[PATCH v3 0/5] arm: ras: Add DT frontend support for ARM RAS

[Umang Chheda <umang.chheda@oss.qualcomm.com>]

This series adds Device Tree support for the ARM64 RAS driver
introduced by Ruidong Tian [1]. The existing driver supports ACPI-based
platforms via the AEST table, this series extends it to DT-based
platforms without any changes to the core driver.

How to test with QEMU
--------------------------
Tian Ruidong's QEMU fork [2] emulates AEST MMIO error records on the
virt machine.  To test the DT frontend:

1. Build QEMU:

     git clone https://github.com/winterddd/qemu.git
     cd qemu
     git checkout c5e2d5dec9fd62ba622314c40bff0fbecb4dfb34
     ./configure --target-list=aarch64-softmmu
     make -j$(nproc)

2. Build the kernel with:

     CONFIG_ARM64_RAS_EXTN=y
     CONFIG_RAS=y
     CONFIG_ACPI_AEST=y
     CONFIG_ARM64_RAS_DRIVER=y
     CONFIG_ARM64_RAS_DT=y

3. Add the following DT node to your virt machine DTB.  The QEMU
   fork maps GIC error source at 0x017a00000 (SPI 0x0d).

   ras-gic-dist@17a00000 {
       compatible = "arm,ras-gic";
       reg = <0x0 0x17a00000 0x0 0x10000>;
       reg-names = "err-group";
       arm,group-format = <ARM_RAS_GROUP_4K>;
       arm,num-records = <1>;
       arm,record-impl = /bits/ 64 <0x1>;
       arm,status-reporting = /bits/ 64 <0x0>;
       arm,gic-ref = <&gic>;
       interrupts = <GIC_SPI 0x0d 0x04>;
       interrupt-names = "fhi";
   };

4. Boot QEMU with acpi=off:

     ./qemu-system-aarch64 \
       -machine virt,accel=tcg,gic-version=3 \
       -cpu cortex-a57 -m 2G -smp 4 \
       -kernel Image -dtb virt-aest.dtb \
       -append "console=ttyAMA0 acpi=off earlycon" \
       -nographic

5. Verify probe:

     dmesg | grep "DT RAS"
     # Expected: DT RAS: registered 1 RAS error source(s) from DT
     ls /sys/kernel/debug/aest/

6. Inject a CE error via the QEMU MMIO fault injection registers.
   The QEMU device accepts 64-bit accesses only (use devmem with
   the 64-bit width flag):

   devmem 0x090e0808 64 0x40000001

   This triggers QEMU's error_record_inj_write() which sets
   ERR<n>STATUS.V=1 and asserts the IRQ.  The kernel driver's
   aest_irq_func() fires, reads the status, and logs:

   arm64_ras: {2}[Hardware Error]: Hardware error from AEST gic.90e0000
   arm64_ras: {2}[Hardware Error]: Error from GIC type 0x0 instance 0x8005
   arm64_ras: {2}[Hardware Error]: ERR0FR: 0x48a5
   arm64_ras: {2}[Hardware Error]: ERR0CTRL: 0x108
   arm64_ras: {2}[Hardware Error]: ERR0STATUS: 0x40000001

Testing
-------
- Validated Processor error nodes/sources for L1-L2 and L3 caches error
  on Qualcomm's lemans-evk, monaco-evk and shikra-cqm-evk boards with DT boot.
- Validated CE and UE injection via debugfs soft_inject.
- Validated GIC and SMMU error sources on QEMU.

[1] https://lore.kernel.org/lkml/20260122094656.73399-1-tianruidong@linux.alibaba.com/
[2] https://github.com/winterddd/qemu/tree/error_record

---
Changes in v3:
 - Changed dt-bindings filename to "arm,ras.yaml" - Krzysztof.
 - Dropped irrelavent nodes from dt-bindings example - Krzysztof.
 - Changed node-name of ras-error sources to generic one - Krzysztof.
 - Updated commit subject text of dt-bindings to drop redundant
   "bindings" keyword - Krzysztof.
 - Drop un-necesarry nodes added in Phandle description - Krzysztof.
 - Fixed reg and reg-names to be same number of entries - Rob.
 - Replaced interrupt property description as suggested by Rob.
 - Defined the order for interrupt-property in bindings - Rob.
 - Dropped re-defining iommu property in the bindings - Rob.
 - Update commit text to be more elaborative and, change the ras node
   name to be generic for monaco DT change - Bjorn.

Changes in v2:
  - Rebased on top of Ruidong Tian's v7 RAS driver series and reworked
    the DT frontend to match the new driver architecture.
  - Moved RAS error source nodes to the DT root, removed the arm,aest
    container node as suggested by Rob Herring.
  - Dropped arm,processor-flags and arm,resource-type properties, these
    are now inferred from the interrupt type and cache phandle
    respectively.
  - Renamed compatible strings from arm,aest-* to arm,ras-* and the
    dt-bindings header from aest.h to arm-ras.h to avoid ACPI terminology
    in DT bindings.
---

Umang Chheda (5):
  dt-bindings: arm: ras: Introduce ARM RAS error sources
  arm64: ras: Add Device Tree frontend
  arm64: dts: qcom: monaco: add RAS error source nodes
  arm64: dts: qcom: lemans: add RAS error source nodes
  arm64: dts: qcom: shikra: add RAS error source nodes

 .../devicetree/bindings/arm/arm,ras.yaml      | 235 +++++++++++
 arch/arm64/boot/dts/qcom/lemans.dtsi          |  30 ++
 arch/arm64/boot/dts/qcom/monaco.dtsi          |  30 ++
 arch/arm64/boot/dts/qcom/shikra.dtsi          |  20 +
 drivers/ras/arm64/Kconfig                     |  25 +-
 drivers/ras/arm64/Makefile                    |   2 +
 drivers/ras/arm64/ras-of.c                    | 383 ++++++++++++++++++
 include/dt-bindings/arm/arm,ras.h             |  11 +
 8 files changed, 731 insertions(+), 5 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/arm,ras.yaml
 create mode 100644 drivers/ras/arm64/ras-of.c
 create mode 100644 include/dt-bindings/arm/arm,ras.h

--
2.34.1