Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / pci / setup-bus.c
diff --git a/kernel/drivers/pci/setup-bus.c b/kernel/drivers/pci/setup-bus.c
new file mode 100644 (file)
index 0000000..508cc56
--- /dev/null
@@ -0,0 +1,1819 @@
+/*
+ *     drivers/pci/setup-bus.c
+ *
+ * Extruded from code written by
+ *      Dave Rusling (david.rusling@reo.mts.dec.com)
+ *      David Mosberger (davidm@cs.arizona.edu)
+ *     David Miller (davem@redhat.com)
+ *
+ * Support routines for initializing a PCI subsystem.
+ */
+
+/*
+ * Nov 2000, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
+ *          PCI-PCI bridges cleanup, sorted resource allocation.
+ * Feb 2002, Ivan Kokshaysky <ink@jurassic.park.msu.ru>
+ *          Converted to allocation in 3 passes, which gives
+ *          tighter packing. Prefetchable range support.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+#include <linux/cache.h>
+#include <linux/slab.h>
+#include <asm-generic/pci-bridge.h>
+#include "pci.h"
+
+unsigned int pci_flags;
+
+struct pci_dev_resource {
+       struct list_head list;
+       struct resource *res;
+       struct pci_dev *dev;
+       resource_size_t start;
+       resource_size_t end;
+       resource_size_t add_size;
+       resource_size_t min_align;
+       unsigned long flags;
+};
+
+static void free_list(struct list_head *head)
+{
+       struct pci_dev_resource *dev_res, *tmp;
+
+       list_for_each_entry_safe(dev_res, tmp, head, list) {
+               list_del(&dev_res->list);
+               kfree(dev_res);
+       }
+}
+
+/**
+ * add_to_list() - add a new resource tracker to the list
+ * @head:      Head of the list
+ * @dev:       device corresponding to which the resource
+ *             belongs
+ * @res:       The resource to be tracked
+ * @add_size:  additional size to be optionally added
+ *              to the resource
+ */
+static int add_to_list(struct list_head *head,
+                struct pci_dev *dev, struct resource *res,
+                resource_size_t add_size, resource_size_t min_align)
+{
+       struct pci_dev_resource *tmp;
+
+       tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
+       if (!tmp) {
+               pr_warn("add_to_list: kmalloc() failed!\n");
+               return -ENOMEM;
+       }
+
+       tmp->res = res;
+       tmp->dev = dev;
+       tmp->start = res->start;
+       tmp->end = res->end;
+       tmp->flags = res->flags;
+       tmp->add_size = add_size;
+       tmp->min_align = min_align;
+
+       list_add(&tmp->list, head);
+
+       return 0;
+}
+
+static void remove_from_list(struct list_head *head,
+                                struct resource *res)
+{
+       struct pci_dev_resource *dev_res, *tmp;
+
+       list_for_each_entry_safe(dev_res, tmp, head, list) {
+               if (dev_res->res == res) {
+                       list_del(&dev_res->list);
+                       kfree(dev_res);
+                       break;
+               }
+       }
+}
+
+static struct pci_dev_resource *res_to_dev_res(struct list_head *head,
+                                              struct resource *res)
+{
+       struct pci_dev_resource *dev_res;
+
+       list_for_each_entry(dev_res, head, list) {
+               if (dev_res->res == res) {
+                       int idx = res - &dev_res->dev->resource[0];
+
+                       dev_printk(KERN_DEBUG, &dev_res->dev->dev,
+                                "res[%d]=%pR res_to_dev_res add_size %llx min_align %llx\n",
+                                idx, dev_res->res,
+                                (unsigned long long)dev_res->add_size,
+                                (unsigned long long)dev_res->min_align);
+
+                       return dev_res;
+               }
+       }
+
+       return NULL;
+}
+
+static resource_size_t get_res_add_size(struct list_head *head,
+                                       struct resource *res)
+{
+       struct pci_dev_resource *dev_res;
+
+       dev_res = res_to_dev_res(head, res);
+       return dev_res ? dev_res->add_size : 0;
+}
+
+static resource_size_t get_res_add_align(struct list_head *head,
+                                        struct resource *res)
+{
+       struct pci_dev_resource *dev_res;
+
+       dev_res = res_to_dev_res(head, res);
+       return dev_res ? dev_res->min_align : 0;
+}
+
+
+/* Sort resources by alignment */
+static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
+{
+       int i;
+
+       for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+               struct resource *r;
+               struct pci_dev_resource *dev_res, *tmp;
+               resource_size_t r_align;
+               struct list_head *n;
+
+               r = &dev->resource[i];
+
+               if (r->flags & IORESOURCE_PCI_FIXED)
+                       continue;
+
+               if (!(r->flags) || r->parent)
+                       continue;
+
+               r_align = pci_resource_alignment(dev, r);
+               if (!r_align) {
+                       dev_warn(&dev->dev, "BAR %d: %pR has bogus alignment\n",
+                                i, r);
+                       continue;
+               }
+
+               tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
+               if (!tmp)
+                       panic("pdev_sort_resources(): kmalloc() failed!\n");
+               tmp->res = r;
+               tmp->dev = dev;
+
+               /* fallback is smallest one or list is empty*/
+               n = head;
+               list_for_each_entry(dev_res, head, list) {
+                       resource_size_t align;
+
+                       align = pci_resource_alignment(dev_res->dev,
+                                                        dev_res->res);
+
+                       if (r_align > align) {
+                               n = &dev_res->list;
+                               break;
+                       }
+               }
+               /* Insert it just before n*/
+               list_add_tail(&tmp->list, n);
+       }
+}
+
+static void __dev_sort_resources(struct pci_dev *dev,
+                                struct list_head *head)
+{
+       u16 class = dev->class >> 8;
+
+       /* Don't touch classless devices or host bridges or ioapics.  */
+       if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)
+               return;
+
+       /* Don't touch ioapic devices already enabled by firmware */
+       if (class == PCI_CLASS_SYSTEM_PIC) {
+               u16 command;
+               pci_read_config_word(dev, PCI_COMMAND, &command);
+               if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))
+                       return;
+       }
+
+       pdev_sort_resources(dev, head);
+}
+
+static inline void reset_resource(struct resource *res)
+{
+       res->start = 0;
+       res->end = 0;
+       res->flags = 0;
+}
+
+/**
+ * reassign_resources_sorted() - satisfy any additional resource requests
+ *
+ * @realloc_head : head of the list tracking requests requiring additional
+ *             resources
+ * @head     : head of the list tracking requests with allocated
+ *             resources
+ *
+ * Walk through each element of the realloc_head and try to procure
+ * additional resources for the element, provided the element
+ * is in the head list.
+ */
+static void reassign_resources_sorted(struct list_head *realloc_head,
+               struct list_head *head)
+{
+       struct resource *res;
+       struct pci_dev_resource *add_res, *tmp;
+       struct pci_dev_resource *dev_res;
+       resource_size_t add_size, align;
+       int idx;
+
+       list_for_each_entry_safe(add_res, tmp, realloc_head, list) {
+               bool found_match = false;
+
+               res = add_res->res;
+               /* skip resource that has been reset */
+               if (!res->flags)
+                       goto out;
+
+               /* skip this resource if not found in head list */
+               list_for_each_entry(dev_res, head, list) {
+                       if (dev_res->res == res) {
+                               found_match = true;
+                               break;
+                       }
+               }
+               if (!found_match)/* just skip */
+                       continue;
+
+               idx = res - &add_res->dev->resource[0];
+               add_size = add_res->add_size;
+               align = add_res->min_align;
+               if (!resource_size(res)) {
+                       res->start = align;
+                       res->end = res->start + add_size - 1;
+                       if (pci_assign_resource(add_res->dev, idx))
+                               reset_resource(res);
+               } else {
+                       res->flags |= add_res->flags &
+                                (IORESOURCE_STARTALIGN|IORESOURCE_SIZEALIGN);
+                       if (pci_reassign_resource(add_res->dev, idx,
+                                                 add_size, align))
+                               dev_printk(KERN_DEBUG, &add_res->dev->dev,
+                                          "failed to add %llx res[%d]=%pR\n",
+                                          (unsigned long long)add_size,
+                                          idx, res);
+               }
+out:
+               list_del(&add_res->list);
+               kfree(add_res);
+       }
+}
+
+/**
+ * assign_requested_resources_sorted() - satisfy resource requests
+ *
+ * @head : head of the list tracking requests for resources
+ * @fail_head : head of the list tracking requests that could
+ *             not be allocated
+ *
+ * Satisfy resource requests of each element in the list. Add
+ * requests that could not satisfied to the failed_list.
+ */
+static void assign_requested_resources_sorted(struct list_head *head,
+                                struct list_head *fail_head)
+{
+       struct resource *res;
+       struct pci_dev_resource *dev_res;
+       int idx;
+
+       list_for_each_entry(dev_res, head, list) {
+               res = dev_res->res;
+               idx = res - &dev_res->dev->resource[0];
+               if (resource_size(res) &&
+                   pci_assign_resource(dev_res->dev, idx)) {
+                       if (fail_head) {
+                               /*
+                                * if the failed res is for ROM BAR, and it will
+                                * be enabled later, don't add it to the list
+                                */
+                               if (!((idx == PCI_ROM_RESOURCE) &&
+                                     (!(res->flags & IORESOURCE_ROM_ENABLE))))
+                                       add_to_list(fail_head,
+                                                   dev_res->dev, res,
+                                                   0 /* don't care */,
+                                                   0 /* don't care */);
+                       }
+                       reset_resource(res);
+               }
+       }
+}
+
+static unsigned long pci_fail_res_type_mask(struct list_head *fail_head)
+{
+       struct pci_dev_resource *fail_res;
+       unsigned long mask = 0;
+
+       /* check failed type */
+       list_for_each_entry(fail_res, fail_head, list)
+               mask |= fail_res->flags;
+
+       /*
+        * one pref failed resource will set IORESOURCE_MEM,
+        * as we can allocate pref in non-pref range.
+        * Will release all assigned non-pref sibling resources
+        * according to that bit.
+        */
+       return mask & (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH);
+}
+
+static bool pci_need_to_release(unsigned long mask, struct resource *res)
+{
+       if (res->flags & IORESOURCE_IO)
+               return !!(mask & IORESOURCE_IO);
+
+       /* check pref at first */
+       if (res->flags & IORESOURCE_PREFETCH) {
+               if (mask & IORESOURCE_PREFETCH)
+                       return true;
+               /* count pref if its parent is non-pref */
+               else if ((mask & IORESOURCE_MEM) &&
+                        !(res->parent->flags & IORESOURCE_PREFETCH))
+                       return true;
+               else
+                       return false;
+       }
+
+       if (res->flags & IORESOURCE_MEM)
+               return !!(mask & IORESOURCE_MEM);
+
+       return false;   /* should not get here */
+}
+
+static void __assign_resources_sorted(struct list_head *head,
+                                struct list_head *realloc_head,
+                                struct list_head *fail_head)
+{
+       /*
+        * Should not assign requested resources at first.
+        *   they could be adjacent, so later reassign can not reallocate
+        *   them one by one in parent resource window.
+        * Try to assign requested + add_size at beginning
+        *  if could do that, could get out early.
+        *  if could not do that, we still try to assign requested at first,
+        *    then try to reassign add_size for some resources.
+        *
+        * Separate three resource type checking if we need to release
+        * assigned resource after requested + add_size try.
+        *      1. if there is io port assign fail, will release assigned
+        *         io port.
+        *      2. if there is pref mmio assign fail, release assigned
+        *         pref mmio.
+        *         if assigned pref mmio's parent is non-pref mmio and there
+        *         is non-pref mmio assign fail, will release that assigned
+        *         pref mmio.
+        *      3. if there is non-pref mmio assign fail or pref mmio
+        *         assigned fail, will release assigned non-pref mmio.
+        */
+       LIST_HEAD(save_head);
+       LIST_HEAD(local_fail_head);
+       struct pci_dev_resource *save_res;
+       struct pci_dev_resource *dev_res, *tmp_res, *dev_res2;
+       unsigned long fail_type;
+       resource_size_t add_align, align;
+
+       /* Check if optional add_size is there */
+       if (!realloc_head || list_empty(realloc_head))
+               goto requested_and_reassign;
+
+       /* Save original start, end, flags etc at first */
+       list_for_each_entry(dev_res, head, list) {
+               if (add_to_list(&save_head, dev_res->dev, dev_res->res, 0, 0)) {
+                       free_list(&save_head);
+                       goto requested_and_reassign;
+               }
+       }
+
+       /* Update res in head list with add_size in realloc_head list */
+       list_for_each_entry_safe(dev_res, tmp_res, head, list) {
+               dev_res->res->end += get_res_add_size(realloc_head,
+                                                       dev_res->res);
+
+               /*
+                * There are two kinds of additional resources in the list:
+                * 1. bridge resource  -- IORESOURCE_STARTALIGN
+                * 2. SR-IOV resource   -- IORESOURCE_SIZEALIGN
+                * Here just fix the additional alignment for bridge
+                */
+               if (!(dev_res->res->flags & IORESOURCE_STARTALIGN))
+                       continue;
+
+               add_align = get_res_add_align(realloc_head, dev_res->res);
+
+               /*
+                * The "head" list is sorted by the alignment to make sure
+                * resources with bigger alignment will be assigned first.
+                * After we change the alignment of a dev_res in "head" list,
+                * we need to reorder the list by alignment to make it
+                * consistent.
+                */
+               if (add_align > dev_res->res->start) {
+                       resource_size_t r_size = resource_size(dev_res->res);
+
+                       dev_res->res->start = add_align;
+                       dev_res->res->end = add_align + r_size - 1;
+
+                       list_for_each_entry(dev_res2, head, list) {
+                               align = pci_resource_alignment(dev_res2->dev,
+                                                              dev_res2->res);
+                               if (add_align > align) {
+                                       list_move_tail(&dev_res->list,
+                                                      &dev_res2->list);
+                                       break;
+                               }
+                       }
+               }
+
+       }
+
+       /* Try updated head list with add_size added */
+       assign_requested_resources_sorted(head, &local_fail_head);
+
+       /* all assigned with add_size ? */
+       if (list_empty(&local_fail_head)) {
+               /* Remove head list from realloc_head list */
+               list_for_each_entry(dev_res, head, list)
+                       remove_from_list(realloc_head, dev_res->res);
+               free_list(&save_head);
+               free_list(head);
+               return;
+       }
+
+       /* check failed type */
+       fail_type = pci_fail_res_type_mask(&local_fail_head);
+       /* remove not need to be released assigned res from head list etc */
+       list_for_each_entry_safe(dev_res, tmp_res, head, list)
+               if (dev_res->res->parent &&
+                   !pci_need_to_release(fail_type, dev_res->res)) {
+                       /* remove it from realloc_head list */
+                       remove_from_list(realloc_head, dev_res->res);
+                       remove_from_list(&save_head, dev_res->res);
+                       list_del(&dev_res->list);
+                       kfree(dev_res);
+               }
+
+       free_list(&local_fail_head);
+       /* Release assigned resource */
+       list_for_each_entry(dev_res, head, list)
+               if (dev_res->res->parent)
+                       release_resource(dev_res->res);
+       /* Restore start/end/flags from saved list */
+       list_for_each_entry(save_res, &save_head, list) {
+               struct resource *res = save_res->res;
+
+               res->start = save_res->start;
+               res->end = save_res->end;
+               res->flags = save_res->flags;
+       }
+       free_list(&save_head);
+
+requested_and_reassign:
+       /* Satisfy the must-have resource requests */
+       assign_requested_resources_sorted(head, fail_head);
+
+       /* Try to satisfy any additional optional resource
+               requests */
+       if (realloc_head)
+               reassign_resources_sorted(realloc_head, head);
+       free_list(head);
+}
+
+static void pdev_assign_resources_sorted(struct pci_dev *dev,
+                                struct list_head *add_head,
+                                struct list_head *fail_head)
+{
+       LIST_HEAD(head);
+
+       __dev_sort_resources(dev, &head);
+       __assign_resources_sorted(&head, add_head, fail_head);
+
+}
+
+static void pbus_assign_resources_sorted(const struct pci_bus *bus,
+                                        struct list_head *realloc_head,
+                                        struct list_head *fail_head)
+{
+       struct pci_dev *dev;
+       LIST_HEAD(head);
+
+       list_for_each_entry(dev, &bus->devices, bus_list)
+               __dev_sort_resources(dev, &head);
+
+       __assign_resources_sorted(&head, realloc_head, fail_head);
+}
+
+void pci_setup_cardbus(struct pci_bus *bus)
+{
+       struct pci_dev *bridge = bus->self;
+       struct resource *res;
+       struct pci_bus_region region;
+
+       dev_info(&bridge->dev, "CardBus bridge to %pR\n",
+                &bus->busn_res);
+
+       res = bus->resource[0];
+       pcibios_resource_to_bus(bridge->bus, &region, res);
+       if (res->flags & IORESOURCE_IO) {
+               /*
+                * The IO resource is allocated a range twice as large as it
+                * would normally need.  This allows us to set both IO regs.
+                */
+               dev_info(&bridge->dev, "  bridge window %pR\n", res);
+               pci_write_config_dword(bridge, PCI_CB_IO_BASE_0,
+                                       region.start);
+               pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_0,
+                                       region.end);
+       }
+
+       res = bus->resource[1];
+       pcibios_resource_to_bus(bridge->bus, &region, res);
+       if (res->flags & IORESOURCE_IO) {
+               dev_info(&bridge->dev, "  bridge window %pR\n", res);
+               pci_write_config_dword(bridge, PCI_CB_IO_BASE_1,
+                                       region.start);
+               pci_write_config_dword(bridge, PCI_CB_IO_LIMIT_1,
+                                       region.end);
+       }
+
+       res = bus->resource[2];
+       pcibios_resource_to_bus(bridge->bus, &region, res);
+       if (res->flags & IORESOURCE_MEM) {
+               dev_info(&bridge->dev, "  bridge window %pR\n", res);
+               pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_0,
+                                       region.start);
+               pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_0,
+                                       region.end);
+       }
+
+       res = bus->resource[3];
+       pcibios_resource_to_bus(bridge->bus, &region, res);
+       if (res->flags & IORESOURCE_MEM) {
+               dev_info(&bridge->dev, "  bridge window %pR\n", res);
+               pci_write_config_dword(bridge, PCI_CB_MEMORY_BASE_1,
+                                       region.start);
+               pci_write_config_dword(bridge, PCI_CB_MEMORY_LIMIT_1,
+                                       region.end);
+       }
+}
+EXPORT_SYMBOL(pci_setup_cardbus);
+
+/* Initialize bridges with base/limit values we have collected.
+   PCI-to-PCI Bridge Architecture Specification rev. 1.1 (1998)
+   requires that if there is no I/O ports or memory behind the
+   bridge, corresponding range must be turned off by writing base
+   value greater than limit to the bridge's base/limit registers.
+
+   Note: care must be taken when updating I/O base/limit registers
+   of bridges which support 32-bit I/O. This update requires two
+   config space writes, so it's quite possible that an I/O window of
+   the bridge will have some undesirable address (e.g. 0) after the
+   first write. Ditto 64-bit prefetchable MMIO.  */
+static void pci_setup_bridge_io(struct pci_dev *bridge)
+{
+       struct resource *res;
+       struct pci_bus_region region;
+       unsigned long io_mask;
+       u8 io_base_lo, io_limit_lo;
+       u16 l;
+       u32 io_upper16;
+
+       io_mask = PCI_IO_RANGE_MASK;
+       if (bridge->io_window_1k)
+               io_mask = PCI_IO_1K_RANGE_MASK;
+
+       /* Set up the top and bottom of the PCI I/O segment for this bus. */
+       res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
+       pcibios_resource_to_bus(bridge->bus, &region, res);
+       if (res->flags & IORESOURCE_IO) {
+               pci_read_config_word(bridge, PCI_IO_BASE, &l);
+               io_base_lo = (region.start >> 8) & io_mask;
+               io_limit_lo = (region.end >> 8) & io_mask;
+               l = ((u16) io_limit_lo << 8) | io_base_lo;
+               /* Set up upper 16 bits of I/O base/limit. */
+               io_upper16 = (region.end & 0xffff0000) | (region.start >> 16);
+               dev_info(&bridge->dev, "  bridge window %pR\n", res);
+       } else {
+               /* Clear upper 16 bits of I/O base/limit. */
+               io_upper16 = 0;
+               l = 0x00f0;
+       }
+       /* Temporarily disable the I/O range before updating PCI_IO_BASE. */
+       pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, 0x0000ffff);
+       /* Update lower 16 bits of I/O base/limit. */
+       pci_write_config_word(bridge, PCI_IO_BASE, l);
+       /* Update upper 16 bits of I/O base/limit. */
+       pci_write_config_dword(bridge, PCI_IO_BASE_UPPER16, io_upper16);
+}
+
+static void pci_setup_bridge_mmio(struct pci_dev *bridge)
+{
+       struct resource *res;
+       struct pci_bus_region region;
+       u32 l;
+
+       /* Set up the top and bottom of the PCI Memory segment for this bus. */
+       res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
+       pcibios_resource_to_bus(bridge->bus, &region, res);
+       if (res->flags & IORESOURCE_MEM) {
+               l = (region.start >> 16) & 0xfff0;
+               l |= region.end & 0xfff00000;
+               dev_info(&bridge->dev, "  bridge window %pR\n", res);
+       } else {
+               l = 0x0000fff0;
+       }
+       pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
+}
+
+static void pci_setup_bridge_mmio_pref(struct pci_dev *bridge)
+{
+       struct resource *res;
+       struct pci_bus_region region;
+       u32 l, bu, lu;
+
+       /* Clear out the upper 32 bits of PREF limit.
+          If PCI_PREF_BASE_UPPER32 was non-zero, this temporarily
+          disables PREF range, which is ok. */
+       pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);
+
+       /* Set up PREF base/limit. */
+       bu = lu = 0;
+       res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
+       pcibios_resource_to_bus(bridge->bus, &region, res);
+       if (res->flags & IORESOURCE_PREFETCH) {
+               l = (region.start >> 16) & 0xfff0;
+               l |= region.end & 0xfff00000;
+               if (res->flags & IORESOURCE_MEM_64) {
+                       bu = upper_32_bits(region.start);
+                       lu = upper_32_bits(region.end);
+               }
+               dev_info(&bridge->dev, "  bridge window %pR\n", res);
+       } else {
+               l = 0x0000fff0;
+       }
+       pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
+
+       /* Set the upper 32 bits of PREF base & limit. */
+       pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, bu);
+       pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, lu);
+}
+
+static void __pci_setup_bridge(struct pci_bus *bus, unsigned long type)
+{
+       struct pci_dev *bridge = bus->self;
+
+       dev_info(&bridge->dev, "PCI bridge to %pR\n",
+                &bus->busn_res);
+
+       if (type & IORESOURCE_IO)
+               pci_setup_bridge_io(bridge);
+
+       if (type & IORESOURCE_MEM)
+               pci_setup_bridge_mmio(bridge);
+
+       if (type & IORESOURCE_PREFETCH)
+               pci_setup_bridge_mmio_pref(bridge);
+
+       pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
+}
+
+void pci_setup_bridge(struct pci_bus *bus)
+{
+       unsigned long type = IORESOURCE_IO | IORESOURCE_MEM |
+                                 IORESOURCE_PREFETCH;
+
+       __pci_setup_bridge(bus, type);
+}
+
+
+int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
+{
+       if (i < PCI_BRIDGE_RESOURCES || i > PCI_BRIDGE_RESOURCE_END)
+               return 0;
+
+       if (pci_claim_resource(bridge, i) == 0)
+               return 0;       /* claimed the window */
+
+       if ((bridge->class >> 8) != PCI_CLASS_BRIDGE_PCI)
+               return 0;
+
+       if (!pci_bus_clip_resource(bridge, i))
+               return -EINVAL; /* clipping didn't change anything */
+
+       switch (i - PCI_BRIDGE_RESOURCES) {
+       case 0:
+               pci_setup_bridge_io(bridge);
+               break;
+       case 1:
+               pci_setup_bridge_mmio(bridge);
+               break;
+       case 2:
+               pci_setup_bridge_mmio_pref(bridge);
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       if (pci_claim_resource(bridge, i) == 0)
+               return 0;       /* claimed a smaller window */
+
+       return -EINVAL;
+}
+
+/* Check whether the bridge supports optional I/O and
+   prefetchable memory ranges. If not, the respective
+   base/limit registers must be read-only and read as 0. */
+static void pci_bridge_check_ranges(struct pci_bus *bus)
+{
+       u16 io;
+       u32 pmem;
+       struct pci_dev *bridge = bus->self;
+       struct resource *b_res;
+
+       b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
+       b_res[1].flags |= IORESOURCE_MEM;
+
+       pci_read_config_word(bridge, PCI_IO_BASE, &io);
+       if (!io) {
+               pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0);
+               pci_read_config_word(bridge, PCI_IO_BASE, &io);
+               pci_write_config_word(bridge, PCI_IO_BASE, 0x0);
+       }
+       if (io)
+               b_res[0].flags |= IORESOURCE_IO;
+
+       /*  DECchip 21050 pass 2 errata: the bridge may miss an address
+           disconnect boundary by one PCI data phase.
+           Workaround: do not use prefetching on this device. */
+       if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001)
+               return;
+
+       pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
+       if (!pmem) {
+               pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE,
+                                              0xffe0fff0);
+               pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem);
+               pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0);
+       }
+       if (pmem) {
+               b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
+               if ((pmem & PCI_PREF_RANGE_TYPE_MASK) ==
+                   PCI_PREF_RANGE_TYPE_64) {
+                       b_res[2].flags |= IORESOURCE_MEM_64;
+                       b_res[2].flags |= PCI_PREF_RANGE_TYPE_64;
+               }
+       }
+
+       /* double check if bridge does support 64 bit pref */
+       if (b_res[2].flags & IORESOURCE_MEM_64) {
+               u32 mem_base_hi, tmp;
+               pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32,
+                                        &mem_base_hi);
+               pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
+                                              0xffffffff);
+               pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp);
+               if (!tmp)
+                       b_res[2].flags &= ~IORESOURCE_MEM_64;
+               pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32,
+                                      mem_base_hi);
+       }
+}
+
+/* Helper function for sizing routines: find first available
+   bus resource of a given type. Note: we intentionally skip
+   the bus resources which have already been assigned (that is,
+   have non-NULL parent resource). */
+static struct resource *find_free_bus_resource(struct pci_bus *bus,
+                        unsigned long type_mask, unsigned long type)
+{
+       int i;
+       struct resource *r;
+
+       pci_bus_for_each_resource(bus, r, i) {
+               if (r == &ioport_resource || r == &iomem_resource)
+                       continue;
+               if (r && (r->flags & type_mask) == type && !r->parent)
+                       return r;
+       }
+       return NULL;
+}
+
+static resource_size_t calculate_iosize(resource_size_t size,
+               resource_size_t min_size,
+               resource_size_t size1,
+               resource_size_t old_size,
+               resource_size_t align)
+{
+       if (size < min_size)
+               size = min_size;
+       if (old_size == 1)
+               old_size = 0;
+       /* To be fixed in 2.5: we should have sort of HAVE_ISA
+          flag in the struct pci_bus. */
+#if defined(CONFIG_ISA) || defined(CONFIG_EISA)
+       size = (size & 0xff) + ((size & ~0xffUL) << 2);
+#endif
+       size = ALIGN(size + size1, align);
+       if (size < old_size)
+               size = old_size;
+       return size;
+}
+
+static resource_size_t calculate_memsize(resource_size_t size,
+               resource_size_t min_size,
+               resource_size_t size1,
+               resource_size_t old_size,
+               resource_size_t align)
+{
+       if (size < min_size)
+               size = min_size;
+       if (old_size == 1)
+               old_size = 0;
+       if (size < old_size)
+               size = old_size;
+       size = ALIGN(size + size1, align);
+       return size;
+}
+
+resource_size_t __weak pcibios_window_alignment(struct pci_bus *bus,
+                                               unsigned long type)
+{
+       return 1;
+}
+
+#define PCI_P2P_DEFAULT_MEM_ALIGN      0x100000        /* 1MiB */
+#define PCI_P2P_DEFAULT_IO_ALIGN       0x1000          /* 4KiB */
+#define PCI_P2P_DEFAULT_IO_ALIGN_1K    0x400           /* 1KiB */
+
+static resource_size_t window_alignment(struct pci_bus *bus,
+                                       unsigned long type)
+{
+       resource_size_t align = 1, arch_align;
+
+       if (type & IORESOURCE_MEM)
+               align = PCI_P2P_DEFAULT_MEM_ALIGN;
+       else if (type & IORESOURCE_IO) {
+               /*
+                * Per spec, I/O windows are 4K-aligned, but some
+                * bridges have an extension to support 1K alignment.
+                */
+               if (bus->self->io_window_1k)
+                       align = PCI_P2P_DEFAULT_IO_ALIGN_1K;
+               else
+                       align = PCI_P2P_DEFAULT_IO_ALIGN;
+       }
+
+       arch_align = pcibios_window_alignment(bus, type);
+       return max(align, arch_align);
+}
+
+/**
+ * pbus_size_io() - size the io window of a given bus
+ *
+ * @bus : the bus
+ * @min_size : the minimum io window that must to be allocated
+ * @add_size : additional optional io window
+ * @realloc_head : track the additional io window on this list
+ *
+ * Sizing the IO windows of the PCI-PCI bridge is trivial,
+ * since these windows have 1K or 4K granularity and the IO ranges
+ * of non-bridge PCI devices are limited to 256 bytes.
+ * We must be careful with the ISA aliasing though.
+ */
+static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
+               resource_size_t add_size, struct list_head *realloc_head)
+{
+       struct pci_dev *dev;
+       struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO,
+                                                       IORESOURCE_IO);
+       resource_size_t size = 0, size0 = 0, size1 = 0;
+       resource_size_t children_add_size = 0;
+       resource_size_t min_align, align;
+
+       if (!b_res)
+               return;
+
+       min_align = window_alignment(bus, IORESOURCE_IO);
+       list_for_each_entry(dev, &bus->devices, bus_list) {
+               int i;
+
+               for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+                       struct resource *r = &dev->resource[i];
+                       unsigned long r_size;
+
+                       if (r->parent || !(r->flags & IORESOURCE_IO))
+                               continue;
+                       r_size = resource_size(r);
+
+                       if (r_size < 0x400)
+                               /* Might be re-aligned for ISA */
+                               size += r_size;
+                       else
+                               size1 += r_size;
+
+                       align = pci_resource_alignment(dev, r);
+                       if (align > min_align)
+                               min_align = align;
+
+                       if (realloc_head)
+                               children_add_size += get_res_add_size(realloc_head, r);
+               }
+       }
+
+       size0 = calculate_iosize(size, min_size, size1,
+                       resource_size(b_res), min_align);
+       if (children_add_size > add_size)
+               add_size = children_add_size;
+       size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
+               calculate_iosize(size, min_size, add_size + size1,
+                       resource_size(b_res), min_align);
+       if (!size0 && !size1) {
+               if (b_res->start || b_res->end)
+                       dev_info(&bus->self->dev, "disabling bridge window %pR to %pR (unused)\n",
+                                b_res, &bus->busn_res);
+               b_res->flags = 0;
+               return;
+       }
+
+       b_res->start = min_align;
+       b_res->end = b_res->start + size0 - 1;
+       b_res->flags |= IORESOURCE_STARTALIGN;
+       if (size1 > size0 && realloc_head) {
+               add_to_list(realloc_head, bus->self, b_res, size1-size0,
+                           min_align);
+               dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window %pR to %pR add_size %llx\n",
+                          b_res, &bus->busn_res,
+                          (unsigned long long)size1-size0);
+       }
+}
+
+static inline resource_size_t calculate_mem_align(resource_size_t *aligns,
+                                                 int max_order)
+{
+       resource_size_t align = 0;
+       resource_size_t min_align = 0;
+       int order;
+
+       for (order = 0; order <= max_order; order++) {
+               resource_size_t align1 = 1;
+
+               align1 <<= (order + 20);
+
+               if (!align)
+                       min_align = align1;
+               else if (ALIGN(align + min_align, min_align) < align1)
+                       min_align = align1 >> 1;
+               align += aligns[order];
+       }
+
+       return min_align;
+}
+
+/**
+ * pbus_size_mem() - size the memory window of a given bus
+ *
+ * @bus : the bus
+ * @mask: mask the resource flag, then compare it with type
+ * @type: the type of free resource from bridge
+ * @type2: second match type
+ * @type3: third match type
+ * @min_size : the minimum memory window that must to be allocated
+ * @add_size : additional optional memory window
+ * @realloc_head : track the additional memory window on this list
+ *
+ * Calculate the size of the bus and minimal alignment which
+ * guarantees that all child resources fit in this size.
+ *
+ * Returns -ENOSPC if there's no available bus resource of the desired type.
+ * Otherwise, sets the bus resource start/end to indicate the required
+ * size, adds things to realloc_head (if supplied), and returns 0.
+ */
+static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
+                        unsigned long type, unsigned long type2,
+                        unsigned long type3,
+                        resource_size_t min_size, resource_size_t add_size,
+                        struct list_head *realloc_head)
+{
+       struct pci_dev *dev;
+       resource_size_t min_align, align, size, size0, size1;
+       resource_size_t aligns[18];     /* Alignments from 1Mb to 128Gb */
+       int order, max_order;
+       struct resource *b_res = find_free_bus_resource(bus,
+                                       mask | IORESOURCE_PREFETCH, type);
+       resource_size_t children_add_size = 0;
+       resource_size_t children_add_align = 0;
+       resource_size_t add_align = 0;
+
+       if (!b_res)
+               return -ENOSPC;
+
+       memset(aligns, 0, sizeof(aligns));
+       max_order = 0;
+       size = 0;
+
+       list_for_each_entry(dev, &bus->devices, bus_list) {
+               int i;
+
+               for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+                       struct resource *r = &dev->resource[i];
+                       resource_size_t r_size;
+
+                       if (r->parent || ((r->flags & mask) != type &&
+                                         (r->flags & mask) != type2 &&
+                                         (r->flags & mask) != type3))
+                               continue;
+                       r_size = resource_size(r);
+#ifdef CONFIG_PCI_IOV
+                       /* put SRIOV requested res to the optional list */
+                       if (realloc_head && i >= PCI_IOV_RESOURCES &&
+                                       i <= PCI_IOV_RESOURCE_END) {
+                               add_align = max(pci_resource_alignment(dev, r), add_align);
+                               r->end = r->start - 1;
+                               add_to_list(realloc_head, dev, r, r_size, 0/* don't care */);
+                               children_add_size += r_size;
+                               continue;
+                       }
+#endif
+                       /*
+                        * aligns[0] is for 1MB (since bridge memory
+                        * windows are always at least 1MB aligned), so
+                        * keep "order" from being negative for smaller
+                        * resources.
+                        */
+                       align = pci_resource_alignment(dev, r);
+                       order = __ffs(align) - 20;
+                       if (order < 0)
+                               order = 0;
+                       if (order >= ARRAY_SIZE(aligns)) {
+                               dev_warn(&dev->dev, "disabling BAR %d: %pR (bad alignment %#llx)\n",
+                                        i, r, (unsigned long long) align);
+                               r->flags = 0;
+                               continue;
+                       }
+                       size += r_size;
+                       /* Exclude ranges with size > align from
+                          calculation of the alignment. */
+                       if (r_size == align)
+                               aligns[order] += align;
+                       if (order > max_order)
+                               max_order = order;
+
+                       if (realloc_head) {
+                               children_add_size += get_res_add_size(realloc_head, r);
+                               children_add_align = get_res_add_align(realloc_head, r);
+                               add_align = max(add_align, children_add_align);
+                       }
+               }
+       }
+
+       min_align = calculate_mem_align(aligns, max_order);
+       min_align = max(min_align, window_alignment(bus, b_res->flags));
+       size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);
+       add_align = max(min_align, add_align);
+       if (children_add_size > add_size)
+               add_size = children_add_size;
+       size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
+               calculate_memsize(size, min_size, add_size,
+                               resource_size(b_res), add_align);
+       if (!size0 && !size1) {
+               if (b_res->start || b_res->end)
+                       dev_info(&bus->self->dev, "disabling bridge window %pR to %pR (unused)\n",
+                                b_res, &bus->busn_res);
+               b_res->flags = 0;
+               return 0;
+       }
+       b_res->start = min_align;
+       b_res->end = size0 + min_align - 1;
+       b_res->flags |= IORESOURCE_STARTALIGN;
+       if (size1 > size0 && realloc_head) {
+               add_to_list(realloc_head, bus->self, b_res, size1-size0, add_align);
+               dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window %pR to %pR add_size %llx add_align %llx\n",
+                          b_res, &bus->busn_res,
+                          (unsigned long long) (size1 - size0),
+                          (unsigned long long) add_align);
+       }
+       return 0;
+}
+
+unsigned long pci_cardbus_resource_alignment(struct resource *res)
+{
+       if (res->flags & IORESOURCE_IO)
+               return pci_cardbus_io_size;
+       if (res->flags & IORESOURCE_MEM)
+               return pci_cardbus_mem_size;
+       return 0;
+}
+
+static void pci_bus_size_cardbus(struct pci_bus *bus,
+                       struct list_head *realloc_head)
+{
+       struct pci_dev *bridge = bus->self;
+       struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
+       resource_size_t b_res_3_size = pci_cardbus_mem_size * 2;
+       u16 ctrl;
+
+       if (b_res[0].parent)
+               goto handle_b_res_1;
+       /*
+        * Reserve some resources for CardBus.  We reserve
+        * a fixed amount of bus space for CardBus bridges.
+        */
+       b_res[0].start = pci_cardbus_io_size;
+       b_res[0].end = b_res[0].start + pci_cardbus_io_size - 1;
+       b_res[0].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
+       if (realloc_head) {
+               b_res[0].end -= pci_cardbus_io_size;
+               add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size,
+                               pci_cardbus_io_size);
+       }
+
+handle_b_res_1:
+       if (b_res[1].parent)
+               goto handle_b_res_2;
+       b_res[1].start = pci_cardbus_io_size;
+       b_res[1].end = b_res[1].start + pci_cardbus_io_size - 1;
+       b_res[1].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
+       if (realloc_head) {
+               b_res[1].end -= pci_cardbus_io_size;
+               add_to_list(realloc_head, bridge, b_res+1, pci_cardbus_io_size,
+                                pci_cardbus_io_size);
+       }
+
+handle_b_res_2:
+       /* MEM1 must not be pref mmio */
+       pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+       if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM1) {
+               ctrl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
+               pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
+               pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+       }
+
+       /*
+        * Check whether prefetchable memory is supported
+        * by this bridge.
+        */
+       pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+       if (!(ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0)) {
+               ctrl |= PCI_CB_BRIDGE_CTL_PREFETCH_MEM0;
+               pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
+               pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+       }
+
+       if (b_res[2].parent)
+               goto handle_b_res_3;
+       /*
+        * If we have prefetchable memory support, allocate
+        * two regions.  Otherwise, allocate one region of
+        * twice the size.
+        */
+       if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
+               b_res[2].start = pci_cardbus_mem_size;
+               b_res[2].end = b_res[2].start + pci_cardbus_mem_size - 1;
+               b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH |
+                                 IORESOURCE_STARTALIGN;
+               if (realloc_head) {
+                       b_res[2].end -= pci_cardbus_mem_size;
+                       add_to_list(realloc_head, bridge, b_res+2,
+                                pci_cardbus_mem_size, pci_cardbus_mem_size);
+               }
+
+               /* reduce that to half */
+               b_res_3_size = pci_cardbus_mem_size;
+       }
+
+handle_b_res_3:
+       if (b_res[3].parent)
+               goto handle_done;
+       b_res[3].start = pci_cardbus_mem_size;
+       b_res[3].end = b_res[3].start + b_res_3_size - 1;
+       b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_STARTALIGN;
+       if (realloc_head) {
+               b_res[3].end -= b_res_3_size;
+               add_to_list(realloc_head, bridge, b_res+3, b_res_3_size,
+                                pci_cardbus_mem_size);
+       }
+
+handle_done:
+       ;
+}
+
+void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
+{
+       struct pci_dev *dev;
+       unsigned long mask, prefmask, type2 = 0, type3 = 0;
+       resource_size_t additional_mem_size = 0, additional_io_size = 0;
+       struct resource *b_res;
+       int ret;
+
+       list_for_each_entry(dev, &bus->devices, bus_list) {
+               struct pci_bus *b = dev->subordinate;
+               if (!b)
+                       continue;
+
+               switch (dev->class >> 8) {
+               case PCI_CLASS_BRIDGE_CARDBUS:
+                       pci_bus_size_cardbus(b, realloc_head);
+                       break;
+
+               case PCI_CLASS_BRIDGE_PCI:
+               default:
+                       __pci_bus_size_bridges(b, realloc_head);
+                       break;
+               }
+       }
+
+       /* The root bus? */
+       if (pci_is_root_bus(bus))
+               return;
+
+       switch (bus->self->class >> 8) {
+       case PCI_CLASS_BRIDGE_CARDBUS:
+               /* don't size cardbuses yet. */
+               break;
+
+       case PCI_CLASS_BRIDGE_PCI:
+               pci_bridge_check_ranges(bus);
+               if (bus->self->is_hotplug_bridge) {
+                       additional_io_size  = pci_hotplug_io_size;
+                       additional_mem_size = pci_hotplug_mem_size;
+               }
+               /* Fall through */
+       default:
+               pbus_size_io(bus, realloc_head ? 0 : additional_io_size,
+                            additional_io_size, realloc_head);
+
+               /*
+                * If there's a 64-bit prefetchable MMIO window, compute
+                * the size required to put all 64-bit prefetchable
+                * resources in it.
+                */
+               b_res = &bus->self->resource[PCI_BRIDGE_RESOURCES];
+               mask = IORESOURCE_MEM;
+               prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
+               if (b_res[2].flags & IORESOURCE_MEM_64) {
+                       prefmask |= IORESOURCE_MEM_64;
+                       ret = pbus_size_mem(bus, prefmask, prefmask,
+                                 prefmask, prefmask,
+                                 realloc_head ? 0 : additional_mem_size,
+                                 additional_mem_size, realloc_head);
+
+                       /*
+                        * If successful, all non-prefetchable resources
+                        * and any 32-bit prefetchable resources will go in
+                        * the non-prefetchable window.
+                        */
+                       if (ret == 0) {
+                               mask = prefmask;
+                               type2 = prefmask & ~IORESOURCE_MEM_64;
+                               type3 = prefmask & ~IORESOURCE_PREFETCH;
+                       }
+               }
+
+               /*
+                * If there is no 64-bit prefetchable window, compute the
+                * size required to put all prefetchable resources in the
+                * 32-bit prefetchable window (if there is one).
+                */
+               if (!type2) {
+                       prefmask &= ~IORESOURCE_MEM_64;
+                       ret = pbus_size_mem(bus, prefmask, prefmask,
+                                        prefmask, prefmask,
+                                        realloc_head ? 0 : additional_mem_size,
+                                        additional_mem_size, realloc_head);
+
+                       /*
+                        * If successful, only non-prefetchable resources
+                        * will go in the non-prefetchable window.
+                        */
+                       if (ret == 0)
+                               mask = prefmask;
+                       else
+                               additional_mem_size += additional_mem_size;
+
+                       type2 = type3 = IORESOURCE_MEM;
+               }
+
+               /*
+                * Compute the size required to put everything else in the
+                * non-prefetchable window.  This includes:
+                *
+                *   - all non-prefetchable resources
+                *   - 32-bit prefetchable resources if there's a 64-bit
+                *     prefetchable window or no prefetchable window at all
+                *   - 64-bit prefetchable resources if there's no
+                *     prefetchable window at all
+                *
+                * Note that the strategy in __pci_assign_resource() must
+                * match that used here.  Specifically, we cannot put a
+                * 32-bit prefetchable resource in a 64-bit prefetchable
+                * window.
+                */
+               pbus_size_mem(bus, mask, IORESOURCE_MEM, type2, type3,
+                               realloc_head ? 0 : additional_mem_size,
+                               additional_mem_size, realloc_head);
+               break;
+       }
+}
+
+void pci_bus_size_bridges(struct pci_bus *bus)
+{
+       __pci_bus_size_bridges(bus, NULL);
+}
+EXPORT_SYMBOL(pci_bus_size_bridges);
+
+void __pci_bus_assign_resources(const struct pci_bus *bus,
+                               struct list_head *realloc_head,
+                               struct list_head *fail_head)
+{
+       struct pci_bus *b;
+       struct pci_dev *dev;
+
+       pbus_assign_resources_sorted(bus, realloc_head, fail_head);
+
+       list_for_each_entry(dev, &bus->devices, bus_list) {
+               b = dev->subordinate;
+               if (!b)
+                       continue;
+
+               __pci_bus_assign_resources(b, realloc_head, fail_head);
+
+               switch (dev->class >> 8) {
+               case PCI_CLASS_BRIDGE_PCI:
+                       if (!pci_is_enabled(dev))
+                               pci_setup_bridge(b);
+                       break;
+
+               case PCI_CLASS_BRIDGE_CARDBUS:
+                       pci_setup_cardbus(b);
+                       break;
+
+               default:
+                       dev_info(&dev->dev, "not setting up bridge for bus %04x:%02x\n",
+                                pci_domain_nr(b), b->number);
+                       break;
+               }
+       }
+}
+
+void pci_bus_assign_resources(const struct pci_bus *bus)
+{
+       __pci_bus_assign_resources(bus, NULL, NULL);
+}
+EXPORT_SYMBOL(pci_bus_assign_resources);
+
+static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
+                                         struct list_head *add_head,
+                                         struct list_head *fail_head)
+{
+       struct pci_bus *b;
+
+       pdev_assign_resources_sorted((struct pci_dev *)bridge,
+                                        add_head, fail_head);
+
+       b = bridge->subordinate;
+       if (!b)
+               return;
+
+       __pci_bus_assign_resources(b, add_head, fail_head);
+
+       switch (bridge->class >> 8) {
+       case PCI_CLASS_BRIDGE_PCI:
+               pci_setup_bridge(b);
+               break;
+
+       case PCI_CLASS_BRIDGE_CARDBUS:
+               pci_setup_cardbus(b);
+               break;
+
+       default:
+               dev_info(&bridge->dev, "not setting up bridge for bus %04x:%02x\n",
+                        pci_domain_nr(b), b->number);
+               break;
+       }
+}
+static void pci_bridge_release_resources(struct pci_bus *bus,
+                                         unsigned long type)
+{
+       struct pci_dev *dev = bus->self;
+       struct resource *r;
+       unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+                                 IORESOURCE_PREFETCH | IORESOURCE_MEM_64;
+       unsigned old_flags = 0;
+       struct resource *b_res;
+       int idx = 1;
+
+       b_res = &dev->resource[PCI_BRIDGE_RESOURCES];
+
+       /*
+        *     1. if there is io port assign fail, will release bridge
+        *        io port.
+        *     2. if there is non pref mmio assign fail, release bridge
+        *        nonpref mmio.
+        *     3. if there is 64bit pref mmio assign fail, and bridge pref
+        *        is 64bit, release bridge pref mmio.
+        *     4. if there is pref mmio assign fail, and bridge pref is
+        *        32bit mmio, release bridge pref mmio
+        *     5. if there is pref mmio assign fail, and bridge pref is not
+        *        assigned, release bridge nonpref mmio.
+        */
+       if (type & IORESOURCE_IO)
+               idx = 0;
+       else if (!(type & IORESOURCE_PREFETCH))
+               idx = 1;
+       else if ((type & IORESOURCE_MEM_64) &&
+                (b_res[2].flags & IORESOURCE_MEM_64))
+               idx = 2;
+       else if (!(b_res[2].flags & IORESOURCE_MEM_64) &&
+                (b_res[2].flags & IORESOURCE_PREFETCH))
+               idx = 2;
+       else
+               idx = 1;
+
+       r = &b_res[idx];
+
+       if (!r->parent)
+               return;
+
+       /*
+        * if there are children under that, we should release them
+        *  all
+        */
+       release_child_resources(r);
+       if (!release_resource(r)) {
+               type = old_flags = r->flags & type_mask;
+               dev_printk(KERN_DEBUG, &dev->dev, "resource %d %pR released\n",
+                                       PCI_BRIDGE_RESOURCES + idx, r);
+               /* keep the old size */
+               r->end = resource_size(r) - 1;
+               r->start = 0;
+               r->flags = 0;
+
+               /* avoiding touch the one without PREF */
+               if (type & IORESOURCE_PREFETCH)
+                       type = IORESOURCE_PREFETCH;
+               __pci_setup_bridge(bus, type);
+               /* for next child res under same bridge */
+               r->flags = old_flags;
+       }
+}
+
+enum release_type {
+       leaf_only,
+       whole_subtree,
+};
+/*
+ * try to release pci bridge resources that is from leaf bridge,
+ * so we can allocate big new one later
+ */
+static void pci_bus_release_bridge_resources(struct pci_bus *bus,
+                                            unsigned long type,
+                                            enum release_type rel_type)
+{
+       struct pci_dev *dev;
+       bool is_leaf_bridge = true;
+
+       list_for_each_entry(dev, &bus->devices, bus_list) {
+               struct pci_bus *b = dev->subordinate;
+               if (!b)
+                       continue;
+
+               is_leaf_bridge = false;
+
+               if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
+                       continue;
+
+               if (rel_type == whole_subtree)
+                       pci_bus_release_bridge_resources(b, type,
+                                                whole_subtree);
+       }
+
+       if (pci_is_root_bus(bus))
+               return;
+
+       if ((bus->self->class >> 8) != PCI_CLASS_BRIDGE_PCI)
+               return;
+
+       if ((rel_type == whole_subtree) || is_leaf_bridge)
+               pci_bridge_release_resources(bus, type);
+}
+
+static void pci_bus_dump_res(struct pci_bus *bus)
+{
+       struct resource *res;
+       int i;
+
+       pci_bus_for_each_resource(bus, res, i) {
+               if (!res || !res->end || !res->flags)
+                       continue;
+
+               dev_printk(KERN_DEBUG, &bus->dev, "resource %d %pR\n", i, res);
+       }
+}
+
+static void pci_bus_dump_resources(struct pci_bus *bus)
+{
+       struct pci_bus *b;
+       struct pci_dev *dev;
+
+
+       pci_bus_dump_res(bus);
+
+       list_for_each_entry(dev, &bus->devices, bus_list) {
+               b = dev->subordinate;
+               if (!b)
+                       continue;
+
+               pci_bus_dump_resources(b);
+       }
+}
+
+static int pci_bus_get_depth(struct pci_bus *bus)
+{
+       int depth = 0;
+       struct pci_bus *child_bus;
+
+       list_for_each_entry(child_bus, &bus->children, node) {
+               int ret;
+
+               ret = pci_bus_get_depth(child_bus);
+               if (ret + 1 > depth)
+                       depth = ret + 1;
+       }
+
+       return depth;
+}
+
+/*
+ * -1: undefined, will auto detect later
+ *  0: disabled by user
+ *  1: disabled by auto detect
+ *  2: enabled by user
+ *  3: enabled by auto detect
+ */
+enum enable_type {
+       undefined = -1,
+       user_disabled,
+       auto_disabled,
+       user_enabled,
+       auto_enabled,
+};
+
+static enum enable_type pci_realloc_enable = undefined;
+void __init pci_realloc_get_opt(char *str)
+{
+       if (!strncmp(str, "off", 3))
+               pci_realloc_enable = user_disabled;
+       else if (!strncmp(str, "on", 2))
+               pci_realloc_enable = user_enabled;
+}
+static bool pci_realloc_enabled(enum enable_type enable)
+{
+       return enable >= user_enabled;
+}
+
+#if defined(CONFIG_PCI_IOV) && defined(CONFIG_PCI_REALLOC_ENABLE_AUTO)
+static int iov_resources_unassigned(struct pci_dev *dev, void *data)
+{
+       int i;
+       bool *unassigned = data;
+
+       for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) {
+               struct resource *r = &dev->resource[i];
+               struct pci_bus_region region;
+
+               /* Not assigned or rejected by kernel? */
+               if (!r->flags)
+                       continue;
+
+               pcibios_resource_to_bus(dev->bus, &region, r);
+               if (!region.start) {
+                       *unassigned = true;
+                       return 1; /* return early from pci_walk_bus() */
+               }
+       }
+
+       return 0;
+}
+
+static enum enable_type pci_realloc_detect(struct pci_bus *bus,
+                        enum enable_type enable_local)
+{
+       bool unassigned = false;
+
+       if (enable_local != undefined)
+               return enable_local;
+
+       pci_walk_bus(bus, iov_resources_unassigned, &unassigned);
+       if (unassigned)
+               return auto_enabled;
+
+       return enable_local;
+}
+#else
+static enum enable_type pci_realloc_detect(struct pci_bus *bus,
+                        enum enable_type enable_local)
+{
+       return enable_local;
+}
+#endif
+
+/*
+ * first try will not touch pci bridge res
+ * second and later try will clear small leaf bridge res
+ * will stop till to the max depth if can not find good one
+ */
+void pci_assign_unassigned_root_bus_resources(struct pci_bus *bus)
+{
+       LIST_HEAD(realloc_head); /* list of resources that
+                                       want additional resources */
+       struct list_head *add_list = NULL;
+       int tried_times = 0;
+       enum release_type rel_type = leaf_only;
+       LIST_HEAD(fail_head);
+       struct pci_dev_resource *fail_res;
+       unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+                                 IORESOURCE_PREFETCH | IORESOURCE_MEM_64;
+       int pci_try_num = 1;
+       enum enable_type enable_local;
+
+       /* don't realloc if asked to do so */
+       enable_local = pci_realloc_detect(bus, pci_realloc_enable);
+       if (pci_realloc_enabled(enable_local)) {
+               int max_depth = pci_bus_get_depth(bus);
+
+               pci_try_num = max_depth + 1;
+               dev_printk(KERN_DEBUG, &bus->dev,
+                          "max bus depth: %d pci_try_num: %d\n",
+                          max_depth, pci_try_num);
+       }
+
+again:
+       /*
+        * last try will use add_list, otherwise will try good to have as
+        * must have, so can realloc parent bridge resource
+        */
+       if (tried_times + 1 == pci_try_num)
+               add_list = &realloc_head;
+       /* Depth first, calculate sizes and alignments of all
+          subordinate buses. */
+       __pci_bus_size_bridges(bus, add_list);
+
+       /* Depth last, allocate resources and update the hardware. */
+       __pci_bus_assign_resources(bus, add_list, &fail_head);
+       if (add_list)
+               BUG_ON(!list_empty(add_list));
+       tried_times++;
+
+       /* any device complain? */
+       if (list_empty(&fail_head))
+               goto dump;
+
+       if (tried_times >= pci_try_num) {
+               if (enable_local == undefined)
+                       dev_info(&bus->dev, "Some PCI device resources are unassigned, try booting with pci=realloc\n");
+               else if (enable_local == auto_enabled)
+                       dev_info(&bus->dev, "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
+
+               free_list(&fail_head);
+               goto dump;
+       }
+
+       dev_printk(KERN_DEBUG, &bus->dev,
+                  "No. %d try to assign unassigned res\n", tried_times + 1);
+
+       /* third times and later will not check if it is leaf */
+       if ((tried_times + 1) > 2)
+               rel_type = whole_subtree;
+
+       /*
+        * Try to release leaf bridge's resources that doesn't fit resource of
+        * child device under that bridge
+        */
+       list_for_each_entry(fail_res, &fail_head, list)
+               pci_bus_release_bridge_resources(fail_res->dev->bus,
+                                                fail_res->flags & type_mask,
+                                                rel_type);
+
+       /* restore size and flags */
+       list_for_each_entry(fail_res, &fail_head, list) {
+               struct resource *res = fail_res->res;
+
+               res->start = fail_res->start;
+               res->end = fail_res->end;
+               res->flags = fail_res->flags;
+               if (fail_res->dev->subordinate)
+                       res->flags = 0;
+       }
+       free_list(&fail_head);
+
+       goto again;
+
+dump:
+       /* dump the resource on buses */
+       pci_bus_dump_resources(bus);
+}
+
+void __init pci_assign_unassigned_resources(void)
+{
+       struct pci_bus *root_bus;
+
+       list_for_each_entry(root_bus, &pci_root_buses, node)
+               pci_assign_unassigned_root_bus_resources(root_bus);
+}
+
+void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
+{
+       struct pci_bus *parent = bridge->subordinate;
+       LIST_HEAD(add_list); /* list of resources that
+                                       want additional resources */
+       int tried_times = 0;
+       LIST_HEAD(fail_head);
+       struct pci_dev_resource *fail_res;
+       int retval;
+       unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+                                 IORESOURCE_PREFETCH | IORESOURCE_MEM_64;
+
+again:
+       __pci_bus_size_bridges(parent, &add_list);
+       __pci_bridge_assign_resources(bridge, &add_list, &fail_head);
+       BUG_ON(!list_empty(&add_list));
+       tried_times++;
+
+       if (list_empty(&fail_head))
+               goto enable_all;
+
+       if (tried_times >= 2) {
+               /* still fail, don't need to try more */
+               free_list(&fail_head);
+               goto enable_all;
+       }
+
+       printk(KERN_DEBUG "PCI: No. %d try to assign unassigned res\n",
+                        tried_times + 1);
+
+       /*
+        * Try to release leaf bridge's resources that doesn't fit resource of
+        * child device under that bridge
+        */
+       list_for_each_entry(fail_res, &fail_head, list)
+               pci_bus_release_bridge_resources(fail_res->dev->bus,
+                                                fail_res->flags & type_mask,
+                                                whole_subtree);
+
+       /* restore size and flags */
+       list_for_each_entry(fail_res, &fail_head, list) {
+               struct resource *res = fail_res->res;
+
+               res->start = fail_res->start;
+               res->end = fail_res->end;
+               res->flags = fail_res->flags;
+               if (fail_res->dev->subordinate)
+                       res->flags = 0;
+       }
+       free_list(&fail_head);
+
+       goto again;
+
+enable_all:
+       retval = pci_reenable_device(bridge);
+       if (retval)
+               dev_err(&bridge->dev, "Error reenabling bridge (%d)\n", retval);
+       pci_set_master(bridge);
+}
+EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
+
+void pci_assign_unassigned_bus_resources(struct pci_bus *bus)
+{
+       struct pci_dev *dev;
+       LIST_HEAD(add_list); /* list of resources that
+                                       want additional resources */
+
+       down_read(&pci_bus_sem);
+       list_for_each_entry(dev, &bus->devices, bus_list)
+               if (pci_is_bridge(dev) && pci_has_subordinate(dev))
+                               __pci_bus_size_bridges(dev->subordinate,
+                                                        &add_list);
+       up_read(&pci_bus_sem);
+       __pci_bus_assign_resources(bus, &add_list, NULL);
+       BUG_ON(!list_empty(&add_list));
+}
+EXPORT_SYMBOL_GPL(pci_assign_unassigned_bus_resources);