From: Dmitry Osipenko digetx@gmail.com
commit d5185965c3b59073c4520bad7dd2adf725b9abba upstream.
Host1x DMA buffer isn't mapped properly when CONFIG_ARM_DMA_USE_IOMMU=y. The memory management code of Host1x driver has a longstanding overhaul overdue and it's not obvious where the problem is in this case. Hence let's add back the old workaround which we already had sometime before. It explicitly detaches Host1x device from the offending implicit IOMMU domain. This fixes a completely broken Host1x DMA in case of ARM32 multiplatform kernel config.
Cc: stable@vger.kernel.org Fixes: af1cbfb9bf0f ("gpu: host1x: Support DMA mapping of buffers") Signed-off-by: Dmitry Osipenko digetx@gmail.com Signed-off-by: Thierry Reding treding@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/host1x/dev.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
--- a/drivers/gpu/host1x/dev.c +++ b/drivers/gpu/host1x/dev.c @@ -18,6 +18,10 @@ #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" @@ -232,6 +236,17 @@ static struct iommu_domain *host1x_iommu struct iommu_domain *domain = iommu_get_domain_for_dev(host->dev); int err;
+#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU) + if (host->dev->archdata.mapping) { + struct dma_iommu_mapping *mapping = + to_dma_iommu_mapping(host->dev); + arm_iommu_detach_device(host->dev); + arm_iommu_release_mapping(mapping); + + domain = iommu_get_domain_for_dev(host->dev); + } +#endif + /* * We may not always want to enable IOMMU support (for example if the * host1x firewall is already enabled and we don't support addressing