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>

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;

arch/mips/math-emu/cp1emu.c

@@ -1230,6 +1230,7 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
 				break;
 			}
 branch_common:
+			MIPS_FPU_EMU_INC_STATS(branches);
 			set_delay_slot(xcp);
 			if (cond) {
 				/*

arch/mips/math-emu/me-debugfs.c

@@ -53,6 +53,7 @@ do {									\
 	FPU_STAT_CREATE(emulated);
 	FPU_STAT_CREATE(loads);
 	FPU_STAT_CREATE(stores);
+	FPU_STAT_CREATE(branches);
 	FPU_STAT_CREATE(cp1ops);
 	FPU_STAT_CREATE(cp1xops);
 	FPU_STAT_CREATE(errors);