2009-04-11 Zoltan Varga <vargaz@gmail.com>
[mono.git] / mono / mini / tramp-s390x.c
1 /*------------------------------------------------------------------*/
2 /*                                                                  */
3 /* Name        - tramp-s390.c                                       */
4 /*                                                                  */
5 /* Function    - JIT trampoline code for S/390.                     */
6 /*                                                                  */
7 /* Name        - Neale Ferguson (Neale.Ferguson@SoftwareAG-usa.com) */
8 /*                                                                  */
9 /* Date        - January, 2004                                      */
10 /*                                                                  */
11 /* Derivation  - From exceptions-x86 & exceptions-ppc               */
12 /*               Paolo Molaro (lupus@ximian.com)                    */
13 /*               Dietmar Maurer (dietmar@ximian.com)                */
14 /*                                                                  */
15 /* Copyright   - 2001 Ximian, Inc.                                  */
16 /*                                                                  */
17 /*------------------------------------------------------------------*/
18
19 /*------------------------------------------------------------------*/
20 /*                 D e f i n e s                                    */
21 /*------------------------------------------------------------------*/
22
23 #define GR_SAVE_SIZE            4*sizeof(long)
24 #define FP_SAVE_SIZE            16*sizeof(double)
25 #define METHOD_SAVE_OFFSET      S390_MINIMAL_STACK_SIZE
26 #define CREATE_GR_OFFSET        METHOD_SAVE_OFFSET+8
27 #define CREATE_FP_OFFSET        CREATE_GR_OFFSET+GR_SAVE_SIZE
28 #define CREATE_LMF_OFFSET       CREATE_FP_OFFSET+FP_SAVE_SIZE
29 #define CREATE_STACK_SIZE       (CREATE_LMF_OFFSET+2*sizeof(long)+sizeof(MonoLMF))
30
31 /*------------------------------------------------------------------*/
32 /* Method-specific trampoline code fragment sizes                   */
33 /*------------------------------------------------------------------*/
34 #define SPECIFIC_TRAMPOLINE_SIZE        96
35
36 /*========================= End of Defines =========================*/
37
38 /*------------------------------------------------------------------*/
39 /*                 I n c l u d e s                                  */
40 /*------------------------------------------------------------------*/
41
42 #include <config.h>
43 #include <glib.h>
44 #include <string.h>
45
46 #include <mono/metadata/appdomain.h>
47 #include <mono/metadata/marshal.h>
48 #include <mono/metadata/tabledefs.h>
49 #include <mono/arch/s390x/s390x-codegen.h>
50
51 #include "mini.h"
52 #include "mini-s390x.h"
53
54 /*========================= End of Includes ========================*/
55
56 /*------------------------------------------------------------------*/
57 /*                 T y p e d e f s                                  */
58 /*------------------------------------------------------------------*/
59
60 /*========================= End of Typedefs ========================*/
61
62 /*------------------------------------------------------------------*/
63 /*                   P r o t o t y p e s                            */
64 /*------------------------------------------------------------------*/
65
66 /*========================= End of Prototypes ======================*/
67
68 /*------------------------------------------------------------------*/
69 /*                 G l o b a l   V a r i a b l e s                  */
70 /*------------------------------------------------------------------*/
71
72
73 /*====================== End of Global Variables ===================*/
74
75 /*------------------------------------------------------------------*/
76 /*                                                                  */
77 /* Name         - mono_arch_get_unbox_trampoline                        */
78 /*                                                                  */
79 /* Function     - Return a pointer to a trampoline which does the   */
80 /*                unboxing before calling the method.               */
81 /*                                                                  */
82 /*                When value type methods are called through the    */
83 /*                vtable we need to unbox the 'this' argument.      */
84 /*                                                                  */
85 /* Parameters   - gsctx  - Generic sharing context                  */
86 /*                method - Methd pointer                            */
87 /*                addr   - Pointer to native code for method        */
88 /*                                                                  */
89 /*------------------------------------------------------------------*/
90
91 gpointer
92 mono_arch_get_unbox_trampoline (MonoGenericSharingContext *gsctx, MonoMethod *method, gpointer addr)
93 {
94         guint8 *code, *start;
95         int this_pos = s390_r2;
96         MonoDomain *domain = mono_domain_get ();
97
98         start = addr;
99         if (MONO_TYPE_ISSTRUCT (mono_method_signature (method)->ret))
100                 this_pos = s390_r3;
101
102         start = code = mono_domain_code_reserve (domain, 28);
103
104         s390_basr (code, s390_r1, 0);
105         s390_j    (code, 6);
106         s390_llong(code, addr);
107         s390_lg   (code, s390_r1, 0, s390_r1, 4);
108         s390_aghi (code, this_pos, sizeof(MonoObject));
109         s390_br   (code, s390_r1);
110
111         g_assert ((code - start) <= 28);
112
113         mono_arch_flush_icache (start, code - start);
114
115         return start;
116 }
117
118 /*========================= End of Function ========================*/
119
120 /*------------------------------------------------------------------*/
121 /*                                                                  */
122 /* Name         - mono_arch_patch_callsite                              */
123 /*                                                                  */
124 /* Function     - Patch a non-virtual callsite so it calls @addr.       */
125 /*                                                                  */
126 /*------------------------------------------------------------------*/
127
128 void
129 mono_arch_patch_callsite (guint8 *method_start, guint8 *orig_code, guint8 *addr)
130 {
131         gint32 displace;
132         unsigned short opcode;
133
134         opcode = *((unsigned short *) (orig_code - 6));
135         if (opcode == 0xc0e5) {
136                 /* This is the 'brasl' instruction */
137                 orig_code    -= 4;
138                 displace = ((gssize) addr - (gssize) (orig_code - 2)) / 2;
139                 s390_patch_rel (orig_code, displace);
140                 mono_arch_flush_icache (orig_code, 4);
141         } else {
142                 /* This should be a 'lg %r14,4(%r13)' then a 'basr r14, r14' instruction */
143                 g_assert (orig_code [-8] == 0xe3);
144                 g_assert (orig_code [-7] == 0xe0);
145                 g_assert (orig_code [-6] == 0xd0);
146                 g_assert (orig_code [-5] == 0x04);
147                 g_assert (orig_code [-4] == 0x00);
148                 g_assert (orig_code [-3] == 0x04);
149                 opcode = *((unsigned short*) (orig_code - 2));
150                 g_assert (opcode == 0x0dee);
151
152                 /* The call address is stored in the 8 bytes preceeding the basr instruction */
153                 s390_patch_addr(orig_code - 16, (gssize)addr);
154                 mono_arch_flush_icache (orig_code - 16, 8);
155         }
156 }
157
158 /*========================= End of Function ========================*/
159
160 void
161 mono_arch_patch_plt_entry (guint8 *code, guint8 *addr)
162 {
163         g_assert_not_reached ();
164 }
165
166 /*========================= End of Function ========================*/
167
168 /*------------------------------------------------------------------*/
169 /*                                                                  */
170 /* Name         - mono_arch_nullify_class_init_trampoline               */
171 /*                                                                  */
172 /* Function     - Nullify a call which calls a class init trampoline    */
173 /*                                                                  */
174 /*------------------------------------------------------------------*/
175
176 void
177 mono_arch_nullify_class_init_trampoline (guint8 *code, gssize *regs)
178 {
179         char patch[2] = {0x07, 0x00};
180
181         code = code - 2;
182
183         memcpy(code, patch, sizeof(patch));
184 }
185
186 /*========================= End of Function ========================*/
187
188 void
189 mono_arch_nullify_plt_entry (guint8 *code)
190 {
191         g_assert_not_reached ();
192 }
193
194 /*========================= End of Function ========================*/
195
196 /*------------------------------------------------------------------*/
197 /*                                                                  */
198 /* Name         - mono_arch_get_vcall_slot                              */
199 /*                                                                  */
200 /* Function     - This method is called by the arch independent         */
201 /*            trampoline code to determine the vtable slot used by  */
202 /*            the call which invoked the trampoline.                */
203 /*                                                                  */
204 /* Parameters   - code   - Pointer into caller code                 */
205 /*                regs   - Register state at the point of the call  */
206 /*                displacement - Out parameter which will receive   */
207 /*                the displacement of the vtable slot               */
208 /*                                                                  */
209 /*------------------------------------------------------------------*/
210
211 gpointer
212 mono_arch_get_vcall_slot (guint8 *code, gpointer *regs, int *displacement)
213 {
214         int reg, lkReg;
215         guchar* base;
216         unsigned short opcode;
217         char *sp;
218
219         // We are passed sp instead of the register array
220         sp = (char*)regs;
221
222         *displacement = 0;
223
224         opcode = *((unsigned short *) (code - 6));
225         if (opcode == 0xc0e5)
226                 /* This is the 'brasl' instruction */
227                 return NULL;
228
229         /*-----------------------------------*/
230         /* This is a bras r14,Rz instruction */
231         /* If it's preceded by a LG Rx,d(Ry) */
232         /* If Rz == 1 then this is virtual   */
233         /* call.                             */
234         /*-----------------------------------*/
235         code    -= 6;
236
237         /*-----------------------------------*/
238         /* If call is preceded by LGR then   */
239         /* there's nothing to patch          */
240         /*-----------------------------------*/
241         if ((code[0] == 0xb9) &&
242                 (code[1] == 0x04))
243                 return NULL;
244
245         /*-----------------------------------*/
246         /* We back up until we're pointing at*/
247         /* the base/displacement portion of  */
248         /* the LG instruction                */
249         /*-----------------------------------*/
250         lkReg    = code[5] & 0x0f;
251
252         /*-----------------------------------*/
253         /* The LG instruction has format:    */
254         /* E3x0ylllhh04 - where:             */
255         /* x = Rx; y = Ry;                   */
256         /* lll = low 12 bits of displacement */
257         /* hh  = high 8 bits of displacement */
258         /*-----------------------------------*/
259         reg      = code[0] >> 4;
260         *displacement = (code[2] << 12) +
261                 ((code[0] & 0x0f) << 8) +
262                 code[1];
263
264         if (reg > 5)
265                 base = *((guchar **) (sp + S390_REG_SAVE_OFFSET +
266                                                           sizeof(long)*(reg-6)));
267         else
268                 base = *((guchar **) ((sp - CREATE_STACK_SIZE) +
269                                                           CREATE_GR_OFFSET +
270                                                           sizeof(long)*(reg-2)));
271         if (lkReg != 1)
272                 /* Non virtual call */
273                 return NULL;
274
275         return base;
276 }
277
278 /*========================= End of Function ========================*/
279
280 gpointer*
281 mono_arch_get_vcall_slot_addr (guint8* code, gpointer *regs)
282 {
283         gpointer vt;
284         int displacement;
285         vt = mono_arch_get_vcall_slot (code, regs, &displacement);
286         if (!vt)
287                 return NULL;
288         return (gpointer*)((char*)vt + displacement);
289 }
290
291 /*========================= End of Function ========================*/
292
293 /*------------------------------------------------------------------*/
294 /*                                                                  */
295 /* Name         - mono_arch_create_trampoline_code                            */
296 /*                                                                  */
297 /* Function     - Create the designated type of trampoline according*/
298 /*                to the 'tramp_type' parameter.                    */
299 /*                                                                  */
300 /*------------------------------------------------------------------*/
301
302 guchar *
303 mono_arch_create_trampoline_code (MonoTrampolineType tramp_type)
304 {
305
306         guint8 *buf, *tramp, *code;
307         int i, offset, lmfOffset;
308
309         /* Now we'll create in 'buf' the S/390 trampoline code. This
310            is the trampoline code common to all methods  */
311                 
312         code = buf = mono_global_codeman_reserve(512);
313                 
314         /*-----------------------------------------------------------
315           STEP 0: First create a non-standard function prologue with a
316           stack size big enough to save our registers.
317           -----------------------------------------------------------*/
318                 
319         s390_stmg (buf, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
320         s390_lgr  (buf, s390_r11, s390_r15);
321         s390_aghi (buf, STK_BASE, -CREATE_STACK_SIZE);
322         s390_stg  (buf, s390_r11, 0, STK_BASE, 0);
323         s390_stg  (buf, s390_r1, 0, STK_BASE, METHOD_SAVE_OFFSET);
324         s390_stmg (buf, s390_r2, s390_r5, STK_BASE, CREATE_GR_OFFSET);
325
326         /* Save the FP registers */
327         offset = CREATE_FP_OFFSET;
328         for (i = s390_f0; i <= s390_f15; ++i) {
329                 s390_std  (buf, i, 0, STK_BASE, offset);
330                 offset += 8;
331         }
332
333         /*----------------------------------------------------------
334           STEP 1: call 'mono_get_lmf_addr()' to get the address of our
335           LMF. We'll need to restore it after the call to
336           's390_magic_trampoline' and before the call to the native
337           method.
338           ----------------------------------------------------------*/
339                                 
340         s390_basr (buf, s390_r13, 0);
341         s390_j    (buf, 6);
342         s390_llong(buf, mono_get_lmf_addr);
343         s390_lg   (buf, s390_r1, 0, s390_r13, 4);
344         s390_basr (buf, s390_r14, s390_r1);
345
346         /*---------------------------------------------------------------*/
347         /* we build the MonoLMF structure on the stack - see mini-s390.h */
348         /* Keep in sync with the code in mono_arch_emit_prolog           */
349         /*---------------------------------------------------------------*/
350         lmfOffset = CREATE_STACK_SIZE - sizeof(MonoLMF);
351                                                                                         
352         s390_lgr   (buf, s390_r13, STK_BASE);
353         s390_aghi  (buf, s390_r13, lmfOffset);  
354                                                                                         
355         /*---------------------------------------------------------------*/     
356         /* Set lmf.lmf_addr = jit_tls->lmf                               */     
357         /*---------------------------------------------------------------*/     
358         s390_stg   (buf, s390_r2, 0, s390_r13,                          
359                             G_STRUCT_OFFSET(MonoLMF, lmf_addr));                        
360                                                                                         
361         /*---------------------------------------------------------------*/     
362         /* Get current lmf                                               */     
363         /*---------------------------------------------------------------*/     
364         s390_lg    (buf, s390_r0, 0, s390_r2, 0);                               
365                                                                                         
366         /*---------------------------------------------------------------*/     
367         /* Set our lmf as the current lmf                                */     
368         /*---------------------------------------------------------------*/     
369         s390_stg   (buf, s390_r13, 0, s390_r2, 0);                              
370                                                                                         
371         /*---------------------------------------------------------------*/     
372         /* Have our lmf.previous_lmf point to the last lmf               */     
373         /*---------------------------------------------------------------*/     
374         s390_stg   (buf, s390_r0, 0, s390_r13,                          
375                             G_STRUCT_OFFSET(MonoLMF, previous_lmf));                    
376                                                                                         
377         /*---------------------------------------------------------------*/     
378         /* save method info                                              */     
379         /*---------------------------------------------------------------*/     
380         s390_lg    (buf, s390_r1, 0, STK_BASE, METHOD_SAVE_OFFSET);
381         s390_stg   (buf, s390_r1, 0, s390_r13,                          
382                             G_STRUCT_OFFSET(MonoLMF, method));                          
383                                                                         
384         /*---------------------------------------------------------------*/     
385         /* save the current SP                                           */     
386         /*---------------------------------------------------------------*/     
387         s390_lg    (buf, s390_r1, 0, STK_BASE, 0);
388         s390_stg   (buf, s390_r1, 0, s390_r13, G_STRUCT_OFFSET(MonoLMF, ebp));  
389                                                                         
390         /*---------------------------------------------------------------*/     
391         /* save the current IP                                           */     
392         /*---------------------------------------------------------------*/     
393         if (tramp_type == MONO_TRAMPOLINE_JUMP) {
394                 s390_lghi  (buf, s390_r1, 0);
395         } else {
396                 s390_lg    (buf, s390_r1, 0, s390_r1, S390_RET_ADDR_OFFSET);
397                 //                      s390_la    (buf, s390_r1, 0, s390_r1, 0);
398         }
399         s390_stg   (buf, s390_r1, 0, s390_r13, G_STRUCT_OFFSET(MonoLMF, eip));  
400                                                                                         
401         /*---------------------------------------------------------------*/     
402         /* Save general and floating point registers                     */     
403         /*---------------------------------------------------------------*/     
404         s390_stmg  (buf, s390_r2, s390_r12, s390_r13,
405                             G_STRUCT_OFFSET(MonoLMF, gregs[2]));                
406         for (i = 0; i < 16; i++) {
407                 s390_std  (buf, i, 0, s390_r13,
408                                    G_STRUCT_OFFSET(MonoLMF, fregs[i]));
409         }                                               
410
411         /*---------------------------------------------------------------*/
412         /* STEP 2: call the C trampoline function                        */
413         /*---------------------------------------------------------------*/
414                                 
415         /* Set arguments */
416
417         /* Arg 1: gssize *regs. We pass sp instead */
418         s390_lgr  (buf, s390_r2, STK_BASE);
419         s390_ahi  (buf, s390_r2, CREATE_STACK_SIZE);
420                 
421         /* Arg 2: code (next address to the instruction that called us) */
422         if (tramp_type == MONO_TRAMPOLINE_JUMP) {
423                 s390_lghi (buf, s390_r3, 0);
424         } else {
425                 s390_lg   (buf, s390_r3, 0, s390_r11, S390_RET_ADDR_OFFSET);
426         }
427
428         /* Arg 3: MonoMethod *method. It was put in r1 by the
429            method-specific trampoline code, and then saved before the call
430            to mono_get_lmf_addr()'. */
431         s390_lg  (buf, s390_r4, 0, STK_BASE, METHOD_SAVE_OFFSET);
432
433         /* Arg 4: trampoline address. Ignore for now */
434                 
435         /* Calculate call address and call the C trampoline. Return value will be in r2 */
436         s390_basr (buf, s390_r13, 0);
437         s390_j    (buf, 6);
438         tramp = (guint8*)mono_get_trampoline_func (tramp_type);
439         s390_llong (buf, tramp);
440         s390_lg   (buf, s390_r1, 0, s390_r13, 4);
441         s390_basr (buf, s390_r14, s390_r1);
442                 
443         /* OK, code address is now on r2. Move it to r1, so that we
444            can restore r2 and use it from r1 later */
445         s390_lgr  (buf, s390_r1, s390_r2);
446
447         /*----------------------------------------------------------
448           STEP 3: Restore the LMF
449           ----------------------------------------------------------*/
450         restoreLMF(buf, STK_BASE, CREATE_STACK_SIZE);
451         
452         /*----------------------------------------------------------
453           STEP 4: call the compiled method
454           ----------------------------------------------------------*/
455                 
456         /* Restore registers */
457
458         s390_lmg  (buf, s390_r2, s390_r5, STK_BASE, CREATE_GR_OFFSET);
459                 
460         /* Restore the FP registers */
461         offset = CREATE_FP_OFFSET;
462         for (i = s390_f0; i <= s390_f15; ++i) {
463                 s390_ld  (buf, i, 0, STK_BASE, offset);
464                 offset += 8;
465         }
466
467         /* Restore stack pointer and jump to the code -
468            R14 contains the return address to our caller */
469         s390_lgr  (buf, STK_BASE, s390_r11);
470         s390_lmg  (buf, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
471
472         if (tramp_type == MONO_TRAMPOLINE_CLASS_INIT || tramp_type == MONO_TRAMPOLINE_GENERIC_CLASS_INIT)
473                 s390_br (buf, s390_r14);
474         else
475                 s390_br (buf, s390_r1);
476
477         /* Flush instruction cache, since we've generated code */
478         mono_arch_flush_icache (code, buf - code);
479         
480         /* Sanity check */
481         g_assert ((buf - code) <= 512);
482
483         return code;
484 }
485
486 /*========================= End of Function ========================*/
487
488 /*------------------------------------------------------------------*/
489 /*                                                                  */
490 /* Name         - mono_arch_create_specific_trampoline                  */
491 /*                                                                  */
492 /* Function     - Creates the given kind of specific trampoline         */
493 /*                                                                  */
494 /*------------------------------------------------------------------*/
495
496 gpointer
497 mono_arch_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
498 {
499         guint8 *code, *buf, *tramp;
500         gint32 displace;
501
502         tramp = mono_get_trampoline_code (tramp_type);
503
504         /*----------------------------------------------------------*/
505         /* This is the method-specific part of the trampoline. Its  */
506         /* purpose is to provide the generic part with the          */
507         /* MonoMethod *method pointer. We'll use r1 to keep it.     */
508         /*----------------------------------------------------------*/
509         code = buf = mono_domain_code_reserve (domain, SPECIFIC_TRAMPOLINE_SIZE);
510
511         s390_basr (buf, s390_r1, 0);
512         s390_j    (buf, 6);
513         s390_llong(buf, arg1);
514         s390_lg   (buf, s390_r1, 0, s390_r1, 4);
515         displace = (tramp - buf) / 2;
516         s390_jcl  (buf, S390_CC_UN, displace);
517
518         /* Flush instruction cache, since we've generated code */
519         mono_arch_flush_icache (code, buf - code);
520
521         /* Sanity check */
522         g_assert ((buf - code) <= SPECIFIC_TRAMPOLINE_SIZE);
523
524         if (code_len)
525                 *code_len = buf - code;
526         
527         return code;
528 }       
529
530 /*========================= End of Function ========================*/
531
532 gpointer
533 mono_arch_create_rgctx_lazy_fetch_trampoline (guint32 encoded_offset)
534 {
535         /* FIXME: implement! */
536         g_assert_not_reached ();
537         return NULL;
538 }