[PATCH v2 3/4] MIPS: adding support for software performance events

[Deng-Cheng Zhu <dengcheng.zhu@gmail.com>]

Software events are required as a part of the measurable stuff by the
Linux performance counter subsystem. Here is the list of events added by
this patch:
PERF_COUNT_SW_PAGE_FAULTS
PERF_COUNT_SW_PAGE_FAULTS_MIN
PERF_COUNT_SW_PAGE_FAULTS_MAJ
PERF_COUNT_SW_ALIGNMENT_FAULTS
PERF_COUNT_SW_EMULATION_FAULTS

Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
---
 arch/mips/Kconfig            |    2 ++
 arch/mips/kernel/traps.c     |   18 +++++++++++++++---
 arch/mips/kernel/unaligned.c |    5 +++++
 arch/mips/math-emu/cp1emu.c  |    3 +++
 arch/mips/mm/fault.c         |   11 +++++++++--
 5 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 469176c..ebf2c79 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -4,6 +4,8 @@ config MIPS
 	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_IDE
 	select HAVE_OPROFILE
+	select HAVE_PERF_EVENTS
+	select PERF_USE_VMALLOC
 	select GENERIC_ATOMIC64 if !64BIT
 	select HAVE_ARCH_KGDB
 	select HAVE_FUNCTION_TRACER
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 1a4dd65..851705b 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -26,6 +26,7 @@
 #include <linux/kgdb.h>
 #include <linux/kdebug.h>
 #include <linux/notifier.h>
+#include <linux/perf_event.h>
 
 #include <asm/bootinfo.h>
 #include <asm/branch.h>
@@ -557,10 +558,16 @@ static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
  */
 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
 {
-	if ((opcode & OPCODE) == LL)
+	if ((opcode & OPCODE) == LL) {
+		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
+				1, 0, regs, 0);
 		return simulate_ll(regs, opcode);
-	if ((opcode & OPCODE) == SC)
+	}
+	if ((opcode & OPCODE) == SC) {
+		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
+				1, 0, regs, 0);
 		return simulate_sc(regs, opcode);
+	}
 
 	return -1;			/* Must be something else ... */
 }
@@ -576,6 +583,8 @@ static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
 		int rd = (opcode & RD) >> 11;
 		int rt = (opcode & RT) >> 16;
+		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
+				1, 0, regs, 0);
 		switch (rd) {
 		case 0:		/* CPU number */
 			regs->regs[rt] = smp_processor_id();
@@ -611,8 +620,11 @@ static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
 
 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
 {
-	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC)
+	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
+		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
+				1, 0, regs, 0);
 		return 0;
+	}
 
 	return -1;			/* Must be something else ... */
 }
diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c
index 69b039c..a319c7a 100644
--- a/arch/mips/kernel/unaligned.c
+++ b/arch/mips/kernel/unaligned.c
@@ -78,6 +78,7 @@
 #include <linux/smp.h>
 #include <linux/sched.h>
 #include <linux/debugfs.h>
+#include <linux/perf_event.h>
 #include <asm/asm.h>
 #include <asm/branch.h>
 #include <asm/byteorder.h>
@@ -109,6 +110,8 @@ static void emulate_load_store_insn(struct pt_regs *regs,
 	unsigned long value;
 	unsigned int res;
 
+	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
+			1, 0, regs, 0);
 	regs->regs[0] = 0;
 
 	/*
@@ -513,6 +516,8 @@ asmlinkage void do_ade(struct pt_regs *regs)
 	unsigned int __user *pc;
 	mm_segment_t seg;
 
+	perf_sw_event(PERF_COUNT_SW_ALIGNMENT_FAULTS,
+			1, 0, regs, regs->cp0_badvaddr);
 	/*
 	 * Did we catch a fault trying to load an instruction?
 	 * Or are we running in MIPS16 mode?
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
index 8f2f8e9..b3fa153 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -37,6 +37,7 @@
 #include <linux/sched.h>
 #include <linux/module.h>
 #include <linux/debugfs.h>
+#include <linux/perf_event.h>
 
 #include <asm/inst.h>
 #include <asm/bootinfo.h>
@@ -256,6 +257,8 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx)
 	}
 
       emul:
+	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
+			1, 0, xcp, 0);
 	MIPS_FPU_EMU_INC_STATS(emulated);
 	switch (MIPSInst_OPCODE(ir)) {
 	case ldc1_op:{
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index b78f7d9..5987d2b 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -18,6 +18,7 @@
 #include <linux/smp.h>
 #include <linux/vt_kern.h>		/* For unblank_screen() */
 #include <linux/module.h>
+#include <linux/perf_event.h>
 
 #include <asm/branch.h>
 #include <asm/mmu_context.h>
@@ -132,6 +133,7 @@ good_area:
 	 * the fault.
 	 */
 	fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0);
+	perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address);
 	if (unlikely(fault & VM_FAULT_ERROR)) {
 		if (fault & VM_FAULT_OOM)
 			goto out_of_memory;
@@ -139,10 +141,15 @@ good_area:
 			goto do_sigbus;
 		BUG();
 	}
-	if (fault & VM_FAULT_MAJOR)
+	if (fault & VM_FAULT_MAJOR) {
+		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
+				1, 0, regs, address);
 		tsk->maj_flt++;
-	else
+	} else {
+		perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
+				1, 0, regs, address);
 		tsk->min_flt++;
+	}
 
 	up_read(&mm->mmap_sem);
 	return;
-- 
1.7.0.4