[PATCH v4 1/6] drm/panfrost: Set IOMMU_CACHE flag

[Adrian Larumbe]

On 17.03.2025 11:52, Ariel D'Alessandro wrote:
> Panfrost does not support uncached mappings, so flag them properly. Also
> flag the pages that are mapped as response to a page fault as cached.
>
> Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
> Signed-off-by: Ariel D'Alessandro <ariel.dalessandro at collabora.com>
> Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>
> Reviewed-by: Steven Price <steven.price at arm.com>

Reviewed-by: Adrián Larumbe <adrian.larumbe at collabora.com>

> ---
>  drivers/gpu/drm/panfrost/panfrost_mmu.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index b91019cd5acb1..9e6f198ef5c1b 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> @@ -327,7 +327,7 @@ int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
>  	struct drm_gem_object *obj = &shmem->base;
>  	struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
>  	struct sg_table *sgt;
> -	int prot = IOMMU_READ | IOMMU_WRITE;
> +	int prot = IOMMU_READ | IOMMU_WRITE | IOMMU_CACHE;
>
>  	if (WARN_ON(mapping->active))
>  		return 0;
> @@ -528,7 +528,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
>  		goto err_map;
>
>  	mmu_map_sg(pfdev, bomapping->mmu, addr,
> -		   IOMMU_WRITE | IOMMU_READ | IOMMU_NOEXEC, sgt);
> +		   IOMMU_WRITE | IOMMU_READ | IOMMU_CACHE | IOMMU_NOEXEC, sgt);
>
>  	bomapping->active = true;
>  	bo->heap_rss_size += SZ_2M;
> --
> 2.47.2


Adrian Larumbe