xref: /linux/drivers/pci/probe.c (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
1 /*
2  * probe.c - PCI detection and setup code
3  */
4 
5 #include <linux/kernel.h>
6 #include <linux/delay.h>
7 #include <linux/init.h>
8 #include <linux/pci.h>
9 #include <linux/slab.h>
10 #include <linux/module.h>
11 #include <linux/cpumask.h>
12 #include <linux/pci-aspm.h>
13 #include <asm-generic/pci-bridge.h>
14 #include "pci.h"
15 
16 #define CARDBUS_LATENCY_TIMER	176	/* secondary latency timer */
17 #define CARDBUS_RESERVE_BUSNR	3
18 
19 static struct resource busn_resource = {
20 	.name	= "PCI busn",
21 	.start	= 0,
22 	.end	= 255,
23 	.flags	= IORESOURCE_BUS,
24 };
25 
26 /* Ugh.  Need to stop exporting this to modules. */
27 LIST_HEAD(pci_root_buses);
28 EXPORT_SYMBOL(pci_root_buses);
29 
30 static LIST_HEAD(pci_domain_busn_res_list);
31 
32 struct pci_domain_busn_res {
33 	struct list_head list;
34 	struct resource res;
35 	int domain_nr;
36 };
37 
38 static struct resource *get_pci_domain_busn_res(int domain_nr)
39 {
40 	struct pci_domain_busn_res *r;
41 
42 	list_for_each_entry(r, &pci_domain_busn_res_list, list)
43 		if (r->domain_nr == domain_nr)
44 			return &r->res;
45 
46 	r = kzalloc(sizeof(*r), GFP_KERNEL);
47 	if (!r)
48 		return NULL;
49 
50 	r->domain_nr = domain_nr;
51 	r->res.start = 0;
52 	r->res.end = 0xff;
53 	r->res.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED;
54 
55 	list_add_tail(&r->list, &pci_domain_busn_res_list);
56 
57 	return &r->res;
58 }
59 
60 static int find_anything(struct device *dev, void *data)
61 {
62 	return 1;
63 }
64 
65 /*
66  * Some device drivers need know if pci is initiated.
67  * Basically, we think pci is not initiated when there
68  * is no device to be found on the pci_bus_type.
69  */
70 int no_pci_devices(void)
71 {
72 	struct device *dev;
73 	int no_devices;
74 
75 	dev = bus_find_device(&pci_bus_type, NULL, NULL, find_anything);
76 	no_devices = (dev == NULL);
77 	put_device(dev);
78 	return no_devices;
79 }
80 EXPORT_SYMBOL(no_pci_devices);
81 
82 /*
83  * PCI Bus Class
84  */
85 static void release_pcibus_dev(struct device *dev)
86 {
87 	struct pci_bus *pci_bus = to_pci_bus(dev);
88 
89 	if (pci_bus->bridge)
90 		put_device(pci_bus->bridge);
91 	pci_bus_remove_resources(pci_bus);
92 	pci_release_bus_of_node(pci_bus);
93 	kfree(pci_bus);
94 }
95 
96 static struct class pcibus_class = {
97 	.name		= "pci_bus",
98 	.dev_release	= &release_pcibus_dev,
99 	.dev_groups	= pcibus_groups,
100 };
101 
102 static int __init pcibus_class_init(void)
103 {
104 	return class_register(&pcibus_class);
105 }
106 postcore_initcall(pcibus_class_init);
107 
108 static u64 pci_size(u64 base, u64 maxbase, u64 mask)
109 {
110 	u64 size = mask & maxbase;	/* Find the significant bits */
111 	if (!size)
112 		return 0;
113 
114 	/* Get the lowest of them to find the decode size, and
115 	   from that the extent.  */
116 	size = (size & ~(size-1)) - 1;
117 
118 	/* base == maxbase can be valid only if the BAR has
119 	   already been programmed with all 1s.  */
120 	if (base == maxbase && ((base | size) & mask) != mask)
121 		return 0;
122 
123 	return size;
124 }
125 
126 static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar)
127 {
128 	u32 mem_type;
129 	unsigned long flags;
130 
131 	if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) {
132 		flags = bar & ~PCI_BASE_ADDRESS_IO_MASK;
133 		flags |= IORESOURCE_IO;
134 		return flags;
135 	}
136 
137 	flags = bar & ~PCI_BASE_ADDRESS_MEM_MASK;
138 	flags |= IORESOURCE_MEM;
139 	if (flags & PCI_BASE_ADDRESS_MEM_PREFETCH)
140 		flags |= IORESOURCE_PREFETCH;
141 
142 	mem_type = bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK;
143 	switch (mem_type) {
144 	case PCI_BASE_ADDRESS_MEM_TYPE_32:
145 		break;
146 	case PCI_BASE_ADDRESS_MEM_TYPE_1M:
147 		/* 1M mem BAR treated as 32-bit BAR */
148 		break;
149 	case PCI_BASE_ADDRESS_MEM_TYPE_64:
150 		flags |= IORESOURCE_MEM_64;
151 		break;
152 	default:
153 		/* mem unknown type treated as 32-bit BAR */
154 		break;
155 	}
156 	return flags;
157 }
158 
159 #define PCI_COMMAND_DECODE_ENABLE	(PCI_COMMAND_MEMORY | PCI_COMMAND_IO)
160 
161 /**
162  * pci_read_base - read a PCI BAR
163  * @dev: the PCI device
164  * @type: type of the BAR
165  * @res: resource buffer to be filled in
166  * @pos: BAR position in the config space
167  *
168  * Returns 1 if the BAR is 64-bit, or 0 if 32-bit.
169  */
170 int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
171 		    struct resource *res, unsigned int pos)
172 {
173 	u32 l, sz, mask;
174 	u64 l64, sz64, mask64;
175 	u16 orig_cmd;
176 	struct pci_bus_region region, inverted_region;
177 	bool bar_too_big = false, bar_too_high = false, bar_invalid = false;
178 
179 	mask = type ? PCI_ROM_ADDRESS_MASK : ~0;
180 
181 	/* No printks while decoding is disabled! */
182 	if (!dev->mmio_always_on) {
183 		pci_read_config_word(dev, PCI_COMMAND, &orig_cmd);
184 		if (orig_cmd & PCI_COMMAND_DECODE_ENABLE) {
185 			pci_write_config_word(dev, PCI_COMMAND,
186 				orig_cmd & ~PCI_COMMAND_DECODE_ENABLE);
187 		}
188 	}
189 
190 	res->name = pci_name(dev);
191 
192 	pci_read_config_dword(dev, pos, &l);
193 	pci_write_config_dword(dev, pos, l | mask);
194 	pci_read_config_dword(dev, pos, &sz);
195 	pci_write_config_dword(dev, pos, l);
196 
197 	/*
198 	 * All bits set in sz means the device isn't working properly.
199 	 * If the BAR isn't implemented, all bits must be 0.  If it's a
200 	 * memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit
201 	 * 1 must be clear.
202 	 */
203 	if (!sz || sz == 0xffffffff)
204 		goto fail;
205 
206 	/*
207 	 * I don't know how l can have all bits set.  Copied from old code.
208 	 * Maybe it fixes a bug on some ancient platform.
209 	 */
210 	if (l == 0xffffffff)
211 		l = 0;
212 
213 	if (type == pci_bar_unknown) {
214 		res->flags = decode_bar(dev, l);
215 		res->flags |= IORESOURCE_SIZEALIGN;
216 		if (res->flags & IORESOURCE_IO) {
217 			l &= PCI_BASE_ADDRESS_IO_MASK;
218 			mask = PCI_BASE_ADDRESS_IO_MASK & (u32) IO_SPACE_LIMIT;
219 		} else {
220 			l &= PCI_BASE_ADDRESS_MEM_MASK;
221 			mask = (u32)PCI_BASE_ADDRESS_MEM_MASK;
222 		}
223 	} else {
224 		res->flags |= (l & IORESOURCE_ROM_ENABLE);
225 		l &= PCI_ROM_ADDRESS_MASK;
226 		mask = (u32)PCI_ROM_ADDRESS_MASK;
227 	}
228 
229 	if (res->flags & IORESOURCE_MEM_64) {
230 		l64 = l;
231 		sz64 = sz;
232 		mask64 = mask | (u64)~0 << 32;
233 
234 		pci_read_config_dword(dev, pos + 4, &l);
235 		pci_write_config_dword(dev, pos + 4, ~0);
236 		pci_read_config_dword(dev, pos + 4, &sz);
237 		pci_write_config_dword(dev, pos + 4, l);
238 
239 		l64 |= ((u64)l << 32);
240 		sz64 |= ((u64)sz << 32);
241 
242 		sz64 = pci_size(l64, sz64, mask64);
243 
244 		if (!sz64)
245 			goto fail;
246 
247 		if ((sizeof(dma_addr_t) < 8 || sizeof(resource_size_t) < 8) &&
248 		    sz64 > 0x100000000ULL) {
249 			res->flags |= IORESOURCE_UNSET | IORESOURCE_DISABLED;
250 			res->start = 0;
251 			res->end = 0;
252 			bar_too_big = true;
253 			goto out;
254 		}
255 
256 		if ((sizeof(dma_addr_t) < 8) && l) {
257 			/* Above 32-bit boundary; try to reallocate */
258 			res->flags |= IORESOURCE_UNSET;
259 			res->start = 0;
260 			res->end = sz64;
261 			bar_too_high = true;
262 			goto out;
263 		} else {
264 			region.start = l64;
265 			region.end = l64 + sz64;
266 		}
267 	} else {
268 		sz = pci_size(l, sz, mask);
269 
270 		if (!sz)
271 			goto fail;
272 
273 		region.start = l;
274 		region.end = l + sz;
275 	}
276 
277 	pcibios_bus_to_resource(dev->bus, res, &region);
278 	pcibios_resource_to_bus(dev->bus, &inverted_region, res);
279 
280 	/*
281 	 * If "A" is a BAR value (a bus address), "bus_to_resource(A)" is
282 	 * the corresponding resource address (the physical address used by
283 	 * the CPU.  Converting that resource address back to a bus address
284 	 * should yield the original BAR value:
285 	 *
286 	 *     resource_to_bus(bus_to_resource(A)) == A
287 	 *
288 	 * If it doesn't, CPU accesses to "bus_to_resource(A)" will not
289 	 * be claimed by the device.
290 	 */
291 	if (inverted_region.start != region.start) {
292 		res->flags |= IORESOURCE_UNSET;
293 		res->start = 0;
294 		res->end = region.end - region.start;
295 		bar_invalid = true;
296 	}
297 
298 	goto out;
299 
300 
301 fail:
302 	res->flags = 0;
303 out:
304 	if (!dev->mmio_always_on &&
305 	    (orig_cmd & PCI_COMMAND_DECODE_ENABLE))
306 		pci_write_config_word(dev, PCI_COMMAND, orig_cmd);
307 
308 	if (bar_too_big)
309 		dev_err(&dev->dev, "reg 0x%x: can't handle BAR larger than 4GB (size %#010llx)\n",
310 			pos, (unsigned long long) sz64);
311 	if (bar_too_high)
312 		dev_info(&dev->dev, "reg 0x%x: can't handle BAR above 4G (bus address %#010llx)\n",
313 			 pos, (unsigned long long) l64);
314 	if (bar_invalid)
315 		dev_info(&dev->dev, "reg 0x%x: initial BAR value %#010llx invalid\n",
316 			 pos, (unsigned long long) region.start);
317 	if (res->flags)
318 		dev_printk(KERN_DEBUG, &dev->dev, "reg 0x%x: %pR\n", pos, res);
319 
320 	return (res->flags & IORESOURCE_MEM_64) ? 1 : 0;
321 }
322 
323 static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
324 {
325 	unsigned int pos, reg;
326 
327 	for (pos = 0; pos < howmany; pos++) {
328 		struct resource *res = &dev->resource[pos];
329 		reg = PCI_BASE_ADDRESS_0 + (pos << 2);
330 		pos += __pci_read_base(dev, pci_bar_unknown, res, reg);
331 	}
332 
333 	if (rom) {
334 		struct resource *res = &dev->resource[PCI_ROM_RESOURCE];
335 		dev->rom_base_reg = rom;
336 		res->flags = IORESOURCE_MEM | IORESOURCE_PREFETCH |
337 				IORESOURCE_READONLY | IORESOURCE_CACHEABLE |
338 				IORESOURCE_SIZEALIGN;
339 		__pci_read_base(dev, pci_bar_mem32, res, rom);
340 	}
341 }
342 
343 static void pci_read_bridge_io(struct pci_bus *child)
344 {
345 	struct pci_dev *dev = child->self;
346 	u8 io_base_lo, io_limit_lo;
347 	unsigned long io_mask, io_granularity, base, limit;
348 	struct pci_bus_region region;
349 	struct resource *res;
350 
351 	io_mask = PCI_IO_RANGE_MASK;
352 	io_granularity = 0x1000;
353 	if (dev->io_window_1k) {
354 		/* Support 1K I/O space granularity */
355 		io_mask = PCI_IO_1K_RANGE_MASK;
356 		io_granularity = 0x400;
357 	}
358 
359 	res = child->resource[0];
360 	pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
361 	pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
362 	base = (io_base_lo & io_mask) << 8;
363 	limit = (io_limit_lo & io_mask) << 8;
364 
365 	if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) {
366 		u16 io_base_hi, io_limit_hi;
367 
368 		pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &io_base_hi);
369 		pci_read_config_word(dev, PCI_IO_LIMIT_UPPER16, &io_limit_hi);
370 		base |= ((unsigned long) io_base_hi << 16);
371 		limit |= ((unsigned long) io_limit_hi << 16);
372 	}
373 
374 	if (base <= limit) {
375 		res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
376 		region.start = base;
377 		region.end = limit + io_granularity - 1;
378 		pcibios_bus_to_resource(dev->bus, res, &region);
379 		dev_printk(KERN_DEBUG, &dev->dev, "  bridge window %pR\n", res);
380 	}
381 }
382 
383 static void pci_read_bridge_mmio(struct pci_bus *child)
384 {
385 	struct pci_dev *dev = child->self;
386 	u16 mem_base_lo, mem_limit_lo;
387 	unsigned long base, limit;
388 	struct pci_bus_region region;
389 	struct resource *res;
390 
391 	res = child->resource[1];
392 	pci_read_config_word(dev, PCI_MEMORY_BASE, &mem_base_lo);
393 	pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo);
394 	base = ((unsigned long) mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16;
395 	limit = ((unsigned long) mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16;
396 	if (base <= limit) {
397 		res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM;
398 		region.start = base;
399 		region.end = limit + 0xfffff;
400 		pcibios_bus_to_resource(dev->bus, res, &region);
401 		dev_printk(KERN_DEBUG, &dev->dev, "  bridge window %pR\n", res);
402 	}
403 }
404 
405 static void pci_read_bridge_mmio_pref(struct pci_bus *child)
406 {
407 	struct pci_dev *dev = child->self;
408 	u16 mem_base_lo, mem_limit_lo;
409 	unsigned long base, limit;
410 	struct pci_bus_region region;
411 	struct resource *res;
412 
413 	res = child->resource[2];
414 	pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo);
415 	pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo);
416 	base = ((unsigned long) mem_base_lo & PCI_PREF_RANGE_MASK) << 16;
417 	limit = ((unsigned long) mem_limit_lo & PCI_PREF_RANGE_MASK) << 16;
418 
419 	if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
420 		u32 mem_base_hi, mem_limit_hi;
421 
422 		pci_read_config_dword(dev, PCI_PREF_BASE_UPPER32, &mem_base_hi);
423 		pci_read_config_dword(dev, PCI_PREF_LIMIT_UPPER32, &mem_limit_hi);
424 
425 		/*
426 		 * Some bridges set the base > limit by default, and some
427 		 * (broken) BIOSes do not initialize them.  If we find
428 		 * this, just assume they are not being used.
429 		 */
430 		if (mem_base_hi <= mem_limit_hi) {
431 #if BITS_PER_LONG == 64
432 			base |= ((unsigned long) mem_base_hi) << 32;
433 			limit |= ((unsigned long) mem_limit_hi) << 32;
434 #else
435 			if (mem_base_hi || mem_limit_hi) {
436 				dev_err(&dev->dev, "can't handle 64-bit address space for bridge\n");
437 				return;
438 			}
439 #endif
440 		}
441 	}
442 	if (base <= limit) {
443 		res->flags = (mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) |
444 					 IORESOURCE_MEM | IORESOURCE_PREFETCH;
445 		if (res->flags & PCI_PREF_RANGE_TYPE_64)
446 			res->flags |= IORESOURCE_MEM_64;
447 		region.start = base;
448 		region.end = limit + 0xfffff;
449 		pcibios_bus_to_resource(dev->bus, res, &region);
450 		dev_printk(KERN_DEBUG, &dev->dev, "  bridge window %pR\n", res);
451 	}
452 }
453 
454 void pci_read_bridge_bases(struct pci_bus *child)
455 {
456 	struct pci_dev *dev = child->self;
457 	struct resource *res;
458 	int i;
459 
460 	if (pci_is_root_bus(child))	/* It's a host bus, nothing to read */
461 		return;
462 
463 	dev_info(&dev->dev, "PCI bridge to %pR%s\n",
464 		 &child->busn_res,
465 		 dev->transparent ? " (subtractive decode)" : "");
466 
467 	pci_bus_remove_resources(child);
468 	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
469 		child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i];
470 
471 	pci_read_bridge_io(child);
472 	pci_read_bridge_mmio(child);
473 	pci_read_bridge_mmio_pref(child);
474 
475 	if (dev->transparent) {
476 		pci_bus_for_each_resource(child->parent, res, i) {
477 			if (res && res->flags) {
478 				pci_bus_add_resource(child, res,
479 						     PCI_SUBTRACTIVE_DECODE);
480 				dev_printk(KERN_DEBUG, &dev->dev,
481 					   "  bridge window %pR (subtractive decode)\n",
482 					   res);
483 			}
484 		}
485 	}
486 }
487 
488 static struct pci_bus *pci_alloc_bus(void)
489 {
490 	struct pci_bus *b;
491 
492 	b = kzalloc(sizeof(*b), GFP_KERNEL);
493 	if (!b)
494 		return NULL;
495 
496 	INIT_LIST_HEAD(&b->node);
497 	INIT_LIST_HEAD(&b->children);
498 	INIT_LIST_HEAD(&b->devices);
499 	INIT_LIST_HEAD(&b->slots);
500 	INIT_LIST_HEAD(&b->resources);
501 	b->max_bus_speed = PCI_SPEED_UNKNOWN;
502 	b->cur_bus_speed = PCI_SPEED_UNKNOWN;
503 	return b;
504 }
505 
506 static void pci_release_host_bridge_dev(struct device *dev)
507 {
508 	struct pci_host_bridge *bridge = to_pci_host_bridge(dev);
509 
510 	if (bridge->release_fn)
511 		bridge->release_fn(bridge);
512 
513 	pci_free_resource_list(&bridge->windows);
514 
515 	kfree(bridge);
516 }
517 
518 static struct pci_host_bridge *pci_alloc_host_bridge(struct pci_bus *b)
519 {
520 	struct pci_host_bridge *bridge;
521 
522 	bridge = kzalloc(sizeof(*bridge), GFP_KERNEL);
523 	if (!bridge)
524 		return NULL;
525 
526 	INIT_LIST_HEAD(&bridge->windows);
527 	bridge->bus = b;
528 	return bridge;
529 }
530 
531 static const unsigned char pcix_bus_speed[] = {
532 	PCI_SPEED_UNKNOWN,		/* 0 */
533 	PCI_SPEED_66MHz_PCIX,		/* 1 */
534 	PCI_SPEED_100MHz_PCIX,		/* 2 */
535 	PCI_SPEED_133MHz_PCIX,		/* 3 */
536 	PCI_SPEED_UNKNOWN,		/* 4 */
537 	PCI_SPEED_66MHz_PCIX_ECC,	/* 5 */
538 	PCI_SPEED_100MHz_PCIX_ECC,	/* 6 */
539 	PCI_SPEED_133MHz_PCIX_ECC,	/* 7 */
540 	PCI_SPEED_UNKNOWN,		/* 8 */
541 	PCI_SPEED_66MHz_PCIX_266,	/* 9 */
542 	PCI_SPEED_100MHz_PCIX_266,	/* A */
543 	PCI_SPEED_133MHz_PCIX_266,	/* B */
544 	PCI_SPEED_UNKNOWN,		/* C */
545 	PCI_SPEED_66MHz_PCIX_533,	/* D */
546 	PCI_SPEED_100MHz_PCIX_533,	/* E */
547 	PCI_SPEED_133MHz_PCIX_533	/* F */
548 };
549 
550 const unsigned char pcie_link_speed[] = {
551 	PCI_SPEED_UNKNOWN,		/* 0 */
552 	PCIE_SPEED_2_5GT,		/* 1 */
553 	PCIE_SPEED_5_0GT,		/* 2 */
554 	PCIE_SPEED_8_0GT,		/* 3 */
555 	PCI_SPEED_UNKNOWN,		/* 4 */
556 	PCI_SPEED_UNKNOWN,		/* 5 */
557 	PCI_SPEED_UNKNOWN,		/* 6 */
558 	PCI_SPEED_UNKNOWN,		/* 7 */
559 	PCI_SPEED_UNKNOWN,		/* 8 */
560 	PCI_SPEED_UNKNOWN,		/* 9 */
561 	PCI_SPEED_UNKNOWN,		/* A */
562 	PCI_SPEED_UNKNOWN,		/* B */
563 	PCI_SPEED_UNKNOWN,		/* C */
564 	PCI_SPEED_UNKNOWN,		/* D */
565 	PCI_SPEED_UNKNOWN,		/* E */
566 	PCI_SPEED_UNKNOWN		/* F */
567 };
568 
569 void pcie_update_link_speed(struct pci_bus *bus, u16 linksta)
570 {
571 	bus->cur_bus_speed = pcie_link_speed[linksta & PCI_EXP_LNKSTA_CLS];
572 }
573 EXPORT_SYMBOL_GPL(pcie_update_link_speed);
574 
575 static unsigned char agp_speeds[] = {
576 	AGP_UNKNOWN,
577 	AGP_1X,
578 	AGP_2X,
579 	AGP_4X,
580 	AGP_8X
581 };
582 
583 static enum pci_bus_speed agp_speed(int agp3, int agpstat)
584 {
585 	int index = 0;
586 
587 	if (agpstat & 4)
588 		index = 3;
589 	else if (agpstat & 2)
590 		index = 2;
591 	else if (agpstat & 1)
592 		index = 1;
593 	else
594 		goto out;
595 
596 	if (agp3) {
597 		index += 2;
598 		if (index == 5)
599 			index = 0;
600 	}
601 
602  out:
603 	return agp_speeds[index];
604 }
605 
606 static void pci_set_bus_speed(struct pci_bus *bus)
607 {
608 	struct pci_dev *bridge = bus->self;
609 	int pos;
610 
611 	pos = pci_find_capability(bridge, PCI_CAP_ID_AGP);
612 	if (!pos)
613 		pos = pci_find_capability(bridge, PCI_CAP_ID_AGP3);
614 	if (pos) {
615 		u32 agpstat, agpcmd;
616 
617 		pci_read_config_dword(bridge, pos + PCI_AGP_STATUS, &agpstat);
618 		bus->max_bus_speed = agp_speed(agpstat & 8, agpstat & 7);
619 
620 		pci_read_config_dword(bridge, pos + PCI_AGP_COMMAND, &agpcmd);
621 		bus->cur_bus_speed = agp_speed(agpstat & 8, agpcmd & 7);
622 	}
623 
624 	pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
625 	if (pos) {
626 		u16 status;
627 		enum pci_bus_speed max;
628 
629 		pci_read_config_word(bridge, pos + PCI_X_BRIDGE_SSTATUS,
630 				     &status);
631 
632 		if (status & PCI_X_SSTATUS_533MHZ) {
633 			max = PCI_SPEED_133MHz_PCIX_533;
634 		} else if (status & PCI_X_SSTATUS_266MHZ) {
635 			max = PCI_SPEED_133MHz_PCIX_266;
636 		} else if (status & PCI_X_SSTATUS_133MHZ) {
637 			if ((status & PCI_X_SSTATUS_VERS) == PCI_X_SSTATUS_V2)
638 				max = PCI_SPEED_133MHz_PCIX_ECC;
639 			else
640 				max = PCI_SPEED_133MHz_PCIX;
641 		} else {
642 			max = PCI_SPEED_66MHz_PCIX;
643 		}
644 
645 		bus->max_bus_speed = max;
646 		bus->cur_bus_speed = pcix_bus_speed[
647 			(status & PCI_X_SSTATUS_FREQ) >> 6];
648 
649 		return;
650 	}
651 
652 	if (pci_is_pcie(bridge)) {
653 		u32 linkcap;
654 		u16 linksta;
655 
656 		pcie_capability_read_dword(bridge, PCI_EXP_LNKCAP, &linkcap);
657 		bus->max_bus_speed = pcie_link_speed[linkcap & PCI_EXP_LNKCAP_SLS];
658 
659 		pcie_capability_read_word(bridge, PCI_EXP_LNKSTA, &linksta);
660 		pcie_update_link_speed(bus, linksta);
661 	}
662 }
663 
664 static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent,
665 					   struct pci_dev *bridge, int busnr)
666 {
667 	struct pci_bus *child;
668 	int i;
669 	int ret;
670 
671 	/*
672 	 * Allocate a new bus, and inherit stuff from the parent..
673 	 */
674 	child = pci_alloc_bus();
675 	if (!child)
676 		return NULL;
677 
678 	child->parent = parent;
679 	child->ops = parent->ops;
680 	child->msi = parent->msi;
681 	child->sysdata = parent->sysdata;
682 	child->bus_flags = parent->bus_flags;
683 
684 	/* initialize some portions of the bus device, but don't register it
685 	 * now as the parent is not properly set up yet.
686 	 */
687 	child->dev.class = &pcibus_class;
688 	dev_set_name(&child->dev, "%04x:%02x", pci_domain_nr(child), busnr);
689 
690 	/*
691 	 * Set up the primary, secondary and subordinate
692 	 * bus numbers.
693 	 */
694 	child->number = child->busn_res.start = busnr;
695 	child->primary = parent->busn_res.start;
696 	child->busn_res.end = 0xff;
697 
698 	if (!bridge) {
699 		child->dev.parent = parent->bridge;
700 		goto add_dev;
701 	}
702 
703 	child->self = bridge;
704 	child->bridge = get_device(&bridge->dev);
705 	child->dev.parent = child->bridge;
706 	pci_set_bus_of_node(child);
707 	pci_set_bus_speed(child);
708 
709 	/* Set up default resource pointers and names.. */
710 	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) {
711 		child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i];
712 		child->resource[i]->name = child->name;
713 	}
714 	bridge->subordinate = child;
715 
716 add_dev:
717 	ret = device_register(&child->dev);
718 	WARN_ON(ret < 0);
719 
720 	pcibios_add_bus(child);
721 
722 	/* Create legacy_io and legacy_mem files for this bus */
723 	pci_create_legacy_files(child);
724 
725 	return child;
726 }
727 
728 struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev,
729 				int busnr)
730 {
731 	struct pci_bus *child;
732 
733 	child = pci_alloc_child_bus(parent, dev, busnr);
734 	if (child) {
735 		down_write(&pci_bus_sem);
736 		list_add_tail(&child->node, &parent->children);
737 		up_write(&pci_bus_sem);
738 	}
739 	return child;
740 }
741 EXPORT_SYMBOL(pci_add_new_bus);
742 
743 /*
744  * If it's a bridge, configure it and scan the bus behind it.
745  * For CardBus bridges, we don't scan behind as the devices will
746  * be handled by the bridge driver itself.
747  *
748  * We need to process bridges in two passes -- first we scan those
749  * already configured by the BIOS and after we are done with all of
750  * them, we proceed to assigning numbers to the remaining buses in
751  * order to avoid overlaps between old and new bus numbers.
752  */
753 int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
754 {
755 	struct pci_bus *child;
756 	int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
757 	u32 buses, i, j = 0;
758 	u16 bctl;
759 	u8 primary, secondary, subordinate;
760 	int broken = 0;
761 
762 	pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
763 	primary = buses & 0xFF;
764 	secondary = (buses >> 8) & 0xFF;
765 	subordinate = (buses >> 16) & 0xFF;
766 
767 	dev_dbg(&dev->dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n",
768 		secondary, subordinate, pass);
769 
770 	if (!primary && (primary != bus->number) && secondary && subordinate) {
771 		dev_warn(&dev->dev, "Primary bus is hard wired to 0\n");
772 		primary = bus->number;
773 	}
774 
775 	/* Check if setup is sensible at all */
776 	if (!pass &&
777 	    (primary != bus->number || secondary <= bus->number ||
778 	     secondary > subordinate)) {
779 		dev_info(&dev->dev, "bridge configuration invalid ([bus %02x-%02x]), reconfiguring\n",
780 			 secondary, subordinate);
781 		broken = 1;
782 	}
783 
784 	/* Disable MasterAbortMode during probing to avoid reporting
785 	   of bus errors (in some architectures) */
786 	pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl);
787 	pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
788 			      bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);
789 
790 	if ((secondary || subordinate) && !pcibios_assign_all_busses() &&
791 	    !is_cardbus && !broken) {
792 		unsigned int cmax;
793 		/*
794 		 * Bus already configured by firmware, process it in the first
795 		 * pass and just note the configuration.
796 		 */
797 		if (pass)
798 			goto out;
799 
800 		/*
801 		 * The bus might already exist for two reasons: Either we are
802 		 * rescanning the bus or the bus is reachable through more than
803 		 * one bridge. The second case can happen with the i450NX
804 		 * chipset.
805 		 */
806 		child = pci_find_bus(pci_domain_nr(bus), secondary);
807 		if (!child) {
808 			child = pci_add_new_bus(bus, dev, secondary);
809 			if (!child)
810 				goto out;
811 			child->primary = primary;
812 			pci_bus_insert_busn_res(child, secondary, subordinate);
813 			child->bridge_ctl = bctl;
814 		}
815 
816 		cmax = pci_scan_child_bus(child);
817 		if (cmax > subordinate)
818 			dev_warn(&dev->dev, "bridge has subordinate %02x but max busn %02x\n",
819 				 subordinate, cmax);
820 		/* subordinate should equal child->busn_res.end */
821 		if (subordinate > max)
822 			max = subordinate;
823 	} else {
824 		/*
825 		 * We need to assign a number to this bus which we always
826 		 * do in the second pass.
827 		 */
828 		if (!pass) {
829 			if (pcibios_assign_all_busses() || broken || is_cardbus)
830 				/* Temporarily disable forwarding of the
831 				   configuration cycles on all bridges in
832 				   this bus segment to avoid possible
833 				   conflicts in the second pass between two
834 				   bridges programmed with overlapping
835 				   bus ranges. */
836 				pci_write_config_dword(dev, PCI_PRIMARY_BUS,
837 						       buses & ~0xffffff);
838 			goto out;
839 		}
840 
841 		/* Clear errors */
842 		pci_write_config_word(dev, PCI_STATUS, 0xffff);
843 
844 		/* Prevent assigning a bus number that already exists.
845 		 * This can happen when a bridge is hot-plugged, so in
846 		 * this case we only re-scan this bus. */
847 		child = pci_find_bus(pci_domain_nr(bus), max+1);
848 		if (!child) {
849 			child = pci_add_new_bus(bus, dev, max+1);
850 			if (!child)
851 				goto out;
852 			pci_bus_insert_busn_res(child, max+1, 0xff);
853 		}
854 		max++;
855 		buses = (buses & 0xff000000)
856 		      | ((unsigned int)(child->primary)     <<  0)
857 		      | ((unsigned int)(child->busn_res.start)   <<  8)
858 		      | ((unsigned int)(child->busn_res.end) << 16);
859 
860 		/*
861 		 * yenta.c forces a secondary latency timer of 176.
862 		 * Copy that behaviour here.
863 		 */
864 		if (is_cardbus) {
865 			buses &= ~0xff000000;
866 			buses |= CARDBUS_LATENCY_TIMER << 24;
867 		}
868 
869 		/*
870 		 * We need to blast all three values with a single write.
871 		 */
872 		pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses);
873 
874 		if (!is_cardbus) {
875 			child->bridge_ctl = bctl;
876 			max = pci_scan_child_bus(child);
877 		} else {
878 			/*
879 			 * For CardBus bridges, we leave 4 bus numbers
880 			 * as cards with a PCI-to-PCI bridge can be
881 			 * inserted later.
882 			 */
883 			for (i = 0; i < CARDBUS_RESERVE_BUSNR; i++) {
884 				struct pci_bus *parent = bus;
885 				if (pci_find_bus(pci_domain_nr(bus),
886 							max+i+1))
887 					break;
888 				while (parent->parent) {
889 					if ((!pcibios_assign_all_busses()) &&
890 					    (parent->busn_res.end > max) &&
891 					    (parent->busn_res.end <= max+i)) {
892 						j = 1;
893 					}
894 					parent = parent->parent;
895 				}
896 				if (j) {
897 					/*
898 					 * Often, there are two cardbus bridges
899 					 * -- try to leave one valid bus number
900 					 * for each one.
901 					 */
902 					i /= 2;
903 					break;
904 				}
905 			}
906 			max += i;
907 		}
908 		/*
909 		 * Set the subordinate bus number to its real value.
910 		 */
911 		pci_bus_update_busn_res_end(child, max);
912 		pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
913 	}
914 
915 	sprintf(child->name,
916 		(is_cardbus ? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"),
917 		pci_domain_nr(bus), child->number);
918 
919 	/* Has only triggered on CardBus, fixup is in yenta_socket */
920 	while (bus->parent) {
921 		if ((child->busn_res.end > bus->busn_res.end) ||
922 		    (child->number > bus->busn_res.end) ||
923 		    (child->number < bus->number) ||
924 		    (child->busn_res.end < bus->number)) {
925 			dev_info(&child->dev, "%pR %s hidden behind%s bridge %s %pR\n",
926 				&child->busn_res,
927 				(bus->number > child->busn_res.end &&
928 				 bus->busn_res.end < child->number) ?
929 					"wholly" : "partially",
930 				bus->self->transparent ? " transparent" : "",
931 				dev_name(&bus->dev),
932 				&bus->busn_res);
933 		}
934 		bus = bus->parent;
935 	}
936 
937 out:
938 	pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl);
939 
940 	return max;
941 }
942 EXPORT_SYMBOL(pci_scan_bridge);
943 
944 /*
945  * Read interrupt line and base address registers.
946  * The architecture-dependent code can tweak these, of course.
947  */
948 static void pci_read_irq(struct pci_dev *dev)
949 {
950 	unsigned char irq;
951 
952 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq);
953 	dev->pin = irq;
954 	if (irq)
955 		pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);
956 	dev->irq = irq;
957 }
958 
959 void set_pcie_port_type(struct pci_dev *pdev)
960 {
961 	int pos;
962 	u16 reg16;
963 
964 	pos = pci_find_capability(pdev, PCI_CAP_ID_EXP);
965 	if (!pos)
966 		return;
967 	pdev->pcie_cap = pos;
968 	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
969 	pdev->pcie_flags_reg = reg16;
970 	pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
971 	pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
972 }
973 
974 void set_pcie_hotplug_bridge(struct pci_dev *pdev)
975 {
976 	u32 reg32;
977 
978 	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &reg32);
979 	if (reg32 & PCI_EXP_SLTCAP_HPC)
980 		pdev->is_hotplug_bridge = 1;
981 }
982 
983 /**
984  * pci_ext_cfg_is_aliased - is ext config space just an alias of std config?
985  * @dev: PCI device
986  *
987  * PCI Express to PCI/PCI-X Bridge Specification, rev 1.0, 4.1.4 says that
988  * when forwarding a type1 configuration request the bridge must check that
989  * the extended register address field is zero.  The bridge is not permitted
990  * to forward the transactions and must handle it as an Unsupported Request.
991  * Some bridges do not follow this rule and simply drop the extended register
992  * bits, resulting in the standard config space being aliased, every 256
993  * bytes across the entire configuration space.  Test for this condition by
994  * comparing the first dword of each potential alias to the vendor/device ID.
995  * Known offenders:
996  *   ASM1083/1085 PCIe-to-PCI Reversible Bridge (1b21:1080, rev 01 & 03)
997  *   AMD/ATI SBx00 PCI to PCI Bridge (1002:4384, rev 40)
998  */
999 static bool pci_ext_cfg_is_aliased(struct pci_dev *dev)
1000 {
1001 #ifdef CONFIG_PCI_QUIRKS
1002 	int pos;
1003 	u32 header, tmp;
1004 
1005 	pci_read_config_dword(dev, PCI_VENDOR_ID, &header);
1006 
1007 	for (pos = PCI_CFG_SPACE_SIZE;
1008 	     pos < PCI_CFG_SPACE_EXP_SIZE; pos += PCI_CFG_SPACE_SIZE) {
1009 		if (pci_read_config_dword(dev, pos, &tmp) != PCIBIOS_SUCCESSFUL
1010 		    || header != tmp)
1011 			return false;
1012 	}
1013 
1014 	return true;
1015 #else
1016 	return false;
1017 #endif
1018 }
1019 
1020 /**
1021  * pci_cfg_space_size - get the configuration space size of the PCI device.
1022  * @dev: PCI device
1023  *
1024  * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices
1025  * have 4096 bytes.  Even if the device is capable, that doesn't mean we can
1026  * access it.  Maybe we don't have a way to generate extended config space
1027  * accesses, or the device is behind a reverse Express bridge.  So we try
1028  * reading the dword at 0x100 which must either be 0 or a valid extended
1029  * capability header.
1030  */
1031 static int pci_cfg_space_size_ext(struct pci_dev *dev)
1032 {
1033 	u32 status;
1034 	int pos = PCI_CFG_SPACE_SIZE;
1035 
1036 	if (pci_read_config_dword(dev, pos, &status) != PCIBIOS_SUCCESSFUL)
1037 		goto fail;
1038 	if (status == 0xffffffff || pci_ext_cfg_is_aliased(dev))
1039 		goto fail;
1040 
1041 	return PCI_CFG_SPACE_EXP_SIZE;
1042 
1043  fail:
1044 	return PCI_CFG_SPACE_SIZE;
1045 }
1046 
1047 int pci_cfg_space_size(struct pci_dev *dev)
1048 {
1049 	int pos;
1050 	u32 status;
1051 	u16 class;
1052 
1053 	class = dev->class >> 8;
1054 	if (class == PCI_CLASS_BRIDGE_HOST)
1055 		return pci_cfg_space_size_ext(dev);
1056 
1057 	if (!pci_is_pcie(dev)) {
1058 		pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
1059 		if (!pos)
1060 			goto fail;
1061 
1062 		pci_read_config_dword(dev, pos + PCI_X_STATUS, &status);
1063 		if (!(status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ)))
1064 			goto fail;
1065 	}
1066 
1067 	return pci_cfg_space_size_ext(dev);
1068 
1069  fail:
1070 	return PCI_CFG_SPACE_SIZE;
1071 }
1072 
1073 #define LEGACY_IO_RESOURCE	(IORESOURCE_IO | IORESOURCE_PCI_FIXED)
1074 
1075 /**
1076  * pci_setup_device - fill in class and map information of a device
1077  * @dev: the device structure to fill
1078  *
1079  * Initialize the device structure with information about the device's
1080  * vendor,class,memory and IO-space addresses,IRQ lines etc.
1081  * Called at initialisation of the PCI subsystem and by CardBus services.
1082  * Returns 0 on success and negative if unknown type of device (not normal,
1083  * bridge or CardBus).
1084  */
1085 int pci_setup_device(struct pci_dev *dev)
1086 {
1087 	u32 class;
1088 	u8 hdr_type;
1089 	struct pci_slot *slot;
1090 	int pos = 0;
1091 	struct pci_bus_region region;
1092 	struct resource *res;
1093 
1094 	if (pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type))
1095 		return -EIO;
1096 
1097 	dev->sysdata = dev->bus->sysdata;
1098 	dev->dev.parent = dev->bus->bridge;
1099 	dev->dev.bus = &pci_bus_type;
1100 	dev->hdr_type = hdr_type & 0x7f;
1101 	dev->multifunction = !!(hdr_type & 0x80);
1102 	dev->error_state = pci_channel_io_normal;
1103 	set_pcie_port_type(dev);
1104 
1105 	list_for_each_entry(slot, &dev->bus->slots, list)
1106 		if (PCI_SLOT(dev->devfn) == slot->number)
1107 			dev->slot = slot;
1108 
1109 	/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
1110 	   set this higher, assuming the system even supports it.  */
1111 	dev->dma_mask = 0xffffffff;
1112 
1113 	dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus),
1114 		     dev->bus->number, PCI_SLOT(dev->devfn),
1115 		     PCI_FUNC(dev->devfn));
1116 
1117 	pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
1118 	dev->revision = class & 0xff;
1119 	dev->class = class >> 8;		    /* upper 3 bytes */
1120 
1121 	dev_printk(KERN_DEBUG, &dev->dev, "[%04x:%04x] type %02x class %#08x\n",
1122 		   dev->vendor, dev->device, dev->hdr_type, dev->class);
1123 
1124 	/* need to have dev->class ready */
1125 	dev->cfg_size = pci_cfg_space_size(dev);
1126 
1127 	/* "Unknown power state" */
1128 	dev->current_state = PCI_UNKNOWN;
1129 
1130 	/* Early fixups, before probing the BARs */
1131 	pci_fixup_device(pci_fixup_early, dev);
1132 	/* device class may be changed after fixup */
1133 	class = dev->class >> 8;
1134 
1135 	switch (dev->hdr_type) {		    /* header type */
1136 	case PCI_HEADER_TYPE_NORMAL:		    /* standard header */
1137 		if (class == PCI_CLASS_BRIDGE_PCI)
1138 			goto bad;
1139 		pci_read_irq(dev);
1140 		pci_read_bases(dev, 6, PCI_ROM_ADDRESS);
1141 		pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
1142 		pci_read_config_word(dev, PCI_SUBSYSTEM_ID, &dev->subsystem_device);
1143 
1144 		/*
1145 		 * Do the ugly legacy mode stuff here rather than broken chip
1146 		 * quirk code. Legacy mode ATA controllers have fixed
1147 		 * addresses. These are not always echoed in BAR0-3, and
1148 		 * BAR0-3 in a few cases contain junk!
1149 		 */
1150 		if (class == PCI_CLASS_STORAGE_IDE) {
1151 			u8 progif;
1152 			pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
1153 			if ((progif & 1) == 0) {
1154 				region.start = 0x1F0;
1155 				region.end = 0x1F7;
1156 				res = &dev->resource[0];
1157 				res->flags = LEGACY_IO_RESOURCE;
1158 				pcibios_bus_to_resource(dev->bus, res, &region);
1159 				dev_info(&dev->dev, "legacy IDE quirk: reg 0x10: %pR\n",
1160 					 res);
1161 				region.start = 0x3F6;
1162 				region.end = 0x3F6;
1163 				res = &dev->resource[1];
1164 				res->flags = LEGACY_IO_RESOURCE;
1165 				pcibios_bus_to_resource(dev->bus, res, &region);
1166 				dev_info(&dev->dev, "legacy IDE quirk: reg 0x14: %pR\n",
1167 					 res);
1168 			}
1169 			if ((progif & 4) == 0) {
1170 				region.start = 0x170;
1171 				region.end = 0x177;
1172 				res = &dev->resource[2];
1173 				res->flags = LEGACY_IO_RESOURCE;
1174 				pcibios_bus_to_resource(dev->bus, res, &region);
1175 				dev_info(&dev->dev, "legacy IDE quirk: reg 0x18: %pR\n",
1176 					 res);
1177 				region.start = 0x376;
1178 				region.end = 0x376;
1179 				res = &dev->resource[3];
1180 				res->flags = LEGACY_IO_RESOURCE;
1181 				pcibios_bus_to_resource(dev->bus, res, &region);
1182 				dev_info(&dev->dev, "legacy IDE quirk: reg 0x1c: %pR\n",
1183 					 res);
1184 			}
1185 		}
1186 		break;
1187 
1188 	case PCI_HEADER_TYPE_BRIDGE:		    /* bridge header */
1189 		if (class != PCI_CLASS_BRIDGE_PCI)
1190 			goto bad;
1191 		/* The PCI-to-PCI bridge spec requires that subtractive
1192 		   decoding (i.e. transparent) bridge must have programming
1193 		   interface code of 0x01. */
1194 		pci_read_irq(dev);
1195 		dev->transparent = ((dev->class & 0xff) == 1);
1196 		pci_read_bases(dev, 2, PCI_ROM_ADDRESS1);
1197 		set_pcie_hotplug_bridge(dev);
1198 		pos = pci_find_capability(dev, PCI_CAP_ID_SSVID);
1199 		if (pos) {
1200 			pci_read_config_word(dev, pos + PCI_SSVID_VENDOR_ID, &dev->subsystem_vendor);
1201 			pci_read_config_word(dev, pos + PCI_SSVID_DEVICE_ID, &dev->subsystem_device);
1202 		}
1203 		break;
1204 
1205 	case PCI_HEADER_TYPE_CARDBUS:		    /* CardBus bridge header */
1206 		if (class != PCI_CLASS_BRIDGE_CARDBUS)
1207 			goto bad;
1208 		pci_read_irq(dev);
1209 		pci_read_bases(dev, 1, 0);
1210 		pci_read_config_word(dev, PCI_CB_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
1211 		pci_read_config_word(dev, PCI_CB_SUBSYSTEM_ID, &dev->subsystem_device);
1212 		break;
1213 
1214 	default:				    /* unknown header */
1215 		dev_err(&dev->dev, "unknown header type %02x, ignoring device\n",
1216 			dev->hdr_type);
1217 		return -EIO;
1218 
1219 	bad:
1220 		dev_err(&dev->dev, "ignoring class %#08x (doesn't match header type %02x)\n",
1221 			dev->class, dev->hdr_type);
1222 		dev->class = PCI_CLASS_NOT_DEFINED;
1223 	}
1224 
1225 	/* We found a fine healthy device, go go go... */
1226 	return 0;
1227 }
1228 
1229 static void pci_release_capabilities(struct pci_dev *dev)
1230 {
1231 	pci_vpd_release(dev);
1232 	pci_iov_release(dev);
1233 	pci_free_cap_save_buffers(dev);
1234 }
1235 
1236 /**
1237  * pci_release_dev - free a pci device structure when all users of it are finished.
1238  * @dev: device that's been disconnected
1239  *
1240  * Will be called only by the device core when all users of this pci device are
1241  * done.
1242  */
1243 static void pci_release_dev(struct device *dev)
1244 {
1245 	struct pci_dev *pci_dev;
1246 
1247 	pci_dev = to_pci_dev(dev);
1248 	pci_release_capabilities(pci_dev);
1249 	pci_release_of_node(pci_dev);
1250 	pcibios_release_device(pci_dev);
1251 	pci_bus_put(pci_dev->bus);
1252 	kfree(pci_dev->driver_override);
1253 	kfree(pci_dev);
1254 }
1255 
1256 struct pci_dev *pci_alloc_dev(struct pci_bus *bus)
1257 {
1258 	struct pci_dev *dev;
1259 
1260 	dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
1261 	if (!dev)
1262 		return NULL;
1263 
1264 	INIT_LIST_HEAD(&dev->bus_list);
1265 	dev->dev.type = &pci_dev_type;
1266 	dev->bus = pci_bus_get(bus);
1267 
1268 	return dev;
1269 }
1270 EXPORT_SYMBOL(pci_alloc_dev);
1271 
1272 bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l,
1273 				int crs_timeout)
1274 {
1275 	int delay = 1;
1276 
1277 	if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l))
1278 		return false;
1279 
1280 	/* some broken boards return 0 or ~0 if a slot is empty: */
1281 	if (*l == 0xffffffff || *l == 0x00000000 ||
1282 	    *l == 0x0000ffff || *l == 0xffff0000)
1283 		return false;
1284 
1285 	/* Configuration request Retry Status */
1286 	while (*l == 0xffff0001) {
1287 		if (!crs_timeout)
1288 			return false;
1289 
1290 		msleep(delay);
1291 		delay *= 2;
1292 		if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l))
1293 			return false;
1294 		/* Card hasn't responded in 60 seconds?  Must be stuck. */
1295 		if (delay > crs_timeout) {
1296 			printk(KERN_WARNING "pci %04x:%02x:%02x.%d: not responding\n",
1297 			       pci_domain_nr(bus), bus->number, PCI_SLOT(devfn),
1298 			       PCI_FUNC(devfn));
1299 			return false;
1300 		}
1301 	}
1302 
1303 	return true;
1304 }
1305 EXPORT_SYMBOL(pci_bus_read_dev_vendor_id);
1306 
1307 /*
1308  * Read the config data for a PCI device, sanity-check it
1309  * and fill in the dev structure...
1310  */
1311 static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
1312 {
1313 	struct pci_dev *dev;
1314 	u32 l;
1315 
1316 	if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000))
1317 		return NULL;
1318 
1319 	dev = pci_alloc_dev(bus);
1320 	if (!dev)
1321 		return NULL;
1322 
1323 	dev->devfn = devfn;
1324 	dev->vendor = l & 0xffff;
1325 	dev->device = (l >> 16) & 0xffff;
1326 
1327 	pci_set_of_node(dev);
1328 
1329 	if (pci_setup_device(dev)) {
1330 		pci_bus_put(dev->bus);
1331 		kfree(dev);
1332 		return NULL;
1333 	}
1334 
1335 	return dev;
1336 }
1337 
1338 static void pci_init_capabilities(struct pci_dev *dev)
1339 {
1340 	/* MSI/MSI-X list */
1341 	pci_msi_init_pci_dev(dev);
1342 
1343 	/* Buffers for saving PCIe and PCI-X capabilities */
1344 	pci_allocate_cap_save_buffers(dev);
1345 
1346 	/* Power Management */
1347 	pci_pm_init(dev);
1348 
1349 	/* Vital Product Data */
1350 	pci_vpd_pci22_init(dev);
1351 
1352 	/* Alternative Routing-ID Forwarding */
1353 	pci_configure_ari(dev);
1354 
1355 	/* Single Root I/O Virtualization */
1356 	pci_iov_init(dev);
1357 
1358 	/* Enable ACS P2P upstream forwarding */
1359 	pci_enable_acs(dev);
1360 }
1361 
1362 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
1363 {
1364 	int ret;
1365 
1366 	device_initialize(&dev->dev);
1367 	dev->dev.release = pci_release_dev;
1368 
1369 	set_dev_node(&dev->dev, pcibus_to_node(bus));
1370 	dev->dev.dma_mask = &dev->dma_mask;
1371 	dev->dev.dma_parms = &dev->dma_parms;
1372 	dev->dev.coherent_dma_mask = 0xffffffffull;
1373 
1374 	pci_set_dma_max_seg_size(dev, 65536);
1375 	pci_set_dma_seg_boundary(dev, 0xffffffff);
1376 
1377 	/* Fix up broken headers */
1378 	pci_fixup_device(pci_fixup_header, dev);
1379 
1380 	/* moved out from quirk header fixup code */
1381 	pci_reassigndev_resource_alignment(dev);
1382 
1383 	/* Clear the state_saved flag. */
1384 	dev->state_saved = false;
1385 
1386 	/* Initialize various capabilities */
1387 	pci_init_capabilities(dev);
1388 
1389 	/*
1390 	 * Add the device to our list of discovered devices
1391 	 * and the bus list for fixup functions, etc.
1392 	 */
1393 	down_write(&pci_bus_sem);
1394 	list_add_tail(&dev->bus_list, &bus->devices);
1395 	up_write(&pci_bus_sem);
1396 
1397 	ret = pcibios_add_device(dev);
1398 	WARN_ON(ret < 0);
1399 
1400 	/* Notifier could use PCI capabilities */
1401 	dev->match_driver = false;
1402 	ret = device_add(&dev->dev);
1403 	WARN_ON(ret < 0);
1404 }
1405 
1406 struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn)
1407 {
1408 	struct pci_dev *dev;
1409 
1410 	dev = pci_get_slot(bus, devfn);
1411 	if (dev) {
1412 		pci_dev_put(dev);
1413 		return dev;
1414 	}
1415 
1416 	dev = pci_scan_device(bus, devfn);
1417 	if (!dev)
1418 		return NULL;
1419 
1420 	pci_device_add(dev, bus);
1421 
1422 	return dev;
1423 }
1424 EXPORT_SYMBOL(pci_scan_single_device);
1425 
1426 static unsigned next_fn(struct pci_bus *bus, struct pci_dev *dev, unsigned fn)
1427 {
1428 	int pos;
1429 	u16 cap = 0;
1430 	unsigned next_fn;
1431 
1432 	if (pci_ari_enabled(bus)) {
1433 		if (!dev)
1434 			return 0;
1435 		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI);
1436 		if (!pos)
1437 			return 0;
1438 
1439 		pci_read_config_word(dev, pos + PCI_ARI_CAP, &cap);
1440 		next_fn = PCI_ARI_CAP_NFN(cap);
1441 		if (next_fn <= fn)
1442 			return 0;	/* protect against malformed list */
1443 
1444 		return next_fn;
1445 	}
1446 
1447 	/* dev may be NULL for non-contiguous multifunction devices */
1448 	if (!dev || dev->multifunction)
1449 		return (fn + 1) % 8;
1450 
1451 	return 0;
1452 }
1453 
1454 static int only_one_child(struct pci_bus *bus)
1455 {
1456 	struct pci_dev *parent = bus->self;
1457 
1458 	if (!parent || !pci_is_pcie(parent))
1459 		return 0;
1460 	if (pci_pcie_type(parent) == PCI_EXP_TYPE_ROOT_PORT)
1461 		return 1;
1462 	if (pci_pcie_type(parent) == PCI_EXP_TYPE_DOWNSTREAM &&
1463 	    !pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS))
1464 		return 1;
1465 	return 0;
1466 }
1467 
1468 /**
1469  * pci_scan_slot - scan a PCI slot on a bus for devices.
1470  * @bus: PCI bus to scan
1471  * @devfn: slot number to scan (must have zero function.)
1472  *
1473  * Scan a PCI slot on the specified PCI bus for devices, adding
1474  * discovered devices to the @bus->devices list.  New devices
1475  * will not have is_added set.
1476  *
1477  * Returns the number of new devices found.
1478  */
1479 int pci_scan_slot(struct pci_bus *bus, int devfn)
1480 {
1481 	unsigned fn, nr = 0;
1482 	struct pci_dev *dev;
1483 
1484 	if (only_one_child(bus) && (devfn > 0))
1485 		return 0; /* Already scanned the entire slot */
1486 
1487 	dev = pci_scan_single_device(bus, devfn);
1488 	if (!dev)
1489 		return 0;
1490 	if (!dev->is_added)
1491 		nr++;
1492 
1493 	for (fn = next_fn(bus, dev, 0); fn > 0; fn = next_fn(bus, dev, fn)) {
1494 		dev = pci_scan_single_device(bus, devfn + fn);
1495 		if (dev) {
1496 			if (!dev->is_added)
1497 				nr++;
1498 			dev->multifunction = 1;
1499 		}
1500 	}
1501 
1502 	/* only one slot has pcie device */
1503 	if (bus->self && nr)
1504 		pcie_aspm_init_link_state(bus->self);
1505 
1506 	return nr;
1507 }
1508 EXPORT_SYMBOL(pci_scan_slot);
1509 
1510 static int pcie_find_smpss(struct pci_dev *dev, void *data)
1511 {
1512 	u8 *smpss = data;
1513 
1514 	if (!pci_is_pcie(dev))
1515 		return 0;
1516 
1517 	/*
1518 	 * We don't have a way to change MPS settings on devices that have
1519 	 * drivers attached.  A hot-added device might support only the minimum
1520 	 * MPS setting (MPS=128).  Therefore, if the fabric contains a bridge
1521 	 * where devices may be hot-added, we limit the fabric MPS to 128 so
1522 	 * hot-added devices will work correctly.
1523 	 *
1524 	 * However, if we hot-add a device to a slot directly below a Root
1525 	 * Port, it's impossible for there to be other existing devices below
1526 	 * the port.  We don't limit the MPS in this case because we can
1527 	 * reconfigure MPS on both the Root Port and the hot-added device,
1528 	 * and there are no other devices involved.
1529 	 *
1530 	 * Note that this PCIE_BUS_SAFE path assumes no peer-to-peer DMA.
1531 	 */
1532 	if (dev->is_hotplug_bridge &&
1533 	    pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
1534 		*smpss = 0;
1535 
1536 	if (*smpss > dev->pcie_mpss)
1537 		*smpss = dev->pcie_mpss;
1538 
1539 	return 0;
1540 }
1541 
1542 static void pcie_write_mps(struct pci_dev *dev, int mps)
1543 {
1544 	int rc;
1545 
1546 	if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
1547 		mps = 128 << dev->pcie_mpss;
1548 
1549 		if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT &&
1550 		    dev->bus->self)
1551 			/* For "Performance", the assumption is made that
1552 			 * downstream communication will never be larger than
1553 			 * the MRRS.  So, the MPS only needs to be configured
1554 			 * for the upstream communication.  This being the case,
1555 			 * walk from the top down and set the MPS of the child
1556 			 * to that of the parent bus.
1557 			 *
1558 			 * Configure the device MPS with the smaller of the
1559 			 * device MPSS or the bridge MPS (which is assumed to be
1560 			 * properly configured at this point to the largest
1561 			 * allowable MPS based on its parent bus).
1562 			 */
1563 			mps = min(mps, pcie_get_mps(dev->bus->self));
1564 	}
1565 
1566 	rc = pcie_set_mps(dev, mps);
1567 	if (rc)
1568 		dev_err(&dev->dev, "Failed attempting to set the MPS\n");
1569 }
1570 
1571 static void pcie_write_mrrs(struct pci_dev *dev)
1572 {
1573 	int rc, mrrs;
1574 
1575 	/* In the "safe" case, do not configure the MRRS.  There appear to be
1576 	 * issues with setting MRRS to 0 on a number of devices.
1577 	 */
1578 	if (pcie_bus_config != PCIE_BUS_PERFORMANCE)
1579 		return;
1580 
1581 	/* For Max performance, the MRRS must be set to the largest supported
1582 	 * value.  However, it cannot be configured larger than the MPS the
1583 	 * device or the bus can support.  This should already be properly
1584 	 * configured by a prior call to pcie_write_mps.
1585 	 */
1586 	mrrs = pcie_get_mps(dev);
1587 
1588 	/* MRRS is a R/W register.  Invalid values can be written, but a
1589 	 * subsequent read will verify if the value is acceptable or not.
1590 	 * If the MRRS value provided is not acceptable (e.g., too large),
1591 	 * shrink the value until it is acceptable to the HW.
1592 	 */
1593 	while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) {
1594 		rc = pcie_set_readrq(dev, mrrs);
1595 		if (!rc)
1596 			break;
1597 
1598 		dev_warn(&dev->dev, "Failed attempting to set the MRRS\n");
1599 		mrrs /= 2;
1600 	}
1601 
1602 	if (mrrs < 128)
1603 		dev_err(&dev->dev, "MRRS was unable to be configured with a safe value.  If problems are experienced, try running with pci=pcie_bus_safe\n");
1604 }
1605 
1606 static void pcie_bus_detect_mps(struct pci_dev *dev)
1607 {
1608 	struct pci_dev *bridge = dev->bus->self;
1609 	int mps, p_mps;
1610 
1611 	if (!bridge)
1612 		return;
1613 
1614 	mps = pcie_get_mps(dev);
1615 	p_mps = pcie_get_mps(bridge);
1616 
1617 	if (mps != p_mps)
1618 		dev_warn(&dev->dev, "Max Payload Size %d, but upstream %s set to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n",
1619 			 mps, pci_name(bridge), p_mps);
1620 }
1621 
1622 static int pcie_bus_configure_set(struct pci_dev *dev, void *data)
1623 {
1624 	int mps, orig_mps;
1625 
1626 	if (!pci_is_pcie(dev))
1627 		return 0;
1628 
1629 	if (pcie_bus_config == PCIE_BUS_TUNE_OFF) {
1630 		pcie_bus_detect_mps(dev);
1631 		return 0;
1632 	}
1633 
1634 	mps = 128 << *(u8 *)data;
1635 	orig_mps = pcie_get_mps(dev);
1636 
1637 	pcie_write_mps(dev, mps);
1638 	pcie_write_mrrs(dev);
1639 
1640 	dev_info(&dev->dev, "Max Payload Size set to %4d/%4d (was %4d), Max Read Rq %4d\n",
1641 		 pcie_get_mps(dev), 128 << dev->pcie_mpss,
1642 		 orig_mps, pcie_get_readrq(dev));
1643 
1644 	return 0;
1645 }
1646 
1647 /* pcie_bus_configure_settings requires that pci_walk_bus work in a top-down,
1648  * parents then children fashion.  If this changes, then this code will not
1649  * work as designed.
1650  */
1651 void pcie_bus_configure_settings(struct pci_bus *bus)
1652 {
1653 	u8 smpss = 0;
1654 
1655 	if (!bus->self)
1656 		return;
1657 
1658 	if (!pci_is_pcie(bus->self))
1659 		return;
1660 
1661 	/* FIXME - Peer to peer DMA is possible, though the endpoint would need
1662 	 * to be aware of the MPS of the destination.  To work around this,
1663 	 * simply force the MPS of the entire system to the smallest possible.
1664 	 */
1665 	if (pcie_bus_config == PCIE_BUS_PEER2PEER)
1666 		smpss = 0;
1667 
1668 	if (pcie_bus_config == PCIE_BUS_SAFE) {
1669 		smpss = bus->self->pcie_mpss;
1670 
1671 		pcie_find_smpss(bus->self, &smpss);
1672 		pci_walk_bus(bus, pcie_find_smpss, &smpss);
1673 	}
1674 
1675 	pcie_bus_configure_set(bus->self, &smpss);
1676 	pci_walk_bus(bus, pcie_bus_configure_set, &smpss);
1677 }
1678 EXPORT_SYMBOL_GPL(pcie_bus_configure_settings);
1679 
1680 unsigned int pci_scan_child_bus(struct pci_bus *bus)
1681 {
1682 	unsigned int devfn, pass, max = bus->busn_res.start;
1683 	struct pci_dev *dev;
1684 
1685 	dev_dbg(&bus->dev, "scanning bus\n");
1686 
1687 	/* Go find them, Rover! */
1688 	for (devfn = 0; devfn < 0x100; devfn += 8)
1689 		pci_scan_slot(bus, devfn);
1690 
1691 	/* Reserve buses for SR-IOV capability. */
1692 	max += pci_iov_bus_range(bus);
1693 
1694 	/*
1695 	 * After performing arch-dependent fixup of the bus, look behind
1696 	 * all PCI-to-PCI bridges on this bus.
1697 	 */
1698 	if (!bus->is_added) {
1699 		dev_dbg(&bus->dev, "fixups for bus\n");
1700 		pcibios_fixup_bus(bus);
1701 		bus->is_added = 1;
1702 	}
1703 
1704 	for (pass = 0; pass < 2; pass++)
1705 		list_for_each_entry(dev, &bus->devices, bus_list) {
1706 			if (pci_is_bridge(dev))
1707 				max = pci_scan_bridge(bus, dev, max, pass);
1708 		}
1709 
1710 	/*
1711 	 * We've scanned the bus and so we know all about what's on
1712 	 * the other side of any bridges that may be on this bus plus
1713 	 * any devices.
1714 	 *
1715 	 * Return how far we've got finding sub-buses.
1716 	 */
1717 	dev_dbg(&bus->dev, "bus scan returning with max=%02x\n", max);
1718 	return max;
1719 }
1720 EXPORT_SYMBOL_GPL(pci_scan_child_bus);
1721 
1722 /**
1723  * pcibios_root_bridge_prepare - Platform-specific host bridge setup.
1724  * @bridge: Host bridge to set up.
1725  *
1726  * Default empty implementation.  Replace with an architecture-specific setup
1727  * routine, if necessary.
1728  */
1729 int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
1730 {
1731 	return 0;
1732 }
1733 
1734 void __weak pcibios_add_bus(struct pci_bus *bus)
1735 {
1736 }
1737 
1738 void __weak pcibios_remove_bus(struct pci_bus *bus)
1739 {
1740 }
1741 
1742 struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
1743 		struct pci_ops *ops, void *sysdata, struct list_head *resources)
1744 {
1745 	int error;
1746 	struct pci_host_bridge *bridge;
1747 	struct pci_bus *b, *b2;
1748 	struct pci_host_bridge_window *window, *n;
1749 	struct resource *res;
1750 	resource_size_t offset;
1751 	char bus_addr[64];
1752 	char *fmt;
1753 
1754 	b = pci_alloc_bus();
1755 	if (!b)
1756 		return NULL;
1757 
1758 	b->sysdata = sysdata;
1759 	b->ops = ops;
1760 	b->number = b->busn_res.start = bus;
1761 	b2 = pci_find_bus(pci_domain_nr(b), bus);
1762 	if (b2) {
1763 		/* If we already got to this bus through a different bridge, ignore it */
1764 		dev_dbg(&b2->dev, "bus already known\n");
1765 		goto err_out;
1766 	}
1767 
1768 	bridge = pci_alloc_host_bridge(b);
1769 	if (!bridge)
1770 		goto err_out;
1771 
1772 	bridge->dev.parent = parent;
1773 	bridge->dev.release = pci_release_host_bridge_dev;
1774 	dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus);
1775 	error = pcibios_root_bridge_prepare(bridge);
1776 	if (error) {
1777 		kfree(bridge);
1778 		goto err_out;
1779 	}
1780 
1781 	error = device_register(&bridge->dev);
1782 	if (error) {
1783 		put_device(&bridge->dev);
1784 		goto err_out;
1785 	}
1786 	b->bridge = get_device(&bridge->dev);
1787 	device_enable_async_suspend(b->bridge);
1788 	pci_set_bus_of_node(b);
1789 
1790 	if (!parent)
1791 		set_dev_node(b->bridge, pcibus_to_node(b));
1792 
1793 	b->dev.class = &pcibus_class;
1794 	b->dev.parent = b->bridge;
1795 	dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), bus);
1796 	error = device_register(&b->dev);
1797 	if (error)
1798 		goto class_dev_reg_err;
1799 
1800 	pcibios_add_bus(b);
1801 
1802 	/* Create legacy_io and legacy_mem files for this bus */
1803 	pci_create_legacy_files(b);
1804 
1805 	if (parent)
1806 		dev_info(parent, "PCI host bridge to bus %s\n", dev_name(&b->dev));
1807 	else
1808 		printk(KERN_INFO "PCI host bridge to bus %s\n", dev_name(&b->dev));
1809 
1810 	/* Add initial resources to the bus */
1811 	list_for_each_entry_safe(window, n, resources, list) {
1812 		list_move_tail(&window->list, &bridge->windows);
1813 		res = window->res;
1814 		offset = window->offset;
1815 		if (res->flags & IORESOURCE_BUS)
1816 			pci_bus_insert_busn_res(b, bus, res->end);
1817 		else
1818 			pci_bus_add_resource(b, res, 0);
1819 		if (offset) {
1820 			if (resource_type(res) == IORESOURCE_IO)
1821 				fmt = " (bus address [%#06llx-%#06llx])";
1822 			else
1823 				fmt = " (bus address [%#010llx-%#010llx])";
1824 			snprintf(bus_addr, sizeof(bus_addr), fmt,
1825 				 (unsigned long long) (res->start - offset),
1826 				 (unsigned long long) (res->end - offset));
1827 		} else
1828 			bus_addr[0] = '\0';
1829 		dev_info(&b->dev, "root bus resource %pR%s\n", res, bus_addr);
1830 	}
1831 
1832 	down_write(&pci_bus_sem);
1833 	list_add_tail(&b->node, &pci_root_buses);
1834 	up_write(&pci_bus_sem);
1835 
1836 	return b;
1837 
1838 class_dev_reg_err:
1839 	put_device(&bridge->dev);
1840 	device_unregister(&bridge->dev);
1841 err_out:
1842 	kfree(b);
1843 	return NULL;
1844 }
1845 
1846 int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
1847 {
1848 	struct resource *res = &b->busn_res;
1849 	struct resource *parent_res, *conflict;
1850 
1851 	res->start = bus;
1852 	res->end = bus_max;
1853 	res->flags = IORESOURCE_BUS;
1854 
1855 	if (!pci_is_root_bus(b))
1856 		parent_res = &b->parent->busn_res;
1857 	else {
1858 		parent_res = get_pci_domain_busn_res(pci_domain_nr(b));
1859 		res->flags |= IORESOURCE_PCI_FIXED;
1860 	}
1861 
1862 	conflict = request_resource_conflict(parent_res, res);
1863 
1864 	if (conflict)
1865 		dev_printk(KERN_DEBUG, &b->dev,
1866 			   "busn_res: can not insert %pR under %s%pR (conflicts with %s %pR)\n",
1867 			    res, pci_is_root_bus(b) ? "domain " : "",
1868 			    parent_res, conflict->name, conflict);
1869 
1870 	return conflict == NULL;
1871 }
1872 
1873 int pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max)
1874 {
1875 	struct resource *res = &b->busn_res;
1876 	struct resource old_res = *res;
1877 	resource_size_t size;
1878 	int ret;
1879 
1880 	if (res->start > bus_max)
1881 		return -EINVAL;
1882 
1883 	size = bus_max - res->start + 1;
1884 	ret = adjust_resource(res, res->start, size);
1885 	dev_printk(KERN_DEBUG, &b->dev,
1886 			"busn_res: %pR end %s updated to %02x\n",
1887 			&old_res, ret ? "can not be" : "is", bus_max);
1888 
1889 	if (!ret && !res->parent)
1890 		pci_bus_insert_busn_res(b, res->start, res->end);
1891 
1892 	return ret;
1893 }
1894 
1895 void pci_bus_release_busn_res(struct pci_bus *b)
1896 {
1897 	struct resource *res = &b->busn_res;
1898 	int ret;
1899 
1900 	if (!res->flags || !res->parent)
1901 		return;
1902 
1903 	ret = release_resource(res);
1904 	dev_printk(KERN_DEBUG, &b->dev,
1905 			"busn_res: %pR %s released\n",
1906 			res, ret ? "can not be" : "is");
1907 }
1908 
1909 struct pci_bus *pci_scan_root_bus(struct device *parent, int bus,
1910 		struct pci_ops *ops, void *sysdata, struct list_head *resources)
1911 {
1912 	struct pci_host_bridge_window *window;
1913 	bool found = false;
1914 	struct pci_bus *b;
1915 	int max;
1916 
1917 	list_for_each_entry(window, resources, list)
1918 		if (window->res->flags & IORESOURCE_BUS) {
1919 			found = true;
1920 			break;
1921 		}
1922 
1923 	b = pci_create_root_bus(parent, bus, ops, sysdata, resources);
1924 	if (!b)
1925 		return NULL;
1926 
1927 	if (!found) {
1928 		dev_info(&b->dev,
1929 		 "No busn resource found for root bus, will use [bus %02x-ff]\n",
1930 			bus);
1931 		pci_bus_insert_busn_res(b, bus, 255);
1932 	}
1933 
1934 	max = pci_scan_child_bus(b);
1935 
1936 	if (!found)
1937 		pci_bus_update_busn_res_end(b, max);
1938 
1939 	pci_bus_add_devices(b);
1940 	return b;
1941 }
1942 EXPORT_SYMBOL(pci_scan_root_bus);
1943 
1944 /* Deprecated; use pci_scan_root_bus() instead */
1945 struct pci_bus *pci_scan_bus_parented(struct device *parent,
1946 		int bus, struct pci_ops *ops, void *sysdata)
1947 {
1948 	LIST_HEAD(resources);
1949 	struct pci_bus *b;
1950 
1951 	pci_add_resource(&resources, &ioport_resource);
1952 	pci_add_resource(&resources, &iomem_resource);
1953 	pci_add_resource(&resources, &busn_resource);
1954 	b = pci_create_root_bus(parent, bus, ops, sysdata, &resources);
1955 	if (b)
1956 		pci_scan_child_bus(b);
1957 	else
1958 		pci_free_resource_list(&resources);
1959 	return b;
1960 }
1961 EXPORT_SYMBOL(pci_scan_bus_parented);
1962 
1963 struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops,
1964 					void *sysdata)
1965 {
1966 	LIST_HEAD(resources);
1967 	struct pci_bus *b;
1968 
1969 	pci_add_resource(&resources, &ioport_resource);
1970 	pci_add_resource(&resources, &iomem_resource);
1971 	pci_add_resource(&resources, &busn_resource);
1972 	b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources);
1973 	if (b) {
1974 		pci_scan_child_bus(b);
1975 		pci_bus_add_devices(b);
1976 	} else {
1977 		pci_free_resource_list(&resources);
1978 	}
1979 	return b;
1980 }
1981 EXPORT_SYMBOL(pci_scan_bus);
1982 
1983 /**
1984  * pci_rescan_bus_bridge_resize - scan a PCI bus for devices.
1985  * @bridge: PCI bridge for the bus to scan
1986  *
1987  * Scan a PCI bus and child buses for new devices, add them,
1988  * and enable them, resizing bridge mmio/io resource if necessary
1989  * and possible.  The caller must ensure the child devices are already
1990  * removed for resizing to occur.
1991  *
1992  * Returns the max number of subordinate bus discovered.
1993  */
1994 unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge)
1995 {
1996 	unsigned int max;
1997 	struct pci_bus *bus = bridge->subordinate;
1998 
1999 	max = pci_scan_child_bus(bus);
2000 
2001 	pci_assign_unassigned_bridge_resources(bridge);
2002 
2003 	pci_bus_add_devices(bus);
2004 
2005 	return max;
2006 }
2007 
2008 /**
2009  * pci_rescan_bus - scan a PCI bus for devices.
2010  * @bus: PCI bus to scan
2011  *
2012  * Scan a PCI bus and child buses for new devices, adds them,
2013  * and enables them.
2014  *
2015  * Returns the max number of subordinate bus discovered.
2016  */
2017 unsigned int pci_rescan_bus(struct pci_bus *bus)
2018 {
2019 	unsigned int max;
2020 
2021 	max = pci_scan_child_bus(bus);
2022 	pci_assign_unassigned_bus_resources(bus);
2023 	pci_bus_add_devices(bus);
2024 
2025 	return max;
2026 }
2027 EXPORT_SYMBOL_GPL(pci_rescan_bus);
2028 
2029 /*
2030  * pci_rescan_bus(), pci_rescan_bus_bridge_resize() and PCI device removal
2031  * routines should always be executed under this mutex.
2032  */
2033 static DEFINE_MUTEX(pci_rescan_remove_lock);
2034 
2035 void pci_lock_rescan_remove(void)
2036 {
2037 	mutex_lock(&pci_rescan_remove_lock);
2038 }
2039 EXPORT_SYMBOL_GPL(pci_lock_rescan_remove);
2040 
2041 void pci_unlock_rescan_remove(void)
2042 {
2043 	mutex_unlock(&pci_rescan_remove_lock);
2044 }
2045 EXPORT_SYMBOL_GPL(pci_unlock_rescan_remove);
2046 
2047 static int __init pci_sort_bf_cmp(const struct device *d_a,
2048 				  const struct device *d_b)
2049 {
2050 	const struct pci_dev *a = to_pci_dev(d_a);
2051 	const struct pci_dev *b = to_pci_dev(d_b);
2052 
2053 	if      (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1;
2054 	else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return  1;
2055 
2056 	if      (a->bus->number < b->bus->number) return -1;
2057 	else if (a->bus->number > b->bus->number) return  1;
2058 
2059 	if      (a->devfn < b->devfn) return -1;
2060 	else if (a->devfn > b->devfn) return  1;
2061 
2062 	return 0;
2063 }
2064 
2065 void __init pci_sort_breadthfirst(void)
2066 {
2067 	bus_sort_breadthfirst(&pci_bus_type, &pci_sort_bf_cmp);
2068 }
2069