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-rw-r--r--include/asm-generic/tlb.h68
1 files changed, 36 insertions, 32 deletions
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
index ff3e82553a76..492dce43236e 100644
--- a/include/asm-generic/tlb.h
+++ b/include/asm-generic/tlb.h
@@ -158,9 +158,24 @@
* Useful if your architecture doesn't use IPIs for remote TLB invalidates
* and therefore doesn't naturally serialize with software page-table walkers.
*
+ * MMU_GATHER_NO_FLUSH_CACHE
+ *
+ * Indicates the architecture has flush_cache_range() but it needs *NOT* be called
+ * before unmapping a VMA.
+ *
+ * NOTE: strictly speaking we shouldn't have this knob and instead rely on
+ * flush_cache_range() being a NOP, except Sparc64 seems to be
+ * different here.
+ *
+ * MMU_GATHER_MERGE_VMAS
+ *
+ * Indicates the architecture wants to merge ranges over VMAs; typical when
+ * multiple range invalidates are more expensive than a full invalidate.
+ *
* MMU_GATHER_NO_RANGE
*
- * Use this if your architecture lacks an efficient flush_tlb_range().
+ * Use this if your architecture lacks an efficient flush_tlb_range(). This
+ * option implies MMU_GATHER_MERGE_VMAS above.
*
* MMU_GATHER_NO_GATHER
*
@@ -288,6 +303,7 @@ struct mmu_gather {
*/
unsigned int vma_exec : 1;
unsigned int vma_huge : 1;
+ unsigned int vma_pfn : 1;
unsigned int batch_count;
@@ -334,8 +350,8 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb)
#ifdef CONFIG_MMU_GATHER_NO_RANGE
-#if defined(tlb_flush) || defined(tlb_start_vma) || defined(tlb_end_vma)
-#error MMU_GATHER_NO_RANGE relies on default tlb_flush(), tlb_start_vma() and tlb_end_vma()
+#if defined(tlb_flush)
+#error MMU_GATHER_NO_RANGE relies on default tlb_flush()
#endif
/*
@@ -352,20 +368,9 @@ 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) { }
-
-#define tlb_end_vma tlb_end_vma
-static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) { }
-
#else /* CONFIG_MMU_GATHER_NO_RANGE */
#ifndef tlb_flush
-
-#if defined(tlb_start_vma) || defined(tlb_end_vma)
-#error Default tlb_flush() relies on default tlb_start_vma() and tlb_end_vma()
-#endif
-
/*
* When an architecture does not provide its own tlb_flush() implementation
* but does have a reasonably efficient flush_vma_range() implementation
@@ -385,6 +390,9 @@ static inline void tlb_flush(struct mmu_gather *tlb)
flush_tlb_range(&vma, tlb->start, tlb->end);
}
}
+#endif
+
+#endif /* CONFIG_MMU_GATHER_NO_RANGE */
static inline void
tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma)
@@ -402,17 +410,9 @@ tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma)
*/
tlb->vma_huge = is_vm_hugetlb_page(vma);
tlb->vma_exec = !!(vma->vm_flags & VM_EXEC);
+ tlb->vma_pfn = !!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP));
}
-#else
-
-static inline void
-tlb_update_vma_flags(struct mmu_gather *tlb, struct vm_area_struct *vma) { }
-
-#endif
-
-#endif /* CONFIG_MMU_GATHER_NO_RANGE */
-
static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
{
/*
@@ -486,32 +486,36 @@ static inline unsigned long tlb_get_unmap_size(struct mmu_gather *tlb)
* case where we're doing a full MM flush. When we're doing a munmap,
* the vmas are adjusted to only cover the region to be torn down.
*/
-#ifndef tlb_start_vma
static inline void tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
{
if (tlb->fullmm)
return;
tlb_update_vma_flags(tlb, vma);
+#ifndef CONFIG_MMU_GATHER_NO_FLUSH_CACHE
flush_cache_range(vma, vma->vm_start, vma->vm_end);
-}
#endif
+}
-#ifndef tlb_end_vma
static inline void tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
{
if (tlb->fullmm)
return;
/*
- * Do a TLB flush and reset the range at VMA boundaries; this avoids
- * the ranges growing with the unused space between consecutive VMAs,
- * but also the mmu_gather::vma_* flags from tlb_start_vma() rely on
- * this.
+ * VM_PFNMAP is more fragile because the core mm will not track the
+ * page mapcount -- there might not be page-frames for these PFNs after
+ * all. Force flush TLBs for such ranges to avoid munmap() vs
+ * unmap_mapping_range() races.
*/
- tlb_flush_mmu_tlbonly(tlb);
+ if (tlb->vma_pfn || !IS_ENABLED(CONFIG_MMU_GATHER_MERGE_VMAS)) {
+ /*
+ * Do a TLB flush and reset the range at VMA boundaries; this avoids
+ * the ranges growing with the unused space between consecutive VMAs.
+ */
+ tlb_flush_mmu_tlbonly(tlb);
+ }
}
-#endif
/*
* tlb_flush_{pte|pmd|pud|p4d}_range() adjust the tlb->start and tlb->end,