[hack] help U-Boot find the correct PCIe inbound offset for NVMe on Raspberry Pi 5

[Pedro Falcato]

Hi Torsten,

On Mon, Mar 02, 2026 at 04:42:56PM +0100, Torsten Duwe wrote:
> On Mon, 2 Mar 2026 13:59:40 +0100
> Torsten Duwe <duwe at lst.de> wrote:
> 
> > This proposed patch uses the already existent dev_phys_to_bus(),
> > which can dig up the correct offset from associated DT nodes and
> > subtract it.
> 
> Just to make it clear, that patch is a necessary but not a sufficient
> condition to boot the RPi5 from NVMe. The PCIe bus node above
> the NVMe is generated dynamically has no DT node with dma-ranges and so
> dev_phys_to_bus() still returns zero. In order to test NVMe on the
> RPi5 you can either:
>

Say I wanted to test NVMe booting on the pi5 (which I actually do).
I would need:
1) this patch
2) one of the two BUS_ADDR() related diffs
3) the fixes posted in https://lore.kernel.org/u-boot/20251105163553.15F2A227AAC@verein.lst.de/
4) anything else?

Thanks,
Pedro

> hard code the 64GiB value when building your private U-Boot binary:
> 
> -#define BUS_ADDR(a)         dev_phys_to_bus(dev->udev, (a))
> +#define BUS_ADDR(a)            ((a)+0x1000000000LL)
> 
> OR use this tricky DT change Andrea has prepared:
> 
> --- a/dts/upstream/src/arm64/broadcom/bcm2712.dtsi
> +++ b/dts/upstream/src/arm64/broadcom/bcm2712.dtsi
> @@ -571,6 +571,15 @@
>  				<0x03000000 0xff 0xfffff000 0x10 0x00131000 0x00 0x00001000>; 
>  			status = "disabled";
> +
> +			pci at 0,0 {
> +				reg = <0x00 0x00 0x00 0x00 0x00>;
> +				device_type = "pci";
> +				#address-cells = <0x03>;
> +				#size-cells = <0x02>;
> +				ranges;
> +				dma-ranges;
> +			};
>  		};
>  
>  		pcie2: pcie at 1000120000 {
> 
> This pci at 0,0 node needs to be below the pcie at 1000110000 RC node so it
> can "bridge" dev_phys_to_bus() to the RC node when it climbs up the
> device tree and so helps it find the correct value.
> 
> AFAICS the proper fix should be to add some dma-ranges property when
> dynamic PCI devices are created during enumeration/scan or make
> dev_phys_to_bus() skip those nodes for the lookup.
> 
> 	Torsten