[PATCH 3/3] mm: cleanup clear_not_present_full_ptes() and rename to clear_non_present_ptes()

[David Hildenbrand (Arm)]

Let's clean it up a bit:

(1) There is no need to pass "full" anymore.

(2) No architecture overwrites it, and there isn't really a good reason
    to do so when dealing with non-resent PTEs.

(3) While at it, call it "non-present", similar to copy_nonpresent_pte()
    and zap_nonpresent_ptes().

It's a shame that we have clear_non_present_ptes() correspond to
pte_clear() and clear_ptes() correspond to ptep_get_and_clear*().

Likely we should rename pte_clear() to pte_clear_nonpresent() or sth.
like that, to make it clearer that it is usually the wrong interface
for dealing with present PTEs.

Signed-off-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
---
 include/linux/pgtable.h | 14 ++++----------
 mm/madvise.c            |  2 +-
 mm/memory.c             |  2 +-
 3 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index cf328f4d1e12..a72c40708461 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -954,24 +954,19 @@ static inline void update_mmu_tlb(struct vm_area_struct *vma,
 	update_mmu_tlb_range(vma, address, ptep, 1);
 }
 
-#ifndef clear_not_present_full_ptes
 /**
- * clear_not_present_full_ptes - Clear multiple not present PTEs which are
- *				 consecutive in the pgtable.
+ * clear_nonpresent_ptes - Clear multiple non-present PTEs which are
+ *			    consecutive in the pgtable.
  * @mm: Address space the ptes represent.
  * @addr: Address of the first pte.
  * @ptep: Page table pointer for the first entry.
  * @nr: Number of entries to clear.
- * @full: Whether we are clearing a full mm.
- *
- * May be overridden by the architecture; otherwise, implemented as a simple
- * loop over pte_clear().
  *
  * Context: The caller holds the page table lock.  The PTEs are all not present.
  * The PTEs are all in the same PMD.
  */
-static inline void clear_not_present_full_ptes(struct mm_struct *mm,
-		unsigned long addr, pte_t *ptep, unsigned int nr, int full)
+static inline void clear_nonpresent_ptes(struct mm_struct *mm,
+		unsigned long addr, pte_t *ptep, unsigned int nr)
 {
 	for (;;) {
 		pte_clear(mm, addr, ptep);
@@ -981,7 +976,6 @@ static inline void clear_not_present_full_ptes(struct mm_struct *mm,
 		addr += PAGE_SIZE;
 	}
 }
-#endif
 
 #ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
 extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
diff --git a/mm/madvise.c b/mm/madvise.c
index f3cda54c1d6a..3db143c442ea 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -695,7 +695,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr,
 				nr = swap_pte_batch(pte, max_nr, ptent);
 				nr_swap -= nr;
 				swap_put_entries_direct(entry, nr);
-				clear_not_present_full_ptes(mm, addr, pte, nr, tlb->fullmm);
+				clear_nonpresent_ptes(mm, addr, pte, nr);
 			} else if (softleaf_is_hwpoison(entry) ||
 				   softleaf_is_poison_marker(entry)) {
 				pte_clear(mm, addr, pte);
diff --git a/mm/memory.c b/mm/memory.c
index 56be920c56d7..d4b3540ae659 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1797,7 +1797,7 @@ static inline int zap_nonpresent_ptes(struct mmu_gather *tlb,
 		pr_alert("unrecognized swap entry 0x%lx\n", entry.val);
 		WARN_ON_ONCE(1);
 	}
-	clear_not_present_full_ptes(vma->vm_mm, addr, pte, nr, tlb->fullmm);
+	clear_nonpresent_ptes(vma->vm_mm, addr, pte, nr);
 	*any_skipped = zap_install_uffd_wp_if_needed(vma, addr, pte, nr, details, ptent);
 
 	return nr;

-- 
2.43.0