1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License.  See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1996, 1997, 1998, 2001 by Ralf Baechle
7 */
8#ifndef _ASM_BRANCH_H
9#define _ASM_BRANCH_H
10
11#include <asm/cpu-features.h>
12#include <asm/mipsregs.h>
13#include <asm/ptrace.h>
14#include <asm/inst.h>
15
16extern int __isa_exception_epc(struct pt_regs *regs);
17extern int __compute_return_epc(struct pt_regs *regs);
18extern int __compute_return_epc_for_insn(struct pt_regs *regs,
19					 union mips_instruction insn);
20extern int __microMIPS_compute_return_epc(struct pt_regs *regs);
21extern int __MIPS16e_compute_return_epc(struct pt_regs *regs);
22
23/*
24 * microMIPS bitfields
25 */
26#define MM_POOL32A_MINOR_MASK	0x3f
27#define MM_POOL32A_MINOR_SHIFT	0x6
28#define MM_MIPS32_COND_FC	0x30
29
30extern int __mm_isBranchInstr(struct pt_regs *regs,
31	struct mm_decoded_insn dec_insn, unsigned long *contpc);
32
33static inline int mm_isBranchInstr(struct pt_regs *regs,
34	struct mm_decoded_insn dec_insn, unsigned long *contpc)
35{
36	if (!cpu_has_mmips)
37		return 0;
38
39	return __mm_isBranchInstr(regs, dec_insn, contpc);
40}
41
42static inline int delay_slot(struct pt_regs *regs)
43{
44	return regs->cp0_cause & CAUSEF_BD;
45}
46
47static inline void clear_delay_slot(struct pt_regs *regs)
48{
49	regs->cp0_cause &= ~CAUSEF_BD;
50}
51
52static inline void set_delay_slot(struct pt_regs *regs)
53{
54	regs->cp0_cause |= CAUSEF_BD;
55}
56
57static inline unsigned long exception_epc(struct pt_regs *regs)
58{
59	if (likely(!delay_slot(regs)))
60		return regs->cp0_epc;
61
62	if (get_isa16_mode(regs->cp0_epc))
63		return __isa_exception_epc(regs);
64
65	return regs->cp0_epc + 4;
66}
67
68#define BRANCH_LIKELY_TAKEN 0x0001
69
70static inline int compute_return_epc(struct pt_regs *regs)
71{
72	if (get_isa16_mode(regs->cp0_epc)) {
73		if (cpu_has_mmips)
74			return __microMIPS_compute_return_epc(regs);
75		if (cpu_has_mips16)
76			return __MIPS16e_compute_return_epc(regs);
77		return regs->cp0_epc;
78	}
79
80	if (!delay_slot(regs)) {
81		regs->cp0_epc += 4;
82		return 0;
83	}
84
85	return __compute_return_epc(regs);
86}
87
88static inline int MIPS16e_compute_return_epc(struct pt_regs *regs,
89					     union mips16e_instruction *inst)
90{
91	if (likely(!delay_slot(regs))) {
92		if (inst->ri.opcode == MIPS16e_extend_op) {
93			regs->cp0_epc += 4;
94			return 0;
95		}
96		regs->cp0_epc += 2;
97		return 0;
98	}
99
100	return __MIPS16e_compute_return_epc(regs);
101}
102
103#endif /* _ASM_BRANCH_H */
104