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
33struct caam_blob_priv {
34	struct device jrdev;
35};
36
37struct caam_blob_job_result {
38	int err;
39	struct completion completion;
40};
41
42static 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
62int 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);
150out_unmap_in:
151	dma_unmap_single(jrdev, dma_in, info->input_len, DMA_TO_DEVICE);
152out_free:
153	kfree(desc);
154
155	return ret;
156}
157EXPORT_SYMBOL(caam_process_blob);
158
159struct 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}
185EXPORT_SYMBOL(caam_blob_gen_init);
186
187void caam_blob_gen_exit(struct caam_blob_priv *priv)
188{
189	caam_jr_free(&priv->jrdev);
190}
191EXPORT_SYMBOL(caam_blob_gen_exit);
192