- first = (vaddr & PAGE_MASK) >> PAGE_SHIFT;
- last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
- buf->num_pages = last - first + 1;
-
- buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
- GFP_KERNEL);
- if (!buf->pages)
- goto userptr_fail_alloc_pages;
-
- vma = find_vma(current->mm, vaddr);
- if (!vma) {
- dprintk(1, "no vma for address %lu\n", vaddr);
- goto userptr_fail_find_vma;
- }
-
- if (vma->vm_end < vaddr + size) {
- dprintk(1, "vma at %lu is too small for %lu bytes\n",
- vaddr, size);
- goto userptr_fail_find_vma;
- }
-
- buf->vma = vb2_get_vma(vma);
- if (!buf->vma) {
- dprintk(1, "failed to copy vma\n");
- goto userptr_fail_find_vma;
- }
-
- if (vma_is_io(buf->vma)) {
- for (num_pages_from_user = 0;
- num_pages_from_user < buf->num_pages;
- ++num_pages_from_user, vaddr += PAGE_SIZE) {
- unsigned long pfn;
-
- if (follow_pfn(vma, vaddr, &pfn)) {
- dprintk(1, "no page for address %lu\n", vaddr);
- break;
- }
- buf->pages[num_pages_from_user] = pfn_to_page(pfn);
- }
- } else
- num_pages_from_user = get_user_pages(current, current->mm,
- vaddr & PAGE_MASK,
- buf->num_pages,
- buf->dma_dir == DMA_FROM_DEVICE,
- 1, /* force */
- buf->pages,
- NULL);
-
- if (num_pages_from_user != buf->num_pages)
- goto userptr_fail_get_user_pages;