xref: /linux/drivers/crypto/mxs-dcp.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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 #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 	struct mutex			mutex[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_ablkcipher	*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 	do {
353 		__set_current_state(TASK_INTERRUPTIBLE);
354 
355 		mutex_lock(&sdcp->mutex[chan]);
356 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
357 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
358 		mutex_unlock(&sdcp->mutex[chan]);
359 
360 		if (backlog)
361 			backlog->complete(backlog, -EINPROGRESS);
362 
363 		if (arq) {
364 			ret = mxs_dcp_aes_block_crypt(arq);
365 			arq->complete(arq, ret);
366 			continue;
367 		}
368 
369 		schedule();
370 	} while (!kthread_should_stop());
371 
372 	return 0;
373 }
374 
375 static int mxs_dcp_block_fallback(struct ablkcipher_request *req, int enc)
376 {
377 	struct crypto_tfm *tfm =
378 		crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
379 	struct dcp_async_ctx *ctx = crypto_ablkcipher_ctx(
380 		crypto_ablkcipher_reqtfm(req));
381 	int ret;
382 
383 	ablkcipher_request_set_tfm(req, ctx->fallback);
384 
385 	if (enc)
386 		ret = crypto_ablkcipher_encrypt(req);
387 	else
388 		ret = crypto_ablkcipher_decrypt(req);
389 
390 	ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
391 
392 	return ret;
393 }
394 
395 static int mxs_dcp_aes_enqueue(struct ablkcipher_request *req, int enc, int ecb)
396 {
397 	struct dcp *sdcp = global_sdcp;
398 	struct crypto_async_request *arq = &req->base;
399 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
400 	struct dcp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
401 	int ret;
402 
403 	if (unlikely(actx->key_len != AES_KEYSIZE_128))
404 		return mxs_dcp_block_fallback(req, enc);
405 
406 	rctx->enc = enc;
407 	rctx->ecb = ecb;
408 	actx->chan = DCP_CHAN_CRYPTO;
409 
410 	mutex_lock(&sdcp->mutex[actx->chan]);
411 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
412 	mutex_unlock(&sdcp->mutex[actx->chan]);
413 
414 	wake_up_process(sdcp->thread[actx->chan]);
415 
416 	return -EINPROGRESS;
417 }
418 
419 static int mxs_dcp_aes_ecb_decrypt(struct ablkcipher_request *req)
420 {
421 	return mxs_dcp_aes_enqueue(req, 0, 1);
422 }
423 
424 static int mxs_dcp_aes_ecb_encrypt(struct ablkcipher_request *req)
425 {
426 	return mxs_dcp_aes_enqueue(req, 1, 1);
427 }
428 
429 static int mxs_dcp_aes_cbc_decrypt(struct ablkcipher_request *req)
430 {
431 	return mxs_dcp_aes_enqueue(req, 0, 0);
432 }
433 
434 static int mxs_dcp_aes_cbc_encrypt(struct ablkcipher_request *req)
435 {
436 	return mxs_dcp_aes_enqueue(req, 1, 0);
437 }
438 
439 static int mxs_dcp_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
440 			      unsigned int len)
441 {
442 	struct dcp_async_ctx *actx = crypto_ablkcipher_ctx(tfm);
443 	unsigned int ret;
444 
445 	/*
446 	 * AES 128 is supposed by the hardware, store key into temporary
447 	 * buffer and exit. We must use the temporary buffer here, since
448 	 * there can still be an operation in progress.
449 	 */
450 	actx->key_len = len;
451 	if (len == AES_KEYSIZE_128) {
452 		memcpy(actx->key, key, len);
453 		return 0;
454 	}
455 
456 	/* Check if the key size is supported by kernel at all. */
457 	if (len != AES_KEYSIZE_192 && len != AES_KEYSIZE_256) {
458 		tfm->base.crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
459 		return -EINVAL;
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 	actx->fallback->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
468 	actx->fallback->base.crt_flags |=
469 		tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK;
470 
471 	ret = crypto_ablkcipher_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 |=
477 		actx->fallback->base.crt_flags & 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_ablkcipher *blk;
488 
489 	blk = crypto_alloc_ablkcipher(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_ablkcipher(actx->fallback);
503 	actx->fallback = NULL;
504 }
505 
506 /*
507  * Hashing (SHA1/SHA256)
508  */
509 static int mxs_dcp_run_sha(struct ahash_request *req)
510 {
511 	struct dcp *sdcp = global_sdcp;
512 	int ret;
513 
514 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
515 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
516 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
517 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
518 
519 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
520 
521 	dma_addr_t digest_phys = 0;
522 	dma_addr_t buf_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_in_buf,
523 					     DCP_BUF_SZ, DMA_TO_DEVICE);
524 
525 	/* Fill in the DMA descriptor. */
526 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
527 		    MXS_DCP_CONTROL0_INTERRUPT |
528 		    MXS_DCP_CONTROL0_ENABLE_HASH;
529 	if (rctx->init)
530 		desc->control0 |= MXS_DCP_CONTROL0_HASH_INIT;
531 
532 	desc->control1 = actx->alg;
533 	desc->next_cmd_addr = 0;
534 	desc->source = buf_phys;
535 	desc->destination = 0;
536 	desc->size = actx->fill;
537 	desc->payload = 0;
538 	desc->status = 0;
539 
540 	/* Set HASH_TERM bit for last transfer block. */
541 	if (rctx->fini) {
542 		digest_phys = dma_map_single(sdcp->dev, req->result,
543 					     halg->digestsize, DMA_FROM_DEVICE);
544 		desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
545 		desc->payload = digest_phys;
546 	}
547 
548 	ret = mxs_dcp_start_dma(actx);
549 
550 	if (rctx->fini)
551 		dma_unmap_single(sdcp->dev, digest_phys, halg->digestsize,
552 				 DMA_FROM_DEVICE);
553 
554 	dma_unmap_single(sdcp->dev, buf_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
555 
556 	return ret;
557 }
558 
559 static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
560 {
561 	struct dcp *sdcp = global_sdcp;
562 
563 	struct ahash_request *req = ahash_request_cast(arq);
564 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
565 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
566 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
567 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
568 	const int nents = sg_nents(req->src);
569 
570 	uint8_t *in_buf = sdcp->coh->sha_in_buf;
571 
572 	uint8_t *src_buf;
573 
574 	struct scatterlist *src;
575 
576 	unsigned int i, len, clen;
577 	int ret;
578 
579 	int fin = rctx->fini;
580 	if (fin)
581 		rctx->fini = 0;
582 
583 	for_each_sg(req->src, src, nents, i) {
584 		src_buf = sg_virt(src);
585 		len = sg_dma_len(src);
586 
587 		do {
588 			if (actx->fill + len > DCP_BUF_SZ)
589 				clen = DCP_BUF_SZ - actx->fill;
590 			else
591 				clen = len;
592 
593 			memcpy(in_buf + actx->fill, src_buf, clen);
594 			len -= clen;
595 			src_buf += clen;
596 			actx->fill += clen;
597 
598 			/*
599 			 * If we filled the buffer and still have some
600 			 * more data, submit the buffer.
601 			 */
602 			if (len && actx->fill == DCP_BUF_SZ) {
603 				ret = mxs_dcp_run_sha(req);
604 				if (ret)
605 					return ret;
606 				actx->fill = 0;
607 				rctx->init = 0;
608 			}
609 		} while (len);
610 	}
611 
612 	if (fin) {
613 		rctx->fini = 1;
614 
615 		/* Submit whatever is left. */
616 		if (!req->result)
617 			return -EINVAL;
618 
619 		ret = mxs_dcp_run_sha(req);
620 		if (ret)
621 			return ret;
622 
623 		actx->fill = 0;
624 
625 		/* For some reason, the result is flipped. */
626 		for (i = 0; i < halg->digestsize / 2; i++) {
627 			swap(req->result[i],
628 			     req->result[halg->digestsize - i - 1]);
629 		}
630 	}
631 
632 	return 0;
633 }
634 
635 static int dcp_chan_thread_sha(void *data)
636 {
637 	struct dcp *sdcp = global_sdcp;
638 	const int chan = DCP_CHAN_HASH_SHA;
639 
640 	struct crypto_async_request *backlog;
641 	struct crypto_async_request *arq;
642 
643 	struct dcp_sha_req_ctx *rctx;
644 
645 	struct ahash_request *req;
646 	int ret, fini;
647 
648 	do {
649 		__set_current_state(TASK_INTERRUPTIBLE);
650 
651 		mutex_lock(&sdcp->mutex[chan]);
652 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
653 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
654 		mutex_unlock(&sdcp->mutex[chan]);
655 
656 		if (backlog)
657 			backlog->complete(backlog, -EINPROGRESS);
658 
659 		if (arq) {
660 			req = ahash_request_cast(arq);
661 			rctx = ahash_request_ctx(req);
662 
663 			ret = dcp_sha_req_to_buf(arq);
664 			fini = rctx->fini;
665 			arq->complete(arq, ret);
666 			if (!fini)
667 				continue;
668 		}
669 
670 		schedule();
671 	} while (!kthread_should_stop());
672 
673 	return 0;
674 }
675 
676 static int dcp_sha_init(struct ahash_request *req)
677 {
678 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
679 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
680 
681 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
682 
683 	/*
684 	 * Start hashing session. The code below only inits the
685 	 * hashing session context, nothing more.
686 	 */
687 	memset(actx, 0, sizeof(*actx));
688 
689 	if (strcmp(halg->base.cra_name, "sha1") == 0)
690 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA1;
691 	else
692 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA256;
693 
694 	actx->fill = 0;
695 	actx->hot = 0;
696 	actx->chan = DCP_CHAN_HASH_SHA;
697 
698 	mutex_init(&actx->mutex);
699 
700 	return 0;
701 }
702 
703 static int dcp_sha_update_fx(struct ahash_request *req, int fini)
704 {
705 	struct dcp *sdcp = global_sdcp;
706 
707 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
708 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
709 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
710 
711 	int ret;
712 
713 	/*
714 	 * Ignore requests that have no data in them and are not
715 	 * the trailing requests in the stream of requests.
716 	 */
717 	if (!req->nbytes && !fini)
718 		return 0;
719 
720 	mutex_lock(&actx->mutex);
721 
722 	rctx->fini = fini;
723 
724 	if (!actx->hot) {
725 		actx->hot = 1;
726 		rctx->init = 1;
727 	}
728 
729 	mutex_lock(&sdcp->mutex[actx->chan]);
730 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
731 	mutex_unlock(&sdcp->mutex[actx->chan]);
732 
733 	wake_up_process(sdcp->thread[actx->chan]);
734 	mutex_unlock(&actx->mutex);
735 
736 	return -EINPROGRESS;
737 }
738 
739 static int dcp_sha_update(struct ahash_request *req)
740 {
741 	return dcp_sha_update_fx(req, 0);
742 }
743 
744 static int dcp_sha_final(struct ahash_request *req)
745 {
746 	ahash_request_set_crypt(req, NULL, req->result, 0);
747 	req->nbytes = 0;
748 	return dcp_sha_update_fx(req, 1);
749 }
750 
751 static int dcp_sha_finup(struct ahash_request *req)
752 {
753 	return dcp_sha_update_fx(req, 1);
754 }
755 
756 static int dcp_sha_digest(struct ahash_request *req)
757 {
758 	int ret;
759 
760 	ret = dcp_sha_init(req);
761 	if (ret)
762 		return ret;
763 
764 	return dcp_sha_finup(req);
765 }
766 
767 static int dcp_sha_cra_init(struct crypto_tfm *tfm)
768 {
769 	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
770 				 sizeof(struct dcp_sha_req_ctx));
771 	return 0;
772 }
773 
774 static void dcp_sha_cra_exit(struct crypto_tfm *tfm)
775 {
776 }
777 
778 /* AES 128 ECB and AES 128 CBC */
779 static struct crypto_alg dcp_aes_algs[] = {
780 	{
781 		.cra_name		= "ecb(aes)",
782 		.cra_driver_name	= "ecb-aes-dcp",
783 		.cra_priority		= 400,
784 		.cra_alignmask		= 15,
785 		.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
786 					  CRYPTO_ALG_ASYNC |
787 					  CRYPTO_ALG_NEED_FALLBACK,
788 		.cra_init		= mxs_dcp_aes_fallback_init,
789 		.cra_exit		= mxs_dcp_aes_fallback_exit,
790 		.cra_blocksize		= AES_BLOCK_SIZE,
791 		.cra_ctxsize		= sizeof(struct dcp_async_ctx),
792 		.cra_type		= &crypto_ablkcipher_type,
793 		.cra_module		= THIS_MODULE,
794 		.cra_u	= {
795 			.ablkcipher = {
796 				.min_keysize	= AES_MIN_KEY_SIZE,
797 				.max_keysize	= AES_MAX_KEY_SIZE,
798 				.setkey		= mxs_dcp_aes_setkey,
799 				.encrypt	= mxs_dcp_aes_ecb_encrypt,
800 				.decrypt	= mxs_dcp_aes_ecb_decrypt
801 			},
802 		},
803 	}, {
804 		.cra_name		= "cbc(aes)",
805 		.cra_driver_name	= "cbc-aes-dcp",
806 		.cra_priority		= 400,
807 		.cra_alignmask		= 15,
808 		.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
809 					  CRYPTO_ALG_ASYNC |
810 					  CRYPTO_ALG_NEED_FALLBACK,
811 		.cra_init		= mxs_dcp_aes_fallback_init,
812 		.cra_exit		= mxs_dcp_aes_fallback_exit,
813 		.cra_blocksize		= AES_BLOCK_SIZE,
814 		.cra_ctxsize		= sizeof(struct dcp_async_ctx),
815 		.cra_type		= &crypto_ablkcipher_type,
816 		.cra_module		= THIS_MODULE,
817 		.cra_u = {
818 			.ablkcipher = {
819 				.min_keysize	= AES_MIN_KEY_SIZE,
820 				.max_keysize	= AES_MAX_KEY_SIZE,
821 				.setkey		= mxs_dcp_aes_setkey,
822 				.encrypt	= mxs_dcp_aes_cbc_encrypt,
823 				.decrypt	= mxs_dcp_aes_cbc_decrypt,
824 				.ivsize		= AES_BLOCK_SIZE,
825 			},
826 		},
827 	},
828 };
829 
830 /* SHA1 */
831 static struct ahash_alg dcp_sha1_alg = {
832 	.init	= dcp_sha_init,
833 	.update	= dcp_sha_update,
834 	.final	= dcp_sha_final,
835 	.finup	= dcp_sha_finup,
836 	.digest	= dcp_sha_digest,
837 	.halg	= {
838 		.digestsize	= SHA1_DIGEST_SIZE,
839 		.base		= {
840 			.cra_name		= "sha1",
841 			.cra_driver_name	= "sha1-dcp",
842 			.cra_priority		= 400,
843 			.cra_alignmask		= 63,
844 			.cra_flags		= CRYPTO_ALG_ASYNC,
845 			.cra_blocksize		= SHA1_BLOCK_SIZE,
846 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
847 			.cra_module		= THIS_MODULE,
848 			.cra_init		= dcp_sha_cra_init,
849 			.cra_exit		= dcp_sha_cra_exit,
850 		},
851 	},
852 };
853 
854 /* SHA256 */
855 static struct ahash_alg dcp_sha256_alg = {
856 	.init	= dcp_sha_init,
857 	.update	= dcp_sha_update,
858 	.final	= dcp_sha_final,
859 	.finup	= dcp_sha_finup,
860 	.digest	= dcp_sha_digest,
861 	.halg	= {
862 		.digestsize	= SHA256_DIGEST_SIZE,
863 		.base		= {
864 			.cra_name		= "sha256",
865 			.cra_driver_name	= "sha256-dcp",
866 			.cra_priority		= 400,
867 			.cra_alignmask		= 63,
868 			.cra_flags		= CRYPTO_ALG_ASYNC,
869 			.cra_blocksize		= SHA256_BLOCK_SIZE,
870 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
871 			.cra_module		= THIS_MODULE,
872 			.cra_init		= dcp_sha_cra_init,
873 			.cra_exit		= dcp_sha_cra_exit,
874 		},
875 	},
876 };
877 
878 static irqreturn_t mxs_dcp_irq(int irq, void *context)
879 {
880 	struct dcp *sdcp = context;
881 	uint32_t stat;
882 	int i;
883 
884 	stat = readl(sdcp->base + MXS_DCP_STAT);
885 	stat &= MXS_DCP_STAT_IRQ_MASK;
886 	if (!stat)
887 		return IRQ_NONE;
888 
889 	/* Clear the interrupts. */
890 	writel(stat, sdcp->base + MXS_DCP_STAT_CLR);
891 
892 	/* Complete the DMA requests that finished. */
893 	for (i = 0; i < DCP_MAX_CHANS; i++)
894 		if (stat & (1 << i))
895 			complete(&sdcp->completion[i]);
896 
897 	return IRQ_HANDLED;
898 }
899 
900 static int mxs_dcp_probe(struct platform_device *pdev)
901 {
902 	struct device *dev = &pdev->dev;
903 	struct dcp *sdcp = NULL;
904 	int i, ret;
905 
906 	struct resource *iores;
907 	int dcp_vmi_irq, dcp_irq;
908 
909 	if (global_sdcp) {
910 		dev_err(dev, "Only one DCP instance allowed!\n");
911 		return -ENODEV;
912 	}
913 
914 	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
915 	dcp_vmi_irq = platform_get_irq(pdev, 0);
916 	if (dcp_vmi_irq < 0)
917 		return dcp_vmi_irq;
918 
919 	dcp_irq = platform_get_irq(pdev, 1);
920 	if (dcp_irq < 0)
921 		return dcp_irq;
922 
923 	sdcp = devm_kzalloc(dev, sizeof(*sdcp), GFP_KERNEL);
924 	if (!sdcp)
925 		return -ENOMEM;
926 
927 	sdcp->dev = dev;
928 	sdcp->base = devm_ioremap_resource(dev, iores);
929 	if (IS_ERR(sdcp->base))
930 		return PTR_ERR(sdcp->base);
931 
932 
933 	ret = devm_request_irq(dev, dcp_vmi_irq, mxs_dcp_irq, 0,
934 			       "dcp-vmi-irq", sdcp);
935 	if (ret) {
936 		dev_err(dev, "Failed to claim DCP VMI IRQ!\n");
937 		return ret;
938 	}
939 
940 	ret = devm_request_irq(dev, dcp_irq, mxs_dcp_irq, 0,
941 			       "dcp-irq", sdcp);
942 	if (ret) {
943 		dev_err(dev, "Failed to claim DCP IRQ!\n");
944 		return ret;
945 	}
946 
947 	/* Allocate coherent helper block. */
948 	sdcp->coh = devm_kzalloc(dev, sizeof(*sdcp->coh) + DCP_ALIGNMENT,
949 				   GFP_KERNEL);
950 	if (!sdcp->coh)
951 		return -ENOMEM;
952 
953 	/* Re-align the structure so it fits the DCP constraints. */
954 	sdcp->coh = PTR_ALIGN(sdcp->coh, DCP_ALIGNMENT);
955 
956 	/* Restart the DCP block. */
957 	ret = stmp_reset_block(sdcp->base);
958 	if (ret)
959 		return ret;
960 
961 	/* Initialize control register. */
962 	writel(MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES |
963 	       MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING | 0xf,
964 	       sdcp->base + MXS_DCP_CTRL);
965 
966 	/* Enable all DCP DMA channels. */
967 	writel(MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK,
968 	       sdcp->base + MXS_DCP_CHANNELCTRL);
969 
970 	/*
971 	 * We do not enable context switching. Give the context buffer a
972 	 * pointer to an illegal address so if context switching is
973 	 * inadvertantly enabled, the DCP will return an error instead of
974 	 * trashing good memory. The DCP DMA cannot access ROM, so any ROM
975 	 * address will do.
976 	 */
977 	writel(0xffff0000, sdcp->base + MXS_DCP_CONTEXT);
978 	for (i = 0; i < DCP_MAX_CHANS; i++)
979 		writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(i));
980 	writel(0xffffffff, sdcp->base + MXS_DCP_STAT_CLR);
981 
982 	global_sdcp = sdcp;
983 
984 	platform_set_drvdata(pdev, sdcp);
985 
986 	for (i = 0; i < DCP_MAX_CHANS; i++) {
987 		mutex_init(&sdcp->mutex[i]);
988 		init_completion(&sdcp->completion[i]);
989 		crypto_init_queue(&sdcp->queue[i], 50);
990 	}
991 
992 	/* Create the SHA and AES handler threads. */
993 	sdcp->thread[DCP_CHAN_HASH_SHA] = kthread_run(dcp_chan_thread_sha,
994 						      NULL, "mxs_dcp_chan/sha");
995 	if (IS_ERR(sdcp->thread[DCP_CHAN_HASH_SHA])) {
996 		dev_err(dev, "Error starting SHA thread!\n");
997 		return PTR_ERR(sdcp->thread[DCP_CHAN_HASH_SHA]);
998 	}
999 
1000 	sdcp->thread[DCP_CHAN_CRYPTO] = kthread_run(dcp_chan_thread_aes,
1001 						    NULL, "mxs_dcp_chan/aes");
1002 	if (IS_ERR(sdcp->thread[DCP_CHAN_CRYPTO])) {
1003 		dev_err(dev, "Error starting SHA thread!\n");
1004 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_CRYPTO]);
1005 		goto err_destroy_sha_thread;
1006 	}
1007 
1008 	/* Register the various crypto algorithms. */
1009 	sdcp->caps = readl(sdcp->base + MXS_DCP_CAPABILITY1);
1010 
1011 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128) {
1012 		ret = crypto_register_algs(dcp_aes_algs,
1013 					   ARRAY_SIZE(dcp_aes_algs));
1014 		if (ret) {
1015 			/* Failed to register algorithm. */
1016 			dev_err(dev, "Failed to register AES crypto!\n");
1017 			goto err_destroy_aes_thread;
1018 		}
1019 	}
1020 
1021 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1) {
1022 		ret = crypto_register_ahash(&dcp_sha1_alg);
1023 		if (ret) {
1024 			dev_err(dev, "Failed to register %s hash!\n",
1025 				dcp_sha1_alg.halg.base.cra_name);
1026 			goto err_unregister_aes;
1027 		}
1028 	}
1029 
1030 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256) {
1031 		ret = crypto_register_ahash(&dcp_sha256_alg);
1032 		if (ret) {
1033 			dev_err(dev, "Failed to register %s hash!\n",
1034 				dcp_sha256_alg.halg.base.cra_name);
1035 			goto err_unregister_sha1;
1036 		}
1037 	}
1038 
1039 	return 0;
1040 
1041 err_unregister_sha1:
1042 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1043 		crypto_unregister_ahash(&dcp_sha1_alg);
1044 
1045 err_unregister_aes:
1046 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1047 		crypto_unregister_algs(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1048 
1049 err_destroy_aes_thread:
1050 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1051 
1052 err_destroy_sha_thread:
1053 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1054 	return ret;
1055 }
1056 
1057 static int mxs_dcp_remove(struct platform_device *pdev)
1058 {
1059 	struct dcp *sdcp = platform_get_drvdata(pdev);
1060 
1061 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256)
1062 		crypto_unregister_ahash(&dcp_sha256_alg);
1063 
1064 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1065 		crypto_unregister_ahash(&dcp_sha1_alg);
1066 
1067 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1068 		crypto_unregister_algs(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1069 
1070 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1071 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1072 
1073 	platform_set_drvdata(pdev, NULL);
1074 
1075 	global_sdcp = NULL;
1076 
1077 	return 0;
1078 }
1079 
1080 static const struct of_device_id mxs_dcp_dt_ids[] = {
1081 	{ .compatible = "fsl,imx23-dcp", .data = NULL, },
1082 	{ .compatible = "fsl,imx28-dcp", .data = NULL, },
1083 	{ /* sentinel */ }
1084 };
1085 
1086 MODULE_DEVICE_TABLE(of, mxs_dcp_dt_ids);
1087 
1088 static struct platform_driver mxs_dcp_driver = {
1089 	.probe	= mxs_dcp_probe,
1090 	.remove	= mxs_dcp_remove,
1091 	.driver	= {
1092 		.name		= "mxs-dcp",
1093 		.of_match_table	= mxs_dcp_dt_ids,
1094 	},
1095 };
1096 
1097 module_platform_driver(mxs_dcp_driver);
1098 
1099 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1100 MODULE_DESCRIPTION("Freescale MXS DCP Driver");
1101 MODULE_LICENSE("GPL");
1102 MODULE_ALIAS("platform:mxs-dcp");
1103