+++++++++++++++++-----------
 include/linux/userfaultfd_k.h |  9 ++++---
 mm/hugetlb.c                  |  6 ++---
 mm/internal.h                 |  6 ++---
 mm/khugepaged.c               | 29 +++++++++++----------
 mm/migrate.c                  |  2 +-
 mm/mprotect.c                 | 43 ++++++++++++++----------------
 mm/mremap.c                   |  7 +++--
 mm/page_table_check.c         | 13 ++++++----
 mm/page_vma_mapped.c          | 27 ++++++++++---------
 10 files changed, 106 insertions(+), 85 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index a7c8501266f4..5475acfa1a33 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1017,7 +1017,9 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 		young = pte_young(ptent);
 		dirty = pte_dirty(ptent);
 		present = true;
-	} else if (is_swap_pte(ptent)) {
+	} else if (pte_none(ptent)) {
+		smaps_pte_hole_lookup(addr, walk);
+	} else {
 		swp_entry_t swpent = pte_to_swp_entry(ptent);
 
 		if (!non_swap_entry(swpent)) {
@@ -1038,9 +1040,6 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,
 				present = true;
 			page = pfn_swap_entry_to_page(swpent);
 		}
-	} else {
-		smaps_pte_hole_lookup(addr, walk);
-		return;
 	}
 
 	if (!page)
@@ -1611,6 +1610,9 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma,
 	 */
 	pte_t ptent = ptep_get(pte);
 
+	if (pte_none(ptent))
+		return;
+
 	if (pte_present(ptent)) {
 		pte_t old_pte;
 
@@ -1620,7 +1622,7 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma,
 		ptent = pte_wrprotect(old_pte);
 		ptent = pte_clear_soft_dirty(ptent);
 		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
-	} else if (is_swap_pte(ptent)) {
+	} else {
 		ptent = pte_swp_clear_soft_dirty(ptent);
 		set_pte_at(vma->vm_mm, addr, pte, ptent);
 	}
@@ -1923,6 +1925,9 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
 	struct page *page = NULL;
 	struct folio *folio;
 
+	if (pte_none(pte))
+		goto out;
+
 	if (pte_present(pte)) {
 		if (pm->show_pfn)
 			frame = pte_pfn(pte);
@@ -1932,8 +1937,9 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
 			flags |= PM_SOFT_DIRTY;
 		if (pte_uffd_wp(pte))
 			flags |= PM_UFFD_WP;
-	} else if (is_swap_pte(pte)) {
+	} else {
 		swp_entry_t entry;
+
 		if (pte_swp_soft_dirty(pte))
 			flags |= PM_SOFT_DIRTY;
 		if (pte_swp_uffd_wp(pte))
@@ -1941,6 +1947,7 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
 		entry = pte_to_swp_entry(pte);
 		if (pm->show_pfn) {
 			pgoff_t offset;
+
 			/*
 			 * For PFN swap offsets, keeping the offset field
 			 * to be PFN only to be compatible with old smaps.
@@ -1969,6 +1976,8 @@ static pagemap_entry_t pte_to_pagemap_entry(struct pagemapread *pm,
 		    __folio_page_mapped_exclusively(folio, page))
 			flags |= PM_MMAP_EXCLUSIVE;
 	}
+
+out:
 	if (vma->vm_flags & VM_SOFTDIRTY)
 		flags |= PM_SOFT_DIRTY;
 
@@ -2310,12 +2319,16 @@ static unsigned long pagemap_page_category(struct pagemap_scan_private *p,
 					   struct vm_area_struct *vma,
 					   unsigned long addr, pte_t pte)
 {
-	unsigned long categories = 0;
+	unsigned long categories;
+
+	if (pte_none(pte))
+		return 0;
 
 	if (pte_present(pte)) {
 		struct page *page;
 
-		categories |= PAGE_IS_PRESENT;
+		categories = PAGE_IS_PRESENT;
+
 		if (!pte_uffd_wp(pte))
 			categories |= PAGE_IS_WRITTEN;
 
@@ -2329,10 +2342,11 @@ static unsigned long pagemap_page_category(struct pagemap_scan_private *p,
 			categories |= PAGE_IS_PFNZERO;
 		if (pte_soft_dirty(pte))
 			categories |= PAGE_IS_SOFT_DIRTY;
-	} else if (is_swap_pte(pte)) {
+	} else {
 		swp_entry_t swp;
 
-		categories |= PAGE_IS_SWAPPED;
+		categories = PAGE_IS_SWAPPED;
+
 		if (!pte_swp_uffd_wp_any(pte))
 			categories |= PAGE_IS_WRITTEN;
 
@@ -2360,12 +2374,12 @@ static void make_uffd_wp_pte(struct vm_area_struct *vma,
 		old_pte = ptep_modify_prot_start(vma, addr, pte);
 		ptent = pte_mkuffd_wp(old_pte);
 		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
-	} else if (is_swap_pte(ptent)) {
-		ptent = pte_swp_mkuffd_wp(ptent);
-		set_pte_at(vma->vm_mm, addr, pte, ptent);
-	} else {
+	} else if (pte_none(ptent)) {
 		set_pte_at(vma->vm_mm, addr, pte,
 			   make_pte_marker(PTE_MARKER_UFFD_WP));
+	} else {
+		ptent = pte_swp_mkuffd_wp(ptent);
+		set_pte_at(vma->vm_mm, addr, pte, ptent);
 	}
 }
 
@@ -2434,6 +2448,9 @@ static unsigned long pagemap_hugetlb_category(pte_t pte)
 {
 	unsigned long categories = PAGE_IS_HUGE;
 
+	if (pte_none(pte))
+		return categories;
+
 	/*
 	 * According to pagemap_hugetlb_range(), file-backed HugeTLB
 	 * page cannot be swapped. So PAGE_IS_FILE is not checked for
@@ -2441,6 +2458,7 @@ static unsigned long pagemap_hugetlb_category(pte_t pte)
 	 */
 	if (pte_present(pte)) {
 		categories |= PAGE_IS_PRESENT;
+
 		if (!huge_pte_uffd_wp(pte))
 			categories |= PAGE_IS_WRITTEN;
 		if (!PageAnon(pte_page(pte)))
@@ -2449,8 +2467,9 @@ static unsigned long pagemap_hugetlb_category(pte_t pte)
 			categories |= PAGE_IS_PFNZERO;
 		if (pte_soft_dirty(pte))
 			categories |= PAGE_IS_SOFT_DIRTY;
-	} else if (is_swap_pte(pte)) {
+	} else {
 		categories |= PAGE_IS_SWAPPED;
+
 		if (!pte_swp_uffd_wp_any(pte))
 			categories |= PAGE_IS_WRITTEN;
 		if (pte_swp_soft_dirty(pte))
diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index 4c65adff2e7a..a362e1619b95 100644
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -462,13 +462,14 @@ static inline bool pte_marker_uffd_wp(pte_t pte)
 static inline bool pte_swp_uffd_wp_any(pte_t pte)
 {
 #ifdef CONFIG_PTE_MARKER_UFFD_WP
-	if (!is_swap_pte(pte))
-		return false;
+	swp_entry_t entry;
 
+	if (pte_present(pte))
+		return false;
 	if (pte_swp_uffd_wp(pte))
 		return true;
-
-	if (pte_marker_uffd_wp(pte))
+	entry = pte_to_swp_entry(pte);
+	if (pte_marker_entry_uffd_wp(entry))
 		return true;
 #endif
 	return false;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 86e672fcb305..4510029761ed 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5798,13 +5798,13 @@ static void move_huge_pte(struct vm_area_struct *vma, unsigned long old_addr,
 
 	pte = huge_ptep_get_and_clear(mm, old_addr, src_pte, sz);
 
-	if (need_clear_uffd_wp && pte_marker_uffd_wp(pte))
+	if (need_clear_uffd_wp && pte_marker_uffd_wp(pte)) {
 		huge_pte_clear(mm, new_addr, dst_pte, sz);
-	else {
+	} else {
 		if (need_clear_uffd_wp) {
 			if (pte_present(pte))
 				pte = huge_pte_clear_uffd_wp(pte);
-			else if (is_swap_pte(pte))
+			else
 				pte = pte_swp_clear_uffd_wp(pte);
 		}
 		set_huge_pte_at(mm, new_addr, dst_pte, pte, sz);
diff --git a/mm/internal.h b/mm/internal.h
index cbd3d897b16c..b855a4412878 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -325,8 +325,7 @@ unsigned int folio_pte_batch(struct folio *folio, pte_t *ptep, pte_t pte,
 /**
  * pte_move_swp_offset - Move the swap entry offset field of a swap pte
  *	 forward or backward by delta
- * @pte: The initial pte state; is_swap_pte(pte) must be true and
- *	 non_swap_entry() must be false.
+ * @pte: The initial pte state; must be a swap entry
  * @delta: The direction and the offset we are moving; forward if delta
  *	 is positive; backward if delta is negative
  *
@@ -352,8 +351,7 @@ static inline pte_t pte_move_swp_offset(pte_t pte, long delta)
 
 /**
  * pte_next_swp_offset - Increment the swap entry offset field of a swap pte.
- * @pte: The initial pte state; is_swap_pte(pte) must be true and
- *	 non_swap_entry() must be false.
+ * @pte: The initial pte state; must be a swap entry.
  *
  * Increments the swap offset, while maintaining all other fields, including
  * swap type, and any swp pte bits. The resulting pte is returned.
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 5b7276bc14b1..2079f270196f 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1019,7 +1019,8 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm,
 		}
 
 		vmf.orig_pte = ptep_get_lockless(pte);
-		if (!is_swap_pte(vmf.orig_pte))
+		if (pte_none(vmf.orig_pte) ||
+		    pte_present(vmf.orig_pte))
 			continue;
 
 		vmf.pte = pte;
@@ -1276,7 +1277,19 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm,
 	for (addr = start_addr, _pte = pte; _pte < pte + HPAGE_PMD_NR;
 	     _pte++, addr += PAGE_SIZE) {
 		pte_t pteval = ptep_get(_pte);
-		if (is_swap_pte(pteval)) {
+		if (pte_none_or_zero(pteval)) {
+			++none_or_zero;
+			if (!userfaultfd_armed(vma) &&
+			    (!cc->is_khugepaged ||
+			     none_or_zero <= khugepaged_max_ptes_none)) {
+				continue;
+			} else {
+				result = SCAN_EXCEED_NONE_PTE;
+				count_vm_event(THP_SCAN_EXCEED_NONE_PTE);
+				goto out_unmap;
+			}
+		}
+		if (!pte_present(pteval)) {
 			++unmapped;
 			if (!cc->is_khugepaged ||
 			    unmapped <= khugepaged_max_ptes_swap) {
@@ -1296,18 +1309,6 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm,
 				goto out_unmap;
 			}
 		}
-		if (pte_none_or_zero(pteval)) {
-			++none_or_zero;
-			if (!userfaultfd_armed(vma) &&
-			    (!cc->is_khugepaged ||
-			     none_or_zero <= khugepaged_max_ptes_none)) {
-				continue;
-			} else {
-				result = SCAN_EXCEED_NONE_PTE;
-				count_vm_event(THP_SCAN_EXCEED_NONE_PTE);
-				goto out_unmap;
-			}
-		}
 		if (pte_uffd_wp(pteval)) {
 			/*
 			 * Don't collapse the page if any of the small
diff --git a/mm/migrate.c b/mm/migrate.c
index 4324fc01bfce..69d8b4a9db25 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -492,7 +492,7 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
 	pte = ptep_get(ptep);
 	pte_unmap(ptep);
 
-	if (!is_swap_pte(pte))
+	if (pte_none(pte) || pte_present(pte))
 		goto out;
 
 	entry = pte_to_swp_entry(pte);
diff --git a/mm/mprotect.c b/mm/mprotect.c
index c090bc063a31..e25ac9835cc2 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -345,7 +345,26 @@ static long change_pte_range(struct mmu_gather *tlb,
 				prot_commit_flush_ptes(vma, addr, pte, oldpte, ptent,
 					nr_ptes, /* idx = */ 0, /* set_write = */ false, tlb);
 			pages += nr_ptes;
-		} else if (is_swap_pte(oldpte)) {
+		} else if (pte_none(oldpte)) {
+			/*
+			 * Nobody plays with any none ptes besides
+			 * userfaultfd when applying the protections.
+			 */
+			if (likely(!uffd_wp))
+				continue;
+
+			if (userfaultfd_wp_use_markers(vma)) {
+				/*
+				 * For file-backed mem, we need to be able to
+				 * wr-protect a none pte, because even if the
+				 * pte is none, the page/swap cache could
+				 * exist.  Doing that by install a marker.
+				 */
+				set_pte_at(vma->vm_mm, addr, pte,
+					   make_pte_marker(PTE_MARKER_UFFD_WP));
+				pages++;
+			}
+		} else  {
 			swp_entry_t entry = pte_to_swp_entry(oldpte);
 			pte_t newpte;
 
@@ -406,28 +425,6 @@ static long change_pte_range(struct mmu_gather *tlb,
 				set_pte_at(vma->vm_mm, addr, pte, newpte);
 				pages++;
 			}
-		} else {
-			/* It must be an none page, or what else?.. */
-			WARN_ON_ONCE(!pte_none(oldpte));
-
-			/*
-			 * Nobody plays with any none ptes besides
-			 * userfaultfd when applying the protections.
-			 */
-			if (likely(!uffd_wp))
-				continue;
-
-			if (userfaultfd_wp_use_markers(vma)) {
-				/*
-				 * For file-backed mem, we need to be able to
-				 * wr-protect a none pte, because even if the
-				 * pte is none, the page/swap cache could
-				 * exist.  Doing that by install a marker.
-				 */
-				set_pte_at(vma->vm_mm, addr, pte,
-					   make_pte_marker(PTE_MARKER_UFFD_WP));
-				pages++;
-			}
 		}
 	} while (pte += nr_ptes, addr += nr_ptes * PAGE_SIZE, addr != end);
 	arch_leave_lazy_mmu_mode();
diff --git a/mm/mremap.c b/mm/mremap.c
index bd7314898ec5..f01c74add990 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -158,6 +158,9 @@ static void drop_rmap_locks(struct vm_area_struct *vma)
 
 static pte_t move_soft_dirty_pte(pte_t pte)
 {
+	if (pte_none(pte))
+		return pte;
+
 	/*
 	 * Set soft dirty bit so we can notice
 	 * in userspace the ptes were moved.
@@ -165,7 +168,7 @@ static pte_t move_soft_dirty_pte(pte_t pte)
 #ifdef CONFIG_MEM_SOFT_DIRTY
 	if (pte_present(pte))
 		pte = pte_mksoft_dirty(pte);
-	else if (is_swap_pte(pte))
+	else
 		pte = pte_swp_mksoft_dirty(pte);
 #endif
 	return pte;
@@ -294,7 +297,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
 			if (need_clear_uffd_wp) {
 				if (pte_present(pte))
 					pte = pte_clear_uffd_wp(pte);
-				else if (is_swap_pte(pte))
+				else
 					pte = pte_swp_clear_uffd_wp(pte);
 			}
 			set_ptes(mm, new_addr, new_ptep, pte, nr_ptes);
diff --git a/mm/page_table_check.c b/mm/page_table_check.c
index 4eeca782b888..43f75d2f7c36 100644
--- a/mm/page_table_check.c
+++ b/mm/page_table_check.c
@@ -185,12 +185,15 @@ static inline bool swap_cached_writable(swp_entry_t entry)
 	       is_writable_migration_entry(entry);
 }
 
-static inline void page_table_check_pte_flags(pte_t pte)
+static void page_table_check_pte_flags(pte_t pte)
 {
-	if (pte_present(pte) && pte_uffd_wp(pte))
-		WARN_ON_ONCE(pte_write(pte));
-	else if (is_swap_pte(pte) && pte_swp_uffd_wp(pte))
-		WARN_ON_ONCE(swap_cached_writable(pte_to_swp_entry(pte)));
+	if (pte_present(pte)) {
+		WARN_ON_ONCE(pte_uffd_wp(pte) && pte_write(pte));
+	} else if (pte_swp_uffd_wp(pte)) {
+		const swp_entry_t entry = pte_to_swp_entry(pte);
+
+		WARN_ON_ONCE(swap_cached_writable(entry));
+	}
 }
 
 void __page_table_check_ptes_set(struct mm_struct *mm, pte_t *ptep, pte_t pte,
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 75a8fbb788b7..2e5ac6572630 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -16,6 +16,7 @@ static inline bool not_found(struct page_vma_mapped_walk *pvmw)
 static bool map_pte(struct page_vma_mapped_walk *pvmw, pmd_t *pmdvalp,
 		    spinlock_t **ptlp)
 {
+	bool is_migration;
 	pte_t ptent;
 
 	if (pvmw->flags & PVMW_SYNC) {
@@ -26,6 +27,7 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw, pmd_t *pmdvalp,
 		return !!pvmw->pte;
 	}
 
+	is_migration = pvmw->flags & PVMW_MIGRATION;
 again:
 	/*
 	 * It is important to return the ptl corresponding to pte,
@@ -41,11 +43,14 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw, pmd_t *pmdvalp,
 
 	ptent = ptep_get(pvmw->pte);
 
-	if (pvmw->flags & PVMW_MIGRATION) {
-		if (!is_swap_pte(ptent))
+	if (pte_none(ptent)) {
+		return false;
+	} else if (pte_present(ptent)) {
+		if (is_migration)
 			return false;
-	} else if (is_swap_pte(ptent)) {
+	} else if (!is_migration) {
 		swp_entry_t entry;
+
 		/*
 		 * Handle un-addressable ZONE_DEVICE memory.
 		 *
@@ -66,8 +71,6 @@ static bool map_pte(struct page_vma_mapped_walk *pvmw, pmd_t *pmdvalp,
 		if (!is_device_private_entry(entry) &&
 		    !is_device_exclusive_entry(entry))
 			return false;
-	} else if (!pte_present(ptent)) {
-		return false;
 	}
 	spin_lock(*ptlp);
 	if (unlikely(!pmd_same(*pmdvalp, pmdp_get_lockless(pvmw->pmd)))) {
@@ -107,27 +110,23 @@ static bool check_pte(struct page_vma_mapped_walk *pvmw, unsigned long pte_nr)
 	pte_t ptent = ptep_get(pvmw->pte);
 
 	if (pvmw->flags & PVMW_MIGRATION) {
-		swp_entry_t entry = pte_to_swp_entry_or_zero(ptent);
+		const swp_entry_t entry = pte_to_swp_entry_or_zero(ptent);
 
 		if (!is_migration_entry(entry))
 			return false;
 
 		pfn = swp_offset_pfn(entry);
-	} else if (is_swap_pte(ptent)) {
-		swp_entry_t entry;
+	} else if (pte_present(ptent)) {
+		pfn = pte_pfn(ptent);
+	} else {
+		const swp_entry_t entry = pte_to_swp_entry(ptent);
 
 		/* Handle un-addressable ZONE_DEVICE memory */
-		entry = pte_to_swp_entry(ptent);
 		if (!is_device_private_entry(entry) &&
 		    !is_device_exclusive_entry(entry))
 			return false;
 
 		pfn = swp_offset_pfn(entry);
-	} else {
-		if (!pte_present(ptent))
-			return false;
-
-		pfn = pte_pfn(ptent);
 	}
 
 	if ((pfn + pte_nr - 1) < pvmw->pfn)
-- 
2.51.0[RFC PATCH 02/12] mm: avoid unnecessary uses of is_swap_pte()Lorenzo Stoakes <lorenzo.stoakes@oracle.com> undefinedAndrew Morton <akpm@linux-foundation.org> undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined undefined