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
16 extern int __isa_exception_epc(struct pt_regs *regs);
17 extern int __compute_return_epc(struct pt_regs *regs);
18 extern int __compute_return_epc_for_insn(struct pt_regs *regs,
19 union mips_instruction insn);
20 extern int __microMIPS_compute_return_epc(struct pt_regs *regs);
21 extern 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
30 int isBranchInstr(struct pt_regs *regs,
31 struct mm_decoded_insn dec_insn, unsigned long *contpc);
32
33 extern int __mm_isBranchInstr(struct pt_regs *regs,
34 struct mm_decoded_insn dec_insn, unsigned long *contpc);
35
mm_isBranchInstr(struct pt_regs * regs,struct mm_decoded_insn dec_insn,unsigned long * contpc)36 static inline int mm_isBranchInstr(struct pt_regs *regs,
37 struct mm_decoded_insn dec_insn, unsigned long *contpc)
38 {
39 if (!cpu_has_mmips)
40 return 0;
41
42 return __mm_isBranchInstr(regs, dec_insn, contpc);
43 }
44
delay_slot(struct pt_regs * regs)45 static inline int delay_slot(struct pt_regs *regs)
46 {
47 return regs->cp0_cause & CAUSEF_BD;
48 }
49
clear_delay_slot(struct pt_regs * regs)50 static inline void clear_delay_slot(struct pt_regs *regs)
51 {
52 regs->cp0_cause &= ~CAUSEF_BD;
53 }
54
set_delay_slot(struct pt_regs * regs)55 static inline void set_delay_slot(struct pt_regs *regs)
56 {
57 regs->cp0_cause |= CAUSEF_BD;
58 }
59
exception_epc(struct pt_regs * regs)60 static inline unsigned long exception_epc(struct pt_regs *regs)
61 {
62 if (likely(!delay_slot(regs)))
63 return regs->cp0_epc;
64
65 if (get_isa16_mode(regs->cp0_epc))
66 return __isa_exception_epc(regs);
67
68 return regs->cp0_epc + 4;
69 }
70
71 #define BRANCH_LIKELY_TAKEN 0x0001
72
compute_return_epc(struct pt_regs * regs)73 static inline int compute_return_epc(struct pt_regs *regs)
74 {
75 if (get_isa16_mode(regs->cp0_epc)) {
76 if (cpu_has_mmips)
77 return __microMIPS_compute_return_epc(regs);
78 if (cpu_has_mips16)
79 return __MIPS16e_compute_return_epc(regs);
80 } else if (!delay_slot(regs)) {
81 regs->cp0_epc += 4;
82 return 0;
83 }
84
85 return __compute_return_epc(regs);
86 }
87
MIPS16e_compute_return_epc(struct pt_regs * regs,union mips16e_instruction * inst)88 static 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