1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2015 Pengutronix, Steffen Trumtrar <kernel@pengutronix.de>
4 * Copyright (C) 2021 Pengutronix, Ahmad Fatoum <kernel@pengutronix.de>
5 */
6
7 #define pr_fmt(fmt) "caam blob_gen: " fmt
8
9 #include <linux/device.h>
10 #include <soc/fsl/caam-blob.h>
11
12 #include "compat.h"
13 #include "desc_constr.h"
14 #include "desc.h"
15 #include "error.h"
16 #include "intern.h"
17 #include "jr.h"
18 #include "regs.h"
19
20 #define CAAM_BLOB_DESC_BYTES_MAX \
21 /* Command to initialize & stating length of descriptor */ \
22 (CAAM_CMD_SZ + \
23 /* Command to append the key-modifier + key-modifier data */ \
24 CAAM_CMD_SZ + CAAM_BLOB_KEYMOD_LENGTH + \
25 /* Command to include input key + pointer to the input key */ \
26 CAAM_CMD_SZ + CAAM_PTR_SZ_MAX + \
27 /* Command to include output key + pointer to the output key */ \
28 CAAM_CMD_SZ + CAAM_PTR_SZ_MAX + \
29 /* Command describing the operation to perform */ \
30 CAAM_CMD_SZ)
31
32 struct caam_blob_priv {
33 struct device jrdev;
34 };
35
36 struct caam_blob_job_result {
37 int err;
38 struct completion completion;
39 };
40
caam_blob_job_done(struct device * dev,u32 * desc,u32 err,void * context)41 static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err, void *context)
42 {
43 struct caam_blob_job_result *res = context;
44 int ecode = 0;
45
46 dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
47
48 if (err)
49 ecode = caam_jr_strstatus(dev, err);
50
51 res->err = ecode;
52
53 /*
54 * Upon completion, desc points to a buffer containing a CAAM job
55 * descriptor which encapsulates data into an externally-storable
56 * blob.
57 */
58 complete(&res->completion);
59 }
60
caam_process_blob(struct caam_blob_priv * priv,struct caam_blob_info * info,bool encap)61 int caam_process_blob(struct caam_blob_priv *priv,
62 struct caam_blob_info *info, bool encap)
63 {
64 struct caam_blob_job_result testres;
65 struct device *jrdev = &priv->jrdev;
66 dma_addr_t dma_in, dma_out;
67 int op = OP_PCLID_BLOB;
68 size_t output_len;
69 u32 *desc;
70 int ret;
71
72 if (info->key_mod_len > CAAM_BLOB_KEYMOD_LENGTH)
73 return -EINVAL;
74
75 if (encap) {
76 op |= OP_TYPE_ENCAP_PROTOCOL;
77 output_len = info->input_len + CAAM_BLOB_OVERHEAD;
78 } else {
79 op |= OP_TYPE_DECAP_PROTOCOL;
80 output_len = info->input_len - CAAM_BLOB_OVERHEAD;
81 }
82
83 desc = kzalloc(CAAM_BLOB_DESC_BYTES_MAX, GFP_KERNEL | GFP_DMA);
84 if (!desc)
85 return -ENOMEM;
86
87 dma_in = dma_map_single(jrdev, info->input, info->input_len,
88 DMA_TO_DEVICE);
89 if (dma_mapping_error(jrdev, dma_in)) {
90 dev_err(jrdev, "unable to map input DMA buffer\n");
91 ret = -ENOMEM;
92 goto out_free;
93 }
94
95 dma_out = dma_map_single(jrdev, info->output, output_len,
96 DMA_FROM_DEVICE);
97 if (dma_mapping_error(jrdev, dma_out)) {
98 dev_err(jrdev, "unable to map output DMA buffer\n");
99 ret = -ENOMEM;
100 goto out_unmap_in;
101 }
102
103 /*
104 * A data blob is encrypted using a blob key (BK); a random number.
105 * The BK is used as an AES-CCM key. The initial block (B0) and the
106 * initial counter (Ctr0) are generated automatically and stored in
107 * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
108 * Class 1 Key Register. Operation Mode is set to AES-CCM.
109 */
110
111 init_job_desc(desc, 0);
112 append_key_as_imm(desc, info->key_mod, info->key_mod_len,
113 info->key_mod_len, CLASS_2 | KEY_DEST_CLASS_REG);
114 append_seq_in_ptr_intlen(desc, dma_in, info->input_len, 0);
115 append_seq_out_ptr_intlen(desc, dma_out, output_len, 0);
116 append_operation(desc, op);
117
118 print_hex_dump_debug("data@"__stringify(__LINE__)": ",
119 DUMP_PREFIX_ADDRESS, 16, 1, info->input,
120 info->input_len, false);
121 print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
122 DUMP_PREFIX_ADDRESS, 16, 1, desc,
123 desc_bytes(desc), false);
124
125 testres.err = 0;
126 init_completion(&testres.completion);
127
128 ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
129 if (ret == -EINPROGRESS) {
130 wait_for_completion(&testres.completion);
131 ret = testres.err;
132 print_hex_dump_debug("output@"__stringify(__LINE__)": ",
133 DUMP_PREFIX_ADDRESS, 16, 1, info->output,
134 output_len, false);
135 }
136
137 if (ret == 0)
138 info->output_len = output_len;
139
140 dma_unmap_single(jrdev, dma_out, output_len, DMA_FROM_DEVICE);
141 out_unmap_in:
142 dma_unmap_single(jrdev, dma_in, info->input_len, DMA_TO_DEVICE);
143 out_free:
144 kfree(desc);
145
146 return ret;
147 }
148 EXPORT_SYMBOL(caam_process_blob);
149
caam_blob_gen_init(void)150 struct caam_blob_priv *caam_blob_gen_init(void)
151 {
152 struct caam_drv_private *ctrlpriv;
153 struct device *jrdev;
154
155 /*
156 * caam_blob_gen_init() may expectedly fail with -ENODEV, e.g. when
157 * CAAM driver didn't probe or when SoC lacks BLOB support. An
158 * error would be harsh in this case, so we stick to info level.
159 */
160
161 jrdev = caam_jr_alloc();
162 if (IS_ERR(jrdev)) {
163 pr_info("job ring requested, but none currently available\n");
164 return ERR_PTR(-ENODEV);
165 }
166
167 ctrlpriv = dev_get_drvdata(jrdev->parent);
168 if (!ctrlpriv->blob_present) {
169 dev_info(jrdev, "no hardware blob generation support\n");
170 caam_jr_free(jrdev);
171 return ERR_PTR(-ENODEV);
172 }
173
174 return container_of(jrdev, struct caam_blob_priv, jrdev);
175 }
176 EXPORT_SYMBOL(caam_blob_gen_init);
177
caam_blob_gen_exit(struct caam_blob_priv * priv)178 void caam_blob_gen_exit(struct caam_blob_priv *priv)
179 {
180 caam_jr_free(&priv->jrdev);
181 }
182 EXPORT_SYMBOL(caam_blob_gen_exit);
183