MIPS: tracing: move insn_has_delay_slot to a shared header

Currently both kprobes and uprobes code have definitions of the
insn_has_delay_slot method. Move it to a separate header as an inline
method that each probe-specific method can later use.
No functional change intended, although the methods slightly varied in
the constraints they set for the methods - the uprobes one was chosen as
it is slightly more specific when filtering opcode fields.

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14335/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/kprobes.c

@@ -32,7 +32,8 @@
 #include <asm/ptrace.h>
 #include <asm/branch.h>
 #include <asm/break.h>
-#include <asm/inst.h>
+
+#include "probes-common.h"
 
 static const union mips_instruction breakpoint_insn = {
 	.b_format = {
@@ -55,63 +56,7 @@ DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
 
 static int __kprobes insn_has_delayslot(union mips_instruction insn)
 {
-	switch (insn.i_format.opcode) {
-
-		/*
-		 * This group contains:
-		 * jr and jalr are in r_format format.
-		 */
-	case spec_op:
-		switch (insn.r_format.func) {
-		case jr_op:
-		case jalr_op:
-			break;
-		default:
-			goto insn_ok;
-		}
-
-		/*
-		 * This group contains:
-		 * bltz_op, bgez_op, bltzl_op, bgezl_op,
-		 * bltzal_op, bgezal_op, bltzall_op, bgezall_op.
-		 */
-	case bcond_op:
-
-		/*
-		 * These are unconditional and in j_format.
-		 */
-	case jal_op:
-	case j_op:
-
-		/*
-		 * These are conditional and in i_format.
-		 */
-	case beq_op:
-	case beql_op:
-	case bne_op:
-	case bnel_op:
-	case blez_op:
-	case blezl_op:
-	case bgtz_op:
-	case bgtzl_op:
-
-		/*
-		 * These are the FPA/cp1 branch instructions.
-		 */
-	case cop1_op:
-
-#ifdef CONFIG_CPU_CAVIUM_OCTEON
-	case lwc2_op: /* This is bbit0 on Octeon */
-	case ldc2_op: /* This is bbit032 on Octeon */
-	case swc2_op: /* This is bbit1 on Octeon */
-	case sdc2_op: /* This is bbit132 on Octeon */
-#endif
-		return 1;
-	default:
-		break;
-	}
-insn_ok:
-	return 0;
+	return __insn_has_delay_slot(insn);
 }
 
 /*

arch/mips/kernel/probes-common.h

@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#ifndef __PROBES_COMMON_H
+#define __PROBES_COMMON_H
+
+#include <asm/inst.h>
+
+static inline int __insn_has_delay_slot(const union mips_instruction insn)
+{
+	switch (insn.i_format.opcode) {
+	/*
+	 * jr and jalr are in r_format format.
+	 */
+	case spec_op:
+		switch (insn.r_format.func) {
+		case jalr_op:
+		case jr_op:
+			return 1;
+		}
+		break;
+
+	/*
+	 * This group contains:
+	 * bltz_op, bgez_op, bltzl_op, bgezl_op,
+	 * bltzal_op, bgezal_op, bltzall_op, bgezall_op.
+	 */
+	case bcond_op:
+		switch (insn.i_format.rt) {
+		case bltz_op:
+		case bltzl_op:
+		case bgez_op:
+		case bgezl_op:
+		case bltzal_op:
+		case bltzall_op:
+		case bgezal_op:
+		case bgezall_op:
+		case bposge32_op:
+			return 1;
+		}
+		break;
+
+	/*
+	 * These are unconditional and in j_format.
+	 */
+	case jal_op:
+	case j_op:
+	case beq_op:
+	case beql_op:
+	case bne_op:
+	case bnel_op:
+	case blez_op: /* not really i_format */
+	case blezl_op:
+	case bgtz_op:
+	case bgtzl_op:
+		return 1;
+
+	/*
+	 * And now the FPA/cp1 branch instructions.
+	 */
+	case cop1_op:
+#ifdef CONFIG_CPU_CAVIUM_OCTEON
+	case lwc2_op: /* This is bbit0 on Octeon */
+	case ldc2_op: /* This is bbit032 on Octeon */
+	case swc2_op: /* This is bbit1 on Octeon */
+	case sdc2_op: /* This is bbit132 on Octeon */
+#endif
+		return 1;
+	}
+
+	return 0;
+}
+
+#endif  /* __PROBES_COMMON_H */

arch/mips/kernel/uprobes.c

@@ -8,71 +8,12 @@
 #include <asm/branch.h>
 #include <asm/cpu-features.h>
 #include <asm/ptrace.h>
-#include <asm/inst.h>
+
+#include "probes-common.h"
 
 static inline int insn_has_delay_slot(const union mips_instruction insn)
 {
-	switch (insn.i_format.opcode) {
-	/*
-	 * jr and jalr are in r_format format.
-	 */
-	case spec_op:
-		switch (insn.r_format.func) {
-		case jalr_op:
-		case jr_op:
-			return 1;
-		}
-		break;
-
-	/*
-	 * This group contains:
-	 * bltz_op, bgez_op, bltzl_op, bgezl_op,
-	 * bltzal_op, bgezal_op, bltzall_op, bgezall_op.
-	 */
-	case bcond_op:
-		switch (insn.i_format.rt) {
-		case bltz_op:
-		case bltzl_op:
-		case bgez_op:
-		case bgezl_op:
-		case bltzal_op:
-		case bltzall_op:
-		case bgezal_op:
-		case bgezall_op:
-		case bposge32_op:
-			return 1;
-		}
-		break;
-
-	/*
-	 * These are unconditional and in j_format.
-	 */
-	case jal_op:
-	case j_op:
-	case beq_op:
-	case beql_op:
-	case bne_op:
-	case bnel_op:
-	case blez_op: /* not really i_format */
-	case blezl_op:
-	case bgtz_op:
-	case bgtzl_op:
-		return 1;
-
-	/*
-	 * And now the FPA/cp1 branch instructions.
-	 */
-	case cop1_op:
-#ifdef CONFIG_CPU_CAVIUM_OCTEON
-	case lwc2_op: /* This is bbit0 on Octeon */
-	case ldc2_op: /* This is bbit032 on Octeon */
-	case swc2_op: /* This is bbit1 on Octeon */
-	case sdc2_op: /* This is bbit132 on Octeon */
-#endif
-		return 1;
-	}
-
-	return 0;
+	return __insn_has_delay_slot(insn);
 }
 
 /**