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 
16 struct 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  */
28 struct 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  */
45 struct 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  */
51 void 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  */
63 int 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  */
caam_encap_blob(struct caam_blob_priv * priv,struct caam_blob_info * info)75 static 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  */
caam_decap_blob(struct caam_blob_priv * priv,struct caam_blob_info * info)93 static 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