arm64: mm: factor out the address and ptep alignment into a new helper

Factor out the contpte block's address and ptep alignment into a new
helper, and will be reused in the following patch.

No functional changes.

Link: https://lkml.kernel.org/r/8076d12cb244b2d9e91119b44dc6d5e4ad9c00af.1770645603.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Harry Yoo <harry.yoo@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c
index 589bcf878938840f24848b200cbbb7993ebe3021..e4ddeb46f25d6e03a8f26b20d0a1ad3249a6414d 100644 (file)
--- a/arch/arm64/mm/contpte.c
+++ b/arch/arm64/mm/contpte.c
@@ -26,6 +26,26 @@ static inline pte_t *contpte_align_down(pte_t *ptep)
        return PTR_ALIGN_DOWN(ptep, sizeof(*ptep) * CONT_PTES);
 }
 
+static inline pte_t *contpte_align_addr_ptep(unsigned long *start,
+                                            unsigned long *end, pte_t *ptep,
+                                            unsigned int nr)
+{
+       /*
+        * Note: caller must ensure these nr PTEs are consecutive (present)
+        * PTEs that map consecutive pages of the same large folio within a
+        * single VMA and a single page table.
+        */
+       if (pte_cont(__ptep_get(ptep + nr - 1)))
+               *end = ALIGN(*end, CONT_PTE_SIZE);
+
+       if (pte_cont(__ptep_get(ptep))) {
+               *start = ALIGN_DOWN(*start, CONT_PTE_SIZE);
+               ptep = contpte_align_down(ptep);
+       }
+
+       return ptep;
+}
+
 static void contpte_try_unfold_partial(struct mm_struct *mm, unsigned long addr,
                                        pte_t *ptep, unsigned int nr)
 {
@@ -569,14 +589,7 @@ void contpte_clear_young_dirty_ptes(struct vm_area_struct *vma,
        unsigned long start = addr;
        unsigned long end = start + nr * PAGE_SIZE;
 
-       if (pte_cont(__ptep_get(ptep + nr - 1)))
-               end = ALIGN(end, CONT_PTE_SIZE);
-
-       if (pte_cont(__ptep_get(ptep))) {
-               start = ALIGN_DOWN(start, CONT_PTE_SIZE);
-               ptep = contpte_align_down(ptep);
-       }
-
+       ptep = contpte_align_addr_ptep(&start, &end, ptep, nr);
        __clear_young_dirty_ptes(vma, start, ptep, (end - start) / PAGE_SIZE, flags);
 }
 EXPORT_SYMBOL_GPL(contpte_clear_young_dirty_ptes);