@@ -69,27 +69,36 @@ extern void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
#include <asm-generic/hugetlb.h>
-#define __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE
-static inline void flush_hugetlb_tlb_range(struct vm_area_struct *vma,
- unsigned long start,
- unsigned long end)
+static inline void __flush_hugetlb_tlb_range(struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end,
+ unsigned long stride,
+ bool last_level)
{
- unsigned long stride = huge_page_size(hstate_vma(vma));
-
switch (stride) {
case PUD_SIZE:
- __flush_tlb_range(vma, start, end, PUD_SIZE, false, 1);
+ __flush_tlb_range(vma, start, end, PUD_SIZE, last_level, 1);
break;
case CONT_PMD_SIZE:
case PMD_SIZE:
- __flush_tlb_range(vma, start, end, PMD_SIZE, false, 2);
+ __flush_tlb_range(vma, start, end, PMD_SIZE, last_level, 2);
break;
case CONT_PTE_SIZE:
- __flush_tlb_range(vma, start, end, PAGE_SIZE, false, 3);
+ __flush_tlb_range(vma, start, end, PAGE_SIZE, last_level, 3);
break;
default:
- __flush_tlb_range(vma, start, end, PAGE_SIZE, false, TLBI_TTL_UNKNOWN);
+ __flush_tlb_range(vma, start, end, PAGE_SIZE, last_level, TLBI_TTL_UNKNOWN);
}
}
+#define __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE
+static inline void flush_hugetlb_tlb_range(struct vm_area_struct *vma,
+ unsigned long start,
+ unsigned long end)
+{
+ unsigned long stride = huge_page_size(hstate_vma(vma));
+
+ __flush_hugetlb_tlb_range(vma, start, end, stride, false);
+}
+
#endif /* __ASM_HUGETLB_H */
@@ -190,8 +190,9 @@ static pte_t get_clear_contig_flush(struct mm_struct *mm,
{
pte_t orig_pte = get_clear_contig(mm, addr, ptep, pgsize, ncontig);
struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
+ unsigned long end = addr + (pgsize * ncontig);
- flush_tlb_range(&vma, addr, addr + (pgsize * ncontig));
+ __flush_hugetlb_tlb_range(&vma, addr, end, pgsize, true);
return orig_pte;
}
@@ -216,7 +217,7 @@ static void clear_flush(struct mm_struct *mm,
for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
__ptep_get_and_clear(mm, addr, ptep);
- flush_tlb_range(&vma, saddr, addr);
+ __flush_hugetlb_tlb_range(&vma, saddr, addr, pgsize, true);
}
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
@@ -245,7 +246,9 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
dpfn = pgsize >> PAGE_SHIFT;
hugeprot = pte_pgprot(pte);
- clear_flush(mm, addr, ptep, pgsize, ncontig);
+ /* Only need to "break" if transitioning valid -> valid. */
+ if (pte_valid(__ptep_get(ptep)))
+ clear_flush(mm, addr, ptep, pgsize, ncontig);
for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
__set_ptes(mm, addr, ptep, pfn_pte(pfn, hugeprot), 1);
When operating on contiguous blocks of ptes (or pmds) for some hugetlb sizes, we must honour break-before-make requirements and clear down the block to invalid state in the pgtable then invalidate the relevant tlb entries before making the pgtable entries valid again. However, the tlb maintenance is currently always done assuming the worst case stride (PAGE_SIZE), last_level (false) and tlb_level (TLBI_TTL_UNKNOWN). We can do much better with the hinting; In reality, we know the stride from the huge_pte pgsize, we are always operating only on the last level, and we always know the tlb_level, again based on pgsize. So let's start providing these hints. Additionally, avoid tlb maintenace in set_huge_pte_at(). Break-before-make is only required if we are transitioning the contiguous pte block from valid -> valid. So let's elide the clear-and-flush ("break") if the pte range was previously invalid. Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> --- arch/arm64/include/asm/hugetlb.h | 29 +++++++++++++++++++---------- arch/arm64/mm/hugetlbpage.c | 9 ++++++--- 2 files changed, 25 insertions(+), 13 deletions(-)