[Intel-gfx] [PATCH] drm/i915/gem: Support discontiguous lmem object maps

[Matthew Auld]

On Thu, 2 Jan 2020 at 10:38, Chris Wilson <chris at chris-wilson.co.uk> wrote:
>
> Create a vmap for discontinguous lmem objects to support
> i915_gem_object_pin_map().

Yes, please.

>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Matthew Auld <matthew.auld at intel.com>
> ---

[snip]

> @@ -288,12 +284,28 @@ static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
>                 pgprot = pgprot_writecombine(PAGE_KERNEL_IO);
>                 break;
>         }
> -       addr = vmap(pages, n_pages, 0, pgprot);
>
> -       if (pages != stack_pages)
> -               kvfree(pages);
> +       if (i915_gem_object_has_struct_page(obj)) {
> +               struct sgt_iter iter;
> +               struct page *page;
> +               pte_t **ptes = mem;
> +
> +               for_each_sgt_page(page, iter, sgt)
> +                       **ptes++ = mk_pte(page, pgprot);
> +       } else {
> +               const resource_size_t iomap = obj->mm.region->iomap.base;
> +               struct sgt_iter iter;
> +               dma_addr_t addr;
> +               pte_t **ptes = mem;
> +
> +               for_each_sgt_daddr(addr, iter, sgt)

addr -= region.start; for poor old fake local-memory.

> +                       **ptes++ = iomap_pte(iomap, addr, pgprot);