include/media/frame_vector.h

   1 // SPDX-License-Identifier: GPL-2.0
   2 #ifndef _MEDIA_FRAME_VECTOR_H
   3 #define _MEDIA_FRAME_VECTOR_H
   4
   5 /* Container for pinned pfns / pages in frame_vector.c */
   6 struct frame_vector {
   7         unsigned int nr_allocated;      /* Number of frames we have space for */
   8         unsigned int nr_frames; /* Number of frames stored in ptrs array */
   9         bool got_ref;           /* Did we pin pages by getting page ref? */
  10         bool is_pfns;           /* Does array contain pages or pfns? */
  11         void *ptrs[];           /* Array of pinned pfns / pages. Use
  12                                  * pfns_vector_pages() or pfns_vector_pfns()
  13                                  * for access */
  14 };
  15
  16 struct frame_vector *frame_vector_create(unsigned int nr_frames);
  17 void frame_vector_destroy(struct frame_vector *vec);
  18 int get_vaddr_frames(unsigned long start, unsigned int nr_pfns,
  19                      bool write, struct frame_vector *vec);
  20 void put_vaddr_frames(struct frame_vector *vec);
  21 int frame_vector_to_pages(struct frame_vector *vec);
  22 void frame_vector_to_pfns(struct frame_vector *vec);
  23
  24 static inline unsigned int frame_vector_count(struct frame_vector *vec)
  25 {
  26         return vec->nr_frames;
  27 }
  28
  29 static inline struct page **frame_vector_pages(struct frame_vector *vec)
  30 {
  31         if (vec->is_pfns) {
  32                 int err = frame_vector_to_pages(vec);
  33
  34                 if (err)
  35                         return ERR_PTR(err);
  36         }
  37         return (struct page **)(vec->ptrs);
  38 }
  39
  40 static inline unsigned long *frame_vector_pfns(struct frame_vector *vec)
  41 {
  42         if (!vec->is_pfns)
  43                 frame_vector_to_pfns(vec);
  44         return (unsigned long *)(vec->ptrs);
  45 }
  46
  47 #endif /* _MEDIA_FRAME_VECTOR_H */