Nouveau - Apr 2022 - [PATCH] drm/nouveau/tegra: Stop using iommu_present()

Even if some IOMMU has registered itself on the platform "bus", that
doesn't necessarily mean it provides translation for the device we
care about. Replace iommu_present() with a more appropriate check.

Signed-off-by: Robin Murphy <robin.murphy at arm.com>
---
 drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
index 992cc285f2fe..2ed528c065fa 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
@@ -123,7 +123,7 @@ nvkm_device_tegra_probe_iommu(struct nvkm_device_tegra
*tdev)
 
 	mutex_init(&tdev->iommu.mutex);
 
-	if (iommu_present(&platform_bus_type)) {
+	if (device_iommu_mapped(dev)) {
 		tdev->iommu.domain = iommu_domain_alloc(&platform_bus_type);
 		if (!tdev->iommu.domain)
 			goto error;
-- 
2.28.0.dirty

Whoops! Was going through my unread emails and noticed I somehow missed this
patch last month.

Reviewed-by: Lyude Paul <lyude at redhat.com>

I will push this to drm-misc-fixes in a little bit (assuming I don't find it
there already)

On Tue, 2022-04-05 at 15:21 +0100, Robin Murphy wrote:
> Even if some IOMMU has registered itself on the platform "bus",
that
> doesn't necessarily mean it provides translation for the device we
> care about. Replace iommu_present() with a more appropriate check.
> 
> Signed-off-by: Robin Murphy <robin.murphy at arm.com>
> ---
> ?drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c | 2 +-
> ?1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
> b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
> index 992cc285f2fe..2ed528c065fa 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/engine/device/tegra.c
> @@ -123,7 +123,7 @@ nvkm_device_tegra_probe_iommu(struct nvkm_device_tegra
> *tdev)
> ?
> ????????mutex_init(&tdev->iommu.mutex);
> ?
> -???????if (iommu_present(&platform_bus_type)) {
> +???????if (device_iommu_mapped(dev)) {
> ????????????????tdev->iommu.domain =
iommu_domain_alloc(&platform_bus_type);
> ????????????????if (!tdev->iommu.domain)
> ????????????????????????goto error;
-- 
Cheers,
 Lyude Paul (she/her)
 Software Engineer at Red Hat