mm: Rename pmd_read_atomic()

There's no point in having the identical routines for PTE/PMD have
different names.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lkml.kernel.org/r/20221022114424.841277397%40infradead.org

Author: Peter Zijlstra

include/linux/pgtable.h

@@ -1352,11 +1352,6 @@ static inline int pud_trans_unstable(pud_t *pud)
 #endif
 }
 
-static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
-{
-	return pmdp_get_lockless(pmdp);
-}
-
 #ifndef arch_needs_pgtable_deposit
 #define arch_needs_pgtable_deposit() (false)
 #endif
@@ -1383,13 +1378,13 @@ static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
  */
 static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
 {
-	pmd_t pmdval = pmd_read_atomic(pmd);
+	pmd_t pmdval = pmdp_get_lockless(pmd);
 	/*
 	 * The barrier will stabilize the pmdval in a register or on
 	 * the stack so that it will stop changing under the code.
 	 *
 	 * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
-	 * pmd_read_atomic is allowed to return a not atomic pmdval
+	 * pmdp_get_lockless is allowed to return a not atomic pmdval
 	 * (for example pointing to an hugepage that has never been
 	 * mapped in the pmd). The below checks will only care about
 	 * the low part of the pmd with 32bit PAE x86 anyway, with the

mm/hmm.c

@@ -361,7 +361,7 @@ static int hmm_vma_walk_pmd(pmd_t *pmdp,
 		 * huge or device mapping one and compute corresponding pfn
 		 * values.
 		 */
-		pmd = pmd_read_atomic(pmdp);
+		pmd = pmdp_get_lockless(pmdp);
 		barrier();
 		if (!pmd_devmap(pmd) && !pmd_trans_huge(pmd))
 			goto again;

mm/khugepaged.c

@@ -862,7 +862,7 @@ static int find_pmd_or_thp_or_none(struct mm_struct *mm,
 	if (!*pmd)
 		return SCAN_PMD_NULL;
 
-	pmde = pmd_read_atomic(*pmd);
+	pmde = pmdp_get_lockless(*pmd);
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 	/* See comments in pmd_none_or_trans_huge_or_clear_bad() */

mm/mapping_dirty_helpers.c

@@ -126,7 +126,7 @@ static int clean_record_pte(pte_t *pte, unsigned long addr,
 static int wp_clean_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long end,
 			      struct mm_walk *walk)
 {
-	pmd_t pmdval = pmd_read_atomic(pmd);
+	pmd_t pmdval = pmdp_get_lockless(pmd);
 
 	if (!pmd_trans_unstable(&pmdval))
 		return 0;

mm/mprotect.c

@@ -294,7 +294,7 @@ static unsigned long change_pte_range(struct mmu_gather *tlb,
  */
 static inline int pmd_none_or_clear_bad_unless_trans_huge(pmd_t *pmd)
 {
-	pmd_t pmdval = pmd_read_atomic(pmd);
+	pmd_t pmdval = pmdp_get_lockless(pmd);
 
 	/* See pmd_none_or_trans_huge_or_clear_bad for info on barrier */
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE

mm/userfaultfd.c

@@ -630,7 +630,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
 			break;
 		}
 
-		dst_pmdval = pmd_read_atomic(dst_pmd);
+		dst_pmdval = pmdp_get_lockless(dst_pmd);
 		/*
 		 * If the dst_pmd is mapped as THP don't
 		 * override it and just be strict.

mm/vmscan.c

@@ -4039,9 +4039,9 @@ static void walk_pmd_range(pud_t *pud, unsigned long start, unsigned long end,
 	/* walk_pte_range() may call get_next_vma() */
 	vma = args->vma;
 	for (i = pmd_index(start), addr = start; addr != end; i++, addr = next) {
-		pmd_t val = pmd_read_atomic(pmd + i);
+		pmd_t val = pmdp_get_lockless(pmd + i);
 
-		/* for pmd_read_atomic() */
+		/* for pmdp_get_lockless() */
 		barrier();
 
 		next = pmd_addr_end(addr, end);