[PATCH v6 6/8] dma-mapping: detect and configure IOMMU in of_dma_configure

[Laurent Pinchart]

Hi Will,

On Monday 01 December 2014 16:57:12 Will Deacon wrote:
> This patch extends of_dma_configure so that it sets up the IOMMU for a
> device, as well as the coherent/non-coherent DMA mapping ops.
> 
> Acked-by: Arnd Bergmann <arnd at arndb.de>
> Acked-by: Marek Szyprowski <m.szyprowski at samsung.com>
> Tested-by: Robin Murphy <robin.murphy at arm.com>
> Signed-off-by: Will Deacon <will.deacon at arm.com>
> ---
>  arch/arm/include/asm/dma-mapping.h |  4 +++-
>  drivers/of/platform.c              | 21 ++++++++++++++-------
>  include/linux/dma-mapping.h        |  8 +++++++-
>  3 files changed, 24 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm/include/asm/dma-mapping.h
> b/arch/arm/include/asm/dma-mapping.h index dc3420e77758..f3c0d953f6a2
> 100644
> --- a/arch/arm/include/asm/dma-mapping.h
> +++ b/arch/arm/include/asm/dma-mapping.h
> @@ -121,7 +121,9 @@ static inline unsigned long dma_max_pfn(struct device
> *dev) }
>  #define dma_max_pfn(dev) dma_max_pfn(dev)
> 
> -static inline void arch_setup_dma_ops(struct device *dev, bool coherent)
> +static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
> +				      u64 size, struct iommu_ops *iommu,
> +				      bool coherent)
>  {
>  	if (coherent)
>  		set_dma_ops(dev, &arm_coherent_dma_ops);
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index ff1f4e9afccb..b89caf8c7586 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -19,6 +19,7 @@
>  #include <linux/slab.h>
>  #include <linux/of_address.h>
>  #include <linux/of_device.h>
> +#include <linux/of_iommu.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> @@ -166,6 +167,7 @@ static void of_dma_configure(struct device *dev)
>  	int ret;
>  	bool coherent;
>  	unsigned long offset;
> +	struct iommu_ops *iommu;
> 
>  	/*
>  	 * Set default dma-mask to 32 bit. Drivers are expected to setup
> @@ -194,7 +196,16 @@ static void of_dma_configure(struct device *dev)
>  	dev_dbg(dev, "device is%sdma coherent\n",
>  		coherent ? " " : " not ");
> 
> -	arch_setup_dma_ops(dev, coherent);
> +	iommu = of_iommu_configure(dev);
> +	dev_dbg(dev, "device is%sbehind an iommu\n",
> +		iommu ? " " : " not ");
> +
> +	arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
> +}
> +
> +static void of_dma_deconfigure(struct device *dev)
> +{
> +	arch_teardown_dma_ops(dev);
>  }
> 
>  /**
> @@ -223,16 +234,12 @@ static struct platform_device
> *of_platform_device_create_pdata( if (!dev)
>  		goto err_clear_flag;
> 
> -	of_dma_configure(&dev->dev);
>  	dev->dev.bus = &platform_bus_type;
>  	dev->dev.platform_data = platform_data;
> -
> -	/* We do not fill the DMA ops for platform devices by default.
> -	 * This is currently the responsibility of the platform code
> -	 * to do such, possibly using a device notifier
> -	 */
> +	of_dma_configure(&dev->dev);
> 
>  	if (of_device_add(dev) != 0) {
> +		of_dma_deconfigure(&dev->dev);

Don't you also need to call of_dma_deconfigure() when the device is destroyed 
? Otherwise the default domain created by arch_setup_dma_ops() will be leaked.

>  		platform_device_put(dev);
>  		goto err_clear_flag;
>  	}
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index 8a1560f95d4a..c3007cb4bfa6 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -130,7 +130,13 @@ static inline int dma_coerce_mask_and_coherent(struct
> device *dev, u64 mask) extern u64 dma_get_required_mask(struct device
> *dev);
> 
>  #ifndef arch_setup_dma_ops
> -static inline void arch_setup_dma_ops(struct device *dev, bool coherent) {
> } +static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
> +				      u64 size, struct iommu_ops *iommu,
> +				      bool coherent) { }
> +#endif
> +
> +#ifndef arch_teardown_dma_ops
> +static inline void arch_teardown_dma_ops(struct device *dev) { }
>  #endif
> 
>  static inline unsigned int dma_get_max_seg_size(struct device *dev)

-- 
Regards,

Laurent Pinchart