On Thu, Feb 20, 2020 at 10:27 AM Jordan Crouse <jcrouse@xxxxxxxxxxxxxx> wrote:
>
> The GMU has very few memory allocations and uses a flat memory space so
> there is no good reason to go out of our way to bypass the DMA APIs which
> were basically designed for this exact scenario.
>
> v2: Pass force_dma false to of_dma_configure to require that the DMA
> region be set up and return error from of_dma_configure to fail probe.
>
> Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
> ---
>
> drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 112 +++-------------------------------
> drivers/gpu/drm/msm/adreno/a6xx_gmu.h | 5 +-
> 2 files changed, 11 insertions(+), 106 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> index 983afea..c36b38b 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
...
> - count = bo->size >> PAGE_SHIFT;
> + bo->virt = dma_alloc_attrs(gmu->dev, bo->size, &bo->iova, GFP_KERNEL,
> + bo->attrs);
>
...
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> index 2af91ed..31bd1987 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> @@ -13,7 +13,7 @@ struct a6xx_gmu_bo {
> void *virt;
> size_t size;
> u64 iova;
> - struct page **pages;
> + unsigned long attrs;
> };
As a head up, Todd reported that this patch is causing build trouble
w/ arm32, as the iova needs to be a dma_attr_t.
I've got a patch for the android-mainline tree to fix this, but you
might want to spin a v3 to address this.
https://android-review.googlesource.com/c/kernel/common/+/1243928
thanks
-john
