1 // SPDX-License-Identifier: GPL-2.0
2 /**
3  * Test driver to test endpoint functionality
4  *
5  * Copyright (C) 2017 Texas Instruments
6  * Author: Kishon Vijay Abraham I <kishon@ti.com>
7  */
8 
9 #include <linux/crc32.h>
10 #include <linux/delay.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/pci_ids.h>
15 #include <linux/random.h>
16 
17 #include <linux/pci-epc.h>
18 #include <linux/pci-epf.h>
19 #include <linux/pci_regs.h>
20 
21 #define IRQ_TYPE_LEGACY			0
22 #define IRQ_TYPE_MSI			1
23 #define IRQ_TYPE_MSIX			2
24 
25 #define COMMAND_RAISE_LEGACY_IRQ	BIT(0)
26 #define COMMAND_RAISE_MSI_IRQ		BIT(1)
27 #define COMMAND_RAISE_MSIX_IRQ		BIT(2)
28 #define COMMAND_READ			BIT(3)
29 #define COMMAND_WRITE			BIT(4)
30 #define COMMAND_COPY			BIT(5)
31 
32 #define STATUS_READ_SUCCESS		BIT(0)
33 #define STATUS_READ_FAIL		BIT(1)
34 #define STATUS_WRITE_SUCCESS		BIT(2)
35 #define STATUS_WRITE_FAIL		BIT(3)
36 #define STATUS_COPY_SUCCESS		BIT(4)
37 #define STATUS_COPY_FAIL		BIT(5)
38 #define STATUS_IRQ_RAISED		BIT(6)
39 #define STATUS_SRC_ADDR_INVALID		BIT(7)
40 #define STATUS_DST_ADDR_INVALID		BIT(8)
41 
42 #define TIMER_RESOLUTION		1
43 
44 static struct workqueue_struct *kpcitest_workqueue;
45 
46 struct pci_epf_test {
47 	void			*reg[6];
48 	struct pci_epf		*epf;
49 	enum pci_barno		test_reg_bar;
50 	struct delayed_work	cmd_handler;
51 	const struct pci_epc_features *epc_features;
52 };
53 
54 struct pci_epf_test_reg {
55 	u32	magic;
56 	u32	command;
57 	u32	status;
58 	u64	src_addr;
59 	u64	dst_addr;
60 	u32	size;
61 	u32	checksum;
62 	u32	irq_type;
63 	u32	irq_number;
64 } __packed;
65 
66 static struct pci_epf_header test_header = {
67 	.vendorid	= PCI_ANY_ID,
68 	.deviceid	= PCI_ANY_ID,
69 	.baseclass_code = PCI_CLASS_OTHERS,
70 	.interrupt_pin	= PCI_INTERRUPT_INTA,
71 };
72 
73 static size_t bar_size[] = { 512, 512, 1024, 16384, 131072, 1048576 };
74 
75 static int pci_epf_test_copy(struct pci_epf_test *epf_test)
76 {
77 	int ret;
78 	void __iomem *src_addr;
79 	void __iomem *dst_addr;
80 	phys_addr_t src_phys_addr;
81 	phys_addr_t dst_phys_addr;
82 	struct pci_epf *epf = epf_test->epf;
83 	struct device *dev = &epf->dev;
84 	struct pci_epc *epc = epf->epc;
85 	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
86 	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
87 
88 	src_addr = pci_epc_mem_alloc_addr(epc, &src_phys_addr, reg->size);
89 	if (!src_addr) {
90 		dev_err(dev, "Failed to allocate source address\n");
91 		reg->status = STATUS_SRC_ADDR_INVALID;
92 		ret = -ENOMEM;
93 		goto err;
94 	}
95 
96 	ret = pci_epc_map_addr(epc, epf->func_no, src_phys_addr, reg->src_addr,
97 			       reg->size);
98 	if (ret) {
99 		dev_err(dev, "Failed to map source address\n");
100 		reg->status = STATUS_SRC_ADDR_INVALID;
101 		goto err_src_addr;
102 	}
103 
104 	dst_addr = pci_epc_mem_alloc_addr(epc, &dst_phys_addr, reg->size);
105 	if (!dst_addr) {
106 		dev_err(dev, "Failed to allocate destination address\n");
107 		reg->status = STATUS_DST_ADDR_INVALID;
108 		ret = -ENOMEM;
109 		goto err_src_map_addr;
110 	}
111 
112 	ret = pci_epc_map_addr(epc, epf->func_no, dst_phys_addr, reg->dst_addr,
113 			       reg->size);
114 	if (ret) {
115 		dev_err(dev, "Failed to map destination address\n");
116 		reg->status = STATUS_DST_ADDR_INVALID;
117 		goto err_dst_addr;
118 	}
119 
120 	memcpy(dst_addr, src_addr, reg->size);
121 
122 	pci_epc_unmap_addr(epc, epf->func_no, dst_phys_addr);
123 
124 err_dst_addr:
125 	pci_epc_mem_free_addr(epc, dst_phys_addr, dst_addr, reg->size);
126 
127 err_src_map_addr:
128 	pci_epc_unmap_addr(epc, epf->func_no, src_phys_addr);
129 
130 err_src_addr:
131 	pci_epc_mem_free_addr(epc, src_phys_addr, src_addr, reg->size);
132 
133 err:
134 	return ret;
135 }
136 
137 static int pci_epf_test_read(struct pci_epf_test *epf_test)
138 {
139 	int ret;
140 	void __iomem *src_addr;
141 	void *buf;
142 	u32 crc32;
143 	phys_addr_t phys_addr;
144 	struct pci_epf *epf = epf_test->epf;
145 	struct device *dev = &epf->dev;
146 	struct pci_epc *epc = epf->epc;
147 	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
148 	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
149 
150 	src_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, reg->size);
151 	if (!src_addr) {
152 		dev_err(dev, "Failed to allocate address\n");
153 		reg->status = STATUS_SRC_ADDR_INVALID;
154 		ret = -ENOMEM;
155 		goto err;
156 	}
157 
158 	ret = pci_epc_map_addr(epc, epf->func_no, phys_addr, reg->src_addr,
159 			       reg->size);
160 	if (ret) {
161 		dev_err(dev, "Failed to map address\n");
162 		reg->status = STATUS_SRC_ADDR_INVALID;
163 		goto err_addr;
164 	}
165 
166 	buf = kzalloc(reg->size, GFP_KERNEL);
167 	if (!buf) {
168 		ret = -ENOMEM;
169 		goto err_map_addr;
170 	}
171 
172 	memcpy_fromio(buf, src_addr, reg->size);
173 
174 	crc32 = crc32_le(~0, buf, reg->size);
175 	if (crc32 != reg->checksum)
176 		ret = -EIO;
177 
178 	kfree(buf);
179 
180 err_map_addr:
181 	pci_epc_unmap_addr(epc, epf->func_no, phys_addr);
182 
183 err_addr:
184 	pci_epc_mem_free_addr(epc, phys_addr, src_addr, reg->size);
185 
186 err:
187 	return ret;
188 }
189 
190 static int pci_epf_test_write(struct pci_epf_test *epf_test)
191 {
192 	int ret;
193 	void __iomem *dst_addr;
194 	void *buf;
195 	phys_addr_t phys_addr;
196 	struct pci_epf *epf = epf_test->epf;
197 	struct device *dev = &epf->dev;
198 	struct pci_epc *epc = epf->epc;
199 	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
200 	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
201 
202 	dst_addr = pci_epc_mem_alloc_addr(epc, &phys_addr, reg->size);
203 	if (!dst_addr) {
204 		dev_err(dev, "Failed to allocate address\n");
205 		reg->status = STATUS_DST_ADDR_INVALID;
206 		ret = -ENOMEM;
207 		goto err;
208 	}
209 
210 	ret = pci_epc_map_addr(epc, epf->func_no, phys_addr, reg->dst_addr,
211 			       reg->size);
212 	if (ret) {
213 		dev_err(dev, "Failed to map address\n");
214 		reg->status = STATUS_DST_ADDR_INVALID;
215 		goto err_addr;
216 	}
217 
218 	buf = kzalloc(reg->size, GFP_KERNEL);
219 	if (!buf) {
220 		ret = -ENOMEM;
221 		goto err_map_addr;
222 	}
223 
224 	get_random_bytes(buf, reg->size);
225 	reg->checksum = crc32_le(~0, buf, reg->size);
226 
227 	memcpy_toio(dst_addr, buf, reg->size);
228 
229 	/*
230 	 * wait 1ms inorder for the write to complete. Without this delay L3
231 	 * error in observed in the host system.
232 	 */
233 	usleep_range(1000, 2000);
234 
235 	kfree(buf);
236 
237 err_map_addr:
238 	pci_epc_unmap_addr(epc, epf->func_no, phys_addr);
239 
240 err_addr:
241 	pci_epc_mem_free_addr(epc, phys_addr, dst_addr, reg->size);
242 
243 err:
244 	return ret;
245 }
246 
247 static void pci_epf_test_raise_irq(struct pci_epf_test *epf_test, u8 irq_type,
248 				   u16 irq)
249 {
250 	struct pci_epf *epf = epf_test->epf;
251 	struct device *dev = &epf->dev;
252 	struct pci_epc *epc = epf->epc;
253 	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
254 	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
255 
256 	reg->status |= STATUS_IRQ_RAISED;
257 
258 	switch (irq_type) {
259 	case IRQ_TYPE_LEGACY:
260 		pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_LEGACY, 0);
261 		break;
262 	case IRQ_TYPE_MSI:
263 		pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_MSI, irq);
264 		break;
265 	case IRQ_TYPE_MSIX:
266 		pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_MSIX, irq);
267 		break;
268 	default:
269 		dev_err(dev, "Failed to raise IRQ, unknown type\n");
270 		break;
271 	}
272 }
273 
274 static void pci_epf_test_cmd_handler(struct work_struct *work)
275 {
276 	int ret;
277 	int count;
278 	u32 command;
279 	struct pci_epf_test *epf_test = container_of(work, struct pci_epf_test,
280 						     cmd_handler.work);
281 	struct pci_epf *epf = epf_test->epf;
282 	struct device *dev = &epf->dev;
283 	struct pci_epc *epc = epf->epc;
284 	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
285 	struct pci_epf_test_reg *reg = epf_test->reg[test_reg_bar];
286 
287 	command = reg->command;
288 	if (!command)
289 		goto reset_handler;
290 
291 	reg->command = 0;
292 	reg->status = 0;
293 
294 	if (reg->irq_type > IRQ_TYPE_MSIX) {
295 		dev_err(dev, "Failed to detect IRQ type\n");
296 		goto reset_handler;
297 	}
298 
299 	if (command & COMMAND_RAISE_LEGACY_IRQ) {
300 		reg->status = STATUS_IRQ_RAISED;
301 		pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_LEGACY, 0);
302 		goto reset_handler;
303 	}
304 
305 	if (command & COMMAND_WRITE) {
306 		ret = pci_epf_test_write(epf_test);
307 		if (ret)
308 			reg->status |= STATUS_WRITE_FAIL;
309 		else
310 			reg->status |= STATUS_WRITE_SUCCESS;
311 		pci_epf_test_raise_irq(epf_test, reg->irq_type,
312 				       reg->irq_number);
313 		goto reset_handler;
314 	}
315 
316 	if (command & COMMAND_READ) {
317 		ret = pci_epf_test_read(epf_test);
318 		if (!ret)
319 			reg->status |= STATUS_READ_SUCCESS;
320 		else
321 			reg->status |= STATUS_READ_FAIL;
322 		pci_epf_test_raise_irq(epf_test, reg->irq_type,
323 				       reg->irq_number);
324 		goto reset_handler;
325 	}
326 
327 	if (command & COMMAND_COPY) {
328 		ret = pci_epf_test_copy(epf_test);
329 		if (!ret)
330 			reg->status |= STATUS_COPY_SUCCESS;
331 		else
332 			reg->status |= STATUS_COPY_FAIL;
333 		pci_epf_test_raise_irq(epf_test, reg->irq_type,
334 				       reg->irq_number);
335 		goto reset_handler;
336 	}
337 
338 	if (command & COMMAND_RAISE_MSI_IRQ) {
339 		count = pci_epc_get_msi(epc, epf->func_no);
340 		if (reg->irq_number > count || count <= 0)
341 			goto reset_handler;
342 		reg->status = STATUS_IRQ_RAISED;
343 		pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_MSI,
344 				  reg->irq_number);
345 		goto reset_handler;
346 	}
347 
348 	if (command & COMMAND_RAISE_MSIX_IRQ) {
349 		count = pci_epc_get_msix(epc, epf->func_no);
350 		if (reg->irq_number > count || count <= 0)
351 			goto reset_handler;
352 		reg->status = STATUS_IRQ_RAISED;
353 		pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_MSIX,
354 				  reg->irq_number);
355 		goto reset_handler;
356 	}
357 
358 reset_handler:
359 	queue_delayed_work(kpcitest_workqueue, &epf_test->cmd_handler,
360 			   msecs_to_jiffies(1));
361 }
362 
363 static void pci_epf_test_linkup(struct pci_epf *epf)
364 {
365 	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
366 
367 	queue_delayed_work(kpcitest_workqueue, &epf_test->cmd_handler,
368 			   msecs_to_jiffies(1));
369 }
370 
371 static void pci_epf_test_unbind(struct pci_epf *epf)
372 {
373 	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
374 	struct pci_epc *epc = epf->epc;
375 	struct pci_epf_bar *epf_bar;
376 	int bar;
377 
378 	cancel_delayed_work(&epf_test->cmd_handler);
379 	pci_epc_stop(epc);
380 	for (bar = BAR_0; bar <= BAR_5; bar++) {
381 		epf_bar = &epf->bar[bar];
382 
383 		if (epf_test->reg[bar]) {
384 			pci_epf_free_space(epf, epf_test->reg[bar], bar);
385 			pci_epc_clear_bar(epc, epf->func_no, epf_bar);
386 		}
387 	}
388 }
389 
390 static int pci_epf_test_set_bar(struct pci_epf *epf)
391 {
392 	int bar;
393 	int ret;
394 	struct pci_epf_bar *epf_bar;
395 	struct pci_epc *epc = epf->epc;
396 	struct device *dev = &epf->dev;
397 	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
398 	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
399 	const struct pci_epc_features *epc_features;
400 
401 	epc_features = epf_test->epc_features;
402 
403 	for (bar = BAR_0; bar <= BAR_5; bar++) {
404 		epf_bar = &epf->bar[bar];
405 
406 		if (!!(epc_features->reserved_bar & (1 << bar)))
407 			continue;
408 
409 		ret = pci_epc_set_bar(epc, epf->func_no, epf_bar);
410 		if (ret) {
411 			pci_epf_free_space(epf, epf_test->reg[bar], bar);
412 			dev_err(dev, "Failed to set BAR%d\n", bar);
413 			if (bar == test_reg_bar)
414 				return ret;
415 		}
416 		/*
417 		 * pci_epc_set_bar() sets PCI_BASE_ADDRESS_MEM_TYPE_64
418 		 * if the specific implementation required a 64-bit BAR,
419 		 * even if we only requested a 32-bit BAR.
420 		 */
421 		if (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64)
422 			bar++;
423 	}
424 
425 	return 0;
426 }
427 
428 static int pci_epf_test_alloc_space(struct pci_epf *epf)
429 {
430 	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
431 	struct device *dev = &epf->dev;
432 	struct pci_epf_bar *epf_bar;
433 	void *base;
434 	int bar;
435 	enum pci_barno test_reg_bar = epf_test->test_reg_bar;
436 	const struct pci_epc_features *epc_features;
437 
438 	epc_features = epf_test->epc_features;
439 
440 	base = pci_epf_alloc_space(epf, sizeof(struct pci_epf_test_reg),
441 				   test_reg_bar);
442 	if (!base) {
443 		dev_err(dev, "Failed to allocated register space\n");
444 		return -ENOMEM;
445 	}
446 	epf_test->reg[test_reg_bar] = base;
447 
448 	for (bar = BAR_0; bar <= BAR_5; bar++) {
449 		epf_bar = &epf->bar[bar];
450 		if (bar == test_reg_bar)
451 			continue;
452 
453 		if (!!(epc_features->reserved_bar & (1 << bar)))
454 			continue;
455 
456 		base = pci_epf_alloc_space(epf, bar_size[bar], bar);
457 		if (!base)
458 			dev_err(dev, "Failed to allocate space for BAR%d\n",
459 				bar);
460 		epf_test->reg[bar] = base;
461 		if (epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64)
462 			bar++;
463 	}
464 
465 	return 0;
466 }
467 
468 static void pci_epf_configure_bar(struct pci_epf *epf,
469 				  const struct pci_epc_features *epc_features)
470 {
471 	struct pci_epf_bar *epf_bar;
472 	bool bar_fixed_64bit;
473 	int i;
474 
475 	for (i = BAR_0; i <= BAR_5; i++) {
476 		epf_bar = &epf->bar[i];
477 		bar_fixed_64bit = !!(epc_features->bar_fixed_64bit & (1 << i));
478 		if (bar_fixed_64bit)
479 			epf_bar->flags |= PCI_BASE_ADDRESS_MEM_TYPE_64;
480 		if (epc_features->bar_fixed_size[i])
481 			bar_size[i] = epc_features->bar_fixed_size[i];
482 	}
483 }
484 
485 static int pci_epf_test_bind(struct pci_epf *epf)
486 {
487 	int ret;
488 	struct pci_epf_test *epf_test = epf_get_drvdata(epf);
489 	struct pci_epf_header *header = epf->header;
490 	const struct pci_epc_features *epc_features;
491 	enum pci_barno test_reg_bar = BAR_0;
492 	struct pci_epc *epc = epf->epc;
493 	struct device *dev = &epf->dev;
494 	bool linkup_notifier = false;
495 	bool msix_capable = false;
496 	bool msi_capable = true;
497 
498 	if (WARN_ON_ONCE(!epc))
499 		return -EINVAL;
500 
501 	epc_features = pci_epc_get_features(epc, epf->func_no);
502 	if (epc_features) {
503 		linkup_notifier = epc_features->linkup_notifier;
504 		msix_capable = epc_features->msix_capable;
505 		msi_capable = epc_features->msi_capable;
506 		test_reg_bar = pci_epc_get_first_free_bar(epc_features);
507 		pci_epf_configure_bar(epf, epc_features);
508 	}
509 
510 	epf_test->test_reg_bar = test_reg_bar;
511 	epf_test->epc_features = epc_features;
512 
513 	ret = pci_epc_write_header(epc, epf->func_no, header);
514 	if (ret) {
515 		dev_err(dev, "Configuration header write failed\n");
516 		return ret;
517 	}
518 
519 	ret = pci_epf_test_alloc_space(epf);
520 	if (ret)
521 		return ret;
522 
523 	ret = pci_epf_test_set_bar(epf);
524 	if (ret)
525 		return ret;
526 
527 	if (msi_capable) {
528 		ret = pci_epc_set_msi(epc, epf->func_no, epf->msi_interrupts);
529 		if (ret) {
530 			dev_err(dev, "MSI configuration failed\n");
531 			return ret;
532 		}
533 	}
534 
535 	if (msix_capable) {
536 		ret = pci_epc_set_msix(epc, epf->func_no, epf->msix_interrupts);
537 		if (ret) {
538 			dev_err(dev, "MSI-X configuration failed\n");
539 			return ret;
540 		}
541 	}
542 
543 	if (!linkup_notifier)
544 		queue_work(kpcitest_workqueue, &epf_test->cmd_handler.work);
545 
546 	return 0;
547 }
548 
549 static const struct pci_epf_device_id pci_epf_test_ids[] = {
550 	{
551 		.name = "pci_epf_test",
552 	},
553 	{},
554 };
555 
556 static int pci_epf_test_probe(struct pci_epf *epf)
557 {
558 	struct pci_epf_test *epf_test;
559 	struct device *dev = &epf->dev;
560 
561 	epf_test = devm_kzalloc(dev, sizeof(*epf_test), GFP_KERNEL);
562 	if (!epf_test)
563 		return -ENOMEM;
564 
565 	epf->header = &test_header;
566 	epf_test->epf = epf;
567 
568 	INIT_DELAYED_WORK(&epf_test->cmd_handler, pci_epf_test_cmd_handler);
569 
570 	epf_set_drvdata(epf, epf_test);
571 	return 0;
572 }
573 
574 static struct pci_epf_ops ops = {
575 	.unbind	= pci_epf_test_unbind,
576 	.bind	= pci_epf_test_bind,
577 	.linkup = pci_epf_test_linkup,
578 };
579 
580 static struct pci_epf_driver test_driver = {
581 	.driver.name	= "pci_epf_test",
582 	.probe		= pci_epf_test_probe,
583 	.id_table	= pci_epf_test_ids,
584 	.ops		= &ops,
585 	.owner		= THIS_MODULE,
586 };
587 
588 static int __init pci_epf_test_init(void)
589 {
590 	int ret;
591 
592 	kpcitest_workqueue = alloc_workqueue("kpcitest",
593 					     WQ_MEM_RECLAIM | WQ_HIGHPRI, 0);
594 	ret = pci_epf_register_driver(&test_driver);
595 	if (ret) {
596 		pr_err("Failed to register pci epf test driver --> %d\n", ret);
597 		return ret;
598 	}
599 
600 	return 0;
601 }
602 module_init(pci_epf_test_init);
603 
604 static void __exit pci_epf_test_exit(void)
605 {
606 	pci_epf_unregister_driver(&test_driver);
607 }
608 module_exit(pci_epf_test_exit);
609 
610 MODULE_DESCRIPTION("PCI EPF TEST DRIVER");
611 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
612 MODULE_LICENSE("GPL v2");
613