PCI/e1000e: Add and use pci_disable_link_state_locked()
[linux-2.6.git] / drivers / pci / setup-bus.c
index 502d170..ebf51ad 100644 (file)
 #include <linux/slab.h>
 #include "pci.h"
 
-static void pbus_assign_resources_sorted(const struct pci_bus *bus)
-{
-       struct pci_dev *dev;
+struct resource_list_x {
+       struct resource_list_x *next;
        struct resource *res;
-       struct resource_list head, *list, *tmp;
-       int idx;
+       struct pci_dev *dev;
+       resource_size_t start;
+       resource_size_t end;
+       resource_size_t add_size;
+       unsigned long flags;
+};
+
+#define free_list(type, head) do {                      \
+       struct type *list, *tmp;                        \
+       for (list = (head)->next; list;) {              \
+               tmp = list;                             \
+               list = list->next;                      \
+               kfree(tmp);                             \
+       }                                               \
+       (head)->next = NULL;                            \
+} while (0)
+
+/**
+ * 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 void add_to_list(struct resource_list_x *head,
+                struct pci_dev *dev, struct resource *res,
+                resource_size_t add_size)
+{
+       struct resource_list_x *list = head;
+       struct resource_list_x *ln = list->next;
+       struct resource_list_x *tmp;
 
-       head.next = NULL;
-       list_for_each_entry(dev, &bus->devices, bus_list) {
-               u16 class = dev->class >> 8;
+       tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
+       if (!tmp) {
+               pr_warning("add_to_list: kmalloc() failed!\n");
+               return;
+       }
 
-               /* Don't touch classless devices or host bridges or ioapics.  */
-               if (class == PCI_CLASS_NOT_DEFINED ||
-                   class == PCI_CLASS_BRIDGE_HOST)
-                       continue;
+       tmp->next = ln;
+       tmp->res = res;
+       tmp->dev = dev;
+       tmp->start = res->start;
+       tmp->end = res->end;
+       tmp->flags = res->flags;
+       tmp->add_size = add_size;
+       list->next = tmp;
+}
 
-               /* 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))
-                               continue;
-               }
+static void add_to_failed_list(struct resource_list_x *head,
+                               struct pci_dev *dev, struct resource *res)
+{
+       add_to_list(head, dev, res, 0);
+}
+
+static void __dev_sort_resources(struct pci_dev *dev,
+                                struct resource_list *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;
 
-               pdev_sort_resources(dev, &head);
+       /* 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;
        }
 
-       for (list = head.next; list;) {
+       pdev_sort_resources(dev, head);
+}
+
+static inline void reset_resource(struct resource *res)
+{
+       res->start = 0;
+       res->end = 0;
+       res->flags = 0;
+}
+
+/**
+ * adjust_resources_sorted() - satisfy any additional resource requests
+ *
+ * @add_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 add_head and try to procure
+ * additional resources for the element, provided the element
+ * is in the head list.
+ */
+static void adjust_resources_sorted(struct resource_list_x *add_head,
+               struct resource_list *head)
+{
+       struct resource *res;
+       struct resource_list_x *list, *tmp, *prev;
+       struct resource_list *hlist;
+       resource_size_t add_size;
+       int idx;
+
+       prev = add_head;
+       for (list = add_head->next; list;) {
                res = list->res;
+               /* skip resource that has been reset */
+               if (!res->flags)
+                       goto out;
+
+               /* skip this resource if not found in head list */
+               for (hlist = head->next; hlist && hlist->res != res;
+                               hlist = hlist->next);
+               if (!hlist) { /* just skip */
+                       prev = list;
+                       list = list->next;
+                       continue;
+               }
+
                idx = res - &list->dev->resource[0];
-               if (pci_assign_resource(list->dev, idx)) {
-                       res->start = 0;
-                       res->end = 0;
-                       res->flags = 0;
+               add_size=list->add_size;
+               if (!resource_size(res) && add_size) {
+                        res->end = res->start + add_size - 1;
+                        if(pci_assign_resource(list->dev, idx))
+                               reset_resource(res);
+               } else if (add_size) {
+                       adjust_resource(res, res->start,
+                               resource_size(res) + add_size);
                }
+out:
                tmp = list;
-               list = list->next;
+               prev->next = list = list->next;
                kfree(tmp);
        }
 }
 
+/**
+ * assign_requested_resources_sorted() - satisfy resource requests
+ *
+ * @head : head of the list tracking requests for resources
+ * @failed_list : 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 resource_list *head,
+                                struct resource_list_x *fail_head)
+{
+       struct resource *res;
+       struct resource_list *list;
+       int idx;
+
+       for (list = head->next; list; list = list->next) {
+               res = list->res;
+               idx = res - &list->dev->resource[0];
+               if (resource_size(res) && pci_assign_resource(list->dev, idx)) {
+                       if (fail_head && !pci_is_root_bus(list->dev->bus)) {
+                               /*
+                                * 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_failed_list(fail_head, list->dev, res);
+                       }
+                       reset_resource(res);
+               }
+       }
+}
+
+static void __assign_resources_sorted(struct resource_list *head,
+                                struct resource_list_x *add_head,
+                                struct resource_list_x *fail_head)
+{
+       /* Satisfy the must-have resource requests */
+       assign_requested_resources_sorted(head, fail_head);
+
+       /* Try to satisfy any additional nice-to-have resource
+               requests */
+       if (add_head)
+               adjust_resources_sorted(add_head, head);
+       free_list(resource_list, head);
+}
+
+static void pdev_assign_resources_sorted(struct pci_dev *dev,
+                                struct resource_list_x *fail_head)
+{
+       struct resource_list head;
+
+       head.next = NULL;
+       __dev_sort_resources(dev, &head);
+       __assign_resources_sorted(&head, NULL, fail_head);
+
+}
+
+static void pbus_assign_resources_sorted(const struct pci_bus *bus,
+                                        struct resource_list_x *add_head,
+                                        struct resource_list_x *fail_head)
+{
+       struct pci_dev *dev;
+       struct resource_list head;
+
+       head.next = NULL;
+       list_for_each_entry(dev, &bus->devices, bus_list)
+               __dev_sort_resources(dev, &head);
+
+       __assign_resources_sorted(&head, add_head, fail_head);
+}
+
 void pci_setup_cardbus(struct pci_bus *bus)
 {
        struct pci_dev *bridge = bus->self;
@@ -134,19 +307,12 @@ EXPORT_SYMBOL(pci_setup_cardbus);
    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(struct pci_bus *bus)
+static void pci_setup_bridge_io(struct pci_bus *bus)
 {
        struct pci_dev *bridge = bus->self;
        struct resource *res;
        struct pci_bus_region region;
-       u32 l, bu, lu, io_upper16;
-       int pref_mem64;
-
-       if (pci_is_enabled(bridge))
-               return;
-
-       dev_info(&bridge->dev, "PCI bridge to [bus %02x-%02x]\n",
-                bus->secondary, bus->subordinate);
+       u32 l, io_upper16;
 
        /* Set up the top and bottom of the PCI I/O segment for this bus. */
        res = bus->resource[0];
@@ -159,8 +325,7 @@ static void pci_setup_bridge(struct pci_bus *bus)
                /* 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 {
+       } else {
                /* Clear upper 16 bits of I/O base/limit. */
                io_upper16 = 0;
                l = 0x00f0;
@@ -172,21 +337,35 @@ static void pci_setup_bridge(struct pci_bus *bus)
        pci_write_config_dword(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_bus *bus)
+{
+       struct pci_dev *bridge = bus->self;
+       struct resource *res;
+       struct pci_bus_region region;
+       u32 l;
 
-       /* Set up the top and bottom of the PCI Memory segment
-          for this bus. */
+       /* Set up the top and bottom of the PCI Memory segment for this bus. */
        res = bus->resource[1];
        pcibios_resource_to_bus(bridge, &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 {
+       } else {
                l = 0x0000fff0;
                dev_info(&bridge->dev, "  bridge window [mem disabled]\n");
        }
        pci_write_config_dword(bridge, PCI_MEMORY_BASE, l);
+}
+
+static void pci_setup_bridge_mmio_pref(struct pci_bus *bus)
+{
+       struct pci_dev *bridge = bus->self;
+       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
@@ -194,7 +373,6 @@ static void pci_setup_bridge(struct pci_bus *bus)
        pci_write_config_dword(bridge, PCI_PREF_LIMIT_UPPER32, 0);
 
        /* Set up PREF base/limit. */
-       pref_mem64 = 0;
        bu = lu = 0;
        res = bus->resource[2];
        pcibios_resource_to_bus(bridge, &region, res);
@@ -202,27 +380,48 @@ static void pci_setup_bridge(struct pci_bus *bus)
                l = (region.start >> 16) & 0xfff0;
                l |= region.end & 0xfff00000;
                if (res->flags & IORESOURCE_MEM_64) {
-                       pref_mem64 = 1;
                        bu = upper_32_bits(region.start);
                        lu = upper_32_bits(region.end);
                }
                dev_info(&bridge->dev, "  bridge window %pR\n", res);
-       }
-       else {
+       } else {
                l = 0x0000fff0;
                dev_info(&bridge->dev, "  bridge window [mem pref disabled]\n");
        }
        pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, l);
 
-       if (pref_mem64) {
-               /* 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);
-       }
+       /* 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 [bus %02x-%02x]\n",
+                bus->secondary, bus->subordinate);
+
+       if (type & IORESOURCE_IO)
+               pci_setup_bridge_io(bus);
+
+       if (type & IORESOURCE_MEM)
+               pci_setup_bridge_mmio(bus);
+
+       if (type & IORESOURCE_PREFETCH)
+               pci_setup_bridge_mmio_pref(bus);
 
        pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, bus->bridge_ctl);
 }
 
+static void pci_setup_bridge(struct pci_bus *bus)
+{
+       unsigned long type = IORESOURCE_IO | IORESOURCE_MEM |
+                                 IORESOURCE_PREFETCH;
+
+       __pci_setup_bridge(bus, type);
+}
+
 /* 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. */
@@ -258,8 +457,11 @@ static void pci_bridge_check_ranges(struct pci_bus *bus)
        }
        if (pmem) {
                b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
-               if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64)
+               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 */
@@ -288,8 +490,7 @@ static struct resource *find_free_bus_resource(struct pci_bus *bus, unsigned lon
        unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
                                  IORESOURCE_PREFETCH;
 
-       for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
-               r = bus->resource[i];
+       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)
@@ -298,15 +499,62 @@ static struct resource *find_free_bus_resource(struct pci_bus *bus, unsigned lon
        return NULL;
 }
 
-/* Sizing the IO windows of the PCI-PCI bridge is trivial,
-   since these windows have 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)
+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;
+}
+
+/**
+ * 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
+ * @add_head : track the additional io window on this list
+ *
+ * Sizing the IO windows of the PCI-PCI bridge is trivial,
+ * since these windows have 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 resource_list_x *add_head)
 {
        struct pci_dev *dev;
        struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
-       unsigned long size = 0, size1 = 0;
+       unsigned long size = 0, size0 = 0, size1 = 0;
 
        if (!b_res)
                return;
@@ -329,15 +577,12 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
                                size1 += r_size;
                }
        }
-       if (size < min_size)
-               size = min_size;
-/* 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, 4096);
-       if (!size) {
+       size0 = calculate_iosize(size, min_size, size1,
+                       resource_size(b_res), 4096);
+       size1 = !add_size? size0:
+               calculate_iosize(size, min_size+add_size, size1,
+                       resource_size(b_res), 4096);
+       if (!size0 && !size1) {
                if (b_res->start || b_res->end)
                        dev_info(&bus->self->dev, "disabling bridge window "
                                 "%pR to [bus %02x-%02x] (unused)\n", b_res,
@@ -347,17 +592,30 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
        }
        /* Alignment of the IO window is always 4K */
        b_res->start = 4096;
-       b_res->end = b_res->start + size - 1;
+       b_res->end = b_res->start + size0 - 1;
        b_res->flags |= IORESOURCE_STARTALIGN;
+       if (size1 > size0 && add_head)
+               add_to_list(add_head, bus->self, b_res, size1-size0);
 }
 
-/* Calculate the size of the bus and minimal alignment which
-   guarantees that all child resources fit in this size. */
+/**
+ * pbus_size_mem() - size the memory window of a given bus
+ *
+ * @bus : the bus
+ * @min_size : the minimum memory window that must to be allocated
+ * @add_size : additional optional memory window
+ * @add_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.
+ */
 static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
-                        unsigned long type, resource_size_t min_size)
+                        unsigned long type, resource_size_t min_size,
+                       resource_size_t add_size,
+                       struct resource_list_x *add_head)
 {
        struct pci_dev *dev;
-       resource_size_t min_align, align, size;
+       resource_size_t min_align, align, size, size0, size1;
        resource_size_t aligns[12];     /* Alignments from 1Mb to 2Gb */
        int order, max_order;
        struct resource *b_res = find_free_bus_resource(bus, type);
@@ -405,9 +663,6 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                        mem64_mask &= r->flags & IORESOURCE_MEM_64;
                }
        }
-       if (size < min_size)
-               size = min_size;
-
        align = 0;
        min_align = 0;
        for (order = 0; order <= max_order; order++) {
@@ -421,8 +676,11 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                        min_align = align1 >> 1;
                align += aligns[order];
        }
-       size = ALIGN(size, min_align);
-       if (!size) {
+       size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);
+       size1 = !add_size ? size :
+               calculate_memsize(size, min_size+add_size, 0,
+                               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 [bus %02x-%02x] (unused)\n", b_res,
@@ -431,9 +689,10 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                return 1;
        }
        b_res->start = min_align;
-       b_res->end = size + min_align - 1;
-       b_res->flags |= IORESOURCE_STARTALIGN;
-       b_res->flags |= mem64_mask;
+       b_res->end = size0 + min_align - 1;
+       b_res->flags |= IORESOURCE_STARTALIGN | mem64_mask;
+       if (size1 > size0 && add_head)
+               add_to_list(add_head, bus->self, b_res, size1-size0);
        return 1;
 }
 
@@ -486,11 +745,12 @@ static void pci_bus_size_cardbus(struct pci_bus *bus)
        }
 }
 
-void __ref pci_bus_size_bridges(struct pci_bus *bus)
+void __ref __pci_bus_size_bridges(struct pci_bus *bus,
+                       struct resource_list_x *add_head)
 {
        struct pci_dev *dev;
        unsigned long mask, prefmask;
-       resource_size_t min_mem_size = 0, min_io_size = 0;
+       resource_size_t additional_mem_size = 0, additional_io_size = 0;
 
        list_for_each_entry(dev, &bus->devices, bus_list) {
                struct pci_bus *b = dev->subordinate;
@@ -504,7 +764,7 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
 
                case PCI_CLASS_BRIDGE_PCI:
                default:
-                       pci_bus_size_bridges(b);
+                       __pci_bus_size_bridges(b, add_head);
                        break;
                }
        }
@@ -521,11 +781,14 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
        case PCI_CLASS_BRIDGE_PCI:
                pci_bridge_check_ranges(bus);
                if (bus->self->is_hotplug_bridge) {
-                       min_io_size  = pci_hotplug_io_size;
-                       min_mem_size = pci_hotplug_mem_size;
+                       additional_io_size  = pci_hotplug_io_size;
+                       additional_mem_size = pci_hotplug_mem_size;
                }
+               /*
+                * Follow thru
+                */
        default:
-               pbus_size_io(bus, min_io_size);
+               pbus_size_io(bus, 0, additional_io_size, add_head);
                /* If the bridge supports prefetchable range, size it
                   separately. If it doesn't, or its prefetchable window
                   has already been allocated by arch code, try
@@ -533,33 +796,41 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
                   resources. */
                mask = IORESOURCE_MEM;
                prefmask = IORESOURCE_MEM | IORESOURCE_PREFETCH;
-               if (pbus_size_mem(bus, prefmask, prefmask, min_mem_size))
+               if (pbus_size_mem(bus, prefmask, prefmask, 0, additional_mem_size, add_head))
                        mask = prefmask; /* Success, size non-prefetch only. */
                else
-                       min_mem_size += min_mem_size;
-               pbus_size_mem(bus, mask, IORESOURCE_MEM, min_mem_size);
+                       additional_mem_size += additional_mem_size;
+               pbus_size_mem(bus, mask, IORESOURCE_MEM, 0, additional_mem_size, add_head);
                break;
        }
 }
+
+void __ref pci_bus_size_bridges(struct pci_bus *bus)
+{
+       __pci_bus_size_bridges(bus, NULL);
+}
 EXPORT_SYMBOL(pci_bus_size_bridges);
 
-void __ref pci_bus_assign_resources(const struct pci_bus *bus)
+static void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
+                                        struct resource_list_x *add_head,
+                                        struct resource_list_x *fail_head)
 {
        struct pci_bus *b;
        struct pci_dev *dev;
 
-       pbus_assign_resources_sorted(bus);
+       pbus_assign_resources_sorted(bus, add_head, fail_head);
 
        list_for_each_entry(dev, &bus->devices, bus_list) {
                b = dev->subordinate;
                if (!b)
                        continue;
 
-               pci_bus_assign_resources(b);
+               __pci_bus_assign_resources(b, add_head, fail_head);
 
                switch (dev->class >> 8) {
                case PCI_CLASS_BRIDGE_PCI:
-                       pci_setup_bridge(b);
+                       if (!pci_is_enabled(dev))
+                               pci_setup_bridge(b);
                        break;
 
                case PCI_CLASS_BRIDGE_CARDBUS:
@@ -573,15 +844,130 @@ void __ref pci_bus_assign_resources(const struct pci_bus *bus)
                }
        }
 }
+
+void __ref pci_bus_assign_resources(const struct pci_bus *bus)
+{
+       __pci_bus_assign_resources(bus, NULL, NULL);
+}
 EXPORT_SYMBOL(pci_bus_assign_resources);
 
+static void __ref __pci_bridge_assign_resources(const struct pci_dev *bridge,
+                                        struct resource_list_x *fail_head)
+{
+       struct pci_bus *b;
+
+       pdev_assign_resources_sorted((struct pci_dev *)bridge, fail_head);
+
+       b = bridge->subordinate;
+       if (!b)
+               return;
+
+       __pci_bus_assign_resources(b, NULL, 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)
+{
+       int idx;
+       bool changed = false;
+       struct pci_dev *dev;
+       struct resource *r;
+       unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+                                 IORESOURCE_PREFETCH;
+
+       dev = bus->self;
+       for (idx = PCI_BRIDGE_RESOURCES; idx <= PCI_BRIDGE_RESOURCE_END;
+            idx++) {
+               r = &dev->resource[idx];
+               if ((r->flags & type_mask) != type)
+                       continue;
+               if (!r->parent)
+                       continue;
+               /*
+                * if there are children under that, we should release them
+                *  all
+                */
+               release_child_resources(r);
+               if (!release_resource(r)) {
+                       dev_printk(KERN_DEBUG, &dev->dev,
+                                "resource %d %pR released\n", idx, r);
+                       /* keep the old size */
+                       r->end = resource_size(r) - 1;
+                       r->start = 0;
+                       r->flags = 0;
+                       changed = true;
+               }
+       }
+
+       if (changed) {
+               /* avoiding touch the one without PREF */
+               if (type & IORESOURCE_PREFETCH)
+                       type = IORESOURCE_PREFETCH;
+               __pci_setup_bridge(bus, type);
+       }
+}
+
+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 __ref 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)
 {
-        int i;
+       struct resource *res;
+       int i;
 
-        for (i = 0; i < PCI_BUS_NUM_RESOURCES; i++) {
-                struct resource *res = bus->resource[i];
-                if (!res || !res->end)
+       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);
@@ -609,20 +995,88 @@ void __init
 pci_assign_unassigned_resources(void)
 {
        struct pci_bus *bus;
-
+       struct resource_list_x add_list; /* list of resources that
+                                       want additional resources */
+       add_list.next = NULL;
        /* Depth first, calculate sizes and alignments of all
           subordinate buses. */
        list_for_each_entry(bus, &pci_root_buses, node) {
-               pci_bus_size_bridges(bus);
+               __pci_bus_size_bridges(bus, &add_list);
        }
+
        /* Depth last, allocate resources and update the hardware. */
        list_for_each_entry(bus, &pci_root_buses, node) {
-               pci_bus_assign_resources(bus);
+               __pci_bus_assign_resources(bus, &add_list, NULL);
                pci_enable_bridges(bus);
        }
+       BUG_ON(add_list.next);
 
        /* dump the resource on buses */
        list_for_each_entry(bus, &pci_root_buses, node) {
                pci_bus_dump_resources(bus);
        }
 }
+
+void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
+{
+       struct pci_bus *parent = bridge->subordinate;
+       int tried_times = 0;
+       struct resource_list_x head, *list;
+       int retval;
+       unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
+                                 IORESOURCE_PREFETCH;
+
+       head.next = NULL;
+
+again:
+       pci_bus_size_bridges(parent);
+       __pci_bridge_assign_resources(bridge, &head);
+
+       tried_times++;
+
+       if (!head.next)
+               goto enable_all;
+
+       if (tried_times >= 2) {
+               /* still fail, don't need to try more */
+               free_list(resource_list_x, &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
+        */
+       for (list = head.next; list;) {
+               struct pci_bus *bus = list->dev->bus;
+               unsigned long flags = list->flags;
+
+               pci_bus_release_bridge_resources(bus, flags & type_mask,
+                                                whole_subtree);
+               list = list->next;
+       }
+       /* restore size and flags */
+       for (list = head.next; list;) {
+               struct resource *res = list->res;
+
+               res->start = list->start;
+               res->end = list->end;
+               res->flags = list->flags;
+               if (list->dev->subordinate)
+                       res->flags = 0;
+
+               list = list->next;
+       }
+       free_list(resource_list_x, &head);
+
+       goto again;
+
+enable_all:
+       retval = pci_reenable_device(bridge);
+       pci_set_master(bridge);
+       pci_enable_bridges(parent);
+}
+EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);