On 29/10/2019 08.43, Christophe Leroy wrote: > > > Le 25/10/2019 à 14:40, Rasmus Villemoes a écrit : >> In preparation for allowing to build QE support for architectures >> other than PPC, replace the ppc-specific io accessors. Done via >> >> $ spatch --sp-file io.cocci --in-place drivers/soc/fsl/qe/ >>
> As discussed already, this patch changes io accesors from inline to > outline, this has a performance impact on powerpc32 like 83xx. > > Could you please include in your series before this patch a patch to > change generic io accessors to inline on powerpc ? Well, it's complicated. I was hoping someone could explain why those are OOL in the first place. The history of arch/powerpc/kernel/iomap.c and the makefile fragment including it is a bit messy - first of all, the file itself talks about "ppc64 implementation" but is obviously used for all ppc32 (while the ppc64 platforms that set PPC_INDIRECT_PIO also get GENERIC_IOMAP, i.e. lib/iomap.c). So, what I wanted to do was to make the accessors inline when !PPC_INDIRECT_PIO && !PPC_INDIRECT_MMIO. But then I need to avoid including asm-generic/iomap.h, because that declares these as extern. OTOH, I think I do need some of the declarations from that file, e.g. at least pci_iounmap, and perhaps also the *_rep versions, unless they should also be inlined. I'm happy to give it a try, but I think that belongs in a separate series. The first few attempts are almost certain to generate some 0day reports. Question for powerpc maintainers: Is there a fundamental reason iowrite32be and friends are out-of-line on PPC32 (more generally, the PPC platforms that set neither PPC_INDIRECT_PIO or PPC_INDIRECT_MMIO)? If so, there's no point trying to make them inline, and I'd have to address Christophe's concern by introducing private qe_iowrite32be() etc. wrappers. Thanks, Rasmus
