Re: [PATCH v6 05/14] ACPI: platform-msi: retrieve dev id from IORT

[Tomasz Nowicki]

On 03.01.2017 09:43, Tomasz Nowicki wrote:
> On 02.01.2017 14:31, Hanjun Guo wrote:
> > For devices connecting to ITS, it needs dev id to identify
> > itself, and this dev id is represented in the IORT table in
> > named componant node [1] for platform devices, so in this
> > patch we will scan the IORT to retrieve device's dev id.
> >
> > Introduce iort_pmsi_get_dev_id() with pointer dev passed
> > in for that purpose.
> >
> > [1]:
> > https://static.docs.arm.com/den0049/b/DEN0049B_IO_Remapping_Table.pdf
> >
> > Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> > Tested-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> > Tested-by: Majun <majun258@xxxxxxxxxx>
> > Tested-by: Xinwei Kong <kong.kongxinwei@xxxxxxxxxxxxx>
> > Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
> > Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> > Cc: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > ---
> >  drivers/acpi/arm64/iort.c                     | 26
> > ++++++++++++++++++++++++++
> >  drivers/irqchip/irq-gic-v3-its-platform-msi.c |  4 +++-
> >  include/linux/acpi_iort.h                     |  8 ++++++++
> >  3 files changed, 37 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> > index 174e983..ab7bae7 100644
> > --- a/drivers/acpi/arm64/iort.c
> > +++ b/drivers/acpi/arm64/iort.c
> > @@ -444,6 +444,32 @@ u32 iort_msi_map_rid(struct device *dev, u32 req_id)
> >  }
> >
> >  /**
> > + * iort_pmsi_get_dev_id() - Get the device id for a device
> > + * @dev: The device for which the mapping is to be done.
> > + * @dev_id: The device ID found.
> > + *
> > + * Returns: 0 for successful find a dev id, errors otherwise
> > + */
> > +int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
> > +{
> > +    struct acpi_iort_node *node;
> > +
> > +    if (!iort_table)
> > +        return -ENODEV;
> > +
> > +    node = iort_find_dev_node(dev);
> > +    if (!node) {
> > +        dev_err(dev, "can't find related IORT node\n");
> > +        return -ENODEV;
> > +    }
> > +
> > +    if(!iort_node_get_id(node, dev_id, IORT_MSI_TYPE, 0))
> > +        return -ENODEV;
> > +
> > +    return 0;
> > +}
> > +
> > +/**
> Giving that you are extending this to NC->
> SMMU->ITS case in later patch, we can use existing helpers from iort.c,
> like that:
>
> +/**
> + * iort_pmsi_get_dev_id() - Get the device id for a device
> + * @dev: The device for which the mapping is to be done.
> + * @dev_id: The device ID found.
> + *
> + * Returns: 0 for successful find a dev id, errors otherwise
> + */
> +int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
> +{
> +    struct acpi_iort_node *node;
> +
> +    node = iort_find_dev_node(dev);
> +    if (!node)
> +        return -ENODEV;
> +
> +    if (!iort_node_map_rid(node, 0, dev_id, IORT_MSI_TYPE))
> +        return -ENODEV;
> +
> +    return 0;
> +}
>
> Correct me if I am wrong.

"0" as rid_in for iort_node_map_rid() isn't good idea, sorry...

Tomasz