1 /**
2  * Host side test driver to test endpoint functionality
3  *
4  * Copyright (C) 2017 Texas Instruments
5  * Author: Kishon Vijay Abraham I <kishon@ti.com>
6  *
7  * This program is free software: you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 of
9  * the License as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include <linux/crc32.h>
21 #include <linux/delay.h>
22 #include <linux/fs.h>
23 #include <linux/io.h>
24 #include <linux/interrupt.h>
25 #include <linux/irq.h>
26 #include <linux/miscdevice.h>
27 #include <linux/module.h>
28 #include <linux/mutex.h>
29 #include <linux/random.h>
30 #include <linux/slab.h>
31 #include <linux/pci.h>
32 #include <linux/pci_ids.h>
33 
34 #include <linux/pci_regs.h>
35 
36 #include <uapi/linux/pcitest.h>
37 
38 #define DRV_MODULE_NAME			"pci-endpoint-test"
39 
40 #define PCI_ENDPOINT_TEST_MAGIC		0x0
41 
42 #define PCI_ENDPOINT_TEST_COMMAND	0x4
43 #define COMMAND_RAISE_LEGACY_IRQ	BIT(0)
44 #define COMMAND_RAISE_MSI_IRQ		BIT(1)
45 #define MSI_NUMBER_SHIFT		2
46 /* 6 bits for MSI number */
47 #define COMMAND_READ                    BIT(8)
48 #define COMMAND_WRITE                   BIT(9)
49 #define COMMAND_COPY                    BIT(10)
50 
51 #define PCI_ENDPOINT_TEST_STATUS	0x8
52 #define STATUS_READ_SUCCESS             BIT(0)
53 #define STATUS_READ_FAIL                BIT(1)
54 #define STATUS_WRITE_SUCCESS            BIT(2)
55 #define STATUS_WRITE_FAIL               BIT(3)
56 #define STATUS_COPY_SUCCESS             BIT(4)
57 #define STATUS_COPY_FAIL                BIT(5)
58 #define STATUS_IRQ_RAISED               BIT(6)
59 #define STATUS_SRC_ADDR_INVALID         BIT(7)
60 #define STATUS_DST_ADDR_INVALID         BIT(8)
61 
62 #define PCI_ENDPOINT_TEST_LOWER_SRC_ADDR	0xc
63 #define PCI_ENDPOINT_TEST_UPPER_SRC_ADDR	0x10
64 
65 #define PCI_ENDPOINT_TEST_LOWER_DST_ADDR	0x14
66 #define PCI_ENDPOINT_TEST_UPPER_DST_ADDR	0x18
67 
68 #define PCI_ENDPOINT_TEST_SIZE		0x1c
69 #define PCI_ENDPOINT_TEST_CHECKSUM	0x20
70 
71 static DEFINE_IDA(pci_endpoint_test_ida);
72 
73 #define to_endpoint_test(priv) container_of((priv), struct pci_endpoint_test, \
74 					    miscdev)
75 
76 static bool no_msi;
77 module_param(no_msi, bool, 0444);
78 MODULE_PARM_DESC(no_msi, "Disable MSI interrupt in pci_endpoint_test");
79 
80 enum pci_barno {
81 	BAR_0,
82 	BAR_1,
83 	BAR_2,
84 	BAR_3,
85 	BAR_4,
86 	BAR_5,
87 };
88 
89 struct pci_endpoint_test {
90 	struct pci_dev	*pdev;
91 	void __iomem	*base;
92 	void __iomem	*bar[6];
93 	struct completion irq_raised;
94 	int		last_irq;
95 	/* mutex to protect the ioctls */
96 	struct mutex	mutex;
97 	struct miscdevice miscdev;
98 	enum pci_barno test_reg_bar;
99 	size_t alignment;
100 };
101 
102 struct pci_endpoint_test_data {
103 	enum pci_barno test_reg_bar;
104 	size_t alignment;
105 	bool no_msi;
106 };
107 
108 static inline u32 pci_endpoint_test_readl(struct pci_endpoint_test *test,
109 					  u32 offset)
110 {
111 	return readl(test->base + offset);
112 }
113 
114 static inline void pci_endpoint_test_writel(struct pci_endpoint_test *test,
115 					    u32 offset, u32 value)
116 {
117 	writel(value, test->base + offset);
118 }
119 
120 static inline u32 pci_endpoint_test_bar_readl(struct pci_endpoint_test *test,
121 					      int bar, int offset)
122 {
123 	return readl(test->bar[bar] + offset);
124 }
125 
126 static inline void pci_endpoint_test_bar_writel(struct pci_endpoint_test *test,
127 						int bar, u32 offset, u32 value)
128 {
129 	writel(value, test->bar[bar] + offset);
130 }
131 
132 static irqreturn_t pci_endpoint_test_irqhandler(int irq, void *dev_id)
133 {
134 	struct pci_endpoint_test *test = dev_id;
135 	u32 reg;
136 
137 	reg = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_STATUS);
138 	if (reg & STATUS_IRQ_RAISED) {
139 		test->last_irq = irq;
140 		complete(&test->irq_raised);
141 		reg &= ~STATUS_IRQ_RAISED;
142 	}
143 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_STATUS,
144 				 reg);
145 
146 	return IRQ_HANDLED;
147 }
148 
149 static bool pci_endpoint_test_bar(struct pci_endpoint_test *test,
150 				  enum pci_barno barno)
151 {
152 	int j;
153 	u32 val;
154 	int size;
155 	struct pci_dev *pdev = test->pdev;
156 
157 	if (!test->bar[barno])
158 		return false;
159 
160 	size = pci_resource_len(pdev, barno);
161 
162 	if (barno == test->test_reg_bar)
163 		size = 0x4;
164 
165 	for (j = 0; j < size; j += 4)
166 		pci_endpoint_test_bar_writel(test, barno, j, 0xA0A0A0A0);
167 
168 	for (j = 0; j < size; j += 4) {
169 		val = pci_endpoint_test_bar_readl(test, barno, j);
170 		if (val != 0xA0A0A0A0)
171 			return false;
172 	}
173 
174 	return true;
175 }
176 
177 static bool pci_endpoint_test_legacy_irq(struct pci_endpoint_test *test)
178 {
179 	u32 val;
180 
181 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_COMMAND,
182 				 COMMAND_RAISE_LEGACY_IRQ);
183 	val = wait_for_completion_timeout(&test->irq_raised,
184 					  msecs_to_jiffies(1000));
185 	if (!val)
186 		return false;
187 
188 	return true;
189 }
190 
191 static bool pci_endpoint_test_msi_irq(struct pci_endpoint_test *test,
192 				      u8 msi_num)
193 {
194 	u32 val;
195 	struct pci_dev *pdev = test->pdev;
196 
197 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_COMMAND,
198 				 msi_num << MSI_NUMBER_SHIFT |
199 				 COMMAND_RAISE_MSI_IRQ);
200 	val = wait_for_completion_timeout(&test->irq_raised,
201 					  msecs_to_jiffies(1000));
202 	if (!val)
203 		return false;
204 
205 	if (test->last_irq - pdev->irq == msi_num - 1)
206 		return true;
207 
208 	return false;
209 }
210 
211 static bool pci_endpoint_test_copy(struct pci_endpoint_test *test, size_t size)
212 {
213 	bool ret = false;
214 	void *src_addr;
215 	void *dst_addr;
216 	dma_addr_t src_phys_addr;
217 	dma_addr_t dst_phys_addr;
218 	struct pci_dev *pdev = test->pdev;
219 	struct device *dev = &pdev->dev;
220 	void *orig_src_addr;
221 	dma_addr_t orig_src_phys_addr;
222 	void *orig_dst_addr;
223 	dma_addr_t orig_dst_phys_addr;
224 	size_t offset;
225 	size_t alignment = test->alignment;
226 	u32 src_crc32;
227 	u32 dst_crc32;
228 
229 	orig_src_addr = dma_alloc_coherent(dev, size + alignment,
230 					   &orig_src_phys_addr, GFP_KERNEL);
231 	if (!orig_src_addr) {
232 		dev_err(dev, "failed to allocate source buffer\n");
233 		ret = false;
234 		goto err;
235 	}
236 
237 	if (alignment && !IS_ALIGNED(orig_src_phys_addr, alignment)) {
238 		src_phys_addr = PTR_ALIGN(orig_src_phys_addr, alignment);
239 		offset = src_phys_addr - orig_src_phys_addr;
240 		src_addr = orig_src_addr + offset;
241 	} else {
242 		src_phys_addr = orig_src_phys_addr;
243 		src_addr = orig_src_addr;
244 	}
245 
246 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_LOWER_SRC_ADDR,
247 				 lower_32_bits(src_phys_addr));
248 
249 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_UPPER_SRC_ADDR,
250 				 upper_32_bits(src_phys_addr));
251 
252 	get_random_bytes(src_addr, size);
253 	src_crc32 = crc32_le(~0, src_addr, size);
254 
255 	orig_dst_addr = dma_alloc_coherent(dev, size + alignment,
256 					   &orig_dst_phys_addr, GFP_KERNEL);
257 	if (!orig_dst_addr) {
258 		dev_err(dev, "failed to allocate destination address\n");
259 		ret = false;
260 		goto err_orig_src_addr;
261 	}
262 
263 	if (alignment && !IS_ALIGNED(orig_dst_phys_addr, alignment)) {
264 		dst_phys_addr = PTR_ALIGN(orig_dst_phys_addr, alignment);
265 		offset = dst_phys_addr - orig_dst_phys_addr;
266 		dst_addr = orig_dst_addr + offset;
267 	} else {
268 		dst_phys_addr = orig_dst_phys_addr;
269 		dst_addr = orig_dst_addr;
270 	}
271 
272 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_LOWER_DST_ADDR,
273 				 lower_32_bits(dst_phys_addr));
274 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_UPPER_DST_ADDR,
275 				 upper_32_bits(dst_phys_addr));
276 
277 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_SIZE,
278 				 size);
279 
280 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_COMMAND,
281 				 1 << MSI_NUMBER_SHIFT | COMMAND_COPY);
282 
283 	wait_for_completion(&test->irq_raised);
284 
285 	dst_crc32 = crc32_le(~0, dst_addr, size);
286 	if (dst_crc32 == src_crc32)
287 		ret = true;
288 
289 	dma_free_coherent(dev, size + alignment, orig_dst_addr,
290 			  orig_dst_phys_addr);
291 
292 err_orig_src_addr:
293 	dma_free_coherent(dev, size + alignment, orig_src_addr,
294 			  orig_src_phys_addr);
295 
296 err:
297 	return ret;
298 }
299 
300 static bool pci_endpoint_test_write(struct pci_endpoint_test *test, size_t size)
301 {
302 	bool ret = false;
303 	u32 reg;
304 	void *addr;
305 	dma_addr_t phys_addr;
306 	struct pci_dev *pdev = test->pdev;
307 	struct device *dev = &pdev->dev;
308 	void *orig_addr;
309 	dma_addr_t orig_phys_addr;
310 	size_t offset;
311 	size_t alignment = test->alignment;
312 	u32 crc32;
313 
314 	orig_addr = dma_alloc_coherent(dev, size + alignment, &orig_phys_addr,
315 				       GFP_KERNEL);
316 	if (!orig_addr) {
317 		dev_err(dev, "failed to allocate address\n");
318 		ret = false;
319 		goto err;
320 	}
321 
322 	if (alignment && !IS_ALIGNED(orig_phys_addr, alignment)) {
323 		phys_addr =  PTR_ALIGN(orig_phys_addr, alignment);
324 		offset = phys_addr - orig_phys_addr;
325 		addr = orig_addr + offset;
326 	} else {
327 		phys_addr = orig_phys_addr;
328 		addr = orig_addr;
329 	}
330 
331 	get_random_bytes(addr, size);
332 
333 	crc32 = crc32_le(~0, addr, size);
334 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_CHECKSUM,
335 				 crc32);
336 
337 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_LOWER_SRC_ADDR,
338 				 lower_32_bits(phys_addr));
339 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_UPPER_SRC_ADDR,
340 				 upper_32_bits(phys_addr));
341 
342 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_SIZE, size);
343 
344 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_COMMAND,
345 				 1 << MSI_NUMBER_SHIFT | COMMAND_READ);
346 
347 	wait_for_completion(&test->irq_raised);
348 
349 	reg = pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_STATUS);
350 	if (reg & STATUS_READ_SUCCESS)
351 		ret = true;
352 
353 	dma_free_coherent(dev, size + alignment, orig_addr, orig_phys_addr);
354 
355 err:
356 	return ret;
357 }
358 
359 static bool pci_endpoint_test_read(struct pci_endpoint_test *test, size_t size)
360 {
361 	bool ret = false;
362 	void *addr;
363 	dma_addr_t phys_addr;
364 	struct pci_dev *pdev = test->pdev;
365 	struct device *dev = &pdev->dev;
366 	void *orig_addr;
367 	dma_addr_t orig_phys_addr;
368 	size_t offset;
369 	size_t alignment = test->alignment;
370 	u32 crc32;
371 
372 	orig_addr = dma_alloc_coherent(dev, size + alignment, &orig_phys_addr,
373 				       GFP_KERNEL);
374 	if (!orig_addr) {
375 		dev_err(dev, "failed to allocate destination address\n");
376 		ret = false;
377 		goto err;
378 	}
379 
380 	if (alignment && !IS_ALIGNED(orig_phys_addr, alignment)) {
381 		phys_addr = PTR_ALIGN(orig_phys_addr, alignment);
382 		offset = phys_addr - orig_phys_addr;
383 		addr = orig_addr + offset;
384 	} else {
385 		phys_addr = orig_phys_addr;
386 		addr = orig_addr;
387 	}
388 
389 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_LOWER_DST_ADDR,
390 				 lower_32_bits(phys_addr));
391 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_UPPER_DST_ADDR,
392 				 upper_32_bits(phys_addr));
393 
394 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_SIZE, size);
395 
396 	pci_endpoint_test_writel(test, PCI_ENDPOINT_TEST_COMMAND,
397 				 1 << MSI_NUMBER_SHIFT | COMMAND_WRITE);
398 
399 	wait_for_completion(&test->irq_raised);
400 
401 	crc32 = crc32_le(~0, addr, size);
402 	if (crc32 == pci_endpoint_test_readl(test, PCI_ENDPOINT_TEST_CHECKSUM))
403 		ret = true;
404 
405 	dma_free_coherent(dev, size + alignment, orig_addr, orig_phys_addr);
406 err:
407 	return ret;
408 }
409 
410 static long pci_endpoint_test_ioctl(struct file *file, unsigned int cmd,
411 				    unsigned long arg)
412 {
413 	int ret = -EINVAL;
414 	enum pci_barno bar;
415 	struct pci_endpoint_test *test = to_endpoint_test(file->private_data);
416 
417 	mutex_lock(&test->mutex);
418 	switch (cmd) {
419 	case PCITEST_BAR:
420 		bar = arg;
421 		if (bar < 0 || bar > 5)
422 			goto ret;
423 		ret = pci_endpoint_test_bar(test, bar);
424 		break;
425 	case PCITEST_LEGACY_IRQ:
426 		ret = pci_endpoint_test_legacy_irq(test);
427 		break;
428 	case PCITEST_MSI:
429 		ret = pci_endpoint_test_msi_irq(test, arg);
430 		break;
431 	case PCITEST_WRITE:
432 		ret = pci_endpoint_test_write(test, arg);
433 		break;
434 	case PCITEST_READ:
435 		ret = pci_endpoint_test_read(test, arg);
436 		break;
437 	case PCITEST_COPY:
438 		ret = pci_endpoint_test_copy(test, arg);
439 		break;
440 	}
441 
442 ret:
443 	mutex_unlock(&test->mutex);
444 	return ret;
445 }
446 
447 static const struct file_operations pci_endpoint_test_fops = {
448 	.owner = THIS_MODULE,
449 	.unlocked_ioctl = pci_endpoint_test_ioctl,
450 };
451 
452 static int pci_endpoint_test_probe(struct pci_dev *pdev,
453 				   const struct pci_device_id *ent)
454 {
455 	int i;
456 	int err;
457 	int irq = 0;
458 	int id;
459 	char name[20];
460 	enum pci_barno bar;
461 	void __iomem *base;
462 	struct device *dev = &pdev->dev;
463 	struct pci_endpoint_test *test;
464 	struct pci_endpoint_test_data *data;
465 	enum pci_barno test_reg_bar = BAR_0;
466 	struct miscdevice *misc_device;
467 
468 	if (pci_is_bridge(pdev))
469 		return -ENODEV;
470 
471 	test = devm_kzalloc(dev, sizeof(*test), GFP_KERNEL);
472 	if (!test)
473 		return -ENOMEM;
474 
475 	test->test_reg_bar = 0;
476 	test->alignment = 0;
477 	test->pdev = pdev;
478 
479 	data = (struct pci_endpoint_test_data *)ent->driver_data;
480 	if (data) {
481 		test_reg_bar = data->test_reg_bar;
482 		test->alignment = data->alignment;
483 		no_msi = data->no_msi;
484 	}
485 
486 	init_completion(&test->irq_raised);
487 	mutex_init(&test->mutex);
488 
489 	err = pci_enable_device(pdev);
490 	if (err) {
491 		dev_err(dev, "Cannot enable PCI device\n");
492 		return err;
493 	}
494 
495 	err = pci_request_regions(pdev, DRV_MODULE_NAME);
496 	if (err) {
497 		dev_err(dev, "Cannot obtain PCI resources\n");
498 		goto err_disable_pdev;
499 	}
500 
501 	pci_set_master(pdev);
502 
503 	if (!no_msi) {
504 		irq = pci_alloc_irq_vectors(pdev, 1, 32, PCI_IRQ_MSI);
505 		if (irq < 0)
506 			dev_err(dev, "failed to get MSI interrupts\n");
507 	}
508 
509 	err = devm_request_irq(dev, pdev->irq, pci_endpoint_test_irqhandler,
510 			       IRQF_SHARED, DRV_MODULE_NAME, test);
511 	if (err) {
512 		dev_err(dev, "failed to request IRQ %d\n", pdev->irq);
513 		goto err_disable_msi;
514 	}
515 
516 	for (i = 1; i < irq; i++) {
517 		err = devm_request_irq(dev, pdev->irq + i,
518 				       pci_endpoint_test_irqhandler,
519 				       IRQF_SHARED, DRV_MODULE_NAME, test);
520 		if (err)
521 			dev_err(dev, "failed to request IRQ %d for MSI %d\n",
522 				pdev->irq + i, i + 1);
523 	}
524 
525 	for (bar = BAR_0; bar <= BAR_5; bar++) {
526 		base = pci_ioremap_bar(pdev, bar);
527 		if (!base) {
528 			dev_err(dev, "failed to read BAR%d\n", bar);
529 			WARN_ON(bar == test_reg_bar);
530 		}
531 		test->bar[bar] = base;
532 	}
533 
534 	test->base = test->bar[test_reg_bar];
535 	if (!test->base) {
536 		dev_err(dev, "Cannot perform PCI test without BAR%d\n",
537 			test_reg_bar);
538 		goto err_iounmap;
539 	}
540 
541 	pci_set_drvdata(pdev, test);
542 
543 	id = ida_simple_get(&pci_endpoint_test_ida, 0, 0, GFP_KERNEL);
544 	if (id < 0) {
545 		dev_err(dev, "unable to get id\n");
546 		goto err_iounmap;
547 	}
548 
549 	snprintf(name, sizeof(name), DRV_MODULE_NAME ".%d", id);
550 	misc_device = &test->miscdev;
551 	misc_device->minor = MISC_DYNAMIC_MINOR;
552 	misc_device->name = name;
553 	misc_device->fops = &pci_endpoint_test_fops,
554 
555 	err = misc_register(misc_device);
556 	if (err) {
557 		dev_err(dev, "failed to register device\n");
558 		goto err_ida_remove;
559 	}
560 
561 	return 0;
562 
563 err_ida_remove:
564 	ida_simple_remove(&pci_endpoint_test_ida, id);
565 
566 err_iounmap:
567 	for (bar = BAR_0; bar <= BAR_5; bar++) {
568 		if (test->bar[bar])
569 			pci_iounmap(pdev, test->bar[bar]);
570 	}
571 
572 err_disable_msi:
573 	pci_disable_msi(pdev);
574 	pci_release_regions(pdev);
575 
576 err_disable_pdev:
577 	pci_disable_device(pdev);
578 
579 	return err;
580 }
581 
582 static void pci_endpoint_test_remove(struct pci_dev *pdev)
583 {
584 	int id;
585 	enum pci_barno bar;
586 	struct pci_endpoint_test *test = pci_get_drvdata(pdev);
587 	struct miscdevice *misc_device = &test->miscdev;
588 
589 	if (sscanf(misc_device->name, DRV_MODULE_NAME ".%d", &id) != 1)
590 		return;
591 
592 	misc_deregister(&test->miscdev);
593 	ida_simple_remove(&pci_endpoint_test_ida, id);
594 	for (bar = BAR_0; bar <= BAR_5; bar++) {
595 		if (test->bar[bar])
596 			pci_iounmap(pdev, test->bar[bar]);
597 	}
598 	pci_disable_msi(pdev);
599 	pci_release_regions(pdev);
600 	pci_disable_device(pdev);
601 }
602 
603 static const struct pci_device_id pci_endpoint_test_tbl[] = {
604 	{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_DRA74x) },
605 	{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_DRA72x) },
606 	{ }
607 };
608 MODULE_DEVICE_TABLE(pci, pci_endpoint_test_tbl);
609 
610 static struct pci_driver pci_endpoint_test_driver = {
611 	.name		= DRV_MODULE_NAME,
612 	.id_table	= pci_endpoint_test_tbl,
613 	.probe		= pci_endpoint_test_probe,
614 	.remove		= pci_endpoint_test_remove,
615 };
616 module_pci_driver(pci_endpoint_test_driver);
617 
618 MODULE_DESCRIPTION("PCI ENDPOINT TEST HOST DRIVER");
619 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
620 MODULE_LICENSE("GPL v2");
621