[PATCH 07/11] arm: perf: document PMU affinity binding

[mark.rutland@arm.com (Mark Rutland)]

To describe the various ways CPU PMU interrupts might be wired up, we
can refer to the topology information in the device tree.

This patch adds a new property to the PMU binding, interrupts-affinity,
which describes the relationship between CPUs and interrupts. This
information is necessary to handle systems with heterogeneous PMU
implementations (e.g. big.LITTLE). Documentation is added describing the
use of said property.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 Documentation/devicetree/bindings/arm/pmu.txt | 104 +++++++++++++++++++++++++-
 1 file changed, 103 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/arm/pmu.txt b/Documentation/devicetree/bindings/arm/pmu.txt
index 75ef91d..23a0675 100644
--- a/Documentation/devicetree/bindings/arm/pmu.txt
+++ b/Documentation/devicetree/bindings/arm/pmu.txt
@@ -24,12 +24,114 @@ Required properties:
 
 Optional properties:
 
+- interrupts-affinity : A list of phandles to topology nodes (see topology.txt) describing
+	     the set of CPUs associated with the interrupt at the same index.
 - qcom,no-pc-write : Indicates that this PMU doesn't support the 0xc and 0xd
                      events.
 
-Example:
+Example 1 (A single CPU):
 
 pmu {
         compatible = "arm,cortex-a9-pmu";
         interrupts = <100 101>;
 };
+
+Example 2 (Multiple clusters with single interrupts):
+
+cpus {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	CPU0: cpu at 0 {
+		reg = <0x0>;
+		compatible = "arm,cortex-a15-pmu";
+	};
+
+	CPU1: cpu at 1 {
+		reg = <0x1>;
+		compatible = "arm,cotex-a15-pmu";
+	};
+
+	CPU100: cpu at 100 {
+		reg = <0x100>;
+		compatible = "arm,cortex-a7-pmu";
+	};
+
+	cpu-map {
+		cluster0 {
+			CORE_0_0: core0 {
+				cpu = <&CPU0>;
+			};
+			CORE_0_1: core1 {
+				cpu = <&CPU1>;
+			};
+		};
+		cluster1 {
+			CORE_1_0: core0 {
+				cpu = <&CPU100>;
+			};
+		};
+	};
+};
+
+pmu_a15 {
+	compatible = "arm,cortex-a15-pmu";
+	interrupts = <100>, <101>;
+	interrupts-affinity = <&CORE0>, <&CORE1>;
+};
+
+pmu_a7 {
+	compatible = "arm,cortex-a7-pmu";
+	interrupts = <105>;
+	interrupts-affinity = <&CORE_1_0>;
+};
+
+Example 3 (Multiple clusters with per-cpu interrupts):
+
+cpus {
+	#address-cells = <1>;
+	#size-cells = <1>;
+
+	CPU0: cpu at 0 {
+		reg = <0x0>;
+		compatible = "arm,cortex-a15-pmu";
+	};
+
+	CPU1: cpu at 1 {
+		reg = <0x1>;
+		compatible = "arm,cotex-a15-pmu";
+	};
+
+	CPU100: cpu at 100 {
+		reg = <0x100>;
+		compatible = "arm,cortex-a7-pmu";
+	};
+
+	cpu-map {
+		CLUSTER0: cluster0 {
+			core0 {
+				cpu = <&CPU0>;
+			};
+			core1 {
+				cpu = <&CPU1>;
+			};
+		};
+		CLUSTER1: cluster1 {
+			 core0 {
+				cpu = <&CPU100>;
+			};
+		};
+	};
+};
+
+pmu_a15 {
+	compatible = "arm,cortex-a15-pmu";
+	interrupts = <100>;
+	interrupts-affinity = <&CLUSTER0>;
+};
+
+pmu_a7 {
+	compatible = "arm,cortex-a7-pmu";
+	interrupts = <105>;
+	interrupts-affinity = <&CLUSTER1>;
+};
-- 
1.9.1