Re: [PATCH v10 09/10] PCI: dwc: ep: Ensure proper iteration over outbound map windows

[Bjorn Helgaas]

On Mon, Mar 10, 2025 at 04:16:47PM -0400, Frank Li wrote:
> Most systems' PCIe outbound map windows have non-zero physical addresses,
> but the possibility of encountering zero increased with commit
> ("PCI: dwc: ep: Add bus_addr_base for outbound window").

What is this commit?  I don't see it in the tree, and I don't see it
in this series.

It look like it might be a fixup for something in this series.  In
that case it should go *before* the other commit (or be squashed into
it if it's logically part of it).

I don't think this series touches ep->ob_window_map, so if it's a fix
it looks like it could go anywhere earlier.

> '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@xxxxxxx>
> ---
> change from v9 to v10
> - remove commit hash value
> 
> 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 62bc71ad20719..e333855633a77 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
>