layoutx/dma_util.h

#ifndef __DMA_UTIL_H__
#define __DMA_UTIL_H__

#include <stddef.h>
#include <stdint.h>
#include <sys/ioctl.h>
#include <linux/dma-buf.h>

/* Allocate one dma-buf from /dev/dma_heap/<heap_name>, falling back to
 * "system-uncached" when the named heap does not exist. Returns 0 and sets
 * *fd on success, -1 on failure. Shared by main/decoder/display/detector. */
int dma_heap_alloc(const char *heap_name, size_t size, int *fd);

/* Convenience wrapper for the DMA_BUF_IOCTL_SYNC START/END handshake,
 * e.g. dmabuf_sync(fd, DMA_BUF_SYNC_START | DMA_BUF_SYNC_WRITE). */
static inline void dmabuf_sync(int fd, int flags) {
    struct dma_buf_sync s = { .flags = (uint64_t)flags };
    ioctl(fd, DMA_BUF_IOCTL_SYNC, &s);
}

#endif