(dd, AES_TWR(0), tweak);
        atmel_aes_write_block(dd, AES_ALPHAR(0), one);
        if (use_dma)
                return atmel_aes_dma_start(dd, req->src, req->dst,
                                           req->cryptlen,
                                           atmel_aes_transfer_complete);

        return atmel_aes_cpu_start(dd, req->src, req->dst, req->cryptlen,
                                   atmel_aes_transfer_complete);
}

static int atmel_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key,
                                unsigned int keylen)
{
        struct atmel_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
        int err;

        err = xts_check_key(crypto_skcipher_tfm(tfm), key, keylen);
        if (err)
                return err;

        memcpy(ctx->base.key, key, keylen/2);
        memcpy(ctx->key2, key + keylen/2, keylen/2);
        ctx->base.keylen = keylen/2;

        return 0;
}

static int atmel_aes_xts_encrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_XTS | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_xts_decrypt(struct skcipher_request *req)
{
        return atmel_aes_crypt(req, AES_FLAGS_XTS);
}

static int atmel_aes_xts_init_tfm(struct crypto_skcipher *tfm)
{
        struct atmel_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);

        crypto_skcipher_set_reqsize(tfm, sizeof(struct atmel_aes_reqctx));
        ctx->base.start = atmel_aes_xts_start;

        return 0;
}

static struct skcipher_alg aes_xts_alg = {
        .base.cra_name          = "xts(aes)",
        .base.cra_driver_name   = "atmel-xts-aes",
        .base.cra_blocksize     = AES_BLOCK_SIZE,
        .base.cra_ctxsize       = sizeof(struct atmel_aes_xts_ctx),

        .min_keysize            = 2 * AES_MIN_KEY_SIZE,
        .max_keysize            = 2 * AES_MAX_KEY_SIZE,
        .ivsize                 = AES_BLOCK_SIZE,
        .setkey                 = atmel_aes_xts_setkey,
        .encrypt                = atmel_aes_xts_encrypt,
        .decrypt                = atmel_aes_xts_decrypt,
        .init                   = atmel_aes_xts_init_tfm,
};

#if IS_ENABLED(CONFIG_CRYPTO_DEV_ATMEL_AUTHENC)
/* authenc aead functions */

static int atmel_aes_authenc_start(struct atmel_aes_dev *dd);
static int atmel_aes_authenc_init(struct atmel_aes_dev *dd, int err,
                                  bool is_async);
static int atmel_aes_authenc_transfer(struct atmel_aes_dev *dd, int err,
                                      bool is_async);
static int atmel_aes_authenc_digest(struct atmel_aes_dev *dd);
static int atmel_aes_authenc_final(struct atmel_aes_dev *dd, int err,
                                   bool is_async);

static void atmel_aes_authenc_complete(struct atmel_aes_dev *dd, int err)
{
        struct aead_request *req = aead_request_cast(dd->areq);
        struct atmel_aes_authenc_reqctx *rctx = aead_request_ctx(req);

        if (err && (dd->flags & AES_FLAGS_OWN_SHA))
                atmel_sha_authenc_abort(&rctx->auth_req);
        dd->flags &= ~AES_FLAGS_OWN_SHA;
}

static int atmel_aes_authenc_start(struct atmel_aes_dev *dd)
{
        struct aead_request *req = aead_request_cast(dd->areq);
        struct atmel_aes_authenc_reqctx *rctx = aead_request_ctx(req);
        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
        struct atmel_aes_authenc_ctx *ctx = crypto_aead_ctx(tfm);
        int err;

        atmel_aes_set_mode(dd, &rctx->base);

        err = atmel_aes_hw_init(dd);
        if (err)
                return atmel_aes_complete(dd, err);

        return atmel_sha_authenc_schedule(&rctx->auth_req, ctx->auth,
                                          atmel_aes_authenc_init, dd);
}

static int atmel_aes_authenc_init(struct atmel_aes_dev *dd, int err,
                                  bool is_async)
{
        struct aead_request *req = aead_request_cast(dd->areq);
        struct atmel_aes_authenc_reqctx *rctx = aead_request_ctx(req);

        if (is_async)
                dd->is_async = true;
        if (err)
                return atmel_aes_complete(dd, err);

        /* If here, we've got the ownership of the SHA device. */
        dd->flags |= AES_FLAGS_OWN_SHA;

        /* Configure the SHA device. */
        return atmel_sha_authenc_init(&rctx->auth_req,
                                      req->src, req->assoclen,
                                      rctx->textlen,
                                      atmel_aes_authenc_transfer, dd);
}

static int atmel_aes_authenc_transfer(struct atmel_aes_dev *dd, int err,
                                      bool is_async)
{
        struct aead_request *req = aead_request_cast(dd->areq);
        struct atmel_aes_authenc_reqctx *rctx = aead_request_ctx(req);
        bool enc = atmel_aes_is_encrypt(dd);
        struct scatterlist *src, *dst;
        __be32 iv[AES_BLOCK_SIZE / sizeof(u32)];
        u32 emr;

        if (is_async)
                dd->is_async = true;
        if (err)
                return atmel_aes_complete(dd, err);

        /* Prepare src and dst scatter-lists to transfer cipher/plain texts. */
        src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen);
        dst = src;

        if (req->src != req->dst)
                dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen);

        /* Configure the AES device. */
        memcpy(iv, req->iv, sizeof(iv));

        /*
         * Here we always set the 2nd parameter of atmel_aes_write_ctrl() to
         * 'true' even if the data transfer is actually performed by the CPU (so
         * not by the DMA) because we must force the AES_MR_SMOD bitfield to the
         * value AES_MR_SMOD_IDATAR0. Indeed, both AES_MR_SMOD and SHA_MR_SMOD
         * must be set to *_MR_SMOD_IDATAR0.
         */
        atmel_aes_write_ctrl(dd, true, iv);
        emr = AES_EMR_PLIPEN;
        if (!enc)
                emr |= AES_EMR_PLIPD;
        atmel_aes_write(dd, AES_EMR, emr);

        /* Transfer data. */
        return atmel_aes_dma_start(dd, src, dst, rctx->textlen,
                                   atmel_aes_authenc_digest);
}

static int atmel_aes_authenc_digest(struct atmel_aes_dev *dd)
{
        struct aead_request *req = aead_request_cast(dd->areq);

        struct atmel_aes_authenc_reqctx *rctx = aead_request_ctx(req);

        /* atmel_sha_authenc_final() releases the SHA device. */
        dd->flags &= ~AES_FLAGS_OWN_SHA;
        return atmel_sha_authenc_final(&rctx->auth_req,
                                       rctx->digest, sizeof(rctx->digest),
                                       atmel_aes_authenc_final, dd);
}

static int atmel_aes_authenc_final(struct atmel_aes_dev *dd, int err,
                                   bool is_async)
{
        struct aead_request *req = aead_request_cast(dd->areq);
        struct atmel_aes_authenc_reqctx *rctx = aead_request_ctx(req);
        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
        bool enc = atmel_aes_is_encrypt(dd);
        u32 idigest[SHA512_DIGEST_SIZE / sizeof(u32)], *odigest = rctx->digest;
        u32 offs, authsize;

        if (is_async)
                dd->is_async = true;
        if (err)
                goto complete;

        offs = req->assoclen + rctx->textlen;
        authsize = crypto_aead_authsize(tfm);
        if (enc) {
                scatterwalk_map_and_copy(odigest, req->dst, offs, authsize, 1);
        } else {
                scatterwalk_map_and_copy(idigest, req->src, offs, authsize, 0);
                if (crypto_memneq(idigest, odigest, authsize))
                        err = -EBADMSG;
        }

complete:
        return atmel_aes_complete(dd, err);
}

static int atmel_aes_authenc_setkey(struct crypto_aead *tfm, const u8 *key,
                                    unsigned int keylen)
{
        struct atmel_aes_authenc_ctx *ctx = crypto_aead_ctx(tfm);
        struct crypto_authenc_keys keys;
        int err;

        if (crypto_authenc_extractkeys(&keys, key, keylen) != 0)
                goto badkey;

        if (keys.enckeylen > sizeof(ctx->base.key))
                goto badkey;

        /* Save auth key. */
        err = atmel_sha_authenc_setkey(ctx->auth,
                                       keys.authkey, keys.authkeylen,
                                       crypto_aead_get_flags(tfm));
        if (err) {
                memzero_explicit(&keys, sizeof(keys));
                return err;
        }

        /* Save enc key. */
        ctx->base.keylen = keys.enckeylen;
        memcpy(ctx->base.key, keys.enckey, keys.enckeylen);

        memzero_explicit(&keys, sizeof(keys));
        return 0;

badkey:
        memzero_explicit(&keys, sizeof(keys));
        return -EINVAL;
}

static int atmel_aes_authenc_init_tfm(struct crypto_aead *tfm,
                                      unsigned long auth_mode)
{
        struct atmel_aes_authenc_ctx *ctx = crypto_aead_ctx(tfm);
        unsigned int auth_reqsize = atmel_sha_authenc_get_reqsize();

        ctx->auth = atmel_sha_authenc_spawn(auth_mode);
        if (IS_ERR(ctx->auth))
                return PTR_ERR(ctx->auth);

        crypto_aead_set_reqsize(tfm, (sizeof(struct atmel_aes_authenc_reqctx) +
                                      auth_reqsize));
        ctx->base.start = atmel_aes_authenc_start;

        return 0;
}

static int atmel_aes_authenc_hmac_sha1_init_tfm(struct crypto_aead *tfm)
{
        return atmel_aes_authenc_init_tfm(tfm, SHA_FLAGS_HMAC_SHA1);
}

static int atmel_aes_authenc_hmac_sha224_init_tfm(struct crypto_aead *tfm)
{
        return atmel_aes_authenc_init_tfm(tfm, SHA_FLAGS_HMAC_SHA224);
}

static int atmel_aes_authenc_hmac_sha256_init_tfm(struct crypto_aead *tfm)
{
        return atmel_aes_authenc_init_tfm(tfm, SHA_FLAGS_HMAC_SHA256);
}

static int atmel_aes_authenc_hmac_sha384_init_tfm(struct crypto_aead *tfm)
{
        return atmel_aes_authenc_init_tfm(tfm, SHA_FLAGS_HMAC_SHA384);
}

static int atmel_aes_authenc_hmac_sha512_init_tfm(struct crypto_aead *tfm)
{
        return atmel_aes_authenc_init_tfm(tfm, SHA_FLAGS_HMAC_SHA512);
}

static void atmel_aes_authenc_exit_tfm(struct crypto_aead *tfm)
{
        struct atmel_aes_authenc_ctx *ctx = crypto_aead_ctx(tfm);

        atmel_sha_authenc_free(ctx->auth);
}

static int atmel_aes_authenc_crypt(struct aead_request *req,
                                   unsigned long mode)
{
        struct atmel_aes_authenc_reqctx *rctx = aead_request_ctx(req);
        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
        struct atmel_aes_base_ctx *ctx = crypto_aead_ctx(tfm);
        u32 authsize = crypto_aead_authsize(tfm);
        bool enc = (mode & AES_FLAGS_ENCRYPT);
        struct atmel_aes_dev *dd;

        /* Compute text length. */
        if (!enc && req->cryptlen < authsize)
                return -EINVAL;
        rctx->textlen = req->cryptlen - (enc ? 0 : authsize);

        /*
         * Currently, empty messages are not supported yet:
         * the SHA auto-padding can be used only on non-empty messages.
         * Hence a special case needs to be implemented for empty message.
         */
        if (!rctx->textlen && !req->assoclen)
                return -EINVAL;

        rctx->base.mode = mode;
        ctx->block_size = AES_BLOCK_SIZE;
        ctx->is_aead = true;

        dd = atmel_aes_find_dev(ctx);
        if (!dd)
                return -ENODEV;

        return atmel_aes_handle_queue(dd, &req->base);
}

static int atmel_aes_authenc_cbc_aes_encrypt(struct aead_request *req)
{
        return atmel_aes_authenc_crypt(req, AES_FLAGS_CBC | AES_FLAGS_ENCRYPT);
}

static int atmel_aes_authenc_cbc_aes_decrypt(struct aead_request *req)
{
        return atmel_aes_authenc_crypt(req, AES_FLAGS_CBC);
}

static struct aead_alg aes_authenc_algs[] = {
{
        .setkey         = atmel_aes_authenc_setkey,
        .encrypt        = atmel_aes_authenc_cbc_aes_encrypt,
        .decrypt        = atmel_aes_authenc_cbc_aes_decrypt,
        .init           = atmel_aes_authenc_hmac_sha1_init_tfm,
        .exit           = atmel_aes_authenc_exit_tfm,
        .ivsize         = AES_BLOCK_SIZE,
        .maxauthsize    = SHA1_DIGEST_SIZE,

        .base = {
                .cra_name               = "authenc(hmac(sha1),cbc(aes))",
                .cra_driver_name        = "atmel-authenc-hmac-sha1-cbc-aes",
                .cra_blocksize          = AES_BLOCK_SIZE,
                .cra_ctxsize            = sizeof(struct atmel_aes_authenc_ctx),
        },
},
{
        .setkey         = atmel_aes_authenc_setkey,
        .encrypt        = atmel_aes_authenc_cbc_aes_encrypt,
        .decrypt        = atmel_aes_authenc_cbc_aes_decrypt,
        .init           = atmel_aes_authenc_hmac_sha224_init_tfm,
        .exit           = atmel_aes_authenc_exit_tfm,
        .ivsize         = AES_BLOCK_SIZE,
        .maxauthsize    = SHA224_DIGEST_SIZE,

        .base = {
                .cra_name               = "authenc(hmac(sha224),cbc(aes))",
                .cra_driver_name        = "atmel-authenc-hmac-sha224-cbc-aes",
                .cra_blocksize          = AES_BLOCK_SIZE,
                .cra_ctxsize            = sizeof(struct atmel_aes_authenc_ctx),
        },
},
{
        .setkey         = atmel_aes_authenc_setkey,
        .encrypt        = atmel_aes_authenc_cbc_aes_encrypt,
        .decrypt        = atmel_aes_authenc_cbc_aes_decrypt,
        .init           = atmel_aes_authenc_hmac_sha256_init_tfm,
        .exit           = atmel_aes_authenc_exit_tfm,
        .ivsize         = AES_BLOCK_SIZE,
        .maxauthsize    = SHA256_DIGEST_SIZE,

        .base = {
                .cra_name               = "authenc(hmac(sha256),cbc(aes))",
                .cra_driver_name        = "atmel-authenc-hmac-sha256-cbc-aes",
                .cra_blocksize          = AES_BLOCK_SIZE,
                .cra_ctxsize            = sizeof(struct atmel_aes_authenc_ctx),
        },
},
{
        .setkey         = atmel_aes_authenc_setkey,
        .encrypt        = atmel_aes_authenc_cbc_aes_encrypt,
        .decrypt        = atmel_aes_authenc_cbc_aes_decrypt,
        .init           = atmel_aes_authenc_hmac_sha384_init_tfm,
        .exit           = atmel_aes_authenc_exit_tfm,
        .ivsize         = AES_BLOCK_SIZE,
        .maxauthsize    = SHA384_DIGEST_SIZE,

        .base = {
                .cra_name               = "authenc(hmac(sha384),cbc(aes))",
                .cra_driver_name        = "atmel-authenc-hmac-sha384-cbc-aes",
                .cra_blocksize          = AES_BLOCK_SIZE,
                .cra_ctxsize            = sizeof(struct atmel_aes_authenc_ctx),
        },
},
{
        .setkey         = atmel_aes_authenc_setkey,
        .encrypt        = atmel_aes_authenc_cbc_aes_encrypt,
        .decrypt        = atmel_aes_authenc_cbc_aes_decrypt,
        .init           = atmel_aes_authenc_hmac_sha512_init_tfm,
        .exit           = atmel_aes_authenc_exit_tfm,
        .ivsize         = AES_BLOCK_SIZE,
        .maxauthsize    = SHA512_DIGEST_SIZE,

        .base = {
                .cra_name               = "authenc(hmac(sha512),cbc(aes))",
                .cra_driver_name        = "atmel-authenc-hmac-sha512-cbc-aes",
                .cra_blocksize          = AES_BLOCK_SIZE,
                .cra_ctxsize            = sizeof(struct atmel_aes_authenc_ctx),
        },
},
};
#endif /* CONFIG_CRYPTO_DEV_ATMEL_AUTHENC */

/* Probe functions */

static int atmel_aes_buff_init(struct atmel_aes_dev *dd)
{
        dd->buf = (void *)__get_free_pages(GFP_KERNEL, ATMEL_AES_BUFFER_ORDER);
        dd->buflen = ATMEL_AES_BUFFER_SIZE;
        dd->buflen &= ~(AES_BLOCK_SIZE - 1);

        if (!dd->buf) {
                dev_err(dd->dev, "unable to alloc pages.\n");
                return -ENOMEM;
        }

        return 0;
}

static void atmel_aes_buff_cleanup(struct atmel_aes_dev *dd)
{
        free_page((unsigned long)dd->buf);
}

static int atmel_aes_dma_init(struct atmel_aes_dev *dd)
{
        int ret;

        /* Try to grab 2 DMA channels */
        dd->src.chan = dma_request_chan(dd->dev, "tx");
        if (IS_ERR(dd->src.chan)) {
                ret = PTR_ERR(dd->src.chan);
                goto err_dma_in;
        }

        dd->dst.chan = dma_request_chan(dd->dev, "rx");
        if (IS_ERR(dd->dst.chan)) {
                ret = PTR_ERR(dd->dst.chan);
                goto err_dma_out;
        }

        return 0;

err_dma_out:
        dma_release_channel(dd->src.chan);
err_dma_in:
        dev_err(dd->dev, "no DMA channel available\n");
        return ret;
}

static void atmel_aes_dma_cleanup(struct atmel_aes_dev *dd)
{
        dma_release_channel(dd->dst.chan);
        dma_release_channel(dd->src.chan);
}

static void atmel_aes_queue_task(unsigned long data)
{
        struct atmel_aes_dev *dd = (struct atmel_aes_dev *)data;

        atmel_aes_handle_queue(dd, NULL);
}

static void atmel_aes_done_task(unsigned long data)
{
        struct atmel_aes_dev *dd = (struct atmel_aes_dev *)data;

        dd->is_async = true;
        (void)dd->resume(dd);
}

static irqreturn_t atmel_aes_irq(int irq, void *dev_id)
{
        struct atmel_aes_dev *aes_dd = dev_id;
        u32 reg;

        reg = atmel_aes_read(aes_dd, AES_ISR);
        if (reg & atmel_aes_read(aes_dd, AES_IMR)) {
                atmel_aes_write(aes_dd, AES_IDR, reg);
                if (AES_FLAGS_BUSY & aes_dd->flags)
                        tasklet_schedule(&aes_dd->done_task);
                else
                        dev_warn(aes_dd->dev, "AES interrupt when no active requests.\n");
                return IRQ_HANDLED;
        }

        return IRQ_NONE;
}

static void atmel_aes_unregister_algs(struct atmel_aes_dev *dd)
{
        int i;

#if IS_ENABLED(CONFIG_CRYPTO_DEV_ATMEL_AUTHENC)
        if (dd->caps.has_authenc)
                for (i = 0; i < ARRAY_SIZE(aes_authenc_algs); i++)
                        crypto_unregister_aead(&aes_authenc_algs[i]);
#endif

        if (dd->caps.has_xts)
                crypto_unregister_skcipher(&aes_xts_alg);

        if (dd->caps.has_gcm)
                crypto_unregister_aead(&aes_gcm_alg);

        if (dd->caps.has_cfb64)
                crypto_unregister_skcipher(&aes_cfb64_alg);

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

static void atmel_aes_crypto_alg_init(struct crypto_alg *alg)
{
        alg->cra_flags = CRYPTO_ALG_ASYNC;
        alg->cra_alignmask = 0xf;
        alg->cra_priority = ATMEL_AES_PRIORITY;
        alg->cra_module = THIS_MODULE;
}

static int atmel_aes_register_algs(struct atmel_aes_dev *dd)
{
        int err, i, j;

        for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
                atmel_aes_crypto_alg_init(&aes_algs[i].base);

                err = crypto_register_skcipher(&aes_algs[i]);
                if (err)
                        goto err_aes_algs;
        }

        if (dd->caps.has_cfb64) {
                atmel_aes_crypto_alg_init(&aes_cfb64_alg.base);

                err = crypto_register_skcipher(&aes_cfb64_alg);
                if (err)
                        goto err_aes_cfb64_alg;
        }

        if (dd->caps.has_gcm) {
                atmel_aes_crypto_alg_init(&aes_gcm_alg.base);

                err = crypto_register_aead(&aes_gcm_alg);
                if (err)
                        goto err_aes_gcm_alg;
        }

        if (dd->caps.has_xts) {
                atmel_aes_crypto_alg_init(&aes_xts_alg.base);

                err = crypto_register_skcipher(&aes_xts_alg);
                if (err)
                        goto err_aes_xts_alg;
        }

#if IS_ENABLED(CONFIG_CRYPTO_DEV_ATMEL_AUTHENC)
        if (dd->caps.has_authenc) {
                for (i = 0; i < ARRAY_SIZE(aes_authenc_algs); i++) {
                        atmel_aes_crypto_alg_init(&aes_authenc_algs[i].base);

                        err = crypto_register_aead(&aes_authenc_algs[i]);
                        if (err)
                                goto err_aes_authenc_alg;
                }
        }
#endif

        return 0;

#if IS_ENABLED(CONFIG_CRYPTO_DEV_ATMEL_AUTHENC)
        /* i = ARRAY_SIZE(aes_authenc_algs); */
err_aes_authenc_alg:
        for (j = 0; j < i; j++)
                crypto_unregister_aead(&aes_authenc_algs[j]);
        crypto_unregister_skcipher(&aes_xts_alg);
#endif
err_aes_xts_alg:
        crypto_unregister_aead(&aes_gcm_alg);
err_aes_gcm_alg:
        crypto_unregister_skcipher(&aes_cfb64_alg);
err_aes_cfb64_alg:
        i = ARRAY_SIZE(aes_algs);
err_aes_algs:
        for (j = 0; j < i; j++)
                crypto_unregister_skcipher(&aes_algs[j]);

        return err;
}

static void atmel_aes_get_cap(struct atmel_aes_dev *dd)
{
        dd->caps.has_dualbuff = 0;
        dd->caps.has_cfb64 = 0;
        dd->caps.has_gcm = 0;
        dd->caps.has_xts = 0;
        dd->caps.has_authenc = 0;
        dd->caps.max_burst_size = 1;

        /* keep only major version number */
        switch (dd->hw_version & 0xff0) {
        case 0x500:
                dd->caps.has_dualbuff = 1;
                dd->caps.has_cfb64 = 1;
                dd->caps.has_gcm = 1;
                dd->caps.has_xts = 1;
                dd->caps.has_authenc = 1;
                dd->caps.max_burst_size = 4;
                break;
        case 0x200:
                dd->caps.has_dualbuff = 1;
                dd->caps.has_cfb64 = 1;
                dd->caps.has_gcm = 1;
                dd->caps.max_burst_size = 4;
                break;
        case 0x130:
                dd->caps.has_dualbuff = 1;
                dd->caps.has_cfb64 = 1;
                dd->caps.max_burst_size = 4;
                break;
        case 0x120:
                break;
        default:
                dev_warn(dd->dev,
                                "Unmanaged aes version, set minimum capabilities\n");
                break;
        }
}

#if defined(CONFIG_OF)
static const struct of_device_id atmel_aes_dt_ids[] = {
        { .compatible = "atmel,at91sam9g46-aes" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, atmel_aes_dt_ids);
#endif

static int atmel_aes_probe(struct platform_device *pdev)
{
        struct atmel_aes_dev *aes_dd;
        struct device *dev = &pdev->dev;
        struct resource *aes_res;
        int err;

        aes_dd = devm_kzalloc(&pdev->dev, sizeof(*aes_dd), GFP_KERNEL);
        if (!aes_dd)
                return -ENOMEM;

        aes_dd->dev = dev;

        platform_set_drvdata(pdev, aes_dd);

        INIT_LIST_HEAD(&aes_dd->list);
        spin_lock_init(&aes_dd->lock);

        tasklet_init(&aes_dd->done_task, atmel_aes_done_task,
                                        (unsigned long)aes_dd);
        tasklet_init(&aes_dd->queue_task, atmel_aes_queue_task,
                                        (unsigned long)aes_dd);

        crypto_init_queue(&aes_dd->queue, ATMEL_AES_QUEUE_LENGTH);

        /* Get the base address */
        aes_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!aes_res) {
                dev_err(dev, "no MEM resource info\n");
                err = -ENODEV;
                goto err_tasklet_kill;
        }
        aes_dd->phys_base = aes_res->start;

        /* Get the IRQ */
        aes_dd->irq = platform_get_irq(pdev,  0);
        if (aes_dd->irq < 0) {
                err = aes_dd->irq;
                goto err_tasklet_kill;
        }

        err = devm_request_irq(&pdev->dev, aes_dd->irq, atmel_aes_irq,
                               IRQF_SHARED, "atmel-aes", aes_dd);
        if (err) {
                dev_err(dev, "unable to request aes irq.\n");
                goto err_tasklet_kill;
        }

        /* Initializing the clock */
        aes_dd->iclk = devm_clk_get(&pdev->dev, "aes_clk");
        if (IS_ERR(aes_dd->iclk)) {
                dev_err(dev, "clock initialization failed.\n");
                err = PTR_ERR(aes_dd->iclk);
                goto err_tasklet_kill;
        }

        aes_dd->io_base = devm_ioremap_resource(&pdev->dev, aes_res);
        if (IS_ERR(aes_dd->io_base)) {
                dev_err(dev, "can't ioremap\n");
                err = PTR_ERR(aes_dd->io_base);
                goto err_tasklet_kill;
        }

        err = clk_prepare(aes_dd->iclk);
        if (err)
                goto err_tasklet_kill;

        err = atmel_aes_hw_version_init(aes_dd);
        if (err)
                goto err_iclk_unprepare;

        atmel_aes_get_cap(aes_dd);

#if IS_ENABLED(CONFIG_CRYPTO_DEV_ATMEL_AUTHENC)
        if (aes_dd->caps.has_authenc && !atmel_sha_authenc_is_ready()) {
                err = -EPROBE_DEFER;
                goto err_iclk_unprepare;
        }
#endif

        err = atmel_aes_buff_init(aes_dd);
        if (err)
                goto err_iclk_unprepare;

        err = atmel_aes_dma_init(aes_dd);
        if (err)
                goto err_buff_cleanup;

        spin_lock(&atmel_aes.lock);
        list_add_tail(&aes_dd->list, &atmel_aes.dev_list);
        spin_unlock(&atmel_aes.lock);

        err = atmel_aes_register_algs(aes_dd);
        if (err)
                goto err_algs;

        dev_info(dev, "Atmel AES - Using %s, %s for DMA transfers\n",
                        dma_chan_name(aes_dd->src.chan),
                        dma_chan_name(aes_dd->dst.chan));

        return 0;

err_algs:
        spin_lock(&atmel_aes.lock);
        list_del(&aes_dd->list);
        spin_unlock(&atmel_aes.lock);
        atmel_aes_dma_cleanup(aes_dd);
err_buff_cleanup:
        atmel_aes_buff_cleanup(aes_dd);
err_iclk_unprepare:
        clk_unprepare(aes_dd->iclk);
err_tasklet_kill:
        tasklet_kill(&aes_dd->done_task);
        tasklet_kill(&aes_dd->queue_task);

        return err;
}

static int atmel_aes_remove(struct platform_device *pdev)
{
        struct atmel_aes_dev *aes_dd;

        aes_dd = platform_get_drvdata(pdev);
        if (!aes_dd)
                return -ENODEV;
        spin_lock(&atmel_aes.lock);
        list_del(&aes_dd->list);
        spin_unlock(&atmel_aes.lock);

        atmel_aes_unregister_algs(aes_dd);

        tasklet_kill(&aes_dd->done_task);
        tasklet_kill(&aes_dd->queue_task);

        atmel_aes_dma_cleanup(aes_dd);
        atmel_aes_buff_cleanup(aes_dd);

        clk_unprepare(aes_dd->iclk);

        return 0;
}

static struct platform_driver atmel_aes_driver = {
        .probe          = atmel_aes_probe,
        .remove         = atmel_aes_remove,
        .driver         = {
                .name   = "atmel_aes",
                .of_match_table = of_match_ptr(atmel_aes_dt_ids),
        },
};

module_platform_driver(atmel_aes_driver);

MODULE_DESCRIPTION("Atmel AES hw acceleration support.");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Nicolas Royer - Eukréa Electromatique");