Re: [PATCH v3 1/4] of: iommu: add ptr to OF node arg to of_iommu_configure()

[Murali Karicheri]

On 01/07/2015 06:30 PM, Rob Herring wrote:
> On Wed, Jan 7, 2015 at 12:49 PM, Murali Karicheri<m-karicheri2@xxxxxx>  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.
> >
> > Signed-off-by: Murali Karicheri<m-karicheri2@xxxxxx>
> > ---
> >   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..396bc77 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 *node)
>
> You use node here, but np in the declaration. However...
>
> >   {
> >          struct of_phandle_args iommu_spec;
> >          struct device_node *np;
>
> We also have np here. I would suggest we rename this to iommu_node or
> iommu_np to be clear which one this is for.
Rob,

Thanks for the comment. Will pick and use iommu_np consistently everywhere.

Murali
> >          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
> >           */
> > -       while (!of_parse_phandle_with_args(dev->of_node, "iommus",
> > +       while (!of_parse_phandle_with_args(node, "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..3258cbb 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 *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 *np)
> >   {
> >          return NULL;
> >   }
> > --
> > 1.7.9.5


--
Murali Karicheri
Linux Kernel, Texas Instruments
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