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
104