On Mon, Dec 11, 2023 at 11:38:01PM -0800, Vivek Kasireddy wrote:
> @@ -42,7 +42,7 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf)
> if (pgoff >= ubuf->pagecount)
> return VM_FAULT_SIGBUS;
>
> - pfn = page_to_pfn(ubuf->pages[pgoff]);
> + pfn = page_to_pfn(&ubuf->folios[pgoff]->page);
We have folio_pfn().
> static int vmap_udmabuf(struct dma_buf *buf, struct iosys_map *map)
> {
> struct udmabuf *ubuf = buf->priv;
> + struct page **pages;
> void *vaddr;
> + pgoff_t pg;
>
> dma_resv_assert_held(buf->resv);
>
> - vaddr = vm_map_ram(ubuf->pages, ubuf->pagecount, -1);
> + pages = kmalloc_array(ubuf->pagecount, sizeof(*pages), GFP_KERNEL);
> + if (!pages)
> + return -ENOMEM;
> +
> + for (pg = 0; pg < ubuf->pagecount; pg++)
> + pages[pg] = &ubuf->folios[pg]->page;
> +
> + vaddr = vm_map_ram(pages, ubuf->pagecount, -1);
> + kfree(pages);
We don't yet have a vm_map_ram() variant that takes an array of
folios. We probably should; there was _something_ I was looking at
recently that would have liked it ...
> @@ -254,31 +262,70 @@ static int handle_shmem_pages(struct udmabuf *ubuf, struct file *memfd,
> pgoff_t *pgbuf)
> {
> pgoff_t pgidx, pgoff = offset >> PAGE_SHIFT;
> - struct page *page;
> + struct folio *folio = NULL;
>
> for (pgidx = 0; pgidx < pgcnt; pgidx++) {
> - page = shmem_read_mapping_page(memfd->f_mapping,
> - pgoff + pgidx);
> - if (IS_ERR(page))
> - return PTR_ERR(page);
> + folio = shmem_read_folio(memfd->f_mapping,
> + pgoff + pgidx);
You could join these two lines.
