On Fri, 15 Sep 2023 17:09:56 -0700 Wesley Cheng <quic_wcheng@xxxxxxxxxxx>
> +static int
> +xhci_ring_to_sgtable(struct xhci_sideband *sb, struct xhci_ring *ring, struct device *dev)
> +{
> + struct sg_table *sgt;
> + struct xhci_segment *seg;
> + struct page **pages;
> + unsigned int n_pages;
> + size_t sz;
> + int i;
> +
> + sz = ring->num_segs * TRB_SEGMENT_SIZE;
> + n_pages = PAGE_ALIGN(sz) >> PAGE_SHIFT;
> + pages = kvmalloc_array(n_pages, sizeof(struct page *), GFP_KERNEL);
> + if (!pages)
> + return 0;
> +
> + sgt = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
> + if (!sgt) {
> + kvfree(pages);
> + return 0;
> + }
> +
> + seg = ring->first_seg;
> +
> + /*
> + * Rings can potentially have multiple segments, create an array that
> + * carries page references to allocated segments. Utilize the
> + * sg_alloc_table_from_pages() to create the sg table, and to ensure
> + * that page links are created.
> + */
> + for (i = 0; i < ring->num_segs; i++) {
> + pages[i] = vmalloc_to_page(seg->trbs);
> + seg = seg->next;
> + }
Given dma_pool_zalloc() in xhci_segment_alloc() and dma_alloc_coherent() in
pool_alloc_page(), it is incorrect to get page from the cpu address returned
by the dma alloc routine.
