summaryrefslogtreecommitdiff
path: root/drivers/crypto/ccp/ccp-crypto-main.c
blob: 8dccbddabef194d5dc14d920d7a9b6e4f06cc0d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
/*
 * AMD Cryptographic Coprocessor (CCP) crypto API support
 *
 * Copyright (C) 2013 Advanced Micro Devices, Inc.
 *
 * Author: Tom Lendacky <thomas.lendacky@amd.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/ccp.h>
#include <linux/scatterlist.h>
#include <crypto/internal/hash.h>

#include "ccp-crypto.h"

MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>");
MODULE_LICENSE("GPL");
MODULE_VERSION("1.0.0");
MODULE_DESCRIPTION("AMD Cryptographic Coprocessor crypto API support");

static unsigned int aes_disable;
module_param(aes_disable, uint, 0444);
MODULE_PARM_DESC(aes_disable, "Disable use of AES - any non-zero value");

static unsigned int sha_disable;
module_param(sha_disable, uint, 0444);
MODULE_PARM_DESC(sha_disable, "Disable use of SHA - any non-zero value");

static unsigned int des3_disable;
module_param(des3_disable, uint, 0444);
MODULE_PARM_DESC(des3_disable, "Disable use of 3DES - any non-zero value");

/* List heads for the supported algorithms */
static LIST_HEAD(hash_algs);
static LIST_HEAD(cipher_algs);
static LIST_HEAD(aead_algs);

/* For any tfm, requests for that tfm must be returned on the order
 * received.  With multiple queues available, the CCP can process more
 * than one cmd at a time.  Therefore we must maintain a cmd list to insure
 * the proper ordering of requests on a given tfm.
 */
struct ccp_crypto_queue {
	struct list_head cmds;
	struct list_head *backlog;
	unsigned int cmd_count;
};

#define CCP_CRYPTO_MAX_QLEN	100

static struct ccp_crypto_queue req_queue;
static spinlock_t req_queue_lock;

struct ccp_crypto_cmd {
	struct list_head entry;

	struct ccp_cmd *cmd;

	/* Save the crypto_tfm and crypto_async_request addresses
	 * separately to avoid any reference to a possibly invalid
	 * crypto_async_request structure after invoking the request
	 * callback
	 */
	struct crypto_async_request *req;
	struct crypto_tfm *tfm;

	/* Used for held command processing to determine state */
	int ret;
};

struct ccp_crypto_cpu {
	struct work_struct work;
	struct completion completion;
	struct ccp_crypto_cmd *crypto_cmd;
	int err;
};

static inline bool ccp_crypto_success(int err)
{
	if (err && (err != -EINPROGRESS) && (err != -EBUSY))
		return false;

	return true;
}

static struct ccp_crypto_cmd *ccp_crypto_cmd_complete(
	struct ccp_crypto_cmd *crypto_cmd, struct ccp_crypto_cmd **backlog)
{
	struct ccp_crypto_cmd *held = NULL, *tmp;
	unsigned long flags;

	*backlog = NULL;

	spin_lock_irqsave(&req_queue_lock, flags);

	/* Held cmds will be after the current cmd in the queue so start
	 * searching for a cmd with a matching tfm for submission.
	 */
	tmp = crypto_cmd;
	list_for_each_entry_continue(tmp, &req_queue.cmds, entry) {
		if (crypto_cmd->tfm != tmp->tfm)
			continue;
		held = tmp;
		break;
	}

	/* Process the backlog:
	 *   Because cmds can be executed from any point in the cmd list
	 *   special precautions have to be taken when handling the backlog.
	 */
	if (req_queue.backlog != &req_queue.cmds) {
		/* Skip over this cmd if it is the next backlog cmd */
		if (req_queue.backlog == &crypto_cmd->entry)
			req_queue.backlog = crypto_cmd->entry.next;

		*backlog = container_of(req_queue.backlog,
					struct ccp_crypto_cmd, entry);
		req_queue.backlog = req_queue.backlog->next;

		/* Skip over this cmd if it is now the next backlog cmd */
		if (req_queue.backlog == &crypto_cmd->entry)
			req_queue.backlog = crypto_cmd->entry.next;
	}

	/* Remove the cmd entry from the list of cmds */
	req_queue.cmd_count--;
	list_del(&crypto_cmd->entry);

	spin_unlock_irqrestore(&req_queue_lock, flags);

	return held;
}

static void ccp_crypto_complete(void *data, int err)
{
	struct ccp_crypto_cmd *crypto_cmd = data;
	struct ccp_crypto_cmd *held, *next, *backlog;
	struct crypto_async_request *req = crypto_cmd->req;
	struct ccp_ctx *ctx = crypto_tfm_ctx(req->tfm);
	int ret;

	if (err == -EINPROGRESS) {
		/* Only propagate the -EINPROGRESS if necessary */
		if (crypto_cmd->ret == -EBUSY) {
			crypto_cmd->ret = -EINPROGRESS;
			req->complete(req, -EINPROGRESS);
		}

		return;
	}

	/* Operation has completed - update the queue before invoking
	 * the completion callbacks and retrieve the next cmd (cmd with
	 * a matching tfm) that can be submitted to the CCP.
	 */
	held = ccp_crypto_cmd_complete(crypto_cmd, &backlog);
	if (backlog) {
		backlog->ret = -EINPROGRESS;
		backlog->req->complete(backlog->req, -EINPROGRESS);
	}

	/* Transition the state from -EBUSY to -EINPROGRESS first */
	if (crypto_cmd->ret == -EBUSY)
		req->complete(req, -EINPROGRESS);

	/* Completion callbacks */
	ret = err;
	if (ctx->complete)
		ret = ctx->complete(req, ret);
	req->complete(req, ret);

	/* Submit the next cmd */
	while (held) {
		/* Since we have already queued the cmd, we must indicate that
		 * we can backlog so as not to "lose" this request.
		 */
		held->cmd->flags |= CCP_CMD_MAY_BACKLOG;
		ret = ccp_enqueue_cmd(held->cmd);
		if (ccp_crypto_success(ret))
			break;

		/* Error occurred, report it and get the next entry */
		ctx = crypto_tfm_ctx(held->req->tfm);
		if (ctx->complete)
			ret = ctx->complete(held->req, ret);
		held->req->complete(held->req, ret);

		next = ccp_crypto_cmd_complete(held, &backlog);
		if (backlog) {
			backlog->ret = -EINPROGRESS;
			backlog->req->complete(backlog->req, -EINPROGRESS);
		}

		kfree(held);
		held = next;
	}

	kfree(crypto_cmd);
}

static int ccp_crypto_enqueue_cmd(struct ccp_crypto_cmd *crypto_cmd)
{
	struct ccp_crypto_cmd *active = NULL, *tmp;
	unsigned long flags;
	bool free_cmd = true;
	int ret;

	spin_lock_irqsave(&req_queue_lock, flags);

	/* Check if the cmd can/should be queued */
	if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) {
		ret = -EBUSY;
		if (!(crypto_cmd->cmd->flags & CCP_CMD_MAY_BACKLOG))
			goto e_lock;
	}

	/* Look for an entry with the same tfm.  If there is a cmd
	 * with the same tfm in the list then the current cmd cannot
	 * be submitted to the CCP yet.
	 */
	list_for_each_entry(tmp, &req_queue.cmds, entry) {
		if (crypto_cmd->tfm != tmp->tfm)
			continue;
		active = tmp;
		break;
	}

	ret = -EINPROGRESS;
	if (!active) {
		ret = ccp_enqueue_cmd(crypto_cmd->cmd);
		if (!ccp_crypto_success(ret))
			goto e_lock;	/* Error, don't queue it */
		if ((ret == -EBUSY) &&
		    !(crypto_cmd->cmd->flags & CCP_CMD_MAY_BACKLOG))
			goto e_lock;	/* Not backlogging, don't queue it */
	}

	if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) {
		ret = -EBUSY;
		if (req_queue.backlog == &req_queue.cmds)
			req_queue.backlog = &crypto_cmd->entry;
	}
	crypto_cmd->ret = ret;

	req_queue.cmd_count++;
	list_add_tail(&crypto_cmd->entry, &req_queue.cmds);

	free_cmd = false;

e_lock:
	spin_unlock_irqrestore(&req_queue_lock, flags);

	if (free_cmd)
		kfree(crypto_cmd);

	return ret;
}

/**
 * ccp_crypto_enqueue_request - queue an crypto async request for processing
 *				by the CCP
 *
 * @req: crypto_async_request struct to be processed
 * @cmd: ccp_cmd struct to be sent to the CCP
 */
int ccp_crypto_enqueue_request(struct crypto_async_request *req,
			       struct ccp_cmd *cmd)
{
	struct ccp_crypto_cmd *crypto_cmd;
	gfp_t gfp;

	gfp = req->flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL : GFP_ATOMIC;

	crypto_cmd = kzalloc(sizeof(*crypto_cmd), gfp);
	if (!crypto_cmd)
		return -ENOMEM;

	/* The tfm pointer must be saved and not referenced from the
	 * crypto_async_request (req) pointer because it is used after
	 * completion callback for the request and the req pointer
	 * might not be valid anymore.
	 */
	crypto_cmd->cmd = cmd;
	crypto_cmd->req = req;
	crypto_cmd->tfm = req->tfm;

	cmd->callback = ccp_crypto_complete;
	cmd->data = crypto_cmd;

	if (req->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)
		cmd->flags |= CCP_CMD_MAY_BACKLOG;
	else
		cmd->flags &= ~CCP_CMD_MAY_BACKLOG;

	return ccp_crypto_enqueue_cmd(crypto_cmd);
}

struct scatterlist *ccp_crypto_sg_table_add(struct sg_table *table,
					    struct scatterlist *sg_add)
{
	struct scatterlist *sg, *sg_last = NULL;

	for (sg = table->sgl; sg; sg = sg_next(sg))
		if (!sg_page(sg))
			break;
	if (WARN_ON(!sg))
		return NULL;

	for (; sg && sg_add; sg = sg_next(sg), sg_add = sg_next(sg_add)) {
		sg_set_page(sg, sg_page(sg_add), sg_add->length,
			    sg_add->offset);
		sg_last = sg;
	}
	if (WARN_ON(sg_add))
		return NULL;

	return sg_last;
}

static int ccp_register_algs(void)
{
	int ret;

	if (!aes_disable) {
		ret = ccp_register_aes_algs(&cipher_algs);
		if (ret)
			return ret;

		ret = ccp_register_aes_cmac_algs(&hash_algs);
		if (ret)
			return ret;

		ret = ccp_register_aes_xts_algs(&cipher_algs);
		if (ret)
			return ret;

		ret = ccp_register_aes_aeads(&aead_algs);
		if (ret)
			return ret;
	}

	if (!des3_disable) {
		ret = ccp_register_des3_algs(&cipher_algs);
		if (ret)
			return ret;
	}

	if (!sha_disable) {
		ret = ccp_register_sha_algs(&hash_algs);
		if (ret)
			return ret;
	}

	return 0;
}

static void ccp_unregister_algs(void)
{
	struct ccp_crypto_ahash_alg *ahash_alg, *ahash_tmp;
	struct ccp_crypto_ablkcipher_alg *ablk_alg, *ablk_tmp;
	struct ccp_crypto_aead *aead_alg, *aead_tmp;

	list_for_each_entry_safe(ahash_alg, ahash_tmp, &hash_algs, entry) {
		crypto_unregister_ahash(&ahash_alg->alg);
		list_del(&ahash_alg->entry);
		kfree(ahash_alg);
	}

	list_for_each_entry_safe(ablk_alg, ablk_tmp, &cipher_algs, entry) {
		crypto_unregister_alg(&ablk_alg->alg);
		list_del(&ablk_alg->entry);
		kfree(ablk_alg);
	}

	list_for_each_entry_safe(aead_alg, aead_tmp, &aead_algs, entry) {
		crypto_unregister_aead(&aead_alg->alg);
		list_del(&aead_alg->entry);
		kfree(aead_alg);
	}
}

static int ccp_crypto_init(void)
{
	int ret;

	ret = ccp_present();
	if (ret)
		return ret;

	spin_lock_init(&req_queue_lock);
	INIT_LIST_HEAD(&req_queue.cmds);
	req_queue.backlog = &req_queue.cmds;
	req_queue.cmd_count = 0;

	ret = ccp_register_algs();
	if (ret)
		ccp_unregister_algs();

	return ret;
}

static void ccp_crypto_exit(void)
{
	ccp_unregister_algs();
}

module_init(ccp_crypto_init);
module_exit(ccp_crypto_exit);