On Mon, Aug 27, 2018 at 09:47:01AM +0200, Peter Zijlstra wrote: > And there's only like 4 architectures that still have a custom > mmu_gather: > > - sh > - arm > - ia64 > - s390 > > sh is trivial, arm seems doable, with a bit of luck we can do 'rm -rf > arch/ia64' leaving us with s390.
The one obvious thing SH and ARM want is a sensible default for tlb_start_vma(). (also: https://lkml.org/lkml/2004/1/15/6 ) The below make tlb_start_vma() default to flush_cache_range(), which should be right and sufficient. The only exceptions that I found where (oddly): - m68k-mmu - sparc64 - unicore Those architectures appear to have a non-NOP flush_cache_range(), but their current tlb_start_vma() does not call it. Furthermore, I think tlb_flush() is broken on arc and parisc; in particular they don't appear to have any TLB invalidate for the shift_arg_pages() case, where we do not call tlb_*_vma() and fullmm=0. Possibly shift_arg_pages() should be fixed instead. Some archs (nds32,sparc32) avoid this by having an unconditional flush_tlb_mm() in tlb_flush(), which seems somewhat suboptimal if you have flush_tlb_range(). TLB_FLUSH_VMA() might be an option, however hideous it is. --- diff --git a/arch/arc/include/asm/tlb.h b/arch/arc/include/asm/tlb.h index a9db5f62aaf3..7af2b373ebe7 100644 --- a/arch/arc/include/asm/tlb.h +++ b/arch/arc/include/asm/tlb.h @@ -23,15 +23,6 @@ do { \ * * Note, read http://lkml.org/lkml/2004/1/15/6 */ -#ifndef CONFIG_ARC_CACHE_VIPT_ALIASING -#define tlb_start_vma(tlb, vma) -#else -#define tlb_start_vma(tlb, vma) \ -do { \ - if (!tlb->fullmm) \ - flush_cache_range(vma, vma->vm_start, vma->vm_end); \ -} while(0) -#endif #define tlb_end_vma(tlb, vma) \ do { \ diff --git a/arch/mips/include/asm/tlb.h b/arch/mips/include/asm/tlb.h index b6823b9e94da..9d04b4649692 100644 --- a/arch/mips/include/asm/tlb.h +++ b/arch/mips/include/asm/tlb.h @@ -5,16 +5,6 @@ #include <asm/cpu-features.h> #include <asm/mipsregs.h> -/* - * MIPS doesn't need any special per-pte or per-vma handling, except - * we need to flush cache for area to be unmapped. - */ -#define tlb_start_vma(tlb, vma) \ - do { \ - if (!tlb->fullmm) \ - flush_cache_range(vma, vma->vm_start, vma->vm_end); \ - } while (0) -#define tlb_end_vma(tlb, vma) do { } while (0) #define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0) /* diff --git a/arch/nds32/include/asm/tlb.h b/arch/nds32/include/asm/tlb.h index b35ae5eae3ab..0bf7c9482381 100644 --- a/arch/nds32/include/asm/tlb.h +++ b/arch/nds32/include/asm/tlb.h @@ -4,12 +4,6 @@ #ifndef __ASMNDS32_TLB_H #define __ASMNDS32_TLB_H -#define tlb_start_vma(tlb,vma) \ - do { \ - if (!tlb->fullmm) \ - flush_cache_range(vma, vma->vm_start, vma->vm_end); \ - } while (0) - #define tlb_end_vma(tlb,vma) \ do { \ if(!tlb->fullmm) \ diff --git a/arch/nios2/include/asm/tlb.h b/arch/nios2/include/asm/tlb.h index d3bc648e08b5..9b518c6d0f62 100644 --- a/arch/nios2/include/asm/tlb.h +++ b/arch/nios2/include/asm/tlb.h @@ -15,16 +15,6 @@ extern void set_mmu_pid(unsigned long pid); -/* - * NiosII doesn't need any special per-pte or per-vma handling, except - * we need to flush cache for the area to be unmapped. - */ -#define tlb_start_vma(tlb, vma) \ - do { \ - if (!tlb->fullmm) \ - flush_cache_range(vma, vma->vm_start, vma->vm_end); \ - } while (0) - #define tlb_end_vma(tlb, vma) do { } while (0) #define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0) diff --git a/arch/parisc/include/asm/tlb.h b/arch/parisc/include/asm/tlb.h index 0c881e74d8a6..b1984f9cd3af 100644 --- a/arch/parisc/include/asm/tlb.h +++ b/arch/parisc/include/asm/tlb.h @@ -7,11 +7,6 @@ do { if ((tlb)->fullmm) \ flush_tlb_mm((tlb)->mm);\ } while (0) -#define tlb_start_vma(tlb, vma) \ -do { if (!(tlb)->fullmm) \ - flush_cache_range(vma, vma->vm_start, vma->vm_end); \ -} while (0) - #define tlb_end_vma(tlb, vma) \ do { if (!(tlb)->fullmm) \ flush_tlb_range(vma, vma->vm_start, vma->vm_end); \ diff --git a/arch/sparc/include/asm/tlb_32.h b/arch/sparc/include/asm/tlb_32.h index 343cea19e573..68d817273de8 100644 --- a/arch/sparc/include/asm/tlb_32.h +++ b/arch/sparc/include/asm/tlb_32.h @@ -2,11 +2,6 @@ #ifndef _SPARC_TLB_H #define _SPARC_TLB_H -#define tlb_start_vma(tlb, vma) \ -do { \ - flush_cache_range(vma, vma->vm_start, vma->vm_end); \ -} while (0) - #define tlb_end_vma(tlb, vma) \ do { \ flush_tlb_range(vma, vma->vm_start, vma->vm_end); \ diff --git a/arch/xtensa/include/asm/tlb.h b/arch/xtensa/include/asm/tlb.h index 0d766f9c1083..1a93e350382e 100644 --- a/arch/xtensa/include/asm/tlb.h +++ b/arch/xtensa/include/asm/tlb.h @@ -16,19 +16,10 @@ #if (DCACHE_WAY_SIZE <= PAGE_SIZE) -/* Note, read http://lkml.org/lkml/2004/1/15/6 */ - -# define tlb_start_vma(tlb,vma) do { } while (0) # define tlb_end_vma(tlb,vma) do { } while (0) #else -# define tlb_start_vma(tlb, vma) \ - do { \ - if (!tlb->fullmm) \ - flush_cache_range(vma, vma->vm_start, vma->vm_end); \ - } while(0) - # define tlb_end_vma(tlb, vma) \ do { \ if (!tlb->fullmm) \ diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index e811ef7b8350..1d037fd5bb7a 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -181,19 +181,21 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb, * the vmas are adjusted to only cover the region to be torn down. */ #ifndef tlb_start_vma -#define tlb_start_vma(tlb, vma) do { } while (0) +#define tlb_start_vma(tlb, vma) \ +do { \ + if (!tlb->fullmm) \ + flush_cache_range(vma, vma->vm_start, vma->vm_end); \ +} while (0) #endif -#define __tlb_end_vma(tlb, vma) \ - do { \ - if (!tlb->fullmm && tlb->end) { \ - tlb_flush(tlb); \ - __tlb_reset_range(tlb); \ - } \ - } while (0) - #ifndef tlb_end_vma -#define tlb_end_vma __tlb_end_vma +#define tlb_end_vma(tlb, vma) \ + do { \ + if (!tlb->fullmm && tlb->end) { \ + tlb_flush(tlb); \ + __tlb_reset_range(tlb); \ + } \ + } while (0) #endif #ifndef __tlb_remove_tlb_entry
