// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
/*
 * caam - Freescale FSL CAAM support for Public Key Cryptography
 *
 * Copyright 2016 Freescale Semiconductor, Inc.
 * Copyright 2018-2019 NXP
 *
 * There is no Shared Descriptor for PKC so that the Job Descriptor must carry
 * all the desired key parameters, input and output pointers.
 */
#include "compat.h"
#include "regs.h"
#include "intern.h"
#include "jr.h"
#include "error.h"
#include "desc_constr.h"
#include "sg_sw_sec4.h"
#include "caampkc.h"

#define DESC_RSA_PUB_LEN        (2 * CAAM_CMD_SZ + sizeof(struct rsa_pub_pdb))
#define DESC_RSA_PRIV_F1_LEN    (2 * CAAM_CMD_SZ + \
                                 sizeof(struct rsa_priv_f1_pdb))
#define DESC_RSA_PRIV_F2_LEN    (2 * CAAM_CMD_SZ + \
                                 sizeof(struct rsa_priv_f2_pdb))
#define DESC_RSA_PRIV_F3_LEN    (2 * CAAM_CMD_SZ + \
                                 sizeof(struct rsa_priv_f3_pdb))
#define CAAM_RSA_MAX_INPUT_SIZE 512 /* for a 4096-bit modulus */

/* buffer filled with zeros, used for padding */
static u8 *zero_buffer;

static void rsa_io_unmap(struct device *dev, struct rsa_edesc *edesc,
                         struct akcipher_request *req)
{
        struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);

        dma_unmap_sg(dev, req->dst, edesc->dst_nents, DMA_FROM_DEVICE);
        dma_unmap_sg(dev, req_ctx->fixup_src, edesc->src_nents, DMA_TO_DEVICE);

        if (edesc->sec4_sg_bytes)
                dma_unmap_single(dev, edesc->sec4_sg_dma, edesc->sec4_sg_bytes,
                                 DMA_TO_DEVICE);
}

static void rsa_pub_unmap(struct device *dev, struct rsa_edesc *edesc,
                          struct akcipher_request *req)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        struct rsa_pub_pdb *pdb = &edesc->pdb.pub;

        dma_unmap_single(dev, pdb->n_dma, key->n_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->e_dma, key->e_sz, DMA_TO_DEVICE);
}

static void rsa_priv_f1_unmap(struct device *dev, struct rsa_edesc *edesc,
                              struct akcipher_request *req)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        struct rsa_priv_f1_pdb *pdb = &edesc->pdb.priv_f1;

        dma_unmap_single(dev, pdb->n_dma, key->n_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->d_dma, key->d_sz, DMA_TO_DEVICE);
}

static void rsa_priv_f2_unmap(struct device *dev, struct rsa_edesc *edesc,
                              struct akcipher_request *req)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        struct rsa_priv_f2_pdb *pdb = &edesc->pdb.priv_f2;
        size_t p_sz = key->p_sz;
        size_t q_sz = key->q_sz;

        dma_unmap_single(dev, pdb->d_dma, key->d_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->p_dma, p_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->q_dma, q_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->tmp1_dma, p_sz, DMA_BIDIRECTIONAL);
        dma_unmap_single(dev, pdb->tmp2_dma, q_sz, DMA_BIDIRECTIONAL);
}

static void rsa_priv_f3_unmap(struct device *dev, struct rsa_edesc *edesc,
                              struct akcipher_request *req)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        struct rsa_priv_f3_pdb *pdb = &edesc->pdb.priv_f3;
        size_t p_sz = key->p_sz;
        size_t q_sz = key->q_sz;

        dma_unmap_single(dev, pdb->p_dma, p_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->q_dma, q_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->dp_dma, p_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->dq_dma, q_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->c_dma, p_sz, DMA_TO_DEVICE);
        dma_unmap_single(dev, pdb->tmp1_dma, p_sz, DMA_BIDIRECTIONAL);
        dma_unmap_single(dev, pdb->tmp2_dma, q_sz, DMA_BIDIRECTIONAL);
}

/* RSA Job Completion handler */
static void rsa_pub_done(struct device *dev, u32 *desc, u32 err, void *context)
{
        struct akcipher_request *req = context;
        struct rsa_edesc *edesc;

        if (err)
                caam_jr_strstatus(dev, err);

        edesc = container_of(desc, struct rsa_edesc, hw_desc[0]);

        rsa_pub_unmap(dev, edesc, req);
        rsa_io_unmap(dev, edesc, req);
        kfree(edesc);

        akcipher_request_complete(req, err);
}

static void rsa_priv_f1_done(struct device *dev, u32 *desc, u32 err,
                             void *context)
{
        struct akcipher_request *req = context;
        struct rsa_edesc *edesc;

        if (err)
                caam_jr_strstatus(dev, err);

        edesc = container_of(desc, struct rsa_edesc, hw_desc[0]);

        rsa_priv_f1_unmap(dev, edesc, req);
        rsa_io_unmap(dev, edesc, req);
        kfree(edesc);

        akcipher_request_complete(req, err);
}

static void rsa_priv_f2_done(struct device *dev, u32 *desc, u32 err,
                             void *context)
{
        struct akcipher_request *req = context;
        struct rsa_edesc *edesc;

        if (err)
                caam_jr_strstatus(dev, err);

        edesc = container_of(desc, struct rsa_edesc, hw_desc[0]);

        rsa_priv_f2_unmap(dev, edesc, req);
        rsa_io_unmap(dev, edesc, req);
        kfree(edesc);

        akcipher_request_complete(req, err);
}

static void rsa_priv_f3_done(struct device *dev, u32 *desc, u32 err,
                             void *context)
{
        struct akcipher_request *req = context;
        struct rsa_edesc *edesc;

        if (err)
                caam_jr_strstatus(dev, err);

        edesc = container_of(desc, struct rsa_edesc, hw_desc[0]);

        rsa_priv_f3_unmap(dev, edesc, req);
        rsa_io_unmap(dev, edesc, req);
        kfree(edesc);

        akcipher_request_complete(req, err);
}

/**
 * Count leading zeros, need it to strip, from a given scatterlist
 *
 * @sgl   : scatterlist to count zeros from
 * @nbytes: number of zeros, in bytes, to strip
 * @flags : operation flags
 */
static int caam_rsa_count_leading_zeros(struct scatterlist *sgl,
                                        unsigned int nbytes,
                                        unsigned int flags)
{
        struct sg_mapping_iter miter;
        int lzeros, ents;
        unsigned int len;
        unsigned int tbytes = nbytes;
        const u8 *buff;

        ents = sg_nents_for_len(sgl, nbytes);
        if (ents < 0)
                return ents;

        sg_miter_start(&miter, sgl, ents, SG_MITER_FROM_SG | flags);

        lzeros = 0;
        len = 0;
        while (nbytes > 0) {
                /* do not strip more than given bytes */
                while (len && !*buff && lzeros < nbytes) {
                        lzeros++;
                        len--;
                        buff++;
                }

                if (len && *buff)
                        break;

                sg_miter_next(&miter);
                buff = miter.addr;
                len = miter.length;

                nbytes -= lzeros;
                lzeros = 0;
        }

        miter.consumed = lzeros;
        sg_miter_stop(&miter);
        nbytes -= lzeros;

        return tbytes - nbytes;
}

static struct rsa_edesc *rsa_edesc_alloc(struct akcipher_request *req,
                                         size_t desclen)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct device *dev = ctx->dev;
        struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);
        struct caam_rsa_key *key = &ctx->key;
        struct rsa_edesc *edesc;
        gfp_t flags = (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
                       GFP_KERNEL : GFP_ATOMIC;
        int sg_flags = (flags == GFP_ATOMIC) ? SG_MITER_ATOMIC : 0;
        int sgc;
        int sec4_sg_index, sec4_sg_len = 0, sec4_sg_bytes;
        int src_nents, dst_nents;
        unsigned int diff_size = 0;
        int lzeros;

        if (req->src_len > key->n_sz) {
                /*
                 * strip leading zeros and
                 * return the number of zeros to skip
                 */
                lzeros = caam_rsa_count_leading_zeros(req->src, req->src_len -
                                                      key->n_sz, sg_flags);
                if (lzeros < 0)
                        return ERR_PTR(lzeros);

                req_ctx->fixup_src = scatterwalk_ffwd(req_ctx->src, req->src,
                                                      lzeros);
                req_ctx->fixup_src_len = req->src_len - lzeros;
        } else {
                /*
                 * input src is less then n key modulus,
                 * so there will be zero padding
                 */
                diff_size = key->n_sz - req->src_len;
                req_ctx->fixup_src = req->src;
                req_ctx->fixup_src_len = req->src_len;
        }

        src_nents = sg_nents_for_len(req_ctx->fixup_src,
                                     req_ctx->fixup_src_len);
        dst_nents = sg_nents_for_len(req->dst, req->dst_len);

        if (!diff_size && src_nents == 1)
                sec4_sg_len = 0; /* no need for an input hw s/g table */
        else
                sec4_sg_len = src_nents + !!diff_size;
        sec4_sg_index = sec4_sg_len;
        if (dst_nents > 1)
                sec4_sg_len += pad_sg_nents(dst_nents);
        else
                sec4_sg_len = pad_sg_nents(sec4_sg_len);

        sec4_sg_bytes = sec4_sg_len * sizeof(struct sec4_sg_entry);

        /* allocate space for base edesc, hw desc commands and link tables */
        edesc = kzalloc(sizeof(*edesc) + desclen + sec4_sg_bytes,
                        GFP_DMA | flags);
        if (!edesc)
                return ERR_PTR(-ENOMEM);

        sgc = dma_map_sg(dev, req_ctx->fixup_src, src_nents, DMA_TO_DEVICE);
        if (unlikely(!sgc)) {
                dev_err(dev, "unable to map source\n");
                goto src_fail;
        }

        sgc = dma_map_sg(dev, req->dst, dst_nents, DMA_FROM_DEVICE);
        if (unlikely(!sgc)) {
                dev_err(dev, "unable to map destination\n");
                goto dst_fail;
        }

        edesc->sec4_sg = (void *)edesc + sizeof(*edesc) + desclen;
        if (diff_size)
                dma_to_sec4_sg_one(edesc->sec4_sg, ctx->padding_dma, diff_size,
                                   0);

        if (sec4_sg_index)
                sg_to_sec4_sg_last(req_ctx->fixup_src, req_ctx->fixup_src_len,
                                   edesc->sec4_sg + !!diff_size, 0);

        if (dst_nents > 1)
                sg_to_sec4_sg_last(req->dst, req->dst_len,
                                   edesc->sec4_sg + sec4_sg_index, 0);

        /* Save nents for later use in Job Descriptor */
        edesc->src_nents = src_nents;
        edesc->dst_nents = dst_nents;

        if (!sec4_sg_bytes)
                return edesc;

        edesc->sec4_sg_dma = dma_map_single(dev, edesc->sec4_sg,
                                            sec4_sg_bytes, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, edesc->sec4_sg_dma)) {
                dev_err(dev, "unable to map S/G table\n");
                goto sec4_sg_fail;
        }

        edesc->sec4_sg_bytes = sec4_sg_bytes;

        print_hex_dump_debug("caampkc sec4_sg@" __stringify(__LINE__) ": ",
                             DUMP_PREFIX_ADDRESS, 16, 4, edesc->sec4_sg,
                             edesc->sec4_sg_bytes, 1);

        return edesc;

sec4_sg_fail:
        dma_unmap_sg(dev, req->dst, dst_nents, DMA_FROM_DEVICE);
dst_fail:
        dma_unmap_sg(dev, req_ctx->fixup_src, src_nents, DMA_TO_DEVICE);
src_fail:
        kfree(edesc);
        return ERR_PTR(-ENOMEM);
}

static int set_rsa_pub_pdb(struct akcipher_request *req,
                           struct rsa_edesc *edesc)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        struct device *dev = ctx->dev;
        struct rsa_pub_pdb *pdb = &edesc->pdb.pub;
        int sec4_sg_index = 0;

        pdb->n_dma = dma_map_single(dev, key->n, key->n_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->n_dma)) {
                dev_err(dev, "Unable to map RSA modulus memory\n");
                return -ENOMEM;
        }

        pdb->e_dma = dma_map_single(dev, key->e, key->e_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->e_dma)) {
                dev_err(dev, "Unable to map RSA public exponent memory\n");
                dma_unmap_single(dev, pdb->n_dma, key->n_sz, DMA_TO_DEVICE);
                return -ENOMEM;
        }

        if (edesc->src_nents > 1) {
                pdb->sgf |= RSA_PDB_SGF_F;
                pdb->f_dma = edesc->sec4_sg_dma;
                sec4_sg_index += edesc->src_nents;
        } else {
                pdb->f_dma = sg_dma_address(req_ctx->fixup_src);
        }

        if (edesc->dst_nents > 1) {
                pdb->sgf |= RSA_PDB_SGF_G;
                pdb->g_dma = edesc->sec4_sg_dma +
                             sec4_sg_index * sizeof(struct sec4_sg_entry);
        } else {
                pdb->g_dma = sg_dma_address(req->dst);
        }

        pdb->sgf |= (key->e_sz << RSA_PDB_E_SHIFT) | key->n_sz;
        pdb->f_len = req_ctx->fixup_src_len;

        return 0;
}

static int set_rsa_priv_f1_pdb(struct akcipher_request *req,
                               struct rsa_edesc *edesc)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        struct device *dev = ctx->dev;
        struct rsa_priv_f1_pdb *pdb = &edesc->pdb.priv_f1;
        int sec4_sg_index = 0;

        pdb->n_dma = dma_map_single(dev, key->n, key->n_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->n_dma)) {
                dev_err(dev, "Unable to map modulus memory\n");
                return -ENOMEM;
        }

        pdb->d_dma = dma_map_single(dev, key->d, key->d_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->d_dma)) {
                dev_err(dev, "Unable to map RSA private exponent memory\n");
                dma_unmap_single(dev, pdb->n_dma, key->n_sz, DMA_TO_DEVICE);
                return -ENOMEM;
        }

        if (edesc->src_nents > 1) {
                pdb->sgf |= RSA_PRIV_PDB_SGF_G;
                pdb->g_dma = edesc->sec4_sg_dma;
                sec4_sg_index += edesc->src_nents;
        } else {
                struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);

                pdb->g_dma = sg_dma_address(req_ctx->fixup_src);
        }

        if (edesc->dst_nents > 1) {
                pdb->sgf |= RSA_PRIV_PDB_SGF_F;
                pdb->f_dma = edesc->sec4_sg_dma +
                             sec4_sg_index * sizeof(struct sec4_sg_entry);
        } else {
                pdb->f_dma = sg_dma_address(req->dst);
        }

        pdb->sgf |= (key->d_sz << RSA_PDB_D_SHIFT) | key->n_sz;

        return 0;
}

static int set_rsa_priv_f2_pdb(struct akcipher_request *req,
                               struct rsa_edesc *edesc)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        struct device *dev = ctx->dev;
        struct rsa_priv_f2_pdb *pdb = &edesc->pdb.priv_f2;
        int sec4_sg_index = 0;
        size_t p_sz = key->p_sz;
        size_t q_sz = key->q_sz;

        pdb->d_dma = dma_map_single(dev, key->d, key->d_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->d_dma)) {
                dev_err(dev, "Unable to map RSA private exponent memory\n");
                return -ENOMEM;
        }

        pdb->p_dma = dma_map_single(dev, key->p, p_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->p_dma)) {
                dev_err(dev, "Unable to map RSA prime factor p memory\n");
                goto unmap_d;
        }

        pdb->q_dma = dma_map_single(dev, key->q, q_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->q_dma)) {
                dev_err(dev, "Unable to map RSA prime factor q memory\n");
                goto unmap_p;
        }

        pdb->tmp1_dma = dma_map_single(dev, key->tmp1, p_sz, DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dev, pdb->tmp1_dma)) {
                dev_err(dev, "Unable to map RSA tmp1 memory\n");
                goto unmap_q;
        }

        pdb->tmp2_dma = dma_map_single(dev, key->tmp2, q_sz, DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dev, pdb->tmp2_dma)) {
                dev_err(dev, "Unable to map RSA tmp2 memory\n");
                goto unmap_tmp1;
        }

        if (edesc->src_nents > 1) {
                pdb->sgf |= RSA_PRIV_PDB_SGF_G;
                pdb->g_dma = edesc->sec4_sg_dma;
                sec4_sg_index += edesc->src_nents;
        } else {
                struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);

                pdb->g_dma = sg_dma_address(req_ctx->fixup_src);
        }

        if (edesc->dst_nents > 1) {
                pdb->sgf |= RSA_PRIV_PDB_SGF_F;
                pdb->f_dma = edesc->sec4_sg_dma +
                             sec4_sg_index * sizeof(struct sec4_sg_entry);
        } else {
                pdb->f_dma = sg_dma_address(req->dst);
        }

        pdb->sgf |= (key->d_sz << RSA_PDB_D_SHIFT) | key->n_sz;
        pdb->p_q_len = (q_sz << RSA_PDB_Q_SHIFT) | p_sz;

        return 0;

unmap_tmp1:
        dma_unmap_single(dev, pdb->tmp1_dma, p_sz, DMA_BIDIRECTIONAL);
unmap_q:
        dma_unmap_single(dev, pdb->q_dma, q_sz, DMA_TO_DEVICE);
unmap_p:
        dma_unmap_single(dev, pdb->p_dma, p_sz, DMA_TO_DEVICE);
unmap_d:
        dma_unmap_single(dev, pdb->d_dma, key->d_sz, DMA_TO_DEVICE);

        return -ENOMEM;
}

static int set_rsa_priv_f3_pdb(struct akcipher_request *req,
                               struct rsa_edesc *edesc)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        struct device *dev = ctx->dev;
        struct rsa_priv_f3_pdb *pdb = &edesc->pdb.priv_f3;
        int sec4_sg_index = 0;
        size_t p_sz = key->p_sz;
        size_t q_sz = key->q_sz;

        pdb->p_dma = dma_map_single(dev, key->p, p_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->p_dma)) {
                dev_err(dev, "Unable to map RSA prime factor p memory\n");
                return -ENOMEM;
        }

        pdb->q_dma = dma_map_single(dev, key->q, q_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->q_dma)) {
                dev_err(dev, "Unable to map RSA prime factor q memory\n");
                goto unmap_p;
        }

        pdb->dp_dma = dma_map_single(dev, key->dp, p_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->dp_dma)) {
                dev_err(dev, "Unable to map RSA exponent dp memory\n");
                goto unmap_q;
        }

        pdb->dq_dma = dma_map_single(dev, key->dq, q_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->dq_dma)) {
                dev_err(dev, "Unable to map RSA exponent dq memory\n");
                goto unmap_dp;
        }

        pdb->c_dma = dma_map_single(dev, key->qinv, p_sz, DMA_TO_DEVICE);
        if (dma_mapping_error(dev, pdb->c_dma)) {
                dev_err(dev, "Unable to map RSA CRT coefficient qinv memory\n");
                goto unmap_dq;
        }

        pdb->tmp1_dma = dma_map_single(dev, key->tmp1, p_sz, DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dev, pdb->tmp1_dma)) {
                dev_err(dev, "Unable to map RSA tmp1 memory\n");
                goto unmap_qinv;
        }

        pdb->tmp2_dma = dma_map_single(dev, key->tmp2, q_sz, DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dev, pdb->tmp2_dma)) {
                dev_err(dev, "Unable to map RSA tmp2 memory\n");
                goto unmap_tmp1;
        }

        if (edesc->src_nents > 1) {
                pdb->sgf |= RSA_PRIV_PDB_SGF_G;
                pdb->g_dma = edesc->sec4_sg_dma;
                sec4_sg_index += edesc->src_nents;
        } else {
                struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);

                pdb->g_dma = sg_dma_address(req_ctx->fixup_src);
        }

        if (edesc->dst_nents > 1) {
                pdb->sgf |= RSA_PRIV_PDB_SGF_F;
                pdb->f_dma = edesc->sec4_sg_dma +
                             sec4_sg_index * sizeof(struct sec4_sg_entry);
        } else {
                pdb->f_dma = sg_dma_address(req->dst);
        }

        pdb->sgf |= key->n_sz;
        pdb->p_q_len = (q_sz << RSA_PDB_Q_SHIFT) | p_sz;

        return 0;

unmap_tmp1:
        dma_unmap_single(dev, pdb->tmp1_dma, p_sz, DMA_BIDIRECTIONAL);
unmap_qinv:
        dma_unmap_single(dev, pdb->c_dma, p_sz, DMA_TO_DEVICE);
unmap_dq:
        dma_unmap_single(dev, pdb->dq_dma, q_sz, DMA_TO_DEVICE);
unmap_dp:
        dma_unmap_single(dev, pdb->dp_dma, p_sz, DMA_TO_DEVICE);
unmap_q:
        dma_unmap_single(dev, pdb->q_dma, q_sz, DMA_TO_DEVICE);
unmap_p:
        dma_unmap_single(dev, pdb->p_dma, p_sz, DMA_TO_DEVICE);

        return -ENOMEM;
}

static int caam_rsa_enc(struct akcipher_request *req)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        struct device *jrdev = ctx->dev;
        struct rsa_edesc *edesc;
        int ret;

        if (unlikely(!key->n || !key->e))
                return -EINVAL;

        if (req->dst_len < key->n_sz) {
                req->dst_len = key->n_sz;
                dev_err(jrdev, "Output buffer length less than parameter n\n");
                return -EOVERFLOW;
        }

        /* Allocate extended descriptor */
        edesc = rsa_edesc_alloc(req, DESC_RSA_PUB_LEN);
        if (IS_ERR(edesc))
                return PTR_ERR(edesc);

        /* Set RSA Encrypt Protocol Data Block */
        ret = set_rsa_pub_pdb(req, edesc);
        if (ret)
                goto init_fail;

        /* Initialize Job Descriptor */
        init_rsa_pub_desc(edesc->hw_desc, &edesc->pdb.pub);

        ret = caam_jr_enqueue(jrdev, edesc->hw_desc, rsa_pub_done, req);
        if (!ret)
                return -EINPROGRESS;

        rsa_pub_unmap(jrdev, edesc, req);

init_fail:
        rsa_io_unmap(jrdev, edesc, req);
        kfree(edesc);
        return ret;
}

static int caam_rsa_dec_priv_f1(struct akcipher_request *req)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct device *jrdev = ctx->dev;
        struct rsa_edesc *edesc;
        int ret;

        /* Allocate extended descriptor */
        edesc = rsa_edesc_alloc(req, DESC_RSA_PRIV_F1_LEN);
        if (IS_ERR(edesc))
                return PTR_ERR(edesc);

        /* Set RSA Decrypt Protocol Data Block - Private Key Form #1 */
        ret = set_rsa_priv_f1_pdb(req, edesc);
        if (ret)
                goto init_fail;

        /* Initialize Job Descriptor */
        init_rsa_priv_f1_desc(edesc->hw_desc, &edesc->pdb.priv_f1);

        ret = caam_jr_enqueue(jrdev, edesc->hw_desc, rsa_priv_f1_done, req);
        if (!ret)
                return -EINPROGRESS;

        rsa_priv_f1_unmap(jrdev, edesc, req);

init_fail:
        rsa_io_unmap(jrdev, edesc, req);
        kfree(edesc);
        return ret;
}

static int caam_rsa_dec_priv_f2(struct akcipher_request *req)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct device *jrdev = ctx->dev;
        struct rsa_edesc *edesc;
        int ret;

        /* Allocate extended descriptor */
        edesc = rsa_edesc_alloc(req, DESC_RSA_PRIV_F2_LEN);
        if (IS_ERR(edesc))
                return PTR_ERR(edesc);

        /* Set RSA Decrypt Protocol Data Block - Private Key Form #2 */
        ret = set_rsa_priv_f2_pdb(req, edesc);
        if (ret)
                goto init_fail;

        /* Initialize Job Descriptor */
        init_rsa_priv_f2_desc(edesc->hw_desc, &edesc->pdb.priv_f2);

        ret = caam_jr_enqueue(jrdev, edesc->hw_desc, rsa_priv_f2_done, req);
        if (!ret)
                return -EINPROGRESS;

        rsa_priv_f2_unmap(jrdev, edesc, req);

init_fail:
        rsa_io_unmap(jrdev, edesc, req);
        kfree(edesc);
        return ret;
}

static int caam_rsa_dec_priv_f3(struct akcipher_request *req)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct device *jrdev = ctx->dev;
        struct rsa_edesc *edesc;
        int ret;

        /* Allocate extended descriptor */
        edesc = rsa_edesc_alloc(req, DESC_RSA_PRIV_F3_LEN);
        if (IS_ERR(edesc))
                return PTR_ERR(edesc);

        /* Set RSA Decrypt Protocol Data Block - Private Key Form #3 */
        ret = set_rsa_priv_f3_pdb(req, edesc);
        if (ret)
                goto init_fail;

        /* Initialize Job Descriptor */
        init_rsa_priv_f3_desc(edesc->hw_desc, &edesc->pdb.priv_f3);

        ret = caam_jr_enqueue(jrdev, edesc->hw_desc, rsa_priv_f3_done, req);
        if (!ret)
                return -EINPROGRESS;

        rsa_priv_f3_unmap(jrdev, edesc, req);

init_fail:
        rsa_io_unmap(jrdev, edesc, req);
        kfree(edesc);
        return ret;
}

static int caam_rsa_dec(struct akcipher_request *req)
{
        struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;
        int ret;

        if (unlikely(!key->n || !key->d))
                return -EINVAL;

        if (req->dst_len < key->n_sz) {
                req->dst_len = key->n_sz;
                dev_err(ctx->dev, "Output buffer length less than parameter n\n");
                return -EOVERFLOW;
        }

        if (key->priv_form == FORM3)
                ret = caam_rsa_dec_priv_f3(req);
        else if (key->priv_form == FORM2)
                ret = caam_rsa_dec_priv_f2(req);
        else
                ret = caam_rsa_dec_priv_f1(req);

        return ret;
}

static void caam_rsa_free_key(struct caam_rsa_key *key)
{
        kzfree(key->d);
        kzfree(key->p);
        kzfree(key->q);
        kzfree(key->dp);
        kzfree(key->dq);
        kzfree(key->qinv);
        kzfree(key->tmp1);
        kzfree(key->tmp2);
        kfree(key->e);
        kfree(key->n);
        memset(key, 0, sizeof(*key));
}

static void caam_rsa_drop_leading_zeros(const u8 **ptr, size_t *nbytes)
{
        while (!**ptr && *nbytes) {
                (*ptr)++;
                (*nbytes)--;
        }
}

/**
 * caam_read_rsa_crt - Used for reading dP, dQ, qInv CRT members.
 * dP, dQ and qInv could decode to less than corresponding p, q length, as the
 * BER-encoding requires that the minimum number of bytes be used to encode the
 * integer. dP, dQ, qInv decoded values have to be zero-padded to appropriate
 * length.
 *
 * @ptr   : pointer to {dP, dQ, qInv} CRT member
 * @nbytes: length in bytes of {dP, dQ, qInv} CRT member
 * @dstlen: length in bytes of corresponding p or q prime factor
 */
static u8 *caam_read_rsa_crt(const u8 *ptr, size_t nbytes, size_t dstlen)
{
        u8 *dst;

        caam_rsa_drop_leading_zeros(&ptr, &nbytes);
        if (!nbytes)
                return NULL;

        dst = kzalloc(dstlen, GFP_DMA | GFP_KERNEL);
        if (!dst)
                return NULL;

        memcpy(dst + (dstlen - nbytes), ptr, nbytes);

        return dst;
}

/**
 * caam_read_raw_data - Read a raw byte stream as a positive integer.
 * The function skips buffer's leading zeros, copies the remained data
 * to a buffer allocated in the GFP_DMA | GFP_KERNEL zone and returns
 * the address of the new buffer.
 *
 * @buf   : The data to read
 * @nbytes: The amount of data to read
 */
static inline u8 *caam_read_raw_data(const u8 *buf, size_t *nbytes)
{

        caam_rsa_drop_leading_zeros(&buf, nbytes);
        if (!*nbytes)
                return NULL;

        return kmemdup(buf, *nbytes, GFP_DMA | GFP_KERNEL);
}

static int caam_rsa_check_key_length(unsigned int len)
{
        if (len > 4096)
                return -EINVAL;
        return 0;
}

static int caam_rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
                                unsigned int keylen)
{
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct rsa_key raw_key = {NULL};
        struct caam_rsa_key *rsa_key = &ctx->key;
        int ret;

        /* Free the old RSA key if any */
        caam_rsa_free_key(rsa_key);

        ret = rsa_parse_pub_key(&raw_key, key, keylen);
        if (ret)
                return ret;

        /* Copy key in DMA zone */
        rsa_key->e = kzalloc(raw_key.e_sz, GFP_DMA | GFP_KERNEL);
        if (!rsa_key->e)
                goto err;

        /*
         * Skip leading zeros and copy the positive integer to a buffer
         * allocated in the GFP_DMA | GFP_KERNEL zone. The decryption descriptor
         * expects a positive integer for the RSA modulus and uses its length as
         * decryption output length.
         */
        rsa_key->n = caam_read_raw_data(raw_key.n, &raw_key.n_sz);
        if (!rsa_key->n)
                goto err;

        if (caam_rsa_check_key_length(raw_key.n_sz << 3)) {
                caam_rsa_free_key(rsa_key);
                return -EINVAL;
        }

        rsa_key->e_sz = raw_key.e_sz;
        rsa_key->n_sz = raw_key.n_sz;

        memcpy(rsa_key->e, raw_key.e, raw_key.e_sz);

        return 0;
err:
        caam_rsa_free_key(rsa_key);
        return -ENOMEM;
}

static void caam_rsa_set_priv_key_form(struct caam_rsa_ctx *ctx,
                                       struct rsa_key *raw_key)
{
        struct caam_rsa_key *rsa_key = &ctx->key;
        size_t p_sz = raw_key->p_sz;
        size_t q_sz = raw_key->q_sz;

        rsa_key->p = caam_read_raw_data(raw_key->p, &p_sz);
        if (!rsa_key->p)
                return;
        rsa_key->p_sz = p_sz;

        rsa_key->q = caam_read_raw_data(raw_key->q, &q_sz);
        if (!rsa_key->q)
                goto free_p;
        rsa_key->q_sz = q_sz;

        rsa_key->tmp1 = kzalloc(raw_key->p_sz, GFP_DMA | GFP_KERNEL);
        if (!rsa_key->tmp1)
                goto free_q;

        rsa_key->tmp2 = kzalloc(raw_key->q_sz, GFP_DMA | GFP_KERNEL);
        if (!rsa_key->tmp2)
                goto free_tmp1;

        rsa_key->priv_form = FORM2;

        rsa_key->dp = caam_read_rsa_crt(raw_key->dp, raw_key->dp_sz, p_sz);
        if (!rsa_key->dp)
                goto free_tmp2;

        rsa_key->dq = caam_read_rsa_crt(raw_key->dq, raw_key->dq_sz, q_sz);
        if (!rsa_key->dq)
                goto free_dp;

        rsa_key->qinv = caam_read_rsa_crt(raw_key->qinv, raw_key->qinv_sz,
                                          q_sz);
        if (!rsa_key->qinv)
                goto free_dq;

        rsa_key->priv_form = FORM3;

        return;

free_dq:
        kzfree(rsa_key->dq);
free_dp:
        kzfree(rsa_key->dp);
free_tmp2:
        kzfree(rsa_key->tmp2);
free_tmp1:
        kzfree(rsa_key->tmp1);
free_q:
        kzfree(rsa_key->q);
free_p:
        kzfree(rsa_key->p);
}

static int caam_rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
                                 unsigned int keylen)
{
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct rsa_key raw_key = {NULL};
        struct caam_rsa_key *rsa_key = &ctx->key;
        int ret;

        /* Free the old RSA key if any */
        caam_rsa_free_key(rsa_key);

        ret = rsa_parse_priv_key(&raw_key, key, keylen);
        if (ret)
                return ret;

        /* Copy key in DMA zone */
        rsa_key->d = kzalloc(raw_key.d_sz, GFP_DMA | GFP_KERNEL);
        if (!rsa_key->d)
                goto err;

        rsa_key->e = kzalloc(raw_key.e_sz, GFP_DMA | GFP_KERNEL);
        if (!rsa_key->e)
                goto err;

        /*
         * Skip leading zeros and copy the positive integer to a buffer
         * allocated in the GFP_DMA | GFP_KERNEL zone. The decryption descriptor
         * expects a positive integer for the RSA modulus and uses its length as
         * decryption output length.
         */
        rsa_key->n = caam_read_raw_data(raw_key.n, &raw_key.n_sz);
        if (!rsa_key->n)
                goto err;

        if (caam_rsa_check_key_length(raw_key.n_sz << 3)) {
                caam_rsa_free_key(rsa_key);
                return -EINVAL;
        }

        rsa_key->d_sz = raw_key.d_sz;
        rsa_key->e_sz = raw_key.e_sz;
        rsa_key->n_sz = raw_key.n_sz;

        memcpy(rsa_key->d, raw_key.d, raw_key.d_sz);
        memcpy(rsa_key->e, raw_key.e, raw_key.e_sz);

        caam_rsa_set_priv_key_form(ctx, &raw_key);

        return 0;

err:
        caam_rsa_free_key(rsa_key);
        return -ENOMEM;
}

static unsigned int caam_rsa_max_size(struct crypto_akcipher *tfm)
{
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);

        return ctx->key.n_sz;
}

/* Per session pkc's driver context creation function */
static int caam_rsa_init_tfm(struct crypto_akcipher *tfm)
{
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);

        ctx->dev = caam_jr_alloc();

        if (IS_ERR(ctx->dev)) {
                pr_err("Job Ring Device allocation for transform failed\n");
                return PTR_ERR(ctx->dev);
        }

        ctx->padding_dma = dma_map_single(ctx->dev, zero_buffer,
                                          CAAM_RSA_MAX_INPUT_SIZE - 1,
                                          DMA_TO_DEVICE);
        if (dma_mapping_error(ctx->dev, ctx->padding_dma)) {
                dev_err(ctx->dev, "unable to map padding\n");
                caam_jr_free(ctx->dev);
                return -ENOMEM;
        }

        return 0;
}

/* Per session pkc's driver context cleanup function */
static void caam_rsa_exit_tfm(struct crypto_akcipher *tfm)
{
        struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
        struct caam_rsa_key *key = &ctx->key;

        dma_unmap_single(ctx->dev, ctx->padding_dma, CAAM_RSA_MAX_INPUT_SIZE -
                         1, DMA_TO_DEVICE);
        caam_rsa_free_key(key);
        caam_jr_free(ctx->dev);
}

static struct akcipher_alg caam_rsa = {
        .encrypt = caam_rsa_enc,
        .decrypt = caam_rsa_dec,
        .set_pub_key = caam_rsa_set_pub_key,
        .set_priv_key = caam_rsa_set_priv_key,
        .max_size = caam_rsa_max_size,
        .init = caam_rsa_init_tfm,
        .exit = caam_rsa_exit_tfm,
        .reqsize = sizeof(struct caam_rsa_req_ctx),
        .base = {
                .cra_name = "rsa",
                .cra_driver_name = "rsa-caam",
                .cra_priority = 3000,
                .cra_module = THIS_MODULE,
                .cra_ctxsize = sizeof(struct caam_rsa_ctx),
        },
};

/* Public Key Cryptography module initialization handler */
int caam_pkc_init(struct device *ctrldev)
{
        struct caam_drv_private *priv = dev_get_drvdata(ctrldev);
        u32 pk_inst;
        int err;

        /* Determine public key hardware accelerator presence. */
        if (priv->era < 10)
                pk_inst = (rd_reg32(&priv->ctrl->perfmon.cha_num_ls) &
                           CHA_ID_LS_PK_MASK) >> CHA_ID_LS_PK_SHIFT;
        else
                pk_inst = rd_reg32(&priv->ctrl->vreg.pkha) & CHA_VER_NUM_MASK;

        /* Do not register algorithms if PKHA is not present. */
        if (!pk_inst)
                return 0;

        /* allocate zero buffer, used for padding input */
        zero_buffer = kzalloc(CAAM_RSA_MAX_INPUT_SIZE - 1, GFP_DMA |
                              GFP_KERNEL);
        if (!zero_buffer)
                return -ENOMEM;

        err = crypto_register_akcipher(&caam_rsa);
        if (err) {
                kfree(zero_buffer);
                dev_warn(ctrldev, "%s alg registration failed\n",
                         caam_rsa.base.cra_driver_name);
        } else {
                dev_info(ctrldev, "caam pkc algorithms registered in /proc/crypto\n");
        }

        return err;
}

void caam_pkc_exit(void)
{
        kfree(zero_buffer);
        crypto_unregister_akcipher(&caam_rsa);
}