xref: /linux/drivers/crypto/mxs-dcp.c (revision 37744feebc086908fd89760650f458ab19071750)
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/sha.h>
21 #include <crypto/internal/hash.h>
22 #include <crypto/internal/skcipher.h>
23 #include <crypto/scatterwalk.h>
24 
25 #define DCP_MAX_CHANS	4
26 #define DCP_BUF_SZ	PAGE_SIZE
27 #define DCP_SHA_PAY_SZ  64
28 
29 #define DCP_ALIGNMENT	64
30 
31 /*
32  * Null hashes to align with hw behavior on imx6sl and ull
33  * these are flipped for consistency with hw output
34  */
35 static const uint8_t sha1_null_hash[] =
36 	"\x09\x07\xd8\xaf\x90\x18\x60\x95\xef\xbf"
37 	"\x55\x32\x0d\x4b\x6b\x5e\xee\xa3\x39\xda";
38 
39 static const uint8_t sha256_null_hash[] =
40 	"\x55\xb8\x52\x78\x1b\x99\x95\xa4"
41 	"\x4c\x93\x9b\x64\xe4\x41\xae\x27"
42 	"\x24\xb9\x6f\x99\xc8\xf4\xfb\x9a"
43 	"\x14\x1c\xfc\x98\x42\xc4\xb0\xe3";
44 
45 /* DCP DMA descriptor. */
46 struct dcp_dma_desc {
47 	uint32_t	next_cmd_addr;
48 	uint32_t	control0;
49 	uint32_t	control1;
50 	uint32_t	source;
51 	uint32_t	destination;
52 	uint32_t	size;
53 	uint32_t	payload;
54 	uint32_t	status;
55 };
56 
57 /* Coherent aligned block for bounce buffering. */
58 struct dcp_coherent_block {
59 	uint8_t			aes_in_buf[DCP_BUF_SZ];
60 	uint8_t			aes_out_buf[DCP_BUF_SZ];
61 	uint8_t			sha_in_buf[DCP_BUF_SZ];
62 	uint8_t			sha_out_buf[DCP_SHA_PAY_SZ];
63 
64 	uint8_t			aes_key[2 * AES_KEYSIZE_128];
65 
66 	struct dcp_dma_desc	desc[DCP_MAX_CHANS];
67 };
68 
69 struct dcp {
70 	struct device			*dev;
71 	void __iomem			*base;
72 
73 	uint32_t			caps;
74 
75 	struct dcp_coherent_block	*coh;
76 
77 	struct completion		completion[DCP_MAX_CHANS];
78 	spinlock_t			lock[DCP_MAX_CHANS];
79 	struct task_struct		*thread[DCP_MAX_CHANS];
80 	struct crypto_queue		queue[DCP_MAX_CHANS];
81 	struct clk			*dcp_clk;
82 };
83 
84 enum dcp_chan {
85 	DCP_CHAN_HASH_SHA	= 0,
86 	DCP_CHAN_CRYPTO		= 2,
87 };
88 
89 struct dcp_async_ctx {
90 	/* Common context */
91 	enum dcp_chan	chan;
92 	uint32_t	fill;
93 
94 	/* SHA Hash-specific context */
95 	struct mutex			mutex;
96 	uint32_t			alg;
97 	unsigned int			hot:1;
98 
99 	/* Crypto-specific context */
100 	struct crypto_sync_skcipher	*fallback;
101 	unsigned int			key_len;
102 	uint8_t				key[AES_KEYSIZE_128];
103 };
104 
105 struct dcp_aes_req_ctx {
106 	unsigned int	enc:1;
107 	unsigned int	ecb:1;
108 };
109 
110 struct dcp_sha_req_ctx {
111 	unsigned int	init:1;
112 	unsigned int	fini:1;
113 };
114 
115 struct dcp_export_state {
116 	struct dcp_sha_req_ctx req_ctx;
117 	struct dcp_async_ctx async_ctx;
118 };
119 
120 /*
121  * There can even be only one instance of the MXS DCP due to the
122  * design of Linux Crypto API.
123  */
124 static struct dcp *global_sdcp;
125 
126 /* DCP register layout. */
127 #define MXS_DCP_CTRL				0x00
128 #define MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES	(1 << 23)
129 #define MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING	(1 << 22)
130 
131 #define MXS_DCP_STAT				0x10
132 #define MXS_DCP_STAT_CLR			0x18
133 #define MXS_DCP_STAT_IRQ_MASK			0xf
134 
135 #define MXS_DCP_CHANNELCTRL			0x20
136 #define MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK	0xff
137 
138 #define MXS_DCP_CAPABILITY1			0x40
139 #define MXS_DCP_CAPABILITY1_SHA256		(4 << 16)
140 #define MXS_DCP_CAPABILITY1_SHA1		(1 << 16)
141 #define MXS_DCP_CAPABILITY1_AES128		(1 << 0)
142 
143 #define MXS_DCP_CONTEXT				0x50
144 
145 #define MXS_DCP_CH_N_CMDPTR(n)			(0x100 + ((n) * 0x40))
146 
147 #define MXS_DCP_CH_N_SEMA(n)			(0x110 + ((n) * 0x40))
148 
149 #define MXS_DCP_CH_N_STAT(n)			(0x120 + ((n) * 0x40))
150 #define MXS_DCP_CH_N_STAT_CLR(n)		(0x128 + ((n) * 0x40))
151 
152 /* DMA descriptor bits. */
153 #define MXS_DCP_CONTROL0_HASH_TERM		(1 << 13)
154 #define MXS_DCP_CONTROL0_HASH_INIT		(1 << 12)
155 #define MXS_DCP_CONTROL0_PAYLOAD_KEY		(1 << 11)
156 #define MXS_DCP_CONTROL0_CIPHER_ENCRYPT		(1 << 8)
157 #define MXS_DCP_CONTROL0_CIPHER_INIT		(1 << 9)
158 #define MXS_DCP_CONTROL0_ENABLE_HASH		(1 << 6)
159 #define MXS_DCP_CONTROL0_ENABLE_CIPHER		(1 << 5)
160 #define MXS_DCP_CONTROL0_DECR_SEMAPHORE		(1 << 1)
161 #define MXS_DCP_CONTROL0_INTERRUPT		(1 << 0)
162 
163 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA256	(2 << 16)
164 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA1	(0 << 16)
165 #define MXS_DCP_CONTROL1_CIPHER_MODE_CBC	(1 << 4)
166 #define MXS_DCP_CONTROL1_CIPHER_MODE_ECB	(0 << 4)
167 #define MXS_DCP_CONTROL1_CIPHER_SELECT_AES128	(0 << 0)
168 
169 static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
170 {
171 	struct dcp *sdcp = global_sdcp;
172 	const int chan = actx->chan;
173 	uint32_t stat;
174 	unsigned long ret;
175 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
176 
177 	dma_addr_t desc_phys = dma_map_single(sdcp->dev, desc, sizeof(*desc),
178 					      DMA_TO_DEVICE);
179 
180 	reinit_completion(&sdcp->completion[chan]);
181 
182 	/* Clear status register. */
183 	writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(chan));
184 
185 	/* Load the DMA descriptor. */
186 	writel(desc_phys, sdcp->base + MXS_DCP_CH_N_CMDPTR(chan));
187 
188 	/* Increment the semaphore to start the DMA transfer. */
189 	writel(1, sdcp->base + MXS_DCP_CH_N_SEMA(chan));
190 
191 	ret = wait_for_completion_timeout(&sdcp->completion[chan],
192 					  msecs_to_jiffies(1000));
193 	if (!ret) {
194 		dev_err(sdcp->dev, "Channel %i timeout (DCP_STAT=0x%08x)\n",
195 			chan, readl(sdcp->base + MXS_DCP_STAT));
196 		return -ETIMEDOUT;
197 	}
198 
199 	stat = readl(sdcp->base + MXS_DCP_CH_N_STAT(chan));
200 	if (stat & 0xff) {
201 		dev_err(sdcp->dev, "Channel %i error (CH_STAT=0x%08x)\n",
202 			chan, stat);
203 		return -EINVAL;
204 	}
205 
206 	dma_unmap_single(sdcp->dev, desc_phys, sizeof(*desc), DMA_TO_DEVICE);
207 
208 	return 0;
209 }
210 
211 /*
212  * Encryption (AES128)
213  */
214 static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
215 			   struct skcipher_request *req, int init)
216 {
217 	struct dcp *sdcp = global_sdcp;
218 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
219 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
220 	int ret;
221 
222 	dma_addr_t key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
223 					     2 * AES_KEYSIZE_128,
224 					     DMA_TO_DEVICE);
225 	dma_addr_t src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
226 					     DCP_BUF_SZ, DMA_TO_DEVICE);
227 	dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
228 					     DCP_BUF_SZ, DMA_FROM_DEVICE);
229 
230 	if (actx->fill % AES_BLOCK_SIZE) {
231 		dev_err(sdcp->dev, "Invalid block size!\n");
232 		ret = -EINVAL;
233 		goto aes_done_run;
234 	}
235 
236 	/* Fill in the DMA descriptor. */
237 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
238 		    MXS_DCP_CONTROL0_INTERRUPT |
239 		    MXS_DCP_CONTROL0_ENABLE_CIPHER;
240 
241 	/* Payload contains the key. */
242 	desc->control0 |= MXS_DCP_CONTROL0_PAYLOAD_KEY;
243 
244 	if (rctx->enc)
245 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_ENCRYPT;
246 	if (init)
247 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_INIT;
248 
249 	desc->control1 = MXS_DCP_CONTROL1_CIPHER_SELECT_AES128;
250 
251 	if (rctx->ecb)
252 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_ECB;
253 	else
254 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_CBC;
255 
256 	desc->next_cmd_addr = 0;
257 	desc->source = src_phys;
258 	desc->destination = dst_phys;
259 	desc->size = actx->fill;
260 	desc->payload = key_phys;
261 	desc->status = 0;
262 
263 	ret = mxs_dcp_start_dma(actx);
264 
265 aes_done_run:
266 	dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
267 			 DMA_TO_DEVICE);
268 	dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
269 	dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
270 
271 	return ret;
272 }
273 
274 static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
275 {
276 	struct dcp *sdcp = global_sdcp;
277 
278 	struct skcipher_request *req = skcipher_request_cast(arq);
279 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
280 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
281 
282 	struct scatterlist *dst = req->dst;
283 	struct scatterlist *src = req->src;
284 	const int nents = sg_nents(req->src);
285 
286 	const int out_off = DCP_BUF_SZ;
287 	uint8_t *in_buf = sdcp->coh->aes_in_buf;
288 	uint8_t *out_buf = sdcp->coh->aes_out_buf;
289 
290 	uint8_t *out_tmp, *src_buf, *dst_buf = NULL;
291 	uint32_t dst_off = 0;
292 	uint32_t last_out_len = 0;
293 
294 	uint8_t *key = sdcp->coh->aes_key;
295 
296 	int ret = 0;
297 	int split = 0;
298 	unsigned int i, len, clen, rem = 0, tlen = 0;
299 	int init = 0;
300 	bool limit_hit = false;
301 
302 	actx->fill = 0;
303 
304 	/* Copy the key from the temporary location. */
305 	memcpy(key, actx->key, actx->key_len);
306 
307 	if (!rctx->ecb) {
308 		/* Copy the CBC IV just past the key. */
309 		memcpy(key + AES_KEYSIZE_128, req->iv, AES_KEYSIZE_128);
310 		/* CBC needs the INIT set. */
311 		init = 1;
312 	} else {
313 		memset(key + AES_KEYSIZE_128, 0, AES_KEYSIZE_128);
314 	}
315 
316 	for_each_sg(req->src, src, nents, i) {
317 		src_buf = sg_virt(src);
318 		len = sg_dma_len(src);
319 		tlen += len;
320 		limit_hit = tlen > req->cryptlen;
321 
322 		if (limit_hit)
323 			len = req->cryptlen - (tlen - len);
324 
325 		do {
326 			if (actx->fill + len > out_off)
327 				clen = out_off - actx->fill;
328 			else
329 				clen = len;
330 
331 			memcpy(in_buf + actx->fill, src_buf, clen);
332 			len -= clen;
333 			src_buf += clen;
334 			actx->fill += clen;
335 
336 			/*
337 			 * If we filled the buffer or this is the last SG,
338 			 * submit the buffer.
339 			 */
340 			if (actx->fill == out_off || sg_is_last(src) ||
341 				limit_hit) {
342 				ret = mxs_dcp_run_aes(actx, req, init);
343 				if (ret)
344 					return ret;
345 				init = 0;
346 
347 				out_tmp = out_buf;
348 				last_out_len = actx->fill;
349 				while (dst && actx->fill) {
350 					if (!split) {
351 						dst_buf = sg_virt(dst);
352 						dst_off = 0;
353 					}
354 					rem = min(sg_dma_len(dst) - dst_off,
355 						  actx->fill);
356 
357 					memcpy(dst_buf + dst_off, out_tmp, rem);
358 					out_tmp += rem;
359 					dst_off += rem;
360 					actx->fill -= rem;
361 
362 					if (dst_off == sg_dma_len(dst)) {
363 						dst = sg_next(dst);
364 						split = 0;
365 					} else {
366 						split = 1;
367 					}
368 				}
369 			}
370 		} while (len);
371 
372 		if (limit_hit)
373 			break;
374 	}
375 
376 	/* Copy the IV for CBC for chaining */
377 	if (!rctx->ecb) {
378 		if (rctx->enc)
379 			memcpy(req->iv, out_buf+(last_out_len-AES_BLOCK_SIZE),
380 				AES_BLOCK_SIZE);
381 		else
382 			memcpy(req->iv, in_buf+(last_out_len-AES_BLOCK_SIZE),
383 				AES_BLOCK_SIZE);
384 	}
385 
386 	return ret;
387 }
388 
389 static int dcp_chan_thread_aes(void *data)
390 {
391 	struct dcp *sdcp = global_sdcp;
392 	const int chan = DCP_CHAN_CRYPTO;
393 
394 	struct crypto_async_request *backlog;
395 	struct crypto_async_request *arq;
396 
397 	int ret;
398 
399 	while (!kthread_should_stop()) {
400 		set_current_state(TASK_INTERRUPTIBLE);
401 
402 		spin_lock(&sdcp->lock[chan]);
403 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
404 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
405 		spin_unlock(&sdcp->lock[chan]);
406 
407 		if (!backlog && !arq) {
408 			schedule();
409 			continue;
410 		}
411 
412 		set_current_state(TASK_RUNNING);
413 
414 		if (backlog)
415 			backlog->complete(backlog, -EINPROGRESS);
416 
417 		if (arq) {
418 			ret = mxs_dcp_aes_block_crypt(arq);
419 			arq->complete(arq, ret);
420 		}
421 	}
422 
423 	return 0;
424 }
425 
426 static int mxs_dcp_block_fallback(struct skcipher_request *req, int enc)
427 {
428 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
429 	struct dcp_async_ctx *ctx = crypto_skcipher_ctx(tfm);
430 	SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
431 	int ret;
432 
433 	skcipher_request_set_sync_tfm(subreq, ctx->fallback);
434 	skcipher_request_set_callback(subreq, req->base.flags, NULL, NULL);
435 	skcipher_request_set_crypt(subreq, req->src, req->dst,
436 				   req->cryptlen, req->iv);
437 
438 	if (enc)
439 		ret = crypto_skcipher_encrypt(subreq);
440 	else
441 		ret = crypto_skcipher_decrypt(subreq);
442 
443 	skcipher_request_zero(subreq);
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_sync_skcipher_clear_flags(actx->fallback, CRYPTO_TFM_REQ_MASK);
514 	crypto_sync_skcipher_set_flags(actx->fallback,
515 				  tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
516 	return crypto_sync_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_sync_skcipher *blk;
524 
525 	blk = crypto_alloc_sync_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 	return 0;
532 }
533 
534 static void mxs_dcp_aes_fallback_exit_tfm(struct crypto_skcipher *tfm)
535 {
536 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
537 
538 	crypto_free_sync_skcipher(actx->fallback);
539 }
540 
541 /*
542  * Hashing (SHA1/SHA256)
543  */
544 static int mxs_dcp_run_sha(struct ahash_request *req)
545 {
546 	struct dcp *sdcp = global_sdcp;
547 	int ret;
548 
549 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
550 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
551 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
552 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
553 
554 	dma_addr_t digest_phys = 0;
555 	dma_addr_t buf_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_in_buf,
556 					     DCP_BUF_SZ, DMA_TO_DEVICE);
557 
558 	/* Fill in the DMA descriptor. */
559 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
560 		    MXS_DCP_CONTROL0_INTERRUPT |
561 		    MXS_DCP_CONTROL0_ENABLE_HASH;
562 	if (rctx->init)
563 		desc->control0 |= MXS_DCP_CONTROL0_HASH_INIT;
564 
565 	desc->control1 = actx->alg;
566 	desc->next_cmd_addr = 0;
567 	desc->source = buf_phys;
568 	desc->destination = 0;
569 	desc->size = actx->fill;
570 	desc->payload = 0;
571 	desc->status = 0;
572 
573 	/*
574 	 * Align driver with hw behavior when generating null hashes
575 	 */
576 	if (rctx->init && rctx->fini && desc->size == 0) {
577 		struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
578 		const uint8_t *sha_buf =
579 			(actx->alg == MXS_DCP_CONTROL1_HASH_SELECT_SHA1) ?
580 			sha1_null_hash : sha256_null_hash;
581 		memcpy(sdcp->coh->sha_out_buf, sha_buf, halg->digestsize);
582 		ret = 0;
583 		goto done_run;
584 	}
585 
586 	/* Set HASH_TERM bit for last transfer block. */
587 	if (rctx->fini) {
588 		digest_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_out_buf,
589 					     DCP_SHA_PAY_SZ, DMA_FROM_DEVICE);
590 		desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
591 		desc->payload = digest_phys;
592 	}
593 
594 	ret = mxs_dcp_start_dma(actx);
595 
596 	if (rctx->fini)
597 		dma_unmap_single(sdcp->dev, digest_phys, DCP_SHA_PAY_SZ,
598 				 DMA_FROM_DEVICE);
599 
600 done_run:
601 	dma_unmap_single(sdcp->dev, buf_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
602 
603 	return ret;
604 }
605 
606 static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
607 {
608 	struct dcp *sdcp = global_sdcp;
609 
610 	struct ahash_request *req = ahash_request_cast(arq);
611 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
612 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
613 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
614 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
615 
616 	uint8_t *in_buf = sdcp->coh->sha_in_buf;
617 	uint8_t *out_buf = sdcp->coh->sha_out_buf;
618 
619 	struct scatterlist *src;
620 
621 	unsigned int i, len, clen, oft = 0;
622 	int ret;
623 
624 	int fin = rctx->fini;
625 	if (fin)
626 		rctx->fini = 0;
627 
628 	src = req->src;
629 	len = req->nbytes;
630 
631 	while (len) {
632 		if (actx->fill + len > DCP_BUF_SZ)
633 			clen = DCP_BUF_SZ - actx->fill;
634 		else
635 			clen = len;
636 
637 		scatterwalk_map_and_copy(in_buf + actx->fill, src, oft, clen,
638 					 0);
639 
640 		len -= clen;
641 		oft += clen;
642 		actx->fill += clen;
643 
644 		/*
645 		 * If we filled the buffer and still have some
646 		 * more data, submit the buffer.
647 		 */
648 		if (len && actx->fill == DCP_BUF_SZ) {
649 			ret = mxs_dcp_run_sha(req);
650 			if (ret)
651 				return ret;
652 			actx->fill = 0;
653 			rctx->init = 0;
654 		}
655 	}
656 
657 	if (fin) {
658 		rctx->fini = 1;
659 
660 		/* Submit whatever is left. */
661 		if (!req->result)
662 			return -EINVAL;
663 
664 		ret = mxs_dcp_run_sha(req);
665 		if (ret)
666 			return ret;
667 
668 		actx->fill = 0;
669 
670 		/* For some reason the result is flipped */
671 		for (i = 0; i < halg->digestsize; i++)
672 			req->result[i] = out_buf[halg->digestsize - i - 1];
673 	}
674 
675 	return 0;
676 }
677 
678 static int dcp_chan_thread_sha(void *data)
679 {
680 	struct dcp *sdcp = global_sdcp;
681 	const int chan = DCP_CHAN_HASH_SHA;
682 
683 	struct crypto_async_request *backlog;
684 	struct crypto_async_request *arq;
685 	int ret;
686 
687 	while (!kthread_should_stop()) {
688 		set_current_state(TASK_INTERRUPTIBLE);
689 
690 		spin_lock(&sdcp->lock[chan]);
691 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
692 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
693 		spin_unlock(&sdcp->lock[chan]);
694 
695 		if (!backlog && !arq) {
696 			schedule();
697 			continue;
698 		}
699 
700 		set_current_state(TASK_RUNNING);
701 
702 		if (backlog)
703 			backlog->complete(backlog, -EINPROGRESS);
704 
705 		if (arq) {
706 			ret = dcp_sha_req_to_buf(arq);
707 			arq->complete(arq, ret);
708 		}
709 	}
710 
711 	return 0;
712 }
713 
714 static int dcp_sha_init(struct ahash_request *req)
715 {
716 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
717 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
718 
719 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
720 
721 	/*
722 	 * Start hashing session. The code below only inits the
723 	 * hashing session context, nothing more.
724 	 */
725 	memset(actx, 0, sizeof(*actx));
726 
727 	if (strcmp(halg->base.cra_name, "sha1") == 0)
728 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA1;
729 	else
730 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA256;
731 
732 	actx->fill = 0;
733 	actx->hot = 0;
734 	actx->chan = DCP_CHAN_HASH_SHA;
735 
736 	mutex_init(&actx->mutex);
737 
738 	return 0;
739 }
740 
741 static int dcp_sha_update_fx(struct ahash_request *req, int fini)
742 {
743 	struct dcp *sdcp = global_sdcp;
744 
745 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
746 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
747 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
748 
749 	int ret;
750 
751 	/*
752 	 * Ignore requests that have no data in them and are not
753 	 * the trailing requests in the stream of requests.
754 	 */
755 	if (!req->nbytes && !fini)
756 		return 0;
757 
758 	mutex_lock(&actx->mutex);
759 
760 	rctx->fini = fini;
761 
762 	if (!actx->hot) {
763 		actx->hot = 1;
764 		rctx->init = 1;
765 	}
766 
767 	spin_lock(&sdcp->lock[actx->chan]);
768 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
769 	spin_unlock(&sdcp->lock[actx->chan]);
770 
771 	wake_up_process(sdcp->thread[actx->chan]);
772 	mutex_unlock(&actx->mutex);
773 
774 	return ret;
775 }
776 
777 static int dcp_sha_update(struct ahash_request *req)
778 {
779 	return dcp_sha_update_fx(req, 0);
780 }
781 
782 static int dcp_sha_final(struct ahash_request *req)
783 {
784 	ahash_request_set_crypt(req, NULL, req->result, 0);
785 	req->nbytes = 0;
786 	return dcp_sha_update_fx(req, 1);
787 }
788 
789 static int dcp_sha_finup(struct ahash_request *req)
790 {
791 	return dcp_sha_update_fx(req, 1);
792 }
793 
794 static int dcp_sha_digest(struct ahash_request *req)
795 {
796 	int ret;
797 
798 	ret = dcp_sha_init(req);
799 	if (ret)
800 		return ret;
801 
802 	return dcp_sha_finup(req);
803 }
804 
805 static int dcp_sha_import(struct ahash_request *req, const void *in)
806 {
807 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
808 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
809 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
810 	const struct dcp_export_state *export = in;
811 
812 	memset(rctx, 0, sizeof(struct dcp_sha_req_ctx));
813 	memset(actx, 0, sizeof(struct dcp_async_ctx));
814 	memcpy(rctx, &export->req_ctx, sizeof(struct dcp_sha_req_ctx));
815 	memcpy(actx, &export->async_ctx, sizeof(struct dcp_async_ctx));
816 
817 	return 0;
818 }
819 
820 static int dcp_sha_export(struct ahash_request *req, void *out)
821 {
822 	struct dcp_sha_req_ctx *rctx_state = ahash_request_ctx(req);
823 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
824 	struct dcp_async_ctx *actx_state = crypto_ahash_ctx(tfm);
825 	struct dcp_export_state *export = out;
826 
827 	memcpy(&export->req_ctx, rctx_state, sizeof(struct dcp_sha_req_ctx));
828 	memcpy(&export->async_ctx, actx_state, sizeof(struct dcp_async_ctx));
829 
830 	return 0;
831 }
832 
833 static int dcp_sha_cra_init(struct crypto_tfm *tfm)
834 {
835 	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
836 				 sizeof(struct dcp_sha_req_ctx));
837 	return 0;
838 }
839 
840 static void dcp_sha_cra_exit(struct crypto_tfm *tfm)
841 {
842 }
843 
844 /* AES 128 ECB and AES 128 CBC */
845 static struct skcipher_alg dcp_aes_algs[] = {
846 	{
847 		.base.cra_name		= "ecb(aes)",
848 		.base.cra_driver_name	= "ecb-aes-dcp",
849 		.base.cra_priority	= 400,
850 		.base.cra_alignmask	= 15,
851 		.base.cra_flags		= CRYPTO_ALG_ASYNC |
852 					  CRYPTO_ALG_NEED_FALLBACK,
853 		.base.cra_blocksize	= AES_BLOCK_SIZE,
854 		.base.cra_ctxsize	= sizeof(struct dcp_async_ctx),
855 		.base.cra_module	= THIS_MODULE,
856 
857 		.min_keysize		= AES_MIN_KEY_SIZE,
858 		.max_keysize		= AES_MAX_KEY_SIZE,
859 		.setkey			= mxs_dcp_aes_setkey,
860 		.encrypt		= mxs_dcp_aes_ecb_encrypt,
861 		.decrypt		= mxs_dcp_aes_ecb_decrypt,
862 		.init			= mxs_dcp_aes_fallback_init_tfm,
863 		.exit			= mxs_dcp_aes_fallback_exit_tfm,
864 	}, {
865 		.base.cra_name		= "cbc(aes)",
866 		.base.cra_driver_name	= "cbc-aes-dcp",
867 		.base.cra_priority	= 400,
868 		.base.cra_alignmask	= 15,
869 		.base.cra_flags		= CRYPTO_ALG_ASYNC |
870 					  CRYPTO_ALG_NEED_FALLBACK,
871 		.base.cra_blocksize	= AES_BLOCK_SIZE,
872 		.base.cra_ctxsize	= sizeof(struct dcp_async_ctx),
873 		.base.cra_module	= THIS_MODULE,
874 
875 		.min_keysize		= AES_MIN_KEY_SIZE,
876 		.max_keysize		= AES_MAX_KEY_SIZE,
877 		.setkey			= mxs_dcp_aes_setkey,
878 		.encrypt		= mxs_dcp_aes_cbc_encrypt,
879 		.decrypt		= mxs_dcp_aes_cbc_decrypt,
880 		.ivsize			= AES_BLOCK_SIZE,
881 		.init			= mxs_dcp_aes_fallback_init_tfm,
882 		.exit			= mxs_dcp_aes_fallback_exit_tfm,
883 	},
884 };
885 
886 /* SHA1 */
887 static struct ahash_alg dcp_sha1_alg = {
888 	.init	= dcp_sha_init,
889 	.update	= dcp_sha_update,
890 	.final	= dcp_sha_final,
891 	.finup	= dcp_sha_finup,
892 	.digest	= dcp_sha_digest,
893 	.import = dcp_sha_import,
894 	.export = dcp_sha_export,
895 	.halg	= {
896 		.digestsize	= SHA1_DIGEST_SIZE,
897 		.statesize	= sizeof(struct dcp_export_state),
898 		.base		= {
899 			.cra_name		= "sha1",
900 			.cra_driver_name	= "sha1-dcp",
901 			.cra_priority		= 400,
902 			.cra_alignmask		= 63,
903 			.cra_flags		= CRYPTO_ALG_ASYNC,
904 			.cra_blocksize		= SHA1_BLOCK_SIZE,
905 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
906 			.cra_module		= THIS_MODULE,
907 			.cra_init		= dcp_sha_cra_init,
908 			.cra_exit		= dcp_sha_cra_exit,
909 		},
910 	},
911 };
912 
913 /* SHA256 */
914 static struct ahash_alg dcp_sha256_alg = {
915 	.init	= dcp_sha_init,
916 	.update	= dcp_sha_update,
917 	.final	= dcp_sha_final,
918 	.finup	= dcp_sha_finup,
919 	.digest	= dcp_sha_digest,
920 	.import = dcp_sha_import,
921 	.export = dcp_sha_export,
922 	.halg	= {
923 		.digestsize	= SHA256_DIGEST_SIZE,
924 		.statesize	= sizeof(struct dcp_export_state),
925 		.base		= {
926 			.cra_name		= "sha256",
927 			.cra_driver_name	= "sha256-dcp",
928 			.cra_priority		= 400,
929 			.cra_alignmask		= 63,
930 			.cra_flags		= CRYPTO_ALG_ASYNC,
931 			.cra_blocksize		= SHA256_BLOCK_SIZE,
932 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
933 			.cra_module		= THIS_MODULE,
934 			.cra_init		= dcp_sha_cra_init,
935 			.cra_exit		= dcp_sha_cra_exit,
936 		},
937 	},
938 };
939 
940 static irqreturn_t mxs_dcp_irq(int irq, void *context)
941 {
942 	struct dcp *sdcp = context;
943 	uint32_t stat;
944 	int i;
945 
946 	stat = readl(sdcp->base + MXS_DCP_STAT);
947 	stat &= MXS_DCP_STAT_IRQ_MASK;
948 	if (!stat)
949 		return IRQ_NONE;
950 
951 	/* Clear the interrupts. */
952 	writel(stat, sdcp->base + MXS_DCP_STAT_CLR);
953 
954 	/* Complete the DMA requests that finished. */
955 	for (i = 0; i < DCP_MAX_CHANS; i++)
956 		if (stat & (1 << i))
957 			complete(&sdcp->completion[i]);
958 
959 	return IRQ_HANDLED;
960 }
961 
962 static int mxs_dcp_probe(struct platform_device *pdev)
963 {
964 	struct device *dev = &pdev->dev;
965 	struct dcp *sdcp = NULL;
966 	int i, ret;
967 	int dcp_vmi_irq, dcp_irq;
968 
969 	if (global_sdcp) {
970 		dev_err(dev, "Only one DCP instance allowed!\n");
971 		return -ENODEV;
972 	}
973 
974 	dcp_vmi_irq = platform_get_irq(pdev, 0);
975 	if (dcp_vmi_irq < 0)
976 		return dcp_vmi_irq;
977 
978 	dcp_irq = platform_get_irq(pdev, 1);
979 	if (dcp_irq < 0)
980 		return dcp_irq;
981 
982 	sdcp = devm_kzalloc(dev, sizeof(*sdcp), GFP_KERNEL);
983 	if (!sdcp)
984 		return -ENOMEM;
985 
986 	sdcp->dev = dev;
987 	sdcp->base = devm_platform_ioremap_resource(pdev, 0);
988 	if (IS_ERR(sdcp->base))
989 		return PTR_ERR(sdcp->base);
990 
991 
992 	ret = devm_request_irq(dev, dcp_vmi_irq, mxs_dcp_irq, 0,
993 			       "dcp-vmi-irq", sdcp);
994 	if (ret) {
995 		dev_err(dev, "Failed to claim DCP VMI IRQ!\n");
996 		return ret;
997 	}
998 
999 	ret = devm_request_irq(dev, dcp_irq, mxs_dcp_irq, 0,
1000 			       "dcp-irq", sdcp);
1001 	if (ret) {
1002 		dev_err(dev, "Failed to claim DCP IRQ!\n");
1003 		return ret;
1004 	}
1005 
1006 	/* Allocate coherent helper block. */
1007 	sdcp->coh = devm_kzalloc(dev, sizeof(*sdcp->coh) + DCP_ALIGNMENT,
1008 				   GFP_KERNEL);
1009 	if (!sdcp->coh)
1010 		return -ENOMEM;
1011 
1012 	/* Re-align the structure so it fits the DCP constraints. */
1013 	sdcp->coh = PTR_ALIGN(sdcp->coh, DCP_ALIGNMENT);
1014 
1015 	/* DCP clock is optional, only used on some SOCs */
1016 	sdcp->dcp_clk = devm_clk_get(dev, "dcp");
1017 	if (IS_ERR(sdcp->dcp_clk)) {
1018 		if (sdcp->dcp_clk != ERR_PTR(-ENOENT))
1019 			return PTR_ERR(sdcp->dcp_clk);
1020 		sdcp->dcp_clk = NULL;
1021 	}
1022 	ret = clk_prepare_enable(sdcp->dcp_clk);
1023 	if (ret)
1024 		return ret;
1025 
1026 	/* Restart the DCP block. */
1027 	ret = stmp_reset_block(sdcp->base);
1028 	if (ret) {
1029 		dev_err(dev, "Failed reset\n");
1030 		goto err_disable_unprepare_clk;
1031 	}
1032 
1033 	/* Initialize control register. */
1034 	writel(MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES |
1035 	       MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING | 0xf,
1036 	       sdcp->base + MXS_DCP_CTRL);
1037 
1038 	/* Enable all DCP DMA channels. */
1039 	writel(MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK,
1040 	       sdcp->base + MXS_DCP_CHANNELCTRL);
1041 
1042 	/*
1043 	 * We do not enable context switching. Give the context buffer a
1044 	 * pointer to an illegal address so if context switching is
1045 	 * inadvertantly enabled, the DCP will return an error instead of
1046 	 * trashing good memory. The DCP DMA cannot access ROM, so any ROM
1047 	 * address will do.
1048 	 */
1049 	writel(0xffff0000, sdcp->base + MXS_DCP_CONTEXT);
1050 	for (i = 0; i < DCP_MAX_CHANS; i++)
1051 		writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(i));
1052 	writel(0xffffffff, sdcp->base + MXS_DCP_STAT_CLR);
1053 
1054 	global_sdcp = sdcp;
1055 
1056 	platform_set_drvdata(pdev, sdcp);
1057 
1058 	for (i = 0; i < DCP_MAX_CHANS; i++) {
1059 		spin_lock_init(&sdcp->lock[i]);
1060 		init_completion(&sdcp->completion[i]);
1061 		crypto_init_queue(&sdcp->queue[i], 50);
1062 	}
1063 
1064 	/* Create the SHA and AES handler threads. */
1065 	sdcp->thread[DCP_CHAN_HASH_SHA] = kthread_run(dcp_chan_thread_sha,
1066 						      NULL, "mxs_dcp_chan/sha");
1067 	if (IS_ERR(sdcp->thread[DCP_CHAN_HASH_SHA])) {
1068 		dev_err(dev, "Error starting SHA thread!\n");
1069 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_HASH_SHA]);
1070 		goto err_disable_unprepare_clk;
1071 	}
1072 
1073 	sdcp->thread[DCP_CHAN_CRYPTO] = kthread_run(dcp_chan_thread_aes,
1074 						    NULL, "mxs_dcp_chan/aes");
1075 	if (IS_ERR(sdcp->thread[DCP_CHAN_CRYPTO])) {
1076 		dev_err(dev, "Error starting SHA thread!\n");
1077 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_CRYPTO]);
1078 		goto err_destroy_sha_thread;
1079 	}
1080 
1081 	/* Register the various crypto algorithms. */
1082 	sdcp->caps = readl(sdcp->base + MXS_DCP_CAPABILITY1);
1083 
1084 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128) {
1085 		ret = crypto_register_skciphers(dcp_aes_algs,
1086 						ARRAY_SIZE(dcp_aes_algs));
1087 		if (ret) {
1088 			/* Failed to register algorithm. */
1089 			dev_err(dev, "Failed to register AES crypto!\n");
1090 			goto err_destroy_aes_thread;
1091 		}
1092 	}
1093 
1094 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1) {
1095 		ret = crypto_register_ahash(&dcp_sha1_alg);
1096 		if (ret) {
1097 			dev_err(dev, "Failed to register %s hash!\n",
1098 				dcp_sha1_alg.halg.base.cra_name);
1099 			goto err_unregister_aes;
1100 		}
1101 	}
1102 
1103 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256) {
1104 		ret = crypto_register_ahash(&dcp_sha256_alg);
1105 		if (ret) {
1106 			dev_err(dev, "Failed to register %s hash!\n",
1107 				dcp_sha256_alg.halg.base.cra_name);
1108 			goto err_unregister_sha1;
1109 		}
1110 	}
1111 
1112 	return 0;
1113 
1114 err_unregister_sha1:
1115 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1116 		crypto_unregister_ahash(&dcp_sha1_alg);
1117 
1118 err_unregister_aes:
1119 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1120 		crypto_unregister_skciphers(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1121 
1122 err_destroy_aes_thread:
1123 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1124 
1125 err_destroy_sha_thread:
1126 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1127 
1128 err_disable_unprepare_clk:
1129 	clk_disable_unprepare(sdcp->dcp_clk);
1130 
1131 	return ret;
1132 }
1133 
1134 static int mxs_dcp_remove(struct platform_device *pdev)
1135 {
1136 	struct dcp *sdcp = platform_get_drvdata(pdev);
1137 
1138 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256)
1139 		crypto_unregister_ahash(&dcp_sha256_alg);
1140 
1141 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1142 		crypto_unregister_ahash(&dcp_sha1_alg);
1143 
1144 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1145 		crypto_unregister_skciphers(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1146 
1147 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1148 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1149 
1150 	clk_disable_unprepare(sdcp->dcp_clk);
1151 
1152 	platform_set_drvdata(pdev, NULL);
1153 
1154 	global_sdcp = NULL;
1155 
1156 	return 0;
1157 }
1158 
1159 static const struct of_device_id mxs_dcp_dt_ids[] = {
1160 	{ .compatible = "fsl,imx23-dcp", .data = NULL, },
1161 	{ .compatible = "fsl,imx28-dcp", .data = NULL, },
1162 	{ /* sentinel */ }
1163 };
1164 
1165 MODULE_DEVICE_TABLE(of, mxs_dcp_dt_ids);
1166 
1167 static struct platform_driver mxs_dcp_driver = {
1168 	.probe	= mxs_dcp_probe,
1169 	.remove	= mxs_dcp_remove,
1170 	.driver	= {
1171 		.name		= "mxs-dcp",
1172 		.of_match_table	= mxs_dcp_dt_ids,
1173 	},
1174 };
1175 
1176 module_platform_driver(mxs_dcp_driver);
1177 
1178 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1179 MODULE_DESCRIPTION("Freescale MXS DCP Driver");
1180 MODULE_LICENSE("GPL");
1181 MODULE_ALIAS("platform:mxs-dcp");
1182