xref: /openbmc/qemu/linux-user/sparc/cpu_loop.c (revision 2113aed687cb0b84ad512c440c1edf6eea8fcde2)
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 #include "signal-common.h"
25 
26 #define SPARC64_STACK_BIAS 2047
27 
28 //#define DEBUG_WIN
29 
30 /* WARNING: dealing with register windows _is_ complicated. More info
31    can be found at http://www.sics.se/~psm/sparcstack.html */
32 static inline int get_reg_index(CPUSPARCState *env, int cwp, int index)
33 {
34     index = (index + cwp * 16) % (16 * env->nwindows);
35     /* wrap handling : if cwp is on the last window, then we use the
36        registers 'after' the end */
37     if (index < 8 && env->cwp == env->nwindows - 1)
38         index += 16 * env->nwindows;
39     return index;
40 }
41 
42 /* save the register window 'cwp1' */
43 static inline void save_window_offset(CPUSPARCState *env, int cwp1)
44 {
45     unsigned int i;
46     abi_ulong sp_ptr;
47 
48     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
49 #ifdef TARGET_SPARC64
50     if (sp_ptr & 3)
51         sp_ptr += SPARC64_STACK_BIAS;
52 #endif
53 #if defined(DEBUG_WIN)
54     printf("win_overflow: sp_ptr=0x" TARGET_ABI_FMT_lx " save_cwp=%d\n",
55            sp_ptr, cwp1);
56 #endif
57     for(i = 0; i < 16; i++) {
58         /* FIXME - what to do if put_user() fails? */
59         put_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
60         sp_ptr += sizeof(abi_ulong);
61     }
62 }
63 
64 static void save_window(CPUSPARCState *env)
65 {
66 #ifndef TARGET_SPARC64
67     unsigned int new_wim;
68     new_wim = ((env->wim >> 1) | (env->wim << (env->nwindows - 1))) &
69         ((1LL << env->nwindows) - 1);
70     save_window_offset(env, cpu_cwp_dec(env, env->cwp - 2));
71     env->wim = new_wim;
72 #else
73     /*
74      * cansave is zero if the spill trap handler is triggered by `save` and
75      * nonzero if triggered by a `flushw`
76      */
77     save_window_offset(env, cpu_cwp_dec(env, env->cwp - env->cansave - 2));
78     env->cansave++;
79     env->canrestore--;
80 #endif
81 }
82 
83 static void restore_window(CPUSPARCState *env)
84 {
85 #ifndef TARGET_SPARC64
86     unsigned int new_wim;
87 #endif
88     unsigned int i, cwp1;
89     abi_ulong sp_ptr;
90 
91 #ifndef TARGET_SPARC64
92     new_wim = ((env->wim << 1) | (env->wim >> (env->nwindows - 1))) &
93         ((1LL << env->nwindows) - 1);
94 #endif
95 
96     /* restore the invalid window */
97     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
98     sp_ptr = env->regbase[get_reg_index(env, cwp1, 6)];
99 #ifdef TARGET_SPARC64
100     if (sp_ptr & 3)
101         sp_ptr += SPARC64_STACK_BIAS;
102 #endif
103 #if defined(DEBUG_WIN)
104     printf("win_underflow: sp_ptr=0x" TARGET_ABI_FMT_lx " load_cwp=%d\n",
105            sp_ptr, cwp1);
106 #endif
107     for(i = 0; i < 16; i++) {
108         /* FIXME - what to do if get_user() fails? */
109         get_user_ual(env->regbase[get_reg_index(env, cwp1, 8 + i)], sp_ptr);
110         sp_ptr += sizeof(abi_ulong);
111     }
112 #ifdef TARGET_SPARC64
113     env->canrestore++;
114     if (env->cleanwin < env->nwindows - 1)
115         env->cleanwin++;
116     env->cansave--;
117 #else
118     env->wim = new_wim;
119 #endif
120 }
121 
122 static void flush_windows(CPUSPARCState *env)
123 {
124     int offset, cwp1;
125 
126     offset = 1;
127     for(;;) {
128         /* if restore would invoke restore_window(), then we can stop */
129         cwp1 = cpu_cwp_inc(env, env->cwp + offset);
130 #ifndef TARGET_SPARC64
131         if (env->wim & (1 << cwp1))
132             break;
133 #else
134         if (env->canrestore == 0)
135             break;
136         env->cansave++;
137         env->canrestore--;
138 #endif
139         save_window_offset(env, cwp1);
140         offset++;
141     }
142     cwp1 = cpu_cwp_inc(env, env->cwp + 1);
143 #ifndef TARGET_SPARC64
144     /* set wim so that restore will reload the registers */
145     env->wim = 1 << cwp1;
146 #endif
147 #if defined(DEBUG_WIN)
148     printf("flush_windows: nb=%d\n", offset - 1);
149 #endif
150 }
151 
152 void cpu_loop (CPUSPARCState *env)
153 {
154     CPUState *cs = env_cpu(env);
155     int trapnr;
156     abi_long ret;
157     target_siginfo_t info;
158 
159     while (1) {
160         cpu_exec_start(cs);
161         trapnr = cpu_exec(cs);
162         cpu_exec_end(cs);
163         process_queued_cpu_work(cs);
164 
165         /* Compute PSR before exposing state.  */
166         if (env->cc_op != CC_OP_FLAGS) {
167             cpu_get_psr(env);
168         }
169 
170         switch (trapnr) {
171 #ifndef TARGET_SPARC64
172         case 0x88:
173         case 0x90:
174 #else
175         case 0x110:
176         case 0x16d:
177 #endif
178             ret = do_syscall (env, env->gregs[1],
179                               env->regwptr[0], env->regwptr[1],
180                               env->regwptr[2], env->regwptr[3],
181                               env->regwptr[4], env->regwptr[5],
182                               0, 0);
183             if (ret == -TARGET_ERESTARTSYS || ret == -TARGET_QEMU_ESIGRETURN) {
184                 break;
185             }
186             if ((abi_ulong)ret >= (abi_ulong)(-515)) {
187 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
188                 env->xcc |= PSR_CARRY;
189 #else
190                 env->psr |= PSR_CARRY;
191 #endif
192                 ret = -ret;
193             } else {
194 #if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
195                 env->xcc &= ~PSR_CARRY;
196 #else
197                 env->psr &= ~PSR_CARRY;
198 #endif
199             }
200             env->regwptr[0] = ret;
201             /* next instruction */
202             env->pc = env->npc;
203             env->npc = env->npc + 4;
204             break;
205         case 0x83: /* flush windows */
206 #ifdef TARGET_ABI32
207         case 0x103:
208 #endif
209             flush_windows(env);
210             /* next instruction */
211             env->pc = env->npc;
212             env->npc = env->npc + 4;
213             break;
214 #ifndef TARGET_SPARC64
215         case TT_WIN_OVF: /* window overflow */
216             save_window(env);
217             break;
218         case TT_WIN_UNF: /* window underflow */
219             restore_window(env);
220             break;
221         case TT_TFAULT:
222         case TT_DFAULT:
223             {
224                 info.si_signo = TARGET_SIGSEGV;
225                 info.si_errno = 0;
226                 /* XXX: check env->error_code */
227                 info.si_code = TARGET_SEGV_MAPERR;
228                 info._sifields._sigfault._addr = env->mmuregs[4];
229                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
230             }
231             break;
232 #else
233         case TT_SPILL: /* window overflow */
234             save_window(env);
235             break;
236         case TT_FILL: /* window underflow */
237             restore_window(env);
238             break;
239         case TT_TFAULT:
240         case TT_DFAULT:
241             {
242                 info.si_signo = TARGET_SIGSEGV;
243                 info.si_errno = 0;
244                 /* XXX: check env->error_code */
245                 info.si_code = TARGET_SEGV_MAPERR;
246                 if (trapnr == TT_DFAULT)
247                     info._sifields._sigfault._addr = env->dmmu.mmuregs[4];
248                 else
249                     info._sifields._sigfault._addr = cpu_tsptr(env)->tpc;
250                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
251             }
252             break;
253 #ifndef TARGET_ABI32
254         case 0x16e:
255             flush_windows(env);
256             sparc64_get_context(env);
257             break;
258         case 0x16f:
259             flush_windows(env);
260             sparc64_set_context(env);
261             break;
262 #endif
263 #endif
264         case EXCP_INTERRUPT:
265             /* just indicate that signals should be handled asap */
266             break;
267         case TT_ILL_INSN:
268             {
269                 info.si_signo = TARGET_SIGILL;
270                 info.si_errno = 0;
271                 info.si_code = TARGET_ILL_ILLOPC;
272                 info._sifields._sigfault._addr = env->pc;
273                 queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
274             }
275             break;
276         case EXCP_DEBUG:
277             info.si_signo = TARGET_SIGTRAP;
278             info.si_errno = 0;
279             info.si_code = TARGET_TRAP_BRKPT;
280             queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
281             break;
282         case EXCP_ATOMIC:
283             cpu_exec_step_atomic(cs);
284             break;
285         default:
286             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
287             cpu_dump_state(cs, stderr, 0);
288             exit(EXIT_FAILURE);
289         }
290         process_pending_signals (env);
291     }
292 }
293 
294 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
295 {
296     int i;
297     env->pc = regs->pc;
298     env->npc = regs->npc;
299     env->y = regs->y;
300     for(i = 0; i < 8; i++)
301         env->gregs[i] = regs->u_regs[i];
302     for(i = 0; i < 8; i++)
303         env->regwptr[i] = regs->u_regs[i + 8];
304 }
305