xref: /openbmc/qemu/linux-user/sparc/cpu_loop.c (revision d0bf492f)
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 #define syscall_cc         psr
201 #else
202 #define TARGET_TT_SYSCALL  (TT_TRAP + 0x6d) /* tl0_linux64 */
203 #define syscall_cc         xcc
204 #endif
205 
206 /* Avoid ifdefs below for the v9 and pre-v9 hw traps. */
207 #ifdef TARGET_SPARC64
208 #define TARGET_TT_SPILL  TT_SPILL
209 #define TARGET_TT_FILL   TT_FILL
210 #else
211 #define TARGET_TT_SPILL  TT_WIN_OVF
212 #define TARGET_TT_FILL   TT_WIN_UNF
213 #endif
214 
215 void cpu_loop (CPUSPARCState *env)
216 {
217     CPUState *cs = env_cpu(env);
218     int trapnr;
219     abi_long ret;
220 
221     while (1) {
222         cpu_exec_start(cs);
223         trapnr = cpu_exec(cs);
224         cpu_exec_end(cs);
225         process_queued_cpu_work(cs);
226 
227         /* Compute PSR before exposing state.  */
228         if (env->cc_op != CC_OP_FLAGS) {
229             cpu_get_psr(env);
230         }
231 
232         switch (trapnr) {
233         case TARGET_TT_SYSCALL:
234             ret = do_syscall (env, env->gregs[1],
235                               env->regwptr[0], env->regwptr[1],
236                               env->regwptr[2], env->regwptr[3],
237                               env->regwptr[4], env->regwptr[5],
238                               0, 0);
239             if (ret == -QEMU_ERESTARTSYS || ret == -QEMU_ESIGRETURN) {
240                 break;
241             }
242             if ((abi_ulong)ret >= (abi_ulong)(-515)) {
243                 env->syscall_cc |= PSR_CARRY;
244                 ret = -ret;
245             } else {
246                 env->syscall_cc &= ~PSR_CARRY;
247             }
248             env->regwptr[0] = ret;
249             /* next instruction */
250             env->pc = env->npc;
251             env->npc = env->npc + 4;
252             break;
253 
254         case TT_TRAP + 0x01: /* breakpoint */
255         case EXCP_DEBUG:
256             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->pc);
257             break;
258 
259         case TT_TRAP + 0x02: /* div0 */
260         case TT_DIV_ZERO:
261             force_sig_fault(TARGET_SIGFPE, TARGET_FPE_INTDIV, env->pc);
262             break;
263 
264         case TT_TRAP + 0x03: /* flush windows */
265             flush_windows(env);
266             next_instruction(env);
267             break;
268 
269         case TT_TRAP + 0x20: /* getcc */
270             env->gregs[1] = do_getcc(env);
271             next_instruction(env);
272             break;
273         case TT_TRAP + 0x21: /* setcc */
274             do_setcc(env, env->gregs[1]);
275             next_instruction(env);
276             break;
277         case TT_TRAP + 0x22: /* getpsr */
278             env->gregs[1] = do_getpsr(env);
279             next_instruction(env);
280             break;
281 
282 #ifdef TARGET_SPARC64
283         case TT_TRAP + 0x6e:
284             flush_windows(env);
285             sparc64_get_context(env);
286             break;
287         case TT_TRAP + 0x6f:
288             flush_windows(env);
289             sparc64_set_context(env);
290             break;
291 #endif
292 
293         case TARGET_TT_SPILL: /* window overflow */
294             save_window(env);
295             break;
296         case TARGET_TT_FILL:  /* window underflow */
297             restore_window(env);
298             break;
299 
300         case TT_FP_EXCP:
301             {
302                 int code = TARGET_FPE_FLTUNK;
303                 target_ulong fsr = env->fsr;
304 
305                 if ((fsr & FSR_FTT_MASK) == FSR_FTT_IEEE_EXCP) {
306                     if (fsr & FSR_NVC) {
307                         code = TARGET_FPE_FLTINV;
308                     } else if (fsr & FSR_OFC) {
309                         code = TARGET_FPE_FLTOVF;
310                     } else if (fsr & FSR_UFC) {
311                         code = TARGET_FPE_FLTUND;
312                     } else if (fsr & FSR_DZC) {
313                         code = TARGET_FPE_FLTDIV;
314                     } else if (fsr & FSR_NXC) {
315                         code = TARGET_FPE_FLTRES;
316                     }
317                 }
318                 force_sig_fault(TARGET_SIGFPE, code, env->pc);
319             }
320             break;
321 
322         case EXCP_INTERRUPT:
323             /* just indicate that signals should be handled asap */
324             break;
325         case TT_ILL_INSN:
326             force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPC, env->pc);
327             break;
328         case TT_PRIV_INSN:
329             force_sig_fault(TARGET_SIGILL, TARGET_ILL_PRVOPC, env->pc);
330             break;
331         case TT_TOVF:
332             force_sig_fault(TARGET_SIGEMT, TARGET_EMT_TAGOVF, env->pc);
333             break;
334 #ifdef TARGET_SPARC64
335         case TT_PRIV_ACT:
336             /* Note do_privact defers to do_privop. */
337             force_sig_fault(TARGET_SIGILL, TARGET_ILL_PRVOPC, env->pc);
338             break;
339 #else
340         case TT_NCP_INSN:
341             force_sig_fault(TARGET_SIGILL, TARGET_ILL_COPROC, env->pc);
342             break;
343         case TT_UNIMP_FLUSH:
344             next_instruction(env);
345             break;
346 #endif
347         case EXCP_ATOMIC:
348             cpu_exec_step_atomic(cs);
349             break;
350         default:
351             /*
352              * Most software trap numbers vector to BAD_TRAP.
353              * Handle anything not explicitly matched above.
354              */
355             if (trapnr >= TT_TRAP && trapnr <= TT_TRAP + 0x7f) {
356                 force_sig_fault(TARGET_SIGILL, ILL_ILLTRP, env->pc);
357                 break;
358             }
359             fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr);
360             cpu_dump_state(cs, stderr, 0);
361             exit(EXIT_FAILURE);
362         }
363         process_pending_signals (env);
364     }
365 }
366 
367 void target_cpu_copy_regs(CPUArchState *env, struct target_pt_regs *regs)
368 {
369     int i;
370     env->pc = regs->pc;
371     env->npc = regs->npc;
372     env->y = regs->y;
373     for(i = 0; i < 8; i++)
374         env->gregs[i] = regs->u_regs[i];
375     for(i = 0; i < 8; i++)
376         env->regwptr[i] = regs->u_regs[i + 8];
377 }
378