hc
2024-05-11 04dd17822334871b23ea2862f7798fb0e0007777
kernel/drivers/crypto/atmel-ecc.c
....@@ -1,22 +1,11 @@
1
+// SPDX-License-Identifier: GPL-2.0
12 /*
23 * Microchip / Atmel ECC (I2C) driver.
34 *
45 * Copyright (c) 2017, Microchip Technology Inc.
56 * Author: Tudor Ambarus <tudor.ambarus@microchip.com>
6
- *
7
- * This software is licensed under the terms of the GNU General Public
8
- * License version 2, as published by the Free Software Foundation, and
9
- * may be copied, distributed, and modified under those terms.
10
- *
11
- * This program is distributed in the hope that it will be useful,
12
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
13
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14
- * GNU General Public License for more details.
15
- *
167 */
178
18
-#include <linux/bitrev.h>
19
-#include <linux/crc16.h>
209 #include <linux/delay.h>
2110 #include <linux/device.h>
2211 #include <linux/err.h>
....@@ -32,40 +21,9 @@
3221 #include <crypto/internal/kpp.h>
3322 #include <crypto/ecdh.h>
3423 #include <crypto/kpp.h>
35
-#include "atmel-ecc.h"
36
-
37
-/* Used for binding tfm objects to i2c clients. */
38
-struct atmel_ecc_driver_data {
39
- struct list_head i2c_client_list;
40
- spinlock_t i2c_list_lock;
41
-} ____cacheline_aligned;
24
+#include "atmel-i2c.h"
4225
4326 static struct atmel_ecc_driver_data driver_data;
44
-
45
-/**
46
- * atmel_ecc_i2c_client_priv - i2c_client private data
47
- * @client : pointer to i2c client device
48
- * @i2c_client_list_node: part of i2c_client_list
49
- * @lock : lock for sending i2c commands
50
- * @wake_token : wake token array of zeros
51
- * @wake_token_sz : size in bytes of the wake_token
52
- * @tfm_count : number of active crypto transformations on i2c client
53
- *
54
- * Reads and writes from/to the i2c client are sequential. The first byte
55
- * transmitted to the device is treated as the byte size. Any attempt to send
56
- * more than this number of bytes will cause the device to not ACK those bytes.
57
- * After the host writes a single command byte to the input buffer, reads are
58
- * prohibited until after the device completes command execution. Use a mutex
59
- * when sending i2c commands.
60
- */
61
-struct atmel_ecc_i2c_client_priv {
62
- struct i2c_client *client;
63
- struct list_head i2c_client_list_node;
64
- struct mutex lock;
65
- u8 wake_token[WAKE_TOKEN_MAX_SIZE];
66
- size_t wake_token_sz;
67
- atomic_t tfm_count ____cacheline_aligned;
68
-};
6927
7028 /**
7129 * atmel_ecdh_ctx - transformation context
....@@ -89,188 +47,12 @@
8947 bool do_fallback;
9048 };
9149
92
-/**
93
- * atmel_ecc_work_data - data structure representing the work
94
- * @ctx : transformation context.
95
- * @cbk : pointer to a callback function to be invoked upon completion of this
96
- * request. This has the form:
97
- * callback(struct atmel_ecc_work_data *work_data, void *areq, u8 status)
98
- * where:
99
- * @work_data: data structure representing the work
100
- * @areq : optional pointer to an argument passed with the original
101
- * request.
102
- * @status : status returned from the i2c client device or i2c error.
103
- * @areq: optional pointer to a user argument for use at callback time.
104
- * @work: describes the task to be executed.
105
- * @cmd : structure used for communicating with the device.
106
- */
107
-struct atmel_ecc_work_data {
108
- struct atmel_ecdh_ctx *ctx;
109
- void (*cbk)(struct atmel_ecc_work_data *work_data, void *areq,
110
- int status);
111
- void *areq;
112
- struct work_struct work;
113
- struct atmel_ecc_cmd cmd;
114
-};
115
-
116
-static u16 atmel_ecc_crc16(u16 crc, const u8 *buffer, size_t len)
117
-{
118
- return cpu_to_le16(bitrev16(crc16(crc, buffer, len)));
119
-}
120
-
121
-/**
122
- * atmel_ecc_checksum() - Generate 16-bit CRC as required by ATMEL ECC.
123
- * CRC16 verification of the count, opcode, param1, param2 and data bytes.
124
- * The checksum is saved in little-endian format in the least significant
125
- * two bytes of the command. CRC polynomial is 0x8005 and the initial register
126
- * value should be zero.
127
- *
128
- * @cmd : structure used for communicating with the device.
129
- */
130
-static void atmel_ecc_checksum(struct atmel_ecc_cmd *cmd)
131
-{
132
- u8 *data = &cmd->count;
133
- size_t len = cmd->count - CRC_SIZE;
134
- u16 *crc16 = (u16 *)(data + len);
135
-
136
- *crc16 = atmel_ecc_crc16(0, data, len);
137
-}
138
-
139
-static void atmel_ecc_init_read_cmd(struct atmel_ecc_cmd *cmd)
140
-{
141
- cmd->word_addr = COMMAND;
142
- cmd->opcode = OPCODE_READ;
143
- /*
144
- * Read the word from Configuration zone that contains the lock bytes
145
- * (UserExtra, Selector, LockValue, LockConfig).
146
- */
147
- cmd->param1 = CONFIG_ZONE;
148
- cmd->param2 = DEVICE_LOCK_ADDR;
149
- cmd->count = READ_COUNT;
150
-
151
- atmel_ecc_checksum(cmd);
152
-
153
- cmd->msecs = MAX_EXEC_TIME_READ;
154
- cmd->rxsize = READ_RSP_SIZE;
155
-}
156
-
157
-static void atmel_ecc_init_genkey_cmd(struct atmel_ecc_cmd *cmd, u16 keyid)
158
-{
159
- cmd->word_addr = COMMAND;
160
- cmd->count = GENKEY_COUNT;
161
- cmd->opcode = OPCODE_GENKEY;
162
- cmd->param1 = GENKEY_MODE_PRIVATE;
163
- /* a random private key will be generated and stored in slot keyID */
164
- cmd->param2 = cpu_to_le16(keyid);
165
-
166
- atmel_ecc_checksum(cmd);
167
-
168
- cmd->msecs = MAX_EXEC_TIME_GENKEY;
169
- cmd->rxsize = GENKEY_RSP_SIZE;
170
-}
171
-
172
-static int atmel_ecc_init_ecdh_cmd(struct atmel_ecc_cmd *cmd,
173
- struct scatterlist *pubkey)
174
-{
175
- size_t copied;
176
-
177
- cmd->word_addr = COMMAND;
178
- cmd->count = ECDH_COUNT;
179
- cmd->opcode = OPCODE_ECDH;
180
- cmd->param1 = ECDH_PREFIX_MODE;
181
- /* private key slot */
182
- cmd->param2 = cpu_to_le16(DATA_SLOT_2);
183
-
184
- /*
185
- * The device only supports NIST P256 ECC keys. The public key size will
186
- * always be the same. Use a macro for the key size to avoid unnecessary
187
- * computations.
188
- */
189
- copied = sg_copy_to_buffer(pubkey,
190
- sg_nents_for_len(pubkey,
191
- ATMEL_ECC_PUBKEY_SIZE),
192
- cmd->data, ATMEL_ECC_PUBKEY_SIZE);
193
- if (copied != ATMEL_ECC_PUBKEY_SIZE)
194
- return -EINVAL;
195
-
196
- atmel_ecc_checksum(cmd);
197
-
198
- cmd->msecs = MAX_EXEC_TIME_ECDH;
199
- cmd->rxsize = ECDH_RSP_SIZE;
200
-
201
- return 0;
202
-}
203
-
204
-/*
205
- * After wake and after execution of a command, there will be error, status, or
206
- * result bytes in the device's output register that can be retrieved by the
207
- * system. When the length of that group is four bytes, the codes returned are
208
- * detailed in error_list.
209
- */
210
-static int atmel_ecc_status(struct device *dev, u8 *status)
211
-{
212
- size_t err_list_len = ARRAY_SIZE(error_list);
213
- int i;
214
- u8 err_id = status[1];
215
-
216
- if (*status != STATUS_SIZE)
217
- return 0;
218
-
219
- if (err_id == STATUS_WAKE_SUCCESSFUL || err_id == STATUS_NOERR)
220
- return 0;
221
-
222
- for (i = 0; i < err_list_len; i++)
223
- if (error_list[i].value == err_id)
224
- break;
225
-
226
- /* if err_id is not in the error_list then ignore it */
227
- if (i != err_list_len) {
228
- dev_err(dev, "%02x: %s:\n", err_id, error_list[i].error_text);
229
- return err_id;
230
- }
231
-
232
- return 0;
233
-}
234
-
235
-static int atmel_ecc_wakeup(struct i2c_client *client)
236
-{
237
- struct atmel_ecc_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
238
- u8 status[STATUS_RSP_SIZE];
239
- int ret;
240
-
241
- /*
242
- * The device ignores any levels or transitions on the SCL pin when the
243
- * device is idle, asleep or during waking up. Don't check for error
244
- * when waking up the device.
245
- */
246
- i2c_master_send(client, i2c_priv->wake_token, i2c_priv->wake_token_sz);
247
-
248
- /*
249
- * Wait to wake the device. Typical execution times for ecdh and genkey
250
- * are around tens of milliseconds. Delta is chosen to 50 microseconds.
251
- */
252
- usleep_range(TWHI_MIN, TWHI_MAX);
253
-
254
- ret = i2c_master_recv(client, status, STATUS_SIZE);
255
- if (ret < 0)
256
- return ret;
257
-
258
- return atmel_ecc_status(&client->dev, status);
259
-}
260
-
261
-static int atmel_ecc_sleep(struct i2c_client *client)
262
-{
263
- u8 sleep = SLEEP_TOKEN;
264
-
265
- return i2c_master_send(client, &sleep, 1);
266
-}
267
-
268
-static void atmel_ecdh_done(struct atmel_ecc_work_data *work_data, void *areq,
50
+static void atmel_ecdh_done(struct atmel_i2c_work_data *work_data, void *areq,
26951 int status)
27052 {
27153 struct kpp_request *req = areq;
27254 struct atmel_ecdh_ctx *ctx = work_data->ctx;
273
- struct atmel_ecc_cmd *cmd = &work_data->cmd;
55
+ struct atmel_i2c_cmd *cmd = &work_data->cmd;
27456 size_t copied, n_sz;
27557
27658 if (status)
....@@ -287,84 +69,8 @@
28769
28870 /* fall through */
28971 free_work_data:
290
- kzfree(work_data);
72
+ kfree_sensitive(work_data);
29173 kpp_request_complete(req, status);
292
-}
293
-
294
-/*
295
- * atmel_ecc_send_receive() - send a command to the device and receive its
296
- * response.
297
- * @client: i2c client device
298
- * @cmd : structure used to communicate with the device
299
- *
300
- * After the device receives a Wake token, a watchdog counter starts within the
301
- * device. After the watchdog timer expires, the device enters sleep mode
302
- * regardless of whether some I/O transmission or command execution is in
303
- * progress. If a command is attempted when insufficient time remains prior to
304
- * watchdog timer execution, the device will return the watchdog timeout error
305
- * code without attempting to execute the command. There is no way to reset the
306
- * counter other than to put the device into sleep or idle mode and then
307
- * wake it up again.
308
- */
309
-static int atmel_ecc_send_receive(struct i2c_client *client,
310
- struct atmel_ecc_cmd *cmd)
311
-{
312
- struct atmel_ecc_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
313
- int ret;
314
-
315
- mutex_lock(&i2c_priv->lock);
316
-
317
- ret = atmel_ecc_wakeup(client);
318
- if (ret)
319
- goto err;
320
-
321
- /* send the command */
322
- ret = i2c_master_send(client, (u8 *)cmd, cmd->count + WORD_ADDR_SIZE);
323
- if (ret < 0)
324
- goto err;
325
-
326
- /* delay the appropriate amount of time for command to execute */
327
- msleep(cmd->msecs);
328
-
329
- /* receive the response */
330
- ret = i2c_master_recv(client, cmd->data, cmd->rxsize);
331
- if (ret < 0)
332
- goto err;
333
-
334
- /* put the device into low-power mode */
335
- ret = atmel_ecc_sleep(client);
336
- if (ret < 0)
337
- goto err;
338
-
339
- mutex_unlock(&i2c_priv->lock);
340
- return atmel_ecc_status(&client->dev, cmd->data);
341
-err:
342
- mutex_unlock(&i2c_priv->lock);
343
- return ret;
344
-}
345
-
346
-static void atmel_ecc_work_handler(struct work_struct *work)
347
-{
348
- struct atmel_ecc_work_data *work_data =
349
- container_of(work, struct atmel_ecc_work_data, work);
350
- struct atmel_ecc_cmd *cmd = &work_data->cmd;
351
- struct i2c_client *client = work_data->ctx->client;
352
- int status;
353
-
354
- status = atmel_ecc_send_receive(client, cmd);
355
- work_data->cbk(work_data, work_data->areq, status);
356
-}
357
-
358
-static void atmel_ecc_enqueue(struct atmel_ecc_work_data *work_data,
359
- void (*cbk)(struct atmel_ecc_work_data *work_data,
360
- void *areq, int status),
361
- void *areq)
362
-{
363
- work_data->cbk = (void *)cbk;
364
- work_data->areq = areq;
365
-
366
- INIT_WORK(&work_data->work, atmel_ecc_work_handler);
367
- schedule_work(&work_data->work);
36874 }
36975
37076 static unsigned int atmel_ecdh_supported_curve(unsigned int curve_id)
....@@ -383,7 +89,7 @@
38389 unsigned int len)
38490 {
38591 struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
386
- struct atmel_ecc_cmd *cmd;
92
+ struct atmel_i2c_cmd *cmd;
38793 void *public_key;
38894 struct ecdh params;
38995 int ret = -ENOMEM;
....@@ -421,9 +127,9 @@
421127 ctx->do_fallback = false;
422128 ctx->curve_id = params.curve_id;
423129
424
- atmel_ecc_init_genkey_cmd(cmd, DATA_SLOT_2);
130
+ atmel_i2c_init_genkey_cmd(cmd, DATA_SLOT_2);
425131
426
- ret = atmel_ecc_send_receive(ctx->client, cmd);
132
+ ret = atmel_i2c_send_receive(ctx->client, cmd);
427133 if (ret)
428134 goto free_public_key;
429135
....@@ -453,6 +159,9 @@
453159 return crypto_kpp_generate_public_key(req);
454160 }
455161
162
+ if (!ctx->public_key)
163
+ return -EINVAL;
164
+
456165 /* might want less than we've got */
457166 nbytes = min_t(size_t, ATMEL_ECC_PUBKEY_SIZE, req->dst_len);
458167
....@@ -470,7 +179,7 @@
470179 {
471180 struct crypto_kpp *tfm = crypto_kpp_reqtfm(req);
472181 struct atmel_ecdh_ctx *ctx = kpp_tfm_ctx(tfm);
473
- struct atmel_ecc_work_data *work_data;
182
+ struct atmel_i2c_work_data *work_data;
474183 gfp_t gfp;
475184 int ret;
476185
....@@ -491,12 +200,13 @@
491200 return -ENOMEM;
492201
493202 work_data->ctx = ctx;
203
+ work_data->client = ctx->client;
494204
495
- ret = atmel_ecc_init_ecdh_cmd(&work_data->cmd, req->src);
205
+ ret = atmel_i2c_init_ecdh_cmd(&work_data->cmd, req->src);
496206 if (ret)
497207 goto free_work_data;
498208
499
- atmel_ecc_enqueue(work_data, atmel_ecdh_done, req);
209
+ atmel_i2c_enqueue(work_data, atmel_ecdh_done, req);
500210
501211 return -EINPROGRESS;
502212
....@@ -507,7 +217,7 @@
507217
508218 static struct i2c_client *atmel_ecc_i2c_client_alloc(void)
509219 {
510
- struct atmel_ecc_i2c_client_priv *i2c_priv, *min_i2c_priv = NULL;
220
+ struct atmel_i2c_client_priv *i2c_priv, *min_i2c_priv = NULL;
511221 struct i2c_client *client = ERR_PTR(-ENODEV);
512222 int min_tfm_cnt = INT_MAX;
513223 int tfm_cnt;
....@@ -542,7 +252,7 @@
542252
543253 static void atmel_ecc_i2c_client_free(struct i2c_client *client)
544254 {
545
- struct atmel_ecc_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
255
+ struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
546256
547257 atomic_dec(&i2c_priv->tfm_count);
548258 }
....@@ -613,95 +323,17 @@
613323 },
614324 };
615325
616
-static inline size_t atmel_ecc_wake_token_sz(u32 bus_clk_rate)
617
-{
618
- u32 no_of_bits = DIV_ROUND_UP(TWLO_USEC * bus_clk_rate, USEC_PER_SEC);
619
-
620
- /* return the size of the wake_token in bytes */
621
- return DIV_ROUND_UP(no_of_bits, 8);
622
-}
623
-
624
-static int device_sanity_check(struct i2c_client *client)
625
-{
626
- struct atmel_ecc_cmd *cmd;
627
- int ret;
628
-
629
- cmd = kmalloc(sizeof(*cmd), GFP_KERNEL);
630
- if (!cmd)
631
- return -ENOMEM;
632
-
633
- atmel_ecc_init_read_cmd(cmd);
634
-
635
- ret = atmel_ecc_send_receive(client, cmd);
636
- if (ret)
637
- goto free_cmd;
638
-
639
- /*
640
- * It is vital that the Configuration, Data and OTP zones be locked
641
- * prior to release into the field of the system containing the device.
642
- * Failure to lock these zones may permit modification of any secret
643
- * keys and may lead to other security problems.
644
- */
645
- if (cmd->data[LOCK_CONFIG_IDX] || cmd->data[LOCK_VALUE_IDX]) {
646
- dev_err(&client->dev, "Configuration or Data and OTP zones are unlocked!\n");
647
- ret = -ENOTSUPP;
648
- }
649
-
650
- /* fall through */
651
-free_cmd:
652
- kfree(cmd);
653
- return ret;
654
-}
655
-
656326 static int atmel_ecc_probe(struct i2c_client *client,
657327 const struct i2c_device_id *id)
658328 {
659
- struct atmel_ecc_i2c_client_priv *i2c_priv;
660
- struct device *dev = &client->dev;
329
+ struct atmel_i2c_client_priv *i2c_priv;
661330 int ret;
662
- u32 bus_clk_rate;
663331
664
- if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
665
- dev_err(dev, "I2C_FUNC_I2C not supported\n");
666
- return -ENODEV;
667
- }
668
-
669
- ret = of_property_read_u32(client->adapter->dev.of_node,
670
- "clock-frequency", &bus_clk_rate);
671
- if (ret) {
672
- dev_err(dev, "of: failed to read clock-frequency property\n");
673
- return ret;
674
- }
675
-
676
- if (bus_clk_rate > 1000000L) {
677
- dev_err(dev, "%d exceeds maximum supported clock frequency (1MHz)\n",
678
- bus_clk_rate);
679
- return -EINVAL;
680
- }
681
-
682
- i2c_priv = devm_kmalloc(dev, sizeof(*i2c_priv), GFP_KERNEL);
683
- if (!i2c_priv)
684
- return -ENOMEM;
685
-
686
- i2c_priv->client = client;
687
- mutex_init(&i2c_priv->lock);
688
-
689
- /*
690
- * WAKE_TOKEN_MAX_SIZE was calculated for the maximum bus_clk_rate -
691
- * 1MHz. The previous bus_clk_rate check ensures us that wake_token_sz
692
- * will always be smaller than or equal to WAKE_TOKEN_MAX_SIZE.
693
- */
694
- i2c_priv->wake_token_sz = atmel_ecc_wake_token_sz(bus_clk_rate);
695
-
696
- memset(i2c_priv->wake_token, 0, sizeof(i2c_priv->wake_token));
697
-
698
- atomic_set(&i2c_priv->tfm_count, 0);
699
-
700
- i2c_set_clientdata(client, i2c_priv);
701
-
702
- ret = device_sanity_check(client);
332
+ ret = atmel_i2c_probe(client, id);
703333 if (ret)
704334 return ret;
335
+
336
+ i2c_priv = i2c_get_clientdata(client);
705337
706338 spin_lock(&driver_data.i2c_list_lock);
707339 list_add_tail(&i2c_priv->i2c_client_list_node,
....@@ -714,10 +346,10 @@
714346 list_del(&i2c_priv->i2c_client_list_node);
715347 spin_unlock(&driver_data.i2c_list_lock);
716348
717
- dev_err(dev, "%s alg registration failed\n",
349
+ dev_err(&client->dev, "%s alg registration failed\n",
718350 atmel_ecdh.base.cra_driver_name);
719351 } else {
720
- dev_info(dev, "atmel ecc algorithms registered in /proc/crypto\n");
352
+ dev_info(&client->dev, "atmel ecc algorithms registered in /proc/crypto\n");
721353 }
722354
723355 return ret;
....@@ -725,7 +357,7 @@
725357
726358 static int atmel_ecc_remove(struct i2c_client *client)
727359 {
728
- struct atmel_ecc_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
360
+ struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
729361
730362 /* Return EBUSY if i2c client already allocated. */
731363 if (atomic_read(&i2c_priv->tfm_count)) {