xref: /linux/drivers/pci/pci-sysfs.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * (C) Copyright 2002-2004 Greg Kroah-Hartman <greg@kroah.com>
4  * (C) Copyright 2002-2004 IBM Corp.
5  * (C) Copyright 2003 Matthew Wilcox
6  * (C) Copyright 2003 Hewlett-Packard
7  * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
8  * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
9  *
10  * File attributes for PCI devices
11  *
12  * Modeled after usb's driverfs.c
13  */
14 
15 #include <linux/bitfield.h>
16 #include <linux/kernel.h>
17 #include <linux/sched.h>
18 #include <linux/pci.h>
19 #include <linux/stat.h>
20 #include <linux/export.h>
21 #include <linux/topology.h>
22 #include <linux/mm.h>
23 #include <linux/fs.h>
24 #include <linux/capability.h>
25 #include <linux/security.h>
26 #include <linux/slab.h>
27 #include <linux/vgaarb.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/msi.h>
30 #include <linux/of.h>
31 #include <linux/aperture.h>
32 #include "pci.h"
33 
34 static int sysfs_initialized;	/* = 0 */
35 
36 /* show configuration fields */
37 #define pci_config_attr(field, format_string)				\
38 static ssize_t								\
39 field##_show(struct device *dev, struct device_attribute *attr, char *buf)				\
40 {									\
41 	struct pci_dev *pdev;						\
42 									\
43 	pdev = to_pci_dev(dev);						\
44 	return sysfs_emit(buf, format_string, pdev->field);		\
45 }									\
46 static DEVICE_ATTR_RO(field)
47 
48 pci_config_attr(vendor, "0x%04x\n");
49 pci_config_attr(device, "0x%04x\n");
50 pci_config_attr(subsystem_vendor, "0x%04x\n");
51 pci_config_attr(subsystem_device, "0x%04x\n");
52 pci_config_attr(revision, "0x%02x\n");
53 pci_config_attr(class, "0x%06x\n");
54 
55 static ssize_t irq_show(struct device *dev,
56 			struct device_attribute *attr,
57 			char *buf)
58 {
59 	struct pci_dev *pdev = to_pci_dev(dev);
60 
61 #ifdef CONFIG_PCI_MSI
62 	/*
63 	 * For MSI, show the first MSI IRQ; for all other cases including
64 	 * MSI-X, show the legacy INTx IRQ.
65 	 */
66 	if (pdev->msi_enabled)
67 		return sysfs_emit(buf, "%u\n", pci_irq_vector(pdev, 0));
68 #endif
69 
70 	return sysfs_emit(buf, "%u\n", pdev->irq);
71 }
72 static DEVICE_ATTR_RO(irq);
73 
74 static ssize_t broken_parity_status_show(struct device *dev,
75 					 struct device_attribute *attr,
76 					 char *buf)
77 {
78 	struct pci_dev *pdev = to_pci_dev(dev);
79 	return sysfs_emit(buf, "%u\n", pdev->broken_parity_status);
80 }
81 
82 static ssize_t broken_parity_status_store(struct device *dev,
83 					  struct device_attribute *attr,
84 					  const char *buf, size_t count)
85 {
86 	struct pci_dev *pdev = to_pci_dev(dev);
87 	unsigned long val;
88 
89 	if (kstrtoul(buf, 0, &val) < 0)
90 		return -EINVAL;
91 
92 	pdev->broken_parity_status = !!val;
93 
94 	return count;
95 }
96 static DEVICE_ATTR_RW(broken_parity_status);
97 
98 static ssize_t pci_dev_show_local_cpu(struct device *dev, bool list,
99 				      struct device_attribute *attr, char *buf)
100 {
101 	const struct cpumask *mask;
102 
103 #ifdef CONFIG_NUMA
104 	if (dev_to_node(dev) == NUMA_NO_NODE)
105 		mask = cpu_online_mask;
106 	else
107 		mask = cpumask_of_node(dev_to_node(dev));
108 #else
109 	mask = cpumask_of_pcibus(to_pci_dev(dev)->bus);
110 #endif
111 	return cpumap_print_to_pagebuf(list, buf, mask);
112 }
113 
114 static ssize_t local_cpus_show(struct device *dev,
115 			       struct device_attribute *attr, char *buf)
116 {
117 	return pci_dev_show_local_cpu(dev, false, attr, buf);
118 }
119 static DEVICE_ATTR_RO(local_cpus);
120 
121 static ssize_t local_cpulist_show(struct device *dev,
122 				  struct device_attribute *attr, char *buf)
123 {
124 	return pci_dev_show_local_cpu(dev, true, attr, buf);
125 }
126 static DEVICE_ATTR_RO(local_cpulist);
127 
128 /*
129  * PCI Bus Class Devices
130  */
131 static ssize_t cpuaffinity_show(struct device *dev,
132 				struct device_attribute *attr, char *buf)
133 {
134 	const struct cpumask *cpumask = cpumask_of_pcibus(to_pci_bus(dev));
135 
136 	return cpumap_print_to_pagebuf(false, buf, cpumask);
137 }
138 static DEVICE_ATTR_RO(cpuaffinity);
139 
140 static ssize_t cpulistaffinity_show(struct device *dev,
141 				    struct device_attribute *attr, char *buf)
142 {
143 	const struct cpumask *cpumask = cpumask_of_pcibus(to_pci_bus(dev));
144 
145 	return cpumap_print_to_pagebuf(true, buf, cpumask);
146 }
147 static DEVICE_ATTR_RO(cpulistaffinity);
148 
149 static ssize_t power_state_show(struct device *dev,
150 				struct device_attribute *attr, char *buf)
151 {
152 	struct pci_dev *pdev = to_pci_dev(dev);
153 
154 	return sysfs_emit(buf, "%s\n", pci_power_name(pdev->current_state));
155 }
156 static DEVICE_ATTR_RO(power_state);
157 
158 /* show resources */
159 static ssize_t resource_show(struct device *dev, struct device_attribute *attr,
160 			     char *buf)
161 {
162 	struct pci_dev *pci_dev = to_pci_dev(dev);
163 	int i;
164 	int max;
165 	resource_size_t start, end;
166 	size_t len = 0;
167 
168 	if (pci_dev->subordinate)
169 		max = DEVICE_COUNT_RESOURCE;
170 	else
171 		max = PCI_BRIDGE_RESOURCES;
172 
173 	for (i = 0; i < max; i++) {
174 		struct resource *res =  &pci_dev->resource[i];
175 		pci_resource_to_user(pci_dev, i, res, &start, &end);
176 		len += sysfs_emit_at(buf, len, "0x%016llx 0x%016llx 0x%016llx\n",
177 				     (unsigned long long)start,
178 				     (unsigned long long)end,
179 				     (unsigned long long)res->flags);
180 	}
181 	return len;
182 }
183 static DEVICE_ATTR_RO(resource);
184 
185 static ssize_t max_link_speed_show(struct device *dev,
186 				   struct device_attribute *attr, char *buf)
187 {
188 	struct pci_dev *pdev = to_pci_dev(dev);
189 
190 	return sysfs_emit(buf, "%s\n",
191 			  pci_speed_string(pcie_get_speed_cap(pdev)));
192 }
193 static DEVICE_ATTR_RO(max_link_speed);
194 
195 static ssize_t max_link_width_show(struct device *dev,
196 				   struct device_attribute *attr, char *buf)
197 {
198 	struct pci_dev *pdev = to_pci_dev(dev);
199 
200 	return sysfs_emit(buf, "%u\n", pcie_get_width_cap(pdev));
201 }
202 static DEVICE_ATTR_RO(max_link_width);
203 
204 static ssize_t current_link_speed_show(struct device *dev,
205 				       struct device_attribute *attr, char *buf)
206 {
207 	struct pci_dev *pci_dev = to_pci_dev(dev);
208 	u16 linkstat;
209 	int err;
210 	enum pci_bus_speed speed;
211 
212 	err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat);
213 	if (err)
214 		return -EINVAL;
215 
216 	speed = pcie_link_speed[linkstat & PCI_EXP_LNKSTA_CLS];
217 
218 	return sysfs_emit(buf, "%s\n", pci_speed_string(speed));
219 }
220 static DEVICE_ATTR_RO(current_link_speed);
221 
222 static ssize_t current_link_width_show(struct device *dev,
223 				       struct device_attribute *attr, char *buf)
224 {
225 	struct pci_dev *pci_dev = to_pci_dev(dev);
226 	u16 linkstat;
227 	int err;
228 
229 	err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat);
230 	if (err)
231 		return -EINVAL;
232 
233 	return sysfs_emit(buf, "%u\n", FIELD_GET(PCI_EXP_LNKSTA_NLW, linkstat));
234 }
235 static DEVICE_ATTR_RO(current_link_width);
236 
237 static ssize_t secondary_bus_number_show(struct device *dev,
238 					 struct device_attribute *attr,
239 					 char *buf)
240 {
241 	struct pci_dev *pci_dev = to_pci_dev(dev);
242 	u8 sec_bus;
243 	int err;
244 
245 	err = pci_read_config_byte(pci_dev, PCI_SECONDARY_BUS, &sec_bus);
246 	if (err)
247 		return -EINVAL;
248 
249 	return sysfs_emit(buf, "%u\n", sec_bus);
250 }
251 static DEVICE_ATTR_RO(secondary_bus_number);
252 
253 static ssize_t subordinate_bus_number_show(struct device *dev,
254 					   struct device_attribute *attr,
255 					   char *buf)
256 {
257 	struct pci_dev *pci_dev = to_pci_dev(dev);
258 	u8 sub_bus;
259 	int err;
260 
261 	err = pci_read_config_byte(pci_dev, PCI_SUBORDINATE_BUS, &sub_bus);
262 	if (err)
263 		return -EINVAL;
264 
265 	return sysfs_emit(buf, "%u\n", sub_bus);
266 }
267 static DEVICE_ATTR_RO(subordinate_bus_number);
268 
269 static ssize_t ari_enabled_show(struct device *dev,
270 				struct device_attribute *attr,
271 				char *buf)
272 {
273 	struct pci_dev *pci_dev = to_pci_dev(dev);
274 
275 	return sysfs_emit(buf, "%u\n", pci_ari_enabled(pci_dev->bus));
276 }
277 static DEVICE_ATTR_RO(ari_enabled);
278 
279 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
280 			     char *buf)
281 {
282 	struct pci_dev *pci_dev = to_pci_dev(dev);
283 
284 	return sysfs_emit(buf, "pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02X\n",
285 			  pci_dev->vendor, pci_dev->device,
286 			  pci_dev->subsystem_vendor, pci_dev->subsystem_device,
287 			  (u8)(pci_dev->class >> 16), (u8)(pci_dev->class >> 8),
288 			  (u8)(pci_dev->class));
289 }
290 static DEVICE_ATTR_RO(modalias);
291 
292 static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
293 			     const char *buf, size_t count)
294 {
295 	struct pci_dev *pdev = to_pci_dev(dev);
296 	unsigned long val;
297 	ssize_t result = 0;
298 
299 	/* this can crash the machine when done on the "wrong" device */
300 	if (!capable(CAP_SYS_ADMIN))
301 		return -EPERM;
302 
303 	if (kstrtoul(buf, 0, &val) < 0)
304 		return -EINVAL;
305 
306 	device_lock(dev);
307 	if (dev->driver)
308 		result = -EBUSY;
309 	else if (val)
310 		result = pci_enable_device(pdev);
311 	else if (pci_is_enabled(pdev))
312 		pci_disable_device(pdev);
313 	else
314 		result = -EIO;
315 	device_unlock(dev);
316 
317 	return result < 0 ? result : count;
318 }
319 
320 static ssize_t enable_show(struct device *dev, struct device_attribute *attr,
321 			    char *buf)
322 {
323 	struct pci_dev *pdev;
324 
325 	pdev = to_pci_dev(dev);
326 	return sysfs_emit(buf, "%u\n", atomic_read(&pdev->enable_cnt));
327 }
328 static DEVICE_ATTR_RW(enable);
329 
330 #ifdef CONFIG_NUMA
331 static ssize_t numa_node_store(struct device *dev,
332 			       struct device_attribute *attr, const char *buf,
333 			       size_t count)
334 {
335 	struct pci_dev *pdev = to_pci_dev(dev);
336 	int node;
337 
338 	if (!capable(CAP_SYS_ADMIN))
339 		return -EPERM;
340 
341 	if (kstrtoint(buf, 0, &node) < 0)
342 		return -EINVAL;
343 
344 	if ((node < 0 && node != NUMA_NO_NODE) || node >= MAX_NUMNODES)
345 		return -EINVAL;
346 
347 	if (node != NUMA_NO_NODE && !node_online(node))
348 		return -EINVAL;
349 
350 	add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
351 	pci_alert(pdev, FW_BUG "Overriding NUMA node to %d.  Contact your vendor for updates.",
352 		  node);
353 
354 	dev->numa_node = node;
355 	return count;
356 }
357 
358 static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr,
359 			      char *buf)
360 {
361 	return sysfs_emit(buf, "%d\n", dev->numa_node);
362 }
363 static DEVICE_ATTR_RW(numa_node);
364 #endif
365 
366 static ssize_t dma_mask_bits_show(struct device *dev,
367 				  struct device_attribute *attr, char *buf)
368 {
369 	struct pci_dev *pdev = to_pci_dev(dev);
370 
371 	return sysfs_emit(buf, "%d\n", fls64(pdev->dma_mask));
372 }
373 static DEVICE_ATTR_RO(dma_mask_bits);
374 
375 static ssize_t consistent_dma_mask_bits_show(struct device *dev,
376 					     struct device_attribute *attr,
377 					     char *buf)
378 {
379 	return sysfs_emit(buf, "%d\n", fls64(dev->coherent_dma_mask));
380 }
381 static DEVICE_ATTR_RO(consistent_dma_mask_bits);
382 
383 static ssize_t msi_bus_show(struct device *dev, struct device_attribute *attr,
384 			    char *buf)
385 {
386 	struct pci_dev *pdev = to_pci_dev(dev);
387 	struct pci_bus *subordinate = pdev->subordinate;
388 
389 	return sysfs_emit(buf, "%u\n", subordinate ?
390 			  !(subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI)
391 			    : !pdev->no_msi);
392 }
393 
394 static ssize_t msi_bus_store(struct device *dev, struct device_attribute *attr,
395 			     const char *buf, size_t count)
396 {
397 	struct pci_dev *pdev = to_pci_dev(dev);
398 	struct pci_bus *subordinate = pdev->subordinate;
399 	unsigned long val;
400 
401 	if (!capable(CAP_SYS_ADMIN))
402 		return -EPERM;
403 
404 	if (kstrtoul(buf, 0, &val) < 0)
405 		return -EINVAL;
406 
407 	/*
408 	 * "no_msi" and "bus_flags" only affect what happens when a driver
409 	 * requests MSI or MSI-X.  They don't affect any drivers that have
410 	 * already requested MSI or MSI-X.
411 	 */
412 	if (!subordinate) {
413 		pdev->no_msi = !val;
414 		pci_info(pdev, "MSI/MSI-X %s for future drivers\n",
415 			 val ? "allowed" : "disallowed");
416 		return count;
417 	}
418 
419 	if (val)
420 		subordinate->bus_flags &= ~PCI_BUS_FLAGS_NO_MSI;
421 	else
422 		subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
423 
424 	dev_info(&subordinate->dev, "MSI/MSI-X %s for future drivers of devices on this bus\n",
425 		 val ? "allowed" : "disallowed");
426 	return count;
427 }
428 static DEVICE_ATTR_RW(msi_bus);
429 
430 static ssize_t rescan_store(const struct bus_type *bus, const char *buf, size_t count)
431 {
432 	unsigned long val;
433 	struct pci_bus *b = NULL;
434 
435 	if (kstrtoul(buf, 0, &val) < 0)
436 		return -EINVAL;
437 
438 	if (val) {
439 		pci_lock_rescan_remove();
440 		while ((b = pci_find_next_bus(b)) != NULL)
441 			pci_rescan_bus(b);
442 		pci_unlock_rescan_remove();
443 	}
444 	return count;
445 }
446 static BUS_ATTR_WO(rescan);
447 
448 static struct attribute *pci_bus_attrs[] = {
449 	&bus_attr_rescan.attr,
450 	NULL,
451 };
452 
453 static const struct attribute_group pci_bus_group = {
454 	.attrs = pci_bus_attrs,
455 };
456 
457 const struct attribute_group *pci_bus_groups[] = {
458 	&pci_bus_group,
459 	NULL,
460 };
461 
462 static ssize_t dev_rescan_store(struct device *dev,
463 				struct device_attribute *attr, const char *buf,
464 				size_t count)
465 {
466 	unsigned long val;
467 	struct pci_dev *pdev = to_pci_dev(dev);
468 
469 	if (kstrtoul(buf, 0, &val) < 0)
470 		return -EINVAL;
471 
472 	if (val) {
473 		pci_lock_rescan_remove();
474 		pci_rescan_bus(pdev->bus);
475 		pci_unlock_rescan_remove();
476 	}
477 	return count;
478 }
479 static struct device_attribute dev_attr_dev_rescan = __ATTR(rescan, 0200, NULL,
480 							    dev_rescan_store);
481 
482 static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
483 			    const char *buf, size_t count)
484 {
485 	unsigned long val;
486 
487 	if (kstrtoul(buf, 0, &val) < 0)
488 		return -EINVAL;
489 
490 	if (val && device_remove_file_self(dev, attr))
491 		pci_stop_and_remove_bus_device_locked(to_pci_dev(dev));
492 	return count;
493 }
494 static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0220, NULL,
495 				  remove_store);
496 
497 static ssize_t bus_rescan_store(struct device *dev,
498 				struct device_attribute *attr,
499 				const char *buf, size_t count)
500 {
501 	unsigned long val;
502 	struct pci_bus *bus = to_pci_bus(dev);
503 
504 	if (kstrtoul(buf, 0, &val) < 0)
505 		return -EINVAL;
506 
507 	if (val) {
508 		pci_lock_rescan_remove();
509 		if (!pci_is_root_bus(bus) && list_empty(&bus->devices))
510 			pci_rescan_bus_bridge_resize(bus->self);
511 		else
512 			pci_rescan_bus(bus);
513 		pci_unlock_rescan_remove();
514 	}
515 	return count;
516 }
517 static struct device_attribute dev_attr_bus_rescan = __ATTR(rescan, 0200, NULL,
518 							    bus_rescan_store);
519 
520 #if defined(CONFIG_PM) && defined(CONFIG_ACPI)
521 static ssize_t d3cold_allowed_store(struct device *dev,
522 				    struct device_attribute *attr,
523 				    const char *buf, size_t count)
524 {
525 	struct pci_dev *pdev = to_pci_dev(dev);
526 	unsigned long val;
527 
528 	if (kstrtoul(buf, 0, &val) < 0)
529 		return -EINVAL;
530 
531 	pdev->d3cold_allowed = !!val;
532 	pci_bridge_d3_update(pdev);
533 
534 	pm_runtime_resume(dev);
535 
536 	return count;
537 }
538 
539 static ssize_t d3cold_allowed_show(struct device *dev,
540 				   struct device_attribute *attr, char *buf)
541 {
542 	struct pci_dev *pdev = to_pci_dev(dev);
543 	return sysfs_emit(buf, "%u\n", pdev->d3cold_allowed);
544 }
545 static DEVICE_ATTR_RW(d3cold_allowed);
546 #endif
547 
548 #ifdef CONFIG_OF
549 static ssize_t devspec_show(struct device *dev,
550 			    struct device_attribute *attr, char *buf)
551 {
552 	struct pci_dev *pdev = to_pci_dev(dev);
553 	struct device_node *np = pci_device_to_OF_node(pdev);
554 
555 	if (np == NULL)
556 		return 0;
557 	return sysfs_emit(buf, "%pOF\n", np);
558 }
559 static DEVICE_ATTR_RO(devspec);
560 #endif
561 
562 static ssize_t driver_override_store(struct device *dev,
563 				     struct device_attribute *attr,
564 				     const char *buf, size_t count)
565 {
566 	struct pci_dev *pdev = to_pci_dev(dev);
567 	int ret;
568 
569 	ret = driver_set_override(dev, &pdev->driver_override, buf, count);
570 	if (ret)
571 		return ret;
572 
573 	return count;
574 }
575 
576 static ssize_t driver_override_show(struct device *dev,
577 				    struct device_attribute *attr, char *buf)
578 {
579 	struct pci_dev *pdev = to_pci_dev(dev);
580 	ssize_t len;
581 
582 	device_lock(dev);
583 	len = sysfs_emit(buf, "%s\n", pdev->driver_override);
584 	device_unlock(dev);
585 	return len;
586 }
587 static DEVICE_ATTR_RW(driver_override);
588 
589 static struct attribute *pci_dev_attrs[] = {
590 	&dev_attr_power_state.attr,
591 	&dev_attr_resource.attr,
592 	&dev_attr_vendor.attr,
593 	&dev_attr_device.attr,
594 	&dev_attr_subsystem_vendor.attr,
595 	&dev_attr_subsystem_device.attr,
596 	&dev_attr_revision.attr,
597 	&dev_attr_class.attr,
598 	&dev_attr_irq.attr,
599 	&dev_attr_local_cpus.attr,
600 	&dev_attr_local_cpulist.attr,
601 	&dev_attr_modalias.attr,
602 #ifdef CONFIG_NUMA
603 	&dev_attr_numa_node.attr,
604 #endif
605 	&dev_attr_dma_mask_bits.attr,
606 	&dev_attr_consistent_dma_mask_bits.attr,
607 	&dev_attr_enable.attr,
608 	&dev_attr_broken_parity_status.attr,
609 	&dev_attr_msi_bus.attr,
610 #if defined(CONFIG_PM) && defined(CONFIG_ACPI)
611 	&dev_attr_d3cold_allowed.attr,
612 #endif
613 #ifdef CONFIG_OF
614 	&dev_attr_devspec.attr,
615 #endif
616 	&dev_attr_driver_override.attr,
617 	&dev_attr_ari_enabled.attr,
618 	NULL,
619 };
620 
621 static struct attribute *pci_bridge_attrs[] = {
622 	&dev_attr_subordinate_bus_number.attr,
623 	&dev_attr_secondary_bus_number.attr,
624 	NULL,
625 };
626 
627 static struct attribute *pcie_dev_attrs[] = {
628 	&dev_attr_current_link_speed.attr,
629 	&dev_attr_current_link_width.attr,
630 	&dev_attr_max_link_width.attr,
631 	&dev_attr_max_link_speed.attr,
632 	NULL,
633 };
634 
635 static struct attribute *pcibus_attrs[] = {
636 	&dev_attr_bus_rescan.attr,
637 	&dev_attr_cpuaffinity.attr,
638 	&dev_attr_cpulistaffinity.attr,
639 	NULL,
640 };
641 
642 static const struct attribute_group pcibus_group = {
643 	.attrs = pcibus_attrs,
644 };
645 
646 const struct attribute_group *pcibus_groups[] = {
647 	&pcibus_group,
648 	NULL,
649 };
650 
651 static ssize_t boot_vga_show(struct device *dev, struct device_attribute *attr,
652 			     char *buf)
653 {
654 	struct pci_dev *pdev = to_pci_dev(dev);
655 	struct pci_dev *vga_dev = vga_default_device();
656 
657 	if (vga_dev)
658 		return sysfs_emit(buf, "%u\n", (pdev == vga_dev));
659 
660 	return sysfs_emit(buf, "%u\n",
661 			  !!(pdev->resource[PCI_ROM_RESOURCE].flags &
662 			     IORESOURCE_ROM_SHADOW));
663 }
664 static DEVICE_ATTR_RO(boot_vga);
665 
666 static ssize_t pci_read_config(struct file *filp, struct kobject *kobj,
667 			       struct bin_attribute *bin_attr, char *buf,
668 			       loff_t off, size_t count)
669 {
670 	struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj));
671 	unsigned int size = 64;
672 	loff_t init_off = off;
673 	u8 *data = (u8 *) buf;
674 
675 	/* Several chips lock up trying to read undefined config space */
676 	if (file_ns_capable(filp, &init_user_ns, CAP_SYS_ADMIN))
677 		size = dev->cfg_size;
678 	else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
679 		size = 128;
680 
681 	if (off > size)
682 		return 0;
683 	if (off + count > size) {
684 		size -= off;
685 		count = size;
686 	} else {
687 		size = count;
688 	}
689 
690 	pci_config_pm_runtime_get(dev);
691 
692 	if ((off & 1) && size) {
693 		u8 val;
694 		pci_user_read_config_byte(dev, off, &val);
695 		data[off - init_off] = val;
696 		off++;
697 		size--;
698 	}
699 
700 	if ((off & 3) && size > 2) {
701 		u16 val;
702 		pci_user_read_config_word(dev, off, &val);
703 		data[off - init_off] = val & 0xff;
704 		data[off - init_off + 1] = (val >> 8) & 0xff;
705 		off += 2;
706 		size -= 2;
707 	}
708 
709 	while (size > 3) {
710 		u32 val;
711 		pci_user_read_config_dword(dev, off, &val);
712 		data[off - init_off] = val & 0xff;
713 		data[off - init_off + 1] = (val >> 8) & 0xff;
714 		data[off - init_off + 2] = (val >> 16) & 0xff;
715 		data[off - init_off + 3] = (val >> 24) & 0xff;
716 		off += 4;
717 		size -= 4;
718 		cond_resched();
719 	}
720 
721 	if (size >= 2) {
722 		u16 val;
723 		pci_user_read_config_word(dev, off, &val);
724 		data[off - init_off] = val & 0xff;
725 		data[off - init_off + 1] = (val >> 8) & 0xff;
726 		off += 2;
727 		size -= 2;
728 	}
729 
730 	if (size > 0) {
731 		u8 val;
732 		pci_user_read_config_byte(dev, off, &val);
733 		data[off - init_off] = val;
734 	}
735 
736 	pci_config_pm_runtime_put(dev);
737 
738 	return count;
739 }
740 
741 static ssize_t pci_write_config(struct file *filp, struct kobject *kobj,
742 				struct bin_attribute *bin_attr, char *buf,
743 				loff_t off, size_t count)
744 {
745 	struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj));
746 	unsigned int size = count;
747 	loff_t init_off = off;
748 	u8 *data = (u8 *) buf;
749 	int ret;
750 
751 	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
752 	if (ret)
753 		return ret;
754 
755 	if (resource_is_exclusive(&dev->driver_exclusive_resource, off,
756 				  count)) {
757 		pci_warn_once(dev, "%s: Unexpected write to kernel-exclusive config offset %llx",
758 			      current->comm, off);
759 		add_taint(TAINT_USER, LOCKDEP_STILL_OK);
760 	}
761 
762 	if (off > dev->cfg_size)
763 		return 0;
764 	if (off + count > dev->cfg_size) {
765 		size = dev->cfg_size - off;
766 		count = size;
767 	}
768 
769 	pci_config_pm_runtime_get(dev);
770 
771 	if ((off & 1) && size) {
772 		pci_user_write_config_byte(dev, off, data[off - init_off]);
773 		off++;
774 		size--;
775 	}
776 
777 	if ((off & 3) && size > 2) {
778 		u16 val = data[off - init_off];
779 		val |= (u16) data[off - init_off + 1] << 8;
780 		pci_user_write_config_word(dev, off, val);
781 		off += 2;
782 		size -= 2;
783 	}
784 
785 	while (size > 3) {
786 		u32 val = data[off - init_off];
787 		val |= (u32) data[off - init_off + 1] << 8;
788 		val |= (u32) data[off - init_off + 2] << 16;
789 		val |= (u32) data[off - init_off + 3] << 24;
790 		pci_user_write_config_dword(dev, off, val);
791 		off += 4;
792 		size -= 4;
793 	}
794 
795 	if (size >= 2) {
796 		u16 val = data[off - init_off];
797 		val |= (u16) data[off - init_off + 1] << 8;
798 		pci_user_write_config_word(dev, off, val);
799 		off += 2;
800 		size -= 2;
801 	}
802 
803 	if (size)
804 		pci_user_write_config_byte(dev, off, data[off - init_off]);
805 
806 	pci_config_pm_runtime_put(dev);
807 
808 	return count;
809 }
810 static BIN_ATTR(config, 0644, pci_read_config, pci_write_config, 0);
811 
812 static struct bin_attribute *pci_dev_config_attrs[] = {
813 	&bin_attr_config,
814 	NULL,
815 };
816 
817 static umode_t pci_dev_config_attr_is_visible(struct kobject *kobj,
818 					      struct bin_attribute *a, int n)
819 {
820 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
821 
822 	a->size = PCI_CFG_SPACE_SIZE;
823 	if (pdev->cfg_size > PCI_CFG_SPACE_SIZE)
824 		a->size = PCI_CFG_SPACE_EXP_SIZE;
825 
826 	return a->attr.mode;
827 }
828 
829 static const struct attribute_group pci_dev_config_attr_group = {
830 	.bin_attrs = pci_dev_config_attrs,
831 	.is_bin_visible = pci_dev_config_attr_is_visible,
832 };
833 
834 /*
835  * llseek operation for mmappable PCI resources.
836  * May be left unused if the arch doesn't provide them.
837  */
838 static __maybe_unused loff_t
839 pci_llseek_resource(struct file *filep,
840 		    struct kobject *kobj __always_unused,
841 		    struct bin_attribute *attr,
842 		    loff_t offset, int whence)
843 {
844 	return fixed_size_llseek(filep, offset, whence, attr->size);
845 }
846 
847 #ifdef HAVE_PCI_LEGACY
848 /**
849  * pci_read_legacy_io - read byte(s) from legacy I/O port space
850  * @filp: open sysfs file
851  * @kobj: kobject corresponding to file to read from
852  * @bin_attr: struct bin_attribute for this file
853  * @buf: buffer to store results
854  * @off: offset into legacy I/O port space
855  * @count: number of bytes to read
856  *
857  * Reads 1, 2, or 4 bytes from legacy I/O port space using an arch specific
858  * callback routine (pci_legacy_read).
859  */
860 static ssize_t pci_read_legacy_io(struct file *filp, struct kobject *kobj,
861 				  struct bin_attribute *bin_attr, char *buf,
862 				  loff_t off, size_t count)
863 {
864 	struct pci_bus *bus = to_pci_bus(kobj_to_dev(kobj));
865 
866 	/* Only support 1, 2 or 4 byte accesses */
867 	if (count != 1 && count != 2 && count != 4)
868 		return -EINVAL;
869 
870 	return pci_legacy_read(bus, off, (u32 *)buf, count);
871 }
872 
873 /**
874  * pci_write_legacy_io - write byte(s) to legacy I/O port space
875  * @filp: open sysfs file
876  * @kobj: kobject corresponding to file to read from
877  * @bin_attr: struct bin_attribute for this file
878  * @buf: buffer containing value to be written
879  * @off: offset into legacy I/O port space
880  * @count: number of bytes to write
881  *
882  * Writes 1, 2, or 4 bytes from legacy I/O port space using an arch specific
883  * callback routine (pci_legacy_write).
884  */
885 static ssize_t pci_write_legacy_io(struct file *filp, struct kobject *kobj,
886 				   struct bin_attribute *bin_attr, char *buf,
887 				   loff_t off, size_t count)
888 {
889 	struct pci_bus *bus = to_pci_bus(kobj_to_dev(kobj));
890 
891 	/* Only support 1, 2 or 4 byte accesses */
892 	if (count != 1 && count != 2 && count != 4)
893 		return -EINVAL;
894 
895 	return pci_legacy_write(bus, off, *(u32 *)buf, count);
896 }
897 
898 /**
899  * pci_mmap_legacy_mem - map legacy PCI memory into user memory space
900  * @filp: open sysfs file
901  * @kobj: kobject corresponding to device to be mapped
902  * @attr: struct bin_attribute for this file
903  * @vma: struct vm_area_struct passed to mmap
904  *
905  * Uses an arch specific callback, pci_mmap_legacy_mem_page_range, to mmap
906  * legacy memory space (first meg of bus space) into application virtual
907  * memory space.
908  */
909 static int pci_mmap_legacy_mem(struct file *filp, struct kobject *kobj,
910 			       struct bin_attribute *attr,
911 			       struct vm_area_struct *vma)
912 {
913 	struct pci_bus *bus = to_pci_bus(kobj_to_dev(kobj));
914 
915 	return pci_mmap_legacy_page_range(bus, vma, pci_mmap_mem);
916 }
917 
918 /**
919  * pci_mmap_legacy_io - map legacy PCI IO into user memory space
920  * @filp: open sysfs file
921  * @kobj: kobject corresponding to device to be mapped
922  * @attr: struct bin_attribute for this file
923  * @vma: struct vm_area_struct passed to mmap
924  *
925  * Uses an arch specific callback, pci_mmap_legacy_io_page_range, to mmap
926  * legacy IO space (first meg of bus space) into application virtual
927  * memory space. Returns -ENOSYS if the operation isn't supported
928  */
929 static int pci_mmap_legacy_io(struct file *filp, struct kobject *kobj,
930 			      struct bin_attribute *attr,
931 			      struct vm_area_struct *vma)
932 {
933 	struct pci_bus *bus = to_pci_bus(kobj_to_dev(kobj));
934 
935 	return pci_mmap_legacy_page_range(bus, vma, pci_mmap_io);
936 }
937 
938 /**
939  * pci_adjust_legacy_attr - adjustment of legacy file attributes
940  * @b: bus to create files under
941  * @mmap_type: I/O port or memory
942  *
943  * Stub implementation. Can be overridden by arch if necessary.
944  */
945 void __weak pci_adjust_legacy_attr(struct pci_bus *b,
946 				   enum pci_mmap_state mmap_type)
947 {
948 }
949 
950 /**
951  * pci_create_legacy_files - create legacy I/O port and memory files
952  * @b: bus to create files under
953  *
954  * Some platforms allow access to legacy I/O port and ISA memory space on
955  * a per-bus basis.  This routine creates the files and ties them into
956  * their associated read, write and mmap files from pci-sysfs.c
957  *
958  * On error unwind, but don't propagate the error to the caller
959  * as it is ok to set up the PCI bus without these files.
960  */
961 void pci_create_legacy_files(struct pci_bus *b)
962 {
963 	int error;
964 
965 	if (!sysfs_initialized)
966 		return;
967 
968 	b->legacy_io = kcalloc(2, sizeof(struct bin_attribute),
969 			       GFP_ATOMIC);
970 	if (!b->legacy_io)
971 		goto kzalloc_err;
972 
973 	sysfs_bin_attr_init(b->legacy_io);
974 	b->legacy_io->attr.name = "legacy_io";
975 	b->legacy_io->size = 0xffff;
976 	b->legacy_io->attr.mode = 0600;
977 	b->legacy_io->read = pci_read_legacy_io;
978 	b->legacy_io->write = pci_write_legacy_io;
979 	/* See pci_create_attr() for motivation */
980 	b->legacy_io->llseek = pci_llseek_resource;
981 	b->legacy_io->mmap = pci_mmap_legacy_io;
982 	b->legacy_io->f_mapping = iomem_get_mapping;
983 	pci_adjust_legacy_attr(b, pci_mmap_io);
984 	error = device_create_bin_file(&b->dev, b->legacy_io);
985 	if (error)
986 		goto legacy_io_err;
987 
988 	/* Allocated above after the legacy_io struct */
989 	b->legacy_mem = b->legacy_io + 1;
990 	sysfs_bin_attr_init(b->legacy_mem);
991 	b->legacy_mem->attr.name = "legacy_mem";
992 	b->legacy_mem->size = 1024*1024;
993 	b->legacy_mem->attr.mode = 0600;
994 	b->legacy_mem->mmap = pci_mmap_legacy_mem;
995 	/* See pci_create_attr() for motivation */
996 	b->legacy_mem->llseek = pci_llseek_resource;
997 	b->legacy_mem->f_mapping = iomem_get_mapping;
998 	pci_adjust_legacy_attr(b, pci_mmap_mem);
999 	error = device_create_bin_file(&b->dev, b->legacy_mem);
1000 	if (error)
1001 		goto legacy_mem_err;
1002 
1003 	return;
1004 
1005 legacy_mem_err:
1006 	device_remove_bin_file(&b->dev, b->legacy_io);
1007 legacy_io_err:
1008 	kfree(b->legacy_io);
1009 	b->legacy_io = NULL;
1010 kzalloc_err:
1011 	dev_warn(&b->dev, "could not create legacy I/O port and ISA memory resources in sysfs\n");
1012 }
1013 
1014 void pci_remove_legacy_files(struct pci_bus *b)
1015 {
1016 	if (b->legacy_io) {
1017 		device_remove_bin_file(&b->dev, b->legacy_io);
1018 		device_remove_bin_file(&b->dev, b->legacy_mem);
1019 		kfree(b->legacy_io); /* both are allocated here */
1020 	}
1021 }
1022 #endif /* HAVE_PCI_LEGACY */
1023 
1024 #if defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)
1025 
1026 int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
1027 		  enum pci_mmap_api mmap_api)
1028 {
1029 	unsigned long nr, start, size;
1030 	resource_size_t pci_start = 0, pci_end;
1031 
1032 	if (pci_resource_len(pdev, resno) == 0)
1033 		return 0;
1034 	nr = vma_pages(vma);
1035 	start = vma->vm_pgoff;
1036 	size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
1037 	if (mmap_api == PCI_MMAP_PROCFS) {
1038 		pci_resource_to_user(pdev, resno, &pdev->resource[resno],
1039 				     &pci_start, &pci_end);
1040 		pci_start >>= PAGE_SHIFT;
1041 	}
1042 	if (start >= pci_start && start < pci_start + size &&
1043 			start + nr <= pci_start + size)
1044 		return 1;
1045 	return 0;
1046 }
1047 
1048 /**
1049  * pci_mmap_resource - map a PCI resource into user memory space
1050  * @kobj: kobject for mapping
1051  * @attr: struct bin_attribute for the file being mapped
1052  * @vma: struct vm_area_struct passed into the mmap
1053  * @write_combine: 1 for write_combine mapping
1054  *
1055  * Use the regular PCI mapping routines to map a PCI resource into userspace.
1056  */
1057 static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
1058 			     struct vm_area_struct *vma, int write_combine)
1059 {
1060 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
1061 	int bar = (unsigned long)attr->private;
1062 	enum pci_mmap_state mmap_type;
1063 	struct resource *res = &pdev->resource[bar];
1064 	int ret;
1065 
1066 	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
1067 	if (ret)
1068 		return ret;
1069 
1070 	if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))
1071 		return -EINVAL;
1072 
1073 	if (!pci_mmap_fits(pdev, bar, vma, PCI_MMAP_SYSFS))
1074 		return -EINVAL;
1075 
1076 	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
1077 
1078 	return pci_mmap_resource_range(pdev, bar, vma, mmap_type, write_combine);
1079 }
1080 
1081 static int pci_mmap_resource_uc(struct file *filp, struct kobject *kobj,
1082 				struct bin_attribute *attr,
1083 				struct vm_area_struct *vma)
1084 {
1085 	return pci_mmap_resource(kobj, attr, vma, 0);
1086 }
1087 
1088 static int pci_mmap_resource_wc(struct file *filp, struct kobject *kobj,
1089 				struct bin_attribute *attr,
1090 				struct vm_area_struct *vma)
1091 {
1092 	return pci_mmap_resource(kobj, attr, vma, 1);
1093 }
1094 
1095 static ssize_t pci_resource_io(struct file *filp, struct kobject *kobj,
1096 			       struct bin_attribute *attr, char *buf,
1097 			       loff_t off, size_t count, bool write)
1098 {
1099 #ifdef CONFIG_HAS_IOPORT
1100 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
1101 	int bar = (unsigned long)attr->private;
1102 	unsigned long port = off;
1103 
1104 	port += pci_resource_start(pdev, bar);
1105 
1106 	if (port > pci_resource_end(pdev, bar))
1107 		return 0;
1108 
1109 	if (port + count - 1 > pci_resource_end(pdev, bar))
1110 		return -EINVAL;
1111 
1112 	switch (count) {
1113 	case 1:
1114 		if (write)
1115 			outb(*(u8 *)buf, port);
1116 		else
1117 			*(u8 *)buf = inb(port);
1118 		return 1;
1119 	case 2:
1120 		if (write)
1121 			outw(*(u16 *)buf, port);
1122 		else
1123 			*(u16 *)buf = inw(port);
1124 		return 2;
1125 	case 4:
1126 		if (write)
1127 			outl(*(u32 *)buf, port);
1128 		else
1129 			*(u32 *)buf = inl(port);
1130 		return 4;
1131 	}
1132 	return -EINVAL;
1133 #else
1134 	return -ENXIO;
1135 #endif
1136 }
1137 
1138 static ssize_t pci_read_resource_io(struct file *filp, struct kobject *kobj,
1139 				    struct bin_attribute *attr, char *buf,
1140 				    loff_t off, size_t count)
1141 {
1142 	return pci_resource_io(filp, kobj, attr, buf, off, count, false);
1143 }
1144 
1145 static ssize_t pci_write_resource_io(struct file *filp, struct kobject *kobj,
1146 				     struct bin_attribute *attr, char *buf,
1147 				     loff_t off, size_t count)
1148 {
1149 	int ret;
1150 
1151 	ret = security_locked_down(LOCKDOWN_PCI_ACCESS);
1152 	if (ret)
1153 		return ret;
1154 
1155 	return pci_resource_io(filp, kobj, attr, buf, off, count, true);
1156 }
1157 
1158 /**
1159  * pci_remove_resource_files - cleanup resource files
1160  * @pdev: dev to cleanup
1161  *
1162  * If we created resource files for @pdev, remove them from sysfs and
1163  * free their resources.
1164  */
1165 static void pci_remove_resource_files(struct pci_dev *pdev)
1166 {
1167 	int i;
1168 
1169 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
1170 		struct bin_attribute *res_attr;
1171 
1172 		res_attr = pdev->res_attr[i];
1173 		if (res_attr) {
1174 			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
1175 			kfree(res_attr);
1176 		}
1177 
1178 		res_attr = pdev->res_attr_wc[i];
1179 		if (res_attr) {
1180 			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
1181 			kfree(res_attr);
1182 		}
1183 	}
1184 }
1185 
1186 static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine)
1187 {
1188 	/* allocate attribute structure, piggyback attribute name */
1189 	int name_len = write_combine ? 13 : 10;
1190 	struct bin_attribute *res_attr;
1191 	char *res_attr_name;
1192 	int retval;
1193 
1194 	res_attr = kzalloc(sizeof(*res_attr) + name_len, GFP_ATOMIC);
1195 	if (!res_attr)
1196 		return -ENOMEM;
1197 
1198 	res_attr_name = (char *)(res_attr + 1);
1199 
1200 	sysfs_bin_attr_init(res_attr);
1201 	if (write_combine) {
1202 		sprintf(res_attr_name, "resource%d_wc", num);
1203 		res_attr->mmap = pci_mmap_resource_wc;
1204 	} else {
1205 		sprintf(res_attr_name, "resource%d", num);
1206 		if (pci_resource_flags(pdev, num) & IORESOURCE_IO) {
1207 			res_attr->read = pci_read_resource_io;
1208 			res_attr->write = pci_write_resource_io;
1209 			if (arch_can_pci_mmap_io())
1210 				res_attr->mmap = pci_mmap_resource_uc;
1211 		} else {
1212 			res_attr->mmap = pci_mmap_resource_uc;
1213 		}
1214 	}
1215 	if (res_attr->mmap) {
1216 		res_attr->f_mapping = iomem_get_mapping;
1217 		/*
1218 		 * generic_file_llseek() consults f_mapping->host to determine
1219 		 * the file size. As iomem_inode knows nothing about the
1220 		 * attribute, it's not going to work, so override it as well.
1221 		 */
1222 		res_attr->llseek = pci_llseek_resource;
1223 	}
1224 	res_attr->attr.name = res_attr_name;
1225 	res_attr->attr.mode = 0600;
1226 	res_attr->size = pci_resource_len(pdev, num);
1227 	res_attr->private = (void *)(unsigned long)num;
1228 	retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
1229 	if (retval) {
1230 		kfree(res_attr);
1231 		return retval;
1232 	}
1233 
1234 	if (write_combine)
1235 		pdev->res_attr_wc[num] = res_attr;
1236 	else
1237 		pdev->res_attr[num] = res_attr;
1238 
1239 	return 0;
1240 }
1241 
1242 /**
1243  * pci_create_resource_files - create resource files in sysfs for @dev
1244  * @pdev: dev in question
1245  *
1246  * Walk the resources in @pdev creating files for each resource available.
1247  */
1248 static int pci_create_resource_files(struct pci_dev *pdev)
1249 {
1250 	int i;
1251 	int retval;
1252 
1253 	/* Expose the PCI resources from this device as files */
1254 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
1255 
1256 		/* skip empty resources */
1257 		if (!pci_resource_len(pdev, i))
1258 			continue;
1259 
1260 		retval = pci_create_attr(pdev, i, 0);
1261 		/* for prefetchable resources, create a WC mappable file */
1262 		if (!retval && arch_can_pci_mmap_wc() &&
1263 		    pdev->resource[i].flags & IORESOURCE_PREFETCH)
1264 			retval = pci_create_attr(pdev, i, 1);
1265 		if (retval) {
1266 			pci_remove_resource_files(pdev);
1267 			return retval;
1268 		}
1269 	}
1270 	return 0;
1271 }
1272 #else /* !(defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE)) */
1273 int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
1274 void __weak pci_remove_resource_files(struct pci_dev *dev) { return; }
1275 #endif
1276 
1277 /**
1278  * pci_write_rom - used to enable access to the PCI ROM display
1279  * @filp: sysfs file
1280  * @kobj: kernel object handle
1281  * @bin_attr: struct bin_attribute for this file
1282  * @buf: user input
1283  * @off: file offset
1284  * @count: number of byte in input
1285  *
1286  * writing anything except 0 enables it
1287  */
1288 static ssize_t pci_write_rom(struct file *filp, struct kobject *kobj,
1289 			     struct bin_attribute *bin_attr, char *buf,
1290 			     loff_t off, size_t count)
1291 {
1292 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
1293 
1294 	if ((off ==  0) && (*buf == '0') && (count == 2))
1295 		pdev->rom_attr_enabled = 0;
1296 	else
1297 		pdev->rom_attr_enabled = 1;
1298 
1299 	return count;
1300 }
1301 
1302 /**
1303  * pci_read_rom - read a PCI ROM
1304  * @filp: sysfs file
1305  * @kobj: kernel object handle
1306  * @bin_attr: struct bin_attribute for this file
1307  * @buf: where to put the data we read from the ROM
1308  * @off: file offset
1309  * @count: number of bytes to read
1310  *
1311  * Put @count bytes starting at @off into @buf from the ROM in the PCI
1312  * device corresponding to @kobj.
1313  */
1314 static ssize_t pci_read_rom(struct file *filp, struct kobject *kobj,
1315 			    struct bin_attribute *bin_attr, char *buf,
1316 			    loff_t off, size_t count)
1317 {
1318 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
1319 	void __iomem *rom;
1320 	size_t size;
1321 
1322 	if (!pdev->rom_attr_enabled)
1323 		return -EINVAL;
1324 
1325 	rom = pci_map_rom(pdev, &size);	/* size starts out as PCI window size */
1326 	if (!rom || !size)
1327 		return -EIO;
1328 
1329 	if (off >= size)
1330 		count = 0;
1331 	else {
1332 		if (off + count > size)
1333 			count = size - off;
1334 
1335 		memcpy_fromio(buf, rom + off, count);
1336 	}
1337 	pci_unmap_rom(pdev, rom);
1338 
1339 	return count;
1340 }
1341 static BIN_ATTR(rom, 0600, pci_read_rom, pci_write_rom, 0);
1342 
1343 static struct bin_attribute *pci_dev_rom_attrs[] = {
1344 	&bin_attr_rom,
1345 	NULL,
1346 };
1347 
1348 static umode_t pci_dev_rom_attr_is_visible(struct kobject *kobj,
1349 					   struct bin_attribute *a, int n)
1350 {
1351 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
1352 	size_t rom_size;
1353 
1354 	/* If the device has a ROM, try to expose it in sysfs. */
1355 	rom_size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
1356 	if (!rom_size)
1357 		return 0;
1358 
1359 	a->size = rom_size;
1360 
1361 	return a->attr.mode;
1362 }
1363 
1364 static const struct attribute_group pci_dev_rom_attr_group = {
1365 	.bin_attrs = pci_dev_rom_attrs,
1366 	.is_bin_visible = pci_dev_rom_attr_is_visible,
1367 };
1368 
1369 static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
1370 			   const char *buf, size_t count)
1371 {
1372 	struct pci_dev *pdev = to_pci_dev(dev);
1373 	unsigned long val;
1374 	ssize_t result;
1375 
1376 	if (kstrtoul(buf, 0, &val) < 0)
1377 		return -EINVAL;
1378 
1379 	if (val != 1)
1380 		return -EINVAL;
1381 
1382 	pm_runtime_get_sync(dev);
1383 	result = pci_reset_function(pdev);
1384 	pm_runtime_put(dev);
1385 	if (result < 0)
1386 		return result;
1387 
1388 	return count;
1389 }
1390 static DEVICE_ATTR_WO(reset);
1391 
1392 static struct attribute *pci_dev_reset_attrs[] = {
1393 	&dev_attr_reset.attr,
1394 	NULL,
1395 };
1396 
1397 static umode_t pci_dev_reset_attr_is_visible(struct kobject *kobj,
1398 					     struct attribute *a, int n)
1399 {
1400 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
1401 
1402 	if (!pci_reset_supported(pdev))
1403 		return 0;
1404 
1405 	return a->mode;
1406 }
1407 
1408 static const struct attribute_group pci_dev_reset_attr_group = {
1409 	.attrs = pci_dev_reset_attrs,
1410 	.is_visible = pci_dev_reset_attr_is_visible,
1411 };
1412 
1413 #define pci_dev_resource_resize_attr(n)					\
1414 static ssize_t resource##n##_resize_show(struct device *dev,		\
1415 					 struct device_attribute *attr,	\
1416 					 char * buf)			\
1417 {									\
1418 	struct pci_dev *pdev = to_pci_dev(dev);				\
1419 	ssize_t ret;							\
1420 									\
1421 	pci_config_pm_runtime_get(pdev);				\
1422 									\
1423 	ret = sysfs_emit(buf, "%016llx\n",				\
1424 			 (u64)pci_rebar_get_possible_sizes(pdev, n));	\
1425 									\
1426 	pci_config_pm_runtime_put(pdev);				\
1427 									\
1428 	return ret;							\
1429 }									\
1430 									\
1431 static ssize_t resource##n##_resize_store(struct device *dev,		\
1432 					  struct device_attribute *attr,\
1433 					  const char *buf, size_t count)\
1434 {									\
1435 	struct pci_dev *pdev = to_pci_dev(dev);				\
1436 	unsigned long size, flags;					\
1437 	int ret, i;							\
1438 	u16 cmd;							\
1439 									\
1440 	if (kstrtoul(buf, 0, &size) < 0)				\
1441 		return -EINVAL;						\
1442 									\
1443 	device_lock(dev);						\
1444 	if (dev->driver) {						\
1445 		ret = -EBUSY;						\
1446 		goto unlock;						\
1447 	}								\
1448 									\
1449 	pci_config_pm_runtime_get(pdev);				\
1450 									\
1451 	if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA) {		\
1452 		ret = aperture_remove_conflicting_pci_devices(pdev,	\
1453 						"resourceN_resize");	\
1454 		if (ret)						\
1455 			goto pm_put;					\
1456 	}								\
1457 									\
1458 	pci_read_config_word(pdev, PCI_COMMAND, &cmd);			\
1459 	pci_write_config_word(pdev, PCI_COMMAND,			\
1460 			      cmd & ~PCI_COMMAND_MEMORY);		\
1461 									\
1462 	flags = pci_resource_flags(pdev, n);				\
1463 									\
1464 	pci_remove_resource_files(pdev);				\
1465 									\
1466 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {			\
1467 		if (pci_resource_len(pdev, i) &&			\
1468 		    pci_resource_flags(pdev, i) == flags)		\
1469 			pci_release_resource(pdev, i);			\
1470 	}								\
1471 									\
1472 	ret = pci_resize_resource(pdev, n, size);			\
1473 									\
1474 	pci_assign_unassigned_bus_resources(pdev->bus);			\
1475 									\
1476 	if (pci_create_resource_files(pdev))				\
1477 		pci_warn(pdev, "Failed to recreate resource files after BAR resizing\n");\
1478 									\
1479 	pci_write_config_word(pdev, PCI_COMMAND, cmd);			\
1480 pm_put:									\
1481 	pci_config_pm_runtime_put(pdev);				\
1482 unlock:									\
1483 	device_unlock(dev);						\
1484 									\
1485 	return ret ? ret : count;					\
1486 }									\
1487 static DEVICE_ATTR_RW(resource##n##_resize)
1488 
1489 pci_dev_resource_resize_attr(0);
1490 pci_dev_resource_resize_attr(1);
1491 pci_dev_resource_resize_attr(2);
1492 pci_dev_resource_resize_attr(3);
1493 pci_dev_resource_resize_attr(4);
1494 pci_dev_resource_resize_attr(5);
1495 
1496 static struct attribute *resource_resize_attrs[] = {
1497 	&dev_attr_resource0_resize.attr,
1498 	&dev_attr_resource1_resize.attr,
1499 	&dev_attr_resource2_resize.attr,
1500 	&dev_attr_resource3_resize.attr,
1501 	&dev_attr_resource4_resize.attr,
1502 	&dev_attr_resource5_resize.attr,
1503 	NULL,
1504 };
1505 
1506 static umode_t resource_resize_is_visible(struct kobject *kobj,
1507 					  struct attribute *a, int n)
1508 {
1509 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
1510 
1511 	return pci_rebar_get_current_size(pdev, n) < 0 ? 0 : a->mode;
1512 }
1513 
1514 static const struct attribute_group pci_dev_resource_resize_group = {
1515 	.attrs = resource_resize_attrs,
1516 	.is_visible = resource_resize_is_visible,
1517 };
1518 
1519 int __must_check pci_create_sysfs_dev_files(struct pci_dev *pdev)
1520 {
1521 	if (!sysfs_initialized)
1522 		return -EACCES;
1523 
1524 	return pci_create_resource_files(pdev);
1525 }
1526 
1527 /**
1528  * pci_remove_sysfs_dev_files - cleanup PCI specific sysfs files
1529  * @pdev: device whose entries we should free
1530  *
1531  * Cleanup when @pdev is removed from sysfs.
1532  */
1533 void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
1534 {
1535 	if (!sysfs_initialized)
1536 		return;
1537 
1538 	pci_remove_resource_files(pdev);
1539 }
1540 
1541 static int __init pci_sysfs_init(void)
1542 {
1543 	struct pci_dev *pdev = NULL;
1544 	struct pci_bus *pbus = NULL;
1545 	int retval;
1546 
1547 	sysfs_initialized = 1;
1548 	for_each_pci_dev(pdev) {
1549 		retval = pci_create_sysfs_dev_files(pdev);
1550 		if (retval) {
1551 			pci_dev_put(pdev);
1552 			return retval;
1553 		}
1554 	}
1555 
1556 	while ((pbus = pci_find_next_bus(pbus)))
1557 		pci_create_legacy_files(pbus);
1558 
1559 	return 0;
1560 }
1561 late_initcall(pci_sysfs_init);
1562 
1563 static struct attribute *pci_dev_dev_attrs[] = {
1564 	&dev_attr_boot_vga.attr,
1565 	NULL,
1566 };
1567 
1568 static umode_t pci_dev_attrs_are_visible(struct kobject *kobj,
1569 					 struct attribute *a, int n)
1570 {
1571 	struct device *dev = kobj_to_dev(kobj);
1572 	struct pci_dev *pdev = to_pci_dev(dev);
1573 
1574 	if (a == &dev_attr_boot_vga.attr && pci_is_vga(pdev))
1575 		return a->mode;
1576 
1577 	return 0;
1578 }
1579 
1580 static struct attribute *pci_dev_hp_attrs[] = {
1581 	&dev_attr_remove.attr,
1582 	&dev_attr_dev_rescan.attr,
1583 	NULL,
1584 };
1585 
1586 static umode_t pci_dev_hp_attrs_are_visible(struct kobject *kobj,
1587 					    struct attribute *a, int n)
1588 {
1589 	struct device *dev = kobj_to_dev(kobj);
1590 	struct pci_dev *pdev = to_pci_dev(dev);
1591 
1592 	if (pdev->is_virtfn)
1593 		return 0;
1594 
1595 	return a->mode;
1596 }
1597 
1598 static umode_t pci_bridge_attrs_are_visible(struct kobject *kobj,
1599 					    struct attribute *a, int n)
1600 {
1601 	struct device *dev = kobj_to_dev(kobj);
1602 	struct pci_dev *pdev = to_pci_dev(dev);
1603 
1604 	if (pci_is_bridge(pdev))
1605 		return a->mode;
1606 
1607 	return 0;
1608 }
1609 
1610 static umode_t pcie_dev_attrs_are_visible(struct kobject *kobj,
1611 					  struct attribute *a, int n)
1612 {
1613 	struct device *dev = kobj_to_dev(kobj);
1614 	struct pci_dev *pdev = to_pci_dev(dev);
1615 
1616 	if (pci_is_pcie(pdev))
1617 		return a->mode;
1618 
1619 	return 0;
1620 }
1621 
1622 static const struct attribute_group pci_dev_group = {
1623 	.attrs = pci_dev_attrs,
1624 };
1625 
1626 const struct attribute_group *pci_dev_groups[] = {
1627 	&pci_dev_group,
1628 	&pci_dev_config_attr_group,
1629 	&pci_dev_rom_attr_group,
1630 	&pci_dev_reset_attr_group,
1631 	&pci_dev_reset_method_attr_group,
1632 	&pci_dev_vpd_attr_group,
1633 #ifdef CONFIG_DMI
1634 	&pci_dev_smbios_attr_group,
1635 #endif
1636 #ifdef CONFIG_ACPI
1637 	&pci_dev_acpi_attr_group,
1638 #endif
1639 	&pci_dev_resource_resize_group,
1640 	NULL,
1641 };
1642 
1643 static const struct attribute_group pci_dev_hp_attr_group = {
1644 	.attrs = pci_dev_hp_attrs,
1645 	.is_visible = pci_dev_hp_attrs_are_visible,
1646 };
1647 
1648 static const struct attribute_group pci_dev_attr_group = {
1649 	.attrs = pci_dev_dev_attrs,
1650 	.is_visible = pci_dev_attrs_are_visible,
1651 };
1652 
1653 static const struct attribute_group pci_bridge_attr_group = {
1654 	.attrs = pci_bridge_attrs,
1655 	.is_visible = pci_bridge_attrs_are_visible,
1656 };
1657 
1658 static const struct attribute_group pcie_dev_attr_group = {
1659 	.attrs = pcie_dev_attrs,
1660 	.is_visible = pcie_dev_attrs_are_visible,
1661 };
1662 
1663 static const struct attribute_group *pci_dev_attr_groups[] = {
1664 	&pci_dev_attr_group,
1665 	&pci_dev_hp_attr_group,
1666 #ifdef CONFIG_PCI_IOV
1667 	&sriov_pf_dev_attr_group,
1668 	&sriov_vf_dev_attr_group,
1669 #endif
1670 	&pci_bridge_attr_group,
1671 	&pcie_dev_attr_group,
1672 #ifdef CONFIG_PCIEAER
1673 	&aer_stats_attr_group,
1674 #endif
1675 #ifdef CONFIG_PCIEASPM
1676 	&aspm_ctrl_attr_group,
1677 #endif
1678 	NULL,
1679 };
1680 
1681 const struct device_type pci_dev_type = {
1682 	.groups = pci_dev_attr_groups,
1683 };
1684