[PATCH v3 7/7] arm64: dts: ti: iot2050: Enforce DMA isolation for devices behind PCI RC

From: Jan Kiszka
Date: Wed Aug 28 2024 - 14:02:46 EST


From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>

Reserve a 64M memory region below the top of 1G RAM (smallest RAM size
across the series, space left for firmware carve-outs) and ensure that
all PCI devices do their DMA only inside that region. This is configured
via a restricted-dma-pool and enforced with the help of the first PVU.

Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
.../arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
index e76828ccf21b..8af4bb132a10 100644
--- a/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
+++ b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
@@ -82,6 +82,11 @@ wdt_reset_memory_region: wdt-memory@a2200000 {
reg = <0x00 0xa2200000 0x00 0x1000>;
no-map;
};
+
+ pci_restricted_dma_region: restricted-dma@ba000000 {
+ compatible = "restricted-dma-pool";
+ reg = <0 0xba000000 0 0x4000000>;
+ };
};

leds {
@@ -571,6 +576,10 @@ seboot-backup@e80000 {
};
};

+&pcie0_rc {
+ memory-region = <&pci_restricted_dma_region>;
+};
+
&pcie1_rc {
status = "okay";
pinctrl-names = "default";
@@ -580,6 +589,8 @@ &pcie1_rc {
phys = <&serdes1 PHY_TYPE_PCIE 0>;
phy-names = "pcie-phy0";
reset-gpios = <&wkup_gpio0 27 GPIO_ACTIVE_HIGH>;
+
+ memory-region = <&pci_restricted_dma_region>;
};

&mailbox0_cluster0 {
@@ -640,3 +651,7 @@ &mcu_r5fss0 {
/* lock-step mode not supported on iot2050 boards */
ti,cluster-mode = <0>;
};
+
+&ti_pvu0 {
+ status = "okay";
+};
--
2.43.0