xref: /linux/drivers/ufs/core/ufshcd-crypto.c (revision 88e45067a30918ebb4942120892963e2311330af)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright 2019 Google LLC
4  */
5 
6 #include <ufs/ufshcd.h>
7 #include "ufshcd-crypto.h"
8 
9 /* Blk-crypto modes supported by UFS crypto */
10 static 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 
ufshcd_program_key(struct ufs_hba * hba,const union ufs_crypto_cfg_entry * cfg,int slot)20 static void 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 
26 	ufshcd_hold(hba);
27 
28 	/* Ensure that CFGE is cleared before programming the key */
29 	ufshcd_writel(hba, 0, slot_offset + 16 * sizeof(cfg->reg_val[0]));
30 	for (i = 0; i < 16; i++) {
31 		ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[i]),
32 			      slot_offset + i * sizeof(cfg->reg_val[0]));
33 	}
34 	/* Write dword 17 */
35 	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[17]),
36 		      slot_offset + 17 * sizeof(cfg->reg_val[0]));
37 	/* Dword 16 must be written last */
38 	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[16]),
39 		      slot_offset + 16 * sizeof(cfg->reg_val[0]));
40 	ufshcd_release(hba);
41 }
42 
ufshcd_crypto_keyslot_program(struct blk_crypto_profile * profile,const struct blk_crypto_key * key,unsigned int slot)43 static int ufshcd_crypto_keyslot_program(struct blk_crypto_profile *profile,
44 					 const struct blk_crypto_key *key,
45 					 unsigned int slot)
46 {
47 	struct ufs_hba *hba = ufs_hba_from_crypto_profile(profile);
48 	const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
49 	const struct ufs_crypto_alg_entry *alg =
50 			&ufs_crypto_algs[key->crypto_cfg.crypto_mode];
51 	u8 data_unit_mask = key->crypto_cfg.data_unit_size / 512;
52 	int i;
53 	int cap_idx = -1;
54 	union ufs_crypto_cfg_entry cfg = {};
55 
56 	BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
57 	for (i = 0; i < hba->crypto_capabilities.num_crypto_cap; i++) {
58 		if (ccap_array[i].algorithm_id == alg->ufs_alg &&
59 		    ccap_array[i].key_size == alg->ufs_key_size &&
60 		    (ccap_array[i].sdus_mask & data_unit_mask)) {
61 			cap_idx = i;
62 			break;
63 		}
64 	}
65 
66 	if (WARN_ON(cap_idx < 0))
67 		return -EOPNOTSUPP;
68 
69 	cfg.data_unit_size = data_unit_mask;
70 	cfg.crypto_cap_idx = cap_idx;
71 	cfg.config_enable = UFS_CRYPTO_CONFIGURATION_ENABLE;
72 
73 	if (ccap_array[cap_idx].algorithm_id == UFS_CRYPTO_ALG_AES_XTS) {
74 		/* In XTS mode, the blk_crypto_key's size is already doubled */
75 		memcpy(cfg.crypto_key, key->raw, key->size/2);
76 		memcpy(cfg.crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
77 		       key->raw + key->size/2, key->size/2);
78 	} else {
79 		memcpy(cfg.crypto_key, key->raw, key->size);
80 	}
81 
82 	ufshcd_program_key(hba, &cfg, slot);
83 
84 	memzero_explicit(&cfg, sizeof(cfg));
85 	return 0;
86 }
87 
ufshcd_crypto_keyslot_evict(struct blk_crypto_profile * profile,const struct blk_crypto_key * key,unsigned int slot)88 static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
89 				       const struct blk_crypto_key *key,
90 				       unsigned int slot)
91 {
92 	struct ufs_hba *hba = ufs_hba_from_crypto_profile(profile);
93 	/*
94 	 * Clear the crypto cfg on the device. Clearing CFGE
95 	 * might not be sufficient, so just clear the entire cfg.
96 	 */
97 	union ufs_crypto_cfg_entry cfg = {};
98 
99 	ufshcd_program_key(hba, &cfg, slot);
100 	return 0;
101 }
102 
103 /*
104  * Reprogram the keyslots if needed, and return true if CRYPTO_GENERAL_ENABLE
105  * should be used in the host controller initialization sequence.
106  */
ufshcd_crypto_enable(struct ufs_hba * hba)107 bool ufshcd_crypto_enable(struct ufs_hba *hba)
108 {
109 	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
110 		return false;
111 
112 	/* Reset might clear all keys, so reprogram all the keys. */
113 	blk_crypto_reprogram_all_keys(&hba->crypto_profile);
114 
115 	if (hba->quirks & UFSHCD_QUIRK_BROKEN_CRYPTO_ENABLE)
116 		return false;
117 
118 	return true;
119 }
120 
121 static const struct blk_crypto_ll_ops ufshcd_crypto_ops = {
122 	.keyslot_program	= ufshcd_crypto_keyslot_program,
123 	.keyslot_evict		= ufshcd_crypto_keyslot_evict,
124 };
125 
126 static enum blk_crypto_mode_num
ufshcd_find_blk_crypto_mode(union ufs_crypto_cap_entry cap)127 ufshcd_find_blk_crypto_mode(union ufs_crypto_cap_entry cap)
128 {
129 	int i;
130 
131 	for (i = 0; i < ARRAY_SIZE(ufs_crypto_algs); i++) {
132 		BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
133 		if (ufs_crypto_algs[i].ufs_alg == cap.algorithm_id &&
134 		    ufs_crypto_algs[i].ufs_key_size == cap.key_size) {
135 			return i;
136 		}
137 	}
138 	return BLK_ENCRYPTION_MODE_INVALID;
139 }
140 
141 /**
142  * ufshcd_hba_init_crypto_capabilities - Read crypto capabilities, init crypto
143  *					 fields in hba
144  * @hba: Per adapter instance
145  *
146  * Return: 0 if crypto was initialized or is not supported, else a -errno value.
147  */
ufshcd_hba_init_crypto_capabilities(struct ufs_hba * hba)148 int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
149 {
150 	int cap_idx;
151 	int err = 0;
152 	enum blk_crypto_mode_num blk_mode_num;
153 
154 	if (hba->quirks & UFSHCD_QUIRK_CUSTOM_CRYPTO_PROFILE)
155 		return 0;
156 
157 	/*
158 	 * Don't use crypto if either the hardware doesn't advertise the
159 	 * standard crypto capability bit *or* if the vendor specific driver
160 	 * hasn't advertised that crypto is supported.
161 	 */
162 	if (!(hba->capabilities & MASK_CRYPTO_SUPPORT) ||
163 	    !(hba->caps & UFSHCD_CAP_CRYPTO))
164 		goto out;
165 
166 	hba->crypto_capabilities.reg_val =
167 			cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
168 	hba->crypto_cfg_register =
169 		(u32)hba->crypto_capabilities.config_array_ptr * 0x100;
170 	hba->crypto_cap_array =
171 		devm_kcalloc(hba->dev, hba->crypto_capabilities.num_crypto_cap,
172 			     sizeof(hba->crypto_cap_array[0]), GFP_KERNEL);
173 	if (!hba->crypto_cap_array) {
174 		err = -ENOMEM;
175 		goto out;
176 	}
177 
178 	/* The actual number of configurations supported is (CFGC+1) */
179 	err = devm_blk_crypto_profile_init(
180 			hba->dev, &hba->crypto_profile,
181 			hba->crypto_capabilities.config_count + 1);
182 	if (err)
183 		goto out;
184 
185 	hba->crypto_profile.ll_ops = ufshcd_crypto_ops;
186 	/* UFS only supports 8 bytes for any DUN */
187 	hba->crypto_profile.max_dun_bytes_supported = 8;
188 	hba->crypto_profile.dev = hba->dev;
189 
190 	/*
191 	 * Cache all the UFS crypto capabilities and advertise the supported
192 	 * crypto modes and data unit sizes to the block layer.
193 	 */
194 	for (cap_idx = 0; cap_idx < hba->crypto_capabilities.num_crypto_cap;
195 	     cap_idx++) {
196 		hba->crypto_cap_array[cap_idx].reg_val =
197 			cpu_to_le32(ufshcd_readl(hba,
198 						 REG_UFS_CRYPTOCAP +
199 						 cap_idx * sizeof(__le32)));
200 		blk_mode_num = ufshcd_find_blk_crypto_mode(
201 						hba->crypto_cap_array[cap_idx]);
202 		if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
203 			hba->crypto_profile.modes_supported[blk_mode_num] |=
204 				hba->crypto_cap_array[cap_idx].sdus_mask * 512;
205 	}
206 
207 	return 0;
208 
209 out:
210 	/* Indicate that init failed by clearing UFSHCD_CAP_CRYPTO */
211 	hba->caps &= ~UFSHCD_CAP_CRYPTO;
212 	return err;
213 }
214 
215 /**
216  * ufshcd_init_crypto - Initialize crypto hardware
217  * @hba: Per adapter instance
218  */
ufshcd_init_crypto(struct ufs_hba * hba)219 void ufshcd_init_crypto(struct ufs_hba *hba)
220 {
221 	int slot;
222 
223 	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
224 		return;
225 
226 	/* Clear all keyslots. */
227 	for (slot = 0; slot < hba->crypto_profile.num_slots; slot++)
228 		hba->crypto_profile.ll_ops.keyslot_evict(&hba->crypto_profile,
229 							 NULL, slot);
230 }
231 
ufshcd_crypto_register(struct ufs_hba * hba,struct request_queue * q)232 void ufshcd_crypto_register(struct ufs_hba *hba, struct request_queue *q)
233 {
234 	if (hba->caps & UFSHCD_CAP_CRYPTO)
235 		blk_crypto_register(&hba->crypto_profile, q);
236 }
237