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     MIPSCPU *cpu = MIPS_CPU(cs);
94     CPUMIPSState *env = &cpu->env;
95 
96     if ((env->hflags & MIPS_HFLAG_BMASK) != 0
97         && !(cs->tcg_cflags & CF_PCREL) && env->active_tc.PC != tb->pc) {
98         env->active_tc.PC -= (env->hflags & MIPS_HFLAG_B16 ? 2 : 4);
99         env->hflags &= ~MIPS_HFLAG_BMASK;
100         return true;
101     }
102     return false;
103 }
104 
105 static inline void exception_return(CPUMIPSState *env)
106 {
107     debug_pre_eret(env);
108     if (env->CP0_Status & (1 << CP0St_ERL)) {
109         mips_env_set_pc(env, env->CP0_ErrorEPC);
110         env->CP0_Status &= ~(1 << CP0St_ERL);
111     } else {
112         mips_env_set_pc(env, env->CP0_EPC);
113         env->CP0_Status &= ~(1 << CP0St_EXL);
114     }
115     compute_hflags(env);
116     debug_post_eret(env);
117 }
118 
119 void helper_eret(CPUMIPSState *env)
120 {
121     exception_return(env);
122     env->CP0_LLAddr = 1;
123     env->lladdr = 1;
124 }
125 
126 void helper_eretnc(CPUMIPSState *env)
127 {
128     exception_return(env);
129 }
130 
131 void helper_deret(CPUMIPSState *env)
132 {
133     debug_pre_eret(env);
134 
135     env->hflags &= ~MIPS_HFLAG_DM;
136     compute_hflags(env);
137 
138     mips_env_set_pc(env, env->CP0_DEPC);
139 
140     debug_post_eret(env);
141 }
142 
143 void helper_cache(CPUMIPSState *env, target_ulong addr, uint32_t op)
144 {
145     static const char *const type_name[] = {
146         "Primary Instruction",
147         "Primary Data or Unified Primary",
148         "Tertiary",
149         "Secondary"
150     };
151     uint32_t cache_type = extract32(op, 0, 2);
152     uint32_t cache_operation = extract32(op, 2, 3);
153     target_ulong index = addr & 0x1fffffff;
154 
155     switch (cache_operation) {
156     case 0b010: /* Index Store Tag */
157         memory_region_dispatch_write(env->itc_tag, index, env->CP0_TagLo,
158                                      MO_64, MEMTXATTRS_UNSPECIFIED);
159         break;
160     case 0b001: /* Index Load Tag */
161         memory_region_dispatch_read(env->itc_tag, index, &env->CP0_TagLo,
162                                     MO_64, MEMTXATTRS_UNSPECIFIED);
163         break;
164     case 0b000: /* Index Invalidate */
165     case 0b100: /* Hit Invalidate */
166     case 0b110: /* Hit Writeback */
167         /* no-op */
168         break;
169     default:
170         qemu_log_mask(LOG_UNIMP, "cache operation:%u (type: %s cache)\n",
171                       cache_operation, type_name[cache_type]);
172         break;
173     }
174 }
175