ARCv3: Add cluster PCTs driver

Driver for supporting ARCv3 cluster performance measurement unit(PMU).

Examples of usage:
1. "perf list" shows a list of availabe core and cluster events.
2. "perf stat -a -e cycles,instructions,branches,NOCnumrd0,NOCnumwr0,CLNcycttl ls"
3. "perf record -a -F 250 -e CLNcycttl ls && perf report > perf.report && vi perf.report"

Perf record/report works on SMP configuration but meant to be used on UP systems.
On multiprocessor systems, it is impossible to determine which executable code is causing
events in the cluster. So only one CPU program counter will be recorded for profiling
report, and usually this CPU is 0.

Author: xxkent

arch/arc/boot/dts/skeleton_haps.dtsi

@@ -58,6 +58,12 @@
 			interrupts = <20>;
 		};
 
+		arcpct2: cluster_pmu {
+			compatible = "snps,arcv3-cluster-pmu";
+			#interrupt-cells = <1>;
+			interrupts = <23>;
+		};
+
 		virtio0: virtio@f0100000 {
 			compatible = "virtio,mmio";
 			reg = <0xf0100000 0x2000>;

arch/arc/boot/dts/skeleton_haps_idu.dtsi

@@ -62,5 +62,11 @@
 			#interrupt-cells = <1>;
 			interrupts = <20>;
 		};
+
+		arcpct2: cluster_pmu {
+			compatible = "snps,arcv3-cluster-pmu";
+			#interrupt-cells = <1>;
+			interrupts = <23>;
+		};
 	};
 };

arch/arc/include/asm/perf_cluster.h

@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Linux cluster performance counters support for ARCv3.
+ *
+ * Copyright (C) 2023 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#ifndef __ASM_PERF_CLUSTER_EVENT_H
+#define __ASM_PERF_CLUSTER_EVENT_H
+
+#ifndef BIT
+#define BIT(x) (1 << (x))
+#endif
+
+#define CLNR_ADDR                   0x640
+#define CLNR_DATA                   0x641
+
+#define SCM_AUX_CPCT_BUILD          0xC00
+#define SCM_AUX_CPCT_CC_NUM         0xC03
+#define SCM_AUX_CPCT_CC_NAME0       0xC04
+#define SCM_AUX_CPCT_CC_NAME1       0xC05
+#define SCM_AUX_CPCT_CC_NAME2       0xC06
+#define SCM_AUX_CPCT_CC_NAME3       0xC07
+#define SCM_AUX_CPCT_CONTROL        0xC08
+#define SCM_AUX_CPCT_INT_CTRL       0xC09
+#define SCM_AUX_CPCT_INT_ACT        0xC0A
+// next registers are one per counter:
+#define SCM_AUX_CPCT_N_CONFIG       0xD00
+#define SCM_AUX_CPCT_COUNTL         0xD02
+#define SCM_AUX_CPCT_COUNTH         0xD03
+#define SCM_AUX_CPCT_N_SNAPL        0xD04
+#define SCM_AUX_CPCT_N_SNAPH        0xD05
+#define SCM_AUX_CPCT_INT_CNTL       0xD06
+#define SCM_AUX_CPCT_INT_CNTH       0xD07
+
+#define ARC_CLUSTER_PERF_MAX_COUNTERS   32
+
+struct cpct_build {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	u32 res2:8, num_ctrs:8, res1:4, i:2, cs:2, ver:8;
+#else
+	u32 ver:8, cs:2, i:2, res1:4, num_ctrs:8, res2:8;
+#endif
+};
+
+struct cpct_cc_num {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	u32 res:17, cc_num:15;
+#else
+	u32 cc_num:15, res:17;
+#endif
+};
+
+#define CPCT_NAME_SZ    (16+1) // +1 zero
+#pragma pack(push, 1)
+union cpct_cc_name{
+    s8 cc[CPCT_NAME_SZ];
+    u32 uu[4];
+};
+#pragma pack(pop)
+
+struct cpct_control {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	u32 res2:14, sn:1, cc:1, res0:15, en:1;
+#else
+	u32 en:1, res0:15, cc:1, sn:1, res2:14;
+#endif
+};
+
+struct cpct_int_cntrl {
+    u32 int_ctrl;
+};
+
+struct cpct_int_act {
+    u32 int_act;
+};
+
+struct cpct_n_config {
+    union{
+        struct{
+#ifdef CONFIG_CPU_BIG_ENDIAN
+            u32 lce:1, len:1, res:12, lsn:1, lcc:1, cc_num:16;
+#else
+	        u32 cc_num:16, lcc:1, lsn:1, res:12, len:1, lce:1;
+#endif
+        };
+        u32 val;
+    };
+};
+
+struct cpct_count {
+    u32 count;
+};
+
+struct cpct_snap {
+    u32 snap;
+};
+
+struct cpct_int_count {
+    u32 int_cnt;
+};
+
+// Events map
+#define MAX_CONDITIONS_NUMBER   0x800 // We can't get the maximum event number from any build in registers, thats why 
+                                        // we need to scan all possible walues up to MAX_CONDITIONS_NUMBER
+
+struct cpct_conditions_entry {
+    u32 cc_number;
+    union cpct_cc_name name;
+};
+
+#endif

arch/arc/kernel/Makefile

@@ -25,7 +25,7 @@ obj-$(CONFIG_KPROBES)      		+= kprobes.o
 obj-$(CONFIG_ARC_EMUL_UNALIGNED) 	+= unaligned.o
 obj-$(CONFIG_KGDB)			+= kgdb.o
 obj-$(CONFIG_ARC_METAWARE_HLINK)	+= arc_hostlink.o
-obj-$(CONFIG_PERF_EVENTS)		+= perf_event.o
+obj-$(CONFIG_PERF_EVENTS)		+= perf_event.o perf_cluster.o
 obj-$(CONFIG_JUMP_LABEL)		+= jump_label.o
 
 obj-$(CONFIG_ARC_FPU_SAVE_RESTORE)	+= fpu.o