MIPS: add support for software performance events

Software events are required as 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>
To: linux-mips@linux-mips.org
Cc: a.p.zijlstra@chello.nl
Cc: paulus@samba.org
Cc: mingo@elte.hu
Cc: acme@redhat.com
Cc: jamie.iles@picochip.com
Acked-by: David Daney <ddaney@caviumnetworks.com>
Reviewed-by: Matt Fleming <matt@console-pimps.org>
Patchwork: https://patchwork.linux-mips.org/patch/1686/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

5 files changed, 36 insertions, 5 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 8fbbef95021f..dc81f39c568e 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 HAVE_ARCH_KGDB
         select HAVE_FUNCTION_TRACER
         select HAVE_FUNCTION_TRACE_MCOUNT_TEST
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index d053bf4759e4..8d79b8774b30 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -29,6 +29,7 @@
 #include <linux/notifier.h>
 #include <linux/kdb.h>
 #include <linux/irq.h>
+#include <linux/perf_event.h>
 
 #include <asm/bootinfo.h>
 #include <asm/branch.h>
@@ -576,10 +577,16 @@ 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 ... */
 }
@@ -595,6 +602,8 @@ 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();
@@ -630,8 +639,11 @@ 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 33d5a5ce4a29..cfea1adfa153 100644
--- a/arch/mips/kernel/unaligned.c
+++ b/arch/mips/kernel/unaligned.c
@@ -78,6 +78,8 @@
 #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 +111,9 @@ 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);
+
         /*
          * This load never faults.
          */
@@ -511,6 +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 ec3faa413f3b..b2ad1b0910ff 100644
--- a/arch/mips/math-emu/cp1emu.c
+++ b/arch/mips/math-emu/cp1emu.c
@@ -36,6 +36,7 @@
 #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>
@@ -258,6 +259,8 @@ 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 783ad0065fdf..137ee76a0045 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -18,6 +18,7 @@
 #include <linux/smp.h>
 #include <linux/module.h>
 #include <linux/kprobes.h>
+#include <linux/perf_event.h>
 
 #include <asm/branch.h>
 #include <asm/mmu_context.h>
@@ -144,6 +145,7 @@ 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;
@@ -151,10 +153,15 @@ 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;