On Mon, Apr 09, 2018 at 05:46:04PM +1000, Oliver O'Halloran wrote: > Some OF platforms (pseries and some SPARC systems) has their own > implementations of NUMA affinity detection rather than using the generic > OF_NUMA driver, which mainly exists for arm64. For other platforms one > of two fallbacks provided by the base OF driver are used depending on > CONFIG_NUMA. > > In the CONFIG_NUMA=n case the fallback is an inline function in of.h. > In the =y case the fallback is a real function which is defined as a > weak symbol so that it may be overwritten by the architecture if desired. > > The problem with this arrangement is that the real implementations all > export of_node_to_nid(). Unfortunately it's not possible to export the > fallback since it would clash with the non-weak version. As a result > we get build failures when: > > a) CONFIG_NUMA=y && CONFIG_OF=y, and > b) The platform doesn't implement of_node_to_nid(), and > c) A module uses of_node_to_nid() > > Given b) will be true for most platforms this is fairly easy to hit > and has been observed on ia64 and x86. > > This patch remedies the problem by introducing the ARCH_HAS_OWN_OF_NUMA > Kconfig option which is selected if an architecture provides an > implementation of of_node_to_nid(). If a platform does not use it's own, > or the generic OF_NUMA, then always use the inline fallback in of.h so > we don't need to futz around with exports.
I'd rather have a specific kconfig symbol for the 'generic' implementation, especially given that it doesn't appear to be all that generic.
