// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
 */

#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/interrupt.h>
#include <crypto/internal/hash.h>

#include "common.h"
#include "core.h"
#include "sha.h"

struct qce_sha_saved_state {
        u8 pending_buf[QCE_SHA_MAX_BLOCKSIZE];
        u8 partial_digest[QCE_SHA_MAX_DIGESTSIZE];
        __be32 byte_count[2];
        unsigned int pending_buflen;
        unsigned int flags;
        u64 count;
        bool first_blk;
};

static LIST_HEAD(ahash_algs);

static const u32 std_iv_sha1[SHA256_DIGEST_SIZE / sizeof(u32)] = {
        SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4, 0, 0, 0
};

static const u32 std_iv_sha256[SHA256_DIGEST_SIZE / sizeof(u32)] = {
        SHA256_H0, SHA256_H1, SHA256_H2, SHA256_H3,
        SHA256_H4, SHA256_H5, SHA256_H6, SHA256_H7
};

static void qce_ahash_done(void *data)
{
        struct crypto_async_request *async_req = data;
        struct ahash_request *req = ahash_request_cast(async_req);
        struct crypto_ahash *ahash = crypto_ahash_reqtfm(req);
        struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
        struct qce_alg_template *tmpl = to_ahash_tmpl(async_req->tfm);
        struct qce_device *qce = tmpl->qce;
        struct qce_result_dump *result = qce->dma.result_buf;
        unsigned int digestsize = crypto_ahash_digestsize(ahash);
        int error;
        u32 status;

        error = qce_dma_terminate_all(&qce->dma);
        if (error)
                dev_dbg(qce->dev, "ahash dma termination error (%d)\n", error);

        dma_unmap_sg(qce->dev, req->src, rctx->src_nents, DMA_TO_DEVICE);
        dma_unmap_sg(qce->dev, &rctx->result_sg, 1, DMA_FROM_DEVICE);

        memcpy(rctx->digest, result->auth_iv, digestsize);
        if (req->result && rctx->last_blk)
                memcpy(req->result, result->auth_iv, digestsize);

        rctx->byte_count[0] = cpu_to_be32(result->auth_byte_count[0]);
        rctx->byte_count[1] = cpu_to_be32(result->auth_byte_count[1]);

        error = qce_check_status(qce, &status);
        if (error < 0)
                dev_dbg(qce->dev, "ahash operation error (%x)\n", status);

        req->src = rctx->src_orig;
        req->nbytes = rctx->nbytes_orig;
        rctx->last_blk = false;
        rctx->first_blk = false;

        qce->async_req_done(tmpl->qce, error);
}

static int qce_ahash_async_req_handle(struct crypto_async_request *async_req)
{
        struct ahash_request *req = ahash_request_cast(async_req);
        struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
        struct qce_sha_ctx *ctx = crypto_tfm_ctx(async_req->tfm);
        struct qce_alg_template *tmpl = to_ahash_tmpl(async_req->tfm);
        struct qce_device *qce = tmpl->qce;
        unsigned long flags = rctx->flags;
        int ret;

        if (IS_SHA_HMAC(flags)) {
                rctx->authkey = ctx->authkey;
                rctx->authklen = QCE_SHA_HMAC_KEY_SIZE;
        } else if (IS_CMAC(flags)) {
                rctx->authkey = ctx->authkey;
                rctx->authklen = AES_KEYSIZE_128;
        }

        rctx->src_nents = sg_nents_for_len(req->src, req->nbytes);
        if (rctx->src_nents < 0) {
                dev_err(qce->dev, "Invalid numbers of src SG.\n");
                return rctx->src_nents;
        }

        ret = dma_map_sg(qce->dev, req->src, rctx->src_nents, DMA_TO_DEVICE);
        if (ret < 0)
                return ret;

        sg_init_one(&rctx->result_sg, qce->dma.result_buf, QCE_RESULT_BUF_SZ);

        ret = dma_map_sg(qce->dev, &rctx->result_sg, 1, DMA_FROM_DEVICE);
        if (ret < 0)
                goto error_unmap_src;

        ret = qce_dma_prep_sgs(&qce->dma, req->src, rctx->src_nents,
                               &rctx->result_sg, 1, qce_ahash_done, async_req);
        if (ret)
                goto error_unmap_dst;

        qce_dma_issue_pending(&qce->dma);

        ret = qce_start(async_req, tmpl->crypto_alg_type);
        if (ret)
                goto error_terminate;

        return 0;

error_terminate:
        qce_dma_terminate_all(&qce->dma);
error_unmap_dst:
        dma_unmap_sg(qce->dev, &rctx->result_sg, 1, DMA_FROM_DEVICE);
error_unmap_src:
        dma_unmap_sg(qce->dev, req->src, rctx->src_nents, DMA_TO_DEVICE);
        return ret;
}

static int qce_ahash_init(struct ahash_request *req)
{
        struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
        struct qce_alg_template *tmpl = to_ahash_tmpl(req->base.tfm);
        const u32 *std_iv = tmpl->std_iv;

        memset(rctx, 0, sizeof(*rctx));
        rctx->first_blk = true;
        rctx->last_blk = false;
        rctx->flags = tmpl->alg_flags;
        memcpy(rctx->digest, std_iv, sizeof(rctx->digest));

        return 0;
}

static int qce_ahash_export(struct ahash_request *req, void *out)
{
        struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
        struct qce_sha_saved_state *export_state = out;

        memcpy(export_state->pending_buf, rctx->buf, rctx->buflen);
        memcpy(export_state->partial_digest, rctx->digest, sizeof(rctx->digest));
        export_state->byte_count[0] = rctx->byte_count[0];
        export_state->byte_count[1] = rctx->byte_count[1];
        export_state->pending_buflen = rctx->buflen;
        export_state->count = rctx->count;
        export_state->first_blk = rctx->first_blk;
        export_state->flags = rctx->flags;

        return 0;
}

static int qce_ahash_import(struct ahash_request *req, const void *in)
{
        struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
        const struct qce_sha_saved_state *import_state = in;

        memset(rctx, 0, sizeof(*rctx));
        rctx->count = import_state->count;
        rctx->buflen = import_state->pending_buflen;
        rctx->first_blk = import_state->first_blk;
        rctx->flags = import_state->flags;
        rctx->byte_count[0] = import_state->byte_count[0];
        rctx->byte_count[1] = import_state->byte_count[1];
        memcpy(rctx->buf, import_state->pending_buf, rctx->buflen);
        memcpy(rctx->digest, import_state->partial_digest, sizeof(rctx->digest));

        return 0;
}

static int qce_ahash_update(struct ahash_request *req)
{
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
        struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
        struct qce_alg_template *tmpl = to_ahash_tmpl(req->base.tfm);
        struct qce_device *qce = tmpl->qce;
        struct scatterlist *sg_last, *sg;
        unsigned int total, len;
        unsigned int hash_later;
        unsigned int nbytes;
        unsigned int blocksize;

        blocksize = crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
        rctx->count += req->nbytes;

        /* check for buffer from previous updates and append it */
        total = req->nbytes + rctx->buflen;

        if (total <= blocksize) {
                scatterwalk_map_and_copy(rctx->buf + rctx->buflen, req->src,
                                         0, req->nbytes, 0);
                rctx->buflen += req->nbytes;
                return 0;
        }

        /* save the original req structure fields */
        rctx->src_orig = req->src;
        rctx->nbytes_orig = req->nbytes;

        /*
         * if we have data from previous update copy them on buffer. The old
         * data will be combined with current request bytes.
         */
        if (rctx->buflen)
                memcpy(rctx->tmpbuf, rctx->buf, rctx->buflen);

        /* calculate how many bytes will be hashed later */
        hash_later = total % blocksize;

        /*
         * At this point, there is more than one block size of data.  If
         * the available data to transfer is exactly a multiple of block
         * size, save the last block to be transferred in qce_ahash_final
         * (with the last block bit set) if this is indeed the end of data
         * stream. If not this saved block will be transferred as part of
         * next update. If this block is not held back and if this is
         * indeed the end of data stream, the digest obtained will be wrong
         * since qce_ahash_final will see that rctx->buflen is 0 and return
         * doing nothing which in turn means that a digest will not be
         * copied to the destination result buffer.  qce_ahash_final cannot
         * be made to alter this behavior and allowed to proceed if
         * rctx->buflen is 0 because the crypto engine BAM does not allow
         * for zero length transfers.
         */
        if (!hash_later)
                hash_later = blocksize;

        if (hash_later) {
                unsigned int src_offset = req->nbytes - hash_later;
                scatterwalk_map_and_copy(rctx->buf, req->src, src_offset,
                                         hash_later, 0);
        }

        /* here nbytes is multiple of blocksize */
        nbytes = total - hash_later;

        len = rctx->buflen;
        sg = sg_last = req->src;

        while (len < nbytes && sg) {
                if (len + sg_dma_len(sg) > nbytes)
                        break;
                len += sg_dma_len(sg);
                sg_last = sg;
                sg = sg_next(sg);
        }

        if (!sg_last)
                return -EINVAL;

        if (rctx->buflen) {
                sg_init_table(rctx->sg, 2);
                sg_set_buf(rctx->sg, rctx->tmpbuf, rctx->buflen);
                sg_chain(rctx->sg, 2, req->src);
                req->src = rctx->sg;
        }

        req->nbytes = nbytes;
        rctx->buflen = hash_later;

        return qce->async_req_enqueue(tmpl->qce, &req->base);
}

static int qce_ahash_final(struct ahash_request *req)
{
        struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
        struct qce_alg_template *tmpl = to_ahash_tmpl(req->base.tfm);
        struct qce_device *qce = tmpl->qce;

        if (!rctx->buflen) {
                if (tmpl->hash_zero)
                        memcpy(req->result, tmpl->hash_zero,
                                        tmpl->alg.ahash.halg.digestsize);
                return 0;
        }

        rctx->last_blk = true;

        rctx->src_orig = req->src;
        rctx->nbytes_orig = req->nbytes;

        memcpy(rctx->tmpbuf, rctx->buf, rctx->buflen);
        sg_init_one(rctx->sg, rctx->tmpbuf, rctx->buflen);

        req->src = rctx->sg;
        req->nbytes = rctx->buflen;

        return qce->async_req_enqueue(tmpl->qce, &req->base);
}

static int qce_ahash_digest(struct ahash_request *req)
{
        struct qce_sha_reqctx *rctx = ahash_request_ctx(req);
        struct qce_alg_template *tmpl = to_ahash_tmpl(req->base.tfm);
        struct qce_device *qce = tmpl->qce;
        int ret;

        ret = qce_ahash_init(req);
        if (ret)
                return ret;

        rctx->src_orig = req->src;
        rctx->nbytes_orig = req->nbytes;
        rctx->first_blk = true;
        rctx->last_blk = true;

        if (!rctx->nbytes_orig) {
                if (tmpl->hash_zero)
                        memcpy(req->result, tmpl->hash_zero,
                                        tmpl->alg.ahash.halg.digestsize);
                return 0;
        }

        return qce->async_req_enqueue(tmpl->qce, &req->base);
}

static int qce_ahash_hmac_setkey(struct crypto_ahash *tfm, const u8 *key,
                                 unsigned int keylen)
{
        unsigned int digestsize = crypto_ahash_digestsize(tfm);
        struct qce_sha_ctx *ctx = crypto_tfm_ctx(&tfm->base);
        struct crypto_wait wait;
        struct ahash_request *req;
        struct scatterlist sg;
        unsigned int blocksize;
        struct crypto_ahash *ahash_tfm;
        u8 *buf;
        int ret;
        const char *alg_name;

        blocksize = crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
        memset(ctx->authkey, 0, sizeof(ctx->authkey));

        if (keylen <= blocksize) {
                memcpy(ctx->authkey, key, keylen);
                return 0;
        }

        if (digestsize == SHA1_DIGEST_SIZE)
                alg_name = "sha1-qce";
        else if (digestsize == SHA256_DIGEST_SIZE)
                alg_name = "sha256-qce";
        else
                return -EINVAL;

        ahash_tfm = crypto_alloc_ahash(alg_name, 0, 0);
        if (IS_ERR(ahash_tfm))
                return PTR_ERR(ahash_tfm);

        req = ahash_request_alloc(ahash_tfm, GFP_KERNEL);
        if (!req) {
                ret = -ENOMEM;
                goto err_free_ahash;
        }

        crypto_init_wait(&wait);
        ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
                                   crypto_req_done, &wait);
        crypto_ahash_clear_flags(ahash_tfm, ~0);

        buf = kzalloc(keylen + QCE_MAX_ALIGN_SIZE, GFP_KERNEL);
        if (!buf) {
                ret = -ENOMEM;
                goto err_free_req;
        }

        memcpy(buf, key, keylen);
        sg_init_one(&sg, buf, keylen);
        ahash_request_set_crypt(req, &sg, ctx->authkey, keylen);

        ret = crypto_wait_req(crypto_ahash_digest(req), &wait);

        kfree(buf);
err_free_req:
        ahash_request_free(req);
err_free_ahash:
        crypto_free_ahash(ahash_tfm);
        return ret;
}

static int qce_ahash_cra_init(struct crypto_tfm *tfm)
{
        struct crypto_ahash *ahash = __crypto_ahash_cast(tfm);
        struct qce_sha_ctx *ctx = crypto_tfm_ctx(tfm);

        crypto_ahash_set_reqsize(ahash, sizeof(struct qce_sha_reqctx));
        memset(ctx, 0, sizeof(*ctx));
        return 0;
}

struct qce_ahash_def {
        unsigned long flags;
        const char *name;
        const char *drv_name;
        unsigned int digestsize;
        unsigned int blocksize;
        unsigned int statesize;
        const u32 *std_iv;
};

static const struct qce_ahash_def ahash_def[] = {
        {
                .flags          = QCE_HASH_SHA1,
                .name           = "sha1",
                .drv_name       = "sha1-qce",
                .digestsize     = SHA1_DIGEST_SIZE,
                .blocksize      = SHA1_BLOCK_SIZE,
                .statesize      = sizeof(struct qce_sha_saved_state),
                .std_iv         = std_iv_sha1,
        },
        {
                .flags          = QCE_HASH_SHA256,
                .name           = "sha256",
                .drv_name       = "sha256-qce",
                .digestsize     = SHA256_DIGEST_SIZE,
                .blocksize      = SHA256_BLOCK_SIZE,
                .statesize      = sizeof(struct qce_sha_saved_state),
                .std_iv         = std_iv_sha256,
        },
        {
                .flags          = QCE_HASH_SHA1_HMAC,
                .name           = "hmac(sha1)",
                .drv_name       = "hmac-sha1-qce",
                .digestsize     = SHA1_DIGEST_SIZE,
                .blocksize      = SHA1_BLOCK_SIZE,
                .statesize      = sizeof(struct qce_sha_saved_state),
                .std_iv         = std_iv_sha1,
        },
        {
                .flags          = QCE_HASH_SHA256_HMAC,
                .name           = "hmac(sha256)",
                .drv_name       = "hmac-sha256-qce",
                .digestsize     = SHA256_DIGEST_SIZE,
                .blocksize      = SHA256_BLOCK_SIZE,
                .statesize      = sizeof(struct qce_sha_saved_state),
                .std_iv         = std_iv_sha256,
        },
};

static int qce_ahash_register_one(const struct qce_ahash_def *def,
                                  struct qce_device *qce)
{
        struct qce_alg_template *tmpl;
        struct ahash_alg *alg;
        struct crypto_alg *base;
        int ret;

        tmpl = kzalloc(sizeof(*tmpl), GFP_KERNEL);
        if (!tmpl)
                return -ENOMEM;

        tmpl->std_iv = def->std_iv;

        alg = &tmpl->alg.ahash;
        alg->init = qce_ahash_init;
        alg->update = qce_ahash_update;
        alg->final = qce_ahash_final;
        alg->digest = qce_ahash_digest;
        alg->export = qce_ahash_export;
        alg->import = qce_ahash_import;
        if (IS_SHA_HMAC(def->flags))
                alg->setkey = qce_ahash_hmac_setkey;
        alg->halg.digestsize = def->digestsize;
        alg->halg.statesize = def->statesize;

        if (IS_SHA1(def->flags))
                tmpl->hash_zero = sha1_zero_message_hash;
        else if (IS_SHA256(def->flags))
                tmpl->hash_zero = sha256_zero_message_hash;

        base = &alg->halg.base;
        base->cra_blocksize = def->blocksize;
        base->cra_priority = 300;
        base->cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY;
        base->cra_ctxsize = sizeof(struct qce_sha_ctx);
        base->cra_alignmask = 0;
        base->cra_module = THIS_MODULE;
        base->cra_init = qce_ahash_cra_init;

        snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
        snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
                 def->drv_name);

        INIT_LIST_HEAD(&tmpl->entry);
        tmpl->crypto_alg_type = CRYPTO_ALG_TYPE_AHASH;
        tmpl->alg_flags = def->flags;
        tmpl->qce = qce;

        ret = crypto_register_ahash(alg);
        if (ret) {
                dev_err(qce->dev, "%s registration failed\n", base->cra_name);
                kfree(tmpl);
                return ret;
        }

        list_add_tail(&tmpl->entry, &ahash_algs);
        dev_dbg(qce->dev, "%s is registered\n", base->cra_name);
        return 0;
}

static void qce_ahash_unregister(struct qce_device *qce)
{
        struct qce_alg_template *tmpl, *n;

        list_for_each_entry_safe(tmpl, n, &ahash_algs, entry) {
                crypto_unregister_ahash(&tmpl->alg.ahash);
                list_del(&tmpl->entry);
                kfree(tmpl);
        }
}

static int qce_ahash_register(struct qce_device *qce)
{
        int ret, i;

        for (i = 0; i < ARRAY_SIZE(ahash_def); i++) {
                ret = qce_ahash_register_one(&ahash_def[i], qce);
                if (ret)
                        goto err;
        }

        return 0;
err:
        qce_ahash_unregister(qce);
        return ret;
}

const struct qce_algo_ops ahash_ops = {
        .type = CRYPTO_ALG_TYPE_AHASH,
        .register_algs = qce_ahash_register,
        .unregister_algs = qce_ahash_unregister,
        .async_req_handle = qce_ahash_async_req_handle,
};