text: /*
   * caam - Freescale FSL CAAM support for Public Key Cryptography
   *
   * Copyright 2016 Freescale Semiconductor, Inc.
   *
   * 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))
  
  static void rsa_io_unmap(struct device *dev, struct rsa_edesc *edesc,
  			 struct akcipher_request *req)
  {
  	dma_unmap_sg(dev, req->dst, edesc->dst_nents, DMA_FROM_DEVICE);
  	dma_unmap_sg(dev, req->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);
  }
  
  /* 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 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 rsa_edesc *edesc;
  	gfp_t flags = (req->base.flags & (CRYPTO_TFM_REQ_MAY_BACKLOG |
  		       CRYPTO_TFM_REQ_MAY_SLEEP)) ? GFP_KERNEL : GFP_ATOMIC;
  	int sgc;
  	int sec4_sg_index, sec4_sg_len = 0, sec4_sg_bytes;
  	int src_nents, dst_nents;
  
  	src_nents = sg_nents_for_len(req->src, req->src_len);
  	dst_nents = sg_nents_for_len(req->dst, req->dst_len);
  
  	if (src_nents > 1)
  		sec4_sg_len = src_nents;
  	if (dst_nents > 1)
  		sec4_sg_len += dst_nents;
  
  	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->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;
  
  	sec4_sg_index = 0;
  	if (src_nents > 1) {
  		sg_to_sec4_sg_last(req->src, src_nents, edesc->sec4_sg, 0);
  		sec4_sg_index += src_nents;
  	}
  	if (dst_nents > 1)
  		sg_to_sec4_sg_last(req->dst, dst_nents,
  				   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;
  
  	return edesc;
  
  sec4_sg_fail:
  	dma_unmap_sg(dev, req->dst, dst_nents, DMA_FROM_DEVICE);
  dst_fail:
  	dma_unmap_sg(dev, req->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_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->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->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 {
  		pdb->g_dma = sg_dma_address(req->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 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(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->d))
  		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_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 void caam_rsa_free_key(struct caam_rsa_key *key)
  {
  	kzfree(key->d);
  	kfree(key->e);
  	kfree(key->n);
  	key->d = NULL;
  	key->e = NULL;
  	key->n = NULL;
  	key->d_sz = 0;
  	key->e_sz = 0;
  	key->n_sz = 0;
  }
  
  /**
   * 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)
  {
  	u8 *val;
  
  	while (!*buf && *nbytes) {
  		buf++;
  		(*nbytes)--;
  	}
  
  	val = kzalloc(*nbytes, GFP_DMA | GFP_KERNEL);
  	if (!val)
  		return NULL;
  
  	memcpy(val, buf, *nbytes);
  
  	return val;
  }
  
  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 = {0};
  	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 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 = {0};
  	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);
  
  	return 0;
  
  err:
  	caam_rsa_free_key(rsa_key);
  	return -ENOMEM;
  }
  
  static int caam_rsa_max_size(struct crypto_akcipher *tfm)
  {
  	struct caam_rsa_ctx *ctx = akcipher_tfm_ctx(tfm);
  	struct caam_rsa_key *key = &ctx->key;
  
  	return (key->n) ? key->n_sz : -EINVAL;
  }
  
  /* 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);
  	}
  
  	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;
  
  	caam_rsa_free_key(key);
  	caam_jr_free(ctx->dev);
  }
  
  static struct akcipher_alg caam_rsa = {
  	.encrypt = caam_rsa_enc,
  	.decrypt = caam_rsa_dec,
  	.sign = caam_rsa_dec,
  	.verify = caam_rsa_enc,
  	.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,
  	.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 */
  static int __init caam_pkc_init(void)
  {
  	struct device_node *dev_node;
  	struct platform_device *pdev;
  	struct device *ctrldev;
  	struct caam_drv_private *priv;
  	u32 cha_inst, pk_inst;
  	int err;
  
  	dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0");
  	if (!dev_node) {
  		dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec4.0");
  		if (!dev_node)
  			return -ENODEV;
  	}
  
  	pdev = of_find_device_by_node(dev_node);
  	if (!pdev) {
  		of_node_put(dev_node);
  		return -ENODEV;
  	}
  
  	ctrldev = &pdev->dev;
  	priv = dev_get_drvdata(ctrldev);
  	of_node_put(dev_node);
  
  	/*
  	 * If priv is NULL, it's probably because the caam driver wasn't
  	 * properly initialized (e.g. RNG4 init failed). Thus, bail out here.
  	 */
  	if (!priv)
  		return -ENODEV;
  
  	/* Determine public key hardware accelerator presence. */
  	cha_inst = rd_reg32(&priv->ctrl->perfmon.cha_num_ls);
  	pk_inst = (cha_inst & CHA_ID_LS_PK_MASK) >> CHA_ID_LS_PK_SHIFT;
  
  	/* Do not register algorithms if PKHA is not present. */
  	if (!pk_inst)
  		return -ENODEV;
  
  	err = crypto_register_akcipher(&caam_rsa);
  	if (err)
  		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;
  }
  
  static void __exit caam_pkc_exit(void)
  {
  	crypto_unregister_akcipher(&caam_rsa);
  }
  
  module_init(caam_pkc_init);
  module_exit(caam_pkc_exit);
  
  MODULE_LICENSE("Dual BSD/GPL");
  MODULE_DESCRIPTION("FSL CAAM support for PKC functions of crypto API");
  MODULE_AUTHOR("Freescale Semiconductor");
  