[PATCH v3 2/3] mm: Move ptep_get() and pmdp_get() helpers

From: Ryan Roberts
Date: Mon Jun 12 2023 - 11:16:18 EST


There are many call sites that directly dereference a pte_t pointer.
This makes it very difficult to properly encapsulate a page table in the
arch code without having to allocate shadow page tables.

We will shortly solve this by replacing all the call sites with
ptep_get() calls. But there are call sites above the function definition
in the header file, so let's move ptep_get() to an earlier location to
solve that problem. And move pmdp_get() at the same time to keep it
close to ptep_get().

Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx>
---
include/linux/pgtable.h | 28 ++++++++++++++--------------
1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index a1326e61d7ee..fc06f6419661 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -212,6 +212,20 @@ static inline int pudp_set_access_flags(struct vm_area_struct *vma,
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif

+#ifndef ptep_get
+static inline pte_t ptep_get(pte_t *ptep)
+{
+ return READ_ONCE(*ptep);
+}
+#endif
+
+#ifndef pmdp_get
+static inline pmd_t pmdp_get(pmd_t *pmdp)
+{
+ return READ_ONCE(*pmdp);
+}
+#endif
+
#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address,
@@ -317,20 +331,6 @@ static inline void ptep_clear(struct mm_struct *mm, unsigned long addr,
ptep_get_and_clear(mm, addr, ptep);
}

-#ifndef ptep_get
-static inline pte_t ptep_get(pte_t *ptep)
-{
- return READ_ONCE(*ptep);
-}
-#endif
-
-#ifndef pmdp_get
-static inline pmd_t pmdp_get(pmd_t *pmdp)
-{
- return READ_ONCE(*pmdp);
-}
-#endif
-
#ifdef CONFIG_GUP_GET_PXX_LOW_HIGH
/*
* For walking the pagetables without holding any locks. Some architectures
--
2.25.1