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/bitops.h>
  18#include <linux/init.h>
  19#include <linux/kernel.h>
  20#include <linux/module.h>
  21#include <linux/pci.h>
  22#include <linux/errno.h>
  23#include <linux/ioport.h>
  24#include <linux/cache.h>
  25#include <linux/limits.h>
  26#include <linux/sizes.h>
  27#include <linux/slab.h>
  28#include <linux/acpi.h>
  29#include "pci.h"
  30
  31unsigned int pci_flags;
  32EXPORT_SYMBOL_GPL(pci_flags);
  33
  34struct pci_dev_resource {
  35	struct list_head list;
  36	struct resource *res;
  37	struct pci_dev *dev;
  38	resource_size_t start;
  39	resource_size_t end;
  40	resource_size_t add_size;
  41	resource_size_t min_align;
  42	unsigned long flags;
  43};
  44
  45static void free_list(struct list_head *head)
  46{
  47	struct pci_dev_resource *dev_res, *tmp;
  48
  49	list_for_each_entry_safe(dev_res, tmp, head, list) {
  50		list_del(&dev_res->list);
  51		kfree(dev_res);
  52	}
  53}
  54
  55/**
  56 * add_to_list() - Add a new resource tracker to the list
  57 * @head:	Head of the list
  58 * @dev:	Device to which the resource belongs
  59 * @res:	Resource to be tracked
  60 * @add_size:	Additional size to be optionally added to the resource
  61 * @min_align:	Minimum memory window alignment
  62 */
  63static int add_to_list(struct list_head *head, struct pci_dev *dev,
  64		       struct resource *res, resource_size_t add_size,
  65		       resource_size_t min_align)
  66{
  67	struct pci_dev_resource *tmp;
  68
  69	tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
  70	if (!tmp)
  71		return -ENOMEM;
  72
  73	tmp->res = res;
  74	tmp->dev = dev;
  75	tmp->start = res->start;
  76	tmp->end = res->end;
  77	tmp->flags = res->flags;
  78	tmp->add_size = add_size;
  79	tmp->min_align = min_align;
  80
  81	list_add(&tmp->list, head);
  82
  83	return 0;
  84}
  85
  86static void remove_from_list(struct list_head *head, struct resource *res)
  87{
  88	struct pci_dev_resource *dev_res, *tmp;
  89
  90	list_for_each_entry_safe(dev_res, tmp, head, list) {
  91		if (dev_res->res == res) {
  92			list_del(&dev_res->list);
  93			kfree(dev_res);
  94			break;
  95		}
  96	}
  97}
  98
  99static struct pci_dev_resource *res_to_dev_res(struct list_head *head,
 100					       struct resource *res)
 101{
 102	struct pci_dev_resource *dev_res;
 103
 104	list_for_each_entry(dev_res, head, list) {
 105		if (dev_res->res == res)
 106			return dev_res;
 107	}
 108
 109	return NULL;
 110}
 111
 112static resource_size_t get_res_add_size(struct list_head *head,
 113					struct resource *res)
 114{
 115	struct pci_dev_resource *dev_res;
 116
 117	dev_res = res_to_dev_res(head, res);
 118	return dev_res ? dev_res->add_size : 0;
 119}
 120
 121static resource_size_t get_res_add_align(struct list_head *head,
 122					 struct resource *res)
 123{
 124	struct pci_dev_resource *dev_res;
 125
 126	dev_res = res_to_dev_res(head, res);
 127	return dev_res ? dev_res->min_align : 0;
 128}
 129
 
 130/* Sort resources by alignment */
 131static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
 132{
 133	struct resource *r;
 134	int i;
 135
 136	pci_dev_for_each_resource(dev, r, i) {
 137		const char *r_name = pci_resource_name(dev, i);
 138		struct pci_dev_resource *dev_res, *tmp;
 139		resource_size_t r_align;
 140		struct list_head *n;
 141
 
 
 142		if (r->flags & IORESOURCE_PCI_FIXED)
 143			continue;
 144
 145		if (!(r->flags) || r->parent)
 146			continue;
 147
 148		r_align = pci_resource_alignment(dev, r);
 149		if (!r_align) {
 150			pci_warn(dev, "%s %pR: alignment must not be zero\n",
 151				 r_name, r);
 152			continue;
 153		}
 154
 155		tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
 156		if (!tmp)
 157			panic("%s: kzalloc() failed!\n", __func__);
 158		tmp->res = r;
 159		tmp->dev = dev;
 160
 161		/* Fallback is smallest one or list is empty */
 162		n = head;
 163		list_for_each_entry(dev_res, head, list) {
 164			resource_size_t align;
 165
 166			align = pci_resource_alignment(dev_res->dev,
 167							 dev_res->res);
 168
 169			if (r_align > align) {
 170				n = &dev_res->list;
 171				break;
 172			}
 173		}
 174		/* Insert it just before n */
 175		list_add_tail(&tmp->list, n);
 176	}
 177}
 178
 179static void __dev_sort_resources(struct pci_dev *dev, struct list_head *head)
 180{
 181	u16 class = dev->class >> 8;
 182
 183	/* Don't touch classless devices or host bridges or IOAPICs */
 184	if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)
 185		return;
 186
 187	/* Don't touch IOAPIC devices already enabled by firmware */
 188	if (class == PCI_CLASS_SYSTEM_PIC) {
 189		u16 command;
 190		pci_read_config_word(dev, PCI_COMMAND, &command);
 191		if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
 192			return;
 193	}
 194
 195	pdev_sort_resources(dev, head);
 196}
 197
 198static inline void reset_resource(struct resource *res)
 199{
 200	res->start = 0;
 201	res->end = 0;
 202	res->flags = 0;
 203}
 204
 205/**
 206 * reassign_resources_sorted() - Satisfy any additional resource requests
 207 *
 208 * @realloc_head:	Head of the list tracking requests requiring
 209 *			additional resources
 210 * @head:		Head of the list tracking requests with allocated
 211 *			resources
 212 *
 213 * Walk through each element of the realloc_head and try to procure additional
 214 * resources for the element, provided the element is in the head list.
 215 */
 216static void reassign_resources_sorted(struct list_head *realloc_head,
 217				      struct list_head *head)
 218{
 219	struct resource *res;
 220	const char *res_name;
 221	struct pci_dev_resource *add_res, *tmp;
 222	struct pci_dev_resource *dev_res;
 223	resource_size_t add_size, align;
 224	int idx;
 225
 226	list_for_each_entry_safe(add_res, tmp, realloc_head, list) {
 227		bool found_match = false;
 228
 229		res = add_res->res;
 230
 231		/* Skip resource that has been reset */
 232		if (!res->flags)
 233			goto out;
 234
 235		/* Skip this resource if not found in head list */
 236		list_for_each_entry(dev_res, head, list) {
 237			if (dev_res->res == res) {
 238				found_match = true;
 239				break;
 240			}
 241		}
 242		if (!found_match) /* Just skip */
 243			continue;
 244
 245		idx = res - &add_res->dev->resource[0];
 246		res_name = pci_resource_name(add_res->dev, idx);
 247		add_size = add_res->add_size;
 248		align = add_res->min_align;
 249		if (!resource_size(res)) {
 250			resource_set_range(res, align, add_size);
 
 251			if (pci_assign_resource(add_res->dev, idx))
 252				reset_resource(res);
 253		} else {
 254			res->flags |= add_res->flags &
 255				 (IORESOURCE_STARTALIGN|IORESOURCE_SIZEALIGN);
 256			if (pci_reassign_resource(add_res->dev, idx,
 257						  add_size, align))
 258				pci_info(add_res->dev, "%s %pR: failed to add %llx\n",
 259					 res_name, res,
 260					 (unsigned long long) add_size);
 261		}
 262out:
 263		list_del(&add_res->list);
 264		kfree(add_res);
 265	}
 266}
 267
 268/**
 269 * assign_requested_resources_sorted() - Satisfy resource requests
 270 *
 271 * @head:	Head of the list tracking requests for resources
 272 * @fail_head:	Head of the list tracking requests that could not be
 273 *		allocated
 274 *
 275 * Satisfy resource requests of each element in the list.  Add requests that
 276 * could not be satisfied to the failed_list.
 277 */
 278static void assign_requested_resources_sorted(struct list_head *head,
 279				 struct list_head *fail_head)
 280{
 281	struct resource *res;
 282	struct pci_dev_resource *dev_res;
 283	int idx;
 284
 285	list_for_each_entry(dev_res, head, list) {
 286		res = dev_res->res;
 287		idx = res - &dev_res->dev->resource[0];
 288		if (resource_size(res) &&
 289		    pci_assign_resource(dev_res->dev, idx)) {
 290			if (fail_head) {
 291				/*
 292				 * If the failed resource is a ROM BAR and
 293				 * it will be enabled later, don't add it
 294				 * to the list.
 295				 */
 296				if (!((idx == PCI_ROM_RESOURCE) &&
 297				      (!(res->flags & IORESOURCE_ROM_ENABLE))))
 298					add_to_list(fail_head,
 299						    dev_res->dev, res,
 300						    0 /* don't care */,
 301						    0 /* don't care */);
 302			}
 303			reset_resource(res);
 304		}
 305	}
 306}
 307
 308static unsigned long pci_fail_res_type_mask(struct list_head *fail_head)
 309{
 310	struct pci_dev_resource *fail_res;
 311	unsigned long mask = 0;
 312
 313	/* Check failed type */
 314	list_for_each_entry(fail_res, fail_head, list)
 315		mask |= fail_res->flags;
 316
 317	/*
 318	 * One pref failed resource will set IORESOURCE_MEM, as we can
 319	 * allocate pref in non-pref range.  Will release all assigned
 320	 * non-pref sibling resources according to that bit.
 321	 */
 322	return mask & (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH);
 323}
 324
 325static bool pci_need_to_release(unsigned long mask, struct resource *res)
 326{
 327	if (res->flags & IORESOURCE_IO)
 328		return !!(mask & IORESOURCE_IO);
 329
 330	/* Check pref at first */
 331	if (res->flags & IORESOURCE_PREFETCH) {
 332		if (mask & IORESOURCE_PREFETCH)
 333			return true;
 334		/* Count pref if its parent is non-pref */
 335		else if ((mask & IORESOURCE_MEM) &&
 336			 !(res->parent->flags & IORESOURCE_PREFETCH))
 337			return true;
 338		else
 339			return false;
 340	}
 341
 342	if (res->flags & IORESOURCE_MEM)
 343		return !!(mask & IORESOURCE_MEM);
 344
 345	return false;	/* Should not get here */
 346}
 347
 348static void __assign_resources_sorted(struct list_head *head,
 349				      struct list_head *realloc_head,
 350				      struct list_head *fail_head)
 351{
 352	/*
 353	 * Should not assign requested resources at first.  They could be
 354	 * adjacent, so later reassign can not reallocate them one by one in
 355	 * parent resource window.
 356	 *
 357	 * Try to assign requested + add_size at beginning.  If could do that,
 358	 * could get out early.  If could not do that, we still try to assign
 359	 * requested at first, then try to reassign add_size for some resources.
 360	 *
 361	 * Separate three resource type checking if we need to release
 362	 * assigned resource after requested + add_size try.
 363	 *
 364	 *	1. If IO port assignment fails, will release assigned IO
 365	 *	   port.
 366	 *	2. If pref MMIO assignment fails, release assigned pref
 367	 *	   MMIO.  If assigned pref MMIO's parent is non-pref MMIO
 368	 *	   and non-pref MMIO assignment fails, will release that
 369	 *	   assigned pref MMIO.
 370	 *	3. If non-pref MMIO assignment fails or pref MMIO
 371	 *	   assignment fails, will release assigned non-pref MMIO.
 372	 */
 373	LIST_HEAD(save_head);
 374	LIST_HEAD(local_fail_head);
 375	struct pci_dev_resource *save_res;
 376	struct pci_dev_resource *dev_res, *tmp_res, *dev_res2;
 377	unsigned long fail_type;
 378	resource_size_t add_align, align;
 379
 380	/* Check if optional add_size is there */
 381	if (!realloc_head || list_empty(realloc_head))
 382		goto requested_and_reassign;
 383
 384	/* Save original start, end, flags etc at first */
 385	list_for_each_entry(dev_res, head, list) {
 386		if (add_to_list(&save_head, dev_res->dev, dev_res->res, 0, 0)) {
 387			free_list(&save_head);
 388			goto requested_and_reassign;
 389		}
 390	}
 391
 392	/* Update res in head list with add_size in realloc_head list */
 393	list_for_each_entry_safe(dev_res, tmp_res, head, list) {
 394		dev_res->res->end += get_res_add_size(realloc_head,
 395							dev_res->res);
 396
 397		/*
 398		 * There are two kinds of additional resources in the list:
 399		 * 1. bridge resource  -- IORESOURCE_STARTALIGN
 400		 * 2. SR-IOV resource  -- IORESOURCE_SIZEALIGN
 401		 * Here just fix the additional alignment for bridge
 402		 */
 403		if (!(dev_res->res->flags & IORESOURCE_STARTALIGN))
 404			continue;
 405
 406		add_align = get_res_add_align(realloc_head, dev_res->res);
 407
 408		/*
 409		 * The "head" list is sorted by alignment so resources with
 410		 * bigger alignment will be assigned first.  After we
 411		 * change the alignment of a dev_res in "head" list, we
 412		 * need to reorder the list by alignment to make it
 413		 * consistent.
 414		 */
 415		if (add_align > dev_res->res->start) {
 416			resource_size_t r_size = resource_size(dev_res->res);
 417
 418			dev_res->res->start = add_align;
 419			dev_res->res->end = add_align + r_size - 1;
 420
 421			list_for_each_entry(dev_res2, head, list) {
 422				align = pci_resource_alignment(dev_res2->dev,
 423							       dev_res2->res);
 424				if (add_align > align) {
 425					list_move_tail(&dev_res->list,
 426						       &dev_res2->list);
 427					break;
 428				}
 429			}
 430		}
 431
 432	}
 433
 434	/* Try updated head list with add_size added */
 435	assign_requested_resources_sorted(head, &local_fail_head);
 436
 437	/* All assigned with add_size? */
 438	if (list_empty(&local_fail_head)) {
 439		/* Remove head list from realloc_head list */
 440		list_for_each_entry(dev_res, head, list)
 441			remove_from_list(realloc_head, dev_res->res);
 442		free_list(&save_head);
 443		free_list(head);
 444		return;
 445	}
 446
 447	/* Check failed type */
 448	fail_type = pci_fail_res_type_mask(&local_fail_head);
 449	/* Remove not need to be released assigned res from head list etc */
 450	list_for_each_entry_safe(dev_res, tmp_res, head, list)
 451		if (dev_res->res->parent &&
 452		    !pci_need_to_release(fail_type, dev_res->res)) {
 453			/* Remove it from realloc_head list */
 454			remove_from_list(realloc_head, dev_res->res);
 455			remove_from_list(&save_head, dev_res->res);
 456			list_del(&dev_res->list);
 457			kfree(dev_res);
 458		}
 459
 460	free_list(&local_fail_head);
 461	/* Release assigned resource */
 462	list_for_each_entry(dev_res, head, list)
 463		if (dev_res->res->parent)
 464			release_resource(dev_res->res);
 465	/* Restore start/end/flags from saved list */
 466	list_for_each_entry(save_res, &save_head, list) {
 467		struct resource *res = save_res->res;
 468
 469		res->start = save_res->start;
 470		res->end = save_res->end;
 471		res->flags = save_res->flags;
 472	}
 473	free_list(&save_head);
 474
 475requested_and_reassign:
 476	/* Satisfy the must-have resource requests */
 477	assign_requested_resources_sorted(head, fail_head);
 478
 479	/* Try to satisfy any additional optional resource requests */
 480	if (realloc_head)
 481		reassign_resources_sorted(realloc_head, head);
 482	free_list(head);
 483}
 484
 485static void pdev_assign_resources_sorted(struct pci_dev *dev,
 486					 struct list_head *add_head,
 487					 struct list_head *fail_head)
 488{
 489	LIST_HEAD(head);
 490
 491	__dev_sort_resources(dev, &head);
 492	__assign_resources_sorted(&head, add_head, fail_head);
 493
 494}
 495
 496static void pbus_assign_resources_sorted(const struct pci_bus *bus,
 497					 struct list_head *realloc_head,
 498					 struct list_head *fail_head)
 499{
 500	struct pci_dev *dev;
 501	LIST_HEAD(head);
 502
 503	list_for_each_entry(dev, &bus->devices, bus_list)
 504		__dev_sort_resources(dev, &head);
 505
 506	__assign_resources_sorted(&head, realloc_head, fail_head);
 507}
 508
 509void pci_setup_cardbus(struct pci_bus *bus)
 510{
 511	struct pci_dev *bridge = bus->self;
 512	struct resource *res;
 513	struct pci_bus_region region;
 514
 515	pci_info(bridge, "CardBus bridge to %pR\n",
 516		 &bus->busn_res);
 517
 518	res = bus->resource[0];
 519	pcibios_resource_to_bus(bridge->bus, &region, res);
 520	if (res->flags & IORESOURCE_IO) {
 521		/*
 522		 * The IO resource is allocated a range twice as large as it
 523		 * would normally need.  This allows us to set both IO regs.
 524		 */
 525		pci_info(bridge, "  bridge window %pR\n", res);
 526		pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
 527					region.start);
 528		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
 529					region.end);
 530	}
 531
 532	res = bus->resource[1];
 533	pcibios_resource_to_bus(bridge->bus, &region, res);
 534	if (res->flags & IORESOURCE_IO) {
 535		pci_info(bridge, "  bridge window %pR\n", res);
 536		pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
 537					region.start);
 538		pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
 539					region.end);
 540	}
 541
 542	res = bus->resource[2];
 543	pcibios_resource_to_bus(bridge->bus, &region, res);
 544	if (res->flags & IORESOURCE_MEM) {
 545		pci_info(bridge, "  bridge window %pR\n", res);
 546		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
 547					region.start);
 548		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
 549					region.end);
 550	}
 551
 552	res = bus->resource[3];
 553	pcibios_resource_to_bus(bridge->bus, &region, res);
 554	if (res->flags & IORESOURCE_MEM) {
 555		pci_info(bridge, "  bridge window %pR\n", res);
 556		pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
 557					region.start);
 558		pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
 559					region.end);
 560	}
 561}
 562EXPORT_SYMBOL(pci_setup_cardbus);
 563
 564/*
 565 * Initialize bridges with base/limit values we have collected.  PCI-to-PCI
 566 * Bridge Architecture Specification rev. 1.1 (1998) requires that if there
 567 * are no I/O ports or memory behind the bridge, the corresponding range
 568 * must be turned off by writing base value greater than limit to the
 569 * bridge's base/limit registers.
 570 *
 571 * Note: care must be taken when updating I/O base/limit registers of
 572 * bridges which support 32-bit I/O.  This update requires two config space
 573 * writes, so it's quite possible that an I/O window of the bridge will
 574 * have some undesirable address (e.g. 0) after the first write.  Ditto
 575 * 64-bit prefetchable MMIO.
 576 */
 577static void pci_setup_bridge_io(struct pci_dev *bridge)
 578{
 579	struct resource *res;
 580	const char *res_name;
 581	struct pci_bus_region region;
 582	unsigned long io_mask;
 583	u8 io_base_lo, io_limit_lo;
 584	u16 l;
 585	u32 io_upper16;
 586
 587	io_mask = PCI_IO_RANGE_MASK;
 588	if (bridge->io_window_1k)
 589		io_mask = PCI_IO_1K_RANGE_MASK;
 590
 591	/* Set up the top and bottom of the PCI I/O segment for this bus */
 592	res = &bridge->resource[PCI_BRIDGE_IO_WINDOW];
 593	res_name = pci_resource_name(bridge, PCI_BRIDGE_IO_WINDOW);
 594	pcibios_resource_to_bus(bridge->bus, &region, res);
 595	if (res->flags & IORESOURCE_IO) {
 596		pci_read_config_word(bridge, PCI_IO_BASE, &l);
 597		io_base_lo = (region.start >> 8) & io_mask;
 598		io_limit_lo = (region.end >> 8) & io_mask;
 599		l = ((u16) io_limit_lo << 8) | io_base_lo;
 600		/* Set up upper 16 bits of I/O base/limit */
 601		io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
 602		pci_info(bridge, "  %s %pR\n", res_name, res);
 603	} else {
 604		/* Clear upper 16 bits of I/O base/limit */
 605		io_upper16 = 0;
 606		l = 0x00f0;
 607	}
 608	/* Temporarily disable the I/O range before updating PCI_IO_BASE */
 609	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff);
 610	/* Update lower 16 bits of I/O base/limit */
 611	pci_write_config_word(bridge, PCI_IO_BASE, l);
 612	/* Update upper 16 bits of I/O base/limit */
 613	pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
 614}
 615
 616static void pci_setup_bridge_mmio(struct pci_dev *bridge)
 617{
 618	struct resource *res;
 619	const char *res_name;
 620	struct pci_bus_region region;
 621	u32 l;
 622
 623	/* Set up the top and bottom of the PCI Memory segment for this bus */
 624	res = &bridge->resource[PCI_BRIDGE_MEM_WINDOW];
 625	res_name = pci_resource_name(bridge, PCI_BRIDGE_MEM_WINDOW);
 626	pcibios_resource_to_bus(bridge->bus, &region, res);
 627	if (res->flags & IORESOURCE_MEM) {
 628		l = (region.start >> 16) & 0xfff0;
 629		l |= region.end & 0xfff00000;
 630		pci_info(bridge, "  %s %pR\n", res_name, res);
 631	} else {
 632		l = 0x0000fff0;
 633	}
 634	pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
 635}
 636
 637static void pci_setup_bridge_mmio_pref(struct pci_dev *bridge)
 638{
 639	struct resource *res;
 640	const char *res_name;
 641	struct pci_bus_region region;
 642	u32 l, bu, lu;
 643
 644	/*
 645	 * Clear out the upper 32 bits of PREF limit.  If
 646	 * PCI_PREF_BASE_UPPER32 was non-zero, this temporarily disables
 647	 * PREF range, which is ok.
 648	 */
 649	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);
 650
 651	/* Set up PREF base/limit */
 652	bu = lu = 0;
 653	res = &bridge->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
 654	res_name = pci_resource_name(bridge, PCI_BRIDGE_PREF_MEM_WINDOW);
 655	pcibios_resource_to_bus(bridge->bus, &region, res);
 656	if (res->flags & IORESOURCE_PREFETCH) {
 657		l = (region.start >> 16) & 0xfff0;
 658		l |= region.end & 0xfff00000;
 659		if (res->flags & IORESOURCE_MEM_64) {
 660			bu = upper_32_bits(region.start);
 661			lu = upper_32_bits(region.end);
 662		}
 663		pci_info(bridge, "  %s %pR\n", res_name, res);
 664	} else {
 665		l = 0x0000fff0;
 666	}
 667	pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
 668
 669	/* Set the upper 32 bits of PREF base & limit */
 670	pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
 671	pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
 672}
 673
 674static void __pci_setup_bridge(struct pci_bus *bus, unsigned long type)
 675{
 676	struct pci_dev *bridge = bus->self;
 677
 678	pci_info(bridge, "PCI bridge to %pR\n",
 679		 &bus->busn_res);
 680
 681	if (type & IORESOURCE_IO)
 682		pci_setup_bridge_io(bridge);
 683
 684	if (type & IORESOURCE_MEM)
 685		pci_setup_bridge_mmio(bridge);
 686
 687	if (type & IORESOURCE_PREFETCH)
 688		pci_setup_bridge_mmio_pref(bridge);
 689
 690	pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
 691}
 692
 693void __weak pcibios_setup_bridge(struct pci_bus *bus, unsigned long type)
 694{
 695}
 696
 697void pci_setup_bridge(struct pci_bus *bus)
 698{
 699	unsigned long type = IORESOURCE_IO | IORESOURCE_MEM |
 700				  IORESOURCE_PREFETCH;
 701
 702	pcibios_setup_bridge(bus, type);
 703	__pci_setup_bridge(bus, type);
 704}
 705
 706
 707int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
 708{
 709	if (i < PCI_BRIDGE_RESOURCES || i > PCI_BRIDGE_RESOURCE_END)
 710		return 0;
 711
 712	if (pci_claim_resource(bridge, i) == 0)
 713		return 0;	/* Claimed the window */
 714
 715	if ((bridge->class >> 8) != PCI_CLASS_BRIDGE_PCI)
 716		return 0;
 717
 718	if (!pci_bus_clip_resource(bridge, i))
 719		return -EINVAL;	/* Clipping didn't change anything */
 720
 721	switch (i) {
 722	case PCI_BRIDGE_IO_WINDOW:
 723		pci_setup_bridge_io(bridge);
 724		break;
 725	case PCI_BRIDGE_MEM_WINDOW:
 726		pci_setup_bridge_mmio(bridge);
 727		break;
 728	case PCI_BRIDGE_PREF_MEM_WINDOW:
 729		pci_setup_bridge_mmio_pref(bridge);
 730		break;
 731	default:
 732		return -EINVAL;
 733	}
 734
 735	if (pci_claim_resource(bridge, i) == 0)
 736		return 0;	/* Claimed a smaller window */
 737
 738	return -EINVAL;
 739}
 740
 741/*
 742 * Check whether the bridge supports optional I/O and prefetchable memory
 743 * ranges.  If not, the respective base/limit registers must be read-only
 744 * and read as 0.
 745 */
 746static void pci_bridge_check_ranges(struct pci_bus *bus)
 747{
 748	struct pci_dev *bridge = bus->self;
 749	struct resource *b_res;
 750
 751	b_res = &bridge->resource[PCI_BRIDGE_MEM_WINDOW];
 752	b_res->flags |= IORESOURCE_MEM;
 753
 754	if (bridge->io_window) {
 755		b_res = &bridge->resource[PCI_BRIDGE_IO_WINDOW];
 756		b_res->flags |= IORESOURCE_IO;
 757	}
 758
 759	if (bridge->pref_window) {
 760		b_res = &bridge->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
 761		b_res->flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
 762		if (bridge->pref_64_window) {
 763			b_res->flags |= IORESOURCE_MEM_64 |
 764					PCI_PREF_RANGE_TYPE_64;
 765		}
 766	}
 767}
 768
 769/*
 770 * Helper function for sizing routines.  Assigned resources have non-NULL
 771 * parent resource.
 772 *
 773 * Return first unassigned resource of the correct type.  If there is none,
 774 * return first assigned resource of the correct type.  If none of the
 775 * above, return NULL.
 776 *
 777 * Returning an assigned resource of the correct type allows the caller to
 778 * distinguish between already assigned and no resource of the correct type.
 779 */
 780static struct resource *find_bus_resource_of_type(struct pci_bus *bus,
 781						  unsigned long type_mask,
 782						  unsigned long type)
 783{
 784	struct resource *r, *r_assigned = NULL;
 
 785
 786	pci_bus_for_each_resource(bus, r) {
 787		if (r == &ioport_resource || r == &iomem_resource)
 788			continue;
 789		if (r && (r->flags & type_mask) == type && !r->parent)
 790			return r;
 791		if (r && (r->flags & type_mask) == type && !r_assigned)
 792			r_assigned = r;
 793	}
 794	return r_assigned;
 795}
 796
 797static resource_size_t calculate_iosize(resource_size_t size,
 798					resource_size_t min_size,
 799					resource_size_t size1,
 800					resource_size_t add_size,
 801					resource_size_t children_add_size,
 802					resource_size_t old_size,
 803					resource_size_t align)
 804{
 805	if (size < min_size)
 806		size = min_size;
 807	if (old_size == 1)
 808		old_size = 0;
 809	/*
 810	 * To be fixed in 2.5: we should have sort of HAVE_ISA flag in the
 811	 * struct pci_bus.
 812	 */
 813#if defined(CONFIG_ISA) || defined(CONFIG_EISA)
 814	size = (size & 0xff) + ((size & ~0xffUL) << 2);
 815#endif
 816	size = size + size1;
 817	if (size < old_size)
 818		size = old_size;
 819
 820	size = ALIGN(max(size, add_size) + children_add_size, align);
 821	return size;
 822}
 823
 824static resource_size_t calculate_memsize(resource_size_t size,
 825					 resource_size_t min_size,
 826					 resource_size_t add_size,
 827					 resource_size_t children_add_size,
 828					 resource_size_t old_size,
 829					 resource_size_t align)
 830{
 831	if (size < min_size)
 832		size = min_size;
 833	if (old_size == 1)
 834		old_size = 0;
 
 
 835
 836	size = max(size, add_size) + children_add_size;
 837	return ALIGN(max(size, old_size), align);
 838}
 839
 840resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus,
 841						unsigned long type)
 842{
 843	return 1;
 844}
 845
 846#define PCI_P2P_DEFAULT_MEM_ALIGN	0x100000	/* 1MiB */
 847#define PCI_P2P_DEFAULT_IO_ALIGN	0x1000		/* 4KiB */
 848#define PCI_P2P_DEFAULT_IO_ALIGN_1K	0x400		/* 1KiB */
 849
 850static resource_size_t window_alignment(struct pci_bus *bus, unsigned long type)
 851{
 852	resource_size_t align = 1, arch_align;
 853
 854	if (type & IORESOURCE_MEM)
 855		align = PCI_P2P_DEFAULT_MEM_ALIGN;
 856	else if (type & IORESOURCE_IO) {
 857		/*
 858		 * Per spec, I/O windows are 4K-aligned, but some bridges have
 859		 * an extension to support 1K alignment.
 860		 */
 861		if (bus->self && bus->self->io_window_1k)
 862			align = PCI_P2P_DEFAULT_IO_ALIGN_1K;
 863		else
 864			align = PCI_P2P_DEFAULT_IO_ALIGN;
 865	}
 866
 867	arch_align = pcibios_window_alignment(bus, type);
 868	return max(align, arch_align);
 869}
 870
 871/**
 872 * pbus_size_io() - Size the I/O window of a given bus
 873 *
 874 * @bus:		The bus
 875 * @min_size:		The minimum I/O window that must be allocated
 876 * @add_size:		Additional optional I/O window
 877 * @realloc_head:	Track the additional I/O window on this list
 878 *
 879 * Sizing the I/O windows of the PCI-PCI bridge is trivial, since these
 880 * windows have 1K or 4K granularity and the I/O ranges of non-bridge PCI
 881 * devices are limited to 256 bytes.  We must be careful with the ISA
 882 * aliasing though.
 883 */
 884static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
 885			 resource_size_t add_size,
 886			 struct list_head *realloc_head)
 887{
 888	struct pci_dev *dev;
 889	struct resource *b_res = find_bus_resource_of_type(bus, IORESOURCE_IO,
 890							   IORESOURCE_IO);
 891	resource_size_t size = 0, size0 = 0, size1 = 0;
 892	resource_size_t children_add_size = 0;
 893	resource_size_t min_align, align;
 894
 895	if (!b_res)
 896		return;
 897
 898	/* If resource is already assigned, nothing more to do */
 899	if (b_res->parent)
 900		return;
 901
 902	min_align = window_alignment(bus, IORESOURCE_IO);
 903	list_for_each_entry(dev, &bus->devices, bus_list) {
 904		struct resource *r;
 905
 906		pci_dev_for_each_resource(dev, r) {
 
 907			unsigned long r_size;
 908
 909			if (r->parent || !(r->flags & IORESOURCE_IO))
 910				continue;
 911			r_size = resource_size(r);
 912
 913			if (r_size < 0x400)
 914				/* Might be re-aligned for ISA */
 915				size += r_size;
 916			else
 917				size1 += r_size;
 918
 919			align = pci_resource_alignment(dev, r);
 920			if (align > min_align)
 921				min_align = align;
 922
 923			if (realloc_head)
 924				children_add_size += get_res_add_size(realloc_head, r);
 925		}
 926	}
 927
 928	size0 = calculate_iosize(size, min_size, size1, 0, 0,
 929			resource_size(b_res), min_align);
 930	size1 = (!realloc_head || (realloc_head && !add_size && !children_add_size)) ? size0 :
 931		calculate_iosize(size, min_size, size1, add_size, children_add_size,
 932			resource_size(b_res), min_align);
 933	if (!size0 && !size1) {
 934		if (bus->self && (b_res->start || b_res->end))
 935			pci_info(bus->self, "disabling bridge window %pR to %pR (unused)\n",
 936				 b_res, &bus->busn_res);
 937		b_res->flags = 0;
 938		return;
 939	}
 940
 941	resource_set_range(b_res, min_align, size0);
 
 942	b_res->flags |= IORESOURCE_STARTALIGN;
 943	if (bus->self && size1 > size0 && realloc_head) {
 944		add_to_list(realloc_head, bus->self, b_res, size1-size0,
 945			    min_align);
 946		pci_info(bus->self, "bridge window %pR to %pR add_size %llx\n",
 947			 b_res, &bus->busn_res,
 948			 (unsigned long long) size1 - size0);
 949	}
 950}
 951
 952static inline resource_size_t calculate_mem_align(resource_size_t *aligns,
 953						  int max_order)
 954{
 955	resource_size_t align = 0;
 956	resource_size_t min_align = 0;
 957	int order;
 958
 959	for (order = 0; order <= max_order; order++) {
 960		resource_size_t align1 = 1;
 961
 962		align1 <<= order + __ffs(SZ_1M);
 963
 964		if (!align)
 965			min_align = align1;
 966		else if (ALIGN(align + min_align, min_align) < align1)
 967			min_align = align1 >> 1;
 968		align += aligns[order];
 969	}
 970
 971	return min_align;
 972}
 973
 974/**
 975 * pbus_upstream_space_available - Check no upstream resource limits allocation
 976 * @bus:	The bus
 977 * @mask:	Mask the resource flag, then compare it with type
 978 * @type:	The type of resource from bridge
 979 * @size:	The size required from the bridge window
 980 * @align:	Required alignment for the resource
 981 *
 982 * Checks that @size can fit inside the upstream bridge resources that are
 983 * already assigned.
 984 *
 985 * Return: %true if enough space is available on all assigned upstream
 986 * resources.
 987 */
 988static bool pbus_upstream_space_available(struct pci_bus *bus, unsigned long mask,
 989					  unsigned long type, resource_size_t size,
 990					  resource_size_t align)
 991{
 992	struct resource_constraint constraint = {
 993		.max = RESOURCE_SIZE_MAX,
 994		.align = align,
 995	};
 996	struct pci_bus *downstream = bus;
 997	struct resource *r;
 998
 999	while ((bus = bus->parent)) {
1000		if (pci_is_root_bus(bus))
1001			break;
1002
1003		pci_bus_for_each_resource(bus, r) {
1004			if (!r || !r->parent || (r->flags & mask) != type)
1005				continue;
1006
1007			if (resource_size(r) >= size) {
1008				struct resource gap = {};
1009
1010				if (find_resource_space(r, &gap, size, &constraint) == 0) {
1011					gap.flags = type;
1012					pci_dbg(bus->self,
1013						"Assigned bridge window %pR to %pR free space at %pR\n",
1014						r, &bus->busn_res, &gap);
1015					return true;
1016				}
1017			}
1018
1019			if (bus->self) {
1020				pci_info(bus->self,
1021					 "Assigned bridge window %pR to %pR cannot fit 0x%llx required for %s bridging to %pR\n",
1022					 r, &bus->busn_res,
1023					 (unsigned long long)size,
1024					 pci_name(downstream->self),
1025					 &downstream->busn_res);
1026			}
1027
1028			return false;
1029		}
1030	}
1031
1032	return true;
1033}
1034
1035/**
1036 * pbus_size_mem() - Size the memory window of a given bus
1037 *
1038 * @bus:		The bus
1039 * @mask:		Mask the resource flag, then compare it with type
1040 * @type:		The type of free resource from bridge
1041 * @type2:		Second match type
1042 * @type3:		Third match type
1043 * @min_size:		The minimum memory window that must be allocated
1044 * @add_size:		Additional optional memory window
1045 * @realloc_head:	Track the additional memory window on this list
1046 *
1047 * Calculate the size of the bus and minimal alignment which guarantees
1048 * that all child resources fit in this size.
1049 *
1050 * Return -ENOSPC if there's no available bus resource of the desired
1051 * type.  Otherwise, set the bus resource start/end to indicate the
1052 * required size, add things to realloc_head (if supplied), and return 0.
1053 */
1054static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
1055			 unsigned long type, unsigned long type2,
1056			 unsigned long type3, resource_size_t min_size,
1057			 resource_size_t add_size,
1058			 struct list_head *realloc_head)
1059{
1060	struct pci_dev *dev;
1061	resource_size_t min_align, win_align, align, size, size0, size1;
1062	resource_size_t aligns[24]; /* Alignments from 1MB to 8TB */
1063	int order, max_order;
1064	struct resource *b_res = find_bus_resource_of_type(bus,
1065					mask | IORESOURCE_PREFETCH, type);
1066	resource_size_t children_add_size = 0;
1067	resource_size_t children_add_align = 0;
1068	resource_size_t add_align = 0;
1069
1070	if (!b_res)
1071		return -ENOSPC;
1072
1073	/* If resource is already assigned, nothing more to do */
1074	if (b_res->parent)
1075		return 0;
1076
1077	memset(aligns, 0, sizeof(aligns));
1078	max_order = 0;
1079	size = 0;
1080
1081	list_for_each_entry(dev, &bus->devices, bus_list) {
1082		struct resource *r;
1083		int i;
1084
1085		pci_dev_for_each_resource(dev, r, i) {
1086			const char *r_name = pci_resource_name(dev, i);
1087			resource_size_t r_size;
1088
1089			if (r->parent || (r->flags & IORESOURCE_PCI_FIXED) ||
1090			    ((r->flags & mask) != type &&
1091			     (r->flags & mask) != type2 &&
1092			     (r->flags & mask) != type3))
1093				continue;
1094			r_size = resource_size(r);
1095#ifdef CONFIG_PCI_IOV
1096			/* Put SRIOV requested res to the optional list */
1097			if (realloc_head && i >= PCI_IOV_RESOURCES &&
1098					i <= PCI_IOV_RESOURCE_END) {
1099				add_align = max(pci_resource_alignment(dev, r), add_align);
1100				r->end = r->start - 1;
1101				add_to_list(realloc_head, dev, r, r_size, 0 /* Don't care */);
1102				children_add_size += r_size;
1103				continue;
1104			}
1105#endif
1106			/*
1107			 * aligns[0] is for 1MB (since bridge memory
1108			 * windows are always at least 1MB aligned), so
1109			 * keep "order" from being negative for smaller
1110			 * resources.
1111			 */
1112			align = pci_resource_alignment(dev, r);
1113			order = __ffs(align) - __ffs(SZ_1M);
1114			if (order < 0)
1115				order = 0;
1116			if (order >= ARRAY_SIZE(aligns)) {
1117				pci_warn(dev, "%s %pR: disabling; bad alignment %#llx\n",
1118					 r_name, r, (unsigned long long) align);
1119				r->flags = 0;
1120				continue;
1121			}
1122			size += max(r_size, align);
1123			/*
1124			 * Exclude ranges with size > align from calculation of
1125			 * the alignment.
1126			 */
1127			if (r_size <= align)
1128				aligns[order] += align;
1129			if (order > max_order)
1130				max_order = order;
1131
1132			if (realloc_head) {
1133				children_add_size += get_res_add_size(realloc_head, r);
1134				children_add_align = get_res_add_align(realloc_head, r);
1135				add_align = max(add_align, children_add_align);
1136			}
1137		}
1138	}
1139
1140	win_align = window_alignment(bus, b_res->flags);
1141	min_align = calculate_mem_align(aligns, max_order);
1142	min_align = max(min_align, win_align);
1143	size0 = calculate_memsize(size, min_size, 0, 0, resource_size(b_res), min_align);
1144	add_align = max(min_align, add_align);
1145
1146	if (bus->self && size0 &&
1147	    !pbus_upstream_space_available(bus, mask | IORESOURCE_PREFETCH, type,
1148					   size0, add_align)) {
1149		min_align = 1ULL << (max_order + __ffs(SZ_1M));
1150		min_align = max(min_align, win_align);
1151		size0 = calculate_memsize(size, min_size, 0, 0, resource_size(b_res), win_align);
1152		add_align = win_align;
1153		pci_info(bus->self, "bridge window %pR to %pR requires relaxed alignment rules\n",
1154			 b_res, &bus->busn_res);
1155	}
1156
1157	size1 = (!realloc_head || (realloc_head && !add_size && !children_add_size)) ? size0 :
1158		calculate_memsize(size, min_size, add_size, children_add_size,
1159				resource_size(b_res), add_align);
1160	if (!size0 && !size1) {
1161		if (bus->self && (b_res->start || b_res->end))
1162			pci_info(bus->self, "disabling bridge window %pR to %pR (unused)\n",
1163				 b_res, &bus->busn_res);
1164		b_res->flags = 0;
1165		return 0;
1166	}
1167	b_res->start = min_align;
1168	b_res->end = size0 + min_align - 1;
1169	b_res->flags |= IORESOURCE_STARTALIGN;
1170	if (bus->self && size1 > size0 && realloc_head) {
1171		add_to_list(realloc_head, bus->self, b_res, size1-size0, add_align);
1172		pci_info(bus->self, "bridge window %pR to %pR add_size %llx add_align %llx\n",
1173			   b_res, &bus->busn_res,
1174			   (unsigned long long) (size1 - size0),
1175			   (unsigned long long) add_align);
1176	}
1177	return 0;
1178}
1179
1180unsigned long pci_cardbus_resource_alignment(struct resource *res)
1181{
1182	if (res->flags & IORESOURCE_IO)
1183		return pci_cardbus_io_size;
1184	if (res->flags & IORESOURCE_MEM)
1185		return pci_cardbus_mem_size;
1186	return 0;
1187}
1188
1189static void pci_bus_size_cardbus(struct pci_bus *bus,
1190				 struct list_head *realloc_head)
1191{
1192	struct pci_dev *bridge = bus->self;
1193	struct resource *b_res;
1194	resource_size_t b_res_3_size = pci_cardbus_mem_size * 2;
1195	u16 ctrl;
1196
1197	b_res = &bridge->resource[PCI_CB_BRIDGE_IO_0_WINDOW];
1198	if (b_res->parent)
1199		goto handle_b_res_1;
1200	/*
1201	 * Reserve some resources for CardBus.  We reserve a fixed amount
1202	 * of bus space for CardBus bridges.
1203	 */
1204	resource_set_range(b_res, pci_cardbus_io_size, pci_cardbus_io_size);
1205	b_res->flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
 
1206	if (realloc_head) {
1207		b_res->end -= pci_cardbus_io_size;
1208		add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size,
1209			    pci_cardbus_io_size);
1210	}
1211
1212handle_b_res_1:
1213	b_res = &bridge->resource[PCI_CB_BRIDGE_IO_1_WINDOW];
1214	if (b_res->parent)
1215		goto handle_b_res_2;
1216	resource_set_range(b_res, pci_cardbus_io_size, pci_cardbus_io_size);
1217	b_res->flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
 
1218	if (realloc_head) {
1219		b_res->end -= pci_cardbus_io_size;
1220		add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size,
1221			    pci_cardbus_io_size);
1222	}
1223
1224handle_b_res_2:
1225	/* MEM1 must not be pref MMIO */
1226	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1227	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM1) {
1228		ctrl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
1229		pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
1230		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1231	}
1232
1233	/* Check whether prefetchable memory is supported by this bridge. */
1234	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1235	if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
1236		ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
1237		pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
1238		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
1239	}
1240
1241	b_res = &bridge->resource[PCI_CB_BRIDGE_MEM_0_WINDOW];
1242	if (b_res->parent)
1243		goto handle_b_res_3;
1244	/*
1245	 * If we have prefetchable memory support, allocate two regions.
1246	 * Otherwise, allocate one region of twice the size.
1247	 */
1248	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
1249		resource_set_range(b_res, pci_cardbus_mem_size,
1250				   pci_cardbus_mem_size);
1251		b_res->flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH |
1252				    IORESOURCE_STARTALIGN;
1253		if (realloc_head) {
1254			b_res->end -= pci_cardbus_mem_size;
1255			add_to_list(realloc_head, bridge, b_res,
1256				    pci_cardbus_mem_size, pci_cardbus_mem_size);
1257		}
1258
1259		/* Reduce that to half */
1260		b_res_3_size = pci_cardbus_mem_size;
1261	}
1262
1263handle_b_res_3:
1264	b_res = &bridge->resource[PCI_CB_BRIDGE_MEM_1_WINDOW];
1265	if (b_res->parent)
1266		goto handle_done;
1267	resource_set_range(b_res, pci_cardbus_mem_size, b_res_3_size);
1268	b_res->flags |= IORESOURCE_MEM | IORESOURCE_STARTALIGN;
 
1269	if (realloc_head) {
1270		b_res->end -= b_res_3_size;
1271		add_to_list(realloc_head, bridge, b_res, b_res_3_size,
1272			    pci_cardbus_mem_size);
1273	}
1274
1275handle_done:
1276	;
1277}
1278
1279void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
1280{
1281	struct pci_dev *dev;
1282	unsigned long mask, prefmask, type2 = 0, type3 = 0;
1283	resource_size_t additional_io_size = 0, additional_mmio_size = 0,
1284			additional_mmio_pref_size = 0;
1285	struct resource *pref;
1286	struct pci_host_bridge *host;
1287	int hdr_type, ret;
1288
1289	list_for_each_entry(dev, &bus->devices, bus_list) {
1290		struct pci_bus *b = dev->subordinate;
1291		if (!b)
1292			continue;
1293
1294		switch (dev->hdr_type) {
1295		case PCI_HEADER_TYPE_CARDBUS:
1296			pci_bus_size_cardbus(b, realloc_head);
1297			break;
1298
1299		case PCI_HEADER_TYPE_BRIDGE:
1300		default:
1301			__pci_bus_size_bridges(b, realloc_head);
1302			break;
1303		}
1304	}
1305
1306	/* The root bus? */
1307	if (pci_is_root_bus(bus)) {
1308		host = to_pci_host_bridge(bus->bridge);
1309		if (!host->size_windows)
1310			return;
1311		pci_bus_for_each_resource(bus, pref)
1312			if (pref && (pref->flags & IORESOURCE_PREFETCH))
1313				break;
1314		hdr_type = -1;	/* Intentionally invalid - not a PCI device. */
1315	} else {
1316		pref = &bus->self->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
1317		hdr_type = bus->self->hdr_type;
1318	}
1319
1320	switch (hdr_type) {
1321	case PCI_HEADER_TYPE_CARDBUS:
1322		/* Don't size CardBuses yet */
1323		break;
1324
1325	case PCI_HEADER_TYPE_BRIDGE:
1326		pci_bridge_check_ranges(bus);
1327		if (bus->self->is_hotplug_bridge) {
1328			additional_io_size  = pci_hotplug_io_size;
1329			additional_mmio_size = pci_hotplug_mmio_size;
1330			additional_mmio_pref_size = pci_hotplug_mmio_pref_size;
1331		}
1332		fallthrough;
1333	default:
1334		pbus_size_io(bus, realloc_head ? 0 : additional_io_size,
1335			     additional_io_size, realloc_head);
1336
1337		/*
1338		 * If there's a 64-bit prefetchable MMIO window, compute
1339		 * the size required to put all 64-bit prefetchable
1340		 * resources in it.
1341		 */
 
1342		mask = IORESOURCE_MEM;
1343		prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
1344		if (pref && (pref->flags & IORESOURCE_MEM_64)) {
1345			prefmask |= IORESOURCE_MEM_64;
1346			ret = pbus_size_mem(bus, prefmask, prefmask,
1347				prefmask, prefmask,
1348				realloc_head ? 0 : additional_mmio_pref_size,
1349				additional_mmio_pref_size, realloc_head);
1350
1351			/*
1352			 * If successful, all non-prefetchable resources
1353			 * and any 32-bit prefetchable resources will go in
1354			 * the non-prefetchable window.
1355			 */
1356			if (ret == 0) {
1357				mask = prefmask;
1358				type2 = prefmask & ~IORESOURCE_MEM_64;
1359				type3 = prefmask & ~IORESOURCE_PREFETCH;
1360			}
1361		}
1362
1363		/*
1364		 * If there is no 64-bit prefetchable window, compute the
1365		 * size required to put all prefetchable resources in the
1366		 * 32-bit prefetchable window (if there is one).
1367		 */
1368		if (!type2) {
1369			prefmask &= ~IORESOURCE_MEM_64;
1370			ret = pbus_size_mem(bus, prefmask, prefmask,
1371				prefmask, prefmask,
1372				realloc_head ? 0 : additional_mmio_pref_size,
1373				additional_mmio_pref_size, realloc_head);
1374
1375			/*
1376			 * If successful, only non-prefetchable resources
1377			 * will go in the non-prefetchable window.
1378			 */
1379			if (ret == 0)
1380				mask = prefmask;
1381			else
1382				additional_mmio_size += additional_mmio_pref_size;
1383
1384			type2 = type3 = IORESOURCE_MEM;
1385		}
1386
1387		/*
1388		 * Compute the size required to put everything else in the
1389		 * non-prefetchable window. This includes:
1390		 *
1391		 *   - all non-prefetchable resources
1392		 *   - 32-bit prefetchable resources if there's a 64-bit
1393		 *     prefetchable window or no prefetchable window at all
1394		 *   - 64-bit prefetchable resources if there's no prefetchable
1395		 *     window at all
1396		 *
1397		 * Note that the strategy in __pci_assign_resource() must match
1398		 * that used here. Specifically, we cannot put a 32-bit
1399		 * prefetchable resource in a 64-bit prefetchable window.
1400		 */
1401		pbus_size_mem(bus, mask, IORESOURCE_MEM, type2, type3,
1402			      realloc_head ? 0 : additional_mmio_size,
1403			      additional_mmio_size, realloc_head);
1404		break;
1405	}
1406}
1407
1408void pci_bus_size_bridges(struct pci_bus *bus)
1409{
1410	__pci_bus_size_bridges(bus, NULL);
1411}
1412EXPORT_SYMBOL(pci_bus_size_bridges);
1413
1414static void assign_fixed_resource_on_bus(struct pci_bus *b, struct resource *r)
1415{
 
1416	struct resource *parent_r;
1417	unsigned long mask = IORESOURCE_IO | IORESOURCE_MEM |
1418			     IORESOURCE_PREFETCH;
1419
1420	pci_bus_for_each_resource(b, parent_r) {
1421		if (!parent_r)
1422			continue;
1423
1424		if ((r->flags & mask) == (parent_r->flags & mask) &&
1425		    resource_contains(parent_r, r))
1426			request_resource(parent_r, r);
1427	}
1428}
1429
1430/*
1431 * Try to assign any resources marked as IORESOURCE_PCI_FIXED, as they are
1432 * skipped by pbus_assign_resources_sorted().
1433 */
1434static void pdev_assign_fixed_resources(struct pci_dev *dev)
1435{
1436	struct resource *r;
1437
1438	pci_dev_for_each_resource(dev, r) {
1439		struct pci_bus *b;
 
1440
1441		if (r->parent || !(r->flags & IORESOURCE_PCI_FIXED) ||
1442		    !(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
1443			continue;
1444
1445		b = dev->bus;
1446		while (b && !r->parent) {
1447			assign_fixed_resource_on_bus(b, r);
1448			b = b->parent;
1449		}
1450	}
1451}
1452
1453void __pci_bus_assign_resources(const struct pci_bus *bus,
1454				struct list_head *realloc_head,
1455				struct list_head *fail_head)
1456{
1457	struct pci_bus *b;
1458	struct pci_dev *dev;
1459
1460	pbus_assign_resources_sorted(bus, realloc_head, fail_head);
1461
1462	list_for_each_entry(dev, &bus->devices, bus_list) {
1463		pdev_assign_fixed_resources(dev);
1464
1465		b = dev->subordinate;
1466		if (!b)
1467			continue;
1468
1469		__pci_bus_assign_resources(b, realloc_head, fail_head);
1470
1471		switch (dev->hdr_type) {
1472		case PCI_HEADER_TYPE_BRIDGE:
1473			if (!pci_is_enabled(dev))
1474				pci_setup_bridge(b);
1475			break;
1476
1477		case PCI_HEADER_TYPE_CARDBUS:
1478			pci_setup_cardbus(b);
1479			break;
1480
1481		default:
1482			pci_info(dev, "not setting up bridge for bus %04x:%02x\n",
1483				 pci_domain_nr(b), b->number);
1484			break;
1485		}
1486	}
1487}
1488
1489void pci_bus_assign_resources(const struct pci_bus *bus)
1490{
1491	__pci_bus_assign_resources(bus, NULL, NULL);
1492}
1493EXPORT_SYMBOL(pci_bus_assign_resources);
1494
1495static void pci_claim_device_resources(struct pci_dev *dev)
1496{
1497	int i;
1498
1499	for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) {
1500		struct resource *r = &dev->resource[i];
1501
1502		if (!r->flags || r->parent)
1503			continue;
1504
1505		pci_claim_resource(dev, i);
1506	}
1507}
1508
1509static void pci_claim_bridge_resources(struct pci_dev *dev)
1510{
1511	int i;
1512
1513	for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
1514		struct resource *r = &dev->resource[i];
1515
1516		if (!r->flags || r->parent)
1517			continue;
1518
1519		pci_claim_bridge_resource(dev, i);
1520	}
1521}
1522
1523static void pci_bus_allocate_dev_resources(struct pci_bus *b)
1524{
1525	struct pci_dev *dev;
1526	struct pci_bus *child;
1527
1528	list_for_each_entry(dev, &b->devices, bus_list) {
1529		pci_claim_device_resources(dev);
1530
1531		child = dev->subordinate;
1532		if (child)
1533			pci_bus_allocate_dev_resources(child);
1534	}
1535}
1536
1537static void pci_bus_allocate_resources(struct pci_bus *b)
1538{
1539	struct pci_bus *child;
1540
1541	/*
1542	 * Carry out a depth-first search on the PCI bus tree to allocate
1543	 * bridge apertures.  Read the programmed bridge bases and
1544	 * recursively claim the respective bridge resources.
1545	 */
1546	if (b->self) {
1547		pci_read_bridge_bases(b);
1548		pci_claim_bridge_resources(b->self);
1549	}
1550
1551	list_for_each_entry(child, &b->children, node)
1552		pci_bus_allocate_resources(child);
1553}
1554
1555void pci_bus_claim_resources(struct pci_bus *b)
1556{
1557	pci_bus_allocate_resources(b);
1558	pci_bus_allocate_dev_resources(b);
1559}
1560EXPORT_SYMBOL(pci_bus_claim_resources);
1561
1562static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
1563					  struct list_head *add_head,
1564					  struct list_head *fail_head)
1565{
1566	struct pci_bus *b;
1567
1568	pdev_assign_resources_sorted((struct pci_dev *)bridge,
1569					 add_head, fail_head);
1570
1571	b = bridge->subordinate;
1572	if (!b)
1573		return;
1574
1575	__pci_bus_assign_resources(b, add_head, fail_head);
1576
1577	switch (bridge->class >> 8) {
1578	case PCI_CLASS_BRIDGE_PCI:
1579		pci_setup_bridge(b);
1580		break;
1581
1582	case PCI_CLASS_BRIDGE_CARDBUS:
1583		pci_setup_cardbus(b);
1584		break;
1585
1586	default:
1587		pci_info(bridge, "not setting up bridge for bus %04x:%02x\n",
1588			 pci_domain_nr(b), b->number);
1589		break;
1590	}
1591}
1592
1593#define PCI_RES_TYPE_MASK \
1594	(IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH |\
1595	 IORESOURCE_MEM_64)
1596
1597static void pci_bridge_release_resources(struct pci_bus *bus,
1598					 unsigned long type)
1599{
1600	struct pci_dev *dev = bus->self;
1601	struct resource *r;
1602	unsigned int old_flags;
1603	struct resource *b_res;
1604	int idx = 1;
1605
1606	b_res = &dev->resource[PCI_BRIDGE_RESOURCES];
1607
1608	/*
1609	 * 1. If IO port assignment fails, release bridge IO port.
1610	 * 2. If non pref MMIO assignment fails, release bridge nonpref MMIO.
1611	 * 3. If 64bit pref MMIO assignment fails, and bridge pref is 64bit,
1612	 *    release bridge pref MMIO.
1613	 * 4. If pref MMIO assignment fails, and bridge pref is 32bit,
1614	 *    release bridge pref MMIO.
1615	 * 5. If pref MMIO assignment fails, and bridge pref is not
1616	 *    assigned, release bridge nonpref MMIO.
1617	 */
1618	if (type & IORESOURCE_IO)
1619		idx = 0;
1620	else if (!(type & IORESOURCE_PREFETCH))
1621		idx = 1;
1622	else if ((type & IORESOURCE_MEM_64) &&
1623		 (b_res[2].flags & IORESOURCE_MEM_64))
1624		idx = 2;
1625	else if (!(b_res[2].flags & IORESOURCE_MEM_64) &&
1626		 (b_res[2].flags & IORESOURCE_PREFETCH))
1627		idx = 2;
1628	else
1629		idx = 1;
1630
1631	r = &b_res[idx];
1632
1633	if (!r->parent)
1634		return;
1635
1636	/* If there are children, release them all */
1637	release_child_resources(r);
1638	if (!release_resource(r)) {
1639		type = old_flags = r->flags & PCI_RES_TYPE_MASK;
1640		pci_info(dev, "resource %d %pR released\n",
1641			 PCI_BRIDGE_RESOURCES + idx, r);
1642		/* Keep the old size */
1643		r->end = resource_size(r) - 1;
1644		r->start = 0;
1645		r->flags = 0;
1646
1647		/* Avoiding touch the one without PREF */
1648		if (type & IORESOURCE_PREFETCH)
1649			type = IORESOURCE_PREFETCH;
1650		__pci_setup_bridge(bus, type);
1651		/* For next child res under same bridge */
1652		r->flags = old_flags;
1653	}
1654}
1655
1656enum release_type {
1657	leaf_only,
1658	whole_subtree,
1659};
1660
1661/*
1662 * Try to release PCI bridge resources from leaf bridge, so we can allocate
1663 * a larger window later.
1664 */
1665static void pci_bus_release_bridge_resources(struct pci_bus *bus,
1666					     unsigned long type,
1667					     enum release_type rel_type)
1668{
1669	struct pci_dev *dev;
1670	bool is_leaf_bridge = true;
1671
1672	list_for_each_entry(dev, &bus->devices, bus_list) {
1673		struct pci_bus *b = dev->subordinate;
1674		if (!b)
1675			continue;
1676
1677		is_leaf_bridge = false;
1678
1679		if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
1680			continue;
1681
1682		if (rel_type == whole_subtree)
1683			pci_bus_release_bridge_resources(b, type,
1684						 whole_subtree);
1685	}
1686
1687	if (pci_is_root_bus(bus))
1688		return;
1689
1690	if ((bus->self->class >> 8) != PCI_CLASS_BRIDGE_PCI)
1691		return;
1692
1693	if ((rel_type == whole_subtree) || is_leaf_bridge)
1694		pci_bridge_release_resources(bus, type);
1695}
1696
1697static void pci_bus_dump_res(struct pci_bus *bus)
1698{
1699	struct resource *res;
1700	int i;
1701
1702	pci_bus_for_each_resource(bus, res, i) {
1703		if (!res || !res->end || !res->flags)
1704			continue;
1705
1706		dev_info(&bus->dev, "resource %d %pR\n", i, res);
1707	}
1708}
1709
1710static void pci_bus_dump_resources(struct pci_bus *bus)
1711{
1712	struct pci_bus *b;
1713	struct pci_dev *dev;
1714
1715
1716	pci_bus_dump_res(bus);
1717
1718	list_for_each_entry(dev, &bus->devices, bus_list) {
1719		b = dev->subordinate;
1720		if (!b)
1721			continue;
1722
1723		pci_bus_dump_resources(b);
1724	}
1725}
1726
1727static int pci_bus_get_depth(struct pci_bus *bus)
1728{
1729	int depth = 0;
1730	struct pci_bus *child_bus;
1731
1732	list_for_each_entry(child_bus, &bus->children, node) {
1733		int ret;
1734
1735		ret = pci_bus_get_depth(child_bus);
1736		if (ret + 1 > depth)
1737			depth = ret + 1;
1738	}
1739
1740	return depth;
1741}
1742
1743/*
1744 * -1: undefined, will auto detect later
1745 *  0: disabled by user
1746 *  1: disabled by auto detect
1747 *  2: enabled by user
1748 *  3: enabled by auto detect
1749 */
1750enum enable_type {
1751	undefined = -1,
1752	user_disabled,
1753	auto_disabled,
1754	user_enabled,
1755	auto_enabled,
1756};
1757
1758static enum enable_type pci_realloc_enable = undefined;
1759void __init pci_realloc_get_opt(char *str)
1760{
1761	if (!strncmp(str, "off", 3))
1762		pci_realloc_enable = user_disabled;
1763	else if (!strncmp(str, "on", 2))
1764		pci_realloc_enable = user_enabled;
1765}
1766static bool pci_realloc_enabled(enum enable_type enable)
1767{
1768	return enable >= user_enabled;
1769}
1770
1771#if defined(CONFIG_PCI_IOV) && defined(CONFIG_PCI_REALLOC_ENABLE_AUTO)
1772static int iov_resources_unassigned(struct pci_dev *dev, void *data)
1773{
1774	int i;
1775	bool *unassigned = data;
1776
1777	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
1778		struct resource *r = &dev->resource[i + PCI_IOV_RESOURCES];
1779		struct pci_bus_region region;
1780
1781		/* Not assigned or rejected by kernel? */
1782		if (!r->flags)
1783			continue;
1784
1785		pcibios_resource_to_bus(dev->bus, &region, r);
1786		if (!region.start) {
1787			*unassigned = true;
1788			return 1; /* Return early from pci_walk_bus() */
1789		}
1790	}
1791
1792	return 0;
1793}
1794
1795static enum enable_type pci_realloc_detect(struct pci_bus *bus,
1796					   enum enable_type enable_local)
1797{
1798	bool unassigned = false;
1799	struct pci_host_bridge *host;
1800
1801	if (enable_local != undefined)
1802		return enable_local;
1803
1804	host = pci_find_host_bridge(bus);
1805	if (host->preserve_config)
1806		return auto_disabled;
1807
1808	pci_walk_bus(bus, iov_resources_unassigned, &unassigned);
1809	if (unassigned)
1810		return auto_enabled;
1811
1812	return enable_local;
1813}
1814#else
1815static enum enable_type pci_realloc_detect(struct pci_bus *bus,
1816					   enum enable_type enable_local)
1817{
1818	return enable_local;
1819}
1820#endif
1821
1822static void adjust_bridge_window(struct pci_dev *bridge, struct resource *res,
1823				 struct list_head *add_list,
1824				 resource_size_t new_size)
1825{
1826	resource_size_t add_size, size = resource_size(res);
1827
1828	if (res->parent)
1829		return;
1830
1831	if (!new_size)
1832		return;
1833
1834	if (new_size > size) {
1835		add_size = new_size - size;
1836		pci_dbg(bridge, "bridge window %pR extended by %pa\n", res,
1837			&add_size);
1838	} else if (new_size < size) {
1839		add_size = size - new_size;
1840		pci_dbg(bridge, "bridge window %pR shrunken by %pa\n", res,
1841			&add_size);
1842	} else {
1843		return;
1844	}
1845
1846	resource_set_size(res, new_size);
1847
1848	/* If the resource is part of the add_list, remove it now */
1849	if (add_list)
1850		remove_from_list(add_list, res);
1851}
1852
1853static void remove_dev_resource(struct resource *avail, struct pci_dev *dev,
1854				struct resource *res)
1855{
1856	resource_size_t size, align, tmp;
1857
1858	size = resource_size(res);
1859	if (!size)
1860		return;
1861
1862	align = pci_resource_alignment(dev, res);
1863	align = align ? ALIGN(avail->start, align) - avail->start : 0;
1864	tmp = align + size;
1865	avail->start = min(avail->start + tmp, avail->end + 1);
1866}
1867
1868static void remove_dev_resources(struct pci_dev *dev, struct resource *io,
1869				 struct resource *mmio,
1870				 struct resource *mmio_pref)
1871{
1872	struct resource *res;
1873
1874	pci_dev_for_each_resource(dev, res) {
1875		if (resource_type(res) == IORESOURCE_IO) {
1876			remove_dev_resource(io, dev, res);
1877		} else if (resource_type(res) == IORESOURCE_MEM) {
1878
1879			/*
1880			 * Make sure prefetchable memory is reduced from
1881			 * the correct resource. Specifically we put 32-bit
1882			 * prefetchable memory in non-prefetchable window
1883			 * if there is an 64-bit prefetchable window.
1884			 *
1885			 * See comments in __pci_bus_size_bridges() for
1886			 * more information.
1887			 */
1888			if ((res->flags & IORESOURCE_PREFETCH) &&
1889			    ((res->flags & IORESOURCE_MEM_64) ==
1890			     (mmio_pref->flags & IORESOURCE_MEM_64)))
1891				remove_dev_resource(mmio_pref, dev, res);
1892			else
1893				remove_dev_resource(mmio, dev, res);
1894		}
1895	}
1896}
1897
1898#define ALIGN_DOWN_IF_NONZERO(addr, align) \
1899			((align) ? ALIGN_DOWN((addr), (align)) : (addr))
1900
1901/*
1902 * io, mmio and mmio_pref contain the total amount of bridge window space
1903 * available. This includes the minimal space needed to cover all the
1904 * existing devices on the bus and the possible extra space that can be
1905 * shared with the bridges.
1906 */
1907static void pci_bus_distribute_available_resources(struct pci_bus *bus,
1908					    struct list_head *add_list,
1909					    struct resource io,
1910					    struct resource mmio,
1911					    struct resource mmio_pref)
1912{
1913	unsigned int normal_bridges = 0, hotplug_bridges = 0;
1914	struct resource *io_res, *mmio_res, *mmio_pref_res;
1915	struct pci_dev *dev, *bridge = bus->self;
1916	resource_size_t io_per_b, mmio_per_b, mmio_pref_per_b, align;
1917
1918	io_res = &bridge->resource[PCI_BRIDGE_IO_WINDOW];
1919	mmio_res = &bridge->resource[PCI_BRIDGE_MEM_WINDOW];
1920	mmio_pref_res = &bridge->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
1921
1922	/*
1923	 * The alignment of this bridge is yet to be considered, hence it must
1924	 * be done now before extending its bridge window.
1925	 */
1926	align = pci_resource_alignment(bridge, io_res);
1927	if (!io_res->parent && align)
1928		io.start = min(ALIGN(io.start, align), io.end + 1);
1929
1930	align = pci_resource_alignment(bridge, mmio_res);
1931	if (!mmio_res->parent && align)
1932		mmio.start = min(ALIGN(mmio.start, align), mmio.end + 1);
1933
1934	align = pci_resource_alignment(bridge, mmio_pref_res);
1935	if (!mmio_pref_res->parent && align)
1936		mmio_pref.start = min(ALIGN(mmio_pref.start, align),
1937			mmio_pref.end + 1);
1938
1939	/*
1940	 * Now that we have adjusted for alignment, update the bridge window
1941	 * resources to fill as much remaining resource space as possible.
1942	 */
1943	adjust_bridge_window(bridge, io_res, add_list, resource_size(&io));
1944	adjust_bridge_window(bridge, mmio_res, add_list, resource_size(&mmio));
1945	adjust_bridge_window(bridge, mmio_pref_res, add_list,
1946			     resource_size(&mmio_pref));
1947
1948	/*
1949	 * Calculate how many hotplug bridges and normal bridges there
1950	 * are on this bus.  We will distribute the additional available
1951	 * resources between hotplug bridges.
1952	 */
1953	for_each_pci_bridge(dev, bus) {
1954		if (dev->is_hotplug_bridge)
1955			hotplug_bridges++;
1956		else
1957			normal_bridges++;
1958	}
1959
1960	if (!(hotplug_bridges + normal_bridges))
1961		return;
1962
1963	/*
1964	 * Calculate the amount of space we can forward from "bus" to any
1965	 * downstream buses, i.e., the space left over after assigning the
1966	 * BARs and windows on "bus".
1967	 */
1968	list_for_each_entry(dev, &bus->devices, bus_list) {
1969		if (!dev->is_virtfn)
1970			remove_dev_resources(dev, &io, &mmio, &mmio_pref);
1971	}
1972
1973	/*
1974	 * If there is at least one hotplug bridge on this bus it gets all
1975	 * the extra resource space that was left after the reductions
1976	 * above.
1977	 *
1978	 * If there are no hotplug bridges the extra resource space is
1979	 * split between non-hotplug bridges. This is to allow possible
1980	 * hotplug bridges below them to get the extra space as well.
1981	 */
1982	if (hotplug_bridges) {
1983		io_per_b = div64_ul(resource_size(&io), hotplug_bridges);
1984		mmio_per_b = div64_ul(resource_size(&mmio), hotplug_bridges);
1985		mmio_pref_per_b = div64_ul(resource_size(&mmio_pref),
1986					   hotplug_bridges);
1987	} else {
1988		io_per_b = div64_ul(resource_size(&io), normal_bridges);
1989		mmio_per_b = div64_ul(resource_size(&mmio), normal_bridges);
1990		mmio_pref_per_b = div64_ul(resource_size(&mmio_pref),
1991					   normal_bridges);
1992	}
1993
1994	for_each_pci_bridge(dev, bus) {
1995		struct resource *res;
1996		struct pci_bus *b;
1997
1998		b = dev->subordinate;
1999		if (!b)
2000			continue;
2001		if (hotplug_bridges && !dev->is_hotplug_bridge)
2002			continue;
2003
2004		res = &dev->resource[PCI_BRIDGE_IO_WINDOW];
2005
2006		/*
2007		 * Make sure the split resource space is properly aligned
2008		 * for bridge windows (align it down to avoid going above
2009		 * what is available).
2010		 */
2011		align = pci_resource_alignment(dev, res);
2012		resource_set_size(&io, ALIGN_DOWN_IF_NONZERO(io_per_b, align));
2013
2014		/*
2015		 * The x_per_b holds the extra resource space that can be
2016		 * added for each bridge but there is the minimal already
2017		 * reserved as well so adjust x.start down accordingly to
2018		 * cover the whole space.
2019		 */
2020		io.start -= resource_size(res);
2021
2022		res = &dev->resource[PCI_BRIDGE_MEM_WINDOW];
2023		align = pci_resource_alignment(dev, res);
2024		resource_set_size(&mmio,
2025				  ALIGN_DOWN_IF_NONZERO(mmio_per_b,align));
2026		mmio.start -= resource_size(res);
2027
2028		res = &dev->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
2029		align = pci_resource_alignment(dev, res);
2030		resource_set_size(&mmio_pref,
2031				  ALIGN_DOWN_IF_NONZERO(mmio_pref_per_b, align));
2032		mmio_pref.start -= resource_size(res);
2033
2034		pci_bus_distribute_available_resources(b, add_list, io, mmio,
2035						       mmio_pref);
2036
2037		io.start += io.end + 1;
2038		mmio.start += mmio.end + 1;
2039		mmio_pref.start += mmio_pref.end + 1;
2040	}
2041}
2042
2043static void pci_bridge_distribute_available_resources(struct pci_dev *bridge,
2044						      struct list_head *add_list)
2045{
2046	struct resource available_io, available_mmio, available_mmio_pref;
2047
2048	if (!bridge->is_hotplug_bridge)
2049		return;
2050
2051	pci_dbg(bridge, "distributing available resources\n");
2052
2053	/* Take the initial extra resources from the hotplug port */
2054	available_io = bridge->resource[PCI_BRIDGE_IO_WINDOW];
2055	available_mmio = bridge->resource[PCI_BRIDGE_MEM_WINDOW];
2056	available_mmio_pref = bridge->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
2057
2058	pci_bus_distribute_available_resources(bridge->subordinate,
2059					       add_list, available_io,
2060					       available_mmio,
2061					       available_mmio_pref);
2062}
2063
2064static bool pci_bridge_resources_not_assigned(struct pci_dev *dev)
2065{
2066	const struct resource *r;
2067
2068	/*
2069	 * If the child device's resources are not yet assigned it means we
2070	 * are configuring them (not the boot firmware), so we should be
2071	 * able to extend the upstream bridge resources in the same way we
2072	 * do with the normal hotplug case.
2073	 */
2074	r = &dev->resource[PCI_BRIDGE_IO_WINDOW];
2075	if (r->flags && !(r->flags & IORESOURCE_STARTALIGN))
2076		return false;
2077	r = &dev->resource[PCI_BRIDGE_MEM_WINDOW];
2078	if (r->flags && !(r->flags & IORESOURCE_STARTALIGN))
2079		return false;
2080	r = &dev->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
2081	if (r->flags && !(r->flags & IORESOURCE_STARTALIGN))
2082		return false;
2083
2084	return true;
2085}
2086
2087static void
2088pci_root_bus_distribute_available_resources(struct pci_bus *bus,
2089					    struct list_head *add_list)
2090{
2091	struct pci_dev *dev, *bridge = bus->self;
2092
2093	for_each_pci_bridge(dev, bus) {
2094		struct pci_bus *b;
2095
2096		b = dev->subordinate;
2097		if (!b)
2098			continue;
2099
2100		/*
2101		 * Need to check "bridge" here too because it is NULL
2102		 * in case of root bus.
2103		 */
2104		if (bridge && pci_bridge_resources_not_assigned(dev))
2105			pci_bridge_distribute_available_resources(bridge,
2106								  add_list);
2107		else
2108			pci_root_bus_distribute_available_resources(b, add_list);
2109	}
2110}
2111
2112/*
2113 * First try will not touch PCI bridge res.
2114 * Second and later try will clear small leaf bridge res.
2115 * Will stop till to the max depth if can not find good one.
2116 */
2117void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
2118{
2119	LIST_HEAD(realloc_head);
2120	/* List of resources that want additional resources */
2121	struct list_head *add_list = NULL;
2122	int tried_times = 0;
2123	enum release_type rel_type = leaf_only;
2124	LIST_HEAD(fail_head);
2125	struct pci_dev_resource *fail_res;
2126	int pci_try_num = 1;
2127	enum enable_type enable_local;
2128
2129	/* Don't realloc if asked to do so */
2130	enable_local = pci_realloc_detect(bus, pci_realloc_enable);
2131	if (pci_realloc_enabled(enable_local)) {
2132		int max_depth = pci_bus_get_depth(bus);
2133
2134		pci_try_num = max_depth + 1;
2135		dev_info(&bus->dev, "max bus depth: %d pci_try_num: %d\n",
2136			 max_depth, pci_try_num);
2137	}
2138
2139again:
2140	/*
2141	 * Last try will use add_list, otherwise will try good to have as must
2142	 * have, so can realloc parent bridge resource
2143	 */
2144	if (tried_times + 1 == pci_try_num)
2145		add_list = &realloc_head;
2146	/*
2147	 * Depth first, calculate sizes and alignments of all subordinate buses.
2148	 */
2149	__pci_bus_size_bridges(bus, add_list);
2150
2151	pci_root_bus_distribute_available_resources(bus, add_list);
2152
2153	/* Depth last, allocate resources and update the hardware. */
2154	__pci_bus_assign_resources(bus, add_list, &fail_head);
2155	if (add_list)
2156		BUG_ON(!list_empty(add_list));
2157	tried_times++;
2158
2159	/* Any device complain? */
2160	if (list_empty(&fail_head))
2161		goto dump;
2162
2163	if (tried_times >= pci_try_num) {
2164		if (enable_local == undefined)
2165			dev_info(&bus->dev, "Some PCI device resources are unassigned, try booting with pci=realloc\n");
2166		else if (enable_local == auto_enabled)
2167			dev_info(&bus->dev, "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
2168
2169		free_list(&fail_head);
2170		goto dump;
2171	}
2172
2173	dev_info(&bus->dev, "No. %d try to assign unassigned res\n",
2174		 tried_times + 1);
2175
2176	/* Third times and later will not check if it is leaf */
2177	if ((tried_times + 1) > 2)
2178		rel_type = whole_subtree;
2179
2180	/*
2181	 * Try to release leaf bridge's resources that doesn't fit resource of
2182	 * child device under that bridge.
2183	 */
2184	list_for_each_entry(fail_res, &fail_head, list)
2185		pci_bus_release_bridge_resources(fail_res->dev->bus,
2186						 fail_res->flags & PCI_RES_TYPE_MASK,
2187						 rel_type);
2188
2189	/* Restore size and flags */
2190	list_for_each_entry(fail_res, &fail_head, list) {
2191		struct resource *res = fail_res->res;
2192		int idx;
2193
2194		res->start = fail_res->start;
2195		res->end = fail_res->end;
2196		res->flags = fail_res->flags;
2197
2198		if (pci_is_bridge(fail_res->dev)) {
2199			idx = res - &fail_res->dev->resource[0];
2200			if (idx >= PCI_BRIDGE_RESOURCES &&
2201			    idx <= PCI_BRIDGE_RESOURCE_END)
2202				res->flags = 0;
2203		}
2204	}
2205	free_list(&fail_head);
2206
2207	goto again;
2208
2209dump:
2210	/* Dump the resource on buses */
2211	pci_bus_dump_resources(bus);
2212}
2213
2214void pci_assign_unassigned_resources(void)
2215{
2216	struct pci_bus *root_bus;
2217
2218	list_for_each_entry(root_bus, &pci_root_buses, node) {
2219		pci_assign_unassigned_root_bus_resources(root_bus);
2220
2221		/* Make sure the root bridge has a companion ACPI device */
2222		if (ACPI_HANDLE(root_bus->bridge))
2223			acpi_ioapic_add(ACPI_HANDLE(root_bus->bridge));
2224	}
2225}
2226
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2227void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
2228{
2229	struct pci_bus *parent = bridge->subordinate;
2230	/* List of resources that want additional resources */
2231	LIST_HEAD(add_list);
2232
2233	int tried_times = 0;
2234	LIST_HEAD(fail_head);
2235	struct pci_dev_resource *fail_res;
2236	int retval;
2237
2238again:
2239	__pci_bus_size_bridges(parent, &add_list);
2240
2241	/*
2242	 * Distribute remaining resources (if any) equally between hotplug
2243	 * bridges below.  This makes it possible to extend the hierarchy
2244	 * later without running out of resources.
2245	 */
2246	pci_bridge_distribute_available_resources(bridge, &add_list);
2247
2248	__pci_bridge_assign_resources(bridge, &add_list, &fail_head);
2249	BUG_ON(!list_empty(&add_list));
2250	tried_times++;
2251
2252	if (list_empty(&fail_head))
2253		goto enable_all;
2254
2255	if (tried_times >= 2) {
2256		/* Still fail, don't need to try more */
2257		free_list(&fail_head);
2258		goto enable_all;
2259	}
2260
2261	printk(KERN_DEBUG "PCI: No. %d try to assign unassigned res\n",
2262			 tried_times + 1);
2263
2264	/*
2265	 * Try to release leaf bridge's resources that aren't big enough
2266	 * to contain child device resources.
2267	 */
2268	list_for_each_entry(fail_res, &fail_head, list)
2269		pci_bus_release_bridge_resources(fail_res->dev->bus,
2270						 fail_res->flags & PCI_RES_TYPE_MASK,
2271						 whole_subtree);
2272
2273	/* Restore size and flags */
2274	list_for_each_entry(fail_res, &fail_head, list) {
2275		struct resource *res = fail_res->res;
2276		int idx;
2277
2278		res->start = fail_res->start;
2279		res->end = fail_res->end;
2280		res->flags = fail_res->flags;
2281
2282		if (pci_is_bridge(fail_res->dev)) {
2283			idx = res - &fail_res->dev->resource[0];
2284			if (idx >= PCI_BRIDGE_RESOURCES &&
2285			    idx <= PCI_BRIDGE_RESOURCE_END)
2286				res->flags = 0;
2287		}
2288	}
2289	free_list(&fail_head);
2290
2291	goto again;
2292
2293enable_all:
2294	retval = pci_reenable_device(bridge);
2295	if (retval)
2296		pci_err(bridge, "Error reenabling bridge (%d)\n", retval);
2297	pci_set_master(bridge);
2298}
2299EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
2300
2301int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type)
2302{
2303	struct pci_dev_resource *dev_res;
2304	struct pci_dev *next;
2305	LIST_HEAD(saved);
2306	LIST_HEAD(added);
2307	LIST_HEAD(failed);
2308	unsigned int i;
2309	int ret;
2310
2311	down_read(&pci_bus_sem);
2312
2313	/* Walk to the root hub, releasing bridge BARs when possible */
2314	next = bridge;
2315	do {
2316		bridge = next;
2317		for (i = PCI_BRIDGE_RESOURCES; i < PCI_BRIDGE_RESOURCE_END;
2318		     i++) {
2319			struct resource *res = &bridge->resource[i];
2320			const char *res_name = pci_resource_name(bridge, i);
2321
2322			if ((res->flags ^ type) & PCI_RES_TYPE_MASK)
2323				continue;
2324
2325			/* Ignore BARs which are still in use */
2326			if (res->child)
2327				continue;
2328
2329			ret = add_to_list(&saved, bridge, res, 0, 0);
2330			if (ret)
2331				goto cleanup;
2332
2333			pci_info(bridge, "%s %pR: releasing\n", res_name, res);
 
2334
2335			if (res->parent)
2336				release_resource(res);
2337			res->start = 0;
2338			res->end = 0;
2339			break;
2340		}
2341		if (i == PCI_BRIDGE_RESOURCE_END)
2342			break;
2343
2344		next = bridge->bus ? bridge->bus->self : NULL;
2345	} while (next);
2346
2347	if (list_empty(&saved)) {
2348		up_read(&pci_bus_sem);
2349		return -ENOENT;
2350	}
2351
2352	__pci_bus_size_bridges(bridge->subordinate, &added);
2353	__pci_bridge_assign_resources(bridge, &added, &failed);
2354	BUG_ON(!list_empty(&added));
2355
2356	if (!list_empty(&failed)) {
2357		ret = -ENOSPC;
2358		goto cleanup;
2359	}
2360
2361	list_for_each_entry(dev_res, &saved, list) {
2362		/* Skip the bridge we just assigned resources for */
2363		if (bridge == dev_res->dev)
2364			continue;
2365
2366		bridge = dev_res->dev;
2367		pci_setup_bridge(bridge->subordinate);
2368	}
2369
2370	free_list(&saved);
2371	up_read(&pci_bus_sem);
2372	return 0;
2373
2374cleanup:
2375	/* Restore size and flags */
2376	list_for_each_entry(dev_res, &failed, list) {
2377		struct resource *res = dev_res->res;
2378
2379		res->start = dev_res->start;
2380		res->end = dev_res->end;
2381		res->flags = dev_res->flags;
2382	}
2383	free_list(&failed);
2384
2385	/* Revert to the old configuration */
2386	list_for_each_entry(dev_res, &saved, list) {
2387		struct resource *res = dev_res->res;
2388
2389		bridge = dev_res->dev;
2390		i = res - bridge->resource;
2391
2392		res->start = dev_res->start;
2393		res->end = dev_res->end;
2394		res->flags = dev_res->flags;
2395
2396		pci_claim_resource(bridge, i);
2397		pci_setup_bridge(bridge->subordinate);
2398	}
2399	free_list(&saved);
2400	up_read(&pci_bus_sem);
2401
2402	return ret;
2403}
2404
2405void pci_assign_unassigned_bus_resources(struct pci_bus *bus)
2406{
2407	struct pci_dev *dev;
2408	/* List of resources that want additional resources */
2409	LIST_HEAD(add_list);
2410
2411	down_read(&pci_bus_sem);
2412	for_each_pci_bridge(dev, bus)
2413		if (pci_has_subordinate(dev))
2414			__pci_bus_size_bridges(dev->subordinate, &add_list);
2415	up_read(&pci_bus_sem);
2416	__pci_bus_assign_resources(bus, &add_list, NULL);
2417	BUG_ON(!list_empty(&add_list));
2418}
2419EXPORT_SYMBOL_GPL(pci_assign_unassigned_bus_resources);