Raspberry Pi support for AXI bus events in Linux perf tool

Documentation/devicetree/bindings/perf/brcm,bcm2835-axiperf.yaml

@@ -0,0 +1,71 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/perf/brcm,bcm2835-axiperf.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom BCM2835/2711/2712 AXI Performance Monitor
+
+maintainers:
+  - Ian Rogers <irogers@google.com>
+  - Raspberry Pi Kernel Maintenance <kernel-list@raspberrypi.com>
+
+description: |
+  The Broadcom BCM2835 series (including BCM2711 and BCM2712) features hardware
+  performance monitors on the AXI bus for evaluating memory bandwidth and
+  system traffic. Depending on the SoC architecture, multiple monitors exist.
+  The primary monitor evaluates the System fabric, while the secondary monitor
+  evaluates the VideoCore VPU hardware.
+
+  Older silicon generally restricts direct MMIO access to the VPU endpoints,
+  requiring them to be accessed over the Raspberry Pi firmware mailbox
+  interface. If the VPU endpoints are memory-mapped, they are supplied as
+  secondary resources.
+
+properties:
+  compatible:
+    enum:
+      - brcm,bcm2835-axiperf
+      - brcm,bcm2711-axiperf
+      - brcm,bcm2712-axiperf
+
+  reg:
+    minItems: 1
+    items:
+      - description: System monitor MMIO surface
+      - description: VPU monitor MMIO surface
+    description: |
+      Memory-mapped I/O resource regions for the AXI PMU endpoints.
+      Typically ordered as System monitor, followed by VPU monitor if directly
+      mapped.
+
+required:
+  - compatible
+  - reg
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - brcm,bcm2712-axiperf
+    then:
+      properties:
+        reg:
+          maxItems: 1
+
+additionalProperties: false
+
+examples:
+  - |
+    pmu@7e009800 {
+        compatible = "brcm,bcm2835-axiperf";
+        reg = <0x7e009800 0x100>,
+              <0x7ee08000 0x100>;
+    };
+  - |
+    pmu@7c012800 {
+        compatible = "brcm,bcm2712-axiperf";
+        reg = <0x7c012800 0x100>;
+    };

drivers/perf/Kconfig

@@ -319,4 +319,17 @@ config MARVELL_PEM_PMU
 	  Enable support for PCIe Interface performance monitoring
 	  on Marvell platform.
 
+config RPI_AXI_PMU
+	tristate "Raspberry Pi AXI Performance Monitor"
+	depends on ARCH_BCM2835 || COMPILE_TEST
+	depends on !RPI_AXIPERF
+	depends on RASPBERRYPI_FIRMWARE || RASPBERRYPI_FIRMWARE=n
+	help
+	  Enable support for the Raspberry Pi AXI Performance Monitor.
+	  This provides access to the System and VideoCore performance
+	  counters on Broadcom BCM2835, BCM2711, and BCM2712 platforms.
+
+	  Expect 100ms ping latencies to the VideoCore firmware mailbox
+	  when reading counters on these platforms.
+
 endmenu

drivers/perf/Makefile

@@ -36,3 +36,4 @@ obj-$(CONFIG_ARM_CORESIGHT_PMU_ARCH_SYSTEM_PMU) += arm_cspmu/
 obj-$(CONFIG_MESON_DDR_PMU) += amlogic/
 obj-$(CONFIG_CXL_PMU) += cxl_pmu.o
 obj-$(CONFIG_RPI_AXIPERF) += raspberrypi_axi_monitor.o
+obj-$(CONFIG_RPI_AXI_PMU) += rpi_axi_pmu.o