mm: introduce do_zap_pte_range()

This commit introduces do_zap_pte_range() to actually zap the PTEs, which
will help improve code readability and facilitate secondary checking of
the processed PTEs in the future.

No functional change.

Link: https://lkml.kernel.org/r/c3fd16807f83bb7d7a376cc6de023a9f5ead17da.1733305182.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 26 insertions, 19 deletions

diff --git a/mm/memory.c b/mm/memory.c
index bed55f8873d5..378576e6b745 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1657,6 +1657,27 @@ static inline int zap_nonpresent_ptes(struct mmu_gather *tlb,
 	return nr;
 }
 
+static inline int do_zap_pte_range(struct mmu_gather *tlb,
+				   struct vm_area_struct *vma, pte_t *pte,
+				   unsigned long addr, unsigned long end,
+				   struct zap_details *details, int *rss,
+				   bool *force_flush, bool *force_break)
+{
+	pte_t ptent = ptep_get(pte);
+	int max_nr = (end - addr) / PAGE_SIZE;
+
+	if (pte_none(ptent))
+		return 1;
+
+	if (pte_present(ptent))
+		return zap_present_ptes(tlb, vma, pte, ptent, max_nr,
+					addr, details, rss, force_flush,
+					force_break);
+
+	return zap_nonpresent_ptes(tlb, vma, pte, ptent, max_nr, addr,
+					 details, rss);
+}
+
 static unsigned long zap_pte_range(struct mmu_gather *tlb,
 				struct vm_area_struct *vma, pmd_t *pmd,
 				unsigned long addr, unsigned long end,
@@ -1679,28 +1700,14 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
 	flush_tlb_batched_pending(mm);
 	arch_enter_lazy_mmu_mode();
 	do {
-		pte_t ptent = ptep_get(pte);
-		int max_nr;
-
-		nr = 1;
-		if (pte_none(ptent))
-			continue;
-
 		if (need_resched())
 			break;
 
-		max_nr = (end - addr) / PAGE_SIZE;
-		if (pte_present(ptent)) {
-			nr = zap_present_ptes(tlb, vma, pte, ptent, max_nr,
-					      addr, details, rss, &force_flush,
-					      &force_break);
-			if (unlikely(force_break)) {
-				addr += nr * PAGE_SIZE;
-				break;
-			}
-		} else {
-			nr = zap_nonpresent_ptes(tlb, vma, pte, ptent, max_nr,
-						 addr, details, rss);
+		nr = do_zap_pte_range(tlb, vma, pte, addr, end, details, rss,
+				      &force_flush, &force_break);
+		if (unlikely(force_break)) {
+			addr += nr * PAGE_SIZE;
+			break;
 		}
 	} while (pte += nr, addr += PAGE_SIZE * nr, addr != end);