nds32: Perf porting

This is the commit that porting the perf for nds32.

1.Raw event:
	The raw events start with 'r'.
		Usage:
			perf stat -e rXYZ ./app
			X: the index of performance counter.
			YZ: the index(convert to hexdecimal) of events

		Example:
			'perf stat -e r101 ./app' means the counter 1 will count the instruction
		event.

		The index of counter and events can be found in
		"Andes System Privilege Architecture Version 3 Manual".

Or you can perform the 'perf list' to find the symbolic name of raw events.

2.Perf mmap2:

	Fix unexpected perf mmap2() page fault

	When the mmap2() called by perf application,
	you will encounter such condition:"failed to write."
	With return value -EFAULT

	This is due to the page fault caused by "reading" buffer
	from the mapped legal address region to write to the descriptor.
	The page_fault handler will get a VM_FAULT_SIGBUS return value,
	which should not happens here.(Due to this is a read request.)

	You can refer to kernel/events/core.c:perf_mmap_fault(...)
	If "(vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))" is evaluated
	as true, you will get VM_FAULT_SIGBUS as return value.

	However, this is not an write request. The flags which indicated
	why the page fault happens is wrong.

	Furthermore, NDS32 SPAv3 is not able to detect it is read or write.
	It only know  either it is instruction fetch or data access.

	Therefore, by removing the wrong flag assignment(actually, the hardware
	is not able to show the reason), we can fix this bug.

3.Perf multiple events map to same counter.

	When there are multiple events map to the same counter, the counter
	counts inaccurately. This is because each counter only counts one event
	in the same time.
	So when there are multiple events map to same counter, they have to take
	turns in each context.

	There are two solution:
	1. Print the error message when multiple events map to the same counter.
	But print the error message would let the program hang in loop. The ltp
	(linux test program) would be failed when the program hang in loop.

	2. Don't print the error message, the ltp would pass. But the user need to
	have the knowledge that don't count the events which map to the same
	counter, or the user will get the inaccurate results.

	We choose method 2 for the solution
Signed-off-by: Nickhu <nickhu@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>

arch/nds32/Kconfig

@@ -30,6 +30,7 @@ config NDS32
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_REGS_AND_STACK_ACCESS_API
+	select HAVE_PERF_EVENTS
 	select IRQ_DOMAIN
 	select LOCKDEP_SUPPORT
 	select MODULES_USE_ELF_RELA

arch/nds32/boot/dts/ae3xx.dts

@@ -82,4 +82,9 @@ mac0: ethernet@e0100000 {
 			interrupts = <18>;
 		};
 	};
+
+	pmu {
+		compatible = "andestech,nds32v3-pmu";
+		interrupts= <13>;
+	};
 };

arch/nds32/include/asm/Kbuild

@@ -36,6 +36,7 @@ generic-y += kprobes.h
 generic-y += kvm_para.h
 generic-y += limits.h
 generic-y += local.h
+generic-y += local64.h
 generic-y += mm-arch-hooks.h
 generic-y += mman.h
 generic-y += parport.h

arch/nds32/include/asm/perf_event.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2008-2018 Andes Technology Corporation */
+
+#ifndef __ASM_PERF_EVENT_H
+#define __ASM_PERF_EVENT_H
+
+/*
+ * This file is request by Perf,
+ * please refer to tools/perf/design.txt for more details
+ */
+struct pt_regs;
+unsigned long perf_instruction_pointer(struct pt_regs *regs);
+unsigned long perf_misc_flags(struct pt_regs *regs);
+#define perf_misc_flags(regs)   perf_misc_flags(regs)
+
+#endif

arch/nds32/include/asm/stacktrace.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2008-2018 Andes Technology Corporation */
+
+#ifndef __ASM_STACKTRACE_H
+#define __ASM_STACKTRACE_H
+
+/* Kernel callchain */
+struct stackframe {
+	unsigned long fp;
+	unsigned long sp;
+	unsigned long lp;
+};
+
+/*
+ * struct frame_tail: User callchain
+ * IMPORTANT:
+ * This struct is used for call-stack walking,
+ * the order and types matters.
+ * Do not use array, it only stores sizeof(pointer)
+ *
+ * The details can refer to arch/arm/kernel/perf_event.c
+ */
+struct frame_tail {
+	unsigned long stack_fp;
+	unsigned long stack_lp;
+};
+
+/* For User callchain with optimize for size */
+struct frame_tail_opt_size {
+	unsigned long stack_r6;
+	unsigned long stack_fp;
+	unsigned long stack_gp;
+	unsigned long stack_lp;
+};
+
+extern void
+get_real_ret_addr(unsigned long *addr, struct task_struct *tsk, int *graph);
+
+#endif /* __ASM_STACKTRACE_H */

arch/nds32/kernel/Makefile

@@ -4,7 +4,6 @@
 
 CPPFLAGS_vmlinux.lds	:= -DTEXTADDR=$(TEXTADDR)
 AFLAGS_head.o		:= -DTEXTADDR=$(TEXTADDR)
-
 # Object file lists.
 
 obj-y			:= ex-entry.o ex-exit.o ex-scall.o irq.o \
@@ -16,10 +15,10 @@ obj-$(CONFIG_MODULES)		+= nds32_ksyms.o module.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_OF)		+= devtree.o
 obj-$(CONFIG_CACHE_L2)		+= atl2c.o
+obj-$(CONFIG_PERF_EVENTS) += perf_event_cpu.o
 
 extra-y := head.o vmlinux.lds
 
-
 obj-y				+= vdso/
 
 obj-$(CONFIG_FUNCTION_TRACER)   += ftrace.o

arch/nds32/mm/fault.c

@@ -9,6 +9,7 @@
 #include <linux/init.h>
 #include <linux/hardirq.h>
 #include <linux/uaccess.h>
+#include <linux/perf_event.h>
 
 #include <asm/pgtable.h>
 #include <asm/tlbflush.h>
@@ -169,8 +170,6 @@ void do_page_fault(unsigned long entry, unsigned long addr,
 			mask = VM_EXEC;
 		else {
 			mask = VM_READ | VM_WRITE;
-			if (vma->vm_flags & VM_WRITE)
-				flags |= FAULT_FLAG_WRITE;
 		}
 	} else if (entry == ENTRY_TLB_MISC) {
 		switch (error_code & ITYPE_mskETYPE) {
@@ -231,11 +230,17 @@ void do_page_fault(unsigned long entry, unsigned long addr,
 	 * attempt. If we go through a retry, it is extremely likely that the
 	 * page will be found in page cache at that point.
 	 */
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
 	if (flags & FAULT_FLAG_ALLOW_RETRY) {
-		if (fault & VM_FAULT_MAJOR)
+		if (fault & VM_FAULT_MAJOR) {
 			tsk->maj_flt++;
-		else
+			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
+				      1, regs, addr);
+		} else {
 			tsk->min_flt++;
+			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
+				      1, regs, addr);
+		}
 		if (fault & VM_FAULT_RETRY) {
 			flags &= ~FAULT_FLAG_ALLOW_RETRY;
 			flags |= FAULT_FLAG_TRIED;

tools/include/asm/barrier.h

@@ -24,6 +24,8 @@
 #include "../../arch/ia64/include/asm/barrier.h"
 #elif defined(__xtensa__)
 #include "../../arch/xtensa/include/asm/barrier.h"
+#elif defined(__nds32__)
+#include "../../arch/nds32/include/asm/barrier.h"
 #else
 #include <asm-generic/barrier.h>
 #endif

tools/perf/arch/nds32/Build

+libperf-y += util/

tools/perf/arch/nds32/util/Build

+libperf-y += header.o

tools/perf/arch/nds32/util/header.c

+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <api/fs/fs.h>
+#include "header.h"
+
+#define STR_LEN 1024
+
+char *get_cpuid_str(struct perf_pmu *pmu)
+{
+	/* In nds32, we only have one cpu */
+	char *buf = NULL;
+	struct cpu_map *cpus;
+	const char *sysfs = sysfs__mountpoint();
+
+	if (!sysfs || !pmu || !pmu->cpus)
+		return NULL;
+
+	buf = malloc(STR_LEN);
+	if (!buf)
+		return NULL;
+
+	cpus = cpu_map__get(pmu->cpus);
+	sprintf(buf, "0x%x", cpus->nr - 1);
+	cpu_map__put(cpus);
+	return buf;
+}

tools/perf/pmu-events/arch/nds32/mapfile.csv

+# Format:
+#	MIDR,Version,JSON/file/pathname,Type
+#
+# where
+#	MIDR	Processor version
+#		Variant[23:20] and Revision [3:0] should be zero.
+#	Version could be used to track version of of JSON file
+#		but currently unused.
+#	JSON/file/pathname is the path to JSON file, relative
+#		to tools/perf/pmu-events/arch/arm64/.
+#	Type is core, uncore etc
+#
+#
+#Family-model,Version,Filename,EventType
+0x0,v3,n13,core

tools/perf/pmu-events/arch/nds32/n13/atcpmu.json

+[
+  {
+	"PublicDescription": "Conditional branch",
+    "EventCode": "0x102",
+    "EventName": "cond_br",
+    "BriefDescription": "V3 Conditional branch"
+  },
+  {
+	"PublicDescription": "Taken conditional branches",
+    "EventCode": "0x103",
+    "EventName": "taken_cond_br",
+    "BriefDescription": "V3 Taken Conditional branch"
+  },
+  {
+	"PublicDescription": "Prefetch Instruction",
+    "EventCode": "0x104",
+    "EventName": "prefetch_inst",
+    "BriefDescription": "V3 Prefetch Instruction"
+  },
+  {
+	"PublicDescription": "RET Inst",
+    "EventCode": "0x105",
+    "EventName": "ret_inst",
+    "BriefDescription": "V3 RET Inst"
+  },
+  {
+	"PublicDescription": "JR(non-RET) instructions",
+    "EventCode": "0x106",
+    "EventName": "jr_inst",
+    "BriefDescription": "V3 JR(non-RET) instructions"
+  },
+  {
+	"PublicDescription": "JAL/JRAL instructions",
+    "EventCode": "0x107",
+    "EventName": "jal_jral_inst",
+    "BriefDescription": "V3 JAL/JRAL instructions"
+  },
+  {
+	"PublicDescription": "NOP instructions",
+    "EventCode": "0x108",
+    "EventName": "nop_inst",
+    "BriefDescription": "V3 NOP instructions"
+  },
+  {
+	"PublicDescription": "SCW instructions",
+    "EventCode": "0x109",
+    "EventName": "scw_inst",
+    "BriefDescription": "V3 SCW instructions"
+  },
+  {
+	"PublicDescription": "ISB/DSB instructions",
+    "EventCode": "0x10a",
+    "EventName": "isb_dsb_inst",
+    "BriefDescription": "V3 ISB/DSB instructions"
+  },
+  {
+	"PublicDescription": "CCTL instructions",
+    "EventCode": "0x10b",
+    "EventName": "cctl_inst",
+    "BriefDescription": "V3 CCTL instructions"
+  },
+  {
+	"PublicDescription": "Taken Interrupts",
+    "EventCode": "0x10c",
+    "EventName": "taken_interrupts",
+    "BriefDescription": "V3 Taken Interrupts"
+  },
+  {
+	"PublicDescription": "Loads Completed",
+    "EventCode": "0x10d",
+    "EventName": "load_completed",
+    "BriefDescription": "V3 Loads Completed"
+  },
+  {
+	"PublicDescription": "uITLB accesses",
+    "EventCode": "0x10e",
+    "EventName": "uitlb_access",
+    "BriefDescription": "V3 uITLB accesses"
+  },
+  {
+	"PublicDescription": "uDTLB accesses",
+    "EventCode": "0x10f",
+    "EventName": "udtlb_access",
+    "BriefDescription": "V3 uDTLB accesses"
+  },
+  {
+	"PublicDescription": "MTLB accesses",
+    "EventCode": "0x110",
+    "EventName": "mtlb_access",
+    "BriefDescription": "V3 MTLB accesses"
+  },
+  {
+	"PublicDescription": "DATA_DEPENDENCY_STALL_CYCLES",
+    "EventCode": "0x112",
+    "EventName": "data_dependency_stall",
+    "BriefDescription": "V3 DATA_DEPENDENCY_STALL_CYCLES"
+  },
+  {
+	"PublicDescription": "DATA_CACHE_MISS_STALL_CYCLES",
+    "EventCode": "0x113",
+    "EventName": "dcache_miss_stall",
+    "BriefDescription": "V3 DATA_CACHE_MISS_STALL_CYCLES"
+  },
+  {
+	"PublicDescription": "ILM access",
+    "EventCode": "0x118",
+    "EventName": "ilm_access",
+    "BriefDescription": "V3 ILM accesses"
+  },
+  {
+	"PublicDescription": "LSU BIU CYCLES",
+    "EventCode": "0x119",
+    "EventName": "lsu_biu_cycles",
+    "BriefDescription": "V3 LSU BIU CYCLES"
+  },
+  {
+	"PublicDescription": "HPTWK BIU CYCLES",
+    "EventCode": "0x11a",
+    "EventName": "hptwk_biu_cycles",
+    "BriefDescription": "V3 HPTWK BIU CYCLES"
+  },
+  {
+	"PublicDescription": "DMA BIU CYCLES",
+    "EventCode": "0x11b",
+    "EventName": "dma_biu_cycles",
+    "BriefDescription": "V3 DMA BIU CYCLES"
+  },
+  {
+	"PublicDescription": "CODE CACHE FILL BIU CYCLES",
+    "EventCode": "0x11c",
+    "EventName": "icache_fill_biu_cycles",
+    "BriefDescription": "V3 CODE CACHE FILL BIU CYCLES"
+  },
+  {
+	"PublicDescription": "LEAGAL UNALIGN DCACHE ACCESS",
+    "EventCode": "0x11d",
+    "EventName": "legal_unalined_dcache_access",
+    "BriefDescription": "V3 LEAGAL UNALIGN DCACHE ACCESS"
+  },
+  {
+	"PublicDescription": "PUSH25 instructions",
+    "EventCode": "0x11e",
+    "EventName": "push25_inst",
+    "BriefDescription": "V3 PUSH25 instructions"
+  },
+  {
+	"PublicDescription": "SYSCALL instructions",
+    "EventCode": "0x11f",
+    "EventName": "syscall_inst",
+    "BriefDescription": "V3 SYSCALL instructions"
+  },
+  {
+	"PublicDescription": "conditional branch miss",
+    "EventCode": "0x202",
+    "EventName": "cond_br_miss",
+    "BriefDescription": "V3 conditional branch miss"
+  },
+  {
+	"PublicDescription": "taken conditional branch miss",
+    "EventCode": "0x203",
+    "EventName": "taken_cond_br_miss",
+    "BriefDescription": "V3 taken conditional branch miss"
+  },
+  {
+	"PublicDescription": "Prefetch Instructions with cache hit",
+    "EventCode": "0x204",
+    "EventName": "prefetch_icache_hit",
+    "BriefDescription": "V3 Prefetch Instructions with cache hit"
+  },
+  {
+	"PublicDescription": "RET mispredict",
+    "EventCode": "0x205",
+    "EventName": "ret_mispredict",
+    "BriefDescription": "V3 RET mispredict"
+  },
+  {
+	"PublicDescription": "Immediate J instructions",
+    "EventCode": "0x206",
+    "EventName": "imm_j_inst",
+    "BriefDescription": "V3 Immediate J instructions"
+  },
+  {
+	"PublicDescription": "Multiply instructions",
+    "EventCode": "0x207",
+    "EventName": "mul_inst",
+    "BriefDescription": "V3 Multiply instructions"
+  },
+  {
+	"PublicDescription": "16 bits instructions",
+    "EventCode": "0x208",
+    "EventName": "sixteen_bits_inst",
+    "BriefDescription": "V3 16 bits instructions"
+  },
+  {
+	"PublicDescription": "Failed SCW instructions",
+    "EventCode": "0x209",
+    "EventName": "fail_scw_inst",
+    "BriefDescription": "V3 Failed SCW instructions"
+  },
+  {
+	"PublicDescription": "ld-after-st conflict replays",
+    "EventCode": "0x20a",
+    "EventName": "ld_af_st_conflict",
+    "BriefDescription": "V3 ld-after-st conflict replays"
+  },
+  {
+	"PublicDescription": "Exception taken",
+    "EventCode": "0x20c",
+    "EventName": "exception_taken",
+    "BriefDescription": "V3 Exception taken"
+  },
+  {
+	"PublicDescription": "Stores completed",
+    "EventCode": "0x20d",
+    "EventName": "store_completed",
+    "BriefDescription": "V3 Stores completed"
+  },
+  {
+	"PublicDescription": "uITLB miss",
+    "EventCode": "0x20e",
+    "EventName": "uitlb_miss",
+    "BriefDescription": "V3 uITLB miss"
+  },
+  {
+	"PublicDescription": "uDTLB miss",
+    "EventCode": "0x20f",
+    "EventName": "udtlb_miss",
+    "BriefDescription": "V3 uDTLB miss"
+  },
+  {
+	"PublicDescription": "MTLB miss",
+    "EventCode": "0x210",
+    "EventName": "mtlb_miss",
+    "BriefDescription": "V3 MTLB miss"
+  },
+  {
+	"PublicDescription": "Empty instructions queue stall cycles",
+    "EventCode": "0x212",
+    "EventName": "empty_inst_q_stall",
+    "BriefDescription": "V3 Empty instructions queue stall cycles"
+  },
+  {
+	"PublicDescription": "Data write back",
+    "EventCode": "0x213",
+    "EventName": "data_wb",
+    "BriefDescription": "V3 Data write back"
+  },
+  {
+	"PublicDescription": "DLM access",
+    "EventCode": "0x218",
+    "EventName": "dlm_access",
+    "BriefDescription": "V3 DLM access"
+  },
+  {
+	"PublicDescription": "LSU BIU request",
+    "EventCode": "0x219",
+    "EventName": "lsu_biu_req",
+    "BriefDescription": "V3 LSU BIU request"
+  },
+  {
+	"PublicDescription": "HPTWK BIU request",
+    "EventCode": "0x21a",
+    "EventName": "hptwk_biu_req",
+    "BriefDescription": "V3 HPTWK BIU request"
+  },
+  {
+	"PublicDescription": "DMA BIU request",
+    "EventCode": "0x21b",
+    "EventName": "dma_biu_req",
+    "BriefDescription": "V3 DMA BIU request"
+  },
+  {
+	"PublicDescription": "Icache fill BIU request",
+    "EventCode": "0x21c",
+    "EventName": "icache_fill_biu_req",
+    "BriefDescription": "V3 Icache fill BIU request"
+  },
+  {
+	"PublicDescription": "External events",
+    "EventCode": "0x21d",
+    "EventName": "external_events",
+    "BriefDescription": "V3 External events"
+  },
+  {
+	"PublicDescription": "POP25 instructions",
+    "EventCode": "0x21e",
+    "EventName": "pop25_inst",
+    "BriefDescription": "V3 POP25 instructions"
+  },
+]