Re: [PATCH V11 2/3] ACPI: Add support for ResourceSource/IRQ domain mapping

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Thu, Jan 26, 2017 at 03:01:18AM +0200, Andy Shevchenko wrote:
> On Fri, Jan 20, 2017 at 4:34 AM, Agustin Vega-Frias
> <agustinv@codeaurora.org> wrote:
> > ACPI extended IRQ resources may contain a ResourceSource to specify
> > an alternate interrupt controller. Introduce acpi_irq_get and use it
> > to implement ResourceSource/IRQ domain mapping.
> >
> > The new API is similar to of_irq_get and allows re-initialization
> > of a platform resource from the ACPI extended IRQ resource, and
> > provides proper behavior for probe deferral when the domain is not
> > yet present when called.
> 
> > +static struct fwnode_handle *
> > +acpi_get_irq_source_fwhandle(const struct acpi_resource_source *source)
> > +{
> > +       struct fwnode_handle *result = NULL;
> > +       struct acpi_device *device;
> > +       struct acpi_hardware_id *hwid;
> > +       struct acpi_device_id *devid;
> > +       acpi_handle handle;
> > +       acpi_status status;
> > +
> > +       if (!source->string_length)
> > +               return acpi_gsi_domain_id;
> > +
> > +       status = acpi_get_handle(NULL, source->string_ptr, &handle);
> > +       if (WARN_ON(ACPI_FAILURE(status)))
> > +               return NULL;
> > +
> > +       device = acpi_bus_get_acpi_device(handle);
> > +       if (WARN_ON(!device))
> > +               return NULL;
> > +
> 
> > +       list_for_each_entry(hwid, &device->pnp.ids, list) {
> 
> > +               for (devid = &__dsdt_irqchip_acpi_probe_table;
> > +                    devid < &__dsdt_irqchip_acpi_probe_table_end; devid++) {
> > +                       if (devid->id && !strcmp(devid->id, hwid->id)) {
> > +                               result = &device->fwnode;
> > +                               break;
> > +                       }
> > +               }
> 
> Looks like a candidate for linker table API. (I recommend to Cc Luis
> for this part)

This linker table entry scheme is just an optimization and should
not gate the series.

> > +       }
> 
> > +/**
> > + * acpi_irq_parse_one_match - Handle a matching IRQ resource.
> > + * @fwnode: matching fwnode
> > + * @hwirq: hardware IRQ number
> > + * @triggering: triggering attributes of hwirq
> > + * @polarity: polarity attributes of hwirq
> > + * @polarity: polarity attributes of hwirq
> > + * @shareable: shareable attributes of hwirq
> > + * @ctx: acpi_irq_parse_one_ctx updated by this function
> > + *
> > + * Description:
> > + * Handle a matching IRQ resource by populating the given ctx with
> > + * the information passed.
> > + */
> > +static inline void acpi_irq_parse_one_match(struct fwnode_handle *fwnode,
> > +                                           u32 hwirq, u8 triggering,
> > +                                           u8 polarity, u8 shareable,
> > +                                           struct acpi_irq_parse_one_ctx *ctx)
> > +{
> 
> > +       if (!fwnode)
> > +               return;
> 
> > +       ctx->rc = 0;
> 
> Perhaps ctx->rc = fwnode ? 0 : -EINVAL; ?
> 
> > +       *ctx->res_flags = acpi_dev_irq_flags(triggering, polarity, shareable);
> > +       ctx->fwspec->fwnode = fwnode;
> > +       ctx->fwspec->param[0] = hwirq;
> > +       ctx->fwspec->param[1] = acpi_dev_get_irq_type(triggering, polarity);
> > +       ctx->fwspec->param_count = 2;
> > +}
> 
> > +int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res)
> > +{
> > +       struct irq_fwspec fwspec;
> > +       struct irq_domain *domain;
> > +       unsigned long flags;
> > +       int rc;
> > +
> > +       rc = acpi_irq_parse_one(handle, index, &fwspec, &flags);
> > +       if (rc)
> > +               return rc;
> > +
> > +       domain = irq_find_matching_fwnode(fwspec.fwnode, DOMAIN_BUS_ANY);
> > +       if (!domain)
> > +               return -EPROBE_DEFER;
> > +
> > +       rc = irq_create_fwspec_mapping(&fwspec);
> > +       if (rc <= 0)
> 
> Is rc = 0 an error?

Yes.

> > +               return -EINVAL;
> > +
> > +       res->start = rc;
> > +       res->end = rc;
> > +       res->flags = flags;
> > +
> > +       return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(acpi_irq_get);
> 
> > --- a/drivers/base/platform.c
> > +++ b/drivers/base/platform.c
> > @@ -102,6 +102,14 @@ int platform_get_irq(struct platform_device *dev, unsigned int num)
> 
> >         r = platform_get_resource(dev, IORESOURCE_IRQ, num);
> > +       if (r && r->flags & IORESOURCE_DISABLED && has_acpi_companion(&dev->dev)) {
> > +               int ret;
> > +
> > +               ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
> > +               if (ret)
> > +                       return ret;
> > +       }
> 
> > +#ifdef CONFIG_ACPI_GENERIC_GSI
> 
> #if IS_ENABLED()
> 
> > +int acpi_irq_get(acpi_handle handle, unsigned int index, struct resource *res);
> > +#else
> > +static inline int acpi_irq_get(acpi_handle handle, unsigned int index,
> > +                              struct resource *res)
> 
> Perhaps
> 
> static inline
> int ...

It is late -rc5 and notwithstanding cosmetics changes, can we make
progress with this patch series or not please ?

Thanks,
Lorenzo