xref: /openbmc/linux/drivers/crypto/mxs-dcp.c (revision b285d2ae)
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_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 	struct skcipher_request fallback_req;	// keep at the end
109 };
110 
111 struct dcp_sha_req_ctx {
112 	unsigned int	init:1;
113 	unsigned int	fini:1;
114 };
115 
116 struct dcp_export_state {
117 	struct dcp_sha_req_ctx req_ctx;
118 	struct dcp_async_ctx async_ctx;
119 };
120 
121 /*
122  * There can even be only one instance of the MXS DCP due to the
123  * design of Linux Crypto API.
124  */
125 static struct dcp *global_sdcp;
126 
127 /* DCP register layout. */
128 #define MXS_DCP_CTRL				0x00
129 #define MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES	(1 << 23)
130 #define MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING	(1 << 22)
131 
132 #define MXS_DCP_STAT				0x10
133 #define MXS_DCP_STAT_CLR			0x18
134 #define MXS_DCP_STAT_IRQ_MASK			0xf
135 
136 #define MXS_DCP_CHANNELCTRL			0x20
137 #define MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK	0xff
138 
139 #define MXS_DCP_CAPABILITY1			0x40
140 #define MXS_DCP_CAPABILITY1_SHA256		(4 << 16)
141 #define MXS_DCP_CAPABILITY1_SHA1		(1 << 16)
142 #define MXS_DCP_CAPABILITY1_AES128		(1 << 0)
143 
144 #define MXS_DCP_CONTEXT				0x50
145 
146 #define MXS_DCP_CH_N_CMDPTR(n)			(0x100 + ((n) * 0x40))
147 
148 #define MXS_DCP_CH_N_SEMA(n)			(0x110 + ((n) * 0x40))
149 
150 #define MXS_DCP_CH_N_STAT(n)			(0x120 + ((n) * 0x40))
151 #define MXS_DCP_CH_N_STAT_CLR(n)		(0x128 + ((n) * 0x40))
152 
153 /* DMA descriptor bits. */
154 #define MXS_DCP_CONTROL0_HASH_TERM		(1 << 13)
155 #define MXS_DCP_CONTROL0_HASH_INIT		(1 << 12)
156 #define MXS_DCP_CONTROL0_PAYLOAD_KEY		(1 << 11)
157 #define MXS_DCP_CONTROL0_CIPHER_ENCRYPT		(1 << 8)
158 #define MXS_DCP_CONTROL0_CIPHER_INIT		(1 << 9)
159 #define MXS_DCP_CONTROL0_ENABLE_HASH		(1 << 6)
160 #define MXS_DCP_CONTROL0_ENABLE_CIPHER		(1 << 5)
161 #define MXS_DCP_CONTROL0_DECR_SEMAPHORE		(1 << 1)
162 #define MXS_DCP_CONTROL0_INTERRUPT		(1 << 0)
163 
164 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA256	(2 << 16)
165 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA1	(0 << 16)
166 #define MXS_DCP_CONTROL1_CIPHER_MODE_CBC	(1 << 4)
167 #define MXS_DCP_CONTROL1_CIPHER_MODE_ECB	(0 << 4)
168 #define MXS_DCP_CONTROL1_CIPHER_SELECT_AES128	(0 << 0)
169 
170 static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
171 {
172 	struct dcp *sdcp = global_sdcp;
173 	const int chan = actx->chan;
174 	uint32_t stat;
175 	unsigned long ret;
176 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
177 
178 	dma_addr_t desc_phys = dma_map_single(sdcp->dev, desc, sizeof(*desc),
179 					      DMA_TO_DEVICE);
180 
181 	reinit_completion(&sdcp->completion[chan]);
182 
183 	/* Clear status register. */
184 	writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(chan));
185 
186 	/* Load the DMA descriptor. */
187 	writel(desc_phys, sdcp->base + MXS_DCP_CH_N_CMDPTR(chan));
188 
189 	/* Increment the semaphore to start the DMA transfer. */
190 	writel(1, sdcp->base + MXS_DCP_CH_N_SEMA(chan));
191 
192 	ret = wait_for_completion_timeout(&sdcp->completion[chan],
193 					  msecs_to_jiffies(1000));
194 	if (!ret) {
195 		dev_err(sdcp->dev, "Channel %i timeout (DCP_STAT=0x%08x)\n",
196 			chan, readl(sdcp->base + MXS_DCP_STAT));
197 		return -ETIMEDOUT;
198 	}
199 
200 	stat = readl(sdcp->base + MXS_DCP_CH_N_STAT(chan));
201 	if (stat & 0xff) {
202 		dev_err(sdcp->dev, "Channel %i error (CH_STAT=0x%08x)\n",
203 			chan, stat);
204 		return -EINVAL;
205 	}
206 
207 	dma_unmap_single(sdcp->dev, desc_phys, sizeof(*desc), DMA_TO_DEVICE);
208 
209 	return 0;
210 }
211 
212 /*
213  * Encryption (AES128)
214  */
215 static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
216 			   struct skcipher_request *req, int init)
217 {
218 	struct dcp *sdcp = global_sdcp;
219 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
220 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
221 	int ret;
222 
223 	dma_addr_t key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
224 					     2 * AES_KEYSIZE_128,
225 					     DMA_TO_DEVICE);
226 	dma_addr_t src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
227 					     DCP_BUF_SZ, DMA_TO_DEVICE);
228 	dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
229 					     DCP_BUF_SZ, DMA_FROM_DEVICE);
230 
231 	if (actx->fill % AES_BLOCK_SIZE) {
232 		dev_err(sdcp->dev, "Invalid block size!\n");
233 		ret = -EINVAL;
234 		goto aes_done_run;
235 	}
236 
237 	/* Fill in the DMA descriptor. */
238 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
239 		    MXS_DCP_CONTROL0_INTERRUPT |
240 		    MXS_DCP_CONTROL0_ENABLE_CIPHER;
241 
242 	/* Payload contains the key. */
243 	desc->control0 |= MXS_DCP_CONTROL0_PAYLOAD_KEY;
244 
245 	if (rctx->enc)
246 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_ENCRYPT;
247 	if (init)
248 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_INIT;
249 
250 	desc->control1 = MXS_DCP_CONTROL1_CIPHER_SELECT_AES128;
251 
252 	if (rctx->ecb)
253 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_ECB;
254 	else
255 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_CBC;
256 
257 	desc->next_cmd_addr = 0;
258 	desc->source = src_phys;
259 	desc->destination = dst_phys;
260 	desc->size = actx->fill;
261 	desc->payload = key_phys;
262 	desc->status = 0;
263 
264 	ret = mxs_dcp_start_dma(actx);
265 
266 aes_done_run:
267 	dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
268 			 DMA_TO_DEVICE);
269 	dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
270 	dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
271 
272 	return ret;
273 }
274 
275 static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
276 {
277 	struct dcp *sdcp = global_sdcp;
278 
279 	struct skcipher_request *req = skcipher_request_cast(arq);
280 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
281 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
282 
283 	struct scatterlist *dst = req->dst;
284 	struct scatterlist *src = req->src;
285 	const int nents = sg_nents(req->src);
286 
287 	const int out_off = DCP_BUF_SZ;
288 	uint8_t *in_buf = sdcp->coh->aes_in_buf;
289 	uint8_t *out_buf = sdcp->coh->aes_out_buf;
290 
291 	uint8_t *out_tmp, *src_buf, *dst_buf = NULL;
292 	uint32_t dst_off = 0;
293 	uint32_t last_out_len = 0;
294 
295 	uint8_t *key = sdcp->coh->aes_key;
296 
297 	int ret = 0;
298 	int split = 0;
299 	unsigned int i, len, clen, rem = 0, tlen = 0;
300 	int init = 0;
301 	bool limit_hit = false;
302 
303 	actx->fill = 0;
304 
305 	/* Copy the key from the temporary location. */
306 	memcpy(key, actx->key, actx->key_len);
307 
308 	if (!rctx->ecb) {
309 		/* Copy the CBC IV just past the key. */
310 		memcpy(key + AES_KEYSIZE_128, req->iv, AES_KEYSIZE_128);
311 		/* CBC needs the INIT set. */
312 		init = 1;
313 	} else {
314 		memset(key + AES_KEYSIZE_128, 0, AES_KEYSIZE_128);
315 	}
316 
317 	for_each_sg(req->src, src, nents, i) {
318 		src_buf = sg_virt(src);
319 		len = sg_dma_len(src);
320 		tlen += len;
321 		limit_hit = tlen > req->cryptlen;
322 
323 		if (limit_hit)
324 			len = req->cryptlen - (tlen - len);
325 
326 		do {
327 			if (actx->fill + len > out_off)
328 				clen = out_off - actx->fill;
329 			else
330 				clen = len;
331 
332 			memcpy(in_buf + actx->fill, src_buf, clen);
333 			len -= clen;
334 			src_buf += clen;
335 			actx->fill += clen;
336 
337 			/*
338 			 * If we filled the buffer or this is the last SG,
339 			 * submit the buffer.
340 			 */
341 			if (actx->fill == out_off || sg_is_last(src) ||
342 				limit_hit) {
343 				ret = mxs_dcp_run_aes(actx, req, init);
344 				if (ret)
345 					return ret;
346 				init = 0;
347 
348 				out_tmp = out_buf;
349 				last_out_len = actx->fill;
350 				while (dst && actx->fill) {
351 					if (!split) {
352 						dst_buf = sg_virt(dst);
353 						dst_off = 0;
354 					}
355 					rem = min(sg_dma_len(dst) - dst_off,
356 						  actx->fill);
357 
358 					memcpy(dst_buf + dst_off, out_tmp, rem);
359 					out_tmp += rem;
360 					dst_off += rem;
361 					actx->fill -= rem;
362 
363 					if (dst_off == sg_dma_len(dst)) {
364 						dst = sg_next(dst);
365 						split = 0;
366 					} else {
367 						split = 1;
368 					}
369 				}
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 	/* Fill in the DMA descriptor. */
560 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
561 		    MXS_DCP_CONTROL0_INTERRUPT |
562 		    MXS_DCP_CONTROL0_ENABLE_HASH;
563 	if (rctx->init)
564 		desc->control0 |= MXS_DCP_CONTROL0_HASH_INIT;
565 
566 	desc->control1 = actx->alg;
567 	desc->next_cmd_addr = 0;
568 	desc->source = buf_phys;
569 	desc->destination = 0;
570 	desc->size = actx->fill;
571 	desc->payload = 0;
572 	desc->status = 0;
573 
574 	/*
575 	 * Align driver with hw behavior when generating null hashes
576 	 */
577 	if (rctx->init && rctx->fini && desc->size == 0) {
578 		struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
579 		const uint8_t *sha_buf =
580 			(actx->alg == MXS_DCP_CONTROL1_HASH_SELECT_SHA1) ?
581 			sha1_null_hash : sha256_null_hash;
582 		memcpy(sdcp->coh->sha_out_buf, sha_buf, halg->digestsize);
583 		ret = 0;
584 		goto done_run;
585 	}
586 
587 	/* Set HASH_TERM bit for last transfer block. */
588 	if (rctx->fini) {
589 		digest_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_out_buf,
590 					     DCP_SHA_PAY_SZ, DMA_FROM_DEVICE);
591 		desc->control0 |= MXS_DCP_CONTROL0_HASH_TERM;
592 		desc->payload = digest_phys;
593 	}
594 
595 	ret = mxs_dcp_start_dma(actx);
596 
597 	if (rctx->fini)
598 		dma_unmap_single(sdcp->dev, digest_phys, DCP_SHA_PAY_SZ,
599 				 DMA_FROM_DEVICE);
600 
601 done_run:
602 	dma_unmap_single(sdcp->dev, buf_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
603 
604 	return ret;
605 }
606 
607 static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
608 {
609 	struct dcp *sdcp = global_sdcp;
610 
611 	struct ahash_request *req = ahash_request_cast(arq);
612 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
613 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
614 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
615 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
616 
617 	uint8_t *in_buf = sdcp->coh->sha_in_buf;
618 	uint8_t *out_buf = sdcp->coh->sha_out_buf;
619 
620 	struct scatterlist *src;
621 
622 	unsigned int i, len, clen, oft = 0;
623 	int ret;
624 
625 	int fin = rctx->fini;
626 	if (fin)
627 		rctx->fini = 0;
628 
629 	src = req->src;
630 	len = req->nbytes;
631 
632 	while (len) {
633 		if (actx->fill + len > DCP_BUF_SZ)
634 			clen = DCP_BUF_SZ - actx->fill;
635 		else
636 			clen = len;
637 
638 		scatterwalk_map_and_copy(in_buf + actx->fill, src, oft, clen,
639 					 0);
640 
641 		len -= clen;
642 		oft += clen;
643 		actx->fill += clen;
644 
645 		/*
646 		 * If we filled the buffer and still have some
647 		 * more data, submit the buffer.
648 		 */
649 		if (len && actx->fill == DCP_BUF_SZ) {
650 			ret = mxs_dcp_run_sha(req);
651 			if (ret)
652 				return ret;
653 			actx->fill = 0;
654 			rctx->init = 0;
655 		}
656 	}
657 
658 	if (fin) {
659 		rctx->fini = 1;
660 
661 		/* Submit whatever is left. */
662 		if (!req->result)
663 			return -EINVAL;
664 
665 		ret = mxs_dcp_run_sha(req);
666 		if (ret)
667 			return ret;
668 
669 		actx->fill = 0;
670 
671 		/* For some reason the result is flipped */
672 		for (i = 0; i < halg->digestsize; i++)
673 			req->result[i] = out_buf[halg->digestsize - i - 1];
674 	}
675 
676 	return 0;
677 }
678 
679 static int dcp_chan_thread_sha(void *data)
680 {
681 	struct dcp *sdcp = global_sdcp;
682 	const int chan = DCP_CHAN_HASH_SHA;
683 
684 	struct crypto_async_request *backlog;
685 	struct crypto_async_request *arq;
686 	int ret;
687 
688 	while (!kthread_should_stop()) {
689 		set_current_state(TASK_INTERRUPTIBLE);
690 
691 		spin_lock(&sdcp->lock[chan]);
692 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
693 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
694 		spin_unlock(&sdcp->lock[chan]);
695 
696 		if (!backlog && !arq) {
697 			schedule();
698 			continue;
699 		}
700 
701 		set_current_state(TASK_RUNNING);
702 
703 		if (backlog)
704 			backlog->complete(backlog, -EINPROGRESS);
705 
706 		if (arq) {
707 			ret = dcp_sha_req_to_buf(arq);
708 			arq->complete(arq, ret);
709 		}
710 	}
711 
712 	return 0;
713 }
714 
715 static int dcp_sha_init(struct ahash_request *req)
716 {
717 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
718 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
719 
720 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
721 
722 	/*
723 	 * Start hashing session. The code below only inits the
724 	 * hashing session context, nothing more.
725 	 */
726 	memset(actx, 0, sizeof(*actx));
727 
728 	if (strcmp(halg->base.cra_name, "sha1") == 0)
729 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA1;
730 	else
731 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA256;
732 
733 	actx->fill = 0;
734 	actx->hot = 0;
735 	actx->chan = DCP_CHAN_HASH_SHA;
736 
737 	mutex_init(&actx->mutex);
738 
739 	return 0;
740 }
741 
742 static int dcp_sha_update_fx(struct ahash_request *req, int fini)
743 {
744 	struct dcp *sdcp = global_sdcp;
745 
746 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
747 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
748 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
749 
750 	int ret;
751 
752 	/*
753 	 * Ignore requests that have no data in them and are not
754 	 * the trailing requests in the stream of requests.
755 	 */
756 	if (!req->nbytes && !fini)
757 		return 0;
758 
759 	mutex_lock(&actx->mutex);
760 
761 	rctx->fini = fini;
762 
763 	if (!actx->hot) {
764 		actx->hot = 1;
765 		rctx->init = 1;
766 	}
767 
768 	spin_lock(&sdcp->lock[actx->chan]);
769 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
770 	spin_unlock(&sdcp->lock[actx->chan]);
771 
772 	wake_up_process(sdcp->thread[actx->chan]);
773 	mutex_unlock(&actx->mutex);
774 
775 	return ret;
776 }
777 
778 static int dcp_sha_update(struct ahash_request *req)
779 {
780 	return dcp_sha_update_fx(req, 0);
781 }
782 
783 static int dcp_sha_final(struct ahash_request *req)
784 {
785 	ahash_request_set_crypt(req, NULL, req->result, 0);
786 	req->nbytes = 0;
787 	return dcp_sha_update_fx(req, 1);
788 }
789 
790 static int dcp_sha_finup(struct ahash_request *req)
791 {
792 	return dcp_sha_update_fx(req, 1);
793 }
794 
795 static int dcp_sha_digest(struct ahash_request *req)
796 {
797 	int ret;
798 
799 	ret = dcp_sha_init(req);
800 	if (ret)
801 		return ret;
802 
803 	return dcp_sha_finup(req);
804 }
805 
806 static int dcp_sha_import(struct ahash_request *req, const void *in)
807 {
808 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
809 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
810 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
811 	const struct dcp_export_state *export = in;
812 
813 	memset(rctx, 0, sizeof(struct dcp_sha_req_ctx));
814 	memset(actx, 0, sizeof(struct dcp_async_ctx));
815 	memcpy(rctx, &export->req_ctx, sizeof(struct dcp_sha_req_ctx));
816 	memcpy(actx, &export->async_ctx, sizeof(struct dcp_async_ctx));
817 
818 	return 0;
819 }
820 
821 static int dcp_sha_export(struct ahash_request *req, void *out)
822 {
823 	struct dcp_sha_req_ctx *rctx_state = ahash_request_ctx(req);
824 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
825 	struct dcp_async_ctx *actx_state = crypto_ahash_ctx(tfm);
826 	struct dcp_export_state *export = out;
827 
828 	memcpy(&export->req_ctx, rctx_state, sizeof(struct dcp_sha_req_ctx));
829 	memcpy(&export->async_ctx, actx_state, sizeof(struct dcp_async_ctx));
830 
831 	return 0;
832 }
833 
834 static int dcp_sha_cra_init(struct crypto_tfm *tfm)
835 {
836 	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
837 				 sizeof(struct dcp_sha_req_ctx));
838 	return 0;
839 }
840 
841 static void dcp_sha_cra_exit(struct crypto_tfm *tfm)
842 {
843 }
844 
845 /* AES 128 ECB and AES 128 CBC */
846 static struct skcipher_alg dcp_aes_algs[] = {
847 	{
848 		.base.cra_name		= "ecb(aes)",
849 		.base.cra_driver_name	= "ecb-aes-dcp",
850 		.base.cra_priority	= 400,
851 		.base.cra_alignmask	= 15,
852 		.base.cra_flags		= CRYPTO_ALG_ASYNC |
853 					  CRYPTO_ALG_NEED_FALLBACK,
854 		.base.cra_blocksize	= AES_BLOCK_SIZE,
855 		.base.cra_ctxsize	= sizeof(struct dcp_async_ctx),
856 		.base.cra_module	= THIS_MODULE,
857 
858 		.min_keysize		= AES_MIN_KEY_SIZE,
859 		.max_keysize		= AES_MAX_KEY_SIZE,
860 		.setkey			= mxs_dcp_aes_setkey,
861 		.encrypt		= mxs_dcp_aes_ecb_encrypt,
862 		.decrypt		= mxs_dcp_aes_ecb_decrypt,
863 		.init			= mxs_dcp_aes_fallback_init_tfm,
864 		.exit			= mxs_dcp_aes_fallback_exit_tfm,
865 	}, {
866 		.base.cra_name		= "cbc(aes)",
867 		.base.cra_driver_name	= "cbc-aes-dcp",
868 		.base.cra_priority	= 400,
869 		.base.cra_alignmask	= 15,
870 		.base.cra_flags		= CRYPTO_ALG_ASYNC |
871 					  CRYPTO_ALG_NEED_FALLBACK,
872 		.base.cra_blocksize	= AES_BLOCK_SIZE,
873 		.base.cra_ctxsize	= sizeof(struct dcp_async_ctx),
874 		.base.cra_module	= THIS_MODULE,
875 
876 		.min_keysize		= AES_MIN_KEY_SIZE,
877 		.max_keysize		= AES_MAX_KEY_SIZE,
878 		.setkey			= mxs_dcp_aes_setkey,
879 		.encrypt		= mxs_dcp_aes_cbc_encrypt,
880 		.decrypt		= mxs_dcp_aes_cbc_decrypt,
881 		.ivsize			= AES_BLOCK_SIZE,
882 		.init			= mxs_dcp_aes_fallback_init_tfm,
883 		.exit			= mxs_dcp_aes_fallback_exit_tfm,
884 	},
885 };
886 
887 /* SHA1 */
888 static struct ahash_alg dcp_sha1_alg = {
889 	.init	= dcp_sha_init,
890 	.update	= dcp_sha_update,
891 	.final	= dcp_sha_final,
892 	.finup	= dcp_sha_finup,
893 	.digest	= dcp_sha_digest,
894 	.import = dcp_sha_import,
895 	.export = dcp_sha_export,
896 	.halg	= {
897 		.digestsize	= SHA1_DIGEST_SIZE,
898 		.statesize	= sizeof(struct dcp_export_state),
899 		.base		= {
900 			.cra_name		= "sha1",
901 			.cra_driver_name	= "sha1-dcp",
902 			.cra_priority		= 400,
903 			.cra_alignmask		= 63,
904 			.cra_flags		= CRYPTO_ALG_ASYNC,
905 			.cra_blocksize		= SHA1_BLOCK_SIZE,
906 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
907 			.cra_module		= THIS_MODULE,
908 			.cra_init		= dcp_sha_cra_init,
909 			.cra_exit		= dcp_sha_cra_exit,
910 		},
911 	},
912 };
913 
914 /* SHA256 */
915 static struct ahash_alg dcp_sha256_alg = {
916 	.init	= dcp_sha_init,
917 	.update	= dcp_sha_update,
918 	.final	= dcp_sha_final,
919 	.finup	= dcp_sha_finup,
920 	.digest	= dcp_sha_digest,
921 	.import = dcp_sha_import,
922 	.export = dcp_sha_export,
923 	.halg	= {
924 		.digestsize	= SHA256_DIGEST_SIZE,
925 		.statesize	= sizeof(struct dcp_export_state),
926 		.base		= {
927 			.cra_name		= "sha256",
928 			.cra_driver_name	= "sha256-dcp",
929 			.cra_priority		= 400,
930 			.cra_alignmask		= 63,
931 			.cra_flags		= CRYPTO_ALG_ASYNC,
932 			.cra_blocksize		= SHA256_BLOCK_SIZE,
933 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
934 			.cra_module		= THIS_MODULE,
935 			.cra_init		= dcp_sha_cra_init,
936 			.cra_exit		= dcp_sha_cra_exit,
937 		},
938 	},
939 };
940 
941 static irqreturn_t mxs_dcp_irq(int irq, void *context)
942 {
943 	struct dcp *sdcp = context;
944 	uint32_t stat;
945 	int i;
946 
947 	stat = readl(sdcp->base + MXS_DCP_STAT);
948 	stat &= MXS_DCP_STAT_IRQ_MASK;
949 	if (!stat)
950 		return IRQ_NONE;
951 
952 	/* Clear the interrupts. */
953 	writel(stat, sdcp->base + MXS_DCP_STAT_CLR);
954 
955 	/* Complete the DMA requests that finished. */
956 	for (i = 0; i < DCP_MAX_CHANS; i++)
957 		if (stat & (1 << i))
958 			complete(&sdcp->completion[i]);
959 
960 	return IRQ_HANDLED;
961 }
962 
963 static int mxs_dcp_probe(struct platform_device *pdev)
964 {
965 	struct device *dev = &pdev->dev;
966 	struct dcp *sdcp = NULL;
967 	int i, ret;
968 	int dcp_vmi_irq, dcp_irq;
969 
970 	if (global_sdcp) {
971 		dev_err(dev, "Only one DCP instance allowed!\n");
972 		return -ENODEV;
973 	}
974 
975 	dcp_vmi_irq = platform_get_irq(pdev, 0);
976 	if (dcp_vmi_irq < 0)
977 		return dcp_vmi_irq;
978 
979 	dcp_irq = platform_get_irq(pdev, 1);
980 	if (dcp_irq < 0)
981 		return dcp_irq;
982 
983 	sdcp = devm_kzalloc(dev, sizeof(*sdcp), GFP_KERNEL);
984 	if (!sdcp)
985 		return -ENOMEM;
986 
987 	sdcp->dev = dev;
988 	sdcp->base = devm_platform_ioremap_resource(pdev, 0);
989 	if (IS_ERR(sdcp->base))
990 		return PTR_ERR(sdcp->base);
991 
992 
993 	ret = devm_request_irq(dev, dcp_vmi_irq, mxs_dcp_irq, 0,
994 			       "dcp-vmi-irq", sdcp);
995 	if (ret) {
996 		dev_err(dev, "Failed to claim DCP VMI IRQ!\n");
997 		return ret;
998 	}
999 
1000 	ret = devm_request_irq(dev, dcp_irq, mxs_dcp_irq, 0,
1001 			       "dcp-irq", sdcp);
1002 	if (ret) {
1003 		dev_err(dev, "Failed to claim DCP IRQ!\n");
1004 		return ret;
1005 	}
1006 
1007 	/* Allocate coherent helper block. */
1008 	sdcp->coh = devm_kzalloc(dev, sizeof(*sdcp->coh) + DCP_ALIGNMENT,
1009 				   GFP_KERNEL);
1010 	if (!sdcp->coh)
1011 		return -ENOMEM;
1012 
1013 	/* Re-align the structure so it fits the DCP constraints. */
1014 	sdcp->coh = PTR_ALIGN(sdcp->coh, DCP_ALIGNMENT);
1015 
1016 	/* DCP clock is optional, only used on some SOCs */
1017 	sdcp->dcp_clk = devm_clk_get(dev, "dcp");
1018 	if (IS_ERR(sdcp->dcp_clk)) {
1019 		if (sdcp->dcp_clk != ERR_PTR(-ENOENT))
1020 			return PTR_ERR(sdcp->dcp_clk);
1021 		sdcp->dcp_clk = NULL;
1022 	}
1023 	ret = clk_prepare_enable(sdcp->dcp_clk);
1024 	if (ret)
1025 		return ret;
1026 
1027 	/* Restart the DCP block. */
1028 	ret = stmp_reset_block(sdcp->base);
1029 	if (ret) {
1030 		dev_err(dev, "Failed reset\n");
1031 		goto err_disable_unprepare_clk;
1032 	}
1033 
1034 	/* Initialize control register. */
1035 	writel(MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES |
1036 	       MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING | 0xf,
1037 	       sdcp->base + MXS_DCP_CTRL);
1038 
1039 	/* Enable all DCP DMA channels. */
1040 	writel(MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK,
1041 	       sdcp->base + MXS_DCP_CHANNELCTRL);
1042 
1043 	/*
1044 	 * We do not enable context switching. Give the context buffer a
1045 	 * pointer to an illegal address so if context switching is
1046 	 * inadvertantly enabled, the DCP will return an error instead of
1047 	 * trashing good memory. The DCP DMA cannot access ROM, so any ROM
1048 	 * address will do.
1049 	 */
1050 	writel(0xffff0000, sdcp->base + MXS_DCP_CONTEXT);
1051 	for (i = 0; i < DCP_MAX_CHANS; i++)
1052 		writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(i));
1053 	writel(0xffffffff, sdcp->base + MXS_DCP_STAT_CLR);
1054 
1055 	global_sdcp = sdcp;
1056 
1057 	platform_set_drvdata(pdev, sdcp);
1058 
1059 	for (i = 0; i < DCP_MAX_CHANS; i++) {
1060 		spin_lock_init(&sdcp->lock[i]);
1061 		init_completion(&sdcp->completion[i]);
1062 		crypto_init_queue(&sdcp->queue[i], 50);
1063 	}
1064 
1065 	/* Create the SHA and AES handler threads. */
1066 	sdcp->thread[DCP_CHAN_HASH_SHA] = kthread_run(dcp_chan_thread_sha,
1067 						      NULL, "mxs_dcp_chan/sha");
1068 	if (IS_ERR(sdcp->thread[DCP_CHAN_HASH_SHA])) {
1069 		dev_err(dev, "Error starting SHA thread!\n");
1070 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_HASH_SHA]);
1071 		goto err_disable_unprepare_clk;
1072 	}
1073 
1074 	sdcp->thread[DCP_CHAN_CRYPTO] = kthread_run(dcp_chan_thread_aes,
1075 						    NULL, "mxs_dcp_chan/aes");
1076 	if (IS_ERR(sdcp->thread[DCP_CHAN_CRYPTO])) {
1077 		dev_err(dev, "Error starting SHA thread!\n");
1078 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_CRYPTO]);
1079 		goto err_destroy_sha_thread;
1080 	}
1081 
1082 	/* Register the various crypto algorithms. */
1083 	sdcp->caps = readl(sdcp->base + MXS_DCP_CAPABILITY1);
1084 
1085 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128) {
1086 		ret = crypto_register_skciphers(dcp_aes_algs,
1087 						ARRAY_SIZE(dcp_aes_algs));
1088 		if (ret) {
1089 			/* Failed to register algorithm. */
1090 			dev_err(dev, "Failed to register AES crypto!\n");
1091 			goto err_destroy_aes_thread;
1092 		}
1093 	}
1094 
1095 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1) {
1096 		ret = crypto_register_ahash(&dcp_sha1_alg);
1097 		if (ret) {
1098 			dev_err(dev, "Failed to register %s hash!\n",
1099 				dcp_sha1_alg.halg.base.cra_name);
1100 			goto err_unregister_aes;
1101 		}
1102 	}
1103 
1104 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256) {
1105 		ret = crypto_register_ahash(&dcp_sha256_alg);
1106 		if (ret) {
1107 			dev_err(dev, "Failed to register %s hash!\n",
1108 				dcp_sha256_alg.halg.base.cra_name);
1109 			goto err_unregister_sha1;
1110 		}
1111 	}
1112 
1113 	return 0;
1114 
1115 err_unregister_sha1:
1116 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1117 		crypto_unregister_ahash(&dcp_sha1_alg);
1118 
1119 err_unregister_aes:
1120 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1121 		crypto_unregister_skciphers(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1122 
1123 err_destroy_aes_thread:
1124 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1125 
1126 err_destroy_sha_thread:
1127 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1128 
1129 err_disable_unprepare_clk:
1130 	clk_disable_unprepare(sdcp->dcp_clk);
1131 
1132 	return ret;
1133 }
1134 
1135 static int mxs_dcp_remove(struct platform_device *pdev)
1136 {
1137 	struct dcp *sdcp = platform_get_drvdata(pdev);
1138 
1139 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256)
1140 		crypto_unregister_ahash(&dcp_sha256_alg);
1141 
1142 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1143 		crypto_unregister_ahash(&dcp_sha1_alg);
1144 
1145 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1146 		crypto_unregister_skciphers(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1147 
1148 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1149 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1150 
1151 	clk_disable_unprepare(sdcp->dcp_clk);
1152 
1153 	platform_set_drvdata(pdev, NULL);
1154 
1155 	global_sdcp = NULL;
1156 
1157 	return 0;
1158 }
1159 
1160 static const struct of_device_id mxs_dcp_dt_ids[] = {
1161 	{ .compatible = "fsl,imx23-dcp", .data = NULL, },
1162 	{ .compatible = "fsl,imx28-dcp", .data = NULL, },
1163 	{ /* sentinel */ }
1164 };
1165 
1166 MODULE_DEVICE_TABLE(of, mxs_dcp_dt_ids);
1167 
1168 static struct platform_driver mxs_dcp_driver = {
1169 	.probe	= mxs_dcp_probe,
1170 	.remove	= mxs_dcp_remove,
1171 	.driver	= {
1172 		.name		= "mxs-dcp",
1173 		.of_match_table	= mxs_dcp_dt_ids,
1174 	},
1175 };
1176 
1177 module_platform_driver(mxs_dcp_driver);
1178 
1179 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1180 MODULE_DESCRIPTION("Freescale MXS DCP Driver");
1181 MODULE_LICENSE("GPL");
1182 MODULE_ALIAS("platform:mxs-dcp");
1183