1 files changed, 44 insertions, 0 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 2e872f92dbac..79ad29a8a60a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -20,6 +20,7 @@
 #include <linux/shrinker.h>
 #include <linux/resource.h>
 #include <linux/page_ext.h>
+#include <linux/err.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -1198,6 +1199,49 @@ long get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
                     int write, int force, struct page **pages);
 int get_user_pages_fast(unsigned long start, int nr_pages, int write,
                         struct page **pages);
+
+/* Container for pinned pfns / pages */
+struct frame_vector {
+        unsigned int nr_allocated;      /* Number of frames we have space for */
+        unsigned int nr_frames; /* Number of frames stored in ptrs array */
+        bool got_ref;           /* Did we pin pages by getting page ref? */
+        bool is_pfns;           /* Does array contain pages or pfns? */
+        void *ptrs[0];          /* Array of pinned pfns / pages. Use
+                                 * pfns_vector_pages() or pfns_vector_pfns()
+                                 * for access */
+};
+
+struct frame_vector *frame_vector_create(unsigned int nr_frames);
+void frame_vector_destroy(struct frame_vector *vec);
+int get_vaddr_frames(unsigned long start, unsigned int nr_pfns,
+                     bool write, bool force, struct frame_vector *vec);
+void put_vaddr_frames(struct frame_vector *vec);
+int frame_vector_to_pages(struct frame_vector *vec);
+void frame_vector_to_pfns(struct frame_vector *vec);
+
+static inline unsigned int frame_vector_count(struct frame_vector *vec)
+{
+        return vec->nr_frames;
+}
+
+static inline struct page **frame_vector_pages(struct frame_vector *vec)
+{
+        if (vec->is_pfns) {
+                int err = frame_vector_to_pages(vec);
+
+                if (err)
+                        return ERR_PTR(err);
+        }
+        return (struct page **)(vec->ptrs);
+}
+
+static inline unsigned long *frame_vector_pfns(struct frame_vector *vec)
+{
+        if (!vec->is_pfns)
+                frame_vector_to_pfns(vec);
+        return (unsigned long *)(vec->ptrs);
+}
+
 struct kvec;
 int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
                         struct page **pages);