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/bitfield.h>
10 #include <linux/device.h>
11 #include <soc/fsl/caam-blob.h>
12
13 #include "compat.h"
14 #include "desc_constr.h"
15 #include "desc.h"
16 #include "error.h"
17 #include "intern.h"
18 #include "jr.h"
19 #include "regs.h"
20
21 #define CAAM_BLOB_DESC_BYTES_MAX \
22 /* Command to initialize & stating length of descriptor */ \
23 (CAAM_CMD_SZ + \
24 /* Command to append the key-modifier + key-modifier data */ \
25 CAAM_CMD_SZ + CAAM_BLOB_KEYMOD_LENGTH + \
26 /* Command to include input key + pointer to the input key */ \
27 CAAM_CMD_SZ + CAAM_PTR_SZ_MAX + \
28 /* Command to include output key + pointer to the output key */ \
29 CAAM_CMD_SZ + CAAM_PTR_SZ_MAX + \
30 /* Command describing the operation to perform */ \
31 CAAM_CMD_SZ)
32
33 struct caam_blob_priv {
34 struct device jrdev;
35 };
36
37 struct caam_blob_job_result {
38 int err;
39 struct completion completion;
40 };
41
caam_blob_job_done(struct device * dev,u32 * desc,u32 err,void * context)42 static void caam_blob_job_done(struct device *dev, u32 *desc, u32 err, void *context)
43 {
44 struct caam_blob_job_result *res = context;
45 int ecode = 0;
46
47 dev_dbg(dev, "%s %d: err 0x%x\n", __func__, __LINE__, err);
48
49 if (err)
50 ecode = caam_jr_strstatus(dev, err);
51
52 res->err = ecode;
53
54 /*
55 * Upon completion, desc points to a buffer containing a CAAM job
56 * descriptor which encapsulates data into an externally-storable
57 * blob.
58 */
59 complete(&res->completion);
60 }
61
caam_process_blob(struct caam_blob_priv * priv,struct caam_blob_info * info,bool encap)62 int caam_process_blob(struct caam_blob_priv *priv,
63 struct caam_blob_info *info, bool encap)
64 {
65 const struct caam_drv_private *ctrlpriv;
66 struct caam_blob_job_result testres;
67 struct device *jrdev = &priv->jrdev;
68 dma_addr_t dma_in, dma_out;
69 int op = OP_PCLID_BLOB;
70 size_t output_len;
71 u32 *desc;
72 u32 moo;
73 int ret;
74
75 if (info->key_mod_len > CAAM_BLOB_KEYMOD_LENGTH)
76 return -EINVAL;
77
78 if (encap) {
79 op |= OP_TYPE_ENCAP_PROTOCOL;
80 output_len = info->input_len + CAAM_BLOB_OVERHEAD;
81 } else {
82 op |= OP_TYPE_DECAP_PROTOCOL;
83 output_len = info->input_len - CAAM_BLOB_OVERHEAD;
84 }
85
86 desc = kzalloc(CAAM_BLOB_DESC_BYTES_MAX, GFP_KERNEL);
87 if (!desc)
88 return -ENOMEM;
89
90 dma_in = dma_map_single(jrdev, info->input, info->input_len,
91 DMA_TO_DEVICE);
92 if (dma_mapping_error(jrdev, dma_in)) {
93 dev_err(jrdev, "unable to map input DMA buffer\n");
94 ret = -ENOMEM;
95 goto out_free;
96 }
97
98 dma_out = dma_map_single(jrdev, info->output, output_len,
99 DMA_FROM_DEVICE);
100 if (dma_mapping_error(jrdev, dma_out)) {
101 dev_err(jrdev, "unable to map output DMA buffer\n");
102 ret = -ENOMEM;
103 goto out_unmap_in;
104 }
105
106 ctrlpriv = dev_get_drvdata(jrdev->parent);
107 moo = FIELD_GET(CSTA_MOO, rd_reg32(&ctrlpriv->ctrl->perfmon.status));
108 if (moo != CSTA_MOO_SECURE && moo != CSTA_MOO_TRUSTED)
109 dev_warn(jrdev,
110 "using insecure test key, enable HAB to use unique device key!\n");
111
112 /*
113 * A data blob is encrypted using a blob key (BK); a random number.
114 * The BK is used as an AES-CCM key. The initial block (B0) and the
115 * initial counter (Ctr0) are generated automatically and stored in
116 * Class 1 Context DWords 0+1+2+3. The random BK is stored in the
117 * Class 1 Key Register. Operation Mode is set to AES-CCM.
118 */
119
120 init_job_desc(desc, 0);
121 append_key_as_imm(desc, info->key_mod, info->key_mod_len,
122 info->key_mod_len, CLASS_2 | KEY_DEST_CLASS_REG);
123 append_seq_in_ptr_intlen(desc, dma_in, info->input_len, 0);
124 append_seq_out_ptr_intlen(desc, dma_out, output_len, 0);
125 append_operation(desc, op);
126
127 print_hex_dump_debug("data@"__stringify(__LINE__)": ",
128 DUMP_PREFIX_ADDRESS, 16, 1, info->input,
129 info->input_len, false);
130 print_hex_dump_debug("jobdesc@"__stringify(__LINE__)": ",
131 DUMP_PREFIX_ADDRESS, 16, 1, desc,
132 desc_bytes(desc), false);
133
134 testres.err = 0;
135 init_completion(&testres.completion);
136
137 ret = caam_jr_enqueue(jrdev, desc, caam_blob_job_done, &testres);
138 if (ret == -EINPROGRESS) {
139 wait_for_completion(&testres.completion);
140 ret = testres.err;
141 print_hex_dump_debug("output@"__stringify(__LINE__)": ",
142 DUMP_PREFIX_ADDRESS, 16, 1, info->output,
143 output_len, false);
144 }
145
146 if (ret == 0)
147 info->output_len = output_len;
148
149 dma_unmap_single(jrdev, dma_out, output_len, DMA_FROM_DEVICE);
150 out_unmap_in:
151 dma_unmap_single(jrdev, dma_in, info->input_len, DMA_TO_DEVICE);
152 out_free:
153 kfree(desc);
154
155 return ret;
156 }
157 EXPORT_SYMBOL(caam_process_blob);
158
caam_blob_gen_init(void)159 struct caam_blob_priv *caam_blob_gen_init(void)
160 {
161 struct caam_drv_private *ctrlpriv;
162 struct device *jrdev;
163
164 /*
165 * caam_blob_gen_init() may expectedly fail with -ENODEV, e.g. when
166 * CAAM driver didn't probe or when SoC lacks BLOB support. An
167 * error would be harsh in this case, so we stick to info level.
168 */
169
170 jrdev = caam_jr_alloc();
171 if (IS_ERR(jrdev)) {
172 pr_info("job ring requested, but none currently available\n");
173 return ERR_PTR(-ENODEV);
174 }
175
176 ctrlpriv = dev_get_drvdata(jrdev->parent);
177 if (!ctrlpriv->blob_present) {
178 dev_info(jrdev, "no hardware blob generation support\n");
179 caam_jr_free(jrdev);
180 return ERR_PTR(-ENODEV);
181 }
182
183 return container_of(jrdev, struct caam_blob_priv, jrdev);
184 }
185 EXPORT_SYMBOL(caam_blob_gen_init);
186
caam_blob_gen_exit(struct caam_blob_priv * priv)187 void caam_blob_gen_exit(struct caam_blob_priv *priv)
188 {
189 caam_jr_free(&priv->jrdev);
190 }
191 EXPORT_SYMBOL(caam_blob_gen_exit);
192