userfaultfd: add minor fault registration mode

[linux-2.6-microblaze.git] / include / linux / userfaultfd_k.h

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index a8e5f3e..0390e5a 100644 (file)
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -17,6 +17,9 @@
 #include <linux/mm.h>
 #include <asm-generic/pgtable_uffd.h>
 
+/* The set of all possible UFFD-related VM flags. */
+#define __VM_UFFD_FLAGS (VM_UFFD_MISSING | VM_UFFD_WP | VM_UFFD_MINOR)
+
 /*
  * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
  * new flags, since they might collide with O_* ones. We want
@@ -52,6 +55,15 @@ static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
        return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
 }
 
+/*
+ * Never enable huge pmd sharing on uffd-wp registered vmas, because uffd-wp
+ * protect information is per pgtable entry.
+ */
+static inline bool uffd_disable_huge_pmd_share(struct vm_area_struct *vma)
+{
+       return vma->vm_flags & VM_UFFD_WP;
+}
+
 static inline bool userfaultfd_missing(struct vm_area_struct *vma)
 {
        return vma->vm_flags & VM_UFFD_MISSING;
@@ -62,6 +74,11 @@ static inline bool userfaultfd_wp(struct vm_area_struct *vma)
        return vma->vm_flags & VM_UFFD_WP;
 }
 
+static inline bool userfaultfd_minor(struct vm_area_struct *vma)
+{
+       return vma->vm_flags & VM_UFFD_MINOR;
+}
+
 static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma,
                                      pte_t pte)
 {
@@ -76,7 +93,7 @@ static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma,
 
 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
 {
-       return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
+       return vma->vm_flags & __VM_UFFD_FLAGS;
 }
 
 extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
@@ -123,6 +140,11 @@ static inline bool userfaultfd_wp(struct vm_area_struct *vma)
        return false;
 }
 
+static inline bool userfaultfd_minor(struct vm_area_struct *vma)
+{
+       return false;
+}
+
 static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma,
                                      pte_t pte)
 {