Re: How to specify IOMMU'able devices in DT (was: [RFC 0/5] ARM:dma-mapping: New dma_map_ops to control IOVA more precisely)

From: James Bottomley
Date: Mon Sep 24 2012 - 05:28:01 EST


On Mon, 2012-09-24 at 12:04 +0300, Hiroshi Doyu wrote:
> diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> index a1a7225..9eae3be 100644
> --- a/drivers/base/platform.c
> +++ b/drivers/base/platform.c
> @@ -21,6 +21,8 @@
> #include <linux/slab.h>
> #include <linux/pm_runtime.h>
>
> +#include <asm/dma-iommu.h>
> +
> #include "base.h"
>
> #define to_platform_driver(drv) (container_of((drv), struct
> platform_driver, \
> @@ -305,8 +307,19 @@ int platform_device_add(struct platform_device
> *pdev)
> dev_name(&pdev->dev), dev_name(pdev->dev.parent));
>
> ret = device_add(&pdev->dev);
> - if (ret == 0)
> - return ret;
> + if (ret)
> + goto failed;
> +
> +#ifdef CONFIG_PLATFORM_ENABLE_IOMMU
> + if (platform_bus_type.map && !pdev->dev.archdata.mapping) {
> + ret = arm_iommu_attach_device(&pdev->dev,
> + platform_bus_type.map);
> + if (ret)
> + goto failed;

This is horrible ... you're adding an architecture specific callback
into our generic code; that's really a no-no. If the concept of
CONFIG_PLATFORM_ENABE_IOMMU is useful to more than just arm, then this
could become a generic callback.

James


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/