Re: [Qemu-devel] [PATCH v3 17/26] Add i21154 bridge chip.

[Blue Swirl]

On Mon, Oct 22, 2012 at 4:17 PM, Michael S. Tsirkin <address@hidden> wrote:
> On Mon, Oct 22, 2012 at 03:26:24PM +0200, Andreas Färber wrote:
>> Am 19.10.2012 22:43, schrieb Jason Baron:
>> > From: Jason Baron <address@hidden>
>> >
>> > This adds support for the DECchip 21154 PCI bridge.
>> >
>> > Signed-off-by: Isaku Yamahata <address@hidden>
>> > Signed-off-by: Jason Baron <address@hidden>
>> > ---
>> >  hw/Makefile.objs |    2 +-
>> >  hw/i21154.c      |  113 
>> > ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> >  hw/i21154.h      |    9 ++++
>> >  3 files changed, 123 insertions(+), 1 deletions(-)
>> >  create mode 100644 hw/i21154.c
>> >  create mode 100644 hw/i21154.h
>>
>> Why is this creating a new file and not reusing dec_pci.c? We shouldn't
>> have two parallel implementations of the same chip.
>>
>> Andreas
>
> Good point I missed this. There's a minor difference
> wrt dec-21154-p2p-bridge in a couple of fields,
> these could be set by properties.
> Also dec_map_irq differs from the spec compliant
> map function. I am guessing this is a bug.
> Would appreciate testing of the patch below.
>
>
> Are you familiar with dec_pci.c? Looking at it, it seems to
> implement a pci host bridge "dec-21154-sysbus" ,
> a pci to pci bridge "dec-21154-p2p-bridge",
> and something called "dec-21154" which sports a comment
> "PCI2PCI bridge same values as PearPC - check this" -
> and implements an empty init function;
> what this last is and why it's useful I am not sure.
>
> Anyone? Blue Swirl? Anyone can test this doesn't break
> things and report?

The device is only linked by PPC but the init function is not invoked.
It should be also used by Sparc64 (it's present on real Ultra-5
machine and several devices should be behind the bridge) but it isn't.

>
> --->
>
> dec_pci: irq swizzle PCI spec compliance
>
> Make IRQ mapping for dec PCI PCI 2 PCI Bridge compliant
> with the PCI spec.
>
> Signed-off-by: Michael S. Tsirkin <address@hidden>
>
> ---
>
> diff --git a/hw/dec_pci.c b/hw/dec_pci.c
> index c30ade3..a49f0bd 100644
> --- a/hw/dec_pci.c
> +++ b/hw/dec_pci.c
> @@ -82,7 +82,7 @@ PCIBus *pci_dec_21154_init(PCIBus *parent_bus, int devfn)
>      dev = pci_create_multifunction(parent_bus, devfn, false,
>                                     "dec-21154-p2p-bridge");
>      br = DO_UPCAST(PCIBridge, dev, dev);
> -    pci_bridge_map_irq(br, "DEC 21154 PCI-PCI bridge", dec_map_irq);

dec_map_irq is now unused and should be removed to avoid build breakage.

> +    pci_bridge_map_irq(br, "DEC 21154 PCI-PCI bridge", 
> pci_swizzle_map_irq_fn);
>      qdev_init_nofail(&dev->qdev);
>      return pci_bridge_get_sec_bus(br);
>  }

Otherwise I think the patch is fine.