[PATCH v2] arm64: dts: rockchip: rk356x: Fix PCIe register map and ranges

[Ondrej Jirman]

I have two Realtek PCIe wifi cards connected over the 4 port PCIe swtich
to Quartz64-A. The cards fail to work, when nvme SSD is connected at the
same time to the bridge. Without nvme connected, cards work fine. The
issue seems to be related to mixed use of devices which make use of I/O
ranges and memory ranges.

This patch changes I/O, MEM and config mappings so that config and I/O
mappings use the 0xf4000000 outbound address space, and MEM range uses
the whole 0x300000000 outbound space.

This is simialar to how BSP does the mappings.

I changed num-ob-windows to value detected by the kernel so if for whatever
reason the kernel ever starts respecting this DT property, it would not
switch to sharing I/O and CFG spaces via a single iATU mapping for
no reason.

This change to the regs/ranges makes the issue go away and both nvme and
wifi cards work when connected at the same time to the bridge. I tested
the nvme with large amount of reads/writes, both behind the PCIe bridge
and when directly connected to Quartz64-A board.

Signed-off-by: Ondrej Jirman <megi at xff.cz>
---
BSP for reference: https://github.com/rockchip-linux/kernel/blob/develop-4.19/arch/arm64/boot/dts/rockchip/rk3568.dtsi#L2370

v2:
- change ranges to use 0x300000000 fully for MEM and make use of
  the 0xf4000000 outbound range for IO and config
- full retest with/without the switch
- if lscpi/dmesg is useful in the future for comparison, see:
  https://xff.cz/kernels/random/quartz64a-pcie/

I used this script for the tests:

#!/bin/bash

OUT=/mnt/data
n=8

test -f /tmp/test.dat || \
    dd if=/dev/urandom of=/tmp/test.dat bs=1M count=1024
md5sum /tmp/test.dat

i=0
while test $i -lt $n
do
    dd if=/tmp/test.dat of=$OUT/test$i.dat bs=4M oflag=direct

    i=$(($i+1))
done

i=0
while test $i -lt $n
do
    dd if=$OUT/test$i.dat bs=4M iflag=direct | md5sum

    i=$(($i+1))
done


 arch/arm64/boot/dts/rockchip/rk356x.dtsi | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/rockchip/rk356x.dtsi b/arch/arm64/boot/dts/rockchip/rk356x.dtsi
index 319981c3e9f7..99fd9543fc6f 100644
--- a/arch/arm64/boot/dts/rockchip/rk356x.dtsi
+++ b/arch/arm64/boot/dts/rockchip/rk356x.dtsi
@@ -855,7 +855,8 @@ pcie2x1: pcie at fe260000 {
 		compatible = "rockchip,rk3568-pcie";
 		reg = <0x3 0xc0000000 0x0 0x00400000>,
 		      <0x0 0xfe260000 0x0 0x00010000>,
-		      <0x3 0x3f000000 0x0 0x01000000>;
+		      <0x0 0xf4000000 0x0 0x01f00000>;
+
 		reg-names = "dbi", "apb", "config";
 		interrupts = <GIC_SPI 75 IRQ_TYPE_LEVEL_HIGH>,
 			     <GIC_SPI 74 IRQ_TYPE_LEVEL_HIGH>,
@@ -877,15 +878,15 @@ pcie2x1: pcie at fe260000 {
 				<0 0 0 4 &pcie_intc 3>;
 		linux,pci-domain = <0>;
 		num-ib-windows = <6>;
-		num-ob-windows = <2>;
+		num-ob-windows = <8>;
 		max-link-speed = <2>;
 		msi-map = <0x0 &gic 0x0 0x1000>;
 		num-lanes = <1>;
 		phys = <&combphy2 PHY_TYPE_PCIE>;
 		phy-names = "pcie-phy";
 		power-domains = <&power RK3568_PD_PIPE>;
-		ranges = <0x01000000 0x0 0x3ef00000 0x3 0x3ef00000 0x0 0x00100000
-			  0x02000000 0x0 0x00000000 0x3 0x00000000 0x0 0x3ef00000>;
+		ranges = <0x01000000 0x0 0x00000000 0x0 0xf5f00000 0x0 0x00100000
+			  0x02000000 0x0 0x40000000 0x3 0x00000000 0x0 0x40000000>;
 		resets = <&cru SRST_PCIE20_POWERUP>;
 		reset-names = "pipe";
 		#address-cells = <3>;
-- 
2.37.3