[Intel-gfx] [PATCH v6 09/19] drm/i915/gen8: Pass sg_iter through pte inserts

[Goel, Akash]

Reviewed the patch & it looks fine.
Reviewed-by: "Akash Goel <akash.goel at intel.com>"

On 7/29/2015 9:53 PM, Michel Thierry wrote:
> As a step towards implementing 4 levels, while not discarding the
> existing pte insert functions, we need to pass the sg_iter through.
> The current function understands to the page directory granularity.
> An object's pages may span the page directory, and so using the iter
> directly as we write the PTEs allows the iterator to stay coherent
> through a VMA insert operation spanning multiple page table levels.
>
> v2: Rebase after s/page_tables/page_table/.
> v3: Rebase after Mika's ppgtt cleanup / scratch merge patch series;
> updated commit message (s/map/insert).
>
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> Signed-off-by: Michel Thierry <michel.thierry at intel.com> (v2+)
> ---
>   drivers/gpu/drm/i915/i915_gem_gtt.c | 11 ++++++-----
>   1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index c6c8af7..7c024e98 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -749,7 +749,7 @@ static void gen8_ppgtt_clear_range(struct i915_address_space *vm,
>   static void
>   gen8_ppgtt_insert_pte_entries(struct i915_address_space *vm,
>   			      struct i915_page_directory_pointer *pdp,
> -			      struct sg_table *pages,
> +			      struct sg_page_iter *sg_iter,
>   			      uint64_t start,
>   			      enum i915_cache_level cache_level)
>   {
> @@ -759,11 +759,10 @@ gen8_ppgtt_insert_pte_entries(struct i915_address_space *vm,
>   	unsigned pdpe = start >> GEN8_PDPE_SHIFT & GEN8_PDPE_MASK;
>   	unsigned pde = start >> GEN8_PDE_SHIFT & GEN8_PDE_MASK;
>   	unsigned pte = start >> GEN8_PTE_SHIFT & GEN8_PTE_MASK;
> -	struct sg_page_iter sg_iter;
>
>   	pt_vaddr = NULL;
>
> -	for_each_sg_page(pages->sgl, &sg_iter, pages->nents, 0) {
> +	while (__sg_page_iter_next(sg_iter)) {
>   		if (pt_vaddr == NULL) {
>   			struct i915_page_directory *pd = pdp->page_directory[pdpe];
>   			struct i915_page_table *pt = pd->page_table[pde];
> @@ -771,7 +770,7 @@ gen8_ppgtt_insert_pte_entries(struct i915_address_space *vm,
>   		}
>
>   		pt_vaddr[pte] =
> -			gen8_pte_encode(sg_page_iter_dma_address(&sg_iter),
> +			gen8_pte_encode(sg_page_iter_dma_address(sg_iter),
>   					cache_level, true);
>   		if (++pte == GEN8_PTES) {
>   			kunmap_px(ppgtt, pt_vaddr);
> @@ -797,8 +796,10 @@ static void gen8_ppgtt_insert_entries(struct i915_address_space *vm,
>   	struct i915_hw_ppgtt *ppgtt =
>   		container_of(vm, struct i915_hw_ppgtt, base);
>   	struct i915_page_directory_pointer *pdp = &ppgtt->pdp; /* FIXME: 48b */
> +	struct sg_page_iter sg_iter;
>
> -	gen8_ppgtt_insert_pte_entries(vm, pdp, pages, start, cache_level);
> +	__sg_page_iter_start(&sg_iter, pages->sgl, sg_nents(pages->sgl), 0);
> +	gen8_ppgtt_insert_pte_entries(vm, pdp, &sg_iter, start, cache_level);
>   }
>
>   static void gen8_free_page_tables(struct drm_device *dev,
>