2009-07-11 Michael Barker <mike@middlesoft.co.uk>
[mono.git] / mono / mini / tramp-s390.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+sizeof(gpointer)
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 /* Specific trampoline code fragment sizes                                  */
33 /*------------------------------------------------------------------*/
34 #define SPECIFIC_TRAMPOLINE_SIZE        64
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/s390/s390-codegen.h>
50
51 #include "mini.h"
52 #include "mini-s390.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_r13, 0);
105         s390_j    (code, 4);
106         s390_word (code, addr);
107         s390_l    (code, s390_r1, 0, s390_r13, 4);
108         s390_ahi  (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         /* This should be a 'brasl' instruction */
136         g_assert (opcode ==  0xc0e5);
137         orig_code    -= 4;
138         displace = ((gint32) addr - (gint32) (orig_code - 2)) / 2;
139         s390_patch (orig_code, displace);
140         mono_arch_flush_icache (orig_code, 4);
141 }
142
143 /*========================= End of Function ========================*/
144
145 void
146 mono_arch_patch_plt_entry (guint8 *code, gpointer *got, mgreg_t *regs, guint8 *addr)
147 {
148         g_assert_not_reached ();
149 }
150
151 /*========================= End of Function ========================*/
152
153 /*------------------------------------------------------------------*/
154 /*                                                                  */
155 /* Name         - mono_arch_nullify_class_init_trampoline               */
156 /*                                                                  */
157 /* Function     - Nullify a call which calls a class init trampoline    */
158 /*                                                                  */
159 /*------------------------------------------------------------------*/
160
161 void
162 mono_arch_nullify_class_init_trampoline (guint8 *code, mgreg_t *regs)
163 {
164         char patch[6] = {0x47, 0x00, 0x00, 0x00, 0x07, 0x00};
165
166         code = code - 6;
167
168         memcpy(code, patch, sizeof(patch));
169 }
170
171 /*========================= End of Function ========================*/
172
173 void
174 mono_arch_nullify_plt_entry (guint8 *code, mgreg_t *regs)
175 {
176         g_assert_not_reached ();
177 }
178
179 /*========================= End of Function ========================*/
180
181 /*------------------------------------------------------------------*/
182 /*                                                                  */
183 /* Name         - mono_arch_get_vcall_slot                              */
184 /*                                                                  */
185 /* Function     - This method is called by the arch independent         */
186 /*            trampoline code to determine the vtable slot used by  */
187 /*            the call which invoked the trampoline.                */
188 /*                The calls                                         */
189 /*                generated by mono for S/390 will look like either:*/
190 /*                1. l     %r1,xxx(%rx)                             */
191 /*                   bras  %r14,%r1                                 */
192 /*                2. brasl %r14,xxxxxx                              */
193 /*                                                                  */
194 /* Parameters   - code   - Pointer into caller code                 */
195 /*                regs   - Register state at the point of the call  */
196 /*                displacement - Out parameter which will receive   */
197 /*                the displacement of the vtable slot               */
198 /*                                                                  */
199 /*------------------------------------------------------------------*/
200
201 gpointer
202 mono_arch_get_vcall_slot (guint8 *code, mgreg_t *regs, int *displacement)
203 {
204         int reg;
205         guchar* base;
206         unsigned short opcode;
207         char *sp;
208
209         // We are passed sp instead of the register array
210         sp = (char*)regs;
211
212         *displacement = 0;
213
214         opcode = *((unsigned short *) (code - 6));
215         switch (opcode) {
216         case 0x5810 :
217                 /* This is a bras r14,r1 instruction */
218                 code    -= 4;
219                 reg      = *code >> 4;
220                 *displacement = *((short *)code) & 0x0fff;
221                 if (reg > 5) 
222                         base = *((guchar **) (sp + S390_REG_SAVE_OFFSET+
223                                                                   sizeof(int)*(reg-6)));
224                 else
225                         base = *((guchar **) ((sp - CREATE_STACK_SIZE) + 
226                                                                   CREATE_GR_OFFSET +
227                                                                   sizeof(int)*(reg-2)));
228                 return base;
229         case 0x581d :
230                 /* l %r1,OFFSET(%r13,%r7) */
231                 code    -= 4;
232                 reg      = *code >> 4;
233                 *displacement = *((short *)code) & 0x0fff;
234                 if (reg > 5) 
235                         base = *((guchar **) (sp + S390_REG_SAVE_OFFSET+
236                                                                   sizeof(int)*(reg-6)));
237                 else
238                         base = *((guchar **) ((sp - CREATE_STACK_SIZE) + 
239                                                                   CREATE_GR_OFFSET +
240                                                                   sizeof(int)*(reg-2)));
241                 base += *((guint32*) (sp + S390_REG_SAVE_OFFSET+
242                                                           sizeof(int)*(s390_r13-6)));
243                 return base;
244         case 0xc0e5 :
245                 /* This is the 'brasl' instruction */
246                 return NULL;
247         default :
248                 g_error("Unable to patch instruction prior to %p",code);
249         }
250
251         return NULL;
252 }
253
254 /*========================= End of Function ========================*/
255
256 /*------------------------------------------------------------------*/
257 /*                                                                  */
258 /* Name         - mono_arch_create_trampoline_code                      */
259 /*                                                                  */
260 /* Function     - Create the designated type of trampoline according*/
261 /*                to the 'tramp_type' parameter.                    */
262 /*                                                                  */
263 /*------------------------------------------------------------------*/
264
265 guchar*
266 mono_arch_create_trampoline_code (MonoTrampolineType tramp_type)
267 {
268
269         guint8 *buf, *tramp, *code;
270         int i, offset, lmfOffset;
271
272         /* Now we'll create in 'buf' the S/390 trampoline code. This
273            is the trampoline code common to all methods  */
274                 
275         code = buf = mono_global_codeman_reserve (512);
276                 
277         /*-----------------------------------------------------------
278           STEP 0: First create a non-standard function prologue with a
279           stack size big enough to save our registers.
280           -----------------------------------------------------------*/
281                 
282         s390_stm  (buf, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
283         s390_lr   (buf, s390_r11, s390_r15);
284         s390_ahi  (buf, STK_BASE, -CREATE_STACK_SIZE);
285         s390_st   (buf, s390_r11, 0, STK_BASE, 0);
286         s390_st   (buf, s390_r1, 0, STK_BASE, METHOD_SAVE_OFFSET);
287         s390_stm  (buf, s390_r2, s390_r5, STK_BASE, CREATE_GR_OFFSET);
288
289         /* Save the FP registers */
290         offset = CREATE_FP_OFFSET;
291         for (i = s390_f0; i <= s390_f15; ++i) {
292                 s390_std  (buf, i, 0, STK_BASE, offset);
293                 offset += 8;
294         }
295
296         /*----------------------------------------------------------
297           STEP 1: call 'mono_get_lmf_addr()' to get the address of our
298           LMF. We'll need to restore it after the call to
299           's390_magic_trampoline' and before the call to the native
300           method.
301           ----------------------------------------------------------*/
302                                 
303         s390_basr (buf, s390_r13, 0);
304         s390_j    (buf, 4);
305         s390_word (buf, mono_get_lmf_addr);
306         s390_l    (buf, s390_r1, 0, s390_r13, 4);
307         s390_basr (buf, s390_r14, s390_r1);
308
309         /*---------------------------------------------------------------*/
310         /* we build the MonoLMF structure on the stack - see mini-s390.h */
311         /* Keep in sync with the code in mono_arch_emit_prolog           */
312         /*---------------------------------------------------------------*/
313         lmfOffset = CREATE_STACK_SIZE - sizeof(MonoLMF);
314                                                                                         
315         s390_lr    (buf, s390_r13, STK_BASE);
316         s390_ahi   (buf, s390_r13, lmfOffset);  
317                                                                                         
318         /*---------------------------------------------------------------*/     
319         /* Set lmf.lmf_addr = jit_tls->lmf                               */     
320         /*---------------------------------------------------------------*/     
321         s390_st    (buf, s390_r2, 0, s390_r13,                          
322                             G_STRUCT_OFFSET(MonoLMF, lmf_addr));                        
323                                                                                         
324         /*---------------------------------------------------------------*/     
325         /* Get current lmf                                               */     
326         /*---------------------------------------------------------------*/     
327         s390_l     (buf, s390_r0, 0, s390_r2, 0);                               
328                                                                                         
329         /*---------------------------------------------------------------*/     
330         /* Set our lmf as the current lmf                                */     
331         /*---------------------------------------------------------------*/     
332         s390_st    (buf, s390_r13, 0, s390_r2, 0);                              
333                                                                                         
334         /*---------------------------------------------------------------*/     
335         /* Have our lmf.previous_lmf point to the last lmf               */     
336         /*---------------------------------------------------------------*/     
337         s390_st    (buf, s390_r0, 0, s390_r13,                          
338                             G_STRUCT_OFFSET(MonoLMF, previous_lmf));                    
339                                                                                         
340         /*---------------------------------------------------------------*/     
341         /* save method info                                              */     
342         /*---------------------------------------------------------------*/     
343         s390_l     (buf, s390_r1, 0, STK_BASE, METHOD_SAVE_OFFSET);
344         s390_st    (buf, s390_r1, 0, s390_r13,                          
345                             G_STRUCT_OFFSET(MonoLMF, method));                          
346                                                                         
347         /*---------------------------------------------------------------*/     
348         /* save the current SP                                           */     
349         /*---------------------------------------------------------------*/     
350         s390_l     (buf, s390_r1, 0, STK_BASE, 0);
351         s390_st    (buf, s390_r1, 0, s390_r13, G_STRUCT_OFFSET(MonoLMF, ebp));  
352                                                                         
353         /*---------------------------------------------------------------*/     
354         /* save the current IP                                           */     
355         /*---------------------------------------------------------------*/     
356         if (tramp_type == MONO_TRAMPOLINE_JUMP) {
357                 s390_lhi   (buf, s390_r1, 0);
358         } else {
359                 s390_l     (buf, s390_r1, 0, s390_r1, S390_RET_ADDR_OFFSET);
360                 s390_la    (buf, s390_r1, 0, s390_r1, 0);
361         }
362         s390_st    (buf, s390_r1, 0, s390_r13, G_STRUCT_OFFSET(MonoLMF, eip));  
363                                                                                         
364         /*---------------------------------------------------------------*/     
365         /* Save general and floating point registers                     */     
366         /*---------------------------------------------------------------*/     
367         s390_stm   (buf, s390_r2, s390_r12, s390_r13,                           
368                             G_STRUCT_OFFSET(MonoLMF, gregs[2]));                        
369         for (i = 0; i < 16; i++) {                                              
370                 s390_std  (buf, i, 0, s390_r13,                                 
371                                    G_STRUCT_OFFSET(MonoLMF, fregs[i]));                 
372         }
373
374         /*---------------------------------------------------------------*/
375         /* STEP 2: call the C trampoline function                        */
376         /*---------------------------------------------------------------*/
377                                 
378         /* Set arguments */
379
380         /* Arg 1: mgreg_t *regs. We pass sp instead */
381         s390_lr   (buf, s390_r2, STK_BASE);
382         s390_ahi  (buf, s390_r2, CREATE_STACK_SIZE);
383                 
384         /* Arg 2: code (next address to the instruction that called us) */
385         if (tramp_type == MONO_TRAMPOLINE_JUMP) {
386                 s390_lhi (buf, s390_r3, 0);
387         } else {
388                 s390_l  (buf, s390_r3, 0, s390_r11, S390_RET_ADDR_OFFSET);
389
390                 /* Mask out bit 31 */
391                 s390_basr (buf, s390_r13, 0);
392                 s390_j    (buf, 4);
393                 s390_word (buf, (~(1 << 31)));
394                 s390_n (buf, s390_r3, 0, s390_r13, 4);
395         }
396                 
397         /* Arg 3: MonoMethod *method. It was put in r1 by the
398            method-specific trampoline code, and then saved before the call
399            to mono_get_lmf_addr()'. */
400         s390_l  (buf, s390_r4, 0, STK_BASE, METHOD_SAVE_OFFSET);
401
402         /* Arg 4: trampoline address. Ignore for now */
403                 
404         /* Calculate call address and call the C trampoline. Return value will be in r2 */
405         s390_basr (buf, s390_r13, 0);
406         s390_j    (buf, 4);
407         tramp = (guint8*)mono_get_trampoline_func (tramp_type);
408         s390_word (buf, tramp);
409         s390_l    (buf, s390_r1, 0, s390_r13, 4);
410         s390_basr (buf, s390_r14, s390_r1);
411                 
412         /* OK, code address is now on r2. Move it to r1, so that we
413            can restore r2 and use it from r1 later */
414         s390_lr   (buf, s390_r1, s390_r2);
415
416         /*----------------------------------------------------------
417           STEP 3: Restore the LMF
418           ----------------------------------------------------------*/
419         restoreLMF(buf, STK_BASE, CREATE_STACK_SIZE);
420         
421         /*----------------------------------------------------------
422           STEP 4: call the compiled method
423           ----------------------------------------------------------*/
424                 
425         /* Restore registers */
426
427         s390_lm   (buf, s390_r2, s390_r5, STK_BASE, CREATE_GR_OFFSET);
428                 
429         /* Restore the FP registers */
430         offset = CREATE_FP_OFFSET;
431         for (i = s390_f0; i <= s390_f15; ++i) {
432                 s390_ld  (buf, i, 0, STK_BASE, offset);
433                 offset += 8;
434         }
435
436         /* Restore stack pointer and jump to the code - 
437            R14 contains the return address to our caller */
438         s390_lr   (buf, STK_BASE, s390_r11);
439         s390_lm   (buf, s390_r6, s390_r14, STK_BASE, S390_REG_SAVE_OFFSET);
440
441         if (tramp_type == MONO_TRAMPOLINE_CLASS_INIT || tramp_type == MONO_TRAMPOLINE_GENERIC_CLASS_INIT)
442                 s390_br (buf, s390_r14);
443         else
444                 s390_br   (buf, s390_r1);
445
446         /* Flush instruction cache, since we've generated code */
447         mono_arch_flush_icache (code, buf - code);
448         
449         /* Sanity check */
450         g_assert ((buf - code) <= 512);
451
452         return code;
453 }
454
455 /*========================= End of Function ========================*/
456
457 /*------------------------------------------------------------------*/
458 /*                                                                  */
459 /* Name         - mono_arch_create_specific_trampoline                  */
460 /*                                                                  */
461 /* Function     - Creates the given kind of specific trampoline         */
462 /*                                                                  */
463 /*------------------------------------------------------------------*/
464
465 gpointer
466 mono_arch_create_specific_trampoline (gpointer arg1, MonoTrampolineType tramp_type, MonoDomain *domain, guint32 *code_len)
467 {
468         guint8 *code, *buf, *tramp;
469         gint32 displace;
470
471         tramp = mono_get_trampoline_code (tramp_type);
472
473         /*----------------------------------------------------------*/
474         /* This is the method-specific part of the trampoline. Its  */
475         /* purpose is to provide the generic part with the          */
476         /* MonoMethod *method pointer. We'll use r1 to keep it.     */
477         /*----------------------------------------------------------*/
478         code = buf = mono_domain_code_reserve (domain, SPECIFIC_TRAMPOLINE_SIZE);
479
480         s390_basr (buf, s390_r1, 0);
481         s390_j    (buf, 4);
482         s390_word (buf, arg1);
483         s390_l    (buf, s390_r1, 0, s390_r1, 4);
484         displace = (tramp - buf) / 2;
485         s390_jcl  (buf, S390_CC_UN, displace);
486
487         /* Flush instruction cache, since we've generated code */
488         mono_arch_flush_icache (code, buf - code);
489
490         /* Sanity check */
491         g_assert ((buf - code) <= SPECIFIC_TRAMPOLINE_SIZE);
492
493         if (code_len)
494                 *code_len = buf - code;
495         
496         return code;
497 }       
498
499 /*========================= End of Function ========================*/
500
501 gpointer
502 mono_arch_create_rgctx_lazy_fetch_trampoline (guint32 encoded_offset)
503 {
504         /* FIXME: implement! */
505         g_assert_not_reached ();
506         return NULL;
507 }