[BUGFIX v2 4/4] ACPIPHP: fix bug 56531 Sony VAIO VPCZ23A4R: can't assign mem/io after docking

[Jiang Liu]

Please refer to https://bugzilla.kernel.org/show_bug.cgi?id=56531 for
more information.

This issue is caused by differences in PCI resource assignment between
boot time and runtime hotplug. On x86 platforms, OS respects PCI
resource assignment from BIOS and only reassign resources for unassigned
BARs at boot time. But with acpiphp, it ignores BIOS resource assignment
and reassign all resources by itself.

If we have enough resources, reassigning all PCI resources should work
too, but it may fail if we are under resource constraints. On the other
handle, current PCI MMIO alignment algorithm may waste huge MMIO address
space if we have some PCI devices with huge MMIO BARs.

On this Sony laptop, BIOS allocates limited MMIO resources for the dock
station and the dock station has a gfx which has a 256MB MMIO BAR.
So current acpiphp driver fails to allocate resources for most devices
on the dock station.

So change acpiphp driver to follow boot time behavior to respect BIOS
resource assignment.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
Reported-by: Alexander E. Patrakov <patrakov@xxxxxxxxx>
Tested-by: Alexander E. Patrakov <patrakov@xxxxxxxxx>
Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
Cc: linux-acpi@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
---
 drivers/pci/hotplug/acpiphp_glue.c | 7 +++++--
 drivers/pci/pci.h                  | 5 +++++
 drivers/pci/setup-bus.c            | 8 ++++----
 3 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index a65203b..f4a53e9 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -687,6 +687,7 @@ static int __ref enable_device(struct acpiphp_slot *slot)
 	struct pci_bus *bus = slot->bridge->pci_bus;
 	struct acpiphp_func *func;
 	int num, max, pass;
+	LIST_HEAD(add_list);
 
 	if (slot->flags & SLOT_ENABLED)
 		goto err_exit;
@@ -711,13 +712,15 @@ static int __ref enable_device(struct acpiphp_slot *slot)
 				max = pci_scan_bridge(bus, dev, max, pass);
 				if (pass && dev->subordinate) {
 					check_hotplug_bridge(slot, dev);
-					pci_bus_size_bridges(dev->subordinate);
+					pcibios_resource_survey_bus(dev->subordinate);
+					__pci_bus_size_bridges(dev->subordinate,
+							       &add_list);
 				}
 			}
 		}
 	}
 
-	pci_bus_assign_resources(bus);
+	__pci_bus_assign_resources(bus, &add_list, NULL);
 	acpiphp_sanitize_bus(bus);
 	acpiphp_set_hpp_values(bus);
 	acpiphp_set_acpi_region(slot);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 68678ed..d1182c4 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -202,6 +202,11 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
 		    struct resource *res, unsigned int reg);
 int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type);
 void pci_configure_ari(struct pci_dev *dev);
+void __ref __pci_bus_size_bridges(struct pci_bus *bus,
+			struct list_head *realloc_head);
+void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
+				      struct list_head *realloc_head,
+				      struct list_head *fail_head);
 
 /**
  * pci_ari_enabled - query ARI forwarding status
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 16abaaa..d254e23 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1044,7 +1044,7 @@ handle_done:
 	;
 }
 
-static void __ref __pci_bus_size_bridges(struct pci_bus *bus,
+void __ref __pci_bus_size_bridges(struct pci_bus *bus,
 			struct list_head *realloc_head)
 {
 	struct pci_dev *dev;
@@ -1115,9 +1115,9 @@ 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 list_head *realloc_head,
-					 struct list_head *fail_head)
+void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
+				      struct list_head *realloc_head,
+				      struct list_head *fail_head)
 {
 	struct pci_bus *b;
 	struct pci_dev *dev;
-- 
1.8.1.2

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