[RFC PATCH 4/9] rpi4: add a mapping for the PCIe XHCI controller MMIO registers (ARM 64bit)

Nicolas Saenz Julienne nsaenzjulienne at suse.de
Wed Apr 22 12:26:06 CEST 2020


On Wed, 2020-04-22 at 11:54 +0200, Marek Szyprowski wrote:
> Hi Nicolas,
> 
> On 22.04.2020 11:46, Nicolas Saenz Julienne wrote:
> > On Tue, 2020-04-21 at 18:50 +0200, Sylwester Nawrocki wrote:
> > > From: Marek Szyprowski <m.szyprowski at samsung.com>
> > > 
> > > Create a non-cacheable mapping for the 0x600000000 physical memory region,
> > > where MMIO registers for the PCIe XHCI controller are instantiated by the
> > > PCIe bridge.
> > > 
> > > Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
> > > ---
> > >   arch/arm/mach-bcm283x/init.c | 18 +++++++++++++++---
> > >   1 file changed, 15 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/arch/arm/mach-bcm283x/init.c b/arch/arm/mach-bcm283x/init.c
> > > index 4295356..6a748da 100644
> > > --- a/arch/arm/mach-bcm283x/init.c
> > > +++ b/arch/arm/mach-bcm283x/init.c
> > > @@ -11,10 +11,15 @@
> > >   #include <dm/device.h>
> > >   #include <fdt_support.h>
> > >   
> > > +#define BCM2711_RPI4_PCIE_XHCI_MMIO_PHYS	0x600000000UL
> > > +#define BCM2711_RPI4_PCIE_XHCI_MMIO_SIZE	0x800000UL
> > Where did you got this size from? I read from the Linux device tree the
> > following:
> > 
> > 	pcie0: pcie at 7d500000 {
> > 		compatible = "brcm,bcm2711-pcie";
> > 		[...]
> > 		ranges = <0x02000000 0x0 0xf8000000 0x6 0x00000000
> > 			  0x0 0x04000000>;
> > 		[...]
> > 	};
> > 
> > Shouldn't the size be 0x4000000 then?
> > 
> > Other than that the patch looks good to me.
> 
> Well, I reduced the window to 0x800000 to make it fit somewhere nicely 
> in the 32bit address space. We can limit it even to a single section 
> (2MiB), that's more than needed by the XHCI controller anyway. I can add 
> a comment about that.

Fair enough.

Thanks,
Nicolas

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: This is a digitally signed message part
URL: <https://lists.denx.de/pipermail/u-boot/attachments/20200422/f26dc25b/attachment.sig>


More information about the U-Boot mailing list