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

Murali Karicheri
2015-01-08T18:29:26Z

On 01/07/2015 06:30 PM, Rob Herring wrote:
> On Wed, Jan 7, 2015 at 12:49 PM, Murali Karicheri<m-karicheri2@ti.com> 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@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..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