[Qemu-devel] Re: [PATCH 04/26] pci: add accessor function to get irq levels

[Michael S. Tsirkin]

On Wed, Mar 16, 2011 at 06:29:15PM +0900, Isaku Yamahata wrote:
> Introduce accessor function to know INTx levels.
> It will be used later by q35.
> Although piix_pci tracks the intx line levels, it can be eliminated
> by this helper function.

At least for piix, the right thing to IMO is to have bit per
IRQ, then the for loop can be replaced with a single !!.  There's a TODO
there which this will fix.  I think we can reuse pci device irq_state
for this: need to check. Haven't looked at q35 yet - applies there as
well?

> 
> Cc: Michael S. Tsirkin <address@hidden>
> Signed-off-by: Isaku Yamahata <address@hidden>
> ---
>  hw/pci.c |    7 +++++++
>  hw/pci.h |    1 +
>  2 files changed, 8 insertions(+), 0 deletions(-)
> 
> diff --git a/hw/pci.c b/hw/pci.c
> index d6c5e66..67cb3d7 100644
> --- a/hw/pci.c
> +++ b/hw/pci.c
> @@ -126,6 +126,13 @@ static void pci_change_irq_level(PCIDevice *pci_dev, int 
> irq_num, int change)
>      bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0);
>  }
>  
> +int pci_bus_get_irq_level(PCIBus *bus, int irq_num)
> +{
> +    assert(irq_num >= 0);
> +    assert(irq_num < bus->nirq);
> +    return !!bus->irq_count[irq_num];
> +}
> +
>  /* Update interrupt status bit in config space on interrupt
>   * state change. */
>  static void pci_update_irq_status(PCIDevice *dev)
> diff --git a/hw/pci.h b/hw/pci.h
> index 46b3ad3..f523722 100644
> --- a/hw/pci.h
> +++ b/hw/pci.h
> @@ -234,6 +234,7 @@ void pci_bus_new_inplace(PCIBus *bus, DeviceState *parent,
>  PCIBus *pci_bus_new(DeviceState *parent, const char *name, int devfn_min);
>  void pci_bus_irqs(PCIBus *bus, pci_set_irq_fn set_irq, pci_map_irq_fn 
> map_irq,
>                    void *irq_opaque, int nirq);
> +int pci_bus_get_irq_level(PCIBus *bus, int irq_num);
>  void pci_bus_hotplug(PCIBus *bus, pci_hotplug_fn hotplug, DeviceState *dev);
>  /* 0 <= pin <= 3 0 = INTA, 1 = INTB, 2 = INTC, 3 = INTD */
>  int pci_swizzle_map_irq_fn(void *opaque, PCIDevice *pci_dev, int pin);
> -- 
> 1.7.1.1