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);