[PATCH v2 11/24] PCI: Add defines for bridge window indexing

Ilpo Järvinen
2025-08-29T13:12:44Z

include/linux/pci.h provides PCI_BRIDGE_{IO,MEM,PREF_MEM}_WINDOW defines,
however, they're based on the resource array indexing in the pci_dev
struct. The struct pci_bus also has pointers to those same resources but
they start from zeroth index.

Add PCI_BUS_BRIDGE_{IO,MEM,PREF_MEM}_WINDOW defines to get rid of literal
indexing.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
---
drivers/pci/pci.h | 4 ++++
drivers/pci/probe.c | 10 +++++++---
2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 34f65d69662e..1dc8a8066761 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -81,6 +81,10 @@ struct pcie_tlp_log;
#define PCIE_MSG_CODE_DEASSERT_INTC 0x26
#define PCIE_MSG_CODE_DEASSERT_INTD 0x27

+#define PCI_BUS_BRIDGE_IO_WINDOW 0
+#define PCI_BUS_BRIDGE_MEM_WINDOW 1
+#define PCI_BUS_BRIDGE_PREF_MEM_WINDOW 2
+
extern const unsigned char pcie_link_speed[];
extern bool pci_early_dump;

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index f31d27c7708a..eaeb66bec433 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -598,9 +598,13 @@ void pci_read_bridge_bases(struct pci_bus *child)
for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i];

- pci_read_bridge_io(child->self, child->resource[0], false);
- pci_read_bridge_mmio(child->self, child->resource[1], false);
- pci_read_bridge_mmio_pref(child->self, child->resource[2], false);
+ pci_read_bridge_io(child->self,
+ child->resource[PCI_BUS_BRIDGE_IO_WINDOW], false);
+ pci_read_bridge_mmio(child->self,
+ child->resource[PCI_BUS_BRIDGE_MEM_WINDOW], false);
+ pci_read_bridge_mmio_pref(child->self,
+ child->resource[PCI_BUS_BRIDGE_PREF_MEM_WINDOW],
+ false);

if (!dev->transparent)
return;
--
2.39.5