1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Xilinx ZynqMP AES Driver.
4 * Copyright (c) 2020 Xilinx Inc.
5 */
6
7 #include <crypto/aes.h>
8 #include <crypto/engine.h>
9 #include <crypto/gcm.h>
10 #include <crypto/internal/aead.h>
11 #include <crypto/scatterwalk.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/err.h>
14 #include <linux/firmware/xlnx-zynqmp.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/mod_devicetable.h>
18 #include <linux/platform_device.h>
19 #include <linux/string.h>
20
21 #define ZYNQMP_DMA_BIT_MASK 32U
22
23 #define ZYNQMP_AES_KEY_SIZE AES_KEYSIZE_256
24 #define ZYNQMP_AES_AUTH_SIZE 16U
25 #define ZYNQMP_KEY_SRC_SEL_KEY_LEN 1U
26 #define ZYNQMP_AES_BLK_SIZE 1U
27 #define ZYNQMP_AES_MIN_INPUT_BLK_SIZE 4U
28 #define ZYNQMP_AES_WORD_LEN 4U
29
30 #define ZYNQMP_AES_GCM_TAG_MISMATCH_ERR 0x01
31 #define ZYNQMP_AES_WRONG_KEY_SRC_ERR 0x13
32 #define ZYNQMP_AES_PUF_NOT_PROGRAMMED 0xE300
33
34 enum zynqmp_aead_op {
35 ZYNQMP_AES_DECRYPT = 0,
36 ZYNQMP_AES_ENCRYPT
37 };
38
39 enum zynqmp_aead_keysrc {
40 ZYNQMP_AES_KUP_KEY = 0,
41 ZYNQMP_AES_DEV_KEY,
42 ZYNQMP_AES_PUF_KEY
43 };
44
45 struct zynqmp_aead_drv_ctx {
46 union {
47 struct aead_engine_alg aead;
48 } alg;
49 struct device *dev;
50 struct crypto_engine *engine;
51 };
52
53 struct zynqmp_aead_hw_req {
54 u64 src;
55 u64 iv;
56 u64 key;
57 u64 dst;
58 u64 size;
59 u64 op;
60 u64 keysrc;
61 };
62
63 struct zynqmp_aead_tfm_ctx {
64 struct device *dev;
65 u8 key[ZYNQMP_AES_KEY_SIZE];
66 u8 *iv;
67 u32 keylen;
68 u32 authsize;
69 enum zynqmp_aead_keysrc keysrc;
70 struct crypto_aead *fbk_cipher;
71 };
72
73 struct zynqmp_aead_req_ctx {
74 enum zynqmp_aead_op op;
75 };
76
zynqmp_aes_aead_cipher(struct aead_request * req)77 static int zynqmp_aes_aead_cipher(struct aead_request *req)
78 {
79 struct crypto_aead *aead = crypto_aead_reqtfm(req);
80 struct zynqmp_aead_tfm_ctx *tfm_ctx = crypto_aead_ctx(aead);
81 struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(req);
82 struct device *dev = tfm_ctx->dev;
83 struct zynqmp_aead_hw_req *hwreq;
84 dma_addr_t dma_addr_data, dma_addr_hw_req;
85 unsigned int data_size;
86 unsigned int status;
87 int ret;
88 size_t dma_size;
89 char *kbuf;
90 int err;
91
92 if (tfm_ctx->keysrc == ZYNQMP_AES_KUP_KEY)
93 dma_size = req->cryptlen + ZYNQMP_AES_KEY_SIZE
94 + GCM_AES_IV_SIZE;
95 else
96 dma_size = req->cryptlen + GCM_AES_IV_SIZE;
97
98 kbuf = dma_alloc_coherent(dev, dma_size, &dma_addr_data, GFP_KERNEL);
99 if (!kbuf)
100 return -ENOMEM;
101
102 hwreq = dma_alloc_coherent(dev, sizeof(struct zynqmp_aead_hw_req),
103 &dma_addr_hw_req, GFP_KERNEL);
104 if (!hwreq) {
105 dma_free_coherent(dev, dma_size, kbuf, dma_addr_data);
106 return -ENOMEM;
107 }
108
109 data_size = req->cryptlen;
110 scatterwalk_map_and_copy(kbuf, req->src, 0, req->cryptlen, 0);
111 memcpy(kbuf + data_size, req->iv, GCM_AES_IV_SIZE);
112
113 hwreq->src = dma_addr_data;
114 hwreq->dst = dma_addr_data;
115 hwreq->iv = hwreq->src + data_size;
116 hwreq->keysrc = tfm_ctx->keysrc;
117 hwreq->op = rq_ctx->op;
118
119 if (hwreq->op == ZYNQMP_AES_ENCRYPT)
120 hwreq->size = data_size;
121 else
122 hwreq->size = data_size - ZYNQMP_AES_AUTH_SIZE;
123
124 if (hwreq->keysrc == ZYNQMP_AES_KUP_KEY) {
125 memcpy(kbuf + data_size + GCM_AES_IV_SIZE,
126 tfm_ctx->key, ZYNQMP_AES_KEY_SIZE);
127
128 hwreq->key = hwreq->src + data_size + GCM_AES_IV_SIZE;
129 } else {
130 hwreq->key = 0;
131 }
132
133 ret = zynqmp_pm_aes_engine(dma_addr_hw_req, &status);
134
135 if (ret) {
136 dev_err(dev, "ERROR: AES PM API failed\n");
137 err = ret;
138 } else if (status) {
139 switch (status) {
140 case ZYNQMP_AES_GCM_TAG_MISMATCH_ERR:
141 dev_err(dev, "ERROR: Gcm Tag mismatch\n");
142 break;
143 case ZYNQMP_AES_WRONG_KEY_SRC_ERR:
144 dev_err(dev, "ERROR: Wrong KeySrc, enable secure mode\n");
145 break;
146 case ZYNQMP_AES_PUF_NOT_PROGRAMMED:
147 dev_err(dev, "ERROR: PUF is not registered\n");
148 break;
149 default:
150 dev_err(dev, "ERROR: Unknown error\n");
151 break;
152 }
153 err = -status;
154 } else {
155 if (hwreq->op == ZYNQMP_AES_ENCRYPT)
156 data_size = data_size + ZYNQMP_AES_AUTH_SIZE;
157 else
158 data_size = data_size - ZYNQMP_AES_AUTH_SIZE;
159
160 sg_copy_from_buffer(req->dst, sg_nents(req->dst),
161 kbuf, data_size);
162 err = 0;
163 }
164
165 if (kbuf) {
166 memzero_explicit(kbuf, dma_size);
167 dma_free_coherent(dev, dma_size, kbuf, dma_addr_data);
168 }
169 if (hwreq) {
170 memzero_explicit(hwreq, sizeof(struct zynqmp_aead_hw_req));
171 dma_free_coherent(dev, sizeof(struct zynqmp_aead_hw_req),
172 hwreq, dma_addr_hw_req);
173 }
174 return err;
175 }
176
zynqmp_fallback_check(struct zynqmp_aead_tfm_ctx * tfm_ctx,struct aead_request * req)177 static int zynqmp_fallback_check(struct zynqmp_aead_tfm_ctx *tfm_ctx,
178 struct aead_request *req)
179 {
180 int need_fallback = 0;
181 struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(req);
182
183 if (tfm_ctx->authsize != ZYNQMP_AES_AUTH_SIZE)
184 need_fallback = 1;
185
186 if (tfm_ctx->keysrc == ZYNQMP_AES_KUP_KEY &&
187 tfm_ctx->keylen != ZYNQMP_AES_KEY_SIZE) {
188 need_fallback = 1;
189 }
190 if (req->assoclen != 0 ||
191 req->cryptlen < ZYNQMP_AES_MIN_INPUT_BLK_SIZE) {
192 need_fallback = 1;
193 }
194 if ((req->cryptlen % ZYNQMP_AES_WORD_LEN) != 0)
195 need_fallback = 1;
196
197 if (rq_ctx->op == ZYNQMP_AES_DECRYPT &&
198 req->cryptlen <= ZYNQMP_AES_AUTH_SIZE) {
199 need_fallback = 1;
200 }
201 return need_fallback;
202 }
203
zynqmp_handle_aes_req(struct crypto_engine * engine,void * req)204 static int zynqmp_handle_aes_req(struct crypto_engine *engine,
205 void *req)
206 {
207 struct aead_request *areq =
208 container_of(req, struct aead_request, base);
209 struct crypto_aead *aead = crypto_aead_reqtfm(req);
210 struct zynqmp_aead_tfm_ctx *tfm_ctx = crypto_aead_ctx(aead);
211 struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(areq);
212 struct aead_request *subreq = aead_request_ctx(req);
213 int need_fallback;
214 int err;
215
216 need_fallback = zynqmp_fallback_check(tfm_ctx, areq);
217
218 if (need_fallback) {
219 aead_request_set_tfm(subreq, tfm_ctx->fbk_cipher);
220
221 aead_request_set_callback(subreq, areq->base.flags,
222 NULL, NULL);
223 aead_request_set_crypt(subreq, areq->src, areq->dst,
224 areq->cryptlen, areq->iv);
225 aead_request_set_ad(subreq, areq->assoclen);
226 if (rq_ctx->op == ZYNQMP_AES_ENCRYPT)
227 err = crypto_aead_encrypt(subreq);
228 else
229 err = crypto_aead_decrypt(subreq);
230 } else {
231 err = zynqmp_aes_aead_cipher(areq);
232 }
233
234 local_bh_disable();
235 crypto_finalize_aead_request(engine, areq, err);
236 local_bh_enable();
237
238 return 0;
239 }
240
zynqmp_aes_aead_setkey(struct crypto_aead * aead,const u8 * key,unsigned int keylen)241 static int zynqmp_aes_aead_setkey(struct crypto_aead *aead, const u8 *key,
242 unsigned int keylen)
243 {
244 struct crypto_tfm *tfm = crypto_aead_tfm(aead);
245 struct zynqmp_aead_tfm_ctx *tfm_ctx =
246 (struct zynqmp_aead_tfm_ctx *)crypto_tfm_ctx(tfm);
247 unsigned char keysrc;
248
249 if (keylen == ZYNQMP_KEY_SRC_SEL_KEY_LEN) {
250 keysrc = *key;
251 if (keysrc == ZYNQMP_AES_KUP_KEY ||
252 keysrc == ZYNQMP_AES_DEV_KEY ||
253 keysrc == ZYNQMP_AES_PUF_KEY) {
254 tfm_ctx->keysrc = (enum zynqmp_aead_keysrc)keysrc;
255 } else {
256 tfm_ctx->keylen = keylen;
257 }
258 } else {
259 tfm_ctx->keylen = keylen;
260 if (keylen == ZYNQMP_AES_KEY_SIZE) {
261 tfm_ctx->keysrc = ZYNQMP_AES_KUP_KEY;
262 memcpy(tfm_ctx->key, key, keylen);
263 }
264 }
265
266 tfm_ctx->fbk_cipher->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
267 tfm_ctx->fbk_cipher->base.crt_flags |= (aead->base.crt_flags &
268 CRYPTO_TFM_REQ_MASK);
269
270 return crypto_aead_setkey(tfm_ctx->fbk_cipher, key, keylen);
271 }
272
zynqmp_aes_aead_setauthsize(struct crypto_aead * aead,unsigned int authsize)273 static int zynqmp_aes_aead_setauthsize(struct crypto_aead *aead,
274 unsigned int authsize)
275 {
276 struct crypto_tfm *tfm = crypto_aead_tfm(aead);
277 struct zynqmp_aead_tfm_ctx *tfm_ctx =
278 (struct zynqmp_aead_tfm_ctx *)crypto_tfm_ctx(tfm);
279
280 tfm_ctx->authsize = authsize;
281 return crypto_aead_setauthsize(tfm_ctx->fbk_cipher, authsize);
282 }
283
zynqmp_aes_aead_encrypt(struct aead_request * req)284 static int zynqmp_aes_aead_encrypt(struct aead_request *req)
285 {
286 struct zynqmp_aead_drv_ctx *drv_ctx;
287 struct crypto_aead *aead = crypto_aead_reqtfm(req);
288 struct aead_alg *alg = crypto_aead_alg(aead);
289 struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(req);
290
291 rq_ctx->op = ZYNQMP_AES_ENCRYPT;
292 drv_ctx = container_of(alg, struct zynqmp_aead_drv_ctx, alg.aead.base);
293
294 return crypto_transfer_aead_request_to_engine(drv_ctx->engine, req);
295 }
296
zynqmp_aes_aead_decrypt(struct aead_request * req)297 static int zynqmp_aes_aead_decrypt(struct aead_request *req)
298 {
299 struct zynqmp_aead_drv_ctx *drv_ctx;
300 struct crypto_aead *aead = crypto_aead_reqtfm(req);
301 struct aead_alg *alg = crypto_aead_alg(aead);
302 struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(req);
303
304 rq_ctx->op = ZYNQMP_AES_DECRYPT;
305 drv_ctx = container_of(alg, struct zynqmp_aead_drv_ctx, alg.aead.base);
306
307 return crypto_transfer_aead_request_to_engine(drv_ctx->engine, req);
308 }
309
zynqmp_aes_aead_init(struct crypto_aead * aead)310 static int zynqmp_aes_aead_init(struct crypto_aead *aead)
311 {
312 struct crypto_tfm *tfm = crypto_aead_tfm(aead);
313 struct zynqmp_aead_tfm_ctx *tfm_ctx =
314 (struct zynqmp_aead_tfm_ctx *)crypto_tfm_ctx(tfm);
315 struct zynqmp_aead_drv_ctx *drv_ctx;
316 struct aead_alg *alg = crypto_aead_alg(aead);
317
318 drv_ctx = container_of(alg, struct zynqmp_aead_drv_ctx, alg.aead.base);
319 tfm_ctx->dev = drv_ctx->dev;
320
321 tfm_ctx->fbk_cipher = crypto_alloc_aead(drv_ctx->alg.aead.base.base.cra_name,
322 0,
323 CRYPTO_ALG_NEED_FALLBACK);
324
325 if (IS_ERR(tfm_ctx->fbk_cipher)) {
326 pr_err("%s() Error: failed to allocate fallback for %s\n",
327 __func__, drv_ctx->alg.aead.base.base.cra_name);
328 return PTR_ERR(tfm_ctx->fbk_cipher);
329 }
330
331 crypto_aead_set_reqsize(aead,
332 max(sizeof(struct zynqmp_aead_req_ctx),
333 sizeof(struct aead_request) +
334 crypto_aead_reqsize(tfm_ctx->fbk_cipher)));
335 return 0;
336 }
337
zynqmp_aes_aead_exit(struct crypto_aead * aead)338 static void zynqmp_aes_aead_exit(struct crypto_aead *aead)
339 {
340 struct crypto_tfm *tfm = crypto_aead_tfm(aead);
341 struct zynqmp_aead_tfm_ctx *tfm_ctx =
342 (struct zynqmp_aead_tfm_ctx *)crypto_tfm_ctx(tfm);
343
344 if (tfm_ctx->fbk_cipher) {
345 crypto_free_aead(tfm_ctx->fbk_cipher);
346 tfm_ctx->fbk_cipher = NULL;
347 }
348 memzero_explicit(tfm_ctx, sizeof(struct zynqmp_aead_tfm_ctx));
349 }
350
351 static struct zynqmp_aead_drv_ctx aes_drv_ctx = {
352 .alg.aead.base = {
353 .setkey = zynqmp_aes_aead_setkey,
354 .setauthsize = zynqmp_aes_aead_setauthsize,
355 .encrypt = zynqmp_aes_aead_encrypt,
356 .decrypt = zynqmp_aes_aead_decrypt,
357 .init = zynqmp_aes_aead_init,
358 .exit = zynqmp_aes_aead_exit,
359 .ivsize = GCM_AES_IV_SIZE,
360 .maxauthsize = ZYNQMP_AES_AUTH_SIZE,
361 .base = {
362 .cra_name = "gcm(aes)",
363 .cra_driver_name = "xilinx-zynqmp-aes-gcm",
364 .cra_priority = 200,
365 .cra_flags = CRYPTO_ALG_TYPE_AEAD |
366 CRYPTO_ALG_ASYNC |
367 CRYPTO_ALG_ALLOCATES_MEMORY |
368 CRYPTO_ALG_KERN_DRIVER_ONLY |
369 CRYPTO_ALG_NEED_FALLBACK,
370 .cra_blocksize = ZYNQMP_AES_BLK_SIZE,
371 .cra_ctxsize = sizeof(struct zynqmp_aead_tfm_ctx),
372 .cra_module = THIS_MODULE,
373 }
374 },
375 .alg.aead.op = {
376 .do_one_request = zynqmp_handle_aes_req,
377 },
378 };
379
zynqmp_aes_aead_probe(struct platform_device * pdev)380 static int zynqmp_aes_aead_probe(struct platform_device *pdev)
381 {
382 struct device *dev = &pdev->dev;
383 int err;
384
385 /* ZynqMP AES driver supports only one instance */
386 if (!aes_drv_ctx.dev)
387 aes_drv_ctx.dev = dev;
388 else
389 return -ENODEV;
390
391 err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(ZYNQMP_DMA_BIT_MASK));
392 if (err < 0) {
393 dev_err(dev, "No usable DMA configuration\n");
394 return err;
395 }
396
397 aes_drv_ctx.engine = crypto_engine_alloc_init(dev, 1);
398 if (!aes_drv_ctx.engine) {
399 dev_err(dev, "Cannot alloc AES engine\n");
400 err = -ENOMEM;
401 goto err_engine;
402 }
403
404 err = crypto_engine_start(aes_drv_ctx.engine);
405 if (err) {
406 dev_err(dev, "Cannot start AES engine\n");
407 goto err_engine;
408 }
409
410 err = crypto_engine_register_aead(&aes_drv_ctx.alg.aead);
411 if (err < 0) {
412 dev_err(dev, "Failed to register AEAD alg.\n");
413 goto err_aead;
414 }
415 return 0;
416
417 err_aead:
418 crypto_engine_unregister_aead(&aes_drv_ctx.alg.aead);
419
420 err_engine:
421 if (aes_drv_ctx.engine)
422 crypto_engine_exit(aes_drv_ctx.engine);
423
424 return err;
425 }
426
zynqmp_aes_aead_remove(struct platform_device * pdev)427 static void zynqmp_aes_aead_remove(struct platform_device *pdev)
428 {
429 crypto_engine_exit(aes_drv_ctx.engine);
430 crypto_engine_unregister_aead(&aes_drv_ctx.alg.aead);
431 }
432
433 static const struct of_device_id zynqmp_aes_dt_ids[] = {
434 { .compatible = "xlnx,zynqmp-aes" },
435 { /* sentinel */ }
436 };
437 MODULE_DEVICE_TABLE(of, zynqmp_aes_dt_ids);
438
439 static struct platform_driver zynqmp_aes_driver = {
440 .probe = zynqmp_aes_aead_probe,
441 .remove_new = zynqmp_aes_aead_remove,
442 .driver = {
443 .name = "zynqmp-aes",
444 .of_match_table = zynqmp_aes_dt_ids,
445 },
446 };
447
448 module_platform_driver(zynqmp_aes_driver);
449 MODULE_LICENSE("GPL");
450