soc/fsl/caam-blob.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * Copyright (C) 2020 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
0004  */
0005
0006 #ifndef __CAAM_BLOB_GEN
0007 #define __CAAM_BLOB_GEN
0008
0009 #include <linux/types.h>
0010 #include <linux/errno.h>
0011
0012 #define CAAM_BLOB_KEYMOD_LENGTH     16
0013 #define CAAM_BLOB_OVERHEAD      (32 + 16)
0014 #define CAAM_BLOB_MAX_LEN       4096
0015
0016 struct caam_blob_priv;
0017
0018 /**
0019  * struct caam_blob_info - information for CAAM blobbing
0020  * @input:       pointer to input buffer (must be DMAable)
0021  * @input_len:   length of @input buffer in bytes.
0022  * @output:      pointer to output buffer (must be DMAable)
0023  * @output_len:  length of @output buffer in bytes.
0024  * @key_mod:     key modifier
0025  * @key_mod_len: length of @key_mod in bytes.
0026  *           May not exceed %CAAM_BLOB_KEYMOD_LENGTH
0027  */
0028 struct caam_blob_info {
0029     void *input;
0030     size_t input_len;
0031
0032     void *output;
0033     size_t output_len;
0034
0035     const void *key_mod;
0036     size_t key_mod_len;
0037 };
0038
0039 /**
0040  * caam_blob_gen_init - initialize blob generation
0041  * Return: pointer to new &struct caam_blob_priv instance on success
0042  * and ``ERR_PTR(-ENODEV)`` if CAAM has no hardware blobbing support
0043  * or no job ring could be allocated.
0044  */
0045 struct caam_blob_priv *caam_blob_gen_init(void);
0046
0047 /**
0048  * caam_blob_gen_exit - free blob generation resources
0049  * @priv: instance returned by caam_blob_gen_init()
0050  */
0051 void caam_blob_gen_exit(struct caam_blob_priv *priv);
0052
0053 /**
0054  * caam_process_blob - encapsulate or decapsulate blob
0055  * @priv:   instance returned by caam_blob_gen_init()
0056  * @info:   pointer to blobbing info describing key, blob and
0057  *          key modifier buffers.
0058  * @encap:  true for encapsulation, false for decapsulation
0059  *
0060  * Return: %0 and sets ``info->output_len`` on success and a negative
0061  * error code otherwise.
0062  */
0063 int caam_process_blob(struct caam_blob_priv *priv,
0064               struct caam_blob_info *info, bool encap);
0065
0066 /**
0067  * caam_encap_blob - encapsulate blob
0068  * @priv:   instance returned by caam_blob_gen_init()
0069  * @info:   pointer to blobbing info describing input key,
0070  *          output blob and key modifier buffers.
0071  *
0072  * Return: %0 and sets ``info->output_len`` on success and
0073  * a negative error code otherwise.
0074  */
0075 static inline int caam_encap_blob(struct caam_blob_priv *priv,
0076                   struct caam_blob_info *info)
0077 {
0078     if (info->output_len < info->input_len + CAAM_BLOB_OVERHEAD)
0079         return -EINVAL;
0080
0081     return caam_process_blob(priv, info, true);
0082 }
0083
0084 /**
0085  * caam_decap_blob - decapsulate blob
0086  * @priv:   instance returned by caam_blob_gen_init()
0087  * @info:   pointer to blobbing info describing output key,
0088  *          input blob and key modifier buffers.
0089  *
0090  * Return: %0 and sets ``info->output_len`` on success and
0091  * a negative error code otherwise.
0092  */
0093 static inline int caam_decap_blob(struct caam_blob_priv *priv,
0094                   struct caam_blob_info *info)
0095 {
0096     if (info->input_len < CAAM_BLOB_OVERHEAD ||
0097         info->output_len < info->input_len - CAAM_BLOB_OVERHEAD)
0098         return -EINVAL;
0099
0100     return caam_process_blob(priv, info, false);
0101 }
0102
0103 #endif