[MIPS] Make get_frame_info() more readable.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Franck Bui-Huu <vagabon.xyz@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 36 insertions, 31 deletions

diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
index 8709a46a45c1..93d5432759db 100644
--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -281,48 +281,53 @@ static struct mips_frame_info {
 } *schedule_frame, mfinfo[64];
 static int mfinfo_num;
 
+static inline int is_ra_save_ins(union mips_instruction *ip)
+{
+        /* sw / sd $ra, offset($sp) */
+        return (ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
+                ip->i_format.rs == 29 &&
+                ip->i_format.rt == 31;
+}
+
+static inline int is_jal_jalr_jr_ins(union mips_instruction *ip)
+{
+        if (ip->j_format.opcode == jal_op)
+                return 1;
+        if (ip->r_format.opcode != spec_op)
+                return 0;
+        return ip->r_format.func == jalr_op || ip->r_format.func == jr_op;
+}
+
+static inline int is_sp_move_ins(union mips_instruction *ip)
+{
+        /* addiu/daddiu sp,sp,-imm */
+        if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
+                return 0;
+        if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op)
+                return 1;
+        return 0;
+}
+
 static int get_frame_info(struct mips_frame_info *info)
 {
-        int i;
-        void *func = info->func;
-        union mips_instruction *ip = (union mips_instruction *)func;
+        union mips_instruction *ip = info->func;
+        int i, max_insns =
+                min(128UL, info->func_size / sizeof(union mips_instruction));
+
         info->pc_offset = -1;
         info->frame_size = 0;
-        for (i = 0; i < 128; i++, ip++) {
-                /* if jal, jalr, jr, stop. */
-                if (ip->j_format.opcode == jal_op ||
-                    (ip->r_format.opcode == spec_op &&
-                     (ip->r_format.func == jalr_op ||
-                      ip->r_format.func == jr_op)))
-                        break;
 
-                if (info->func_size && i >= info->func_size / 4)
+        for (i = 0; i < max_insns; i++, ip++) {
+
+                if (is_jal_jalr_jr_ins(ip))
                         break;
-                if (
-#ifdef CONFIG_32BIT
-                    ip->i_format.opcode == addiu_op &&
-#endif
-#ifdef CONFIG_64BIT
-                    ip->i_format.opcode == daddiu_op &&
-#endif
-                    ip->i_format.rs == 29 &&
-                    ip->i_format.rt == 29) {
-                        /* addiu/daddiu sp,sp,-imm */
+                if (is_sp_move_ins(ip)) {
                         if (info->frame_size)
                                 continue;
                         info->frame_size = - ip->i_format.simmediate;
                 }
 
-                if (
-#ifdef CONFIG_32BIT
-                    ip->i_format.opcode == sw_op &&
-#endif
-#ifdef CONFIG_64BIT
-                    ip->i_format.opcode == sd_op &&
-#endif
-                    ip->i_format.rs == 29 &&
-                    ip->i_format.rt == 31) {
-                        /* sw / sd $ra, offset($sp) */
+                if (is_ra_save_ins(ip)) {
                         if (info->pc_offset != -1)
                                 continue;
                         info->pc_offset =