xref: /openbmc/qemu/linux-user/sparc/cpu_loop.c (revision 3d9569b8)
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 "cpu_loop-common.h"
24 
25 #define SPARC64_STACK_BIAS 2047
26 
27 //#define DEBUG_WIN
28 
29 /* WARNING: dealing with register windows _is_ complicated. More info
30    can be found at http://www.sics.se/~psm/sparcstack.html */
31 static inline int get_reg_index(CPUSPARCState *env, int cwp, int index)
32 {
33     index = (index + cwp * 16) % (16 * env->nwindows);
34     /* wrap handling : if cwp is on the last window, then we use the
35        registers 'after' the end */
36     if (index < 8 && env->cwp == env->nwindows - 1)
37         index += 16 * env->nwindows;
38     return index;
39 }
40 
41 /* save the register window 'cwp1' */
42 static inline void save_window_offset(CPUSPARCState *env, int cwp1)
43 {
44     unsigned int i;
45     abi_ulong sp_ptr;
46 
47     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
48 #ifdef TARGET_SPARC64
49     if (sp_ptr & 3)
50         sp_ptr += SPARC64_STACK_BIAS;
51 #endif
52 #if defined(DEBUG_WIN)
53     printf("win_overflow: sp_ptr=0x" TARGET_ABI_FMT_lx " save_cwp=%d\n",
54            sp_ptr, cwp1);
55 #endif
56     for(i = 0; i < 16; i++) {
57         /* FIXME - what to do if put_user() fails? */
58         put_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
59         sp_ptr += sizeof(abi_ulong);
60     }
61 }
62 
63 static void save_window(CPUSPARCState *env)
64 {
65 #ifndef TARGET_SPARC64
66     unsigned int new_wim;
67     new_wim = ((env->wim >> 1) | (env->wim << (env->nwindows - 1))) &
68         ((1LL << env->nwindows) - 1);
69     save_window_offset(env, cpu_cwp_dec(env, env->cwp - 2));
70     env->wim = new_wim;
71 #else
72     save_window_offset(env, cpu_cwp_dec(env, env->cwp - 2));
73     env->cansave++;
74     env->canrestore--;
75 #endif
76 }
77 
78 static void restore_window(CPUSPARCState *env)
79 {
80 #ifndef TARGET_SPARC64
81     unsigned int new_wim;
82 #endif
83     unsigned int i, cwp1;
84     abi_ulong sp_ptr;
85 
86 #ifndef TARGET_SPARC64
87     new_wim = ((env->wim << 1) | (env->wim >> (env->nwindows - 1))) &
88         ((1LL << env->nwindows) - 1);
89 #endif
90 
91     /* restore the invalid window */
92     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
93     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
94 #ifdef TARGET_SPARC64
95     if (sp_ptr & 3)
96         sp_ptr += SPARC64_STACK_BIAS;
97 #endif
98 #if defined(DEBUG_WIN)
99     printf("win_underflow: sp_ptr=0x" TARGET_ABI_FMT_lx " load_cwp=%d\n",
100            sp_ptr, cwp1);
101 #endif
102     for(i = 0; i < 16; i++) {
103         /* FIXME - what to do if get_user() fails? */
104         get_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
105         sp_ptr += sizeof(abi_ulong);
106     }
107 #ifdef TARGET_SPARC64
108     env->canrestore++;
109     if (env->cleanwin < env->nwindows - 1)
110         env->cleanwin++;
111     env->cansave--;
112 #else
113     env->wim = new_wim;
114 #endif
115 }
116 
117 static void flush_windows(CPUSPARCState *env)
118 {
119     int offset, cwp1;
120 
121     offset = 1;
122     for(;;) {
123         /* if restore would invoke restore_window(), then we can stop */
124         cwp1 = cpu_cwp_inc(env, env->cwp + offset);
125 #ifndef TARGET_SPARC64
126         if (env->wim & (1 << cwp1))
127             break;
128 #else
129         if (env->canrestore == 0)
130             break;
131         env->cansave++;
132         env->canrestore--;
133 #endif
134         save_window_offset(env, cwp1);
135         offset++;
136     }
137     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
138 #ifndef TARGET_SPARC64
139     /* set wim so that restore will reload the registers */
140     env->wim = 1 << cwp1;
141 #endif
142 #if defined(DEBUG_WIN)
143     printf("flush_windows: nb=%d\n", offset - 1);
144 #endif
145 }
146 
147 void cpu_loop (CPUSPARCState *env)
148 {
149     CPUState *cs = env_cpu(env);
150     int trapnr;
151     abi_long ret;
152     target_siginfo_t info;
153 
154     while (1) {
155         cpu_exec_start(cs);
156         trapnr = cpu_exec(cs);
157         cpu_exec_end(cs);
158         process_queued_cpu_work(cs);
159 
160         /* Compute PSR before exposing state.  */
161         if (env->cc_op != CC_OP_FLAGS) {
162             cpu_get_psr(env);
163         }
164 
165         switch (trapnr) {
166 #ifndef TARGET_SPARC64
167         case 0x88:
168         case 0x90:
169 #else
170         case 0x110:
171         case 0x16d:
172 #endif
173             ret = do_syscall (env, env->gregs[1],
174                               env->regwptr[0], env->regwptr[1],
175                               env->regwptr[2], env->regwptr[3],
176                               env->regwptr[4], env->regwptr[5],
177                               0, 0);
178             if (ret == -TARGET_ERESTARTSYS || ret == -TARGET_QEMU_ESIGRETURN) {
179                 break;
180             }
181             if ((abi_ulong)ret >= (abi_ulong)(-515)) {
182 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
183                 env->xcc |= PSR_CARRY;
184 #else
185                 env->psr |= PSR_CARRY;
186 #endif
187                 ret = -ret;
188             } else {
189 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
190                 env->xcc &= ~PSR_CARRY;
191 #else
192                 env->psr &= ~PSR_CARRY;
193 #endif
194             }
195             env->regwptr[0] = ret;
196             /* next instruction */
197             env->pc = env->npc;
198             env->npc = env->npc + 4;
199             break;
200         case 0x83: /* flush windows */
201 #ifdef TARGET_ABI32
202         case 0x103:
203 #endif
204             flush_windows(env);
205             /* next instruction */
206             env->pc = env->npc;
207             env->npc = env->npc + 4;
208             break;
209 #ifndef TARGET_SPARC64
210         case TT_WIN_OVF: /* window overflow */
211             save_window(env);
212             break;
213         case TT_WIN_UNF: /* window underflow */
214             restore_window(env);
215             break;
216         case TT_TFAULT:
217         case TT_DFAULT:
218             {
219                 info.si_signo = TARGET_SIGSEGV;
220                 info.si_errno = 0;
221                 /* XXX: check env->error_code */
222                 info.si_code = TARGET_SEGV_MAPERR;
223                 info._sifields._sigfault._addr = env->mmuregs[4];
224                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
225             }
226             break;
227 #else
228         case TT_SPILL: /* window overflow */
229             save_window(env);
230             break;
231         case TT_FILL: /* window underflow */
232             restore_window(env);
233             break;
234         case TT_TFAULT:
235         case TT_DFAULT:
236             {
237                 info.si_signo = TARGET_SIGSEGV;
238                 info.si_errno = 0;
239                 /* XXX: check env->error_code */
240                 info.si_code = TARGET_SEGV_MAPERR;
241                 if (trapnr == TT_DFAULT)
242                     info._sifields._sigfault._addr = env->dmmu.mmuregs[4];
243                 else
244                     info._sifields._sigfault._addr = cpu_tsptr(env)->tpc;
245                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
246             }
247             break;
248 #ifndef TARGET_ABI32
249         case 0x16e:
250             flush_windows(env);
251             sparc64_get_context(env);
252             break;
253         case 0x16f:
254             flush_windows(env);
255             sparc64_set_context(env);
256             break;
257 #endif
258 #endif
259         case EXCP_INTERRUPT:
260             /* just indicate that signals should be handled asap */
261             break;
262         case TT_ILL_INSN:
263             {
264                 info.si_signo = TARGET_SIGILL;
265                 info.si_errno = 0;
266                 info.si_code = TARGET_ILL_ILLOPC;
267                 info._sifields._sigfault._addr = env->pc;
268                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
269             }
270             break;
271         case EXCP_DEBUG:
272             info.si_signo = TARGET_SIGTRAP;
273             info.si_errno = 0;
274             info.si_code = TARGET_TRAP_BRKPT;
275             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
276             break;
277         case EXCP_ATOMIC:
278             cpu_exec_step_atomic(cs);
279             break;
280         default:
281             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
282             cpu_dump_state(cs, stderr, 0);
283             exit(EXIT_FAILURE);
284         }
285         process_pending_signals (env);
286     }
287 }
288 
289 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
290 {
291     int i;
292     env->pc = regs->pc;
293     env->npc = regs->npc;
294     env->y = regs->y;
295     for(i = 0; i < 8; i++)
296         env->gregs[i] = regs->u_regs[i];
297     for(i = 0; i < 8; i++)
298         env->regwptr[i] = regs->u_regs[i + 8];
299 }
300