linux/include/media/frame_vector.h

48 lines
1.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
#ifndef _MEDIA_FRAME_VECTOR_H
#define _MEDIA_FRAME_VECTOR_H
/* Container for pinned pfns / pages in frame_vector.c */
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[]; /* 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,
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);
}
#endif /* _MEDIA_FRAME_VECTOR_H */