1/*
2 *	drivers/pci/setup-bus.c
3 *
4 * Extruded from code written by
5 *      Dave Rusling (david.rusling@reo.mts.dec.com)
6 *      David Mosberger (davidm@cs.arizona.edu)
7 *	David Miller (davem@redhat.com)
8 *
9 * Support routines for initializing a PCI subsystem.
10 */
11
12/*
13 * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
14 *	     PCI-PCI bridges cleanup, sorted resource allocation.
15 * Feb 2002, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
16 *	     Converted to allocation in 3 passes, which gives
17 *	     tighter packing. Prefetchable range support.
18 */
19
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/pci.h>
24#include <linux/errno.h>
25#include <linux/ioport.h>
26#include <linux/cache.h>
27#include <linux/slab.h>
28#include <asm-generic/pci-bridge.h>
29#include "pci.h"
30
31unsigned int pci_flags;
32
33struct pci_dev_resource {
34	struct list_head list;
35	struct resource *res;
36	struct pci_dev *dev;
37	resource_size_t start;
38	resource_size_t end;
39	resource_size_t add_size;
40	resource_size_t min_align;
41	unsigned long flags;
42};
43
44static void free_list(struct list_head *head)
45{
46	struct pci_dev_resource *dev_res, *tmp;
47
48	list_for_each_entry_safe(dev_res, tmp, head, list) {
49		list_del(&dev_res->list);
50		kfree(dev_res);
51	}
52}
53
54/**
55 * add_to_list() - add a new resource tracker to the list
56 * @head:	Head of the list
57 * @dev:	device corresponding to which the resource
58 *		belongs
59 * @res:	The resource to be tracked
60 * @add_size:	additional size to be optionally added
61 *              to the resource
62 */
63static int add_to_list(struct list_head *head,
64		 struct pci_dev *dev, struct resource *res,
65		 resource_size_t add_size, resource_size_t min_align)
66{
67	struct pci_dev_resource *tmp;
68
69	tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
70	if (!tmp) {
71		pr_warn("add_to_list: kmalloc() failed!\n");
72		return -ENOMEM;
73	}
74
75	tmp->res = res;
76	tmp->dev = dev;
77	tmp->start = res->start;
78	tmp->end = res->end;
79	tmp->flags = res->flags;
80	tmp->add_size = add_size;
81	tmp->min_align = min_align;
82
83	list_add(&tmp->list, head);
84
85	return 0;
86}
87
88static void remove_from_list(struct list_head *head,
89				 struct resource *res)
90{
91	struct pci_dev_resource *dev_res, *tmp;
92
93	list_for_each_entry_safe(dev_res, tmp, head, list) {
94		if (dev_res->res == res) {
95			list_del(&dev_res->list);
96			kfree(dev_res);
97			break;
98		}
99	}
100}
101
102static struct pci_dev_resource *res_to_dev_res(struct list_head *head,
103					       struct resource *res)
104{
105	struct pci_dev_resource *dev_res;
106
107	list_for_each_entry(dev_res, head, list) {
108		if (dev_res->res == res) {
109			int idx = res - &dev_res->dev->resource[0];
110
111			dev_printk(KERN_DEBUG, &dev_res->dev->dev,
112				 "res[%d]=%pR res_to_dev_res add_size %llx min_align %llx\n",
113				 idx, dev_res->res,
114				 (unsigned long long)dev_res->add_size,
115				 (unsigned long long)dev_res->min_align);
116
117			return dev_res;
118		}
119	}
120
121	return NULL;
122}
123
124static resource_size_t get_res_add_size(struct list_head *head,
125					struct resource *res)
126{
127	struct pci_dev_resource *dev_res;
128
129	dev_res = res_to_dev_res(head, res);
130	return dev_res ? dev_res->add_size : 0;
131}
132
133static resource_size_t get_res_add_align(struct list_head *head,
134					 struct resource *res)
135{
136	struct pci_dev_resource *dev_res;
137
138	dev_res = res_to_dev_res(head, res);
139	return dev_res ? dev_res->min_align : 0;
140}
141
142
143/* Sort resources by alignment */
144static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
145{
146	int i;
147
148	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
149		struct resource *r;
150		struct pci_dev_resource *dev_res, *tmp;
151		resource_size_t r_align;
152		struct list_head *n;
153
154		r = &dev->resource[i];
155
156		if (r->flags & IORESOURCE_PCI_FIXED)
157			continue;
158
159		if (!(r->flags) || r->parent)
160			continue;
161
162		r_align = pci_resource_alignment(dev, r);
163		if (!r_align) {
164			dev_warn(&dev->dev, "BAR %d: %pR has bogus alignment\n",
165				 i, r);
166			continue;
167		}
168
169		tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
170		if (!tmp)
171			panic("pdev_sort_resources(): kmalloc() failed!\n");
172		tmp->res = r;
173		tmp->dev = dev;
174
175		/* fallback is smallest one or list is empty*/
176		n = head;
177		list_for_each_entry(dev_res, head, list) {
178			resource_size_t align;
179
180			align = pci_resource_alignment(dev_res->dev,
181							 dev_res->res);
182
183			if (r_align > align) {
184				n = &dev_res->list;
185				break;
186			}
187		}
188		/* Insert it just before n*/
189		list_add_tail(&tmp->list, n);
190	}
191}
192
193static void __dev_sort_resources(struct pci_dev *dev,
194				 struct list_head *head)
195{
196	u16 class = dev->class >> 8;
197
198	/* Don't touch classless devices or host bridges or ioapics.  */
199	if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)
200		return;
201
202	/* Don't touch ioapic devices already enabled by firmware */
203	if (class == PCI_CLASS_SYSTEM_PIC) {
204		u16 command;
205		pci_read_config_word(dev, PCI_COMMAND, &command);
206		if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
207			return;
208	}
209
210	pdev_sort_resources(dev, head);
211}
212
213static inline void reset_resource(struct resource *res)
214{
215	res->start = 0;
216	res->end = 0;
217	res->flags = 0;
218}
219
220/**
221 * reassign_resources_sorted() - satisfy any additional resource requests
222 *
223 * @realloc_head : head of the list tracking requests requiring additional
224 *             resources
225 * @head     : head of the list tracking requests with allocated
226 *             resources
227 *
228 * Walk through each element of the realloc_head and try to procure
229 * additional resources for the element, provided the element
230 * is in the head list.
231 */
232static void reassign_resources_sorted(struct list_head *realloc_head,
233		struct list_head *head)
234{
235	struct resource *res;
236	struct pci_dev_resource *add_res, *tmp;
237	struct pci_dev_resource *dev_res;
238	resource_size_t add_size, align;
239	int idx;
240
241	list_for_each_entry_safe(add_res, tmp, realloc_head, list) {
242		bool found_match = false;
243
244		res = add_res->res;
245		/* skip resource that has been reset */
246		if (!res->flags)
247			goto out;
248
249		/* skip this resource if not found in head list */
250		list_for_each_entry(dev_res, head, list) {
251			if (dev_res->res == res) {
252				found_match = true;
253				break;
254			}
255		}
256		if (!found_match)/* just skip */
257			continue;
258
259		idx = res - &add_res->dev->resource[0];
260		add_size = add_res->add_size;
261		align = add_res->min_align;
262		if (!resource_size(res)) {
263			res->start = align;
264			res->end = res->start + add_size - 1;
265			if (pci_assign_resource(add_res->dev, idx))
266				reset_resource(res);
267		} else {
268			res->flags |= add_res->flags &
269				 (IORESOURCE_STARTALIGN|IORESOURCE_SIZEALIGN);
270			if (pci_reassign_resource(add_res->dev, idx,
271						  add_size, align))
272				dev_printk(KERN_DEBUG, &add_res->dev->dev,
273					   "failed to add %llx res[%d]=%pR\n",
274					   (unsigned long long)add_size,
275					   idx, res);
276		}
277out:
278		list_del(&add_res->list);
279		kfree(add_res);
280	}
281}
282
283/**
284 * assign_requested_resources_sorted() - satisfy resource requests
285 *
286 * @head : head of the list tracking requests for resources
287 * @fail_head : head of the list tracking requests that could
288 *		not be allocated
289 *
290 * Satisfy resource requests of each element in the list. Add
291 * requests that could not satisfied to the failed_list.
292 */
293static void assign_requested_resources_sorted(struct list_head *head,
294				 struct list_head *fail_head)
295{
296	struct resource *res;
297	struct pci_dev_resource *dev_res;
298	int idx;
299
300	list_for_each_entry(dev_res, head, list) {
301		res = dev_res->res;
302		idx = res - &dev_res->dev->resource[0];
303		if (resource_size(res) &&
304		    pci_assign_resource(dev_res->dev, idx)) {
305			if (fail_head) {
306				/*
307				 * if the failed res is for ROM BAR, and it will
308				 * be enabled later, don't add it to the list
309				 */
310				if (!((idx == PCI_ROM_RESOURCE) &&
311				      (!(res->flags & IORESOURCE_ROM_ENABLE))))
312					add_to_list(fail_head,
313						    dev_res->dev, res,
314						    0 /* don't care */,
315						    0 /* don't care */);
316			}
317			reset_resource(res);
318		}
319	}
320}
321
322static unsigned long pci_fail_res_type_mask(struct list_head *fail_head)
323{
324	struct pci_dev_resource *fail_res;
325	unsigned long mask = 0;
326
327	/* check failed type */
328	list_for_each_entry(fail_res, fail_head, list)
329		mask |= fail_res->flags;
330
331	/*
332	 * one pref failed resource will set IORESOURCE_MEM,
333	 * as we can allocate pref in non-pref range.
334	 * Will release all assigned non-pref sibling resources
335	 * according to that bit.
336	 */
337	return mask & (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH);
338}
339
340static bool pci_need_to_release(unsigned long mask, struct resource *res)
341{
342	if (res->flags & IORESOURCE_IO)
343		return !!(mask & IORESOURCE_IO);
344
345	/* check pref at first */
346	if (res->flags & IORESOURCE_PREFETCH) {
347		if (mask & IORESOURCE_PREFETCH)
348			return true;
349		/* count pref if its parent is non-pref */
350		else if ((mask & IORESOURCE_MEM) &&
351			 !(res->parent->flags & IORESOURCE_PREFETCH))
352			return true;
353		else
354			return false;
355	}
356
357	if (res->flags & IORESOURCE_MEM)
358		return !!(mask & IORESOURCE_MEM);
359
360	return false;	/* should not get here */
361}
362
363static void __assign_resources_sorted(struct list_head *head,
364				 struct list_head *realloc_head,
365				 struct list_head *fail_head)
366{
367	/*
368	 * Should not assign requested resources at first.
369	 *   they could be adjacent, so later reassign can not reallocate
370	 *   them one by one in parent resource window.
371	 * Try to assign requested + add_size at beginning
372	 *  if could do that, could get out early.
373	 *  if could not do that, we still try to assign requested at first,
374	 *    then try to reassign add_size for some resources.
375	 *
376	 * Separate three resource type checking if we need to release
377	 * assigned resource after requested + add_size try.
378	 *	1. if there is io port assign fail, will release assigned
379	 *	   io port.
380	 *	2. if there is pref mmio assign fail, release assigned
381	 *	   pref mmio.
382	 *	   if assigned pref mmio's parent is non-pref mmio and there
383	 *	   is non-pref mmio assign fail, will release that assigned
384	 *	   pref mmio.
385	 *	3. if there is non-pref mmio assign fail or pref mmio
386	 *	   assigned fail, will release assigned non-pref mmio.
387	 */
388	LIST_HEAD(save_head);
389	LIST_HEAD(local_fail_head);
390	struct pci_dev_resource *save_res;
391	struct pci_dev_resource *dev_res, *tmp_res, *dev_res2;
392	unsigned long fail_type;
393	resource_size_t add_align, align;
394
395	/* Check if optional add_size is there */
396	if (!realloc_head || list_empty(realloc_head))
397		goto requested_and_reassign;
398
399	/* Save original start, end, flags etc at first */
400	list_for_each_entry(dev_res, head, list) {
401		if (add_to_list(&save_head, dev_res->dev, dev_res->res, 0, 0)) {
402			free_list(&save_head);
403			goto requested_and_reassign;
404		}
405	}
406
407	/* Update res in head list with add_size in realloc_head list */
408	list_for_each_entry_safe(dev_res, tmp_res, head, list) {
409		dev_res->res->end += get_res_add_size(realloc_head,
410							dev_res->res);
411
412		/*
413		 * There are two kinds of additional resources in the list:
414		 * 1. bridge resource  -- IORESOURCE_STARTALIGN
415		 * 2. SR-IOV resource   -- IORESOURCE_SIZEALIGN
416		 * Here just fix the additional alignment for bridge
417		 */
418		if (!(dev_res->res->flags & IORESOURCE_STARTALIGN))
419			continue;
420
421		add_align = get_res_add_align(realloc_head, dev_res->res);
422
423		/*
424		 * The "head" list is sorted by the alignment to make sure
425		 * resources with bigger alignment will be assigned first.
426		 * After we change the alignment of a dev_res in "head" list,
427		 * we need to reorder the list by alignment to make it
428		 * consistent.
429		 */
430		if (add_align > dev_res->res->start) {
431			resource_size_t r_size = resource_size(dev_res->res);
432
433			dev_res->res->start = add_align;
434			dev_res->res->end = add_align + r_size - 1;
435
436			list_for_each_entry(dev_res2, head, list) {
437				align = pci_resource_alignment(dev_res2->dev,
438							       dev_res2->res);
439				if (add_align > align) {
440					list_move_tail(&dev_res->list,
441						       &dev_res2->list);
442					break;
443				}
444			}
445               }
446
447	}
448
449	/* Try updated head list with add_size added */
450	assign_requested_resources_sorted(head, &local_fail_head);
451
452	/* all assigned with add_size ? */
453	if (list_empty(&local_fail_head)) {
454		/* Remove head list from realloc_head list */
455		list_for_each_entry(dev_res, head, list)
456			remove_from_list(realloc_head, dev_res->res);
457		free_list(&save_head);
458		free_list(head);
459		return;
460	}
461
462	/* check failed type */
463	fail_type = pci_fail_res_type_mask(&local_fail_head);
464	/* remove not need to be released assigned res from head list etc */
465	list_for_each_entry_safe(dev_res, tmp_res, head, list)
466		if (dev_res->res->parent &&
467		    !pci_need_to_release(fail_type, dev_res->res)) {
468			/* remove it from realloc_head list */
469			remove_from_list(realloc_head, dev_res->res);
470			remove_from_list(&save_head, dev_res->res);
471			list_del(&dev_res->list);
472			kfree(dev_res);
473		}
474
475	free_list(&local_fail_head);
476	/* Release assigned resource */
477	list_for_each_entry(dev_res, head, list)
478		if (dev_res->res->parent)
479			release_resource(dev_res->res);
480	/* Restore start/end/flags from saved list */
481	list_for_each_entry(save_res, &save_head, list) {
482		struct resource *res = save_res->res;
483
484		res->start = save_res->start;
485		res->end = save_res->end;
486		res->flags = save_res->flags;
487	}
488	free_list(&save_head);
489
490requested_and_reassign:
491	/* Satisfy the must-have resource requests */
492	assign_requested_resources_sorted(head, fail_head);
493
494	/* Try to satisfy any additional optional resource
495		requests */
496	if (realloc_head)
497		reassign_resources_sorted(realloc_head, head);
498	free_list(head);
499}
500
501static void pdev_assign_resources_sorted(struct pci_dev *dev,
502				 struct list_head *add_head,
503				 struct list_head *fail_head)
504{
505	LIST_HEAD(head);
506
507	__dev_sort_resources(dev, &head);
508	__assign_resources_sorted(&head, add_head, fail_head);
509
510}
511
512static void pbus_assign_resources_sorted(const struct pci_bus *bus,
513					 struct list_head *realloc_head,
514					 struct list_head *fail_head)
515{
516	struct pci_dev *dev;
517	LIST_HEAD(head);
518
519	list_for_each_entry(dev, &bus->devices, bus_list)
520		__dev_sort_resources(dev, &head);
521
522	__assign_resources_sorted(&head, realloc_head, fail_head);
523}
524
525void pci_setup_cardbus(struct pci_bus *bus)
526{
527	struct pci_dev *bridge = bus->self;
528	struct resource *res;
529	struct pci_bus_region region;
530
531	dev_info(&bridge->dev, "CardBus bridge to %pR\n",
532		 &bus->busn_res);
533
534	res = bus->resource[0];
535	pcibios_resource_to_bus(bridge->bus, &region, res);
536	if (res->flags & IORESOURCE_IO) {
537		/*
538		 * The IO resource is allocated a range twice as large as it
539		 * would normally need.  This allows us to set both IO regs.
540		 */
541		dev_info(&bridge->dev, "  bridge window %pR\n", res);
542		pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
543					region.start);
544		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
545					region.end);
546	}
547
548	res = bus->resource[1];
549	pcibios_resource_to_bus(bridge->bus, &region, res);
550	if (res->flags & IORESOURCE_IO) {
551		dev_info(&bridge->dev, "  bridge window %pR\n", res);
552		pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
553					region.start);
554		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
555					region.end);
556	}
557
558	res = bus->resource[2];
559	pcibios_resource_to_bus(bridge->bus, &region, res);
560	if (res->flags & IORESOURCE_MEM) {
561		dev_info(&bridge->dev, "  bridge window %pR\n", res);
562		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
563					region.start);
564		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
565					region.end);
566	}
567
568	res = bus->resource[3];
569	pcibios_resource_to_bus(bridge->bus, &region, res);
570	if (res->flags & IORESOURCE_MEM) {
571		dev_info(&bridge->dev, "  bridge window %pR\n", res);
572		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
573					region.start);
574		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
575					region.end);
576	}
577}
578EXPORT_SYMBOL(pci_setup_cardbus);
579
580/* Initialize bridges with base/limit values we have collected.
581   PCI-to-PCI Bridge Architecture Specification rev. 1.1 (1998)
582   requires that if there is no I/O ports or memory behind the
583   bridge, corresponding range must be turned off by writing base
584   value greater than limit to the bridge's base/limit registers.
585
586   Note: care must be taken when updating I/O base/limit registers
587   of bridges which support 32-bit I/O. This update requires two
588   config space writes, so it's quite possible that an I/O window of
589   the bridge will have some undesirable address (e.g. 0) after the
590   first write. Ditto 64-bit prefetchable MMIO.  */
591static void pci_setup_bridge_io(struct pci_dev *bridge)
592{
593	struct resource *res;
594	struct pci_bus_region region;
595	unsigned long io_mask;
596	u8 io_base_lo, io_limit_lo;
597	u16 l;
598	u32 io_upper16;
599
600	io_mask = PCI_IO_RANGE_MASK;
601	if (bridge->io_window_1k)
602		io_mask = PCI_IO_1K_RANGE_MASK;
603
604	/* Set up the top and bottom of the PCI I/O segment for this bus. */
605	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
606	pcibios_resource_to_bus(bridge->bus, &region, res);
607	if (res->flags & IORESOURCE_IO) {
608		pci_read_config_word(bridge, PCI_IO_BASE, &l);
609		io_base_lo = (region.start >> 8) & io_mask;
610		io_limit_lo = (region.end >> 8) & io_mask;
611		l = ((u16) io_limit_lo << 8) | io_base_lo;
612		/* Set up upper 16 bits of I/O base/limit. */
613		io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
614		dev_info(&bridge->dev, "  bridge window %pR\n", res);
615	} else {
616		/* Clear upper 16 bits of I/O base/limit. */
617		io_upper16 = 0;
618		l = 0x00f0;
619	}
620	/* Temporarily disable the I/O range before updating PCI_IO_BASE. */
621	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff);
622	/* Update lower 16 bits of I/O base/limit. */
623	pci_write_config_word(bridge, PCI_IO_BASE, l);
624	/* Update upper 16 bits of I/O base/limit. */
625	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
626}
627
628static void pci_setup_bridge_mmio(struct pci_dev *bridge)
629{
630	struct resource *res;
631	struct pci_bus_region region;
632	u32 l;
633
634	/* Set up the top and bottom of the PCI Memory segment for this bus. */
635	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
636	pcibios_resource_to_bus(bridge->bus, &region, res);
637	if (res->flags & IORESOURCE_MEM) {
638		l = (region.start >> 16) & 0xfff0;
639		l |= region.end & 0xfff00000;
640		dev_info(&bridge->dev, "  bridge window %pR\n", res);
641	} else {
642		l = 0x0000fff0;
643	}
644	pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
645}
646
647static void pci_setup_bridge_mmio_pref(struct pci_dev *bridge)
648{
649	struct resource *res;
650	struct pci_bus_region region;
651	u32 l, bu, lu;
652
653	/* Clear out the upper 32 bits of PREF limit.
654	   If PCI_PREF_BASE_UPPER32 was non-zero, this temporarily
655	   disables PREF range, which is ok. */
656	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);
657
658	/* Set up PREF base/limit. */
659	bu = lu = 0;
660	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
661	pcibios_resource_to_bus(bridge->bus, &region, res);
662	if (res->flags & IORESOURCE_PREFETCH) {
663		l = (region.start >> 16) & 0xfff0;
664		l |= region.end & 0xfff00000;
665		if (res->flags & IORESOURCE_MEM_64) {
666			bu = upper_32_bits(region.start);
667			lu = upper_32_bits(region.end);
668		}
669		dev_info(&bridge->dev, "  bridge window %pR\n", res);
670	} else {
671		l = 0x0000fff0;
672	}
673	pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
674
675	/* Set the upper 32 bits of PREF base & limit. */
676	pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
677	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
678}
679
680static void __pci_setup_bridge(struct pci_bus *bus, unsigned long type)
681{
682	struct pci_dev *bridge = bus->self;
683
684	dev_info(&bridge->dev, "PCI bridge to %pR\n",
685		 &bus->busn_res);
686
687	if (type & IORESOURCE_IO)
688		pci_setup_bridge_io(bridge);
689
690	if (type & IORESOURCE_MEM)
691		pci_setup_bridge_mmio(bridge);
692
693	if (type & IORESOURCE_PREFETCH)
694		pci_setup_bridge_mmio_pref(bridge);
695
696	pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
697}
698
699void pci_setup_bridge(struct pci_bus *bus)
700{
701	unsigned long type = IORESOURCE_IO | IORESOURCE_MEM |
702				  IORESOURCE_PREFETCH;
703
704	__pci_setup_bridge(bus, type);
705}
706
707
708int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
709{
710	if (i < PCI_BRIDGE_RESOURCES || i > PCI_BRIDGE_RESOURCE_END)
711		return 0;
712
713	if (pci_claim_resource(bridge, i) == 0)
714		return 0;	/* claimed the window */
715
716	if ((bridge->class >> 8) != PCI_CLASS_BRIDGE_PCI)
717		return 0;
718
719	if (!pci_bus_clip_resource(bridge, i))
720		return -EINVAL;	/* clipping didn't change anything */
721
722	switch (i - PCI_BRIDGE_RESOURCES) {
723	case 0:
724		pci_setup_bridge_io(bridge);
725		break;
726	case 1:
727		pci_setup_bridge_mmio(bridge);
728		break;
729	case 2:
730		pci_setup_bridge_mmio_pref(bridge);
731		break;
732	default:
733		return -EINVAL;
734	}
735
736	if (pci_claim_resource(bridge, i) == 0)
737		return 0;	/* claimed a smaller window */
738
739	return -EINVAL;
740}
741
742/* Check whether the bridge supports optional I/O and
743   prefetchable memory ranges. If not, the respective
744   base/limit registers must be read-only and read as 0. */
745static void pci_bridge_check_ranges(struct pci_bus *bus)
746{
747	u16 io;
748	u32 pmem;
749	struct pci_dev *bridge = bus->self;
750	struct resource *b_res;
751
752	b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
753	b_res[1].flags |= IORESOURCE_MEM;
754
755	pci_read_config_word(bridge, PCI_IO_BASE, &io);
756	if (!io) {
757		pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0);
758		pci_read_config_word(bridge, PCI_IO_BASE, &io);
759		pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
760	}
761	if (io)
762		b_res[0].flags |= IORESOURCE_IO;
763
764	/*  DECchip 21050 pass 2 errata: the bridge may miss an address
765	    disconnect boundary by one PCI data phase.
766	    Workaround: do not use prefetching on this device. */
767	if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
768		return;
769
770	pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
771	if (!pmem) {
772		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
773					       0xffe0fff0);
774		pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
775		pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
776	}
777	if (pmem) {
778		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
779		if ((pmem & PCI_PREF_RANGE_TYPE_MASK) ==
780		    PCI_PREF_RANGE_TYPE_64) {
781			b_res[2].flags |= IORESOURCE_MEM_64;
782			b_res[2].flags |= PCI_PREF_RANGE_TYPE_64;
783		}
784	}
785
786	/* double check if bridge does support 64 bit pref */
787	if (b_res[2].flags & IORESOURCE_MEM_64) {
788		u32 mem_base_hi, tmp;
789		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32,
790					 &mem_base_hi);
791		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
792					       0xffffffff);
793		pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
794		if (!tmp)
795			b_res[2].flags &= ~IORESOURCE_MEM_64;
796		pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
797				       mem_base_hi);
798	}
799}
800
801/* Helper function for sizing routines: find first available
802   bus resource of a given type. Note: we intentionally skip
803   the bus resources which have already been assigned (that is,
804   have non-NULL parent resource). */
805static struct resource *find_free_bus_resource(struct pci_bus *bus,
806			 unsigned long type_mask, unsigned long type)
807{
808	int i;
809	struct resource *r;
810
811	pci_bus_for_each_resource(bus, r, i) {
812		if (r == &ioport_resource || r == &iomem_resource)
813			continue;
814		if (r && (r->flags & type_mask) == type && !r->parent)
815			return r;
816	}
817	return NULL;
818}
819
820static resource_size_t calculate_iosize(resource_size_t size,
821		resource_size_t min_size,
822		resource_size_t size1,
823		resource_size_t old_size,
824		resource_size_t align)
825{
826	if (size < min_size)
827		size = min_size;
828	if (old_size == 1)
829		old_size = 0;
830	/* To be fixed in 2.5: we should have sort of HAVE_ISA
831	   flag in the struct pci_bus. */
832#if defined(CONFIG_ISA) || defined(CONFIG_EISA)
833	size = (size & 0xff) + ((size & ~0xffUL) << 2);
834#endif
835	size = ALIGN(size + size1, align);
836	if (size < old_size)
837		size = old_size;
838	return size;
839}
840
841static resource_size_t calculate_memsize(resource_size_t size,
842		resource_size_t min_size,
843		resource_size_t size1,
844		resource_size_t old_size,
845		resource_size_t align)
846{
847	if (size < min_size)
848		size = min_size;
849	if (old_size == 1)
850		old_size = 0;
851	if (size < old_size)
852		size = old_size;
853	size = ALIGN(size + size1, align);
854	return size;
855}
856
857resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus,
858						unsigned long type)
859{
860	return 1;
861}
862
863#define PCI_P2P_DEFAULT_MEM_ALIGN	0x100000	/* 1MiB */
864#define PCI_P2P_DEFAULT_IO_ALIGN	0x1000		/* 4KiB */
865#define PCI_P2P_DEFAULT_IO_ALIGN_1K	0x400		/* 1KiB */
866
867static resource_size_t window_alignment(struct pci_bus *bus,
868					unsigned long type)
869{
870	resource_size_t align = 1, arch_align;
871
872	if (type & IORESOURCE_MEM)
873		align = PCI_P2P_DEFAULT_MEM_ALIGN;
874	else if (type & IORESOURCE_IO) {
875		/*
876		 * Per spec, I/O windows are 4K-aligned, but some
877		 * bridges have an extension to support 1K alignment.
878		 */
879		if (bus->self->io_window_1k)
880			align = PCI_P2P_DEFAULT_IO_ALIGN_1K;
881		else
882			align = PCI_P2P_DEFAULT_IO_ALIGN;
883	}
884
885	arch_align = pcibios_window_alignment(bus, type);
886	return max(align, arch_align);
887}
888
889/**
890 * pbus_size_io() - size the io window of a given bus
891 *
892 * @bus : the bus
893 * @min_size : the minimum io window that must to be allocated
894 * @add_size : additional optional io window
895 * @realloc_head : track the additional io window on this list
896 *
897 * Sizing the IO windows of the PCI-PCI bridge is trivial,
898 * since these windows have 1K or 4K granularity and the IO ranges
899 * of non-bridge PCI devices are limited to 256 bytes.
900 * We must be careful with the ISA aliasing though.
901 */
902static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
903		resource_size_t add_size, struct list_head *realloc_head)
904{
905	struct pci_dev *dev;
906	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO,
907							IORESOURCE_IO);
908	resource_size_t size = 0, size0 = 0, size1 = 0;
909	resource_size_t children_add_size = 0;
910	resource_size_t min_align, align;
911
912	if (!b_res)
913		return;
914
915	min_align = window_alignment(bus, IORESOURCE_IO);
916	list_for_each_entry(dev, &bus->devices, bus_list) {
917		int i;
918
919		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
920			struct resource *r = &dev->resource[i];
921			unsigned long r_size;
922
923			if (r->parent || !(r->flags & IORESOURCE_IO))
924				continue;
925			r_size = resource_size(r);
926
927			if (r_size < 0x400)
928				/* Might be re-aligned for ISA */
929				size += r_size;
930			else
931				size1 += r_size;
932
933			align = pci_resource_alignment(dev, r);
934			if (align > min_align)
935				min_align = align;
936
937			if (realloc_head)
938				children_add_size += get_res_add_size(realloc_head, r);
939		}
940	}
941
942	size0 = calculate_iosize(size, min_size, size1,
943			resource_size(b_res), min_align);
944	if (children_add_size > add_size)
945		add_size = children_add_size;
946	size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
947		calculate_iosize(size, min_size, add_size + size1,
948			resource_size(b_res), min_align);
949	if (!size0 && !size1) {
950		if (b_res->start || b_res->end)
951			dev_info(&bus->self->dev, "disabling bridge window %pR to %pR (unused)\n",
952				 b_res, &bus->busn_res);
953		b_res->flags = 0;
954		return;
955	}
956
957	b_res->start = min_align;
958	b_res->end = b_res->start + size0 - 1;
959	b_res->flags |= IORESOURCE_STARTALIGN;
960	if (size1 > size0 && realloc_head) {
961		add_to_list(realloc_head, bus->self, b_res, size1-size0,
962			    min_align);
963		dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window %pR to %pR add_size %llx\n",
964			   b_res, &bus->busn_res,
965			   (unsigned long long)size1-size0);
966	}
967}
968
969static inline resource_size_t calculate_mem_align(resource_size_t *aligns,
970						  int max_order)
971{
972	resource_size_t align = 0;
973	resource_size_t min_align = 0;
974	int order;
975
976	for (order = 0; order <= max_order; order++) {
977		resource_size_t align1 = 1;
978
979		align1 <<= (order + 20);
980
981		if (!align)
982			min_align = align1;
983		else if (ALIGN(align + min_align, min_align) < align1)
984			min_align = align1 >> 1;
985		align += aligns[order];
986	}
987
988	return min_align;
989}
990
991/**
992 * pbus_size_mem() - size the memory window of a given bus
993 *
994 * @bus : the bus
995 * @mask: mask the resource flag, then compare it with type
996 * @type: the type of free resource from bridge
997 * @type2: second match type
998 * @type3: third match type
999 * @min_size : the minimum memory window that must to be allocated
1000 * @add_size : additional optional memory window
1001 * @realloc_head : track the additional memory window on this list
1002 *
1003 * Calculate the size of the bus and minimal alignment which
1004 * guarantees that all child resources fit in this size.
1005 *
1006 * Returns -ENOSPC if there's no available bus resource of the desired type.
1007 * Otherwise, sets the bus resource start/end to indicate the required
1008 * size, adds things to realloc_head (if supplied), and returns 0.
1009 */
1010static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
1011			 unsigned long type, unsigned long type2,
1012			 unsigned long type3,
1013			 resource_size_t min_size, resource_size_t add_size,
1014			 struct list_head *realloc_head)
1015{
1016	struct pci_dev *dev;
1017	resource_size_t min_align, align, size, size0, size1;
1018	resource_size_t aligns[18];	/* Alignments from 1Mb to 128Gb */
1019	int order, max_order;
1020	struct resource *b_res = find_free_bus_resource(bus,
1021					mask | IORESOURCE_PREFETCH, type);
1022	resource_size_t children_add_size = 0;
1023	resource_size_t children_add_align = 0;
1024	resource_size_t add_align = 0;
1025
1026	if (!b_res)
1027		return -ENOSPC;
1028
1029	memset(aligns, 0, sizeof(aligns));
1030	max_order = 0;
1031	size = 0;
1032
1033	list_for_each_entry(dev, &bus->devices, bus_list) {
1034		int i;
1035
1036		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
1037			struct resource *r = &dev->resource[i];
1038			resource_size_t r_size;
1039
1040			if (r->parent || ((r->flags & mask) != type &&
1041					  (r->flags & mask) != type2 &&
1042					  (r->flags & mask) != type3))
1043				continue;
1044			r_size = resource_size(r);
1045#ifdef CONFIG_PCI_IOV
1046			/* put SRIOV requested res to the optional list */
1047			if (realloc_head && i >= PCI_IOV_RESOURCES &&
1048					i <= PCI_IOV_RESOURCE_END) {
1049				add_align = max(pci_resource_alignment(dev, r), add_align);
1050				r->end = r->start - 1;
1051				add_to_list(realloc_head, dev, r, r_size, 0/* don't care */);
1052				children_add_size += r_size;
1053				continue;
1054			}
1055#endif
1056			/*
1057			 * aligns[0] is for 1MB (since bridge memory
1058			 * windows are always at least 1MB aligned), so
1059			 * keep "order" from being negative for smaller
1060			 * resources.
1061			 */
1062			align = pci_resource_alignment(dev, r);
1063			order = __ffs(align) - 20;
1064			if (order < 0)
1065				order = 0;
1066			if (order >= ARRAY_SIZE(aligns)) {
1067				dev_warn(&dev->dev, "disabling BAR %d: %pR (bad alignment %#llx)\n",
1068					 i, r, (unsigned long long) align);
1069				r->flags = 0;
1070				continue;
1071			}
1072			size += r_size;
1073			/* Exclude ranges with size > align from
1074			   calculation of the alignment. */
1075			if (r_size == align)
1076				aligns[order] += align;
1077			if (order > max_order)
1078				max_order = order;
1079
1080			if (realloc_head) {
1081				children_add_size += get_res_add_size(realloc_head, r);
1082				children_add_align = get_res_add_align(realloc_head, r);
1083				add_align = max(add_align, children_add_align);
1084			}
1085		}
1086	}
1087
1088	min_align = calculate_mem_align(aligns, max_order);
1089	min_align = max(min_align, window_alignment(bus, b_res->flags));
1090	size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);
1091	add_align = max(min_align, add_align);
1092	if (children_add_size > add_size)
1093		add_size = children_add_size;
1094	size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
1095		calculate_memsize(size, min_size, add_size,
1096				resource_size(b_res), add_align);
1097	if (!size0 && !size1) {
1098		if (b_res->start || b_res->end)
1099			dev_info(&bus->self->dev, "disabling bridge window %pR to %pR (unused)\n",
1100				 b_res, &bus->busn_res);
1101		b_res->flags = 0;
1102		return 0;
1103	}
1104	b_res->start = min_align;
1105	b_res->end = size0 + min_align - 1;
1106	b_res->flags |= IORESOURCE_STARTALIGN;
1107	if (size1 > size0 && realloc_head) {
1108		add_to_list(realloc_head, bus->self, b_res, size1-size0, add_align);
1109		dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window %pR to %pR add_size %llx add_align %llx\n",
1110			   b_res, &bus->busn_res,
1111			   (unsigned long long) (size1 - size0),
1112			   (unsigned long long) add_align);
1113	}
1114	return 0;
1115}
1116
1117unsigned long pci_cardbus_resource_alignment(struct resource *res)
1118{
1119	if (res->flags & IORESOURCE_IO)
1120		return pci_cardbus_io_size;
1121	if (res->flags & IORESOURCE_MEM)
1122		return pci_cardbus_mem_size;
1123	return 0;
1124}
1125
1126static void pci_bus_size_cardbus(struct pci_bus *bus,
1127			struct list_head *realloc_head)
1128{
1129	struct pci_dev *bridge = bus->self;
1130	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
1131	resource_size_t b_res_3_size = pci_cardbus_mem_size * 2;
1132	u16 ctrl;
1133
1134	if (b_res[0].parent)
1135		goto handle_b_res_1;
1136	/*
1137	 * Reserve some resources for CardBus.  We reserve
1138	 * a fixed amount of bus space for CardBus bridges.
1139	 */
1140	b_res[0].start = pci_cardbus_io_size;
1141	b_res[0].end = b_res[0].start + pci_cardbus_io_size - 1;
1142	b_res[0].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
1143	if (realloc_head) {
1144		b_res[0].end -= pci_cardbus_io_size;
1145		add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size,
1146				pci_cardbus_io_size);
1147	}
1148
1149handle_b_res_1:
1150	if (b_res[1].parent)
1151		goto handle_b_res_2;
1152	b_res[1].start = pci_cardbus_io_size;
1153	b_res[1].end = b_res[1].start + pci_cardbus_io_size - 1;
1154	b_res[1].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
1155	if (realloc_head) {
1156		b_res[1].end -= pci_cardbus_io_size;
1157		add_to_list(realloc_head, bridge, b_res+1, pci_cardbus_io_size,
1158				 pci_cardbus_io_size);
1159	}
1160
1161handle_b_res_2:
1162	/* MEM1 must not be pref mmio */
1163	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1164	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM1) {
1165		ctrl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
1166		pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
1167		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1168	}
1169
1170	/*
1171	 * Check whether prefetchable memory is supported
1172	 * by this bridge.
1173	 */
1174	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1175	if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
1176		ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
1177		pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
1178		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1179	}
1180
1181	if (b_res[2].parent)
1182		goto handle_b_res_3;
1183	/*
1184	 * If we have prefetchable memory support, allocate
1185	 * two regions.  Otherwise, allocate one region of
1186	 * twice the size.
1187	 */
1188	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
1189		b_res[2].start = pci_cardbus_mem_size;
1190		b_res[2].end = b_res[2].start + pci_cardbus_mem_size - 1;
1191		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH |
1192				  IORESOURCE_STARTALIGN;
1193		if (realloc_head) {
1194			b_res[2].end -= pci_cardbus_mem_size;
1195			add_to_list(realloc_head, bridge, b_res+2,
1196				 pci_cardbus_mem_size, pci_cardbus_mem_size);
1197		}
1198
1199		/* reduce that to half */
1200		b_res_3_size = pci_cardbus_mem_size;
1201	}
1202
1203handle_b_res_3:
1204	if (b_res[3].parent)
1205		goto handle_done;
1206	b_res[3].start = pci_cardbus_mem_size;
1207	b_res[3].end = b_res[3].start + b_res_3_size - 1;
1208	b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_STARTALIGN;
1209	if (realloc_head) {
1210		b_res[3].end -= b_res_3_size;
1211		add_to_list(realloc_head, bridge, b_res+3, b_res_3_size,
1212				 pci_cardbus_mem_size);
1213	}
1214
1215handle_done:
1216	;
1217}
1218
1219void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
1220{
1221	struct pci_dev *dev;
1222	unsigned long mask, prefmask, type2 = 0, type3 = 0;
1223	resource_size_t additional_mem_size = 0, additional_io_size = 0;
1224	struct resource *b_res;
1225	int ret;
1226
1227	list_for_each_entry(dev, &bus->devices, bus_list) {
1228		struct pci_bus *b = dev->subordinate;
1229		if (!b)
1230			continue;
1231
1232		switch (dev->class >> 8) {
1233		case PCI_CLASS_BRIDGE_CARDBUS:
1234			pci_bus_size_cardbus(b, realloc_head);
1235			break;
1236
1237		case PCI_CLASS_BRIDGE_PCI:
1238		default:
1239			__pci_bus_size_bridges(b, realloc_head);
1240			break;
1241		}
1242	}
1243
1244	/* The root bus? */
1245	if (pci_is_root_bus(bus))
1246		return;
1247
1248	switch (bus->self->class >> 8) {
1249	case PCI_CLASS_BRIDGE_CARDBUS:
1250		/* don't size cardbuses yet. */
1251		break;
1252
1253	case PCI_CLASS_BRIDGE_PCI:
1254		pci_bridge_check_ranges(bus);
1255		if (bus->self->is_hotplug_bridge) {
1256			additional_io_size  = pci_hotplug_io_size;
1257			additional_mem_size = pci_hotplug_mem_size;
1258		}
1259		/* Fall through */
1260	default:
1261		pbus_size_io(bus, realloc_head ? 0 : additional_io_size,
1262			     additional_io_size, realloc_head);
1263
1264		/*
1265		 * If there's a 64-bit prefetchable MMIO window, compute
1266		 * the size required to put all 64-bit prefetchable
1267		 * resources in it.
1268		 */
1269		b_res = &bus->self->resource[PCI_BRIDGE_RESOURCES];
1270		mask = IORESOURCE_MEM;
1271		prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
1272		if (b_res[2].flags & IORESOURCE_MEM_64) {
1273			prefmask |= IORESOURCE_MEM_64;
1274			ret = pbus_size_mem(bus, prefmask, prefmask,
1275				  prefmask, prefmask,
1276				  realloc_head ? 0 : additional_mem_size,
1277				  additional_mem_size, realloc_head);
1278
1279			/*
1280			 * If successful, all non-prefetchable resources
1281			 * and any 32-bit prefetchable resources will go in
1282			 * the non-prefetchable window.
1283			 */
1284			if (ret == 0) {
1285				mask = prefmask;
1286				type2 = prefmask & ~IORESOURCE_MEM_64;
1287				type3 = prefmask & ~IORESOURCE_PREFETCH;
1288			}
1289		}
1290
1291		/*
1292		 * If there is no 64-bit prefetchable window, compute the
1293		 * size required to put all prefetchable resources in the
1294		 * 32-bit prefetchable window (if there is one).
1295		 */
1296		if (!type2) {
1297			prefmask &= ~IORESOURCE_MEM_64;
1298			ret = pbus_size_mem(bus, prefmask, prefmask,
1299					 prefmask, prefmask,
1300					 realloc_head ? 0 : additional_mem_size,
1301					 additional_mem_size, realloc_head);
1302
1303			/*
1304			 * If successful, only non-prefetchable resources
1305			 * will go in the non-prefetchable window.
1306			 */
1307			if (ret == 0)
1308				mask = prefmask;
1309			else
1310				additional_mem_size += additional_mem_size;
1311
1312			type2 = type3 = IORESOURCE_MEM;
1313		}
1314
1315		/*
1316		 * Compute the size required to put everything else in the
1317		 * non-prefetchable window.  This includes:
1318		 *
1319		 *   - all non-prefetchable resources
1320		 *   - 32-bit prefetchable resources if there's a 64-bit
1321		 *     prefetchable window or no prefetchable window at all
1322		 *   - 64-bit prefetchable resources if there's no
1323		 *     prefetchable window at all
1324		 *
1325		 * Note that the strategy in __pci_assign_resource() must
1326		 * match that used here.  Specifically, we cannot put a
1327		 * 32-bit prefetchable resource in a 64-bit prefetchable
1328		 * window.
1329		 */
1330		pbus_size_mem(bus, mask, IORESOURCE_MEM, type2, type3,
1331				realloc_head ? 0 : additional_mem_size,
1332				additional_mem_size, realloc_head);
1333		break;
1334	}
1335}
1336
1337void pci_bus_size_bridges(struct pci_bus *bus)
1338{
1339	__pci_bus_size_bridges(bus, NULL);
1340}
1341EXPORT_SYMBOL(pci_bus_size_bridges);
1342
1343void __pci_bus_assign_resources(const struct pci_bus *bus,
1344				struct list_head *realloc_head,
1345				struct list_head *fail_head)
1346{
1347	struct pci_bus *b;
1348	struct pci_dev *dev;
1349
1350	pbus_assign_resources_sorted(bus, realloc_head, fail_head);
1351
1352	list_for_each_entry(dev, &bus->devices, bus_list) {
1353		b = dev->subordinate;
1354		if (!b)
1355			continue;
1356
1357		__pci_bus_assign_resources(b, realloc_head, fail_head);
1358
1359		switch (dev->class >> 8) {
1360		case PCI_CLASS_BRIDGE_PCI:
1361			if (!pci_is_enabled(dev))
1362				pci_setup_bridge(b);
1363			break;
1364
1365		case PCI_CLASS_BRIDGE_CARDBUS:
1366			pci_setup_cardbus(b);
1367			break;
1368
1369		default:
1370			dev_info(&dev->dev, "not setting up bridge for bus %04x:%02x\n",
1371				 pci_domain_nr(b), b->number);
1372			break;
1373		}
1374	}
1375}
1376
1377void pci_bus_assign_resources(const struct pci_bus *bus)
1378{
1379	__pci_bus_assign_resources(bus, NULL, NULL);
1380}
1381EXPORT_SYMBOL(pci_bus_assign_resources);
1382
1383static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
1384					  struct list_head *add_head,
1385					  struct list_head *fail_head)
1386{
1387	struct pci_bus *b;
1388
1389	pdev_assign_resources_sorted((struct pci_dev *)bridge,
1390					 add_head, fail_head);
1391
1392	b = bridge->subordinate;
1393	if (!b)
1394		return;
1395
1396	__pci_bus_assign_resources(b, add_head, fail_head);
1397
1398	switch (bridge->class >> 8) {
1399	case PCI_CLASS_BRIDGE_PCI:
1400		pci_setup_bridge(b);
1401		break;
1402
1403	case PCI_CLASS_BRIDGE_CARDBUS:
1404		pci_setup_cardbus(b);
1405		break;
1406
1407	default:
1408		dev_info(&bridge->dev, "not setting up bridge for bus %04x:%02x\n",
1409			 pci_domain_nr(b), b->number);
1410		break;
1411	}
1412}
1413static void pci_bridge_release_resources(struct pci_bus *bus,
1414					  unsigned long type)
1415{
1416	struct pci_dev *dev = bus->self;
1417	struct resource *r;
1418	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
1419				  IORESOURCE_PREFETCH | IORESOURCE_MEM_64;
1420	unsigned old_flags = 0;
1421	struct resource *b_res;
1422	int idx = 1;
1423
1424	b_res = &dev->resource[PCI_BRIDGE_RESOURCES];
1425
1426	/*
1427	 *     1. if there is io port assign fail, will release bridge
1428	 *	  io port.
1429	 *     2. if there is non pref mmio assign fail, release bridge
1430	 *	  nonpref mmio.
1431	 *     3. if there is 64bit pref mmio assign fail, and bridge pref
1432	 *	  is 64bit, release bridge pref mmio.
1433	 *     4. if there is pref mmio assign fail, and bridge pref is
1434	 *	  32bit mmio, release bridge pref mmio
1435	 *     5. if there is pref mmio assign fail, and bridge pref is not
1436	 *	  assigned, release bridge nonpref mmio.
1437	 */
1438	if (type & IORESOURCE_IO)
1439		idx = 0;
1440	else if (!(type & IORESOURCE_PREFETCH))
1441		idx = 1;
1442	else if ((type & IORESOURCE_MEM_64) &&
1443		 (b_res[2].flags & IORESOURCE_MEM_64))
1444		idx = 2;
1445	else if (!(b_res[2].flags & IORESOURCE_MEM_64) &&
1446		 (b_res[2].flags & IORESOURCE_PREFETCH))
1447		idx = 2;
1448	else
1449		idx = 1;
1450
1451	r = &b_res[idx];
1452
1453	if (!r->parent)
1454		return;
1455
1456	/*
1457	 * if there are children under that, we should release them
1458	 *  all
1459	 */
1460	release_child_resources(r);
1461	if (!release_resource(r)) {
1462		type = old_flags = r->flags & type_mask;
1463		dev_printk(KERN_DEBUG, &dev->dev, "resource %d %pR released\n",
1464					PCI_BRIDGE_RESOURCES + idx, r);
1465		/* keep the old size */
1466		r->end = resource_size(r) - 1;
1467		r->start = 0;
1468		r->flags = 0;
1469
1470		/* avoiding touch the one without PREF */
1471		if (type & IORESOURCE_PREFETCH)
1472			type = IORESOURCE_PREFETCH;
1473		__pci_setup_bridge(bus, type);
1474		/* for next child res under same bridge */
1475		r->flags = old_flags;
1476	}
1477}
1478
1479enum release_type {
1480	leaf_only,
1481	whole_subtree,
1482};
1483/*
1484 * try to release pci bridge resources that is from leaf bridge,
1485 * so we can allocate big new one later
1486 */
1487static void pci_bus_release_bridge_resources(struct pci_bus *bus,
1488					     unsigned long type,
1489					     enum release_type rel_type)
1490{
1491	struct pci_dev *dev;
1492	bool is_leaf_bridge = true;
1493
1494	list_for_each_entry(dev, &bus->devices, bus_list) {
1495		struct pci_bus *b = dev->subordinate;
1496		if (!b)
1497			continue;
1498
1499		is_leaf_bridge = false;
1500
1501		if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
1502			continue;
1503
1504		if (rel_type == whole_subtree)
1505			pci_bus_release_bridge_resources(b, type,
1506						 whole_subtree);
1507	}
1508
1509	if (pci_is_root_bus(bus))
1510		return;
1511
1512	if ((bus->self->class >> 8) != PCI_CLASS_BRIDGE_PCI)
1513		return;
1514
1515	if ((rel_type == whole_subtree) || is_leaf_bridge)
1516		pci_bridge_release_resources(bus, type);
1517}
1518
1519static void pci_bus_dump_res(struct pci_bus *bus)
1520{
1521	struct resource *res;
1522	int i;
1523
1524	pci_bus_for_each_resource(bus, res, i) {
1525		if (!res || !res->end || !res->flags)
1526			continue;
1527
1528		dev_printk(KERN_DEBUG, &bus->dev, "resource %d %pR\n", i, res);
1529	}
1530}
1531
1532static void pci_bus_dump_resources(struct pci_bus *bus)
1533{
1534	struct pci_bus *b;
1535	struct pci_dev *dev;
1536
1537
1538	pci_bus_dump_res(bus);
1539
1540	list_for_each_entry(dev, &bus->devices, bus_list) {
1541		b = dev->subordinate;
1542		if (!b)
1543			continue;
1544
1545		pci_bus_dump_resources(b);
1546	}
1547}
1548
1549static int pci_bus_get_depth(struct pci_bus *bus)
1550{
1551	int depth = 0;
1552	struct pci_bus *child_bus;
1553
1554	list_for_each_entry(child_bus, &bus->children, node) {
1555		int ret;
1556
1557		ret = pci_bus_get_depth(child_bus);
1558		if (ret + 1 > depth)
1559			depth = ret + 1;
1560	}
1561
1562	return depth;
1563}
1564
1565/*
1566 * -1: undefined, will auto detect later
1567 *  0: disabled by user
1568 *  1: disabled by auto detect
1569 *  2: enabled by user
1570 *  3: enabled by auto detect
1571 */
1572enum enable_type {
1573	undefined = -1,
1574	user_disabled,
1575	auto_disabled,
1576	user_enabled,
1577	auto_enabled,
1578};
1579
1580static enum enable_type pci_realloc_enable = undefined;
1581void __init pci_realloc_get_opt(char *str)
1582{
1583	if (!strncmp(str, "off", 3))
1584		pci_realloc_enable = user_disabled;
1585	else if (!strncmp(str, "on", 2))
1586		pci_realloc_enable = user_enabled;
1587}
1588static bool pci_realloc_enabled(enum enable_type enable)
1589{
1590	return enable >= user_enabled;
1591}
1592
1593#if defined(CONFIG_PCI_IOV) && defined(CONFIG_PCI_REALLOC_ENABLE_AUTO)
1594static int iov_resources_unassigned(struct pci_dev *dev, void *data)
1595{
1596	int i;
1597	bool *unassigned = data;
1598
1599	for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) {
1600		struct resource *r = &dev->resource[i];
1601		struct pci_bus_region region;
1602
1603		/* Not assigned or rejected by kernel? */
1604		if (!r->flags)
1605			continue;
1606
1607		pcibios_resource_to_bus(dev->bus, &region, r);
1608		if (!region.start) {
1609			*unassigned = true;
1610			return 1; /* return early from pci_walk_bus() */
1611		}
1612	}
1613
1614	return 0;
1615}
1616
1617static enum enable_type pci_realloc_detect(struct pci_bus *bus,
1618			 enum enable_type enable_local)
1619{
1620	bool unassigned = false;
1621
1622	if (enable_local != undefined)
1623		return enable_local;
1624
1625	pci_walk_bus(bus, iov_resources_unassigned, &unassigned);
1626	if (unassigned)
1627		return auto_enabled;
1628
1629	return enable_local;
1630}
1631#else
1632static enum enable_type pci_realloc_detect(struct pci_bus *bus,
1633			 enum enable_type enable_local)
1634{
1635	return enable_local;
1636}
1637#endif
1638
1639/*
1640 * first try will not touch pci bridge res
1641 * second and later try will clear small leaf bridge res
1642 * will stop till to the max depth if can not find good one
1643 */
1644void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
1645{
1646	LIST_HEAD(realloc_head); /* list of resources that
1647					want additional resources */
1648	struct list_head *add_list = NULL;
1649	int tried_times = 0;
1650	enum release_type rel_type = leaf_only;
1651	LIST_HEAD(fail_head);
1652	struct pci_dev_resource *fail_res;
1653	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
1654				  IORESOURCE_PREFETCH | IORESOURCE_MEM_64;
1655	int pci_try_num = 1;
1656	enum enable_type enable_local;
1657
1658	/* don't realloc if asked to do so */
1659	enable_local = pci_realloc_detect(bus, pci_realloc_enable);
1660	if (pci_realloc_enabled(enable_local)) {
1661		int max_depth = pci_bus_get_depth(bus);
1662
1663		pci_try_num = max_depth + 1;
1664		dev_printk(KERN_DEBUG, &bus->dev,
1665			   "max bus depth: %d pci_try_num: %d\n",
1666			   max_depth, pci_try_num);
1667	}
1668
1669again:
1670	/*
1671	 * last try will use add_list, otherwise will try good to have as
1672	 * must have, so can realloc parent bridge resource
1673	 */
1674	if (tried_times + 1 == pci_try_num)
1675		add_list = &realloc_head;
1676	/* Depth first, calculate sizes and alignments of all
1677	   subordinate buses. */
1678	__pci_bus_size_bridges(bus, add_list);
1679
1680	/* Depth last, allocate resources and update the hardware. */
1681	__pci_bus_assign_resources(bus, add_list, &fail_head);
1682	if (add_list)
1683		BUG_ON(!list_empty(add_list));
1684	tried_times++;
1685
1686	/* any device complain? */
1687	if (list_empty(&fail_head))
1688		goto dump;
1689
1690	if (tried_times >= pci_try_num) {
1691		if (enable_local == undefined)
1692			dev_info(&bus->dev, "Some PCI device resources are unassigned, try booting with pci=realloc\n");
1693		else if (enable_local == auto_enabled)
1694			dev_info(&bus->dev, "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
1695
1696		free_list(&fail_head);
1697		goto dump;
1698	}
1699
1700	dev_printk(KERN_DEBUG, &bus->dev,
1701		   "No. %d try to assign unassigned res\n", tried_times + 1);
1702
1703	/* third times and later will not check if it is leaf */
1704	if ((tried_times + 1) > 2)
1705		rel_type = whole_subtree;
1706
1707	/*
1708	 * Try to release leaf bridge's resources that doesn't fit resource of
1709	 * child device under that bridge
1710	 */
1711	list_for_each_entry(fail_res, &fail_head, list)
1712		pci_bus_release_bridge_resources(fail_res->dev->bus,
1713						 fail_res->flags & type_mask,
1714						 rel_type);
1715
1716	/* restore size and flags */
1717	list_for_each_entry(fail_res, &fail_head, list) {
1718		struct resource *res = fail_res->res;
1719
1720		res->start = fail_res->start;
1721		res->end = fail_res->end;
1722		res->flags = fail_res->flags;
1723		if (fail_res->dev->subordinate)
1724			res->flags = 0;
1725	}
1726	free_list(&fail_head);
1727
1728	goto again;
1729
1730dump:
1731	/* dump the resource on buses */
1732	pci_bus_dump_resources(bus);
1733}
1734
1735void __init pci_assign_unassigned_resources(void)
1736{
1737	struct pci_bus *root_bus;
1738
1739	list_for_each_entry(root_bus, &pci_root_buses, node)
1740		pci_assign_unassigned_root_bus_resources(root_bus);
1741}
1742
1743void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
1744{
1745	struct pci_bus *parent = bridge->subordinate;
1746	LIST_HEAD(add_list); /* list of resources that
1747					want additional resources */
1748	int tried_times = 0;
1749	LIST_HEAD(fail_head);
1750	struct pci_dev_resource *fail_res;
1751	int retval;
1752	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
1753				  IORESOURCE_PREFETCH | IORESOURCE_MEM_64;
1754
1755again:
1756	__pci_bus_size_bridges(parent, &add_list);
1757	__pci_bridge_assign_resources(bridge, &add_list, &fail_head);
1758	BUG_ON(!list_empty(&add_list));
1759	tried_times++;
1760
1761	if (list_empty(&fail_head))
1762		goto enable_all;
1763
1764	if (tried_times >= 2) {
1765		/* still fail, don't need to try more */
1766		free_list(&fail_head);
1767		goto enable_all;
1768	}
1769
1770	printk(KERN_DEBUG "PCI: No. %d try to assign unassigned res\n",
1771			 tried_times + 1);
1772
1773	/*
1774	 * Try to release leaf bridge's resources that doesn't fit resource of
1775	 * child device under that bridge
1776	 */
1777	list_for_each_entry(fail_res, &fail_head, list)
1778		pci_bus_release_bridge_resources(fail_res->dev->bus,
1779						 fail_res->flags & type_mask,
1780						 whole_subtree);
1781
1782	/* restore size and flags */
1783	list_for_each_entry(fail_res, &fail_head, list) {
1784		struct resource *res = fail_res->res;
1785
1786		res->start = fail_res->start;
1787		res->end = fail_res->end;
1788		res->flags = fail_res->flags;
1789		if (fail_res->dev->subordinate)
1790			res->flags = 0;
1791	}
1792	free_list(&fail_head);
1793
1794	goto again;
1795
1796enable_all:
1797	retval = pci_reenable_device(bridge);
1798	if (retval)
1799		dev_err(&bridge->dev, "Error reenabling bridge (%d)\n", retval);
1800	pci_set_master(bridge);
1801}
1802EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
1803
1804void pci_assign_unassigned_bus_resources(struct pci_bus *bus)
1805{
1806	struct pci_dev *dev;
1807	LIST_HEAD(add_list); /* list of resources that
1808					want additional resources */
1809
1810	down_read(&pci_bus_sem);
1811	list_for_each_entry(dev, &bus->devices, bus_list)
1812		if (pci_is_bridge(dev) && pci_has_subordinate(dev))
1813				__pci_bus_size_bridges(dev->subordinate,
1814							 &add_list);
1815	up_read(&pci_bus_sem);
1816	__pci_bus_assign_resources(bus, &add_list, NULL);
1817	BUG_ON(!list_empty(&add_list));
1818}
1819EXPORT_SYMBOL_GPL(pci_assign_unassigned_bus_resources);
1820