[PATCH v9 6/7] PCI: dwc: ep: Ensure proper iteration over outbound map windows

Frank Li
2025-01-28T22:08:55Z

Most systems' PCIe outbound map windows have non-zero physical addresses,
but the possibility of encountering zero increased with commit
700cafbb642b ("PCI: dwc: ep: Add bus_addr_base for outbound window").

'ep->outbound_addr[n]', representing 'parent_bus_address', might be 0 on
some hardware, which trims high address bits through bus fabric before
sending to the PCIe controller.

Replace the iteration logic with 'for_each_set_bit()' to ensure only
allocated map windows are iterated when determining the ATU index from a
given address.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change from v8 to v9
- new patch
---
drivers/pci/controller/dwc/pcie-designware-ep.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index d0d6c4e8df80c..c1767450541a4 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -284,7 +284,7 @@ static int dw_pcie_find_index(struct dw_pcie_ep *ep, phys_addr_t addr,
u32 index;
struct dw_pcie *pci = to_dw_pcie_from_ep(ep);

- for (index = 0; index < pci->num_ob_windows; index++) {
+ for_each_set_bit(index, ep->ob_window_map, pci->num_ob_windows) {
if (ep->outbound_addr[index] != parent_bus_addr)
continue;
*atu_index = index;

--
2.34.1