Re: [PATCH v11 6/7] ACPI/IORT: Stub out ACS functions when CONFIG_PCI is not set

From: Hanjun Guo
Date: Tue Dec 18 2018 - 02:44:52 EST


On 2018/12/18 10:56, Sinan Kaya wrote:
> Remove PCI dependent code out of iort.c when CONFIG_PCI is not defined.
> A quick search reveals the following functions:
> 1. pci_request_acs()
> 2. pci_domain_nr()
> 3. pci_is_root_bus()
> 4. to_pci_dev()
>
> Both pci_domain_nr() and pci_is_root_bus() are defined in linux/pci.h.
> pci_domain_nr() is a stub function when CONFIG_PCI is not set and
> pci_is_root_bus() just returns a reference to a structure member which
> is still valid without CONFIG_PCI set.
>
> to_pci_dev() is a macro that expands to container_of.
>
> pci_request_acs() is the only code that gets pulled in from drivers/pci/*.c

Actually we have pci_for_each_dma_alias() too which is from
drivers/pci/search.c without stub function in linux/pci.h, but I
didn't get the compile error at link time, I think the compiler
just do some optimization to remove the dead code because
dev_is_pci() is obvious false.

Thanks
Hanjun