diff mbox series

[v1] drm/tegra: Detach devices from IOMMU DMA domain on arm32

Message ID 20180819142421.22567-1-digetx@gmail.com (mailing list archive)
State New, archived
Headers show
Series [v1] drm/tegra: Detach devices from IOMMU DMA domain on arm32 | expand

Commit Message

Dmitry Osipenko Aug. 19, 2018, 2:24 p.m. UTC
All Tegra DRM devices are getting attached to an implicit IOMMU DMA
domain if CONFIG_ARM_DMA_USE_IOMMU=y. Since Tegra DRM driver manages IOMMU
by itself, the devices must be detached from the implicit domain using
arch-specific IOMMU-API. Note that this works only for arm32 and not for
arm64, which will remain broken if CONFIG_IOMMU_DMA is enabled.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/gpu/drm/tegra/drm.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

Thierry Reding Sept. 26, 2018, 3:24 p.m. UTC | #1
On Sun, Aug 19, 2018 at 05:24:20PM +0300, Dmitry Osipenko wrote:
> All Tegra DRM devices are getting attached to an implicit IOMMU DMA
> domain if CONFIG_ARM_DMA_USE_IOMMU=y. Since Tegra DRM driver manages IOMMU
> by itself, the devices must be detached from the implicit domain using
> arch-specific IOMMU-API. Note that this works only for arm32 and not for
> arm64, which will remain broken if CONFIG_IOMMU_DMA is enabled.
> 
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
>  drivers/gpu/drm/tegra/drm.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)

Applied, thanks.

Thierry
diff mbox series

Patch

diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index a2bd5876c633..b2ac2411e0ff 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -15,6 +15,10 @@ 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 
+#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
+#include <asm/dma-iommu.h>
+#endif
+
 #include "drm.h"
 #include "gem.h"
 
@@ -1068,6 +1072,14 @@  struct iommu_group *host1x_client_iommu_attach(struct host1x_client *client,
 		}
 
 		if (!shared || (shared && (group != tegra->group))) {
+#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
+			if (client->dev->archdata.mapping) {
+				struct dma_iommu_mapping *mapping =
+					to_dma_iommu_mapping(client->dev);
+				arm_iommu_detach_device(client->dev);
+				arm_iommu_release_mapping(mapping);
+			}
+#endif
 			err = iommu_attach_group(tegra->domain, group);
 			if (err < 0) {
 				iommu_group_put(group);