[PATCH 03/11] PCI: Use Header Type to detect CardBus bridges in pci_resource_alignment()

[Ilpo Järvinen]

pci_resource_alignment() detects CardBus bridges by the Class Code while
the rest of the PCI core uses the Header Type.

When CONFIG_CARDBUS is not set, pci_cardbus_resource_alignment() returns
zero. A non-CardBus device that reports the CardBus Class Code then gets
zero alignment for all its resources, and pbus_size_mem() calls __ffs()
on it, which is undefined behavior. When CARDBUS is set, the device gets
CardBus window alignment instead of its own alignment.

Use pci_is_cardbus_bridge() in pci_resource_alignment() and make it take
a const pointer as pci_resource_alignment() has one.

Fixes: fd29d4ea09ba ("PCI: Separate CardBus setup & build it only with CONFIG_CARDBUS")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
 drivers/pci/pci.h       | 2 +-
 drivers/pci/setup-res.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 77efa4c5c960..519918e24cc5 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -419,7 +419,7 @@ extern unsigned long pci_hotplug_mmio_size;
 extern unsigned long pci_hotplug_mmio_pref_size;
 extern unsigned long pci_hotplug_bus_size;
 
-static inline bool pci_is_cardbus_bridge(struct pci_dev *dev)
+static inline bool pci_is_cardbus_bridge(const struct pci_dev *dev)
 {
 	return dev->hdr_type == PCI_HEADER_TYPE_CARDBUS;
 }
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 376f09630a4a..d8d53861b4a6 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -255,7 +255,7 @@ resource_size_t pci_resource_alignment(const struct pci_dev *dev,
 
 	if (pci_resource_is_iov(resno))
 		return pci_sriov_resource_alignment(dev, resno);
-	if (dev->class >> 8 == PCI_CLASS_BRIDGE_CARDBUS)
+	if (pci_is_cardbus_bridge(dev))
 		return pci_cardbus_resource_alignment(res);
 	return resource_alignment(res);
 }
-- 
2.47.3