// 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 <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <crypto/aes.h>
#include <crypto/internal/des.h>
#include <crypto/internal/skcipher.h>

#include "cipher.h"

static unsigned int aes_sw_max_len = CONFIG_CRYPTO_DEV_QCE_SW_MAX_LEN;
module_param(aes_sw_max_len, uint, 0644);
MODULE_PARM_DESC(aes_sw_max_len,
                 "Only use hardware for AES requests larger than this "
                 "[0=always use hardware; anything <16 breaks AES-GCM; default="
                 __stringify(CONFIG_CRYPTO_DEV_QCE_SW_MAX_LEN)"]");

static LIST_HEAD(skcipher_algs);

static void qce_skcipher_done(void *data)
{
        struct crypto_async_request *async_req = data;
        struct skcipher_request *req = skcipher_request_cast(async_req);
        struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
        struct qce_alg_template *tmpl = to_cipher_tmpl(crypto_skcipher_reqtfm(req));
        struct qce_device *qce = tmpl->qce;
        struct qce_result_dump *result_buf = qce->dma.result_buf;
        enum dma_data_direction dir_src, dir_dst;
        u32 status;
        int error;
        bool diff_dst;

        diff_dst = (req->src != req->dst) ? true : false;
        dir_src = diff_dst ? DMA_TO_DEVICE : DMA_BIDIRECTIONAL;
        dir_dst = diff_dst ? DMA_FROM_DEVICE : DMA_BIDIRECTIONAL;

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

        if (diff_dst)
                dma_unmap_sg(qce->dev, rctx->src_sg, rctx->src_nents, dir_src);
        dma_unmap_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);

        sg_free_table(&rctx->dst_tbl);

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

        memcpy(rctx->iv, result_buf->encr_cntr_iv, rctx->ivsize);
        qce->async_req_done(tmpl->qce, error);
}

static int
qce_skcipher_async_req_handle(struct crypto_async_request *async_req)
{
        struct skcipher_request *req = skcipher_request_cast(async_req);
        struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
        struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
        struct qce_alg_template *tmpl = to_cipher_tmpl(crypto_skcipher_reqtfm(req));
        struct qce_device *qce = tmpl->qce;
        enum dma_data_direction dir_src, dir_dst;
        struct scatterlist *sg;
        bool diff_dst;
        gfp_t gfp;
        int dst_nents, src_nents, ret;

        rctx->iv = req->iv;
        rctx->ivsize = crypto_skcipher_ivsize(skcipher);
        rctx->cryptlen = req->cryptlen;

        diff_dst = (req->src != req->dst) ? true : false;
        dir_src = diff_dst ? DMA_TO_DEVICE : DMA_BIDIRECTIONAL;
        dir_dst = diff_dst ? DMA_FROM_DEVICE : DMA_BIDIRECTIONAL;

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

        rctx->dst_nents += 1;

        gfp = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
                                                GFP_KERNEL : GFP_ATOMIC;

        ret = sg_alloc_table(&rctx->dst_tbl, rctx->dst_nents, gfp);
        if (ret)
                return ret;

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

        sg = qce_sgtable_add(&rctx->dst_tbl, req->dst, req->cryptlen);
        if (IS_ERR(sg)) {
                ret = PTR_ERR(sg);
                goto error_free;
        }

        sg = qce_sgtable_add(&rctx->dst_tbl, &rctx->result_sg,
                             QCE_RESULT_BUF_SZ);
        if (IS_ERR(sg)) {
                ret = PTR_ERR(sg);
                goto error_free;
        }

        sg_mark_end(sg);
        rctx->dst_sg = rctx->dst_tbl.sgl;

        dst_nents = dma_map_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);
        if (!dst_nents) {
                ret = -EIO;
                goto error_free;
        }

        if (diff_dst) {
                src_nents = dma_map_sg(qce->dev, req->src, rctx->src_nents, dir_src);
                if (!src_nents) {
                        ret = -EIO;
                        goto error_unmap_dst;
                }
                rctx->src_sg = req->src;
        } else {
                rctx->src_sg = rctx->dst_sg;
                src_nents = dst_nents - 1;
        }

        ret = qce_dma_prep_sgs(&qce->dma, rctx->src_sg, src_nents,
                               rctx->dst_sg, dst_nents,
                               qce_skcipher_done, async_req);
        if (ret)
                goto error_unmap_src;

        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_src:
        if (diff_dst)
                dma_unmap_sg(qce->dev, req->src, rctx->src_nents, dir_src);
error_unmap_dst:
        dma_unmap_sg(qce->dev, rctx->dst_sg, rctx->dst_nents, dir_dst);
error_free:
        sg_free_table(&rctx->dst_tbl);
        return ret;
}

static int qce_skcipher_setkey(struct crypto_skcipher *ablk, const u8 *key,
                                 unsigned int keylen)
{
        struct crypto_tfm *tfm = crypto_skcipher_tfm(ablk);
        struct qce_cipher_ctx *ctx = crypto_tfm_ctx(tfm);
        unsigned long flags = to_cipher_tmpl(ablk)->alg_flags;
        unsigned int __keylen;
        int ret;

        if (!key || !keylen)
                return -EINVAL;

        /*
         * AES XTS key1 = key2 not supported by crypto engine.
         * Revisit to request a fallback cipher in this case.
         */
        if (IS_XTS(flags)) {
                __keylen = keylen >> 1;
                if (!memcmp(key, key + __keylen, __keylen))
                        return -ENOKEY;
        } else {
                __keylen = keylen;
        }

        switch (__keylen) {
        case AES_KEYSIZE_128:
        case AES_KEYSIZE_256:
                memcpy(ctx->enc_key, key, keylen);
                break;
        case AES_KEYSIZE_192:
                break;
        default:
                return -EINVAL;
        }

        ret = crypto_skcipher_setkey(ctx->fallback, key, keylen);
        if (!ret)
                ctx->enc_keylen = keylen;
        return ret;
}

static int qce_des_setkey(struct crypto_skcipher *ablk, const u8 *key,
                          unsigned int keylen)
{
        struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(ablk);
        int err;

        err = verify_skcipher_des_key(ablk, key);
        if (err)
                return err;

        ctx->enc_keylen = keylen;
        memcpy(ctx->enc_key, key, keylen);
        return 0;
}

static int qce_des3_setkey(struct crypto_skcipher *ablk, const u8 *key,
                           unsigned int keylen)
{
        struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(ablk);
        u32 _key[6];
        int err;

        err = verify_skcipher_des3_key(ablk, key);
        if (err)
                return err;

        /*
         * The crypto engine does not support any two keys
         * being the same for triple des algorithms. The
         * verify_skcipher_des3_key does not check for all the
         * below conditions. Return -ENOKEY in case any two keys
         * are the same. Revisit to see if a fallback cipher
         * is needed to handle this condition.
         */
        memcpy(_key, key, DES3_EDE_KEY_SIZE);
        if (!((_key[0] ^ _key[2]) | (_key[1] ^ _key[3])) ||
            !((_key[2] ^ _key[4]) | (_key[3] ^ _key[5])) ||
            !((_key[0] ^ _key[4]) | (_key[1] ^ _key[5])))
                return -ENOKEY;

        ctx->enc_keylen = keylen;
        memcpy(ctx->enc_key, key, keylen);
        return 0;
}

static int qce_skcipher_crypt(struct skcipher_request *req, int encrypt)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct qce_cipher_reqctx *rctx = skcipher_request_ctx(req);
        struct qce_alg_template *tmpl = to_cipher_tmpl(tfm);
        unsigned int blocksize = crypto_skcipher_blocksize(tfm);
        int keylen;
        int ret;

        rctx->flags = tmpl->alg_flags;
        rctx->flags |= encrypt ? QCE_ENCRYPT : QCE_DECRYPT;
        keylen = IS_XTS(rctx->flags) ? ctx->enc_keylen >> 1 : ctx->enc_keylen;

        /* CE does not handle 0 length messages */
        if (!req->cryptlen)
                return 0;

        /*
         * ECB and CBC algorithms require message lengths to be
         * multiples of block size.
         */
        if (IS_ECB(rctx->flags) || IS_CBC(rctx->flags))
                if (!IS_ALIGNED(req->cryptlen, blocksize))
                        return -EINVAL;

        /*
         * Conditions for requesting a fallback cipher
         * AES-192 (not supported by crypto engine (CE))
         * AES-XTS request with len <= 512 byte (not recommended to use CE)
         * AES-XTS request with len > QCE_SECTOR_SIZE and
         * is not a multiple of it.(Revisit this condition to check if it is
         * needed in all versions of CE)
         */
        if (IS_AES(rctx->flags) &&
            ((keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_256) ||
            (IS_XTS(rctx->flags) && ((req->cryptlen <= aes_sw_max_len) ||
            (req->cryptlen > QCE_SECTOR_SIZE &&
            req->cryptlen % QCE_SECTOR_SIZE))))) {
                skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
                skcipher_request_set_callback(&rctx->fallback_req,
                                              req->base.flags,
                                              req->base.complete,
                                              req->base.data);
                skcipher_request_set_crypt(&rctx->fallback_req, req->src,
                                           req->dst, req->cryptlen, req->iv);
                ret = encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) :
                                crypto_skcipher_decrypt(&rctx->fallback_req);
                return ret;
        }

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

static int qce_skcipher_encrypt(struct skcipher_request *req)
{
        return qce_skcipher_crypt(req, 1);
}

static int qce_skcipher_decrypt(struct skcipher_request *req)
{
        return qce_skcipher_crypt(req, 0);
}

static int qce_skcipher_init(struct crypto_skcipher *tfm)
{
        /* take the size without the fallback skcipher_request at the end */
        crypto_skcipher_set_reqsize(tfm, offsetof(struct qce_cipher_reqctx,
                                                  fallback_req));
        return 0;
}

static int qce_skcipher_init_fallback(struct crypto_skcipher *tfm)
{
        struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);

        ctx->fallback = crypto_alloc_skcipher(crypto_tfm_alg_name(&tfm->base),
                                              0, CRYPTO_ALG_NEED_FALLBACK);
        if (IS_ERR(ctx->fallback))
                return PTR_ERR(ctx->fallback);

        crypto_skcipher_set_reqsize(tfm, sizeof(struct qce_cipher_reqctx) +
                                         crypto_skcipher_reqsize(ctx->fallback));
        return 0;
}

static void qce_skcipher_exit(struct crypto_skcipher *tfm)
{
        struct qce_cipher_ctx *ctx = crypto_skcipher_ctx(tfm);

        crypto_free_skcipher(ctx->fallback);
}

struct qce_skcipher_def {
        unsigned long flags;
        const char *name;
        const char *drv_name;
        unsigned int blocksize;
        unsigned int chunksize;
        unsigned int ivsize;
        unsigned int min_keysize;
        unsigned int max_keysize;
};

static const struct qce_skcipher_def skcipher_def[] = {
        {
                .flags          = QCE_ALG_AES | QCE_MODE_ECB,
                .name           = "ecb(aes)",
                .drv_name       = "ecb-aes-qce",
                .blocksize      = AES_BLOCK_SIZE,
                .ivsize         = 0,
                .min_keysize    = AES_MIN_KEY_SIZE,
                .max_keysize    = AES_MAX_KEY_SIZE,
        },
        {
                .flags          = QCE_ALG_AES | QCE_MODE_CBC,
                .name           = "cbc(aes)",
                .drv_name       = "cbc-aes-qce",
                .blocksize      = AES_BLOCK_SIZE,
                .ivsize         = AES_BLOCK_SIZE,
                .min_keysize    = AES_MIN_KEY_SIZE,
                .max_keysize    = AES_MAX_KEY_SIZE,
        },
        {
                .flags          = QCE_ALG_AES | QCE_MODE_CTR,
                .name           = "ctr(aes)",
                .drv_name       = "ctr-aes-qce",
                .blocksize      = 1,
                .chunksize      = AES_BLOCK_SIZE,
                .ivsize         = AES_BLOCK_SIZE,
                .min_keysize    = AES_MIN_KEY_SIZE,
                .max_keysize    = AES_MAX_KEY_SIZE,
        },
        {
                .flags          = QCE_ALG_AES | QCE_MODE_XTS,
                .name           = "xts(aes)",
                .drv_name       = "xts-aes-qce",
                .blocksize      = AES_BLOCK_SIZE,
                .ivsize         = AES_BLOCK_SIZE,
                .min_keysize    = AES_MIN_KEY_SIZE * 2,
                .max_keysize    = AES_MAX_KEY_SIZE * 2,
        },
        {
                .flags          = QCE_ALG_DES | QCE_MODE_ECB,
                .name           = "ecb(des)",
                .drv_name       = "ecb-des-qce",
                .blocksize      = DES_BLOCK_SIZE,
                .ivsize         = 0,
                .min_keysize    = DES_KEY_SIZE,
                .max_keysize    = DES_KEY_SIZE,
        },
        {
                .flags          = QCE_ALG_DES | QCE_MODE_CBC,
                .name           = "cbc(des)",
                .drv_name       = "cbc-des-qce",
                .blocksize      = DES_BLOCK_SIZE,
                .ivsize         = DES_BLOCK_SIZE,
                .min_keysize    = DES_KEY_SIZE,
                .max_keysize    = DES_KEY_SIZE,
        },
        {
                .flags          = QCE_ALG_3DES | QCE_MODE_ECB,
                .name           = "ecb(des3_ede)",
                .drv_name       = "ecb-3des-qce",
                .blocksize      = DES3_EDE_BLOCK_SIZE,
                .ivsize         = 0,
                .min_keysize    = DES3_EDE_KEY_SIZE,
                .max_keysize    = DES3_EDE_KEY_SIZE,
        },
        {
                .flags          = QCE_ALG_3DES | QCE_MODE_CBC,
                .name           = "cbc(des3_ede)",
                .drv_name       = "cbc-3des-qce",
                .blocksize      = DES3_EDE_BLOCK_SIZE,
                .ivsize         = DES3_EDE_BLOCK_SIZE,
                .min_keysize    = DES3_EDE_KEY_SIZE,
                .max_keysize    = DES3_EDE_KEY_SIZE,
        },
};

static int qce_skcipher_register_one(const struct qce_skcipher_def *def,
                                       struct qce_device *qce)
{
        struct qce_alg_template *tmpl;
        struct skcipher_alg *alg;
        int ret;

        tmpl = kzalloc_obj(*tmpl);
        if (!tmpl)
                return -ENOMEM;

        alg = &tmpl->alg.skcipher;

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

        alg->base.cra_blocksize         = def->blocksize;
        alg->chunksize                  = def->chunksize;
        alg->ivsize                     = def->ivsize;
        alg->min_keysize                = def->min_keysize;
        alg->max_keysize                = def->max_keysize;
        alg->setkey                     = IS_3DES(def->flags) ? qce_des3_setkey :
                                          IS_DES(def->flags) ? qce_des_setkey :
                                          qce_skcipher_setkey;
        alg->encrypt                    = qce_skcipher_encrypt;
        alg->decrypt                    = qce_skcipher_decrypt;

        alg->base.cra_priority          = 275;
        alg->base.cra_flags             = CRYPTO_ALG_ASYNC |
                                          CRYPTO_ALG_ALLOCATES_MEMORY |
                                          CRYPTO_ALG_KERN_DRIVER_ONLY;
        alg->base.cra_ctxsize           = sizeof(struct qce_cipher_ctx);
        alg->base.cra_alignmask         = 0;
        alg->base.cra_module            = THIS_MODULE;

        if (IS_AES(def->flags)) {
                alg->base.cra_flags    |= CRYPTO_ALG_NEED_FALLBACK;
                alg->init               = qce_skcipher_init_fallback;
                alg->exit               = qce_skcipher_exit;
        } else {
                alg->init               = qce_skcipher_init;
        }

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

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

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

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

        list_for_each_entry_safe(tmpl, n, &skcipher_algs, entry) {
                crypto_unregister_skcipher(&tmpl->alg.skcipher);
                list_del(&tmpl->entry);
                kfree(tmpl);
        }
}

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

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

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

const struct qce_algo_ops skcipher_ops = {
        .type = CRYPTO_ALG_TYPE_SKCIPHER,
        .register_algs = qce_skcipher_register,
        .unregister_algs = qce_skcipher_unregister,
        .async_req_handle = qce_skcipher_async_req_handle,
};