[PATCH 3/3] PCI: Cleanup pci_scan_child_bus_extend() loop

From: Ilpo Järvinen
Date: Tue Jun 10 2025 - 07:00:04 EST


pci_scan_child_bus_extend() open-codes device number iteration in the
for loop. Convert to use PCI_DEVFN() and add PCI_MAX_NR_DEVS (there
seems to be no pre-existing defines for this purpose).

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
drivers/pci/pci.h | 1 +
drivers/pci/probe.c | 6 +++---
2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 12215ee72afb..caa6e02a9aea 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -8,6 +8,7 @@ struct pcie_tlp_log;

/* Number of possible devfns: 0.0 to 1f.7 inclusive */
#define MAX_NR_DEVFNS 256
+#define PCI_MAX_NR_DEVS 32

#define MAX_NR_LANES 16

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index f08e754c404b..963cab481327 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -3029,14 +3029,14 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
{
unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0;
unsigned int start = bus->busn_res.start;
- unsigned int devfn, cmax, max = start;
+ unsigned int devnr, cmax, max = start;
struct pci_dev *dev;

dev_dbg(&bus->dev, "scanning bus\n");

/* Go find them, Rover! */
- for (devfn = 0; devfn < 256; devfn += 8)
- pci_scan_slot(bus, devfn);
+ for (devnr = 0; devnr < PCI_MAX_NR_DEVS; devnr++)
+ pci_scan_slot(bus, PCI_DEVFN(devnr, 0));

/* Reserve buses for SR-IOV capability */
used_buses = pci_iov_bus_range(bus);
--
2.39.5