Function alloc_bounce_pages

freebsd/arm64/arm64/busdma_bounce.c:1314–1347

}

static int
alloc_bounce_pages(bus_dma_tag_t dmat, u_int numpages)
{
	struct bounce_zone *bz;
	int count;

	bz = dmat->bounce_zone;
	count = 0;
	while (numpages > 0) {
		struct bounce_page *bpage;

		bpage = (struct bounce_page *)malloc(sizeof(*bpage), M_DEVBUF,
						     M_NOWAIT | M_ZERO);

		if (bpage == NULL)
			break;
		bpage->vaddr = (vm_offset_t)contigmalloc(PAGE_SIZE, M_DEVBUF,
		    M_NOWAIT, 0ul, bz->lowaddr, PAGE_SIZE, 0);
		if (bpage->vaddr == 0) {
			free(bpage, M_DEVBUF);
			break;
		}
		bpage->busaddr = pmap_kextract(bpage->vaddr);
		mtx_lock(&bounce_lock);
		STAILQ_INSERT_TAIL(&bz->bounce_page_list, bpage, links);
		total_bpages++;
		bz->total_bpages++;
		bz->free_bpages++;
		mtx_unlock(&bounce_lock);
		count++;
		numpages--;
	}
	return (count);
}

static int
reserve_bounce_pages(bus_dma_tag_t dmat, bus_dmamap_t map, int commit)