[PATCH 2/9] pci: add failed_list to record failed one for pci_bus_assign_resources

[Yinghai Lu <yinghai@kernel.org>]

so later we can try to assign resource those failed devices again.

-v2: store start, end, flags aside. so could keep res cleared when assign
     failed. and make following assignment of its children do not go wild
-v3: update comments

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
---
 drivers/pci/setup-bus.c |   66 ++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 5b42255..41578ba 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -27,7 +27,52 @@
 #include <linux/slab.h>
 #include "pci.h"
 
-static void pbus_assign_resources_sorted(const struct pci_bus *bus)
+struct resource_list_x {
+	struct resource_list_x *next;
+	struct resource *res;
+	struct pci_dev *dev;
+	resource_size_t start;
+	resource_size_t end;
+	unsigned long flags;
+};
+
+static void add_to_failed_list(struct resource_list_x *head,
+				 struct pci_dev *dev, struct resource *res)
+{
+	struct resource_list_x *list = head;
+	struct resource_list_x *ln = list->next;
+	struct resource_list_x *tmp;
+
+	tmp = kmalloc(sizeof(*tmp), GFP_KERNEL);
+	if (!tmp) {
+		pr_warning("add_to_failed_list: kmalloc() failed!\n");
+		return;
+	}
+
+	tmp->next = ln;
+	tmp->res = res;
+	tmp->dev = dev;
+	tmp->start = res->start;
+	tmp->end = res->end;
+	tmp->flags = res->flags;
+	list->next = tmp;
+}
+
+static void free_failed_list(struct resource_list_x *head)
+{
+	struct resource_list_x *list, *tmp;
+
+	for (list = head->next; list;) {
+		tmp = list;
+		list = list->next;
+		kfree(tmp);
+	}
+
+	head->next = NULL;
+}
+
+static void pbus_assign_resources_sorted(const struct pci_bus *bus,
+					 struct resource_list_x *fail_head)
 {
 	struct pci_dev *dev;
 	struct resource *res;
@@ -58,6 +103,13 @@ static void pbus_assign_resources_sorted(const struct pci_bus *bus)
 		res = list->res;
 		idx = res - &list->dev->resource[0];
 		if (pci_assign_resource(list->dev, idx)) {
+			if (fail_head && !pci_is_root_bus(list->dev->bus)) {
+				/*
+				 * device need to keep flags and size
+				 * for next try
+				 */
+				add_to_failed_list(fail_head, list->dev, res);
+			}
 			res->start = 0;
 			res->end = 0;
 			res->flags = 0;
@@ -572,19 +624,20 @@ void __ref pci_bus_size_bridges(struct pci_bus *bus)
 }
 EXPORT_SYMBOL(pci_bus_size_bridges);
 
-void __ref pci_bus_assign_resources(const struct pci_bus *bus)
+static void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
+					 struct resource_list_x *fail_head)
 {
 	struct pci_bus *b;
 	struct pci_dev *dev;
 
-	pbus_assign_resources_sorted(bus);
+	pbus_assign_resources_sorted(bus, fail_head);
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		b = dev->subordinate;
 		if (!b)
 			continue;
 
-		pci_bus_assign_resources(b);
+		__pci_bus_assign_resources(b, fail_head);
 
 		switch (dev->class >> 8) {
 		case PCI_CLASS_BRIDGE_PCI:
@@ -602,6 +655,11 @@ void __ref pci_bus_assign_resources(const struct pci_bus *bus)
 		}
 	}
 }
+
+void __ref pci_bus_assign_resources(const struct pci_bus *bus)
+{
+	__pci_bus_assign_resources(bus, NULL);
+}
 EXPORT_SYMBOL(pci_bus_assign_resources);
 
 static void pci_bridge_release_resources(struct pci_bus *bus,
-- 
1.6.4.2