xref: /openbmc/linux/arch/m68k/kernel/traps.c (revision c8ec3743)
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/sched/debug.h>
23 #include <linux/signal.h>
24 #include <linux/kernel.h>
25 #include <linux/mm.h>
26 #include <linux/module.h>
27 #include <linux/user.h>
28 #include <linux/string.h>
29 #include <linux/linkage.h>
30 #include <linux/init.h>
31 #include <linux/ptrace.h>
32 #include <linux/kallsyms.h>
33 
34 #include <asm/setup.h>
35 #include <asm/fpu.h>
36 #include <linux/uaccess.h>
37 #include <asm/traps.h>
38 #include <asm/pgalloc.h>
39 #include <asm/machdep.h>
40 #include <asm/siginfo.h>
41 
42 
43 static const char *vec_names[] = {
44 	[VEC_RESETSP]	= "RESET SP",
45 	[VEC_RESETPC]	= "RESET PC",
46 	[VEC_BUSERR]	= "BUS ERROR",
47 	[VEC_ADDRERR]	= "ADDRESS ERROR",
48 	[VEC_ILLEGAL]	= "ILLEGAL INSTRUCTION",
49 	[VEC_ZERODIV]	= "ZERO DIVIDE",
50 	[VEC_CHK]	= "CHK",
51 	[VEC_TRAP]	= "TRAPcc",
52 	[VEC_PRIV]	= "PRIVILEGE VIOLATION",
53 	[VEC_TRACE]	= "TRACE",
54 	[VEC_LINE10]	= "LINE 1010",
55 	[VEC_LINE11]	= "LINE 1111",
56 	[VEC_RESV12]	= "UNASSIGNED RESERVED 12",
57 	[VEC_COPROC]	= "COPROCESSOR PROTOCOL VIOLATION",
58 	[VEC_FORMAT]	= "FORMAT ERROR",
59 	[VEC_UNINT]	= "UNINITIALIZED INTERRUPT",
60 	[VEC_RESV16]	= "UNASSIGNED RESERVED 16",
61 	[VEC_RESV17]	= "UNASSIGNED RESERVED 17",
62 	[VEC_RESV18]	= "UNASSIGNED RESERVED 18",
63 	[VEC_RESV19]	= "UNASSIGNED RESERVED 19",
64 	[VEC_RESV20]	= "UNASSIGNED RESERVED 20",
65 	[VEC_RESV21]	= "UNASSIGNED RESERVED 21",
66 	[VEC_RESV22]	= "UNASSIGNED RESERVED 22",
67 	[VEC_RESV23]	= "UNASSIGNED RESERVED 23",
68 	[VEC_SPUR]	= "SPURIOUS INTERRUPT",
69 	[VEC_INT1]	= "LEVEL 1 INT",
70 	[VEC_INT2]	= "LEVEL 2 INT",
71 	[VEC_INT3]	= "LEVEL 3 INT",
72 	[VEC_INT4]	= "LEVEL 4 INT",
73 	[VEC_INT5]	= "LEVEL 5 INT",
74 	[VEC_INT6]	= "LEVEL 6 INT",
75 	[VEC_INT7]	= "LEVEL 7 INT",
76 	[VEC_SYS]	= "SYSCALL",
77 	[VEC_TRAP1]	= "TRAP #1",
78 	[VEC_TRAP2]	= "TRAP #2",
79 	[VEC_TRAP3]	= "TRAP #3",
80 	[VEC_TRAP4]	= "TRAP #4",
81 	[VEC_TRAP5]	= "TRAP #5",
82 	[VEC_TRAP6]	= "TRAP #6",
83 	[VEC_TRAP7]	= "TRAP #7",
84 	[VEC_TRAP8]	= "TRAP #8",
85 	[VEC_TRAP9]	= "TRAP #9",
86 	[VEC_TRAP10]	= "TRAP #10",
87 	[VEC_TRAP11]	= "TRAP #11",
88 	[VEC_TRAP12]	= "TRAP #12",
89 	[VEC_TRAP13]	= "TRAP #13",
90 	[VEC_TRAP14]	= "TRAP #14",
91 	[VEC_TRAP15]	= "TRAP #15",
92 	[VEC_FPBRUC]	= "FPCP BSUN",
93 	[VEC_FPIR]	= "FPCP INEXACT",
94 	[VEC_FPDIVZ]	= "FPCP DIV BY 0",
95 	[VEC_FPUNDER]	= "FPCP UNDERFLOW",
96 	[VEC_FPOE]	= "FPCP OPERAND ERROR",
97 	[VEC_FPOVER]	= "FPCP OVERFLOW",
98 	[VEC_FPNAN]	= "FPCP SNAN",
99 	[VEC_FPUNSUP]	= "FPCP UNSUPPORTED OPERATION",
100 	[VEC_MMUCFG]	= "MMU CONFIGURATION ERROR",
101 	[VEC_MMUILL]	= "MMU ILLEGAL OPERATION ERROR",
102 	[VEC_MMUACC]	= "MMU ACCESS LEVEL VIOLATION ERROR",
103 	[VEC_RESV59]	= "UNASSIGNED RESERVED 59",
104 	[VEC_UNIMPEA]	= "UNASSIGNED RESERVED 60",
105 	[VEC_UNIMPII]	= "UNASSIGNED RESERVED 61",
106 	[VEC_RESV62]	= "UNASSIGNED RESERVED 62",
107 	[VEC_RESV63]	= "UNASSIGNED RESERVED 63",
108 };
109 
110 static const char *space_names[] = {
111 	[0]		= "Space 0",
112 	[USER_DATA]	= "User Data",
113 	[USER_PROGRAM]	= "User Program",
114 #ifndef CONFIG_SUN3
115 	[3]		= "Space 3",
116 #else
117 	[FC_CONTROL]	= "Control",
118 #endif
119 	[4]		= "Space 4",
120 	[SUPER_DATA]	= "Super Data",
121 	[SUPER_PROGRAM]	= "Super Program",
122 	[CPU_SPACE]	= "CPU"
123 };
124 
125 void die_if_kernel(char *,struct pt_regs *,int);
126 asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
127                              unsigned long error_code);
128 int send_fault_sig(struct pt_regs *regs);
129 
130 asmlinkage void trap_c(struct frame *fp);
131 
132 #if defined (CONFIG_M68060)
133 static inline void access_error060 (struct frame *fp)
134 {
135 	unsigned long fslw = fp->un.fmt4.pc; /* is really FSLW for access error */
136 
137 	pr_debug("fslw=%#lx, fa=%#lx\n", fslw, fp->un.fmt4.effaddr);
138 
139 	if (fslw & MMU060_BPE) {
140 		/* branch prediction error -> clear branch cache */
141 		__asm__ __volatile__ ("movec %/cacr,%/d0\n\t"
142 				      "orl   #0x00400000,%/d0\n\t"
143 				      "movec %/d0,%/cacr"
144 				      : : : "d0" );
145 		/* return if there's no other error */
146 		if (!(fslw & MMU060_ERR_BITS) && !(fslw & MMU060_SEE))
147 			return;
148 	}
149 
150 	if (fslw & (MMU060_DESC_ERR | MMU060_WP | MMU060_SP)) {
151 		unsigned long errorcode;
152 		unsigned long addr = fp->un.fmt4.effaddr;
153 
154 		if (fslw & MMU060_MA)
155 			addr = (addr + PAGE_SIZE - 1) & PAGE_MASK;
156 
157 		errorcode = 1;
158 		if (fslw & MMU060_DESC_ERR) {
159 			__flush_tlb040_one(addr);
160 			errorcode = 0;
161 		}
162 		if (fslw & MMU060_W)
163 			errorcode |= 2;
164 		pr_debug("errorcode = %ld\n", errorcode);
165 		do_page_fault(&fp->ptregs, addr, errorcode);
166 	} else if (fslw & (MMU060_SEE)){
167 		/* Software Emulation Error.
168 		 * fault during mem_read/mem_write in ifpsp060/os.S
169 		 */
170 		send_fault_sig(&fp->ptregs);
171 	} else if (!(fslw & (MMU060_RE|MMU060_WE)) ||
172 		   send_fault_sig(&fp->ptregs) > 0) {
173 		pr_err("pc=%#lx, fa=%#lx\n", fp->ptregs.pc,
174 		       fp->un.fmt4.effaddr);
175 		pr_err("68060 access error, fslw=%lx\n", fslw);
176 		trap_c( fp );
177 	}
178 }
179 #endif /* CONFIG_M68060 */
180 
181 #if defined (CONFIG_M68040)
182 static inline unsigned long probe040(int iswrite, unsigned long addr, int wbs)
183 {
184 	unsigned long mmusr;
185 	mm_segment_t old_fs = get_fs();
186 
187 	set_fs(MAKE_MM_SEG(wbs));
188 
189 	if (iswrite)
190 		asm volatile (".chip 68040; ptestw (%0); .chip 68k" : : "a" (addr));
191 	else
192 		asm volatile (".chip 68040; ptestr (%0); .chip 68k" : : "a" (addr));
193 
194 	asm volatile (".chip 68040; movec %%mmusr,%0; .chip 68k" : "=r" (mmusr));
195 
196 	set_fs(old_fs);
197 
198 	return mmusr;
199 }
200 
201 static inline int do_040writeback1(unsigned short wbs, unsigned long wba,
202 				   unsigned long wbd)
203 {
204 	int res = 0;
205 	mm_segment_t old_fs = get_fs();
206 
207 	/* set_fs can not be moved, otherwise put_user() may oops */
208 	set_fs(MAKE_MM_SEG(wbs));
209 
210 	switch (wbs & WBSIZ_040) {
211 	case BA_SIZE_BYTE:
212 		res = put_user(wbd & 0xff, (char __user *)wba);
213 		break;
214 	case BA_SIZE_WORD:
215 		res = put_user(wbd & 0xffff, (short __user *)wba);
216 		break;
217 	case BA_SIZE_LONG:
218 		res = put_user(wbd, (int __user *)wba);
219 		break;
220 	}
221 
222 	/* set_fs can not be moved, otherwise put_user() may oops */
223 	set_fs(old_fs);
224 
225 
226 	pr_debug("do_040writeback1, res=%d\n", res);
227 
228 	return res;
229 }
230 
231 /* after an exception in a writeback the stack frame corresponding
232  * to that exception is discarded, set a few bits in the old frame
233  * to simulate what it should look like
234  */
235 static inline void fix_xframe040(struct frame *fp, unsigned long wba, unsigned short wbs)
236 {
237 	fp->un.fmt7.faddr = wba;
238 	fp->un.fmt7.ssw = wbs & 0xff;
239 	if (wba != current->thread.faddr)
240 	    fp->un.fmt7.ssw |= MA_040;
241 }
242 
243 static inline void do_040writebacks(struct frame *fp)
244 {
245 	int res = 0;
246 #if 0
247 	if (fp->un.fmt7.wb1s & WBV_040)
248 		pr_err("access_error040: cannot handle 1st writeback. oops.\n");
249 #endif
250 
251 	if ((fp->un.fmt7.wb2s & WBV_040) &&
252 	    !(fp->un.fmt7.wb2s & WBTT_040)) {
253 		res = do_040writeback1(fp->un.fmt7.wb2s, fp->un.fmt7.wb2a,
254 				       fp->un.fmt7.wb2d);
255 		if (res)
256 			fix_xframe040(fp, fp->un.fmt7.wb2a, fp->un.fmt7.wb2s);
257 		else
258 			fp->un.fmt7.wb2s = 0;
259 	}
260 
261 	/* do the 2nd wb only if the first one was successful (except for a kernel wb) */
262 	if (fp->un.fmt7.wb3s & WBV_040 && (!res || fp->un.fmt7.wb3s & 4)) {
263 		res = do_040writeback1(fp->un.fmt7.wb3s, fp->un.fmt7.wb3a,
264 				       fp->un.fmt7.wb3d);
265 		if (res)
266 		    {
267 			fix_xframe040(fp, fp->un.fmt7.wb3a, fp->un.fmt7.wb3s);
268 
269 			fp->un.fmt7.wb2s = fp->un.fmt7.wb3s;
270 			fp->un.fmt7.wb3s &= (~WBV_040);
271 			fp->un.fmt7.wb2a = fp->un.fmt7.wb3a;
272 			fp->un.fmt7.wb2d = fp->un.fmt7.wb3d;
273 		    }
274 		else
275 			fp->un.fmt7.wb3s = 0;
276 	}
277 
278 	if (res)
279 		send_fault_sig(&fp->ptregs);
280 }
281 
282 /*
283  * called from sigreturn(), must ensure userspace code didn't
284  * manipulate exception frame to circumvent protection, then complete
285  * pending writebacks
286  * we just clear TM2 to turn it into a userspace access
287  */
288 asmlinkage void berr_040cleanup(struct frame *fp)
289 {
290 	fp->un.fmt7.wb2s &= ~4;
291 	fp->un.fmt7.wb3s &= ~4;
292 
293 	do_040writebacks(fp);
294 }
295 
296 static inline void access_error040(struct frame *fp)
297 {
298 	unsigned short ssw = fp->un.fmt7.ssw;
299 	unsigned long mmusr;
300 
301 	pr_debug("ssw=%#x, fa=%#lx\n", ssw, fp->un.fmt7.faddr);
302 	pr_debug("wb1s=%#x, wb2s=%#x, wb3s=%#x\n", fp->un.fmt7.wb1s,
303 		fp->un.fmt7.wb2s, fp->un.fmt7.wb3s);
304 	pr_debug("wb2a=%lx, wb3a=%lx, wb2d=%lx, wb3d=%lx\n",
305 		fp->un.fmt7.wb2a, fp->un.fmt7.wb3a,
306 		fp->un.fmt7.wb2d, fp->un.fmt7.wb3d);
307 
308 	if (ssw & ATC_040) {
309 		unsigned long addr = fp->un.fmt7.faddr;
310 		unsigned long errorcode;
311 
312 		/*
313 		 * The MMU status has to be determined AFTER the address
314 		 * has been corrected if there was a misaligned access (MA).
315 		 */
316 		if (ssw & MA_040)
317 			addr = (addr + 7) & -8;
318 
319 		/* MMU error, get the MMUSR info for this access */
320 		mmusr = probe040(!(ssw & RW_040), addr, ssw);
321 		pr_debug("mmusr = %lx\n", mmusr);
322 		errorcode = 1;
323 		if (!(mmusr & MMU_R_040)) {
324 			/* clear the invalid atc entry */
325 			__flush_tlb040_one(addr);
326 			errorcode = 0;
327 		}
328 
329 		/* despite what documentation seems to say, RMW
330 		 * accesses have always both the LK and RW bits set */
331 		if (!(ssw & RW_040) || (ssw & LK_040))
332 			errorcode |= 2;
333 
334 		if (do_page_fault(&fp->ptregs, addr, errorcode)) {
335 			pr_debug("do_page_fault() !=0\n");
336 			if (user_mode(&fp->ptregs)){
337 				/* delay writebacks after signal delivery */
338 				pr_debug(".. was usermode - return\n");
339 				return;
340 			}
341 			/* disable writeback into user space from kernel
342 			 * (if do_page_fault didn't fix the mapping,
343                          * the writeback won't do good)
344 			 */
345 disable_wb:
346 			pr_debug(".. disabling wb2\n");
347 			if (fp->un.fmt7.wb2a == fp->un.fmt7.faddr)
348 				fp->un.fmt7.wb2s &= ~WBV_040;
349 			if (fp->un.fmt7.wb3a == fp->un.fmt7.faddr)
350 				fp->un.fmt7.wb3s &= ~WBV_040;
351 		}
352 	} else {
353 		/* In case of a bus error we either kill the process or expect
354 		 * the kernel to catch the fault, which then is also responsible
355 		 * for cleaning up the mess.
356 		 */
357 		current->thread.signo = SIGBUS;
358 		current->thread.faddr = fp->un.fmt7.faddr;
359 		if (send_fault_sig(&fp->ptregs) >= 0)
360 			pr_err("68040 bus error (ssw=%x, faddr=%lx)\n", ssw,
361 			       fp->un.fmt7.faddr);
362 		goto disable_wb;
363 	}
364 
365 	do_040writebacks(fp);
366 }
367 #endif /* CONFIG_M68040 */
368 
369 #if defined(CONFIG_SUN3)
370 #include <asm/sun3mmu.h>
371 
372 extern int mmu_emu_handle_fault (unsigned long, int, int);
373 
374 /* sun3 version of bus_error030 */
375 
376 static inline void bus_error030 (struct frame *fp)
377 {
378 	unsigned char buserr_type = sun3_get_buserr ();
379 	unsigned long addr, errorcode;
380 	unsigned short ssw = fp->un.fmtb.ssw;
381 	extern unsigned long _sun3_map_test_start, _sun3_map_test_end;
382 
383 	if (ssw & (FC | FB))
384 		pr_debug("Instruction fault at %#010lx\n",
385 			ssw & FC ?
386 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
387 			:
388 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
389 	if (ssw & DF)
390 		pr_debug("Data %s fault at %#010lx in %s (pc=%#lx)\n",
391 			ssw & RW ? "read" : "write",
392 			fp->un.fmtb.daddr,
393 			space_names[ssw & DFC], fp->ptregs.pc);
394 
395 	/*
396 	 * Check if this page should be demand-mapped. This needs to go before
397 	 * the testing for a bad kernel-space access (demand-mapping applies
398 	 * to kernel accesses too).
399 	 */
400 
401 	if ((ssw & DF)
402 	    && (buserr_type & (SUN3_BUSERR_PROTERR | SUN3_BUSERR_INVALID))) {
403 		if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 0))
404 			return;
405 	}
406 
407 	/* Check for kernel-space pagefault (BAD). */
408 	if (fp->ptregs.sr & PS_S) {
409 		/* kernel fault must be a data fault to user space */
410 		if (! ((ssw & DF) && ((ssw & DFC) == USER_DATA))) {
411 		     // try checking the kernel mappings before surrender
412 		     if (mmu_emu_handle_fault (fp->un.fmtb.daddr, ssw & RW, 1))
413 			  return;
414 			/* instruction fault or kernel data fault! */
415 			if (ssw & (FC | FB))
416 				pr_err("Instruction fault at %#010lx\n",
417 					fp->ptregs.pc);
418 			if (ssw & DF) {
419 				/* was this fault incurred testing bus mappings? */
420 				if((fp->ptregs.pc >= (unsigned long)&_sun3_map_test_start) &&
421 				   (fp->ptregs.pc <= (unsigned long)&_sun3_map_test_end)) {
422 					send_fault_sig(&fp->ptregs);
423 					return;
424 				}
425 
426 				pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n",
427 					ssw & RW ? "read" : "write",
428 					fp->un.fmtb.daddr,
429 					space_names[ssw & DFC], fp->ptregs.pc);
430 			}
431 			pr_err("BAD KERNEL BUSERR\n");
432 
433 			die_if_kernel("Oops", &fp->ptregs,0);
434 			force_sig(SIGKILL, current);
435 			return;
436 		}
437 	} else {
438 		/* user fault */
439 		if (!(ssw & (FC | FB)) && !(ssw & DF))
440 			/* not an instruction fault or data fault! BAD */
441 			panic ("USER BUSERR w/o instruction or data fault");
442 	}
443 
444 
445 	/* First handle the data fault, if any.  */
446 	if (ssw & DF) {
447 		addr = fp->un.fmtb.daddr;
448 
449 // errorcode bit 0:	0 -> no page		1 -> protection fault
450 // errorcode bit 1:	0 -> read fault		1 -> write fault
451 
452 // (buserr_type & SUN3_BUSERR_PROTERR)	-> protection fault
453 // (buserr_type & SUN3_BUSERR_INVALID)	-> invalid page fault
454 
455 		if (buserr_type & SUN3_BUSERR_PROTERR)
456 			errorcode = 0x01;
457 		else if (buserr_type & SUN3_BUSERR_INVALID)
458 			errorcode = 0x00;
459 		else {
460 			pr_debug("*** unexpected busfault type=%#04x\n",
461 				 buserr_type);
462 			pr_debug("invalid %s access at %#lx from pc %#lx\n",
463 				 !(ssw & RW) ? "write" : "read", addr,
464 				 fp->ptregs.pc);
465 			die_if_kernel ("Oops", &fp->ptregs, buserr_type);
466 			force_sig (SIGBUS, current);
467 			return;
468 		}
469 
470 //todo: wtf is RM bit? --m
471 		if (!(ssw & RW) || ssw & RM)
472 			errorcode |= 0x02;
473 
474 		/* Handle page fault. */
475 		do_page_fault (&fp->ptregs, addr, errorcode);
476 
477 		/* Retry the data fault now. */
478 		return;
479 	}
480 
481 	/* Now handle the instruction fault. */
482 
483 	/* Get the fault address. */
484 	if (fp->ptregs.format == 0xA)
485 		addr = fp->ptregs.pc + 4;
486 	else
487 		addr = fp->un.fmtb.baddr;
488 	if (ssw & FC)
489 		addr -= 2;
490 
491 	if (buserr_type & SUN3_BUSERR_INVALID) {
492 		if (!mmu_emu_handle_fault(addr, 1, 0))
493 			do_page_fault (&fp->ptregs, addr, 0);
494        } else {
495 		pr_debug("protection fault on insn access (segv).\n");
496 		force_sig (SIGSEGV, current);
497        }
498 }
499 #else
500 #if defined(CPU_M68020_OR_M68030)
501 static inline void bus_error030 (struct frame *fp)
502 {
503 	volatile unsigned short temp;
504 	unsigned short mmusr;
505 	unsigned long addr, errorcode;
506 	unsigned short ssw = fp->un.fmtb.ssw;
507 #ifdef DEBUG
508 	unsigned long desc;
509 #endif
510 
511 	pr_debug("pid = %x  ", current->pid);
512 	pr_debug("SSW=%#06x  ", ssw);
513 
514 	if (ssw & (FC | FB))
515 		pr_debug("Instruction fault at %#010lx\n",
516 			ssw & FC ?
517 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2
518 			:
519 			fp->ptregs.format == 0xa ? fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
520 	if (ssw & DF)
521 		pr_debug("Data %s fault at %#010lx in %s (pc=%#lx)\n",
522 			ssw & RW ? "read" : "write",
523 			fp->un.fmtb.daddr,
524 			space_names[ssw & DFC], fp->ptregs.pc);
525 
526 	/* ++andreas: If a data fault and an instruction fault happen
527 	   at the same time map in both pages.  */
528 
529 	/* First handle the data fault, if any.  */
530 	if (ssw & DF) {
531 		addr = fp->un.fmtb.daddr;
532 
533 #ifdef DEBUG
534 		asm volatile ("ptestr %3,%2@,#7,%0\n\t"
535 			      "pmove %%psr,%1"
536 			      : "=a&" (desc), "=m" (temp)
537 			      : "a" (addr), "d" (ssw));
538 		pr_debug("mmusr is %#x for addr %#lx in task %p\n",
539 			 temp, addr, current);
540 		pr_debug("descriptor address is 0x%p, contents %#lx\n",
541 			 __va(desc), *(unsigned long *)__va(desc));
542 #else
543 		asm volatile ("ptestr %2,%1@,#7\n\t"
544 			      "pmove %%psr,%0"
545 			      : "=m" (temp) : "a" (addr), "d" (ssw));
546 #endif
547 		mmusr = temp;
548 		errorcode = (mmusr & MMU_I) ? 0 : 1;
549 		if (!(ssw & RW) || (ssw & RM))
550 			errorcode |= 2;
551 
552 		if (mmusr & (MMU_I | MMU_WP)) {
553 			if (ssw & 4) {
554 				pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n",
555 				       ssw & RW ? "read" : "write",
556 				       fp->un.fmtb.daddr,
557 				       space_names[ssw & DFC], fp->ptregs.pc);
558 				goto buserr;
559 			}
560 			/* Don't try to do anything further if an exception was
561 			   handled. */
562 			if (do_page_fault (&fp->ptregs, addr, errorcode) < 0)
563 				return;
564 		} else if (!(mmusr & MMU_I)) {
565 			/* probably a 020 cas fault */
566 			if (!(ssw & RM) && send_fault_sig(&fp->ptregs) > 0)
567 				pr_err("unexpected bus error (%#x,%#x)\n", ssw,
568 				       mmusr);
569 		} else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
570 			pr_err("invalid %s access at %#lx from pc %#lx\n",
571 			       !(ssw & RW) ? "write" : "read", addr,
572 			       fp->ptregs.pc);
573 			die_if_kernel("Oops",&fp->ptregs,mmusr);
574 			force_sig(SIGSEGV, current);
575 			return;
576 		} else {
577 #if 0
578 			static volatile long tlong;
579 #endif
580 
581 			pr_err("weird %s access at %#lx from pc %#lx (ssw is %#x)\n",
582 			       !(ssw & RW) ? "write" : "read", addr,
583 			       fp->ptregs.pc, ssw);
584 			asm volatile ("ptestr #1,%1@,#0\n\t"
585 				      "pmove %%psr,%0"
586 				      : "=m" (temp)
587 				      : "a" (addr));
588 			mmusr = temp;
589 
590 			pr_err("level 0 mmusr is %#x\n", mmusr);
591 #if 0
592 			asm volatile ("pmove %%tt0,%0"
593 				      : "=m" (tlong));
594 			pr_debug("tt0 is %#lx, ", tlong);
595 			asm volatile ("pmove %%tt1,%0"
596 				      : "=m" (tlong));
597 			pr_debug("tt1 is %#lx\n", tlong);
598 #endif
599 			pr_debug("Unknown SIGSEGV - 1\n");
600 			die_if_kernel("Oops",&fp->ptregs,mmusr);
601 			force_sig(SIGSEGV, current);
602 			return;
603 		}
604 
605 		/* setup an ATC entry for the access about to be retried */
606 		if (!(ssw & RW) || (ssw & RM))
607 			asm volatile ("ploadw %1,%0@" : /* no outputs */
608 				      : "a" (addr), "d" (ssw));
609 		else
610 			asm volatile ("ploadr %1,%0@" : /* no outputs */
611 				      : "a" (addr), "d" (ssw));
612 	}
613 
614 	/* Now handle the instruction fault. */
615 
616 	if (!(ssw & (FC|FB)))
617 		return;
618 
619 	if (fp->ptregs.sr & PS_S) {
620 		pr_err("Instruction fault at %#010lx\n", fp->ptregs.pc);
621 	buserr:
622 		pr_err("BAD KERNEL BUSERR\n");
623 		die_if_kernel("Oops",&fp->ptregs,0);
624 		force_sig(SIGKILL, current);
625 		return;
626 	}
627 
628 	/* get the fault address */
629 	if (fp->ptregs.format == 10)
630 		addr = fp->ptregs.pc + 4;
631 	else
632 		addr = fp->un.fmtb.baddr;
633 	if (ssw & FC)
634 		addr -= 2;
635 
636 	if ((ssw & DF) && ((addr ^ fp->un.fmtb.daddr) & PAGE_MASK) == 0)
637 		/* Insn fault on same page as data fault.  But we
638 		   should still create the ATC entry.  */
639 		goto create_atc_entry;
640 
641 #ifdef DEBUG
642 	asm volatile ("ptestr #1,%2@,#7,%0\n\t"
643 		      "pmove %%psr,%1"
644 		      : "=a&" (desc), "=m" (temp)
645 		      : "a" (addr));
646 	pr_debug("mmusr is %#x for addr %#lx in task %p\n",
647 		temp, addr, current);
648 	pr_debug("descriptor address is 0x%p, contents %#lx\n",
649 		__va(desc), *(unsigned long *)__va(desc));
650 #else
651 	asm volatile ("ptestr #1,%1@,#7\n\t"
652 		      "pmove %%psr,%0"
653 		      : "=m" (temp) : "a" (addr));
654 #endif
655 	mmusr = temp;
656 	if (mmusr & MMU_I)
657 		do_page_fault (&fp->ptregs, addr, 0);
658 	else if (mmusr & (MMU_B|MMU_L|MMU_S)) {
659 		pr_err("invalid insn access at %#lx from pc %#lx\n",
660 			addr, fp->ptregs.pc);
661 		pr_debug("Unknown SIGSEGV - 2\n");
662 		die_if_kernel("Oops",&fp->ptregs,mmusr);
663 		force_sig(SIGSEGV, current);
664 		return;
665 	}
666 
667 create_atc_entry:
668 	/* setup an ATC entry for the access about to be retried */
669 	asm volatile ("ploadr #2,%0@" : /* no outputs */
670 		      : "a" (addr));
671 }
672 #endif /* CPU_M68020_OR_M68030 */
673 #endif /* !CONFIG_SUN3 */
674 
675 #if defined(CONFIG_COLDFIRE) && defined(CONFIG_MMU)
676 #include <asm/mcfmmu.h>
677 
678 /*
679  *	The following table converts the FS encoding of a ColdFire
680  *	exception stack frame into the error_code value needed by
681  *	do_fault.
682 */
683 static const unsigned char fs_err_code[] = {
684 	0,  /* 0000 */
685 	0,  /* 0001 */
686 	0,  /* 0010 */
687 	0,  /* 0011 */
688 	1,  /* 0100 */
689 	0,  /* 0101 */
690 	0,  /* 0110 */
691 	0,  /* 0111 */
692 	2,  /* 1000 */
693 	3,  /* 1001 */
694 	2,  /* 1010 */
695 	0,  /* 1011 */
696 	1,  /* 1100 */
697 	1,  /* 1101 */
698 	0,  /* 1110 */
699 	0   /* 1111 */
700 };
701 
702 static inline void access_errorcf(unsigned int fs, struct frame *fp)
703 {
704 	unsigned long mmusr, addr;
705 	unsigned int err_code;
706 	int need_page_fault;
707 
708 	mmusr = mmu_read(MMUSR);
709 	addr = mmu_read(MMUAR);
710 
711 	/*
712 	 * error_code:
713 	 *	bit 0 == 0 means no page found, 1 means protection fault
714 	 *	bit 1 == 0 means read, 1 means write
715 	 */
716 	switch (fs) {
717 	case  5:  /* 0101 TLB opword X miss */
718 		need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 0, 0);
719 		addr = fp->ptregs.pc;
720 		break;
721 	case  6:  /* 0110 TLB extension word X miss */
722 		need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 0, 1);
723 		addr = fp->ptregs.pc + sizeof(long);
724 		break;
725 	case 10:  /* 1010 TLB W miss */
726 		need_page_fault = cf_tlb_miss(&fp->ptregs, 1, 1, 0);
727 		break;
728 	case 14: /* 1110 TLB R miss */
729 		need_page_fault = cf_tlb_miss(&fp->ptregs, 0, 1, 0);
730 		break;
731 	default:
732 		/* 0000 Normal  */
733 		/* 0001 Reserved */
734 		/* 0010 Interrupt during debug service routine */
735 		/* 0011 Reserved */
736 		/* 0100 X Protection */
737 		/* 0111 IFP in emulator mode */
738 		/* 1000 W Protection*/
739 		/* 1001 Write error*/
740 		/* 1011 Reserved*/
741 		/* 1100 R Protection*/
742 		/* 1101 R Protection*/
743 		/* 1111 OEP in emulator mode*/
744 		need_page_fault = 1;
745 		break;
746 	}
747 
748 	if (need_page_fault) {
749 		err_code = fs_err_code[fs];
750 		if ((fs == 13) && (mmusr & MMUSR_WF)) /* rd-mod-wr access */
751 			err_code |= 2; /* bit1 - write, bit0 - protection */
752 		do_page_fault(&fp->ptregs, addr, err_code);
753 	}
754 }
755 #endif /* CONFIG_COLDFIRE CONFIG_MMU */
756 
757 asmlinkage void buserr_c(struct frame *fp)
758 {
759 	/* Only set esp0 if coming from user mode */
760 	if (user_mode(&fp->ptregs))
761 		current->thread.esp0 = (unsigned long) fp;
762 
763 	pr_debug("*** Bus Error *** Format is %x\n", fp->ptregs.format);
764 
765 #if defined(CONFIG_COLDFIRE) && defined(CONFIG_MMU)
766 	if (CPU_IS_COLDFIRE) {
767 		unsigned int fs;
768 		fs = (fp->ptregs.vector & 0x3) |
769 			((fp->ptregs.vector & 0xc00) >> 8);
770 		switch (fs) {
771 		case 0x5:
772 		case 0x6:
773 		case 0x7:
774 		case 0x9:
775 		case 0xa:
776 		case 0xd:
777 		case 0xe:
778 		case 0xf:
779 			access_errorcf(fs, fp);
780 			return;
781 		default:
782 			break;
783 		}
784 	}
785 #endif /* CONFIG_COLDFIRE && CONFIG_MMU */
786 
787 	switch (fp->ptregs.format) {
788 #if defined (CONFIG_M68060)
789 	case 4:				/* 68060 access error */
790 	  access_error060 (fp);
791 	  break;
792 #endif
793 #if defined (CONFIG_M68040)
794 	case 0x7:			/* 68040 access error */
795 	  access_error040 (fp);
796 	  break;
797 #endif
798 #if defined (CPU_M68020_OR_M68030)
799 	case 0xa:
800 	case 0xb:
801 	  bus_error030 (fp);
802 	  break;
803 #endif
804 	default:
805 	  die_if_kernel("bad frame format",&fp->ptregs,0);
806 	  pr_debug("Unknown SIGSEGV - 4\n");
807 	  force_sig(SIGSEGV, current);
808 	}
809 }
810 
811 
812 static int kstack_depth_to_print = 48;
813 
814 void show_trace(unsigned long *stack)
815 {
816 	unsigned long *endstack;
817 	unsigned long addr;
818 	int i;
819 
820 	pr_info("Call Trace:");
821 	addr = (unsigned long)stack + THREAD_SIZE - 1;
822 	endstack = (unsigned long *)(addr & -THREAD_SIZE);
823 	i = 0;
824 	while (stack + 1 <= endstack) {
825 		addr = *stack++;
826 		/*
827 		 * If the address is either in the text segment of the
828 		 * kernel, or in the region which contains vmalloc'ed
829 		 * memory, it *may* be the address of a calling
830 		 * routine; if so, print it so that someone tracing
831 		 * down the cause of the crash will be able to figure
832 		 * out the call path that was taken.
833 		 */
834 		if (__kernel_text_address(addr)) {
835 #ifndef CONFIG_KALLSYMS
836 			if (i % 5 == 0)
837 				pr_cont("\n       ");
838 #endif
839 			pr_cont(" [<%08lx>] %pS\n", addr, (void *)addr);
840 			i++;
841 		}
842 	}
843 	pr_cont("\n");
844 }
845 
846 void show_registers(struct pt_regs *regs)
847 {
848 	struct frame *fp = (struct frame *)regs;
849 	mm_segment_t old_fs = get_fs();
850 	u16 c, *cp;
851 	unsigned long addr;
852 	int i;
853 
854 	print_modules();
855 	pr_info("PC: [<%08lx>] %pS\n", regs->pc, (void *)regs->pc);
856 	pr_info("SR: %04x  SP: %p  a2: %08lx\n", regs->sr, regs, regs->a2);
857 	pr_info("d0: %08lx    d1: %08lx    d2: %08lx    d3: %08lx\n",
858 	       regs->d0, regs->d1, regs->d2, regs->d3);
859 	pr_info("d4: %08lx    d5: %08lx    a0: %08lx    a1: %08lx\n",
860 	       regs->d4, regs->d5, regs->a0, regs->a1);
861 
862 	pr_info("Process %s (pid: %d, task=%p)\n",
863 		current->comm, task_pid_nr(current), current);
864 	addr = (unsigned long)&fp->un;
865 	pr_info("Frame format=%X ", regs->format);
866 	switch (regs->format) {
867 	case 0x2:
868 		pr_cont("instr addr=%08lx\n", fp->un.fmt2.iaddr);
869 		addr += sizeof(fp->un.fmt2);
870 		break;
871 	case 0x3:
872 		pr_cont("eff addr=%08lx\n", fp->un.fmt3.effaddr);
873 		addr += sizeof(fp->un.fmt3);
874 		break;
875 	case 0x4:
876 		if (CPU_IS_060)
877 			pr_cont("fault addr=%08lx fslw=%08lx\n",
878 				fp->un.fmt4.effaddr, fp->un.fmt4.pc);
879 		else
880 			pr_cont("eff addr=%08lx pc=%08lx\n",
881 				fp->un.fmt4.effaddr, fp->un.fmt4.pc);
882 		addr += sizeof(fp->un.fmt4);
883 		break;
884 	case 0x7:
885 		pr_cont("eff addr=%08lx ssw=%04x faddr=%08lx\n",
886 			fp->un.fmt7.effaddr, fp->un.fmt7.ssw, fp->un.fmt7.faddr);
887 		pr_info("wb 1 stat/addr/data: %04x %08lx %08lx\n",
888 			fp->un.fmt7.wb1s, fp->un.fmt7.wb1a, fp->un.fmt7.wb1dpd0);
889 		pr_info("wb 2 stat/addr/data: %04x %08lx %08lx\n",
890 			fp->un.fmt7.wb2s, fp->un.fmt7.wb2a, fp->un.fmt7.wb2d);
891 		pr_info("wb 3 stat/addr/data: %04x %08lx %08lx\n",
892 			fp->un.fmt7.wb3s, fp->un.fmt7.wb3a, fp->un.fmt7.wb3d);
893 		pr_info("push data: %08lx %08lx %08lx %08lx\n",
894 			fp->un.fmt7.wb1dpd0, fp->un.fmt7.pd1, fp->un.fmt7.pd2,
895 			fp->un.fmt7.pd3);
896 		addr += sizeof(fp->un.fmt7);
897 		break;
898 	case 0x9:
899 		pr_cont("instr addr=%08lx\n", fp->un.fmt9.iaddr);
900 		addr += sizeof(fp->un.fmt9);
901 		break;
902 	case 0xa:
903 		pr_cont("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
904 			fp->un.fmta.ssw, fp->un.fmta.isc, fp->un.fmta.isb,
905 			fp->un.fmta.daddr, fp->un.fmta.dobuf);
906 		addr += sizeof(fp->un.fmta);
907 		break;
908 	case 0xb:
909 		pr_cont("ssw=%04x isc=%04x isb=%04x daddr=%08lx dobuf=%08lx\n",
910 			fp->un.fmtb.ssw, fp->un.fmtb.isc, fp->un.fmtb.isb,
911 			fp->un.fmtb.daddr, fp->un.fmtb.dobuf);
912 		pr_info("baddr=%08lx dibuf=%08lx ver=%x\n",
913 			fp->un.fmtb.baddr, fp->un.fmtb.dibuf, fp->un.fmtb.ver);
914 		addr += sizeof(fp->un.fmtb);
915 		break;
916 	default:
917 		pr_cont("\n");
918 	}
919 	show_stack(NULL, (unsigned long *)addr);
920 
921 	pr_info("Code:");
922 	set_fs(KERNEL_DS);
923 	cp = (u16 *)regs->pc;
924 	for (i = -8; i < 16; i++) {
925 		if (get_user(c, cp + i) && i >= 0) {
926 			pr_cont(" Bad PC value.");
927 			break;
928 		}
929 		if (i)
930 			pr_cont(" %04x", c);
931 		else
932 			pr_cont(" <%04x>", c);
933 	}
934 	set_fs(old_fs);
935 	pr_cont("\n");
936 }
937 
938 void show_stack(struct task_struct *task, unsigned long *stack)
939 {
940 	unsigned long *p;
941 	unsigned long *endstack;
942 	int i;
943 
944 	if (!stack) {
945 		if (task)
946 			stack = (unsigned long *)task->thread.esp0;
947 		else
948 			stack = (unsigned long *)&stack;
949 	}
950 	endstack = (unsigned long *)(((unsigned long)stack + THREAD_SIZE - 1) & -THREAD_SIZE);
951 
952 	pr_info("Stack from %08lx:", (unsigned long)stack);
953 	p = stack;
954 	for (i = 0; i < kstack_depth_to_print; i++) {
955 		if (p + 1 > endstack)
956 			break;
957 		if (i % 8 == 0)
958 			pr_cont("\n       ");
959 		pr_cont(" %08lx", *p++);
960 	}
961 	pr_cont("\n");
962 	show_trace(stack);
963 }
964 
965 /*
966  * The vector number returned in the frame pointer may also contain
967  * the "fs" (Fault Status) bits on ColdFire. These are in the bottom
968  * 2 bits, and upper 2 bits. So we need to mask out the real vector
969  * number before using it in comparisons. You don't need to do this on
970  * real 68k parts, but it won't hurt either.
971  */
972 
973 void bad_super_trap (struct frame *fp)
974 {
975 	int vector = (fp->ptregs.vector >> 2) & 0xff;
976 
977 	console_verbose();
978 	if (vector < ARRAY_SIZE(vec_names))
979 		pr_err("*** %s ***   FORMAT=%X\n",
980 			vec_names[vector],
981 			fp->ptregs.format);
982 	else
983 		pr_err("*** Exception %d ***   FORMAT=%X\n",
984 			vector, fp->ptregs.format);
985 	if (vector == VEC_ADDRERR && CPU_IS_020_OR_030) {
986 		unsigned short ssw = fp->un.fmtb.ssw;
987 
988 		pr_err("SSW=%#06x  ", ssw);
989 
990 		if (ssw & RC)
991 			pr_err("Pipe stage C instruction fault at %#010lx\n",
992 				(fp->ptregs.format) == 0xA ?
993 				fp->ptregs.pc + 2 : fp->un.fmtb.baddr - 2);
994 		if (ssw & RB)
995 			pr_err("Pipe stage B instruction fault at %#010lx\n",
996 				(fp->ptregs.format) == 0xA ?
997 				fp->ptregs.pc + 4 : fp->un.fmtb.baddr);
998 		if (ssw & DF)
999 			pr_err("Data %s fault at %#010lx in %s (pc=%#lx)\n",
1000 				ssw & RW ? "read" : "write",
1001 				fp->un.fmtb.daddr, space_names[ssw & DFC],
1002 				fp->ptregs.pc);
1003 	}
1004 	pr_err("Current process id is %d\n", task_pid_nr(current));
1005 	die_if_kernel("BAD KERNEL TRAP", &fp->ptregs, 0);
1006 }
1007 
1008 asmlinkage void trap_c(struct frame *fp)
1009 {
1010 	int sig, si_code;
1011 	void __user *addr;
1012 	int vector = (fp->ptregs.vector >> 2) & 0xff;
1013 
1014 	if (fp->ptregs.sr & PS_S) {
1015 		if (vector == VEC_TRACE) {
1016 			/* traced a trapping instruction on a 68020/30,
1017 			 * real exception will be executed afterwards.
1018 			 */
1019 			return;
1020 		}
1021 #ifdef CONFIG_MMU
1022 		if (fixup_exception(&fp->ptregs))
1023 			return;
1024 #endif
1025 		bad_super_trap(fp);
1026 		return;
1027 	}
1028 
1029 	/* send the appropriate signal to the user program */
1030 	switch (vector) {
1031 	    case VEC_ADDRERR:
1032 		si_code = BUS_ADRALN;
1033 		sig = SIGBUS;
1034 		break;
1035 	    case VEC_ILLEGAL:
1036 	    case VEC_LINE10:
1037 	    case VEC_LINE11:
1038 		si_code = ILL_ILLOPC;
1039 		sig = SIGILL;
1040 		break;
1041 	    case VEC_PRIV:
1042 		si_code = ILL_PRVOPC;
1043 		sig = SIGILL;
1044 		break;
1045 	    case VEC_COPROC:
1046 		si_code = ILL_COPROC;
1047 		sig = SIGILL;
1048 		break;
1049 	    case VEC_TRAP1:
1050 	    case VEC_TRAP2:
1051 	    case VEC_TRAP3:
1052 	    case VEC_TRAP4:
1053 	    case VEC_TRAP5:
1054 	    case VEC_TRAP6:
1055 	    case VEC_TRAP7:
1056 	    case VEC_TRAP8:
1057 	    case VEC_TRAP9:
1058 	    case VEC_TRAP10:
1059 	    case VEC_TRAP11:
1060 	    case VEC_TRAP12:
1061 	    case VEC_TRAP13:
1062 	    case VEC_TRAP14:
1063 		si_code = ILL_ILLTRP;
1064 		sig = SIGILL;
1065 		break;
1066 	    case VEC_FPBRUC:
1067 	    case VEC_FPOE:
1068 	    case VEC_FPNAN:
1069 		si_code = FPE_FLTINV;
1070 		sig = SIGFPE;
1071 		break;
1072 	    case VEC_FPIR:
1073 		si_code = FPE_FLTRES;
1074 		sig = SIGFPE;
1075 		break;
1076 	    case VEC_FPDIVZ:
1077 		si_code = FPE_FLTDIV;
1078 		sig = SIGFPE;
1079 		break;
1080 	    case VEC_FPUNDER:
1081 		si_code = FPE_FLTUND;
1082 		sig = SIGFPE;
1083 		break;
1084 	    case VEC_FPOVER:
1085 		si_code = FPE_FLTOVF;
1086 		sig = SIGFPE;
1087 		break;
1088 	    case VEC_ZERODIV:
1089 		si_code = FPE_INTDIV;
1090 		sig = SIGFPE;
1091 		break;
1092 	    case VEC_CHK:
1093 	    case VEC_TRAP:
1094 		si_code = FPE_INTOVF;
1095 		sig = SIGFPE;
1096 		break;
1097 	    case VEC_TRACE:		/* ptrace single step */
1098 		si_code = TRAP_TRACE;
1099 		sig = SIGTRAP;
1100 		break;
1101 	    case VEC_TRAP15:		/* breakpoint */
1102 		si_code = TRAP_BRKPT;
1103 		sig = SIGTRAP;
1104 		break;
1105 	    default:
1106 		si_code = ILL_ILLOPC;
1107 		sig = SIGILL;
1108 		break;
1109 	}
1110 	switch (fp->ptregs.format) {
1111 	    default:
1112 		addr = (void __user *) fp->ptregs.pc;
1113 		break;
1114 	    case 2:
1115 		addr = (void __user *) fp->un.fmt2.iaddr;
1116 		break;
1117 	    case 7:
1118 		addr = (void __user *) fp->un.fmt7.effaddr;
1119 		break;
1120 	    case 9:
1121 		addr = (void __user *) fp->un.fmt9.iaddr;
1122 		break;
1123 	    case 10:
1124 		addr = (void __user *) fp->un.fmta.daddr;
1125 		break;
1126 	    case 11:
1127 		addr = (void __user*) fp->un.fmtb.daddr;
1128 		break;
1129 	}
1130 	force_sig_fault(sig, si_code, addr, current);
1131 }
1132 
1133 void die_if_kernel (char *str, struct pt_regs *fp, int nr)
1134 {
1135 	if (!(fp->sr & PS_S))
1136 		return;
1137 
1138 	console_verbose();
1139 	pr_crit("%s: %08x\n", str, nr);
1140 	show_registers(fp);
1141 	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
1142 	do_exit(SIGSEGV);
1143 }
1144 
1145 asmlinkage void set_esp0(unsigned long ssp)
1146 {
1147 	current->thread.esp0 = ssp;
1148 }
1149 
1150 /*
1151  * This function is called if an error occur while accessing
1152  * user-space from the fpsp040 code.
1153  */
1154 asmlinkage void fpsp040_die(void)
1155 {
1156 	do_exit(SIGSEGV);
1157 }
1158 
1159 #ifdef CONFIG_M68KFPU_EMU
1160 asmlinkage void fpemu_signal(int signal, int code, void *addr)
1161 {
1162 	force_sig_fault(signal, code, addr, current);
1163 }
1164 #endif
1165