/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2020 Pengutronix, Ahmad Fatoum <[email protected]>
*/
#ifndef __CAAM_BLOB_GEN
#define __CAAM_BLOB_GEN
#include <linux/types.h>
#include <linux/errno.h>
#define CAAM_BLOB_KEYMOD_LENGTH 16
#define CAAM_BLOB_OVERHEAD (32 + 16)
#define CAAM_BLOB_MAX_LEN 4096
struct caam_blob_priv;
/**
* struct caam_blob_info - information for CAAM blobbing
* @input: pointer to input buffer (must be DMAable)
* @input_len: length of @input buffer in bytes.
* @output: pointer to output buffer (must be DMAable)
* @output_len: length of @output buffer in bytes.
* @key_mod: key modifier
* @key_mod_len: length of @key_mod in bytes.
* May not exceed %CAAM_BLOB_KEYMOD_LENGTH
*/
struct caam_blob_info {
void *input;
size_t input_len;
void *output;
size_t output_len;
const void *key_mod;
size_t key_mod_len;
};
/**
* caam_blob_gen_init - initialize blob generation
* Return: pointer to new &struct caam_blob_priv instance on success
* and ``ERR_PTR(-ENODEV)`` if CAAM has no hardware blobbing support
* or no job ring could be allocated.
*/
struct caam_blob_priv *caam_blob_gen_init(void);
/**
* caam_blob_gen_exit - free blob generation resources
* @priv: instance returned by caam_blob_gen_init()
*/
void caam_blob_gen_exit(struct caam_blob_priv *priv);
/**
* caam_process_blob - encapsulate or decapsulate blob
* @priv: instance returned by caam_blob_gen_init()
* @info: pointer to blobbing info describing key, blob and
* key modifier buffers.
* @encap: true for encapsulation, false for decapsulation
*
* Return: %0 and sets ``info->output_len`` on success and a negative
* error code otherwise.
*/
int caam_process_blob(struct caam_blob_priv *priv,
struct caam_blob_info *info, bool encap);
/**
* caam_encap_blob - encapsulate blob
* @priv: instance returned by caam_blob_gen_init()
* @info: pointer to blobbing info describing input key,
* output blob and key modifier buffers.
*
* Return: %0 and sets ``info->output_len`` on success and
* a negative error code otherwise.
*/
static inline int caam_encap_blob(struct caam_blob_priv *priv,
struct caam_blob_info *info)
{
if (info->output_len < info->input_len + CAAM_BLOB_OVERHEAD)
return -EINVAL;
return caam_process_blob(priv, info, true);
}
/**
* caam_decap_blob - decapsulate blob
* @priv: instance returned by caam_blob_gen_init()
* @info: pointer to blobbing info describing output key,
* input blob and key modifier buffers.
*
* Return: %0 and sets ``info->output_len`` on success and
* a negative error code otherwise.
*/
static inline int caam_decap_blob(struct caam_blob_priv *priv,
struct caam_blob_info *info)
{
if (info->input_len < CAAM_BLOB_OVERHEAD ||
info->output_len < info->input_len - CAAM_BLOB_OVERHEAD)
return -EINVAL;
return caam_process_blob(priv, info, false);
}
#endif