[PATCH v3] gpu: host1x: Detach Host1x from IOMMU DMA domain on arm32

[Mikko Perttunen]

Reviewed-by: Mikko Perttunen <mperttunen at nvidia.com>

On 30/08/2018 9.12, Dmitry Osipenko wrote:
> 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.
> 
> Signed-off-by: Dmitry Osipenko <digetx at gmail.com>
> ---
> 
> Changelog:
> 
> v2: Correctly placed the detachment code, now Host1x is detached regardless
>      of the firewall state.
> 
> v3: Compiles now.
> 
>   drivers/gpu/host1x/dev.c | 13 ++++++++++++-
>   1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
> index d88073e7d22d..de6bc4e7fa23 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"
> @@ -217,7 +221,14 @@ static int host1x_probe(struct platform_device *pdev)
>   		dev_err(&pdev->dev, "failed to get reset: %d\n", err);
>   		return 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);
> +	}
> +#endif
>   	if (IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL))
>   		goto skip_iommu;
>   
>