Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: OF: Don't crash when bridge parent is NULL.
  PCI: export pcie_bus_configure_settings symbol
  PCI: code and comments cleanup
  PCI: make cardbus-bridge resources optional
  PCI: make SRIOV resources optional
  PCI : ability to relocate assigned pci-resources
  PCI: honor child buses add_size in hot plug configuration
  PCI: Set PCI-E Max Payload Size on fabric

7 files changed, 430 insertions, 152 deletions

diff --git a/drivers/pci/hotplug/pcihp_slot.c b/drivers/pci/hotplug/pcihp_slot.c
index 749fdf070319..753b21aaea61 100644
--- a/drivers/pci/hotplug/pcihp_slot.c
+++ b/drivers/pci/hotplug/pcihp_slot.c
@@ -158,47 +158,6 @@ static void program_hpp_type2(struct pci_dev *dev, struct hpp_type2 *hpp)
          */
 }
 
-/* Program PCIE MaxPayload setting on device: ensure parent maxpayload <= device */
-static int pci_set_payload(struct pci_dev *dev)
-{
-       int pos, ppos;
-       u16 pctl, psz;
-       u16 dctl, dsz, dcap, dmax;
-       struct pci_dev *parent;
-
-       parent = dev->bus->self;
-       pos = pci_find_capability(dev, PCI_CAP_ID_EXP);
-       if (!pos)
-               return 0;
-
-       /* Read Device MaxPayload capability and setting */
-       pci_read_config_word(dev, pos + PCI_EXP_DEVCTL, &dctl);
-       pci_read_config_word(dev, pos + PCI_EXP_DEVCAP, &dcap);
-       dsz = (dctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5;
-       dmax = (dcap & PCI_EXP_DEVCAP_PAYLOAD);
-
-       /* Read Parent MaxPayload setting */
-       ppos = pci_find_capability(parent, PCI_CAP_ID_EXP);
-       if (!ppos)
-               return 0;
-       pci_read_config_word(parent, ppos + PCI_EXP_DEVCTL, &pctl);
-       psz = (pctl &  PCI_EXP_DEVCTL_PAYLOAD) >> 5;
-
-       /* If parent payload > device max payload -> error
-        * If parent payload > device payload -> set speed
-        * If parent payload <= device payload -> do nothing
-        */
-       if (psz > dmax)
-               return -1;
-       else if (psz > dsz) {
-               dev_info(&dev->dev, "Setting MaxPayload to %d\n", 128 << psz);
-               pci_write_config_word(dev, pos + PCI_EXP_DEVCTL,
-                                     (dctl & ~PCI_EXP_DEVCTL_PAYLOAD) +
-                                     (psz << 5));
-       }
-       return 0;
-}
-
 void pci_configure_slot(struct pci_dev *dev)
 {
         struct pci_dev *cdev;
@@ -210,9 +169,7 @@ void pci_configure_slot(struct pci_dev *dev)
                         (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI)))
                 return;
 
-       ret = pci_set_payload(dev);
-       if (ret)
-               dev_warn(&dev->dev, "could not set device max payload\n");
+        pcie_bus_configure_settings(dev->bus, dev->bus->self->pcie_mpss);
 
         memset(&hpp, 0, sizeof(hpp));
         ret = pci_get_hp_params(dev, &hpp);
diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index c94d37ec55c8..f0929934bb7a 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -55,7 +55,7 @@ struct device_node * __weak pcibios_get_phb_of_node(struct pci_bus *bus)
          */
         if (bus->bridge->of_node)
                 return of_node_get(bus->bridge->of_node);
-        if (bus->bridge->parent->of_node)
+        if (bus->bridge->parent && bus->bridge->parent->of_node)
                 return of_node_get(bus->bridge->parent->of_node);
         return NULL;
 }
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 08a95b369d85..466fad6e6ee2 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -77,6 +77,8 @@ unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE;
 unsigned long pci_hotplug_io_size  = DEFAULT_HOTPLUG_IO_SIZE;
 unsigned long pci_hotplug_mem_size = DEFAULT_HOTPLUG_MEM_SIZE;
 
+enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PERFORMANCE;
+
 /*
  * The default CLS is used if arch didn't set CLS explicitly and not
  * all pci devices agree on the same value.  Arch can override either
@@ -3223,6 +3225,67 @@ out:
 EXPORT_SYMBOL(pcie_set_readrq);
 
 /**
+ * pcie_get_mps - get PCI Express maximum payload size
+ * @dev: PCI device to query
+ *
+ * Returns maximum payload size in bytes
+ *    or appropriate error value.
+ */
+int pcie_get_mps(struct pci_dev *dev)
+{
+        int ret, cap;
+        u16 ctl;
+
+        cap = pci_pcie_cap(dev);
+        if (!cap)
+                return -EINVAL;
+
+        ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
+        if (!ret)
+                ret = 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5);
+
+        return ret;
+}
+
+/**
+ * pcie_set_mps - set PCI Express maximum payload size
+ * @dev: PCI device to query
+ * @rq: maximum payload size in bytes
+ *    valid values are 128, 256, 512, 1024, 2048, 4096
+ *
+ * If possible sets maximum payload size
+ */
+int pcie_set_mps(struct pci_dev *dev, int mps)
+{
+        int cap, err = -EINVAL;
+        u16 ctl, v;
+
+        if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
+                goto out;
+
+        v = ffs(mps) - 8;
+        if (v > dev->pcie_mpss) 
+                goto out;
+        v <<= 5;
+
+        cap = pci_pcie_cap(dev);
+        if (!cap)
+                goto out;
+
+        err = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl);
+        if (err)
+                goto out;
+
+        if ((ctl & PCI_EXP_DEVCTL_PAYLOAD) != v) {
+                ctl &= ~PCI_EXP_DEVCTL_PAYLOAD;
+                ctl |= v;
+                err = pci_write_config_word(dev, cap + PCI_EXP_DEVCTL, ctl);
+        }
+out:
+        return err;
+}
+
+/**
  * pci_select_bars - Make BAR mask from the type of resource
  * @dev: the PCI device for which BAR mask is made
  * @flags: resource type mask to be selected
@@ -3505,6 +3568,10 @@ static int __init pci_setup(char *str)
                                 pci_hotplug_io_size = memparse(str + 9, &str);
                         } else if (!strncmp(str, "hpmemsize=", 10)) {
                                 pci_hotplug_mem_size = memparse(str + 10, &str);
+                        } else if (!strncmp(str, "pcie_bus_safe", 13)) {
+                                pcie_bus_config = PCIE_BUS_SAFE;
+                        } else if (!strncmp(str, "pcie_bus_perf", 13)) {
+                                pcie_bus_config = PCIE_BUS_PERFORMANCE;
                         } else {
                                 printk(KERN_ERR "PCI: Unknown option `%s'\n",
                                                 str);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index c8cee764b0de..b74084e9ca12 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -283,6 +283,8 @@ static inline int pci_iov_bus_range(struct pci_bus *bus)
 
 #endif /* CONFIG_PCI_IOV */
 
+extern unsigned long pci_cardbus_resource_alignment(struct resource *);
+
 static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
                                          struct resource *res)
 {
@@ -292,6 +294,8 @@ static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
         if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END)
                 return pci_sriov_resource_alignment(dev, resno);
 #endif
+        if (dev->class >> 8  == PCI_CLASS_BRIDGE_CARDBUS)
+                return pci_cardbus_resource_alignment(res);
         return resource_alignment(res);
 }
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 795c9026d55f..8473727b29fa 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -856,6 +856,8 @@ void set_pcie_port_type(struct pci_dev *pdev)
         pdev->pcie_cap = pos;
         pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
         pdev->pcie_type = (reg16 & PCI_EXP_FLAGS_TYPE) >> 4;
+        pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
+        pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
 }
 
 void set_pcie_hotplug_bridge(struct pci_dev *pdev)
@@ -1326,6 +1328,150 @@ int pci_scan_slot(struct pci_bus *bus, int devfn)
         return nr;
 }
 
+static int pcie_find_smpss(struct pci_dev *dev, void *data)
+{
+        u8 *smpss = data;
+
+        if (!pci_is_pcie(dev))
+                return 0;
+
+        /* For PCIE hotplug enabled slots not connected directly to a
+         * PCI-E root port, there can be problems when hotplugging
+         * devices.  This is due to the possibility of hotplugging a
+         * device into the fabric with a smaller MPS that the devices
+         * currently running have configured.  Modifying the MPS on the
+         * running devices could cause a fatal bus error due to an
+         * incoming frame being larger than the newly configured MPS.
+         * To work around this, the MPS for the entire fabric must be
+         * set to the minimum size.  Any devices hotplugged into this
+         * fabric will have the minimum MPS set.  If the PCI hotplug
+         * slot is directly connected to the root port and there are not
+         * other devices on the fabric (which seems to be the most
+         * common case), then this is not an issue and MPS discovery
+         * will occur as normal.
+         */
+        if (dev->is_hotplug_bridge && (!list_is_singular(&dev->bus->devices) ||
+            dev->bus->self->pcie_type != PCI_EXP_TYPE_ROOT_PORT))
+                *smpss = 0;
+
+        if (*smpss > dev->pcie_mpss)
+                *smpss = dev->pcie_mpss;
+
+        return 0;
+}
+
+static void pcie_write_mps(struct pci_dev *dev, int mps)
+{
+        int rc, dev_mpss;
+
+        dev_mpss = 128 << dev->pcie_mpss;
+
+        if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
+                if (dev->bus->self) {
+                        dev_dbg(&dev->bus->dev, "Bus MPSS %d\n",
+                                128 << dev->bus->self->pcie_mpss);
+
+                        /* For "MPS Force Max", the assumption is made that
+                         * downstream communication will never be larger than
+                         * the MRRS.  So, the MPS only needs to be configured
+                         * for the upstream communication.  This being the case,
+                         * walk from the top down and set the MPS of the child
+                         * to that of the parent bus.
+                         */
+                        mps = 128 << dev->bus->self->pcie_mpss;
+                        if (mps > dev_mpss)
+                                dev_warn(&dev->dev, "MPS configured higher than"
+                                         " maximum supported by the device.  If"
+                                         " a bus issue occurs, try running with"
+                                         " pci=pcie_bus_safe.\n");
+                }
+
+                dev->pcie_mpss = ffs(mps) - 8;
+        }
+
+        rc = pcie_set_mps(dev, mps);
+        if (rc)
+                dev_err(&dev->dev, "Failed attempting to set the MPS\n");
+}
+
+static void pcie_write_mrrs(struct pci_dev *dev, int mps)
+{
+        int rc, mrrs;
+
+        if (pcie_bus_config == PCIE_BUS_PERFORMANCE) {
+                int dev_mpss = 128 << dev->pcie_mpss;
+
+                /* For Max performance, the MRRS must be set to the largest
+                 * supported value.  However, it cannot be configured larger
+                 * than the MPS the device or the bus can support.  This assumes
+                 * that the largest MRRS available on the device cannot be
+                 * smaller than the device MPSS.
+                 */
+                mrrs = mps < dev_mpss ? mps : dev_mpss;
+        } else
+                /* In the "safe" case, configure the MRRS for fairness on the
+                 * bus by making all devices have the same size
+                 */
+                mrrs = mps;
+
+
+        /* MRRS is a R/W register.  Invalid values can be written, but a
+         * subsiquent read will verify if the value is acceptable or not.
+         * If the MRRS value provided is not acceptable (e.g., too large),
+         * shrink the value until it is acceptable to the HW.
+         */
+        while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) {
+                rc = pcie_set_readrq(dev, mrrs);
+                if (rc)
+                        dev_err(&dev->dev, "Failed attempting to set the MRRS\n");
+
+                mrrs /= 2;
+        }
+}
+
+static int pcie_bus_configure_set(struct pci_dev *dev, void *data)
+{
+        int mps = 128 << *(u8 *)data;
+
+        if (!pci_is_pcie(dev))
+                return 0;
+
+        dev_info(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
+                 pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev));
+
+        pcie_write_mps(dev, mps);
+        pcie_write_mrrs(dev, mps);
+
+        dev_info(&dev->dev, "Dev MPS %d MPSS %d MRRS %d\n",
+                 pcie_get_mps(dev), 128<<dev->pcie_mpss, pcie_get_readrq(dev));
+
+        return 0;
+}
+
+/* pcie_bus_configure_mps requires that pci_walk_bus work in a top-down,
+ * parents then children fashion.  If this changes, then this code will not
+ * work as designed.
+ */
+void pcie_bus_configure_settings(struct pci_bus *bus, u8 mpss)
+{
+        u8 smpss = mpss;
+
+        if (!bus->self)
+                return;
+
+        if (!pci_is_pcie(bus->self))
+                return;
+
+        if (pcie_bus_config == PCIE_BUS_SAFE) {
+                pcie_find_smpss(bus->self, &smpss);
+                pci_walk_bus(bus, pcie_find_smpss, &smpss);
+        }
+
+        pcie_bus_configure_set(bus->self, &smpss);
+        pci_walk_bus(bus, pcie_bus_configure_set, &smpss);
+}
+EXPORT_SYMBOL_GPL(pcie_bus_configure_settings);
+
 unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus)
 {
         unsigned int devfn, pass, max = bus->secondary;
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 8a1d3c7863a8..784da9d36029 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -34,6 +34,7 @@ struct resource_list_x {
         resource_size_t start;
         resource_size_t end;
         resource_size_t add_size;
+        resource_size_t min_align;
         unsigned long flags;
 };
 
@@ -65,7 +66,7 @@ void pci_realloc(void)
  */
 static void add_to_list(struct resource_list_x *head,
                  struct pci_dev *dev, struct resource *res,
-                 resource_size_t add_size)
+                 resource_size_t add_size, resource_size_t min_align)
 {
         struct resource_list_x *list = head;
         struct resource_list_x *ln = list->next;
@@ -84,13 +85,16 @@ static void add_to_list(struct resource_list_x *head,
         tmp->end = res->end;
         tmp->flags = res->flags;
         tmp->add_size = add_size;
+        tmp->min_align = min_align;
         list->next = tmp;
 }
 
 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);
+        add_to_list(head, dev, res,
+                        0 /* dont care */,
+                        0 /* dont care */);
 }
 
 static void __dev_sort_resources(struct pci_dev *dev,
@@ -121,18 +125,18 @@ static inline void reset_resource(struct resource *res)
 }
 
 /**
- * adjust_resources_sorted() - satisfy any additional resource requests
+ * reassign_resources_sorted() - satisfy any additional resource requests
  *
- * @add_head : head of the list tracking requests requiring additional
+ * @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 add_head and try to procure
+ * 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 adjust_resources_sorted(struct resource_list_x *add_head,
+static void reassign_resources_sorted(struct resource_list_x *realloc_head,
                 struct resource_list *head)
 {
         struct resource *res;
@@ -141,8 +145,8 @@ static void adjust_resources_sorted(struct resource_list_x *add_head,
         resource_size_t add_size;
         int idx;
 
-        prev = add_head;
-        for (list = add_head->next; list;) {
+        prev = realloc_head;
+        for (list = realloc_head->next; list;) {
                 res = list->res;
                 /* skip resource that has been reset */
                 if (!res->flags)
@@ -159,13 +163,17 @@ static void adjust_resources_sorted(struct resource_list_x *add_head,
 
                 idx = res - &list->dev->resource[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))
+                if (!resource_size(res)) {
+                        res->start = list->start;
+                        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);
+                } else {
+                        resource_size_t align = list->min_align;
+                        res->flags |= list->flags & (IORESOURCE_STARTALIGN|IORESOURCE_SIZEALIGN);
+                        if (pci_reassign_resource(list->dev, idx, add_size, align))
+                                dev_printk(KERN_DEBUG, &list->dev->dev, "failed to add optional resources res=%pR\n",
+                                                        res);
                 }
 out:
                 tmp = list;
@@ -210,16 +218,16 @@ static void assign_requested_resources_sorted(struct resource_list *head,
 }
 
 static void __assign_resources_sorted(struct resource_list *head,
-                                 struct resource_list_x *add_head,
+                                 struct resource_list_x *realloc_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
+        /* Try to satisfy any additional optional resource
                 requests */
-        if (add_head)
-                adjust_resources_sorted(add_head, head);
+        if (realloc_head)
+                reassign_resources_sorted(realloc_head, head);
         free_list(resource_list, head);
 }
 
@@ -235,7 +243,7 @@ static void pdev_assign_resources_sorted(struct pci_dev *dev,
 }
 
 static void pbus_assign_resources_sorted(const struct pci_bus *bus,
-                                         struct resource_list_x *add_head,
+                                         struct resource_list_x *realloc_head,
                                          struct resource_list_x *fail_head)
 {
         struct pci_dev *dev;
@@ -245,7 +253,7 @@ static void pbus_assign_resources_sorted(const struct pci_bus *bus,
         list_for_each_entry(dev, &bus->devices, bus_list)
                 __dev_sort_resources(dev, &head);
 
-        __assign_resources_sorted(&head, add_head, fail_head);
+        __assign_resources_sorted(&head, realloc_head, fail_head);
 }
 
 void pci_setup_cardbus(struct pci_bus *bus)
@@ -540,13 +548,27 @@ static resource_size_t calculate_memsize(resource_size_t size,
         return size;
 }
 
+static resource_size_t get_res_add_size(struct resource_list_x *realloc_head,
+                                        struct resource *res)
+{
+        struct resource_list_x *list;
+
+        /* check if it is in realloc_head list */
+        for (list = realloc_head->next; list && list->res != res;
+                        list = list->next);
+        if (list)
+                return list->add_size;
+
+        return 0;
+}
+
 /**
  * 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
+ * @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 4K granularity and the IO ranges
@@ -554,11 +576,12 @@ static resource_size_t calculate_memsize(resource_size_t size,
  * 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)
+                resource_size_t add_size, struct resource_list_x *realloc_head)
 {
         struct pci_dev *dev;
         struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
         unsigned long size = 0, size0 = 0, size1 = 0;
+        resource_size_t children_add_size = 0;
 
         if (!b_res)
                 return;
@@ -579,11 +602,16 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
                                 size += r_size;
                         else
                                 size1 += r_size;
+
+                        if (realloc_head)
+                                children_add_size += get_res_add_size(realloc_head, r);
                 }
         }
         size0 = calculate_iosize(size, min_size, size1,
                         resource_size(b_res), 4096);
-        size1 = (!add_head || (add_head && !add_size)) ? size0 :
+        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), 4096);
         if (!size0 && !size1) {
@@ -598,8 +626,8 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
         b_res->start = 4096;
         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);
+        if (size1 > size0 && realloc_head)
+                add_to_list(realloc_head, bus->self, b_res, size1-size0, 4096);
 }
 
 /**
@@ -608,7 +636,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
  * @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
+ * @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.
@@ -616,7 +644,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
 static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                          unsigned long type, resource_size_t min_size,
                         resource_size_t add_size,
-                        struct resource_list_x *add_head)
+                        struct resource_list_x *realloc_head)
 {
         struct pci_dev *dev;
         resource_size_t min_align, align, size, size0, size1;
@@ -624,6 +652,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
         int order, max_order;
         struct resource *b_res = find_free_bus_resource(bus, type);
         unsigned int mem64_mask = 0;
+        resource_size_t children_add_size = 0;
 
         if (!b_res)
                 return 0;
@@ -645,6 +674,16 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                         if (r->parent || (r->flags & mask) != type)
                                 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) {
+                                r->end = r->start - 1;
+                                add_to_list(realloc_head, dev, r, r_size, 0/* dont' care */);
+                                children_add_size += r_size;
+                                continue;
+                        }
+#endif
                         /* For bridges size != alignment */
                         align = pci_resource_alignment(dev, r);
                         order = __ffs(align) - 20;
@@ -665,6 +704,9 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                         if (order > max_order)
                                 max_order = order;
                         mem64_mask &= r->flags & IORESOURCE_MEM_64;
+
+                        if (realloc_head)
+                                children_add_size += get_res_add_size(realloc_head, r);
                 }
         }
         align = 0;
@@ -681,7 +723,9 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
                 align += aligns[order];
         }
         size0 = calculate_memsize(size, min_size, 0, resource_size(b_res), min_align);
-        size1 = (!add_head || (add_head && !add_size)) ? size0 :
+        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, 0,
                                 resource_size(b_res), min_align);
         if (!size0 && !size1) {
@@ -695,12 +739,22 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
         b_res->start = min_align;
         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);
+        if (size1 > size0 && realloc_head)
+                add_to_list(realloc_head, bus->self, b_res, size1-size0, min_align);
         return 1;
 }
 
-static void pci_bus_size_cardbus(struct pci_bus *bus)
+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 resource_list_x *realloc_head)
 {
         struct pci_dev *bridge = bus->self;
         struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
@@ -711,12 +765,14 @@ static void pci_bus_size_cardbus(struct pci_bus *bus)
          * a fixed amount of bus space for CardBus bridges.
          */
         b_res[0].start = 0;
-        b_res[0].end = pci_cardbus_io_size - 1;
         b_res[0].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN;
+        if (realloc_head)
+                add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size, 0 /* dont care */);
 
         b_res[1].start = 0;
-        b_res[1].end = pci_cardbus_io_size - 1;
         b_res[1].flags |= IORESOURCE_IO | IORESOURCE_SIZEALIGN;
+        if (realloc_head)
+                add_to_list(realloc_head, bridge, b_res+1, pci_cardbus_io_size, 0 /* dont care */);
 
         /*
          * Check whether prefetchable memory is supported
@@ -736,21 +792,31 @@ static void pci_bus_size_cardbus(struct pci_bus *bus)
          */
         if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
                 b_res[2].start = 0;
-                b_res[2].end = pci_cardbus_mem_size - 1;
                 b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH | IORESOURCE_SIZEALIGN;
+                if (realloc_head)
+                        add_to_list(realloc_head, bridge, b_res+2, pci_cardbus_mem_size, 0 /* dont care */);
 
                 b_res[3].start = 0;
-                b_res[3].end = pci_cardbus_mem_size - 1;
                 b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN;
+                if (realloc_head)
+                        add_to_list(realloc_head, bridge, b_res+3, pci_cardbus_mem_size, 0 /* dont care */);
         } else {
                 b_res[3].start = 0;
-                b_res[3].end = pci_cardbus_mem_size * 2 - 1;
                 b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_SIZEALIGN;
+                if (realloc_head)
+                        add_to_list(realloc_head, bridge, b_res+3, pci_cardbus_mem_size * 2, 0 /* dont care */);
         }
+
+        /* set the size of the resource to zero, so that the resource does not
+         * get assigned during required-resource allocation cycle but gets assigned
+         * during the optional-resource allocation cycle.
+         */
+        b_res[0].start = b_res[1].start = b_res[2].start = b_res[3].start = 1;
+        b_res[0].end = b_res[1].end = b_res[2].end = b_res[3].end = 0;
 }
 
 void __ref __pci_bus_size_bridges(struct pci_bus *bus,
-                        struct resource_list_x *add_head)
+                        struct resource_list_x *realloc_head)
 {
         struct pci_dev *dev;
         unsigned long mask, prefmask;
@@ -763,12 +829,12 @@ void __ref __pci_bus_size_bridges(struct pci_bus *bus,
 
                 switch (dev->class >> 8) {
                 case PCI_CLASS_BRIDGE_CARDBUS:
-                        pci_bus_size_cardbus(b);
+                        pci_bus_size_cardbus(b, realloc_head);
                         break;
 
                 case PCI_CLASS_BRIDGE_PCI:
                 default:
-                        __pci_bus_size_bridges(b, add_head);
+                        __pci_bus_size_bridges(b, realloc_head);
                         break;
                 }
         }
@@ -792,7 +858,7 @@ void __ref __pci_bus_size_bridges(struct pci_bus *bus,
                  * Follow thru
                  */
         default:
-                pbus_size_io(bus, 0, additional_io_size, add_head);
+                pbus_size_io(bus, 0, additional_io_size, realloc_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
@@ -800,11 +866,11 @@ 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, 0, additional_mem_size, add_head))
+                if (pbus_size_mem(bus, prefmask, prefmask, 0, additional_mem_size, realloc_head))
                         mask = prefmask; /* Success, size non-prefetch only. */
                 else
                         additional_mem_size += additional_mem_size;
-                pbus_size_mem(bus, mask, IORESOURCE_MEM, 0, additional_mem_size, add_head);
+                pbus_size_mem(bus, mask, IORESOURCE_MEM, 0, additional_mem_size, realloc_head);
                 break;
         }
 }
@@ -816,20 +882,20 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
 EXPORT_SYMBOL(pci_bus_size_bridges);
 
 static void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
-                                         struct resource_list_x *add_head,
+                                         struct resource_list_x *realloc_head,
                                          struct resource_list_x *fail_head)
 {
         struct pci_bus *b;
         struct pci_dev *dev;
 
-        pbus_assign_resources_sorted(bus, add_head, fail_head);
+        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, add_head, fail_head);
+                __pci_bus_assign_resources(b, realloc_head, fail_head);
 
                 switch (dev->class >> 8) {
                 case PCI_CLASS_BRIDGE_PCI:
@@ -1039,7 +1105,7 @@ void __init
 pci_assign_unassigned_resources(void)
 {
         struct pci_bus *bus;
-        struct resource_list_x add_list; /* list of resources that
+        struct resource_list_x realloc_list; /* list of resources that
                                         want additional resources */
         int tried_times = 0;
         enum release_type rel_type = leaf_only;
@@ -1052,7 +1118,7 @@ pci_assign_unassigned_resources(void)
 
 
         head.next = NULL;
-        add_list.next = NULL;
+        realloc_list.next = NULL;
 
         pci_try_num = max_depth + 1;
         printk(KERN_DEBUG "PCI: max bus depth: %d pci_try_num: %d\n",
@@ -1062,12 +1128,12 @@ again:
         /* Depth first, calculate sizes and alignments of all
            subordinate buses. */
         list_for_each_entry(bus, &pci_root_buses, node)
-                __pci_bus_size_bridges(bus, &add_list);
+                __pci_bus_size_bridges(bus, &realloc_list);
 
         /* Depth last, allocate resources and update the hardware. */
         list_for_each_entry(bus, &pci_root_buses, node)
-                __pci_bus_assign_resources(bus, &add_list, &head);
-        BUG_ON(add_list.next);
+                __pci_bus_assign_resources(bus, &realloc_list, &head);
+        BUG_ON(realloc_list.next);
         tried_times++;
 
         /* any device complain? */
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 319f359906e8..51a9095c7da4 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -128,16 +128,16 @@ void pci_disable_bridge_window(struct pci_dev *dev)
 }
 #endif  /* CONFIG_PCI_QUIRKS */
 
+
+
 static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
-                                 int resno)
+                int resno, resource_size_t size, resource_size_t align)
 {
         struct resource *res = dev->resource + resno;
-        resource_size_t size, min, align;
+        resource_size_t min;
         int ret;
 
-        size = resource_size(res);
         min = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
-        align = pci_resource_alignment(dev, res);
 
         /* First, try exact prefetching match.. */
         ret = pci_bus_alloc_resource(bus, res, size, align, min,
@@ -154,56 +154,101 @@ static int __pci_assign_resource(struct pci_bus *bus, struct pci_dev *dev,
                 ret = pci_bus_alloc_resource(bus, res, size, align, min, 0,
                                              pcibios_align_resource, dev);
         }
+        return ret;
+}
 
-        if (ret < 0 && dev->fw_addr[resno]) {
-                struct resource *root, *conflict;
-                resource_size_t start, end;
+static int pci_revert_fw_address(struct resource *res, struct pci_dev *dev, 
+                int resno, resource_size_t size)
+{
+        struct resource *root, *conflict;
+        resource_size_t start, end;
+        int ret = 0;
 
-                /*
-                 * If we failed to assign anything, let's try the address
-                 * where firmware left it.  That at least has a chance of
-                 * working, which is better than just leaving it disabled.
-                 */
+        if (res->flags & IORESOURCE_IO)
+                root = &ioport_resource;
+        else
+                root = &iomem_resource;
+
+        start = res->start;
+        end = res->end;
+        res->start = dev->fw_addr[resno];
+        res->end = res->start + size - 1;
+        dev_info(&dev->dev, "BAR %d: trying firmware assignment %pR\n",
+                 resno, res);
+        conflict = request_resource_conflict(root, res);
+        if (conflict) {
+                dev_info(&dev->dev,
+                         "BAR %d: %pR conflicts with %s %pR\n", resno,
+                         res, conflict->name, conflict);
+                res->start = start;
+                res->end = end;
+                ret = 1;
+        }
+        return ret;
+}
+
+static int _pci_assign_resource(struct pci_dev *dev, int resno, int size, resource_size_t min_align)
+{
+        struct resource *res = dev->resource + resno;
+        struct pci_bus *bus;
+        int ret;
+        char *type;
 
-                if (res->flags & IORESOURCE_IO)
-                        root = &ioport_resource;
+        bus = dev->bus;
+        while ((ret = __pci_assign_resource(bus, dev, resno, size, min_align))) {
+                if (!bus->parent || !bus->self->transparent)
+                        break;
+                bus = bus->parent;
+        }
+
+        if (ret) {
+                if (res->flags & IORESOURCE_MEM)
+                        if (res->flags & IORESOURCE_PREFETCH)
+                                type = "mem pref";
+                        else
+                                type = "mem";
+                else if (res->flags & IORESOURCE_IO)
+                        type = "io";
                 else
-                        root = &iomem_resource;
-
-                start = res->start;
-                end = res->end;
-                res->start = dev->fw_addr[resno];
-                res->end = res->start + size - 1;
-                dev_info(&dev->dev, "BAR %d: trying firmware assignment %pR\n",
-                         resno, res);
-                conflict = request_resource_conflict(root, res);
-                if (conflict) {
-                        dev_info(&dev->dev,
-                                 "BAR %d: %pR conflicts with %s %pR\n", resno,
-                                 res, conflict->name, conflict);
-                        res->start = start;
-                        res->end = end;
-                } else
-                        ret = 0;
+                        type = "unknown";
+                dev_info(&dev->dev,
+                         "BAR %d: can't assign %s (size %#llx)\n",
+                         resno, type, (unsigned long long) resource_size(res));
         }
 
+        return ret;
+}
+
+int pci_reassign_resource(struct pci_dev *dev, int resno, resource_size_t addsize,
+                        resource_size_t min_align)
+{
+        struct resource *res = dev->resource + resno;
+        resource_size_t new_size;
+        int ret;
+
+        if (!res->parent) {
+                dev_info(&dev->dev, "BAR %d: can't reassign an unassigned resouce %pR "
+                         "\n", resno, res);
+                return -EINVAL;
+        }
+
+        new_size = resource_size(res) + addsize + min_align;
+        ret = _pci_assign_resource(dev, resno, new_size, min_align);
         if (!ret) {
                 res->flags &= ~IORESOURCE_STARTALIGN;
                 dev_info(&dev->dev, "BAR %d: assigned %pR\n", resno, res);
                 if (resno < PCI_BRIDGE_RESOURCES)
                         pci_update_resource(dev, resno);
         }
-
         return ret;
 }
 
 int pci_assign_resource(struct pci_dev *dev, int resno)
 {
         struct resource *res = dev->resource + resno;
-        resource_size_t align;
+        resource_size_t align, size;
         struct pci_bus *bus;
         int ret;
-        char *type;
 
         align = pci_resource_alignment(dev, res);
         if (!align) {
@@ -213,34 +258,27 @@ int pci_assign_resource(struct pci_dev *dev, int resno)
         }
 
         bus = dev->bus;
-        while ((ret = __pci_assign_resource(bus, dev, resno))) {
-                if (bus->parent && bus->self->transparent)
-                        bus = bus->parent;
-                else
-                        bus = NULL;
-                if (bus)
-                        continue;
-                break;
-        }
+        size = resource_size(res);
+        ret = _pci_assign_resource(dev, resno, size, align);
 
-        if (ret) {
-                if (res->flags & IORESOURCE_MEM)
-                        if (res->flags & IORESOURCE_PREFETCH)
-                                type = "mem pref";
-                        else
-                                type = "mem";
-                else if (res->flags & IORESOURCE_IO)
-                        type = "io";
-                else
-                        type = "unknown";
-                dev_info(&dev->dev,
-                         "BAR %d: can't assign %s (size %#llx)\n",
-                         resno, type, (unsigned long long) resource_size(res));
-        }
+        /*
+         * If we failed to assign anything, let's try the address
+         * where firmware left it.  That at least has a chance of
+         * working, which is better than just leaving it disabled.
+         */
+        if (ret < 0 && dev->fw_addr[resno])
+                ret = pci_revert_fw_address(res, dev, resno, size);
 
+        if (!ret) {
+                res->flags &= ~IORESOURCE_STARTALIGN;
+                dev_info(&dev->dev, "BAR %d: assigned %pR\n", resno, res);
+                if (resno < PCI_BRIDGE_RESOURCES)
+                        pci_update_resource(dev, resno);
+        }
         return ret;
 }
 
+
 /* Sort resources by alignment */
 void pdev_sort_resources(struct pci_dev *dev, struct resource_list *head)
 {