Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 22af9d8..877fd23 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -6,6 +6,8 @@
 #include <linux/bug.h>
 #include <linux/mm_types.h>
 
+#ifdef CONFIG_MMU
+
 /*
  * swapcache pages are stored in the swapper_space radix tree.  We want to
  * get good packing density in that tree, so the index should be dense in
@@ -18,9 +20,8 @@
  *
  * swp_entry_t's are *never* stored anywhere in their arch-dependent format.
  */
-#define SWP_TYPE_SHIFT(e)	((sizeof(e.val) * 8) - \
-			(MAX_SWAPFILES_SHIFT + RADIX_TREE_EXCEPTIONAL_SHIFT))
-#define SWP_OFFSET_MASK(e)	((1UL << SWP_TYPE_SHIFT(e)) - 1)
+#define SWP_TYPE_SHIFT	(BITS_PER_XA_VALUE - MAX_SWAPFILES_SHIFT)
+#define SWP_OFFSET_MASK	((1UL << SWP_TYPE_SHIFT) - 1)
 
 /*
  * Store a type+offset into a swp_entry_t in an arch-independent format
@@ -29,8 +30,7 @@
 {
 	swp_entry_t ret;
 
-	ret.val = (type << SWP_TYPE_SHIFT(ret)) |
-			(offset & SWP_OFFSET_MASK(ret));
+	ret.val = (type << SWP_TYPE_SHIFT) | (offset & SWP_OFFSET_MASK);
 	return ret;
 }
 
@@ -40,7 +40,7 @@
  */
 static inline unsigned swp_type(swp_entry_t entry)
 {
-	return (entry.val >> SWP_TYPE_SHIFT(entry));
+	return (entry.val >> SWP_TYPE_SHIFT);
 }
 
 /*
@@ -49,16 +49,14 @@
  */
 static inline pgoff_t swp_offset(swp_entry_t entry)
 {
-	return entry.val & SWP_OFFSET_MASK(entry);
+	return entry.val & SWP_OFFSET_MASK;
 }
 
-#ifdef CONFIG_MMU
 /* check whether a pte points to a swap entry */
 static inline int is_swap_pte(pte_t pte)
 {
 	return !pte_none(pte) && !pte_present(pte);
 }
-#endif
 
 /*
  * Convert the arch-dependent pte representation of a swp_entry_t into an
@@ -90,16 +88,13 @@
 {
 	swp_entry_t entry;
 
-	entry.val = (unsigned long)arg >> RADIX_TREE_EXCEPTIONAL_SHIFT;
+	entry.val = xa_to_value(arg);
 	return entry;
 }
 
 static inline void *swp_to_radix_entry(swp_entry_t entry)
 {
-	unsigned long value;
-
-	value = entry.val << RADIX_TREE_EXCEPTIONAL_SHIFT;
-	return (void *)(value | RADIX_TREE_EXCEPTIONAL_ENTRY);
+	return xa_mk_value(entry.val);
 }
 
 #if IS_ENABLED(CONFIG_DEVICE_PRIVATE)
@@ -134,12 +129,6 @@
 {
 	return pfn_to_page(swp_offset(entry));
 }
-
-vm_fault_t device_private_entry_fault(struct vm_area_struct *vma,
-		       unsigned long addr,
-		       swp_entry_t entry,
-		       unsigned int flags,
-		       pmd_t *pmdp);
 #else /* CONFIG_DEVICE_PRIVATE */
 static inline swp_entry_t make_device_private_entry(struct page *page, bool write)
 {
@@ -169,15 +158,6 @@
 {
 	return NULL;
 }
-
-static inline vm_fault_t device_private_entry_fault(struct vm_area_struct *vma,
-				     unsigned long addr,
-				     swp_entry_t entry,
-				     unsigned int flags,
-				     pmd_t *pmdp)
-{
-	return VM_FAULT_SIGBUS;
-}
 #endif /* CONFIG_DEVICE_PRIVATE */
 
 #ifdef CONFIG_MIGRATION
@@ -380,4 +360,5 @@
 }
 #endif
 
+#endif /* CONFIG_MMU */
 #endif /* _LINUX_SWAPOPS_H */