1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright (C) 2020 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
  4 */
  5
  6#ifndef __CAAM_BLOB_GEN
  7#define __CAAM_BLOB_GEN
  8
  9#include <linux/types.h>
 10#include <linux/errno.h>
 11
 12#define CAAM_BLOB_KEYMOD_LENGTH		16
 13#define CAAM_BLOB_OVERHEAD		(32 + 16)
 14#define CAAM_BLOB_MAX_LEN		4096
 15
 16struct caam_blob_priv;
 17
 18/**
 19 * struct caam_blob_info - information for CAAM blobbing
 20 * @input:       pointer to input buffer (must be DMAable)
 21 * @input_len:   length of @input buffer in bytes.
 22 * @output:      pointer to output buffer (must be DMAable)
 23 * @output_len:  length of @output buffer in bytes.
 24 * @key_mod:     key modifier
 25 * @key_mod_len: length of @key_mod in bytes.
 26 *	         May not exceed %CAAM_BLOB_KEYMOD_LENGTH
 27 */
 28struct caam_blob_info {
 29	void *input;
 30	size_t input_len;
 31
 32	void *output;
 33	size_t output_len;
 34
 35	const void *key_mod;
 36	size_t key_mod_len;
 37};
 38
 39/**
 40 * caam_blob_gen_init - initialize blob generation
 41 * Return: pointer to new &struct caam_blob_priv instance on success
 42 * and ``ERR_PTR(-ENODEV)`` if CAAM has no hardware blobbing support
 43 * or no job ring could be allocated.
 44 */
 45struct caam_blob_priv *caam_blob_gen_init(void);
 46
 47/**
 48 * caam_blob_gen_exit - free blob generation resources
 49 * @priv: instance returned by caam_blob_gen_init()
 50 */
 51void caam_blob_gen_exit(struct caam_blob_priv *priv);
 52
 53/**
 54 * caam_process_blob - encapsulate or decapsulate blob
 55 * @priv:   instance returned by caam_blob_gen_init()
 56 * @info:   pointer to blobbing info describing key, blob and
 57 *          key modifier buffers.
 58 * @encap:  true for encapsulation, false for decapsulation
 59 *
 60 * Return: %0 and sets ``info->output_len`` on success and a negative
 61 * error code otherwise.
 62 */
 63int caam_process_blob(struct caam_blob_priv *priv,
 64		      struct caam_blob_info *info, bool encap);
 65
 66/**
 67 * caam_encap_blob - encapsulate blob
 68 * @priv:   instance returned by caam_blob_gen_init()
 69 * @info:   pointer to blobbing info describing input key,
 70 *          output blob and key modifier buffers.
 71 *
 72 * Return: %0 and sets ``info->output_len`` on success and
 73 * a negative error code otherwise.
 74 */
 75static inline int caam_encap_blob(struct caam_blob_priv *priv,
 76				  struct caam_blob_info *info)
 77{
 78	if (info->output_len < info->input_len + CAAM_BLOB_OVERHEAD)
 79		return -EINVAL;
 80
 81	return caam_process_blob(priv, info, true);
 82}
 83
 84/**
 85 * caam_decap_blob - decapsulate blob
 86 * @priv:   instance returned by caam_blob_gen_init()
 87 * @info:   pointer to blobbing info describing output key,
 88 *          input blob and key modifier buffers.
 89 *
 90 * Return: %0 and sets ``info->output_len`` on success and
 91 * a negative error code otherwise.
 92 */
 93static inline int caam_decap_blob(struct caam_blob_priv *priv,
 94				  struct caam_blob_info *info)
 95{
 96	if (info->input_len < CAAM_BLOB_OVERHEAD ||
 97	    info->output_len < info->input_len - CAAM_BLOB_OVERHEAD)
 98		return -EINVAL;
 99
100	return caam_process_blob(priv, info, false);
101}
102
103#endif