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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 #undef CREATE_TRACE_POINTS
10 #include <trace/hooks/ufshcd.h>
11 
12 /* Blk-crypto modes supported by UFS crypto */
13 static const struct ufs_crypto_alg_entry {
14 	enum ufs_crypto_alg ufs_alg;
15 	enum ufs_crypto_key_size ufs_key_size;
16 } ufs_crypto_algs[BLK_ENCRYPTION_MODE_MAX] = {
17 	[BLK_ENCRYPTION_MODE_AES_256_XTS] = {
18 		.ufs_alg = UFS_CRYPTO_ALG_AES_XTS,
19 		.ufs_key_size = UFS_CRYPTO_KEY_SIZE_256,
20 	},
21 };
22 
ufshcd_program_key(struct ufs_hba * hba,const union ufs_crypto_cfg_entry * cfg,int slot)23 static int ufshcd_program_key(struct ufs_hba *hba,
24 			      const union ufs_crypto_cfg_entry *cfg, int slot)
25 {
26 	int i;
27 	u32 slot_offset = hba->crypto_cfg_register + slot * sizeof(*cfg);
28 	int err = 0;
29 
30 	ufshcd_hold(hba, false);
31 
32 	if (hba->vops && hba->vops->program_key) {
33 		err = hba->vops->program_key(hba, cfg, slot);
34 		goto out;
35 	}
36 
37 	/* Ensure that CFGE is cleared before programming the key */
38 	ufshcd_writel(hba, 0, slot_offset + 16 * sizeof(cfg->reg_val[0]));
39 	for (i = 0; i < 16; i++) {
40 		ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[i]),
41 			      slot_offset + i * sizeof(cfg->reg_val[0]));
42 	}
43 	/* Write dword 17 */
44 	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[17]),
45 		      slot_offset + 17 * sizeof(cfg->reg_val[0]));
46 	/* Dword 16 must be written last */
47 	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[16]),
48 		      slot_offset + 16 * sizeof(cfg->reg_val[0]));
49 out:
50 	ufshcd_release(hba);
51 	return err;
52 }
53 
ufshcd_crypto_keyslot_program(struct blk_keyslot_manager * ksm,const struct blk_crypto_key * key,unsigned int slot)54 static int ufshcd_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
55 					 const struct blk_crypto_key *key,
56 					 unsigned int slot)
57 {
58 	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
59 	const union ufs_crypto_cap_entry *ccap_array = hba->crypto_cap_array;
60 	const struct ufs_crypto_alg_entry *alg =
61 			&ufs_crypto_algs[key->crypto_cfg.crypto_mode];
62 	u8 data_unit_mask = key->crypto_cfg.data_unit_size / 512;
63 	int i;
64 	int cap_idx = -1;
65 	union ufs_crypto_cfg_entry cfg = {};
66 	int err;
67 
68 	BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
69 	for (i = 0; i < hba->crypto_capabilities.num_crypto_cap; i++) {
70 		if (ccap_array[i].algorithm_id == alg->ufs_alg &&
71 		    ccap_array[i].key_size == alg->ufs_key_size &&
72 		    (ccap_array[i].sdus_mask & data_unit_mask)) {
73 			cap_idx = i;
74 			break;
75 		}
76 	}
77 
78 	if (WARN_ON(cap_idx < 0))
79 		return -EOPNOTSUPP;
80 
81 	cfg.data_unit_size = data_unit_mask;
82 	cfg.crypto_cap_idx = cap_idx;
83 	cfg.config_enable = UFS_CRYPTO_CONFIGURATION_ENABLE;
84 
85 	if (ccap_array[cap_idx].algorithm_id == UFS_CRYPTO_ALG_AES_XTS) {
86 		/* In XTS mode, the blk_crypto_key's size is already doubled */
87 		memcpy(cfg.crypto_key, key->raw, key->size/2);
88 		memcpy(cfg.crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
89 		       key->raw + key->size/2, key->size/2);
90 	} else {
91 		memcpy(cfg.crypto_key, key->raw, key->size);
92 	}
93 
94 	err = ufshcd_program_key(hba, &cfg, slot);
95 
96 	memzero_explicit(&cfg, sizeof(cfg));
97 	return err;
98 }
99 
ufshcd_clear_keyslot(struct ufs_hba * hba,int slot)100 static int ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)
101 {
102 	/*
103 	 * Clear the crypto cfg on the device. Clearing CFGE
104 	 * might not be sufficient, so just clear the entire cfg.
105 	 */
106 	union ufs_crypto_cfg_entry cfg = {};
107 
108 	return ufshcd_program_key(hba, &cfg, slot);
109 }
110 
ufshcd_crypto_keyslot_evict(struct blk_keyslot_manager * ksm,const struct blk_crypto_key * key,unsigned int slot)111 static int ufshcd_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
112 				       const struct blk_crypto_key *key,
113 				       unsigned int slot)
114 {
115 	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);
116 
117 	return ufshcd_clear_keyslot(hba, slot);
118 }
119 
ufshcd_crypto_enable(struct ufs_hba * hba)120 bool ufshcd_crypto_enable(struct ufs_hba *hba)
121 {
122 	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
123 		return false;
124 
125 	/* Reset might clear all keys, so reprogram all the keys. */
126 	if (hba->ksm.num_slots) {
127 		int err = -EOPNOTSUPP;
128 
129 		trace_android_rvh_ufs_reprogram_all_keys(hba, &err);
130 		if (err == -EOPNOTSUPP)
131 			blk_ksm_reprogram_all_keys(&hba->ksm);
132 	}
133 
134 	if (hba->quirks & UFSHCD_QUIRK_BROKEN_CRYPTO_ENABLE)
135 		return false;
136 
137 	return true;
138 }
139 
140 static const struct blk_ksm_ll_ops ufshcd_ksm_ops = {
141 	.keyslot_program	= ufshcd_crypto_keyslot_program,
142 	.keyslot_evict		= ufshcd_crypto_keyslot_evict,
143 };
144 
145 static enum blk_crypto_mode_num
ufshcd_find_blk_crypto_mode(union ufs_crypto_cap_entry cap)146 ufshcd_find_blk_crypto_mode(union ufs_crypto_cap_entry cap)
147 {
148 	int i;
149 
150 	for (i = 0; i < ARRAY_SIZE(ufs_crypto_algs); i++) {
151 		BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);
152 		if (ufs_crypto_algs[i].ufs_alg == cap.algorithm_id &&
153 		    ufs_crypto_algs[i].ufs_key_size == cap.key_size) {
154 			return i;
155 		}
156 	}
157 	return BLK_ENCRYPTION_MODE_INVALID;
158 }
159 
160 /**
161  * ufshcd_hba_init_crypto_capabilities - Read crypto capabilities, init crypto
162  *					 fields in hba
163  * @hba: Per adapter instance
164  *
165  * Return: 0 if crypto was initialized or is not supported, else a -errno value.
166  */
ufshcd_hba_init_crypto_capabilities(struct ufs_hba * hba)167 int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
168 {
169 	int cap_idx;
170 	int err = 0;
171 	enum blk_crypto_mode_num blk_mode_num;
172 
173 	if (hba->quirks & UFSHCD_QUIRK_CUSTOM_KEYSLOT_MANAGER)
174 		return 0;
175 
176 	/*
177 	 * Don't use crypto if either the hardware doesn't advertise the
178 	 * standard crypto capability bit *or* if the vendor specific driver
179 	 * hasn't advertised that crypto is supported.
180 	 */
181 	if (!(hba->capabilities & MASK_CRYPTO_SUPPORT) ||
182 	    !(hba->caps & UFSHCD_CAP_CRYPTO))
183 		goto out;
184 
185 	hba->crypto_capabilities.reg_val =
186 			cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
187 	hba->crypto_cfg_register =
188 		(u32)hba->crypto_capabilities.config_array_ptr * 0x100;
189 	hba->crypto_cap_array =
190 		devm_kcalloc(hba->dev, hba->crypto_capabilities.num_crypto_cap,
191 			     sizeof(hba->crypto_cap_array[0]), GFP_KERNEL);
192 	if (!hba->crypto_cap_array) {
193 		err = -ENOMEM;
194 		goto out;
195 	}
196 
197 	/* The actual number of configurations supported is (CFGC+1) */
198 	err = devm_blk_ksm_init(hba->dev, &hba->ksm,
199 				hba->crypto_capabilities.config_count + 1);
200 	if (err)
201 		goto out;
202 
203 	hba->ksm.ksm_ll_ops = ufshcd_ksm_ops;
204 	/* UFS only supports 8 bytes for any DUN */
205 	hba->ksm.max_dun_bytes_supported = 8;
206 	hba->ksm.features = BLK_CRYPTO_FEATURE_STANDARD_KEYS;
207 	hba->ksm.dev = hba->dev;
208 
209 	/*
210 	 * Cache all the UFS crypto capabilities and advertise the supported
211 	 * crypto modes and data unit sizes to the block layer.
212 	 */
213 	for (cap_idx = 0; cap_idx < hba->crypto_capabilities.num_crypto_cap;
214 	     cap_idx++) {
215 		hba->crypto_cap_array[cap_idx].reg_val =
216 			cpu_to_le32(ufshcd_readl(hba,
217 						 REG_UFS_CRYPTOCAP +
218 						 cap_idx * sizeof(__le32)));
219 		blk_mode_num = ufshcd_find_blk_crypto_mode(
220 						hba->crypto_cap_array[cap_idx]);
221 		if (blk_mode_num != BLK_ENCRYPTION_MODE_INVALID)
222 			hba->ksm.crypto_modes_supported[blk_mode_num] |=
223 				hba->crypto_cap_array[cap_idx].sdus_mask * 512;
224 	}
225 
226 	return 0;
227 
228 out:
229 	/* Indicate that init failed by clearing UFSHCD_CAP_CRYPTO */
230 	hba->caps &= ~UFSHCD_CAP_CRYPTO;
231 	return err;
232 }
233 
234 /**
235  * ufshcd_init_crypto - Initialize crypto hardware
236  * @hba: Per adapter instance
237  */
ufshcd_init_crypto(struct ufs_hba * hba)238 void ufshcd_init_crypto(struct ufs_hba *hba)
239 {
240 	int slot;
241 
242 	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
243 		return;
244 
245 	/* Clear all keyslots */
246 	for (slot = 0; slot < hba->ksm.num_slots; slot++)
247 		hba->ksm.ksm_ll_ops.keyslot_evict(&hba->ksm, NULL, slot);
248 }
249 
ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba * hba,struct request_queue * q)250 void ufshcd_crypto_setup_rq_keyslot_manager(struct ufs_hba *hba,
251 					    struct request_queue *q)
252 {
253 	if (hba->caps & UFSHCD_CAP_CRYPTO)
254 		blk_ksm_register(&hba->ksm, q);
255 }
256