xref: /openbmc/linux/drivers/pci/pci-sysfs.c (revision 384740dc)
1 /*
2  * drivers/pci/pci-sysfs.c
3  *
4  * (C) Copyright 2002-2004 Greg Kroah-Hartman <greg@kroah.com>
5  * (C) Copyright 2002-2004 IBM Corp.
6  * (C) Copyright 2003 Matthew Wilcox
7  * (C) Copyright 2003 Hewlett-Packard
8  * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
9  * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
10  *
11  * File attributes for PCI devices
12  *
13  * Modeled after usb's driverfs.c
14  *
15  */
16 
17 
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/pci.h>
21 #include <linux/stat.h>
22 #include <linux/topology.h>
23 #include <linux/mm.h>
24 #include <linux/capability.h>
25 #include <linux/pci-aspm.h>
26 #include "pci.h"
27 
28 static int sysfs_initialized;	/* = 0 */
29 
30 /* show configuration fields */
31 #define pci_config_attr(field, format_string)				\
32 static ssize_t								\
33 field##_show(struct device *dev, struct device_attribute *attr, char *buf)				\
34 {									\
35 	struct pci_dev *pdev;						\
36 									\
37 	pdev = to_pci_dev (dev);					\
38 	return sprintf (buf, format_string, pdev->field);		\
39 }
40 
41 pci_config_attr(vendor, "0x%04x\n");
42 pci_config_attr(device, "0x%04x\n");
43 pci_config_attr(subsystem_vendor, "0x%04x\n");
44 pci_config_attr(subsystem_device, "0x%04x\n");
45 pci_config_attr(class, "0x%06x\n");
46 pci_config_attr(irq, "%u\n");
47 
48 static ssize_t broken_parity_status_show(struct device *dev,
49 					 struct device_attribute *attr,
50 					 char *buf)
51 {
52 	struct pci_dev *pdev = to_pci_dev(dev);
53 	return sprintf (buf, "%u\n", pdev->broken_parity_status);
54 }
55 
56 static ssize_t broken_parity_status_store(struct device *dev,
57 					  struct device_attribute *attr,
58 					  const char *buf, size_t count)
59 {
60 	struct pci_dev *pdev = to_pci_dev(dev);
61 	ssize_t consumed = -EINVAL;
62 
63 	if ((count > 0) && (*buf == '0' || *buf == '1')) {
64 		pdev->broken_parity_status = *buf == '1' ? 1 : 0;
65 		consumed = count;
66 	}
67 	return consumed;
68 }
69 
70 static ssize_t local_cpus_show(struct device *dev,
71 			struct device_attribute *attr, char *buf)
72 {
73 	cpumask_t mask;
74 	int len;
75 
76 	mask = pcibus_to_cpumask(to_pci_dev(dev)->bus);
77 	len = cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
78 	buf[len++] = '\n';
79 	buf[len] = '\0';
80 	return len;
81 }
82 
83 
84 static ssize_t local_cpulist_show(struct device *dev,
85 			struct device_attribute *attr, char *buf)
86 {
87 	cpumask_t mask;
88 	int len;
89 
90 	mask = pcibus_to_cpumask(to_pci_dev(dev)->bus);
91 	len = cpulist_scnprintf(buf, PAGE_SIZE-2, mask);
92 	buf[len++] = '\n';
93 	buf[len] = '\0';
94 	return len;
95 }
96 
97 /* show resources */
98 static ssize_t
99 resource_show(struct device * dev, struct device_attribute *attr, char * buf)
100 {
101 	struct pci_dev * pci_dev = to_pci_dev(dev);
102 	char * str = buf;
103 	int i;
104 	int max = 7;
105 	resource_size_t start, end;
106 
107 	if (pci_dev->subordinate)
108 		max = DEVICE_COUNT_RESOURCE;
109 
110 	for (i = 0; i < max; i++) {
111 		struct resource *res =  &pci_dev->resource[i];
112 		pci_resource_to_user(pci_dev, i, res, &start, &end);
113 		str += sprintf(str,"0x%016llx 0x%016llx 0x%016llx\n",
114 			       (unsigned long long)start,
115 			       (unsigned long long)end,
116 			       (unsigned long long)res->flags);
117 	}
118 	return (str - buf);
119 }
120 
121 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
122 {
123 	struct pci_dev *pci_dev = to_pci_dev(dev);
124 
125 	return sprintf(buf, "pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02x\n",
126 		       pci_dev->vendor, pci_dev->device,
127 		       pci_dev->subsystem_vendor, pci_dev->subsystem_device,
128 		       (u8)(pci_dev->class >> 16), (u8)(pci_dev->class >> 8),
129 		       (u8)(pci_dev->class));
130 }
131 
132 static ssize_t is_enabled_store(struct device *dev,
133 				struct device_attribute *attr, const char *buf,
134 				size_t count)
135 {
136 	ssize_t result = -EINVAL;
137 	struct pci_dev *pdev = to_pci_dev(dev);
138 
139 	/* this can crash the machine when done on the "wrong" device */
140 	if (!capable(CAP_SYS_ADMIN))
141 		return count;
142 
143 	if (*buf == '0') {
144 		if (atomic_read(&pdev->enable_cnt) != 0)
145 			pci_disable_device(pdev);
146 		else
147 			result = -EIO;
148 	} else if (*buf == '1')
149 		result = pci_enable_device(pdev);
150 
151 	return result < 0 ? result : count;
152 }
153 
154 static ssize_t is_enabled_show(struct device *dev,
155 			       struct device_attribute *attr, char *buf)
156 {
157 	struct pci_dev *pdev;
158 
159 	pdev = to_pci_dev (dev);
160 	return sprintf (buf, "%u\n", atomic_read(&pdev->enable_cnt));
161 }
162 
163 #ifdef CONFIG_NUMA
164 static ssize_t
165 numa_node_show(struct device *dev, struct device_attribute *attr, char *buf)
166 {
167 	return sprintf (buf, "%d\n", dev->numa_node);
168 }
169 #endif
170 
171 static ssize_t
172 msi_bus_show(struct device *dev, struct device_attribute *attr, char *buf)
173 {
174 	struct pci_dev *pdev = to_pci_dev(dev);
175 
176 	if (!pdev->subordinate)
177 		return 0;
178 
179 	return sprintf (buf, "%u\n",
180 			!(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI));
181 }
182 
183 static ssize_t
184 msi_bus_store(struct device *dev, struct device_attribute *attr,
185 	      const char *buf, size_t count)
186 {
187 	struct pci_dev *pdev = to_pci_dev(dev);
188 
189 	/* bad things may happen if the no_msi flag is changed
190 	 * while some drivers are loaded */
191 	if (!capable(CAP_SYS_ADMIN))
192 		return count;
193 
194 	if (!pdev->subordinate)
195 		return count;
196 
197 	if (*buf == '0') {
198 		pdev->subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
199 		dev_warn(&pdev->dev, "forced subordinate bus to not support MSI,"
200 			 " bad things could happen.\n");
201 	}
202 
203 	if (*buf == '1') {
204 		pdev->subordinate->bus_flags &= ~PCI_BUS_FLAGS_NO_MSI;
205 		dev_warn(&pdev->dev, "forced subordinate bus to support MSI,"
206 			 " bad things could happen.\n");
207 	}
208 
209 	return count;
210 }
211 
212 struct device_attribute pci_dev_attrs[] = {
213 	__ATTR_RO(resource),
214 	__ATTR_RO(vendor),
215 	__ATTR_RO(device),
216 	__ATTR_RO(subsystem_vendor),
217 	__ATTR_RO(subsystem_device),
218 	__ATTR_RO(class),
219 	__ATTR_RO(irq),
220 	__ATTR_RO(local_cpus),
221 	__ATTR_RO(local_cpulist),
222 	__ATTR_RO(modalias),
223 #ifdef CONFIG_NUMA
224 	__ATTR_RO(numa_node),
225 #endif
226 	__ATTR(enable, 0600, is_enabled_show, is_enabled_store),
227 	__ATTR(broken_parity_status,(S_IRUGO|S_IWUSR),
228 		broken_parity_status_show,broken_parity_status_store),
229 	__ATTR(msi_bus, 0644, msi_bus_show, msi_bus_store),
230 	__ATTR_NULL,
231 };
232 
233 static ssize_t
234 pci_read_config(struct kobject *kobj, struct bin_attribute *bin_attr,
235 		char *buf, loff_t off, size_t count)
236 {
237 	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
238 	unsigned int size = 64;
239 	loff_t init_off = off;
240 	u8 *data = (u8*) buf;
241 
242 	/* Several chips lock up trying to read undefined config space */
243 	if (capable(CAP_SYS_ADMIN)) {
244 		size = dev->cfg_size;
245 	} else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
246 		size = 128;
247 	}
248 
249 	if (off > size)
250 		return 0;
251 	if (off + count > size) {
252 		size -= off;
253 		count = size;
254 	} else {
255 		size = count;
256 	}
257 
258 	if ((off & 1) && size) {
259 		u8 val;
260 		pci_user_read_config_byte(dev, off, &val);
261 		data[off - init_off] = val;
262 		off++;
263 		size--;
264 	}
265 
266 	if ((off & 3) && size > 2) {
267 		u16 val;
268 		pci_user_read_config_word(dev, off, &val);
269 		data[off - init_off] = val & 0xff;
270 		data[off - init_off + 1] = (val >> 8) & 0xff;
271 		off += 2;
272 		size -= 2;
273 	}
274 
275 	while (size > 3) {
276 		u32 val;
277 		pci_user_read_config_dword(dev, off, &val);
278 		data[off - init_off] = val & 0xff;
279 		data[off - init_off + 1] = (val >> 8) & 0xff;
280 		data[off - init_off + 2] = (val >> 16) & 0xff;
281 		data[off - init_off + 3] = (val >> 24) & 0xff;
282 		off += 4;
283 		size -= 4;
284 	}
285 
286 	if (size >= 2) {
287 		u16 val;
288 		pci_user_read_config_word(dev, off, &val);
289 		data[off - init_off] = val & 0xff;
290 		data[off - init_off + 1] = (val >> 8) & 0xff;
291 		off += 2;
292 		size -= 2;
293 	}
294 
295 	if (size > 0) {
296 		u8 val;
297 		pci_user_read_config_byte(dev, off, &val);
298 		data[off - init_off] = val;
299 		off++;
300 		--size;
301 	}
302 
303 	return count;
304 }
305 
306 static ssize_t
307 pci_write_config(struct kobject *kobj, struct bin_attribute *bin_attr,
308 		 char *buf, loff_t off, size_t count)
309 {
310 	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
311 	unsigned int size = count;
312 	loff_t init_off = off;
313 	u8 *data = (u8*) buf;
314 
315 	if (off > dev->cfg_size)
316 		return 0;
317 	if (off + count > dev->cfg_size) {
318 		size = dev->cfg_size - off;
319 		count = size;
320 	}
321 
322 	if ((off & 1) && size) {
323 		pci_user_write_config_byte(dev, off, data[off - init_off]);
324 		off++;
325 		size--;
326 	}
327 
328 	if ((off & 3) && size > 2) {
329 		u16 val = data[off - init_off];
330 		val |= (u16) data[off - init_off + 1] << 8;
331                 pci_user_write_config_word(dev, off, val);
332                 off += 2;
333                 size -= 2;
334         }
335 
336 	while (size > 3) {
337 		u32 val = data[off - init_off];
338 		val |= (u32) data[off - init_off + 1] << 8;
339 		val |= (u32) data[off - init_off + 2] << 16;
340 		val |= (u32) data[off - init_off + 3] << 24;
341 		pci_user_write_config_dword(dev, off, val);
342 		off += 4;
343 		size -= 4;
344 	}
345 
346 	if (size >= 2) {
347 		u16 val = data[off - init_off];
348 		val |= (u16) data[off - init_off + 1] << 8;
349 		pci_user_write_config_word(dev, off, val);
350 		off += 2;
351 		size -= 2;
352 	}
353 
354 	if (size) {
355 		pci_user_write_config_byte(dev, off, data[off - init_off]);
356 		off++;
357 		--size;
358 	}
359 
360 	return count;
361 }
362 
363 static ssize_t
364 pci_read_vpd(struct kobject *kobj, struct bin_attribute *bin_attr,
365 	     char *buf, loff_t off, size_t count)
366 {
367 	struct pci_dev *dev =
368 		to_pci_dev(container_of(kobj, struct device, kobj));
369 	int end;
370 	int ret;
371 
372 	if (off > bin_attr->size)
373 		count = 0;
374 	else if (count > bin_attr->size - off)
375 		count = bin_attr->size - off;
376 	end = off + count;
377 
378 	while (off < end) {
379 		ret = dev->vpd->ops->read(dev, off, end - off, buf);
380 		if (ret < 0)
381 			return ret;
382 		buf += ret;
383 		off += ret;
384 	}
385 
386 	return count;
387 }
388 
389 static ssize_t
390 pci_write_vpd(struct kobject *kobj, struct bin_attribute *bin_attr,
391 	      char *buf, loff_t off, size_t count)
392 {
393 	struct pci_dev *dev =
394 		to_pci_dev(container_of(kobj, struct device, kobj));
395 	int end;
396 	int ret;
397 
398 	if (off > bin_attr->size)
399 		count = 0;
400 	else if (count > bin_attr->size - off)
401 		count = bin_attr->size - off;
402 	end = off + count;
403 
404 	while (off < end) {
405 		ret = dev->vpd->ops->write(dev, off, end - off, buf);
406 		if (ret < 0)
407 			return ret;
408 		buf += ret;
409 		off += ret;
410 	}
411 
412 	return count;
413 }
414 
415 #ifdef HAVE_PCI_LEGACY
416 /**
417  * pci_read_legacy_io - read byte(s) from legacy I/O port space
418  * @kobj: kobject corresponding to file to read from
419  * @buf: buffer to store results
420  * @off: offset into legacy I/O port space
421  * @count: number of bytes to read
422  *
423  * Reads 1, 2, or 4 bytes from legacy I/O port space using an arch specific
424  * callback routine (pci_legacy_read).
425  */
426 ssize_t
427 pci_read_legacy_io(struct kobject *kobj, struct bin_attribute *bin_attr,
428 		   char *buf, loff_t off, size_t count)
429 {
430         struct pci_bus *bus = to_pci_bus(container_of(kobj,
431                                                       struct device,
432 						      kobj));
433 
434         /* Only support 1, 2 or 4 byte accesses */
435         if (count != 1 && count != 2 && count != 4)
436                 return -EINVAL;
437 
438         return pci_legacy_read(bus, off, (u32 *)buf, count);
439 }
440 
441 /**
442  * pci_write_legacy_io - write byte(s) to legacy I/O port space
443  * @kobj: kobject corresponding to file to read from
444  * @buf: buffer containing value to be written
445  * @off: offset into legacy I/O port space
446  * @count: number of bytes to write
447  *
448  * Writes 1, 2, or 4 bytes from legacy I/O port space using an arch specific
449  * callback routine (pci_legacy_write).
450  */
451 ssize_t
452 pci_write_legacy_io(struct kobject *kobj, struct bin_attribute *bin_attr,
453 		    char *buf, loff_t off, size_t count)
454 {
455         struct pci_bus *bus = to_pci_bus(container_of(kobj,
456 						      struct device,
457 						      kobj));
458         /* Only support 1, 2 or 4 byte accesses */
459         if (count != 1 && count != 2 && count != 4)
460                 return -EINVAL;
461 
462         return pci_legacy_write(bus, off, *(u32 *)buf, count);
463 }
464 
465 /**
466  * pci_mmap_legacy_mem - map legacy PCI memory into user memory space
467  * @kobj: kobject corresponding to device to be mapped
468  * @attr: struct bin_attribute for this file
469  * @vma: struct vm_area_struct passed to mmap
470  *
471  * Uses an arch specific callback, pci_mmap_legacy_page_range, to mmap
472  * legacy memory space (first meg of bus space) into application virtual
473  * memory space.
474  */
475 int
476 pci_mmap_legacy_mem(struct kobject *kobj, struct bin_attribute *attr,
477                     struct vm_area_struct *vma)
478 {
479         struct pci_bus *bus = to_pci_bus(container_of(kobj,
480                                                       struct device,
481 						      kobj));
482 
483         return pci_mmap_legacy_page_range(bus, vma);
484 }
485 #endif /* HAVE_PCI_LEGACY */
486 
487 #ifdef HAVE_PCI_MMAP
488 
489 static int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma)
490 {
491 	unsigned long nr, start, size;
492 
493 	nr = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
494 	start = vma->vm_pgoff;
495 	size = pci_resource_len(pdev, resno) >> PAGE_SHIFT;
496 	if (start < size && size - start >= nr)
497 		return 1;
498 	WARN(1, "process \"%s\" tried to map 0x%08lx-0x%08lx on %s BAR %d (size 0x%08lx)\n",
499 		current->comm, start, start+nr, pci_name(pdev), resno, size);
500 	return 0;
501 }
502 
503 /**
504  * pci_mmap_resource - map a PCI resource into user memory space
505  * @kobj: kobject for mapping
506  * @attr: struct bin_attribute for the file being mapped
507  * @vma: struct vm_area_struct passed into the mmap
508  * @write_combine: 1 for write_combine mapping
509  *
510  * Use the regular PCI mapping routines to map a PCI resource into userspace.
511  */
512 static int
513 pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
514 		  struct vm_area_struct *vma, int write_combine)
515 {
516 	struct pci_dev *pdev = to_pci_dev(container_of(kobj,
517 						       struct device, kobj));
518 	struct resource *res = (struct resource *)attr->private;
519 	enum pci_mmap_state mmap_type;
520 	resource_size_t start, end;
521 	int i;
522 
523 	for (i = 0; i < PCI_ROM_RESOURCE; i++)
524 		if (res == &pdev->resource[i])
525 			break;
526 	if (i >= PCI_ROM_RESOURCE)
527 		return -ENODEV;
528 
529 	if (!pci_mmap_fits(pdev, i, vma))
530 		return -EINVAL;
531 
532 	/* pci_mmap_page_range() expects the same kind of entry as coming
533 	 * from /proc/bus/pci/ which is a "user visible" value. If this is
534 	 * different from the resource itself, arch will do necessary fixup.
535 	 */
536 	pci_resource_to_user(pdev, i, res, &start, &end);
537 	vma->vm_pgoff += start >> PAGE_SHIFT;
538 	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
539 
540 	return pci_mmap_page_range(pdev, vma, mmap_type, write_combine);
541 }
542 
543 static int
544 pci_mmap_resource_uc(struct kobject *kobj, struct bin_attribute *attr,
545 		     struct vm_area_struct *vma)
546 {
547 	return pci_mmap_resource(kobj, attr, vma, 0);
548 }
549 
550 static int
551 pci_mmap_resource_wc(struct kobject *kobj, struct bin_attribute *attr,
552 		     struct vm_area_struct *vma)
553 {
554 	return pci_mmap_resource(kobj, attr, vma, 1);
555 }
556 
557 /**
558  * pci_remove_resource_files - cleanup resource files
559  * @dev: dev to cleanup
560  *
561  * If we created resource files for @dev, remove them from sysfs and
562  * free their resources.
563  */
564 static void
565 pci_remove_resource_files(struct pci_dev *pdev)
566 {
567 	int i;
568 
569 	for (i = 0; i < PCI_ROM_RESOURCE; i++) {
570 		struct bin_attribute *res_attr;
571 
572 		res_attr = pdev->res_attr[i];
573 		if (res_attr) {
574 			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
575 			kfree(res_attr);
576 		}
577 
578 		res_attr = pdev->res_attr_wc[i];
579 		if (res_attr) {
580 			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
581 			kfree(res_attr);
582 		}
583 	}
584 }
585 
586 static int pci_create_attr(struct pci_dev *pdev, int num, int write_combine)
587 {
588 	/* allocate attribute structure, piggyback attribute name */
589 	int name_len = write_combine ? 13 : 10;
590 	struct bin_attribute *res_attr;
591 	int retval;
592 
593 	res_attr = kzalloc(sizeof(*res_attr) + name_len, GFP_ATOMIC);
594 	if (res_attr) {
595 		char *res_attr_name = (char *)(res_attr + 1);
596 
597 		if (write_combine) {
598 			pdev->res_attr_wc[num] = res_attr;
599 			sprintf(res_attr_name, "resource%d_wc", num);
600 			res_attr->mmap = pci_mmap_resource_wc;
601 		} else {
602 			pdev->res_attr[num] = res_attr;
603 			sprintf(res_attr_name, "resource%d", num);
604 			res_attr->mmap = pci_mmap_resource_uc;
605 		}
606 		res_attr->attr.name = res_attr_name;
607 		res_attr->attr.mode = S_IRUSR | S_IWUSR;
608 		res_attr->size = pci_resource_len(pdev, num);
609 		res_attr->private = &pdev->resource[num];
610 		retval = sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
611 	} else
612 		retval = -ENOMEM;
613 
614 	return retval;
615 }
616 
617 /**
618  * pci_create_resource_files - create resource files in sysfs for @dev
619  * @dev: dev in question
620  *
621  * Walk the resources in @dev creating files for each resource available.
622  */
623 static int pci_create_resource_files(struct pci_dev *pdev)
624 {
625 	int i;
626 	int retval;
627 
628 	/* Expose the PCI resources from this device as files */
629 	for (i = 0; i < PCI_ROM_RESOURCE; i++) {
630 
631 		/* skip empty resources */
632 		if (!pci_resource_len(pdev, i))
633 			continue;
634 
635 		retval = pci_create_attr(pdev, i, 0);
636 		/* for prefetchable resources, create a WC mappable file */
637 		if (!retval && pdev->resource[i].flags & IORESOURCE_PREFETCH)
638 			retval = pci_create_attr(pdev, i, 1);
639 
640 		if (retval) {
641 			pci_remove_resource_files(pdev);
642 			return retval;
643 		}
644 	}
645 	return 0;
646 }
647 #else /* !HAVE_PCI_MMAP */
648 static inline int pci_create_resource_files(struct pci_dev *dev) { return 0; }
649 static inline void pci_remove_resource_files(struct pci_dev *dev) { return; }
650 #endif /* HAVE_PCI_MMAP */
651 
652 /**
653  * pci_write_rom - used to enable access to the PCI ROM display
654  * @kobj: kernel object handle
655  * @buf: user input
656  * @off: file offset
657  * @count: number of byte in input
658  *
659  * writing anything except 0 enables it
660  */
661 static ssize_t
662 pci_write_rom(struct kobject *kobj, struct bin_attribute *bin_attr,
663 	      char *buf, loff_t off, size_t count)
664 {
665 	struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
666 
667 	if ((off ==  0) && (*buf == '0') && (count == 2))
668 		pdev->rom_attr_enabled = 0;
669 	else
670 		pdev->rom_attr_enabled = 1;
671 
672 	return count;
673 }
674 
675 /**
676  * pci_read_rom - read a PCI ROM
677  * @kobj: kernel object handle
678  * @buf: where to put the data we read from the ROM
679  * @off: file offset
680  * @count: number of bytes to read
681  *
682  * Put @count bytes starting at @off into @buf from the ROM in the PCI
683  * device corresponding to @kobj.
684  */
685 static ssize_t
686 pci_read_rom(struct kobject *kobj, struct bin_attribute *bin_attr,
687 	     char *buf, loff_t off, size_t count)
688 {
689 	struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
690 	void __iomem *rom;
691 	size_t size;
692 
693 	if (!pdev->rom_attr_enabled)
694 		return -EINVAL;
695 
696 	rom = pci_map_rom(pdev, &size);	/* size starts out as PCI window size */
697 	if (!rom)
698 		return 0;
699 
700 	if (off >= size)
701 		count = 0;
702 	else {
703 		if (off + count > size)
704 			count = size - off;
705 
706 		memcpy_fromio(buf, rom + off, count);
707 	}
708 	pci_unmap_rom(pdev, rom);
709 
710 	return count;
711 }
712 
713 static struct bin_attribute pci_config_attr = {
714 	.attr =	{
715 		.name = "config",
716 		.mode = S_IRUGO | S_IWUSR,
717 	},
718 	.size = 256,
719 	.read = pci_read_config,
720 	.write = pci_write_config,
721 };
722 
723 static struct bin_attribute pcie_config_attr = {
724 	.attr =	{
725 		.name = "config",
726 		.mode = S_IRUGO | S_IWUSR,
727 	},
728 	.size = 4096,
729 	.read = pci_read_config,
730 	.write = pci_write_config,
731 };
732 
733 int __attribute__ ((weak)) pcibios_add_platform_entries(struct pci_dev *dev)
734 {
735 	return 0;
736 }
737 
738 int __must_check pci_create_sysfs_dev_files (struct pci_dev *pdev)
739 {
740 	struct bin_attribute *attr = NULL;
741 	int retval;
742 
743 	if (!sysfs_initialized)
744 		return -EACCES;
745 
746 	if (pdev->cfg_size < 4096)
747 		retval = sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
748 	else
749 		retval = sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
750 	if (retval)
751 		goto err;
752 
753 	/* If the device has VPD, try to expose it in sysfs. */
754 	if (pdev->vpd) {
755 		attr = kzalloc(sizeof(*attr), GFP_ATOMIC);
756 		if (attr) {
757 			pdev->vpd->attr = attr;
758 			attr->size = pdev->vpd->len;
759 			attr->attr.name = "vpd";
760 			attr->attr.mode = S_IRUSR | S_IWUSR;
761 			attr->read = pci_read_vpd;
762 			attr->write = pci_write_vpd;
763 			retval = sysfs_create_bin_file(&pdev->dev.kobj, attr);
764 			if (retval)
765 				goto err_vpd;
766 		} else {
767 			retval = -ENOMEM;
768 			goto err_config_file;
769 		}
770 	}
771 
772 	retval = pci_create_resource_files(pdev);
773 	if (retval)
774 		goto err_vpd_file;
775 
776 	/* If the device has a ROM, try to expose it in sysfs. */
777 	if (pci_resource_len(pdev, PCI_ROM_RESOURCE) ||
778 	    (pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW)) {
779 		attr = kzalloc(sizeof(*attr), GFP_ATOMIC);
780 		if (attr) {
781 			pdev->rom_attr = attr;
782 			attr->size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
783 			attr->attr.name = "rom";
784 			attr->attr.mode = S_IRUSR;
785 			attr->read = pci_read_rom;
786 			attr->write = pci_write_rom;
787 			retval = sysfs_create_bin_file(&pdev->dev.kobj, attr);
788 			if (retval)
789 				goto err_rom;
790 		} else {
791 			retval = -ENOMEM;
792 			goto err_resource_files;
793 		}
794 	}
795 	/* add platform-specific attributes */
796 	if (pcibios_add_platform_entries(pdev))
797 		goto err_rom_file;
798 
799 	pcie_aspm_create_sysfs_dev_files(pdev);
800 
801 	return 0;
802 
803 err_rom_file:
804 	if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
805 		sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
806 err_rom:
807 	kfree(pdev->rom_attr);
808 err_resource_files:
809 	pci_remove_resource_files(pdev);
810 err_vpd_file:
811 	if (pdev->vpd) {
812 		sysfs_remove_bin_file(&pdev->dev.kobj, pdev->vpd->attr);
813 err_vpd:
814 		kfree(pdev->vpd->attr);
815 	}
816 err_config_file:
817 	if (pdev->cfg_size < 4096)
818 		sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
819 	else
820 		sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
821 err:
822 	return retval;
823 }
824 
825 /**
826  * pci_remove_sysfs_dev_files - cleanup PCI specific sysfs files
827  * @pdev: device whose entries we should free
828  *
829  * Cleanup when @pdev is removed from sysfs.
830  */
831 void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
832 {
833 	if (!sysfs_initialized)
834 		return;
835 
836 	pcie_aspm_remove_sysfs_dev_files(pdev);
837 
838 	if (pdev->vpd) {
839 		sysfs_remove_bin_file(&pdev->dev.kobj, pdev->vpd->attr);
840 		kfree(pdev->vpd->attr);
841 	}
842 	if (pdev->cfg_size < 4096)
843 		sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
844 	else
845 		sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
846 
847 	pci_remove_resource_files(pdev);
848 
849 	if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
850 		if (pdev->rom_attr) {
851 			sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
852 			kfree(pdev->rom_attr);
853 		}
854 	}
855 }
856 
857 static int __init pci_sysfs_init(void)
858 {
859 	struct pci_dev *pdev = NULL;
860 	int retval;
861 
862 	sysfs_initialized = 1;
863 	for_each_pci_dev(pdev) {
864 		retval = pci_create_sysfs_dev_files(pdev);
865 		if (retval) {
866 			pci_dev_put(pdev);
867 			return retval;
868 		}
869 	}
870 
871 	return 0;
872 }
873 
874 late_initcall(pci_sysfs_init);
875