Hi Murali,

Thank you for the patch.

On Friday 23 January 2015 17:32:34 Murali Karicheri wrote:
> Function of_iommu_configure() is called from of_dma_configure() to
> setup iommu ops using DT property. This API is currently used for
> platform devices for which DMA configuration (including iommu ops)
> may come from device's parent. To extend this functionality for PCI
> devices, this API need to take a parent node ptr as an argument
> instead of assuming device's parent. This is needed since for PCI, the
> dma configuration may be defined in the DT node of the root bus bridge's
> parent device. Currently only dma-range is used for PCI and iommu is not
> supported. So return error if the device is PCI.
> 
> Cc: Joerg Roedel <j...@8bytes.org>
> Cc: Grant Likely <grant.lik...@linaro.org>
> Cc: Rob Herring <robh...@kernel.org>
> Cc: Bjorn Helgaas <bhelg...@google.com>
> Cc: Will Deacon <will.dea...@arm.com>
> Cc: Russell King <li...@arm.linux.org.uk>
> Cc: Arnd Bergmann <a...@arndb.de>
> Cc: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
> 
> Signed-off-by: Murali Karicheri <m-kariche...@ti.com>
> ---
>  drivers/iommu/of_iommu.c |   10 ++++++++--
>  drivers/of/platform.c    |    2 +-
>  include/linux/of_iommu.h |    6 ++++--
>  3 files changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
> index af1dc6a..439235b 100644
> --- a/drivers/iommu/of_iommu.c
> +++ b/drivers/iommu/of_iommu.c
> @@ -133,19 +133,25 @@ struct iommu_ops *of_iommu_get_ops(struct device_node
> *np) return ops;
>  }
> 
> -struct iommu_ops *of_iommu_configure(struct device *dev)
> +struct iommu_ops *of_iommu_configure(struct device *dev,
> +                                  struct device_node *iommu_np)
>  {
>       struct of_phandle_args iommu_spec;
>       struct device_node *np;
>       struct iommu_ops *ops = NULL;
>       int idx = 0;
> 
> +     if (dev_is_pci(dev)) {
> +             dev_err(dev, "iommu is currently not supported for PCI\n");
> +             return NULL;
> +     }
> +
>       /*
>        * We don't currently walk up the tree looking for a parent IOMMU.
>        * See the `Notes:' section of
>        * Documentation/devicetree/bindings/iommu/iommu.txt
>        */

Wouldn't it be better to fix this rather than passing the device node pointer 
to the function ? The solution would be more generic.

> -     while (!of_parse_phandle_with_args(dev->of_node, "iommus",
> +     while (!of_parse_phandle_with_args(iommu_np, "iommus",
>                                          "#iommu-cells", idx,
>                                          &iommu_spec)) {
>               np = iommu_spec.np;
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index a54ec10..7675b79 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -196,7 +196,7 @@ static void of_dma_configure(struct device *dev)
>       dev_dbg(dev, "device is%sdma coherent\n",
>               coherent ? " " : " not ");
> 
> -     iommu = of_iommu_configure(dev);
> +     iommu = of_iommu_configure(dev, dev->of_node);
>       dev_dbg(dev, "device is%sbehind an iommu\n",
>               iommu ? " " : " not ");
> 
> diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h
> index 16c7554..a97e5bd 100644
> --- a/include/linux/of_iommu.h
> +++ b/include/linux/of_iommu.h
> @@ -12,7 +12,8 @@ extern int of_get_dma_window(struct device_node *dn, const
> char *prefix, size_t *size);
> 
>  extern void of_iommu_init(void);
> -extern struct iommu_ops *of_iommu_configure(struct device *dev);
> +extern struct iommu_ops *of_iommu_configure(struct device *dev,
> +                                     struct device_node *iommu_np);
> 
>  #else
> 
> @@ -24,7 +25,8 @@ static inline int of_get_dma_window(struct device_node
> *dn, const char *prefix, }
> 
>  static inline void of_iommu_init(void) { }
> -static inline struct iommu_ops *of_iommu_configure(struct device *dev)
> +static inline struct iommu_ops *of_iommu_configure(struct device *dev,
> +                                      struct device_node *iommu_np)
>  {
>       return NULL;
>  }

-- 
Regards,

Laurent Pinchart

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