xref: /openbmc/linux/drivers/crypto/mxs-dcp.c (revision aad7ebb5)
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 
24 #define DCP_MAX_CHANS	4
25 #define DCP_BUF_SZ	PAGE_SIZE
26 #define DCP_SHA_PAY_SZ  64
27 
28 #define DCP_ALIGNMENT	64
29 
30 /*
31  * Null hashes to align with hw behavior on imx6sl and ull
32  * these are flipped for consistency with hw output
33  */
34 static const uint8_t sha1_null_hash[] =
35 	"\x09\x07\xd8\xaf\x90\x18\x60\x95\xef\xbf"
36 	"\x55\x32\x0d\x4b\x6b\x5e\xee\xa3\x39\xda";
37 
38 static const uint8_t sha256_null_hash[] =
39 	"\x55\xb8\x52\x78\x1b\x99\x95\xa4"
40 	"\x4c\x93\x9b\x64\xe4\x41\xae\x27"
41 	"\x24\xb9\x6f\x99\xc8\xf4\xfb\x9a"
42 	"\x14\x1c\xfc\x98\x42\xc4\xb0\xe3";
43 
44 /* DCP DMA descriptor. */
45 struct dcp_dma_desc {
46 	uint32_t	next_cmd_addr;
47 	uint32_t	control0;
48 	uint32_t	control1;
49 	uint32_t	source;
50 	uint32_t	destination;
51 	uint32_t	size;
52 	uint32_t	payload;
53 	uint32_t	status;
54 };
55 
56 /* Coherent aligned block for bounce buffering. */
57 struct dcp_coherent_block {
58 	uint8_t			aes_in_buf[DCP_BUF_SZ];
59 	uint8_t			aes_out_buf[DCP_BUF_SZ];
60 	uint8_t			sha_in_buf[DCP_BUF_SZ];
61 	uint8_t			sha_out_buf[DCP_SHA_PAY_SZ];
62 
63 	uint8_t			aes_key[2 * AES_KEYSIZE_128];
64 
65 	struct dcp_dma_desc	desc[DCP_MAX_CHANS];
66 };
67 
68 struct dcp {
69 	struct device			*dev;
70 	void __iomem			*base;
71 
72 	uint32_t			caps;
73 
74 	struct dcp_coherent_block	*coh;
75 
76 	struct completion		completion[DCP_MAX_CHANS];
77 	spinlock_t			lock[DCP_MAX_CHANS];
78 	struct task_struct		*thread[DCP_MAX_CHANS];
79 	struct crypto_queue		queue[DCP_MAX_CHANS];
80 	struct clk			*dcp_clk;
81 };
82 
83 enum dcp_chan {
84 	DCP_CHAN_HASH_SHA	= 0,
85 	DCP_CHAN_CRYPTO		= 2,
86 };
87 
88 struct dcp_async_ctx {
89 	/* Common context */
90 	enum dcp_chan	chan;
91 	uint32_t	fill;
92 
93 	/* SHA Hash-specific context */
94 	struct mutex			mutex;
95 	uint32_t			alg;
96 	unsigned int			hot:1;
97 
98 	/* Crypto-specific context */
99 	struct crypto_sync_skcipher	*fallback;
100 	unsigned int			key_len;
101 	uint8_t				key[AES_KEYSIZE_128];
102 };
103 
104 struct dcp_aes_req_ctx {
105 	unsigned int	enc:1;
106 	unsigned int	ecb:1;
107 };
108 
109 struct dcp_sha_req_ctx {
110 	unsigned int	init:1;
111 	unsigned int	fini:1;
112 };
113 
114 struct dcp_export_state {
115 	struct dcp_sha_req_ctx req_ctx;
116 	struct dcp_async_ctx async_ctx;
117 };
118 
119 /*
120  * There can even be only one instance of the MXS DCP due to the
121  * design of Linux Crypto API.
122  */
123 static struct dcp *global_sdcp;
124 
125 /* DCP register layout. */
126 #define MXS_DCP_CTRL				0x00
127 #define MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES	(1 << 23)
128 #define MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING	(1 << 22)
129 
130 #define MXS_DCP_STAT				0x10
131 #define MXS_DCP_STAT_CLR			0x18
132 #define MXS_DCP_STAT_IRQ_MASK			0xf
133 
134 #define MXS_DCP_CHANNELCTRL			0x20
135 #define MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK	0xff
136 
137 #define MXS_DCP_CAPABILITY1			0x40
138 #define MXS_DCP_CAPABILITY1_SHA256		(4 << 16)
139 #define MXS_DCP_CAPABILITY1_SHA1		(1 << 16)
140 #define MXS_DCP_CAPABILITY1_AES128		(1 << 0)
141 
142 #define MXS_DCP_CONTEXT				0x50
143 
144 #define MXS_DCP_CH_N_CMDPTR(n)			(0x100 + ((n) * 0x40))
145 
146 #define MXS_DCP_CH_N_SEMA(n)			(0x110 + ((n) * 0x40))
147 
148 #define MXS_DCP_CH_N_STAT(n)			(0x120 + ((n) * 0x40))
149 #define MXS_DCP_CH_N_STAT_CLR(n)		(0x128 + ((n) * 0x40))
150 
151 /* DMA descriptor bits. */
152 #define MXS_DCP_CONTROL0_HASH_TERM		(1 << 13)
153 #define MXS_DCP_CONTROL0_HASH_INIT		(1 << 12)
154 #define MXS_DCP_CONTROL0_PAYLOAD_KEY		(1 << 11)
155 #define MXS_DCP_CONTROL0_CIPHER_ENCRYPT		(1 << 8)
156 #define MXS_DCP_CONTROL0_CIPHER_INIT		(1 << 9)
157 #define MXS_DCP_CONTROL0_ENABLE_HASH		(1 << 6)
158 #define MXS_DCP_CONTROL0_ENABLE_CIPHER		(1 << 5)
159 #define MXS_DCP_CONTROL0_DECR_SEMAPHORE		(1 << 1)
160 #define MXS_DCP_CONTROL0_INTERRUPT		(1 << 0)
161 
162 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA256	(2 << 16)
163 #define MXS_DCP_CONTROL1_HASH_SELECT_SHA1	(0 << 16)
164 #define MXS_DCP_CONTROL1_CIPHER_MODE_CBC	(1 << 4)
165 #define MXS_DCP_CONTROL1_CIPHER_MODE_ECB	(0 << 4)
166 #define MXS_DCP_CONTROL1_CIPHER_SELECT_AES128	(0 << 0)
167 
168 static int mxs_dcp_start_dma(struct dcp_async_ctx *actx)
169 {
170 	struct dcp *sdcp = global_sdcp;
171 	const int chan = actx->chan;
172 	uint32_t stat;
173 	unsigned long ret;
174 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
175 
176 	dma_addr_t desc_phys = dma_map_single(sdcp->dev, desc, sizeof(*desc),
177 					      DMA_TO_DEVICE);
178 
179 	reinit_completion(&sdcp->completion[chan]);
180 
181 	/* Clear status register. */
182 	writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(chan));
183 
184 	/* Load the DMA descriptor. */
185 	writel(desc_phys, sdcp->base + MXS_DCP_CH_N_CMDPTR(chan));
186 
187 	/* Increment the semaphore to start the DMA transfer. */
188 	writel(1, sdcp->base + MXS_DCP_CH_N_SEMA(chan));
189 
190 	ret = wait_for_completion_timeout(&sdcp->completion[chan],
191 					  msecs_to_jiffies(1000));
192 	if (!ret) {
193 		dev_err(sdcp->dev, "Channel %i timeout (DCP_STAT=0x%08x)\n",
194 			chan, readl(sdcp->base + MXS_DCP_STAT));
195 		return -ETIMEDOUT;
196 	}
197 
198 	stat = readl(sdcp->base + MXS_DCP_CH_N_STAT(chan));
199 	if (stat & 0xff) {
200 		dev_err(sdcp->dev, "Channel %i error (CH_STAT=0x%08x)\n",
201 			chan, stat);
202 		return -EINVAL;
203 	}
204 
205 	dma_unmap_single(sdcp->dev, desc_phys, sizeof(*desc), DMA_TO_DEVICE);
206 
207 	return 0;
208 }
209 
210 /*
211  * Encryption (AES128)
212  */
213 static int mxs_dcp_run_aes(struct dcp_async_ctx *actx,
214 			   struct skcipher_request *req, int init)
215 {
216 	struct dcp *sdcp = global_sdcp;
217 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
218 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
219 	int ret;
220 
221 	dma_addr_t key_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_key,
222 					     2 * AES_KEYSIZE_128,
223 					     DMA_TO_DEVICE);
224 	dma_addr_t src_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_in_buf,
225 					     DCP_BUF_SZ, DMA_TO_DEVICE);
226 	dma_addr_t dst_phys = dma_map_single(sdcp->dev, sdcp->coh->aes_out_buf,
227 					     DCP_BUF_SZ, DMA_FROM_DEVICE);
228 
229 	if (actx->fill % AES_BLOCK_SIZE) {
230 		dev_err(sdcp->dev, "Invalid block size!\n");
231 		ret = -EINVAL;
232 		goto aes_done_run;
233 	}
234 
235 	/* Fill in the DMA descriptor. */
236 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
237 		    MXS_DCP_CONTROL0_INTERRUPT |
238 		    MXS_DCP_CONTROL0_ENABLE_CIPHER;
239 
240 	/* Payload contains the key. */
241 	desc->control0 |= MXS_DCP_CONTROL0_PAYLOAD_KEY;
242 
243 	if (rctx->enc)
244 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_ENCRYPT;
245 	if (init)
246 		desc->control0 |= MXS_DCP_CONTROL0_CIPHER_INIT;
247 
248 	desc->control1 = MXS_DCP_CONTROL1_CIPHER_SELECT_AES128;
249 
250 	if (rctx->ecb)
251 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_ECB;
252 	else
253 		desc->control1 |= MXS_DCP_CONTROL1_CIPHER_MODE_CBC;
254 
255 	desc->next_cmd_addr = 0;
256 	desc->source = src_phys;
257 	desc->destination = dst_phys;
258 	desc->size = actx->fill;
259 	desc->payload = key_phys;
260 	desc->status = 0;
261 
262 	ret = mxs_dcp_start_dma(actx);
263 
264 aes_done_run:
265 	dma_unmap_single(sdcp->dev, key_phys, 2 * AES_KEYSIZE_128,
266 			 DMA_TO_DEVICE);
267 	dma_unmap_single(sdcp->dev, src_phys, DCP_BUF_SZ, DMA_TO_DEVICE);
268 	dma_unmap_single(sdcp->dev, dst_phys, DCP_BUF_SZ, DMA_FROM_DEVICE);
269 
270 	return ret;
271 }
272 
273 static int mxs_dcp_aes_block_crypt(struct crypto_async_request *arq)
274 {
275 	struct dcp *sdcp = global_sdcp;
276 
277 	struct skcipher_request *req = skcipher_request_cast(arq);
278 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
279 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
280 
281 	struct scatterlist *dst = req->dst;
282 	struct scatterlist *src = req->src;
283 	const int nents = sg_nents(req->src);
284 
285 	const int out_off = DCP_BUF_SZ;
286 	uint8_t *in_buf = sdcp->coh->aes_in_buf;
287 	uint8_t *out_buf = sdcp->coh->aes_out_buf;
288 
289 	uint8_t *out_tmp, *src_buf, *dst_buf = NULL;
290 	uint32_t dst_off = 0;
291 	uint32_t last_out_len = 0;
292 
293 	uint8_t *key = sdcp->coh->aes_key;
294 
295 	int ret = 0;
296 	int split = 0;
297 	unsigned int i, len, clen, rem = 0, tlen = 0;
298 	int init = 0;
299 	bool limit_hit = false;
300 
301 	actx->fill = 0;
302 
303 	/* Copy the key from the temporary location. */
304 	memcpy(key, actx->key, actx->key_len);
305 
306 	if (!rctx->ecb) {
307 		/* Copy the CBC IV just past the key. */
308 		memcpy(key + AES_KEYSIZE_128, req->iv, AES_KEYSIZE_128);
309 		/* CBC needs the INIT set. */
310 		init = 1;
311 	} else {
312 		memset(key + AES_KEYSIZE_128, 0, AES_KEYSIZE_128);
313 	}
314 
315 	for_each_sg(req->src, src, nents, i) {
316 		src_buf = sg_virt(src);
317 		len = sg_dma_len(src);
318 		tlen += len;
319 		limit_hit = tlen > req->cryptlen;
320 
321 		if (limit_hit)
322 			len = req->cryptlen - (tlen - len);
323 
324 		do {
325 			if (actx->fill + len > out_off)
326 				clen = out_off - actx->fill;
327 			else
328 				clen = len;
329 
330 			memcpy(in_buf + actx->fill, src_buf, clen);
331 			len -= clen;
332 			src_buf += clen;
333 			actx->fill += clen;
334 
335 			/*
336 			 * If we filled the buffer or this is the last SG,
337 			 * submit the buffer.
338 			 */
339 			if (actx->fill == out_off || sg_is_last(src) ||
340 				limit_hit) {
341 				ret = mxs_dcp_run_aes(actx, req, init);
342 				if (ret)
343 					return ret;
344 				init = 0;
345 
346 				out_tmp = out_buf;
347 				last_out_len = actx->fill;
348 				while (dst && actx->fill) {
349 					if (!split) {
350 						dst_buf = sg_virt(dst);
351 						dst_off = 0;
352 					}
353 					rem = min(sg_dma_len(dst) - dst_off,
354 						  actx->fill);
355 
356 					memcpy(dst_buf + dst_off, out_tmp, rem);
357 					out_tmp += rem;
358 					dst_off += rem;
359 					actx->fill -= rem;
360 
361 					if (dst_off == sg_dma_len(dst)) {
362 						dst = sg_next(dst);
363 						split = 0;
364 					} else {
365 						split = 1;
366 					}
367 				}
368 			}
369 		} while (len);
370 
371 		if (limit_hit)
372 			break;
373 	}
374 
375 	/* Copy the IV for CBC for chaining */
376 	if (!rctx->ecb) {
377 		if (rctx->enc)
378 			memcpy(req->iv, out_buf+(last_out_len-AES_BLOCK_SIZE),
379 				AES_BLOCK_SIZE);
380 		else
381 			memcpy(req->iv, in_buf+(last_out_len-AES_BLOCK_SIZE),
382 				AES_BLOCK_SIZE);
383 	}
384 
385 	return ret;
386 }
387 
388 static int dcp_chan_thread_aes(void *data)
389 {
390 	struct dcp *sdcp = global_sdcp;
391 	const int chan = DCP_CHAN_CRYPTO;
392 
393 	struct crypto_async_request *backlog;
394 	struct crypto_async_request *arq;
395 
396 	int ret;
397 
398 	while (!kthread_should_stop()) {
399 		set_current_state(TASK_INTERRUPTIBLE);
400 
401 		spin_lock(&sdcp->lock[chan]);
402 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
403 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
404 		spin_unlock(&sdcp->lock[chan]);
405 
406 		if (!backlog && !arq) {
407 			schedule();
408 			continue;
409 		}
410 
411 		set_current_state(TASK_RUNNING);
412 
413 		if (backlog)
414 			backlog->complete(backlog, -EINPROGRESS);
415 
416 		if (arq) {
417 			ret = mxs_dcp_aes_block_crypt(arq);
418 			arq->complete(arq, ret);
419 		}
420 	}
421 
422 	return 0;
423 }
424 
425 static int mxs_dcp_block_fallback(struct skcipher_request *req, int enc)
426 {
427 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
428 	struct dcp_async_ctx *ctx = crypto_skcipher_ctx(tfm);
429 	SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
430 	int ret;
431 
432 	skcipher_request_set_sync_tfm(subreq, ctx->fallback);
433 	skcipher_request_set_callback(subreq, req->base.flags, NULL, NULL);
434 	skcipher_request_set_crypt(subreq, req->src, req->dst,
435 				   req->cryptlen, req->iv);
436 
437 	if (enc)
438 		ret = crypto_skcipher_encrypt(subreq);
439 	else
440 		ret = crypto_skcipher_decrypt(subreq);
441 
442 	skcipher_request_zero(subreq);
443 
444 	return ret;
445 }
446 
447 static int mxs_dcp_aes_enqueue(struct skcipher_request *req, int enc, int ecb)
448 {
449 	struct dcp *sdcp = global_sdcp;
450 	struct crypto_async_request *arq = &req->base;
451 	struct dcp_async_ctx *actx = crypto_tfm_ctx(arq->tfm);
452 	struct dcp_aes_req_ctx *rctx = skcipher_request_ctx(req);
453 	int ret;
454 
455 	if (unlikely(actx->key_len != AES_KEYSIZE_128))
456 		return mxs_dcp_block_fallback(req, enc);
457 
458 	rctx->enc = enc;
459 	rctx->ecb = ecb;
460 	actx->chan = DCP_CHAN_CRYPTO;
461 
462 	spin_lock(&sdcp->lock[actx->chan]);
463 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
464 	spin_unlock(&sdcp->lock[actx->chan]);
465 
466 	wake_up_process(sdcp->thread[actx->chan]);
467 
468 	return ret;
469 }
470 
471 static int mxs_dcp_aes_ecb_decrypt(struct skcipher_request *req)
472 {
473 	return mxs_dcp_aes_enqueue(req, 0, 1);
474 }
475 
476 static int mxs_dcp_aes_ecb_encrypt(struct skcipher_request *req)
477 {
478 	return mxs_dcp_aes_enqueue(req, 1, 1);
479 }
480 
481 static int mxs_dcp_aes_cbc_decrypt(struct skcipher_request *req)
482 {
483 	return mxs_dcp_aes_enqueue(req, 0, 0);
484 }
485 
486 static int mxs_dcp_aes_cbc_encrypt(struct skcipher_request *req)
487 {
488 	return mxs_dcp_aes_enqueue(req, 1, 0);
489 }
490 
491 static int mxs_dcp_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,
492 			      unsigned int len)
493 {
494 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
495 	unsigned int ret;
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 
517 	ret = crypto_sync_skcipher_setkey(actx->fallback, key, len);
518 	if (!ret)
519 		return 0;
520 
521 	tfm->base.crt_flags &= ~CRYPTO_TFM_RES_MASK;
522 	tfm->base.crt_flags |= crypto_sync_skcipher_get_flags(actx->fallback) &
523 			       CRYPTO_TFM_RES_MASK;
524 
525 	return ret;
526 }
527 
528 static int mxs_dcp_aes_fallback_init_tfm(struct crypto_skcipher *tfm)
529 {
530 	const char *name = crypto_tfm_alg_name(crypto_skcipher_tfm(tfm));
531 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
532 	struct crypto_sync_skcipher *blk;
533 
534 	blk = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
535 	if (IS_ERR(blk))
536 		return PTR_ERR(blk);
537 
538 	actx->fallback = blk;
539 	crypto_skcipher_set_reqsize(tfm, sizeof(struct dcp_aes_req_ctx));
540 	return 0;
541 }
542 
543 static void mxs_dcp_aes_fallback_exit_tfm(struct crypto_skcipher *tfm)
544 {
545 	struct dcp_async_ctx *actx = crypto_skcipher_ctx(tfm);
546 
547 	crypto_free_sync_skcipher(actx->fallback);
548 }
549 
550 /*
551  * Hashing (SHA1/SHA256)
552  */
553 static int mxs_dcp_run_sha(struct ahash_request *req)
554 {
555 	struct dcp *sdcp = global_sdcp;
556 	int ret;
557 
558 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
559 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
560 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
561 	struct dcp_dma_desc *desc = &sdcp->coh->desc[actx->chan];
562 
563 	dma_addr_t digest_phys = 0;
564 	dma_addr_t buf_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_in_buf,
565 					     DCP_BUF_SZ, DMA_TO_DEVICE);
566 
567 	/* Fill in the DMA descriptor. */
568 	desc->control0 = MXS_DCP_CONTROL0_DECR_SEMAPHORE |
569 		    MXS_DCP_CONTROL0_INTERRUPT |
570 		    MXS_DCP_CONTROL0_ENABLE_HASH;
571 	if (rctx->init)
572 		desc->control0 |= MXS_DCP_CONTROL0_HASH_INIT;
573 
574 	desc->control1 = actx->alg;
575 	desc->next_cmd_addr = 0;
576 	desc->source = buf_phys;
577 	desc->destination = 0;
578 	desc->size = actx->fill;
579 	desc->payload = 0;
580 	desc->status = 0;
581 
582 	/*
583 	 * Align driver with hw behavior when generating null hashes
584 	 */
585 	if (rctx->init && rctx->fini && desc->size == 0) {
586 		struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
587 		const uint8_t *sha_buf =
588 			(actx->alg == MXS_DCP_CONTROL1_HASH_SELECT_SHA1) ?
589 			sha1_null_hash : sha256_null_hash;
590 		memcpy(sdcp->coh->sha_out_buf, sha_buf, halg->digestsize);
591 		ret = 0;
592 		goto done_run;
593 	}
594 
595 	/* Set HASH_TERM bit for last transfer block. */
596 	if (rctx->fini) {
597 		digest_phys = dma_map_single(sdcp->dev, sdcp->coh->sha_out_buf,
598 					     DCP_SHA_PAY_SZ, DMA_FROM_DEVICE);
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 	const int nents = sg_nents(req->src);
625 
626 	uint8_t *in_buf = sdcp->coh->sha_in_buf;
627 	uint8_t *out_buf = sdcp->coh->sha_out_buf;
628 
629 	uint8_t *src_buf;
630 
631 	struct scatterlist *src;
632 
633 	unsigned int i, len, clen;
634 	int ret;
635 
636 	int fin = rctx->fini;
637 	if (fin)
638 		rctx->fini = 0;
639 
640 	for_each_sg(req->src, src, nents, i) {
641 		src_buf = sg_virt(src);
642 		len = sg_dma_len(src);
643 
644 		do {
645 			if (actx->fill + len > DCP_BUF_SZ)
646 				clen = DCP_BUF_SZ - actx->fill;
647 			else
648 				clen = len;
649 
650 			memcpy(in_buf + actx->fill, src_buf, clen);
651 			len -= clen;
652 			src_buf += clen;
653 			actx->fill += clen;
654 
655 			/*
656 			 * If we filled the buffer and still have some
657 			 * more data, submit the buffer.
658 			 */
659 			if (len && actx->fill == DCP_BUF_SZ) {
660 				ret = mxs_dcp_run_sha(req);
661 				if (ret)
662 					return ret;
663 				actx->fill = 0;
664 				rctx->init = 0;
665 			}
666 		} while (len);
667 	}
668 
669 	if (fin) {
670 		rctx->fini = 1;
671 
672 		/* Submit whatever is left. */
673 		if (!req->result)
674 			return -EINVAL;
675 
676 		ret = mxs_dcp_run_sha(req);
677 		if (ret)
678 			return ret;
679 
680 		actx->fill = 0;
681 
682 		/* For some reason the result is flipped */
683 		for (i = 0; i < halg->digestsize; i++)
684 			req->result[i] = out_buf[halg->digestsize - i - 1];
685 	}
686 
687 	return 0;
688 }
689 
690 static int dcp_chan_thread_sha(void *data)
691 {
692 	struct dcp *sdcp = global_sdcp;
693 	const int chan = DCP_CHAN_HASH_SHA;
694 
695 	struct crypto_async_request *backlog;
696 	struct crypto_async_request *arq;
697 	int ret;
698 
699 	while (!kthread_should_stop()) {
700 		set_current_state(TASK_INTERRUPTIBLE);
701 
702 		spin_lock(&sdcp->lock[chan]);
703 		backlog = crypto_get_backlog(&sdcp->queue[chan]);
704 		arq = crypto_dequeue_request(&sdcp->queue[chan]);
705 		spin_unlock(&sdcp->lock[chan]);
706 
707 		if (!backlog && !arq) {
708 			schedule();
709 			continue;
710 		}
711 
712 		set_current_state(TASK_RUNNING);
713 
714 		if (backlog)
715 			backlog->complete(backlog, -EINPROGRESS);
716 
717 		if (arq) {
718 			ret = dcp_sha_req_to_buf(arq);
719 			arq->complete(arq, ret);
720 		}
721 	}
722 
723 	return 0;
724 }
725 
726 static int dcp_sha_init(struct ahash_request *req)
727 {
728 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
729 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
730 
731 	struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
732 
733 	/*
734 	 * Start hashing session. The code below only inits the
735 	 * hashing session context, nothing more.
736 	 */
737 	memset(actx, 0, sizeof(*actx));
738 
739 	if (strcmp(halg->base.cra_name, "sha1") == 0)
740 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA1;
741 	else
742 		actx->alg = MXS_DCP_CONTROL1_HASH_SELECT_SHA256;
743 
744 	actx->fill = 0;
745 	actx->hot = 0;
746 	actx->chan = DCP_CHAN_HASH_SHA;
747 
748 	mutex_init(&actx->mutex);
749 
750 	return 0;
751 }
752 
753 static int dcp_sha_update_fx(struct ahash_request *req, int fini)
754 {
755 	struct dcp *sdcp = global_sdcp;
756 
757 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
758 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
759 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
760 
761 	int ret;
762 
763 	/*
764 	 * Ignore requests that have no data in them and are not
765 	 * the trailing requests in the stream of requests.
766 	 */
767 	if (!req->nbytes && !fini)
768 		return 0;
769 
770 	mutex_lock(&actx->mutex);
771 
772 	rctx->fini = fini;
773 
774 	if (!actx->hot) {
775 		actx->hot = 1;
776 		rctx->init = 1;
777 	}
778 
779 	spin_lock(&sdcp->lock[actx->chan]);
780 	ret = crypto_enqueue_request(&sdcp->queue[actx->chan], &req->base);
781 	spin_unlock(&sdcp->lock[actx->chan]);
782 
783 	wake_up_process(sdcp->thread[actx->chan]);
784 	mutex_unlock(&actx->mutex);
785 
786 	return ret;
787 }
788 
789 static int dcp_sha_update(struct ahash_request *req)
790 {
791 	return dcp_sha_update_fx(req, 0);
792 }
793 
794 static int dcp_sha_final(struct ahash_request *req)
795 {
796 	ahash_request_set_crypt(req, NULL, req->result, 0);
797 	req->nbytes = 0;
798 	return dcp_sha_update_fx(req, 1);
799 }
800 
801 static int dcp_sha_finup(struct ahash_request *req)
802 {
803 	return dcp_sha_update_fx(req, 1);
804 }
805 
806 static int dcp_sha_digest(struct ahash_request *req)
807 {
808 	int ret;
809 
810 	ret = dcp_sha_init(req);
811 	if (ret)
812 		return ret;
813 
814 	return dcp_sha_finup(req);
815 }
816 
817 static int dcp_sha_import(struct ahash_request *req, const void *in)
818 {
819 	struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
820 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
821 	struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
822 	const struct dcp_export_state *export = in;
823 
824 	memset(rctx, 0, sizeof(struct dcp_sha_req_ctx));
825 	memset(actx, 0, sizeof(struct dcp_async_ctx));
826 	memcpy(rctx, &export->req_ctx, sizeof(struct dcp_sha_req_ctx));
827 	memcpy(actx, &export->async_ctx, sizeof(struct dcp_async_ctx));
828 
829 	return 0;
830 }
831 
832 static int dcp_sha_export(struct ahash_request *req, void *out)
833 {
834 	struct dcp_sha_req_ctx *rctx_state = ahash_request_ctx(req);
835 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
836 	struct dcp_async_ctx *actx_state = crypto_ahash_ctx(tfm);
837 	struct dcp_export_state *export = out;
838 
839 	memcpy(&export->req_ctx, rctx_state, sizeof(struct dcp_sha_req_ctx));
840 	memcpy(&export->async_ctx, actx_state, sizeof(struct dcp_async_ctx));
841 
842 	return 0;
843 }
844 
845 static int dcp_sha_cra_init(struct crypto_tfm *tfm)
846 {
847 	crypto_ahash_set_reqsize(__crypto_ahash_cast(tfm),
848 				 sizeof(struct dcp_sha_req_ctx));
849 	return 0;
850 }
851 
852 static void dcp_sha_cra_exit(struct crypto_tfm *tfm)
853 {
854 }
855 
856 /* AES 128 ECB and AES 128 CBC */
857 static struct skcipher_alg dcp_aes_algs[] = {
858 	{
859 		.base.cra_name		= "ecb(aes)",
860 		.base.cra_driver_name	= "ecb-aes-dcp",
861 		.base.cra_priority	= 400,
862 		.base.cra_alignmask	= 15,
863 		.base.cra_flags		= CRYPTO_ALG_ASYNC |
864 					  CRYPTO_ALG_NEED_FALLBACK,
865 		.base.cra_blocksize	= AES_BLOCK_SIZE,
866 		.base.cra_ctxsize	= sizeof(struct dcp_async_ctx),
867 		.base.cra_module	= THIS_MODULE,
868 
869 		.min_keysize		= AES_MIN_KEY_SIZE,
870 		.max_keysize		= AES_MAX_KEY_SIZE,
871 		.setkey			= mxs_dcp_aes_setkey,
872 		.encrypt		= mxs_dcp_aes_ecb_encrypt,
873 		.decrypt		= mxs_dcp_aes_ecb_decrypt,
874 		.init			= mxs_dcp_aes_fallback_init_tfm,
875 		.exit			= mxs_dcp_aes_fallback_exit_tfm,
876 	}, {
877 		.base.cra_name		= "cbc(aes)",
878 		.base.cra_driver_name	= "cbc-aes-dcp",
879 		.base.cra_priority	= 400,
880 		.base.cra_alignmask	= 15,
881 		.base.cra_flags		= CRYPTO_ALG_ASYNC |
882 					  CRYPTO_ALG_NEED_FALLBACK,
883 		.base.cra_blocksize	= AES_BLOCK_SIZE,
884 		.base.cra_ctxsize	= sizeof(struct dcp_async_ctx),
885 		.base.cra_module	= THIS_MODULE,
886 
887 		.min_keysize		= AES_MIN_KEY_SIZE,
888 		.max_keysize		= AES_MAX_KEY_SIZE,
889 		.setkey			= mxs_dcp_aes_setkey,
890 		.encrypt		= mxs_dcp_aes_cbc_encrypt,
891 		.decrypt		= mxs_dcp_aes_cbc_decrypt,
892 		.ivsize			= AES_BLOCK_SIZE,
893 		.init			= mxs_dcp_aes_fallback_init_tfm,
894 		.exit			= mxs_dcp_aes_fallback_exit_tfm,
895 	},
896 };
897 
898 /* SHA1 */
899 static struct ahash_alg dcp_sha1_alg = {
900 	.init	= dcp_sha_init,
901 	.update	= dcp_sha_update,
902 	.final	= dcp_sha_final,
903 	.finup	= dcp_sha_finup,
904 	.digest	= dcp_sha_digest,
905 	.import = dcp_sha_import,
906 	.export = dcp_sha_export,
907 	.halg	= {
908 		.digestsize	= SHA1_DIGEST_SIZE,
909 		.statesize	= sizeof(struct dcp_export_state),
910 		.base		= {
911 			.cra_name		= "sha1",
912 			.cra_driver_name	= "sha1-dcp",
913 			.cra_priority		= 400,
914 			.cra_alignmask		= 63,
915 			.cra_flags		= CRYPTO_ALG_ASYNC,
916 			.cra_blocksize		= SHA1_BLOCK_SIZE,
917 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
918 			.cra_module		= THIS_MODULE,
919 			.cra_init		= dcp_sha_cra_init,
920 			.cra_exit		= dcp_sha_cra_exit,
921 		},
922 	},
923 };
924 
925 /* SHA256 */
926 static struct ahash_alg dcp_sha256_alg = {
927 	.init	= dcp_sha_init,
928 	.update	= dcp_sha_update,
929 	.final	= dcp_sha_final,
930 	.finup	= dcp_sha_finup,
931 	.digest	= dcp_sha_digest,
932 	.import = dcp_sha_import,
933 	.export = dcp_sha_export,
934 	.halg	= {
935 		.digestsize	= SHA256_DIGEST_SIZE,
936 		.statesize	= sizeof(struct dcp_export_state),
937 		.base		= {
938 			.cra_name		= "sha256",
939 			.cra_driver_name	= "sha256-dcp",
940 			.cra_priority		= 400,
941 			.cra_alignmask		= 63,
942 			.cra_flags		= CRYPTO_ALG_ASYNC,
943 			.cra_blocksize		= SHA256_BLOCK_SIZE,
944 			.cra_ctxsize		= sizeof(struct dcp_async_ctx),
945 			.cra_module		= THIS_MODULE,
946 			.cra_init		= dcp_sha_cra_init,
947 			.cra_exit		= dcp_sha_cra_exit,
948 		},
949 	},
950 };
951 
952 static irqreturn_t mxs_dcp_irq(int irq, void *context)
953 {
954 	struct dcp *sdcp = context;
955 	uint32_t stat;
956 	int i;
957 
958 	stat = readl(sdcp->base + MXS_DCP_STAT);
959 	stat &= MXS_DCP_STAT_IRQ_MASK;
960 	if (!stat)
961 		return IRQ_NONE;
962 
963 	/* Clear the interrupts. */
964 	writel(stat, sdcp->base + MXS_DCP_STAT_CLR);
965 
966 	/* Complete the DMA requests that finished. */
967 	for (i = 0; i < DCP_MAX_CHANS; i++)
968 		if (stat & (1 << i))
969 			complete(&sdcp->completion[i]);
970 
971 	return IRQ_HANDLED;
972 }
973 
974 static int mxs_dcp_probe(struct platform_device *pdev)
975 {
976 	struct device *dev = &pdev->dev;
977 	struct dcp *sdcp = NULL;
978 	int i, ret;
979 	int dcp_vmi_irq, dcp_irq;
980 
981 	if (global_sdcp) {
982 		dev_err(dev, "Only one DCP instance allowed!\n");
983 		return -ENODEV;
984 	}
985 
986 	dcp_vmi_irq = platform_get_irq(pdev, 0);
987 	if (dcp_vmi_irq < 0)
988 		return dcp_vmi_irq;
989 
990 	dcp_irq = platform_get_irq(pdev, 1);
991 	if (dcp_irq < 0)
992 		return dcp_irq;
993 
994 	sdcp = devm_kzalloc(dev, sizeof(*sdcp), GFP_KERNEL);
995 	if (!sdcp)
996 		return -ENOMEM;
997 
998 	sdcp->dev = dev;
999 	sdcp->base = devm_platform_ioremap_resource(pdev, 0);
1000 	if (IS_ERR(sdcp->base))
1001 		return PTR_ERR(sdcp->base);
1002 
1003 
1004 	ret = devm_request_irq(dev, dcp_vmi_irq, mxs_dcp_irq, 0,
1005 			       "dcp-vmi-irq", sdcp);
1006 	if (ret) {
1007 		dev_err(dev, "Failed to claim DCP VMI IRQ!\n");
1008 		return ret;
1009 	}
1010 
1011 	ret = devm_request_irq(dev, dcp_irq, mxs_dcp_irq, 0,
1012 			       "dcp-irq", sdcp);
1013 	if (ret) {
1014 		dev_err(dev, "Failed to claim DCP IRQ!\n");
1015 		return ret;
1016 	}
1017 
1018 	/* Allocate coherent helper block. */
1019 	sdcp->coh = devm_kzalloc(dev, sizeof(*sdcp->coh) + DCP_ALIGNMENT,
1020 				   GFP_KERNEL);
1021 	if (!sdcp->coh)
1022 		return -ENOMEM;
1023 
1024 	/* Re-align the structure so it fits the DCP constraints. */
1025 	sdcp->coh = PTR_ALIGN(sdcp->coh, DCP_ALIGNMENT);
1026 
1027 	/* DCP clock is optional, only used on some SOCs */
1028 	sdcp->dcp_clk = devm_clk_get(dev, "dcp");
1029 	if (IS_ERR(sdcp->dcp_clk)) {
1030 		if (sdcp->dcp_clk != ERR_PTR(-ENOENT))
1031 			return PTR_ERR(sdcp->dcp_clk);
1032 		sdcp->dcp_clk = NULL;
1033 	}
1034 	ret = clk_prepare_enable(sdcp->dcp_clk);
1035 	if (ret)
1036 		return ret;
1037 
1038 	/* Restart the DCP block. */
1039 	ret = stmp_reset_block(sdcp->base);
1040 	if (ret) {
1041 		dev_err(dev, "Failed reset\n");
1042 		goto err_disable_unprepare_clk;
1043 	}
1044 
1045 	/* Initialize control register. */
1046 	writel(MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES |
1047 	       MXS_DCP_CTRL_ENABLE_CONTEXT_CACHING | 0xf,
1048 	       sdcp->base + MXS_DCP_CTRL);
1049 
1050 	/* Enable all DCP DMA channels. */
1051 	writel(MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK,
1052 	       sdcp->base + MXS_DCP_CHANNELCTRL);
1053 
1054 	/*
1055 	 * We do not enable context switching. Give the context buffer a
1056 	 * pointer to an illegal address so if context switching is
1057 	 * inadvertantly enabled, the DCP will return an error instead of
1058 	 * trashing good memory. The DCP DMA cannot access ROM, so any ROM
1059 	 * address will do.
1060 	 */
1061 	writel(0xffff0000, sdcp->base + MXS_DCP_CONTEXT);
1062 	for (i = 0; i < DCP_MAX_CHANS; i++)
1063 		writel(0xffffffff, sdcp->base + MXS_DCP_CH_N_STAT_CLR(i));
1064 	writel(0xffffffff, sdcp->base + MXS_DCP_STAT_CLR);
1065 
1066 	global_sdcp = sdcp;
1067 
1068 	platform_set_drvdata(pdev, sdcp);
1069 
1070 	for (i = 0; i < DCP_MAX_CHANS; i++) {
1071 		spin_lock_init(&sdcp->lock[i]);
1072 		init_completion(&sdcp->completion[i]);
1073 		crypto_init_queue(&sdcp->queue[i], 50);
1074 	}
1075 
1076 	/* Create the SHA and AES handler threads. */
1077 	sdcp->thread[DCP_CHAN_HASH_SHA] = kthread_run(dcp_chan_thread_sha,
1078 						      NULL, "mxs_dcp_chan/sha");
1079 	if (IS_ERR(sdcp->thread[DCP_CHAN_HASH_SHA])) {
1080 		dev_err(dev, "Error starting SHA thread!\n");
1081 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_HASH_SHA]);
1082 		goto err_disable_unprepare_clk;
1083 	}
1084 
1085 	sdcp->thread[DCP_CHAN_CRYPTO] = kthread_run(dcp_chan_thread_aes,
1086 						    NULL, "mxs_dcp_chan/aes");
1087 	if (IS_ERR(sdcp->thread[DCP_CHAN_CRYPTO])) {
1088 		dev_err(dev, "Error starting SHA thread!\n");
1089 		ret = PTR_ERR(sdcp->thread[DCP_CHAN_CRYPTO]);
1090 		goto err_destroy_sha_thread;
1091 	}
1092 
1093 	/* Register the various crypto algorithms. */
1094 	sdcp->caps = readl(sdcp->base + MXS_DCP_CAPABILITY1);
1095 
1096 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128) {
1097 		ret = crypto_register_skciphers(dcp_aes_algs,
1098 						ARRAY_SIZE(dcp_aes_algs));
1099 		if (ret) {
1100 			/* Failed to register algorithm. */
1101 			dev_err(dev, "Failed to register AES crypto!\n");
1102 			goto err_destroy_aes_thread;
1103 		}
1104 	}
1105 
1106 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1) {
1107 		ret = crypto_register_ahash(&dcp_sha1_alg);
1108 		if (ret) {
1109 			dev_err(dev, "Failed to register %s hash!\n",
1110 				dcp_sha1_alg.halg.base.cra_name);
1111 			goto err_unregister_aes;
1112 		}
1113 	}
1114 
1115 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256) {
1116 		ret = crypto_register_ahash(&dcp_sha256_alg);
1117 		if (ret) {
1118 			dev_err(dev, "Failed to register %s hash!\n",
1119 				dcp_sha256_alg.halg.base.cra_name);
1120 			goto err_unregister_sha1;
1121 		}
1122 	}
1123 
1124 	return 0;
1125 
1126 err_unregister_sha1:
1127 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1128 		crypto_unregister_ahash(&dcp_sha1_alg);
1129 
1130 err_unregister_aes:
1131 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1132 		crypto_unregister_skciphers(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1133 
1134 err_destroy_aes_thread:
1135 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1136 
1137 err_destroy_sha_thread:
1138 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1139 
1140 err_disable_unprepare_clk:
1141 	clk_disable_unprepare(sdcp->dcp_clk);
1142 
1143 	return ret;
1144 }
1145 
1146 static int mxs_dcp_remove(struct platform_device *pdev)
1147 {
1148 	struct dcp *sdcp = platform_get_drvdata(pdev);
1149 
1150 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA256)
1151 		crypto_unregister_ahash(&dcp_sha256_alg);
1152 
1153 	if (sdcp->caps & MXS_DCP_CAPABILITY1_SHA1)
1154 		crypto_unregister_ahash(&dcp_sha1_alg);
1155 
1156 	if (sdcp->caps & MXS_DCP_CAPABILITY1_AES128)
1157 		crypto_unregister_skciphers(dcp_aes_algs, ARRAY_SIZE(dcp_aes_algs));
1158 
1159 	kthread_stop(sdcp->thread[DCP_CHAN_HASH_SHA]);
1160 	kthread_stop(sdcp->thread[DCP_CHAN_CRYPTO]);
1161 
1162 	clk_disable_unprepare(sdcp->dcp_clk);
1163 
1164 	platform_set_drvdata(pdev, NULL);
1165 
1166 	global_sdcp = NULL;
1167 
1168 	return 0;
1169 }
1170 
1171 static const struct of_device_id mxs_dcp_dt_ids[] = {
1172 	{ .compatible = "fsl,imx23-dcp", .data = NULL, },
1173 	{ .compatible = "fsl,imx28-dcp", .data = NULL, },
1174 	{ /* sentinel */ }
1175 };
1176 
1177 MODULE_DEVICE_TABLE(of, mxs_dcp_dt_ids);
1178 
1179 static struct platform_driver mxs_dcp_driver = {
1180 	.probe	= mxs_dcp_probe,
1181 	.remove	= mxs_dcp_remove,
1182 	.driver	= {
1183 		.name		= "mxs-dcp",
1184 		.of_match_table	= mxs_dcp_dt_ids,
1185 	},
1186 };
1187 
1188 module_platform_driver(mxs_dcp_driver);
1189 
1190 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1191 MODULE_DESCRIPTION("Freescale MXS DCP Driver");
1192 MODULE_LICENSE("GPL");
1193 MODULE_ALIAS("platform:mxs-dcp");
1194