MIPS: math-emu: Add FP emu debugfs statistics for branches

Add FP emu debugfs counter for branches.

The new counter is displayed the same way as existing counter, and
its default path is /sys/kernel/debug/mips/fpuemustats/.

The limitation of this counter is that it counts only R6 branch
instructions BC1NEZ and BC1EQZ.

Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/17143/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/fpu_emulator.h b/arch/mips/include/asm/fpu_emulator.h
index 8e50fa3..4c8ab27 100644
--- a/arch/mips/include/asm/fpu_emulator.h
+++ b/arch/mips/include/asm/fpu_emulator.h
@@ -36,6 +36,7 @@ struct mips_fpu_emulator_stats {
 	unsigned long emulated;
 	unsigned long loads;
 	unsigned long stores;
+	unsigned long branches;
 	unsigned long cp1ops;
 	unsigned long cp1xops;
 	unsigned long errors;