xref: /openbmc/qemu/linux-user/sparc/cpu_loop.c (revision 878502e5)
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.h"
22 #include "user-internals.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 static void next_instruction(CPUSPARCState *env)
153 {
154     env->pc = env->npc;
155     env->npc = env->npc + 4;
156 }
157 
158 static uint32_t do_getcc(CPUSPARCState *env)
159 {
160 #ifdef TARGET_SPARC64
161     return cpu_get_ccr(env) & 0xf;
162 #else
163     return extract32(cpu_get_psr(env), 20, 4);
164 #endif
165 }
166 
167 static void do_setcc(CPUSPARCState *env, uint32_t icc)
168 {
169 #ifdef TARGET_SPARC64
170     cpu_put_ccr(env, (cpu_get_ccr(env) & 0xf0) | (icc & 0xf));
171 #else
172     cpu_put_psr(env, deposit32(cpu_get_psr(env), 20, 4, icc));
173 #endif
174 }
175 
176 static uint32_t do_getpsr(CPUSPARCState *env)
177 {
178 #ifdef TARGET_SPARC64
179     const uint64_t TSTATE_CWP = 0x1f;
180     const uint64_t TSTATE_ICC = 0xfull << 32;
181     const uint64_t TSTATE_XCC = 0xfull << 36;
182     const uint32_t PSR_S      = 0x00000080u;
183     const uint32_t PSR_V8PLUS = 0xff000000u;
184     uint64_t tstate = sparc64_tstate(env);
185 
186     /* See <asm/psrcompat.h>, tstate_to_psr. */
187     return ((tstate & TSTATE_CWP)                   |
188             PSR_S                                   |
189             ((tstate & TSTATE_ICC) >> 12)           |
190             ((tstate & TSTATE_XCC) >> 20)           |
191             PSR_V8PLUS);
192 #else
193     return (cpu_get_psr(env) & (PSR_ICC | PSR_CWP)) | PSR_S;
194 #endif
195 }
196 
197 /* Avoid ifdefs below for the abi32 and abi64 paths. */
198 #ifdef TARGET_ABI32
199 #define TARGET_TT_SYSCALL  (TT_TRAP + 0x10) /* t_linux */
200 #else
201 #define TARGET_TT_SYSCALL  (TT_TRAP + 0x6d) /* tl0_linux64 */
202 #endif
203 
204 /* Avoid ifdefs below for the v9 and pre-v9 hw traps. */
205 #ifdef TARGET_SPARC64
206 #define TARGET_TT_SPILL  TT_SPILL
207 #define TARGET_TT_FILL   TT_FILL
208 #else
209 #define TARGET_TT_SPILL  TT_WIN_OVF
210 #define TARGET_TT_FILL   TT_WIN_UNF
211 #endif
212 
213 void cpu_loop (CPUSPARCState *env)
214 {
215     CPUState *cs = env_cpu(env);
216     int trapnr;
217     abi_long ret;
218 
219     while (1) {
220         cpu_exec_start(cs);
221         trapnr = cpu_exec(cs);
222         cpu_exec_end(cs);
223         process_queued_cpu_work(cs);
224 
225         switch (trapnr) {
226         case TARGET_TT_SYSCALL:
227             ret = do_syscall (env, env->gregs[1],
228                               env->regwptr[0], env->regwptr[1],
229                               env->regwptr[2], env->regwptr[3],
230                               env->regwptr[4], env->regwptr[5],
231                               0, 0);
232             if (ret == -QEMU_ERESTARTSYS || ret == -QEMU_ESIGRETURN) {
233                 break;
234             }
235             if ((abi_ulong)ret >= (abi_ulong)(-515)) {
236                 set_syscall_C(env, 1);
237                 ret = -ret;
238             } else {
239                 set_syscall_C(env, 0);
240             }
241             env->regwptr[0] = ret;
242             /* next instruction */
243             env->pc = env->npc;
244             env->npc = env->npc + 4;
245             break;
246 
247         case TT_TRAP + 0x01: /* breakpoint */
248         case EXCP_DEBUG:
249             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
250             break;
251 
252         case TT_TRAP + 0x02: /* div0 */
253         case TT_DIV_ZERO:
254             force_sig_fault(TARGET_SIGFPE, TARGET_FPE_INTDIV, env->pc);
255             break;
256 
257         case TT_TRAP + 0x03: /* flush windows */
258             flush_windows(env);
259             next_instruction(env);
260             break;
261 
262         case TT_TRAP + 0x20: /* getcc */
263             env->gregs[1] = do_getcc(env);
264             next_instruction(env);
265             break;
266         case TT_TRAP + 0x21: /* setcc */
267             do_setcc(env, env->gregs[1]);
268             next_instruction(env);
269             break;
270         case TT_TRAP + 0x22: /* getpsr */
271             env->gregs[1] = do_getpsr(env);
272             next_instruction(env);
273             break;
274 
275 #ifdef TARGET_SPARC64
276         case TT_TRAP + 0x6e:
277             flush_windows(env);
278             sparc64_get_context(env);
279             break;
280         case TT_TRAP + 0x6f:
281             flush_windows(env);
282             sparc64_set_context(env);
283             break;
284 #endif
285 
286         case TARGET_TT_SPILL: /* window overflow */
287             save_window(env);
288             break;
289         case TARGET_TT_FILL:  /* window underflow */
290             restore_window(env);
291             break;
292 
293         case TT_FP_EXCP:
294             {
295                 int code = TARGET_FPE_FLTUNK;
296                 target_ulong fsr = cpu_get_fsr(env);
297 
298                 if ((fsr & FSR_FTT_MASK) == FSR_FTT_IEEE_EXCP) {
299                     if (fsr & FSR_NVC) {
300                         code = TARGET_FPE_FLTINV;
301                     } else if (fsr & FSR_OFC) {
302                         code = TARGET_FPE_FLTOVF;
303                     } else if (fsr & FSR_UFC) {
304                         code = TARGET_FPE_FLTUND;
305                     } else if (fsr & FSR_DZC) {
306                         code = TARGET_FPE_FLTDIV;
307                     } else if (fsr & FSR_NXC) {
308                         code = TARGET_FPE_FLTRES;
309                     }
310                 }
311                 force_sig_fault(TARGET_SIGFPE, code, env->pc);
312             }
313             break;
314 
315         case EXCP_INTERRUPT:
316             /* just indicate that signals should be handled asap */
317             break;
318         case TT_ILL_INSN:
319             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
320             break;
321         case TT_PRIV_INSN:
322             force_sig_fault(TARGET_SIGILL, TARGET_ILL_PRVOPC, env->pc);
323             break;
324         case TT_TOVF:
325             force_sig_fault(TARGET_SIGEMT, TARGET_EMT_TAGOVF, env->pc);
326             break;
327 #ifdef TARGET_SPARC64
328         case TT_PRIV_ACT:
329             /* Note do_privact defers to do_privop. */
330             force_sig_fault(TARGET_SIGILL, TARGET_ILL_PRVOPC, env->pc);
331             break;
332 #else
333         case TT_NCP_INSN:
334             force_sig_fault(TARGET_SIGILL, TARGET_ILL_COPROC, env->pc);
335             break;
336         case TT_UNIMP_FLUSH:
337             next_instruction(env);
338             break;
339 #endif
340         case EXCP_ATOMIC:
341             cpu_exec_step_atomic(cs);
342             break;
343         default:
344             /*
345              * Most software trap numbers vector to BAD_TRAP.
346              * Handle anything not explicitly matched above.
347              */
348             if (trapnr >= TT_TRAP && trapnr <= TT_TRAP + 0x7f) {
349                 force_sig_fault(TARGET_SIGILL, ILL_ILLTRP, env->pc);
350                 break;
351             }
352             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
353             cpu_dump_state(cs, stderr, 0);
354             exit(EXIT_FAILURE);
355         }
356         process_pending_signals (env);
357     }
358 }
359 
360 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
361 {
362     int i;
363     env->pc = regs->pc;
364     env->npc = regs->npc;
365     env->y = regs->y;
366     for(i = 0; i < 8; i++)
367         env->gregs[i] = regs->u_regs[i];
368     for(i = 0; i < 8; i++)
369         env->regwptr[i] = regs->u_regs[i + 8];
370 }
371