Host1x is getting attached to an implicit IOMMU DMA domain if
CONFIG_ARM_DMA_USE_IOMMU=y. Since Host1x driver manages IOMMU by
itself, Host1x device 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 <dig...@gmail.com>
---
 drivers/gpu/host1x/dev.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index d88073e7d22d..47624f20718d 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -29,6 +29,10 @@
 #include <trace/events/host1x.h>
 #undef CREATE_TRACE_POINTS
 
+#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
+#include <asm/dma-iommu.h>
+#endif
+
 #include "bus.h"
 #include "channel.h"
 #include "debug.h"
@@ -236,6 +240,14 @@ static int host1x_probe(struct platform_device *pdev)
                        goto put_cache;
                }
 
+#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
+               if (pdev->dev->archdata.mapping) {
+                       struct dma_iommu_mapping *mapping =
+                                       to_dma_iommu_mapping(pdev->dev);
+                       arm_iommu_detach_device(pdev->dev);
+                       arm_iommu_release_mapping(mapping);
+               }
+#endif
                err = iommu_attach_group(host->domain, host->group);
                if (err) {
                        if (err == -ENODEV) {
-- 
2.18.0

_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Reply via email to