1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright 2019 Google LLC
4 */
5
6#include "ufshcd.h"
7#include "ufshcd-crypto.h"
8
9/* Blk-crypto modes supported by UFS crypto */
10static const struct ufs_crypto_alg_entry {
11	enum ufs_crypto_alg ufs_alg;
12	enum ufs_crypto_key_size ufs_key_size;
13} ufs_crypto_algs[BLK_ENCRYPTION_MODE_MAX] = {
14	[BLK_ENCRYPTION_MODE_AES_256_XTS] = {
15		.ufs_alg = UFS_CRYPTO_ALG_AES_XTS,
16		.ufs_key_size = UFS_CRYPTO_KEY_SIZE_256,
17	},
18};
19
20static int ufshcd_program_key(struct ufs_hba *hba,
21			      const union ufs_crypto_cfg_entry *cfg, int slot)
22{
23	int i;
24	u32 slot_offset = hba->crypto_cfg_register + slot * sizeof(*cfg);
25	int err = 0;
26
27	ufshcd_hold(hba, false);
28
29	if (hba->vops && hba->vops->program_key) {
30		err = hba->vops->program_key(hba, cfg, slot);
31		goto out;
32	}
33
34	/* Ensure that CFGE is cleared before programming the key */
35	ufshcd_writel(hba, 0, slot_offset + 16 * sizeof(cfg->reg_val[0]));
36	for (i = 0; i < 16; i++) {
37		ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[i]),
38			      slot_offset + i * sizeof(cfg->reg_val[0]));
39	}
40	/* Write dword 17 */
41	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[17]),
42		      slot_offset + 17 * sizeof(cfg->reg_val[0]));
43	/* Dword 16 must be written last */
44	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[16]),
45		      slot_offset + 16 * sizeof(cfg->reg_val[0]));
46out:
47	ufshcd_release(hba);
48	return err;
49}
50
51static int ufshcd_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
52					 const struct blk_crypto_key *key,
53					 unsigned int slot)
54{
55	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
56	const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
57	const struct ufs_crypto_alg_entry *alg =
58			&ufs_crypto_algs[key->crypto_cfg.crypto_mode];
59	u8 data_unit_mask = key->crypto_cfg.data_unit_size / 512;
60	int i;
61	int cap_idx = -1;
62	union ufs_crypto_cfg_entry cfg = {};
63	int err;
64
65	BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
66	for (i = 0; i < hba->crypto_capabilities.num_crypto_cap; i++) {
67		if (ccap_array[i].algorithm_id == alg->ufs_alg &&
68		    ccap_array[i].key_size == alg->ufs_key_size &&
69		    (ccap_array[i].sdus_mask & data_unit_mask)) {
70			cap_idx = i;
71			break;
72		}
73	}
74
75	if (WARN_ON(cap_idx < 0))
76		return -EOPNOTSUPP;
77
78	cfg.data_unit_size = data_unit_mask;
79	cfg.crypto_cap_idx = cap_idx;
80	cfg.config_enable = UFS_CRYPTO_CONFIGURATION_ENABLE;
81
82	if (ccap_array[cap_idx].algorithm_id == UFS_CRYPTO_ALG_AES_XTS) {
83		/* In XTS mode, the blk_crypto_key's size is already doubled */
84		memcpy(cfg.crypto_key, key->raw, key->size/2);
85		memcpy(cfg.crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
86		       key->raw + key->size/2, key->size/2);
87	} else {
88		memcpy(cfg.crypto_key, key->raw, key->size);
89	}
90
91	err = ufshcd_program_key(hba, &cfg, slot);
92
93	memzero_explicit(&cfg, sizeof(cfg));
94	return err;
95}
96
97static int ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)
98{
99	/*
100	 * Clear the crypto cfg on the device. Clearing CFGE
101	 * might not be sufficient, so just clear the entire cfg.
102	 */
103	union ufs_crypto_cfg_entry cfg = {};
104
105	return ufshcd_program_key(hba, &cfg, slot);
106}
107
108static int ufshcd_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
109				       const struct blk_crypto_key *key,
110				       unsigned int slot)
111{
112	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
113
114	return ufshcd_clear_keyslot(hba, slot);
115}
116
117bool ufshcd_crypto_enable(struct ufs_hba *hba)
118{
119	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
120		return false;
121
122	/* Reset might clear all keys, so reprogram all the keys. */
123	blk_ksm_reprogram_all_keys(&hba->ksm);
124	return true;
125}
126
127static const struct blk_ksm_ll_ops ufshcd_ksm_ops = {
128	.keyslot_program	= ufshcd_crypto_keyslot_program,
129	.keyslot_evict		= ufshcd_crypto_keyslot_evict,
130};
131
132static enum blk_crypto_mode_num
133ufshcd_find_blk_crypto_mode(union ufs_crypto_cap_entry cap)
134{
135	int i;
136
137	for (i = 0; i < ARRAY_SIZE(ufs_crypto_algs); i++) {
138		BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
139		if (ufs_crypto_algs[i].ufs_alg == cap.algorithm_id &&
140		    ufs_crypto_algs[i].ufs_key_size == cap.key_size) {
141			return i;
142		}
143	}
144	return BLK_ENCRYPTION_MODE_INVALID;
145}
146
147/**
148 * ufshcd_hba_init_crypto_capabilities - Read crypto capabilities, init crypto
149 *					 fields in hba
150 * @hba: Per adapter instance
151 *
152 * Return: 0 if crypto was initialized or is not supported, else a -errno value.
153 */
154int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
155{
156	int cap_idx;
157	int err = 0;
158	enum blk_crypto_mode_num blk_mode_num;
159
160	/*
161	 * Don't use crypto if either the hardware doesn't advertise the
162	 * standard crypto capability bit *or* if the vendor specific driver
163	 * hasn't advertised that crypto is supported.
164	 */
165	if (!(hba->capabilities & MASK_CRYPTO_SUPPORT) ||
166	    !(hba->caps & UFSHCD_CAP_CRYPTO))
167		goto out;
168
169	hba->crypto_capabilities.reg_val =
170			cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
171	hba->crypto_cfg_register =
172		(u32)hba->crypto_capabilities.config_array_ptr * 0x100;
173	hba->crypto_cap_array =
174		devm_kcalloc(hba->dev, hba->crypto_capabilities.num_crypto_cap,
175			     sizeof(hba->crypto_cap_array[0]), GFP_KERNEL);
176	if (!hba->crypto_cap_array) {
177		err = -ENOMEM;
178		goto out;
179	}
180
181	/* The actual number of configurations supported is (CFGC+1) */
182	err = blk_ksm_init(&hba->ksm,
183			   hba->crypto_capabilities.config_count + 1);
184	if (err)
185		goto out_free_caps;
186
187	hba->ksm.ksm_ll_ops = ufshcd_ksm_ops;
188	/* UFS only supports 8 bytes for any DUN */
189	hba->ksm.max_dun_bytes_supported = 8;
190	hba->ksm.dev = hba->dev;
191
192	/*
193	 * Cache all the UFS crypto capabilities and advertise the supported
194	 * crypto modes and data unit sizes to the block layer.
195	 */
196	for (cap_idx = 0; cap_idx < hba->crypto_capabilities.num_crypto_cap;
197	     cap_idx++) {
198		hba->crypto_cap_array[cap_idx].reg_val =
199			cpu_to_le32(ufshcd_readl(hba,
200						 REG_UFS_CRYPTOCAP +
201						 cap_idx * sizeof(__le32)));
202		blk_mode_num = ufshcd_find_blk_crypto_mode(
203						hba->crypto_cap_array[cap_idx]);
204		if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
205			hba->ksm.crypto_modes_supported[blk_mode_num] |=
206				hba->crypto_cap_array[cap_idx].sdus_mask * 512;
207	}
208
209	return 0;
210
211out_free_caps:
212	devm_kfree(hba->dev, hba->crypto_cap_array);
213out:
214	/* Indicate that init failed by clearing UFSHCD_CAP_CRYPTO */
215	hba->caps &= ~UFSHCD_CAP_CRYPTO;
216	return err;
217}
218
219/**
220 * ufshcd_init_crypto - Initialize crypto hardware
221 * @hba: Per adapter instance
222 */
223void ufshcd_init_crypto(struct ufs_hba *hba)
224{
225	int slot;
226
227	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
228		return;
229
230	/* Clear all keyslots - the number of keyslots is (CFGC + 1) */
231	for (slot = 0; slot < hba->crypto_capabilities.config_count + 1; slot++)
232		ufshcd_clear_keyslot(hba, slot);
233}
234
235void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
236					    struct request_queue *q)
237{
238	if (hba->caps & UFSHCD_CAP_CRYPTO)
239		blk_ksm_register(&hba->ksm, q);
240}
241
242void ufshcd_crypto_destroy_keyslot_manager(struct ufs_hba *hba)
243{
244	blk_ksm_destroy(&hba->ksm);
245}
246