// SPDX-License-Identifier: GPL-2.0
/*
 * Cryptographic API.
 *
 * Support for ATMEL SHA1/SHA256 HW acceleration.
 *
 * Copyright (c) 2012 Eukréa Electromatique - ATMEL
 * Author: Nicolas Royer <nicolas@eukrea.com>
 *
 * Some ideas are from omap-sham.c drivers.
 */


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

#include <linux/device.h>
#include <linux/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 <linux/cryptohash.h>
#include <crypto/scatterwalk.h>
#include <crypto/algapi.h>
#include <crypto/sha.h>
#include <crypto/hash.h>
#include <crypto/internal/hash.h>
#include "atmel-sha-regs.h"
#include "atmel-authenc.h"

#define ATMEL_SHA_PRIORITY      300

/* SHA flags */
#define SHA_FLAGS_BUSY                  BIT(0)
#define SHA_FLAGS_FINAL                 BIT(1)
#define SHA_FLAGS_DMA_ACTIVE    BIT(2)
#define SHA_FLAGS_OUTPUT_READY  BIT(3)
#define SHA_FLAGS_INIT                  BIT(4)
#define SHA_FLAGS_CPU                   BIT(5)
#define SHA_FLAGS_DMA_READY             BIT(6)
#define SHA_FLAGS_DUMP_REG      BIT(7)

/* bits[11:8] are reserved. */

#define SHA_FLAGS_FINUP         BIT(16)
#define SHA_FLAGS_SG            BIT(17)
#define SHA_FLAGS_ERROR         BIT(23)
#define SHA_FLAGS_PAD           BIT(24)
#define SHA_FLAGS_RESTORE       BIT(25)
#define SHA_FLAGS_IDATAR0       BIT(26)
#define SHA_FLAGS_WAIT_DATARDY  BIT(27)

#define SHA_OP_INIT     0
#define SHA_OP_UPDATE   1
#define SHA_OP_FINAL    2
#define SHA_OP_DIGEST   3

#define SHA_BUFFER_LEN          (PAGE_SIZE / 16)

#define ATMEL_SHA_DMA_THRESHOLD         56

struct atmel_sha_caps {
        bool    has_dma;
        bool    has_dualbuff;
        bool    has_sha224;
        bool    has_sha_384_512;
        bool    has_uihv;
        bool    has_hmac;
};

struct atmel_sha_dev;

/*
 * .statesize = sizeof(struct atmel_sha_reqctx) must be <= PAGE_SIZE / 8 as
 * tested by the ahash_prepare_alg() function.
 */
struct atmel_sha_reqctx {
        struct atmel_sha_dev    *dd;
        unsigned long   flags;
        unsigned long   op;

        u8      digest[SHA512_DIGEST_SIZE] __aligned(sizeof(u32));
        u64     digcnt[2];
        size_t  bufcnt;
        size_t  buflen;
        dma_addr_t      dma_addr;

        /* walk state */
        struct scatterlist      *sg;
        unsigned int    offset; /* offset in current sg */
        unsigned int    total;  /* total request */

        size_t block_size;
        size_t hash_size;

        u8 buffer[SHA_BUFFER_LEN + SHA512_BLOCK_SIZE] __aligned(sizeof(u32));
};

typedef int (*atmel_sha_fn_t)(struct atmel_sha_dev *);

struct atmel_sha_ctx {
        struct atmel_sha_dev    *dd;
        atmel_sha_fn_t          start;

        unsigned long           flags;
};

#define ATMEL_SHA_QUEUE_LENGTH  50

struct atmel_sha_dma {
        struct dma_chan                 *chan;
        struct dma_slave_config dma_conf;
        struct scatterlist      *sg;
        int                     nents;
        unsigned int            last_sg_length;
};

struct atmel_sha_dev {
        struct list_head        list;
        unsigned long           phys_base;
        struct device           *dev;
        struct clk                      *iclk;
        int                                     irq;
        void __iomem            *io_base;

        spinlock_t              lock;
        struct tasklet_struct   done_task;
        struct tasklet_struct   queue_task;

        unsigned long           flags;
        struct crypto_queue     queue;
        struct ahash_request    *req;
        bool                    is_async;
        bool                    force_complete;
        atmel_sha_fn_t          resume;
        atmel_sha_fn_t          cpu_transfer_complete;

        struct atmel_sha_dma    dma_lch_in;

        struct atmel_sha_caps   caps;

        struct scatterlist      tmp;

        u32     hw_version;
};

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

static struct atmel_sha_drv atmel_sha = {
        .dev_list = LIST_HEAD_INIT(atmel_sha.dev_list),
        .lock = __SPIN_LOCK_UNLOCKED(atmel_sha.lock),
};

#ifdef VERBOSE_DEBUG
static const char *atmel_sha_reg_name(u32 offset, char *tmp, size_t sz, bool wr)
{
        switch (offset) {
        case SHA_CR:
                return "CR";

        case SHA_MR:
                return "MR";

        case SHA_IER:
                return "IER";

        case SHA_IDR:
                return "IDR";

        case SHA_IMR:
                return "IMR";

        case SHA_ISR:
                return "ISR";

        case SHA_MSR:
                return "MSR";

        case SHA_BCR:
                return "BCR";

        case SHA_REG_DIN(0):
        case SHA_REG_DIN(1):
        case SHA_REG_DIN(2):
        case SHA_REG_DIN(3):
        case SHA_REG_DIN(4):
        case SHA_REG_DIN(5):
        case SHA_REG_DIN(6):
        case SHA_REG_DIN(7):
        case SHA_REG_DIN(8):
        case SHA_REG_DIN(9):
        case SHA_REG_DIN(10):
        case SHA_REG_DIN(11):
        case SHA_REG_DIN(12):
        case SHA_REG_DIN(13):
        case SHA_REG_DIN(14):
        case SHA_REG_DIN(15):
                snprintf(tmp, sz, "IDATAR[%u]", (offset - SHA_REG_DIN(0)) >> 2);
                break;

        case SHA_REG_DIGEST(0):
        case SHA_REG_DIGEST(1):
        case SHA_REG_DIGEST(2):
        case SHA_REG_DIGEST(3):
        case SHA_REG_DIGEST(4):
        case SHA_REG_DIGEST(5):
        case SHA_REG_DIGEST(6):
        case SHA_REG_DIGEST(7):
        case SHA_REG_DIGEST(8):
        case SHA_REG_DIGEST(9):
        case SHA_REG_DIGEST(10):
        case SHA_REG_DIGEST(11):
        case SHA_REG_DIGEST(12):
        case SHA_REG_DIGEST(13):
        case SHA_REG_DIGEST(14):
        case SHA_REG_DIGEST(15):
                if (wr)
                        snprintf(tmp, sz, "IDATAR[%u]",
                                 16u + ((offset - SHA_REG_DIGEST(0)) >> 2));
                else
                        snprintf(tmp, sz, "ODATAR[%u]",
                                 (offset - SHA_REG_DIGEST(0)) >> 2);
                break;

        case SHA_HW_VERSION:
                return "HWVER";

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

        return tmp;
}

#endif /* VERBOSE_DEBUG */

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

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

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

        return value;
}

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

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

        writel_relaxed(value, dd->io_base + offset);
}

static inline int atmel_sha_complete(struct atmel_sha_dev *dd, int err)
{
        struct ahash_request *req = dd->req;

        dd->flags &= ~(SHA_FLAGS_BUSY | SHA_FLAGS_FINAL | SHA_FLAGS_CPU |
                       SHA_FLAGS_DMA_READY | SHA_FLAGS_OUTPUT_READY |
                       SHA_FLAGS_DUMP_REG);

        clk_disable(dd->iclk);

        if ((dd->is_async || dd->force_complete) && req->base.complete)
                req->base.complete(&req->base, err);

        /* handle new request */
        tasklet_schedule(&dd->queue_task);

        return err;
}

static size_t atmel_sha_append_sg(struct atmel_sha_reqctx *ctx)
{
        size_t count;

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

                if (count <= 0) {
                        /*
                        * Check if count <= 0 because the buffer is full or
                        * because the sg length is 0. In the latest case,
                        * check if there is another sg in the list, a 0 length
                        * sg doesn't necessarily mean the end of the sg list.
                        */
                        if ((ctx->sg->length == 0) && !sg_is_last(ctx->sg)) {
                                ctx->sg = sg_next(ctx->sg);
                                continue;
                        } else {
                                break;
                        }
                }

                scatterwalk_map_and_copy(ctx->buffer + ctx->bufcnt, ctx->sg,
                        ctx->offset, count, 0);

                ctx->bufcnt += count;
                ctx->offset += count;
                ctx->total -= count;

                if (ctx->offset == ctx->sg->length) {
                        ctx->sg = sg_next(ctx->sg);
                        if (ctx->sg)
                                ctx->offset = 0;
                        else
                                ctx->total = 0;
                }
        }

        return 0;
}

/*
 * The purpose of this padding is to ensure that the padded message is a
 * multiple of 512 bits (SHA1/SHA224/SHA256) or 1024 bits (SHA384/SHA512).
 * The bit "1" is appended at the end of the message followed by
 * "padlen-1" zero bits. Then a 64 bits block (SHA1/SHA224/SHA256) or
 * 128 bits block (SHA384/SHA512) equals to the message length in bits
 * is appended.
 *
 * For SHA1/SHA224/SHA256, padlen is calculated as followed:
 *  - if message length < 56 bytes then padlen = 56 - message length
 *  - else padlen = 64 + 56 - message length
 *
 * For SHA384/SHA512, padlen is calculated as followed:
 *  - if message length < 112 bytes then padlen = 112 - message length
 *  - else padlen = 128 + 112 - message length
 */
static void atmel_sha_fill_padding(struct atmel_sha_reqctx *ctx, int length)
{
        unsigned int index, padlen;
        __be64 bits[2];
        u64 size[2];

        size[0] = ctx->digcnt[0];
        size[1] = ctx->digcnt[1];

        size[0] += ctx->bufcnt;
        if (size[0] < ctx->bufcnt)
                size[1]++;

        size[0] += length;
        if (size[0]  < length)
                size[1]++;

        bits[1] = cpu_to_be64(size[0] << 3);
        bits[0] = cpu_to_be64(size[1] << 3 | size[0] >> 61);

        switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
        case SHA_FLAGS_SHA384:
        case SHA_FLAGS_SHA512:
                index = ctx->bufcnt & 0x7f;
                padlen = (index < 112) ? (112 - index) : ((128+112) - index);
                *(ctx->buffer + ctx->bufcnt) = 0x80;
                memset(ctx->buffer + ctx->bufcnt + 1, 0, padlen-1);
                memcpy(ctx->buffer + ctx->bufcnt + padlen, bits, 16);
                ctx->bufcnt += padlen + 16;
                ctx->flags |= SHA_FLAGS_PAD;
                break;

        default:
                index = ctx->bufcnt & 0x3f;
                padlen = (index < 56) ? (56 - index) : ((64+56) - index);
                *(ctx->buffer + ctx->bufcnt) = 0x80;
                memset(ctx->buffer + ctx->bufcnt + 1, 0, padlen-1);
                memcpy(ctx->buffer + ctx->bufcnt + padlen, &bits[1], 8);
                ctx->bufcnt += padlen + 8;
                ctx->flags |= SHA_FLAGS_PAD;
                break;
        }
}

static struct atmel_sha_dev *atmel_sha_find_dev(struct atmel_sha_ctx *tctx)
{
        struct atmel_sha_dev *dd = NULL;
        struct atmel_sha_dev *tmp;

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

        spin_unlock_bh(&atmel_sha.lock);

        return dd;
}

static int atmel_sha_init(struct ahash_request *req)
{
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_ctx *tctx = crypto_ahash_ctx(tfm);
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        struct atmel_sha_dev *dd = atmel_sha_find_dev(tctx);

        ctx->dd = dd;

        ctx->flags = 0;

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

        switch (crypto_ahash_digestsize(tfm)) {
        case SHA1_DIGEST_SIZE:
                ctx->flags |= SHA_FLAGS_SHA1;
                ctx->block_size = SHA1_BLOCK_SIZE;
                break;
        case SHA224_DIGEST_SIZE:
                ctx->flags |= SHA_FLAGS_SHA224;
                ctx->block_size = SHA224_BLOCK_SIZE;
                break;
        case SHA256_DIGEST_SIZE:
                ctx->flags |= SHA_FLAGS_SHA256;
                ctx->block_size = SHA256_BLOCK_SIZE;
                break;
        case SHA384_DIGEST_SIZE:
                ctx->flags |= SHA_FLAGS_SHA384;
                ctx->block_size = SHA384_BLOCK_SIZE;
                break;
        case SHA512_DIGEST_SIZE:
                ctx->flags |= SHA_FLAGS_SHA512;
                ctx->block_size = SHA512_BLOCK_SIZE;
                break;
        default:
                return -EINVAL;
                break;
        }

        ctx->bufcnt = 0;
        ctx->digcnt[0] = 0;
        ctx->digcnt[1] = 0;
        ctx->buflen = SHA_BUFFER_LEN;

        return 0;
}

static void atmel_sha_write_ctrl(struct atmel_sha_dev *dd, int dma)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
        u32 valmr = SHA_MR_MODE_AUTO;
        unsigned int i, hashsize = 0;

        if (likely(dma)) {
                if (!dd->caps.has_dma)
                        atmel_sha_write(dd, SHA_IER, SHA_INT_TXBUFE);
                valmr = SHA_MR_MODE_PDC;
                if (dd->caps.has_dualbuff)
                        valmr |= SHA_MR_DUALBUFF;
        } else {
                atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);
        }

        switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
        case SHA_FLAGS_SHA1:
                valmr |= SHA_MR_ALGO_SHA1;
                hashsize = SHA1_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA224:
                valmr |= SHA_MR_ALGO_SHA224;
                hashsize = SHA256_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA256:
                valmr |= SHA_MR_ALGO_SHA256;
                hashsize = SHA256_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA384:
                valmr |= SHA_MR_ALGO_SHA384;
                hashsize = SHA512_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA512:
                valmr |= SHA_MR_ALGO_SHA512;
                hashsize = SHA512_DIGEST_SIZE;
                break;

        default:
                break;
        }

        /* Setting CR_FIRST only for the first iteration */
        if (!(ctx->digcnt[0] || ctx->digcnt[1])) {
                atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);
        } else if (dd->caps.has_uihv && (ctx->flags & SHA_FLAGS_RESTORE)) {
                const u32 *hash = (const u32 *)ctx->digest;

                /*
                 * Restore the hardware context: update the User Initialize
                 * Hash Value (UIHV) with the value saved when the latest
                 * 'update' operation completed on this very same crypto
                 * request.
                 */
                ctx->flags &= ~SHA_FLAGS_RESTORE;
                atmel_sha_write(dd, SHA_CR, SHA_CR_WUIHV);
                for (i = 0; i < hashsize / sizeof(u32); ++i)
                        atmel_sha_write(dd, SHA_REG_DIN(i), hash[i]);
                atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);
                valmr |= SHA_MR_UIHV;
        }
        /*
         * WARNING: If the UIHV feature is not available, the hardware CANNOT
         * process concurrent requests: the internal registers used to store
         * the hash/digest are still set to the partial digest output values
         * computed during the latest round.
         */

        atmel_sha_write(dd, SHA_MR, valmr);
}

static inline int atmel_sha_wait_for_data_ready(struct atmel_sha_dev *dd,
                                                atmel_sha_fn_t resume)
{
        u32 isr = atmel_sha_read(dd, SHA_ISR);

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

        dd->resume = resume;
        atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);
        return -EINPROGRESS;
}

static int atmel_sha_xmit_cpu(struct atmel_sha_dev *dd, const u8 *buf,
                              size_t length, int final)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
        int count, len32;
        const u32 *buffer = (const u32 *)buf;

        dev_dbg(dd->dev, "xmit_cpu: digcnt: 0x%llx 0x%llx, length: %zd, final: %d\n",
                ctx->digcnt[1], ctx->digcnt[0], length, final);

        atmel_sha_write_ctrl(dd, 0);

        /* should be non-zero before next lines to disable clocks later */
        ctx->digcnt[0] += length;
        if (ctx->digcnt[0] < length)
                ctx->digcnt[1]++;

        if (final)
                dd->flags |= SHA_FLAGS_FINAL; /* catch last interrupt */

        len32 = DIV_ROUND_UP(length, sizeof(u32));

        dd->flags |= SHA_FLAGS_CPU;

        for (count = 0; count < len32; count++)
                atmel_sha_write(dd, SHA_REG_DIN(count), buffer[count]);

        return -EINPROGRESS;
}

static int atmel_sha_xmit_pdc(struct atmel_sha_dev *dd, dma_addr_t dma_addr1,
                size_t length1, dma_addr_t dma_addr2, size_t length2, int final)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
        int len32;

        dev_dbg(dd->dev, "xmit_pdc: digcnt: 0x%llx 0x%llx, length: %zd, final: %d\n",
                ctx->digcnt[1], ctx->digcnt[0], length1, final);

        len32 = DIV_ROUND_UP(length1, sizeof(u32));
        atmel_sha_write(dd, SHA_PTCR, SHA_PTCR_TXTDIS);
        atmel_sha_write(dd, SHA_TPR, dma_addr1);
        atmel_sha_write(dd, SHA_TCR, len32);

        len32 = DIV_ROUND_UP(length2, sizeof(u32));
        atmel_sha_write(dd, SHA_TNPR, dma_addr2);
        atmel_sha_write(dd, SHA_TNCR, len32);

        atmel_sha_write_ctrl(dd, 1);

        /* should be non-zero before next lines to disable clocks later */
        ctx->digcnt[0] += length1;
        if (ctx->digcnt[0] < length1)
                ctx->digcnt[1]++;

        if (final)
                dd->flags |= SHA_FLAGS_FINAL; /* catch last interrupt */

        dd->flags |=  SHA_FLAGS_DMA_ACTIVE;

        /* Start DMA transfer */
        atmel_sha_write(dd, SHA_PTCR, SHA_PTCR_TXTEN);

        return -EINPROGRESS;
}

static void atmel_sha_dma_callback(void *data)
{
        struct atmel_sha_dev *dd = data;

        dd->is_async = true;

        /* dma_lch_in - completed - wait DATRDY */
        atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);
}

static int atmel_sha_xmit_dma(struct atmel_sha_dev *dd, dma_addr_t dma_addr1,
                size_t length1, dma_addr_t dma_addr2, size_t length2, int final)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
        struct dma_async_tx_descriptor  *in_desc;
        struct scatterlist sg[2];

        dev_dbg(dd->dev, "xmit_dma: digcnt: 0x%llx 0x%llx, length: %zd, final: %d\n",
                ctx->digcnt[1], ctx->digcnt[0], length1, final);

        dd->dma_lch_in.dma_conf.src_maxburst = 16;
        dd->dma_lch_in.dma_conf.dst_maxburst = 16;

        dmaengine_slave_config(dd->dma_lch_in.chan, &dd->dma_lch_in.dma_conf);

        if (length2) {
                sg_init_table(sg, 2);
                sg_dma_address(&sg[0]) = dma_addr1;
                sg_dma_len(&sg[0]) = length1;
                sg_dma_address(&sg[1]) = dma_addr2;
                sg_dma_len(&sg[1]) = length2;
                in_desc = dmaengine_prep_slave_sg(dd->dma_lch_in.chan, sg, 2,
                        DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        } else {
                sg_init_table(sg, 1);
                sg_dma_address(&sg[0]) = dma_addr1;
                sg_dma_len(&sg[0]) = length1;
                in_desc = dmaengine_prep_slave_sg(dd->dma_lch_in.chan, sg, 1,
                        DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        }
        if (!in_desc)
                return atmel_sha_complete(dd, -EINVAL);

        in_desc->callback = atmel_sha_dma_callback;
        in_desc->callback_param = dd;

        atmel_sha_write_ctrl(dd, 1);

        /* should be non-zero before next lines to disable clocks later */
        ctx->digcnt[0] += length1;
        if (ctx->digcnt[0] < length1)
                ctx->digcnt[1]++;

        if (final)
                dd->flags |= SHA_FLAGS_FINAL; /* catch last interrupt */

        dd->flags |=  SHA_FLAGS_DMA_ACTIVE;

        /* Start DMA transfer */
        dmaengine_submit(in_desc);
        dma_async_issue_pending(dd->dma_lch_in.chan);

        return -EINPROGRESS;
}

static int atmel_sha_xmit_start(struct atmel_sha_dev *dd, dma_addr_t dma_addr1,
                size_t length1, dma_addr_t dma_addr2, size_t length2, int final)
{
        if (dd->caps.has_dma)
                return atmel_sha_xmit_dma(dd, dma_addr1, length1,
                                dma_addr2, length2, final);
        else
                return atmel_sha_xmit_pdc(dd, dma_addr1, length1,
                                dma_addr2, length2, final);
}

static int atmel_sha_update_cpu(struct atmel_sha_dev *dd)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
        int bufcnt;

        atmel_sha_append_sg(ctx);
        atmel_sha_fill_padding(ctx, 0);
        bufcnt = ctx->bufcnt;
        ctx->bufcnt = 0;

        return atmel_sha_xmit_cpu(dd, ctx->buffer, bufcnt, 1);
}

static int atmel_sha_xmit_dma_map(struct atmel_sha_dev *dd,
                                        struct atmel_sha_reqctx *ctx,
                                        size_t length, int final)
{
        ctx->dma_addr = dma_map_single(dd->dev, ctx->buffer,
                                ctx->buflen + ctx->block_size, DMA_TO_DEVICE);
        if (dma_mapping_error(dd->dev, ctx->dma_addr)) {
                dev_err(dd->dev, "dma %zu bytes error\n", ctx->buflen +
                                ctx->block_size);
                return atmel_sha_complete(dd, -EINVAL);
        }

        ctx->flags &= ~SHA_FLAGS_SG;

        /* next call does not fail... so no unmap in the case of error */
        return atmel_sha_xmit_start(dd, ctx->dma_addr, length, 0, 0, final);
}

static int atmel_sha_update_dma_slow(struct atmel_sha_dev *dd)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
        unsigned int final;
        size_t count;

        atmel_sha_append_sg(ctx);

        final = (ctx->flags & SHA_FLAGS_FINUP) && !ctx->total;

        dev_dbg(dd->dev, "slow: bufcnt: %zu, digcnt: 0x%llx 0x%llx, final: %d\n",
                 ctx->bufcnt, ctx->digcnt[1], ctx->digcnt[0], final);

        if (final)
                atmel_sha_fill_padding(ctx, 0);

        if (final || (ctx->bufcnt == ctx->buflen)) {
                count = ctx->bufcnt;
                ctx->bufcnt = 0;
                return atmel_sha_xmit_dma_map(dd, ctx, count, final);
        }

        return 0;
}

static int atmel_sha_update_dma_start(struct atmel_sha_dev *dd)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);
        unsigned int length, final, tail;
        struct scatterlist *sg;
        unsigned int count;

        if (!ctx->total)
                return 0;

        if (ctx->bufcnt || ctx->offset)
                return atmel_sha_update_dma_slow(dd);

        dev_dbg(dd->dev, "fast: digcnt: 0x%llx 0x%llx, bufcnt: %zd, total: %u\n",
                ctx->digcnt[1], ctx->digcnt[0], ctx->bufcnt, ctx->total);

        sg = ctx->sg;

        if (!IS_ALIGNED(sg->offset, sizeof(u32)))
                return atmel_sha_update_dma_slow(dd);

        if (!sg_is_last(sg) && !IS_ALIGNED(sg->length, ctx->block_size))
                /* size is not ctx->block_size aligned */
                return atmel_sha_update_dma_slow(dd);

        length = min(ctx->total, sg->length);

        if (sg_is_last(sg)) {
                if (!(ctx->flags & SHA_FLAGS_FINUP)) {
                        /* not last sg must be ctx->block_size aligned */
                        tail = length & (ctx->block_size - 1);
                        length -= tail;
                }
        }

        ctx->total -= length;
        ctx->offset = length; /* offset where to start slow */

        final = (ctx->flags & SHA_FLAGS_FINUP) && !ctx->total;

        /* Add padding */
        if (final) {
                tail = length & (ctx->block_size - 1);
                length -= tail;
                ctx->total += tail;
                ctx->offset = length; /* offset where to start slow */

                sg = ctx->sg;
                atmel_sha_append_sg(ctx);

                atmel_sha_fill_padding(ctx, length);

                ctx->dma_addr = dma_map_single(dd->dev, ctx->buffer,
                        ctx->buflen + ctx->block_size, DMA_TO_DEVICE);
                if (dma_mapping_error(dd->dev, ctx->dma_addr)) {
                        dev_err(dd->dev, "dma %zu bytes error\n",
                                ctx->buflen + ctx->block_size);
                        return atmel_sha_complete(dd, -EINVAL);
                }

                if (length == 0) {
                        ctx->flags &= ~SHA_FLAGS_SG;
                        count = ctx->bufcnt;
                        ctx->bufcnt = 0;
                        return atmel_sha_xmit_start(dd, ctx->dma_addr, count, 0,
                                        0, final);
                } else {
                        ctx->sg = sg;
                        if (!dma_map_sg(dd->dev, ctx->sg, 1,
                                DMA_TO_DEVICE)) {
                                        dev_err(dd->dev, "dma_map_sg  error\n");
                                        return atmel_sha_complete(dd, -EINVAL);
                        }

                        ctx->flags |= SHA_FLAGS_SG;

                        count = ctx->bufcnt;
                        ctx->bufcnt = 0;
                        return atmel_sha_xmit_start(dd, sg_dma_address(ctx->sg),
                                        length, ctx->dma_addr, count, final);
                }
        }

        if (!dma_map_sg(dd->dev, ctx->sg, 1, DMA_TO_DEVICE)) {
                dev_err(dd->dev, "dma_map_sg  error\n");
                return atmel_sha_complete(dd, -EINVAL);
        }

        ctx->flags |= SHA_FLAGS_SG;

        /* next call does not fail... so no unmap in the case of error */
        return atmel_sha_xmit_start(dd, sg_dma_address(ctx->sg), length, 0,
                                                                0, final);
}

static void atmel_sha_update_dma_stop(struct atmel_sha_dev *dd)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(dd->req);

        if (ctx->flags & SHA_FLAGS_SG) {
                dma_unmap_sg(dd->dev, ctx->sg, 1, DMA_TO_DEVICE);
                if (ctx->sg->length == ctx->offset) {
                        ctx->sg = sg_next(ctx->sg);
                        if (ctx->sg)
                                ctx->offset = 0;
                }
                if (ctx->flags & SHA_FLAGS_PAD) {
                        dma_unmap_single(dd->dev, ctx->dma_addr,
                                ctx->buflen + ctx->block_size, DMA_TO_DEVICE);
                }
        } else {
                dma_unmap_single(dd->dev, ctx->dma_addr, ctx->buflen +
                                                ctx->block_size, DMA_TO_DEVICE);
        }
}

static int atmel_sha_update_req(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        int err;

        dev_dbg(dd->dev, "update_req: total: %u, digcnt: 0x%llx 0x%llx\n",
                ctx->total, ctx->digcnt[1], ctx->digcnt[0]);

        if (ctx->flags & SHA_FLAGS_CPU)
                err = atmel_sha_update_cpu(dd);
        else
                err = atmel_sha_update_dma_start(dd);

        /* wait for dma completion before can take more data */
        dev_dbg(dd->dev, "update: err: %d, digcnt: 0x%llx 0%llx\n",
                        err, ctx->digcnt[1], ctx->digcnt[0]);

        return err;
}

static int atmel_sha_final_req(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        int err = 0;
        int count;

        if (ctx->bufcnt >= ATMEL_SHA_DMA_THRESHOLD) {
                atmel_sha_fill_padding(ctx, 0);
                count = ctx->bufcnt;
                ctx->bufcnt = 0;
                err = atmel_sha_xmit_dma_map(dd, ctx, count, 1);
        }
        /* faster to handle last block with cpu */
        else {
                atmel_sha_fill_padding(ctx, 0);
                count = ctx->bufcnt;
                ctx->bufcnt = 0;
                err = atmel_sha_xmit_cpu(dd, ctx->buffer, count, 1);
        }

        dev_dbg(dd->dev, "final_req: err: %d\n", err);

        return err;
}

static void atmel_sha_copy_hash(struct ahash_request *req)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        u32 *hash = (u32 *)ctx->digest;
        unsigned int i, hashsize;

        switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
        case SHA_FLAGS_SHA1:
                hashsize = SHA1_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA224:
        case SHA_FLAGS_SHA256:
                hashsize = SHA256_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA384:
        case SHA_FLAGS_SHA512:
                hashsize = SHA512_DIGEST_SIZE;
                break;

        default:
                /* Should not happen... */
                return;
        }

        for (i = 0; i < hashsize / sizeof(u32); ++i)
                hash[i] = atmel_sha_read(ctx->dd, SHA_REG_DIGEST(i));
        ctx->flags |= SHA_FLAGS_RESTORE;
}

static void atmel_sha_copy_ready_hash(struct ahash_request *req)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

        if (!req->result)
                return;

        switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
        default:
        case SHA_FLAGS_SHA1:
                memcpy(req->result, ctx->digest, SHA1_DIGEST_SIZE);
                break;

        case SHA_FLAGS_SHA224:
                memcpy(req->result, ctx->digest, SHA224_DIGEST_SIZE);
                break;

        case SHA_FLAGS_SHA256:
                memcpy(req->result, ctx->digest, SHA256_DIGEST_SIZE);
                break;

        case SHA_FLAGS_SHA384:
                memcpy(req->result, ctx->digest, SHA384_DIGEST_SIZE);
                break;

        case SHA_FLAGS_SHA512:
                memcpy(req->result, ctx->digest, SHA512_DIGEST_SIZE);
                break;
        }
}

static int atmel_sha_finish(struct ahash_request *req)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        struct atmel_sha_dev *dd = ctx->dd;

        if (ctx->digcnt[0] || ctx->digcnt[1])
                atmel_sha_copy_ready_hash(req);

        dev_dbg(dd->dev, "digcnt: 0x%llx 0x%llx, bufcnt: %zd\n", ctx->digcnt[1],
                ctx->digcnt[0], ctx->bufcnt);

        return 0;
}

static void atmel_sha_finish_req(struct ahash_request *req, int err)
{

        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        struct atmel_sha_dev *dd = ctx->dd;

        if (!err) {
                atmel_sha_copy_hash(req);
                if (SHA_FLAGS_FINAL & dd->flags)
                        err = atmel_sha_finish(req);
        } else {
                ctx->flags |= SHA_FLAGS_ERROR;
        }

        /* atomic operation is not needed here */
        (void)atmel_sha_complete(dd, err);
}

static int atmel_sha_hw_init(struct atmel_sha_dev *dd)
{
        int err;

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

        if (!(SHA_FLAGS_INIT & dd->flags)) {
                atmel_sha_write(dd, SHA_CR, SHA_CR_SWRST);
                dd->flags |= SHA_FLAGS_INIT;
        }

        return 0;
}

static inline unsigned int atmel_sha_get_version(struct atmel_sha_dev *dd)
{
        return atmel_sha_read(dd, SHA_HW_VERSION) & 0x00000fff;
}

static int atmel_sha_hw_version_init(struct atmel_sha_dev *dd)
{
        int err;

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

        dd->hw_version = atmel_sha_get_version(dd);

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

        clk_disable(dd->iclk);

        return 0;
}

static int atmel_sha_handle_queue(struct atmel_sha_dev *dd,
                                  struct ahash_request *req)
{
        struct crypto_async_request *async_req, *backlog;
        struct atmel_sha_ctx *ctx;
        unsigned long flags;
        bool start_async;
        int err = 0, ret = 0;

        spin_lock_irqsave(&dd->lock, flags);
        if (req)
                ret = ahash_enqueue_request(&dd->queue, req);

        if (SHA_FLAGS_BUSY & dd->flags) {
                spin_unlock_irqrestore(&dd->lock, flags);
                return ret;
        }

        backlog = crypto_get_backlog(&dd->queue);
        async_req = crypto_dequeue_request(&dd->queue);
        if (async_req)
                dd->flags |= SHA_FLAGS_BUSY;

        spin_unlock_irqrestore(&dd->lock, flags);

        if (!async_req)
                return ret;

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

        ctx = crypto_tfm_ctx(async_req->tfm);

        dd->req = ahash_request_cast(async_req);
        start_async = (dd->req != req);
        dd->is_async = start_async;
        dd->force_complete = false;

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

static int atmel_sha_done(struct atmel_sha_dev *dd);

static int atmel_sha_start(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        int err;

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

        err = atmel_sha_hw_init(dd);
        if (err)
                return atmel_sha_complete(dd, err);

        /*
         * atmel_sha_update_req() and atmel_sha_final_req() can return either:
         *  -EINPROGRESS: the hardware is busy and the SHA driver will resume
         *                its job later in the done_task.
         *                This is the main path.
         *
         * 0: the SHA driver can continue its job then release the hardware
         *    later, if needed, with atmel_sha_finish_req().
         *    This is the alternate path.
         *
         * < 0: an error has occurred so atmel_sha_complete(dd, err) has already
         *      been called, hence the hardware has been released.
         *      The SHA driver must stop its job without calling
         *      atmel_sha_finish_req(), otherwise atmel_sha_complete() would be
         *      called a second time.
         *
         * Please note that currently, atmel_sha_final_req() never returns 0.
         */

        dd->resume = atmel_sha_done;
        if (ctx->op == SHA_OP_UPDATE) {
                err = atmel_sha_update_req(dd);
                if (!err && (ctx->flags & SHA_FLAGS_FINUP))
                        /* no final() after finup() */
                        err = atmel_sha_final_req(dd);
        } else if (ctx->op == SHA_OP_FINAL) {
                err = atmel_sha_final_req(dd);
        }

        if (!err)
                /* done_task will not finish it, so do it here */
                atmel_sha_finish_req(req, err);

        dev_dbg(dd->dev, "exit, err: %d\n", err);

        return err;
}

static int atmel_sha_enqueue(struct ahash_request *req, unsigned int op)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        struct atmel_sha_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
        struct atmel_sha_dev *dd = tctx->dd;

        ctx->op = op;

        return atmel_sha_handle_queue(dd, req);
}

static int atmel_sha_update(struct ahash_request *req)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

        if (!req->nbytes)
                return 0;

        ctx->total = req->nbytes;
        ctx->sg = req->src;
        ctx->offset = 0;

        if (ctx->flags & SHA_FLAGS_FINUP) {
                if (ctx->bufcnt + ctx->total < ATMEL_SHA_DMA_THRESHOLD)
                        /* faster to use CPU for short transfers */
                        ctx->flags |= SHA_FLAGS_CPU;
        } else if (ctx->bufcnt + ctx->total < ctx->buflen) {
                atmel_sha_append_sg(ctx);
                return 0;
        }
        return atmel_sha_enqueue(req, SHA_OP_UPDATE);
}

static int atmel_sha_final(struct ahash_request *req)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

        ctx->flags |= SHA_FLAGS_FINUP;

        if (ctx->flags & SHA_FLAGS_ERROR)
                return 0; /* uncompleted hash is not needed */

        if (ctx->flags & SHA_FLAGS_PAD)
                /* copy ready hash (+ finalize hmac) */
                return atmel_sha_finish(req);

        return atmel_sha_enqueue(req, SHA_OP_FINAL);
}

static int atmel_sha_finup(struct ahash_request *req)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        int err1, err2;

        ctx->flags |= SHA_FLAGS_FINUP;

        err1 = atmel_sha_update(req);
        if (err1 == -EINPROGRESS ||
            (err1 == -EBUSY && (ahash_request_flags(req) &
                                CRYPTO_TFM_REQ_MAY_BACKLOG)))
                return err1;

        /*
         * final() has to be always called to cleanup resources
         * even if udpate() failed, except EINPROGRESS
         */
        err2 = atmel_sha_final(req);

        return err1 ?: err2;
}

static int atmel_sha_digest(struct ahash_request *req)
{
        return atmel_sha_init(req) ?: atmel_sha_finup(req);
}


static int atmel_sha_export(struct ahash_request *req, void *out)
{
        const struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

        memcpy(out, ctx, sizeof(*ctx));
        return 0;
}

static int atmel_sha_import(struct ahash_request *req, const void *in)
{
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

        memcpy(ctx, in, sizeof(*ctx));
        return 0;
}

static int atmel_sha_cra_init(struct crypto_tfm *tfm)
{
        struct atmel_sha_ctx *ctx = crypto_tfm_ctx(tfm);

        crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
                                 sizeof(struct atmel_sha_reqctx));
        ctx->start = atmel_sha_start;

        return 0;
}

static void atmel_sha_alg_init(struct ahash_alg *alg)
{
        alg->halg.base.cra_priority = ATMEL_SHA_PRIORITY;
        alg->halg.base.cra_flags = CRYPTO_ALG_ASYNC;
        alg->halg.base.cra_ctxsize = sizeof(struct atmel_sha_ctx);
        alg->halg.base.cra_module = THIS_MODULE;
        alg->halg.base.cra_init = atmel_sha_cra_init;

        alg->halg.statesize = sizeof(struct atmel_sha_reqctx);

        alg->init = atmel_sha_init;
        alg->update = atmel_sha_update;
        alg->final = atmel_sha_final;
        alg->finup = atmel_sha_finup;
        alg->digest = atmel_sha_digest;
        alg->export = atmel_sha_export;
        alg->import = atmel_sha_import;
}

static struct ahash_alg sha_1_256_algs[] = {
{
        .halg.base.cra_name             = "sha1",
        .halg.base.cra_driver_name      = "atmel-sha1",
        .halg.base.cra_blocksize        = SHA1_BLOCK_SIZE,

        .halg.digestsize = SHA1_DIGEST_SIZE,
},
{
        .halg.base.cra_name             = "sha256",
        .halg.base.cra_driver_name      = "atmel-sha256",
        .halg.base.cra_blocksize        = SHA256_BLOCK_SIZE,

        .halg.digestsize = SHA256_DIGEST_SIZE,
},
};

static struct ahash_alg sha_224_alg = {
        .halg.base.cra_name             = "sha224",
        .halg.base.cra_driver_name      = "atmel-sha224",
        .halg.base.cra_blocksize        = SHA224_BLOCK_SIZE,

        .halg.digestsize = SHA224_DIGEST_SIZE,
};

static struct ahash_alg sha_384_512_algs[] = {
{
        .halg.base.cra_name             = "sha384",
        .halg.base.cra_driver_name      = "atmel-sha384",
        .halg.base.cra_blocksize        = SHA384_BLOCK_SIZE,
        .halg.base.cra_alignmask        = 0x3,

        .halg.digestsize = SHA384_DIGEST_SIZE,
},
{
        .halg.base.cra_name             = "sha512",
        .halg.base.cra_driver_name      = "atmel-sha512",
        .halg.base.cra_blocksize        = SHA512_BLOCK_SIZE,
        .halg.base.cra_alignmask        = 0x3,

        .halg.digestsize = SHA512_DIGEST_SIZE,
},
};

static void atmel_sha_queue_task(unsigned long data)
{
        struct atmel_sha_dev *dd = (struct atmel_sha_dev *)data;

        atmel_sha_handle_queue(dd, NULL);
}

static int atmel_sha_done(struct atmel_sha_dev *dd)
{
        int err = 0;

        if (SHA_FLAGS_CPU & dd->flags) {
                if (SHA_FLAGS_OUTPUT_READY & dd->flags) {
                        dd->flags &= ~SHA_FLAGS_OUTPUT_READY;
                        goto finish;
                }
        } else if (SHA_FLAGS_DMA_READY & dd->flags) {
                if (SHA_FLAGS_DMA_ACTIVE & dd->flags) {
                        dd->flags &= ~SHA_FLAGS_DMA_ACTIVE;
                        atmel_sha_update_dma_stop(dd);
                }
                if (SHA_FLAGS_OUTPUT_READY & dd->flags) {
                        /* hash or semi-hash ready */
                        dd->flags &= ~(SHA_FLAGS_DMA_READY |
                                                SHA_FLAGS_OUTPUT_READY);
                        err = atmel_sha_update_dma_start(dd);
                        if (err != -EINPROGRESS)
                                goto finish;
                }
        }
        return err;

finish:
        /* finish curent request */
        atmel_sha_finish_req(dd->req, err);

        return err;
}

static void atmel_sha_done_task(unsigned long data)
{
        struct atmel_sha_dev *dd = (struct atmel_sha_dev *)data;

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

static irqreturn_t atmel_sha_irq(int irq, void *dev_id)
{
        struct atmel_sha_dev *sha_dd = dev_id;
        u32 reg;

        reg = atmel_sha_read(sha_dd, SHA_ISR);
        if (reg & atmel_sha_read(sha_dd, SHA_IMR)) {
                atmel_sha_write(sha_dd, SHA_IDR, reg);
                if (SHA_FLAGS_BUSY & sha_dd->flags) {
                        sha_dd->flags |= SHA_FLAGS_OUTPUT_READY;
                        if (!(SHA_FLAGS_CPU & sha_dd->flags))
                                sha_dd->flags |= SHA_FLAGS_DMA_READY;
                        tasklet_schedule(&sha_dd->done_task);
                } else {
                        dev_warn(sha_dd->dev, "SHA interrupt when no active requests.\n");
                }
                return IRQ_HANDLED;
        }

        return IRQ_NONE;
}


/* DMA transfer functions */

static bool atmel_sha_dma_check_aligned(struct atmel_sha_dev *dd,
                                        struct scatterlist *sg,
                                        size_t len)
{
        struct atmel_sha_dma *dma = &dd->dma_lch_in;
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        size_t bs = ctx->block_size;
        int nents;

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

                /*
                 * This is the last sg, the only one that is allowed to
                 * have an unaligned length.
                 */
                if (len <= sg->length) {
                        dma->nents = nents + 1;
                        dma->last_sg_length = sg->length;
                        sg->length = ALIGN(len, sizeof(u32));
                        return true;
                }

                /* All other sg lengths MUST be aligned to the block size. */
                if (!IS_ALIGNED(sg->length, bs))
                        return false;

                len -= sg->length;
        }

        return false;
}

static void atmel_sha_dma_callback2(void *data)
{
        struct atmel_sha_dev *dd = data;
        struct atmel_sha_dma *dma = &dd->dma_lch_in;
        struct scatterlist *sg;
        int nents;

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

        sg = dma->sg;
        for (nents = 0; nents < dma->nents - 1; ++nents)
                sg = sg_next(sg);
        sg->length = dma->last_sg_length;

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

static int atmel_sha_dma_start(struct atmel_sha_dev *dd,
                               struct scatterlist *src,
                               size_t len,
                               atmel_sha_fn_t resume)
{
        struct atmel_sha_dma *dma = &dd->dma_lch_in;
        struct dma_slave_config *config = &dma->dma_conf;
        struct dma_chan *chan = dma->chan;
        struct dma_async_tx_descriptor *desc;
        dma_cookie_t cookie;
        unsigned int sg_len;
        int err;

        dd->resume = resume;

        /*
         * dma->nents has already been initialized by
         * atmel_sha_dma_check_aligned().
         */
        dma->sg = src;
        sg_len = dma_map_sg(dd->dev, dma->sg, dma->nents, DMA_TO_DEVICE);
        if (!sg_len) {
                err = -ENOMEM;
                goto exit;
        }

        config->src_maxburst = 16;
        config->dst_maxburst = 16;
        err = dmaengine_slave_config(chan, config);
        if (err)
                goto unmap_sg;

        desc = dmaengine_prep_slave_sg(chan, dma->sg, sg_len, DMA_MEM_TO_DEV,
                                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!desc) {
                err = -ENOMEM;
                goto unmap_sg;
        }

        desc->callback = atmel_sha_dma_callback2;
        desc->callback_param = dd;
        cookie = dmaengine_submit(desc);
        err = dma_submit_error(cookie);
        if (err)
                goto unmap_sg;

        dma_async_issue_pending(chan);

        return -EINPROGRESS;

unmap_sg:
        dma_unmap_sg(dd->dev, dma->sg, dma->nents, DMA_TO_DEVICE);
exit:
        return atmel_sha_complete(dd, err);
}


/* CPU transfer functions */

static int atmel_sha_cpu_transfer(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        const u32 *words = (const u32 *)ctx->buffer;
        size_t i, num_words;
        u32 isr, din, din_inc;

        din_inc = (ctx->flags & SHA_FLAGS_IDATAR0) ? 0 : 1;
        for (;;) {
                /* Write data into the Input Data Registers. */
                num_words = DIV_ROUND_UP(ctx->bufcnt, sizeof(u32));
                for (i = 0, din = 0; i < num_words; ++i, din += din_inc)
                        atmel_sha_write(dd, SHA_REG_DIN(din), words[i]);

                ctx->offset += ctx->bufcnt;
                ctx->total -= ctx->bufcnt;

                if (!ctx->total)
                        break;

                /*
                 * Prepare next block:
                 * Fill ctx->buffer now with the next data to be written into
                 * IDATARx: it gives time for the SHA hardware to process
                 * the current data so the SHA_INT_DATARDY flag might be set
                 * in SHA_ISR when polling this register at the beginning of
                 * the next loop.
                 */
                ctx->bufcnt = min_t(size_t, ctx->block_size, ctx->total);
                scatterwalk_map_and_copy(ctx->buffer, ctx->sg,
                                         ctx->offset, ctx->bufcnt, 0);

                /* Wait for hardware to be ready again. */
                isr = atmel_sha_read(dd, SHA_ISR);
                if (!(isr & SHA_INT_DATARDY)) {
                        /* Not ready yet. */
                        dd->resume = atmel_sha_cpu_transfer;
                        atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);
                        return -EINPROGRESS;
                }
        }

        if (unlikely(!(ctx->flags & SHA_FLAGS_WAIT_DATARDY)))
                return dd->cpu_transfer_complete(dd);

        return atmel_sha_wait_for_data_ready(dd, dd->cpu_transfer_complete);
}

static int atmel_sha_cpu_start(struct atmel_sha_dev *dd,
                               struct scatterlist *sg,
                               unsigned int len,
                               bool idatar0_only,
                               bool wait_data_ready,
                               atmel_sha_fn_t resume)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

        if (!len)
                return resume(dd);

        ctx->flags &= ~(SHA_FLAGS_IDATAR0 | SHA_FLAGS_WAIT_DATARDY);

        if (idatar0_only)
                ctx->flags |= SHA_FLAGS_IDATAR0;

        if (wait_data_ready)
                ctx->flags |= SHA_FLAGS_WAIT_DATARDY;

        ctx->sg = sg;
        ctx->total = len;
        ctx->offset = 0;

        /* Prepare the first block to be written. */
        ctx->bufcnt = min_t(size_t, ctx->block_size, ctx->total);
        scatterwalk_map_and_copy(ctx->buffer, ctx->sg,
                                 ctx->offset, ctx->bufcnt, 0);

        dd->cpu_transfer_complete = resume;
        return atmel_sha_cpu_transfer(dd);
}

static int atmel_sha_cpu_hash(struct atmel_sha_dev *dd,
                              const void *data, unsigned int datalen,
                              bool auto_padding,
                              atmel_sha_fn_t resume)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        u32 msglen = (auto_padding) ? datalen : 0;
        u32 mr = SHA_MR_MODE_AUTO;

        if (!(IS_ALIGNED(datalen, ctx->block_size) || auto_padding))
                return atmel_sha_complete(dd, -EINVAL);

        mr |= (ctx->flags & SHA_FLAGS_ALGO_MASK);
        atmel_sha_write(dd, SHA_MR, mr);
        atmel_sha_write(dd, SHA_MSR, msglen);
        atmel_sha_write(dd, SHA_BCR, msglen);
        atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);

        sg_init_one(&dd->tmp, data, datalen);
        return atmel_sha_cpu_start(dd, &dd->tmp, datalen, false, true, resume);
}


/* hmac functions */

struct atmel_sha_hmac_key {
        bool                    valid;
        unsigned int            keylen;
        u8                      buffer[SHA512_BLOCK_SIZE];
        u8                      *keydup;
};

static inline void atmel_sha_hmac_key_init(struct atmel_sha_hmac_key *hkey)
{
        memset(hkey, 0, sizeof(*hkey));
}

static inline void atmel_sha_hmac_key_release(struct atmel_sha_hmac_key *hkey)
{
        kfree(hkey->keydup);
        memset(hkey, 0, sizeof(*hkey));
}

static inline int atmel_sha_hmac_key_set(struct atmel_sha_hmac_key *hkey,
                                         const u8 *key,
                                         unsigned int keylen)
{
        atmel_sha_hmac_key_release(hkey);

        if (keylen > sizeof(hkey->buffer)) {
                hkey->keydup = kmemdup(key, keylen, GFP_KERNEL);
                if (!hkey->keydup)
                        return -ENOMEM;

        } else {
                memcpy(hkey->buffer, key, keylen);
        }

        hkey->valid = true;
        hkey->keylen = keylen;
        return 0;
}

static inline bool atmel_sha_hmac_key_get(const struct atmel_sha_hmac_key *hkey,
                                          const u8 **key,
                                          unsigned int *keylen)
{
        if (!hkey->valid)
                return false;

        *keylen = hkey->keylen;
        *key = (hkey->keydup) ? hkey->keydup : hkey->buffer;
        return true;
}


struct atmel_sha_hmac_ctx {
        struct atmel_sha_ctx    base;

        struct atmel_sha_hmac_key       hkey;
        u32                     ipad[SHA512_BLOCK_SIZE / sizeof(u32)];
        u32                     opad[SHA512_BLOCK_SIZE / sizeof(u32)];
        atmel_sha_fn_t          resume;
};

static int atmel_sha_hmac_setup(struct atmel_sha_dev *dd,
                                atmel_sha_fn_t resume);
static int atmel_sha_hmac_prehash_key(struct atmel_sha_dev *dd,
                                      const u8 *key, unsigned int keylen);
static int atmel_sha_hmac_prehash_key_done(struct atmel_sha_dev *dd);
static int atmel_sha_hmac_compute_ipad_hash(struct atmel_sha_dev *dd);
static int atmel_sha_hmac_compute_opad_hash(struct atmel_sha_dev *dd);
static int atmel_sha_hmac_setup_done(struct atmel_sha_dev *dd);

static int atmel_sha_hmac_init_done(struct atmel_sha_dev *dd);
static int atmel_sha_hmac_final(struct atmel_sha_dev *dd);
static int atmel_sha_hmac_final_done(struct atmel_sha_dev *dd);
static int atmel_sha_hmac_digest2(struct atmel_sha_dev *dd);

static int atmel_sha_hmac_setup(struct atmel_sha_dev *dd,
                                atmel_sha_fn_t resume)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        unsigned int keylen;
        const u8 *key;
        size_t bs;

        hmac->resume = resume;
        switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
        case SHA_FLAGS_SHA1:
                ctx->block_size = SHA1_BLOCK_SIZE;
                ctx->hash_size = SHA1_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA224:
                ctx->block_size = SHA224_BLOCK_SIZE;
                ctx->hash_size = SHA256_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA256:
                ctx->block_size = SHA256_BLOCK_SIZE;
                ctx->hash_size = SHA256_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA384:
                ctx->block_size = SHA384_BLOCK_SIZE;
                ctx->hash_size = SHA512_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA512:
                ctx->block_size = SHA512_BLOCK_SIZE;
                ctx->hash_size = SHA512_DIGEST_SIZE;
                break;

        default:
                return atmel_sha_complete(dd, -EINVAL);
        }
        bs = ctx->block_size;

        if (likely(!atmel_sha_hmac_key_get(&hmac->hkey, &key, &keylen)))
                return resume(dd);

        /* Compute K' from K. */
        if (unlikely(keylen > bs))
                return atmel_sha_hmac_prehash_key(dd, key, keylen);

        /* Prepare ipad. */
        memcpy((u8 *)hmac->ipad, key, keylen);
        memset((u8 *)hmac->ipad + keylen, 0, bs - keylen);
        return atmel_sha_hmac_compute_ipad_hash(dd);
}

static int atmel_sha_hmac_prehash_key(struct atmel_sha_dev *dd,
                                      const u8 *key, unsigned int keylen)
{
        return atmel_sha_cpu_hash(dd, key, keylen, true,
                                  atmel_sha_hmac_prehash_key_done);
}

static int atmel_sha_hmac_prehash_key_done(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        size_t ds = crypto_ahash_digestsize(tfm);
        size_t bs = ctx->block_size;
        size_t i, num_words = ds / sizeof(u32);

        /* Prepare ipad. */
        for (i = 0; i < num_words; ++i)
                hmac->ipad[i] = atmel_sha_read(dd, SHA_REG_DIGEST(i));
        memset((u8 *)hmac->ipad + ds, 0, bs - ds);
        return atmel_sha_hmac_compute_ipad_hash(dd);
}

static int atmel_sha_hmac_compute_ipad_hash(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        size_t bs = ctx->block_size;
        size_t i, num_words = bs / sizeof(u32);

        memcpy(hmac->opad, hmac->ipad, bs);
        for (i = 0; i < num_words; ++i) {
                hmac->ipad[i] ^= 0x36363636;
                hmac->opad[i] ^= 0x5c5c5c5c;
        }

        return atmel_sha_cpu_hash(dd, hmac->ipad, bs, false,
                                  atmel_sha_hmac_compute_opad_hash);
}

static int atmel_sha_hmac_compute_opad_hash(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        size_t bs = ctx->block_size;
        size_t hs = ctx->hash_size;
        size_t i, num_words = hs / sizeof(u32);

        for (i = 0; i < num_words; ++i)
                hmac->ipad[i] = atmel_sha_read(dd, SHA_REG_DIGEST(i));
        return atmel_sha_cpu_hash(dd, hmac->opad, bs, false,
                                  atmel_sha_hmac_setup_done);
}

static int atmel_sha_hmac_setup_done(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        size_t hs = ctx->hash_size;
        size_t i, num_words = hs / sizeof(u32);

        for (i = 0; i < num_words; ++i)
                hmac->opad[i] = atmel_sha_read(dd, SHA_REG_DIGEST(i));
        atmel_sha_hmac_key_release(&hmac->hkey);
        return hmac->resume(dd);
}

static int atmel_sha_hmac_start(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        int err;

        err = atmel_sha_hw_init(dd);
        if (err)
                return atmel_sha_complete(dd, err);

        switch (ctx->op) {
        case SHA_OP_INIT:
                err = atmel_sha_hmac_setup(dd, atmel_sha_hmac_init_done);
                break;

        case SHA_OP_UPDATE:
                dd->resume = atmel_sha_done;
                err = atmel_sha_update_req(dd);
                break;

        case SHA_OP_FINAL:
                dd->resume = atmel_sha_hmac_final;
                err = atmel_sha_final_req(dd);
                break;

        case SHA_OP_DIGEST:
                err = atmel_sha_hmac_setup(dd, atmel_sha_hmac_digest2);
                break;

        default:
                return atmel_sha_complete(dd, -EINVAL);
        }

        return err;
}

static int atmel_sha_hmac_setkey(struct crypto_ahash *tfm, const u8 *key,
                                 unsigned int keylen)
{
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);

        return atmel_sha_hmac_key_set(&hmac->hkey, key, keylen);
}

static int atmel_sha_hmac_init(struct ahash_request *req)
{
        int err;

        err = atmel_sha_init(req);
        if (err)
                return err;

        return atmel_sha_enqueue(req, SHA_OP_INIT);
}

static int atmel_sha_hmac_init_done(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        size_t bs = ctx->block_size;
        size_t hs = ctx->hash_size;

        ctx->bufcnt = 0;
        ctx->digcnt[0] = bs;
        ctx->digcnt[1] = 0;
        ctx->flags |= SHA_FLAGS_RESTORE;
        memcpy(ctx->digest, hmac->ipad, hs);
        return atmel_sha_complete(dd, 0);
}

static int atmel_sha_hmac_final(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        u32 *digest = (u32 *)ctx->digest;
        size_t ds = crypto_ahash_digestsize(tfm);
        size_t bs = ctx->block_size;
        size_t hs = ctx->hash_size;
        size_t i, num_words;
        u32 mr;

        /* Save d = SHA((K' + ipad) | msg). */
        num_words = ds / sizeof(u32);
        for (i = 0; i < num_words; ++i)
                digest[i] = atmel_sha_read(dd, SHA_REG_DIGEST(i));

        /* Restore context to finish computing SHA((K' + opad) | d). */
        atmel_sha_write(dd, SHA_CR, SHA_CR_WUIHV);
        num_words = hs / sizeof(u32);
        for (i = 0; i < num_words; ++i)
                atmel_sha_write(dd, SHA_REG_DIN(i), hmac->opad[i]);

        mr = SHA_MR_MODE_AUTO | SHA_MR_UIHV;
        mr |= (ctx->flags & SHA_FLAGS_ALGO_MASK);
        atmel_sha_write(dd, SHA_MR, mr);
        atmel_sha_write(dd, SHA_MSR, bs + ds);
        atmel_sha_write(dd, SHA_BCR, ds);
        atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);

        sg_init_one(&dd->tmp, digest, ds);
        return atmel_sha_cpu_start(dd, &dd->tmp, ds, false, true,
                                   atmel_sha_hmac_final_done);
}

static int atmel_sha_hmac_final_done(struct atmel_sha_dev *dd)
{
        /*
         * req->result might not be sizeof(u32) aligned, so copy the
         * digest into ctx->digest[] before memcpy() the data into
         * req->result.
         */
        atmel_sha_copy_hash(dd->req);
        atmel_sha_copy_ready_hash(dd->req);
        return atmel_sha_complete(dd, 0);
}

static int atmel_sha_hmac_digest(struct ahash_request *req)
{
        int err;

        err = atmel_sha_init(req);
        if (err)
                return err;

        return atmel_sha_enqueue(req, SHA_OP_DIGEST);
}

static int atmel_sha_hmac_digest2(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        size_t hs = ctx->hash_size;
        size_t i, num_words = hs / sizeof(u32);
        bool use_dma = false;
        u32 mr;

        /* Special case for empty message. */
        if (!req->nbytes)
                return atmel_sha_complete(dd, -EINVAL); // TODO:

        /* Check DMA threshold and alignment. */
        if (req->nbytes > ATMEL_SHA_DMA_THRESHOLD &&
            atmel_sha_dma_check_aligned(dd, req->src, req->nbytes))
                use_dma = true;

        /* Write both initial hash values to compute a HMAC. */
        atmel_sha_write(dd, SHA_CR, SHA_CR_WUIHV);
        for (i = 0; i < num_words; ++i)
                atmel_sha_write(dd, SHA_REG_DIN(i), hmac->ipad[i]);

        atmel_sha_write(dd, SHA_CR, SHA_CR_WUIEHV);
        for (i = 0; i < num_words; ++i)
                atmel_sha_write(dd, SHA_REG_DIN(i), hmac->opad[i]);

        /* Write the Mode, Message Size, Bytes Count then Control Registers. */
        mr = (SHA_MR_HMAC | SHA_MR_DUALBUFF);
        mr |= ctx->flags & SHA_FLAGS_ALGO_MASK;
        if (use_dma)
                mr |= SHA_MR_MODE_IDATAR0;
        else
                mr |= SHA_MR_MODE_AUTO;
        atmel_sha_write(dd, SHA_MR, mr);

        atmel_sha_write(dd, SHA_MSR, req->nbytes);
        atmel_sha_write(dd, SHA_BCR, req->nbytes);

        atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);

        /* Process data. */
        if (use_dma)
                return atmel_sha_dma_start(dd, req->src, req->nbytes,
                                           atmel_sha_hmac_final_done);

        return atmel_sha_cpu_start(dd, req->src, req->nbytes, false, true,
                                   atmel_sha_hmac_final_done);
}

static int atmel_sha_hmac_cra_init(struct crypto_tfm *tfm)
{
        struct atmel_sha_hmac_ctx *hmac = crypto_tfm_ctx(tfm);

        crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
                                 sizeof(struct atmel_sha_reqctx));
        hmac->base.start = atmel_sha_hmac_start;
        atmel_sha_hmac_key_init(&hmac->hkey);

        return 0;
}

static void atmel_sha_hmac_cra_exit(struct crypto_tfm *tfm)
{
        struct atmel_sha_hmac_ctx *hmac = crypto_tfm_ctx(tfm);

        atmel_sha_hmac_key_release(&hmac->hkey);
}

static void atmel_sha_hmac_alg_init(struct ahash_alg *alg)
{
        alg->halg.base.cra_priority = ATMEL_SHA_PRIORITY;
        alg->halg.base.cra_flags = CRYPTO_ALG_ASYNC;
        alg->halg.base.cra_ctxsize = sizeof(struct atmel_sha_hmac_ctx);
        alg->halg.base.cra_module = THIS_MODULE;
        alg->halg.base.cra_init = atmel_sha_hmac_cra_init;
        alg->halg.base.cra_exit = atmel_sha_hmac_cra_exit;

        alg->halg.statesize = sizeof(struct atmel_sha_reqctx);

        alg->init = atmel_sha_hmac_init;
        alg->update = atmel_sha_update;
        alg->final = atmel_sha_final;
        alg->digest = atmel_sha_hmac_digest;
        alg->setkey = atmel_sha_hmac_setkey;
        alg->export = atmel_sha_export;
        alg->import = atmel_sha_import;
}

static struct ahash_alg sha_hmac_algs[] = {
{
        .halg.base.cra_name             = "hmac(sha1)",
        .halg.base.cra_driver_name      = "atmel-hmac-sha1",
        .halg.base.cra_blocksize        = SHA1_BLOCK_SIZE,

        .halg.digestsize = SHA1_DIGEST_SIZE,
},
{
        .halg.base.cra_name             = "hmac(sha224)",
        .halg.base.cra_driver_name      = "atmel-hmac-sha224",
        .halg.base.cra_blocksize        = SHA224_BLOCK_SIZE,

        .halg.digestsize = SHA224_DIGEST_SIZE,
},
{
        .halg.base.cra_name             = "hmac(sha256)",
        .halg.base.cra_driver_name      = "atmel-hmac-sha256",
        .halg.base.cra_blocksize        = SHA256_BLOCK_SIZE,

        .halg.digestsize = SHA256_DIGEST_SIZE,
},
{
        .halg.base.cra_name             = "hmac(sha384)",
        .halg.base.cra_driver_name      = "atmel-hmac-sha384",
        .halg.base.cra_blocksize        = SHA384_BLOCK_SIZE,

        .halg.digestsize = SHA384_DIGEST_SIZE,
},
{
        .halg.base.cra_name             = "hmac(sha512)",
        .halg.base.cra_driver_name      = "atmel-hmac-sha512",
        .halg.base.cra_blocksize        = SHA512_BLOCK_SIZE,

        .halg.digestsize = SHA512_DIGEST_SIZE,
},
};

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

static int atmel_sha_authenc_init2(struct atmel_sha_dev *dd);
static int atmel_sha_authenc_init_done(struct atmel_sha_dev *dd);
static int atmel_sha_authenc_final_done(struct atmel_sha_dev *dd);


struct atmel_sha_authenc_ctx {
        struct crypto_ahash     *tfm;
};

struct atmel_sha_authenc_reqctx {
        struct atmel_sha_reqctx base;

        atmel_aes_authenc_fn_t  cb;
        struct atmel_aes_dev    *aes_dev;

        /* _init() parameters. */
        struct scatterlist      *assoc;
        u32                     assoclen;
        u32                     textlen;

        /* _final() parameters. */
        u32                     *digest;
        unsigned int            digestlen;
};

static void atmel_sha_authenc_complete(struct crypto_async_request *areq,
                                       int err)
{
        struct ahash_request *req = areq->data;
        struct atmel_sha_authenc_reqctx *authctx  = ahash_request_ctx(req);

        authctx->cb(authctx->aes_dev, err, authctx->base.dd->is_async);
}

static int atmel_sha_authenc_start(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
        int err;

        /*
         * Force atmel_sha_complete() to call req->base.complete(), ie
         * atmel_sha_authenc_complete(), which in turn calls authctx->cb().
         */
        dd->force_complete = true;

        err = atmel_sha_hw_init(dd);
        return authctx->cb(authctx->aes_dev, err, dd->is_async);
}

bool atmel_sha_authenc_is_ready(void)
{
        struct atmel_sha_ctx dummy;

        dummy.dd = NULL;
        return (atmel_sha_find_dev(&dummy) != NULL);
}
EXPORT_SYMBOL_GPL(atmel_sha_authenc_is_ready);

unsigned int atmel_sha_authenc_get_reqsize(void)
{
        return sizeof(struct atmel_sha_authenc_reqctx);
}
EXPORT_SYMBOL_GPL(atmel_sha_authenc_get_reqsize);

struct atmel_sha_authenc_ctx *atmel_sha_authenc_spawn(unsigned long mode)
{
        struct atmel_sha_authenc_ctx *auth;
        struct crypto_ahash *tfm;
        struct atmel_sha_ctx *tctx;
        const char *name;
        int err = -EINVAL;

        switch (mode & SHA_FLAGS_MODE_MASK) {
        case SHA_FLAGS_HMAC_SHA1:
                name = "atmel-hmac-sha1";
                break;

        case SHA_FLAGS_HMAC_SHA224:
                name = "atmel-hmac-sha224";
                break;

        case SHA_FLAGS_HMAC_SHA256:
                name = "atmel-hmac-sha256";
                break;

        case SHA_FLAGS_HMAC_SHA384:
                name = "atmel-hmac-sha384";
                break;

        case SHA_FLAGS_HMAC_SHA512:
                name = "atmel-hmac-sha512";
                break;

        default:
                goto error;
        }

        tfm = crypto_alloc_ahash(name, 0, 0);
        if (IS_ERR(tfm)) {
                err = PTR_ERR(tfm);
                goto error;
        }
        tctx = crypto_ahash_ctx(tfm);
        tctx->start = atmel_sha_authenc_start;
        tctx->flags = mode;

        auth = kzalloc(sizeof(*auth), GFP_KERNEL);
        if (!auth) {
                err = -ENOMEM;
                goto err_free_ahash;
        }
        auth->tfm = tfm;

        return auth;

err_free_ahash:
        crypto_free_ahash(tfm);
error:
        return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(atmel_sha_authenc_spawn);

void atmel_sha_authenc_free(struct atmel_sha_authenc_ctx *auth)
{
        if (auth)
                crypto_free_ahash(auth->tfm);
        kfree(auth);
}
EXPORT_SYMBOL_GPL(atmel_sha_authenc_free);

int atmel_sha_authenc_setkey(struct atmel_sha_authenc_ctx *auth,
                             const u8 *key, unsigned int keylen, u32 flags)
{
        struct crypto_ahash *tfm = auth->tfm;

        crypto_ahash_clear_flags(tfm, CRYPTO_TFM_REQ_MASK);
        crypto_ahash_set_flags(tfm, flags & CRYPTO_TFM_REQ_MASK);
        return crypto_ahash_setkey(tfm, key, keylen);
}
EXPORT_SYMBOL_GPL(atmel_sha_authenc_setkey);

int atmel_sha_authenc_schedule(struct ahash_request *req,
                               struct atmel_sha_authenc_ctx *auth,
                               atmel_aes_authenc_fn_t cb,
                               struct atmel_aes_dev *aes_dev)
{
        struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
        struct atmel_sha_reqctx *ctx = &authctx->base;
        struct crypto_ahash *tfm = auth->tfm;
        struct atmel_sha_ctx *tctx = crypto_ahash_ctx(tfm);
        struct atmel_sha_dev *dd;

        /* Reset request context (MUST be done first). */
        memset(authctx, 0, sizeof(*authctx));

        /* Get SHA device. */
        dd = atmel_sha_find_dev(tctx);
        if (!dd)
                return cb(aes_dev, -ENODEV, false);

        /* Init request context. */
        ctx->dd = dd;
        ctx->buflen = SHA_BUFFER_LEN;
        authctx->cb = cb;
        authctx->aes_dev = aes_dev;
        ahash_request_set_tfm(req, tfm);
        ahash_request_set_callback(req, 0, atmel_sha_authenc_complete, req);

        return atmel_sha_handle_queue(dd, req);
}
EXPORT_SYMBOL_GPL(atmel_sha_authenc_schedule);

int atmel_sha_authenc_init(struct ahash_request *req,
                           struct scatterlist *assoc, unsigned int assoclen,
                           unsigned int textlen,
                           atmel_aes_authenc_fn_t cb,
                           struct atmel_aes_dev *aes_dev)
{
        struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
        struct atmel_sha_reqctx *ctx = &authctx->base;
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        struct atmel_sha_dev *dd = ctx->dd;

        if (unlikely(!IS_ALIGNED(assoclen, sizeof(u32))))
                return atmel_sha_complete(dd, -EINVAL);

        authctx->cb = cb;
        authctx->aes_dev = aes_dev;
        authctx->assoc = assoc;
        authctx->assoclen = assoclen;
        authctx->textlen = textlen;

        ctx->flags = hmac->base.flags;
        return atmel_sha_hmac_setup(dd, atmel_sha_authenc_init2);
}
EXPORT_SYMBOL_GPL(atmel_sha_authenc_init);

static int atmel_sha_authenc_init2(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
        struct atmel_sha_reqctx *ctx = &authctx->base;
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
        size_t hs = ctx->hash_size;
        size_t i, num_words = hs / sizeof(u32);
        u32 mr, msg_size;

        atmel_sha_write(dd, SHA_CR, SHA_CR_WUIHV);
        for (i = 0; i < num_words; ++i)
                atmel_sha_write(dd, SHA_REG_DIN(i), hmac->ipad[i]);

        atmel_sha_write(dd, SHA_CR, SHA_CR_WUIEHV);
        for (i = 0; i < num_words; ++i)
                atmel_sha_write(dd, SHA_REG_DIN(i), hmac->opad[i]);

        mr = (SHA_MR_MODE_IDATAR0 |
              SHA_MR_HMAC |
              SHA_MR_DUALBUFF);
        mr |= ctx->flags & SHA_FLAGS_ALGO_MASK;
        atmel_sha_write(dd, SHA_MR, mr);

        msg_size = authctx->assoclen + authctx->textlen;
        atmel_sha_write(dd, SHA_MSR, msg_size);
        atmel_sha_write(dd, SHA_BCR, msg_size);

        atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);

        /* Process assoc data. */
        return atmel_sha_cpu_start(dd, authctx->assoc, authctx->assoclen,
                                   true, false,
                                   atmel_sha_authenc_init_done);
}

static int atmel_sha_authenc_init_done(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);

        return authctx->cb(authctx->aes_dev, 0, dd->is_async);
}

int atmel_sha_authenc_final(struct ahash_request *req,
                            u32 *digest, unsigned int digestlen,
                            atmel_aes_authenc_fn_t cb,
                            struct atmel_aes_dev *aes_dev)
{
        struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
        struct atmel_sha_reqctx *ctx = &authctx->base;
        struct atmel_sha_dev *dd = ctx->dd;

        switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
        case SHA_FLAGS_SHA1:
                authctx->digestlen = SHA1_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA224:
                authctx->digestlen = SHA224_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA256:
                authctx->digestlen = SHA256_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA384:
                authctx->digestlen = SHA384_DIGEST_SIZE;
                break;

        case SHA_FLAGS_SHA512:
                authctx->digestlen = SHA512_DIGEST_SIZE;
                break;

        default:
                return atmel_sha_complete(dd, -EINVAL);
        }
        if (authctx->digestlen > digestlen)
                authctx->digestlen = digestlen;

        authctx->cb = cb;
        authctx->aes_dev = aes_dev;
        authctx->digest = digest;
        return atmel_sha_wait_for_data_ready(dd,
                                             atmel_sha_authenc_final_done);
}
EXPORT_SYMBOL_GPL(atmel_sha_authenc_final);

static int atmel_sha_authenc_final_done(struct atmel_sha_dev *dd)
{
        struct ahash_request *req = dd->req;
        struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
        size_t i, num_words = authctx->digestlen / sizeof(u32);

        for (i = 0; i < num_words; ++i)
                authctx->digest[i] = atmel_sha_read(dd, SHA_REG_DIGEST(i));

        return atmel_sha_complete(dd, 0);
}

void atmel_sha_authenc_abort(struct ahash_request *req)
{
        struct atmel_sha_authenc_reqctx *authctx = ahash_request_ctx(req);
        struct atmel_sha_reqctx *ctx = &authctx->base;
        struct atmel_sha_dev *dd = ctx->dd;

        /* Prevent atmel_sha_complete() from calling req->base.complete(). */
        dd->is_async = false;
        dd->force_complete = false;
        (void)atmel_sha_complete(dd, 0);
}
EXPORT_SYMBOL_GPL(atmel_sha_authenc_abort);

#endif /* CONFIG_CRYPTO_DEV_ATMEL_AUTHENC */


static void atmel_sha_unregister_algs(struct atmel_sha_dev *dd)
{
        int i;

        if (dd->caps.has_hmac)
                for (i = 0; i < ARRAY_SIZE(sha_hmac_algs); i++)
                        crypto_unregister_ahash(&sha_hmac_algs[i]);

        for (i = 0; i < ARRAY_SIZE(sha_1_256_algs); i++)
                crypto_unregister_ahash(&sha_1_256_algs[i]);

        if (dd->caps.has_sha224)
                crypto_unregister_ahash(&sha_224_alg);

        if (dd->caps.has_sha_384_512) {
                for (i = 0; i < ARRAY_SIZE(sha_384_512_algs); i++)
                        crypto_unregister_ahash(&sha_384_512_algs[i]);
        }
}

static int atmel_sha_register_algs(struct atmel_sha_dev *dd)
{
        int err, i, j;

        for (i = 0; i < ARRAY_SIZE(sha_1_256_algs); i++) {
                atmel_sha_alg_init(&sha_1_256_algs[i]);

                err = crypto_register_ahash(&sha_1_256_algs[i]);
                if (err)
                        goto err_sha_1_256_algs;
        }

        if (dd->caps.has_sha224) {
                atmel_sha_alg_init(&sha_224_alg);

                err = crypto_register_ahash(&sha_224_alg);
                if (err)
                        goto err_sha_224_algs;
        }

        if (dd->caps.has_sha_384_512) {
                for (i = 0; i < ARRAY_SIZE(sha_384_512_algs); i++) {
                        atmel_sha_alg_init(&sha_384_512_algs[i]);

                        err = crypto_register_ahash(&sha_384_512_algs[i]);
                        if (err)
                                goto err_sha_384_512_algs;
                }
        }

        if (dd->caps.has_hmac) {
                for (i = 0; i < ARRAY_SIZE(sha_hmac_algs); i++) {
                        atmel_sha_hmac_alg_init(&sha_hmac_algs[i]);

                        err = crypto_register_ahash(&sha_hmac_algs[i]);
                        if (err)
                                goto err_sha_hmac_algs;
                }
        }

        return 0;

        /*i = ARRAY_SIZE(sha_hmac_algs);*/
err_sha_hmac_algs:
        for (j = 0; j < i; j++)
                crypto_unregister_ahash(&sha_hmac_algs[j]);
        i = ARRAY_SIZE(sha_384_512_algs);
err_sha_384_512_algs:
        for (j = 0; j < i; j++)
                crypto_unregister_ahash(&sha_384_512_algs[j]);
        crypto_unregister_ahash(&sha_224_alg);
err_sha_224_algs:
        i = ARRAY_SIZE(sha_1_256_algs);
err_sha_1_256_algs:
        for (j = 0; j < i; j++)
                crypto_unregister_ahash(&sha_1_256_algs[j]);

        return err;
}

static int atmel_sha_dma_init(struct atmel_sha_dev *dd)
{
        dd->dma_lch_in.chan = dma_request_chan(dd->dev, "tx");
        if (IS_ERR(dd->dma_lch_in.chan)) {
                dev_err(dd->dev, "DMA channel is not available\n");
                return PTR_ERR(dd->dma_lch_in.chan);
        }

        dd->dma_lch_in.dma_conf.dst_addr = dd->phys_base +
                SHA_REG_DIN(0);
        dd->dma_lch_in.dma_conf.src_maxburst = 1;
        dd->dma_lch_in.dma_conf.src_addr_width =
                DMA_SLAVE_BUSWIDTH_4_BYTES;
        dd->dma_lch_in.dma_conf.dst_maxburst = 1;
        dd->dma_lch_in.dma_conf.dst_addr_width =
                DMA_SLAVE_BUSWIDTH_4_BYTES;
        dd->dma_lch_in.dma_conf.device_fc = false;

        return 0;
}

static void atmel_sha_dma_cleanup(struct atmel_sha_dev *dd)
{
        dma_release_channel(dd->dma_lch_in.chan);
}

static void atmel_sha_get_cap(struct atmel_sha_dev *dd)
{

        dd->caps.has_dma = 0;
        dd->caps.has_dualbuff = 0;
        dd->caps.has_sha224 = 0;
        dd->caps.has_sha_384_512 = 0;
        dd->caps.has_uihv = 0;
        dd->caps.has_hmac = 0;

        /* keep only major version number */
        switch (dd->hw_version & 0xff0) {
        case 0x510:
                dd->caps.has_dma = 1;
                dd->caps.has_dualbuff = 1;
                dd->caps.has_sha224 = 1;
                dd->caps.has_sha_384_512 = 1;
                dd->caps.has_uihv = 1;
                dd->caps.has_hmac = 1;
                break;
        case 0x420:
                dd->caps.has_dma = 1;
                dd->caps.has_dualbuff = 1;
                dd->caps.has_sha224 = 1;
                dd->caps.has_sha_384_512 = 1;
                dd->caps.has_uihv = 1;
                break;
        case 0x410:
                dd->caps.has_dma = 1;
                dd->caps.has_dualbuff = 1;
                dd->caps.has_sha224 = 1;
                dd->caps.has_sha_384_512 = 1;
                break;
        case 0x400:
                dd->caps.has_dma = 1;
                dd->caps.has_dualbuff = 1;
                dd->caps.has_sha224 = 1;
                break;
        case 0x320:
                break;
        default:
                dev_warn(dd->dev,
                                "Unmanaged sha version, set minimum capabilities\n");
                break;
        }
}

#if defined(CONFIG_OF)
static const struct of_device_id atmel_sha_dt_ids[] = {
        { .compatible = "atmel,at91sam9g46-sha" },
        { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, atmel_sha_dt_ids);
#endif

static int atmel_sha_probe(struct platform_device *pdev)
{
        struct atmel_sha_dev *sha_dd;
        struct device *dev = &pdev->dev;
        struct resource *sha_res;
        int err;

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

        sha_dd->dev = dev;

        platform_set_drvdata(pdev, sha_dd);

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

        tasklet_init(&sha_dd->done_task, atmel_sha_done_task,
                                        (unsigned long)sha_dd);
        tasklet_init(&sha_dd->queue_task, atmel_sha_queue_task,
                                        (unsigned long)sha_dd);

        crypto_init_queue(&sha_dd->queue, ATMEL_SHA_QUEUE_LENGTH);

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

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

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

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

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

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

        err = atmel_sha_hw_version_init(sha_dd);
        if (err)
                goto err_iclk_unprepare;

        atmel_sha_get_cap(sha_dd);

        if (sha_dd->caps.has_dma) {
                err = atmel_sha_dma_init(sha_dd);
                if (err)
                        goto err_iclk_unprepare;

                dev_info(dev, "using %s for DMA transfers\n",
                                dma_chan_name(sha_dd->dma_lch_in.chan));
        }

        spin_lock(&atmel_sha.lock);
        list_add_tail(&sha_dd->list, &atmel_sha.dev_list);
        spin_unlock(&atmel_sha.lock);

        err = atmel_sha_register_algs(sha_dd);
        if (err)
                goto err_algs;

        dev_info(dev, "Atmel SHA1/SHA256%s%s\n",
                        sha_dd->caps.has_sha224 ? "/SHA224" : "",
                        sha_dd->caps.has_sha_384_512 ? "/SHA384/SHA512" : "");

        return 0;

err_algs:
        spin_lock(&atmel_sha.lock);
        list_del(&sha_dd->list);
        spin_unlock(&atmel_sha.lock);
        if (sha_dd->caps.has_dma)
                atmel_sha_dma_cleanup(sha_dd);
err_iclk_unprepare:
        clk_unprepare(sha_dd->iclk);
err_tasklet_kill:
        tasklet_kill(&sha_dd->queue_task);
        tasklet_kill(&sha_dd->done_task);

        return err;
}

static int atmel_sha_remove(struct platform_device *pdev)
{
        struct atmel_sha_dev *sha_dd;

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

        atmel_sha_unregister_algs(sha_dd);

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

        if (sha_dd->caps.has_dma)
                atmel_sha_dma_cleanup(sha_dd);

        clk_unprepare(sha_dd->iclk);

        return 0;
}

static struct platform_driver atmel_sha_driver = {
        .probe          = atmel_sha_probe,
        .remove         = atmel_sha_remove,
        .driver         = {
                .name   = "atmel_sha",
                .of_match_table = of_match_ptr(atmel_sha_dt_ids),
        },
};

module_platform_driver(atmel_sha_driver);

MODULE_DESCRIPTION("Atmel SHA (1/256/224/384/512) hw acceleration support.");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Nicolas Royer - Eukréa Electromatique");