RE: [PATCH] PCI: layerscape: Add the SRIOV support in host side

[Xiaowei Bao]

> -----Original Message-----
> From: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
> Sent: 2019å12æ5æ 18:45
> To: Xiaowei Bao <xiaowei.bao@xxxxxxx>; Marc Zyngier
> <maz@xxxxxxxxxxxxxxx>
> Cc: Roy Zang <roy.zang@xxxxxxx>; lorenzo.pieralisi@xxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; Z.q. Hou
> <zhiqiang.hou@xxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; M.h. Lian
> <minghuan.lian@xxxxxxx>; robh+dt@xxxxxxxxxx;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; bhelgaas@xxxxxxxxxx;
> andrew.murray@xxxxxxx; frowand.list@xxxxxxxxx; Mingkai Hu
> <mingkai.hu@xxxxxxx>; Diana Madalina Craciun <diana.craciun@xxxxxxx>
> Subject: RE: [PATCH] PCI: layerscape: Add the SRIOV support in host side
> 
> Hi Xiaowei,
> 
> > -----Original Message-----
> > From: linux-arm-kernel <linux-arm-kernel-bounces@xxxxxxxxxxxxxxxxxxx>
> > On Behalf Of Xiaowei Bao
> >
> > > -----Original Message-----
> > > From: Marc Zyngier <maz@xxxxxxxxxxxxxxx>
> > > Sent: 2019å12æ2æ 20:48
> > > To: Xiaowei Bao <xiaowei.bao@xxxxxxx>
> > > Cc: robh+dt@xxxxxxxxxx; frowand.list@xxxxxxxxx; M.h. Lian
> > > <minghuan.lian@xxxxxxx>; Mingkai Hu <mingkai.hu@xxxxxxx>; Roy
> Zang
> > > <roy.zang@xxxxxxx>; lorenzo.pieralisi@xxxxxxx;
> > > andrew.murray@xxxxxxx; bhelgaas@xxxxxxxxxx;
> > > devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> > > linux-pci@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> > > Z.q. Hou <zhiqiang.hou@xxxxxxx>
> > > Subject: Re: [PATCH] PCI: layerscape: Add the SRIOV support in host
> > > side
> > >
> > > On 2019-12-02 10:45, Xiaowei Bao wrote:
> > > > GIC get the map relations of devid and stream id from the msi-map
> > > > property of DTS, our platform add this property in u-boot base on
> > > > the PCIe device in the bus, but if enable the vf device in kernel,
> > > > the vf device msi-map will not set, so the vf device can't work,
> > > > this patch purpose is that manage the stream id and device id map
> > > > relations dynamically in kernel, and make the new PCIe device work in
> kernel.
> > > >
> > > > Signed-off-by: Xiaowei Bao <xiaowei.bao@xxxxxxx>
> > > > ---
> > > >  drivers/of/irq.c                            |  9 +++
> > > >  drivers/pci/controller/dwc/pci-layerscape.c | 94
> > > > +++++++++++++++++++++++++++++
> > > >  drivers/pci/probe.c                         |  6 ++
> > > >  drivers/pci/remove.c                        |  6 ++
> > > >  4 files changed, 115 insertions(+)
> > > >
> > > > diff --git a/drivers/of/irq.c b/drivers/of/irq.c index
> > > > a296eaf..791e609 100644
> > > > --- a/drivers/of/irq.c
> > > > +++ b/drivers/of/irq.c
> > > > @@ -576,6 +576,11 @@ void __init of_irq_init(const struct
> > > > of_device_id
> > > > *matches)
> > > >  	}
> > > >  }
> > > >
> > > > +u32 __weak ls_pcie_streamid_fix(struct device *dev, u32 rid) {
> > > > +	return rid;
> > > > +}
> > > > +
> > > >  static u32 __of_msi_map_rid(struct device *dev, struct
> > > > device_node **np,
> > > >  			    u32 rid_in)
> > > >  {
> > > > @@ -590,6 +595,10 @@ static u32 __of_msi_map_rid(struct device
> > > > *dev, struct device_node **np,
> > > >  		if (!of_map_rid(parent_dev->of_node, rid_in, "msi-map",
> > > >  				"msi-map-mask", np, &rid_out))
> > > >  			break;
> > > > +
> > > > +	if (rid_out == rid_in)
> > > > +		rid_out = ls_pcie_streamid_fix(parent_dev, rid_in);
> > >
> > > Over my dead body. Get your firmware to properly program the LUT so
> > > that
> > it
> > > presents the ITS with a reasonable topology. There is absolutely no
> > > way
> > this
> > > kind of change makes it into the kernel.
> >
> > Sorry for this, I know it is not reasonable, but I have no other way,
> > as I know, ARM get the mapping of stream ID to request ID from the
> > msi-map property of DTS, if add a new device which need the stream ID
> > and try to get it from the msi- map of DTS, it will failed and not
> > work, yes? So could you give me a better advice to fix this issue, I
> > would really appreciate any comments or suggestions, thanks a lot.
> >
> 
> I agree with the community that this should be tackled in firmware. I actually
> submitted (by mistake, but let's disregard that :-)) a simple proposal in u-boot
> [1] that should take care of it. We can discuss further on it, if you wish.
> 
> [1] https://patchwork.ozlabs.org/patch/1033466/


I will do a experiment to verify whether all PCIe request ID map one stream ID,
and I will show the result when I complete the experiment.

Thanks 
Xiaowei

> 
> ---
> Best Regards, Laurentiu