[PATCH v2 1/7] mm: factor out generic PTE batch detection from swap_pte_batch()

Factor out the generic PTE batch detection logic from swap_pte_batch()
into softleaf_pte_batch() helper, so that it can be reused by upcoming
patch that adds restore-side batching of migration entries.

swap_pte_batch() now keeps only its swap-specific concerns and
delegates the batch detection to softleaf_pte_batch().

No functional changes intended.

Signed-off-by: Shivank Garg <[email protected]>
---
 mm/internal.h | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index a5d0488a54dc..1e1ab53b642e 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -560,6 +560,26 @@ static inline void set_softleaf_ptes(struct mm_struct *mm, unsigned long addr,
 	}
 }
 
+static inline int softleaf_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte)
+{
+	pte_t expected_pte = pte_next_softleaf_offset(pte);
+	const pte_t *end_ptep = start_ptep + max_nr;
+	pte_t *ptep = start_ptep + 1;
+
+	VM_WARN_ON(max_nr < 1);
+
+	while (ptep < end_ptep) {
+		pte = ptep_get(ptep);
+
+		if (!pte_same(pte, expected_pte))
+			break;
+		expected_pte = pte_next_softleaf_offset(expected_pte);
+		ptep++;
+	}
+
+	return ptep - start_ptep;
+}
+
 /**
  * swap_pte_batch - detect a PTE batch for a set of contiguous swap entries
  * @start_ptep: Page table pointer for the first entry.
@@ -577,23 +597,9 @@ static inline void set_softleaf_ptes(struct mm_struct *mm, unsigned long addr,
  */
 static inline int swap_pte_batch(pte_t *start_ptep, int max_nr, pte_t pte)
 {
-	pte_t expected_pte = pte_next_softleaf_offset(pte);
-	const pte_t *end_ptep = start_ptep + max_nr;
-	pte_t *ptep = start_ptep + 1;
-
-	VM_WARN_ON(max_nr < 1);
 	VM_WARN_ON(!softleaf_is_swap(softleaf_from_pte(pte)));
 
-	while (ptep < end_ptep) {
-		pte = ptep_get(ptep);
-
-		if (!pte_same(pte, expected_pte))
-			break;
-		expected_pte = pte_next_softleaf_offset(expected_pte);
-		ptep++;
-	}
-
-	return ptep - start_ptep;
+	return softleaf_pte_batch(start_ptep, max_nr, pte);
 }
 #endif /* CONFIG_MMU */
 

-- 
2.43.0