xref: /openbmc/linux/drivers/crypto/mxs-dcp.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Freescale i.MX23/i.MX28 Data Co-Processor driver
4  *
5  * Copyright (C) 2013 Marek Vasut <marex@denx.de>
6  */
7 
8 #include <linux/dma-mapping.h>
9 #include <linux/interrupt.h>
10 #include <linux/io.h>
11 #include <linux/kernel.h>
12 #include <linux/kthread.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/stmp_device.h>
17 #include <linux/clk.h>
18 
19 #include <crypto/aes.h>
20 #include <crypto/sha1.h>
21 #include <crypto/sha2.h>
22 #include <crypto/internal/hash.h>
23 #include <crypto/internal/skcipher.h>
24 #include <crypto/scatterwalk.h>
25 
26 #define DCP_MAX_CHANS	4
27 #define DCP_BUF_SZ	PAGE_SIZE
28 #define DCP_SHA_PAY_SZ  64
29 
30 #define DCP_ALIGNMENT	64
31 
32 /*
33  * Null hashes to align with hw behavior on imx6sl and ull
34  * these are flipped for consistency with hw output
35  */
36 static const uint8_t sha1_null_hash[] =
37 	"\x09\x07\xd8\xaf\x90\x18\x60\x95\xef\xbf"
38 	"\x55\x32\x0d\x4b\x6b\x5e\xee\xa3\x39\xda";
39 
40 static const uint8_t sha256_null_hash[] =
41 	"\x55\xb8\x52\x78\x1b\x99\x95\xa4"
42 	"\x4c\x93\x9b\x64\xe4\x41\xae\x27"
43 	"\x24\xb9\x6f\x99\xc8\xf4\xfb\x9a"
44 	"\x14\x1c\xfc\x98\x42\xc4\xb0\xe3";
45 
46 /* DCP DMA descriptor. */
47 struct dcp_dma_desc {
48 	uint32_t	next_cmd_addr;
49 	uint32_t	control0;
50 	uint32_t	control1;
51 	uint32_t	source;
52 	uint32_t	destination;
53 	uint32_t	size;
54 	uint32_t	payload;
55 	uint32_t	status;
56 };
57 
58 /* Coherent aligned block for bounce buffering. */
59 struct dcp_coherent_block {
60 	uint8_t			aes_in_buf[DCP_BUF_SZ];
61 	uint8_t			aes_out_buf[DCP_BUF_SZ];
62 	uint8_t			sha_in_buf[DCP_BUF_SZ];
63 	uint8_t			sha_out_buf[DCP_SHA_PAY_SZ];
64 
65 	uint8_t			aes_key[2 * AES_KEYSIZE_128];
66 
67 	struct dcp_dma_desc	desc[DCP_MAX_CHANS];
68 };
69 
70 struct dcp {
71 	struct device			*dev;
72 	void __iomem			*base;
73 
74 	uint32_t			caps;
75 
76 	struct dcp_coherent_block	*coh;
77 
78 	struct completion		completion[DCP_MAX_CHANS];
79 	spinlock_t			lock[DCP_MAX_CHANS];
80 	struct task_struct		*thread[DCP_MAX_CHANS];
81 	struct crypto_queue		queue[DCP_MAX_CHANS];
82 	struct clk			*dcp_clk;
83 };
84 
85 enum dcp_chan {
86 	DCP_CHAN_HASH_SHA	= 0,
87 	DCP_CHAN_CRYPTO		= 2,
88 };
89 
90 struct dcp_async_ctx {
91 	/* Common context */
92 	enum dcp_chan	chan;
93 	uint32_t	fill;
94 
95 	/* SHA Hash-specific context */
96 	struct mutex			mutex;
97 	uint32_t			alg;
98 	unsigned int			hot:1;
99 
100 	/* Crypto-specific context */
101 	struct crypto_skcipher		*fallback;
102 	unsigned int			key_len;
103 	uint8_t				key[AES_KEYSIZE_128];
104 };
105 
106 struct dcp_aes_req_ctx {
107 	unsigned int	enc:1;
108 	unsigned int	ecb:1;
109 	struct skcipher_request fallback_req;	// keep at the end
110 };
111 
112 struct dcp_sha_req_ctx {
113 	unsigned int	init:1;
114 	unsigned int	fini:1;
115 };
116 
117 struct dcp_export_state {
118 	struct dcp_sha_req_ctx req_ctx;
119 	struct dcp_async_ctx async_ctx;
120 };
121 
122 /*
123  * There can even be only one instance of the MXS DCP due to the
124  * design of Linux Crypto API.
125  */
126 static struct dcp *global_sdcp;
127 
128 /* DCP register layout. */
129 #define MXS_DCP_CTRL				0x00
130 #define MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES	(1 << 23)
131 #define MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING	(1 << 22)
132 
133 #define MXS_DCP_STAT				0x10
134 #define MXS_DCP_STAT_CLR			0x18
135 #define MXS_DCP_STAT_IRQ_MASK			0xf
136 
137 #define MXS_DCP_CHANNELCTRL			0x20
138 #define MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK	0xff
139 
140 #define MXS_DCP_CAPABILITY1			0x40
141 #define MXS_DCP_CAPABILITY1_SHA256		(4 << 16)
142 #define MXS_DCP_CAPABILITY1_SHA1		(1 << 16)
143 #define MXS_DCP_CAPABILITY1_AES128		(1 << 0)
144 
145 #define MXS_DCP_CONTEXT				0x50
146 
147 #define MXS_DCP_CH_N_CMDPTR(n)			(0x100 + ((n) * 0x40))
148 
149 #define MXS_DCP_CH_N_SEMA(n)			(0x110 + ((n) * 0x40))
150 
151 #define MXS_DCP_CH_N_STAT(n)			(0x120 + ((n) * 0x40))
152 #define MXS_DCP_CH_N_STAT_CLR(n)		(0x128 + ((n) * 0x40))
153 
154 /* DMA descriptor bits. */
155 #define MXS_DCP_CONTROL0_HASH_TERM		(1 << 13)
156 #define MXS_DCP_CONTROL0_HASH_INIT		(1 << 12)
157 #define MXS_DCP_CONTROL0_PAYLOAD_KEY		(1 << 11)
158 #define MXS_DCP_CONTROL0_CIPHER_ENCRYPT		(1 << 8)
159 #define MXS_DCP_CONTROL0_CIPHER_INIT		(1 << 9)
160 #define MXS_DCP_CONTROL0_ENABLE_HASH		(1 << 6)
161 #define MXS_DCP_CONTROL0_ENABLE_CIPHER		(1 << 5)
162 #define MXS_DCP_CONTROL0_DECR_SEMAPHORE		(1 << 1)
163 #define MXS_DCP_CONTROL0_INTERRUPT		(1 << 0)
164 
165 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA256	(2 << 16)
166 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA1	(0 << 16)
167 #define MXS_DCP_CONTROL1_CIPHER_MODE_CBC	(1 << 4)
168 #define MXS_DCP_CONTROL1_CIPHER_MODE_ECB	(0 << 4)
169 #define MXS_DCP_CONTROL1_CIPHER_SELECT_AES128	(0 << 0)
170 
171 static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
172 {
173 	int dma_err;
174 	struct dcp *sdcp = global_sdcp;
175 	const int chan = actx->chan;
176 	uint32_t stat;
177 	unsigned long ret;
178 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
179 	dma_addr_t desc_phys = dma_map_single(sdcp->dev, desc, sizeof(*desc),
180 					      DMA_TO_DEVICE);
181 
182 	dma_err = dma_mapping_error(sdcp->dev, desc_phys);
183 	if (dma_err)
184 		return dma_err;
185 
186 	reinit_completion(&sdcp->completion[chan]);
187 
188 	/* Clear status register. */
189 	writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(chan));
190 
191 	/* Load the DMA descriptor. */
192 	writel(desc_phys, sdcp->base + MXS_DCP_CH_N_CMDPTR(chan));
193 
194 	/* Increment the semaphore to start the DMA transfer. */
195 	writel(1, sdcp->base + MXS_DCP_CH_N_SEMA(chan));
196 
197 	ret = wait_for_completion_timeout(&sdcp->completion[chan],
198 					  msecs_to_jiffies(1000));
199 	if (!ret) {
200 		dev_err(sdcp->dev, "Channel %i timeout (DCP_STAT=0x%08x)\n",
201 			chan, readl(sdcp->base + MXS_DCP_STAT));
202 		return -ETIMEDOUT;
203 	}
204 
205 	stat = readl(sdcp->base + MXS_DCP_CH_N_STAT(chan));
206 	if (stat & 0xff) {
207 		dev_err(sdcp->dev, "Channel %i error (CH_STAT=0x%08x)\n",
208 			chan, stat);
209 		return -EINVAL;
210 	}
211 
212 	dma_unmap_single(sdcp->dev, desc_phys, sizeof(*desc), DMA_TO_DEVICE);
213 
214 	return 0;
215 }
216 
217 /*
218  * Encryption (AES128)
219  */
220 static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
221 			   struct skcipher_request *req, int init)
222 {
223 	dma_addr_t key_phys, src_phys, dst_phys;
224 	struct dcp *sdcp = global_sdcp;
225 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
226 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
227 	int ret;
228 
229 	key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
230 				  2 * AES_KEYSIZE_128, DMA_TO_DEVICE);
231 	ret = dma_mapping_error(sdcp->dev, key_phys);
232 	if (ret)
233 		return ret;
234 
235 	src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
236 				  DCP_BUF_SZ, DMA_TO_DEVICE);
237 	ret = dma_mapping_error(sdcp->dev, src_phys);
238 	if (ret)
239 		goto err_src;
240 
241 	dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
242 				  DCP_BUF_SZ, DMA_FROM_DEVICE);
243 	ret = dma_mapping_error(sdcp->dev, dst_phys);
244 	if (ret)
245 		goto err_dst;
246 
247 	if (actx->fill % AES_BLOCK_SIZE) {
248 		dev_err(sdcp->dev, "Invalid block size!\n");
249 		ret = -EINVAL;
250 		goto aes_done_run;
251 	}
252 
253 	/* Fill in the DMA descriptor. */
254 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
255 		    MXS_DCP_CONTROL0_INTERRUPT |
256 		    MXS_DCP_CONTROL0_ENABLE_CIPHER;
257 
258 	/* Payload contains the key. */
259 	desc->control0 |= MXS_DCP_CONTROL0_PAYLOAD_KEY;
260 
261 	if (rctx->enc)
262 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_ENCRYPT;
263 	if (init)
264 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_INIT;
265 
266 	desc->control1 = MXS_DCP_CONTROL1_CIPHER_SELECT_AES128;
267 
268 	if (rctx->ecb)
269 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_ECB;
270 	else
271 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_CBC;
272 
273 	desc->next_cmd_addr = 0;
274 	desc->source = src_phys;
275 	desc->destination = dst_phys;
276 	desc->size = actx->fill;
277 	desc->payload = key_phys;
278 	desc->status = 0;
279 
280 	ret = mxs_dcp_start_dma(actx);
281 
282 aes_done_run:
283 	dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
284 err_dst:
285 	dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
286 err_src:
287 	dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
288 			 DMA_TO_DEVICE);
289 
290 	return ret;
291 }
292 
293 static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
294 {
295 	struct dcp *sdcp = global_sdcp;
296 
297 	struct skcipher_request *req = skcipher_request_cast(arq);
298 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
299 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
300 
301 	struct scatterlist *dst = req->dst;
302 	struct scatterlist *src = req->src;
303 	int dst_nents = sg_nents(dst);
304 
305 	const int out_off = DCP_BUF_SZ;
306 	uint8_t *in_buf = sdcp->coh->aes_in_buf;
307 	uint8_t *out_buf = sdcp->coh->aes_out_buf;
308 
309 	uint32_t dst_off = 0;
310 	uint8_t *src_buf = NULL;
311 	uint32_t last_out_len = 0;
312 
313 	uint8_t *key = sdcp->coh->aes_key;
314 
315 	int ret = 0;
316 	unsigned int i, len, clen, tlen = 0;
317 	int init = 0;
318 	bool limit_hit = false;
319 
320 	actx->fill = 0;
321 
322 	/* Copy the key from the temporary location. */
323 	memcpy(key, actx->key, actx->key_len);
324 
325 	if (!rctx->ecb) {
326 		/* Copy the CBC IV just past the key. */
327 		memcpy(key + AES_KEYSIZE_128, req->iv, AES_KEYSIZE_128);
328 		/* CBC needs the INIT set. */
329 		init = 1;
330 	} else {
331 		memset(key + AES_KEYSIZE_128, 0, AES_KEYSIZE_128);
332 	}
333 
334 	for_each_sg(req->src, src, sg_nents(src), i) {
335 		src_buf = sg_virt(src);
336 		len = sg_dma_len(src);
337 		tlen += len;
338 		limit_hit = tlen > req->cryptlen;
339 
340 		if (limit_hit)
341 			len = req->cryptlen - (tlen - len);
342 
343 		do {
344 			if (actx->fill + len > out_off)
345 				clen = out_off - actx->fill;
346 			else
347 				clen = len;
348 
349 			memcpy(in_buf + actx->fill, src_buf, clen);
350 			len -= clen;
351 			src_buf += clen;
352 			actx->fill += clen;
353 
354 			/*
355 			 * If we filled the buffer or this is the last SG,
356 			 * submit the buffer.
357 			 */
358 			if (actx->fill == out_off || sg_is_last(src) ||
359 			    limit_hit) {
360 				ret = mxs_dcp_run_aes(actx, req, init);
361 				if (ret)
362 					return ret;
363 				init = 0;
364 
365 				sg_pcopy_from_buffer(dst, dst_nents, out_buf,
366 						     actx->fill, dst_off);
367 				dst_off += actx->fill;
368 				last_out_len = actx->fill;
369 				actx->fill = 0;
370 			}
371 		} while (len);
372 
373 		if (limit_hit)
374 			break;
375 	}
376 
377 	/* Copy the IV for CBC for chaining */
378 	if (!rctx->ecb) {
379 		if (rctx->enc)
380 			memcpy(req->iv, out_buf+(last_out_len-AES_BLOCK_SIZE),
381 				AES_BLOCK_SIZE);
382 		else
383 			memcpy(req->iv, in_buf+(last_out_len-AES_BLOCK_SIZE),
384 				AES_BLOCK_SIZE);
385 	}
386 
387 	return ret;
388 }
389 
390 static int dcp_chan_thread_aes(void *data)
391 {
392 	struct dcp *sdcp = global_sdcp;
393 	const int chan = DCP_CHAN_CRYPTO;
394 
395 	struct crypto_async_request *backlog;
396 	struct crypto_async_request *arq;
397 
398 	int ret;
399 
400 	while (!kthread_should_stop()) {
401 		set_current_state(TASK_INTERRUPTIBLE);
402 
403 		spin_lock(&sdcp->lock[chan]);
404 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
405 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
406 		spin_unlock(&sdcp->lock[chan]);
407 
408 		if (!backlog && !arq) {
409 			schedule();
410 			continue;
411 		}
412 
413 		set_current_state(TASK_RUNNING);
414 
415 		if (backlog)
416 			backlog->complete(backlog, -EINPROGRESS);
417 
418 		if (arq) {
419 			ret = mxs_dcp_aes_block_crypt(arq);
420 			arq->complete(arq, ret);
421 		}
422 	}
423 
424 	return 0;
425 }
426 
427 static int mxs_dcp_block_fallback(struct skcipher_request *req, int enc)
428 {
429 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
430 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
431 	struct dcp_async_ctx *ctx = crypto_skcipher_ctx(tfm);
432 	int ret;
433 
434 	skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
435 	skcipher_request_set_callback(&rctx->fallback_req, req->base.flags,
436 				      req->base.complete, req->base.data);
437 	skcipher_request_set_crypt(&rctx->fallback_req, req->src, req->dst,
438 				   req->cryptlen, req->iv);
439 
440 	if (enc)
441 		ret = crypto_skcipher_encrypt(&rctx->fallback_req);
442 	else
443 		ret = crypto_skcipher_decrypt(&rctx->fallback_req);
444 
445 	return ret;
446 }
447 
448 static int mxs_dcp_aes_enqueue(struct skcipher_request *req, int enc, int ecb)
449 {
450 	struct dcp *sdcp = global_sdcp;
451 	struct crypto_async_request *arq = &req->base;
452 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
453 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
454 	int ret;
455 
456 	if (unlikely(actx->key_len != AES_KEYSIZE_128))
457 		return mxs_dcp_block_fallback(req, enc);
458 
459 	rctx->enc = enc;
460 	rctx->ecb = ecb;
461 	actx->chan = DCP_CHAN_CRYPTO;
462 
463 	spin_lock(&sdcp->lock[actx->chan]);
464 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
465 	spin_unlock(&sdcp->lock[actx->chan]);
466 
467 	wake_up_process(sdcp->thread[actx->chan]);
468 
469 	return ret;
470 }
471 
472 static int mxs_dcp_aes_ecb_decrypt(struct skcipher_request *req)
473 {
474 	return mxs_dcp_aes_enqueue(req, 0, 1);
475 }
476 
477 static int mxs_dcp_aes_ecb_encrypt(struct skcipher_request *req)
478 {
479 	return mxs_dcp_aes_enqueue(req, 1, 1);
480 }
481 
482 static int mxs_dcp_aes_cbc_decrypt(struct skcipher_request *req)
483 {
484 	return mxs_dcp_aes_enqueue(req, 0, 0);
485 }
486 
487 static int mxs_dcp_aes_cbc_encrypt(struct skcipher_request *req)
488 {
489 	return mxs_dcp_aes_enqueue(req, 1, 0);
490 }
491 
492 static int mxs_dcp_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
493 			      unsigned int len)
494 {
495 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
496 
497 	/*
498 	 * AES 128 is supposed by the hardware, store key into temporary
499 	 * buffer and exit. We must use the temporary buffer here, since
500 	 * there can still be an operation in progress.
501 	 */
502 	actx->key_len = len;
503 	if (len == AES_KEYSIZE_128) {
504 		memcpy(actx->key, key, len);
505 		return 0;
506 	}
507 
508 	/*
509 	 * If the requested AES key size is not supported by the hardware,
510 	 * but is supported by in-kernel software implementation, we use
511 	 * software fallback.
512 	 */
513 	crypto_skcipher_clear_flags(actx->fallback, CRYPTO_TFM_REQ_MASK);
514 	crypto_skcipher_set_flags(actx->fallback,
515 				  tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
516 	return crypto_skcipher_setkey(actx->fallback, key, len);
517 }
518 
519 static int mxs_dcp_aes_fallback_init_tfm(struct crypto_skcipher *tfm)
520 {
521 	const char *name = crypto_tfm_alg_name(crypto_skcipher_tfm(tfm));
522 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
523 	struct crypto_skcipher *blk;
524 
525 	blk = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
526 	if (IS_ERR(blk))
527 		return PTR_ERR(blk);
528 
529 	actx->fallback = blk;
530 	crypto_skcipher_set_reqsize(tfm, sizeof(struct dcp_aes_req_ctx) +
531 					 crypto_skcipher_reqsize(blk));
532 	return 0;
533 }
534 
535 static void mxs_dcp_aes_fallback_exit_tfm(struct crypto_skcipher *tfm)
536 {
537 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
538 
539 	crypto_free_skcipher(actx->fallback);
540 }
541 
542 /*
543  * Hashing (SHA1/SHA256)
544  */
545 static int mxs_dcp_run_sha(struct ahash_request *req)
546 {
547 	struct dcp *sdcp = global_sdcp;
548 	int ret;
549 
550 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
551 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
552 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
553 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
554 
555 	dma_addr_t digest_phys = 0;
556 	dma_addr_t buf_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_in_buf,
557 					     DCP_BUF_SZ, DMA_TO_DEVICE);
558 
559 	ret = dma_mapping_error(sdcp->dev, buf_phys);
560 	if (ret)
561 		return ret;
562 
563 	/* Fill in the DMA descriptor. */
564 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
565 		    MXS_DCP_CONTROL0_INTERRUPT |
566 		    MXS_DCP_CONTROL0_ENABLE_HASH;
567 	if (rctx->init)
568 		desc->control0 |= MXS_DCP_CONTROL0_HASH_INIT;
569 
570 	desc->control1 = actx->alg;
571 	desc->next_cmd_addr = 0;
572 	desc->source = buf_phys;
573 	desc->destination = 0;
574 	desc->size = actx->fill;
575 	desc->payload = 0;
576 	desc->status = 0;
577 
578 	/*
579 	 * Align driver with hw behavior when generating null hashes
580 	 */
581 	if (rctx->init && rctx->fini && desc->size == 0) {
582 		struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
583 		const uint8_t *sha_buf =
584 			(actx->alg == MXS_DCP_CONTROL1_HASH_SELECT_SHA1) ?
585 			sha1_null_hash : sha256_null_hash;
586 		memcpy(sdcp->coh->sha_out_buf, sha_buf, halg->digestsize);
587 		ret = 0;
588 		goto done_run;
589 	}
590 
591 	/* Set HASH_TERM bit for last transfer block. */
592 	if (rctx->fini) {
593 		digest_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_out_buf,
594 					     DCP_SHA_PAY_SZ, DMA_FROM_DEVICE);
595 		ret = dma_mapping_error(sdcp->dev, digest_phys);
596 		if (ret)
597 			goto done_run;
598 
599 		desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
600 		desc->payload = digest_phys;
601 	}
602 
603 	ret = mxs_dcp_start_dma(actx);
604 
605 	if (rctx->fini)
606 		dma_unmap_single(sdcp->dev, digest_phys, DCP_SHA_PAY_SZ,
607 				 DMA_FROM_DEVICE);
608 
609 done_run:
610 	dma_unmap_single(sdcp->dev, buf_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
611 
612 	return ret;
613 }
614 
615 static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
616 {
617 	struct dcp *sdcp = global_sdcp;
618 
619 	struct ahash_request *req = ahash_request_cast(arq);
620 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
621 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
622 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
623 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
624 
625 	uint8_t *in_buf = sdcp->coh->sha_in_buf;
626 	uint8_t *out_buf = sdcp->coh->sha_out_buf;
627 
628 	struct scatterlist *src;
629 
630 	unsigned int i, len, clen, oft = 0;
631 	int ret;
632 
633 	int fin = rctx->fini;
634 	if (fin)
635 		rctx->fini = 0;
636 
637 	src = req->src;
638 	len = req->nbytes;
639 
640 	while (len) {
641 		if (actx->fill + len > DCP_BUF_SZ)
642 			clen = DCP_BUF_SZ - actx->fill;
643 		else
644 			clen = len;
645 
646 		scatterwalk_map_and_copy(in_buf + actx->fill, src, oft, clen,
647 					 0);
648 
649 		len -= clen;
650 		oft += clen;
651 		actx->fill += clen;
652 
653 		/*
654 		 * If we filled the buffer and still have some
655 		 * more data, submit the buffer.
656 		 */
657 		if (len && actx->fill == DCP_BUF_SZ) {
658 			ret = mxs_dcp_run_sha(req);
659 			if (ret)
660 				return ret;
661 			actx->fill = 0;
662 			rctx->init = 0;
663 		}
664 	}
665 
666 	if (fin) {
667 		rctx->fini = 1;
668 
669 		/* Submit whatever is left. */
670 		if (!req->result)
671 			return -EINVAL;
672 
673 		ret = mxs_dcp_run_sha(req);
674 		if (ret)
675 			return ret;
676 
677 		actx->fill = 0;
678 
679 		/* For some reason the result is flipped */
680 		for (i = 0; i < halg->digestsize; i++)
681 			req->result[i] = out_buf[halg->digestsize - i - 1];
682 	}
683 
684 	return 0;
685 }
686 
687 static int dcp_chan_thread_sha(void *data)
688 {
689 	struct dcp *sdcp = global_sdcp;
690 	const int chan = DCP_CHAN_HASH_SHA;
691 
692 	struct crypto_async_request *backlog;
693 	struct crypto_async_request *arq;
694 	int ret;
695 
696 	while (!kthread_should_stop()) {
697 		set_current_state(TASK_INTERRUPTIBLE);
698 
699 		spin_lock(&sdcp->lock[chan]);
700 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
701 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
702 		spin_unlock(&sdcp->lock[chan]);
703 
704 		if (!backlog && !arq) {
705 			schedule();
706 			continue;
707 		}
708 
709 		set_current_state(TASK_RUNNING);
710 
711 		if (backlog)
712 			backlog->complete(backlog, -EINPROGRESS);
713 
714 		if (arq) {
715 			ret = dcp_sha_req_to_buf(arq);
716 			arq->complete(arq, ret);
717 		}
718 	}
719 
720 	return 0;
721 }
722 
723 static int dcp_sha_init(struct ahash_request *req)
724 {
725 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
726 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
727 
728 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
729 
730 	/*
731 	 * Start hashing session. The code below only inits the
732 	 * hashing session context, nothing more.
733 	 */
734 	memset(actx, 0, sizeof(*actx));
735 
736 	if (strcmp(halg->base.cra_name, "sha1") == 0)
737 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA1;
738 	else
739 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA256;
740 
741 	actx->fill = 0;
742 	actx->hot = 0;
743 	actx->chan = DCP_CHAN_HASH_SHA;
744 
745 	mutex_init(&actx->mutex);
746 
747 	return 0;
748 }
749 
750 static int dcp_sha_update_fx(struct ahash_request *req, int fini)
751 {
752 	struct dcp *sdcp = global_sdcp;
753 
754 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
755 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
756 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
757 
758 	int ret;
759 
760 	/*
761 	 * Ignore requests that have no data in them and are not
762 	 * the trailing requests in the stream of requests.
763 	 */
764 	if (!req->nbytes && !fini)
765 		return 0;
766 
767 	mutex_lock(&actx->mutex);
768 
769 	rctx->fini = fini;
770 
771 	if (!actx->hot) {
772 		actx->hot = 1;
773 		rctx->init = 1;
774 	}
775 
776 	spin_lock(&sdcp->lock[actx->chan]);
777 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
778 	spin_unlock(&sdcp->lock[actx->chan]);
779 
780 	wake_up_process(sdcp->thread[actx->chan]);
781 	mutex_unlock(&actx->mutex);
782 
783 	return ret;
784 }
785 
786 static int dcp_sha_update(struct ahash_request *req)
787 {
788 	return dcp_sha_update_fx(req, 0);
789 }
790 
791 static int dcp_sha_final(struct ahash_request *req)
792 {
793 	ahash_request_set_crypt(req, NULL, req->result, 0);
794 	req->nbytes = 0;
795 	return dcp_sha_update_fx(req, 1);
796 }
797 
798 static int dcp_sha_finup(struct ahash_request *req)
799 {
800 	return dcp_sha_update_fx(req, 1);
801 }
802 
803 static int dcp_sha_digest(struct ahash_request *req)
804 {
805 	int ret;
806 
807 	ret = dcp_sha_init(req);
808 	if (ret)
809 		return ret;
810 
811 	return dcp_sha_finup(req);
812 }
813 
814 static int dcp_sha_import(struct ahash_request *req, const void *in)
815 {
816 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
817 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
818 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
819 	const struct dcp_export_state *export = in;
820 
821 	memset(rctx, 0, sizeof(struct dcp_sha_req_ctx));
822 	memset(actx, 0, sizeof(struct dcp_async_ctx));
823 	memcpy(rctx, &export->req_ctx, sizeof(struct dcp_sha_req_ctx));
824 	memcpy(actx, &export->async_ctx, sizeof(struct dcp_async_ctx));
825 
826 	return 0;
827 }
828 
829 static int dcp_sha_export(struct ahash_request *req, void *out)
830 {
831 	struct dcp_sha_req_ctx *rctx_state = ahash_request_ctx(req);
832 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
833 	struct dcp_async_ctx *actx_state = crypto_ahash_ctx(tfm);
834 	struct dcp_export_state *export = out;
835 
836 	memcpy(&export->req_ctx, rctx_state, sizeof(struct dcp_sha_req_ctx));
837 	memcpy(&export->async_ctx, actx_state, sizeof(struct dcp_async_ctx));
838 
839 	return 0;
840 }
841 
842 static int dcp_sha_cra_init(struct crypto_tfm *tfm)
843 {
844 	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
845 				 sizeof(struct dcp_sha_req_ctx));
846 	return 0;
847 }
848 
849 static void dcp_sha_cra_exit(struct crypto_tfm *tfm)
850 {
851 }
852 
853 /* AES 128 ECB and AES 128 CBC */
854 static struct skcipher_alg dcp_aes_algs[] = {
855 	{
856 		.base.cra_name		= "ecb(aes)",
857 		.base.cra_driver_name	= "ecb-aes-dcp",
858 		.base.cra_priority	= 400,
859 		.base.cra_alignmask	= 15,
860 		.base.cra_flags		= CRYPTO_ALG_ASYNC |
861 					  CRYPTO_ALG_NEED_FALLBACK,
862 		.base.cra_blocksize	= AES_BLOCK_SIZE,
863 		.base.cra_ctxsize	= sizeof(struct dcp_async_ctx),
864 		.base.cra_module	= THIS_MODULE,
865 
866 		.min_keysize		= AES_MIN_KEY_SIZE,
867 		.max_keysize		= AES_MAX_KEY_SIZE,
868 		.setkey			= mxs_dcp_aes_setkey,
869 		.encrypt		= mxs_dcp_aes_ecb_encrypt,
870 		.decrypt		= mxs_dcp_aes_ecb_decrypt,
871 		.init			= mxs_dcp_aes_fallback_init_tfm,
872 		.exit			= mxs_dcp_aes_fallback_exit_tfm,
873 	}, {
874 		.base.cra_name		= "cbc(aes)",
875 		.base.cra_driver_name	= "cbc-aes-dcp",
876 		.base.cra_priority	= 400,
877 		.base.cra_alignmask	= 15,
878 		.base.cra_flags		= CRYPTO_ALG_ASYNC |
879 					  CRYPTO_ALG_NEED_FALLBACK,
880 		.base.cra_blocksize	= AES_BLOCK_SIZE,
881 		.base.cra_ctxsize	= sizeof(struct dcp_async_ctx),
882 		.base.cra_module	= THIS_MODULE,
883 
884 		.min_keysize		= AES_MIN_KEY_SIZE,
885 		.max_keysize		= AES_MAX_KEY_SIZE,
886 		.setkey			= mxs_dcp_aes_setkey,
887 		.encrypt		= mxs_dcp_aes_cbc_encrypt,
888 		.decrypt		= mxs_dcp_aes_cbc_decrypt,
889 		.ivsize			= AES_BLOCK_SIZE,
890 		.init			= mxs_dcp_aes_fallback_init_tfm,
891 		.exit			= mxs_dcp_aes_fallback_exit_tfm,
892 	},
893 };
894 
895 /* SHA1 */
896 static struct ahash_alg dcp_sha1_alg = {
897 	.init	= dcp_sha_init,
898 	.update	= dcp_sha_update,
899 	.final	= dcp_sha_final,
900 	.finup	= dcp_sha_finup,
901 	.digest	= dcp_sha_digest,
902 	.import = dcp_sha_import,
903 	.export = dcp_sha_export,
904 	.halg	= {
905 		.digestsize	= SHA1_DIGEST_SIZE,
906 		.statesize	= sizeof(struct dcp_export_state),
907 		.base		= {
908 			.cra_name		= "sha1",
909 			.cra_driver_name	= "sha1-dcp",
910 			.cra_priority		= 400,
911 			.cra_alignmask		= 63,
912 			.cra_flags		= CRYPTO_ALG_ASYNC,
913 			.cra_blocksize		= SHA1_BLOCK_SIZE,
914 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
915 			.cra_module		= THIS_MODULE,
916 			.cra_init		= dcp_sha_cra_init,
917 			.cra_exit		= dcp_sha_cra_exit,
918 		},
919 	},
920 };
921 
922 /* SHA256 */
923 static struct ahash_alg dcp_sha256_alg = {
924 	.init	= dcp_sha_init,
925 	.update	= dcp_sha_update,
926 	.final	= dcp_sha_final,
927 	.finup	= dcp_sha_finup,
928 	.digest	= dcp_sha_digest,
929 	.import = dcp_sha_import,
930 	.export = dcp_sha_export,
931 	.halg	= {
932 		.digestsize	= SHA256_DIGEST_SIZE,
933 		.statesize	= sizeof(struct dcp_export_state),
934 		.base		= {
935 			.cra_name		= "sha256",
936 			.cra_driver_name	= "sha256-dcp",
937 			.cra_priority		= 400,
938 			.cra_alignmask		= 63,
939 			.cra_flags		= CRYPTO_ALG_ASYNC,
940 			.cra_blocksize		= SHA256_BLOCK_SIZE,
941 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
942 			.cra_module		= THIS_MODULE,
943 			.cra_init		= dcp_sha_cra_init,
944 			.cra_exit		= dcp_sha_cra_exit,
945 		},
946 	},
947 };
948 
949 static irqreturn_t mxs_dcp_irq(int irq, void *context)
950 {
951 	struct dcp *sdcp = context;
952 	uint32_t stat;
953 	int i;
954 
955 	stat = readl(sdcp->base + MXS_DCP_STAT);
956 	stat &= MXS_DCP_STAT_IRQ_MASK;
957 	if (!stat)
958 		return IRQ_NONE;
959 
960 	/* Clear the interrupts. */
961 	writel(stat, sdcp->base + MXS_DCP_STAT_CLR);
962 
963 	/* Complete the DMA requests that finished. */
964 	for (i = 0; i < DCP_MAX_CHANS; i++)
965 		if (stat & (1 << i))
966 			complete(&sdcp->completion[i]);
967 
968 	return IRQ_HANDLED;
969 }
970 
971 static int mxs_dcp_probe(struct platform_device *pdev)
972 {
973 	struct device *dev = &pdev->dev;
974 	struct dcp *sdcp = NULL;
975 	int i, ret;
976 	int dcp_vmi_irq, dcp_irq;
977 
978 	if (global_sdcp) {
979 		dev_err(dev, "Only one DCP instance allowed!\n");
980 		return -ENODEV;
981 	}
982 
983 	dcp_vmi_irq = platform_get_irq(pdev, 0);
984 	if (dcp_vmi_irq < 0)
985 		return dcp_vmi_irq;
986 
987 	dcp_irq = platform_get_irq(pdev, 1);
988 	if (dcp_irq < 0)
989 		return dcp_irq;
990 
991 	sdcp = devm_kzalloc(dev, sizeof(*sdcp), GFP_KERNEL);
992 	if (!sdcp)
993 		return -ENOMEM;
994 
995 	sdcp->dev = dev;
996 	sdcp->base = devm_platform_ioremap_resource(pdev, 0);
997 	if (IS_ERR(sdcp->base))
998 		return PTR_ERR(sdcp->base);
999 
1000 
1001 	ret = devm_request_irq(dev, dcp_vmi_irq, mxs_dcp_irq, 0,
1002 			       "dcp-vmi-irq", sdcp);
1003 	if (ret) {
1004 		dev_err(dev, "Failed to claim DCP VMI IRQ!\n");
1005 		return ret;
1006 	}
1007 
1008 	ret = devm_request_irq(dev, dcp_irq, mxs_dcp_irq, 0,
1009 			       "dcp-irq", sdcp);
1010 	if (ret) {
1011 		dev_err(dev, "Failed to claim DCP IRQ!\n");
1012 		return ret;
1013 	}
1014 
1015 	/* Allocate coherent helper block. */
1016 	sdcp->coh = devm_kzalloc(dev, sizeof(*sdcp->coh) + DCP_ALIGNMENT,
1017 				   GFP_KERNEL);
1018 	if (!sdcp->coh)
1019 		return -ENOMEM;
1020 
1021 	/* Re-align the structure so it fits the DCP constraints. */
1022 	sdcp->coh = PTR_ALIGN(sdcp->coh, DCP_ALIGNMENT);
1023 
1024 	/* DCP clock is optional, only used on some SOCs */
1025 	sdcp->dcp_clk = devm_clk_get(dev, "dcp");
1026 	if (IS_ERR(sdcp->dcp_clk)) {
1027 		if (sdcp->dcp_clk != ERR_PTR(-ENOENT))
1028 			return PTR_ERR(sdcp->dcp_clk);
1029 		sdcp->dcp_clk = NULL;
1030 	}
1031 	ret = clk_prepare_enable(sdcp->dcp_clk);
1032 	if (ret)
1033 		return ret;
1034 
1035 	/* Restart the DCP block. */
1036 	ret = stmp_reset_block(sdcp->base);
1037 	if (ret) {
1038 		dev_err(dev, "Failed reset\n");
1039 		goto err_disable_unprepare_clk;
1040 	}
1041 
1042 	/* Initialize control register. */
1043 	writel(MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES |
1044 	       MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING | 0xf,
1045 	       sdcp->base + MXS_DCP_CTRL);
1046 
1047 	/* Enable all DCP DMA channels. */
1048 	writel(MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK,
1049 	       sdcp->base + MXS_DCP_CHANNELCTRL);
1050 
1051 	/*
1052 	 * We do not enable context switching. Give the context buffer a
1053 	 * pointer to an illegal address so if context switching is
1054 	 * inadvertantly enabled, the DCP will return an error instead of
1055 	 * trashing good memory. The DCP DMA cannot access ROM, so any ROM
1056 	 * address will do.
1057 	 */
1058 	writel(0xffff0000, sdcp->base + MXS_DCP_CONTEXT);
1059 	for (i = 0; i < DCP_MAX_CHANS; i++)
1060 		writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(i));
1061 	writel(0xffffffff, sdcp->base + MXS_DCP_STAT_CLR);
1062 
1063 	global_sdcp = sdcp;
1064 
1065 	platform_set_drvdata(pdev, sdcp);
1066 
1067 	for (i = 0; i < DCP_MAX_CHANS; i++) {
1068 		spin_lock_init(&sdcp->lock[i]);
1069 		init_completion(&sdcp->completion[i]);
1070 		crypto_init_queue(&sdcp->queue[i], 50);
1071 	}
1072 
1073 	/* Create the SHA and AES handler threads. */
1074 	sdcp->thread[DCP_CHAN_HASH_SHA] = kthread_run(dcp_chan_thread_sha,
1075 						      NULL, "mxs_dcp_chan/sha");
1076 	if (IS_ERR(sdcp->thread[DCP_CHAN_HASH_SHA])) {
1077 		dev_err(dev, "Error starting SHA thread!\n");
1078 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_HASH_SHA]);
1079 		goto err_disable_unprepare_clk;
1080 	}
1081 
1082 	sdcp->thread[DCP_CHAN_CRYPTO] = kthread_run(dcp_chan_thread_aes,
1083 						    NULL, "mxs_dcp_chan/aes");
1084 	if (IS_ERR(sdcp->thread[DCP_CHAN_CRYPTO])) {
1085 		dev_err(dev, "Error starting SHA thread!\n");
1086 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_CRYPTO]);
1087 		goto err_destroy_sha_thread;
1088 	}
1089 
1090 	/* Register the various crypto algorithms. */
1091 	sdcp->caps = readl(sdcp->base + MXS_DCP_CAPABILITY1);
1092 
1093 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128) {
1094 		ret = crypto_register_skciphers(dcp_aes_algs,
1095 						ARRAY_SIZE(dcp_aes_algs));
1096 		if (ret) {
1097 			/* Failed to register algorithm. */
1098 			dev_err(dev, "Failed to register AES crypto!\n");
1099 			goto err_destroy_aes_thread;
1100 		}
1101 	}
1102 
1103 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1) {
1104 		ret = crypto_register_ahash(&dcp_sha1_alg);
1105 		if (ret) {
1106 			dev_err(dev, "Failed to register %s hash!\n",
1107 				dcp_sha1_alg.halg.base.cra_name);
1108 			goto err_unregister_aes;
1109 		}
1110 	}
1111 
1112 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256) {
1113 		ret = crypto_register_ahash(&dcp_sha256_alg);
1114 		if (ret) {
1115 			dev_err(dev, "Failed to register %s hash!\n",
1116 				dcp_sha256_alg.halg.base.cra_name);
1117 			goto err_unregister_sha1;
1118 		}
1119 	}
1120 
1121 	return 0;
1122 
1123 err_unregister_sha1:
1124 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1125 		crypto_unregister_ahash(&dcp_sha1_alg);
1126 
1127 err_unregister_aes:
1128 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1129 		crypto_unregister_skciphers(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1130 
1131 err_destroy_aes_thread:
1132 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1133 
1134 err_destroy_sha_thread:
1135 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1136 
1137 err_disable_unprepare_clk:
1138 	clk_disable_unprepare(sdcp->dcp_clk);
1139 
1140 	return ret;
1141 }
1142 
1143 static int mxs_dcp_remove(struct platform_device *pdev)
1144 {
1145 	struct dcp *sdcp = platform_get_drvdata(pdev);
1146 
1147 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256)
1148 		crypto_unregister_ahash(&dcp_sha256_alg);
1149 
1150 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1151 		crypto_unregister_ahash(&dcp_sha1_alg);
1152 
1153 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1154 		crypto_unregister_skciphers(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1155 
1156 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1157 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1158 
1159 	clk_disable_unprepare(sdcp->dcp_clk);
1160 
1161 	platform_set_drvdata(pdev, NULL);
1162 
1163 	global_sdcp = NULL;
1164 
1165 	return 0;
1166 }
1167 
1168 static const struct of_device_id mxs_dcp_dt_ids[] = {
1169 	{ .compatible = "fsl,imx23-dcp", .data = NULL, },
1170 	{ .compatible = "fsl,imx28-dcp", .data = NULL, },
1171 	{ /* sentinel */ }
1172 };
1173 
1174 MODULE_DEVICE_TABLE(of, mxs_dcp_dt_ids);
1175 
1176 static struct platform_driver mxs_dcp_driver = {
1177 	.probe	= mxs_dcp_probe,
1178 	.remove	= mxs_dcp_remove,
1179 	.driver	= {
1180 		.name		= "mxs-dcp",
1181 		.of_match_table	= mxs_dcp_dt_ids,
1182 	},
1183 };
1184 
1185 module_platform_driver(mxs_dcp_driver);
1186 
1187 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1188 MODULE_DESCRIPTION("Freescale MXS DCP Driver");
1189 MODULE_LICENSE("GPL");
1190 MODULE_ALIAS("platform:mxs-dcp");
1191