[PATCH v12 11/13] PCI: dwc: ep: Ensure proper iteration over outbound map windows

Bjorn Helgaas
2025-03-15T20:37:25Z

From: Frank Li <Frank.Li@nxp.com>

Most systems' PCIe outbound map windows have non-zero physical addresses,
but the possibility of encountering zero increased after following commit
("PCI: dwc: Use parent_bus_offset").

'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.

Link: https://lore.kernel.org/r/20250313-pci_fixup_addr-v11-8-01d2313502ab@nxp.com
Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
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 bb87d0c5c665..2ef9964fa080 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -282,7 +282,7 @@ 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] != addr)
continue;
*atu_index = index;
--
2.34.1