// SPDX-License-Identifier: GPL-2.0
/*
 * sun8i-ce-hash.c - hardware cryptographic offloader for
 * Allwinner H3/A64/H5/H2+/H6/R40 SoC
 *
 * Copyright (C) 2015-2020 Corentin Labbe <clabbe@baylibre.com>
 *
 * This file add support for MD5 and SHA1/SHA224/SHA256/SHA384/SHA512.
 *
 * You could find the datasheet in Documentation/arch/arm/sunxi.rst
 */

#include <crypto/internal/hash.h>
#include <crypto/md5.h>
#include <crypto/sha1.h>
#include <crypto/sha2.h>
#include <linux/bottom_half.h>
#include <linux/dma-mapping.h>
#include <linux/kernel.h>
#include <linux/pm_runtime.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "sun8i-ce.h"

static void sun8i_ce_hash_stat_fb_inc(struct crypto_ahash *tfm)
{
        if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG)) {
                struct sun8i_ce_alg_template *algt;
                struct ahash_alg *alg = crypto_ahash_alg(tfm);

                algt = container_of(alg, struct sun8i_ce_alg_template,
                                    alg.hash.base);
                algt->stat_fb++;
        }
}

int sun8i_ce_hash_init_tfm(struct crypto_ahash *tfm)
{
        struct sun8i_ce_hash_tfm_ctx *op = crypto_ahash_ctx(tfm);
        struct ahash_alg *alg = crypto_ahash_alg(tfm);
        struct sun8i_ce_alg_template *algt;
        int err;

        algt = container_of(alg, struct sun8i_ce_alg_template, alg.hash.base);
        op->ce = algt->ce;

        /* FALLBACK */
        op->fallback_tfm = crypto_alloc_ahash(crypto_ahash_alg_name(tfm), 0,
                                              CRYPTO_ALG_NEED_FALLBACK);
        if (IS_ERR(op->fallback_tfm)) {
                dev_err(algt->ce->dev, "Fallback driver could no be loaded\n");
                return PTR_ERR(op->fallback_tfm);
        }

        crypto_ahash_set_statesize(tfm,
                                   crypto_ahash_statesize(op->fallback_tfm));

        crypto_ahash_set_reqsize(tfm,
                                 sizeof(struct sun8i_ce_hash_reqctx) +
                                 crypto_ahash_reqsize(op->fallback_tfm) +
                                 CRYPTO_DMA_PADDING);

        if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG))
                memcpy(algt->fbname,
                       crypto_ahash_driver_name(op->fallback_tfm),
                       CRYPTO_MAX_ALG_NAME);

        err = pm_runtime_resume_and_get(op->ce->dev);
        if (err < 0)
                goto error_pm;
        return 0;
error_pm:
        crypto_free_ahash(op->fallback_tfm);
        return err;
}

void sun8i_ce_hash_exit_tfm(struct crypto_ahash *tfm)
{
        struct sun8i_ce_hash_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);

        crypto_free_ahash(tfmctx->fallback_tfm);
        pm_runtime_put_sync_suspend(tfmctx->ce->dev);
}

int sun8i_ce_hash_init(struct ahash_request *areq)
{
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);

        memset(rctx, 0, sizeof(struct sun8i_ce_hash_reqctx));

        ahash_request_set_tfm(&rctx->fallback_req, tfmctx->fallback_tfm);
        ahash_request_set_callback(&rctx->fallback_req,
                                   areq->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP,
                                   areq->base.complete, areq->base.data);

        return crypto_ahash_init(&rctx->fallback_req);
}

int sun8i_ce_hash_export(struct ahash_request *areq, void *out)
{
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);

        ahash_request_set_tfm(&rctx->fallback_req, tfmctx->fallback_tfm);
        ahash_request_set_callback(&rctx->fallback_req,
                                   areq->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP,
                                   areq->base.complete, areq->base.data);

        return crypto_ahash_export(&rctx->fallback_req, out);
}

int sun8i_ce_hash_import(struct ahash_request *areq, const void *in)
{
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);

        ahash_request_set_tfm(&rctx->fallback_req, tfmctx->fallback_tfm);
        ahash_request_set_callback(&rctx->fallback_req,
                                   areq->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP,
                                   areq->base.complete, areq->base.data);

        return crypto_ahash_import(&rctx->fallback_req, in);
}

int sun8i_ce_hash_final(struct ahash_request *areq)
{
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);

        sun8i_ce_hash_stat_fb_inc(tfm);

        ahash_request_set_tfm(&rctx->fallback_req, tfmctx->fallback_tfm);
        ahash_request_set_callback(&rctx->fallback_req,
                                   areq->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP,
                                   areq->base.complete, areq->base.data);
        ahash_request_set_crypt(&rctx->fallback_req, NULL, areq->result, 0);

        return crypto_ahash_final(&rctx->fallback_req);
}

int sun8i_ce_hash_update(struct ahash_request *areq)
{
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);

        ahash_request_set_tfm(&rctx->fallback_req, tfmctx->fallback_tfm);
        ahash_request_set_callback(&rctx->fallback_req,
                                   areq->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP,
                                   areq->base.complete, areq->base.data);
        ahash_request_set_crypt(&rctx->fallback_req, areq->src, NULL, areq->nbytes);

        return crypto_ahash_update(&rctx->fallback_req);
}

int sun8i_ce_hash_finup(struct ahash_request *areq)
{
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);

        sun8i_ce_hash_stat_fb_inc(tfm);

        ahash_request_set_tfm(&rctx->fallback_req, tfmctx->fallback_tfm);
        ahash_request_set_callback(&rctx->fallback_req,
                                   areq->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP,
                                   areq->base.complete, areq->base.data);
        ahash_request_set_crypt(&rctx->fallback_req, areq->src, areq->result,
                                areq->nbytes);

        return crypto_ahash_finup(&rctx->fallback_req);
}

static int sun8i_ce_hash_digest_fb(struct ahash_request *areq)
{
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *tfmctx = crypto_ahash_ctx(tfm);

        sun8i_ce_hash_stat_fb_inc(tfm);

        ahash_request_set_tfm(&rctx->fallback_req, tfmctx->fallback_tfm);
        ahash_request_set_callback(&rctx->fallback_req,
                                   areq->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP,
                                   areq->base.complete, areq->base.data);
        ahash_request_set_crypt(&rctx->fallback_req, areq->src, areq->result,
                                areq->nbytes);

        return crypto_ahash_digest(&rctx->fallback_req);
}

static bool sun8i_ce_hash_need_fallback(struct ahash_request *areq)
{
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct ahash_alg *alg = __crypto_ahash_alg(tfm->base.__crt_alg);
        struct sun8i_ce_alg_template *algt;
        struct scatterlist *sg;

        algt = container_of(alg, struct sun8i_ce_alg_template, alg.hash.base);

        if (areq->nbytes == 0) {
                if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG))
                        algt->stat_fb_len0++;

                return true;
        }
        /* we need to reserve one SG for padding one */
        if (sg_nents_for_len(areq->src, areq->nbytes) > MAX_SG - 1) {
                if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG))
                        algt->stat_fb_maxsg++;

                return true;
        }
        sg = areq->src;
        while (sg) {
                if (sg->length % 4) {
                        if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG))
                                algt->stat_fb_srclen++;

                        return true;
                }
                if (!IS_ALIGNED(sg->offset, sizeof(u32))) {
                        if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG))
                                algt->stat_fb_srcali++;

                        return true;
                }
                sg = sg_next(sg);
        }
        return false;
}

int sun8i_ce_hash_digest(struct ahash_request *areq)
{
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *ctx = crypto_ahash_ctx(tfm);
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct sun8i_ce_dev *ce = ctx->ce;
        struct crypto_engine *engine;
        int e;

        if (sun8i_ce_hash_need_fallback(areq))
                return sun8i_ce_hash_digest_fb(areq);

        e = sun8i_ce_get_engine_number(ce);
        rctx->flow = e;
        engine = ce->chanlist[e].engine;

        return crypto_transfer_hash_request_to_engine(engine, areq);
}

static u64 hash_pad(__le32 *buf, unsigned int bufsize, u64 padi, u64 byte_count, bool le, int bs)
{
        u64 fill, min_fill, j, k;
        __be64 *bebits;
        __le64 *lebits;

        j = padi;
        buf[j++] = cpu_to_le32(0x80);

        if (bs == 64) {
                fill = 64 - (byte_count % 64);
                min_fill = 2 * sizeof(u32) + sizeof(u32);
        } else {
                fill = 128 - (byte_count % 128);
                min_fill = 4 * sizeof(u32) + sizeof(u32);
        }

        if (fill < min_fill)
                fill += bs;

        k = j;
        j += (fill - min_fill) / sizeof(u32);
        if (j * 4 > bufsize) {
                pr_err("%s OVERFLOW %llu\n", __func__, j);
                return 0;
        }
        for (; k < j; k++)
                buf[k] = 0;

        if (le) {
                /* MD5 */
                lebits = (__le64 *)&buf[j];
                *lebits = cpu_to_le64(byte_count << 3);
                j += 2;
        } else {
                if (bs == 64) {
                        /* sha1 sha224 sha256 */
                        bebits = (__be64 *)&buf[j];
                        *bebits = cpu_to_be64(byte_count << 3);
                        j += 2;
                } else {
                        /* sha384 sha512*/
                        bebits = (__be64 *)&buf[j];
                        *bebits = cpu_to_be64(byte_count >> 61);
                        j += 2;
                        bebits = (__be64 *)&buf[j];
                        *bebits = cpu_to_be64(byte_count << 3);
                        j += 2;
                }
        }
        if (j * 4 > bufsize) {
                pr_err("%s OVERFLOW %llu\n", __func__, j);
                return 0;
        }

        return j;
}

static int sun8i_ce_hash_prepare(struct ahash_request *areq, struct ce_task *cet)
{
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct ahash_alg *alg = __crypto_ahash_alg(tfm->base.__crt_alg);
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct sun8i_ce_alg_template *algt;
        struct sun8i_ce_dev *ce;
        struct scatterlist *sg;
        int nr_sgs, err;
        unsigned int len;
        u32 common;
        u64 byte_count;
        __le32 *bf;
        int j, i, todo;
        u64 bs;
        int digestsize;

        algt = container_of(alg, struct sun8i_ce_alg_template, alg.hash.base);
        ce = algt->ce;

        bs = crypto_ahash_blocksize(tfm);
        digestsize = crypto_ahash_digestsize(tfm);
        if (digestsize == SHA224_DIGEST_SIZE)
                digestsize = SHA256_DIGEST_SIZE;
        if (digestsize == SHA384_DIGEST_SIZE)
                digestsize = SHA512_DIGEST_SIZE;

        bf = (__le32 *)rctx->pad;

        if (IS_ENABLED(CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG))
                algt->stat_req++;

        dev_dbg(ce->dev, "%s %s len=%d\n", __func__, crypto_tfm_alg_name(areq->base.tfm), areq->nbytes);

        memset(cet, 0, sizeof(struct ce_task));

        cet->t_id = cpu_to_le32(rctx->flow);
        common = ce->variant->alg_hash[algt->ce_algo_id];
        common |= CE_COMM_INT;
        cet->t_common_ctl = cpu_to_le32(common);

        cet->t_sym_ctl = 0;
        cet->t_asym_ctl = 0;

        rctx->nr_sgs = sg_nents_for_len(areq->src, areq->nbytes);
        nr_sgs = dma_map_sg(ce->dev, areq->src, rctx->nr_sgs, DMA_TO_DEVICE);
        if (nr_sgs <= 0 || nr_sgs > MAX_SG) {
                dev_err(ce->dev, "Invalid sg number %d\n", nr_sgs);
                err = -EINVAL;
                goto err_out;
        }

        len = areq->nbytes;
        for_each_sg(areq->src, sg, nr_sgs, i) {
                cet->t_src[i].addr = desc_addr_val_le32(ce, sg_dma_address(sg));
                todo = min(len, sg_dma_len(sg));
                cet->t_src[i].len = cpu_to_le32(todo / 4);
                len -= todo;
        }
        if (len > 0) {
                dev_err(ce->dev, "remaining len %d\n", len);
                err = -EINVAL;
                goto err_unmap_src;
        }

        rctx->result_len = digestsize;
        rctx->addr_res = dma_map_single(ce->dev, rctx->result, rctx->result_len,
                                        DMA_FROM_DEVICE);
        cet->t_dst[0].addr = desc_addr_val_le32(ce, rctx->addr_res);
        cet->t_dst[0].len = cpu_to_le32(rctx->result_len / 4);
        if (dma_mapping_error(ce->dev, rctx->addr_res)) {
                dev_err(ce->dev, "DMA map dest\n");
                err = -EINVAL;
                goto err_unmap_src;
        }

        byte_count = areq->nbytes;
        j = 0;

        switch (algt->ce_algo_id) {
        case CE_ID_HASH_MD5:
                j = hash_pad(bf, 2 * bs, j, byte_count, true, bs);
                break;
        case CE_ID_HASH_SHA1:
        case CE_ID_HASH_SHA224:
        case CE_ID_HASH_SHA256:
                j = hash_pad(bf, 2 * bs, j, byte_count, false, bs);
                break;
        case CE_ID_HASH_SHA384:
        case CE_ID_HASH_SHA512:
                j = hash_pad(bf, 2 * bs, j, byte_count, false, bs);
                break;
        }
        if (!j) {
                err = -EINVAL;
                goto err_unmap_result;
        }

        rctx->pad_len = j * 4;
        rctx->addr_pad = dma_map_single(ce->dev, rctx->pad, rctx->pad_len,
                                        DMA_TO_DEVICE);
        cet->t_src[i].addr = desc_addr_val_le32(ce, rctx->addr_pad);
        cet->t_src[i].len = cpu_to_le32(j);
        if (dma_mapping_error(ce->dev, rctx->addr_pad)) {
                dev_err(ce->dev, "DMA error on padding SG\n");
                err = -EINVAL;
                goto err_unmap_result;
        }

        if (ce->variant->hash_t_dlen_in_bits)
                cet->t_dlen = cpu_to_le32((areq->nbytes + j * 4) * 8);
        else
                cet->t_dlen = cpu_to_le32(areq->nbytes / 4 + j);

        return 0;

err_unmap_result:
        dma_unmap_single(ce->dev, rctx->addr_res, rctx->result_len,
                         DMA_FROM_DEVICE);

err_unmap_src:
        dma_unmap_sg(ce->dev, areq->src, rctx->nr_sgs, DMA_TO_DEVICE);

err_out:
        return err;
}

static void sun8i_ce_hash_unprepare(struct ahash_request *areq,
                                    struct ce_task *cet)
{
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *ctx = crypto_ahash_ctx(tfm);
        struct sun8i_ce_dev *ce = ctx->ce;

        dma_unmap_single(ce->dev, rctx->addr_pad, rctx->pad_len, DMA_TO_DEVICE);
        dma_unmap_single(ce->dev, rctx->addr_res, rctx->result_len,
                         DMA_FROM_DEVICE);
        dma_unmap_sg(ce->dev, areq->src, rctx->nr_sgs, DMA_TO_DEVICE);
}

int sun8i_ce_hash_run(struct crypto_engine *engine, void *async_req)
{
        struct ahash_request *areq = ahash_request_cast(async_req);
        struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
        struct sun8i_ce_hash_tfm_ctx *ctx = crypto_ahash_ctx(tfm);
        struct sun8i_ce_hash_reqctx *rctx = ahash_request_ctx_dma(areq);
        struct sun8i_ce_dev *ce = ctx->ce;
        struct sun8i_ce_flow *chan;
        int err;

        chan = &ce->chanlist[rctx->flow];

        err = sun8i_ce_hash_prepare(areq, chan->tl);
        if (err)
                return err;

        err = sun8i_ce_run_task(ce, rctx->flow, crypto_ahash_alg_name(tfm));

        sun8i_ce_hash_unprepare(areq, chan->tl);

        if (!err)
                memcpy(areq->result, rctx->result,
                       crypto_ahash_digestsize(tfm));

        local_bh_disable();
        crypto_finalize_hash_request(engine, async_req, err);
        local_bh_enable();

        return 0;
}