Remove checks for resource size in extend_bridge_window(). This is
necessary to allow the pci_bus_distribute_available_resources() to
function when the kernel parameter pci=hpmemsize=nn[KMG] is used to
allocate resources. Because the kernel parameter sets the size of all
hotplug bridges to be the same, there are problems when nested hotplug
bridges are encountered. Fitting a downstream hotplug bridge with size X
and normal bridges with size Y into parent hotplug bridge with size X is
impossible, and hence the downstream hotplug bridge needs to shrink to
fit into its parent.
Add check for if bridge is extended or shrunken and adjust pci_dbg to
reflect this.
Reset the resource if its new size is zero (if we have run out of a
bridge window resource). If it is set to zero size and left, it can
cause significant problems when it comes to enabling devices.
Signed-off-by: Nicholas Johnson <nicholas.johnson-opensource@xxxxxxxxxxxxxx>
---
drivers/pci/setup-bus.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index d65982438..9064fd964 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1818,13 +1818,19 @@ static void extend_bridge_window(struct pci_dev *bridge, struct resource *res,
if (res->parent)
return;
- if (resource_size(res) >= new_size)
- return;
-
- add_size = new_size - resource_size(res);
- pci_dbg(bridge, "bridge window %pR extended by %pa\n", res, &add_size);
+ if (new_size > resource_size(res)) {
+ add_size = new_size - resource_size(res);
+ pci_dbg(bridge, "bridge window %pR extended by %pa\n", res,
+ &add_size);
+ } else if (new_size < resource_size(res)) {
+ add_size = resource_size(res) - new_size;
+ pci_dbg(bridge, "bridge window %pR shrunken by %pa\n", res,
+ &add_size);
+ }
res->end = res->start + new_size - 1;
remove_from_list(add_list, res);
+ if (!new_size)
+ reset_resource(res);
}
static void pci_bus_distribute_available_resources(struct pci_bus *bus,
--
2.20.1
