[PATCH v3 04/12] PCI: rockchip-ep: Improve rockchip_pcie_ep_map_addr()

[Manivannan Sadhasivam]

On Thu, Oct 10, 2024 at 12:43:57PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Oct 07, 2024 at 01:12:10PM +0900, Damien Le Moal wrote:
> > Add a check to verify that the outbound region to be used for mapping an
> > address is not already in use.
> > 
> > Signed-off-by: Damien Le Moal <dlemoal at kernel.org>
> 
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam at linaro.org>
> 

I'm trying to understand the ob window mapping here. So if rockchip_ob_region()
returns same index for different *CPU* addresses, then you cannot map both of
them? Is this a hardware ATU limitation?

Also rockchip_pcie_prog_ep_ob_atu() is not taking into account of the cpu_addr.
So I'm not sure how the mapping happens either.

- Mani

> - Mani
> 
> > ---
> >  drivers/pci/controller/pcie-rockchip-ep.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/pci/controller/pcie-rockchip-ep.c b/drivers/pci/controller/pcie-rockchip-ep.c
> > index 89ebdf3e4737..edb84fb1ba39 100644
> > --- a/drivers/pci/controller/pcie-rockchip-ep.c
> > +++ b/drivers/pci/controller/pcie-rockchip-ep.c
> > @@ -243,6 +243,9 @@ static int rockchip_pcie_ep_map_addr(struct pci_epc *epc, u8 fn, u8 vfn,
> >  	struct rockchip_pcie *pcie = &ep->rockchip;
> >  	u32 r = rockchip_ob_region(addr);
> >  
> > +	if (test_bit(r, &ep->ob_region_map))
> > +		return -EBUSY;
> > +
> >  	rockchip_pcie_prog_ep_ob_atu(pcie, fn, r, addr, pci_addr, size);
> >  
> >  	set_bit(r, &ep->ob_region_map);
> > -- 
> > 2.46.2
> > 
> 
> -- 
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