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

commit a1cc1697bb56cdf880ad4d17b79a39ef2c294bc9 upstream.

Legacy and old 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") kernel can set different PCIe address on CPU and
different on the bus for the one A37xx address mapping without any firmware
support in case the bus address does not conflict with other A37xx mapping.

So remap I/O space to the bus address 0x0 to enable support for old legacy
I/O port based cards which have hardcoded I/O ports in low address space.

Note that DDR on A37xx is mapped to bus address 0x0. And mapping of I/O
space can be set to address 0x0 too because MEM space and I/O space are
separate and so do not conflict.

Remapping IO space on Turris Mox to different address is not possible to
due bootloader bug.

Signed-off-by: Pali Rohár <pali@kernel.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 76f6386b25cc ("arm64: dts: marvell: Add Aardvark PCIe support for Armada 3700")
Cc: stable@vger.kernel.org # 64f160e19e92 ("PCI: aardvark: Configure PCIe resources from 'ranges' DT property")
Cc: stable@vger.kernel.org # 514ef1e62d65 ("arm64: dts: marvell: armada-37xx: Extend PCIe MEM space")
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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 1eddf31d8bd8ad2eea8557d1f09f0cdf7abaa6dc..1cee26479bfecec78480ab73703067ed43d9e20a 100644 (file)
--- a/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
+++ b/arch/arm64/boot/dts/marvell/armada-3720-turris-mox.dts
@@ -139,7 +139,9 @@
        /*
         * U-Boot port for Turris Mox has a bug which always expects that "ranges" DT property
         * contains exactly 2 ranges with 3 (child) address cells, 2 (parent) address cells and
-        * 2 size cells and also expects that the second range starts at 16 MB offset. If these
+        * 2 size cells and also expects that the second range starts at 16 MB offset. Also it
+        * expects that first range uses same address for PCI (child) and CPU (parent) cells (so
+        * no remapping) and that this address is the lowest from all specified ranges. If these
         * conditions are not met then U-Boot crashes during loading kernel DTB file. PCIe address
         * space is 128 MB long, so the best split between MEM and IO is to use fixed 16 MB window
         * for IO and the rest 112 MB (64+32+16) for MEM, despite that maximal IO size is just 64 kB.
@@ -148,6 +150,9 @@
         * https://source.denx.de/u-boot/u-boot/-/commit/cb2ddb291ee6fcbddd6d8f4ff49089dfe580f5d7
         * https://source.denx.de/u-boot/u-boot/-/commit/c64ac3b3185aeb3846297ad7391fc6df8ecd73bf
         * https://source.denx.de/u-boot/u-boot/-/commit/4a82fca8e330157081fc132a591ebd99ba02ee33
+        * Bug related to requirement of same child and parent addresses for first range is fixed
+        * in U-Boot version 2022.04 by following commit:
+        * https://source.denx.de/u-boot/u-boot/-/commit/1fd54253bca7d43d046bba4853fe5fafd034bc17
         */
        #address-cells = <3>;
        #size-cells = <2>;

diff --git a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
index 9acc5d2b5a002dfab9078ee3267f0e48e3a1f28f..0adc194e46d15298e4b8b08cc1acd7245ab66cce 100644 (file)
--- a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
+++ b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
@@ -497,7 +497,7 @@
                         * (totaling 127 MiB) for MEM.
                         */
                        ranges = <0x82000000 0 0xe8000000   0 0xe8000000   0 0x07f00000   /* Port 0 MEM */
-                                 0x81000000 0 0xefff0000   0 0xefff0000   0 0x00010000>; /* Port 0 IO */
+                                 0x81000000 0 0x00000000   0 0xefff0000   0 0x00010000>; /* 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>,