summaryrefslogtreecommitdiffstats
path: root/linux-user/mips/cpu_loop.c
blob: 553e8ca7f576467e54d7b23f3d2d836062645d37 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
/*
 *  qemu user cpu loop
 *
 *  Copyright (c) 2003-2008 Fabrice Bellard
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qemu.h"
#include "cpu_loop-common.h"
#include "elf.h"
#include "internal.h"

# ifdef TARGET_ABI_MIPSO32
#  define MIPS_SYSCALL_NUMBER_UNUSED -1
static const int8_t mips_syscall_args[] = {
#include "syscall-args-o32.c.inc"
};
# endif /* O32 */

/* Break codes */
enum {
    BRK_OVERFLOW = 6,
    BRK_DIVZERO = 7
};

static int do_break(CPUMIPSState *env, target_siginfo_t *info,
                    unsigned int code)
{
    int ret = -1;

    switch (code) {
    case BRK_OVERFLOW:
    case BRK_DIVZERO:
        info->si_signo = TARGET_SIGFPE;
        info->si_errno = 0;
        info->si_code = (code == BRK_OVERFLOW) ? FPE_INTOVF : FPE_INTDIV;
        queue_signal(env, info->si_signo, QEMU_SI_FAULT, &*info);
        ret = 0;
        break;
    default:
        info->si_signo = TARGET_SIGTRAP;
        info->si_errno = 0;
        queue_signal(env, info->si_signo, QEMU_SI_FAULT, &*info);
        ret = 0;
        break;
    }

    return ret;
}

void cpu_loop(CPUMIPSState *env)
{
    CPUState *cs = env_cpu(env);
    target_siginfo_t info;
    int trapnr;
    abi_long ret;
# ifdef TARGET_ABI_MIPSO32
    unsigned int syscall_num;
# endif

    for(;;) {
        cpu_exec_start(cs);
        trapnr = cpu_exec(cs);
        cpu_exec_end(cs);
        process_queued_cpu_work(cs);

        switch(trapnr) {
        case EXCP_SYSCALL:
            env->active_tc.PC += 4;
# ifdef TARGET_ABI_MIPSO32
            syscall_num = env->active_tc.gpr[2] - 4000;
            if (syscall_num >= sizeof(mips_syscall_args)) {
                /* syscall_num is larger that any defined for MIPS O32 */
                ret = -TARGET_ENOSYS;
            } else if (mips_syscall_args[syscall_num] ==
                       MIPS_SYSCALL_NUMBER_UNUSED) {
                /* syscall_num belongs to the range not defined for MIPS O32 */
                ret = -TARGET_ENOSYS;
            } else {
                /* syscall_num is valid */
                int nb_args;
                abi_ulong sp_reg;
                abi_ulong arg5 = 0, arg6 = 0, arg7 = 0, arg8 = 0;

                nb_args = mips_syscall_args[syscall_num];
                sp_reg = env->active_tc.gpr[29];
                switch (nb_args) {
                /* these arguments are taken from the stack */
                case 8:
                    if ((ret = get_user_ual(arg8, sp_reg + 28)) != 0) {
                        goto done_syscall;
                    }
                case 7:
                    if ((ret = get_user_ual(arg7, sp_reg + 24)) != 0) {
                        goto done_syscall;
                    }
                case 6:
                    if ((ret = get_user_ual(arg6, sp_reg + 20)) != 0) {
                        goto done_syscall;
                    }
                case 5:
                    if ((ret = get_user_ual(arg5, sp_reg + 16)) != 0) {
                        goto done_syscall;
                    }
                default:
                    break;
                }
                ret = do_syscall(env, env->active_tc.gpr[2],
                                 env->active_tc.gpr[4],
                                 env->active_tc.gpr[5],
                                 env->active_tc.gpr[6],
                                 env->active_tc.gpr[7],
                                 arg5, arg6, arg7, arg8);
            }
done_syscall:
# else
            ret = do_syscall(env, env->active_tc.gpr[2],
                             env->active_tc.gpr[4], env->active_tc.gpr[5],
                             env->active_tc.gpr[6], env->active_tc.gpr[7],
                             env->active_tc.gpr[8], env->active_tc.gpr[9],
                             env->active_tc.gpr[10], env->active_tc.gpr[11]);
# endif /* O32 */
            if (ret == -TARGET_ERESTARTSYS) {
                env->active_tc.PC -= 4;
                break;
            }
            if (ret == -TARGET_QEMU_ESIGRETURN) {
                /* Returning from a successful sigreturn syscall.
                   Avoid clobbering register state.  */
                break;
            }
            if ((abi_ulong)ret >= (abi_ulong)-1133) {
                env->active_tc.gpr[7] = 1; /* error flag */
                ret = -ret;
            } else {
                env->active_tc.gpr[7] = 0; /* error flag */
            }
            env->active_tc.gpr[2] = ret;
            break;
        case EXCP_TLBL:
        case EXCP_TLBS:
        case EXCP_AdEL:
        case EXCP_AdES:
            info.si_signo = TARGET_SIGSEGV;
            info.si_errno = 0;
            /* XXX: check env->error_code */
            info.si_code = TARGET_SEGV_MAPERR;
            info._sifields._sigfault._addr = env->CP0_BadVAddr;
            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
            break;
        case EXCP_CpU:
        case EXCP_RI:
            info.si_signo = TARGET_SIGILL;
            info.si_errno = 0;
            info.si_code = 0;
            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
            break;
        case EXCP_INTERRUPT:
            /* just indicate that signals should be handled asap */
            break;
        case EXCP_DEBUG:
            info.si_signo = TARGET_SIGTRAP;
            info.si_errno = 0;
            info.si_code = TARGET_TRAP_BRKPT;
            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
            break;
        case EXCP_DSPDIS:
            info.si_signo = TARGET_SIGILL;
            info.si_errno = 0;
            info.si_code = TARGET_ILL_ILLOPC;
            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
            break;
        case EXCP_FPE:
            info.si_signo = TARGET_SIGFPE;
            info.si_errno = 0;
            info.si_code = TARGET_FPE_FLTUNK;
            if (GET_FP_CAUSE(env->active_fpu.fcr31) & FP_INVALID) {
                info.si_code = TARGET_FPE_FLTINV;
            } else if (GET_FP_CAUSE(env->active_fpu.fcr31) & FP_DIV0) {
                info.si_code = TARGET_FPE_FLTDIV;
            } else if (GET_FP_CAUSE(env->active_fpu.fcr31) & FP_OVERFLOW) {
                info.si_code = TARGET_FPE_FLTOVF;
            } else if (GET_FP_CAUSE(env->active_fpu.fcr31) & FP_UNDERFLOW) {
                info.si_code = TARGET_FPE_FLTUND;
            } else if (GET_FP_CAUSE(env->active_fpu.fcr31) & FP_INEXACT) {
                info.si_code = TARGET_FPE_FLTRES;
            }
            queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
            break;
        /* The code below was inspired by the MIPS Linux kernel trap
         * handling code in arch/mips/kernel/traps.c.
         */
        case EXCP_BREAK:
            {
                abi_ulong trap_instr;
                unsigned int code;

                if (env->hflags & MIPS_HFLAG_M16) {
                    if (env->insn_flags & ASE_MICROMIPS) {
                        /* microMIPS mode */
                        ret = get_user_u16(trap_instr, env->active_tc.PC);
                        if (ret != 0) {
                            goto error;
                        }

                        if ((trap_instr >> 10) == 0x11) {
                            /* 16-bit instruction */
                            code = trap_instr & 0xf;
                        } else {
                            /* 32-bit instruction */
                            abi_ulong instr_lo;

                            ret = get_user_u16(instr_lo,
                                               env->active_tc.PC + 2);
                            if (ret != 0) {
                                goto error;
                            }
                            trap_instr = (trap_instr << 16) | instr_lo;
                            code = ((trap_instr >> 6) & ((1 << 20) - 1));
                            /* Unfortunately, microMIPS also suffers from
                               the old assembler bug...  */
                            if (code >= (1 << 10)) {
                                code >>= 10;
                            }
                        }
                    } else {
                        /* MIPS16e mode */
                        ret = get_user_u16(trap_instr, env->active_tc.PC);
                        if (ret != 0) {
                            goto error;
                        }
                        code = (trap_instr >> 6) & 0x3f;
                    }
                } else {
                    ret = get_user_u32(trap_instr, env->active_tc.PC);
                    if (ret != 0) {
                        goto error;
                    }

                    /* As described in the original Linux kernel code, the
                     * below checks on 'code' are to work around an old
                     * assembly bug.
                     */
                    code = ((trap_instr >> 6) & ((1 << 20) - 1));
                    if (code >= (1 << 10)) {
                        code >>= 10;
                    }
                }

                if (do_break(env, &info, code) != 0) {
                    goto error;
                }
            }
            break;
        case EXCP_TRAP:
            {
                abi_ulong trap_instr;
                unsigned int code = 0;

                if (env->hflags & MIPS_HFLAG_M16) {
                    /* microMIPS mode */
                    abi_ulong instr[2];

                    ret = get_user_u16(instr[0], env->active_tc.PC) ||
                          get_user_u16(instr[1], env->active_tc.PC + 2);

                    trap_instr = (instr[0] << 16) | instr[1];
                } else {
                    ret = get_user_u32(trap_instr, env->active_tc.PC);
                }

                if (ret != 0) {
                    goto error;
                }

                /* The immediate versions don't provide a code.  */
                if (!(trap_instr & 0xFC000000)) {
                    if (env->hflags & MIPS_HFLAG_M16) {
                        /* microMIPS mode */
                        code = ((trap_instr >> 12) & ((1 << 4) - 1));
                    } else {
                        code = ((trap_instr >> 6) & ((1 << 10) - 1));
                    }
                }

                if (do_break(env, &info, code) != 0) {
                    goto error;
                }
            }
            break;
        case EXCP_ATOMIC:
            cpu_exec_step_atomic(cs);
            break;
        default:
error:
            EXCP_DUMP(env, "qemu: unhandled CPU exception 0x%x - aborting\n", trapnr);
            abort();
        }
        process_pending_signals(env);
    }
}

void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
{
    CPUState *cpu = env_cpu(env);
    TaskState *ts = cpu->opaque;
    struct image_info *info = ts->info;
    int i;

    struct mode_req {
        bool single;
        bool soft;
        bool fr1;
        bool frdefault;
        bool fre;
    };

    static const struct mode_req fpu_reqs[] = {
        [MIPS_ABI_FP_ANY]    = { true,  true,  true,  true,  true  },
        [MIPS_ABI_FP_DOUBLE] = { false, false, false, true,  true  },
        [MIPS_ABI_FP_SINGLE] = { true,  false, false, false, false },
        [MIPS_ABI_FP_SOFT]   = { false, true,  false, false, false },
        [MIPS_ABI_FP_OLD_64] = { false, false, false, false, false },
        [MIPS_ABI_FP_XX]     = { false, false, true,  true,  true  },
        [MIPS_ABI_FP_64]     = { false, false, true,  false, false },
        [MIPS_ABI_FP_64A]    = { false, false, true,  false, true  }
    };

    /*
     * Mode requirements when .MIPS.abiflags is not present in the ELF.
     * Not present means that everything is acceptable except FR1.
     */
    static struct mode_req none_req = { true, true, false, true, true };

    struct mode_req prog_req;
    struct mode_req interp_req;

    for(i = 0; i < 32; i++) {
        env->active_tc.gpr[i] = regs->regs[i];
    }
    env->active_tc.PC = regs->cp0_epc & ~(target_ulong)1;
    if (regs->cp0_epc & 1) {
        env->hflags |= MIPS_HFLAG_M16;
    }

#ifdef TARGET_ABI_MIPSO32
# define MAX_FP_ABI MIPS_ABI_FP_64A
#else
# define MAX_FP_ABI MIPS_ABI_FP_SOFT
#endif
     if ((info->fp_abi > MAX_FP_ABI && info->fp_abi != MIPS_ABI_FP_UNKNOWN)
        || (info->interp_fp_abi > MAX_FP_ABI &&
            info->interp_fp_abi != MIPS_ABI_FP_UNKNOWN)) {
        fprintf(stderr, "qemu: Unexpected FPU mode\n");
        exit(1);
    }

    prog_req = (info->fp_abi == MIPS_ABI_FP_UNKNOWN) ? none_req
                                            : fpu_reqs[info->fp_abi];
    interp_req = (info->interp_fp_abi == MIPS_ABI_FP_UNKNOWN) ? none_req
                                            : fpu_reqs[info->interp_fp_abi];

    prog_req.single &= interp_req.single;
    prog_req.soft &= interp_req.soft;
    prog_req.fr1 &= interp_req.fr1;
    prog_req.frdefault &= interp_req.frdefault;
    prog_req.fre &= interp_req.fre;

    bool cpu_has_mips_r2_r6 = env->insn_flags & ISA_MIPS32R2 ||
                              env->insn_flags & ISA_MIPS64R2 ||
                              env->insn_flags & ISA_MIPS32R6 ||
                              env->insn_flags & ISA_MIPS64R6;

    if (prog_req.fre && !prog_req.frdefault && !prog_req.fr1) {
        env->CP0_Config5 |= (1 << CP0C5_FRE);
        if (env->active_fpu.fcr0 & (1 << FCR0_FREP)) {
            env->hflags |= MIPS_HFLAG_FRE;
        }
    } else if ((prog_req.fr1 && prog_req.frdefault) ||
         (prog_req.single && !prog_req.frdefault)) {
        if ((env->active_fpu.fcr0 & (1 << FCR0_F64)
            && cpu_has_mips_r2_r6) || prog_req.fr1) {
            env->CP0_Status |= (1 << CP0St_FR);
            env->hflags |= MIPS_HFLAG_F64;
        }
    } else  if (!prog_req.fre && !prog_req.frdefault &&
          !prog_req.fr1 && !prog_req.single && !prog_req.soft) {
        fprintf(stderr, "qemu: Can't find a matching FPU mode\n");
        exit(1);
    }

    if (env->insn_flags & ISA_NANOMIPS32) {
        return;
    }
    if (((info->elf_flags & EF_MIPS_NAN2008) != 0) !=
        ((env->active_fpu.fcr31 & (1 << FCR31_NAN2008)) != 0)) {
        if ((env->active_fpu.fcr31_rw_bitmask &
              (1 << FCR31_NAN2008)) == 0) {
            fprintf(stderr, "ELF binary's NaN mode not supported by CPU\n");
            exit(1);
        }
        if ((info->elf_flags & EF_MIPS_NAN2008) != 0) {
            env->active_fpu.fcr31 |= (1 << FCR31_NAN2008);
        } else {
            env->active_fpu.fcr31 &= ~(1 << FCR31_NAN2008);
        }
        restore_snan_bit_mode(env);
    }
}