linux-user/sparc/cpu_loop.c

   1 /*
   2  *  qemu user cpu loop
   3  *
   4  *  Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program 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
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "qemu-common.h"
  22 #include "qemu.h"
  23 #include "user-internals.h"
  24 #include "cpu_loop-common.h"
  25 #include "signal-common.h"
  26
  27 #define SPARC64_STACK_BIAS 2047
  28
  29 //#define DEBUG_WIN
  30
  31 /* WARNING: dealing with register windows _is_ complicated. More info
  32    can be found at http://www.sics.se/~psm/sparcstack.html */
  33 static inline int get_reg_index(CPUSPARCState *env, int cwp, int index)
  34 {
  35     index = (index + cwp * 16) % (16 * env->nwindows);
  36     /* wrap handling : if cwp is on the last window, then we use the
  37        registers 'after' the end */
  38     if (index < 8 && env->cwp == env->nwindows - 1)
  39         index += 16 * env->nwindows;
  40     return index;
  41 }
  42
  43 /* save the register window 'cwp1' */
  44 static inline void save_window_offset(CPUSPARCState *env, int cwp1)
  45 {
  46     unsigned int i;
  47     abi_ulong sp_ptr;
  48
  49     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
  50 #ifdef TARGET_SPARC64
  51     if (sp_ptr & 3)
  52         sp_ptr += SPARC64_STACK_BIAS;
  53 #endif
  54 #if defined(DEBUG_WIN)
  55     printf("win_overflow: sp_ptr=0x" TARGET_ABI_FMT_lx " save_cwp=%d\n",
  56            sp_ptr, cwp1);
  57 #endif
  58     for(i = 0; i < 16; i++) {
  59         /* FIXME - what to do if put_user() fails? */
  60         put_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
  61         sp_ptr += sizeof(abi_ulong);
  62     }
  63 }
  64
  65 static void save_window(CPUSPARCState *env)
  66 {
  67 #ifndef TARGET_SPARC64
  68     unsigned int new_wim;
  69     new_wim = ((env->wim >> 1) | (env->wim << (env->nwindows - 1))) &
  70         ((1LL << env->nwindows) - 1);
  71     save_window_offset(env, cpu_cwp_dec(env, env->cwp - 2));
  72     env->wim = new_wim;
  73 #else
  74     /*
  75      * cansave is zero if the spill trap handler is triggered by `save` and
  76      * nonzero if triggered by a `flushw`
  77      */
  78     save_window_offset(env, cpu_cwp_dec(env, env->cwp - env->cansave - 2));
  79     env->cansave++;
  80     env->canrestore--;
  81 #endif
  82 }
  83
  84 static void restore_window(CPUSPARCState *env)
  85 {
  86 #ifndef TARGET_SPARC64
  87     unsigned int new_wim;
  88 #endif
  89     unsigned int i, cwp1;
  90     abi_ulong sp_ptr;
  91
  92 #ifndef TARGET_SPARC64
  93     new_wim = ((env->wim << 1) | (env->wim >> (env->nwindows - 1))) &
  94         ((1LL << env->nwindows) - 1);
  95 #endif
  96
  97     /* restore the invalid window */
  98     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
  99     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
 100 #ifdef TARGET_SPARC64
 101     if (sp_ptr & 3)
 102         sp_ptr += SPARC64_STACK_BIAS;
 103 #endif
 104 #if defined(DEBUG_WIN)
 105     printf("win_underflow: sp_ptr=0x" TARGET_ABI_FMT_lx " load_cwp=%d\n",
 106            sp_ptr, cwp1);
 107 #endif
 108     for(i = 0; i < 16; i++) {
 109         /* FIXME - what to do if get_user() fails? */
 110         get_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
 111         sp_ptr += sizeof(abi_ulong);
 112     }
 113 #ifdef TARGET_SPARC64
 114     env->canrestore++;
 115     if (env->cleanwin < env->nwindows - 1)
 116         env->cleanwin++;
 117     env->cansave--;
 118 #else
 119     env->wim = new_wim;
 120 #endif
 121 }
 122
 123 static void flush_windows(CPUSPARCState *env)
 124 {
 125     int offset, cwp1;
 126
 127     offset = 1;
 128     for(;;) {
 129         /* if restore would invoke restore_window(), then we can stop */
 130         cwp1 = cpu_cwp_inc(env, env->cwp + offset);
 131 #ifndef TARGET_SPARC64
 132         if (env->wim & (1 << cwp1))
 133             break;
 134 #else
 135         if (env->canrestore == 0)
 136             break;
 137         env->cansave++;
 138         env->canrestore--;
 139 #endif
 140         save_window_offset(env, cwp1);
 141         offset++;
 142     }
 143     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
 144 #ifndef TARGET_SPARC64
 145     /* set wim so that restore will reload the registers */
 146     env->wim = 1 << cwp1;
 147 #endif
 148 #if defined(DEBUG_WIN)
 149     printf("flush_windows: nb=%d\n", offset - 1);
 150 #endif
 151 }
 152
 153 void cpu_loop (CPUSPARCState *env)
 154 {
 155     CPUState *cs = env_cpu(env);
 156     int trapnr;
 157     abi_long ret;
 158     target_siginfo_t info;
 159
 160     while (1) {
 161         cpu_exec_start(cs);
 162         trapnr = cpu_exec(cs);
 163         cpu_exec_end(cs);
 164         process_queued_cpu_work(cs);
 165
 166         /* Compute PSR before exposing state.  */
 167         if (env->cc_op != CC_OP_FLAGS) {
 168             cpu_get_psr(env);
 169         }
 170
 171         switch (trapnr) {
 172 #ifndef TARGET_SPARC64
 173         case 0x88:
 174         case 0x90:
 175 #else
 176         case 0x110:
 177         case 0x16d:
 178 #endif
 179             ret = do_syscall (env, env->gregs[1],
 180                               env->regwptr[0], env->regwptr[1],
 181                               env->regwptr[2], env->regwptr[3],
 182                               env->regwptr[4], env->regwptr[5],
 183                               0, 0);
 184             if (ret == -TARGET_ERESTARTSYS || ret == -TARGET_QEMU_ESIGRETURN) {
 185                 break;
 186             }
 187             if ((abi_ulong)ret >= (abi_ulong)(-515)) {
 188 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
 189                 env->xcc |= PSR_CARRY;
 190 #else
 191                 env->psr |= PSR_CARRY;
 192 #endif
 193                 ret = -ret;
 194             } else {
 195 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
 196                 env->xcc &= ~PSR_CARRY;
 197 #else
 198                 env->psr &= ~PSR_CARRY;
 199 #endif
 200             }
 201             env->regwptr[0] = ret;
 202             /* next instruction */
 203             env->pc = env->npc;
 204             env->npc = env->npc + 4;
 205             break;
 206         case 0x83: /* flush windows */
 207 #ifdef TARGET_ABI32
 208         case 0x103:
 209 #endif
 210             flush_windows(env);
 211             /* next instruction */
 212             env->pc = env->npc;
 213             env->npc = env->npc + 4;
 214             break;
 215 #ifndef TARGET_SPARC64
 216         case TT_WIN_OVF: /* window overflow */
 217             save_window(env);
 218             break;
 219         case TT_WIN_UNF: /* window underflow */
 220             restore_window(env);
 221             break;
 222 #else
 223         case TT_SPILL: /* window overflow */
 224             save_window(env);
 225             break;
 226         case TT_FILL: /* window underflow */
 227             restore_window(env);
 228             break;
 229 #ifndef TARGET_ABI32
 230         case 0x16e:
 231             flush_windows(env);
 232             sparc64_get_context(env);
 233             break;
 234         case 0x16f:
 235             flush_windows(env);
 236             sparc64_set_context(env);
 237             break;
 238 #endif
 239 #endif
 240         case EXCP_INTERRUPT:
 241             /* just indicate that signals should be handled asap */
 242             break;
 243         case TT_ILL_INSN:
 244             {
 245                 info.si_signo = TARGET_SIGILL;
 246                 info.si_errno = 0;
 247                 info.si_code = TARGET_ILL_ILLOPC;
 248                 info._sifields._sigfault._addr = env->pc;
 249                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
 250             }
 251             break;
 252         case EXCP_DEBUG:
 253             info.si_signo = TARGET_SIGTRAP;
 254             info.si_errno = 0;
 255             info.si_code = TARGET_TRAP_BRKPT;
 256             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
 257             break;
 258         case EXCP_ATOMIC:
 259             cpu_exec_step_atomic(cs);
 260             break;
 261         default:
 262             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
 263             cpu_dump_state(cs, stderr, 0);
 264             exit(EXIT_FAILURE);
 265         }
 266         process_pending_signals (env);
 267     }
 268 }
 269
 270 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
 271 {
 272     int i;
 273     env->pc = regs->pc;
 274     env->npc = regs->npc;
 275     env->y = regs->y;
 276     for(i = 0; i < 8; i++)
 277         env->gregs[i] = regs->u_regs[i];
 278     for(i = 0; i < 8; i++)
 279         env->regwptr[i] = regs->u_regs[i + 8];
 280 }