xref: /linux/drivers/crypto/atmel-tdes.c (revision fab183d632628381b466a41479489541ac0e29a0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Cryptographic API.
4  *
5  * Support for ATMEL DES/TDES HW acceleration.
6  *
7  * Copyright (c) 2012 Eukréa Electromatique - ATMEL
8  * Author: Nicolas Royer <nicolas@eukrea.com>
9  *
10  * Some ideas are from omap-aes.c drivers.
11  */
12 
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/err.h>
18 #include <linux/clk.h>
19 #include <linux/io.h>
20 #include <linux/hw_random.h>
21 #include <linux/platform_device.h>
22 
23 #include <linux/device.h>
24 #include <linux/dmaengine.h>
25 #include <linux/init.h>
26 #include <linux/errno.h>
27 #include <linux/interrupt.h>
28 #include <linux/irq.h>
29 #include <linux/scatterlist.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/delay.h>
32 #include <linux/crypto.h>
33 #include <crypto/scatterwalk.h>
34 #include <crypto/algapi.h>
35 #include <crypto/internal/des.h>
36 #include <crypto/internal/skcipher.h>
37 #include "atmel-tdes-regs.h"
38 
39 #define ATMEL_TDES_PRIORITY	300
40 
41 /* TDES flags  */
42 /* Reserve bits [17:16], [13:12], [2:0] for AES Mode Register */
43 #define TDES_FLAGS_ENCRYPT	TDES_MR_CYPHER_ENC
44 #define TDES_FLAGS_OPMODE_MASK	(TDES_MR_OPMOD_MASK | TDES_MR_CFBS_MASK)
45 #define TDES_FLAGS_ECB		TDES_MR_OPMOD_ECB
46 #define TDES_FLAGS_CBC		TDES_MR_OPMOD_CBC
47 
48 #define TDES_FLAGS_MODE_MASK	(TDES_FLAGS_OPMODE_MASK | TDES_FLAGS_ENCRYPT)
49 
50 #define TDES_FLAGS_INIT		BIT(3)
51 #define TDES_FLAGS_FAST		BIT(4)
52 #define TDES_FLAGS_BUSY		BIT(5)
53 #define TDES_FLAGS_DMA		BIT(6)
54 
55 #define ATMEL_TDES_QUEUE_LENGTH	50
56 
57 struct atmel_tdes_caps {
58 	bool	has_dma;
59 };
60 
61 struct atmel_tdes_dev;
62 
63 struct atmel_tdes_ctx {
64 	struct atmel_tdes_dev *dd;
65 
66 	int		keylen;
67 	u32		key[DES3_EDE_KEY_SIZE / sizeof(u32)];
68 	unsigned long	flags;
69 
70 	u16		block_size;
71 };
72 
73 struct atmel_tdes_reqctx {
74 	unsigned long mode;
75 	u8 lastc[DES_BLOCK_SIZE];
76 };
77 
78 struct atmel_tdes_dma {
79 	struct dma_chan			*chan;
80 	struct dma_slave_config dma_conf;
81 };
82 
83 struct atmel_tdes_dev {
84 	struct list_head	list;
85 	unsigned long		phys_base;
86 	void __iomem		*io_base;
87 
88 	struct atmel_tdes_ctx	*ctx;
89 	struct device		*dev;
90 	struct clk			*iclk;
91 	int					irq;
92 
93 	unsigned long		flags;
94 
95 	spinlock_t		lock;
96 	struct crypto_queue	queue;
97 
98 	struct tasklet_struct	done_task;
99 	struct tasklet_struct	queue_task;
100 
101 	struct skcipher_request	*req;
102 	size_t				total;
103 
104 	struct scatterlist	*in_sg;
105 	unsigned int		nb_in_sg;
106 	size_t				in_offset;
107 	struct scatterlist	*out_sg;
108 	unsigned int		nb_out_sg;
109 	size_t				out_offset;
110 
111 	size_t	buflen;
112 	size_t	dma_size;
113 
114 	void	*buf_in;
115 	int		dma_in;
116 	dma_addr_t	dma_addr_in;
117 	struct atmel_tdes_dma	dma_lch_in;
118 
119 	void	*buf_out;
120 	int		dma_out;
121 	dma_addr_t	dma_addr_out;
122 	struct atmel_tdes_dma	dma_lch_out;
123 
124 	struct atmel_tdes_caps	caps;
125 
126 	u32	hw_version;
127 };
128 
129 struct atmel_tdes_drv {
130 	struct list_head	dev_list;
131 	spinlock_t		lock;
132 };
133 
134 static struct atmel_tdes_drv atmel_tdes = {
135 	.dev_list = LIST_HEAD_INIT(atmel_tdes.dev_list),
136 	.lock = __SPIN_LOCK_UNLOCKED(atmel_tdes.lock),
137 };
138 
atmel_tdes_sg_copy(struct scatterlist ** sg,size_t * offset,void * buf,size_t buflen,size_t total,int out)139 static int atmel_tdes_sg_copy(struct scatterlist **sg, size_t *offset,
140 			void *buf, size_t buflen, size_t total, int out)
141 {
142 	size_t count, off = 0;
143 
144 	while (buflen && total) {
145 		count = min((*sg)->length - *offset, total);
146 		count = min(count, buflen);
147 
148 		if (!count)
149 			return off;
150 
151 		scatterwalk_map_and_copy(buf + off, *sg, *offset, count, out);
152 
153 		off += count;
154 		buflen -= count;
155 		*offset += count;
156 		total -= count;
157 
158 		if (*offset == (*sg)->length) {
159 			*sg = sg_next(*sg);
160 			if (*sg)
161 				*offset = 0;
162 			else
163 				total = 0;
164 		}
165 	}
166 
167 	return off;
168 }
169 
atmel_tdes_read(struct atmel_tdes_dev * dd,u32 offset)170 static inline u32 atmel_tdes_read(struct atmel_tdes_dev *dd, u32 offset)
171 {
172 	return readl_relaxed(dd->io_base + offset);
173 }
174 
atmel_tdes_write(struct atmel_tdes_dev * dd,u32 offset,u32 value)175 static inline void atmel_tdes_write(struct atmel_tdes_dev *dd,
176 					u32 offset, u32 value)
177 {
178 	writel_relaxed(value, dd->io_base + offset);
179 }
180 
atmel_tdes_write_n(struct atmel_tdes_dev * dd,u32 offset,const u32 * value,int count)181 static void atmel_tdes_write_n(struct atmel_tdes_dev *dd, u32 offset,
182 			       const u32 *value, int count)
183 {
184 	for (; count--; value++, offset += 4)
185 		atmel_tdes_write(dd, offset, *value);
186 }
187 
atmel_tdes_dev_alloc(void)188 static struct atmel_tdes_dev *atmel_tdes_dev_alloc(void)
189 {
190 	struct atmel_tdes_dev *tdes_dd;
191 
192 	spin_lock_bh(&atmel_tdes.lock);
193 	/* One TDES IP per SoC. */
194 	tdes_dd = list_first_entry_or_null(&atmel_tdes.dev_list,
195 					   struct atmel_tdes_dev, list);
196 	spin_unlock_bh(&atmel_tdes.lock);
197 	return tdes_dd;
198 }
199 
atmel_tdes_hw_init(struct atmel_tdes_dev * dd)200 static int atmel_tdes_hw_init(struct atmel_tdes_dev *dd)
201 {
202 	int err;
203 
204 	err = clk_prepare_enable(dd->iclk);
205 	if (err)
206 		return err;
207 
208 	if (!(dd->flags & TDES_FLAGS_INIT)) {
209 		atmel_tdes_write(dd, TDES_CR, TDES_CR_SWRST);
210 		dd->flags |= TDES_FLAGS_INIT;
211 	}
212 
213 	return 0;
214 }
215 
atmel_tdes_get_version(struct atmel_tdes_dev * dd)216 static inline unsigned int atmel_tdes_get_version(struct atmel_tdes_dev *dd)
217 {
218 	return atmel_tdes_read(dd, TDES_HW_VERSION) & 0x00000fff;
219 }
220 
atmel_tdes_hw_version_init(struct atmel_tdes_dev * dd)221 static int atmel_tdes_hw_version_init(struct atmel_tdes_dev *dd)
222 {
223 	int err;
224 
225 	err = atmel_tdes_hw_init(dd);
226 	if (err)
227 		return err;
228 
229 	dd->hw_version = atmel_tdes_get_version(dd);
230 
231 	dev_info(dd->dev,
232 			"version: 0x%x\n", dd->hw_version);
233 
234 	clk_disable_unprepare(dd->iclk);
235 
236 	return 0;
237 }
238 
atmel_tdes_dma_callback(void * data)239 static void atmel_tdes_dma_callback(void *data)
240 {
241 	struct atmel_tdes_dev *dd = data;
242 
243 	/* dma_lch_out - completed */
244 	tasklet_schedule(&dd->done_task);
245 }
246 
atmel_tdes_write_ctrl(struct atmel_tdes_dev * dd)247 static int atmel_tdes_write_ctrl(struct atmel_tdes_dev *dd)
248 {
249 	int err;
250 	u32 valmr = TDES_MR_SMOD_PDC;
251 
252 	err = atmel_tdes_hw_init(dd);
253 
254 	if (err)
255 		return err;
256 
257 	if (!dd->caps.has_dma)
258 		atmel_tdes_write(dd, TDES_PTCR,
259 			TDES_PTCR_TXTDIS | TDES_PTCR_RXTDIS);
260 
261 	/* MR register must be set before IV registers */
262 	if (dd->ctx->keylen > (DES_KEY_SIZE << 1)) {
263 		valmr |= TDES_MR_KEYMOD_3KEY;
264 		valmr |= TDES_MR_TDESMOD_TDES;
265 	} else if (dd->ctx->keylen > DES_KEY_SIZE) {
266 		valmr |= TDES_MR_KEYMOD_2KEY;
267 		valmr |= TDES_MR_TDESMOD_TDES;
268 	} else {
269 		valmr |= TDES_MR_TDESMOD_DES;
270 	}
271 
272 	valmr |= dd->flags & TDES_FLAGS_MODE_MASK;
273 
274 	atmel_tdes_write(dd, TDES_MR, valmr);
275 
276 	atmel_tdes_write_n(dd, TDES_KEY1W1R, dd->ctx->key,
277 						dd->ctx->keylen >> 2);
278 
279 	if (dd->req->iv && (valmr & TDES_MR_OPMOD_MASK) != TDES_MR_OPMOD_ECB)
280 		atmel_tdes_write_n(dd, TDES_IV1R, (void *)dd->req->iv, 2);
281 
282 	return 0;
283 }
284 
atmel_tdes_crypt_pdc_stop(struct atmel_tdes_dev * dd)285 static int atmel_tdes_crypt_pdc_stop(struct atmel_tdes_dev *dd)
286 {
287 	size_t count;
288 
289 	atmel_tdes_write(dd, TDES_PTCR, TDES_PTCR_TXTDIS|TDES_PTCR_RXTDIS);
290 
291 	if (dd->flags & TDES_FLAGS_FAST) {
292 		dma_unmap_sg(dd->dev, dd->out_sg, 1, DMA_FROM_DEVICE);
293 		dma_unmap_sg(dd->dev, dd->in_sg, 1, DMA_TO_DEVICE);
294 	} else {
295 		dma_sync_single_for_cpu(dd->dev, dd->dma_addr_out,
296 					dd->dma_size, DMA_FROM_DEVICE);
297 
298 		count = atmel_tdes_sg_copy(&dd->out_sg, &dd->out_offset,
299 				dd->buf_out, dd->buflen, dd->dma_size, 1);
300 		if (count != dd->dma_size) {
301 			dev_dbg(dd->dev, "not all data converted: %zu\n", count);
302 			return -EINVAL;
303 		}
304 	}
305 
306 	return 0;
307 }
308 
atmel_tdes_buff_init(struct atmel_tdes_dev * dd)309 static int atmel_tdes_buff_init(struct atmel_tdes_dev *dd)
310 {
311 	int err = -ENOMEM;
312 
313 	dd->buf_in = (void *)__get_free_page(GFP_KERNEL);
314 	dd->buf_out = (void *)__get_free_page(GFP_KERNEL);
315 	dd->buflen = PAGE_SIZE;
316 	dd->buflen &= ~(DES_BLOCK_SIZE - 1);
317 
318 	if (!dd->buf_in || !dd->buf_out) {
319 		dev_dbg(dd->dev, "unable to alloc pages.\n");
320 		goto err_alloc;
321 	}
322 
323 	/* MAP here */
324 	dd->dma_addr_in = dma_map_single(dd->dev, dd->buf_in,
325 					dd->buflen, DMA_TO_DEVICE);
326 	err = dma_mapping_error(dd->dev, dd->dma_addr_in);
327 	if (err) {
328 		dev_dbg(dd->dev, "dma %zd bytes error\n", dd->buflen);
329 		goto err_map_in;
330 	}
331 
332 	dd->dma_addr_out = dma_map_single(dd->dev, dd->buf_out,
333 					dd->buflen, DMA_FROM_DEVICE);
334 	err = dma_mapping_error(dd->dev, dd->dma_addr_out);
335 	if (err) {
336 		dev_dbg(dd->dev, "dma %zd bytes error\n", dd->buflen);
337 		goto err_map_out;
338 	}
339 
340 	return 0;
341 
342 err_map_out:
343 	dma_unmap_single(dd->dev, dd->dma_addr_in, dd->buflen,
344 		DMA_TO_DEVICE);
345 err_map_in:
346 err_alloc:
347 	free_page((unsigned long)dd->buf_out);
348 	free_page((unsigned long)dd->buf_in);
349 	return err;
350 }
351 
atmel_tdes_buff_cleanup(struct atmel_tdes_dev * dd)352 static void atmel_tdes_buff_cleanup(struct atmel_tdes_dev *dd)
353 {
354 	dma_unmap_single(dd->dev, dd->dma_addr_out, dd->buflen,
355 			 DMA_FROM_DEVICE);
356 	dma_unmap_single(dd->dev, dd->dma_addr_in, dd->buflen,
357 		DMA_TO_DEVICE);
358 	free_page((unsigned long)dd->buf_out);
359 	free_page((unsigned long)dd->buf_in);
360 }
361 
atmel_tdes_crypt_pdc(struct atmel_tdes_dev * dd,dma_addr_t dma_addr_in,dma_addr_t dma_addr_out,int length)362 static int atmel_tdes_crypt_pdc(struct atmel_tdes_dev *dd,
363 				dma_addr_t dma_addr_in,
364 				dma_addr_t dma_addr_out, int length)
365 {
366 	int len32;
367 
368 	dd->dma_size = length;
369 
370 	if (!(dd->flags & TDES_FLAGS_FAST)) {
371 		dma_sync_single_for_device(dd->dev, dma_addr_in, length,
372 					   DMA_TO_DEVICE);
373 	}
374 
375 	len32 = DIV_ROUND_UP(length, sizeof(u32));
376 
377 	atmel_tdes_write(dd, TDES_PTCR, TDES_PTCR_TXTDIS|TDES_PTCR_RXTDIS);
378 	atmel_tdes_write(dd, TDES_TPR, dma_addr_in);
379 	atmel_tdes_write(dd, TDES_TCR, len32);
380 	atmel_tdes_write(dd, TDES_RPR, dma_addr_out);
381 	atmel_tdes_write(dd, TDES_RCR, len32);
382 
383 	/* Enable Interrupt */
384 	atmel_tdes_write(dd, TDES_IER, TDES_INT_ENDRX);
385 
386 	/* Start DMA transfer */
387 	atmel_tdes_write(dd, TDES_PTCR, TDES_PTCR_TXTEN | TDES_PTCR_RXTEN);
388 
389 	return 0;
390 }
391 
atmel_tdes_crypt_dma(struct atmel_tdes_dev * dd,dma_addr_t dma_addr_in,dma_addr_t dma_addr_out,int length)392 static int atmel_tdes_crypt_dma(struct atmel_tdes_dev *dd,
393 				dma_addr_t dma_addr_in,
394 				dma_addr_t dma_addr_out, int length)
395 {
396 	struct scatterlist sg[2];
397 	struct dma_async_tx_descriptor	*in_desc, *out_desc;
398 	enum dma_slave_buswidth addr_width;
399 
400 	dd->dma_size = length;
401 
402 	if (!(dd->flags & TDES_FLAGS_FAST)) {
403 		dma_sync_single_for_device(dd->dev, dma_addr_in, length,
404 					   DMA_TO_DEVICE);
405 	}
406 
407 	addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
408 
409 	dd->dma_lch_in.dma_conf.dst_addr_width = addr_width;
410 	dd->dma_lch_out.dma_conf.src_addr_width = addr_width;
411 
412 	dmaengine_slave_config(dd->dma_lch_in.chan, &dd->dma_lch_in.dma_conf);
413 	dmaengine_slave_config(dd->dma_lch_out.chan, &dd->dma_lch_out.dma_conf);
414 
415 	dd->flags |= TDES_FLAGS_DMA;
416 
417 	sg_init_table(&sg[0], 1);
418 	sg_dma_address(&sg[0]) = dma_addr_in;
419 	sg_dma_len(&sg[0]) = length;
420 
421 	sg_init_table(&sg[1], 1);
422 	sg_dma_address(&sg[1]) = dma_addr_out;
423 	sg_dma_len(&sg[1]) = length;
424 
425 	in_desc = dmaengine_prep_slave_sg(dd->dma_lch_in.chan, &sg[0],
426 				1, DMA_MEM_TO_DEV,
427 				DMA_PREP_INTERRUPT  |  DMA_CTRL_ACK);
428 	if (!in_desc)
429 		return -EINVAL;
430 
431 	out_desc = dmaengine_prep_slave_sg(dd->dma_lch_out.chan, &sg[1],
432 				1, DMA_DEV_TO_MEM,
433 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
434 	if (!out_desc)
435 		return -EINVAL;
436 
437 	out_desc->callback = atmel_tdes_dma_callback;
438 	out_desc->callback_param = dd;
439 
440 	dmaengine_submit(out_desc);
441 	dma_async_issue_pending(dd->dma_lch_out.chan);
442 
443 	dmaengine_submit(in_desc);
444 	dma_async_issue_pending(dd->dma_lch_in.chan);
445 
446 	return 0;
447 }
448 
atmel_tdes_crypt_start(struct atmel_tdes_dev * dd)449 static int atmel_tdes_crypt_start(struct atmel_tdes_dev *dd)
450 {
451 	bool fast;
452 	int err;
453 	size_t count;
454 	dma_addr_t addr_in, addr_out;
455 
456 	fast = !dd->in_offset && !dd->out_offset &&
457 		dd->in_sg->length == dd->out_sg->length &&
458 		IS_ALIGNED(dd->in_sg->offset, sizeof(u32)) &&
459 		IS_ALIGNED(dd->out_sg->offset, sizeof(u32)) &&
460 		IS_ALIGNED(dd->in_sg->length, dd->ctx->block_size);
461 
462 	if (fast) {
463 		count = min(dd->total, dd->in_sg->length);
464 
465 		err = dma_map_sg(dd->dev, dd->in_sg, 1, DMA_TO_DEVICE);
466 		if (!err) {
467 			dev_dbg(dd->dev, "dma_map_sg() error\n");
468 			return -EINVAL;
469 		}
470 
471 		err = dma_map_sg(dd->dev, dd->out_sg, 1,
472 				DMA_FROM_DEVICE);
473 		if (!err) {
474 			dev_dbg(dd->dev, "dma_map_sg() error\n");
475 			dma_unmap_sg(dd->dev, dd->in_sg, 1,
476 				DMA_TO_DEVICE);
477 			return -EINVAL;
478 		}
479 
480 		addr_in = sg_dma_address(dd->in_sg);
481 		addr_out = sg_dma_address(dd->out_sg);
482 
483 		dd->flags |= TDES_FLAGS_FAST;
484 
485 	} else {
486 		/* use cache buffers */
487 		count = atmel_tdes_sg_copy(&dd->in_sg, &dd->in_offset,
488 				dd->buf_in, dd->buflen, dd->total, 0);
489 
490 		addr_in = dd->dma_addr_in;
491 		addr_out = dd->dma_addr_out;
492 
493 		dd->flags &= ~TDES_FLAGS_FAST;
494 	}
495 
496 	dd->total -= count;
497 
498 	if (dd->caps.has_dma)
499 		err = atmel_tdes_crypt_dma(dd, addr_in, addr_out, count);
500 	else
501 		err = atmel_tdes_crypt_pdc(dd, addr_in, addr_out, count);
502 
503 	if (err && (dd->flags & TDES_FLAGS_FAST)) {
504 		dma_unmap_sg(dd->dev, dd->in_sg, 1, DMA_TO_DEVICE);
505 		dma_unmap_sg(dd->dev, dd->out_sg, 1, DMA_FROM_DEVICE);
506 	}
507 
508 	return err;
509 }
510 
511 static void
atmel_tdes_set_iv_as_last_ciphertext_block(struct atmel_tdes_dev * dd)512 atmel_tdes_set_iv_as_last_ciphertext_block(struct atmel_tdes_dev *dd)
513 {
514 	struct skcipher_request *req = dd->req;
515 	struct atmel_tdes_reqctx *rctx = skcipher_request_ctx(req);
516 	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
517 	unsigned int ivsize = crypto_skcipher_ivsize(skcipher);
518 
519 	if (req->cryptlen < ivsize)
520 		return;
521 
522 	if (rctx->mode & TDES_FLAGS_ENCRYPT)
523 		scatterwalk_map_and_copy(req->iv, req->dst,
524 					 req->cryptlen - ivsize, ivsize, 0);
525 	else
526 		memcpy(req->iv, rctx->lastc, ivsize);
527 
528 }
529 
atmel_tdes_finish_req(struct atmel_tdes_dev * dd,int err)530 static void atmel_tdes_finish_req(struct atmel_tdes_dev *dd, int err)
531 {
532 	struct skcipher_request *req = dd->req;
533 	struct atmel_tdes_reqctx *rctx = skcipher_request_ctx(req);
534 
535 	clk_disable_unprepare(dd->iclk);
536 
537 	dd->flags &= ~TDES_FLAGS_BUSY;
538 
539 	if (!err && (rctx->mode & TDES_FLAGS_OPMODE_MASK) != TDES_FLAGS_ECB)
540 		atmel_tdes_set_iv_as_last_ciphertext_block(dd);
541 
542 	skcipher_request_complete(req, err);
543 }
544 
atmel_tdes_handle_queue(struct atmel_tdes_dev * dd,struct skcipher_request * req)545 static int atmel_tdes_handle_queue(struct atmel_tdes_dev *dd,
546 			       struct skcipher_request *req)
547 {
548 	struct crypto_async_request *async_req, *backlog;
549 	struct atmel_tdes_ctx *ctx;
550 	struct atmel_tdes_reqctx *rctx;
551 	unsigned long flags;
552 	int err, ret = 0;
553 
554 	spin_lock_irqsave(&dd->lock, flags);
555 	if (req)
556 		ret = crypto_enqueue_request(&dd->queue, &req->base);
557 	if (dd->flags & TDES_FLAGS_BUSY) {
558 		spin_unlock_irqrestore(&dd->lock, flags);
559 		return ret;
560 	}
561 	backlog = crypto_get_backlog(&dd->queue);
562 	async_req = crypto_dequeue_request(&dd->queue);
563 	if (async_req)
564 		dd->flags |= TDES_FLAGS_BUSY;
565 	spin_unlock_irqrestore(&dd->lock, flags);
566 
567 	if (!async_req)
568 		return ret;
569 
570 	if (backlog)
571 		crypto_request_complete(backlog, -EINPROGRESS);
572 
573 	req = skcipher_request_cast(async_req);
574 
575 	/* assign new request to device */
576 	dd->req = req;
577 	dd->total = req->cryptlen;
578 	dd->in_offset = 0;
579 	dd->in_sg = req->src;
580 	dd->out_offset = 0;
581 	dd->out_sg = req->dst;
582 
583 	rctx = skcipher_request_ctx(req);
584 	ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
585 	rctx->mode &= TDES_FLAGS_MODE_MASK;
586 	dd->flags = (dd->flags & ~TDES_FLAGS_MODE_MASK) | rctx->mode;
587 	dd->ctx = ctx;
588 
589 	err = atmel_tdes_write_ctrl(dd);
590 	if (!err)
591 		err = atmel_tdes_crypt_start(dd);
592 	if (err) {
593 		/* des_task will not finish it, so do it here */
594 		atmel_tdes_finish_req(dd, err);
595 		tasklet_schedule(&dd->queue_task);
596 	}
597 
598 	return ret;
599 }
600 
atmel_tdes_crypt_dma_stop(struct atmel_tdes_dev * dd)601 static int atmel_tdes_crypt_dma_stop(struct atmel_tdes_dev *dd)
602 {
603 	size_t count;
604 
605 	if  (dd->flags & TDES_FLAGS_FAST) {
606 		dma_unmap_sg(dd->dev, dd->out_sg, 1, DMA_FROM_DEVICE);
607 		dma_unmap_sg(dd->dev, dd->in_sg, 1, DMA_TO_DEVICE);
608 	} else {
609 		dma_sync_single_for_cpu(dd->dev, dd->dma_addr_out, dd->dma_size,
610 					DMA_FROM_DEVICE);
611 
612 		count = atmel_tdes_sg_copy(&dd->out_sg, &dd->out_offset,
613 					   dd->buf_out, dd->buflen,
614 					   dd->dma_size, 1);
615 		if (count != dd->dma_size) {
616 			dev_dbg(dd->dev, "not all data converted: %zu\n", count);
617 			return -EINVAL;
618 		}
619 	}
620 
621 	return 0;
622 }
623 
atmel_tdes_crypt(struct skcipher_request * req,unsigned long mode)624 static int atmel_tdes_crypt(struct skcipher_request *req, unsigned long mode)
625 {
626 	struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
627 	struct atmel_tdes_ctx *ctx = crypto_skcipher_ctx(skcipher);
628 	struct atmel_tdes_reqctx *rctx = skcipher_request_ctx(req);
629 	struct device *dev = ctx->dd->dev;
630 
631 	if (!req->cryptlen)
632 		return 0;
633 
634 	if (!IS_ALIGNED(req->cryptlen, DES_BLOCK_SIZE)) {
635 		dev_dbg(dev, "request size is not exact amount of DES blocks\n");
636 		return -EINVAL;
637 	}
638 	ctx->block_size = DES_BLOCK_SIZE;
639 
640 	rctx->mode = mode;
641 
642 	if ((mode & TDES_FLAGS_OPMODE_MASK) != TDES_FLAGS_ECB &&
643 	    !(mode & TDES_FLAGS_ENCRYPT)) {
644 		unsigned int ivsize = crypto_skcipher_ivsize(skcipher);
645 
646 		if (req->cryptlen >= ivsize)
647 			scatterwalk_map_and_copy(rctx->lastc, req->src,
648 						 req->cryptlen - ivsize,
649 						 ivsize, 0);
650 	}
651 
652 	return atmel_tdes_handle_queue(ctx->dd, req);
653 }
654 
atmel_tdes_dma_init(struct atmel_tdes_dev * dd)655 static int atmel_tdes_dma_init(struct atmel_tdes_dev *dd)
656 {
657 	int ret;
658 
659 	/* Try to grab 2 DMA channels */
660 	dd->dma_lch_in.chan = dma_request_chan(dd->dev, "tx");
661 	if (IS_ERR(dd->dma_lch_in.chan)) {
662 		ret = PTR_ERR(dd->dma_lch_in.chan);
663 		goto err_dma_in;
664 	}
665 
666 	dd->dma_lch_in.dma_conf.dst_addr = dd->phys_base +
667 		TDES_IDATA1R;
668 	dd->dma_lch_in.dma_conf.src_maxburst = 1;
669 	dd->dma_lch_in.dma_conf.src_addr_width =
670 		DMA_SLAVE_BUSWIDTH_4_BYTES;
671 	dd->dma_lch_in.dma_conf.dst_maxburst = 1;
672 	dd->dma_lch_in.dma_conf.dst_addr_width =
673 		DMA_SLAVE_BUSWIDTH_4_BYTES;
674 	dd->dma_lch_in.dma_conf.device_fc = false;
675 
676 	dd->dma_lch_out.chan = dma_request_chan(dd->dev, "rx");
677 	if (IS_ERR(dd->dma_lch_out.chan)) {
678 		ret = PTR_ERR(dd->dma_lch_out.chan);
679 		goto err_dma_out;
680 	}
681 
682 	dd->dma_lch_out.dma_conf.src_addr = dd->phys_base +
683 		TDES_ODATA1R;
684 	dd->dma_lch_out.dma_conf.src_maxburst = 1;
685 	dd->dma_lch_out.dma_conf.src_addr_width =
686 		DMA_SLAVE_BUSWIDTH_4_BYTES;
687 	dd->dma_lch_out.dma_conf.dst_maxburst = 1;
688 	dd->dma_lch_out.dma_conf.dst_addr_width =
689 		DMA_SLAVE_BUSWIDTH_4_BYTES;
690 	dd->dma_lch_out.dma_conf.device_fc = false;
691 
692 	return 0;
693 
694 err_dma_out:
695 	dma_release_channel(dd->dma_lch_in.chan);
696 err_dma_in:
697 	dev_err(dd->dev, "no DMA channel available\n");
698 	return ret;
699 }
700 
atmel_tdes_dma_cleanup(struct atmel_tdes_dev * dd)701 static void atmel_tdes_dma_cleanup(struct atmel_tdes_dev *dd)
702 {
703 	dma_release_channel(dd->dma_lch_in.chan);
704 	dma_release_channel(dd->dma_lch_out.chan);
705 }
706 
atmel_des_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)707 static int atmel_des_setkey(struct crypto_skcipher *tfm, const u8 *key,
708 			   unsigned int keylen)
709 {
710 	struct atmel_tdes_ctx *ctx = crypto_skcipher_ctx(tfm);
711 	int err;
712 
713 	err = verify_skcipher_des_key(tfm, key);
714 	if (err)
715 		return err;
716 
717 	memcpy(ctx->key, key, keylen);
718 	ctx->keylen = keylen;
719 
720 	return 0;
721 }
722 
atmel_tdes_setkey(struct crypto_skcipher * tfm,const u8 * key,unsigned int keylen)723 static int atmel_tdes_setkey(struct crypto_skcipher *tfm, const u8 *key,
724 			   unsigned int keylen)
725 {
726 	struct atmel_tdes_ctx *ctx = crypto_skcipher_ctx(tfm);
727 	int err;
728 
729 	err = verify_skcipher_des3_key(tfm, key);
730 	if (err)
731 		return err;
732 
733 	memcpy(ctx->key, key, keylen);
734 	ctx->keylen = keylen;
735 
736 	return 0;
737 }
738 
atmel_tdes_ecb_encrypt(struct skcipher_request * req)739 static int atmel_tdes_ecb_encrypt(struct skcipher_request *req)
740 {
741 	return atmel_tdes_crypt(req, TDES_FLAGS_ECB | TDES_FLAGS_ENCRYPT);
742 }
743 
atmel_tdes_ecb_decrypt(struct skcipher_request * req)744 static int atmel_tdes_ecb_decrypt(struct skcipher_request *req)
745 {
746 	return atmel_tdes_crypt(req, TDES_FLAGS_ECB);
747 }
748 
atmel_tdes_cbc_encrypt(struct skcipher_request * req)749 static int atmel_tdes_cbc_encrypt(struct skcipher_request *req)
750 {
751 	return atmel_tdes_crypt(req, TDES_FLAGS_CBC | TDES_FLAGS_ENCRYPT);
752 }
753 
atmel_tdes_cbc_decrypt(struct skcipher_request * req)754 static int atmel_tdes_cbc_decrypt(struct skcipher_request *req)
755 {
756 	return atmel_tdes_crypt(req, TDES_FLAGS_CBC);
757 }
758 
atmel_tdes_init_tfm(struct crypto_skcipher * tfm)759 static int atmel_tdes_init_tfm(struct crypto_skcipher *tfm)
760 {
761 	struct atmel_tdes_ctx *ctx = crypto_skcipher_ctx(tfm);
762 
763 	ctx->dd = atmel_tdes_dev_alloc();
764 	if (!ctx->dd)
765 		return -ENODEV;
766 
767 	crypto_skcipher_set_reqsize(tfm, sizeof(struct atmel_tdes_reqctx));
768 
769 	return 0;
770 }
771 
atmel_tdes_skcipher_alg_init(struct skcipher_alg * alg)772 static void atmel_tdes_skcipher_alg_init(struct skcipher_alg *alg)
773 {
774 	alg->base.cra_priority = ATMEL_TDES_PRIORITY;
775 	alg->base.cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_KERN_DRIVER_ONLY;
776 	alg->base.cra_ctxsize = sizeof(struct atmel_tdes_ctx);
777 	alg->base.cra_module = THIS_MODULE;
778 
779 	alg->init = atmel_tdes_init_tfm;
780 }
781 
782 static struct skcipher_alg tdes_algs[] = {
783 {
784 	.base.cra_name		= "ecb(des)",
785 	.base.cra_driver_name	= "atmel-ecb-des",
786 	.base.cra_blocksize	= DES_BLOCK_SIZE,
787 	.base.cra_alignmask	= 0x7,
788 
789 	.min_keysize		= DES_KEY_SIZE,
790 	.max_keysize		= DES_KEY_SIZE,
791 	.setkey			= atmel_des_setkey,
792 	.encrypt		= atmel_tdes_ecb_encrypt,
793 	.decrypt		= atmel_tdes_ecb_decrypt,
794 },
795 {
796 	.base.cra_name		= "cbc(des)",
797 	.base.cra_driver_name	= "atmel-cbc-des",
798 	.base.cra_blocksize	= DES_BLOCK_SIZE,
799 	.base.cra_alignmask	= 0x7,
800 
801 	.min_keysize		= DES_KEY_SIZE,
802 	.max_keysize		= DES_KEY_SIZE,
803 	.ivsize			= DES_BLOCK_SIZE,
804 	.setkey			= atmel_des_setkey,
805 	.encrypt		= atmel_tdes_cbc_encrypt,
806 	.decrypt		= atmel_tdes_cbc_decrypt,
807 },
808 {
809 	.base.cra_name		= "ecb(des3_ede)",
810 	.base.cra_driver_name	= "atmel-ecb-tdes",
811 	.base.cra_blocksize	= DES_BLOCK_SIZE,
812 	.base.cra_alignmask	= 0x7,
813 
814 	.min_keysize		= DES3_EDE_KEY_SIZE,
815 	.max_keysize		= DES3_EDE_KEY_SIZE,
816 	.setkey			= atmel_tdes_setkey,
817 	.encrypt		= atmel_tdes_ecb_encrypt,
818 	.decrypt		= atmel_tdes_ecb_decrypt,
819 },
820 {
821 	.base.cra_name		= "cbc(des3_ede)",
822 	.base.cra_driver_name	= "atmel-cbc-tdes",
823 	.base.cra_blocksize	= DES_BLOCK_SIZE,
824 	.base.cra_alignmask	= 0x7,
825 
826 	.min_keysize		= DES3_EDE_KEY_SIZE,
827 	.max_keysize		= DES3_EDE_KEY_SIZE,
828 	.setkey			= atmel_tdes_setkey,
829 	.encrypt		= atmel_tdes_cbc_encrypt,
830 	.decrypt		= atmel_tdes_cbc_decrypt,
831 	.ivsize			= DES_BLOCK_SIZE,
832 },
833 };
834 
atmel_tdes_queue_task(unsigned long data)835 static void atmel_tdes_queue_task(unsigned long data)
836 {
837 	struct atmel_tdes_dev *dd = (struct atmel_tdes_dev *)data;
838 
839 	atmel_tdes_handle_queue(dd, NULL);
840 }
841 
atmel_tdes_done_task(unsigned long data)842 static void atmel_tdes_done_task(unsigned long data)
843 {
844 	struct atmel_tdes_dev *dd = (struct atmel_tdes_dev *) data;
845 	int err;
846 
847 	if (!(dd->flags & TDES_FLAGS_DMA))
848 		err = atmel_tdes_crypt_pdc_stop(dd);
849 	else
850 		err = atmel_tdes_crypt_dma_stop(dd);
851 
852 	if (dd->total && !err) {
853 		if (dd->flags & TDES_FLAGS_FAST) {
854 			dd->in_sg = sg_next(dd->in_sg);
855 			dd->out_sg = sg_next(dd->out_sg);
856 			if (!dd->in_sg || !dd->out_sg)
857 				err = -EINVAL;
858 		}
859 		if (!err)
860 			err = atmel_tdes_crypt_start(dd);
861 		if (!err)
862 			return; /* DMA started. Not finishing. */
863 	}
864 
865 	atmel_tdes_finish_req(dd, err);
866 	atmel_tdes_handle_queue(dd, NULL);
867 }
868 
atmel_tdes_irq(int irq,void * dev_id)869 static irqreturn_t atmel_tdes_irq(int irq, void *dev_id)
870 {
871 	struct atmel_tdes_dev *tdes_dd = dev_id;
872 	u32 reg;
873 
874 	reg = atmel_tdes_read(tdes_dd, TDES_ISR);
875 	if (reg & atmel_tdes_read(tdes_dd, TDES_IMR)) {
876 		atmel_tdes_write(tdes_dd, TDES_IDR, reg);
877 		if (TDES_FLAGS_BUSY & tdes_dd->flags)
878 			tasklet_schedule(&tdes_dd->done_task);
879 		else
880 			dev_warn(tdes_dd->dev, "TDES interrupt when no active requests.\n");
881 		return IRQ_HANDLED;
882 	}
883 
884 	return IRQ_NONE;
885 }
886 
atmel_tdes_register_algs(struct atmel_tdes_dev * dd)887 static int atmel_tdes_register_algs(struct atmel_tdes_dev *dd)
888 {
889 	int err, i;
890 
891 	for (i = 0; i < ARRAY_SIZE(tdes_algs); i++) {
892 		atmel_tdes_skcipher_alg_init(&tdes_algs[i]);
893 
894 		err = crypto_register_skcipher(&tdes_algs[i]);
895 		if (err) {
896 			crypto_unregister_skciphers(tdes_algs, i);
897 			return err;
898 		}
899 	}
900 
901 	return 0;
902 }
903 
atmel_tdes_get_cap(struct atmel_tdes_dev * dd)904 static void atmel_tdes_get_cap(struct atmel_tdes_dev *dd)
905 {
906 	dd->caps.has_dma = 0;
907 
908 	/* keep only major version number */
909 	switch (dd->hw_version & 0xf00) {
910 	case 0x800:
911 	case 0x700:
912 		dd->caps.has_dma = 1;
913 		break;
914 	case 0x600:
915 		break;
916 	default:
917 		dev_warn(dd->dev,
918 				"Unmanaged tdes version, set minimum capabilities\n");
919 		break;
920 	}
921 }
922 
923 static const struct of_device_id atmel_tdes_dt_ids[] = {
924 	{ .compatible = "atmel,at91sam9g46-tdes" },
925 	{ /* sentinel */ }
926 };
927 MODULE_DEVICE_TABLE(of, atmel_tdes_dt_ids);
928 
atmel_tdes_probe(struct platform_device * pdev)929 static int atmel_tdes_probe(struct platform_device *pdev)
930 {
931 	struct atmel_tdes_dev *tdes_dd;
932 	struct device *dev = &pdev->dev;
933 	struct resource *tdes_res;
934 	int err;
935 
936 	tdes_dd = devm_kmalloc(&pdev->dev, sizeof(*tdes_dd), GFP_KERNEL);
937 	if (!tdes_dd)
938 		return -ENOMEM;
939 
940 	tdes_dd->dev = dev;
941 
942 	platform_set_drvdata(pdev, tdes_dd);
943 
944 	INIT_LIST_HEAD(&tdes_dd->list);
945 	spin_lock_init(&tdes_dd->lock);
946 
947 	tasklet_init(&tdes_dd->done_task, atmel_tdes_done_task,
948 					(unsigned long)tdes_dd);
949 	tasklet_init(&tdes_dd->queue_task, atmel_tdes_queue_task,
950 					(unsigned long)tdes_dd);
951 
952 	crypto_init_queue(&tdes_dd->queue, ATMEL_TDES_QUEUE_LENGTH);
953 
954 	tdes_dd->io_base = devm_platform_get_and_ioremap_resource(pdev, 0, &tdes_res);
955 	if (IS_ERR(tdes_dd->io_base)) {
956 		err = PTR_ERR(tdes_dd->io_base);
957 		goto err_tasklet_kill;
958 	}
959 	tdes_dd->phys_base = tdes_res->start;
960 
961 	/* Get the IRQ */
962 	tdes_dd->irq = platform_get_irq(pdev,  0);
963 	if (tdes_dd->irq < 0) {
964 		err = tdes_dd->irq;
965 		goto err_tasklet_kill;
966 	}
967 
968 	err = devm_request_irq(&pdev->dev, tdes_dd->irq, atmel_tdes_irq,
969 			       IRQF_SHARED, "atmel-tdes", tdes_dd);
970 	if (err)
971 		goto err_tasklet_kill;
972 
973 	/* Initializing the clock */
974 	tdes_dd->iclk = devm_clk_get(&pdev->dev, "tdes_clk");
975 	if (IS_ERR(tdes_dd->iclk)) {
976 		dev_err(dev, "clock initialization failed.\n");
977 		err = PTR_ERR(tdes_dd->iclk);
978 		goto err_tasklet_kill;
979 	}
980 
981 	err = atmel_tdes_hw_version_init(tdes_dd);
982 	if (err)
983 		goto err_tasklet_kill;
984 
985 	atmel_tdes_get_cap(tdes_dd);
986 
987 	err = atmel_tdes_buff_init(tdes_dd);
988 	if (err)
989 		goto err_tasklet_kill;
990 
991 	if (tdes_dd->caps.has_dma) {
992 		err = atmel_tdes_dma_init(tdes_dd);
993 		if (err)
994 			goto err_buff_cleanup;
995 
996 		dev_info(dev, "using %s, %s for DMA transfers\n",
997 				dma_chan_name(tdes_dd->dma_lch_in.chan),
998 				dma_chan_name(tdes_dd->dma_lch_out.chan));
999 	}
1000 
1001 	spin_lock(&atmel_tdes.lock);
1002 	list_add_tail(&tdes_dd->list, &atmel_tdes.dev_list);
1003 	spin_unlock(&atmel_tdes.lock);
1004 
1005 	err = atmel_tdes_register_algs(tdes_dd);
1006 	if (err)
1007 		goto err_algs;
1008 
1009 	dev_info(dev, "Atmel DES/TDES\n");
1010 
1011 	return 0;
1012 
1013 err_algs:
1014 	spin_lock(&atmel_tdes.lock);
1015 	list_del(&tdes_dd->list);
1016 	spin_unlock(&atmel_tdes.lock);
1017 	if (tdes_dd->caps.has_dma)
1018 		atmel_tdes_dma_cleanup(tdes_dd);
1019 err_buff_cleanup:
1020 	atmel_tdes_buff_cleanup(tdes_dd);
1021 err_tasklet_kill:
1022 	tasklet_kill(&tdes_dd->done_task);
1023 	tasklet_kill(&tdes_dd->queue_task);
1024 
1025 	return err;
1026 }
1027 
atmel_tdes_remove(struct platform_device * pdev)1028 static void atmel_tdes_remove(struct platform_device *pdev)
1029 {
1030 	struct atmel_tdes_dev *tdes_dd = platform_get_drvdata(pdev);
1031 
1032 	spin_lock(&atmel_tdes.lock);
1033 	list_del(&tdes_dd->list);
1034 	spin_unlock(&atmel_tdes.lock);
1035 
1036 	crypto_unregister_skciphers(tdes_algs, ARRAY_SIZE(tdes_algs));
1037 
1038 	tasklet_kill(&tdes_dd->done_task);
1039 	tasklet_kill(&tdes_dd->queue_task);
1040 
1041 	if (tdes_dd->caps.has_dma)
1042 		atmel_tdes_dma_cleanup(tdes_dd);
1043 
1044 	atmel_tdes_buff_cleanup(tdes_dd);
1045 }
1046 
1047 static struct platform_driver atmel_tdes_driver = {
1048 	.probe		= atmel_tdes_probe,
1049 	.remove		= atmel_tdes_remove,
1050 	.driver		= {
1051 		.name	= "atmel_tdes",
1052 		.of_match_table = atmel_tdes_dt_ids,
1053 	},
1054 };
1055 
1056 module_platform_driver(atmel_tdes_driver);
1057 
1058 MODULE_DESCRIPTION("Atmel DES/TDES hw acceleration support.");
1059 MODULE_LICENSE("GPL v2");
1060 MODULE_AUTHOR("Nicolas Royer - Eukréa Electromatique");
1061