xref: /linux/drivers/pci/probe.c (revision 606d099cdd1080bbb50ea50dc52d98252f8f10a1)
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 "pci.h"
13 
14 #define CARDBUS_LATENCY_TIMER	176	/* secondary latency timer */
15 #define CARDBUS_RESERVE_BUSNR	3
16 #define PCI_CFG_SPACE_SIZE	256
17 #define PCI_CFG_SPACE_EXP_SIZE	4096
18 
19 /* Ugh.  Need to stop exporting this to modules. */
20 LIST_HEAD(pci_root_buses);
21 EXPORT_SYMBOL(pci_root_buses);
22 
23 LIST_HEAD(pci_devices);
24 
25 #ifdef HAVE_PCI_LEGACY
26 /**
27  * pci_create_legacy_files - create legacy I/O port and memory files
28  * @b: bus to create files under
29  *
30  * Some platforms allow access to legacy I/O port and ISA memory space on
31  * a per-bus basis.  This routine creates the files and ties them into
32  * their associated read, write and mmap files from pci-sysfs.c
33  */
34 static void pci_create_legacy_files(struct pci_bus *b)
35 {
36 	b->legacy_io = kzalloc(sizeof(struct bin_attribute) * 2,
37 			       GFP_ATOMIC);
38 	if (b->legacy_io) {
39 		b->legacy_io->attr.name = "legacy_io";
40 		b->legacy_io->size = 0xffff;
41 		b->legacy_io->attr.mode = S_IRUSR | S_IWUSR;
42 		b->legacy_io->attr.owner = THIS_MODULE;
43 		b->legacy_io->read = pci_read_legacy_io;
44 		b->legacy_io->write = pci_write_legacy_io;
45 		class_device_create_bin_file(&b->class_dev, b->legacy_io);
46 
47 		/* Allocated above after the legacy_io struct */
48 		b->legacy_mem = b->legacy_io + 1;
49 		b->legacy_mem->attr.name = "legacy_mem";
50 		b->legacy_mem->size = 1024*1024;
51 		b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
52 		b->legacy_mem->attr.owner = THIS_MODULE;
53 		b->legacy_mem->mmap = pci_mmap_legacy_mem;
54 		class_device_create_bin_file(&b->class_dev, b->legacy_mem);
55 	}
56 }
57 
58 void pci_remove_legacy_files(struct pci_bus *b)
59 {
60 	if (b->legacy_io) {
61 		class_device_remove_bin_file(&b->class_dev, b->legacy_io);
62 		class_device_remove_bin_file(&b->class_dev, b->legacy_mem);
63 		kfree(b->legacy_io); /* both are allocated here */
64 	}
65 }
66 #else /* !HAVE_PCI_LEGACY */
67 static inline void pci_create_legacy_files(struct pci_bus *bus) { return; }
68 void pci_remove_legacy_files(struct pci_bus *bus) { return; }
69 #endif /* HAVE_PCI_LEGACY */
70 
71 /*
72  * PCI Bus Class Devices
73  */
74 static ssize_t pci_bus_show_cpuaffinity(struct class_device *class_dev,
75 					char *buf)
76 {
77 	int ret;
78 	cpumask_t cpumask;
79 
80 	cpumask = pcibus_to_cpumask(to_pci_bus(class_dev));
81 	ret = cpumask_scnprintf(buf, PAGE_SIZE, cpumask);
82 	if (ret < PAGE_SIZE)
83 		buf[ret++] = '\n';
84 	return ret;
85 }
86 CLASS_DEVICE_ATTR(cpuaffinity, S_IRUGO, pci_bus_show_cpuaffinity, NULL);
87 
88 /*
89  * PCI Bus Class
90  */
91 static void release_pcibus_dev(struct class_device *class_dev)
92 {
93 	struct pci_bus *pci_bus = to_pci_bus(class_dev);
94 
95 	if (pci_bus->bridge)
96 		put_device(pci_bus->bridge);
97 	kfree(pci_bus);
98 }
99 
100 static struct class pcibus_class = {
101 	.name		= "pci_bus",
102 	.release	= &release_pcibus_dev,
103 };
104 
105 static int __init pcibus_class_init(void)
106 {
107 	return class_register(&pcibus_class);
108 }
109 postcore_initcall(pcibus_class_init);
110 
111 /*
112  * Translate the low bits of the PCI base
113  * to the resource type
114  */
115 static inline unsigned int pci_calc_resource_flags(unsigned int flags)
116 {
117 	if (flags & PCI_BASE_ADDRESS_SPACE_IO)
118 		return IORESOURCE_IO;
119 
120 	if (flags & PCI_BASE_ADDRESS_MEM_PREFETCH)
121 		return IORESOURCE_MEM | IORESOURCE_PREFETCH;
122 
123 	return IORESOURCE_MEM;
124 }
125 
126 /*
127  * Find the extent of a PCI decode..
128  */
129 static u32 pci_size(u32 base, u32 maxbase, u32 mask)
130 {
131 	u32 size = mask & maxbase;	/* Find the significant bits */
132 	if (!size)
133 		return 0;
134 
135 	/* Get the lowest of them to find the decode size, and
136 	   from that the extent.  */
137 	size = (size & ~(size-1)) - 1;
138 
139 	/* base == maxbase can be valid only if the BAR has
140 	   already been programmed with all 1s.  */
141 	if (base == maxbase && ((base | size) & mask) != mask)
142 		return 0;
143 
144 	return size;
145 }
146 
147 static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom)
148 {
149 	unsigned int pos, reg, next;
150 	u32 l, sz;
151 	struct resource *res;
152 
153 	for(pos=0; pos<howmany; pos = next) {
154 		next = pos+1;
155 		res = &dev->resource[pos];
156 		res->name = pci_name(dev);
157 		reg = PCI_BASE_ADDRESS_0 + (pos << 2);
158 		pci_read_config_dword(dev, reg, &l);
159 		pci_write_config_dword(dev, reg, ~0);
160 		pci_read_config_dword(dev, reg, &sz);
161 		pci_write_config_dword(dev, reg, l);
162 		if (!sz || sz == 0xffffffff)
163 			continue;
164 		if (l == 0xffffffff)
165 			l = 0;
166 		if ((l & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_MEMORY) {
167 			sz = pci_size(l, sz, (u32)PCI_BASE_ADDRESS_MEM_MASK);
168 			if (!sz)
169 				continue;
170 			res->start = l & PCI_BASE_ADDRESS_MEM_MASK;
171 			res->flags |= l & ~PCI_BASE_ADDRESS_MEM_MASK;
172 		} else {
173 			sz = pci_size(l, sz, PCI_BASE_ADDRESS_IO_MASK & 0xffff);
174 			if (!sz)
175 				continue;
176 			res->start = l & PCI_BASE_ADDRESS_IO_MASK;
177 			res->flags |= l & ~PCI_BASE_ADDRESS_IO_MASK;
178 		}
179 		res->end = res->start + (unsigned long) sz;
180 		res->flags |= pci_calc_resource_flags(l);
181 		if ((l & (PCI_BASE_ADDRESS_SPACE | PCI_BASE_ADDRESS_MEM_TYPE_MASK))
182 		    == (PCI_BASE_ADDRESS_SPACE_MEMORY | PCI_BASE_ADDRESS_MEM_TYPE_64)) {
183 			u32 szhi, lhi;
184 			pci_read_config_dword(dev, reg+4, &lhi);
185 			pci_write_config_dword(dev, reg+4, ~0);
186 			pci_read_config_dword(dev, reg+4, &szhi);
187 			pci_write_config_dword(dev, reg+4, lhi);
188 			szhi = pci_size(lhi, szhi, 0xffffffff);
189 			next++;
190 #if BITS_PER_LONG == 64
191 			res->start |= ((unsigned long) lhi) << 32;
192 			res->end = res->start + sz;
193 			if (szhi) {
194 				/* This BAR needs > 4GB?  Wow. */
195 				res->end |= (unsigned long)szhi<<32;
196 			}
197 #else
198 			if (szhi) {
199 				printk(KERN_ERR "PCI: Unable to handle 64-bit BAR for device %s\n", pci_name(dev));
200 				res->start = 0;
201 				res->flags = 0;
202 			} else if (lhi) {
203 				/* 64-bit wide address, treat as disabled */
204 				pci_write_config_dword(dev, reg, l & ~(u32)PCI_BASE_ADDRESS_MEM_MASK);
205 				pci_write_config_dword(dev, reg+4, 0);
206 				res->start = 0;
207 				res->end = sz;
208 			}
209 #endif
210 		}
211 	}
212 	if (rom) {
213 		dev->rom_base_reg = rom;
214 		res = &dev->resource[PCI_ROM_RESOURCE];
215 		res->name = pci_name(dev);
216 		pci_read_config_dword(dev, rom, &l);
217 		pci_write_config_dword(dev, rom, ~PCI_ROM_ADDRESS_ENABLE);
218 		pci_read_config_dword(dev, rom, &sz);
219 		pci_write_config_dword(dev, rom, l);
220 		if (l == 0xffffffff)
221 			l = 0;
222 		if (sz && sz != 0xffffffff) {
223 			sz = pci_size(l, sz, (u32)PCI_ROM_ADDRESS_MASK);
224 			if (sz) {
225 				res->flags = (l & IORESOURCE_ROM_ENABLE) |
226 				  IORESOURCE_MEM | IORESOURCE_PREFETCH |
227 				  IORESOURCE_READONLY | IORESOURCE_CACHEABLE;
228 				res->start = l & PCI_ROM_ADDRESS_MASK;
229 				res->end = res->start + (unsigned long) sz;
230 			}
231 		}
232 	}
233 }
234 
235 void __devinit pci_read_bridge_bases(struct pci_bus *child)
236 {
237 	struct pci_dev *dev = child->self;
238 	u8 io_base_lo, io_limit_lo;
239 	u16 mem_base_lo, mem_limit_lo;
240 	unsigned long base, limit;
241 	struct resource *res;
242 	int i;
243 
244 	if (!dev)		/* It's a host bus, nothing to read */
245 		return;
246 
247 	if (dev->transparent) {
248 		printk(KERN_INFO "PCI: Transparent bridge - %s\n", pci_name(dev));
249 		for(i = 3; i < PCI_BUS_NUM_RESOURCES; i++)
250 			child->resource[i] = child->parent->resource[i - 3];
251 	}
252 
253 	for(i=0; i<3; i++)
254 		child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i];
255 
256 	res = child->resource[0];
257 	pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
258 	pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
259 	base = (io_base_lo & PCI_IO_RANGE_MASK) << 8;
260 	limit = (io_limit_lo & PCI_IO_RANGE_MASK) << 8;
261 
262 	if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) {
263 		u16 io_base_hi, io_limit_hi;
264 		pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &io_base_hi);
265 		pci_read_config_word(dev, PCI_IO_LIMIT_UPPER16, &io_limit_hi);
266 		base |= (io_base_hi << 16);
267 		limit |= (io_limit_hi << 16);
268 	}
269 
270 	if (base <= limit) {
271 		res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
272 		if (!res->start)
273 			res->start = base;
274 		if (!res->end)
275 			res->end = limit + 0xfff;
276 	}
277 
278 	res = child->resource[1];
279 	pci_read_config_word(dev, PCI_MEMORY_BASE, &mem_base_lo);
280 	pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo);
281 	base = (mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16;
282 	limit = (mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16;
283 	if (base <= limit) {
284 		res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM;
285 		res->start = base;
286 		res->end = limit + 0xfffff;
287 	}
288 
289 	res = child->resource[2];
290 	pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo);
291 	pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo);
292 	base = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16;
293 	limit = (mem_limit_lo & PCI_PREF_RANGE_MASK) << 16;
294 
295 	if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) {
296 		u32 mem_base_hi, mem_limit_hi;
297 		pci_read_config_dword(dev, PCI_PREF_BASE_UPPER32, &mem_base_hi);
298 		pci_read_config_dword(dev, PCI_PREF_LIMIT_UPPER32, &mem_limit_hi);
299 
300 		/*
301 		 * Some bridges set the base > limit by default, and some
302 		 * (broken) BIOSes do not initialize them.  If we find
303 		 * this, just assume they are not being used.
304 		 */
305 		if (mem_base_hi <= mem_limit_hi) {
306 #if BITS_PER_LONG == 64
307 			base |= ((long) mem_base_hi) << 32;
308 			limit |= ((long) mem_limit_hi) << 32;
309 #else
310 			if (mem_base_hi || mem_limit_hi) {
311 				printk(KERN_ERR "PCI: Unable to handle 64-bit address space for bridge %s\n", pci_name(dev));
312 				return;
313 			}
314 #endif
315 		}
316 	}
317 	if (base <= limit) {
318 		res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM | IORESOURCE_PREFETCH;
319 		res->start = base;
320 		res->end = limit + 0xfffff;
321 	}
322 }
323 
324 static struct pci_bus * __devinit pci_alloc_bus(void)
325 {
326 	struct pci_bus *b;
327 
328 	b = kzalloc(sizeof(*b), GFP_KERNEL);
329 	if (b) {
330 		INIT_LIST_HEAD(&b->node);
331 		INIT_LIST_HEAD(&b->children);
332 		INIT_LIST_HEAD(&b->devices);
333 	}
334 	return b;
335 }
336 
337 static struct pci_bus * __devinit
338 pci_alloc_child_bus(struct pci_bus *parent, struct pci_dev *bridge, int busnr)
339 {
340 	struct pci_bus *child;
341 	int i;
342 	int retval;
343 
344 	/*
345 	 * Allocate a new bus, and inherit stuff from the parent..
346 	 */
347 	child = pci_alloc_bus();
348 	if (!child)
349 		return NULL;
350 
351 	child->self = bridge;
352 	child->parent = parent;
353 	child->ops = parent->ops;
354 	child->sysdata = parent->sysdata;
355 	child->bus_flags = parent->bus_flags;
356 	child->bridge = get_device(&bridge->dev);
357 
358 	child->class_dev.class = &pcibus_class;
359 	sprintf(child->class_dev.class_id, "%04x:%02x", pci_domain_nr(child), busnr);
360 	retval = class_device_register(&child->class_dev);
361 	if (retval)
362 		goto error_register;
363 	retval = class_device_create_file(&child->class_dev,
364 					  &class_device_attr_cpuaffinity);
365 	if (retval)
366 		goto error_file_create;
367 
368 	/*
369 	 * Set up the primary, secondary and subordinate
370 	 * bus numbers.
371 	 */
372 	child->number = child->secondary = busnr;
373 	child->primary = parent->secondary;
374 	child->subordinate = 0xff;
375 
376 	/* Set up default resource pointers and names.. */
377 	for (i = 0; i < 4; i++) {
378 		child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i];
379 		child->resource[i]->name = child->name;
380 	}
381 	bridge->subordinate = child;
382 
383 	return child;
384 
385 error_file_create:
386 	class_device_unregister(&child->class_dev);
387 error_register:
388 	kfree(child);
389 	return NULL;
390 }
391 
392 struct pci_bus * __devinit pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev, int busnr)
393 {
394 	struct pci_bus *child;
395 
396 	child = pci_alloc_child_bus(parent, dev, busnr);
397 	if (child) {
398 		down_write(&pci_bus_sem);
399 		list_add_tail(&child->node, &parent->children);
400 		up_write(&pci_bus_sem);
401 	}
402 	return child;
403 }
404 
405 static void pci_enable_crs(struct pci_dev *dev)
406 {
407 	u16 cap, rpctl;
408 	int rpcap = pci_find_capability(dev, PCI_CAP_ID_EXP);
409 	if (!rpcap)
410 		return;
411 
412 	pci_read_config_word(dev, rpcap + PCI_CAP_FLAGS, &cap);
413 	if (((cap & PCI_EXP_FLAGS_TYPE) >> 4) != PCI_EXP_TYPE_ROOT_PORT)
414 		return;
415 
416 	pci_read_config_word(dev, rpcap + PCI_EXP_RTCTL, &rpctl);
417 	rpctl |= PCI_EXP_RTCTL_CRSSVE;
418 	pci_write_config_word(dev, rpcap + PCI_EXP_RTCTL, rpctl);
419 }
420 
421 static void __devinit pci_fixup_parent_subordinate_busnr(struct pci_bus *child, int max)
422 {
423 	struct pci_bus *parent = child->parent;
424 
425 	/* Attempts to fix that up are really dangerous unless
426 	   we're going to re-assign all bus numbers. */
427 	if (!pcibios_assign_all_busses())
428 		return;
429 
430 	while (parent->parent && parent->subordinate < max) {
431 		parent->subordinate = max;
432 		pci_write_config_byte(parent->self, PCI_SUBORDINATE_BUS, max);
433 		parent = parent->parent;
434 	}
435 }
436 
437 unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus);
438 
439 /*
440  * If it's a bridge, configure it and scan the bus behind it.
441  * For CardBus bridges, we don't scan behind as the devices will
442  * be handled by the bridge driver itself.
443  *
444  * We need to process bridges in two passes -- first we scan those
445  * already configured by the BIOS and after we are done with all of
446  * them, we proceed to assigning numbers to the remaining buses in
447  * order to avoid overlaps between old and new bus numbers.
448  */
449 int __devinit pci_scan_bridge(struct pci_bus *bus, struct pci_dev * dev, int max, int pass)
450 {
451 	struct pci_bus *child;
452 	int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
453 	u32 buses, i, j = 0;
454 	u16 bctl;
455 
456 	pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
457 
458 	pr_debug("PCI: Scanning behind PCI bridge %s, config %06x, pass %d\n",
459 		 pci_name(dev), buses & 0xffffff, pass);
460 
461 	/* Disable MasterAbortMode during probing to avoid reporting
462 	   of bus errors (in some architectures) */
463 	pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl);
464 	pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
465 			      bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT);
466 
467 	pci_enable_crs(dev);
468 
469 	if ((buses & 0xffff00) && !pcibios_assign_all_busses() && !is_cardbus) {
470 		unsigned int cmax, busnr;
471 		/*
472 		 * Bus already configured by firmware, process it in the first
473 		 * pass and just note the configuration.
474 		 */
475 		if (pass)
476 			goto out;
477 		busnr = (buses >> 8) & 0xFF;
478 
479 		/*
480 		 * If we already got to this bus through a different bridge,
481 		 * ignore it.  This can happen with the i450NX chipset.
482 		 */
483 		if (pci_find_bus(pci_domain_nr(bus), busnr)) {
484 			printk(KERN_INFO "PCI: Bus %04x:%02x already known\n",
485 					pci_domain_nr(bus), busnr);
486 			goto out;
487 		}
488 
489 		child = pci_add_new_bus(bus, dev, busnr);
490 		if (!child)
491 			goto out;
492 		child->primary = buses & 0xFF;
493 		child->subordinate = (buses >> 16) & 0xFF;
494 		child->bridge_ctl = bctl;
495 
496 		cmax = pci_scan_child_bus(child);
497 		if (cmax > max)
498 			max = cmax;
499 		if (child->subordinate > max)
500 			max = child->subordinate;
501 	} else {
502 		/*
503 		 * We need to assign a number to this bus which we always
504 		 * do in the second pass.
505 		 */
506 		if (!pass) {
507 			if (pcibios_assign_all_busses())
508 				/* Temporarily disable forwarding of the
509 				   configuration cycles on all bridges in
510 				   this bus segment to avoid possible
511 				   conflicts in the second pass between two
512 				   bridges programmed with overlapping
513 				   bus ranges. */
514 				pci_write_config_dword(dev, PCI_PRIMARY_BUS,
515 						       buses & ~0xffffff);
516 			goto out;
517 		}
518 
519 		/* Clear errors */
520 		pci_write_config_word(dev, PCI_STATUS, 0xffff);
521 
522 		/* Prevent assigning a bus number that already exists.
523 		 * This can happen when a bridge is hot-plugged */
524 		if (pci_find_bus(pci_domain_nr(bus), max+1))
525 			goto out;
526 		child = pci_add_new_bus(bus, dev, ++max);
527 		buses = (buses & 0xff000000)
528 		      | ((unsigned int)(child->primary)     <<  0)
529 		      | ((unsigned int)(child->secondary)   <<  8)
530 		      | ((unsigned int)(child->subordinate) << 16);
531 
532 		/*
533 		 * yenta.c forces a secondary latency timer of 176.
534 		 * Copy that behaviour here.
535 		 */
536 		if (is_cardbus) {
537 			buses &= ~0xff000000;
538 			buses |= CARDBUS_LATENCY_TIMER << 24;
539 		}
540 
541 		/*
542 		 * We need to blast all three values with a single write.
543 		 */
544 		pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses);
545 
546 		if (!is_cardbus) {
547 			child->bridge_ctl = bctl | PCI_BRIDGE_CTL_NO_ISA;
548 			/*
549 			 * Adjust subordinate busnr in parent buses.
550 			 * We do this before scanning for children because
551 			 * some devices may not be detected if the bios
552 			 * was lazy.
553 			 */
554 			pci_fixup_parent_subordinate_busnr(child, max);
555 			/* Now we can scan all subordinate buses... */
556 			max = pci_scan_child_bus(child);
557 			/*
558 			 * now fix it up again since we have found
559 			 * the real value of max.
560 			 */
561 			pci_fixup_parent_subordinate_busnr(child, max);
562 		} else {
563 			/*
564 			 * For CardBus bridges, we leave 4 bus numbers
565 			 * as cards with a PCI-to-PCI bridge can be
566 			 * inserted later.
567 			 */
568 			for (i=0; i<CARDBUS_RESERVE_BUSNR; i++) {
569 				struct pci_bus *parent = bus;
570 				if (pci_find_bus(pci_domain_nr(bus),
571 							max+i+1))
572 					break;
573 				while (parent->parent) {
574 					if ((!pcibios_assign_all_busses()) &&
575 					    (parent->subordinate > max) &&
576 					    (parent->subordinate <= max+i)) {
577 						j = 1;
578 					}
579 					parent = parent->parent;
580 				}
581 				if (j) {
582 					/*
583 					 * Often, there are two cardbus bridges
584 					 * -- try to leave one valid bus number
585 					 * for each one.
586 					 */
587 					i /= 2;
588 					break;
589 				}
590 			}
591 			max += i;
592 			pci_fixup_parent_subordinate_busnr(child, max);
593 		}
594 		/*
595 		 * Set the subordinate bus number to its real value.
596 		 */
597 		child->subordinate = max;
598 		pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max);
599 	}
600 
601 	sprintf(child->name, (is_cardbus ? "PCI CardBus #%02x" : "PCI Bus #%02x"), child->number);
602 
603 	while (bus->parent) {
604 		if ((child->subordinate > bus->subordinate) ||
605 		    (child->number > bus->subordinate) ||
606 		    (child->number < bus->number) ||
607 		    (child->subordinate < bus->number)) {
608 			printk(KERN_WARNING "PCI: Bus #%02x (-#%02x) is "
609 			       "hidden behind%s bridge #%02x (-#%02x)%s\n",
610 			       child->number, child->subordinate,
611 			       bus->self->transparent ? " transparent" : " ",
612 			       bus->number, bus->subordinate,
613 			       pcibios_assign_all_busses() ? " " :
614 			       " (try 'pci=assign-busses')");
615 			printk(KERN_WARNING "Please report the result to "
616 			       "linux-kernel to fix this permanently\n");
617 		}
618 		bus = bus->parent;
619 	}
620 
621 out:
622 	pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl);
623 
624 	return max;
625 }
626 
627 /*
628  * Read interrupt line and base address registers.
629  * The architecture-dependent code can tweak these, of course.
630  */
631 static void pci_read_irq(struct pci_dev *dev)
632 {
633 	unsigned char irq;
634 
635 	pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq);
636 	dev->pin = irq;
637 	if (irq)
638 		pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);
639 	dev->irq = irq;
640 }
641 
642 /**
643  * pci_setup_device - fill in class and map information of a device
644  * @dev: the device structure to fill
645  *
646  * Initialize the device structure with information about the device's
647  * vendor,class,memory and IO-space addresses,IRQ lines etc.
648  * Called at initialisation of the PCI subsystem and by CardBus services.
649  * Returns 0 on success and -1 if unknown type of device (not normal, bridge
650  * or CardBus).
651  */
652 static int pci_setup_device(struct pci_dev * dev)
653 {
654 	u32 class;
655 
656 	sprintf(pci_name(dev), "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus),
657 		dev->bus->number, PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
658 
659 	pci_read_config_dword(dev, PCI_CLASS_REVISION, &class);
660 	class >>= 8;				    /* upper 3 bytes */
661 	dev->class = class;
662 	class >>= 8;
663 
664 	pr_debug("PCI: Found %s [%04x/%04x] %06x %02x\n", pci_name(dev),
665 		 dev->vendor, dev->device, class, dev->hdr_type);
666 
667 	/* "Unknown power state" */
668 	dev->current_state = PCI_UNKNOWN;
669 
670 	/* Early fixups, before probing the BARs */
671 	pci_fixup_device(pci_fixup_early, dev);
672 	class = dev->class >> 8;
673 
674 	switch (dev->hdr_type) {		    /* header type */
675 	case PCI_HEADER_TYPE_NORMAL:		    /* standard header */
676 		if (class == PCI_CLASS_BRIDGE_PCI)
677 			goto bad;
678 		pci_read_irq(dev);
679 		pci_read_bases(dev, 6, PCI_ROM_ADDRESS);
680 		pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
681 		pci_read_config_word(dev, PCI_SUBSYSTEM_ID, &dev->subsystem_device);
682 
683 		/*
684 		 *	Do the ugly legacy mode stuff here rather than broken chip
685 		 *	quirk code. Legacy mode ATA controllers have fixed
686 		 *	addresses. These are not always echoed in BAR0-3, and
687 		 *	BAR0-3 in a few cases contain junk!
688 		 */
689 		if (class == PCI_CLASS_STORAGE_IDE) {
690 			u8 progif;
691 			pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
692 			if ((progif & 1) == 0) {
693 				dev->resource[0].start = 0x1F0;
694 				dev->resource[0].end = 0x1F7;
695 				dev->resource[0].flags = IORESOURCE_IO;
696 				dev->resource[1].start = 0x3F6;
697 				dev->resource[1].end = 0x3F6;
698 				dev->resource[1].flags = IORESOURCE_IO;
699 			}
700 			if ((progif & 4) == 0) {
701 				dev->resource[2].start = 0x170;
702 				dev->resource[2].end = 0x177;
703 				dev->resource[2].flags = IORESOURCE_IO;
704 				dev->resource[3].start = 0x376;
705 				dev->resource[3].end = 0x376;
706 				dev->resource[3].flags = IORESOURCE_IO;
707 			}
708 		}
709 		break;
710 
711 	case PCI_HEADER_TYPE_BRIDGE:		    /* bridge header */
712 		if (class != PCI_CLASS_BRIDGE_PCI)
713 			goto bad;
714 		/* The PCI-to-PCI bridge spec requires that subtractive
715 		   decoding (i.e. transparent) bridge must have programming
716 		   interface code of 0x01. */
717 		pci_read_irq(dev);
718 		dev->transparent = ((dev->class & 0xff) == 1);
719 		pci_read_bases(dev, 2, PCI_ROM_ADDRESS1);
720 		break;
721 
722 	case PCI_HEADER_TYPE_CARDBUS:		    /* CardBus bridge header */
723 		if (class != PCI_CLASS_BRIDGE_CARDBUS)
724 			goto bad;
725 		pci_read_irq(dev);
726 		pci_read_bases(dev, 1, 0);
727 		pci_read_config_word(dev, PCI_CB_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor);
728 		pci_read_config_word(dev, PCI_CB_SUBSYSTEM_ID, &dev->subsystem_device);
729 		break;
730 
731 	default:				    /* unknown header */
732 		printk(KERN_ERR "PCI: device %s has unknown header type %02x, ignoring.\n",
733 			pci_name(dev), dev->hdr_type);
734 		return -1;
735 
736 	bad:
737 		printk(KERN_ERR "PCI: %s: class %x doesn't match header type %02x. Ignoring class.\n",
738 		       pci_name(dev), class, dev->hdr_type);
739 		dev->class = PCI_CLASS_NOT_DEFINED;
740 	}
741 
742 	/* We found a fine healthy device, go go go... */
743 	return 0;
744 }
745 
746 /**
747  * pci_release_dev - free a pci device structure when all users of it are finished.
748  * @dev: device that's been disconnected
749  *
750  * Will be called only by the device core when all users of this pci device are
751  * done.
752  */
753 static void pci_release_dev(struct device *dev)
754 {
755 	struct pci_dev *pci_dev;
756 
757 	pci_dev = to_pci_dev(dev);
758 	kfree(pci_dev);
759 }
760 
761 /**
762  * pci_cfg_space_size - get the configuration space size of the PCI device.
763  * @dev: PCI device
764  *
765  * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices
766  * have 4096 bytes.  Even if the device is capable, that doesn't mean we can
767  * access it.  Maybe we don't have a way to generate extended config space
768  * accesses, or the device is behind a reverse Express bridge.  So we try
769  * reading the dword at 0x100 which must either be 0 or a valid extended
770  * capability header.
771  */
772 int pci_cfg_space_size(struct pci_dev *dev)
773 {
774 	int pos;
775 	u32 status;
776 
777 	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
778 	if (!pos) {
779 		pos = pci_find_capability(dev, PCI_CAP_ID_PCIX);
780 		if (!pos)
781 			goto fail;
782 
783 		pci_read_config_dword(dev, pos + PCI_X_STATUS, &status);
784 		if (!(status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ)))
785 			goto fail;
786 	}
787 
788 	if (pci_read_config_dword(dev, 256, &status) != PCIBIOS_SUCCESSFUL)
789 		goto fail;
790 	if (status == 0xffffffff)
791 		goto fail;
792 
793 	return PCI_CFG_SPACE_EXP_SIZE;
794 
795  fail:
796 	return PCI_CFG_SPACE_SIZE;
797 }
798 
799 static void pci_release_bus_bridge_dev(struct device *dev)
800 {
801 	kfree(dev);
802 }
803 
804 /*
805  * Read the config data for a PCI device, sanity-check it
806  * and fill in the dev structure...
807  */
808 static struct pci_dev * __devinit
809 pci_scan_device(struct pci_bus *bus, int devfn)
810 {
811 	struct pci_dev *dev;
812 	u32 l;
813 	u8 hdr_type;
814 	int delay = 1;
815 
816 	if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
817 		return NULL;
818 
819 	/* some broken boards return 0 or ~0 if a slot is empty: */
820 	if (l == 0xffffffff || l == 0x00000000 ||
821 	    l == 0x0000ffff || l == 0xffff0000)
822 		return NULL;
823 
824 	/* Configuration request Retry Status */
825 	while (l == 0xffff0001) {
826 		msleep(delay);
827 		delay *= 2;
828 		if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, &l))
829 			return NULL;
830 		/* Card hasn't responded in 60 seconds?  Must be stuck. */
831 		if (delay > 60 * 1000) {
832 			printk(KERN_WARNING "Device %04x:%02x:%02x.%d not "
833 					"responding\n", pci_domain_nr(bus),
834 					bus->number, PCI_SLOT(devfn),
835 					PCI_FUNC(devfn));
836 			return NULL;
837 		}
838 	}
839 
840 	if (pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type))
841 		return NULL;
842 
843 	dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL);
844 	if (!dev)
845 		return NULL;
846 
847 	dev->bus = bus;
848 	dev->sysdata = bus->sysdata;
849 	dev->dev.parent = bus->bridge;
850 	dev->dev.bus = &pci_bus_type;
851 	dev->devfn = devfn;
852 	dev->hdr_type = hdr_type & 0x7f;
853 	dev->multifunction = !!(hdr_type & 0x80);
854 	dev->vendor = l & 0xffff;
855 	dev->device = (l >> 16) & 0xffff;
856 	dev->cfg_size = pci_cfg_space_size(dev);
857 	dev->error_state = pci_channel_io_normal;
858 
859 	/* Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer)
860 	   set this higher, assuming the system even supports it.  */
861 	dev->dma_mask = 0xffffffff;
862 	if (pci_setup_device(dev) < 0) {
863 		kfree(dev);
864 		return NULL;
865 	}
866 
867 	return dev;
868 }
869 
870 void __devinit pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
871 {
872 	device_initialize(&dev->dev);
873 	dev->dev.release = pci_release_dev;
874 	pci_dev_get(dev);
875 
876 	set_dev_node(&dev->dev, pcibus_to_node(bus));
877 	dev->dev.dma_mask = &dev->dma_mask;
878 	dev->dev.coherent_dma_mask = 0xffffffffull;
879 
880 	/* Fix up broken headers */
881 	pci_fixup_device(pci_fixup_header, dev);
882 
883 	/*
884 	 * Add the device to our list of discovered devices
885 	 * and the bus list for fixup functions, etc.
886 	 */
887 	INIT_LIST_HEAD(&dev->global_list);
888 	down_write(&pci_bus_sem);
889 	list_add_tail(&dev->bus_list, &bus->devices);
890 	up_write(&pci_bus_sem);
891 }
892 
893 struct pci_dev * __devinit
894 pci_scan_single_device(struct pci_bus *bus, int devfn)
895 {
896 	struct pci_dev *dev;
897 
898 	dev = pci_scan_device(bus, devfn);
899 	if (!dev)
900 		return NULL;
901 
902 	pci_device_add(dev, bus);
903 	pci_scan_msi_device(dev);
904 
905 	return dev;
906 }
907 
908 /**
909  * pci_scan_slot - scan a PCI slot on a bus for devices.
910  * @bus: PCI bus to scan
911  * @devfn: slot number to scan (must have zero function.)
912  *
913  * Scan a PCI slot on the specified PCI bus for devices, adding
914  * discovered devices to the @bus->devices list.  New devices
915  * will have an empty dev->global_list head.
916  */
917 int __devinit pci_scan_slot(struct pci_bus *bus, int devfn)
918 {
919 	int func, nr = 0;
920 	int scan_all_fns;
921 
922 	scan_all_fns = pcibios_scan_all_fns(bus, devfn);
923 
924 	for (func = 0; func < 8; func++, devfn++) {
925 		struct pci_dev *dev;
926 
927 		dev = pci_scan_single_device(bus, devfn);
928 		if (dev) {
929 			nr++;
930 
931 			/*
932 		 	 * If this is a single function device,
933 		 	 * don't scan past the first function.
934 		 	 */
935 			if (!dev->multifunction) {
936 				if (func > 0) {
937 					dev->multifunction = 1;
938 				} else {
939  					break;
940 				}
941 			}
942 		} else {
943 			if (func == 0 && !scan_all_fns)
944 				break;
945 		}
946 	}
947 	return nr;
948 }
949 
950 unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
951 {
952 	unsigned int devfn, pass, max = bus->secondary;
953 	struct pci_dev *dev;
954 
955 	pr_debug("PCI: Scanning bus %04x:%02x\n", pci_domain_nr(bus), bus->number);
956 
957 	/* Go find them, Rover! */
958 	for (devfn = 0; devfn < 0x100; devfn += 8)
959 		pci_scan_slot(bus, devfn);
960 
961 	/*
962 	 * After performing arch-dependent fixup of the bus, look behind
963 	 * all PCI-to-PCI bridges on this bus.
964 	 */
965 	pr_debug("PCI: Fixups for bus %04x:%02x\n", pci_domain_nr(bus), bus->number);
966 	pcibios_fixup_bus(bus);
967 	for (pass=0; pass < 2; pass++)
968 		list_for_each_entry(dev, &bus->devices, bus_list) {
969 			if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
970 			    dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
971 				max = pci_scan_bridge(bus, dev, max, pass);
972 		}
973 
974 	/*
975 	 * We've scanned the bus and so we know all about what's on
976 	 * the other side of any bridges that may be on this bus plus
977 	 * any devices.
978 	 *
979 	 * Return how far we've got finding sub-buses.
980 	 */
981 	pr_debug("PCI: Bus scan for %04x:%02x returning with max=%02x\n",
982 		pci_domain_nr(bus), bus->number, max);
983 	return max;
984 }
985 
986 unsigned int __devinit pci_do_scan_bus(struct pci_bus *bus)
987 {
988 	unsigned int max;
989 
990 	max = pci_scan_child_bus(bus);
991 
992 	/*
993 	 * Make the discovered devices available.
994 	 */
995 	pci_bus_add_devices(bus);
996 
997 	return max;
998 }
999 
1000 struct pci_bus * __devinit pci_create_bus(struct device *parent,
1001 		int bus, struct pci_ops *ops, void *sysdata)
1002 {
1003 	int error;
1004 	struct pci_bus *b;
1005 	struct device *dev;
1006 
1007 	b = pci_alloc_bus();
1008 	if (!b)
1009 		return NULL;
1010 
1011 	dev = kmalloc(sizeof(*dev), GFP_KERNEL);
1012 	if (!dev){
1013 		kfree(b);
1014 		return NULL;
1015 	}
1016 
1017 	b->sysdata = sysdata;
1018 	b->ops = ops;
1019 
1020 	if (pci_find_bus(pci_domain_nr(b), bus)) {
1021 		/* If we already got to this bus through a different bridge, ignore it */
1022 		pr_debug("PCI: Bus %04x:%02x already known\n", pci_domain_nr(b), bus);
1023 		goto err_out;
1024 	}
1025 
1026 	down_write(&pci_bus_sem);
1027 	list_add_tail(&b->node, &pci_root_buses);
1028 	up_write(&pci_bus_sem);
1029 
1030 	memset(dev, 0, sizeof(*dev));
1031 	dev->parent = parent;
1032 	dev->release = pci_release_bus_bridge_dev;
1033 	sprintf(dev->bus_id, "pci%04x:%02x", pci_domain_nr(b), bus);
1034 	error = device_register(dev);
1035 	if (error)
1036 		goto dev_reg_err;
1037 	b->bridge = get_device(dev);
1038 
1039 	b->class_dev.class = &pcibus_class;
1040 	sprintf(b->class_dev.class_id, "%04x:%02x", pci_domain_nr(b), bus);
1041 	error = class_device_register(&b->class_dev);
1042 	if (error)
1043 		goto class_dev_reg_err;
1044 	error = class_device_create_file(&b->class_dev, &class_device_attr_cpuaffinity);
1045 	if (error)
1046 		goto class_dev_create_file_err;
1047 
1048 	/* Create legacy_io and legacy_mem files for this bus */
1049 	pci_create_legacy_files(b);
1050 
1051 	error = sysfs_create_link(&b->class_dev.kobj, &b->bridge->kobj, "bridge");
1052 	if (error)
1053 		goto sys_create_link_err;
1054 
1055 	b->number = b->secondary = bus;
1056 	b->resource[0] = &ioport_resource;
1057 	b->resource[1] = &iomem_resource;
1058 
1059 	return b;
1060 
1061 sys_create_link_err:
1062 	class_device_remove_file(&b->class_dev, &class_device_attr_cpuaffinity);
1063 class_dev_create_file_err:
1064 	class_device_unregister(&b->class_dev);
1065 class_dev_reg_err:
1066 	device_unregister(dev);
1067 dev_reg_err:
1068 	down_write(&pci_bus_sem);
1069 	list_del(&b->node);
1070 	up_write(&pci_bus_sem);
1071 err_out:
1072 	kfree(dev);
1073 	kfree(b);
1074 	return NULL;
1075 }
1076 EXPORT_SYMBOL_GPL(pci_create_bus);
1077 
1078 struct pci_bus * __devinit pci_scan_bus_parented(struct device *parent,
1079 		int bus, struct pci_ops *ops, void *sysdata)
1080 {
1081 	struct pci_bus *b;
1082 
1083 	b = pci_create_bus(parent, bus, ops, sysdata);
1084 	if (b)
1085 		b->subordinate = pci_scan_child_bus(b);
1086 	return b;
1087 }
1088 EXPORT_SYMBOL(pci_scan_bus_parented);
1089 
1090 #ifdef CONFIG_HOTPLUG
1091 EXPORT_SYMBOL(pci_add_new_bus);
1092 EXPORT_SYMBOL(pci_do_scan_bus);
1093 EXPORT_SYMBOL(pci_scan_slot);
1094 EXPORT_SYMBOL(pci_scan_bridge);
1095 EXPORT_SYMBOL(pci_scan_single_device);
1096 EXPORT_SYMBOL_GPL(pci_scan_child_bus);
1097 #endif
1098 
1099 static int __init pci_sort_bf_cmp(const struct pci_dev *a, const struct pci_dev *b)
1100 {
1101 	if      (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1;
1102 	else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return  1;
1103 
1104 	if      (a->bus->number < b->bus->number) return -1;
1105 	else if (a->bus->number > b->bus->number) return  1;
1106 
1107 	if      (a->devfn < b->devfn) return -1;
1108 	else if (a->devfn > b->devfn) return  1;
1109 
1110 	return 0;
1111 }
1112 
1113 /*
1114  * Yes, this forcably breaks the klist abstraction temporarily.  It
1115  * just wants to sort the klist, not change reference counts and
1116  * take/drop locks rapidly in the process.  It does all this while
1117  * holding the lock for the list, so objects can't otherwise be
1118  * added/removed while we're swizzling.
1119  */
1120 static void __init pci_insertion_sort_klist(struct pci_dev *a, struct list_head *list)
1121 {
1122 	struct list_head *pos;
1123 	struct klist_node *n;
1124 	struct device *dev;
1125 	struct pci_dev *b;
1126 
1127 	list_for_each(pos, list) {
1128 		n = container_of(pos, struct klist_node, n_node);
1129 		dev = container_of(n, struct device, knode_bus);
1130 		b = to_pci_dev(dev);
1131 		if (pci_sort_bf_cmp(a, b) <= 0) {
1132 			list_move_tail(&a->dev.knode_bus.n_node, &b->dev.knode_bus.n_node);
1133 			return;
1134 		}
1135 	}
1136 	list_move_tail(&a->dev.knode_bus.n_node, list);
1137 }
1138 
1139 static void __init pci_sort_breadthfirst_klist(void)
1140 {
1141 	LIST_HEAD(sorted_devices);
1142 	struct list_head *pos, *tmp;
1143 	struct klist_node *n;
1144 	struct device *dev;
1145 	struct pci_dev *pdev;
1146 
1147 	spin_lock(&pci_bus_type.klist_devices.k_lock);
1148 	list_for_each_safe(pos, tmp, &pci_bus_type.klist_devices.k_list) {
1149 		n = container_of(pos, struct klist_node, n_node);
1150 		dev = container_of(n, struct device, knode_bus);
1151 		pdev = to_pci_dev(dev);
1152 		pci_insertion_sort_klist(pdev, &sorted_devices);
1153 	}
1154 	list_splice(&sorted_devices, &pci_bus_type.klist_devices.k_list);
1155 	spin_unlock(&pci_bus_type.klist_devices.k_lock);
1156 }
1157 
1158 static void __init pci_insertion_sort_devices(struct pci_dev *a, struct list_head *list)
1159 {
1160 	struct pci_dev *b;
1161 
1162 	list_for_each_entry(b, list, global_list) {
1163 		if (pci_sort_bf_cmp(a, b) <= 0) {
1164 			list_move_tail(&a->global_list, &b->global_list);
1165 			return;
1166 		}
1167 	}
1168 	list_move_tail(&a->global_list, list);
1169 }
1170 
1171 static void __init pci_sort_breadthfirst_devices(void)
1172 {
1173 	LIST_HEAD(sorted_devices);
1174 	struct pci_dev *dev, *tmp;
1175 
1176 	down_write(&pci_bus_sem);
1177 	list_for_each_entry_safe(dev, tmp, &pci_devices, global_list) {
1178 		pci_insertion_sort_devices(dev, &sorted_devices);
1179 	}
1180 	list_splice(&sorted_devices, &pci_devices);
1181 	up_write(&pci_bus_sem);
1182 }
1183 
1184 void __init pci_sort_breadthfirst(void)
1185 {
1186 	pci_sort_breadthfirst_devices();
1187 	pci_sort_breadthfirst_klist();
1188 }
1189 
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