arm64: tlbflush: avoid flushing when fullmm == 1

The TLB gather code sets fullmm=1 when tearing down the entire address
space for an mm_struct on exit or execve. Given that the ASID allocator
will never re-allocate a dirty ASID, this flushing is not needed and can
simply be avoided in the flushing code.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Will Deacon 2015-10-06 18:46:26 +01:00 committed by Catalin Marinas
parent f3e002c24e
commit 5a7862e830

View File

@ -37,17 +37,21 @@ static inline void __tlb_remove_table(void *_table)
static inline void tlb_flush(struct mmu_gather *tlb)
{
if (tlb->fullmm) {
flush_tlb_mm(tlb->mm);
} else {
struct vm_area_struct vma = { .vm_mm = tlb->mm, };
/*
* The intermediate page table levels are already handled by
* the __(pte|pmd|pud)_free_tlb() functions, so last level
* TLBI is sufficient here.
*/
__flush_tlb_range(&vma, tlb->start, tlb->end, true);
}
struct vm_area_struct vma = { .vm_mm = tlb->mm, };
/*
* The ASID allocator will either invalidate the ASID or mark
* it as used.
*/
if (tlb->fullmm)
return;
/*
* The intermediate page table levels are already handled by
* the __(pte|pmd|pud)_free_tlb() functions, so last level
* TLBI is sufficient here.
*/
__flush_tlb_range(&vma, tlb->start, tlb->end, true);
}
static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,