Re: [PATCH 04/20] xics: Eliminate reset hook

[Greg Kurz <groug@kaod.org>]

On Wed, 25 Sep 2019 16:45:18 +1000
David Gibson <david@gibson.dropbear.id.au> wrote:

> Currently TYPE_XICS_BASE and TYPE_XICS_SIMPLE have their own reset methods,
> using the standard technique for having the subtype call the supertype's
> methods before doing its own thing.
> 
> But TYPE_XICS_SIMPLE is the only subtype of TYPE_XICS_BASE ever
> instantiated, so there's no point having the split here.  Merge them
> together into just an ics_reset() function.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  hw/intc/xics.c        | 57 ++++++++++++++++++-------------------------
>  include/hw/ppc/xics.h |  1 -
>  2 files changed, 24 insertions(+), 34 deletions(-)
> 
> diff --git a/hw/intc/xics.c b/hw/intc/xics.c
> index 310dc72b46..82e6f09259 100644
> --- a/hw/intc/xics.c
> +++ b/hw/intc/xics.c
> @@ -547,11 +547,28 @@ static void ics_eoi(ICSState *ics, uint32_t nr)
>      }
>  }
>  
> -static void ics_simple_reset(DeviceState *dev)
> +static void ics_reset_irq(ICSIRQState *irq)
>  {
> -    ICSStateClass *icsc = ICS_BASE_GET_CLASS(dev);
> +    irq->priority = 0xff;
> +    irq->saved_priority = 0xff;
> +}
>  
> -    icsc->parent_reset(dev);
> +static void ics_reset(DeviceState *dev)
> +{
> +    ICSState *ics = ICS_BASE(dev);
> +    int i;
> +    uint8_t flags[ics->nr_irqs];
> +
> +    for (i = 0; i < ics->nr_irqs; i++) {
> +        flags[i] = ics->irqs[i].flags;
> +    }
> +
> +    memset(ics->irqs, 0, sizeof(ICSIRQState) * ics->nr_irqs);
> +
> +    for (i = 0; i < ics->nr_irqs; i++) {
> +        ics_reset_irq(ics->irqs + i);
> +        ics->irqs[i].flags = flags[i];
> +    }
>  
>      if (kvm_irqchip_in_kernel()) {
>          Error *local_err = NULL;
> @@ -563,9 +580,9 @@ static void ics_simple_reset(DeviceState *dev)
>      }
>  }
>  
> -static void ics_simple_reset_handler(void *dev)
> +static void ics_reset_handler(void *dev)
>  {
> -    ics_simple_reset(dev);
> +    ics_reset(dev);
>  }
>  
>  static void ics_simple_realize(DeviceState *dev, Error **errp)
> @@ -580,7 +597,7 @@ static void ics_simple_realize(DeviceState *dev, Error **errp)
>          return;
>      }
>  
> -    qemu_register_reset(ics_simple_reset_handler, ics);
> +    qemu_register_reset(ics_reset_handler, ics);

As suggested by Philippe, this could be the opportunity to add
a comment that explain why we rely on qemu_register_reset()
rather than dc->reset.

>  }
>  
>  static void ics_simple_class_init(ObjectClass *klass, void *data)
> @@ -590,8 +607,6 @@ static void ics_simple_class_init(ObjectClass *klass, void *data)
>  
>      device_class_set_parent_realize(dc, ics_simple_realize,
>                                      &isc->parent_realize);
> -    device_class_set_parent_reset(dc, ics_simple_reset,
> -                                  &isc->parent_reset);
>  }
>  
>  static const TypeInfo ics_simple_info = {
> @@ -602,30 +617,6 @@ static const TypeInfo ics_simple_info = {
>      .class_size = sizeof(ICSStateClass),
>  };
>  
> -static void ics_reset_irq(ICSIRQState *irq)
> -{
> -    irq->priority = 0xff;
> -    irq->saved_priority = 0xff;
> -}
> -
> -static void ics_base_reset(DeviceState *dev)
> -{
> -    ICSState *ics = ICS_BASE(dev);
> -    int i;
> -    uint8_t flags[ics->nr_irqs];
> -
> -    for (i = 0; i < ics->nr_irqs; i++) {
> -        flags[i] = ics->irqs[i].flags;
> -    }
> -
> -    memset(ics->irqs, 0, sizeof(ICSIRQState) * ics->nr_irqs);
> -
> -    for (i = 0; i < ics->nr_irqs; i++) {
> -        ics_reset_irq(ics->irqs + i);
> -        ics->irqs[i].flags = flags[i];
> -    }
> -}
> -
>  static void ics_base_realize(DeviceState *dev, Error **errp)
>  {
>      ICSState *ics = ICS_BASE(dev);
> @@ -726,7 +717,7 @@ static void ics_base_class_init(ObjectClass *klass, void *data)
>  
>      dc->realize = ics_base_realize;
>      dc->props = ics_base_properties;
> -    dc->reset = ics_base_reset;
> +    dc->reset = ics_reset;

I hadn't spotted it previously but since you're removing the call to
device_class_set_parent_reset(), we don't need dc->reset anymore.

This basically reverts:

commit eeefd43b3cf342d1696128462a16e092995ff1b5
Author: Cédric Le Goater <clg@kaod.org>
Date:   Mon Jun 25 11:17:16 2018 +0200

    ppx/xics: introduce a parent_reset in ICSStateClass
    
    Just like for the realize handlers, this makes possible to move the
    common ICSState code of the reset handlers in the ics-base class.
    
    Signed-off-by: Cédric Le Goater <clg@kaod.org>
    Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

With dc->reset removed,

Reviewed-by: Greg Kurz <groug@kaod.org>

>      dc->vmsd = &vmstate_ics_base;
>  }
>  
> diff --git a/include/hw/ppc/xics.h b/include/hw/ppc/xics.h
> index e72fb67968..18fcd2b11c 100644
> --- a/include/hw/ppc/xics.h
> +++ b/include/hw/ppc/xics.h
> @@ -105,7 +105,6 @@ struct ICSStateClass {
>      DeviceClass parent_class;
>  
>      DeviceRealize parent_realize;
> -    DeviceReset parent_reset;
>  };
>  
>  struct ICSState {