1 /*
2  *  QEMU MIPS emulation: Special opcode helpers
3  *
4  *  Copyright (c) 2004-2005 Jocelyn Mayer
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  *
19  */
20 
21 #include "qemu/osdep.h"
22 #include "qemu/log.h"
23 #include "cpu.h"
24 #include "exec/helper-proto.h"
25 #include "exec/exec-all.h"
26 #include "internal.h"
27 
28 /* Specials */
29 target_ulong helper_di(CPUMIPSState *env)
30 {
31     target_ulong t0 = env->CP0_Status;
32 
33     env->CP0_Status = t0 & ~(1 << CP0St_IE);
34     return t0;
35 }
36 
37 target_ulong helper_ei(CPUMIPSState *env)
38 {
39     target_ulong t0 = env->CP0_Status;
40 
41     env->CP0_Status = t0 | (1 << CP0St_IE);
42     return t0;
43 }
44 
45 static void debug_pre_eret(CPUMIPSState *env)
46 {
47     if (qemu_loglevel_mask(CPU_LOG_EXEC)) {
48         qemu_log("ERET: PC " TARGET_FMT_lx " EPC " TARGET_FMT_lx,
49                 env->active_tc.PC, env->CP0_EPC);
50         if (env->CP0_Status & (1 << CP0St_ERL)) {
51             qemu_log(" ErrorEPC " TARGET_FMT_lx, env->CP0_ErrorEPC);
52         }
53         if (env->hflags & MIPS_HFLAG_DM) {
54             qemu_log(" DEPC " TARGET_FMT_lx, env->CP0_DEPC);
55         }
56         qemu_log("\n");
57     }
58 }
59 
60 static void debug_post_eret(CPUMIPSState *env)
61 {
62     if (qemu_loglevel_mask(CPU_LOG_EXEC)) {
63         qemu_log("  =>  PC " TARGET_FMT_lx " EPC " TARGET_FMT_lx,
64                 env->active_tc.PC, env->CP0_EPC);
65         if (env->CP0_Status & (1 << CP0St_ERL)) {
66             qemu_log(" ErrorEPC " TARGET_FMT_lx, env->CP0_ErrorEPC);
67         }
68         if (env->hflags & MIPS_HFLAG_DM) {
69             qemu_log(" DEPC " TARGET_FMT_lx, env->CP0_DEPC);
70         }
71         switch (mips_env_mmu_index(env)) {
72         case 3:
73             qemu_log(", ERL\n");
74             break;
75         case MIPS_HFLAG_UM:
76             qemu_log(", UM\n");
77             break;
78         case MIPS_HFLAG_SM:
79             qemu_log(", SM\n");
80             break;
81         case MIPS_HFLAG_KM:
82             qemu_log("\n");
83             break;
84         default:
85             cpu_abort(env_cpu(env), "Invalid MMU mode!\n");
86             break;
87         }
88     }
89 }
90 
91 bool mips_io_recompile_replay_branch(CPUState *cs, const TranslationBlock *tb)
92 {
93     CPUMIPSState *env = cpu_env(cs);
94 
95     if ((env->hflags & MIPS_HFLAG_BMASK) != 0
96         && !(cs->tcg_cflags & CF_PCREL) && env->active_tc.PC != tb->pc) {
97         env->active_tc.PC -= (env->hflags & MIPS_HFLAG_B16 ? 2 : 4);
98         env->hflags &= ~MIPS_HFLAG_BMASK;
99         return true;
100     }
101     return false;
102 }
103 
104 static inline void exception_return(CPUMIPSState *env)
105 {
106     debug_pre_eret(env);
107     if (env->CP0_Status & (1 << CP0St_ERL)) {
108         mips_env_set_pc(env, env->CP0_ErrorEPC);
109         env->CP0_Status &= ~(1 << CP0St_ERL);
110     } else {
111         mips_env_set_pc(env, env->CP0_EPC);
112         env->CP0_Status &= ~(1 << CP0St_EXL);
113     }
114     compute_hflags(env);
115     debug_post_eret(env);
116 }
117 
118 void helper_eret(CPUMIPSState *env)
119 {
120     exception_return(env);
121     env->CP0_LLAddr = 1;
122     env->lladdr = 1;
123 }
124 
125 void helper_eretnc(CPUMIPSState *env)
126 {
127     exception_return(env);
128 }
129 
130 void helper_deret(CPUMIPSState *env)
131 {
132     debug_pre_eret(env);
133 
134     env->hflags &= ~MIPS_HFLAG_DM;
135     compute_hflags(env);
136 
137     mips_env_set_pc(env, env->CP0_DEPC);
138 
139     debug_post_eret(env);
140 }
141 
142 void helper_cache(CPUMIPSState *env, target_ulong addr, uint32_t op)
143 {
144     static const char *const type_name[] = {
145         "Primary Instruction",
146         "Primary Data or Unified Primary",
147         "Tertiary",
148         "Secondary"
149     };
150     uint32_t cache_type = extract32(op, 0, 2);
151     uint32_t cache_operation = extract32(op, 2, 3);
152     target_ulong index = addr & 0x1fffffff;
153 
154     switch (cache_operation) {
155     case 0b010: /* Index Store Tag */
156         memory_region_dispatch_write(env->itc_tag, index, env->CP0_TagLo,
157                                      MO_64, MEMTXATTRS_UNSPECIFIED);
158         break;
159     case 0b001: /* Index Load Tag */
160         memory_region_dispatch_read(env->itc_tag, index, &env->CP0_TagLo,
161                                     MO_64, MEMTXATTRS_UNSPECIFIED);
162         break;
163     case 0b000: /* Index Invalidate */
164     case 0b100: /* Hit Invalidate */
165     case 0b110: /* Hit Writeback */
166         /* no-op */
167         break;
168     default:
169         qemu_log_mask(LOG_UNIMP, "cache operation:%u (type: %s cache)\n",
170                       cache_operation, type_name[cache_type]);
171         break;
172     }
173 }
174