diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 398e9c9..4e78094 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -18,9 +18,16 @@
 #define VM_ALLOC		0x00000002	/* vmalloc() */
 #define VM_MAP			0x00000004	/* vmap()ed pages */
 #define VM_USERMAP		0x00000008	/* suitable for remap_vmalloc_range */
+#define VM_DMA_COHERENT		0x00000010	/* dma_alloc_coherent */
 #define VM_UNINITIALIZED	0x00000020	/* vm_struct is not fully initialized */
 #define VM_NO_GUARD		0x00000040      /* don't add guard page */
 #define VM_KASAN		0x00000080      /* has allocated kasan shadow memory */
+/*
+ * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with
+ * vfree_atomic().
+ */
+#define VM_FLUSH_RESET_PERMS	0x00000100      /* Reset direct map and flush TLB on unmap */
+
 /* bits [20..32] reserved for arch specific ioremap internals */
 
 /*
@@ -45,12 +52,22 @@
 struct vmap_area {
 	unsigned long va_start;
 	unsigned long va_end;
-	unsigned long flags;
+
 	struct rb_node rb_node;         /* address sorted rbtree */
 	struct list_head list;          /* address sorted list */
-	struct llist_node purge_list;    /* "lazy purge" list */
-	struct vm_struct *vm;
-	struct rcu_head rcu_head;
+
+	/*
+	 * The following three variables can be packed, because
+	 * a vmap_area object is always one of the three states:
+	 *    1) in "free" tree (root is vmap_area_root)
+	 *    2) in "busy" tree (root is free_vmap_area_root)
+	 *    3) in purge list  (head is vmap_purge_list)
+	 */
+	union {
+		unsigned long subtree_max_size; /* in "free" tree */
+		struct vm_struct *vm;           /* in "busy" tree */
+		struct llist_node purge_list;   /* in purge list */
+	};
 };
 
 /*
@@ -63,10 +80,12 @@
 
 #ifdef CONFIG_MMU
 extern void __init vmalloc_init(void);
+extern unsigned long vmalloc_nr_pages(void);
 #else
 static inline void vmalloc_init(void)
 {
 }
+static inline unsigned long vmalloc_nr_pages(void) { return 0; }
 #endif
 
 extern void *vmalloc(unsigned long size);
@@ -142,6 +161,13 @@
 				    pgprot_t prot, struct page **pages);
 extern void unmap_kernel_range_noflush(unsigned long addr, unsigned long size);
 extern void unmap_kernel_range(unsigned long addr, unsigned long size);
+static inline void set_vm_flush_reset_perms(void *addr)
+{
+	struct vm_struct *vm = find_vm_area(addr);
+
+	if (vm)
+		vm->flags |= VM_FLUSH_RESET_PERMS;
+}
 #else
 static inline int
 map_kernel_range_noflush(unsigned long start, unsigned long size,
@@ -157,6 +183,9 @@
 unmap_kernel_range(unsigned long addr, unsigned long size)
 {
 }
+static inline void set_vm_flush_reset_perms(void *addr)
+{
+}
 #endif
 
 /* Allocate/destroy a 'vmalloc' VM area. */