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

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>]

On Mon, Mar 16, 2026 at 10:37:25PM +0530, Vijayanand Jitta wrote:
> 
> 
> 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.

As this changes the params, you will also need to change the semantics,
removing the of_node_put() from the function and making the caller
release the reference (as it should be).

-- 
With best wishes
Dmitry