Re: [PATCH v8 2/5] PCI: endpoint: Add BAR subrange mapping support

Frank Li
2026-01-15T19:44:44Z

On Thu, Jan 15, 2026 at 04:21:21PM +0100, Niklas Cassel wrote:
> On Thu, Jan 15, 2026 at 09:52:58AM -0500, Frank Li wrote:
> > > @@ -127,6 +150,10 @@ struct pci_epf_bar {
> > > size_t mem_size;
> > > enum pci_barno barno;
> > > int flags;
> > > +
> > > + /* Optional sub-range mapping */
> > > + unsigned int num_submap;
> > > + struct pci_epf_bar_submap *submap;
> >
> > struct pci_epf_bar_submap submap[] __counted_by(num_submap);
> >
> > Not sure if use this simplify alloc/free.
>
> Your suggestion changes the submap from a pointer to a flexible array
> member.
>
> A flexible array member must always be last in the struct,
> and you can only have one flexible array member per struct.
>
> Additionally, using a flexible array member requires the struct to
> always be allocated on the heap. You can't allocate a struct with a
> flexible array member on the stack.
>
> So I'm not sure that if your suggestion is something we want.

Yes, forget my comments if not fit.

Frank
>
>
> Kind regards,
> Niklas