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asm-generic/tlb: provide MMU_GATHER_TABLE_FREE

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As described in the comment, the correct order for freeing pages is:

 1) unhook page
 2) TLB invalidate page
 3) free page

This order equally applies to page directories.

Currently there are two correct options:

 - use tlb_remove_page(), when all page directores are full pages and
   there are no futher contraints placed by things like software
   walkers (HAVE_FAST_GUP).

 - use MMU_GATHER_RCU_TABLE_FREE and tlb_remove_table() when the
   architecture does not do IPI based TLB invalidate and has
   HAVE_FAST_GUP (or software TLB fill).

This however leaves architectures that don't have page based directories
but don't need RCU in a bind.  For those, provide MMU_GATHER_TABLE_FREE,
which provides the independent batching for directories without the
additional RCU freeing.

Link: http://lkml.kernel.org/r/20200116064531.483522-10-aneesh.kumar@linux.ibm.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Peter Zijlstra
2020-02-03 17:37:11 -08:00
committed by Linus Torvalds
parent 580a586c40
commit 0d6e24d430
4 changed files with 132 additions and 73 deletions
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4
arch/arm/include/asm/tlb.h
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@@ -37,10 +37,6 @@ static inline void __tlb_remove_table(void *_table)
#include <asm-generic/tlb.h>
#ifndef CONFIG_MMU_GATHER_RCU_TABLE_FREE
#define tlb_remove_table(tlb, entry) tlb_remove_page(tlb, entry)
#endif
static inline void
__pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte, unsigned long addr)
{