[PATCH 2/6] PCI: restore resource alignment

Stewart Hildebrand
2024-07-09T13:36:36Z

Devices with alignment specified will lose their alignment in cases when
the bridge resources have been released, e.g. due to insufficient bridge
window size. Restore the alignment.

Signed-off-by: Stewart Hildebrand <stewart.hildebrand@amd.com>
---
drivers/pci/setup-bus.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 23082bc0ca37..ab7510ce6917 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1594,6 +1594,23 @@ static void __pci_bridge_assign_resources(const struct pci_dev *bridge,
}
}

+static void restore_child_resource_alignment(struct pci_bus *bus)
+{
+ struct pci_dev *dev;
+
+ list_for_each_entry(dev, &bus->devices, bus_list) {
+ struct pci_bus *b;
+
+ pci_reassigndev_resource_alignment(dev);
+
+ b = dev->subordinate;
+ if (!b)
+ continue;
+
+ restore_child_resource_alignment(b);
+ }
+}
+
#define PCI_RES_TYPE_MASK \
(IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH |\
IORESOURCE_MEM_64)
@@ -1648,6 +1665,8 @@ static void pci_bridge_release_resources(struct pci_bus *bus,
r->start = 0;
r->flags = 0;

+ restore_child_resource_alignment(bus);
+
/* Avoiding touch the one without PREF */
if (type & IORESOURCE_PREFETCH)
type = IORESOURCE_PREFETCH;
--
2.45.2