Re: [Qemu-devel] [Qemu-ppc] [PATCH] ppc: Make uninorth interrupt swizzling identical to Grackle

[Thomas Huth <thuth@redhat.com>]

On 20.11.2016 15:12, BALATON Zoltan wrote:
> From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> 
> It's currently broken as it uses an incorrect shift, it tries
> to use the slot number but uses the top bits of the bus number
> instead.
> 
> Note: Neither implementation matches what OpenBIOS ends up putting
> in the device-tree either, which will have to be fixed separately.
> 
> This is not quite correct for modelling a real Mac since Apple
> tend to tie all 4 interrupt lines of a slot together and have
> separate interrupts for every slot and every motherboard devices
> going straight to the PIC but we'll sort that out later.
> 
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> ---
>  hw/pci-host/uninorth.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> This needs a corresponding fix in OpenBIOS but this has to be
> committed first for that. As this is already broken making this change
> should not make things worse as they are now. Could we get this in now
> as a bugfix commit?
> 
> diff --git a/hw/pci-host/uninorth.c b/hw/pci-host/uninorth.c
> index 7aac4d6..df342ac 100644
> --- a/hw/pci-host/uninorth.c
> +++ b/hw/pci-host/uninorth.c
> @@ -62,9 +62,7 @@ typedef struct UNINState {
>  
>  static int pci_unin_map_irq(PCIDevice *pci_dev, int irq_num)
>  {
> -    int devfn = pci_dev->devfn & 0x00FFFFFF;
> -
> -    return (((devfn >> 11) & 0x1F) + irq_num) & 3;
> +    return (irq_num + (pci_dev->devfn >> 3)) & 3;
>  }
>  
>  static void pci_unin_set_irq(void *opaque, int irq_num, int level)
> 

Looks reasonable.

Reviewed-by: Thomas Huth <thuth@redhat.com>