xref: /openbmc/linux/drivers/crypto/mxs-dcp.c (revision 96de2506)
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/dma-mapping.h>
15 #include <linux/interrupt.h>
16 #include <linux/io.h>
17 #include <linux/kernel.h>
18 #include <linux/kthread.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/platform_device.h>
22 #include <linux/stmp_device.h>
23 
24 #include <crypto/aes.h>
25 #include <crypto/sha.h>
26 #include <crypto/internal/hash.h>
27 #include <crypto/internal/skcipher.h>
28 
29 #define DCP_MAX_CHANS	4
30 #define DCP_BUF_SZ	PAGE_SIZE
31 
32 #define DCP_ALIGNMENT	64
33 
34 /* DCP DMA descriptor. */
35 struct dcp_dma_desc {
36 	uint32_t	next_cmd_addr;
37 	uint32_t	control0;
38 	uint32_t	control1;
39 	uint32_t	source;
40 	uint32_t	destination;
41 	uint32_t	size;
42 	uint32_t	payload;
43 	uint32_t	status;
44 };
45 
46 /* Coherent aligned block for bounce buffering. */
47 struct dcp_coherent_block {
48 	uint8_t			aes_in_buf[DCP_BUF_SZ];
49 	uint8_t			aes_out_buf[DCP_BUF_SZ];
50 	uint8_t			sha_in_buf[DCP_BUF_SZ];
51 
52 	uint8_t			aes_key[2 * AES_KEYSIZE_128];
53 
54 	struct dcp_dma_desc	desc[DCP_MAX_CHANS];
55 };
56 
57 struct dcp {
58 	struct device			*dev;
59 	void __iomem			*base;
60 
61 	uint32_t			caps;
62 
63 	struct dcp_coherent_block	*coh;
64 
65 	struct completion		completion[DCP_MAX_CHANS];
66 	spinlock_t			lock[DCP_MAX_CHANS];
67 	struct task_struct		*thread[DCP_MAX_CHANS];
68 	struct crypto_queue		queue[DCP_MAX_CHANS];
69 };
70 
71 enum dcp_chan {
72 	DCP_CHAN_HASH_SHA	= 0,
73 	DCP_CHAN_CRYPTO		= 2,
74 };
75 
76 struct dcp_async_ctx {
77 	/* Common context */
78 	enum dcp_chan	chan;
79 	uint32_t	fill;
80 
81 	/* SHA Hash-specific context */
82 	struct mutex			mutex;
83 	uint32_t			alg;
84 	unsigned int			hot:1;
85 
86 	/* Crypto-specific context */
87 	struct crypto_skcipher		*fallback;
88 	unsigned int			key_len;
89 	uint8_t				key[AES_KEYSIZE_128];
90 };
91 
92 struct dcp_aes_req_ctx {
93 	unsigned int	enc:1;
94 	unsigned int	ecb:1;
95 };
96 
97 struct dcp_sha_req_ctx {
98 	unsigned int	init:1;
99 	unsigned int	fini:1;
100 };
101 
102 /*
103  * There can even be only one instance of the MXS DCP due to the
104  * design of Linux Crypto API.
105  */
106 static struct dcp *global_sdcp;
107 
108 /* DCP register layout. */
109 #define MXS_DCP_CTRL				0x00
110 #define MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES	(1 << 23)
111 #define MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING	(1 << 22)
112 
113 #define MXS_DCP_STAT				0x10
114 #define MXS_DCP_STAT_CLR			0x18
115 #define MXS_DCP_STAT_IRQ_MASK			0xf
116 
117 #define MXS_DCP_CHANNELCTRL			0x20
118 #define MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK	0xff
119 
120 #define MXS_DCP_CAPABILITY1			0x40
121 #define MXS_DCP_CAPABILITY1_SHA256		(4 << 16)
122 #define MXS_DCP_CAPABILITY1_SHA1		(1 << 16)
123 #define MXS_DCP_CAPABILITY1_AES128		(1 << 0)
124 
125 #define MXS_DCP_CONTEXT				0x50
126 
127 #define MXS_DCP_CH_N_CMDPTR(n)			(0x100 + ((n) * 0x40))
128 
129 #define MXS_DCP_CH_N_SEMA(n)			(0x110 + ((n) * 0x40))
130 
131 #define MXS_DCP_CH_N_STAT(n)			(0x120 + ((n) * 0x40))
132 #define MXS_DCP_CH_N_STAT_CLR(n)		(0x128 + ((n) * 0x40))
133 
134 /* DMA descriptor bits. */
135 #define MXS_DCP_CONTROL0_HASH_TERM		(1 << 13)
136 #define MXS_DCP_CONTROL0_HASH_INIT		(1 << 12)
137 #define MXS_DCP_CONTROL0_PAYLOAD_KEY		(1 << 11)
138 #define MXS_DCP_CONTROL0_CIPHER_ENCRYPT		(1 << 8)
139 #define MXS_DCP_CONTROL0_CIPHER_INIT		(1 << 9)
140 #define MXS_DCP_CONTROL0_ENABLE_HASH		(1 << 6)
141 #define MXS_DCP_CONTROL0_ENABLE_CIPHER		(1 << 5)
142 #define MXS_DCP_CONTROL0_DECR_SEMAPHORE		(1 << 1)
143 #define MXS_DCP_CONTROL0_INTERRUPT		(1 << 0)
144 
145 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA256	(2 << 16)
146 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA1	(0 << 16)
147 #define MXS_DCP_CONTROL1_CIPHER_MODE_CBC	(1 << 4)
148 #define MXS_DCP_CONTROL1_CIPHER_MODE_ECB	(0 << 4)
149 #define MXS_DCP_CONTROL1_CIPHER_SELECT_AES128	(0 << 0)
150 
151 static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
152 {
153 	struct dcp *sdcp = global_sdcp;
154 	const int chan = actx->chan;
155 	uint32_t stat;
156 	unsigned long ret;
157 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
158 
159 	dma_addr_t desc_phys = dma_map_single(sdcp->dev, desc, sizeof(*desc),
160 					      DMA_TO_DEVICE);
161 
162 	reinit_completion(&sdcp->completion[chan]);
163 
164 	/* Clear status register. */
165 	writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(chan));
166 
167 	/* Load the DMA descriptor. */
168 	writel(desc_phys, sdcp->base + MXS_DCP_CH_N_CMDPTR(chan));
169 
170 	/* Increment the semaphore to start the DMA transfer. */
171 	writel(1, sdcp->base + MXS_DCP_CH_N_SEMA(chan));
172 
173 	ret = wait_for_completion_timeout(&sdcp->completion[chan],
174 					  msecs_to_jiffies(1000));
175 	if (!ret) {
176 		dev_err(sdcp->dev, "Channel %i timeout (DCP_STAT=0x%08x)\n",
177 			chan, readl(sdcp->base + MXS_DCP_STAT));
178 		return -ETIMEDOUT;
179 	}
180 
181 	stat = readl(sdcp->base + MXS_DCP_CH_N_STAT(chan));
182 	if (stat & 0xff) {
183 		dev_err(sdcp->dev, "Channel %i error (CH_STAT=0x%08x)\n",
184 			chan, stat);
185 		return -EINVAL;
186 	}
187 
188 	dma_unmap_single(sdcp->dev, desc_phys, sizeof(*desc), DMA_TO_DEVICE);
189 
190 	return 0;
191 }
192 
193 /*
194  * Encryption (AES128)
195  */
196 static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
197 			   struct ablkcipher_request *req, int init)
198 {
199 	struct dcp *sdcp = global_sdcp;
200 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
201 	struct dcp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
202 	int ret;
203 
204 	dma_addr_t key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
205 					     2 * AES_KEYSIZE_128,
206 					     DMA_TO_DEVICE);
207 	dma_addr_t src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
208 					     DCP_BUF_SZ, DMA_TO_DEVICE);
209 	dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
210 					     DCP_BUF_SZ, DMA_FROM_DEVICE);
211 
212 	/* Fill in the DMA descriptor. */
213 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
214 		    MXS_DCP_CONTROL0_INTERRUPT |
215 		    MXS_DCP_CONTROL0_ENABLE_CIPHER;
216 
217 	/* Payload contains the key. */
218 	desc->control0 |= MXS_DCP_CONTROL0_PAYLOAD_KEY;
219 
220 	if (rctx->enc)
221 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_ENCRYPT;
222 	if (init)
223 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_INIT;
224 
225 	desc->control1 = MXS_DCP_CONTROL1_CIPHER_SELECT_AES128;
226 
227 	if (rctx->ecb)
228 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_ECB;
229 	else
230 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_CBC;
231 
232 	desc->next_cmd_addr = 0;
233 	desc->source = src_phys;
234 	desc->destination = dst_phys;
235 	desc->size = actx->fill;
236 	desc->payload = key_phys;
237 	desc->status = 0;
238 
239 	ret = mxs_dcp_start_dma(actx);
240 
241 	dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
242 			 DMA_TO_DEVICE);
243 	dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
244 	dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
245 
246 	return ret;
247 }
248 
249 static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
250 {
251 	struct dcp *sdcp = global_sdcp;
252 
253 	struct ablkcipher_request *req = ablkcipher_request_cast(arq);
254 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
255 	struct dcp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
256 
257 	struct scatterlist *dst = req->dst;
258 	struct scatterlist *src = req->src;
259 	const int nents = sg_nents(req->src);
260 
261 	const int out_off = DCP_BUF_SZ;
262 	uint8_t *in_buf = sdcp->coh->aes_in_buf;
263 	uint8_t *out_buf = sdcp->coh->aes_out_buf;
264 
265 	uint8_t *out_tmp, *src_buf, *dst_buf = NULL;
266 	uint32_t dst_off = 0;
267 
268 	uint8_t *key = sdcp->coh->aes_key;
269 
270 	int ret = 0;
271 	int split = 0;
272 	unsigned int i, len, clen, rem = 0;
273 	int init = 0;
274 
275 	actx->fill = 0;
276 
277 	/* Copy the key from the temporary location. */
278 	memcpy(key, actx->key, actx->key_len);
279 
280 	if (!rctx->ecb) {
281 		/* Copy the CBC IV just past the key. */
282 		memcpy(key + AES_KEYSIZE_128, req->info, AES_KEYSIZE_128);
283 		/* CBC needs the INIT set. */
284 		init = 1;
285 	} else {
286 		memset(key + AES_KEYSIZE_128, 0, AES_KEYSIZE_128);
287 	}
288 
289 	for_each_sg(req->src, src, nents, i) {
290 		src_buf = sg_virt(src);
291 		len = sg_dma_len(src);
292 
293 		do {
294 			if (actx->fill + len > out_off)
295 				clen = out_off - actx->fill;
296 			else
297 				clen = len;
298 
299 			memcpy(in_buf + actx->fill, src_buf, clen);
300 			len -= clen;
301 			src_buf += clen;
302 			actx->fill += clen;
303 
304 			/*
305 			 * If we filled the buffer or this is the last SG,
306 			 * submit the buffer.
307 			 */
308 			if (actx->fill == out_off || sg_is_last(src)) {
309 				ret = mxs_dcp_run_aes(actx, req, init);
310 				if (ret)
311 					return ret;
312 				init = 0;
313 
314 				out_tmp = out_buf;
315 				while (dst && actx->fill) {
316 					if (!split) {
317 						dst_buf = sg_virt(dst);
318 						dst_off = 0;
319 					}
320 					rem = min(sg_dma_len(dst) - dst_off,
321 						  actx->fill);
322 
323 					memcpy(dst_buf + dst_off, out_tmp, rem);
324 					out_tmp += rem;
325 					dst_off += rem;
326 					actx->fill -= rem;
327 
328 					if (dst_off == sg_dma_len(dst)) {
329 						dst = sg_next(dst);
330 						split = 0;
331 					} else {
332 						split = 1;
333 					}
334 				}
335 			}
336 		} while (len);
337 	}
338 
339 	return ret;
340 }
341 
342 static int dcp_chan_thread_aes(void *data)
343 {
344 	struct dcp *sdcp = global_sdcp;
345 	const int chan = DCP_CHAN_CRYPTO;
346 
347 	struct crypto_async_request *backlog;
348 	struct crypto_async_request *arq;
349 
350 	int ret;
351 
352 	while (!kthread_should_stop()) {
353 		set_current_state(TASK_INTERRUPTIBLE);
354 
355 		spin_lock(&sdcp->lock[chan]);
356 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
357 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
358 		spin_unlock(&sdcp->lock[chan]);
359 
360 		if (!backlog && !arq) {
361 			schedule();
362 			continue;
363 		}
364 
365 		set_current_state(TASK_RUNNING);
366 
367 		if (backlog)
368 			backlog->complete(backlog, -EINPROGRESS);
369 
370 		if (arq) {
371 			ret = mxs_dcp_aes_block_crypt(arq);
372 			arq->complete(arq, ret);
373 		}
374 	}
375 
376 	return 0;
377 }
378 
379 static int mxs_dcp_block_fallback(struct ablkcipher_request *req, int enc)
380 {
381 	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
382 	struct dcp_async_ctx *ctx = crypto_ablkcipher_ctx(tfm);
383 	SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
384 	int ret;
385 
386 	skcipher_request_set_tfm(subreq, ctx->fallback);
387 	skcipher_request_set_callback(subreq, req->base.flags, NULL, NULL);
388 	skcipher_request_set_crypt(subreq, req->src, req->dst,
389 				   req->nbytes, req->info);
390 
391 	if (enc)
392 		ret = crypto_skcipher_encrypt(subreq);
393 	else
394 		ret = crypto_skcipher_decrypt(subreq);
395 
396 	skcipher_request_zero(subreq);
397 
398 	return ret;
399 }
400 
401 static int mxs_dcp_aes_enqueue(struct ablkcipher_request *req, int enc, int ecb)
402 {
403 	struct dcp *sdcp = global_sdcp;
404 	struct crypto_async_request *arq = &req->base;
405 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
406 	struct dcp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
407 	int ret;
408 
409 	if (unlikely(actx->key_len != AES_KEYSIZE_128))
410 		return mxs_dcp_block_fallback(req, enc);
411 
412 	rctx->enc = enc;
413 	rctx->ecb = ecb;
414 	actx->chan = DCP_CHAN_CRYPTO;
415 
416 	spin_lock(&sdcp->lock[actx->chan]);
417 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
418 	spin_unlock(&sdcp->lock[actx->chan]);
419 
420 	wake_up_process(sdcp->thread[actx->chan]);
421 
422 	return -EINPROGRESS;
423 }
424 
425 static int mxs_dcp_aes_ecb_decrypt(struct ablkcipher_request *req)
426 {
427 	return mxs_dcp_aes_enqueue(req, 0, 1);
428 }
429 
430 static int mxs_dcp_aes_ecb_encrypt(struct ablkcipher_request *req)
431 {
432 	return mxs_dcp_aes_enqueue(req, 1, 1);
433 }
434 
435 static int mxs_dcp_aes_cbc_decrypt(struct ablkcipher_request *req)
436 {
437 	return mxs_dcp_aes_enqueue(req, 0, 0);
438 }
439 
440 static int mxs_dcp_aes_cbc_encrypt(struct ablkcipher_request *req)
441 {
442 	return mxs_dcp_aes_enqueue(req, 1, 0);
443 }
444 
445 static int mxs_dcp_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
446 			      unsigned int len)
447 {
448 	struct dcp_async_ctx *actx = crypto_ablkcipher_ctx(tfm);
449 	unsigned int ret;
450 
451 	/*
452 	 * AES 128 is supposed by the hardware, store key into temporary
453 	 * buffer and exit. We must use the temporary buffer here, since
454 	 * there can still be an operation in progress.
455 	 */
456 	actx->key_len = len;
457 	if (len == AES_KEYSIZE_128) {
458 		memcpy(actx->key, key, len);
459 		return 0;
460 	}
461 
462 	/*
463 	 * If the requested AES key size is not supported by the hardware,
464 	 * but is supported by in-kernel software implementation, we use
465 	 * software fallback.
466 	 */
467 	crypto_skcipher_clear_flags(actx->fallback, CRYPTO_TFM_REQ_MASK);
468 	crypto_skcipher_set_flags(actx->fallback,
469 				  tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
470 
471 	ret = crypto_skcipher_setkey(actx->fallback, key, len);
472 	if (!ret)
473 		return 0;
474 
475 	tfm->base.crt_flags &= ~CRYPTO_TFM_RES_MASK;
476 	tfm->base.crt_flags |= crypto_skcipher_get_flags(actx->fallback) &
477 			       CRYPTO_TFM_RES_MASK;
478 
479 	return ret;
480 }
481 
482 static int mxs_dcp_aes_fallback_init(struct crypto_tfm *tfm)
483 {
484 	const char *name = crypto_tfm_alg_name(tfm);
485 	const uint32_t flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK;
486 	struct dcp_async_ctx *actx = crypto_tfm_ctx(tfm);
487 	struct crypto_skcipher *blk;
488 
489 	blk = crypto_alloc_skcipher(name, 0, flags);
490 	if (IS_ERR(blk))
491 		return PTR_ERR(blk);
492 
493 	actx->fallback = blk;
494 	tfm->crt_ablkcipher.reqsize = sizeof(struct dcp_aes_req_ctx);
495 	return 0;
496 }
497 
498 static void mxs_dcp_aes_fallback_exit(struct crypto_tfm *tfm)
499 {
500 	struct dcp_async_ctx *actx = crypto_tfm_ctx(tfm);
501 
502 	crypto_free_skcipher(actx->fallback);
503 }
504 
505 /*
506  * Hashing (SHA1/SHA256)
507  */
508 static int mxs_dcp_run_sha(struct ahash_request *req)
509 {
510 	struct dcp *sdcp = global_sdcp;
511 	int ret;
512 
513 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
514 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
515 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
516 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
517 
518 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
519 
520 	dma_addr_t digest_phys = 0;
521 	dma_addr_t buf_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_in_buf,
522 					     DCP_BUF_SZ, DMA_TO_DEVICE);
523 
524 	/* Fill in the DMA descriptor. */
525 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
526 		    MXS_DCP_CONTROL0_INTERRUPT |
527 		    MXS_DCP_CONTROL0_ENABLE_HASH;
528 	if (rctx->init)
529 		desc->control0 |= MXS_DCP_CONTROL0_HASH_INIT;
530 
531 	desc->control1 = actx->alg;
532 	desc->next_cmd_addr = 0;
533 	desc->source = buf_phys;
534 	desc->destination = 0;
535 	desc->size = actx->fill;
536 	desc->payload = 0;
537 	desc->status = 0;
538 
539 	/* Set HASH_TERM bit for last transfer block. */
540 	if (rctx->fini) {
541 		digest_phys = dma_map_single(sdcp->dev, req->result,
542 					     halg->digestsize, DMA_FROM_DEVICE);
543 		desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
544 		desc->payload = digest_phys;
545 	}
546 
547 	ret = mxs_dcp_start_dma(actx);
548 
549 	if (rctx->fini)
550 		dma_unmap_single(sdcp->dev, digest_phys, halg->digestsize,
551 				 DMA_FROM_DEVICE);
552 
553 	dma_unmap_single(sdcp->dev, buf_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
554 
555 	return ret;
556 }
557 
558 static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
559 {
560 	struct dcp *sdcp = global_sdcp;
561 
562 	struct ahash_request *req = ahash_request_cast(arq);
563 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
564 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
565 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
566 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
567 	const int nents = sg_nents(req->src);
568 
569 	uint8_t *in_buf = sdcp->coh->sha_in_buf;
570 
571 	uint8_t *src_buf;
572 
573 	struct scatterlist *src;
574 
575 	unsigned int i, len, clen;
576 	int ret;
577 
578 	int fin = rctx->fini;
579 	if (fin)
580 		rctx->fini = 0;
581 
582 	for_each_sg(req->src, src, nents, i) {
583 		src_buf = sg_virt(src);
584 		len = sg_dma_len(src);
585 
586 		do {
587 			if (actx->fill + len > DCP_BUF_SZ)
588 				clen = DCP_BUF_SZ - actx->fill;
589 			else
590 				clen = len;
591 
592 			memcpy(in_buf + actx->fill, src_buf, clen);
593 			len -= clen;
594 			src_buf += clen;
595 			actx->fill += clen;
596 
597 			/*
598 			 * If we filled the buffer and still have some
599 			 * more data, submit the buffer.
600 			 */
601 			if (len && actx->fill == DCP_BUF_SZ) {
602 				ret = mxs_dcp_run_sha(req);
603 				if (ret)
604 					return ret;
605 				actx->fill = 0;
606 				rctx->init = 0;
607 			}
608 		} while (len);
609 	}
610 
611 	if (fin) {
612 		rctx->fini = 1;
613 
614 		/* Submit whatever is left. */
615 		if (!req->result)
616 			return -EINVAL;
617 
618 		ret = mxs_dcp_run_sha(req);
619 		if (ret)
620 			return ret;
621 
622 		actx->fill = 0;
623 
624 		/* For some reason, the result is flipped. */
625 		for (i = 0; i < halg->digestsize / 2; i++) {
626 			swap(req->result[i],
627 			     req->result[halg->digestsize - i - 1]);
628 		}
629 	}
630 
631 	return 0;
632 }
633 
634 static int dcp_chan_thread_sha(void *data)
635 {
636 	struct dcp *sdcp = global_sdcp;
637 	const int chan = DCP_CHAN_HASH_SHA;
638 
639 	struct crypto_async_request *backlog;
640 	struct crypto_async_request *arq;
641 
642 	struct dcp_sha_req_ctx *rctx;
643 
644 	struct ahash_request *req;
645 	int ret, fini;
646 
647 	while (!kthread_should_stop()) {
648 		set_current_state(TASK_INTERRUPTIBLE);
649 
650 		spin_lock(&sdcp->lock[chan]);
651 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
652 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
653 		spin_unlock(&sdcp->lock[chan]);
654 
655 		if (!backlog && !arq) {
656 			schedule();
657 			continue;
658 		}
659 
660 		set_current_state(TASK_RUNNING);
661 
662 		if (backlog)
663 			backlog->complete(backlog, -EINPROGRESS);
664 
665 		if (arq) {
666 			req = ahash_request_cast(arq);
667 			rctx = ahash_request_ctx(req);
668 
669 			ret = dcp_sha_req_to_buf(arq);
670 			fini = rctx->fini;
671 			arq->complete(arq, ret);
672 		}
673 	}
674 
675 	return 0;
676 }
677 
678 static int dcp_sha_init(struct ahash_request *req)
679 {
680 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
681 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
682 
683 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
684 
685 	/*
686 	 * Start hashing session. The code below only inits the
687 	 * hashing session context, nothing more.
688 	 */
689 	memset(actx, 0, sizeof(*actx));
690 
691 	if (strcmp(halg->base.cra_name, "sha1") == 0)
692 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA1;
693 	else
694 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA256;
695 
696 	actx->fill = 0;
697 	actx->hot = 0;
698 	actx->chan = DCP_CHAN_HASH_SHA;
699 
700 	mutex_init(&actx->mutex);
701 
702 	return 0;
703 }
704 
705 static int dcp_sha_update_fx(struct ahash_request *req, int fini)
706 {
707 	struct dcp *sdcp = global_sdcp;
708 
709 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
710 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
711 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
712 
713 	int ret;
714 
715 	/*
716 	 * Ignore requests that have no data in them and are not
717 	 * the trailing requests in the stream of requests.
718 	 */
719 	if (!req->nbytes && !fini)
720 		return 0;
721 
722 	mutex_lock(&actx->mutex);
723 
724 	rctx->fini = fini;
725 
726 	if (!actx->hot) {
727 		actx->hot = 1;
728 		rctx->init = 1;
729 	}
730 
731 	spin_lock(&sdcp->lock[actx->chan]);
732 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
733 	spin_unlock(&sdcp->lock[actx->chan]);
734 
735 	wake_up_process(sdcp->thread[actx->chan]);
736 	mutex_unlock(&actx->mutex);
737 
738 	return -EINPROGRESS;
739 }
740 
741 static int dcp_sha_update(struct ahash_request *req)
742 {
743 	return dcp_sha_update_fx(req, 0);
744 }
745 
746 static int dcp_sha_final(struct ahash_request *req)
747 {
748 	ahash_request_set_crypt(req, NULL, req->result, 0);
749 	req->nbytes = 0;
750 	return dcp_sha_update_fx(req, 1);
751 }
752 
753 static int dcp_sha_finup(struct ahash_request *req)
754 {
755 	return dcp_sha_update_fx(req, 1);
756 }
757 
758 static int dcp_sha_digest(struct ahash_request *req)
759 {
760 	int ret;
761 
762 	ret = dcp_sha_init(req);
763 	if (ret)
764 		return ret;
765 
766 	return dcp_sha_finup(req);
767 }
768 
769 static int dcp_sha_noimport(struct ahash_request *req, const void *in)
770 {
771 	return -ENOSYS;
772 }
773 
774 static int dcp_sha_noexport(struct ahash_request *req, void *out)
775 {
776 	return -ENOSYS;
777 }
778 
779 static int dcp_sha_cra_init(struct crypto_tfm *tfm)
780 {
781 	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
782 				 sizeof(struct dcp_sha_req_ctx));
783 	return 0;
784 }
785 
786 static void dcp_sha_cra_exit(struct crypto_tfm *tfm)
787 {
788 }
789 
790 /* AES 128 ECB and AES 128 CBC */
791 static struct crypto_alg dcp_aes_algs[] = {
792 	{
793 		.cra_name		= "ecb(aes)",
794 		.cra_driver_name	= "ecb-aes-dcp",
795 		.cra_priority		= 400,
796 		.cra_alignmask		= 15,
797 		.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
798 					  CRYPTO_ALG_ASYNC |
799 					  CRYPTO_ALG_NEED_FALLBACK,
800 		.cra_init		= mxs_dcp_aes_fallback_init,
801 		.cra_exit		= mxs_dcp_aes_fallback_exit,
802 		.cra_blocksize		= AES_BLOCK_SIZE,
803 		.cra_ctxsize		= sizeof(struct dcp_async_ctx),
804 		.cra_type		= &crypto_ablkcipher_type,
805 		.cra_module		= THIS_MODULE,
806 		.cra_u	= {
807 			.ablkcipher = {
808 				.min_keysize	= AES_MIN_KEY_SIZE,
809 				.max_keysize	= AES_MAX_KEY_SIZE,
810 				.setkey		= mxs_dcp_aes_setkey,
811 				.encrypt	= mxs_dcp_aes_ecb_encrypt,
812 				.decrypt	= mxs_dcp_aes_ecb_decrypt
813 			},
814 		},
815 	}, {
816 		.cra_name		= "cbc(aes)",
817 		.cra_driver_name	= "cbc-aes-dcp",
818 		.cra_priority		= 400,
819 		.cra_alignmask		= 15,
820 		.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
821 					  CRYPTO_ALG_ASYNC |
822 					  CRYPTO_ALG_NEED_FALLBACK,
823 		.cra_init		= mxs_dcp_aes_fallback_init,
824 		.cra_exit		= mxs_dcp_aes_fallback_exit,
825 		.cra_blocksize		= AES_BLOCK_SIZE,
826 		.cra_ctxsize		= sizeof(struct dcp_async_ctx),
827 		.cra_type		= &crypto_ablkcipher_type,
828 		.cra_module		= THIS_MODULE,
829 		.cra_u = {
830 			.ablkcipher = {
831 				.min_keysize	= AES_MIN_KEY_SIZE,
832 				.max_keysize	= AES_MAX_KEY_SIZE,
833 				.setkey		= mxs_dcp_aes_setkey,
834 				.encrypt	= mxs_dcp_aes_cbc_encrypt,
835 				.decrypt	= mxs_dcp_aes_cbc_decrypt,
836 				.ivsize		= AES_BLOCK_SIZE,
837 			},
838 		},
839 	},
840 };
841 
842 /* SHA1 */
843 static struct ahash_alg dcp_sha1_alg = {
844 	.init	= dcp_sha_init,
845 	.update	= dcp_sha_update,
846 	.final	= dcp_sha_final,
847 	.finup	= dcp_sha_finup,
848 	.digest	= dcp_sha_digest,
849 	.import = dcp_sha_noimport,
850 	.export = dcp_sha_noexport,
851 	.halg	= {
852 		.digestsize	= SHA1_DIGEST_SIZE,
853 		.base		= {
854 			.cra_name		= "sha1",
855 			.cra_driver_name	= "sha1-dcp",
856 			.cra_priority		= 400,
857 			.cra_alignmask		= 63,
858 			.cra_flags		= CRYPTO_ALG_ASYNC,
859 			.cra_blocksize		= SHA1_BLOCK_SIZE,
860 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
861 			.cra_module		= THIS_MODULE,
862 			.cra_init		= dcp_sha_cra_init,
863 			.cra_exit		= dcp_sha_cra_exit,
864 		},
865 	},
866 };
867 
868 /* SHA256 */
869 static struct ahash_alg dcp_sha256_alg = {
870 	.init	= dcp_sha_init,
871 	.update	= dcp_sha_update,
872 	.final	= dcp_sha_final,
873 	.finup	= dcp_sha_finup,
874 	.digest	= dcp_sha_digest,
875 	.import = dcp_sha_noimport,
876 	.export = dcp_sha_noexport,
877 	.halg	= {
878 		.digestsize	= SHA256_DIGEST_SIZE,
879 		.base		= {
880 			.cra_name		= "sha256",
881 			.cra_driver_name	= "sha256-dcp",
882 			.cra_priority		= 400,
883 			.cra_alignmask		= 63,
884 			.cra_flags		= CRYPTO_ALG_ASYNC,
885 			.cra_blocksize		= SHA256_BLOCK_SIZE,
886 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
887 			.cra_module		= THIS_MODULE,
888 			.cra_init		= dcp_sha_cra_init,
889 			.cra_exit		= dcp_sha_cra_exit,
890 		},
891 	},
892 };
893 
894 static irqreturn_t mxs_dcp_irq(int irq, void *context)
895 {
896 	struct dcp *sdcp = context;
897 	uint32_t stat;
898 	int i;
899 
900 	stat = readl(sdcp->base + MXS_DCP_STAT);
901 	stat &= MXS_DCP_STAT_IRQ_MASK;
902 	if (!stat)
903 		return IRQ_NONE;
904 
905 	/* Clear the interrupts. */
906 	writel(stat, sdcp->base + MXS_DCP_STAT_CLR);
907 
908 	/* Complete the DMA requests that finished. */
909 	for (i = 0; i < DCP_MAX_CHANS; i++)
910 		if (stat & (1 << i))
911 			complete(&sdcp->completion[i]);
912 
913 	return IRQ_HANDLED;
914 }
915 
916 static int mxs_dcp_probe(struct platform_device *pdev)
917 {
918 	struct device *dev = &pdev->dev;
919 	struct dcp *sdcp = NULL;
920 	int i, ret;
921 
922 	struct resource *iores;
923 	int dcp_vmi_irq, dcp_irq;
924 
925 	if (global_sdcp) {
926 		dev_err(dev, "Only one DCP instance allowed!\n");
927 		return -ENODEV;
928 	}
929 
930 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
931 	dcp_vmi_irq = platform_get_irq(pdev, 0);
932 	if (dcp_vmi_irq < 0) {
933 		dev_err(dev, "Failed to get IRQ: (%d)!\n", dcp_vmi_irq);
934 		return dcp_vmi_irq;
935 	}
936 
937 	dcp_irq = platform_get_irq(pdev, 1);
938 	if (dcp_irq < 0) {
939 		dev_err(dev, "Failed to get IRQ: (%d)!\n", dcp_irq);
940 		return dcp_irq;
941 	}
942 
943 	sdcp = devm_kzalloc(dev, sizeof(*sdcp), GFP_KERNEL);
944 	if (!sdcp)
945 		return -ENOMEM;
946 
947 	sdcp->dev = dev;
948 	sdcp->base = devm_ioremap_resource(dev, iores);
949 	if (IS_ERR(sdcp->base))
950 		return PTR_ERR(sdcp->base);
951 
952 
953 	ret = devm_request_irq(dev, dcp_vmi_irq, mxs_dcp_irq, 0,
954 			       "dcp-vmi-irq", sdcp);
955 	if (ret) {
956 		dev_err(dev, "Failed to claim DCP VMI IRQ!\n");
957 		return ret;
958 	}
959 
960 	ret = devm_request_irq(dev, dcp_irq, mxs_dcp_irq, 0,
961 			       "dcp-irq", sdcp);
962 	if (ret) {
963 		dev_err(dev, "Failed to claim DCP IRQ!\n");
964 		return ret;
965 	}
966 
967 	/* Allocate coherent helper block. */
968 	sdcp->coh = devm_kzalloc(dev, sizeof(*sdcp->coh) + DCP_ALIGNMENT,
969 				   GFP_KERNEL);
970 	if (!sdcp->coh)
971 		return -ENOMEM;
972 
973 	/* Re-align the structure so it fits the DCP constraints. */
974 	sdcp->coh = PTR_ALIGN(sdcp->coh, DCP_ALIGNMENT);
975 
976 	/* Restart the DCP block. */
977 	ret = stmp_reset_block(sdcp->base);
978 	if (ret)
979 		return ret;
980 
981 	/* Initialize control register. */
982 	writel(MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES |
983 	       MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING | 0xf,
984 	       sdcp->base + MXS_DCP_CTRL);
985 
986 	/* Enable all DCP DMA channels. */
987 	writel(MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK,
988 	       sdcp->base + MXS_DCP_CHANNELCTRL);
989 
990 	/*
991 	 * We do not enable context switching. Give the context buffer a
992 	 * pointer to an illegal address so if context switching is
993 	 * inadvertantly enabled, the DCP will return an error instead of
994 	 * trashing good memory. The DCP DMA cannot access ROM, so any ROM
995 	 * address will do.
996 	 */
997 	writel(0xffff0000, sdcp->base + MXS_DCP_CONTEXT);
998 	for (i = 0; i < DCP_MAX_CHANS; i++)
999 		writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(i));
1000 	writel(0xffffffff, sdcp->base + MXS_DCP_STAT_CLR);
1001 
1002 	global_sdcp = sdcp;
1003 
1004 	platform_set_drvdata(pdev, sdcp);
1005 
1006 	for (i = 0; i < DCP_MAX_CHANS; i++) {
1007 		spin_lock_init(&sdcp->lock[i]);
1008 		init_completion(&sdcp->completion[i]);
1009 		crypto_init_queue(&sdcp->queue[i], 50);
1010 	}
1011 
1012 	/* Create the SHA and AES handler threads. */
1013 	sdcp->thread[DCP_CHAN_HASH_SHA] = kthread_run(dcp_chan_thread_sha,
1014 						      NULL, "mxs_dcp_chan/sha");
1015 	if (IS_ERR(sdcp->thread[DCP_CHAN_HASH_SHA])) {
1016 		dev_err(dev, "Error starting SHA thread!\n");
1017 		return PTR_ERR(sdcp->thread[DCP_CHAN_HASH_SHA]);
1018 	}
1019 
1020 	sdcp->thread[DCP_CHAN_CRYPTO] = kthread_run(dcp_chan_thread_aes,
1021 						    NULL, "mxs_dcp_chan/aes");
1022 	if (IS_ERR(sdcp->thread[DCP_CHAN_CRYPTO])) {
1023 		dev_err(dev, "Error starting SHA thread!\n");
1024 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_CRYPTO]);
1025 		goto err_destroy_sha_thread;
1026 	}
1027 
1028 	/* Register the various crypto algorithms. */
1029 	sdcp->caps = readl(sdcp->base + MXS_DCP_CAPABILITY1);
1030 
1031 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128) {
1032 		ret = crypto_register_algs(dcp_aes_algs,
1033 					   ARRAY_SIZE(dcp_aes_algs));
1034 		if (ret) {
1035 			/* Failed to register algorithm. */
1036 			dev_err(dev, "Failed to register AES crypto!\n");
1037 			goto err_destroy_aes_thread;
1038 		}
1039 	}
1040 
1041 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1) {
1042 		ret = crypto_register_ahash(&dcp_sha1_alg);
1043 		if (ret) {
1044 			dev_err(dev, "Failed to register %s hash!\n",
1045 				dcp_sha1_alg.halg.base.cra_name);
1046 			goto err_unregister_aes;
1047 		}
1048 	}
1049 
1050 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256) {
1051 		ret = crypto_register_ahash(&dcp_sha256_alg);
1052 		if (ret) {
1053 			dev_err(dev, "Failed to register %s hash!\n",
1054 				dcp_sha256_alg.halg.base.cra_name);
1055 			goto err_unregister_sha1;
1056 		}
1057 	}
1058 
1059 	return 0;
1060 
1061 err_unregister_sha1:
1062 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1063 		crypto_unregister_ahash(&dcp_sha1_alg);
1064 
1065 err_unregister_aes:
1066 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1067 		crypto_unregister_algs(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1068 
1069 err_destroy_aes_thread:
1070 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1071 
1072 err_destroy_sha_thread:
1073 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1074 	return ret;
1075 }
1076 
1077 static int mxs_dcp_remove(struct platform_device *pdev)
1078 {
1079 	struct dcp *sdcp = platform_get_drvdata(pdev);
1080 
1081 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256)
1082 		crypto_unregister_ahash(&dcp_sha256_alg);
1083 
1084 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1085 		crypto_unregister_ahash(&dcp_sha1_alg);
1086 
1087 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1088 		crypto_unregister_algs(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1089 
1090 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1091 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1092 
1093 	platform_set_drvdata(pdev, NULL);
1094 
1095 	global_sdcp = NULL;
1096 
1097 	return 0;
1098 }
1099 
1100 static const struct of_device_id mxs_dcp_dt_ids[] = {
1101 	{ .compatible = "fsl,imx23-dcp", .data = NULL, },
1102 	{ .compatible = "fsl,imx28-dcp", .data = NULL, },
1103 	{ /* sentinel */ }
1104 };
1105 
1106 MODULE_DEVICE_TABLE(of, mxs_dcp_dt_ids);
1107 
1108 static struct platform_driver mxs_dcp_driver = {
1109 	.probe	= mxs_dcp_probe,
1110 	.remove	= mxs_dcp_remove,
1111 	.driver	= {
1112 		.name		= "mxs-dcp",
1113 		.of_match_table	= mxs_dcp_dt_ids,
1114 	},
1115 };
1116 
1117 module_platform_driver(mxs_dcp_driver);
1118 
1119 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1120 MODULE_DESCRIPTION("Freescale MXS DCP Driver");
1121 MODULE_LICENSE("GPL");
1122 MODULE_ALIAS("platform:mxs-dcp");
1123