From 7fb5e508319068de1d69e6d7230416c390cb3cbb Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 22 Jul 2022 09:28:34 -0700 Subject: mmu_gather: fix the CONFIG_MMU_GATHER_NO_RANGE case Sudip reports that alpha doesn't build properly, with errors like include/asm-generic/tlb.h:401:1: error: redefinition of 'tlb_update_vma_flags' 401 | tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) | ^~~~~~~~~~~~~~~~~~~~ include/asm-generic/tlb.h:372:1: note: previous definition of 'tlb_update_vma_flags' with type 'void(struct mmu_gather *, struct vm_area_struct *)' 372 | tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) { } the cause being that We have this odd situation where some architectures were never converted to the newer TLB flushing interfaces that have a range for the flush. Instead people left them alone, and we have them select the MMU_GATHER_NO_RANGE config option to make the tlb header files account for this. Peter Zijlstra cleaned some of these nasty header file games up in commits 1e9fdf21a433 ("mmu_gather: Remove per arch tlb_{start,end}_vma()") 18ba064e42df ("mmu_gather: Let there be one tlb_{start,end}_vma() implementation") but tlb_update_vma_flags() was left alone, and then commit b67fbebd4cf9 ("mmu_gather: Force tlb-flush VM_PFNMAP vmas") ended up removing only _one_ of the two stale duplicate dummy inline functions. This removes the other stale one. Somebody braver than me should try to remove MMU_GATHER_NO_RANGE entirely, but it requires fixing up the oddball architectures that use it: alpha, m68k, microblaze, nios2 and openrisc. The fixups should be fairly straightforward ("fix the build errors it exposes by adding the appropriate range arguments"), but the reason this wasn't done in the first place is that so few people end up working on those architectures. But it could be done one architecture at a time, hint, hint. Reported-by: Sudip Mukherjee (Codethink) Fixes: b67fbebd4cf9 ("mmu_gather: Force tlb-flush VM_PFNMAP vmas") Link: https://lore.kernel.org/all/YtpXh0QHWwaEWVAY@debian/ Cc: Peter Zijlstra Cc: Will Deacon Cc: "Aneesh Kumar K.V" Cc: Andrew Morton Cc: Nick Piggin Cc: Arnd Bergmann Signed-off-by: Linus Torvalds --- include/asm-generic/tlb.h | 3 --- 1 file changed, 3 deletions(-) diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index cb2167c89eee..492dce43236e 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -368,9 +368,6 @@ static inline void tlb_flush(struct mmu_gather *tlb) flush_tlb_mm(tlb->mm); } -static inline void -tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) { } - #else /* CONFIG_MMU_GATHER_NO_RANGE */ #ifndef tlb_flush -- cgit v1.2.3