1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AMD Cryptographic Coprocessor (CCP) crypto API support
4 *
5 * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
6 *
7 * Author: Tom Lendacky <thomas.lendacky@amd.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/moduleparam.h>
12 #include <linux/kernel.h>
13 #include <linux/list.h>
14 #include <linux/ccp.h>
15 #include <linux/scatterlist.h>
16 #include <crypto/internal/hash.h>
17 #include <crypto/internal/akcipher.h>
18
19 #include "ccp-crypto.h"
20
21 MODULE_AUTHOR("Tom Lendacky <thomas.lendacky@amd.com>");
22 MODULE_LICENSE("GPL");
23 MODULE_VERSION("1.0.0");
24 MODULE_DESCRIPTION("AMD Cryptographic Coprocessor crypto API support");
25
26 static unsigned int aes_disable;
27 module_param(aes_disable, uint, 0444);
28 MODULE_PARM_DESC(aes_disable, "Disable use of AES - any non-zero value");
29
30 static unsigned int sha_disable;
31 module_param(sha_disable, uint, 0444);
32 MODULE_PARM_DESC(sha_disable, "Disable use of SHA - any non-zero value");
33
34 static unsigned int des3_disable;
35 module_param(des3_disable, uint, 0444);
36 MODULE_PARM_DESC(des3_disable, "Disable use of 3DES - any non-zero value");
37
38 static unsigned int rsa_disable;
39 module_param(rsa_disable, uint, 0444);
40 MODULE_PARM_DESC(rsa_disable, "Disable use of RSA - any non-zero value");
41
42 /* List heads for the supported algorithms */
43 static LIST_HEAD(hash_algs);
44 static LIST_HEAD(skcipher_algs);
45 static LIST_HEAD(aead_algs);
46 static LIST_HEAD(akcipher_algs);
47
48 /* For any tfm, requests for that tfm must be returned on the order
49 * received. With multiple queues available, the CCP can process more
50 * than one cmd at a time. Therefore we must maintain a cmd list to insure
51 * the proper ordering of requests on a given tfm.
52 */
53 struct ccp_crypto_queue {
54 struct list_head cmds;
55 struct list_head *backlog;
56 unsigned int cmd_count;
57 };
58
59 #define CCP_CRYPTO_MAX_QLEN 100
60
61 static struct ccp_crypto_queue req_queue;
62 static DEFINE_SPINLOCK(req_queue_lock);
63
64 struct ccp_crypto_cmd {
65 struct list_head entry;
66
67 struct ccp_cmd *cmd;
68
69 /* Save the crypto_tfm and crypto_async_request addresses
70 * separately to avoid any reference to a possibly invalid
71 * crypto_async_request structure after invoking the request
72 * callback
73 */
74 struct crypto_async_request *req;
75 struct crypto_tfm *tfm;
76
77 /* Used for held command processing to determine state */
78 int ret;
79 };
80
ccp_crypto_success(int err)81 static inline bool ccp_crypto_success(int err)
82 {
83 if (err && (err != -EINPROGRESS) && (err != -EBUSY))
84 return false;
85
86 return true;
87 }
88
ccp_crypto_cmd_complete(struct ccp_crypto_cmd * crypto_cmd,struct ccp_crypto_cmd ** backlog)89 static struct ccp_crypto_cmd *ccp_crypto_cmd_complete(
90 struct ccp_crypto_cmd *crypto_cmd, struct ccp_crypto_cmd **backlog)
91 {
92 struct ccp_crypto_cmd *held = NULL, *tmp;
93 unsigned long flags;
94
95 *backlog = NULL;
96
97 spin_lock_irqsave(&req_queue_lock, flags);
98
99 /* Held cmds will be after the current cmd in the queue so start
100 * searching for a cmd with a matching tfm for submission.
101 */
102 tmp = crypto_cmd;
103 list_for_each_entry_continue(tmp, &req_queue.cmds, entry) {
104 if (crypto_cmd->tfm != tmp->tfm)
105 continue;
106 held = tmp;
107 break;
108 }
109
110 /* Process the backlog:
111 * Because cmds can be executed from any point in the cmd list
112 * special precautions have to be taken when handling the backlog.
113 */
114 if (req_queue.backlog != &req_queue.cmds) {
115 /* Skip over this cmd if it is the next backlog cmd */
116 if (req_queue.backlog == &crypto_cmd->entry)
117 req_queue.backlog = crypto_cmd->entry.next;
118
119 *backlog = container_of(req_queue.backlog,
120 struct ccp_crypto_cmd, entry);
121 req_queue.backlog = req_queue.backlog->next;
122
123 /* Skip over this cmd if it is now the next backlog cmd */
124 if (req_queue.backlog == &crypto_cmd->entry)
125 req_queue.backlog = crypto_cmd->entry.next;
126 }
127
128 /* Remove the cmd entry from the list of cmds */
129 req_queue.cmd_count--;
130 list_del(&crypto_cmd->entry);
131
132 spin_unlock_irqrestore(&req_queue_lock, flags);
133
134 return held;
135 }
136
ccp_crypto_complete(void * data,int err)137 static void ccp_crypto_complete(void *data, int err)
138 {
139 struct ccp_crypto_cmd *crypto_cmd = data;
140 struct ccp_crypto_cmd *held, *next, *backlog;
141 struct crypto_async_request *req = crypto_cmd->req;
142 struct ccp_ctx *ctx = crypto_tfm_ctx_dma(req->tfm);
143 int ret;
144
145 if (err == -EINPROGRESS) {
146 /* Only propagate the -EINPROGRESS if necessary */
147 if (crypto_cmd->ret == -EBUSY) {
148 crypto_cmd->ret = -EINPROGRESS;
149 crypto_request_complete(req, -EINPROGRESS);
150 }
151
152 return;
153 }
154
155 /* Operation has completed - update the queue before invoking
156 * the completion callbacks and retrieve the next cmd (cmd with
157 * a matching tfm) that can be submitted to the CCP.
158 */
159 held = ccp_crypto_cmd_complete(crypto_cmd, &backlog);
160 if (backlog) {
161 backlog->ret = -EINPROGRESS;
162 crypto_request_complete(backlog->req, -EINPROGRESS);
163 }
164
165 /* Transition the state from -EBUSY to -EINPROGRESS first */
166 if (crypto_cmd->ret == -EBUSY)
167 crypto_request_complete(req, -EINPROGRESS);
168
169 /* Completion callbacks */
170 ret = err;
171 if (ctx->complete)
172 ret = ctx->complete(req, ret);
173 crypto_request_complete(req, ret);
174
175 /* Submit the next cmd */
176 while (held) {
177 /* Since we have already queued the cmd, we must indicate that
178 * we can backlog so as not to "lose" this request.
179 */
180 held->cmd->flags |= CCP_CMD_MAY_BACKLOG;
181 ret = ccp_enqueue_cmd(held->cmd);
182 if (ccp_crypto_success(ret))
183 break;
184
185 /* Error occurred, report it and get the next entry */
186 ctx = crypto_tfm_ctx_dma(held->req->tfm);
187 if (ctx->complete)
188 ret = ctx->complete(held->req, ret);
189 crypto_request_complete(held->req, ret);
190
191 next = ccp_crypto_cmd_complete(held, &backlog);
192 if (backlog) {
193 backlog->ret = -EINPROGRESS;
194 crypto_request_complete(backlog->req, -EINPROGRESS);
195 }
196
197 kfree(held);
198 held = next;
199 }
200
201 kfree(crypto_cmd);
202 }
203
ccp_crypto_enqueue_cmd(struct ccp_crypto_cmd * crypto_cmd)204 static int ccp_crypto_enqueue_cmd(struct ccp_crypto_cmd *crypto_cmd)
205 {
206 struct ccp_crypto_cmd *active = NULL, *tmp;
207 unsigned long flags;
208 bool free_cmd = true;
209 int ret;
210
211 spin_lock_irqsave(&req_queue_lock, flags);
212
213 /* Check if the cmd can/should be queued */
214 if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) {
215 if (!(crypto_cmd->cmd->flags & CCP_CMD_MAY_BACKLOG)) {
216 ret = -ENOSPC;
217 goto e_lock;
218 }
219 }
220
221 /* Look for an entry with the same tfm. If there is a cmd
222 * with the same tfm in the list then the current cmd cannot
223 * be submitted to the CCP yet.
224 */
225 list_for_each_entry(tmp, &req_queue.cmds, entry) {
226 if (crypto_cmd->tfm != tmp->tfm)
227 continue;
228 active = tmp;
229 break;
230 }
231
232 ret = -EINPROGRESS;
233 if (!active) {
234 ret = ccp_enqueue_cmd(crypto_cmd->cmd);
235 if (!ccp_crypto_success(ret))
236 goto e_lock; /* Error, don't queue it */
237 }
238
239 if (req_queue.cmd_count >= CCP_CRYPTO_MAX_QLEN) {
240 ret = -EBUSY;
241 if (req_queue.backlog == &req_queue.cmds)
242 req_queue.backlog = &crypto_cmd->entry;
243 }
244 crypto_cmd->ret = ret;
245
246 req_queue.cmd_count++;
247 list_add_tail(&crypto_cmd->entry, &req_queue.cmds);
248
249 free_cmd = false;
250
251 e_lock:
252 spin_unlock_irqrestore(&req_queue_lock, flags);
253
254 if (free_cmd)
255 kfree(crypto_cmd);
256
257 return ret;
258 }
259
260 /**
261 * ccp_crypto_enqueue_request - queue an crypto async request for processing
262 * by the CCP
263 *
264 * @req: crypto_async_request struct to be processed
265 * @cmd: ccp_cmd struct to be sent to the CCP
266 */
ccp_crypto_enqueue_request(struct crypto_async_request * req,struct ccp_cmd * cmd)267 int ccp_crypto_enqueue_request(struct crypto_async_request *req,
268 struct ccp_cmd *cmd)
269 {
270 struct ccp_crypto_cmd *crypto_cmd;
271 gfp_t gfp;
272
273 gfp = req->flags & CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL : GFP_ATOMIC;
274
275 crypto_cmd = kzalloc(sizeof(*crypto_cmd), gfp);
276 if (!crypto_cmd)
277 return -ENOMEM;
278
279 /* The tfm pointer must be saved and not referenced from the
280 * crypto_async_request (req) pointer because it is used after
281 * completion callback for the request and the req pointer
282 * might not be valid anymore.
283 */
284 crypto_cmd->cmd = cmd;
285 crypto_cmd->req = req;
286 crypto_cmd->tfm = req->tfm;
287
288 cmd->callback = ccp_crypto_complete;
289 cmd->data = crypto_cmd;
290
291 if (req->flags & CRYPTO_TFM_REQ_MAY_BACKLOG)
292 cmd->flags |= CCP_CMD_MAY_BACKLOG;
293 else
294 cmd->flags &= ~CCP_CMD_MAY_BACKLOG;
295
296 return ccp_crypto_enqueue_cmd(crypto_cmd);
297 }
298
ccp_crypto_sg_table_add(struct sg_table * table,struct scatterlist * sg_add)299 struct scatterlist *ccp_crypto_sg_table_add(struct sg_table *table,
300 struct scatterlist *sg_add)
301 {
302 struct scatterlist *sg, *sg_last = NULL;
303
304 for (sg = table->sgl; sg; sg = sg_next(sg))
305 if (!sg_page(sg))
306 break;
307 if (WARN_ON(!sg))
308 return NULL;
309
310 for (; sg && sg_add; sg = sg_next(sg), sg_add = sg_next(sg_add)) {
311 sg_set_page(sg, sg_page(sg_add), sg_add->length,
312 sg_add->offset);
313 sg_last = sg;
314 }
315 if (WARN_ON(sg_add))
316 return NULL;
317
318 return sg_last;
319 }
320
ccp_register_algs(void)321 static int ccp_register_algs(void)
322 {
323 int ret;
324
325 if (!aes_disable) {
326 ret = ccp_register_aes_algs(&skcipher_algs);
327 if (ret)
328 return ret;
329
330 ret = ccp_register_aes_cmac_algs(&hash_algs);
331 if (ret)
332 return ret;
333
334 ret = ccp_register_aes_xts_algs(&skcipher_algs);
335 if (ret)
336 return ret;
337
338 ret = ccp_register_aes_aeads(&aead_algs);
339 if (ret)
340 return ret;
341 }
342
343 if (!des3_disable) {
344 ret = ccp_register_des3_algs(&skcipher_algs);
345 if (ret)
346 return ret;
347 }
348
349 if (!sha_disable) {
350 ret = ccp_register_sha_algs(&hash_algs);
351 if (ret)
352 return ret;
353 }
354
355 if (!rsa_disable) {
356 ret = ccp_register_rsa_algs(&akcipher_algs);
357 if (ret)
358 return ret;
359 }
360
361 return 0;
362 }
363
ccp_unregister_algs(void)364 static void ccp_unregister_algs(void)
365 {
366 struct ccp_crypto_ahash_alg *ahash_alg, *ahash_tmp;
367 struct ccp_crypto_skcipher_alg *ablk_alg, *ablk_tmp;
368 struct ccp_crypto_aead *aead_alg, *aead_tmp;
369 struct ccp_crypto_akcipher_alg *akc_alg, *akc_tmp;
370
371 list_for_each_entry_safe(ahash_alg, ahash_tmp, &hash_algs, entry) {
372 crypto_unregister_ahash(&ahash_alg->alg);
373 list_del(&ahash_alg->entry);
374 kfree(ahash_alg);
375 }
376
377 list_for_each_entry_safe(ablk_alg, ablk_tmp, &skcipher_algs, entry) {
378 crypto_unregister_skcipher(&ablk_alg->alg);
379 list_del(&ablk_alg->entry);
380 kfree(ablk_alg);
381 }
382
383 list_for_each_entry_safe(aead_alg, aead_tmp, &aead_algs, entry) {
384 crypto_unregister_aead(&aead_alg->alg);
385 list_del(&aead_alg->entry);
386 kfree(aead_alg);
387 }
388
389 list_for_each_entry_safe(akc_alg, akc_tmp, &akcipher_algs, entry) {
390 crypto_unregister_akcipher(&akc_alg->alg);
391 list_del(&akc_alg->entry);
392 kfree(akc_alg);
393 }
394 }
395
ccp_crypto_init(void)396 static int __init ccp_crypto_init(void)
397 {
398 int ret;
399
400 ret = ccp_present();
401 if (ret) {
402 pr_err("Cannot load: there are no available CCPs\n");
403 return ret;
404 }
405
406 INIT_LIST_HEAD(&req_queue.cmds);
407 req_queue.backlog = &req_queue.cmds;
408 req_queue.cmd_count = 0;
409
410 ret = ccp_register_algs();
411 if (ret)
412 ccp_unregister_algs();
413
414 return ret;
415 }
416
ccp_crypto_exit(void)417 static void __exit ccp_crypto_exit(void)
418 {
419 ccp_unregister_algs();
420 }
421
422 module_init(ccp_crypto_init);
423 module_exit(ccp_crypto_exit);
424