Re: [Qemu-devel] [PATCH v3 0/2] 40p: fix PCI interrupt routing

[Mark Cave-Ayland]

On 17/09/18 04:54, David Gibson wrote:

> On Mon, Sep 10, 2018 at 09:46:29PM +0100, Mark Cave-Ayland wrote:
>> According to the PReP specification section 6.1.6 "System Interrupt
>> Assignments", all PCI interrupts are routed via IRQ 15.
>>
>> In the case of the 40p machine this isn't quite true in that it has a routing
>> quirk: the LSI SCSI device is always routed to IRQ 13. At least Linux and
>> NetBSD compare the model name presented by the firmware to "IBM PPS Model
>> 6015", and if it matches will active this quirk.
>>
>> In order for guest OSs to make use of the fixed IRQ routing, the model name
>> in the residual data must be changed in OpenBIOS using the diff below:
>>
>> diff --git a/arch/ppc/qemu/context.c b/arch/ppc/qemu/context.c
>> index 06e0122..5815895 100644
>> --- a/arch/ppc/qemu/context.c
>> +++ b/arch/ppc/qemu/context.c
>> @@ -111,7 +111,7 @@ static void *
>>  residual_build(uint32_t memsize, uint32_t load_base, uint32_t load_size)
>>  {
>>      residual_t *res;
>> -    const unsigned char model[] = "Qemu\0PPC\0";
>> +    const unsigned char model[] = "IBM PPS Model 6015\0";
>>      int i;
>>  
>>      res = malloc(sizeof(residual_t));
>>
>> With the above OpenBIOS patch applied as well as this patchset, it is now
>> possible to boot the sandalfoot zImage all the way through to a working
>> userspace when using OpenBIOS.
>>
>> (Note: this patchset requires the changes in my previous patchset "scsi:
>> replace lsi53c895a_create() and lsi53c810_create() functions)
>>
>> Signed-off-by: Mark Cave-Ayland <address@hidden>
>> Based-on: <address@hidden>
> 
> Mark,
> 
> I think we have all the necessary acks to go ahead with this.
> However, I'm afraid I've lost track of the various prereq patches that
> were necessary here.  Can you resend with all the necessary pieces
> rebased against ppc-for-3.1 and the appropriate acked-bys included?

Sure, no problem. I'll resend it this evening as a new 40p PCI routing
"roll-up" patchset.


ATB,

Mark.