RE: sysbus usb xhci

[Sai Pavan Boddu]

Hi Gred/Philippe,

In the process of making hcd-xhci.c free of pci wrapper, I came across a dma 
command " ldq_le_pci_dma" for which I don’t see any low level alternative to 
replace.
Even I cannot find the source of it, do you have any thoughts on this ?

Regards,
Sai Pavan

> -----Original Message-----
> From: Sai Pavan Boddu
> Sent: Friday, January 3, 2020 10:44 AM
> To: Philippe Mathieu-Daudé <address@hidden>; address@hidden
> Cc: address@hidden; address@hidden
> Subject: RE: sysbus usb xhci
> 
> Thanks Philippe & Gred. I would start with the below pointers.
> 
> Regards,
> Sai Pavan
> 
> > -----Original Message-----
> > From: Philippe Mathieu-Daudé <address@hidden>
> > Sent: Thursday, January 2, 2020 4:56 PM
> > To: address@hidden; Sai Pavan Boddu <address@hidden>
> > Cc: address@hidden; address@hidden
> > Subject: Re: sysbus usb xhci
> >
> > On 1/2/20 10:45 AM, address@hidden wrote:
> > > On Thu, Jan 02, 2020 at 07:13:25AM +0000, Sai Pavan Boddu wrote:
> > >> Hi Gred,
> > >>
> > >> We are seeing of options to reuse the hcd-xhci model and use it
> > >> over system bus interface rather than pci. (for Xilinx ZynqMP SOC,
> > >> usb
> > emulation) Are there any plans of implementing a sysbus device ? if
> > none it would be good if provided few pointers to start.
> > >
> > > There have been some discussions about this for a (IIRC) sbsa
> > > machine, but I'm not sure whenever that where just ideas or some code
> exists.
> > >
> > >> Im looking at hcd-ehci/ochi as a reference, let me know if there
> > >> are any
> > know limitations for this usecase.
> > >
> > > Yep, the path for xhci would be quite simliar:  Create a new
> > > XHCIPciState struct, move over all pci-specific bits from XHCIState,
> > > leaving the generic stuff in XHCIState for sharing with sysbus.
> > > Possibly move all pci-specific code bits into a new source file (for
> > > cleanup, will also allow to build qemu with CONFIG_PCI=n and still
> > > have XHCI enabled).
> > >
> > > Once this separation is done you should be able to create a sysbus
> > > device, reusing the generic xhci code and adding sysbus plumbing
> > > (mmio, irq, ...)
> >
> > The SDHCI commits b635d98cf32..8b7455c75e seem similar to what you
> > want to achieve (see also commit ce8646034).