On 18.11.2020 16:02, Rahul Singh wrote: > Hello Jan, > >> On 17 Nov 2020, at 10:55 am, Jan Beulich <jbeul...@suse.com> wrote: >> >> On 16.11.2020 13:25, Rahul Singh wrote: >>> NS16550 driver has PCI support that is under HAS_PCI flag. When HAS_PCI >>> is enabled for ARM, compilation error is observed for ARM architecture >>> because ARM platforms do not have full PCI support available. >> >> While you've extended the sentence, it remains unclear to me what >> compilation error it is that results here. I've requested such >> clarification for v2 already. > > Compilation error is related to the code that refer to x86 functions > (create_irq()..) and MSI implementation related error. > For more details please find the attached file for compilation error.
The use of mmio_ro_ranges is almost quite possibly going to remain x86-specific, but then I guess this wants abstracting in a suitable way. The remaining look to all be MSI-related, so perhaps what you want to avoid is just that part rather than everything PCI-ish? >>> --- a/xen/drivers/char/ns16550.c >>> +++ b/xen/drivers/char/ns16550.c >>> @@ -16,7 +16,7 @@ >>> #include <xen/timer.h> >>> #include <xen/serial.h> >>> #include <xen/iocap.h> >>> -#ifdef CONFIG_HAS_PCI >>> +#ifdef CONFIG_HAS_NS16550_PCI >>> #include <xen/pci.h> >>> #include <xen/pci_regs.h> >>> #include <xen/pci_ids.h> >> >> ... #undef-ining CONFIG_HAS_PCI at a suitable position in this >> file (e.g. after all #include-s, to make sure all structure >> layouts remain correct)? This would then be far easier to revert >> down the road, and would confine the oddity to a single file >> (and there a single place) in the code base. >> > > As for ARM platforms, PCI implementation is in the development process and I > am not sure if after completion of PCI work, ns16500 PCI part of code will > work out of the box. I think there is some effort required to test the > ns16550 PCI part of the code on ARM. > As this code is tested on X86 only so I make the options depends on X86 and > enable it by default for x86. > > I feel that adding a new Kconfig options is ok to enable/disable the PCI > NS16550 support as compared to #undef CONFIG_HAS_PCI in the particular file. > If in future other architecture wants to implement the PCI they will face the > similar compilation error issues. > > Please suggest how we can proceed on this. Introduce CONFIG_HAS_PCI_MSI (selected only by x86), if there's no immediate plan to support it on Arm together with the rest of PCI? Jan
