Merge branch 'perf/core' into perf/uprobes

Merge in latest upstream (and the latest perf development tree),
to prepare for tooling changes, and also to pick up v3.4 MM
changes that the uprobes code needs to take care of.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 459 insertions, 201 deletions

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 86b69f85f90..8fa2d4be88d 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -25,10 +25,13 @@
 #include <linux/ioport.h>
 #include <linux/cache.h>
 #include <linux/slab.h>
+#include <asm-generic/pci-bridge.h>
 #include "pci.h"
 
-struct resource_list_x {
-	struct resource_list_x *next;
+unsigned int pci_flags;
+
+struct pci_dev_resource {
+	struct list_head list;
 	struct resource *res;
 	struct pci_dev *dev;
 	resource_size_t start;
@@ -38,21 +41,14 @@ struct resource_list_x {
 	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)
-
-int pci_realloc_enable = 0;
-#define pci_realloc_enabled() pci_realloc_enable
-void pci_realloc(void)
+static void free_list(struct list_head *head)
 {
-	pci_realloc_enable = 1;
+	struct pci_dev_resource *dev_res, *tmp;
+
+	list_for_each_entry_safe(dev_res, tmp, head, list) {
+		list_del(&dev_res->list);
+		kfree(dev_res);
+	}
 }
 
 /**
@@ -64,21 +60,18 @@ void pci_realloc(void)
  * @add_size:	additional size to be optionally added
  *              to the resource
  */
-static void add_to_list(struct resource_list_x *head,
+static int add_to_list(struct list_head *head,
 		 struct pci_dev *dev, struct resource *res,
 		 resource_size_t add_size, resource_size_t min_align)
 {
-	struct resource_list_x *list = head;
-	struct resource_list_x *ln = list->next;
-	struct resource_list_x *tmp;
+	struct pci_dev_resource *tmp;
 
-	tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
+	tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
 	if (!tmp) {
 		pr_warning("add_to_list: kmalloc() failed!\n");
-		return;
+		return -ENOMEM;
 	}
 
-	tmp->next = ln;
 	tmp->res = res;
 	tmp->dev = dev;
 	tmp->start = res->start;
@@ -86,19 +79,100 @@ static void add_to_list(struct resource_list_x *head,
 	tmp->flags = res->flags;
 	tmp->add_size = add_size;
 	tmp->min_align = min_align;
-	list->next = tmp;
+
+	list_add(&tmp->list, head);
+
+	return 0;
 }
 
-static void add_to_failed_list(struct resource_list_x *head,
-				struct pci_dev *dev, struct resource *res)
+static void remove_from_list(struct list_head *head,
+				 struct resource *res)
 {
-	add_to_list(head, dev, res,
-			0 /* dont care */,
-			0 /* dont care */);
+	struct pci_dev_resource *dev_res, *tmp;
+
+	list_for_each_entry_safe(dev_res, tmp, head, list) {
+		if (dev_res->res == res) {
+			list_del(&dev_res->list);
+			kfree(dev_res);
+			break;
+		}
+	}
+}
+
+static resource_size_t get_res_add_size(struct list_head *head,
+					struct resource *res)
+{
+	struct pci_dev_resource *dev_res;
+
+	list_for_each_entry(dev_res, head, list) {
+		if (dev_res->res == res) {
+			int idx = res - &dev_res->dev->resource[0];
+
+			dev_printk(KERN_DEBUG, &dev_res->dev->dev,
+				 "res[%d]=%pR get_res_add_size add_size %llx\n",
+				 idx, dev_res->res,
+				 (unsigned long long)dev_res->add_size);
+
+			return dev_res->add_size;
+		}
+	}
+
+	return 0;
+}
+
+/* Sort resources by alignment */
+static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)
+{
+	int i;
+
+	for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+		struct resource *r;
+		struct pci_dev_resource *dev_res, *tmp;
+		resource_size_t r_align;
+		struct list_head *n;
+
+		r = &dev->resource[i];
+
+		if (r->flags & IORESOURCE_PCI_FIXED)
+			continue;
+
+		if (!(r->flags) || r->parent)
+			continue;
+
+		r_align = pci_resource_alignment(dev, r);
+		if (!r_align) {
+			dev_warn(&dev->dev, "BAR %d: %pR has bogus alignment\n",
+				 i, r);
+			continue;
+		}
+
+		tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
+		if (!tmp)
+			panic("pdev_sort_resources(): "
+			      "kmalloc() failed!\n");
+		tmp->res = r;
+		tmp->dev = dev;
+
+		/* fallback is smallest one or list is empty*/
+		n = head;
+		list_for_each_entry(dev_res, head, list) {
+			resource_size_t align;
+
+			align = pci_resource_alignment(dev_res->dev,
+							 dev_res->res);
+
+			if (r_align > align) {
+				n = &dev_res->list;
+				break;
+			}
+		}
+		/* Insert it just before n*/
+		list_add_tail(&tmp->list, n);
+	}
 }
 
 static void __dev_sort_resources(struct pci_dev *dev,
-				 struct resource_list *head)
+				 struct list_head *head)
 {
 	u16 class = dev->class >> 8;
 
@@ -136,49 +210,54 @@ static inline void reset_resource(struct resource *res)
  * additional resources for the element, provided the element
  * is in the head list.
  */
-static void reassign_resources_sorted(struct resource_list_x *realloc_head,
-		struct resource_list *head)
+static void reassign_resources_sorted(struct list_head *realloc_head,
+		struct list_head *head)
 {
 	struct resource *res;
-	struct resource_list_x *list, *tmp, *prev;
-	struct resource_list *hlist;
+	struct pci_dev_resource *add_res, *tmp;
+	struct pci_dev_resource *dev_res;
 	resource_size_t add_size;
 	int idx;
 
-	prev = realloc_head;
-	for (list = realloc_head->next; list;) {
-		res = list->res;
+	list_for_each_entry_safe(add_res, tmp, realloc_head, list) {
+		bool found_match = false;
+
+		res = add_res->res;
 		/* skip resource that has been reset */
 		if (!res->flags)
 			goto out;
 
 		/* skip this resource if not found in head list */
-		for (hlist = head->next; hlist && hlist->res != res;
-				hlist = hlist->next);
-		if (!hlist) { /* just skip */
-			prev = list;
-			list = list->next;
-			continue;
+		list_for_each_entry(dev_res, head, list) {
+			if (dev_res->res == res) {
+				found_match = true;
+				break;
+			}
 		}
+		if (!found_match)/* just skip */
+			continue;
 
-		idx = res - &list->dev->resource[0];
-		add_size=list->add_size;
+		idx = res - &add_res->dev->resource[0];
+		add_size = add_res->add_size;
 		if (!resource_size(res)) {
-			res->start = list->start;
+			res->start = add_res->start;
 			res->end = res->start + add_size - 1;
-			if(pci_assign_resource(list->dev, idx))
+			if (pci_assign_resource(add_res->dev, idx))
 				reset_resource(res);
 		} 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);
+			resource_size_t align = add_res->min_align;
+			res->flags |= add_res->flags &
+				 (IORESOURCE_STARTALIGN|IORESOURCE_SIZEALIGN);
+			if (pci_reassign_resource(add_res->dev, idx,
+						  add_size, align))
+				dev_printk(KERN_DEBUG, &add_res->dev->dev,
+					   "failed to add %llx res[%d]=%pR\n",
+					   (unsigned long long)add_size,
+					   idx, res);
 		}
 out:
-		tmp = list;
-		prev->next = list = list->next;
-		kfree(tmp);
+		list_del(&add_res->list);
+		kfree(add_res);
 	}
 }
 
@@ -192,35 +271,99 @@ out:
  * 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)
+static void assign_requested_resources_sorted(struct list_head *head,
+				 struct list_head *fail_head)
 {
 	struct resource *res;
-	struct resource_list *list;
+	struct pci_dev_resource *dev_res;
 	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)) {
+	list_for_each_entry(dev_res, head, list) {
+		res = dev_res->res;
+		idx = res - &dev_res->dev->resource[0];
+		if (resource_size(res) &&
+		    pci_assign_resource(dev_res->dev, idx)) {
+			if (fail_head && !pci_is_root_bus(dev_res->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);
+					add_to_list(fail_head,
+						    dev_res->dev, res,
+						    0 /* dont care */,
+						    0 /* dont care */);
 			}
 			reset_resource(res);
 		}
 	}
 }
 
-static void __assign_resources_sorted(struct resource_list *head,
-				 struct resource_list_x *realloc_head,
-				 struct resource_list_x *fail_head)
+static void __assign_resources_sorted(struct list_head *head,
+				 struct list_head *realloc_head,
+				 struct list_head *fail_head)
 {
+	/*
+	 * Should not assign requested resources at first.
+	 *   they could be adjacent, so later reassign can not reallocate
+	 *   them one by one in parent resource window.
+	 * Try to assign requested + add_size at begining
+	 *  if could do that, could get out early.
+	 *  if could not do that, we still try to assign requested at first,
+	 *    then try to reassign add_size for some resources.
+	 */
+	LIST_HEAD(save_head);
+	LIST_HEAD(local_fail_head);
+	struct pci_dev_resource *save_res;
+	struct pci_dev_resource *dev_res;
+
+	/* Check if optional add_size is there */
+	if (!realloc_head || list_empty(realloc_head))
+		goto requested_and_reassign;
+
+	/* Save original start, end, flags etc at first */
+	list_for_each_entry(dev_res, head, list) {
+		if (add_to_list(&save_head, dev_res->dev, dev_res->res, 0, 0)) {
+			free_list(&save_head);
+			goto requested_and_reassign;
+		}
+	}
+
+	/* Update res in head list with add_size in realloc_head list */
+	list_for_each_entry(dev_res, head, list)
+		dev_res->res->end += get_res_add_size(realloc_head,
+							dev_res->res);
+
+	/* Try updated head list with add_size added */
+	assign_requested_resources_sorted(head, &local_fail_head);
+
+	/* all assigned with add_size ? */
+	if (list_empty(&local_fail_head)) {
+		/* Remove head list from realloc_head list */
+		list_for_each_entry(dev_res, head, list)
+			remove_from_list(realloc_head, dev_res->res);
+		free_list(&save_head);
+		free_list(head);
+		return;
+	}
+
+	free_list(&local_fail_head);
+	/* Release assigned resource */
+	list_for_each_entry(dev_res, head, list)
+		if (dev_res->res->parent)
+			release_resource(dev_res->res);
+	/* Restore start/end/flags from saved list */
+	list_for_each_entry(save_res, &save_head, list) {
+		struct resource *res = save_res->res;
+
+		res->start = save_res->start;
+		res->end = save_res->end;
+		res->flags = save_res->flags;
+	}
+	free_list(&save_head);
+
+requested_and_reassign:
 	/* Satisfy the must-have resource requests */
 	assign_requested_resources_sorted(head, fail_head);
 
@@ -228,28 +371,27 @@ static void __assign_resources_sorted(struct resource_list *head,
 		requests */
 	if (realloc_head)
 		reassign_resources_sorted(realloc_head, head);
-	free_list(resource_list, head);
+	free_list(head);
 }
 
 static void pdev_assign_resources_sorted(struct pci_dev *dev,
-				 struct resource_list_x *fail_head)
+				 struct list_head *add_head,
+				 struct list_head *fail_head)
 {
-	struct resource_list head;
+	LIST_HEAD(head);
 
-	head.next = NULL;
 	__dev_sort_resources(dev, &head);
-	__assign_resources_sorted(&head, NULL, fail_head);
+	__assign_resources_sorted(&head, add_head, fail_head);
 
 }
 
 static void pbus_assign_resources_sorted(const struct pci_bus *bus,
-					 struct resource_list_x *realloc_head,
-					 struct resource_list_x *fail_head)
+					 struct list_head *realloc_head,
+					 struct list_head *fail_head)
 {
 	struct pci_dev *dev;
-	struct resource_list head;
+	LIST_HEAD(head);
 
-	head.next = NULL;
 	list_for_each_entry(dev, &bus->devices, bus_list)
 		__dev_sort_resources(dev, &head);
 
@@ -548,20 +690,6 @@ 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
  *
@@ -576,7 +704,7 @@ static resource_size_t get_res_add_size(struct resource_list_x *realloc_head,
  * 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 *realloc_head)
+		resource_size_t add_size, struct list_head *realloc_head)
 {
 	struct pci_dev *dev;
 	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
@@ -612,7 +740,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size,
 	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,
+		calculate_iosize(size, min_size, add_size + size1,
 			resource_size(b_res), 4096);
 	if (!size0 && !size1) {
 		if (b_res->start || b_res->end)
@@ -626,8 +754,12 @@ 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 && realloc_head)
+	if (size1 > size0 && realloc_head) {
 		add_to_list(realloc_head, bus->self, b_res, size1-size0, 4096);
+		dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window "
+				 "%pR to [bus %02x-%02x] add_size %lx\n", b_res,
+				 bus->secondary, bus->subordinate, size1-size0);
+	}
 }
 
 /**
@@ -644,7 +776,7 @@ 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 *realloc_head)
+			struct list_head *realloc_head)
 {
 	struct pci_dev *dev;
 	resource_size_t min_align, align, size, size0, size1;
@@ -726,7 +858,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 	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,
+		calculate_memsize(size, min_size, add_size,
 				resource_size(b_res), min_align);
 	if (!size0 && !size1) {
 		if (b_res->start || b_res->end)
@@ -739,8 +871,12 @@ 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 && realloc_head)
+	if (size1 > size0 && realloc_head) {
 		add_to_list(realloc_head, bus->self, b_res, size1-size0, min_align);
+		dev_printk(KERN_DEBUG, &bus->self->dev, "bridge window "
+				 "%pR to [bus %02x-%02x] add_size %llx\n", b_res,
+				 bus->secondary, bus->subordinate, (unsigned long long)size1-size0);
+	}
 	return 1;
 }
 
@@ -754,25 +890,48 @@ unsigned long pci_cardbus_resource_alignment(struct resource *res)
 }
 
 static void pci_bus_size_cardbus(struct pci_bus *bus,
-			struct resource_list_x *realloc_head)
+			struct list_head *realloc_head)
 {
 	struct pci_dev *bridge = bus->self;
 	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
+	resource_size_t b_res_3_size = pci_cardbus_mem_size * 2;
 	u16 ctrl;
 
+	if (b_res[0].parent)
+		goto handle_b_res_1;
 	/*
 	 * Reserve some resources for CardBus.  We reserve
 	 * a fixed amount of bus space for CardBus bridges.
 	 */
-	b_res[0].start = 0;
-	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[0].start = pci_cardbus_io_size;
+	b_res[0].end = b_res[0].start + pci_cardbus_io_size - 1;
+	b_res[0].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
+	if (realloc_head) {
+		b_res[0].end -= pci_cardbus_io_size;
+		add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size,
+				pci_cardbus_io_size);
+	}
 
-	b_res[1].start = 0;
-	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 */);
+handle_b_res_1:
+	if (b_res[1].parent)
+		goto handle_b_res_2;
+	b_res[1].start = pci_cardbus_io_size;
+	b_res[1].end = b_res[1].start + pci_cardbus_io_size - 1;
+	b_res[1].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
+	if (realloc_head) {
+		b_res[1].end -= pci_cardbus_io_size;
+		add_to_list(realloc_head, bridge, b_res+1, pci_cardbus_io_size,
+				 pci_cardbus_io_size);
+	}
+
+handle_b_res_2:
+	/* MEM1 must not be pref mmio */
+	pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM1) {
+		ctrl &= ~PCI_CB_BRIDGE_CTL_PREFETCH_MEM1;
+		pci_write_config_word(bridge, PCI_CB_BRIDGE_CONTROL, ctrl);
+		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
+	}
 
 	/*
 	 * Check whether prefetchable memory is supported
@@ -785,38 +944,46 @@ static void pci_bus_size_cardbus(struct pci_bus *bus,
 		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
 	}
 
+	if (b_res[2].parent)
+		goto handle_b_res_3;
 	/*
 	 * If we have prefetchable memory support, allocate
 	 * two regions.  Otherwise, allocate one region of
 	 * twice the size.
 	 */
 	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
-		b_res[2].start = 0;
-		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].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].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 */);
+		b_res[2].start = pci_cardbus_mem_size;
+		b_res[2].end = b_res[2].start + pci_cardbus_mem_size - 1;
+		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH |
+				  IORESOURCE_STARTALIGN;
+		if (realloc_head) {
+			b_res[2].end -= pci_cardbus_mem_size;
+			add_to_list(realloc_head, bridge, b_res+2,
+				 pci_cardbus_mem_size, pci_cardbus_mem_size);
+		}
+
+		/* reduce that to half */
+		b_res_3_size = pci_cardbus_mem_size;
+	}
+
+handle_b_res_3:
+	if (b_res[3].parent)
+		goto handle_done;
+	b_res[3].start = pci_cardbus_mem_size;
+	b_res[3].end = b_res[3].start + b_res_3_size - 1;
+	b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_STARTALIGN;
+	if (realloc_head) {
+		b_res[3].end -= b_res_3_size;
+		add_to_list(realloc_head, bridge, b_res+3, b_res_3_size,
+				 pci_cardbus_mem_size);
 	}
 
-	/* 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;
+handle_done:
+	;
 }
 
 void __ref __pci_bus_size_bridges(struct pci_bus *bus,
-			struct resource_list_x *realloc_head)
+			struct list_head *realloc_head)
 {
 	struct pci_dev *dev;
 	unsigned long mask, prefmask;
@@ -858,7 +1025,8 @@ void __ref __pci_bus_size_bridges(struct pci_bus *bus,
 		 * Follow thru
 		 */
 	default:
-		pbus_size_io(bus, 0, additional_io_size, realloc_head);
+		pbus_size_io(bus, realloc_head ? 0 : additional_io_size,
+			     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
@@ -866,11 +1034,15 @@ 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, realloc_head))
+		if (pbus_size_mem(bus, prefmask, prefmask,
+				  realloc_head ? 0 : additional_mem_size,
+				  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, realloc_head);
+		pbus_size_mem(bus, mask, IORESOURCE_MEM,
+				realloc_head ? 0 : additional_mem_size,
+				additional_mem_size, realloc_head);
 		break;
 	}
 }
@@ -882,8 +1054,8 @@ 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 *realloc_head,
-					 struct resource_list_x *fail_head)
+					 struct list_head *realloc_head,
+					 struct list_head *fail_head)
 {
 	struct pci_bus *b;
 	struct pci_dev *dev;
@@ -922,17 +1094,19 @@ void __ref pci_bus_assign_resources(const struct pci_bus *bus)
 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 list_head *add_head,
+					 struct list_head *fail_head)
 {
 	struct pci_bus *b;
 
-	pdev_assign_resources_sorted((struct pci_dev *)bridge, fail_head);
+	pdev_assign_resources_sorted((struct pci_dev *)bridge,
+					 add_head, fail_head);
 
 	b = bridge->subordinate;
 	if (!b)
 		return;
 
-	__pci_bus_assign_resources(b, NULL, fail_head);
+	__pci_bus_assign_resources(b, add_head, fail_head);
 
 	switch (bridge->class >> 8) {
 	case PCI_CLASS_BRIDGE_PCI:
@@ -1095,6 +1269,58 @@ static int __init pci_get_max_depth(void)
 	return depth;
 }
 
+/*
+ * -1: undefined, will auto detect later
+ *  0: disabled by user
+ *  1: disabled by auto detect
+ *  2: enabled by user
+ *  3: enabled by auto detect
+ */
+enum enable_type {
+	undefined = -1,
+	user_disabled,
+	auto_disabled,
+	user_enabled,
+	auto_enabled,
+};
+
+static enum enable_type pci_realloc_enable __initdata = undefined;
+void __init pci_realloc_get_opt(char *str)
+{
+	if (!strncmp(str, "off", 3))
+		pci_realloc_enable = user_disabled;
+	else if (!strncmp(str, "on", 2))
+		pci_realloc_enable = user_enabled;
+}
+static bool __init pci_realloc_enabled(void)
+{
+	return pci_realloc_enable >= user_enabled;
+}
+
+static void __init pci_realloc_detect(void)
+{
+#if defined(CONFIG_PCI_IOV) && defined(CONFIG_PCI_REALLOC_ENABLE_AUTO)
+	struct pci_dev *dev = NULL;
+
+	if (pci_realloc_enable != undefined)
+		return;
+
+	for_each_pci_dev(dev) {
+		int i;
+
+		for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) {
+			struct resource *r = &dev->resource[i];
+
+			/* Not assigned, or rejected by kernel ? */
+			if (r->flags && !r->start) {
+				pci_realloc_enable = auto_enabled;
+
+				return;
+			}
+		}
+	}
+#endif
+}
 
 /*
  * first try will not touch pci bridge res
@@ -1105,59 +1331,57 @@ void __init
 pci_assign_unassigned_resources(void)
 {
 	struct pci_bus *bus;
-	struct resource_list_x realloc_list; /* list of resources that
+	LIST_HEAD(realloc_head); /* list of resources that
 					want additional resources */
+	struct list_head *add_list = NULL;
 	int tried_times = 0;
 	enum release_type rel_type = leaf_only;
-	struct resource_list_x head, *list;
+	LIST_HEAD(fail_head);
+	struct pci_dev_resource *fail_res;
 	unsigned long type_mask = IORESOURCE_IO | IORESOURCE_MEM |
 				  IORESOURCE_PREFETCH;
-	unsigned long failed_type;
-	int max_depth = pci_get_max_depth();
-	int pci_try_num;
-
+	int pci_try_num = 1;
 
-	head.next = NULL;
-	realloc_list.next = NULL;
+	/* don't realloc if asked to do so */
+	pci_realloc_detect();
+	if (pci_realloc_enabled()) {
+		int max_depth = pci_get_max_depth();
 
-	pci_try_num = max_depth + 1;
-	printk(KERN_DEBUG "PCI: max bus depth: %d pci_try_num: %d\n",
-		 max_depth, pci_try_num);
+		pci_try_num = max_depth + 1;
+		printk(KERN_DEBUG "PCI: max bus depth: %d pci_try_num: %d\n",
+			 max_depth, pci_try_num);
+	}
 
 again:
+	/*
+	 * last try will use add_list, otherwise will try good to have as
+	 * must have, so can realloc parent bridge resource
+	 */
+	if (tried_times + 1 == pci_try_num)
+		add_list = &realloc_head;
 	/* Depth first, calculate sizes and alignments of all
 	   subordinate buses. */
 	list_for_each_entry(bus, &pci_root_buses, node)
-		__pci_bus_size_bridges(bus, &realloc_list);
+		__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, &realloc_list, &head);
-	BUG_ON(realloc_list.next);
+		__pci_bus_assign_resources(bus, add_list, &fail_head);
+	if (add_list)
+		BUG_ON(!list_empty(add_list));
 	tried_times++;
 
 	/* any device complain? */
-	if (!head.next)
+	if (list_empty(&fail_head))
 		goto enable_and_dump;
 
-	/* don't realloc if asked to do so */
-	if (!pci_realloc_enabled()) {
-		free_list(resource_list_x, &head);
-		goto enable_and_dump;
-	}
+	if (tried_times >= pci_try_num) {
+		if (pci_realloc_enable == undefined)
+			printk(KERN_INFO "Some PCI device resources are unassigned, try booting with pci=realloc\n");
+		else if (pci_realloc_enable == auto_enabled)
+			printk(KERN_INFO "Automatically enabled pci realloc, if you have problem, try booting with pci=realloc=off\n");
 
-	failed_type = 0;
-	for (list = head.next; list;) {
-		failed_type |= list->flags;
-		list = list->next;
-	}
-	/*
-	 * io port are tight, don't try extra
-	 * or if reach the limit, don't want to try more
-	 */
-	failed_type &= type_mask;
-	if ((failed_type == IORESOURCE_IO) || (tried_times >= pci_try_num)) {
-		free_list(resource_list_x, &head);
+		free_list(&fail_head);
 		goto enable_and_dump;
 	}
 
@@ -1172,25 +1396,23 @@ again:
 	 * Try to release leaf bridge's resources that doesn't fit resource of
 	 * child device under that bridge
 	 */
-	for (list = head.next; list;) {
-		bus = list->dev->bus;
-		pci_bus_release_bridge_resources(bus, list->flags & type_mask,
-						  rel_type);
-		list = list->next;
+	list_for_each_entry(fail_res, &fail_head, list) {
+		bus = fail_res->dev->bus;
+		pci_bus_release_bridge_resources(bus,
+						 fail_res->flags & type_mask,
+						 rel_type);
 	}
 	/* restore size and flags */
-	for (list = head.next; list;) {
-		struct resource *res = list->res;
+	list_for_each_entry(fail_res, &fail_head, list) {
+		struct resource *res = fail_res->res;
 
-		res->start = list->start;
-		res->end = list->end;
-		res->flags = list->flags;
-		if (list->dev->subordinate)
+		res->start = fail_res->start;
+		res->end = fail_res->end;
+		res->flags = fail_res->flags;
+		if (fail_res->dev->subordinate)
 			res->flags = 0;
-
-		list = list->next;
 	}
-	free_list(resource_list_x, &head);
+	free_list(&fail_head);
 
 	goto again;
 
@@ -1207,26 +1429,27 @@ enable_and_dump:
 void pci_assign_unassigned_bridge_resources(struct pci_dev *bridge)
 {
 	struct pci_bus *parent = bridge->subordinate;
+	LIST_HEAD(add_list); /* list of resources that
+					want additional resources */
 	int tried_times = 0;
-	struct resource_list_x head, *list;
+	LIST_HEAD(fail_head);
+	struct pci_dev_resource *fail_res;
 	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);
-
+	__pci_bus_size_bridges(parent, &add_list);
+	__pci_bridge_assign_resources(bridge, &add_list, &fail_head);
+	BUG_ON(!list_empty(&add_list));
 	tried_times++;
 
-	if (!head.next)
+	if (list_empty(&fail_head))
 		goto enable_all;
 
 	if (tried_times >= 2) {
 		/* still fail, don't need to try more */
-		free_list(resource_list_x, &head);
+		free_list(&fail_head);
 		goto enable_all;
 	}
 
@@ -1237,27 +1460,24 @@ again:
 	 * 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;
+	list_for_each_entry(fail_res, &fail_head, list) {
+		struct pci_bus *bus = fail_res->dev->bus;
+		unsigned long flags = fail_res->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;
+	list_for_each_entry(fail_res, &fail_head, list) {
+		struct resource *res = fail_res->res;
 
-		res->start = list->start;
-		res->end = list->end;
-		res->flags = list->flags;
-		if (list->dev->subordinate)
+		res->start = fail_res->start;
+		res->end = fail_res->end;
+		res->flags = fail_res->flags;
+		if (fail_res->dev->subordinate)
 			res->flags = 0;
-
-		list = list->next;
 	}
-	free_list(resource_list_x, &head);
+	free_list(&fail_head);
 
 	goto again;
 
@@ -1267,3 +1487,41 @@ enable_all:
 	pci_enable_bridges(parent);
 }
 EXPORT_SYMBOL_GPL(pci_assign_unassigned_bridge_resources);
+
+#ifdef CONFIG_HOTPLUG
+/**
+ * pci_rescan_bus - scan a PCI bus for devices.
+ * @bus: PCI bus to scan
+ *
+ * Scan a PCI bus and child buses for new devices, adds them,
+ * and enables them.
+ *
+ * Returns the max number of subordinate bus discovered.
+ */
+unsigned int __ref pci_rescan_bus(struct pci_bus *bus)
+{
+	unsigned int max;
+	struct pci_dev *dev;
+	LIST_HEAD(add_list); /* list of resources that
+					want additional resources */
+
+	max = pci_scan_child_bus(bus);
+
+	down_read(&pci_bus_sem);
+	list_for_each_entry(dev, &bus->devices, bus_list)
+		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
+		    dev->hdr_type == PCI_HEADER_TYPE_CARDBUS)
+			if (dev->subordinate)
+				__pci_bus_size_bridges(dev->subordinate,
+							 &add_list);
+	up_read(&pci_bus_sem);
+	__pci_bus_assign_resources(bus, &add_list, NULL);
+	BUG_ON(!list_empty(&add_list));
+
+	pci_enable_bridges(bus);
+	pci_bus_add_devices(bus);
+
+	return max;
+}
+EXPORT_SYMBOL_GPL(pci_rescan_bus);
+#endif