asm-generic/tlb, arch: Provide generic VIPT cache flush

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 )

Avoid all VIPT architectures providing their own tlb_start_vma()
implementation and rely on architectures to provide a no-op
flush_cache_range() when it is not relevant.

This patch makes 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 flush_cache_range(), but their
current tlb_start_vma() does not call it.

No change in behavior intended.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nick Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 0 insertions, 9 deletions

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)					      \