Commit c0efbb6d authored by Franck Bui-Huu's avatar Franck Bui-Huu Committed by Ralf Baechle
Browse files

[MIPS] Make get_frame_info() more readable. 



Signed-off-by: default avatarAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: default avatarFranck Bui-Huu <vagabon.xyz@gmail.com>
Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent df586d59

arch/mips/kernel/process.c

+36 −31
Original line number Diff line number Diff line
@@ -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 =