text: // 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_RSA_PUB_PDB)
  #define DESC_RSA_PRIV_F1_LEN	(2 * CAAM_CMD_SZ + \
  				 SIZEOF_RSA_PRIV_F1_PDB)
  #define DESC_RSA_PRIV_F2_LEN	(2 * CAAM_CMD_SZ + \
  				 SIZEOF_RSA_PRIV_F2_PDB)
  #define DESC_RSA_PRIV_F3_LEN	(2 * CAAM_CMD_SZ + \
  				 SIZEOF_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;
  
  /*
   * variable used to avoid double free of resources in case
   * algorithm registration was unsuccessful
   */
  static bool init_done;
  
  struct caam_akcipher_alg {
  	struct akcipher_alg akcipher;
  	bool registered;
  };
  
  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 caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);
  	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
  	struct rsa_edesc *edesc;
  	int ecode = 0;
  	bool has_bklog;
  
  	if (err)
  		ecode = caam_jr_strstatus(dev, err);
  
  	edesc = req_ctx->edesc;
  	has_bklog = edesc->bklog;
  
  	rsa_pub_unmap(dev, edesc, req);
  	rsa_io_unmap(dev, edesc, req);
  	kfree(edesc);
  
  	/*
  	 * If no backlog flag, the completion of the request is done
  	 * by CAAM, not crypto engine.
  	 */
  	if (!has_bklog)
  		akcipher_request_complete(req, ecode);
  	else
  		crypto_finalize_akcipher_request(jrp->engine, req, ecode);
  }
  
  static void rsa_priv_f_done(struct device *dev, u32 *desc, u32 err,
  			    void *context)
  {
  	struct akcipher_request *req = context;
  	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
  	struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
  	struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
  	struct caam_rsa_key *key = &ctx->key;
  	struct caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);
  	struct rsa_edesc *edesc;
  	int ecode = 0;
  	bool has_bklog;
  
  	if (err)
  		ecode = caam_jr_strstatus(dev, err);
  
  	edesc = req_ctx->edesc;
  	has_bklog = edesc->bklog;
  
  	switch (key->priv_form) {
  	case FORM1:
  		rsa_priv_f1_unmap(dev, edesc, req);
  		break;
  	case FORM2:
  		rsa_priv_f2_unmap(dev, edesc, req);
  		break;
  	case FORM3:
  		rsa_priv_f3_unmap(dev, edesc, req);
  	}
  
  	rsa_io_unmap(dev, edesc, req);
  	kfree(edesc);
  
  	/*
  	 * If no backlog flag, the completion of the request is done
  	 * by CAAM, not crypto engine.
  	 */
  	if (!has_bklog)
  		akcipher_request_complete(req, ecode);
  	else
  		crypto_finalize_akcipher_request(jrp->engine, req, ecode);
  }
  
  /**
   * 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 sec4_sg_index, sec4_sg_len = 0, sec4_sg_bytes;
  	int src_nents, dst_nents;
  	int mapped_src_nents, mapped_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);
  
  	mapped_src_nents = dma_map_sg(dev, req_ctx->fixup_src, src_nents,
  				      DMA_TO_DEVICE);
  	if (unlikely(!mapped_src_nents)) {
  		dev_err(dev, "unable to map source\n");
  		return ERR_PTR(-ENOMEM);
  	}
  	mapped_dst_nents = dma_map_sg(dev, req->dst, dst_nents,
  				      DMA_FROM_DEVICE);
  	if (unlikely(!mapped_dst_nents)) {
  		dev_err(dev, "unable to map destination\n");
  		goto src_fail;
  	}
  
  	if (!diff_size && mapped_src_nents == 1)
  		sec4_sg_len = 0; /* no need for an input hw s/g table */
  	else
  		sec4_sg_len = mapped_src_nents + !!diff_size;
  	sec4_sg_index = sec4_sg_len;
  
  	if (mapped_dst_nents > 1)
  		sec4_sg_len += pad_sg_nents(mapped_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)
  		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 (mapped_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;
  
  	req_ctx->edesc = edesc;
  
  	if (!sec4_sg_bytes)
  		return edesc;
  
  	edesc->mapped_src_nents = mapped_src_nents;
  	edesc->mapped_dst_nents = mapped_dst_nents;
  
  	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:
  	kfree(edesc);
  dst_fail:
  	dma_unmap_sg(dev, req->dst, dst_nents, DMA_FROM_DEVICE);
  src_fail:
  	dma_unmap_sg(dev, req_ctx->fixup_src, src_nents, DMA_TO_DEVICE);
  	return ERR_PTR(-ENOMEM);
  }
  
  static int akcipher_do_one_req(struct crypto_engine *engine, void *areq)
  {
  	struct akcipher_request *req = container_of(areq,
  						    struct akcipher_request,
  						    base);
  	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 device *jrdev = ctx->dev;
  	u32 *desc = req_ctx->edesc->hw_desc;
  	int ret;
  
  	req_ctx->edesc->bklog = true;
  
  	ret = caam_jr_enqueue(jrdev, desc, req_ctx->akcipher_op_done, req);
  
  	if (ret != -EINPROGRESS) {
  		rsa_pub_unmap(jrdev, req_ctx->edesc, req);
  		rsa_io_unmap(jrdev, req_ctx->edesc, req);
  		kfree(req_ctx->edesc);
  	} else {
  		ret = 0;
  	}
  
  	return ret;
  }
  
  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->mapped_src_nents > 1) {
  		pdb->sgf |= RSA_PDB_SGF_F;
  		pdb->f_dma = edesc->sec4_sg_dma;
  		sec4_sg_index += edesc->mapped_src_nents;
  	} else {
  		pdb->f_dma = sg_dma_address(req_ctx->fixup_src);
  	}
  
  	if (edesc->mapped_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->mapped_src_nents > 1) {
  		pdb->sgf |= RSA_PRIV_PDB_SGF_G;
  		pdb->g_dma = edesc->sec4_sg_dma;
  		sec4_sg_index += edesc->mapped_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->mapped_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->mapped_src_nents > 1) {
  		pdb->sgf |= RSA_PRIV_PDB_SGF_G;
  		pdb->g_dma = edesc->sec4_sg_dma;
  		sec4_sg_index += edesc->mapped_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->mapped_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->mapped_src_nents > 1) {
  		pdb->sgf |= RSA_PRIV_PDB_SGF_G;
  		pdb->g_dma = edesc->sec4_sg_dma;
  		sec4_sg_index += edesc->mapped_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->mapped_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 akcipher_enqueue_req(struct device *jrdev,
  				void (*cbk)(struct device *jrdev, u32 *desc,
  					    u32 err, void *context),
  				struct akcipher_request *req)
  {
  	struct caam_drv_private_jr *jrpriv = dev_get_drvdata(jrdev);
  	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 caam_rsa_req_ctx *req_ctx = akcipher_request_ctx(req);
  	struct rsa_edesc *edesc = req_ctx->edesc;
  	u32 *desc = edesc->hw_desc;
  	int ret;
  
  	req_ctx->akcipher_op_done = cbk;
  	/*
  	 * Only the backlog request are sent to crypto-engine since the others
  	 * can be handled by CAAM, if free, especially since JR has up to 1024
  	 * entries (more than the 10 entries from crypto-engine).
  	 */
  	if (req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)
  		ret = crypto_transfer_akcipher_request_to_engine(jrpriv->engine,
  								 req);
  	else
  		ret = caam_jr_enqueue(jrdev, desc, cbk, req);
  
  	if ((ret != -EINPROGRESS) && (ret != -EBUSY)) {
  		switch (key->priv_form) {
  		case FORM1:
  			rsa_priv_f1_unmap(jrdev, edesc, req);
  			break;
  		case FORM2:
  			rsa_priv_f2_unmap(jrdev, edesc, req);
  			break;
  		case FORM3:
  			rsa_priv_f3_unmap(jrdev, edesc, req);
  			break;
  		default:
  			rsa_pub_unmap(jrdev, edesc, req);
  		}
  		rsa_io_unmap(jrdev, edesc, req);
  		kfree(edesc);
  	}
  
  	return ret;
  }
  
  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);
  
  	return akcipher_enqueue_req(jrdev, rsa_pub_done, 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);
  
  	return akcipher_enqueue_req(jrdev, rsa_priv_f_done, 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);
  
  	return akcipher_enqueue_req(jrdev, rsa_priv_f_done, 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);
  
  	return akcipher_enqueue_req(jrdev, rsa_priv_f_done, 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)
  {
  	kfree_sensitive(key->d);
  	kfree_sensitive(key->p);
  	kfree_sensitive(key->q);
  	kfree_sensitive(key->dp);
  	kfree_sensitive(key->dq);
  	kfree_sensitive(key->qinv);
  	kfree_sensitive(key->tmp1);
  	kfree_sensitive(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 = kmemdup(raw_key.e, 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;
  
  	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:
  	kfree_sensitive(rsa_key->dq);
  free_dp:
  	kfree_sensitive(rsa_key->dp);
  free_tmp2:
  	kfree_sensitive(rsa_key->tmp2);
  free_tmp1:
  	kfree_sensitive(rsa_key->tmp1);
  free_q:
  	kfree_sensitive(rsa_key->q);
  free_p:
  	kfree_sensitive(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 = kmemdup(raw_key.d, raw_key.d_sz, GFP_DMA | GFP_KERNEL);
  	if (!rsa_key->d)
  		goto err;
  
  	rsa_key->e = kmemdup(raw_key.e, 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;
  
  	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;
  	}
  
  	ctx->enginectx.op.do_one_request = akcipher_do_one_req;
  
  	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 caam_akcipher_alg caam_rsa = {
  	.akcipher = {
  		.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;
  	init_done = false;
  
  	/* 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.akcipher);
  
  	if (err) {
  		kfree(zero_buffer);
  		dev_warn(ctrldev, "%s alg registration failed\n",
  			 caam_rsa.akcipher.base.cra_driver_name);
  	} else {
  		init_done = true;
  		caam_rsa.registered = true;
  		dev_info(ctrldev, "caam pkc algorithms registered in /proc/crypto\n");
  	}
  
  	return err;
  }
  
  void caam_pkc_exit(void)
  {
  	if (!init_done)
  		return;
  
  	if (caam_rsa.registered)
  		crypto_unregister_akcipher(&caam_rsa.akcipher);
  
  	kfree(zero_buffer);
  }
  