trivial: fix an -> a typos in documentation and comments
[linux-2.6.git] / arch / m68k / kernel / traps.c
1 /*
2  *  linux/arch/m68k/kernel/traps.c
3  *
4  *  Copyright (C) 1993, 1994 by Hamish Macdonald
5  *
6  *  68040 fixes by Michael Rausch
7  *  68040 fixes by Martin Apel
8  *  68040 fixes and writeback by Richard Zidlicky
9  *  68060 fixes by Roman Hodek
10  *  68060 fixes by Jesper Skov
11  *
12  * This file is subject to the terms and conditions of the GNU General Public
13  * License.  See the file COPYING in the main directory of this archive
14  * for more details.
15  */
16
17 /*
18  * Sets up all exception vectors
19  */
20
21 #include <linux/sched.h>
22 #include <linux/signal.h>
23 #include <linux/kernel.h>
24 #include <linux/mm.h>
25 #include <linux/module.h>
26 #include <linux/user.h>
27 #include <linux/string.h>
28 #include <linux/linkage.h>
29 #include <linux/init.h>
30 #include <linux/ptrace.h>
31 #include <linux/kallsyms.h>
32
33 #include <asm/setup.h>
34 #include <asm/fpu.h>
35 #include <asm/system.h>
36 #include <asm/uaccess.h>
37 #include <asm/traps.h>
38 #include <asm/pgalloc.h>
39 #include <asm/machdep.h>
40 #include <asm/siginfo.h>
41
42 /* assembler routines */
43 asmlinkage void system_call(void);
44 asmlinkage void buserr(void);
45 asmlinkage void trap(void);
46 asmlinkage void nmihandler(void);
47 #ifdef CONFIG_M68KFPU_EMU
48 asmlinkage void fpu_emu(void);
49 #endif
50
51 e_vector vectors[256] = {
52         [VEC_BUSERR]    = buserr,
53         [VEC_SYS]       = system_call,
54 };
55
56 /* nmi handler for the Amiga */
57 asm(".text\n"
58     __ALIGN_STR "\n"
59     "nmihandler: rte");
60
61 /*
62  * this must be called very early as the kernel might
63  * use some instruction that are emulated on the 060
64  */
65 void __init base_trap_init(void)
66 {
67         if(MACH_IS_SUN3X) {
68                 extern e_vector *sun3x_prom_vbr;
69
70                 __asm__ volatile ("movec %%vbr, %0" : "=r" (sun3x_prom_vbr));
71         }
72
73         /* setup the exception vector table */
74         __asm__ volatile ("movec %0,%%vbr" : : "r" ((void*)vectors));
75
76         if (CPU_IS_060) {
77                 /* set up ISP entry points */
78                 asmlinkage void unimp_vec(void) asm ("_060_isp_unimp");
79
80                 vectors[VEC_UNIMPII] = unimp_vec;
81         }
82 }
83
84 void __init trap_init (void)
85 {
86         int i;
87
88         for (i = VEC_SPUR; i <= VEC_INT7; i++)
89                 vectors[i] = bad_inthandler;
90
91         for (i = 0; i < VEC_USER; i++)
92                 if (!vectors[i])
93                         vectors[i] = trap;
94
95         for (i = VEC_USER; i < 256; i++)
96                 vectors[i] = bad_inthandler;
97
98 #ifdef CONFIG_M68KFPU_EMU
99         if (FPU_IS_EMU)
100                 vectors[VEC_LINE11] = fpu_emu;
101 #endif
102
103         if (CPU_IS_040 && !FPU_IS_EMU) {
104                 /* set up FPSP entry points */
105                 asmlinkage void dz_vec(void) asm ("dz");
106                 asmlinkage void inex_vec(void) asm ("inex");
107                 asmlinkage void ovfl_vec(void) asm ("ovfl");
108                 asmlinkage void unfl_vec(void) asm ("unfl");
109                 asmlinkage void snan_vec(void) asm ("snan");
110                 asmlinkage void operr_vec(void) asm ("operr");
111                 asmlinkage void bsun_vec(void) asm ("bsun");
112                 asmlinkage void fline_vec(void) asm ("fline");
113                 asmlinkage void unsupp_vec(void) asm ("unsupp");
114
115                 vectors[VEC_FPDIVZ] = dz_vec;
116                 vectors[VEC_FPIR] = inex_vec;
117                 vectors[VEC_FPOVER] = ovfl_vec;
118                 vectors[VEC_FPUNDER] = unfl_vec;
119                 vectors[VEC_FPNAN] = snan_vec;
120                 vectors[VEC_FPOE] = operr_vec;
121                 vectors[VEC_FPBRUC] = bsun_vec;
122                 vectors[VEC_LINE11] = fline_vec;
123                 vectors[VEC_FPUNSUP] = unsupp_vec;
124         }
125
126         if (CPU_IS_060 && !FPU_IS_EMU) {
127                 /* set up IFPSP entry points */
128                 asmlinkage void snan_vec6(void) asm ("_060_fpsp_snan");
129                 asmlinkage void operr_vec6(void) asm ("_060_fpsp_operr");
130                 asmlinkage void ovfl_vec6(void) asm ("_060_fpsp_ovfl");
131                 asmlinkage void unfl_vec6(void) asm ("_060_fpsp_unfl");
132                 asmlinkage void dz_vec6(void) asm ("_060_fpsp_dz");
133                 asmlinkage void inex_vec6(void) asm ("_060_fpsp_inex");
134                 asmlinkage void fline_vec6(void) asm ("_060_fpsp_fline");
135                 asmlinkage void unsupp_vec6(void) asm ("_060_fpsp_unsupp");
136                 asmlinkage void effadd_vec6(void) asm ("_060_fpsp_effadd");
137
138                 vectors[VEC_FPNAN] = snan_vec6;
139                 vectors[VEC_FPOE] = operr_vec6;
140                 vectors[VEC_FPOVER] = ovfl_vec6;
141                 vectors[VEC_FPUNDER] = unfl_vec6;
142                 vectors[VEC_FPDIVZ] = dz_vec6;
143                 vectors[VEC_FPIR] = inex_vec6;
144                 vectors[VEC_LINE11] = fline_vec6;
145                 vectors[VEC_FPUNSUP] = unsupp_vec6;
146                 vectors[VEC_UNIMPEA] = effadd_vec6;
147         }
148
149         /* if running on an amiga, make the NMI interrupt do nothing */
150         if (MACH_IS_AMIGA) {
151                 vectors[VEC_INT7] = nmihandler;
152         }
153 }
154
155
156 static const char *vec_names[] = {
157         [VEC_RESETSP]   = "RESET SP",
158         [VEC_RESETPC]   = "RESET PC",
159         [VEC_BUSERR]    = "BUS ERROR",
160         [VEC_ADDRERR]   = "ADDRESS ERROR",
161         [VEC_ILLEGAL]   = "ILLEGAL INSTRUCTION",
162         [VEC_ZERODIV]   = "ZERO DIVIDE",
163         [VEC_CHK]       = "CHK",
164         [VEC_TRAP]      = "TRAPcc",
165         [VEC_PRIV]      = "PRIVILEGE VIOLATION",
166         [VEC_TRACE]     = "TRACE",
167         [VEC_LINE10]    = "LINE 1010",
168         [VEC_LINE11]    = "LINE 1111",
169         [VEC_RESV12]    = "UNASSIGNED RESERVED 12",
170         [VEC_COPROC]    = "COPROCESSOR PROTOCOL VIOLATION",
171         [VEC_FORMAT]    = "FORMAT ERROR",
172         [VEC_UNINT]     = "UNINITIALIZED INTERRUPT",
173         [VEC_RESV16]    = "UNASSIGNED RESERVED 16",
174         [VEC_RESV17]    = "UNASSIGNED RESERVED 17",
175         [VEC_RESV18]    = "UNASSIGNED RESERVED 18",
176         [VEC_RESV19]    = "UNASSIGNED RESERVED 19",
177         [VEC_RESV20]    = "UNASSIGNED RESERVED 20",
178         [VEC_RESV21]    = "UNASSIGNED RESERVED 21",
179         [VEC_RESV22]    = "UNASSIGNED RESERVED 22",
180         [VEC_RESV23]    = "UNASSIGNED RESERVED 23",
181         [VEC_SPUR]      = "SPURIOUS INTERRUPT",
182         [VEC_INT1]      = "LEVEL 1 INT",
183         [VEC_INT2]      = "LEVEL 2 INT",
184         [VEC_INT3]      = "LEVEL 3 INT",
185         [VEC_INT4]      = "LEVEL 4 INT",
186         [VEC_INT5]      = "LEVEL 5 INT",
187         [VEC_INT6]      = "LEVEL 6 INT",
188         [VEC_INT7]      = "LEVEL 7 INT",
189         [VEC_SYS]       = "SYSCALL",
190         [VEC_TRAP1]     = "TRAP #1",
191         [VEC_TRAP2]     = "TRAP #2",
192         [VEC_TRAP3]     = "TRAP #3",
193         [VEC_TRAP4]     = "TRAP #4",
194         [VEC_TRAP5]     = "TRAP #5",
195         [VEC_TRAP6]     = "TRAP #6",
196         [VEC_TRAP7]     = "TRAP #7",
197         [VEC_TRAP8]     = "TRAP #8",
198         [VEC_TRAP9]     = "TRAP #9",
199         [VEC_TRAP10]    = "TRAP #10",
200         [VEC_TRAP11]    = "TRAP #11",
201         [VEC_TRAP12]    = "TRAP #12",
202         [VEC_TRAP13]    = "TRAP #13",
203         [VEC_TRAP14]    = "TRAP #14",
204         [VEC_TRAP15]    = "TRAP #15",
205         [VEC_FPBRUC]    = "FPCP BSUN",
206         [VEC_FPIR]      = "FPCP INEXACT",
207         [VEC_FPDIVZ]    = "FPCP DIV BY 0",
208         [VEC_FPUNDER]   = "FPCP UNDERFLOW",
209         [VEC_FPOE]      = "FPCP OPERAND ERROR",
210         [VEC_FPOVER]    = "FPCP OVERFLOW",
211         [VEC_FPNAN]     = "FPCP SNAN",
212         [VEC_FPUNSUP]   = "FPCP UNSUPPORTED OPERATION",
213         [VEC_MMUCFG]    = "MMU CONFIGURATION ERROR",
214         [VEC_MMUILL]    = "MMU ILLEGAL OPERATION ERROR",
215         [VEC_MMUACC]    = "MMU ACCESS LEVEL VIOLATION ERROR",
216         [VEC_RESV59]    = "UNASSIGNED RESERVED 59",
217         [VEC_UNIMPEA]   = "UNASSIGNED RESERVED 60",
218         [VEC_UNIMPII]   = "UNASSIGNED RESERVED 61",
219         [VEC_RESV62]    = "UNASSIGNED RESERVED 62",
220         [VEC_RESV63]    = "UNASSIGNED RESERVED 63",
221 };
222
223 static const char *space_names[] = {
224         [0]             = "Space 0",
225         [USER_DATA]     = "User Data",
226         [USER_PROGRAM]  = "User Program",
227 #ifndef CONFIG_SUN3
228         [3]             = "Space 3",
229 #else
230         [FC_CONTROL]    = "Control",
231 #endif
232         [4]             = "Space 4",
233         [SUPER_DATA]    = "Super Data",
234         [SUPER_PROGRAM] = "Super Program",
235         [CPU_SPACE]     = "CPU"
236 };
237
238 void die_if_kernel(char *,struct pt_regs *,int);
239 asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
240                              unsigned long error_code);
241 int send_fault_sig(struct pt_regs *regs);
242
243 asmlinkage void trap_c(struct frame *fp);
244
245 #if defined (CONFIG_M68060)
246 static inline void access_error060 (struct frame *fp)
247 {
248         unsigned long fslw = fp->un.fmt4.pc; /* is really FSLW for access error */
249
250 #ifdef DEBUG
251         printk("fslw=%#lx, fa=%#lx\n", fslw, fp->un.fmt4.effaddr);
252 #endif
253
254         if (fslw & MMU060_BPE) {
255                 /* branch prediction error -> clear branch cache */
256                 __asm__ __volatile__ ("movec %/cacr,%/d0\n\t"
257                                       "orl   #0x00400000,%/d0\n\t"
258                                       "movec %/d0,%/cacr"
259                                       : : : "d0" );
260                 /* return if there's no other error */
261                 if (!(fslw & MMU060_ERR_BITS) && !(fslw & MMU060_SEE))
262                         return;
263         }
264
265         if (fslw & (MMU060_DESC_ERR | MMU060_WP | MMU060_SP)) {
266                 unsigned long errorcode;
267                 unsigned long addr = fp->un.fmt4.effaddr;
268
269                 if (fslw & MMU060_MA)
270                         addr = (addr + PAGE_SIZE - 1) & PAGE_MASK;
271
272                 errorcode = 1;
273                 if (fslw & MMU060_DESC_ERR) {
274                         __flush_tlb040_one(addr);
275                         errorcode = 0;
276                 }
277                 if (fslw & MMU060_W)
278                         errorcode |= 2;
279 #ifdef DEBUG
280                 printk("errorcode = %d\n", errorcode );
281 #endif
282                 do_page_fault(&fp->ptregs, addr, errorcode);
283         } else if (fslw & (MMU060_SEE)){
284                 /* Software Emulation Error.
285                  * fault during mem_read/mem_write in ifpsp060/os.S
286                  */
287                 send_fault_sig(&fp->ptregs);
288         } else if (!(fslw & (MMU060_RE|MMU060_WE)) ||
289                    send_fault_sig(&fp->ptregs) > 0) {
290                 printk("pc=%#lx, fa=%#lx\n", fp->ptregs.pc, fp->un.fmt4.effaddr);
291                 printk( "68060 access error, fslw=%lx\n", fslw );
292                 trap_c( fp );
293         }
294 }
295 #endif /* CONFIG_M68060 */
296
297 #if defined (CONFIG_M68040)
298 static inline unsigned long probe040(int iswrite, unsigned long addr, int wbs)
299 {
300         unsigned long mmusr;
301         mm_segment_t old_fs = get_fs();
302
303         set_fs(MAKE_MM_SEG(wbs));
304
305         if (iswrite)
306                 asm volatile (".chip 68040; ptestw (%0); .chip 68k" : : "a" (addr));
307         else
308                 asm volatile (".chip 68040; ptestr (%0); .chip 68k" : : "a" (addr));
309
310         asm volatile (".chip 68040; movec %%mmusr,%0; .chip 68k" : "=r" (mmusr));
311
312         set_fs(old_fs);
313
314         return mmusr;
315 }
316
317 static inline int do_040writeback1(unsigned short wbs, unsigned long wba,
318                                    unsigned long wbd)
319 {
320         int res = 0;
321         mm_segment_t old_fs = get_fs();
322
323         /* set_fs can not be moved, otherwise put_user() may oops */
324         set_fs(MAKE_MM_SEG(wbs));
325
326         switch (wbs & WBSIZ_040) {
327         case BA_SIZE_BYTE:
328                 res = put_user(wbd & 0xff, (char __user *)wba);
329                 break;
330         case BA_SIZE_WORD:
331                 res = put_user(wbd & 0xffff, (short __user *)wba);
332                 break;
333         case BA_SIZE_LONG:
334                 res = put_user(wbd, (int __user *)wba);
335                 break;
336         }
337
338         /* set_fs can not be moved, otherwise put_user() may oops */
339         set_fs(old_fs);
340
341
342 #ifdef DEBUG
343         printk("do_040writeback1, res=%d\n",res);
344 #endif
345
346         return res;
347 }
348
349 /* after an exception in a writeback the stack frame corresponding
350  * to that exception is discarded, set a few bits in the old frame
351  * to simulate what it should look like
352  */
353 static inline void fix_xframe040(struct frame *fp, unsigned long wba, unsigned short wbs)
354 {
355         fp->un.fmt7.faddr = wba;
356         fp->un.fmt7.ssw = wbs & 0xff;
357         if (wba != current->thread.faddr)
358             fp->un.fmt7.ssw |= MA_040;
359 }
360
361 static inline void do_040writebacks(struct frame *fp)
362 {
363         int res = 0;
364 #if 0
365         if (fp->un.fmt7.wb1s & WBV_040)
366                 printk("access_error040: cannot handle 1st writeback. oops.\n");
367 #endif
368
369         if ((fp->un.fmt7.wb2s & WBV_040) &&
370             !(fp->un.fmt7.wb2s & WBTT_040)) {
371                 res = do_040writeback1(fp->un.fmt7.wb2s, fp->un.fmt7.wb2a,
372                                        fp->un.fmt7.wb2d);
373                 if (res)
374                         fix_xframe040(fp, fp->un.fmt7.wb2a, fp->un.fmt7.wb2s);
375                 else
376                         fp->un.fmt7.wb2s = 0;
377         }
378
379         /* do the 2nd wb only if the first one was successful (except for a kernel wb) */
380         if (fp->un.fmt7.wb3s & WBV_040 && (!res || fp->un.fmt7.wb3s & 4)) {
381                 res = do_040writeback1(fp->un.fmt7.wb3s, fp->un.fmt7.wb3a,
382                                        fp->un.fmt7.wb3d);
383                 if (res)
384                     {
385                         fix_xframe040(fp, fp->un.fmt7.wb3a, fp->un.fmt7.wb3s);
386
387                         fp->un.fmt7.wb2s = fp->un.fmt7.wb3s;
388                         fp->un.fmt7.wb3s &= (~WBV_040);
389                         fp->un.fmt7.wb2a = fp->un.fmt7.wb3a;
390                         fp->un.fmt7.wb2d = fp->un.fmt7.wb3d;
391                     }
392                 else
393                         fp->un.fmt7.wb3s = 0;
394         }
395
396         if (res)
397                 send_fault_sig(&fp->ptregs);
398 }
399
400 /*
401  * called from sigreturn(), must ensure userspace code didn't
402  * manipulate exception frame to circumvent protection, then complete
403  * pending writebacks
404  * we just clear TM2 to turn it into a userspace access
405  */
406 asmlinkage void berr_040cleanup(struct frame *fp)
407 {
408         fp->un.fmt7.wb2s &= ~4;
409         fp->un.fmt7.wb3s &= ~4;
410
411         do_040writebacks(fp);
412 }
413
414 static inline void access_error040(struct frame *fp)
415 {
416         unsigned short ssw = fp->un.fmt7.ssw;
417         unsigned long mmusr;
418
419 #ifdef DEBUG
420         printk("ssw=%#x, fa=%#lx\n", ssw, fp->un.fmt7.faddr);
421         printk("wb1s=%#x, wb2s=%#x, wb3s=%#x\n", fp->un.fmt7.wb1s,
422                 fp->un.fmt7.wb2s, fp->un.fmt7.wb3s);
423         printk ("wb2a=%lx, wb3a=%lx, wb2d=%lx, wb3d=%lx\n",
424                 fp->un.fmt7.wb2a, fp->un.fmt7.wb3a,
425                 fp->un.fmt7.wb2d, fp->un.fmt7.wb3d);
426 #endif
427
428         if (ssw & ATC_040) {
429                 unsigned long addr = fp->un.fmt7.faddr;
430                 unsigned long errorcode;
431
432                 /*
433                  * The MMU status has to be determined AFTER the address
434                  * has been corrected if there was a misaligned access (MA).
435                  */
436                 if (ssw & MA_040)
437                         addr = (addr + 7) & -8;
438
439                 /* MMU error, get the MMUSR info for this access */
440                 mmusr = probe040(!(ssw & RW_040), addr, ssw);
441 #ifdef DEBUG
442                 printk("mmusr = %lx\n", mmusr);
443 #endif
444                 errorcode = 1;
445                 if (!(mmusr & MMU_R_040)) {
446                         /* clear the invalid atc entry */
447                         __flush_tlb040_one(addr);
448                         errorcode = 0;
449                 }
450
451                 /* despite what documentation seems to say, RMW
452                  * accesses have always both the LK and RW bits set */
453                 if (!(ssw & RW_040) || (ssw & LK_040))
454                         errorcode |= 2;
455
456                 if (do_page_fault(&fp->ptregs, addr, errorcode)) {
457 #ifdef DEBUG
458                         printk("do_page_fault() !=0 \n");
459 #endif
460                         if (user_mode(&fp->ptregs)){
461                                 /* delay writebacks after signal delivery */
462 #ifdef DEBUG
463                                 printk(".. was usermode - return\n");
464 #endif
465                                 return;
466                         }
467                         /* disable writeback into user space from kernel
468                          * (if do_page_fault didn't fix the mapping,
469                          * the writeback won't do good)
470                          */
471 disable_wb:
472 #ifdef DEBUG
473                         printk(".. disabling wb2\n");
474 #endif
475                         if (fp->un.fmt7.wb2a == fp->un.fmt7.faddr)
476                                 fp->un.fmt7.wb2s &= ~WBV_040;
477                         if (fp->un.fmt7.wb3a == fp->un.fmt7.faddr)
478                                 fp->un.fmt7.wb3s &= ~WBV_040;
479                 }
480         } else {
481                 /* In case of a bus error we either kill the process or expect
482                  * the kernel to catch the fault, which then is also responsible
483                  * for cleaning up the mess.
484                  */
485                 current->thread.signo = SIGBUS;
486                 current->thread.faddr = fp->un.fmt7.faddr;
487                 if (send_fault_sig(&fp->ptregs) >= 0)
488                         printk("68040 bus error (ssw=%x, faddr=%lx)\n", ssw,
489                                fp->un.fmt7.faddr);
490                 goto disable_wb;
491         }
492
493         do_040writebacks(fp);
494 }
495 #endif /* CONFIG_M68040 */
496
497 #if defined(CONFIG_SUN3)
498 #include <asm/sun3mmu.h>
499
500 extern int mmu_emu_handle_fault (unsigned long, int, int);
501
502 /* sun3 version of bus_error030 */
503
504 static inline void bus_error030 (struct frame *fp)
505 {
506         unsigned char buserr_type = sun3_get_buserr ();
507         unsigned long addr, errorcode;
508         unsigned short ssw = fp->un.fmtb.ssw;
509         extern unsigned long _sun3_map_test_start, _sun3_map_test_end;
510
511 #ifdef DEBUG
512         if (ssw & (FC | FB))
513                 printk ("Instruction fault at %#010lx\n",
514                         ssw & FC ?
515                         fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
516                         :
517                         fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
518         if (ssw & DF)
519                 printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
520                         ssw & RW ? "read" : "write",
521                         fp->un.fmtb.daddr,
522                         space_names[ssw & DFC], fp->ptregs.pc);
523 #endif
524
525         /*
526          * Check if this page should be demand-mapped. This needs to go before
527          * the testing for a bad kernel-space access (demand-mapping applies
528          * to kernel accesses too).
529          */
530
531         if ((ssw & DF)
532             && (buserr_type & (SUN3_BUSERR_PROTERR | SUN3_BUSERR_INVALID))) {
533                 if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 0))
534                         return;
535         }
536
537         /* Check for kernel-space pagefault (BAD). */
538         if (fp->ptregs.sr & PS_S) {
539                 /* kernel fault must be a data fault to user space */
540                 if (! ((ssw & DF) && ((ssw & DFC) == USER_DATA))) {
541                      // try checking the kernel mappings before surrender
542                      if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 1))
543                           return;
544                         /* instruction fault or kernel data fault! */
545                         if (ssw & (FC | FB))
546                                 printk ("Instruction fault at %#010lx\n",
547                                         fp->ptregs.pc);
548                         if (ssw & DF) {
549                                 /* was this fault incurred testing bus mappings? */
550                                 if((fp->ptregs.pc >= (unsigned long)&_sun3_map_test_start) &&
551                                    (fp->ptregs.pc <= (unsigned long)&_sun3_map_test_end)) {
552                                         send_fault_sig(&fp->ptregs);
553                                         return;
554                                 }
555
556                                 printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
557                                         ssw & RW ? "read" : "write",
558                                         fp->un.fmtb.daddr,
559                                         space_names[ssw & DFC], fp->ptregs.pc);
560                         }
561                         printk ("BAD KERNEL BUSERR\n");
562
563                         die_if_kernel("Oops", &fp->ptregs,0);
564                         force_sig(SIGKILL, current);
565                         return;
566                 }
567         } else {
568                 /* user fault */
569                 if (!(ssw & (FC | FB)) && !(ssw & DF))
570                         /* not an instruction fault or data fault! BAD */
571                         panic ("USER BUSERR w/o instruction or data fault");
572         }
573
574
575         /* First handle the data fault, if any.  */
576         if (ssw & DF) {
577                 addr = fp->un.fmtb.daddr;
578
579 // errorcode bit 0:     0 -> no page            1 -> protection fault
580 // errorcode bit 1:     0 -> read fault         1 -> write fault
581
582 // (buserr_type & SUN3_BUSERR_PROTERR)  -> protection fault
583 // (buserr_type & SUN3_BUSERR_INVALID)  -> invalid page fault
584
585                 if (buserr_type & SUN3_BUSERR_PROTERR)
586                         errorcode = 0x01;
587                 else if (buserr_type & SUN3_BUSERR_INVALID)
588                         errorcode = 0x00;
589                 else {
590 #ifdef DEBUG
591                         printk ("*** unexpected busfault type=%#04x\n", buserr_type);
592                         printk ("invalid %s access at %#lx from pc %#lx\n",
593                                 !(ssw & RW) ? "write" : "read", addr,
594                                 fp->ptregs.pc);
595 #endif
596                         die_if_kernel ("Oops", &fp->ptregs, buserr_type);
597                         force_sig (SIGBUS, current);
598                         return;
599                 }
600
601 //todo: wtf is RM bit? --m
602                 if (!(ssw & RW) || ssw & RM)
603                         errorcode |= 0x02;
604
605                 /* Handle page fault. */
606                 do_page_fault (&fp->ptregs, addr, errorcode);
607
608                 /* Retry the data fault now. */
609                 return;
610         }
611
612         /* Now handle the instruction fault. */
613
614         /* Get the fault address. */
615         if (fp->ptregs.format == 0xA)
616                 addr = fp->ptregs.pc + 4;
617         else
618                 addr = fp->un.fmtb.baddr;
619         if (ssw & FC)
620                 addr -= 2;
621
622         if (buserr_type & SUN3_BUSERR_INVALID) {
623                 if (!mmu_emu_handle_fault (fp->un.fmtb.daddr, 1, 0))
624                         do_page_fault (&fp->ptregs, addr, 0);
625        } else {
626 #ifdef DEBUG
627                 printk ("protection fault on insn access (segv).\n");
628 #endif
629                 force_sig (SIGSEGV, current);
630        }
631 }
632 #else
633 #if defined(CPU_M68020_OR_M68030)
634 static inline void bus_error030 (struct frame *fp)
635 {
636         volatile unsigned short temp;
637         unsigned short mmusr;
638         unsigned long addr, errorcode;
639         unsigned short ssw = fp->un.fmtb.ssw;
640 #ifdef DEBUG
641         unsigned long desc;
642
643         printk ("pid = %x  ", current->pid);
644         printk ("SSW=%#06x  ", ssw);
645
646         if (ssw & (FC | FB))
647                 printk ("Instruction fault at %#010lx\n",
648                         ssw & FC ?
649                         fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
650                         :
651                         fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
652         if (ssw & DF)
653                 printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
654                         ssw & RW ? "read" : "write",
655                         fp->un.fmtb.daddr,
656                         space_names[ssw & DFC], fp->ptregs.pc);
657 #endif
658
659         /* ++andreas: If a data fault and an instruction fault happen
660            at the same time map in both pages.  */
661
662         /* First handle the data fault, if any.  */
663         if (ssw & DF) {
664                 addr = fp->un.fmtb.daddr;
665
666 #ifdef DEBUG
667                 asm volatile ("ptestr %3,%2@,#7,%0\n\t"
668                               "pmove %%psr,%1@"
669                               : "=a&" (desc)
670                               : "a" (&temp), "a" (addr), "d" (ssw));
671 #else
672                 asm volatile ("ptestr %2,%1@,#7\n\t"
673                               "pmove %%psr,%0@"
674                               : : "a" (&temp), "a" (addr), "d" (ssw));
675 #endif
676                 mmusr = temp;
677
678 #ifdef DEBUG
679                 printk("mmusr is %#x for addr %#lx in task %p\n",
680                        mmusr, addr, current);
681                 printk("descriptor address is %#lx, contents %#lx\n",
682                        __va(desc), *(unsigned long *)__va(desc));
683 #endif
684
685                 errorcode = (mmusr & MMU_I) ? 0 : 1;
686                 if (!(ssw & RW) || (ssw & RM))
687                         errorcode |= 2;
688
689                 if (mmusr & (MMU_I | MMU_WP)) {
690                         if (ssw & 4) {
691                                 printk("Data %s fault at %#010lx in %s (pc=%#lx)\n",
692                                        ssw & RW ? "read" : "write",
693                                        fp->un.fmtb.daddr,
694                                        space_names[ssw & DFC], fp->ptregs.pc);
695                                 goto buserr;
696                         }
697                         /* Don't try to do anything further if an exception was
698                            handled. */
699                         if (do_page_fault (&fp->ptregs, addr, errorcode) < 0)
700                                 return;
701                 } else if (!(mmusr & MMU_I)) {
702                         /* probably a 020 cas fault */
703                         if (!(ssw & RM) && send_fault_sig(&fp->ptregs) > 0)
704                                 printk("unexpected bus error (%#x,%#x)\n", ssw, mmusr);
705                 } else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
706                         printk("invalid %s access at %#lx from pc %#lx\n",
707                                !(ssw & RW) ? "write" : "read", addr,
708                                fp->ptregs.pc);
709                         die_if_kernel("Oops",&fp->ptregs,mmusr);
710                         force_sig(SIGSEGV, current);
711                         return;
712                 } else {
713 #if 0
714                         static volatile long tlong;
715 #endif
716
717                         printk("weird %s access at %#lx from pc %#lx (ssw is %#x)\n",
718                                !(ssw & RW) ? "write" : "read", addr,
719                                fp->ptregs.pc, ssw);
720                         asm volatile ("ptestr #1,%1@,#0\n\t"
721                                       "pmove %%psr,%0@"
722                                       : /* no outputs */
723                                       : "a" (&temp), "a" (addr));
724                         mmusr = temp;
725
726                         printk ("level 0 mmusr is %#x\n", mmusr);
727 #if 0
728                         asm volatile ("pmove %%tt0,%0@"
729                                       : /* no outputs */
730                                       : "a" (&tlong));
731                         printk("tt0 is %#lx, ", tlong);
732                         asm volatile ("pmove %%tt1,%0@"
733                                       : /* no outputs */
734                                       : "a" (&tlong));
735                         printk("tt1 is %#lx\n", tlong);
736 #endif
737 #ifdef DEBUG
738                         printk("Unknown SIGSEGV - 1\n");
739 #endif
740                         die_if_kernel("Oops",&fp->ptregs,mmusr);
741                         force_sig(SIGSEGV, current);
742                         return;
743                 }
744
745                 /* setup an ATC entry for the access about to be retried */
746                 if (!(ssw & RW) || (ssw & RM))
747                         asm volatile ("ploadw %1,%0@" : /* no outputs */
748                                       : "a" (addr), "d" (ssw));
749                 else
750                         asm volatile ("ploadr %1,%0@" : /* no outputs */
751                                       : "a" (addr), "d" (ssw));
752         }
753
754         /* Now handle the instruction fault. */
755
756         if (!(ssw & (FC|FB)))
757                 return;
758
759         if (fp->ptregs.sr & PS_S) {
760                 printk("Instruction fault at %#010lx\n",
761                         fp->ptregs.pc);
762         buserr:
763                 printk ("BAD KERNEL BUSERR\n");
764                 die_if_kernel("Oops",&fp->ptregs,0);
765                 force_sig(SIGKILL, current);
766                 return;
767         }
768
769         /* get the fault address */
770         if (fp->ptregs.format == 10)
771                 addr = fp->ptregs.pc + 4;
772         else
773                 addr = fp->un.fmtb.baddr;
774         if (ssw & FC)
775                 addr -= 2;
776
777         if ((ssw & DF) && ((addr ^ fp->un.fmtb.daddr) & PAGE_MASK) == 0)
778                 /* Insn fault on same page as data fault.  But we
779                    should still create the ATC entry.  */
780                 goto create_atc_entry;
781
782 #ifdef DEBUG
783         asm volatile ("ptestr #1,%2@,#7,%0\n\t"
784                       "pmove %%psr,%1@"
785                       : "=a&" (desc)
786                       : "a" (&temp), "a" (addr));
787 #else
788         asm volatile ("ptestr #1,%1@,#7\n\t"
789                       "pmove %%psr,%0@"
790                       : : "a" (&temp), "a" (addr));
791 #endif
792         mmusr = temp;
793
794 #ifdef DEBUG
795         printk ("mmusr is %#x for addr %#lx in task %p\n",
796                 mmusr, addr, current);
797         printk ("descriptor address is %#lx, contents %#lx\n",
798                 __va(desc), *(unsigned long *)__va(desc));
799 #endif
800
801         if (mmusr & MMU_I)
802                 do_page_fault (&fp->ptregs, addr, 0);
803         else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
804                 printk ("invalid insn access at %#lx from pc %#lx\n",
805                         addr, fp->ptregs.pc);
806 #ifdef DEBUG
807                 printk("Unknown SIGSEGV - 2\n");
808 #endif
809                 die_if_kernel("Oops",&fp->ptregs,mmusr);
810                 force_sig(SIGSEGV, current);
811                 return;
812         }
813
814 create_atc_entry:
815         /* setup an ATC entry for the access about to be retried */
816         asm volatile ("ploadr #2,%0@" : /* no outputs */
817                       : "a" (addr));
818 }
819 #endif /* CPU_M68020_OR_M68030 */
820 #endif /* !CONFIG_SUN3 */
821
822 asmlinkage void buserr_c(struct frame *fp)
823 {
824         /* Only set esp0 if coming from user mode */
825         if (user_mode(&fp->ptregs))
826                 current->thread.esp0 = (unsigned long) fp;
827
828 #ifdef DEBUG
829         printk ("*** Bus Error *** Format is %x\n", fp->ptregs.format);
830 #endif
831
832         switch (fp->ptregs.format) {
833 #if defined (CONFIG_M68060)
834         case 4:                         /* 68060 access error */
835           access_error060 (fp);
836           break;
837 #endif
838 #if defined (CONFIG_M68040)
839         case 0x7:                       /* 68040 access error */
840           access_error040 (fp);
841           break;
842 #endif
843 #if defined (CPU_M68020_OR_M68030)
844         case 0xa:
845         case 0xb:
846           bus_error030 (fp);
847           break;
848 #endif
849         default:
850           die_if_kernel("bad frame format",&fp->ptregs,0);
851 #ifdef DEBUG
852           printk("Unknown SIGSEGV - 4\n");
853 #endif
854           force_sig(SIGSEGV, current);
855         }
856 }
857
858
859 static int kstack_depth_to_print = 48;
860
861 void show_trace(unsigned long *stack)
862 {
863         unsigned long *endstack;
864         unsigned long addr;
865         int i;
866
867         printk("Call Trace:");
868         addr = (unsigned long)stack + THREAD_SIZE - 1;
869         endstack = (unsigned long *)(addr & -THREAD_SIZE);
870         i = 0;
871         while (stack + 1 <= endstack) {
872                 addr = *stack++;
873                 /*
874                  * If the address is either in the text segment of the
875                  * kernel, or in the region which contains vmalloc'ed
876                  * memory, it *may* be the address of a calling
877                  * routine; if so, print it so that someone tracing
878                  * down the cause of the crash will be able to figure
879                  * out the call path that was taken.
880                  */
881                 if (__kernel_text_address(addr)) {
882 #ifndef CONFIG_KALLSYMS
883                         if (i % 5 == 0)
884                                 printk("\n       ");
885 #endif
886                         printk(" [<%08lx>] %pS\n", addr, (void *)addr);
887                         i++;
888                 }
889         }
890         printk("\n");
891 }
892
893 void show_registers(struct pt_regs *regs)
894 {
895         struct frame *fp = (struct frame *)regs;
896         mm_segment_t old_fs = get_fs();
897         u16 c, *cp;
898         unsigned long addr;
899         int i;
900
901         print_modules();
902         printk("PC: [<%08lx>] %pS\n", regs->pc, (void *)regs->pc);
903         printk("SR: %04x  SP: %p  a2: %08lx\n", regs->sr, regs, regs->a2);
904         printk("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
905                regs->d0, regs->d1, regs->d2, regs->d3);
906         printk("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
907                regs->d4, regs->d5, regs->a0, regs->a1);
908
909         printk("Process %s (pid: %d, task=%p)\n",
910                 current->comm, task_pid_nr(current), current);
911         addr = (unsigned long)&fp->un;
912         printk("Frame format=%X ", regs->format);
913         switch (regs->format) {
914         case 0x2:
915                 printk("instr addr=%08lx\n", fp->un.fmt2.iaddr);
916                 addr += sizeof(fp->un.fmt2);
917                 break;
918         case 0x3:
919                 printk("eff addr=%08lx\n", fp->un.fmt3.effaddr);
920                 addr += sizeof(fp->un.fmt3);
921                 break;
922         case 0x4:
923                 printk((CPU_IS_060 ? "fault addr=%08lx fslw=%08lx\n"
924                         : "eff addr=%08lx pc=%08lx\n"),
925                         fp->un.fmt4.effaddr, fp->un.fmt4.pc);
926                 addr += sizeof(fp->un.fmt4);
927                 break;
928         case 0x7:
929                 printk("eff addr=%08lx ssw=%04x faddr=%08lx\n",
930                         fp->un.fmt7.effaddr, fp->un.fmt7.ssw, fp->un.fmt7.faddr);
931                 printk("wb 1 stat/addr/data: %04x %08lx %08lx\n",
932                         fp->un.fmt7.wb1s, fp->un.fmt7.wb1a, fp->un.fmt7.wb1dpd0);
933                 printk("wb 2 stat/addr/data: %04x %08lx %08lx\n",
934                         fp->un.fmt7.wb2s, fp->un.fmt7.wb2a, fp->un.fmt7.wb2d);
935                 printk("wb 3 stat/addr/data: %04x %08lx %08lx\n",
936                         fp->un.fmt7.wb3s, fp->un.fmt7.wb3a, fp->un.fmt7.wb3d);
937                 printk("push data: %08lx %08lx %08lx %08lx\n",
938                         fp->un.fmt7.wb1dpd0, fp->un.fmt7.pd1, fp->un.fmt7.pd2,
939                         fp->un.fmt7.pd3);
940                 addr += sizeof(fp->un.fmt7);
941                 break;
942         case 0x9:
943                 printk("instr addr=%08lx\n", fp->un.fmt9.iaddr);
944                 addr += sizeof(fp->un.fmt9);
945                 break;
946         case 0xa:
947                 printk("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
948                         fp->un.fmta.ssw, fp->un.fmta.isc, fp->un.fmta.isb,
949                         fp->un.fmta.daddr, fp->un.fmta.dobuf);
950                 addr += sizeof(fp->un.fmta);
951                 break;
952         case 0xb:
953                 printk("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
954                         fp->un.fmtb.ssw, fp->un.fmtb.isc, fp->un.fmtb.isb,
955                         fp->un.fmtb.daddr, fp->un.fmtb.dobuf);
956                 printk("baddr=%08lx dibuf=%08lx ver=%x\n",
957                         fp->un.fmtb.baddr, fp->un.fmtb.dibuf, fp->un.fmtb.ver);
958                 addr += sizeof(fp->un.fmtb);
959                 break;
960         default:
961                 printk("\n");
962         }
963         show_stack(NULL, (unsigned long *)addr);
964
965         printk("Code:");
966         set_fs(KERNEL_DS);
967         cp = (u16 *)regs->pc;
968         for (i = -8; i < 16; i++) {
969                 if (get_user(c, cp + i) && i >= 0) {
970                         printk(" Bad PC value.");
971                         break;
972                 }
973                 printk(i ? " %04x" : " <%04x>", c);
974         }
975         set_fs(old_fs);
976         printk ("\n");
977 }
978
979 void show_stack(struct task_struct *task, unsigned long *stack)
980 {
981         unsigned long *p;
982         unsigned long *endstack;
983         int i;
984
985         if (!stack) {
986                 if (task)
987                         stack = (unsigned long *)task->thread.esp0;
988                 else
989                         stack = (unsigned long *)&stack;
990         }
991         endstack = (unsigned long *)(((unsigned long)stack + THREAD_SIZE - 1) & -THREAD_SIZE);
992
993         printk("Stack from %08lx:", (unsigned long)stack);
994         p = stack;
995         for (i = 0; i < kstack_depth_to_print; i++) {
996                 if (p + 1 > endstack)
997                         break;
998                 if (i % 8 == 0)
999                         printk("\n       ");
1000                 printk(" %08lx", *p++);
1001         }
1002         printk("\n");
1003         show_trace(stack);
1004 }
1005
1006 /*
1007  * The architecture-independent backtrace generator
1008  */
1009 void dump_stack(void)
1010 {
1011         unsigned long stack;
1012
1013         show_trace(&stack);
1014 }
1015
1016 EXPORT_SYMBOL(dump_stack);
1017
1018 void bad_super_trap (struct frame *fp)
1019 {
1020         console_verbose();
1021         if (fp->ptregs.vector < 4 * ARRAY_SIZE(vec_names))
1022                 printk ("*** %s ***   FORMAT=%X\n",
1023                         vec_names[(fp->ptregs.vector) >> 2],
1024                         fp->ptregs.format);
1025         else
1026                 printk ("*** Exception %d ***   FORMAT=%X\n",
1027                         (fp->ptregs.vector) >> 2,
1028                         fp->ptregs.format);
1029         if (fp->ptregs.vector >> 2 == VEC_ADDRERR && CPU_IS_020_OR_030) {
1030                 unsigned short ssw = fp->un.fmtb.ssw;
1031
1032                 printk ("SSW=%#06x  ", ssw);
1033
1034                 if (ssw & RC)
1035                         printk ("Pipe stage C instruction fault at %#010lx\n",
1036                                 (fp->ptregs.format) == 0xA ?
1037                                 fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2);
1038                 if (ssw & RB)
1039                         printk ("Pipe stage B instruction fault at %#010lx\n",
1040                                 (fp->ptregs.format) == 0xA ?
1041                                 fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
1042                 if (ssw & DF)
1043                         printk ("Data %s fault at %#010lx in %s (pc=%#lx)\n",
1044                                 ssw & RW ? "read" : "write",
1045                                 fp->un.fmtb.daddr, space_names[ssw & DFC],
1046                                 fp->ptregs.pc);
1047         }
1048         printk ("Current process id is %d\n", task_pid_nr(current));
1049         die_if_kernel("BAD KERNEL TRAP", &fp->ptregs, 0);
1050 }
1051
1052 asmlinkage void trap_c(struct frame *fp)
1053 {
1054         int sig;
1055         siginfo_t info;
1056
1057         if (fp->ptregs.sr & PS_S) {
1058                 if ((fp->ptregs.vector >> 2) == VEC_TRACE) {
1059                         /* traced a trapping instruction */
1060                         current->ptrace |= PT_DTRACE;
1061                 } else
1062                         bad_super_trap(fp);
1063                 return;
1064         }
1065
1066         /* send the appropriate signal to the user program */
1067         switch ((fp->ptregs.vector) >> 2) {
1068             case VEC_ADDRERR:
1069                 info.si_code = BUS_ADRALN;
1070                 sig = SIGBUS;
1071                 break;
1072             case VEC_ILLEGAL:
1073             case VEC_LINE10:
1074             case VEC_LINE11:
1075                 info.si_code = ILL_ILLOPC;
1076                 sig = SIGILL;
1077                 break;
1078             case VEC_PRIV:
1079                 info.si_code = ILL_PRVOPC;
1080                 sig = SIGILL;
1081                 break;
1082             case VEC_COPROC:
1083                 info.si_code = ILL_COPROC;
1084                 sig = SIGILL;
1085                 break;
1086             case VEC_TRAP1:
1087             case VEC_TRAP2:
1088             case VEC_TRAP3:
1089             case VEC_TRAP4:
1090             case VEC_TRAP5:
1091             case VEC_TRAP6:
1092             case VEC_TRAP7:
1093             case VEC_TRAP8:
1094             case VEC_TRAP9:
1095             case VEC_TRAP10:
1096             case VEC_TRAP11:
1097             case VEC_TRAP12:
1098             case VEC_TRAP13:
1099             case VEC_TRAP14:
1100                 info.si_code = ILL_ILLTRP;
1101                 sig = SIGILL;
1102                 break;
1103             case VEC_FPBRUC:
1104             case VEC_FPOE:
1105             case VEC_FPNAN:
1106                 info.si_code = FPE_FLTINV;
1107                 sig = SIGFPE;
1108                 break;
1109             case VEC_FPIR:
1110                 info.si_code = FPE_FLTRES;
1111                 sig = SIGFPE;
1112                 break;
1113             case VEC_FPDIVZ:
1114                 info.si_code = FPE_FLTDIV;
1115                 sig = SIGFPE;
1116                 break;
1117             case VEC_FPUNDER:
1118                 info.si_code = FPE_FLTUND;
1119                 sig = SIGFPE;
1120                 break;
1121             case VEC_FPOVER:
1122                 info.si_code = FPE_FLTOVF;
1123                 sig = SIGFPE;
1124                 break;
1125             case VEC_ZERODIV:
1126                 info.si_code = FPE_INTDIV;
1127                 sig = SIGFPE;
1128                 break;
1129             case VEC_CHK:
1130             case VEC_TRAP:
1131                 info.si_code = FPE_INTOVF;
1132                 sig = SIGFPE;
1133                 break;
1134             case VEC_TRACE:             /* ptrace single step */
1135                 info.si_code = TRAP_TRACE;
1136                 sig = SIGTRAP;
1137                 break;
1138             case VEC_TRAP15:            /* breakpoint */
1139                 info.si_code = TRAP_BRKPT;
1140                 sig = SIGTRAP;
1141                 break;
1142             default:
1143                 info.si_code = ILL_ILLOPC;
1144                 sig = SIGILL;
1145                 break;
1146         }
1147         info.si_signo = sig;
1148         info.si_errno = 0;
1149         switch (fp->ptregs.format) {
1150             default:
1151                 info.si_addr = (void *) fp->ptregs.pc;
1152                 break;
1153             case 2:
1154                 info.si_addr = (void *) fp->un.fmt2.iaddr;
1155                 break;
1156             case 7:
1157                 info.si_addr = (void *) fp->un.fmt7.effaddr;
1158                 break;
1159             case 9:
1160                 info.si_addr = (void *) fp->un.fmt9.iaddr;
1161                 break;
1162             case 10:
1163                 info.si_addr = (void *) fp->un.fmta.daddr;
1164                 break;
1165             case 11:
1166                 info.si_addr = (void *) fp->un.fmtb.daddr;
1167                 break;
1168         }
1169         force_sig_info (sig, &info, current);
1170 }
1171
1172 void die_if_kernel (char *str, struct pt_regs *fp, int nr)
1173 {
1174         if (!(fp->sr & PS_S))
1175                 return;
1176
1177         console_verbose();
1178         printk("%s: %08x\n",str,nr);
1179         show_registers(fp);
1180         add_taint(TAINT_DIE);
1181         do_exit(SIGSEGV);
1182 }
1183
1184 /*
1185  * This function is called if an error occur while accessing
1186  * user-space from the fpsp040 code.
1187  */
1188 asmlinkage void fpsp040_die(void)
1189 {
1190         do_exit(SIGSEGV);
1191 }
1192
1193 #ifdef CONFIG_M68KFPU_EMU
1194 asmlinkage void fpemu_signal(int signal, int code, void *addr)
1195 {
1196         siginfo_t info;
1197
1198         info.si_signo = signal;
1199         info.si_errno = 0;
1200         info.si_code = code;
1201         info.si_addr = addr;
1202         force_sig_info(signal, &info, current);
1203 }
1204 #endif