arm64: hugetlb: enable __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE

It is better to use huge page size instead of PAGE_SIZE for stride when
flush hugepage, which reduces the loop in __flush_tlb_range().

Let's support arch's flush_hugetlb_tlb_range(), which is used in
hugetlb_unshare_all_pmds(), move_hugetlb_page_tables() and
hugetlb_change_protection() for now.

Note,: for hugepages based on contiguous bit, it has to be invalidated
individually since the contiguous PTE bit is just a hint, the hardware may
or may not take it into account.

Link: https://lkml.kernel.org/r/20230802012731.62512-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Barry Song <21cnbao@gmail.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index 6a4a1ab..a91d621 100644 (file)
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -60,4 +60,19 @@ 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)
+{
+       unsigned long stride = huge_page_size(hstate_vma(vma));
+
+       if (stride == PMD_SIZE)
+               __flush_tlb_range(vma, start, end, stride, false, 2);
+       else if (stride == PUD_SIZE)
+               __flush_tlb_range(vma, start, end, stride, false, 1);
+       else
+               __flush_tlb_range(vma, start, end, PAGE_SIZE, false, 0);
+}
+
 #endif /* __ASM_HUGETLB_H */