Re: [Qemu-devel] [Qemu-ppc] [PATCH 1/2] ppc: Allow clients of the 440 pcix bus to specify the number of interrupts

[Cédric Le Goater]

On 07/31/2018 06:36 AM, Sebastian Bauer wrote:
> This can be done by using the newly introduced num_irqs property. In
> particular, this change introduces a special case if num_irqs is 1 in which
> case any interrupt pin will be connected to the single irq. The default
> case is untouched (but note that the only client is the Sam460ex board for
> which the special case was actually created).
> 
> Signed-off-by: Sebastian Bauer <address@hidden>
> ---
>  hw/ppc/ppc440_pcix.c | 28 +++++++++++++++++++++++++---
>  1 file changed, 25 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/ppc/ppc440_pcix.c b/hw/ppc/ppc440_pcix.c
> index d8af04b70f..cb7d7cfd2b 100644
> --- a/hw/ppc/ppc440_pcix.c
> +++ b/hw/ppc/ppc440_pcix.c
> @@ -57,6 +57,7 @@ typedef struct PPC440PCIXState {
>      struct PLBOutMap pom[PPC440_PCIX_NR_POMS];
>      struct PLBInMap pim[PPC440_PCIX_NR_PIMS];
>      uint32_t sts;
> +    uint16_t num_irqs;
>      qemu_irq irq[PCI_NUM_PINS];
>      AddressSpace bm_as;
>      MemoryRegion bm;
> @@ -423,6 +424,12 @@ static int ppc440_pcix_map_irq(PCIDevice *pci_dev, int 
> irq_num)
>      return slot - 1;
>  }
>  
> +/* All pins from each slot are tied the same and only board IRQ. */
> +static int ppc440_pcix_map_irq_single(PCIDevice *pci_dev, int irq_num)
> +{
> +    return 0;
> +}
> +
>  static void ppc440_pcix_set_irq(void *opaque, int irq_num, int level)
>  {
>      qemu_irq *pci_irqs = opaque;
> @@ -469,6 +476,7 @@ const MemoryRegionOps ppc440_pcix_host_data_ops = {
>  
>  static int ppc440_pcix_initfn(SysBusDevice *dev)
>  {
> +    pci_map_irq_fn map_irq;
>      PPC440PCIXState *s;
>      PCIHostState *h;
>      int i;
> @@ -476,14 +484,22 @@ static int ppc440_pcix_initfn(SysBusDevice *dev)
>      h = PCI_HOST_BRIDGE(dev);
>      s = PPC440_PCIX_HOST_BRIDGE(dev);
>  
> -    for (i = 0; i < ARRAY_SIZE(s->irq); i++) {
> +    if (s->num_irqs > 4) {

may be use PCI_NUM_PINS

> +        fprintf(stderr, "%s: Number of irqs must not exceed 4\n", __func__);

error_report would be better.
 
> +        return -1;
> +    }

It might be the right time to QOM'ify a bit more "ppc440-pcix-host" and 
introduce a realize() operation to handle errors. 

> +    for (i = 0; i < s->num_irqs; i++) {
>          sysbus_init_irq(dev, &s->irq[i]);
>      }
>  
>      memory_region_init(&s->busmem, OBJECT(dev), "pci bus memory", 
> UINT64_MAX);
> +
> +    map_irq = s->num_irqs == 1 ?
> +            ppc440_pcix_map_irq_single : ppc440_pcix_map_irq;
>      h->bus = pci_register_root_bus(DEVICE(dev), NULL, ppc440_pcix_set_irq,
> -                         ppc440_pcix_map_irq, s->irq, &s->busmem,
> -                         get_system_io(), PCI_DEVFN(0, 0), 4, TYPE_PCI_BUS);
> +                         map_irq, s->irq, &s->busmem, get_system_io(),
> +                         PCI_DEVFN(0, 0), s->num_irqs, TYPE_PCI_BUS);
>  
>      s->dev = pci_create_simple(h->bus, PCI_DEVFN(0, 0), 
> "ppc4xx-host-bridge");
>  
> @@ -507,6 +523,11 @@ static int ppc440_pcix_initfn(SysBusDevice *dev)
>      return 0;
>  }
>  
> +static Property ppc440_pcix_properties[] = {
> +    DEFINE_PROP_UINT16("num-irqs", PPC440PCIXState, num_irqs, 4),

PCI_NUM_PINS ?

> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>  static void ppc440_pcix_class_init(ObjectClass *klass, void *data)
>  {
>      SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
> @@ -514,6 +535,7 @@ static void ppc440_pcix_class_init(ObjectClass *klass, 
> void *data)
>  
>      k->init = ppc440_pcix_initfn;
>      dc->reset = ppc440_pcix_reset;
> +    dc->props = ppc440_pcix_properties;
>  }
>  
>  static const TypeInfo ppc440_pcix_info = {
>