xref: /openbmc/linux/drivers/crypto/caam/blob_gen.c (revision 199354d7)
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