Re: [PATCH v10 2/3] of: factor arguments passed to of_map_id() into a struct

[Vijayanand Jitta <vijayanand.jitta@xxxxxxxxxxxxxxxx>]

On 3/12/2026 7:48 PM, Dmitry Baryshkov wrote:
> On Thu, Mar 12, 2026 at 05:12:51PM +0530, Vijayanand Jitta wrote:
>>
>>
>> On 3/10/2026 2:53 AM, Dmitry Baryshkov wrote:
>>> On Mon, Mar 09, 2026 at 01:03:38AM +0530, Vijayanand Jitta wrote:
>>>> From: Charan Teja Kalla <charan.kalla@xxxxxxxxxxxxxxxx>
>>>>
>>>> Change of_map_id() to take a pointer to struct of_phandle_args
>>>> instead of passing target device node and translated IDs separately.
>>>> Update all callers accordingly.
>>>>
>>>> Subsequent patch will make use of the args_count field in
>>>> struct of_phandle_args.
>>>>
>>>> Suggested-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
>>>> Signed-off-by: Charan Teja Kalla <charan.kalla@xxxxxxxxxxxxxxxx>
>>>> Signed-off-by: Vijayanand Jitta <vijayanand.jitta@xxxxxxxxxxxxxxxx>
>>>> ---
>>>>  drivers/cdx/cdx_msi.c                    |  5 ++-
>>>>  drivers/iommu/of_iommu.c                 |  2 +-
>>>>  drivers/irqchip/irq-gic-its-msi-parent.c | 11 ++++--
>>>>  drivers/of/base.c                        | 63 
>>>> ++++++++++++++++----------------
>>>>  drivers/of/irq.c                         |  8 +++-
>>>>  drivers/pci/controller/dwc/pci-imx6.c    | 16 ++++++--
>>>>  drivers/pci/controller/pcie-apple.c      |  5 ++-
>>>>  drivers/xen/grant-dma-ops.c              |  4 +-
>>>>  include/linux/of.h                       | 12 +++---
>>>>  9 files changed, 76 insertions(+), 50 deletions(-)
>>>>
>>>> diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c
>>>> index 63b3544ec997..03232b5ffbca 100644
>>>> --- a/drivers/cdx/cdx_msi.c
>>>> +++ b/drivers/cdx/cdx_msi.c
>>>> @@ -121,6 +121,7 @@ static int cdx_msi_prepare(struct irq_domain 
>>>> *msi_domain,
>>>>                       struct device *dev,
>>>>                       int nvec, msi_alloc_info_t *info)
>>>>  {
>>>> +  struct of_phandle_args msi_spec = { .np = NULL };
>>>
>>> Why do you need to set it? Parse functions ignore passed args, don't
>>> they?
>>>
>>
>> The parse function does check arg->np on input — if it is non-NULL,
>> it is used to match only entries targeting that specific node.
>>
>> Also, there is this existing path in drivers/pci/msi/irqdomain.c which
>> pre-sets the node and passes it as input to of_msi_xlate(), so the node
>> pointer is not ignored by the parse code:
> 
> Is it only being used for MSIs? If so, can we make that explicit in the
> API by having the 'filter' device_node pointer?
> 

Yes, I see this is used only in the MSI path via of_msi_xlate(). 

By filter do you mean the below changes ? here of_map_id() and of_map_msi_id() 
would accept the filter
as a separate parameter so that arg becomes a pure output:


int of_map_id(const struct device_node *np, u32 id, const char *map_name,
              const char *cells_name, const char *map_mask_name,
              const struct device_node *filter_np, struct of_phandle_args *arg);

int of_map_msi_id(const struct device_node *np, u32 id,
                  const struct device_node *filter_np, struct of_phandle_args 
*arg);

of_msi_xlate() would then pass *msi_np as filter_np down to of_map_msi_id
and IOMMU callers would pass NULL to of_map_id. 

Does this look fine ? I can include this in v11.

Thanks,
Vijay

>>
>> u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev 
>> *pdev)
>> {
>>         struct device_node *of_node;
>>         u32 rid = pci_dev_id(pdev);
>>
>>         pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
>>
>>         of_node = irq_domain_get_of_node(domain);
>>         rid = of_node ? of_msi_xlate(&pdev->dev, &of_node, rid) :
>>                         iort_msi_map_id(&pdev->dev, rid);
>>
>>         return rid;
>> }
>>
>