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 749fdf0..753b21a 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 c94d37e..f092993 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 08a95b3..466fad6 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 c8cee76..b74084e 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 795c902..8473727 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 8a1d3c7..784da9d 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 319f359..51a9095 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)
 {