include/media/frame_vector.h

0001 // SPDX-License-Identifier: GPL-2.0
0002 #ifndef _MEDIA_FRAME_VECTOR_H
0003 #define _MEDIA_FRAME_VECTOR_H
0004
0005 /* Container for pinned pfns / pages in frame_vector.c */
0006 struct frame_vector {
0007     unsigned int nr_allocated;  /* Number of frames we have space for */
0008     unsigned int nr_frames; /* Number of frames stored in ptrs array */
0009     bool got_ref;       /* Did we pin pages by getting page ref? */
0010     bool is_pfns;       /* Does array contain pages or pfns? */
0011     void *ptrs[];       /* Array of pinned pfns / pages. Use
0012                  * pfns_vector_pages() or pfns_vector_pfns()
0013                  * for access */
0014 };
0015
0016 struct frame_vector *frame_vector_create(unsigned int nr_frames);
0017 void frame_vector_destroy(struct frame_vector *vec);
0018 int get_vaddr_frames(unsigned long start, unsigned int nr_pfns,
0019              struct frame_vector *vec);
0020 void put_vaddr_frames(struct frame_vector *vec);
0021 int frame_vector_to_pages(struct frame_vector *vec);
0022 void frame_vector_to_pfns(struct frame_vector *vec);
0023
0024 static inline unsigned int frame_vector_count(struct frame_vector *vec)
0025 {
0026     return vec->nr_frames;
0027 }
0028
0029 static inline struct page **frame_vector_pages(struct frame_vector *vec)
0030 {
0031     if (vec->is_pfns) {
0032         int err = frame_vector_to_pages(vec);
0033
0034         if (err)
0035             return ERR_PTR(err);
0036     }
0037     return (struct page **)(vec->ptrs);
0038 }
0039
0040 static inline unsigned long *frame_vector_pfns(struct frame_vector *vec)
0041 {
0042     if (!vec->is_pfns)
0043         frame_vector_to_pfns(vec);
0044     return (unsigned long *)(vec->ptrs);
0045 }
0046
0047 #endif /* _MEDIA_FRAME_VECTOR_H */