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 
10 #include <crypto/engine.h>
11 #include <crypto/internal/rng.h>
12 #include <crypto/internal/skcipher.h>
13 #include <linux/clk.h>
14 #include <linux/debugfs.h>
15 #include <linux/dev_printk.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/err.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/irq.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/of.h>
24 #include <linux/platform_device.h>
25 #include <linux/pm_runtime.h>
26 #include <linux/reset.h>
27 
28 #include "sl3516-ce.h"
29 
30 static int sl3516_ce_desc_init(struct sl3516_ce_dev *ce)
31 {
32 	const size_t sz = sizeof(struct descriptor) * MAXDESC;
33 	int i;
34 
35 	ce->tx = dma_alloc_coherent(ce->dev, sz, &ce->dtx, GFP_KERNEL);
36 	if (!ce->tx)
37 		return -ENOMEM;
38 	ce->rx = dma_alloc_coherent(ce->dev, sz, &ce->drx, GFP_KERNEL);
39 	if (!ce->rx)
40 		goto err_rx;
41 
42 	for (i = 0; i < MAXDESC; i++) {
43 		ce->tx[i].frame_ctrl.bits.own = CE_CPU;
44 		ce->tx[i].next_desc.next_descriptor = ce->dtx + (i + 1) * sizeof(struct descriptor);
45 	}
46 	ce->tx[MAXDESC - 1].next_desc.next_descriptor = ce->dtx;
47 
48 	for (i = 0; i < MAXDESC; i++) {
49 		ce->rx[i].frame_ctrl.bits.own = CE_CPU;
50 		ce->rx[i].next_desc.next_descriptor = ce->drx + (i + 1) * sizeof(struct descriptor);
51 	}
52 	ce->rx[MAXDESC - 1].next_desc.next_descriptor = ce->drx;
53 
54 	ce->pctrl = dma_alloc_coherent(ce->dev, sizeof(struct pkt_control_ecb),
55 				       &ce->dctrl, GFP_KERNEL);
56 	if (!ce->pctrl)
57 		goto err_pctrl;
58 
59 	return 0;
60 err_pctrl:
61 	dma_free_coherent(ce->dev, sz, ce->rx, ce->drx);
62 err_rx:
63 	dma_free_coherent(ce->dev, sz, ce->tx, ce->dtx);
64 	return -ENOMEM;
65 }
66 
67 static void sl3516_ce_free_descs(struct sl3516_ce_dev *ce)
68 {
69 	const size_t sz = sizeof(struct descriptor) * MAXDESC;
70 
71 	dma_free_coherent(ce->dev, sz, ce->tx, ce->dtx);
72 	dma_free_coherent(ce->dev, sz, ce->rx, ce->drx);
73 	dma_free_coherent(ce->dev, sizeof(struct pkt_control_ecb), ce->pctrl,
74 			  ce->dctrl);
75 }
76 
77 static void start_dma_tx(struct sl3516_ce_dev *ce)
78 {
79 	u32 v;
80 
81 	v = TXDMA_CTRL_START | TXDMA_CTRL_CHAIN_MODE | TXDMA_CTRL_CONTINUE | \
82 		TXDMA_CTRL_INT_FAIL | TXDMA_CTRL_INT_PERR | TXDMA_CTRL_BURST_UNK;
83 
84 	writel(v, ce->base + IPSEC_TXDMA_CTRL);
85 }
86 
87 static void start_dma_rx(struct sl3516_ce_dev *ce)
88 {
89 	u32 v;
90 
91 	v = RXDMA_CTRL_START | RXDMA_CTRL_CHAIN_MODE | RXDMA_CTRL_CONTINUE | \
92 		RXDMA_CTRL_BURST_UNK | RXDMA_CTRL_INT_FINISH | \
93 		RXDMA_CTRL_INT_FAIL | RXDMA_CTRL_INT_PERR | \
94 		RXDMA_CTRL_INT_EOD | RXDMA_CTRL_INT_EOF;
95 
96 	writel(v, ce->base + IPSEC_RXDMA_CTRL);
97 }
98 
99 static struct descriptor *get_desc_tx(struct sl3516_ce_dev *ce)
100 {
101 	struct descriptor *dd;
102 
103 	dd = &ce->tx[ce->ctx];
104 	ce->ctx++;
105 	if (ce->ctx >= MAXDESC)
106 		ce->ctx = 0;
107 	return dd;
108 }
109 
110 static struct descriptor *get_desc_rx(struct sl3516_ce_dev *ce)
111 {
112 	struct descriptor *rdd;
113 
114 	rdd = &ce->rx[ce->crx];
115 	ce->crx++;
116 	if (ce->crx >= MAXDESC)
117 		ce->crx = 0;
118 	return rdd;
119 }
120 
121 int sl3516_ce_run_task(struct sl3516_ce_dev *ce, struct sl3516_ce_cipher_req_ctx *rctx,
122 		       const char *name)
123 {
124 	struct descriptor *dd, *rdd = NULL;
125 	u32 v;
126 	int i, err = 0;
127 
128 	ce->stat_req++;
129 
130 	reinit_completion(&ce->complete);
131 	ce->status = 0;
132 
133 	for (i = 0; i < rctx->nr_sgd; i++) {
134 		dev_dbg(ce->dev, "%s handle DST SG %d/%d len=%d\n", __func__,
135 			i, rctx->nr_sgd, rctx->t_dst[i].len);
136 		rdd = get_desc_rx(ce);
137 		rdd->buf_adr = rctx->t_dst[i].addr;
138 		rdd->frame_ctrl.bits.buffer_size = rctx->t_dst[i].len;
139 		rdd->frame_ctrl.bits.own = CE_DMA;
140 	}
141 	rdd->next_desc.bits.eofie = 1;
142 
143 	for (i = 0; i < rctx->nr_sgs; i++) {
144 		dev_dbg(ce->dev, "%s handle SRC SG %d/%d len=%d\n", __func__,
145 			i, rctx->nr_sgs, rctx->t_src[i].len);
146 		rctx->h->algorithm_len = rctx->t_src[i].len;
147 
148 		dd = get_desc_tx(ce);
149 		dd->frame_ctrl.raw = 0;
150 		dd->flag_status.raw = 0;
151 		dd->frame_ctrl.bits.buffer_size = rctx->pctrllen;
152 		dd->buf_adr = ce->dctrl;
153 		dd->flag_status.tx_flag.tqflag = rctx->tqflag;
154 		dd->next_desc.bits.eofie = 0;
155 		dd->next_desc.bits.dec = 0;
156 		dd->next_desc.bits.sof_eof = DESC_FIRST | DESC_LAST;
157 		dd->frame_ctrl.bits.own = CE_DMA;
158 
159 		dd = get_desc_tx(ce);
160 		dd->frame_ctrl.raw = 0;
161 		dd->flag_status.raw = 0;
162 		dd->frame_ctrl.bits.buffer_size = rctx->t_src[i].len;
163 		dd->buf_adr = rctx->t_src[i].addr;
164 		dd->flag_status.tx_flag.tqflag = 0;
165 		dd->next_desc.bits.eofie = 0;
166 		dd->next_desc.bits.dec = 0;
167 		dd->next_desc.bits.sof_eof = DESC_FIRST | DESC_LAST;
168 		dd->frame_ctrl.bits.own = CE_DMA;
169 		start_dma_tx(ce);
170 		start_dma_rx(ce);
171 	}
172 	wait_for_completion_interruptible_timeout(&ce->complete,
173 						  msecs_to_jiffies(5000));
174 	if (ce->status == 0) {
175 		dev_err(ce->dev, "DMA timeout for %s\n", name);
176 		err = -EFAULT;
177 	}
178 	v = readl(ce->base + IPSEC_STATUS_REG);
179 	if (v & 0xFFF) {
180 		dev_err(ce->dev, "IPSEC_STATUS_REG %x\n", v);
181 		err = -EFAULT;
182 	}
183 
184 	return err;
185 }
186 
187 static irqreturn_t ce_irq_handler(int irq, void *data)
188 {
189 	struct sl3516_ce_dev *ce = (struct sl3516_ce_dev *)data;
190 	u32 v;
191 
192 	ce->stat_irq++;
193 
194 	v = readl(ce->base + IPSEC_DMA_STATUS);
195 	writel(v, ce->base + IPSEC_DMA_STATUS);
196 
197 	if (v & DMA_STATUS_TS_DERR)
198 		dev_err(ce->dev, "AHB bus Error While Tx !!!\n");
199 	if (v & DMA_STATUS_TS_PERR)
200 		dev_err(ce->dev, "Tx Descriptor Protocol Error !!!\n");
201 	if (v & DMA_STATUS_RS_DERR)
202 		dev_err(ce->dev, "AHB bus Error While Rx !!!\n");
203 	if (v & DMA_STATUS_RS_PERR)
204 		dev_err(ce->dev, "Rx Descriptor Protocol Error !!!\n");
205 
206 	if (v & DMA_STATUS_TS_EOFI)
207 		ce->stat_irq_tx++;
208 	if (v & DMA_STATUS_RS_EOFI) {
209 		ce->status = 1;
210 		complete(&ce->complete);
211 		ce->stat_irq_rx++;
212 		return IRQ_HANDLED;
213 	}
214 
215 	return IRQ_HANDLED;
216 }
217 
218 static struct sl3516_ce_alg_template ce_algs[] = {
219 {
220 	.type = CRYPTO_ALG_TYPE_SKCIPHER,
221 	.mode = ECB_AES,
222 	.alg.skcipher.base = {
223 		.base = {
224 			.cra_name = "ecb(aes)",
225 			.cra_driver_name = "ecb-aes-sl3516",
226 			.cra_priority = 400,
227 			.cra_blocksize = AES_BLOCK_SIZE,
228 			.cra_flags = CRYPTO_ALG_TYPE_SKCIPHER |
229 				CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
230 			.cra_ctxsize = sizeof(struct sl3516_ce_cipher_tfm_ctx),
231 			.cra_module = THIS_MODULE,
232 			.cra_alignmask = 0xf,
233 			.cra_init = sl3516_ce_cipher_init,
234 			.cra_exit = sl3516_ce_cipher_exit,
235 		},
236 		.min_keysize	= AES_MIN_KEY_SIZE,
237 		.max_keysize	= AES_MAX_KEY_SIZE,
238 		.setkey		= sl3516_ce_aes_setkey,
239 		.encrypt	= sl3516_ce_skencrypt,
240 		.decrypt	= sl3516_ce_skdecrypt,
241 	},
242 	.alg.skcipher.op = {
243 		.do_one_request = sl3516_ce_handle_cipher_request,
244 	},
245 },
246 };
247 
248 static int sl3516_ce_debugfs_show(struct seq_file *seq, void *v)
249 {
250 	struct sl3516_ce_dev *ce = seq->private;
251 	unsigned int i;
252 
253 	seq_printf(seq, "HWRNG %lu %lu\n",
254 		   ce->hwrng_stat_req, ce->hwrng_stat_bytes);
255 	seq_printf(seq, "IRQ %lu\n", ce->stat_irq);
256 	seq_printf(seq, "IRQ TX %lu\n", ce->stat_irq_tx);
257 	seq_printf(seq, "IRQ RX %lu\n", ce->stat_irq_rx);
258 	seq_printf(seq, "nreq %lu\n", ce->stat_req);
259 	seq_printf(seq, "fallback SG count TX %lu\n", ce->fallback_sg_count_tx);
260 	seq_printf(seq, "fallback SG count RX %lu\n", ce->fallback_sg_count_rx);
261 	seq_printf(seq, "fallback modulo16 %lu\n", ce->fallback_mod16);
262 	seq_printf(seq, "fallback align16 %lu\n", ce->fallback_align16);
263 	seq_printf(seq, "fallback not same len %lu\n", ce->fallback_not_same_len);
264 
265 	for (i = 0; i < ARRAY_SIZE(ce_algs); i++) {
266 		if (!ce_algs[i].ce)
267 			continue;
268 		switch (ce_algs[i].type) {
269 		case CRYPTO_ALG_TYPE_SKCIPHER:
270 			seq_printf(seq, "%s %s reqs=%lu fallback=%lu\n",
271 				   ce_algs[i].alg.skcipher.base.base.cra_driver_name,
272 				   ce_algs[i].alg.skcipher.base.base.cra_name,
273 				   ce_algs[i].stat_req, ce_algs[i].stat_fb);
274 			break;
275 		}
276 	}
277 	return 0;
278 }
279 
280 DEFINE_SHOW_ATTRIBUTE(sl3516_ce_debugfs);
281 
282 static int sl3516_ce_register_algs(struct sl3516_ce_dev *ce)
283 {
284 	int err;
285 	unsigned int i;
286 
287 	for (i = 0; i < ARRAY_SIZE(ce_algs); i++) {
288 		ce_algs[i].ce = ce;
289 		switch (ce_algs[i].type) {
290 		case CRYPTO_ALG_TYPE_SKCIPHER:
291 			dev_info(ce->dev, "DEBUG: Register %s\n",
292 				 ce_algs[i].alg.skcipher.base.base.cra_name);
293 			err = crypto_engine_register_skcipher(&ce_algs[i].alg.skcipher);
294 			if (err) {
295 				dev_err(ce->dev, "Fail to register %s\n",
296 					ce_algs[i].alg.skcipher.base.base.cra_name);
297 				ce_algs[i].ce = NULL;
298 				return err;
299 			}
300 			break;
301 		default:
302 			ce_algs[i].ce = NULL;
303 			dev_err(ce->dev, "ERROR: tried to register an unknown algo\n");
304 		}
305 	}
306 	return 0;
307 }
308 
309 static void sl3516_ce_unregister_algs(struct sl3516_ce_dev *ce)
310 {
311 	unsigned int i;
312 
313 	for (i = 0; i < ARRAY_SIZE(ce_algs); i++) {
314 		if (!ce_algs[i].ce)
315 			continue;
316 		switch (ce_algs[i].type) {
317 		case CRYPTO_ALG_TYPE_SKCIPHER:
318 			dev_info(ce->dev, "Unregister %d %s\n", i,
319 				 ce_algs[i].alg.skcipher.base.base.cra_name);
320 			crypto_engine_unregister_skcipher(&ce_algs[i].alg.skcipher);
321 			break;
322 		}
323 	}
324 }
325 
326 static void sl3516_ce_start(struct sl3516_ce_dev *ce)
327 {
328 	ce->ctx = 0;
329 	ce->crx = 0;
330 	writel(ce->dtx, ce->base + IPSEC_TXDMA_CURR_DESC);
331 	writel(ce->drx, ce->base + IPSEC_RXDMA_CURR_DESC);
332 	writel(0, ce->base + IPSEC_DMA_STATUS);
333 }
334 
335 /*
336  * Power management strategy: The device is suspended unless a TFM exists for
337  * one of the algorithms proposed by this driver.
338  */
339 static int sl3516_ce_pm_suspend(struct device *dev)
340 {
341 	struct sl3516_ce_dev *ce = dev_get_drvdata(dev);
342 
343 	reset_control_assert(ce->reset);
344 	clk_disable_unprepare(ce->clks);
345 	return 0;
346 }
347 
348 static int sl3516_ce_pm_resume(struct device *dev)
349 {
350 	struct sl3516_ce_dev *ce = dev_get_drvdata(dev);
351 	int err;
352 
353 	err = clk_prepare_enable(ce->clks);
354 	if (err) {
355 		dev_err(ce->dev, "Cannot prepare_enable\n");
356 		goto error;
357 	}
358 	err = reset_control_deassert(ce->reset);
359 	if (err) {
360 		dev_err(ce->dev, "Cannot deassert reset control\n");
361 		goto error;
362 	}
363 
364 	sl3516_ce_start(ce);
365 
366 	return 0;
367 error:
368 	sl3516_ce_pm_suspend(dev);
369 	return err;
370 }
371 
372 static const struct dev_pm_ops sl3516_ce_pm_ops = {
373 	SET_RUNTIME_PM_OPS(sl3516_ce_pm_suspend, sl3516_ce_pm_resume, NULL)
374 };
375 
376 static int sl3516_ce_pm_init(struct sl3516_ce_dev *ce)
377 {
378 	int err;
379 
380 	pm_runtime_use_autosuspend(ce->dev);
381 	pm_runtime_set_autosuspend_delay(ce->dev, 2000);
382 
383 	err = pm_runtime_set_suspended(ce->dev);
384 	if (err)
385 		return err;
386 	pm_runtime_enable(ce->dev);
387 	return err;
388 }
389 
390 static void sl3516_ce_pm_exit(struct sl3516_ce_dev *ce)
391 {
392 	pm_runtime_disable(ce->dev);
393 }
394 
395 static int sl3516_ce_probe(struct platform_device *pdev)
396 {
397 	struct sl3516_ce_dev *ce;
398 	int err, irq;
399 	u32 v;
400 
401 	ce = devm_kzalloc(&pdev->dev, sizeof(*ce), GFP_KERNEL);
402 	if (!ce)
403 		return -ENOMEM;
404 
405 	ce->dev = &pdev->dev;
406 	platform_set_drvdata(pdev, ce);
407 
408 	ce->base = devm_platform_ioremap_resource(pdev, 0);
409 	if (IS_ERR(ce->base))
410 		return PTR_ERR(ce->base);
411 
412 	irq = platform_get_irq(pdev, 0);
413 	if (irq < 0)
414 		return irq;
415 
416 	err = devm_request_irq(&pdev->dev, irq, ce_irq_handler, 0, "crypto", ce);
417 	if (err) {
418 		dev_err(ce->dev, "Cannot request Crypto Engine IRQ (err=%d)\n", err);
419 		return err;
420 	}
421 
422 	ce->reset = devm_reset_control_get(&pdev->dev, NULL);
423 	if (IS_ERR(ce->reset))
424 		return dev_err_probe(&pdev->dev, PTR_ERR(ce->reset),
425 				     "No reset control found\n");
426 	ce->clks = devm_clk_get(ce->dev, NULL);
427 	if (IS_ERR(ce->clks)) {
428 		err = PTR_ERR(ce->clks);
429 		dev_err(ce->dev, "Cannot get clock err=%d\n", err);
430 		return err;
431 	}
432 
433 	err = sl3516_ce_desc_init(ce);
434 	if (err)
435 		return err;
436 
437 	err = sl3516_ce_pm_init(ce);
438 	if (err)
439 		goto error_pm;
440 
441 	init_completion(&ce->complete);
442 
443 	ce->engine = crypto_engine_alloc_init(ce->dev, true);
444 	if (!ce->engine) {
445 		dev_err(ce->dev, "Cannot allocate engine\n");
446 		err = -ENOMEM;
447 		goto error_engine;
448 	}
449 
450 	err = crypto_engine_start(ce->engine);
451 	if (err) {
452 		dev_err(ce->dev, "Cannot start engine\n");
453 		goto error_engine;
454 	}
455 
456 	err = sl3516_ce_register_algs(ce);
457 	if (err)
458 		goto error_alg;
459 
460 	err = sl3516_ce_rng_register(ce);
461 	if (err)
462 		goto error_rng;
463 
464 	err = pm_runtime_resume_and_get(ce->dev);
465 	if (err < 0)
466 		goto error_pmuse;
467 
468 	v = readl(ce->base + IPSEC_ID);
469 	dev_info(ce->dev, "SL3516 dev %lx rev %lx\n",
470 		 v & GENMASK(31, 4),
471 		 v & GENMASK(3, 0));
472 	v = readl(ce->base + IPSEC_DMA_DEVICE_ID);
473 	dev_info(ce->dev, "SL3516 DMA dev %lx rev %lx\n",
474 		 v & GENMASK(15, 4),
475 		 v & GENMASK(3, 0));
476 
477 	pm_runtime_put_sync(ce->dev);
478 
479 	if (IS_ENABLED(CONFIG_CRYPTO_DEV_SL3516_DEBUG)) {
480 		struct dentry *dbgfs_dir __maybe_unused;
481 		struct dentry *dbgfs_stats __maybe_unused;
482 
483 		/* Ignore error of debugfs */
484 		dbgfs_dir = debugfs_create_dir("sl3516", NULL);
485 		dbgfs_stats = debugfs_create_file("stats", 0444,
486 						  dbgfs_dir, ce,
487 						  &sl3516_ce_debugfs_fops);
488 #ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG
489 		ce->dbgfs_dir = dbgfs_dir;
490 		ce->dbgfs_stats = dbgfs_stats;
491 #endif
492 	}
493 
494 	return 0;
495 error_pmuse:
496 	sl3516_ce_rng_unregister(ce);
497 error_rng:
498 	sl3516_ce_unregister_algs(ce);
499 error_alg:
500 	crypto_engine_exit(ce->engine);
501 error_engine:
502 	sl3516_ce_pm_exit(ce);
503 error_pm:
504 	sl3516_ce_free_descs(ce);
505 	return err;
506 }
507 
508 static int sl3516_ce_remove(struct platform_device *pdev)
509 {
510 	struct sl3516_ce_dev *ce = platform_get_drvdata(pdev);
511 
512 	sl3516_ce_rng_unregister(ce);
513 	sl3516_ce_unregister_algs(ce);
514 	crypto_engine_exit(ce->engine);
515 	sl3516_ce_pm_exit(ce);
516 	sl3516_ce_free_descs(ce);
517 
518 #ifdef CONFIG_CRYPTO_DEV_SL3516_DEBUG
519 	debugfs_remove_recursive(ce->dbgfs_dir);
520 #endif
521 
522 	return 0;
523 }
524 
525 static const struct of_device_id sl3516_ce_crypto_of_match_table[] = {
526 	{ .compatible = "cortina,sl3516-crypto"},
527 	{}
528 };
529 MODULE_DEVICE_TABLE(of, sl3516_ce_crypto_of_match_table);
530 
531 static struct platform_driver sl3516_ce_driver = {
532 	.probe		 = sl3516_ce_probe,
533 	.remove		 = sl3516_ce_remove,
534 	.driver		 = {
535 		.name		= "sl3516-crypto",
536 		.pm		= &sl3516_ce_pm_ops,
537 		.of_match_table	= sl3516_ce_crypto_of_match_table,
538 	},
539 };
540 
541 module_platform_driver(sl3516_ce_driver);
542 
543 MODULE_DESCRIPTION("SL3516 cryptographic offloader");
544 MODULE_LICENSE("GPL");
545 MODULE_AUTHOR("Corentin Labbe <clabbe@baylibre.com>");
546