Re: [PATCH] arm64: dts: marvell: armada-37xx: Remap IO space to bus address 0x0

Gregory CLEMENT
2022-02-28T15:42:36Z

Hello Pali,

> Remap PCI I/O space to the bus address 0x0 in the Armada 37xx
> device-tree in order to support legacy I/O port based cards which have
> hardcoded I/O ports in low address space.
>
> Some legacy PCI I/O based cards do not support 32-bit I/O addressing.
>
> Since commit 64f160e19e92 ("PCI: aardvark: Configure PCIe resources from
> 'ranges' DT property") this driver can work with I/O windows which
> have

Should we add a "Fixes: 64f160e19e92 ("PCI: aardvark: Configure PCIe
resources from 'ranges' DT property")" tag ?

Gregory

> a different address for CPU than for PCI bus (unless there is some
> conflict with other A37xx mapping), without needing additional support
> for this in the firmware.
>
> Note that DDR on A37xx is mapped to bus address 0x0 and that mapping of
> I/O space can be set to address 0x0 too because MEM space and I/O space
> are separate and so they do not conflict.
>
> Signed-off-by: Pali Rohár <pali@kernel.org>
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> ---
> arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts | 2 +-
> arch/arm64/boot/dts/marvell/armada-37xx.dtsi | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
> index 6581092c2c90..7d1b9153a901 100644
> --- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
> +++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
> @@ -163,7 +163,7 @@
> */
> #address-cells = <3>;
> #size-cells = <2>;
> - ranges = <0x81000000 0 0xe8000000 0 0xe8000000 0 0x01000000 /* Port 0 IO */
> + ranges = <0x81000000 0 0x00000000 0 0xe8000000 0 0x01000000 /* Port 0 IO */
> 0x82000000 0 0xe9000000 0 0xe9000000 0 0x07000000>; /* Port 0 MEM */
>
> /* enabled by U-Boot if PCIe module is present */
> diff --git a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
> index 549c3f7c5b27..a099b7787429 100644
> --- a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
> +++ b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
> @@ -515,7 +515,7 @@
> * (totaling 127 MiB) for MEM.
> */
> ranges = <0x82000000 0 0xe8000000 0 0xe8000000 0 0x07f00000 /* Port 0 MEM */
> - 0x81000000 0 0xeff00000 0 0xeff00000 0 0x00100000>; /* Port 0 IO*/
> + 0x81000000 0 0x00000000 0 0xeff00000 0 0x00100000>; /* Port 0 IO */
> interrupt-map-mask = <0 0 0 7>;
> interrupt-map = <0 0 0 1 &pcie_intc 0>,
> <0 0 0 2 &pcie_intc 1>,
> --
> 2.20.1
>

--
Gregory Clement, Bootlin
Embedded Linux and Kernel engineering