[PATCH 04/18] asm-generic/tlb: Provide generic VIPT cache flush

From: Peter Zijlstra
Date: Wed Sep 26 2018 - 07:54:38 EST


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.

The below 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.

Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxxxx>
Cc: David Miller <davem@xxxxxxxxxxxxx>
Cc: Guan Xuetao <gxt@xxxxxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
arch/arc/include/asm/tlb.h | 9 ---------
arch/mips/include/asm/tlb.h | 9 ---------
arch/nds32/include/asm/tlb.h | 6 ------
arch/nios2/include/asm/tlb.h | 10 ----------
arch/parisc/include/asm/tlb.h | 5 -----
arch/sparc/include/asm/tlb_32.h | 5 -----
arch/xtensa/include/asm/tlb.h | 9 ---------
include/asm-generic/tlb.h | 19 +++++++++++--------
8 files changed, 11 insertions(+), 61 deletions(-)

--- 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 { \
--- a/arch/mips/include/asm/tlb.h
+++ b/arch/mips/include/asm/tlb.h
@@ -5,15 +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)

--- 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) \
--- 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)

--- 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); \
--- 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); \
--- 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) \
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -19,6 +19,7 @@
#include <linux/swap.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>

#ifdef CONFIG_MMU

@@ -351,17 +352,19 @@ static inline unsigned long tlb_get_unma
* 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_flush_mmu_tlbonly(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_flush_mmu_tlbonly(tlb); \
+} while (0)
#endif

#ifndef __tlb_remove_tlb_entry