1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * sl3516-ce-core.c - hardware cryptographic offloader for Storlink SL3516 SoC
4  *
5  * Copyright (C) 2021 Corentin Labbe <clabbe@baylibre.com>
6  *
7  * Core file which registers crypto algorithms supported by the CryptoEngine
8  */
9 #include <linux/clk.h>
10 #include <linux/crypto.h>
11 #include <linux/debugfs.h>
12 #include <linux/dev_printk.h>
13 #include <linux/dma-mapping.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/irq.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_device.h>
20 #include <linux/platform_device.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/reset.h>
23 #include <crypto/internal/rng.h>
24 #include <crypto/internal/skcipher.h>
25 
26 #include "sl3516-ce.h"
27 
28 static int sl3516_ce_desc_init(struct sl3516_ce_dev *ce)
29 {
30 	const size_t sz = sizeof(struct descriptor) * MAXDESC;
31 	int i;
32 
33 	ce->tx = dma_alloc_coherent(ce->dev, sz, &ce->dtx, GFP_KERNEL);
34 	if (!ce->tx)
35 		return -ENOMEM;
36 	ce->rx = dma_alloc_coherent(ce->dev, sz, &ce->drx, GFP_KERNEL);
37 	if (!ce->rx)
38 		goto err_rx;
39 
40 	for (i = 0; i < MAXDESC; i++) {
41 		ce->tx[i].frame_ctrl.bits.own = CE_CPU;
42 		ce->tx[i].next_desc.next_descriptor = ce->dtx + (i + 1) * sizeof(struct descriptor);
43 	}
44 	ce->tx[MAXDESC - 1].next_desc.next_descriptor = ce->dtx;
45 
46 	for (i = 0; i < MAXDESC; i++) {
47 		ce->rx[i].frame_ctrl.bits.own = CE_CPU;
48 		ce->rx[i].next_desc.next_descriptor = ce->drx + (i + 1) * sizeof(struct descriptor);
49 	}
50 	ce->rx[MAXDESC - 1].next_desc.next_descriptor = ce->drx;
51 
52 	ce->pctrl = dma_alloc_coherent(ce->dev, sizeof(struct pkt_control_ecb),
53 				       &ce->dctrl, GFP_KERNEL);
54 	if (!ce->pctrl)
55 		goto err_pctrl;
56 
57 	return 0;
58 err_pctrl:
59 	dma_free_coherent(ce->dev, sz, ce->rx, ce->drx);
60 err_rx:
61 	dma_free_coherent(ce->dev, sz, ce->tx, ce->dtx);
62 	return -ENOMEM;
63 }
64 
65 static void sl3516_ce_free_descs(struct sl3516_ce_dev *ce)
66 {
67 	const size_t sz = sizeof(struct descriptor) * MAXDESC;
68 
69 	dma_free_coherent(ce->dev, sz, ce->tx, ce->dtx);
70 	dma_free_coherent(ce->dev, sz, ce->rx, ce->drx);
71 	dma_free_coherent(ce->dev, sizeof(struct pkt_control_ecb), ce->pctrl,
72 			  ce->dctrl);
73 }
74 
75 static void start_dma_tx(struct sl3516_ce_dev *ce)
76 {
77 	u32 v;
78 
79 	v = TXDMA_CTRL_START | TXDMA_CTRL_CHAIN_MODE | TXDMA_CTRL_CONTINUE | \
80 		TXDMA_CTRL_INT_FAIL | TXDMA_CTRL_INT_PERR | TXDMA_CTRL_BURST_UNK;
81 
82 	writel(v, ce->base + IPSEC_TXDMA_CTRL);
83 }
84 
85 static void start_dma_rx(struct sl3516_ce_dev *ce)
86 {
87 	u32 v;
88 
89 	v = RXDMA_CTRL_START | RXDMA_CTRL_CHAIN_MODE | RXDMA_CTRL_CONTINUE | \
90 		RXDMA_CTRL_BURST_UNK | RXDMA_CTRL_INT_FINISH | \
91 		RXDMA_CTRL_INT_FAIL | RXDMA_CTRL_INT_PERR | \
92 		RXDMA_CTRL_INT_EOD | RXDMA_CTRL_INT_EOF;
93 
94 	writel(v, ce->base + IPSEC_RXDMA_CTRL);
95 }
96 
97 static struct descriptor *get_desc_tx(struct sl3516_ce_dev *ce)
98 {
99 	struct descriptor *dd;
100 
101 	dd = &ce->tx[ce->ctx];
102 	ce->ctx++;
103 	if (ce->ctx >= MAXDESC)
104 		ce->ctx = 0;
105 	return dd;
106 }
107 
108 static struct descriptor *get_desc_rx(struct sl3516_ce_dev *ce)
109 {
110 	struct descriptor *rdd;
111 
112 	rdd = &ce->rx[ce->crx];
113 	ce->crx++;
114 	if (ce->crx >= MAXDESC)
115 		ce->crx = 0;
116 	return rdd;
117 }
118 
119 int sl3516_ce_run_task(struct sl3516_ce_dev *ce, struct sl3516_ce_cipher_req_ctx *rctx,
120 		       const char *name)
121 {
122 	struct descriptor *dd, *rdd = NULL;
123 	u32 v;
124 	int i, err = 0;
125 
126 	ce->stat_req++;
127 
128 	reinit_completion(&ce->complete);
129 	ce->status = 0;
130 
131 	for (i = 0; i < rctx->nr_sgd; i++) {
132 		dev_dbg(ce->dev, "%s handle DST SG %d/%d len=%d\n", __func__,
133 			i, rctx->nr_sgd, rctx->t_dst[i].len);
134 		rdd = get_desc_rx(ce);
135 		rdd->buf_adr = rctx->t_dst[i].addr;
136 		rdd->frame_ctrl.bits.buffer_size = rctx->t_dst[i].len;
137 		rdd->frame_ctrl.bits.own = CE_DMA;
138 	}
139 	rdd->next_desc.bits.eofie = 1;
140 
141 	for (i = 0; i < rctx->nr_sgs; i++) {
142 		dev_dbg(ce->dev, "%s handle SRC SG %d/%d len=%d\n", __func__,
143 			i, rctx->nr_sgs, rctx->t_src[i].len);
144 		rctx->h->algorithm_len = rctx->t_src[i].len;
145 
146 		dd = get_desc_tx(ce);
147 		dd->frame_ctrl.raw = 0;
148 		dd->flag_status.raw = 0;
149 		dd->frame_ctrl.bits.buffer_size = rctx->pctrllen;
150 		dd->buf_adr = ce->dctrl;
151 		dd->flag_status.tx_flag.tqflag = rctx->tqflag;
152 		dd->next_desc.bits.eofie = 0;
153 		dd->next_desc.bits.dec = 0;
154 		dd->next_desc.bits.sof_eof = DESC_FIRST | DESC_LAST;
155 		dd->frame_ctrl.bits.own = CE_DMA;
156 
157 		dd = get_desc_tx(ce);
158 		dd->frame_ctrl.raw = 0;
159 		dd->flag_status.raw = 0;
160 		dd->frame_ctrl.bits.buffer_size = rctx->t_src[i].len;
161 		dd->buf_adr = rctx->t_src[i].addr;
162 		dd->flag_status.tx_flag.tqflag = 0;
163 		dd->next_desc.bits.eofie = 0;
164 		dd->next_desc.bits.dec = 0;
165 		dd->next_desc.bits.sof_eof = DESC_FIRST | DESC_LAST;
166 		dd->frame_ctrl.bits.own = CE_DMA;
167 		start_dma_tx(ce);
168 		start_dma_rx(ce);
169 	}
170 	wait_for_completion_interruptible_timeout(&ce->complete,
171 						  msecs_to_jiffies(5000));
172 	if (ce->status == 0) {
173 		dev_err(ce->dev, "DMA timeout for %s\n", name);
174 		err = -EFAULT;
175 	}
176 	v = readl(ce->base + IPSEC_STATUS_REG);
177 	if (v & 0xFFF) {
178 		dev_err(ce->dev, "IPSEC_STATUS_REG %x\n", v);
179 		err = -EFAULT;
180 	}
181 
182 	return err;
183 }
184 
185 static irqreturn_t ce_irq_handler(int irq, void *data)
186 {
187 	struct sl3516_ce_dev *ce = (struct sl3516_ce_dev *)data;
188 	u32 v;
189 
190 	ce->stat_irq++;
191 
192 	v = readl(ce->base + IPSEC_DMA_STATUS);
193 	writel(v, ce->base + IPSEC_DMA_STATUS);
194 
195 	if (v & DMA_STATUS_TS_DERR)
196 		dev_err(ce->dev, "AHB bus Error While Tx !!!\n");
197 	if (v & DMA_STATUS_TS_PERR)
198 		dev_err(ce->dev, "Tx Descriptor Protocol Error !!!\n");
199 	if (v & DMA_STATUS_RS_DERR)
200 		dev_err(ce->dev, "AHB bus Error While Rx !!!\n");
201 	if (v & DMA_STATUS_RS_PERR)
202 		dev_err(ce->dev, "Rx Descriptor Protocol Error !!!\n");
203 
204 	if (v & DMA_STATUS_TS_EOFI)
205 		ce->stat_irq_tx++;
206 	if (v & DMA_STATUS_RS_EOFI) {
207 		ce->status = 1;
208 		complete(&ce->complete);
209 		ce->stat_irq_rx++;
210 		return IRQ_HANDLED;
211 	}
212 
213 	return IRQ_HANDLED;
214 }
215 
216 static struct sl3516_ce_alg_template ce_algs[] = {
217 {
218 	.type = CRYPTO_ALG_TYPE_SKCIPHER,
219 	.mode = ECB_AES,
220 	.alg.skcipher = {
221 		.base = {
222 			.cra_name = "ecb(aes)",
223 			.cra_driver_name = "ecb-aes-sl3516",
224 			.cra_priority = 400,
225 			.cra_blocksize = AES_BLOCK_SIZE,
226 			.cra_flags = CRYPTO_ALG_TYPE_SKCIPHER |
227 				CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
228 			.cra_ctxsize = sizeof(struct sl3516_ce_cipher_tfm_ctx),
229 			.cra_module = THIS_MODULE,
230 			.cra_alignmask = 0xf,
231 			.cra_init = sl3516_ce_cipher_init,
232 			.cra_exit = sl3516_ce_cipher_exit,
233 		},
234 		.min_keysize	= AES_MIN_KEY_SIZE,
235 		.max_keysize	= AES_MAX_KEY_SIZE,
236 		.setkey		= sl3516_ce_aes_setkey,
237 		.encrypt	= sl3516_ce_skencrypt,
238 		.decrypt	= sl3516_ce_skdecrypt,
239 	}
240 },
241 };
242 
243 #ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG
244 static int sl3516_ce_debugfs_show(struct seq_file *seq, void *v)
245 {
246 	struct sl3516_ce_dev *ce = seq->private;
247 	unsigned int i;
248 
249 	seq_printf(seq, "HWRNG %lu %lu\n",
250 		   ce->hwrng_stat_req, ce->hwrng_stat_bytes);
251 	seq_printf(seq, "IRQ %lu\n", ce->stat_irq);
252 	seq_printf(seq, "IRQ TX %lu\n", ce->stat_irq_tx);
253 	seq_printf(seq, "IRQ RX %lu\n", ce->stat_irq_rx);
254 	seq_printf(seq, "nreq %lu\n", ce->stat_req);
255 	seq_printf(seq, "fallback SG count TX %lu\n", ce->fallback_sg_count_tx);
256 	seq_printf(seq, "fallback SG count RX %lu\n", ce->fallback_sg_count_rx);
257 	seq_printf(seq, "fallback modulo16 %lu\n", ce->fallback_mod16);
258 	seq_printf(seq, "fallback align16 %lu\n", ce->fallback_align16);
259 	seq_printf(seq, "fallback not same len %lu\n", ce->fallback_not_same_len);
260 
261 	for (i = 0; i < ARRAY_SIZE(ce_algs); i++) {
262 		if (!ce_algs[i].ce)
263 			continue;
264 		switch (ce_algs[i].type) {
265 		case CRYPTO_ALG_TYPE_SKCIPHER:
266 			seq_printf(seq, "%s %s reqs=%lu fallback=%lu\n",
267 				   ce_algs[i].alg.skcipher.base.cra_driver_name,
268 				   ce_algs[i].alg.skcipher.base.cra_name,
269 				   ce_algs[i].stat_req, ce_algs[i].stat_fb);
270 			break;
271 		}
272 	}
273 	return 0;
274 }
275 
276 DEFINE_SHOW_ATTRIBUTE(sl3516_ce_debugfs);
277 #endif
278 
279 static int sl3516_ce_register_algs(struct sl3516_ce_dev *ce)
280 {
281 	int err;
282 	unsigned int i;
283 
284 	for (i = 0; i < ARRAY_SIZE(ce_algs); i++) {
285 		ce_algs[i].ce = ce;
286 		switch (ce_algs[i].type) {
287 		case CRYPTO_ALG_TYPE_SKCIPHER:
288 			dev_info(ce->dev, "DEBUG: Register %s\n",
289 				 ce_algs[i].alg.skcipher.base.cra_name);
290 			err = crypto_register_skcipher(&ce_algs[i].alg.skcipher);
291 			if (err) {
292 				dev_err(ce->dev, "Fail to register %s\n",
293 					ce_algs[i].alg.skcipher.base.cra_name);
294 				ce_algs[i].ce = NULL;
295 				return err;
296 			}
297 			break;
298 		default:
299 			ce_algs[i].ce = NULL;
300 			dev_err(ce->dev, "ERROR: tried to register an unknown algo\n");
301 		}
302 	}
303 	return 0;
304 }
305 
306 static void sl3516_ce_unregister_algs(struct sl3516_ce_dev *ce)
307 {
308 	unsigned int i;
309 
310 	for (i = 0; i < ARRAY_SIZE(ce_algs); i++) {
311 		if (!ce_algs[i].ce)
312 			continue;
313 		switch (ce_algs[i].type) {
314 		case CRYPTO_ALG_TYPE_SKCIPHER:
315 			dev_info(ce->dev, "Unregister %d %s\n", i,
316 				 ce_algs[i].alg.skcipher.base.cra_name);
317 			crypto_unregister_skcipher(&ce_algs[i].alg.skcipher);
318 			break;
319 		}
320 	}
321 }
322 
323 static void sl3516_ce_start(struct sl3516_ce_dev *ce)
324 {
325 	ce->ctx = 0;
326 	ce->crx = 0;
327 	writel(ce->dtx, ce->base + IPSEC_TXDMA_CURR_DESC);
328 	writel(ce->drx, ce->base + IPSEC_RXDMA_CURR_DESC);
329 	writel(0, ce->base + IPSEC_DMA_STATUS);
330 }
331 
332 /*
333  * Power management strategy: The device is suspended unless a TFM exists for
334  * one of the algorithms proposed by this driver.
335  */
336 static int sl3516_ce_pm_suspend(struct device *dev)
337 {
338 	struct sl3516_ce_dev *ce = dev_get_drvdata(dev);
339 
340 	reset_control_assert(ce->reset);
341 	clk_disable_unprepare(ce->clks);
342 	return 0;
343 }
344 
345 static int sl3516_ce_pm_resume(struct device *dev)
346 {
347 	struct sl3516_ce_dev *ce = dev_get_drvdata(dev);
348 	int err;
349 
350 	err = clk_prepare_enable(ce->clks);
351 	if (err) {
352 		dev_err(ce->dev, "Cannot prepare_enable\n");
353 		goto error;
354 	}
355 	err = reset_control_deassert(ce->reset);
356 	if (err) {
357 		dev_err(ce->dev, "Cannot deassert reset control\n");
358 		goto error;
359 	}
360 
361 	sl3516_ce_start(ce);
362 
363 	return 0;
364 error:
365 	sl3516_ce_pm_suspend(dev);
366 	return err;
367 }
368 
369 static const struct dev_pm_ops sl3516_ce_pm_ops = {
370 	SET_RUNTIME_PM_OPS(sl3516_ce_pm_suspend, sl3516_ce_pm_resume, NULL)
371 };
372 
373 static int sl3516_ce_pm_init(struct sl3516_ce_dev *ce)
374 {
375 	int err;
376 
377 	pm_runtime_use_autosuspend(ce->dev);
378 	pm_runtime_set_autosuspend_delay(ce->dev, 2000);
379 
380 	err = pm_runtime_set_suspended(ce->dev);
381 	if (err)
382 		return err;
383 	pm_runtime_enable(ce->dev);
384 	return err;
385 }
386 
387 static void sl3516_ce_pm_exit(struct sl3516_ce_dev *ce)
388 {
389 	pm_runtime_disable(ce->dev);
390 }
391 
392 static int sl3516_ce_probe(struct platform_device *pdev)
393 {
394 	struct sl3516_ce_dev *ce;
395 	int err, irq;
396 	u32 v;
397 
398 	ce = devm_kzalloc(&pdev->dev, sizeof(*ce), GFP_KERNEL);
399 	if (!ce)
400 		return -ENOMEM;
401 
402 	ce->dev = &pdev->dev;
403 	platform_set_drvdata(pdev, ce);
404 
405 	ce->base = devm_platform_ioremap_resource(pdev, 0);
406 	if (IS_ERR(ce->base))
407 		return PTR_ERR(ce->base);
408 
409 	irq = platform_get_irq(pdev, 0);
410 	if (irq < 0)
411 		return irq;
412 
413 	err = devm_request_irq(&pdev->dev, irq, ce_irq_handler, 0, "crypto", ce);
414 	if (err) {
415 		dev_err(ce->dev, "Cannot request Crypto Engine IRQ (err=%d)\n", err);
416 		return err;
417 	}
418 
419 	ce->reset = devm_reset_control_get(&pdev->dev, NULL);
420 	if (IS_ERR(ce->reset))
421 		return dev_err_probe(&pdev->dev, PTR_ERR(ce->reset),
422 				     "No reset control found\n");
423 	ce->clks = devm_clk_get(ce->dev, NULL);
424 	if (IS_ERR(ce->clks)) {
425 		err = PTR_ERR(ce->clks);
426 		dev_err(ce->dev, "Cannot get clock err=%d\n", err);
427 		return err;
428 	}
429 
430 	err = sl3516_ce_desc_init(ce);
431 	if (err)
432 		return err;
433 
434 	err = sl3516_ce_pm_init(ce);
435 	if (err)
436 		goto error_pm;
437 
438 	init_completion(&ce->complete);
439 
440 	ce->engine = crypto_engine_alloc_init(ce->dev, true);
441 	if (!ce->engine) {
442 		dev_err(ce->dev, "Cannot allocate engine\n");
443 		err = -ENOMEM;
444 		goto error_engine;
445 	}
446 
447 	err = crypto_engine_start(ce->engine);
448 	if (err) {
449 		dev_err(ce->dev, "Cannot start engine\n");
450 		goto error_engine;
451 	}
452 
453 	err = sl3516_ce_register_algs(ce);
454 	if (err)
455 		goto error_alg;
456 
457 	err = sl3516_ce_rng_register(ce);
458 	if (err)
459 		goto error_rng;
460 
461 	err = pm_runtime_resume_and_get(ce->dev);
462 	if (err < 0)
463 		goto error_pmuse;
464 
465 	v = readl(ce->base + IPSEC_ID);
466 	dev_info(ce->dev, "SL3516 dev %lx rev %lx\n",
467 		 v & GENMASK(31, 4),
468 		 v & GENMASK(3, 0));
469 	v = readl(ce->base + IPSEC_DMA_DEVICE_ID);
470 	dev_info(ce->dev, "SL3516 DMA dev %lx rev %lx\n",
471 		 v & GENMASK(15, 4),
472 		 v & GENMASK(3, 0));
473 
474 	pm_runtime_put_sync(ce->dev);
475 
476 #ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG
477 	/* Ignore error of debugfs */
478 	ce->dbgfs_dir = debugfs_create_dir("sl3516", NULL);
479 	ce->dbgfs_stats = debugfs_create_file("stats", 0444,
480 					      ce->dbgfs_dir, ce,
481 					      &sl3516_ce_debugfs_fops);
482 #endif
483 
484 	return 0;
485 error_pmuse:
486 	sl3516_ce_rng_unregister(ce);
487 error_rng:
488 	sl3516_ce_unregister_algs(ce);
489 error_alg:
490 	crypto_engine_exit(ce->engine);
491 error_engine:
492 	sl3516_ce_pm_exit(ce);
493 error_pm:
494 	sl3516_ce_free_descs(ce);
495 	return err;
496 }
497 
498 static int sl3516_ce_remove(struct platform_device *pdev)
499 {
500 	struct sl3516_ce_dev *ce = platform_get_drvdata(pdev);
501 
502 	sl3516_ce_rng_unregister(ce);
503 	sl3516_ce_unregister_algs(ce);
504 	crypto_engine_exit(ce->engine);
505 	sl3516_ce_pm_exit(ce);
506 	sl3516_ce_free_descs(ce);
507 
508 #ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG
509 	debugfs_remove_recursive(ce->dbgfs_dir);
510 #endif
511 
512 	return 0;
513 }
514 
515 static const struct of_device_id sl3516_ce_crypto_of_match_table[] = {
516 	{ .compatible = "cortina,sl3516-crypto"},
517 	{}
518 };
519 MODULE_DEVICE_TABLE(of, sl3516_ce_crypto_of_match_table);
520 
521 static struct platform_driver sl3516_ce_driver = {
522 	.probe		 = sl3516_ce_probe,
523 	.remove		 = sl3516_ce_remove,
524 	.driver		 = {
525 		.name		= "sl3516-crypto",
526 		.pm		= &sl3516_ce_pm_ops,
527 		.of_match_table	= sl3516_ce_crypto_of_match_table,
528 	},
529 };
530 
531 module_platform_driver(sl3516_ce_driver);
532 
533 MODULE_DESCRIPTION("SL3516 cryptographic offloader");
534 MODULE_LICENSE("GPL");
535 MODULE_AUTHOR("Corentin Labbe <clabbe@baylibre.com>");
536