xref: /openbmc/linux/drivers/crypto/sahara.c (revision 7b6d864b)
1 /*
2  * Cryptographic API.
3  *
4  * Support for SAHARA cryptographic accelerator.
5  *
6  * Copyright (c) 2013 Vista Silicon S.L.
7  * Author: Javier Martin <javier.martin@vista-silicon.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as published
11  * by the Free Software Foundation.
12  *
13  * Based on omap-aes.c and tegra-aes.c
14  */
15 
16 #include <crypto/algapi.h>
17 #include <crypto/aes.h>
18 
19 #include <linux/clk.h>
20 #include <linux/crypto.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/irq.h>
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/of.h>
27 #include <linux/platform_device.h>
28 
29 #define SAHARA_NAME "sahara"
30 #define SAHARA_VERSION_3	3
31 #define SAHARA_TIMEOUT_MS	1000
32 #define SAHARA_MAX_HW_DESC	2
33 #define SAHARA_MAX_HW_LINK	20
34 
35 #define FLAGS_MODE_MASK		0x000f
36 #define FLAGS_ENCRYPT		BIT(0)
37 #define FLAGS_CBC		BIT(1)
38 #define FLAGS_NEW_KEY		BIT(3)
39 #define FLAGS_BUSY		4
40 
41 #define SAHARA_HDR_BASE			0x00800000
42 #define SAHARA_HDR_SKHA_ALG_AES	0
43 #define SAHARA_HDR_SKHA_OP_ENC		(1 << 2)
44 #define SAHARA_HDR_SKHA_MODE_ECB	(0 << 3)
45 #define SAHARA_HDR_SKHA_MODE_CBC	(1 << 3)
46 #define SAHARA_HDR_FORM_DATA		(5 << 16)
47 #define SAHARA_HDR_FORM_KEY		(8 << 16)
48 #define SAHARA_HDR_LLO			(1 << 24)
49 #define SAHARA_HDR_CHA_SKHA		(1 << 28)
50 #define SAHARA_HDR_CHA_MDHA		(2 << 28)
51 #define SAHARA_HDR_PARITY_BIT		(1 << 31)
52 
53 /* SAHARA can only process one request at a time */
54 #define SAHARA_QUEUE_LENGTH	1
55 
56 #define SAHARA_REG_VERSION	0x00
57 #define SAHARA_REG_DAR		0x04
58 #define SAHARA_REG_CONTROL	0x08
59 #define		SAHARA_CONTROL_SET_THROTTLE(x)	(((x) & 0xff) << 24)
60 #define		SAHARA_CONTROL_SET_MAXBURST(x)	(((x) & 0xff) << 16)
61 #define		SAHARA_CONTROL_RNG_AUTORSD	(1 << 7)
62 #define		SAHARA_CONTROL_ENABLE_INT	(1 << 4)
63 #define SAHARA_REG_CMD		0x0C
64 #define		SAHARA_CMD_RESET		(1 << 0)
65 #define		SAHARA_CMD_CLEAR_INT		(1 << 8)
66 #define		SAHARA_CMD_CLEAR_ERR		(1 << 9)
67 #define		SAHARA_CMD_SINGLE_STEP		(1 << 10)
68 #define		SAHARA_CMD_MODE_BATCH		(1 << 16)
69 #define		SAHARA_CMD_MODE_DEBUG		(1 << 18)
70 #define	SAHARA_REG_STATUS	0x10
71 #define		SAHARA_STATUS_GET_STATE(x)	((x) & 0x7)
72 #define			SAHARA_STATE_IDLE	0
73 #define			SAHARA_STATE_BUSY	1
74 #define			SAHARA_STATE_ERR	2
75 #define			SAHARA_STATE_FAULT	3
76 #define			SAHARA_STATE_COMPLETE	4
77 #define			SAHARA_STATE_COMP_FLAG	(1 << 2)
78 #define		SAHARA_STATUS_DAR_FULL		(1 << 3)
79 #define		SAHARA_STATUS_ERROR		(1 << 4)
80 #define		SAHARA_STATUS_SECURE		(1 << 5)
81 #define		SAHARA_STATUS_FAIL		(1 << 6)
82 #define		SAHARA_STATUS_INIT		(1 << 7)
83 #define		SAHARA_STATUS_RNG_RESEED	(1 << 8)
84 #define		SAHARA_STATUS_ACTIVE_RNG	(1 << 9)
85 #define		SAHARA_STATUS_ACTIVE_MDHA	(1 << 10)
86 #define		SAHARA_STATUS_ACTIVE_SKHA	(1 << 11)
87 #define		SAHARA_STATUS_MODE_BATCH	(1 << 16)
88 #define		SAHARA_STATUS_MODE_DEDICATED	(1 << 17)
89 #define		SAHARA_STATUS_MODE_DEBUG	(1 << 18)
90 #define		SAHARA_STATUS_GET_ISTATE(x)	(((x) >> 24) & 0xff)
91 #define SAHARA_REG_ERRSTATUS	0x14
92 #define		SAHARA_ERRSTATUS_GET_SOURCE(x)	((x) & 0xf)
93 #define			SAHARA_ERRSOURCE_CHA	14
94 #define			SAHARA_ERRSOURCE_DMA	15
95 #define		SAHARA_ERRSTATUS_DMA_DIR	(1 << 8)
96 #define		SAHARA_ERRSTATUS_GET_DMASZ(x)(((x) >> 9) & 0x3)
97 #define		SAHARA_ERRSTATUS_GET_DMASRC(x) (((x) >> 13) & 0x7)
98 #define		SAHARA_ERRSTATUS_GET_CHASRC(x)	(((x) >> 16) & 0xfff)
99 #define		SAHARA_ERRSTATUS_GET_CHAERR(x)	(((x) >> 28) & 0x3)
100 #define SAHARA_REG_FADDR	0x18
101 #define SAHARA_REG_CDAR		0x1C
102 #define SAHARA_REG_IDAR		0x20
103 
104 struct sahara_hw_desc {
105 	u32		hdr;
106 	u32		len1;
107 	dma_addr_t	p1;
108 	u32		len2;
109 	dma_addr_t	p2;
110 	dma_addr_t	next;
111 };
112 
113 struct sahara_hw_link {
114 	u32		len;
115 	dma_addr_t	p;
116 	dma_addr_t	next;
117 };
118 
119 struct sahara_ctx {
120 	struct sahara_dev *dev;
121 	unsigned long flags;
122 	int keylen;
123 	u8 key[AES_KEYSIZE_128];
124 	struct crypto_ablkcipher *fallback;
125 };
126 
127 struct sahara_aes_reqctx {
128 	unsigned long mode;
129 };
130 
131 struct sahara_dev {
132 	struct device		*device;
133 	void __iomem		*regs_base;
134 	struct clk		*clk_ipg;
135 	struct clk		*clk_ahb;
136 
137 	struct sahara_ctx	*ctx;
138 	spinlock_t		lock;
139 	struct crypto_queue	queue;
140 	unsigned long		flags;
141 
142 	struct tasklet_struct	done_task;
143 	struct tasklet_struct	queue_task;
144 
145 	struct sahara_hw_desc	*hw_desc[SAHARA_MAX_HW_DESC];
146 	dma_addr_t		hw_phys_desc[SAHARA_MAX_HW_DESC];
147 
148 	u8			*key_base;
149 	dma_addr_t		key_phys_base;
150 
151 	u8			*iv_base;
152 	dma_addr_t		iv_phys_base;
153 
154 	struct sahara_hw_link	*hw_link[SAHARA_MAX_HW_LINK];
155 	dma_addr_t		hw_phys_link[SAHARA_MAX_HW_LINK];
156 
157 	struct ablkcipher_request *req;
158 	size_t			total;
159 	struct scatterlist	*in_sg;
160 	unsigned int		nb_in_sg;
161 	struct scatterlist	*out_sg;
162 	unsigned int		nb_out_sg;
163 
164 	u32			error;
165 	struct timer_list	watchdog;
166 };
167 
168 static struct sahara_dev *dev_ptr;
169 
170 static inline void sahara_write(struct sahara_dev *dev, u32 data, u32 reg)
171 {
172 	writel(data, dev->regs_base + reg);
173 }
174 
175 static inline unsigned int sahara_read(struct sahara_dev *dev, u32 reg)
176 {
177 	return readl(dev->regs_base + reg);
178 }
179 
180 static u32 sahara_aes_key_hdr(struct sahara_dev *dev)
181 {
182 	u32 hdr = SAHARA_HDR_BASE | SAHARA_HDR_SKHA_ALG_AES |
183 			SAHARA_HDR_FORM_KEY | SAHARA_HDR_LLO |
184 			SAHARA_HDR_CHA_SKHA | SAHARA_HDR_PARITY_BIT;
185 
186 	if (dev->flags & FLAGS_CBC) {
187 		hdr |= SAHARA_HDR_SKHA_MODE_CBC;
188 		hdr ^= SAHARA_HDR_PARITY_BIT;
189 	}
190 
191 	if (dev->flags & FLAGS_ENCRYPT) {
192 		hdr |= SAHARA_HDR_SKHA_OP_ENC;
193 		hdr ^= SAHARA_HDR_PARITY_BIT;
194 	}
195 
196 	return hdr;
197 }
198 
199 static u32 sahara_aes_data_link_hdr(struct sahara_dev *dev)
200 {
201 	return SAHARA_HDR_BASE | SAHARA_HDR_FORM_DATA |
202 			SAHARA_HDR_CHA_SKHA | SAHARA_HDR_PARITY_BIT;
203 }
204 
205 static int sahara_sg_length(struct scatterlist *sg,
206 			    unsigned int total)
207 {
208 	int sg_nb;
209 	unsigned int len;
210 	struct scatterlist *sg_list;
211 
212 	sg_nb = 0;
213 	sg_list = sg;
214 
215 	while (total) {
216 		len = min(sg_list->length, total);
217 
218 		sg_nb++;
219 		total -= len;
220 
221 		sg_list = sg_next(sg_list);
222 		if (!sg_list)
223 			total = 0;
224 	}
225 
226 	return sg_nb;
227 }
228 
229 static char *sahara_err_src[16] = {
230 	"No error",
231 	"Header error",
232 	"Descriptor length error",
233 	"Descriptor length or pointer error",
234 	"Link length error",
235 	"Link pointer error",
236 	"Input buffer error",
237 	"Output buffer error",
238 	"Output buffer starvation",
239 	"Internal state fault",
240 	"General descriptor problem",
241 	"Reserved",
242 	"Descriptor address error",
243 	"Link address error",
244 	"CHA error",
245 	"DMA error"
246 };
247 
248 static char *sahara_err_dmasize[4] = {
249 	"Byte transfer",
250 	"Half-word transfer",
251 	"Word transfer",
252 	"Reserved"
253 };
254 
255 static char *sahara_err_dmasrc[8] = {
256 	"No error",
257 	"AHB bus error",
258 	"Internal IP bus error",
259 	"Parity error",
260 	"DMA crosses 256 byte boundary",
261 	"DMA is busy",
262 	"Reserved",
263 	"DMA HW error"
264 };
265 
266 static char *sahara_cha_errsrc[12] = {
267 	"Input buffer non-empty",
268 	"Illegal address",
269 	"Illegal mode",
270 	"Illegal data size",
271 	"Illegal key size",
272 	"Write during processing",
273 	"CTX read during processing",
274 	"HW error",
275 	"Input buffer disabled/underflow",
276 	"Output buffer disabled/overflow",
277 	"DES key parity error",
278 	"Reserved"
279 };
280 
281 static char *sahara_cha_err[4] = { "No error", "SKHA", "MDHA", "RNG" };
282 
283 static void sahara_decode_error(struct sahara_dev *dev, unsigned int error)
284 {
285 	u8 source = SAHARA_ERRSTATUS_GET_SOURCE(error);
286 	u16 chasrc = ffs(SAHARA_ERRSTATUS_GET_CHASRC(error));
287 
288 	dev_err(dev->device, "%s: Error Register = 0x%08x\n", __func__, error);
289 
290 	dev_err(dev->device, "	- %s.\n", sahara_err_src[source]);
291 
292 	if (source == SAHARA_ERRSOURCE_DMA) {
293 		if (error & SAHARA_ERRSTATUS_DMA_DIR)
294 			dev_err(dev->device, "		* DMA read.\n");
295 		else
296 			dev_err(dev->device, "		* DMA write.\n");
297 
298 		dev_err(dev->device, "		* %s.\n",
299 		       sahara_err_dmasize[SAHARA_ERRSTATUS_GET_DMASZ(error)]);
300 		dev_err(dev->device, "		* %s.\n",
301 		       sahara_err_dmasrc[SAHARA_ERRSTATUS_GET_DMASRC(error)]);
302 	} else if (source == SAHARA_ERRSOURCE_CHA) {
303 		dev_err(dev->device, "		* %s.\n",
304 			sahara_cha_errsrc[chasrc]);
305 		dev_err(dev->device, "		* %s.\n",
306 		       sahara_cha_err[SAHARA_ERRSTATUS_GET_CHAERR(error)]);
307 	}
308 	dev_err(dev->device, "\n");
309 }
310 
311 static char *sahara_state[4] = { "Idle", "Busy", "Error", "HW Fault" };
312 
313 static void sahara_decode_status(struct sahara_dev *dev, unsigned int status)
314 {
315 	u8 state;
316 
317 	if (!IS_ENABLED(DEBUG))
318 		return;
319 
320 	state = SAHARA_STATUS_GET_STATE(status);
321 
322 	dev_dbg(dev->device, "%s: Status Register = 0x%08x\n",
323 		__func__, status);
324 
325 	dev_dbg(dev->device, "	- State = %d:\n", state);
326 	if (state & SAHARA_STATE_COMP_FLAG)
327 		dev_dbg(dev->device, "		* Descriptor completed. IRQ pending.\n");
328 
329 	dev_dbg(dev->device, "		* %s.\n",
330 	       sahara_state[state & ~SAHARA_STATE_COMP_FLAG]);
331 
332 	if (status & SAHARA_STATUS_DAR_FULL)
333 		dev_dbg(dev->device, "	- DAR Full.\n");
334 	if (status & SAHARA_STATUS_ERROR)
335 		dev_dbg(dev->device, "	- Error.\n");
336 	if (status & SAHARA_STATUS_SECURE)
337 		dev_dbg(dev->device, "	- Secure.\n");
338 	if (status & SAHARA_STATUS_FAIL)
339 		dev_dbg(dev->device, "	- Fail.\n");
340 	if (status & SAHARA_STATUS_RNG_RESEED)
341 		dev_dbg(dev->device, "	- RNG Reseed Request.\n");
342 	if (status & SAHARA_STATUS_ACTIVE_RNG)
343 		dev_dbg(dev->device, "	- RNG Active.\n");
344 	if (status & SAHARA_STATUS_ACTIVE_MDHA)
345 		dev_dbg(dev->device, "	- MDHA Active.\n");
346 	if (status & SAHARA_STATUS_ACTIVE_SKHA)
347 		dev_dbg(dev->device, "	- SKHA Active.\n");
348 
349 	if (status & SAHARA_STATUS_MODE_BATCH)
350 		dev_dbg(dev->device, "	- Batch Mode.\n");
351 	else if (status & SAHARA_STATUS_MODE_DEDICATED)
352 		dev_dbg(dev->device, "	- Decidated Mode.\n");
353 	else if (status & SAHARA_STATUS_MODE_DEBUG)
354 		dev_dbg(dev->device, "	- Debug Mode.\n");
355 
356 	dev_dbg(dev->device, "	- Internal state = 0x%02x\n",
357 	       SAHARA_STATUS_GET_ISTATE(status));
358 
359 	dev_dbg(dev->device, "Current DAR: 0x%08x\n",
360 		sahara_read(dev, SAHARA_REG_CDAR));
361 	dev_dbg(dev->device, "Initial DAR: 0x%08x\n\n",
362 		sahara_read(dev, SAHARA_REG_IDAR));
363 }
364 
365 static void sahara_dump_descriptors(struct sahara_dev *dev)
366 {
367 	int i;
368 
369 	if (!IS_ENABLED(DEBUG))
370 		return;
371 
372 	for (i = 0; i < SAHARA_MAX_HW_DESC; i++) {
373 		dev_dbg(dev->device, "Descriptor (%d) (0x%08x):\n",
374 			i, dev->hw_phys_desc[i]);
375 		dev_dbg(dev->device, "\thdr = 0x%08x\n", dev->hw_desc[i]->hdr);
376 		dev_dbg(dev->device, "\tlen1 = %u\n", dev->hw_desc[i]->len1);
377 		dev_dbg(dev->device, "\tp1 = 0x%08x\n", dev->hw_desc[i]->p1);
378 		dev_dbg(dev->device, "\tlen2 = %u\n", dev->hw_desc[i]->len2);
379 		dev_dbg(dev->device, "\tp2 = 0x%08x\n", dev->hw_desc[i]->p2);
380 		dev_dbg(dev->device, "\tnext = 0x%08x\n",
381 			dev->hw_desc[i]->next);
382 	}
383 	dev_dbg(dev->device, "\n");
384 }
385 
386 static void sahara_dump_links(struct sahara_dev *dev)
387 {
388 	int i;
389 
390 	if (!IS_ENABLED(DEBUG))
391 		return;
392 
393 	for (i = 0; i < SAHARA_MAX_HW_LINK; i++) {
394 		dev_dbg(dev->device, "Link (%d) (0x%08x):\n",
395 			i, dev->hw_phys_link[i]);
396 		dev_dbg(dev->device, "\tlen = %u\n", dev->hw_link[i]->len);
397 		dev_dbg(dev->device, "\tp = 0x%08x\n", dev->hw_link[i]->p);
398 		dev_dbg(dev->device, "\tnext = 0x%08x\n",
399 			dev->hw_link[i]->next);
400 	}
401 	dev_dbg(dev->device, "\n");
402 }
403 
404 static void sahara_aes_done_task(unsigned long data)
405 {
406 	struct sahara_dev *dev = (struct sahara_dev *)data;
407 
408 	dma_unmap_sg(dev->device, dev->out_sg, dev->nb_out_sg,
409 		DMA_TO_DEVICE);
410 	dma_unmap_sg(dev->device, dev->in_sg, dev->nb_in_sg,
411 		DMA_FROM_DEVICE);
412 
413 	spin_lock(&dev->lock);
414 	clear_bit(FLAGS_BUSY, &dev->flags);
415 	spin_unlock(&dev->lock);
416 
417 	dev->req->base.complete(&dev->req->base, dev->error);
418 }
419 
420 void sahara_watchdog(unsigned long data)
421 {
422 	struct sahara_dev *dev = (struct sahara_dev *)data;
423 	unsigned int err = sahara_read(dev, SAHARA_REG_ERRSTATUS);
424 	unsigned int stat = sahara_read(dev, SAHARA_REG_STATUS);
425 
426 	sahara_decode_status(dev, stat);
427 	sahara_decode_error(dev, err);
428 	dev->error = -ETIMEDOUT;
429 	sahara_aes_done_task(data);
430 }
431 
432 static int sahara_hw_descriptor_create(struct sahara_dev *dev)
433 {
434 	struct sahara_ctx *ctx = dev->ctx;
435 	struct scatterlist *sg;
436 	int ret;
437 	int i, j;
438 
439 	/* Copy new key if necessary */
440 	if (ctx->flags & FLAGS_NEW_KEY) {
441 		memcpy(dev->key_base, ctx->key, ctx->keylen);
442 		ctx->flags &= ~FLAGS_NEW_KEY;
443 
444 		if (dev->flags & FLAGS_CBC) {
445 			dev->hw_desc[0]->len1 = AES_BLOCK_SIZE;
446 			dev->hw_desc[0]->p1 = dev->iv_phys_base;
447 		} else {
448 			dev->hw_desc[0]->len1 = 0;
449 			dev->hw_desc[0]->p1 = 0;
450 		}
451 		dev->hw_desc[0]->len2 = ctx->keylen;
452 		dev->hw_desc[0]->p2 = dev->key_phys_base;
453 		dev->hw_desc[0]->next = dev->hw_phys_desc[1];
454 	}
455 	dev->hw_desc[0]->hdr = sahara_aes_key_hdr(dev);
456 
457 	dev->nb_in_sg = sahara_sg_length(dev->in_sg, dev->total);
458 	dev->nb_out_sg = sahara_sg_length(dev->out_sg, dev->total);
459 	if ((dev->nb_in_sg + dev->nb_out_sg) > SAHARA_MAX_HW_LINK) {
460 		dev_err(dev->device, "not enough hw links (%d)\n",
461 			dev->nb_in_sg + dev->nb_out_sg);
462 		return -EINVAL;
463 	}
464 
465 	ret = dma_map_sg(dev->device, dev->in_sg, dev->nb_in_sg,
466 			 DMA_TO_DEVICE);
467 	if (ret != dev->nb_in_sg) {
468 		dev_err(dev->device, "couldn't map in sg\n");
469 		goto unmap_in;
470 	}
471 	ret = dma_map_sg(dev->device, dev->out_sg, dev->nb_out_sg,
472 			 DMA_FROM_DEVICE);
473 	if (ret != dev->nb_out_sg) {
474 		dev_err(dev->device, "couldn't map out sg\n");
475 		goto unmap_out;
476 	}
477 
478 	/* Create input links */
479 	dev->hw_desc[1]->p1 = dev->hw_phys_link[0];
480 	sg = dev->in_sg;
481 	for (i = 0; i < dev->nb_in_sg; i++) {
482 		dev->hw_link[i]->len = sg->length;
483 		dev->hw_link[i]->p = sg->dma_address;
484 		if (i == (dev->nb_in_sg - 1)) {
485 			dev->hw_link[i]->next = 0;
486 		} else {
487 			dev->hw_link[i]->next = dev->hw_phys_link[i + 1];
488 			sg = sg_next(sg);
489 		}
490 	}
491 
492 	/* Create output links */
493 	dev->hw_desc[1]->p2 = dev->hw_phys_link[i];
494 	sg = dev->out_sg;
495 	for (j = i; j < dev->nb_out_sg + i; j++) {
496 		dev->hw_link[j]->len = sg->length;
497 		dev->hw_link[j]->p = sg->dma_address;
498 		if (j == (dev->nb_out_sg + i - 1)) {
499 			dev->hw_link[j]->next = 0;
500 		} else {
501 			dev->hw_link[j]->next = dev->hw_phys_link[j + 1];
502 			sg = sg_next(sg);
503 		}
504 	}
505 
506 	/* Fill remaining fields of hw_desc[1] */
507 	dev->hw_desc[1]->hdr = sahara_aes_data_link_hdr(dev);
508 	dev->hw_desc[1]->len1 = dev->total;
509 	dev->hw_desc[1]->len2 = dev->total;
510 	dev->hw_desc[1]->next = 0;
511 
512 	sahara_dump_descriptors(dev);
513 	sahara_dump_links(dev);
514 
515 	/* Start processing descriptor chain. */
516 	mod_timer(&dev->watchdog,
517 		  jiffies + msecs_to_jiffies(SAHARA_TIMEOUT_MS));
518 	sahara_write(dev, dev->hw_phys_desc[0], SAHARA_REG_DAR);
519 
520 	return 0;
521 
522 unmap_out:
523 	dma_unmap_sg(dev->device, dev->out_sg, dev->nb_out_sg,
524 		DMA_TO_DEVICE);
525 unmap_in:
526 	dma_unmap_sg(dev->device, dev->in_sg, dev->nb_in_sg,
527 		DMA_FROM_DEVICE);
528 
529 	return -EINVAL;
530 }
531 
532 static void sahara_aes_queue_task(unsigned long data)
533 {
534 	struct sahara_dev *dev = (struct sahara_dev *)data;
535 	struct crypto_async_request *async_req, *backlog;
536 	struct sahara_ctx *ctx;
537 	struct sahara_aes_reqctx *rctx;
538 	struct ablkcipher_request *req;
539 	int ret;
540 
541 	spin_lock(&dev->lock);
542 	backlog = crypto_get_backlog(&dev->queue);
543 	async_req = crypto_dequeue_request(&dev->queue);
544 	if (!async_req)
545 		clear_bit(FLAGS_BUSY, &dev->flags);
546 	spin_unlock(&dev->lock);
547 
548 	if (!async_req)
549 		return;
550 
551 	if (backlog)
552 		backlog->complete(backlog, -EINPROGRESS);
553 
554 	req = ablkcipher_request_cast(async_req);
555 
556 	/* Request is ready to be dispatched by the device */
557 	dev_dbg(dev->device,
558 		"dispatch request (nbytes=%d, src=%p, dst=%p)\n",
559 		req->nbytes, req->src, req->dst);
560 
561 	/* assign new request to device */
562 	dev->req = req;
563 	dev->total = req->nbytes;
564 	dev->in_sg = req->src;
565 	dev->out_sg = req->dst;
566 
567 	rctx = ablkcipher_request_ctx(req);
568 	ctx = crypto_ablkcipher_ctx(crypto_ablkcipher_reqtfm(req));
569 	rctx->mode &= FLAGS_MODE_MASK;
570 	dev->flags = (dev->flags & ~FLAGS_MODE_MASK) | rctx->mode;
571 
572 	if ((dev->flags & FLAGS_CBC) && req->info)
573 		memcpy(dev->iv_base, req->info, AES_KEYSIZE_128);
574 
575 	/* assign new context to device */
576 	ctx->dev = dev;
577 	dev->ctx = ctx;
578 
579 	ret = sahara_hw_descriptor_create(dev);
580 	if (ret < 0) {
581 		spin_lock(&dev->lock);
582 		clear_bit(FLAGS_BUSY, &dev->flags);
583 		spin_unlock(&dev->lock);
584 		dev->req->base.complete(&dev->req->base, ret);
585 	}
586 }
587 
588 static int sahara_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
589 			     unsigned int keylen)
590 {
591 	struct sahara_ctx *ctx = crypto_ablkcipher_ctx(tfm);
592 	int ret;
593 
594 	ctx->keylen = keylen;
595 
596 	/* SAHARA only supports 128bit keys */
597 	if (keylen == AES_KEYSIZE_128) {
598 		memcpy(ctx->key, key, keylen);
599 		ctx->flags |= FLAGS_NEW_KEY;
600 		return 0;
601 	}
602 
603 	if (keylen != AES_KEYSIZE_128 &&
604 	    keylen != AES_KEYSIZE_192 && keylen != AES_KEYSIZE_256)
605 		return -EINVAL;
606 
607 	/*
608 	 * The requested key size is not supported by HW, do a fallback.
609 	 */
610 	ctx->fallback->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
611 	ctx->fallback->base.crt_flags |=
612 		(tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);
613 
614 	ret = crypto_ablkcipher_setkey(ctx->fallback, key, keylen);
615 	if (ret) {
616 		struct crypto_tfm *tfm_aux = crypto_ablkcipher_tfm(tfm);
617 
618 		tfm_aux->crt_flags &= ~CRYPTO_TFM_RES_MASK;
619 		tfm_aux->crt_flags |=
620 			(ctx->fallback->base.crt_flags & CRYPTO_TFM_RES_MASK);
621 	}
622 	return ret;
623 }
624 
625 static int sahara_aes_crypt(struct ablkcipher_request *req, unsigned long mode)
626 {
627 	struct sahara_ctx *ctx = crypto_ablkcipher_ctx(
628 		crypto_ablkcipher_reqtfm(req));
629 	struct sahara_aes_reqctx *rctx = ablkcipher_request_ctx(req);
630 	struct sahara_dev *dev = dev_ptr;
631 	int err = 0;
632 	int busy;
633 
634 	dev_dbg(dev->device, "nbytes: %d, enc: %d, cbc: %d\n",
635 		req->nbytes, !!(mode & FLAGS_ENCRYPT), !!(mode & FLAGS_CBC));
636 
637 	if (!IS_ALIGNED(req->nbytes, AES_BLOCK_SIZE)) {
638 		dev_err(dev->device,
639 			"request size is not exact amount of AES blocks\n");
640 		return -EINVAL;
641 	}
642 
643 	ctx->dev = dev;
644 
645 	rctx->mode = mode;
646 	spin_lock_bh(&dev->lock);
647 	err = ablkcipher_enqueue_request(&dev->queue, req);
648 	busy = test_and_set_bit(FLAGS_BUSY, &dev->flags);
649 	spin_unlock_bh(&dev->lock);
650 
651 	if (!busy)
652 		tasklet_schedule(&dev->queue_task);
653 
654 	return err;
655 }
656 
657 static int sahara_aes_ecb_encrypt(struct ablkcipher_request *req)
658 {
659 	struct crypto_tfm *tfm =
660 		crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
661 	struct sahara_ctx *ctx = crypto_ablkcipher_ctx(
662 		crypto_ablkcipher_reqtfm(req));
663 	int err;
664 
665 	if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
666 		ablkcipher_request_set_tfm(req, ctx->fallback);
667 		err = crypto_ablkcipher_encrypt(req);
668 		ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
669 		return err;
670 	}
671 
672 	return sahara_aes_crypt(req, FLAGS_ENCRYPT);
673 }
674 
675 static int sahara_aes_ecb_decrypt(struct ablkcipher_request *req)
676 {
677 	struct crypto_tfm *tfm =
678 		crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
679 	struct sahara_ctx *ctx = crypto_ablkcipher_ctx(
680 		crypto_ablkcipher_reqtfm(req));
681 	int err;
682 
683 	if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
684 		ablkcipher_request_set_tfm(req, ctx->fallback);
685 		err = crypto_ablkcipher_decrypt(req);
686 		ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
687 		return err;
688 	}
689 
690 	return sahara_aes_crypt(req, 0);
691 }
692 
693 static int sahara_aes_cbc_encrypt(struct ablkcipher_request *req)
694 {
695 	struct crypto_tfm *tfm =
696 		crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
697 	struct sahara_ctx *ctx = crypto_ablkcipher_ctx(
698 		crypto_ablkcipher_reqtfm(req));
699 	int err;
700 
701 	if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
702 		ablkcipher_request_set_tfm(req, ctx->fallback);
703 		err = crypto_ablkcipher_encrypt(req);
704 		ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
705 		return err;
706 	}
707 
708 	return sahara_aes_crypt(req, FLAGS_ENCRYPT | FLAGS_CBC);
709 }
710 
711 static int sahara_aes_cbc_decrypt(struct ablkcipher_request *req)
712 {
713 	struct crypto_tfm *tfm =
714 		crypto_ablkcipher_tfm(crypto_ablkcipher_reqtfm(req));
715 	struct sahara_ctx *ctx = crypto_ablkcipher_ctx(
716 		crypto_ablkcipher_reqtfm(req));
717 	int err;
718 
719 	if (unlikely(ctx->keylen != AES_KEYSIZE_128)) {
720 		ablkcipher_request_set_tfm(req, ctx->fallback);
721 		err = crypto_ablkcipher_decrypt(req);
722 		ablkcipher_request_set_tfm(req, __crypto_ablkcipher_cast(tfm));
723 		return err;
724 	}
725 
726 	return sahara_aes_crypt(req, FLAGS_CBC);
727 }
728 
729 static int sahara_aes_cra_init(struct crypto_tfm *tfm)
730 {
731 	const char *name = tfm->__crt_alg->cra_name;
732 	struct sahara_ctx *ctx = crypto_tfm_ctx(tfm);
733 
734 	ctx->fallback = crypto_alloc_ablkcipher(name, 0,
735 				CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
736 	if (IS_ERR(ctx->fallback)) {
737 		pr_err("Error allocating fallback algo %s\n", name);
738 		return PTR_ERR(ctx->fallback);
739 	}
740 
741 	tfm->crt_ablkcipher.reqsize = sizeof(struct sahara_aes_reqctx);
742 
743 	return 0;
744 }
745 
746 static void sahara_aes_cra_exit(struct crypto_tfm *tfm)
747 {
748 	struct sahara_ctx *ctx = crypto_tfm_ctx(tfm);
749 
750 	if (ctx->fallback)
751 		crypto_free_ablkcipher(ctx->fallback);
752 	ctx->fallback = NULL;
753 }
754 
755 static struct crypto_alg aes_algs[] = {
756 {
757 	.cra_name		= "ecb(aes)",
758 	.cra_driver_name	= "sahara-ecb-aes",
759 	.cra_priority		= 300,
760 	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
761 			CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
762 	.cra_blocksize		= AES_BLOCK_SIZE,
763 	.cra_ctxsize		= sizeof(struct sahara_ctx),
764 	.cra_alignmask		= 0x0,
765 	.cra_type		= &crypto_ablkcipher_type,
766 	.cra_module		= THIS_MODULE,
767 	.cra_init		= sahara_aes_cra_init,
768 	.cra_exit		= sahara_aes_cra_exit,
769 	.cra_u.ablkcipher = {
770 		.min_keysize	= AES_MIN_KEY_SIZE ,
771 		.max_keysize	= AES_MAX_KEY_SIZE,
772 		.setkey		= sahara_aes_setkey,
773 		.encrypt	= sahara_aes_ecb_encrypt,
774 		.decrypt	= sahara_aes_ecb_decrypt,
775 	}
776 }, {
777 	.cra_name		= "cbc(aes)",
778 	.cra_driver_name	= "sahara-cbc-aes",
779 	.cra_priority		= 300,
780 	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
781 			CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
782 	.cra_blocksize		= AES_BLOCK_SIZE,
783 	.cra_ctxsize		= sizeof(struct sahara_ctx),
784 	.cra_alignmask		= 0x0,
785 	.cra_type		= &crypto_ablkcipher_type,
786 	.cra_module		= THIS_MODULE,
787 	.cra_init		= sahara_aes_cra_init,
788 	.cra_exit		= sahara_aes_cra_exit,
789 	.cra_u.ablkcipher = {
790 		.min_keysize	= AES_MIN_KEY_SIZE ,
791 		.max_keysize	= AES_MAX_KEY_SIZE,
792 		.ivsize		= AES_BLOCK_SIZE,
793 		.setkey		= sahara_aes_setkey,
794 		.encrypt	= sahara_aes_cbc_encrypt,
795 		.decrypt	= sahara_aes_cbc_decrypt,
796 	}
797 }
798 };
799 
800 static irqreturn_t sahara_irq_handler(int irq, void *data)
801 {
802 	struct sahara_dev *dev = (struct sahara_dev *)data;
803 	unsigned int stat = sahara_read(dev, SAHARA_REG_STATUS);
804 	unsigned int err = sahara_read(dev, SAHARA_REG_ERRSTATUS);
805 
806 	del_timer(&dev->watchdog);
807 
808 	sahara_write(dev, SAHARA_CMD_CLEAR_INT | SAHARA_CMD_CLEAR_ERR,
809 		     SAHARA_REG_CMD);
810 
811 	sahara_decode_status(dev, stat);
812 
813 	if (SAHARA_STATUS_GET_STATE(stat) == SAHARA_STATE_BUSY) {
814 		return IRQ_NONE;
815 	} else if (SAHARA_STATUS_GET_STATE(stat) == SAHARA_STATE_COMPLETE) {
816 		dev->error = 0;
817 	} else {
818 		sahara_decode_error(dev, err);
819 		dev->error = -EINVAL;
820 	}
821 
822 	tasklet_schedule(&dev->done_task);
823 
824 	return IRQ_HANDLED;
825 }
826 
827 
828 static int sahara_register_algs(struct sahara_dev *dev)
829 {
830 	int err, i, j;
831 
832 	for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
833 		INIT_LIST_HEAD(&aes_algs[i].cra_list);
834 		err = crypto_register_alg(&aes_algs[i]);
835 		if (err)
836 			goto err_aes_algs;
837 	}
838 
839 	return 0;
840 
841 err_aes_algs:
842 	for (j = 0; j < i; j++)
843 		crypto_unregister_alg(&aes_algs[j]);
844 
845 	return err;
846 }
847 
848 static void sahara_unregister_algs(struct sahara_dev *dev)
849 {
850 	int i;
851 
852 	for (i = 0; i < ARRAY_SIZE(aes_algs); i++)
853 		crypto_unregister_alg(&aes_algs[i]);
854 }
855 
856 static struct platform_device_id sahara_platform_ids[] = {
857 	{ .name = "sahara-imx27" },
858 	{ /* sentinel */ }
859 };
860 MODULE_DEVICE_TABLE(platform, sahara_platform_ids);
861 
862 static struct of_device_id sahara_dt_ids[] = {
863 	{ .compatible = "fsl,imx27-sahara" },
864 	{ /* sentinel */ }
865 };
866 MODULE_DEVICE_TABLE(of, sahara_dt_ids);
867 
868 static int sahara_probe(struct platform_device *pdev)
869 {
870 	struct sahara_dev *dev;
871 	struct resource *res;
872 	u32 version;
873 	int irq;
874 	int err;
875 	int i;
876 
877 	dev = devm_kzalloc(&pdev->dev, sizeof(struct sahara_dev), GFP_KERNEL);
878 	if (dev == NULL) {
879 		dev_err(&pdev->dev, "unable to alloc data struct.\n");
880 		return -ENOMEM;
881 	}
882 
883 	dev->device = &pdev->dev;
884 	platform_set_drvdata(pdev, dev);
885 
886 	/* Get the base address */
887 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
888 	if (!res) {
889 		dev_err(&pdev->dev, "failed to get memory region resource\n");
890 		return -ENODEV;
891 	}
892 
893 	if (devm_request_mem_region(&pdev->dev, res->start,
894 			resource_size(res), SAHARA_NAME) == NULL) {
895 		dev_err(&pdev->dev, "failed to request memory region\n");
896 		return -ENOENT;
897 	}
898 	dev->regs_base = devm_ioremap(&pdev->dev, res->start,
899 				      resource_size(res));
900 	if (!dev->regs_base) {
901 		dev_err(&pdev->dev, "failed to ioremap address region\n");
902 		return -ENOENT;
903 	}
904 
905 	/* Get the IRQ */
906 	irq = platform_get_irq(pdev,  0);
907 	if (irq < 0) {
908 		dev_err(&pdev->dev, "failed to get irq resource\n");
909 		return irq;
910 	}
911 
912 	if (devm_request_irq(&pdev->dev, irq, sahara_irq_handler,
913 		0, SAHARA_NAME, dev) < 0) {
914 		dev_err(&pdev->dev, "failed to request irq\n");
915 		return -ENOENT;
916 	}
917 
918 	/* clocks */
919 	dev->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
920 	if (IS_ERR(dev->clk_ipg)) {
921 		dev_err(&pdev->dev, "Could not get ipg clock\n");
922 		return PTR_ERR(dev->clk_ipg);
923 	}
924 
925 	dev->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
926 	if (IS_ERR(dev->clk_ahb)) {
927 		dev_err(&pdev->dev, "Could not get ahb clock\n");
928 		return PTR_ERR(dev->clk_ahb);
929 	}
930 
931 	/* Allocate HW descriptors */
932 	dev->hw_desc[0] = dma_alloc_coherent(&pdev->dev,
933 			SAHARA_MAX_HW_DESC * sizeof(struct sahara_hw_desc),
934 			&dev->hw_phys_desc[0], GFP_KERNEL);
935 	if (!dev->hw_desc[0]) {
936 		dev_err(&pdev->dev, "Could not allocate hw descriptors\n");
937 		return -ENOMEM;
938 	}
939 	dev->hw_desc[1] = dev->hw_desc[0] + 1;
940 	dev->hw_phys_desc[1] = dev->hw_phys_desc[0] +
941 				sizeof(struct sahara_hw_desc);
942 
943 	/* Allocate space for iv and key */
944 	dev->key_base = dma_alloc_coherent(&pdev->dev, 2 * AES_KEYSIZE_128,
945 				&dev->key_phys_base, GFP_KERNEL);
946 	if (!dev->key_base) {
947 		dev_err(&pdev->dev, "Could not allocate memory for key\n");
948 		err = -ENOMEM;
949 		goto err_key;
950 	}
951 	dev->iv_base = dev->key_base + AES_KEYSIZE_128;
952 	dev->iv_phys_base = dev->key_phys_base + AES_KEYSIZE_128;
953 
954 	/* Allocate space for HW links */
955 	dev->hw_link[0] = dma_alloc_coherent(&pdev->dev,
956 			SAHARA_MAX_HW_LINK * sizeof(struct sahara_hw_link),
957 			&dev->hw_phys_link[0], GFP_KERNEL);
958 	if (!dev->hw_link) {
959 		dev_err(&pdev->dev, "Could not allocate hw links\n");
960 		err = -ENOMEM;
961 		goto err_link;
962 	}
963 	for (i = 1; i < SAHARA_MAX_HW_LINK; i++) {
964 		dev->hw_phys_link[i] = dev->hw_phys_link[i - 1] +
965 					sizeof(struct sahara_hw_link);
966 		dev->hw_link[i] = dev->hw_link[i - 1] + 1;
967 	}
968 
969 	crypto_init_queue(&dev->queue, SAHARA_QUEUE_LENGTH);
970 
971 	dev_ptr = dev;
972 
973 	tasklet_init(&dev->queue_task, sahara_aes_queue_task,
974 		     (unsigned long)dev);
975 	tasklet_init(&dev->done_task, sahara_aes_done_task,
976 		     (unsigned long)dev);
977 
978 	init_timer(&dev->watchdog);
979 	dev->watchdog.function = &sahara_watchdog;
980 	dev->watchdog.data = (unsigned long)dev;
981 
982 	clk_prepare_enable(dev->clk_ipg);
983 	clk_prepare_enable(dev->clk_ahb);
984 
985 	version = sahara_read(dev, SAHARA_REG_VERSION);
986 	if (version != SAHARA_VERSION_3) {
987 		dev_err(&pdev->dev, "SAHARA version %d not supported\n",
988 			version);
989 		err = -ENODEV;
990 		goto err_algs;
991 	}
992 
993 	sahara_write(dev, SAHARA_CMD_RESET | SAHARA_CMD_MODE_BATCH,
994 		     SAHARA_REG_CMD);
995 	sahara_write(dev, SAHARA_CONTROL_SET_THROTTLE(0) |
996 			SAHARA_CONTROL_SET_MAXBURST(8) |
997 			SAHARA_CONTROL_RNG_AUTORSD |
998 			SAHARA_CONTROL_ENABLE_INT,
999 			SAHARA_REG_CONTROL);
1000 
1001 	err = sahara_register_algs(dev);
1002 	if (err)
1003 		goto err_algs;
1004 
1005 	dev_info(&pdev->dev, "SAHARA version %d initialized\n", version);
1006 
1007 	return 0;
1008 
1009 err_algs:
1010 	dma_free_coherent(&pdev->dev,
1011 			  SAHARA_MAX_HW_LINK * sizeof(struct sahara_hw_link),
1012 			  dev->hw_link[0], dev->hw_phys_link[0]);
1013 	clk_disable_unprepare(dev->clk_ipg);
1014 	clk_disable_unprepare(dev->clk_ahb);
1015 	dev_ptr = NULL;
1016 err_link:
1017 	dma_free_coherent(&pdev->dev,
1018 			  2 * AES_KEYSIZE_128,
1019 			  dev->key_base, dev->key_phys_base);
1020 err_key:
1021 	dma_free_coherent(&pdev->dev,
1022 			  SAHARA_MAX_HW_DESC * sizeof(struct sahara_hw_desc),
1023 			  dev->hw_desc[0], dev->hw_phys_desc[0]);
1024 
1025 	return err;
1026 }
1027 
1028 static int sahara_remove(struct platform_device *pdev)
1029 {
1030 	struct sahara_dev *dev = platform_get_drvdata(pdev);
1031 
1032 	dma_free_coherent(&pdev->dev,
1033 			  SAHARA_MAX_HW_LINK * sizeof(struct sahara_hw_link),
1034 			  dev->hw_link[0], dev->hw_phys_link[0]);
1035 	dma_free_coherent(&pdev->dev,
1036 			  2 * AES_KEYSIZE_128,
1037 			  dev->key_base, dev->key_phys_base);
1038 	dma_free_coherent(&pdev->dev,
1039 			  SAHARA_MAX_HW_DESC * sizeof(struct sahara_hw_desc),
1040 			  dev->hw_desc[0], dev->hw_phys_desc[0]);
1041 
1042 	tasklet_kill(&dev->done_task);
1043 	tasklet_kill(&dev->queue_task);
1044 
1045 	sahara_unregister_algs(dev);
1046 
1047 	clk_disable_unprepare(dev->clk_ipg);
1048 	clk_disable_unprepare(dev->clk_ahb);
1049 
1050 	dev_ptr = NULL;
1051 
1052 	return 0;
1053 }
1054 
1055 static struct platform_driver sahara_driver = {
1056 	.probe		= sahara_probe,
1057 	.remove		= sahara_remove,
1058 	.driver		= {
1059 		.name	= SAHARA_NAME,
1060 		.owner	= THIS_MODULE,
1061 		.of_match_table = of_match_ptr(sahara_dt_ids),
1062 	},
1063 	.id_table = sahara_platform_ids,
1064 };
1065 
1066 module_platform_driver(sahara_driver);
1067 
1068 MODULE_LICENSE("GPL");
1069 MODULE_AUTHOR("Javier Martin <javier.martin@vista-silicon.com>");
1070 MODULE_DESCRIPTION("SAHARA2 HW crypto accelerator");
1071