Re: [Qemu-devel] [Qemu-ppc] [PATCH 2/2] Add Enhanced Three-Speed Ethernet Controller (eTSEC)

[Scott Wood]

On 07/16/2013 11:15:51 AM, Fabien Chouteau wrote:
> On 07/16/2013 05:37 PM, Alexander Graf wrote:
> > On 07/16/2013 05:28 PM, Fabien Chouteau wrote:
> >> On 07/16/2013 04:06 AM, Scott Wood wrote:
> >>> On 07/10/2013 12:10:02 PM, Fabien Chouteau wrote:
> >>>> This implementation doesn't include ring priority, TCP/IP  
> Off-Load, QoS.
> >>>>
> >>>> Signed-off-by: Fabien Chouteau<address@hidden>
> >>>  From the code comments I gather this has been tested on  
> VxWorks.  Has it
> >>> been tested on Linux, or anywhere else?
> >>>
> >> You're right, as I said in the cover letter, this has only been  
> tested on vxWorks.
> >
> > Could you please give it a try? IIRC eTSEC support should be in  
> upstream Linux.
> >
>
> I don't have time for that. As I said in the cover letter, I submit  
> this
> patch for those interested in eTSEC, but I won't be able to test/fix  
> it
> for Linux.

Could you please at least document more fully the known limitations,  
such as "I'm only interested in 32bits address spaces"?

> >>>> +    /* ring_base = (etsec->regs[RBASEH].value&  0xF)<<  32; */
> >>>> +    ring_base     += etsec->regs[RBASE0 + ring_nbr].value&   
> ~0x7;
> >>>> +    start_bd_addr  = bd_addr = etsec->regs[RBPTR0 +  
> ring_nbr].value&  ~0x7;
> >>> What about RBDBPH (upper bits of physical address)?  Likewise for  
> TX.
> >>>
> >> I'm only interested in 32bits address spaces, so RBASEH, TBASEH,  
> RBDBPH or TBDBPH.
> >
> > Why? I thought e500mc and above can access more than 32bits of  
> physical address space?
>
> Yes but this is not emulated by QEMU, right? sizeof (hwaddr) for
> qemu-system-ppc is 8...

36bit physical is emulated by QEMU.  Currently we put CCSR in a place  
that would make it difficult to use memory above 4G, but that should  
change at some point.

> > Oh, but they're always DPAA?
> >
>
> I don't understand...

It doesn't matter, because it's not true.  We do support 36-bit address  
layouts on mpc85xx and mpc86xx, though we don't make it the only  
supported config in U-Boot as we do on e500mc+.

-Scott