bge driver and MSI

[David Christensen]

> Can the bge driver use more than one MSI message? If 
> possible, what the advantage of this on a SMP system (better 
> CPU distribution on interrupts?)?
> 
> I have an Broadcom BCM5703X, with 8 MSI messages:
> --
> bge0 at pci0:1:2:0:    class=0x020000 card=0x00cb0e11 
> chip=0x16a714e4 rev=0x02
> hdr=0x00
>     vendor     = 'Broadcom Corporation'
>     device     = 'BCM5703X NetXtreme Gigabit Ethernet'
>     class      = network
>     subclass   = ethernet
>     cap 07[40] = PCI-X 64-bit supports 133MHz, 2048 burst 
> read, 1 split transaction
>     cap 01[48] = powerspec 2  supports D0 D3  current D0
>     cap 03[50] = VPD
>     cap 05[58] = MSI supports 8 messages, 64 bit
> --

MSI is broken on this device (actually all PCI/PCI-X devices
in the 57XX family).  The interrupt will be asserted as 
expected but masking the interrupt does not work.  For those
newer 1Gb PCIe devices that do work correctly with MSI, only 
a single message is actually supported.

Dave