1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Support routines for initializing a PCI subsystem
   4 *
   5 * Extruded from code written by
   6 *      Dave Rusling (david.rusling@reo.mts.dec.com)
   7 *      David Mosberger (davidm@cs.arizona.edu)
   8 *	David Miller (davem@redhat.com)
   9 *
  10 * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
  11 *	     PCI-PCI bridges cleanup, sorted resource allocation.
  12 * Feb 2002, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
  13 *	     Converted to allocation in 3 passes, which gives
  14 *	     tighter packing. Prefetchable range support.
  15 */
  16
  17#include <linux/init.h>
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/pci.h>
  21#include <linux/errno.h>
  22#include <linux/ioport.h>
  23#include <linux/cache.h>
  24#include <linux/slab.h>
  25#include <linux/acpi.h>
  26#include "pci.h"
  27
  28unsigned int pci_flags;
  29
  30struct pci_dev_resource {
  31	struct list_head list;
  32	struct resource *res;
  33	struct pci_dev *dev;
  34	resource_size_t start;
  35	resource_size_t end;
  36	resource_size_t add_size;
  37	resource_size_t min_align;
  38	unsigned long flags;
  39};
  40
  41static void free_list(struct list_head *head)
  42{
  43	struct pci_dev_resource *dev_res, *tmp;
  44
  45	list_for_each_entry_safe(dev_res, tmp, head, list) {
  46		list_del(&dev_res->list);
  47		kfree(dev_res);
  48	}
  49}
  50
  51/**
  52 * add_to_list() - Add a new resource tracker to the list
  53 * @head:	Head of the list
  54 * @dev:	Device to which the resource belongs
  55 * @res:	Resource to be tracked
  56 * @add_size:	Additional size to be optionally added to the resource
 
 
  57 */
  58static int add_to_list(struct list_head *head, struct pci_dev *dev,
  59		       struct resource *res, resource_size_t add_size,
  60		       resource_size_t min_align)
  61{
  62	struct pci_dev_resource *tmp;
  63
  64	tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
  65	if (!tmp)
  66		return -ENOMEM;
  67
  68	tmp->res = res;
  69	tmp->dev = dev;
  70	tmp->start = res->start;
  71	tmp->end = res->end;
  72	tmp->flags = res->flags;
  73	tmp->add_size = add_size;
  74	tmp->min_align = min_align;
  75
  76	list_add(&tmp->list, head);
  77
  78	return 0;
  79}
  80
  81static void remove_from_list(struct list_head *head, struct resource *res)
 
  82{
  83	struct pci_dev_resource *dev_res, *tmp;
  84
  85	list_for_each_entry_safe(dev_res, tmp, head, list) {
  86		if (dev_res->res == res) {
  87			list_del(&dev_res->list);
  88			kfree(dev_res);
  89			break;
  90		}
  91	}
  92}
  93
  94static struct pci_dev_resource *res_to_dev_res(struct list_head *head,
  95					       struct resource *res)
  96{
  97	struct pci_dev_resource *dev_res;
  98
  99	list_for_each_entry(dev_res, head, list) {
 100		if (dev_res->res == res)
 101			return dev_res;
 102	}
 103
 104	return NULL;
 105}
 106
 107static resource_size_t get_res_add_size(struct list_head *head,
 108					struct resource *res)
 109{
 110	struct pci_dev_resource *dev_res;
 111
 112	dev_res = res_to_dev_res(head, res);
 113	return dev_res ? dev_res->add_size : 0;
 114}
 115
 116static resource_size_t get_res_add_align(struct list_head *head,
 117					 struct resource *res)
 118{
 119	struct pci_dev_resource *dev_res;
 120
 121	dev_res = res_to_dev_res(head, res);
 122	return dev_res ? dev_res->min_align : 0;
 123}
 124
 125
 126/* Sort resources by alignment */
 127static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
 128{
 129	int i;
 130
 131	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 132		struct resource *r;
 133		struct pci_dev_resource *dev_res, *tmp;
 134		resource_size_t r_align;
 135		struct list_head *n;
 136
 137		r = &dev->resource[i];
 138
 139		if (r->flags & IORESOURCE_PCI_FIXED)
 140			continue;
 141
 142		if (!(r->flags) || r->parent)
 143			continue;
 144
 145		r_align = pci_resource_alignment(dev, r);
 146		if (!r_align) {
 147			pci_warn(dev, "BAR %d: %pR has bogus alignment\n",
 148				 i, r);
 149			continue;
 150		}
 151
 152		tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
 153		if (!tmp)
 154			panic("pdev_sort_resources(): kmalloc() failed!\n");
 155		tmp->res = r;
 156		tmp->dev = dev;
 157
 158		/* Fallback is smallest one or list is empty */
 159		n = head;
 160		list_for_each_entry(dev_res, head, list) {
 161			resource_size_t align;
 162
 163			align = pci_resource_alignment(dev_res->dev,
 164							 dev_res->res);
 165
 166			if (r_align > align) {
 167				n = &dev_res->list;
 168				break;
 169			}
 170		}
 171		/* Insert it just before n */
 172		list_add_tail(&tmp->list, n);
 173	}
 174}
 175
 176static void __dev_sort_resources(struct pci_dev *dev, struct list_head *head)
 
 177{
 178	u16 class = dev->class >> 8;
 179
 180	/* Don't touch classless devices or host bridges or IOAPICs */
 181	if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)
 182		return;
 183
 184	/* Don't touch IOAPIC devices already enabled by firmware */
 185	if (class == PCI_CLASS_SYSTEM_PIC) {
 186		u16 command;
 187		pci_read_config_word(dev, PCI_COMMAND, &command);
 188		if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
 189			return;
 190	}
 191
 192	pdev_sort_resources(dev, head);
 193}
 194
 195static inline void reset_resource(struct resource *res)
 196{
 197	res->start = 0;
 198	res->end = 0;
 199	res->flags = 0;
 200}
 201
 202/**
 203 * reassign_resources_sorted() - Satisfy any additional resource requests
 204 *
 205 * @realloc_head:	Head of the list tracking requests requiring
 206 *			additional resources
 207 * @head:		Head of the list tracking requests with allocated
 208 *			resources
 209 *
 210 * Walk through each element of the realloc_head and try to procure additional
 211 * resources for the element, provided the element is in the head list.
 
 212 */
 213static void reassign_resources_sorted(struct list_head *realloc_head,
 214				      struct list_head *head)
 215{
 216	struct resource *res;
 217	struct pci_dev_resource *add_res, *tmp;
 218	struct pci_dev_resource *dev_res;
 219	resource_size_t add_size, align;
 220	int idx;
 221
 222	list_for_each_entry_safe(add_res, tmp, realloc_head, list) {
 223		bool found_match = false;
 224
 225		res = add_res->res;
 226		/* Skip resource that has been reset */
 227		if (!res->flags)
 228			goto out;
 229
 230		/* Skip this resource if not found in head list */
 231		list_for_each_entry(dev_res, head, list) {
 232			if (dev_res->res == res) {
 233				found_match = true;
 234				break;
 235			}
 236		}
 237		if (!found_match) /* Just skip */
 238			continue;
 239
 240		idx = res - &add_res->dev->resource[0];
 241		add_size = add_res->add_size;
 242		align = add_res->min_align;
 243		if (!resource_size(res)) {
 244			res->start = align;
 245			res->end = res->start + add_size - 1;
 246			if (pci_assign_resource(add_res->dev, idx))
 247				reset_resource(res);
 248		} else {
 249			res->flags |= add_res->flags &
 250				 (IORESOURCE_STARTALIGN|IORESOURCE_SIZEALIGN);
 251			if (pci_reassign_resource(add_res->dev, idx,
 252						  add_size, align))
 253				pci_info(add_res->dev, "failed to add %llx res[%d]=%pR\n",
 254					 (unsigned long long) add_size, idx,
 255					 res);
 
 256		}
 257out:
 258		list_del(&add_res->list);
 259		kfree(add_res);
 260	}
 261}
 262
 263/**
 264 * assign_requested_resources_sorted() - Satisfy resource requests
 265 *
 266 * @head:	Head of the list tracking requests for resources
 267 * @fail_head:	Head of the list tracking requests that could not be
 268 *		allocated
 269 *
 270 * Satisfy resource requests of each element in the list.  Add requests that
 271 * could not be satisfied to the failed_list.
 272 */
 273static void assign_requested_resources_sorted(struct list_head *head,
 274				 struct list_head *fail_head)
 275{
 276	struct resource *res;
 277	struct pci_dev_resource *dev_res;
 278	int idx;
 279
 280	list_for_each_entry(dev_res, head, list) {
 281		res = dev_res->res;
 282		idx = res - &dev_res->dev->resource[0];
 283		if (resource_size(res) &&
 284		    pci_assign_resource(dev_res->dev, idx)) {
 285			if (fail_head) {
 286				/*
 287				 * If the failed resource is a ROM BAR and
 288				 * it will be enabled later, don't add it
 289				 * to the list.
 290				 */
 291				if (!((idx == PCI_ROM_RESOURCE) &&
 292				      (!(res->flags & IORESOURCE_ROM_ENABLE))))
 293					add_to_list(fail_head,
 294						    dev_res->dev, res,
 295						    0 /* don't care */,
 296						    0 /* don't care */);
 297			}
 298			reset_resource(res);
 299		}
 300	}
 301}
 302
 303static unsigned long pci_fail_res_type_mask(struct list_head *fail_head)
 304{
 305	struct pci_dev_resource *fail_res;
 306	unsigned long mask = 0;
 307
 308	/* Check failed type */
 309	list_for_each_entry(fail_res, fail_head, list)
 310		mask |= fail_res->flags;
 311
 312	/*
 313	 * One pref failed resource will set IORESOURCE_MEM, as we can
 314	 * allocate pref in non-pref range.  Will release all assigned
 315	 * non-pref sibling resources according to that bit.
 
 316	 */
 317	return mask & (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH);
 318}
 319
 320static bool pci_need_to_release(unsigned long mask, struct resource *res)
 321{
 322	if (res->flags & IORESOURCE_IO)
 323		return !!(mask & IORESOURCE_IO);
 324
 325	/* Check pref at first */
 326	if (res->flags & IORESOURCE_PREFETCH) {
 327		if (mask & IORESOURCE_PREFETCH)
 328			return true;
 329		/* Count pref if its parent is non-pref */
 330		else if ((mask & IORESOURCE_MEM) &&
 331			 !(res->parent->flags & IORESOURCE_PREFETCH))
 332			return true;
 333		else
 334			return false;
 335	}
 336
 337	if (res->flags & IORESOURCE_MEM)
 338		return !!(mask & IORESOURCE_MEM);
 339
 340	return false;	/* Should not get here */
 341}
 342
 343static void __assign_resources_sorted(struct list_head *head,
 344				      struct list_head *realloc_head,
 345				      struct list_head *fail_head)
 346{
 347	/*
 348	 * Should not assign requested resources at first.  They could be
 349	 * adjacent, so later reassign can not reallocate them one by one in
 350	 * parent resource window.
 351	 *
 352	 * Try to assign requested + add_size at beginning.  If could do that,
 353	 * could get out early.  If could not do that, we still try to assign
 354	 * requested at first, then try to reassign add_size for some resources.
 355	 *
 356	 * Separate three resource type checking if we need to release
 357	 * assigned resource after requested + add_size try.
 358	 *
 359	 *	1. If IO port assignment fails, will release assigned IO
 360	 *	   port.
 361	 *	2. If pref MMIO assignment fails, release assigned pref
 362	 *	   MMIO.  If assigned pref MMIO's parent is non-pref MMIO
 363	 *	   and non-pref MMIO assignment fails, will release that
 364	 *	   assigned pref MMIO.
 365	 *	3. If non-pref MMIO assignment fails or pref MMIO
 366	 *	   assignment fails, will release assigned non-pref MMIO.
 367	 */
 368	LIST_HEAD(save_head);
 369	LIST_HEAD(local_fail_head);
 370	struct pci_dev_resource *save_res;
 371	struct pci_dev_resource *dev_res, *tmp_res, *dev_res2;
 372	unsigned long fail_type;
 373	resource_size_t add_align, align;
 374
 375	/* Check if optional add_size is there */
 376	if (!realloc_head || list_empty(realloc_head))
 377		goto requested_and_reassign;
 378
 379	/* Save original start, end, flags etc at first */
 380	list_for_each_entry(dev_res, head, list) {
 381		if (add_to_list(&save_head, dev_res->dev, dev_res->res, 0, 0)) {
 382			free_list(&save_head);
 383			goto requested_and_reassign;
 384		}
 385	}
 386
 387	/* Update res in head list with add_size in realloc_head list */
 388	list_for_each_entry_safe(dev_res, tmp_res, head, list) {
 389		dev_res->res->end += get_res_add_size(realloc_head,
 390							dev_res->res);
 391
 392		/*
 393		 * There are two kinds of additional resources in the list:
 394		 * 1. bridge resource  -- IORESOURCE_STARTALIGN
 395		 * 2. SR-IOV resource  -- IORESOURCE_SIZEALIGN
 396		 * Here just fix the additional alignment for bridge
 397		 */
 398		if (!(dev_res->res->flags & IORESOURCE_STARTALIGN))
 399			continue;
 400
 401		add_align = get_res_add_align(realloc_head, dev_res->res);
 402
 403		/*
 404		 * The "head" list is sorted by alignment so resources with
 405		 * bigger alignment will be assigned first.  After we
 406		 * change the alignment of a dev_res in "head" list, we
 407		 * need to reorder the list by alignment to make it
 408		 * consistent.
 409		 */
 410		if (add_align > dev_res->res->start) {
 411			resource_size_t r_size = resource_size(dev_res->res);
 412
 413			dev_res->res->start = add_align;
 414			dev_res->res->end = add_align + r_size - 1;
 415
 416			list_for_each_entry(dev_res2, head, list) {
 417				align = pci_resource_alignment(dev_res2->dev,
 418							       dev_res2->res);
 419				if (add_align > align) {
 420					list_move_tail(&dev_res->list,
 421						       &dev_res2->list);
 422					break;
 423				}
 424			}
 425		}
 426
 427	}
 428
 429	/* Try updated head list with add_size added */
 430	assign_requested_resources_sorted(head, &local_fail_head);
 431
 432	/* All assigned with add_size? */
 433	if (list_empty(&local_fail_head)) {
 434		/* Remove head list from realloc_head list */
 435		list_for_each_entry(dev_res, head, list)
 436			remove_from_list(realloc_head, dev_res->res);
 437		free_list(&save_head);
 438		free_list(head);
 439		return;
 440	}
 441
 442	/* Check failed type */
 443	fail_type = pci_fail_res_type_mask(&local_fail_head);
 444	/* Remove not need to be released assigned res from head list etc */
 445	list_for_each_entry_safe(dev_res, tmp_res, head, list)
 446		if (dev_res->res->parent &&
 447		    !pci_need_to_release(fail_type, dev_res->res)) {
 448			/* Remove it from realloc_head list */
 449			remove_from_list(realloc_head, dev_res->res);
 450			remove_from_list(&save_head, dev_res->res);
 451			list_del(&dev_res->list);
 452			kfree(dev_res);
 453		}
 454
 455	free_list(&local_fail_head);
 456	/* Release assigned resource */
 457	list_for_each_entry(dev_res, head, list)
 458		if (dev_res->res->parent)
 459			release_resource(dev_res->res);
 460	/* Restore start/end/flags from saved list */
 461	list_for_each_entry(save_res, &save_head, list) {
 462		struct resource *res = save_res->res;
 463
 464		res->start = save_res->start;
 465		res->end = save_res->end;
 466		res->flags = save_res->flags;
 467	}
 468	free_list(&save_head);
 469
 470requested_and_reassign:
 471	/* Satisfy the must-have resource requests */
 472	assign_requested_resources_sorted(head, fail_head);
 473
 474	/* Try to satisfy any additional optional resource requests */
 
 475	if (realloc_head)
 476		reassign_resources_sorted(realloc_head, head);
 477	free_list(head);
 478}
 479
 480static void pdev_assign_resources_sorted(struct pci_dev *dev,
 481					 struct list_head *add_head,
 482					 struct list_head *fail_head)
 483{
 484	LIST_HEAD(head);
 485
 486	__dev_sort_resources(dev, &head);
 487	__assign_resources_sorted(&head, add_head, fail_head);
 488
 489}
 490
 491static void pbus_assign_resources_sorted(const struct pci_bus *bus,
 492					 struct list_head *realloc_head,
 493					 struct list_head *fail_head)
 494{
 495	struct pci_dev *dev;
 496	LIST_HEAD(head);
 497
 498	list_for_each_entry(dev, &bus->devices, bus_list)
 499		__dev_sort_resources(dev, &head);
 500
 501	__assign_resources_sorted(&head, realloc_head, fail_head);
 502}
 503
 504void pci_setup_cardbus(struct pci_bus *bus)
 505{
 506	struct pci_dev *bridge = bus->self;
 507	struct resource *res;
 508	struct pci_bus_region region;
 509
 510	pci_info(bridge, "CardBus bridge to %pR\n",
 511		 &bus->busn_res);
 512
 513	res = bus->resource[0];
 514	pcibios_resource_to_bus(bridge->bus, &region, res);
 515	if (res->flags & IORESOURCE_IO) {
 516		/*
 517		 * The IO resource is allocated a range twice as large as it
 518		 * would normally need.  This allows us to set both IO regs.
 519		 */
 520		pci_info(bridge, "  bridge window %pR\n", res);
 521		pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
 522					region.start);
 523		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
 524					region.end);
 525	}
 526
 527	res = bus->resource[1];
 528	pcibios_resource_to_bus(bridge->bus, &region, res);
 529	if (res->flags & IORESOURCE_IO) {
 530		pci_info(bridge, "  bridge window %pR\n", res);
 531		pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
 532					region.start);
 533		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
 534					region.end);
 535	}
 536
 537	res = bus->resource[2];
 538	pcibios_resource_to_bus(bridge->bus, &region, res);
 539	if (res->flags & IORESOURCE_MEM) {
 540		pci_info(bridge, "  bridge window %pR\n", res);
 541		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
 542					region.start);
 543		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
 544					region.end);
 545	}
 546
 547	res = bus->resource[3];
 548	pcibios_resource_to_bus(bridge->bus, &region, res);
 549	if (res->flags & IORESOURCE_MEM) {
 550		pci_info(bridge, "  bridge window %pR\n", res);
 551		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
 552					region.start);
 553		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
 554					region.end);
 555	}
 556}
 557EXPORT_SYMBOL(pci_setup_cardbus);
 558
 559/*
 560 * Initialize bridges with base/limit values we have collected.  PCI-to-PCI
 561 * Bridge Architecture Specification rev. 1.1 (1998) requires that if there
 562 * are no I/O ports or memory behind the bridge, the corresponding range
 563 * must be turned off by writing base value greater than limit to the
 564 * bridge's base/limit registers.
 565 *
 566 * Note: care must be taken when updating I/O base/limit registers of
 567 * bridges which support 32-bit I/O.  This update requires two config space
 568 * writes, so it's quite possible that an I/O window of the bridge will
 569 * have some undesirable address (e.g. 0) after the first write.  Ditto
 570 * 64-bit prefetchable MMIO.
 571 */
 572static void pci_setup_bridge_io(struct pci_dev *bridge)
 573{
 574	struct resource *res;
 575	struct pci_bus_region region;
 576	unsigned long io_mask;
 577	u8 io_base_lo, io_limit_lo;
 578	u16 l;
 579	u32 io_upper16;
 580
 581	io_mask = PCI_IO_RANGE_MASK;
 582	if (bridge->io_window_1k)
 583		io_mask = PCI_IO_1K_RANGE_MASK;
 584
 585	/* Set up the top and bottom of the PCI I/O segment for this bus */
 586	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
 587	pcibios_resource_to_bus(bridge->bus, &region, res);
 588	if (res->flags & IORESOURCE_IO) {
 589		pci_read_config_word(bridge, PCI_IO_BASE, &l);
 590		io_base_lo = (region.start >> 8) & io_mask;
 591		io_limit_lo = (region.end >> 8) & io_mask;
 592		l = ((u16) io_limit_lo << 8) | io_base_lo;
 593		/* Set up upper 16 bits of I/O base/limit */
 594		io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
 595		pci_info(bridge, "  bridge window %pR\n", res);
 596	} else {
 597		/* Clear upper 16 bits of I/O base/limit */
 598		io_upper16 = 0;
 599		l = 0x00f0;
 600	}
 601	/* Temporarily disable the I/O range before updating PCI_IO_BASE */
 602	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff);
 603	/* Update lower 16 bits of I/O base/limit */
 604	pci_write_config_word(bridge, PCI_IO_BASE, l);
 605	/* Update upper 16 bits of I/O base/limit */
 606	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
 607}
 608
 609static void pci_setup_bridge_mmio(struct pci_dev *bridge)
 610{
 611	struct resource *res;
 612	struct pci_bus_region region;
 613	u32 l;
 614
 615	/* Set up the top and bottom of the PCI Memory segment for this bus */
 616	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
 617	pcibios_resource_to_bus(bridge->bus, &region, res);
 618	if (res->flags & IORESOURCE_MEM) {
 619		l = (region.start >> 16) & 0xfff0;
 620		l |= region.end & 0xfff00000;
 621		pci_info(bridge, "  bridge window %pR\n", res);
 622	} else {
 623		l = 0x0000fff0;
 624	}
 625	pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
 626}
 627
 628static void pci_setup_bridge_mmio_pref(struct pci_dev *bridge)
 629{
 630	struct resource *res;
 631	struct pci_bus_region region;
 632	u32 l, bu, lu;
 633
 634	/*
 635	 * Clear out the upper 32 bits of PREF limit.  If
 636	 * PCI_PREF_BASE_UPPER32 was non-zero, this temporarily disables
 637	 * PREF range, which is ok.
 638	 */
 639	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);
 640
 641	/* Set up PREF base/limit */
 642	bu = lu = 0;
 643	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
 644	pcibios_resource_to_bus(bridge->bus, &region, res);
 645	if (res->flags & IORESOURCE_PREFETCH) {
 646		l = (region.start >> 16) & 0xfff0;
 647		l |= region.end & 0xfff00000;
 648		if (res->flags & IORESOURCE_MEM_64) {
 649			bu = upper_32_bits(region.start);
 650			lu = upper_32_bits(region.end);
 651		}
 652		pci_info(bridge, "  bridge window %pR\n", res);
 653	} else {
 654		l = 0x0000fff0;
 655	}
 656	pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
 657
 658	/* Set the upper 32 bits of PREF base & limit */
 659	pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
 660	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
 661}
 662
 663static void __pci_setup_bridge(struct pci_bus *bus, unsigned long type)
 664{
 665	struct pci_dev *bridge = bus->self;
 666
 667	pci_info(bridge, "PCI bridge to %pR\n",
 668		 &bus->busn_res);
 669
 670	if (type & IORESOURCE_IO)
 671		pci_setup_bridge_io(bridge);
 672
 673	if (type & IORESOURCE_MEM)
 674		pci_setup_bridge_mmio(bridge);
 675
 676	if (type & IORESOURCE_PREFETCH)
 677		pci_setup_bridge_mmio_pref(bridge);
 678
 679	pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
 680}
 681
 682void __weak pcibios_setup_bridge(struct pci_bus *bus, unsigned long type)
 683{
 684}
 685
 686void pci_setup_bridge(struct pci_bus *bus)
 687{
 688	unsigned long type = IORESOURCE_IO | IORESOURCE_MEM |
 689				  IORESOURCE_PREFETCH;
 690
 691	pcibios_setup_bridge(bus, type);
 692	__pci_setup_bridge(bus, type);
 693}
 694
 695
 696int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
 697{
 698	if (i < PCI_BRIDGE_RESOURCES || i > PCI_BRIDGE_RESOURCE_END)
 699		return 0;
 700
 701	if (pci_claim_resource(bridge, i) == 0)
 702		return 0;	/* Claimed the window */
 703
 704	if ((bridge->class >> 8) != PCI_CLASS_BRIDGE_PCI)
 705		return 0;
 706
 707	if (!pci_bus_clip_resource(bridge, i))
 708		return -EINVAL;	/* Clipping didn't change anything */
 709
 710	switch (i - PCI_BRIDGE_RESOURCES) {
 711	case 0:
 712		pci_setup_bridge_io(bridge);
 713		break;
 714	case 1:
 715		pci_setup_bridge_mmio(bridge);
 716		break;
 717	case 2:
 718		pci_setup_bridge_mmio_pref(bridge);
 719		break;
 720	default:
 721		return -EINVAL;
 722	}
 723
 724	if (pci_claim_resource(bridge, i) == 0)
 725		return 0;	/* Claimed a smaller window */
 726
 727	return -EINVAL;
 728}
 729
 730/*
 731 * Check whether the bridge supports optional I/O and prefetchable memory
 732 * ranges.  If not, the respective base/limit registers must be read-only
 733 * and read as 0.
 734 */
 735static void pci_bridge_check_ranges(struct pci_bus *bus)
 736{
 
 
 737	struct pci_dev *bridge = bus->self;
 738	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
 739
 
 740	b_res[1].flags |= IORESOURCE_MEM;
 741
 742	if (bridge->io_window)
 
 
 
 
 
 
 743		b_res[0].flags |= IORESOURCE_IO;
 744
 745	if (bridge->pref_window) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 746		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
 747		if (bridge->pref_64_window) {
 
 748			b_res[2].flags |= IORESOURCE_MEM_64;
 749			b_res[2].flags |= PCI_PREF_RANGE_TYPE_64;
 750		}
 751	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 752}
 753
 754/*
 755 * Helper function for sizing routines: find first available bus resource
 756 * of a given type.  Note: we intentionally skip the bus resources which
 757 * have already been assigned (that is, have non-NULL parent resource).
 758 */
 759static struct resource *find_free_bus_resource(struct pci_bus *bus,
 760					       unsigned long type_mask,
 761					       unsigned long type)
 762{
 763	int i;
 764	struct resource *r;
 765
 766	pci_bus_for_each_resource(bus, r, i) {
 767		if (r == &ioport_resource || r == &iomem_resource)
 768			continue;
 769		if (r && (r->flags & type_mask) == type && !r->parent)
 770			return r;
 771	}
 772	return NULL;
 773}
 774
 775static resource_size_t calculate_iosize(resource_size_t size,
 776					resource_size_t min_size,
 777					resource_size_t size1,
 778					resource_size_t add_size,
 779					resource_size_t children_add_size,
 780					resource_size_t old_size,
 781					resource_size_t align)
 782{
 783	if (size < min_size)
 784		size = min_size;
 785	if (old_size == 1)
 786		old_size = 0;
 787	/*
 788	 * To be fixed in 2.5: we should have sort of HAVE_ISA flag in the
 789	 * struct pci_bus.
 790	 */
 791#if defined(CONFIG_ISA) || defined(CONFIG_EISA)
 792	size = (size & 0xff) + ((size & ~0xffUL) << 2);
 793#endif
 794	size = size + size1;
 795	if (size < old_size)
 796		size = old_size;
 797
 798	size = ALIGN(max(size, add_size) + children_add_size, align);
 799	return size;
 800}
 801
 802static resource_size_t calculate_memsize(resource_size_t size,
 803					 resource_size_t min_size,
 804					 resource_size_t add_size,
 805					 resource_size_t children_add_size,
 806					 resource_size_t old_size,
 807					 resource_size_t align)
 808{
 809	if (size < min_size)
 810		size = min_size;
 811	if (old_size == 1)
 812		old_size = 0;
 813	if (size < old_size)
 814		size = old_size;
 815
 816	size = ALIGN(max(size, add_size) + children_add_size, align);
 817	return size;
 818}
 819
 820resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus,
 821						unsigned long type)
 822{
 823	return 1;
 824}
 825
 826#define PCI_P2P_DEFAULT_MEM_ALIGN	0x100000	/* 1MiB */
 827#define PCI_P2P_DEFAULT_IO_ALIGN	0x1000		/* 4KiB */
 828#define PCI_P2P_DEFAULT_IO_ALIGN_1K	0x400		/* 1KiB */
 829
 830static resource_size_t window_alignment(struct pci_bus *bus, unsigned long type)
 
 831{
 832	resource_size_t align = 1, arch_align;
 833
 834	if (type & IORESOURCE_MEM)
 835		align = PCI_P2P_DEFAULT_MEM_ALIGN;
 836	else if (type & IORESOURCE_IO) {
 837		/*
 838		 * Per spec, I/O windows are 4K-aligned, but some bridges have
 839		 * an extension to support 1K alignment.
 840		 */
 841		if (bus->self->io_window_1k)
 842			align = PCI_P2P_DEFAULT_IO_ALIGN_1K;
 843		else
 844			align = PCI_P2P_DEFAULT_IO_ALIGN;
 845	}
 846
 847	arch_align = pcibios_window_alignment(bus, type);
 848	return max(align, arch_align);
 849}
 850
 851/**
 852 * pbus_size_io() - Size the I/O window of a given bus
 853 *
 854 * @bus:		The bus
 855 * @min_size:		The minimum I/O window that must be allocated
 856 * @add_size:		Additional optional I/O window
 857 * @realloc_head:	Track the additional I/O window on this list
 858 *
 859 * Sizing the I/O windows of the PCI-PCI bridge is trivial, since these
 860 * windows have 1K or 4K granularity and the I/O ranges of non-bridge PCI
 861 * devices are limited to 256 bytes.  We must be careful with the ISA
 862 * aliasing though.
 863 */
 864static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
 865			 resource_size_t add_size,
 866			 struct list_head *realloc_head)
 867{
 868	struct pci_dev *dev;
 869	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO,
 870							IORESOURCE_IO);
 871	resource_size_t size = 0, size0 = 0, size1 = 0;
 872	resource_size_t children_add_size = 0;
 873	resource_size_t min_align, align;
 874
 875	if (!b_res)
 876		return;
 877
 878	min_align = window_alignment(bus, IORESOURCE_IO);
 879	list_for_each_entry(dev, &bus->devices, bus_list) {
 880		int i;
 881
 882		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 883			struct resource *r = &dev->resource[i];
 884			unsigned long r_size;
 885
 886			if (r->parent || !(r->flags & IORESOURCE_IO))
 887				continue;
 888			r_size = resource_size(r);
 889
 890			if (r_size < 0x400)
 891				/* Might be re-aligned for ISA */
 892				size += r_size;
 893			else
 894				size1 += r_size;
 895
 896			align = pci_resource_alignment(dev, r);
 897			if (align > min_align)
 898				min_align = align;
 899
 900			if (realloc_head)
 901				children_add_size += get_res_add_size(realloc_head, r);
 902		}
 903	}
 904
 905	size0 = calculate_iosize(size, min_size, size1, 0, 0,
 906			resource_size(b_res), min_align);
 907	size1 = (!realloc_head || (realloc_head && !add_size && !children_add_size)) ? size0 :
 908		calculate_iosize(size, min_size, size1, add_size, children_add_size,
 
 
 909			resource_size(b_res), min_align);
 910	if (!size0 && !size1) {
 911		if (b_res->start || b_res->end)
 912			pci_info(bus->self, "disabling bridge window %pR to %pR (unused)\n",
 913				 b_res, &bus->busn_res);
 914		b_res->flags = 0;
 915		return;
 916	}
 917
 918	b_res->start = min_align;
 919	b_res->end = b_res->start + size0 - 1;
 920	b_res->flags |= IORESOURCE_STARTALIGN;
 921	if (size1 > size0 && realloc_head) {
 922		add_to_list(realloc_head, bus->self, b_res, size1-size0,
 923			    min_align);
 924		pci_info(bus->self, "bridge window %pR to %pR add_size %llx\n",
 925			 b_res, &bus->busn_res,
 926			 (unsigned long long) size1 - size0);
 927	}
 928}
 929
 930static inline resource_size_t calculate_mem_align(resource_size_t *aligns,
 931						  int max_order)
 932{
 933	resource_size_t align = 0;
 934	resource_size_t min_align = 0;
 935	int order;
 936
 937	for (order = 0; order <= max_order; order++) {
 938		resource_size_t align1 = 1;
 939
 940		align1 <<= (order + 20);
 941
 942		if (!align)
 943			min_align = align1;
 944		else if (ALIGN(align + min_align, min_align) < align1)
 945			min_align = align1 >> 1;
 946		align += aligns[order];
 947	}
 948
 949	return min_align;
 950}
 951
 952/**
 953 * pbus_size_mem() - Size the memory window of a given bus
 954 *
 955 * @bus:		The bus
 956 * @mask:		Mask the resource flag, then compare it with type
 957 * @type:		The type of free resource from bridge
 958 * @type2:		Second match type
 959 * @type3:		Third match type
 960 * @min_size:		The minimum memory window that must be allocated
 961 * @add_size:		Additional optional memory window
 962 * @realloc_head:	Track the additional memory window on this list
 963 *
 964 * Calculate the size of the bus and minimal alignment which guarantees
 965 * that all child resources fit in this size.
 966 *
 967 * Return -ENOSPC if there's no available bus resource of the desired
 968 * type.  Otherwise, set the bus resource start/end to indicate the
 969 * required size, add things to realloc_head (if supplied), and return 0.
 970 */
 971static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 972			 unsigned long type, unsigned long type2,
 973			 unsigned long type3, resource_size_t min_size,
 974			 resource_size_t add_size,
 975			 struct list_head *realloc_head)
 976{
 977	struct pci_dev *dev;
 978	resource_size_t min_align, align, size, size0, size1;
 979	resource_size_t aligns[18]; /* Alignments from 1MB to 128GB */
 980	int order, max_order;
 981	struct resource *b_res = find_free_bus_resource(bus,
 982					mask | IORESOURCE_PREFETCH, type);
 983	resource_size_t children_add_size = 0;
 984	resource_size_t children_add_align = 0;
 985	resource_size_t add_align = 0;
 986
 987	if (!b_res)
 988		return -ENOSPC;
 989
 990	memset(aligns, 0, sizeof(aligns));
 991	max_order = 0;
 992	size = 0;
 993
 994	list_for_each_entry(dev, &bus->devices, bus_list) {
 995		int i;
 996
 997		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 998			struct resource *r = &dev->resource[i];
 999			resource_size_t r_size;
1000
1001			if (r->parent || (r->flags & IORESOURCE_PCI_FIXED) ||
1002			    ((r->flags & mask) != type &&
1003			     (r->flags & mask) != type2 &&
1004			     (r->flags & mask) != type3))
1005				continue;
1006			r_size = resource_size(r);
1007#ifdef CONFIG_PCI_IOV
1008			/* Put SRIOV requested res to the optional list */
1009			if (realloc_head && i >= PCI_IOV_RESOURCES &&
1010					i <= PCI_IOV_RESOURCE_END) {
1011				add_align = max(pci_resource_alignment(dev, r), add_align);
1012				r->end = r->start - 1;
1013				add_to_list(realloc_head, dev, r, r_size, 0 /* Don't care */);
1014				children_add_size += r_size;
1015				continue;
1016			}
1017#endif
1018			/*
1019			 * aligns[0] is for 1MB (since bridge memory
1020			 * windows are always at least 1MB aligned), so
1021			 * keep "order" from being negative for smaller
1022			 * resources.
1023			 */
1024			align = pci_resource_alignment(dev, r);
1025			order = __ffs(align) - 20;
1026			if (order < 0)
1027				order = 0;
1028			if (order >= ARRAY_SIZE(aligns)) {
1029				pci_warn(dev, "disabling BAR %d: %pR (bad alignment %#llx)\n",
1030					 i, r, (unsigned long long) align);
1031				r->flags = 0;
1032				continue;
1033			}
1034			size += max(r_size, align);
1035			/*
1036			 * Exclude ranges with size > align from calculation of
1037			 * the alignment.
1038			 */
1039			if (r_size <= align)
1040				aligns[order] += align;
1041			if (order > max_order)
1042				max_order = order;
1043
1044			if (realloc_head) {
1045				children_add_size += get_res_add_size(realloc_head, r);
1046				children_add_align = get_res_add_align(realloc_head, r);
1047				add_align = max(add_align, children_add_align);
1048			}
1049		}
1050	}
1051
1052	min_align = calculate_mem_align(aligns, max_order);
1053	min_align = max(min_align, window_alignment(bus, b_res->flags));
1054	size0 = calculate_memsize(size, min_size, 0, 0, resource_size(b_res), min_align);
1055	add_align = max(min_align, add_align);
1056	size1 = (!realloc_head || (realloc_head && !add_size && !children_add_size)) ? size0 :
1057		calculate_memsize(size, min_size, add_size, children_add_size,
 
 
1058				resource_size(b_res), add_align);
1059	if (!size0 && !size1) {
1060		if (b_res->start || b_res->end)
1061			pci_info(bus->self, "disabling bridge window %pR to %pR (unused)\n",
1062				 b_res, &bus->busn_res);
1063		b_res->flags = 0;
1064		return 0;
1065	}
1066	b_res->start = min_align;
1067	b_res->end = size0 + min_align - 1;
1068	b_res->flags |= IORESOURCE_STARTALIGN;
1069	if (size1 > size0 && realloc_head) {
1070		add_to_list(realloc_head, bus->self, b_res, size1-size0, add_align);
1071		pci_info(bus->self, "bridge window %pR to %pR add_size %llx add_align %llx\n",
1072			   b_res, &bus->busn_res,
1073			   (unsigned long long) (size1 - size0),
1074			   (unsigned long long) add_align);
1075	}
1076	return 0;
1077}
1078
1079unsigned long pci_cardbus_resource_alignment(struct resource *res)
1080{
1081	if (res->flags & IORESOURCE_IO)
1082		return pci_cardbus_io_size;
1083	if (res->flags & IORESOURCE_MEM)
1084		return pci_cardbus_mem_size;
1085	return 0;
1086}
1087
1088static void pci_bus_size_cardbus(struct pci_bus *bus,
1089				 struct list_head *realloc_head)
1090{
1091	struct pci_dev *bridge = bus->self;
1092	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
1093	resource_size_t b_res_3_size = pci_cardbus_mem_size * 2;
1094	u16 ctrl;
1095
1096	if (b_res[0].parent)
1097		goto handle_b_res_1;
1098	/*
1099	 * Reserve some resources for CardBus.  We reserve a fixed amount
1100	 * of bus space for CardBus bridges.
1101	 */
1102	b_res[0].start = pci_cardbus_io_size;
1103	b_res[0].end = b_res[0].start + pci_cardbus_io_size - 1;
1104	b_res[0].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
1105	if (realloc_head) {
1106		b_res[0].end -= pci_cardbus_io_size;
1107		add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size,
1108				pci_cardbus_io_size);
1109	}
1110
1111handle_b_res_1:
1112	if (b_res[1].parent)
1113		goto handle_b_res_2;
1114	b_res[1].start = pci_cardbus_io_size;
1115	b_res[1].end = b_res[1].start + pci_cardbus_io_size - 1;
1116	b_res[1].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
1117	if (realloc_head) {
1118		b_res[1].end -= pci_cardbus_io_size;
1119		add_to_list(realloc_head, bridge, b_res+1, pci_cardbus_io_size,
1120				 pci_cardbus_io_size);
1121	}
1122
1123handle_b_res_2:
1124	/* MEM1 must not be pref MMIO */
1125	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1126	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM1) {
1127		ctrl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
1128		pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
1129		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1130	}
1131
1132	/* Check whether prefetchable memory is supported by this bridge. */
 
 
 
1133	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1134	if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
1135		ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
1136		pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
1137		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1138	}
1139
1140	if (b_res[2].parent)
1141		goto handle_b_res_3;
1142	/*
1143	 * If we have prefetchable memory support, allocate two regions.
1144	 * Otherwise, allocate one region of twice the size.
 
1145	 */
1146	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
1147		b_res[2].start = pci_cardbus_mem_size;
1148		b_res[2].end = b_res[2].start + pci_cardbus_mem_size - 1;
1149		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH |
1150				  IORESOURCE_STARTALIGN;
1151		if (realloc_head) {
1152			b_res[2].end -= pci_cardbus_mem_size;
1153			add_to_list(realloc_head, bridge, b_res+2,
1154				 pci_cardbus_mem_size, pci_cardbus_mem_size);
1155		}
1156
1157		/* Reduce that to half */
1158		b_res_3_size = pci_cardbus_mem_size;
1159	}
1160
1161handle_b_res_3:
1162	if (b_res[3].parent)
1163		goto handle_done;
1164	b_res[3].start = pci_cardbus_mem_size;
1165	b_res[3].end = b_res[3].start + b_res_3_size - 1;
1166	b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_STARTALIGN;
1167	if (realloc_head) {
1168		b_res[3].end -= b_res_3_size;
1169		add_to_list(realloc_head, bridge, b_res+3, b_res_3_size,
1170				 pci_cardbus_mem_size);
1171	}
1172
1173handle_done:
1174	;
1175}
1176
1177void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
1178{
1179	struct pci_dev *dev;
1180	unsigned long mask, prefmask, type2 = 0, type3 = 0;
1181	resource_size_t additional_mem_size = 0, additional_io_size = 0;
1182	struct resource *b_res;
1183	int ret;
1184
1185	list_for_each_entry(dev, &bus->devices, bus_list) {
1186		struct pci_bus *b = dev->subordinate;
1187		if (!b)
1188			continue;
1189
1190		switch (dev->hdr_type) {
1191		case PCI_HEADER_TYPE_CARDBUS:
1192			pci_bus_size_cardbus(b, realloc_head);
1193			break;
1194
1195		case PCI_HEADER_TYPE_BRIDGE:
1196		default:
1197			__pci_bus_size_bridges(b, realloc_head);
1198			break;
1199		}
1200	}
1201
1202	/* The root bus? */
1203	if (pci_is_root_bus(bus))
1204		return;
1205
1206	switch (bus->self->hdr_type) {
1207	case PCI_HEADER_TYPE_CARDBUS:
1208		/* Don't size CardBuses yet */
1209		break;
1210
1211	case PCI_HEADER_TYPE_BRIDGE:
1212		pci_bridge_check_ranges(bus);
1213		if (bus->self->is_hotplug_bridge) {
1214			additional_io_size  = pci_hotplug_io_size;
1215			additional_mem_size = pci_hotplug_mem_size;
1216		}
1217		/* Fall through */
1218	default:
1219		pbus_size_io(bus, realloc_head ? 0 : additional_io_size,
1220			     additional_io_size, realloc_head);
1221
1222		/*
1223		 * If there's a 64-bit prefetchable MMIO window, compute
1224		 * the size required to put all 64-bit prefetchable
1225		 * resources in it.
1226		 */
1227		b_res = &bus->self->resource[PCI_BRIDGE_RESOURCES];
1228		mask = IORESOURCE_MEM;
1229		prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
1230		if (b_res[2].flags & IORESOURCE_MEM_64) {
1231			prefmask |= IORESOURCE_MEM_64;
1232			ret = pbus_size_mem(bus, prefmask, prefmask,
1233				  prefmask, prefmask,
1234				  realloc_head ? 0 : additional_mem_size,
1235				  additional_mem_size, realloc_head);
1236
1237			/*
1238			 * If successful, all non-prefetchable resources
1239			 * and any 32-bit prefetchable resources will go in
1240			 * the non-prefetchable window.
1241			 */
1242			if (ret == 0) {
1243				mask = prefmask;
1244				type2 = prefmask & ~IORESOURCE_MEM_64;
1245				type3 = prefmask & ~IORESOURCE_PREFETCH;
1246			}
1247		}
1248
1249		/*
1250		 * If there is no 64-bit prefetchable window, compute the
1251		 * size required to put all prefetchable resources in the
1252		 * 32-bit prefetchable window (if there is one).
1253		 */
1254		if (!type2) {
1255			prefmask &= ~IORESOURCE_MEM_64;
1256			ret = pbus_size_mem(bus, prefmask, prefmask,
1257					 prefmask, prefmask,
1258					 realloc_head ? 0 : additional_mem_size,
1259					 additional_mem_size, realloc_head);
1260
1261			/*
1262			 * If successful, only non-prefetchable resources
1263			 * will go in the non-prefetchable window.
1264			 */
1265			if (ret == 0)
1266				mask = prefmask;
1267			else
1268				additional_mem_size += additional_mem_size;
1269
1270			type2 = type3 = IORESOURCE_MEM;
1271		}
1272
1273		/*
1274		 * Compute the size required to put everything else in the
1275		 * non-prefetchable window. This includes:
1276		 *
1277		 *   - all non-prefetchable resources
1278		 *   - 32-bit prefetchable resources if there's a 64-bit
1279		 *     prefetchable window or no prefetchable window at all
1280		 *   - 64-bit prefetchable resources if there's no prefetchable
1281		 *     window at all
1282		 *
1283		 * Note that the strategy in __pci_assign_resource() must match
1284		 * that used here. Specifically, we cannot put a 32-bit
1285		 * prefetchable resource in a 64-bit prefetchable window.
 
1286		 */
1287		pbus_size_mem(bus, mask, IORESOURCE_MEM, type2, type3,
1288				realloc_head ? 0 : additional_mem_size,
1289				additional_mem_size, realloc_head);
1290		break;
1291	}
1292}
1293
1294void pci_bus_size_bridges(struct pci_bus *bus)
1295{
1296	__pci_bus_size_bridges(bus, NULL);
1297}
1298EXPORT_SYMBOL(pci_bus_size_bridges);
1299
1300static void assign_fixed_resource_on_bus(struct pci_bus *b, struct resource *r)
1301{
1302	int i;
1303	struct resource *parent_r;
1304	unsigned long mask = IORESOURCE_IO | IORESOURCE_MEM |
1305			     IORESOURCE_PREFETCH;
1306
1307	pci_bus_for_each_resource(b, parent_r, i) {
1308		if (!parent_r)
1309			continue;
1310
1311		if ((r->flags & mask) == (parent_r->flags & mask) &&
1312		    resource_contains(parent_r, r))
1313			request_resource(parent_r, r);
1314	}
1315}
1316
1317/*
1318 * Try to assign any resources marked as IORESOURCE_PCI_FIXED, as they are
1319 * skipped by pbus_assign_resources_sorted().
1320 */
1321static void pdev_assign_fixed_resources(struct pci_dev *dev)
1322{
1323	int i;
1324
1325	for (i = 0; i <  PCI_NUM_RESOURCES; i++) {
1326		struct pci_bus *b;
1327		struct resource *r = &dev->resource[i];
1328
1329		if (r->parent || !(r->flags & IORESOURCE_PCI_FIXED) ||
1330		    !(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
1331			continue;
1332
1333		b = dev->bus;
1334		while (b && !r->parent) {
1335			assign_fixed_resource_on_bus(b, r);
1336			b = b->parent;
1337		}
1338	}
1339}
1340
1341void __pci_bus_assign_resources(const struct pci_bus *bus,
1342				struct list_head *realloc_head,
1343				struct list_head *fail_head)
1344{
1345	struct pci_bus *b;
1346	struct pci_dev *dev;
1347
1348	pbus_assign_resources_sorted(bus, realloc_head, fail_head);
1349
1350	list_for_each_entry(dev, &bus->devices, bus_list) {
1351		pdev_assign_fixed_resources(dev);
1352
1353		b = dev->subordinate;
1354		if (!b)
1355			continue;
1356
1357		__pci_bus_assign_resources(b, realloc_head, fail_head);
1358
1359		switch (dev->hdr_type) {
1360		case PCI_HEADER_TYPE_BRIDGE:
1361			if (!pci_is_enabled(dev))
1362				pci_setup_bridge(b);
1363			break;
1364
1365		case PCI_HEADER_TYPE_CARDBUS:
1366			pci_setup_cardbus(b);
1367			break;
1368
1369		default:
1370			pci_info(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_claim_device_resources(struct pci_dev *dev)
1384{
1385	int i;
1386
1387	for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
1388		struct resource *r = &dev->resource[i];
1389
1390		if (!r->flags || r->parent)
1391			continue;
1392
1393		pci_claim_resource(dev, i);
1394	}
1395}
1396
1397static void pci_claim_bridge_resources(struct pci_dev *dev)
1398{
1399	int i;
1400
1401	for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
1402		struct resource *r = &dev->resource[i];
1403
1404		if (!r->flags || r->parent)
1405			continue;
1406
1407		pci_claim_bridge_resource(dev, i);
1408	}
1409}
1410
1411static void pci_bus_allocate_dev_resources(struct pci_bus *b)
1412{
1413	struct pci_dev *dev;
1414	struct pci_bus *child;
1415
1416	list_for_each_entry(dev, &b->devices, bus_list) {
1417		pci_claim_device_resources(dev);
1418
1419		child = dev->subordinate;
1420		if (child)
1421			pci_bus_allocate_dev_resources(child);
1422	}
1423}
1424
1425static void pci_bus_allocate_resources(struct pci_bus *b)
1426{
1427	struct pci_bus *child;
1428
1429	/*
1430	 * Carry out a depth-first search on the PCI bus tree to allocate
1431	 * bridge apertures.  Read the programmed bridge bases and
1432	 * recursively claim the respective bridge resources.
 
1433	 */
1434	if (b->self) {
1435		pci_read_bridge_bases(b);
1436		pci_claim_bridge_resources(b->self);
1437	}
1438
1439	list_for_each_entry(child, &b->children, node)
1440		pci_bus_allocate_resources(child);
1441}
1442
1443void pci_bus_claim_resources(struct pci_bus *b)
1444{
1445	pci_bus_allocate_resources(b);
1446	pci_bus_allocate_dev_resources(b);
1447}
1448EXPORT_SYMBOL(pci_bus_claim_resources);
1449
1450static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
1451					  struct list_head *add_head,
1452					  struct list_head *fail_head)
1453{
1454	struct pci_bus *b;
1455
1456	pdev_assign_resources_sorted((struct pci_dev *)bridge,
1457					 add_head, fail_head);
1458
1459	b = bridge->subordinate;
1460	if (!b)
1461		return;
1462
1463	__pci_bus_assign_resources(b, add_head, fail_head);
1464
1465	switch (bridge->class >> 8) {
1466	case PCI_CLASS_BRIDGE_PCI:
1467		pci_setup_bridge(b);
1468		break;
1469
1470	case PCI_CLASS_BRIDGE_CARDBUS:
1471		pci_setup_cardbus(b);
1472		break;
1473
1474	default:
1475		pci_info(bridge, "not setting up bridge for bus %04x:%02x\n",
1476			 pci_domain_nr(b), b->number);
1477		break;
1478	}
1479}
1480
1481#define PCI_RES_TYPE_MASK \
1482	(IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH |\
1483	 IORESOURCE_MEM_64)
1484
1485static void pci_bridge_release_resources(struct pci_bus *bus,
1486					 unsigned long type)
1487{
1488	struct pci_dev *dev = bus->self;
1489	struct resource *r;
1490	unsigned old_flags = 0;
1491	struct resource *b_res;
1492	int idx = 1;
1493
1494	b_res = &dev->resource[PCI_BRIDGE_RESOURCES];
1495
1496	/*
1497	 * 1. If IO port assignment fails, release bridge IO port.
1498	 * 2. If non pref MMIO assignment fails, release bridge nonpref MMIO.
1499	 * 3. If 64bit pref MMIO assignment fails, and bridge pref is 64bit,
1500	 *    release bridge pref MMIO.
1501	 * 4. If pref MMIO assignment fails, and bridge pref is 32bit,
1502	 *    release bridge pref MMIO.
1503	 * 5. If pref MMIO assignment fails, and bridge pref is not
1504	 *    assigned, release bridge nonpref MMIO.
 
 
1505	 */
1506	if (type & IORESOURCE_IO)
1507		idx = 0;
1508	else if (!(type & IORESOURCE_PREFETCH))
1509		idx = 1;
1510	else if ((type & IORESOURCE_MEM_64) &&
1511		 (b_res[2].flags & IORESOURCE_MEM_64))
1512		idx = 2;
1513	else if (!(b_res[2].flags & IORESOURCE_MEM_64) &&
1514		 (b_res[2].flags & IORESOURCE_PREFETCH))
1515		idx = 2;
1516	else
1517		idx = 1;
1518
1519	r = &b_res[idx];
1520
1521	if (!r->parent)
1522		return;
1523
1524	/* If there are children, release them all */
 
 
 
1525	release_child_resources(r);
1526	if (!release_resource(r)) {
1527		type = old_flags = r->flags & PCI_RES_TYPE_MASK;
1528		pci_info(dev, "resource %d %pR released\n",
1529			 PCI_BRIDGE_RESOURCES + idx, r);
1530		/* Keep the old size */
1531		r->end = resource_size(r) - 1;
1532		r->start = 0;
1533		r->flags = 0;
1534
1535		/* Avoiding touch the one without PREF */
1536		if (type & IORESOURCE_PREFETCH)
1537			type = IORESOURCE_PREFETCH;
1538		__pci_setup_bridge(bus, type);
1539		/* For next child res under same bridge */
1540		r->flags = old_flags;
1541	}
1542}
1543
1544enum release_type {
1545	leaf_only,
1546	whole_subtree,
1547};
1548
1549/*
1550 * Try to release PCI bridge resources from leaf bridge, so we can allocate
1551 * a larger window later.
1552 */
1553static void pci_bus_release_bridge_resources(struct pci_bus *bus,
1554					     unsigned long type,
1555					     enum release_type rel_type)
1556{
1557	struct pci_dev *dev;
1558	bool is_leaf_bridge = true;
1559
1560	list_for_each_entry(dev, &bus->devices, bus_list) {
1561		struct pci_bus *b = dev->subordinate;
1562		if (!b)
1563			continue;
1564
1565		is_leaf_bridge = false;
1566
1567		if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
1568			continue;
1569
1570		if (rel_type == whole_subtree)
1571			pci_bus_release_bridge_resources(b, type,
1572						 whole_subtree);
1573	}
1574
1575	if (pci_is_root_bus(bus))
1576		return;
1577
1578	if ((bus->self->class >> 8) != PCI_CLASS_BRIDGE_PCI)
1579		return;
1580
1581	if ((rel_type == whole_subtree) || is_leaf_bridge)
1582		pci_bridge_release_resources(bus, type);
1583}
1584
1585static void pci_bus_dump_res(struct pci_bus *bus)
1586{
1587	struct resource *res;
1588	int i;
1589
1590	pci_bus_for_each_resource(bus, res, i) {
1591		if (!res || !res->end || !res->flags)
1592			continue;
1593
1594		dev_info(&bus->dev, "resource %d %pR\n", i, res);
1595	}
1596}
1597
1598static void pci_bus_dump_resources(struct pci_bus *bus)
1599{
1600	struct pci_bus *b;
1601	struct pci_dev *dev;
1602
1603
1604	pci_bus_dump_res(bus);
1605
1606	list_for_each_entry(dev, &bus->devices, bus_list) {
1607		b = dev->subordinate;
1608		if (!b)
1609			continue;
1610
1611		pci_bus_dump_resources(b);
1612	}
1613}
1614
1615static int pci_bus_get_depth(struct pci_bus *bus)
1616{
1617	int depth = 0;
1618	struct pci_bus *child_bus;
1619
1620	list_for_each_entry(child_bus, &bus->children, node) {
1621		int ret;
1622
1623		ret = pci_bus_get_depth(child_bus);
1624		if (ret + 1 > depth)
1625			depth = ret + 1;
1626	}
1627
1628	return depth;
1629}
1630
1631/*
1632 * -1: undefined, will auto detect later
1633 *  0: disabled by user
1634 *  1: disabled by auto detect
1635 *  2: enabled by user
1636 *  3: enabled by auto detect
1637 */
1638enum enable_type {
1639	undefined = -1,
1640	user_disabled,
1641	auto_disabled,
1642	user_enabled,
1643	auto_enabled,
1644};
1645
1646static enum enable_type pci_realloc_enable = undefined;
1647void __init pci_realloc_get_opt(char *str)
1648{
1649	if (!strncmp(str, "off", 3))
1650		pci_realloc_enable = user_disabled;
1651	else if (!strncmp(str, "on", 2))
1652		pci_realloc_enable = user_enabled;
1653}
1654static bool pci_realloc_enabled(enum enable_type enable)
1655{
1656	return enable >= user_enabled;
1657}
1658
1659#if defined(CONFIG_PCI_IOV) && defined(CONFIG_PCI_REALLOC_ENABLE_AUTO)
1660static int iov_resources_unassigned(struct pci_dev *dev, void *data)
1661{
1662	int i;
1663	bool *unassigned = data;
1664
1665	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
1666		struct resource *r = &dev->resource[i + PCI_IOV_RESOURCES];
1667		struct pci_bus_region region;
1668
1669		/* Not assigned or rejected by kernel? */
1670		if (!r->flags)
1671			continue;
1672
1673		pcibios_resource_to_bus(dev->bus, &region, r);
1674		if (!region.start) {
1675			*unassigned = true;
1676			return 1; /* Return early from pci_walk_bus() */
1677		}
1678	}
1679
1680	return 0;
1681}
1682
1683static enum enable_type pci_realloc_detect(struct pci_bus *bus,
1684					   enum enable_type enable_local)
1685{
1686	bool unassigned = false;
1687	struct pci_host_bridge *host;
1688
1689	if (enable_local != undefined)
1690		return enable_local;
1691
1692	host = pci_find_host_bridge(bus);
1693	if (host->preserve_config)
1694		return auto_disabled;
1695
1696	pci_walk_bus(bus, iov_resources_unassigned, &unassigned);
1697	if (unassigned)
1698		return auto_enabled;
1699
1700	return enable_local;
1701}
1702#else
1703static enum enable_type pci_realloc_detect(struct pci_bus *bus,
1704					   enum enable_type enable_local)
1705{
1706	return enable_local;
1707}
1708#endif
1709
1710/*
1711 * First try will not touch PCI bridge res.
1712 * Second and later try will clear small leaf bridge res.
1713 * Will stop till to the max depth if can not find good one.
1714 */
1715void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
1716{
1717	LIST_HEAD(realloc_head);
1718	/* List of resources that want additional resources */
1719	struct list_head *add_list = NULL;
1720	int tried_times = 0;
1721	enum release_type rel_type = leaf_only;
1722	LIST_HEAD(fail_head);
1723	struct pci_dev_resource *fail_res;
1724	int pci_try_num = 1;
1725	enum enable_type enable_local;
1726
1727	/* Don't realloc if asked to do so */
1728	enable_local = pci_realloc_detect(bus, pci_realloc_enable);
1729	if (pci_realloc_enabled(enable_local)) {
1730		int max_depth = pci_bus_get_depth(bus);
1731
1732		pci_try_num = max_depth + 1;
1733		dev_info(&bus->dev, "max bus depth: %d pci_try_num: %d\n",
1734			 max_depth, pci_try_num);
 
1735	}
1736
1737again:
1738	/*
1739	 * Last try will use add_list, otherwise will try good to have as must
1740	 * have, so can realloc parent bridge resource
1741	 */
1742	if (tried_times + 1 == pci_try_num)
1743		add_list = &realloc_head;
1744	/*
1745	 * Depth first, calculate sizes and alignments of all subordinate buses.
1746	 */
1747	__pci_bus_size_bridges(bus, add_list);
1748
1749	/* Depth last, allocate resources and update the hardware. */
1750	__pci_bus_assign_resources(bus, add_list, &fail_head);
1751	if (add_list)
1752		BUG_ON(!list_empty(add_list));
1753	tried_times++;
1754
1755	/* Any device complain? */
1756	if (list_empty(&fail_head))
1757		goto dump;
1758
1759	if (tried_times >= pci_try_num) {
1760		if (enable_local == undefined)
1761			dev_info(&bus->dev, "Some PCI device resources are unassigned, try booting with pci=realloc\n");
1762		else if (enable_local == auto_enabled)
1763			dev_info(&bus->dev, "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
1764
1765		free_list(&fail_head);
1766		goto dump;
1767	}
1768
1769	dev_info(&bus->dev, "No. %d try to assign unassigned res\n",
1770		 tried_times + 1);
1771
1772	/* Third times and later will not check if it is leaf */
1773	if ((tried_times + 1) > 2)
1774		rel_type = whole_subtree;
1775
1776	/*
1777	 * Try to release leaf bridge's resources that doesn't fit resource of
1778	 * child device under that bridge.
1779	 */
1780	list_for_each_entry(fail_res, &fail_head, list)
1781		pci_bus_release_bridge_resources(fail_res->dev->bus,
1782						 fail_res->flags & PCI_RES_TYPE_MASK,
1783						 rel_type);
1784
1785	/* Restore size and flags */
1786	list_for_each_entry(fail_res, &fail_head, list) {
1787		struct resource *res = fail_res->res;
1788
1789		res->start = fail_res->start;
1790		res->end = fail_res->end;
1791		res->flags = fail_res->flags;
1792		if (fail_res->dev->subordinate)
1793			res->flags = 0;
1794	}
1795	free_list(&fail_head);
1796
1797	goto again;
1798
1799dump:
1800	/* Dump the resource on buses */
1801	pci_bus_dump_resources(bus);
1802}
1803
1804void __init pci_assign_unassigned_resources(void)
1805{
1806	struct pci_bus *root_bus;
1807
1808	list_for_each_entry(root_bus, &pci_root_buses, node) {
1809		pci_assign_unassigned_root_bus_resources(root_bus);
1810
1811		/* Make sure the root bridge has a companion ACPI device */
1812		if (ACPI_HANDLE(root_bus->bridge))
1813			acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
1814	}
1815}
1816
1817static void extend_bridge_window(struct pci_dev *bridge, struct resource *res,
1818				 struct list_head *add_list,
1819				 resource_size_t available)
1820{
1821	struct pci_dev_resource *dev_res;
1822
1823	if (res->parent)
1824		return;
1825
1826	if (resource_size(res) >= available)
1827		return;
1828
1829	dev_res = res_to_dev_res(add_list, res);
1830	if (!dev_res)
1831		return;
1832
1833	/* Is there room to extend the window? */
1834	if (available - resource_size(res) <= dev_res->add_size)
1835		return;
1836
1837	dev_res->add_size = available - resource_size(res);
1838	pci_dbg(bridge, "bridge window %pR extended by %pa\n", res,
1839		&dev_res->add_size);
1840}
1841
1842static void pci_bus_distribute_available_resources(struct pci_bus *bus,
1843					    struct list_head *add_list,
1844					    resource_size_t available_io,
1845					    resource_size_t available_mmio,
1846					    resource_size_t available_mmio_pref)
1847{
1848	resource_size_t remaining_io, remaining_mmio, remaining_mmio_pref;
1849	unsigned int normal_bridges = 0, hotplug_bridges = 0;
1850	struct resource *io_res, *mmio_res, *mmio_pref_res;
1851	struct pci_dev *dev, *bridge = bus->self;
1852
1853	io_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
1854	mmio_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
1855	mmio_pref_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
1856
1857	/*
1858	 * Update additional resource list (add_list) to fill all the
1859	 * extra resource space available for this port except the space
1860	 * calculated in __pci_bus_size_bridges() which covers all the
1861	 * devices currently connected to the port and below.
1862	 */
1863	extend_bridge_window(bridge, io_res, add_list, available_io);
1864	extend_bridge_window(bridge, mmio_res, add_list, available_mmio);
1865	extend_bridge_window(bridge, mmio_pref_res, add_list,
1866			     available_mmio_pref);
1867
1868	/*
 
 
 
 
 
 
 
 
 
 
1869	 * Calculate how many hotplug bridges and normal bridges there
1870	 * are on this bus.  We will distribute the additional available
1871	 * resources between hotplug bridges.
1872	 */
1873	for_each_pci_bridge(dev, bus) {
1874		if (dev->is_hotplug_bridge)
1875			hotplug_bridges++;
1876		else
1877			normal_bridges++;
1878	}
1879
1880	/*
1881	 * There is only one bridge on the bus so it gets all available
1882	 * resources which it can then distribute to the possible hotplug
1883	 * bridges below.
1884	 */
1885	if (hotplug_bridges + normal_bridges == 1) {
1886		dev = list_first_entry(&bus->devices, struct pci_dev, bus_list);
1887		if (dev->subordinate) {
1888			pci_bus_distribute_available_resources(dev->subordinate,
1889				add_list, available_io, available_mmio,
1890				available_mmio_pref);
1891		}
1892		return;
1893	}
1894
1895	if (hotplug_bridges == 0)
1896		return;
1897
1898	/*
1899	 * Calculate the total amount of extra resource space we can
1900	 * pass to bridges below this one.  This is basically the
1901	 * extra space reduced by the minimal required space for the
1902	 * non-hotplug bridges.
1903	 */
1904	remaining_io = available_io;
1905	remaining_mmio = available_mmio;
1906	remaining_mmio_pref = available_mmio_pref;
1907
1908	for_each_pci_bridge(dev, bus) {
1909		const struct resource *res;
1910
1911		if (dev->is_hotplug_bridge)
1912			continue;
1913
1914		/*
1915		 * Reduce the available resource space by what the
1916		 * bridge and devices below it occupy.
1917		 */
1918		res = &dev->resource[PCI_BRIDGE_RESOURCES + 0];
1919		if (!res->parent && available_io > resource_size(res))
1920			remaining_io -= resource_size(res);
1921
1922		res = &dev->resource[PCI_BRIDGE_RESOURCES + 1];
1923		if (!res->parent && available_mmio > resource_size(res))
1924			remaining_mmio -= resource_size(res);
1925
1926		res = &dev->resource[PCI_BRIDGE_RESOURCES + 2];
1927		if (!res->parent && available_mmio_pref > resource_size(res))
1928			remaining_mmio_pref -= resource_size(res);
1929	}
1930
1931	/*
1932	 * Go over devices on this bus and distribute the remaining
1933	 * resource space between hotplug bridges.
1934	 */
1935	for_each_pci_bridge(dev, bus) {
1936		resource_size_t align, io, mmio, mmio_pref;
1937		struct pci_bus *b;
1938
1939		b = dev->subordinate;
1940		if (!b || !dev->is_hotplug_bridge)
1941			continue;
1942
1943		/*
1944		 * Distribute available extra resources equally between
1945		 * hotplug-capable downstream ports taking alignment into
1946		 * account.
1947		 */
1948		align = pci_resource_alignment(bridge, io_res);
1949		io = div64_ul(available_io, hotplug_bridges);
1950		io = min(ALIGN(io, align), remaining_io);
1951		remaining_io -= io;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1952
1953		align = pci_resource_alignment(bridge, mmio_res);
1954		mmio = div64_ul(available_mmio, hotplug_bridges);
1955		mmio = min(ALIGN(mmio, align), remaining_mmio);
1956		remaining_mmio -= mmio;
1957
1958		align = pci_resource_alignment(bridge, mmio_pref_res);
1959		mmio_pref = div64_ul(available_mmio_pref, hotplug_bridges);
1960		mmio_pref = min(ALIGN(mmio_pref, align), remaining_mmio_pref);
1961		remaining_mmio_pref -= mmio_pref;
 
 
1962
1963		pci_bus_distribute_available_resources(b, add_list, io, mmio,
1964						       mmio_pref);
 
1965	}
1966}
1967
1968static void pci_bridge_distribute_available_resources(struct pci_dev *bridge,
1969						     struct list_head *add_list)
 
1970{
1971	resource_size_t available_io, available_mmio, available_mmio_pref;
1972	const struct resource *res;
1973
1974	if (!bridge->is_hotplug_bridge)
1975		return;
1976
1977	/* Take the initial extra resources from the hotplug port */
1978	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
1979	available_io = resource_size(res);
1980	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
1981	available_mmio = resource_size(res);
1982	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
1983	available_mmio_pref = resource_size(res);
1984
1985	pci_bus_distribute_available_resources(bridge->subordinate,
1986					       add_list, available_io,
1987					       available_mmio,
1988					       available_mmio_pref);
1989}
1990
1991void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
1992{
1993	struct pci_bus *parent = bridge->subordinate;
1994	/* List of resources that want additional resources */
1995	LIST_HEAD(add_list);
1996
1997	int tried_times = 0;
1998	LIST_HEAD(fail_head);
1999	struct pci_dev_resource *fail_res;
2000	int retval;
2001
2002again:
2003	__pci_bus_size_bridges(parent, &add_list);
2004
2005	/*
2006	 * Distribute remaining resources (if any) equally between hotplug
2007	 * bridges below.  This makes it possible to extend the hierarchy
2008	 * later without running out of resources.
2009	 */
2010	pci_bridge_distribute_available_resources(bridge, &add_list);
2011
2012	__pci_bridge_assign_resources(bridge, &add_list, &fail_head);
2013	BUG_ON(!list_empty(&add_list));
2014	tried_times++;
2015
2016	if (list_empty(&fail_head))
2017		goto enable_all;
2018
2019	if (tried_times >= 2) {
2020		/* Still fail, don't need to try more */
2021		free_list(&fail_head);
2022		goto enable_all;
2023	}
2024
2025	printk(KERN_DEBUG "PCI: No. %d try to assign unassigned res\n",
2026			 tried_times + 1);
2027
2028	/*
2029	 * Try to release leaf bridge's resources that aren't big enough
2030	 * to contain child device resources.
2031	 */
2032	list_for_each_entry(fail_res, &fail_head, list)
2033		pci_bus_release_bridge_resources(fail_res->dev->bus,
2034						 fail_res->flags & PCI_RES_TYPE_MASK,
2035						 whole_subtree);
2036
2037	/* Restore size and flags */
2038	list_for_each_entry(fail_res, &fail_head, list) {
2039		struct resource *res = fail_res->res;
2040
2041		res->start = fail_res->start;
2042		res->end = fail_res->end;
2043		res->flags = fail_res->flags;
2044		if (fail_res->dev->subordinate)
2045			res->flags = 0;
2046	}
2047	free_list(&fail_head);
2048
2049	goto again;
2050
2051enable_all:
2052	retval = pci_reenable_device(bridge);
2053	if (retval)
2054		pci_err(bridge, "Error reenabling bridge (%d)\n", retval);
2055	pci_set_master(bridge);
2056}
2057EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
2058
2059int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
2060{
2061	struct pci_dev_resource *dev_res;
2062	struct pci_dev *next;
2063	LIST_HEAD(saved);
2064	LIST_HEAD(added);
2065	LIST_HEAD(failed);
2066	unsigned int i;
2067	int ret;
2068
2069	/* Walk to the root hub, releasing bridge BARs when possible */
2070	next = bridge;
2071	do {
2072		bridge = next;
2073		for (i = PCI_BRIDGE_RESOURCES; i < PCI_BRIDGE_RESOURCE_END;
2074		     i++) {
2075			struct resource *res = &bridge->resource[i];
2076
2077			if ((res->flags ^ type) & PCI_RES_TYPE_MASK)
2078				continue;
2079
2080			/* Ignore BARs which are still in use */
2081			if (res->child)
2082				continue;
2083
2084			ret = add_to_list(&saved, bridge, res, 0, 0);
2085			if (ret)
2086				goto cleanup;
2087
2088			pci_info(bridge, "BAR %d: releasing %pR\n",
2089				 i, res);
2090
2091			if (res->parent)
2092				release_resource(res);
2093			res->start = 0;
2094			res->end = 0;
2095			break;
2096		}
2097		if (i == PCI_BRIDGE_RESOURCE_END)
2098			break;
2099
2100		next = bridge->bus ? bridge->bus->self : NULL;
2101	} while (next);
2102
2103	if (list_empty(&saved))
2104		return -ENOENT;
2105
2106	__pci_bus_size_bridges(bridge->subordinate, &added);
2107	__pci_bridge_assign_resources(bridge, &added, &failed);
2108	BUG_ON(!list_empty(&added));
2109
2110	if (!list_empty(&failed)) {
2111		ret = -ENOSPC;
2112		goto cleanup;
2113	}
2114
2115	list_for_each_entry(dev_res, &saved, list) {
2116		/* Skip the bridge we just assigned resources for */
2117		if (bridge == dev_res->dev)
2118			continue;
2119
2120		bridge = dev_res->dev;
2121		pci_setup_bridge(bridge->subordinate);
2122	}
2123
2124	free_list(&saved);
2125	return 0;
2126
2127cleanup:
2128	/* Restore size and flags */
2129	list_for_each_entry(dev_res, &failed, list) {
2130		struct resource *res = dev_res->res;
2131
2132		res->start = dev_res->start;
2133		res->end = dev_res->end;
2134		res->flags = dev_res->flags;
2135	}
2136	free_list(&failed);
2137
2138	/* Revert to the old configuration */
2139	list_for_each_entry(dev_res, &saved, list) {
2140		struct resource *res = dev_res->res;
2141
2142		bridge = dev_res->dev;
2143		i = res - bridge->resource;
2144
2145		res->start = dev_res->start;
2146		res->end = dev_res->end;
2147		res->flags = dev_res->flags;
2148
2149		pci_claim_resource(bridge, i);
2150		pci_setup_bridge(bridge->subordinate);
2151	}
2152	free_list(&saved);
2153
2154	return ret;
2155}
2156
2157void pci_assign_unassigned_bus_resources(struct pci_bus *bus)
2158{
2159	struct pci_dev *dev;
2160	/* List of resources that want additional resources */
2161	LIST_HEAD(add_list);
2162
2163	down_read(&pci_bus_sem);
2164	for_each_pci_bridge(dev, bus)
2165		if (pci_has_subordinate(dev))
2166			__pci_bus_size_bridges(dev->subordinate, &add_list);
2167	up_read(&pci_bus_sem);
2168	__pci_bus_assign_resources(bus, &add_list, NULL);
2169	BUG_ON(!list_empty(&add_list));
2170}
2171EXPORT_SYMBOL_GPL(pci_assign_unassigned_bus_resources);