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

On Tue, Jan 28, 2025 at 05:07:39PM -0500, Frank Li wrote:
> 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").

I don't know what commit 700cafbb642b is.  It doesn't appear
upstream, and there's no subject line or patch match for
bus_addr_base.

Bjorn

On Wed, Feb 26, 2025 at 06:12:13PM -0600, Bjorn Helgaas wrote:
> On Tue, Jan 28, 2025 at 05:07:39PM -0500, Frank Li wrote:
> > 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").
> 
> I don't know what commit 700cafbb642b is.  It doesn't appear
> upstream, and there's no subject line or patch match for
> bus_addr_base.

Never mind, I see it's patch 5/7 of *this* series.  I looked at the
0/7 list, but missed it.

In any case, the commit ID will be different since we apply patches
from email, so the ID from your tree won't be useful.

Bjorn