[OpenBIOS] [PATCH 1/2] 40p: update interrupt routing code to match QEMU

[Mark Cave-Ayland]

On 01/10/2018 20:27, Mark Cave-Ayland wrote:

> On 01/10/2018 20:20, Hervé Poussineau wrote:
> 
>> Le 01/10/2018 à 19:55, Mark Cave-Ayland a écrit :
>>> Note that whilst guest OSs should be relying on residual data rather than the
>>> OF device tree to determine the hardware, we still update the interrupt
>>> properties to match the new code in QEMU for consistency.
>>>
>>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland at ilande.co.uk>
>>> ---
>>>   arch/ppc/qemu/init.c |  2 +-
>>>   drivers/pci.c        | 24 ++++++++++++++++++++----
>>>   2 files changed, 21 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/arch/ppc/qemu/init.c b/arch/ppc/qemu/init.c
>>> index 759f7ac..f72728c 100644
>>> --- a/arch/ppc/qemu/init.c
>>> +++ b/arch/ppc/qemu/init.c
>>> @@ -130,7 +130,7 @@ static const pci_arch_t known_arch[] = {
>>>               { .type = MEMORY_SPACE_32, .parentaddr = 0, .childaddr = 0xc0100000,
>>> .len = 0x10000000 },
>>>               { .type = 0, .parentaddr = 0, .childaddr = 0, .len = 0 }
>>>            },
>>> -        .irqs = { 9, 11, 9, 11 }
>>> +        .irqs = { 15, 15, 15, 15 }
>>>       },
>>>       [ARCH_MAC99] = {
>>>           .name = "MAC99",
>>> diff --git a/drivers/pci.c b/drivers/pci.c
>>> index 8f97ae1..92fd4af 100644
>>> --- a/drivers/pci.c
>>> +++ b/drivers/pci.c
>>> @@ -1986,10 +1986,26 @@ static phandle_t ob_pci_host_set_interrupt_map(phandle_t host)
>>>   static void ob_pci_host_bus_interrupt(ucell dnode, u32 *props, int *ncells, u32
>>> addr, u32 intno)
>>>   {
>>>       *ncells += pci_encode_phys_addr(props + *ncells, 0, 0, addr, 0, 0);
>>> -    props[(*ncells)++] = intno;
>>> -    props[(*ncells)++] = dnode;
>>> -    props[(*ncells)++] = arch->irqs[((intno - 1) + (addr >> 11)) & 3];
>>> -    props[(*ncells)++] = 1;
>>> +
>>> +    if (is_oldworld() || is_newworld()) {
>>> +        /* Mac machines */
>>> +        props[(*ncells)++] = intno;
>>> +        props[(*ncells)++] = dnode;
>>> +        props[(*ncells)++] = arch->irqs[((intno - 1) + (addr >> 11)) & 3];
>>> +        props[(*ncells)++] = 1;
>>> +    } else {
>>> +        /* PReP machines */
>>> +        props[(*ncells)++] = intno;
>>> +        props[(*ncells)++] = dnode;
>>> +
>>> +        if (PCI_DEV(addr) == 1 && PCI_FN(addr) == 0) {
>>> +            /* LSI SCSI has fixed routing to IRQ 13 */
>>> +            props[(*ncells)++] = 13;
>>> +        } else {
>>> +            props[(*ncells)++] = arch->irqs[((intno - 1) + (addr >> 11)) & 1];
>>
>> In that case, arch.irqs = { 15, 15, 15, 15 }.
>> Why doing a "& 1", instead of doing arch->irqs[0], or hard-coding 15?
> 
> Mainly for consistency so it matches the same algorithm in raven_map_irq() - see
> https://git.qemu.org/?p=qemu.git;a=blob;f=hw/pci-host/prep.c;h=b1b6b16badb38ff35e4c50f358fdc6aab08f5b51;hb=a2ef4d9e95400cd387ab4ae19a317741e458fb07#l193
> 
> I was under the impression that this was how it was modelled on real hardware,
> although I don't personally have any documentation to support this.

Hi Hervé,

Even though you had some questions, are you still happy for me to merge this? It
would be good to get the sandalfoot zImage working in QEMU master :)


ATB,

Mark.