xref: /linux/drivers/crypto/mxs-dcp.c (revision d91517839e5d95adc0cf4b28caa7af62a71de526)
1 /*
2  * Freescale i.MX23/i.MX28 Data Co-Processor driver
3  *
4  * Copyright (C) 2013 Marek Vasut <marex@denx.de>
5  *
6  * The code contained herein is licensed under the GNU General Public
7  * License. You may obtain a copy of the GNU General Public License
8  * Version 2 or later at the following locations:
9  *
10  * http://www.opensource.org/licenses/gpl-license.html
11  * http://www.gnu.org/copyleft/gpl.html
12  */
13 
14 #include <linux/crypto.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/interrupt.h>
17 #include <linux/io.h>
18 #include <linux/kernel.h>
19 #include <linux/kthread.h>
20 #include <linux/module.h>
21 #include <linux/of.h>
22 #include <linux/platform_device.h>
23 #include <linux/stmp_device.h>
24 
25 #include <crypto/aes.h>
26 #include <crypto/sha.h>
27 #include <crypto/internal/hash.h>
28 
29 #define DCP_MAX_CHANS	4
30 #define DCP_BUF_SZ	PAGE_SIZE
31 
32 /* DCP DMA descriptor. */
33 struct dcp_dma_desc {
34 	uint32_t	next_cmd_addr;
35 	uint32_t	control0;
36 	uint32_t	control1;
37 	uint32_t	source;
38 	uint32_t	destination;
39 	uint32_t	size;
40 	uint32_t	payload;
41 	uint32_t	status;
42 };
43 
44 /* Coherent aligned block for bounce buffering. */
45 struct dcp_coherent_block {
46 	uint8_t			aes_in_buf[DCP_BUF_SZ];
47 	uint8_t			aes_out_buf[DCP_BUF_SZ];
48 	uint8_t			sha_in_buf[DCP_BUF_SZ];
49 
50 	uint8_t			aes_key[2 * AES_KEYSIZE_128];
51 	uint8_t			sha_digest[SHA256_DIGEST_SIZE];
52 
53 	struct dcp_dma_desc	desc[DCP_MAX_CHANS];
54 };
55 
56 struct dcp {
57 	struct device			*dev;
58 	void __iomem			*base;
59 
60 	uint32_t			caps;
61 
62 	struct dcp_coherent_block	*coh;
63 
64 	struct completion		completion[DCP_MAX_CHANS];
65 	struct mutex			mutex[DCP_MAX_CHANS];
66 	struct task_struct		*thread[DCP_MAX_CHANS];
67 	struct crypto_queue		queue[DCP_MAX_CHANS];
68 };
69 
70 enum dcp_chan {
71 	DCP_CHAN_HASH_SHA	= 0,
72 	DCP_CHAN_CRYPTO		= 2,
73 };
74 
75 struct dcp_async_ctx {
76 	/* Common context */
77 	enum dcp_chan	chan;
78 	uint32_t	fill;
79 
80 	/* SHA Hash-specific context */
81 	struct mutex			mutex;
82 	uint32_t			alg;
83 	unsigned int			hot:1;
84 
85 	/* Crypto-specific context */
86 	unsigned int			enc:1;
87 	unsigned int			ecb:1;
88 	struct crypto_ablkcipher	*fallback;
89 	unsigned int			key_len;
90 	uint8_t				key[AES_KEYSIZE_128];
91 };
92 
93 struct dcp_sha_req_ctx {
94 	unsigned int	init:1;
95 	unsigned int	fini:1;
96 };
97 
98 /*
99  * There can even be only one instance of the MXS DCP due to the
100  * design of Linux Crypto API.
101  */
102 static struct dcp *global_sdcp;
103 static DEFINE_MUTEX(global_mutex);
104 
105 /* DCP register layout. */
106 #define MXS_DCP_CTRL				0x00
107 #define MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES	(1 << 23)
108 #define MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING	(1 << 22)
109 
110 #define MXS_DCP_STAT				0x10
111 #define MXS_DCP_STAT_CLR			0x18
112 #define MXS_DCP_STAT_IRQ_MASK			0xf
113 
114 #define MXS_DCP_CHANNELCTRL			0x20
115 #define MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK	0xff
116 
117 #define MXS_DCP_CAPABILITY1			0x40
118 #define MXS_DCP_CAPABILITY1_SHA256		(4 << 16)
119 #define MXS_DCP_CAPABILITY1_SHA1		(1 << 16)
120 #define MXS_DCP_CAPABILITY1_AES128		(1 << 0)
121 
122 #define MXS_DCP_CONTEXT				0x50
123 
124 #define MXS_DCP_CH_N_CMDPTR(n)			(0x100 + ((n) * 0x40))
125 
126 #define MXS_DCP_CH_N_SEMA(n)			(0x110 + ((n) * 0x40))
127 
128 #define MXS_DCP_CH_N_STAT(n)			(0x120 + ((n) * 0x40))
129 #define MXS_DCP_CH_N_STAT_CLR(n)		(0x128 + ((n) * 0x40))
130 
131 /* DMA descriptor bits. */
132 #define MXS_DCP_CONTROL0_HASH_TERM		(1 << 13)
133 #define MXS_DCP_CONTROL0_HASH_INIT		(1 << 12)
134 #define MXS_DCP_CONTROL0_PAYLOAD_KEY		(1 << 11)
135 #define MXS_DCP_CONTROL0_CIPHER_ENCRYPT		(1 << 8)
136 #define MXS_DCP_CONTROL0_CIPHER_INIT		(1 << 9)
137 #define MXS_DCP_CONTROL0_ENABLE_HASH		(1 << 6)
138 #define MXS_DCP_CONTROL0_ENABLE_CIPHER		(1 << 5)
139 #define MXS_DCP_CONTROL0_DECR_SEMAPHORE		(1 << 1)
140 #define MXS_DCP_CONTROL0_INTERRUPT		(1 << 0)
141 
142 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA256	(2 << 16)
143 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA1	(0 << 16)
144 #define MXS_DCP_CONTROL1_CIPHER_MODE_CBC	(1 << 4)
145 #define MXS_DCP_CONTROL1_CIPHER_MODE_ECB	(0 << 4)
146 #define MXS_DCP_CONTROL1_CIPHER_SELECT_AES128	(0 << 0)
147 
148 static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
149 {
150 	struct dcp *sdcp = global_sdcp;
151 	const int chan = actx->chan;
152 	uint32_t stat;
153 	int ret;
154 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
155 
156 	dma_addr_t desc_phys = dma_map_single(sdcp->dev, desc, sizeof(*desc),
157 					      DMA_TO_DEVICE);
158 
159 	reinit_completion(&sdcp->completion[chan]);
160 
161 	/* Clear status register. */
162 	writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(chan));
163 
164 	/* Load the DMA descriptor. */
165 	writel(desc_phys, sdcp->base + MXS_DCP_CH_N_CMDPTR(chan));
166 
167 	/* Increment the semaphore to start the DMA transfer. */
168 	writel(1, sdcp->base + MXS_DCP_CH_N_SEMA(chan));
169 
170 	ret = wait_for_completion_timeout(&sdcp->completion[chan],
171 					  msecs_to_jiffies(1000));
172 	if (!ret) {
173 		dev_err(sdcp->dev, "Channel %i timeout (DCP_STAT=0x%08x)\n",
174 			chan, readl(sdcp->base + MXS_DCP_STAT));
175 		return -ETIMEDOUT;
176 	}
177 
178 	stat = readl(sdcp->base + MXS_DCP_CH_N_STAT(chan));
179 	if (stat & 0xff) {
180 		dev_err(sdcp->dev, "Channel %i error (CH_STAT=0x%08x)\n",
181 			chan, stat);
182 		return -EINVAL;
183 	}
184 
185 	dma_unmap_single(sdcp->dev, desc_phys, sizeof(*desc), DMA_TO_DEVICE);
186 
187 	return 0;
188 }
189 
190 /*
191  * Encryption (AES128)
192  */
193 static int mxs_dcp_run_aes(struct dcp_async_ctx *actx, int init)
194 {
195 	struct dcp *sdcp = global_sdcp;
196 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
197 	int ret;
198 
199 	dma_addr_t key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
200 					     2 * AES_KEYSIZE_128,
201 					     DMA_TO_DEVICE);
202 	dma_addr_t src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
203 					     DCP_BUF_SZ, DMA_TO_DEVICE);
204 	dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
205 					     DCP_BUF_SZ, DMA_FROM_DEVICE);
206 
207 	/* Fill in the DMA descriptor. */
208 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
209 		    MXS_DCP_CONTROL0_INTERRUPT |
210 		    MXS_DCP_CONTROL0_ENABLE_CIPHER;
211 
212 	/* Payload contains the key. */
213 	desc->control0 |= MXS_DCP_CONTROL0_PAYLOAD_KEY;
214 
215 	if (actx->enc)
216 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_ENCRYPT;
217 	if (init)
218 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_INIT;
219 
220 	desc->control1 = MXS_DCP_CONTROL1_CIPHER_SELECT_AES128;
221 
222 	if (actx->ecb)
223 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_ECB;
224 	else
225 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_CBC;
226 
227 	desc->next_cmd_addr = 0;
228 	desc->source = src_phys;
229 	desc->destination = dst_phys;
230 	desc->size = actx->fill;
231 	desc->payload = key_phys;
232 	desc->status = 0;
233 
234 	ret = mxs_dcp_start_dma(actx);
235 
236 	dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
237 			 DMA_TO_DEVICE);
238 	dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
239 	dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
240 
241 	return ret;
242 }
243 
244 static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
245 {
246 	struct dcp *sdcp = global_sdcp;
247 
248 	struct ablkcipher_request *req = ablkcipher_request_cast(arq);
249 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
250 
251 	struct scatterlist *dst = req->dst;
252 	struct scatterlist *src = req->src;
253 	const int nents = sg_nents(req->src);
254 
255 	const int out_off = DCP_BUF_SZ;
256 	uint8_t *in_buf = sdcp->coh->aes_in_buf;
257 	uint8_t *out_buf = sdcp->coh->aes_out_buf;
258 
259 	uint8_t *out_tmp, *src_buf, *dst_buf = NULL;
260 	uint32_t dst_off = 0;
261 
262 	uint8_t *key = sdcp->coh->aes_key;
263 
264 	int ret = 0;
265 	int split = 0;
266 	unsigned int i, len, clen, rem = 0;
267 	int init = 0;
268 
269 	actx->fill = 0;
270 
271 	/* Copy the key from the temporary location. */
272 	memcpy(key, actx->key, actx->key_len);
273 
274 	if (!actx->ecb) {
275 		/* Copy the CBC IV just past the key. */
276 		memcpy(key + AES_KEYSIZE_128, req->info, AES_KEYSIZE_128);
277 		/* CBC needs the INIT set. */
278 		init = 1;
279 	} else {
280 		memset(key + AES_KEYSIZE_128, 0, AES_KEYSIZE_128);
281 	}
282 
283 	for_each_sg(req->src, src, nents, i) {
284 		src_buf = sg_virt(src);
285 		len = sg_dma_len(src);
286 
287 		do {
288 			if (actx->fill + len > out_off)
289 				clen = out_off - actx->fill;
290 			else
291 				clen = len;
292 
293 			memcpy(in_buf + actx->fill, src_buf, clen);
294 			len -= clen;
295 			src_buf += clen;
296 			actx->fill += clen;
297 
298 			/*
299 			 * If we filled the buffer or this is the last SG,
300 			 * submit the buffer.
301 			 */
302 			if (actx->fill == out_off || sg_is_last(src)) {
303 				ret = mxs_dcp_run_aes(actx, init);
304 				if (ret)
305 					return ret;
306 				init = 0;
307 
308 				out_tmp = out_buf;
309 				while (dst && actx->fill) {
310 					if (!split) {
311 						dst_buf = sg_virt(dst);
312 						dst_off = 0;
313 					}
314 					rem = min(sg_dma_len(dst) - dst_off,
315 						  actx->fill);
316 
317 					memcpy(dst_buf + dst_off, out_tmp, rem);
318 					out_tmp += rem;
319 					dst_off += rem;
320 					actx->fill -= rem;
321 
322 					if (dst_off == sg_dma_len(dst)) {
323 						dst = sg_next(dst);
324 						split = 0;
325 					} else {
326 						split = 1;
327 					}
328 				}
329 			}
330 		} while (len);
331 	}
332 
333 	return ret;
334 }
335 
336 static int dcp_chan_thread_aes(void *data)
337 {
338 	struct dcp *sdcp = global_sdcp;
339 	const int chan = DCP_CHAN_CRYPTO;
340 
341 	struct crypto_async_request *backlog;
342 	struct crypto_async_request *arq;
343 
344 	int ret;
345 
346 	do {
347 		__set_current_state(TASK_INTERRUPTIBLE);
348 
349 		mutex_lock(&sdcp->mutex[chan]);
350 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
351 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
352 		mutex_unlock(&sdcp->mutex[chan]);
353 
354 		if (backlog)
355 			backlog->complete(backlog, -EINPROGRESS);
356 
357 		if (arq) {
358 			ret = mxs_dcp_aes_block_crypt(arq);
359 			arq->complete(arq, ret);
360 			continue;
361 		}
362 
363 		schedule();
364 	} while (!kthread_should_stop());
365 
366 	return 0;
367 }
368 
369 static int mxs_dcp_block_fallback(struct ablkcipher_request *req, int enc)
370 {
371 	struct crypto_tfm *tfm =
372 		crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
373 	struct dcp_async_ctx *ctx = crypto_ablkcipher_ctx(
374 		crypto_ablkcipher_reqtfm(req));
375 	int ret;
376 
377 	ablkcipher_request_set_tfm(req, ctx->fallback);
378 
379 	if (enc)
380 		ret = crypto_ablkcipher_encrypt(req);
381 	else
382 		ret = crypto_ablkcipher_decrypt(req);
383 
384 	ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
385 
386 	return ret;
387 }
388 
389 static int mxs_dcp_aes_enqueue(struct ablkcipher_request *req, int enc, int ecb)
390 {
391 	struct dcp *sdcp = global_sdcp;
392 	struct crypto_async_request *arq = &req->base;
393 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
394 	int ret;
395 
396 	if (unlikely(actx->key_len != AES_KEYSIZE_128))
397 		return mxs_dcp_block_fallback(req, enc);
398 
399 	actx->enc = enc;
400 	actx->ecb = ecb;
401 	actx->chan = DCP_CHAN_CRYPTO;
402 
403 	mutex_lock(&sdcp->mutex[actx->chan]);
404 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
405 	mutex_unlock(&sdcp->mutex[actx->chan]);
406 
407 	wake_up_process(sdcp->thread[actx->chan]);
408 
409 	return -EINPROGRESS;
410 }
411 
412 static int mxs_dcp_aes_ecb_decrypt(struct ablkcipher_request *req)
413 {
414 	return mxs_dcp_aes_enqueue(req, 0, 1);
415 }
416 
417 static int mxs_dcp_aes_ecb_encrypt(struct ablkcipher_request *req)
418 {
419 	return mxs_dcp_aes_enqueue(req, 1, 1);
420 }
421 
422 static int mxs_dcp_aes_cbc_decrypt(struct ablkcipher_request *req)
423 {
424 	return mxs_dcp_aes_enqueue(req, 0, 0);
425 }
426 
427 static int mxs_dcp_aes_cbc_encrypt(struct ablkcipher_request *req)
428 {
429 	return mxs_dcp_aes_enqueue(req, 1, 0);
430 }
431 
432 static int mxs_dcp_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
433 			      unsigned int len)
434 {
435 	struct dcp_async_ctx *actx = crypto_ablkcipher_ctx(tfm);
436 	unsigned int ret;
437 
438 	/*
439 	 * AES 128 is supposed by the hardware, store key into temporary
440 	 * buffer and exit. We must use the temporary buffer here, since
441 	 * there can still be an operation in progress.
442 	 */
443 	actx->key_len = len;
444 	if (len == AES_KEYSIZE_128) {
445 		memcpy(actx->key, key, len);
446 		return 0;
447 	}
448 
449 	/* Check if the key size is supported by kernel at all. */
450 	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256) {
451 		tfm->base.crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
452 		return -EINVAL;
453 	}
454 
455 	/*
456 	 * If the requested AES key size is not supported by the hardware,
457 	 * but is supported by in-kernel software implementation, we use
458 	 * software fallback.
459 	 */
460 	actx->fallback->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
461 	actx->fallback->base.crt_flags |=
462 		tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK;
463 
464 	ret = crypto_ablkcipher_setkey(actx->fallback, key, len);
465 	if (!ret)
466 		return 0;
467 
468 	tfm->base.crt_flags &= ~CRYPTO_TFM_RES_MASK;
469 	tfm->base.crt_flags |=
470 		actx->fallback->base.crt_flags & CRYPTO_TFM_RES_MASK;
471 
472 	return ret;
473 }
474 
475 static int mxs_dcp_aes_fallback_init(struct crypto_tfm *tfm)
476 {
477 	const char *name = tfm->__crt_alg->cra_name;
478 	const uint32_t flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK;
479 	struct dcp_async_ctx *actx = crypto_tfm_ctx(tfm);
480 	struct crypto_ablkcipher *blk;
481 
482 	blk = crypto_alloc_ablkcipher(name, 0, flags);
483 	if (IS_ERR(blk))
484 		return PTR_ERR(blk);
485 
486 	actx->fallback = blk;
487 	tfm->crt_ablkcipher.reqsize = sizeof(struct dcp_async_ctx);
488 	return 0;
489 }
490 
491 static void mxs_dcp_aes_fallback_exit(struct crypto_tfm *tfm)
492 {
493 	struct dcp_async_ctx *actx = crypto_tfm_ctx(tfm);
494 
495 	crypto_free_ablkcipher(actx->fallback);
496 	actx->fallback = NULL;
497 }
498 
499 /*
500  * Hashing (SHA1/SHA256)
501  */
502 static int mxs_dcp_run_sha(struct ahash_request *req)
503 {
504 	struct dcp *sdcp = global_sdcp;
505 	int ret;
506 
507 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
508 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
509 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
510 
511 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
512 	dma_addr_t digest_phys = dma_map_single(sdcp->dev,
513 						sdcp->coh->sha_digest,
514 						SHA256_DIGEST_SIZE,
515 						DMA_FROM_DEVICE);
516 
517 	dma_addr_t buf_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_in_buf,
518 					     DCP_BUF_SZ, DMA_TO_DEVICE);
519 
520 	/* Fill in the DMA descriptor. */
521 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
522 		    MXS_DCP_CONTROL0_INTERRUPT |
523 		    MXS_DCP_CONTROL0_ENABLE_HASH;
524 	if (rctx->init)
525 		desc->control0 |= MXS_DCP_CONTROL0_HASH_INIT;
526 
527 	desc->control1 = actx->alg;
528 	desc->next_cmd_addr = 0;
529 	desc->source = buf_phys;
530 	desc->destination = 0;
531 	desc->size = actx->fill;
532 	desc->payload = 0;
533 	desc->status = 0;
534 
535 	/* Set HASH_TERM bit for last transfer block. */
536 	if (rctx->fini) {
537 		desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
538 		desc->payload = digest_phys;
539 	}
540 
541 	ret = mxs_dcp_start_dma(actx);
542 
543 	dma_unmap_single(sdcp->dev, digest_phys, SHA256_DIGEST_SIZE,
544 			 DMA_FROM_DEVICE);
545 	dma_unmap_single(sdcp->dev, buf_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
546 
547 	return ret;
548 }
549 
550 static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
551 {
552 	struct dcp *sdcp = global_sdcp;
553 
554 	struct ahash_request *req = ahash_request_cast(arq);
555 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
556 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
557 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
558 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
559 	const int nents = sg_nents(req->src);
560 
561 	uint8_t *digest = sdcp->coh->sha_digest;
562 	uint8_t *in_buf = sdcp->coh->sha_in_buf;
563 
564 	uint8_t *src_buf;
565 
566 	struct scatterlist *src;
567 
568 	unsigned int i, len, clen;
569 	int ret;
570 
571 	int fin = rctx->fini;
572 	if (fin)
573 		rctx->fini = 0;
574 
575 	for_each_sg(req->src, src, nents, i) {
576 		src_buf = sg_virt(src);
577 		len = sg_dma_len(src);
578 
579 		do {
580 			if (actx->fill + len > DCP_BUF_SZ)
581 				clen = DCP_BUF_SZ - actx->fill;
582 			else
583 				clen = len;
584 
585 			memcpy(in_buf + actx->fill, src_buf, clen);
586 			len -= clen;
587 			src_buf += clen;
588 			actx->fill += clen;
589 
590 			/*
591 			 * If we filled the buffer and still have some
592 			 * more data, submit the buffer.
593 			 */
594 			if (len && actx->fill == DCP_BUF_SZ) {
595 				ret = mxs_dcp_run_sha(req);
596 				if (ret)
597 					return ret;
598 				actx->fill = 0;
599 				rctx->init = 0;
600 			}
601 		} while (len);
602 	}
603 
604 	if (fin) {
605 		rctx->fini = 1;
606 
607 		/* Submit whatever is left. */
608 		ret = mxs_dcp_run_sha(req);
609 		if (ret || !req->result)
610 			return ret;
611 		actx->fill = 0;
612 
613 		/* For some reason, the result is flipped. */
614 		for (i = 0; i < halg->digestsize; i++)
615 			req->result[i] = digest[halg->digestsize - i - 1];
616 	}
617 
618 	return 0;
619 }
620 
621 static int dcp_chan_thread_sha(void *data)
622 {
623 	struct dcp *sdcp = global_sdcp;
624 	const int chan = DCP_CHAN_HASH_SHA;
625 
626 	struct crypto_async_request *backlog;
627 	struct crypto_async_request *arq;
628 
629 	struct dcp_sha_req_ctx *rctx;
630 
631 	struct ahash_request *req;
632 	int ret, fini;
633 
634 	do {
635 		__set_current_state(TASK_INTERRUPTIBLE);
636 
637 		mutex_lock(&sdcp->mutex[chan]);
638 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
639 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
640 		mutex_unlock(&sdcp->mutex[chan]);
641 
642 		if (backlog)
643 			backlog->complete(backlog, -EINPROGRESS);
644 
645 		if (arq) {
646 			req = ahash_request_cast(arq);
647 			rctx = ahash_request_ctx(req);
648 
649 			ret = dcp_sha_req_to_buf(arq);
650 			fini = rctx->fini;
651 			arq->complete(arq, ret);
652 			if (!fini)
653 				continue;
654 		}
655 
656 		schedule();
657 	} while (!kthread_should_stop());
658 
659 	return 0;
660 }
661 
662 static int dcp_sha_init(struct ahash_request *req)
663 {
664 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
665 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
666 
667 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
668 
669 	/*
670 	 * Start hashing session. The code below only inits the
671 	 * hashing session context, nothing more.
672 	 */
673 	memset(actx, 0, sizeof(*actx));
674 
675 	if (strcmp(halg->base.cra_name, "sha1") == 0)
676 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA1;
677 	else
678 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA256;
679 
680 	actx->fill = 0;
681 	actx->hot = 0;
682 	actx->chan = DCP_CHAN_HASH_SHA;
683 
684 	mutex_init(&actx->mutex);
685 
686 	return 0;
687 }
688 
689 static int dcp_sha_update_fx(struct ahash_request *req, int fini)
690 {
691 	struct dcp *sdcp = global_sdcp;
692 
693 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
694 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
695 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
696 
697 	int ret;
698 
699 	/*
700 	 * Ignore requests that have no data in them and are not
701 	 * the trailing requests in the stream of requests.
702 	 */
703 	if (!req->nbytes && !fini)
704 		return 0;
705 
706 	mutex_lock(&actx->mutex);
707 
708 	rctx->fini = fini;
709 
710 	if (!actx->hot) {
711 		actx->hot = 1;
712 		rctx->init = 1;
713 	}
714 
715 	mutex_lock(&sdcp->mutex[actx->chan]);
716 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
717 	mutex_unlock(&sdcp->mutex[actx->chan]);
718 
719 	wake_up_process(sdcp->thread[actx->chan]);
720 	mutex_unlock(&actx->mutex);
721 
722 	return -EINPROGRESS;
723 }
724 
725 static int dcp_sha_update(struct ahash_request *req)
726 {
727 	return dcp_sha_update_fx(req, 0);
728 }
729 
730 static int dcp_sha_final(struct ahash_request *req)
731 {
732 	ahash_request_set_crypt(req, NULL, req->result, 0);
733 	req->nbytes = 0;
734 	return dcp_sha_update_fx(req, 1);
735 }
736 
737 static int dcp_sha_finup(struct ahash_request *req)
738 {
739 	return dcp_sha_update_fx(req, 1);
740 }
741 
742 static int dcp_sha_digest(struct ahash_request *req)
743 {
744 	int ret;
745 
746 	ret = dcp_sha_init(req);
747 	if (ret)
748 		return ret;
749 
750 	return dcp_sha_finup(req);
751 }
752 
753 static int dcp_sha_cra_init(struct crypto_tfm *tfm)
754 {
755 	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
756 				 sizeof(struct dcp_sha_req_ctx));
757 	return 0;
758 }
759 
760 static void dcp_sha_cra_exit(struct crypto_tfm *tfm)
761 {
762 }
763 
764 /* AES 128 ECB and AES 128 CBC */
765 static struct crypto_alg dcp_aes_algs[] = {
766 	{
767 		.cra_name		= "ecb(aes)",
768 		.cra_driver_name	= "ecb-aes-dcp",
769 		.cra_priority		= 400,
770 		.cra_alignmask		= 15,
771 		.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
772 					  CRYPTO_ALG_ASYNC |
773 					  CRYPTO_ALG_NEED_FALLBACK,
774 		.cra_init		= mxs_dcp_aes_fallback_init,
775 		.cra_exit		= mxs_dcp_aes_fallback_exit,
776 		.cra_blocksize		= AES_BLOCK_SIZE,
777 		.cra_ctxsize		= sizeof(struct dcp_async_ctx),
778 		.cra_type		= &crypto_ablkcipher_type,
779 		.cra_module		= THIS_MODULE,
780 		.cra_u	= {
781 			.ablkcipher = {
782 				.min_keysize	= AES_MIN_KEY_SIZE,
783 				.max_keysize	= AES_MAX_KEY_SIZE,
784 				.setkey		= mxs_dcp_aes_setkey,
785 				.encrypt	= mxs_dcp_aes_ecb_encrypt,
786 				.decrypt	= mxs_dcp_aes_ecb_decrypt
787 			},
788 		},
789 	}, {
790 		.cra_name		= "cbc(aes)",
791 		.cra_driver_name	= "cbc-aes-dcp",
792 		.cra_priority		= 400,
793 		.cra_alignmask		= 15,
794 		.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
795 					  CRYPTO_ALG_ASYNC |
796 					  CRYPTO_ALG_NEED_FALLBACK,
797 		.cra_init		= mxs_dcp_aes_fallback_init,
798 		.cra_exit		= mxs_dcp_aes_fallback_exit,
799 		.cra_blocksize		= AES_BLOCK_SIZE,
800 		.cra_ctxsize		= sizeof(struct dcp_async_ctx),
801 		.cra_type		= &crypto_ablkcipher_type,
802 		.cra_module		= THIS_MODULE,
803 		.cra_u = {
804 			.ablkcipher = {
805 				.min_keysize	= AES_MIN_KEY_SIZE,
806 				.max_keysize	= AES_MAX_KEY_SIZE,
807 				.setkey		= mxs_dcp_aes_setkey,
808 				.encrypt	= mxs_dcp_aes_cbc_encrypt,
809 				.decrypt	= mxs_dcp_aes_cbc_decrypt,
810 				.ivsize		= AES_BLOCK_SIZE,
811 			},
812 		},
813 	},
814 };
815 
816 /* SHA1 */
817 static struct ahash_alg dcp_sha1_alg = {
818 	.init	= dcp_sha_init,
819 	.update	= dcp_sha_update,
820 	.final	= dcp_sha_final,
821 	.finup	= dcp_sha_finup,
822 	.digest	= dcp_sha_digest,
823 	.halg	= {
824 		.digestsize	= SHA1_DIGEST_SIZE,
825 		.base		= {
826 			.cra_name		= "sha1",
827 			.cra_driver_name	= "sha1-dcp",
828 			.cra_priority		= 400,
829 			.cra_alignmask		= 63,
830 			.cra_flags		= CRYPTO_ALG_ASYNC,
831 			.cra_blocksize		= SHA1_BLOCK_SIZE,
832 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
833 			.cra_module		= THIS_MODULE,
834 			.cra_init		= dcp_sha_cra_init,
835 			.cra_exit		= dcp_sha_cra_exit,
836 		},
837 	},
838 };
839 
840 /* SHA256 */
841 static struct ahash_alg dcp_sha256_alg = {
842 	.init	= dcp_sha_init,
843 	.update	= dcp_sha_update,
844 	.final	= dcp_sha_final,
845 	.finup	= dcp_sha_finup,
846 	.digest	= dcp_sha_digest,
847 	.halg	= {
848 		.digestsize	= SHA256_DIGEST_SIZE,
849 		.base		= {
850 			.cra_name		= "sha256",
851 			.cra_driver_name	= "sha256-dcp",
852 			.cra_priority		= 400,
853 			.cra_alignmask		= 63,
854 			.cra_flags		= CRYPTO_ALG_ASYNC,
855 			.cra_blocksize		= SHA256_BLOCK_SIZE,
856 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
857 			.cra_module		= THIS_MODULE,
858 			.cra_init		= dcp_sha_cra_init,
859 			.cra_exit		= dcp_sha_cra_exit,
860 		},
861 	},
862 };
863 
864 static irqreturn_t mxs_dcp_irq(int irq, void *context)
865 {
866 	struct dcp *sdcp = context;
867 	uint32_t stat;
868 	int i;
869 
870 	stat = readl(sdcp->base + MXS_DCP_STAT);
871 	stat &= MXS_DCP_STAT_IRQ_MASK;
872 	if (!stat)
873 		return IRQ_NONE;
874 
875 	/* Clear the interrupts. */
876 	writel(stat, sdcp->base + MXS_DCP_STAT_CLR);
877 
878 	/* Complete the DMA requests that finished. */
879 	for (i = 0; i < DCP_MAX_CHANS; i++)
880 		if (stat & (1 << i))
881 			complete(&sdcp->completion[i]);
882 
883 	return IRQ_HANDLED;
884 }
885 
886 static int mxs_dcp_probe(struct platform_device *pdev)
887 {
888 	struct device *dev = &pdev->dev;
889 	struct dcp *sdcp = NULL;
890 	int i, ret;
891 
892 	struct resource *iores;
893 	int dcp_vmi_irq, dcp_irq;
894 
895 	mutex_lock(&global_mutex);
896 	if (global_sdcp) {
897 		dev_err(dev, "Only one DCP instance allowed!\n");
898 		ret = -ENODEV;
899 		goto err_mutex;
900 	}
901 
902 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
903 	dcp_vmi_irq = platform_get_irq(pdev, 0);
904 	dcp_irq = platform_get_irq(pdev, 1);
905 	if (dcp_vmi_irq < 0 || dcp_irq < 0) {
906 		ret = -EINVAL;
907 		goto err_mutex;
908 	}
909 
910 	sdcp = devm_kzalloc(dev, sizeof(*sdcp), GFP_KERNEL);
911 	if (!sdcp) {
912 		ret = -ENOMEM;
913 		goto err_mutex;
914 	}
915 
916 	sdcp->dev = dev;
917 	sdcp->base = devm_ioremap_resource(dev, iores);
918 	if (IS_ERR(sdcp->base)) {
919 		ret = PTR_ERR(sdcp->base);
920 		goto err_mutex;
921 	}
922 
923 	ret = devm_request_irq(dev, dcp_vmi_irq, mxs_dcp_irq, 0,
924 			       "dcp-vmi-irq", sdcp);
925 	if (ret) {
926 		dev_err(dev, "Failed to claim DCP VMI IRQ!\n");
927 		goto err_mutex;
928 	}
929 
930 	ret = devm_request_irq(dev, dcp_irq, mxs_dcp_irq, 0,
931 			       "dcp-irq", sdcp);
932 	if (ret) {
933 		dev_err(dev, "Failed to claim DCP IRQ!\n");
934 		goto err_mutex;
935 	}
936 
937 	/* Allocate coherent helper block. */
938 	sdcp->coh = kzalloc(sizeof(struct dcp_coherent_block), GFP_KERNEL);
939 	if (!sdcp->coh) {
940 		dev_err(dev, "Error allocating coherent block\n");
941 		ret = -ENOMEM;
942 		goto err_mutex;
943 	}
944 
945 	/* Restart the DCP block. */
946 	stmp_reset_block(sdcp->base);
947 
948 	/* Initialize control register. */
949 	writel(MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES |
950 	       MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING | 0xf,
951 	       sdcp->base + MXS_DCP_CTRL);
952 
953 	/* Enable all DCP DMA channels. */
954 	writel(MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK,
955 	       sdcp->base + MXS_DCP_CHANNELCTRL);
956 
957 	/*
958 	 * We do not enable context switching. Give the context buffer a
959 	 * pointer to an illegal address so if context switching is
960 	 * inadvertantly enabled, the DCP will return an error instead of
961 	 * trashing good memory. The DCP DMA cannot access ROM, so any ROM
962 	 * address will do.
963 	 */
964 	writel(0xffff0000, sdcp->base + MXS_DCP_CONTEXT);
965 	for (i = 0; i < DCP_MAX_CHANS; i++)
966 		writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(i));
967 	writel(0xffffffff, sdcp->base + MXS_DCP_STAT_CLR);
968 
969 	global_sdcp = sdcp;
970 
971 	platform_set_drvdata(pdev, sdcp);
972 
973 	for (i = 0; i < DCP_MAX_CHANS; i++) {
974 		mutex_init(&sdcp->mutex[i]);
975 		init_completion(&sdcp->completion[i]);
976 		crypto_init_queue(&sdcp->queue[i], 50);
977 	}
978 
979 	/* Create the SHA and AES handler threads. */
980 	sdcp->thread[DCP_CHAN_HASH_SHA] = kthread_run(dcp_chan_thread_sha,
981 						      NULL, "mxs_dcp_chan/sha");
982 	if (IS_ERR(sdcp->thread[DCP_CHAN_HASH_SHA])) {
983 		dev_err(dev, "Error starting SHA thread!\n");
984 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_HASH_SHA]);
985 		goto err_free_coherent;
986 	}
987 
988 	sdcp->thread[DCP_CHAN_CRYPTO] = kthread_run(dcp_chan_thread_aes,
989 						    NULL, "mxs_dcp_chan/aes");
990 	if (IS_ERR(sdcp->thread[DCP_CHAN_CRYPTO])) {
991 		dev_err(dev, "Error starting SHA thread!\n");
992 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_CRYPTO]);
993 		goto err_destroy_sha_thread;
994 	}
995 
996 	/* Register the various crypto algorithms. */
997 	sdcp->caps = readl(sdcp->base + MXS_DCP_CAPABILITY1);
998 
999 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128) {
1000 		ret = crypto_register_algs(dcp_aes_algs,
1001 					   ARRAY_SIZE(dcp_aes_algs));
1002 		if (ret) {
1003 			/* Failed to register algorithm. */
1004 			dev_err(dev, "Failed to register AES crypto!\n");
1005 			goto err_destroy_aes_thread;
1006 		}
1007 	}
1008 
1009 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1) {
1010 		ret = crypto_register_ahash(&dcp_sha1_alg);
1011 		if (ret) {
1012 			dev_err(dev, "Failed to register %s hash!\n",
1013 				dcp_sha1_alg.halg.base.cra_name);
1014 			goto err_unregister_aes;
1015 		}
1016 	}
1017 
1018 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256) {
1019 		ret = crypto_register_ahash(&dcp_sha256_alg);
1020 		if (ret) {
1021 			dev_err(dev, "Failed to register %s hash!\n",
1022 				dcp_sha256_alg.halg.base.cra_name);
1023 			goto err_unregister_sha1;
1024 		}
1025 	}
1026 
1027 	return 0;
1028 
1029 err_unregister_sha1:
1030 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1031 		crypto_unregister_ahash(&dcp_sha1_alg);
1032 
1033 err_unregister_aes:
1034 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1035 		crypto_unregister_algs(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1036 
1037 err_destroy_aes_thread:
1038 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1039 
1040 err_destroy_sha_thread:
1041 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1042 
1043 err_free_coherent:
1044 	kfree(sdcp->coh);
1045 err_mutex:
1046 	mutex_unlock(&global_mutex);
1047 	return ret;
1048 }
1049 
1050 static int mxs_dcp_remove(struct platform_device *pdev)
1051 {
1052 	struct dcp *sdcp = platform_get_drvdata(pdev);
1053 
1054 	kfree(sdcp->coh);
1055 
1056 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256)
1057 		crypto_unregister_ahash(&dcp_sha256_alg);
1058 
1059 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1060 		crypto_unregister_ahash(&dcp_sha1_alg);
1061 
1062 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1063 		crypto_unregister_algs(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1064 
1065 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1066 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1067 
1068 	platform_set_drvdata(pdev, NULL);
1069 
1070 	mutex_lock(&global_mutex);
1071 	global_sdcp = NULL;
1072 	mutex_unlock(&global_mutex);
1073 
1074 	return 0;
1075 }
1076 
1077 static const struct of_device_id mxs_dcp_dt_ids[] = {
1078 	{ .compatible = "fsl,imx23-dcp", .data = NULL, },
1079 	{ .compatible = "fsl,imx28-dcp", .data = NULL, },
1080 	{ /* sentinel */ }
1081 };
1082 
1083 MODULE_DEVICE_TABLE(of, mxs_dcp_dt_ids);
1084 
1085 static struct platform_driver mxs_dcp_driver = {
1086 	.probe	= mxs_dcp_probe,
1087 	.remove	= mxs_dcp_remove,
1088 	.driver	= {
1089 		.name		= "mxs-dcp",
1090 		.owner		= THIS_MODULE,
1091 		.of_match_table	= mxs_dcp_dt_ids,
1092 	},
1093 };
1094 
1095 module_platform_driver(mxs_dcp_driver);
1096 
1097 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1098 MODULE_DESCRIPTION("Freescale MXS DCP Driver");
1099 MODULE_LICENSE("GPL");
1100 MODULE_ALIAS("platform:mxs-dcp");
1101