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[v6,7/7] arm64: dts: ti: iot2050: Add overlay for DMA isolation for devices behind PCI RC

Message ID 6cc76d4f83e725353e9508d5b5814daec6df92e8.1725901439.git.jan.kiszka@siemens.com
State New
Headers show
Series soc: ti: Add and use PVU on K3-AM65 for DMA isolation | expand

Commit Message

Jan Kiszka Sept. 9, 2024, 5:04 p.m. UTC 
From: Jan Kiszka <jan.kiszka@siemens.com>

Reserve a 64M memory region 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.

Applying this isolation is not totally free in terms of overhead and
memory consumption. It  makes only sense for variants that support
secure booting, and generally only when this is actually enable.
Therefore model it as overlay that can be activated on demand. The
firmware will take care of this via DT fixup during boot and will also
provide a way to adjust the pool size.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 arch/arm64/boot/dts/ti/Makefile               |  5 +++
 ...am6548-iot2050-advanced-dma-isolation.dtso | 33 +++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-dma-isolation.dtso
diff mbox series

Patch

diff --git a/arch/arm64/boot/dts/ti/Makefile b/arch/arm64/boot/dts/ti/Makefile
index bcd392c3206e..b6ee943be8c6 100644
--- a/arch/arm64/boot/dts/ti/Makefile
+++ b/arch/arm64/boot/dts/ti/Makefile
@@ -74,8 +74,10 @@  k3-am654-gp-evm-dtbs := k3-am654-base-board.dtb \
 k3-am654-evm-dtbs := k3-am654-base-board.dtb k3-am654-icssg2.dtbo
 k3-am654-idk-dtbs := k3-am654-evm.dtb k3-am654-idk.dtbo k3-am654-pcie-usb2.dtbo
 k3-am6548-iot2050-advanced-m2-bkey-ekey-pcie-dtbs := k3-am6548-iot2050-advanced-m2.dtb \
+	k3-am6548-iot2050-advanced-dma-isolation.dtbo \
 	k3-am6548-iot2050-advanced-m2-bkey-ekey-pcie.dtbo
 k3-am6548-iot2050-advanced-m2-bkey-usb3-dtbs := k3-am6548-iot2050-advanced-m2.dtb \
+	k3-am6548-iot2050-advanced-dma-isolation.dtbo \
 	k3-am6548-iot2050-advanced-m2-bkey-usb3.dtbo
 dtb-$(CONFIG_ARCH_K3) += k3-am6528-iot2050-basic.dtb
 dtb-$(CONFIG_ARCH_K3) += k3-am6528-iot2050-basic-pg2.dtb
@@ -240,7 +242,10 @@  DTC_FLAGS_k3-am62p5-sk += -@
 DTC_FLAGS_k3-am642-evm += -@
 DTC_FLAGS_k3-am642-phyboard-electra-rdk += -@
 DTC_FLAGS_k3-am642-tqma64xxl-mbax4xxl += -@
+DTC_FLAGS_k3-am6548-iot2050-advanced += -@
 DTC_FLAGS_k3-am6548-iot2050-advanced-m2 += -@
+DTC_FLAGS_k3-am6548-iot2050-advanced-pg2 += -@
+DTC_FLAGS_k3-am6548-iot2050-advanced-sm += -@
 DTC_FLAGS_k3-am68-sk-base-board += -@
 DTC_FLAGS_k3-am69-sk += -@
 DTC_FLAGS_k3-j721e-common-proc-board += -@
diff --git a/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-dma-isolation.dtso b/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-dma-isolation.dtso
new file mode 100644
index 000000000000..dfd75d2dc245
--- /dev/null
+++ b/arch/arm64/boot/dts/ti/k3-am6548-iot2050-advanced-dma-isolation.dtso
@@ -0,0 +1,33 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IOT2050, overlay for isolating DMA requests via PVU
+ * Copyright (c) Siemens AG, 2024
+ *
+ * Authors:
+ *   Jan Kiszka <jan.kiszka@siemens.com>
+ */
+
+/dts-v1/;
+/plugin/;
+
+&{/reserved-memory} {
+	#address-cells = <2>;
+	#size-cells = <2>;
+
+	pci_restricted_dma_region: restricted-dma@c0000000 {
+		compatible = "restricted-dma-pool";
+		reg = <0 0xc0000000 0 0x4000000>;
+	};
+};
+
+&pcie0_rc {
+	memory-region = <&pci_restricted_dma_region>;
+};
+
+&pcie1_rc {
+	memory-region = <&pci_restricted_dma_region>;
+};
+
+&ti_pvu0 {
+	status = "okay";
+};