xref: /linux/drivers/pci/pci-sysfs.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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/config.h>
19 #include <linux/kernel.h>
20 #include <linux/pci.h>
21 #include <linux/stat.h>
22 #include <linux/topology.h>
23 #include <linux/mm.h>
24 
25 #include "pci.h"
26 
27 static int sysfs_initialized;	/* = 0 */
28 
29 /* show configuration fields */
30 #define pci_config_attr(field, format_string)				\
31 static ssize_t								\
32 field##_show(struct device *dev, struct device_attribute *attr, char *buf)				\
33 {									\
34 	struct pci_dev *pdev;						\
35 									\
36 	pdev = to_pci_dev (dev);					\
37 	return sprintf (buf, format_string, pdev->field);		\
38 }
39 
40 pci_config_attr(vendor, "0x%04x\n");
41 pci_config_attr(device, "0x%04x\n");
42 pci_config_attr(subsystem_vendor, "0x%04x\n");
43 pci_config_attr(subsystem_device, "0x%04x\n");
44 pci_config_attr(class, "0x%06x\n");
45 pci_config_attr(irq, "%u\n");
46 
47 static ssize_t local_cpus_show(struct device *dev,
48 			struct device_attribute *attr, char *buf)
49 {
50 	cpumask_t mask;
51 	int len;
52 
53 	mask = pcibus_to_cpumask(to_pci_dev(dev)->bus);
54 	len = cpumask_scnprintf(buf, PAGE_SIZE-2, mask);
55 	strcat(buf,"\n");
56 	return 1+len;
57 }
58 
59 /* show resources */
60 static ssize_t
61 resource_show(struct device * dev, struct device_attribute *attr, char * buf)
62 {
63 	struct pci_dev * pci_dev = to_pci_dev(dev);
64 	char * str = buf;
65 	int i;
66 	int max = 7;
67 	u64 start, end;
68 
69 	if (pci_dev->subordinate)
70 		max = DEVICE_COUNT_RESOURCE;
71 
72 	for (i = 0; i < max; i++) {
73 		struct resource *res =  &pci_dev->resource[i];
74 		pci_resource_to_user(pci_dev, i, res, &start, &end);
75 		str += sprintf(str,"0x%016llx 0x%016llx 0x%016llx\n",
76 			       (unsigned long long)start,
77 			       (unsigned long long)end,
78 			       (unsigned long long)res->flags);
79 	}
80 	return (str - buf);
81 }
82 
83 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
84 {
85 	struct pci_dev *pci_dev = to_pci_dev(dev);
86 
87 	return sprintf(buf, "pci:v%08Xd%08Xsv%08Xsd%08Xbc%02Xsc%02Xi%02x\n",
88 		       pci_dev->vendor, pci_dev->device,
89 		       pci_dev->subsystem_vendor, pci_dev->subsystem_device,
90 		       (u8)(pci_dev->class >> 16), (u8)(pci_dev->class >> 8),
91 		       (u8)(pci_dev->class));
92 }
93 
94 struct device_attribute pci_dev_attrs[] = {
95 	__ATTR_RO(resource),
96 	__ATTR_RO(vendor),
97 	__ATTR_RO(device),
98 	__ATTR_RO(subsystem_vendor),
99 	__ATTR_RO(subsystem_device),
100 	__ATTR_RO(class),
101 	__ATTR_RO(irq),
102 	__ATTR_RO(local_cpus),
103 	__ATTR_RO(modalias),
104 	__ATTR_NULL,
105 };
106 
107 static ssize_t
108 pci_read_config(struct kobject *kobj, char *buf, loff_t off, size_t count)
109 {
110 	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
111 	unsigned int size = 64;
112 	loff_t init_off = off;
113 	u8 *data = (u8*) buf;
114 
115 	/* Several chips lock up trying to read undefined config space */
116 	if (capable(CAP_SYS_ADMIN)) {
117 		size = dev->cfg_size;
118 	} else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
119 		size = 128;
120 	}
121 
122 	if (off > size)
123 		return 0;
124 	if (off + count > size) {
125 		size -= off;
126 		count = size;
127 	} else {
128 		size = count;
129 	}
130 
131 	if ((off & 1) && size) {
132 		u8 val;
133 		pci_user_read_config_byte(dev, off, &val);
134 		data[off - init_off] = val;
135 		off++;
136 		size--;
137 	}
138 
139 	if ((off & 3) && size > 2) {
140 		u16 val;
141 		pci_user_read_config_word(dev, off, &val);
142 		data[off - init_off] = val & 0xff;
143 		data[off - init_off + 1] = (val >> 8) & 0xff;
144 		off += 2;
145 		size -= 2;
146 	}
147 
148 	while (size > 3) {
149 		u32 val;
150 		pci_user_read_config_dword(dev, off, &val);
151 		data[off - init_off] = val & 0xff;
152 		data[off - init_off + 1] = (val >> 8) & 0xff;
153 		data[off - init_off + 2] = (val >> 16) & 0xff;
154 		data[off - init_off + 3] = (val >> 24) & 0xff;
155 		off += 4;
156 		size -= 4;
157 	}
158 
159 	if (size >= 2) {
160 		u16 val;
161 		pci_user_read_config_word(dev, off, &val);
162 		data[off - init_off] = val & 0xff;
163 		data[off - init_off + 1] = (val >> 8) & 0xff;
164 		off += 2;
165 		size -= 2;
166 	}
167 
168 	if (size > 0) {
169 		u8 val;
170 		pci_user_read_config_byte(dev, off, &val);
171 		data[off - init_off] = val;
172 		off++;
173 		--size;
174 	}
175 
176 	return count;
177 }
178 
179 static ssize_t
180 pci_write_config(struct kobject *kobj, char *buf, loff_t off, size_t count)
181 {
182 	struct pci_dev *dev = to_pci_dev(container_of(kobj,struct device,kobj));
183 	unsigned int size = count;
184 	loff_t init_off = off;
185 	u8 *data = (u8*) buf;
186 
187 	if (off > dev->cfg_size)
188 		return 0;
189 	if (off + count > dev->cfg_size) {
190 		size = dev->cfg_size - off;
191 		count = size;
192 	}
193 
194 	if ((off & 1) && size) {
195 		pci_user_write_config_byte(dev, off, data[off - init_off]);
196 		off++;
197 		size--;
198 	}
199 
200 	if ((off & 3) && size > 2) {
201 		u16 val = data[off - init_off];
202 		val |= (u16) data[off - init_off + 1] << 8;
203                 pci_user_write_config_word(dev, off, val);
204                 off += 2;
205                 size -= 2;
206         }
207 
208 	while (size > 3) {
209 		u32 val = data[off - init_off];
210 		val |= (u32) data[off - init_off + 1] << 8;
211 		val |= (u32) data[off - init_off + 2] << 16;
212 		val |= (u32) data[off - init_off + 3] << 24;
213 		pci_user_write_config_dword(dev, off, val);
214 		off += 4;
215 		size -= 4;
216 	}
217 
218 	if (size >= 2) {
219 		u16 val = data[off - init_off];
220 		val |= (u16) data[off - init_off + 1] << 8;
221 		pci_user_write_config_word(dev, off, val);
222 		off += 2;
223 		size -= 2;
224 	}
225 
226 	if (size) {
227 		pci_user_write_config_byte(dev, off, data[off - init_off]);
228 		off++;
229 		--size;
230 	}
231 
232 	return count;
233 }
234 
235 #ifdef HAVE_PCI_LEGACY
236 /**
237  * pci_read_legacy_io - read byte(s) from legacy I/O port space
238  * @kobj: kobject corresponding to file to read from
239  * @buf: buffer to store results
240  * @off: offset into legacy I/O port space
241  * @count: number of bytes to read
242  *
243  * Reads 1, 2, or 4 bytes from legacy I/O port space using an arch specific
244  * callback routine (pci_legacy_read).
245  */
246 ssize_t
247 pci_read_legacy_io(struct kobject *kobj, char *buf, loff_t off, size_t count)
248 {
249         struct pci_bus *bus = to_pci_bus(container_of(kobj,
250                                                       struct class_device,
251 						      kobj));
252 
253         /* Only support 1, 2 or 4 byte accesses */
254         if (count != 1 && count != 2 && count != 4)
255                 return -EINVAL;
256 
257         return pci_legacy_read(bus, off, (u32 *)buf, count);
258 }
259 
260 /**
261  * pci_write_legacy_io - write byte(s) to legacy I/O port space
262  * @kobj: kobject corresponding to file to read from
263  * @buf: buffer containing value to be written
264  * @off: offset into legacy I/O port space
265  * @count: number of bytes to write
266  *
267  * Writes 1, 2, or 4 bytes from legacy I/O port space using an arch specific
268  * callback routine (pci_legacy_write).
269  */
270 ssize_t
271 pci_write_legacy_io(struct kobject *kobj, char *buf, loff_t off, size_t count)
272 {
273         struct pci_bus *bus = to_pci_bus(container_of(kobj,
274 						      struct class_device,
275 						      kobj));
276         /* Only support 1, 2 or 4 byte accesses */
277         if (count != 1 && count != 2 && count != 4)
278                 return -EINVAL;
279 
280         return pci_legacy_write(bus, off, *(u32 *)buf, count);
281 }
282 
283 /**
284  * pci_mmap_legacy_mem - map legacy PCI memory into user memory space
285  * @kobj: kobject corresponding to device to be mapped
286  * @attr: struct bin_attribute for this file
287  * @vma: struct vm_area_struct passed to mmap
288  *
289  * Uses an arch specific callback, pci_mmap_legacy_page_range, to mmap
290  * legacy memory space (first meg of bus space) into application virtual
291  * memory space.
292  */
293 int
294 pci_mmap_legacy_mem(struct kobject *kobj, struct bin_attribute *attr,
295                     struct vm_area_struct *vma)
296 {
297         struct pci_bus *bus = to_pci_bus(container_of(kobj,
298                                                       struct class_device,
299 						      kobj));
300 
301         return pci_mmap_legacy_page_range(bus, vma);
302 }
303 #endif /* HAVE_PCI_LEGACY */
304 
305 #ifdef HAVE_PCI_MMAP
306 /**
307  * pci_mmap_resource - map a PCI resource into user memory space
308  * @kobj: kobject for mapping
309  * @attr: struct bin_attribute for the file being mapped
310  * @vma: struct vm_area_struct passed into the mmap
311  *
312  * Use the regular PCI mapping routines to map a PCI resource into userspace.
313  * FIXME: write combining?  maybe automatic for prefetchable regions?
314  */
315 static int
316 pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
317 		  struct vm_area_struct *vma)
318 {
319 	struct pci_dev *pdev = to_pci_dev(container_of(kobj,
320 						       struct device, kobj));
321 	struct resource *res = (struct resource *)attr->private;
322 	enum pci_mmap_state mmap_type;
323 	u64 start, end;
324 	int i;
325 
326 	for (i = 0; i < PCI_ROM_RESOURCE; i++)
327 		if (res == &pdev->resource[i])
328 			break;
329 	if (i >= PCI_ROM_RESOURCE)
330 		return -ENODEV;
331 
332 	/* pci_mmap_page_range() expects the same kind of entry as coming
333 	 * from /proc/bus/pci/ which is a "user visible" value. If this is
334 	 * different from the resource itself, arch will do necessary fixup.
335 	 */
336 	pci_resource_to_user(pdev, i, res, &start, &end);
337 	vma->vm_pgoff += start >> PAGE_SHIFT;
338 	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
339 
340 	return pci_mmap_page_range(pdev, vma, mmap_type, 0);
341 }
342 
343 /**
344  * pci_create_resource_files - create resource files in sysfs for @dev
345  * @dev: dev in question
346  *
347  * Walk the resources in @dev creating files for each resource available.
348  */
349 static void
350 pci_create_resource_files(struct pci_dev *pdev)
351 {
352 	int i;
353 
354 	/* Expose the PCI resources from this device as files */
355 	for (i = 0; i < PCI_ROM_RESOURCE; i++) {
356 		struct bin_attribute *res_attr;
357 
358 		/* skip empty resources */
359 		if (!pci_resource_len(pdev, i))
360 			continue;
361 
362 		/* allocate attribute structure, piggyback attribute name */
363 		res_attr = kzalloc(sizeof(*res_attr) + 10, GFP_ATOMIC);
364 		if (res_attr) {
365 			char *res_attr_name = (char *)(res_attr + 1);
366 
367 			pdev->res_attr[i] = res_attr;
368 			sprintf(res_attr_name, "resource%d", i);
369 			res_attr->attr.name = res_attr_name;
370 			res_attr->attr.mode = S_IRUSR | S_IWUSR;
371 			res_attr->attr.owner = THIS_MODULE;
372 			res_attr->size = pci_resource_len(pdev, i);
373 			res_attr->mmap = pci_mmap_resource;
374 			res_attr->private = &pdev->resource[i];
375 			sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
376 		}
377 	}
378 }
379 
380 /**
381  * pci_remove_resource_files - cleanup resource files
382  * @dev: dev to cleanup
383  *
384  * If we created resource files for @dev, remove them from sysfs and
385  * free their resources.
386  */
387 static void
388 pci_remove_resource_files(struct pci_dev *pdev)
389 {
390 	int i;
391 
392 	for (i = 0; i < PCI_ROM_RESOURCE; i++) {
393 		struct bin_attribute *res_attr;
394 
395 		res_attr = pdev->res_attr[i];
396 		if (res_attr) {
397 			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
398 			kfree(res_attr);
399 		}
400 	}
401 }
402 #else /* !HAVE_PCI_MMAP */
403 static inline void pci_create_resource_files(struct pci_dev *dev) { return; }
404 static inline void pci_remove_resource_files(struct pci_dev *dev) { return; }
405 #endif /* HAVE_PCI_MMAP */
406 
407 /**
408  * pci_write_rom - used to enable access to the PCI ROM display
409  * @kobj: kernel object handle
410  * @buf: user input
411  * @off: file offset
412  * @count: number of byte in input
413  *
414  * writing anything except 0 enables it
415  */
416 static ssize_t
417 pci_write_rom(struct kobject *kobj, char *buf, loff_t off, size_t count)
418 {
419 	struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
420 
421 	if ((off ==  0) && (*buf == '0') && (count == 2))
422 		pdev->rom_attr_enabled = 0;
423 	else
424 		pdev->rom_attr_enabled = 1;
425 
426 	return count;
427 }
428 
429 /**
430  * pci_read_rom - read a PCI ROM
431  * @kobj: kernel object handle
432  * @buf: where to put the data we read from the ROM
433  * @off: file offset
434  * @count: number of bytes to read
435  *
436  * Put @count bytes starting at @off into @buf from the ROM in the PCI
437  * device corresponding to @kobj.
438  */
439 static ssize_t
440 pci_read_rom(struct kobject *kobj, char *buf, loff_t off, size_t count)
441 {
442 	struct pci_dev *pdev = to_pci_dev(container_of(kobj, struct device, kobj));
443 	void __iomem *rom;
444 	size_t size;
445 
446 	if (!pdev->rom_attr_enabled)
447 		return -EINVAL;
448 
449 	rom = pci_map_rom(pdev, &size);	/* size starts out as PCI window size */
450 	if (!rom)
451 		return 0;
452 
453 	if (off >= size)
454 		count = 0;
455 	else {
456 		if (off + count > size)
457 			count = size - off;
458 
459 		memcpy_fromio(buf, rom + off, count);
460 	}
461 	pci_unmap_rom(pdev, rom);
462 
463 	return count;
464 }
465 
466 static struct bin_attribute pci_config_attr = {
467 	.attr =	{
468 		.name = "config",
469 		.mode = S_IRUGO | S_IWUSR,
470 		.owner = THIS_MODULE,
471 	},
472 	.size = 256,
473 	.read = pci_read_config,
474 	.write = pci_write_config,
475 };
476 
477 static struct bin_attribute pcie_config_attr = {
478 	.attr =	{
479 		.name = "config",
480 		.mode = S_IRUGO | S_IWUSR,
481 		.owner = THIS_MODULE,
482 	},
483 	.size = 4096,
484 	.read = pci_read_config,
485 	.write = pci_write_config,
486 };
487 
488 int pci_create_sysfs_dev_files (struct pci_dev *pdev)
489 {
490 	if (!sysfs_initialized)
491 		return -EACCES;
492 
493 	if (pdev->cfg_size < 4096)
494 		sysfs_create_bin_file(&pdev->dev.kobj, &pci_config_attr);
495 	else
496 		sysfs_create_bin_file(&pdev->dev.kobj, &pcie_config_attr);
497 
498 	pci_create_resource_files(pdev);
499 
500 	/* If the device has a ROM, try to expose it in sysfs. */
501 	if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
502 		struct bin_attribute *rom_attr;
503 
504 		rom_attr = kzalloc(sizeof(*rom_attr), GFP_ATOMIC);
505 		if (rom_attr) {
506 			pdev->rom_attr = rom_attr;
507 			rom_attr->size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
508 			rom_attr->attr.name = "rom";
509 			rom_attr->attr.mode = S_IRUSR;
510 			rom_attr->attr.owner = THIS_MODULE;
511 			rom_attr->read = pci_read_rom;
512 			rom_attr->write = pci_write_rom;
513 			sysfs_create_bin_file(&pdev->dev.kobj, rom_attr);
514 		}
515 	}
516 	/* add platform-specific attributes */
517 	pcibios_add_platform_entries(pdev);
518 
519 	return 0;
520 }
521 
522 /**
523  * pci_remove_sysfs_dev_files - cleanup PCI specific sysfs files
524  * @pdev: device whose entries we should free
525  *
526  * Cleanup when @pdev is removed from sysfs.
527  */
528 void pci_remove_sysfs_dev_files(struct pci_dev *pdev)
529 {
530 	if (pdev->cfg_size < 4096)
531 		sysfs_remove_bin_file(&pdev->dev.kobj, &pci_config_attr);
532 	else
533 		sysfs_remove_bin_file(&pdev->dev.kobj, &pcie_config_attr);
534 
535 	pci_remove_resource_files(pdev);
536 
537 	if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) {
538 		if (pdev->rom_attr) {
539 			sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
540 			kfree(pdev->rom_attr);
541 		}
542 	}
543 }
544 
545 static int __init pci_sysfs_init(void)
546 {
547 	struct pci_dev *pdev = NULL;
548 
549 	sysfs_initialized = 1;
550 	for_each_pci_dev(pdev)
551 		pci_create_sysfs_dev_files(pdev);
552 
553 	return 0;
554 }
555 
556 __initcall(pci_sysfs_init);
557