1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle
7  * Copyright (C) 1995, 1996 Paul M. Antoine
8  * Copyright (C) 1998 Ulf Carlsson
9  * Copyright (C) 1999 Silicon Graphics, Inc.
10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11  * Copyright (C) 2000, 01 MIPS Technologies, Inc.
12  * Copyright (C) 2002, 2003, 2004, 2005, 2007  Maciej W. Rozycki
13  */
14 #include <linux/bug.h>
15 #include <linux/compiler.h>
16 #include <linux/init.h>
17 #include <linux/mm.h>
18 #include <linux/module.h>
19 #include <linux/sched.h>
20 #include <linux/smp.h>
21 #include <linux/spinlock.h>
22 #include <linux/kallsyms.h>
23 #include <linux/bootmem.h>
24 #include <linux/interrupt.h>
25 #include <linux/ptrace.h>
26 #include <linux/kgdb.h>
27 #include <linux/kdebug.h>
28 #include <linux/kprobes.h>
29 #include <linux/notifier.h>
30 #include <linux/kdb.h>
31 #include <linux/irq.h>
32 #include <linux/perf_event.h>
33 
34 #include <asm/bootinfo.h>
35 #include <asm/branch.h>
36 #include <asm/break.h>
37 #include <asm/cop2.h>
38 #include <asm/cpu.h>
39 #include <asm/dsp.h>
40 #include <asm/fpu.h>
41 #include <asm/fpu_emulator.h>
42 #include <asm/mipsregs.h>
43 #include <asm/mipsmtregs.h>
44 #include <asm/module.h>
45 #include <asm/pgtable.h>
46 #include <asm/ptrace.h>
47 #include <asm/sections.h>
48 #include <asm/system.h>
49 #include <asm/tlbdebug.h>
50 #include <asm/traps.h>
51 #include <asm/uaccess.h>
52 #include <asm/watch.h>
53 #include <asm/mmu_context.h>
54 #include <asm/types.h>
55 #include <asm/stacktrace.h>
56 #include <asm/uasm.h>
57 
58 extern void check_wait(void);
59 extern asmlinkage void r4k_wait(void);
60 extern asmlinkage void rollback_handle_int(void);
61 extern asmlinkage void handle_int(void);
62 extern asmlinkage void handle_tlbm(void);
63 extern asmlinkage void handle_tlbl(void);
64 extern asmlinkage void handle_tlbs(void);
65 extern asmlinkage void handle_adel(void);
66 extern asmlinkage void handle_ades(void);
67 extern asmlinkage void handle_ibe(void);
68 extern asmlinkage void handle_dbe(void);
69 extern asmlinkage void handle_sys(void);
70 extern asmlinkage void handle_bp(void);
71 extern asmlinkage void handle_ri(void);
72 extern asmlinkage void handle_ri_rdhwr_vivt(void);
73 extern asmlinkage void handle_ri_rdhwr(void);
74 extern asmlinkage void handle_cpu(void);
75 extern asmlinkage void handle_ov(void);
76 extern asmlinkage void handle_tr(void);
77 extern asmlinkage void handle_fpe(void);
78 extern asmlinkage void handle_mdmx(void);
79 extern asmlinkage void handle_watch(void);
80 extern asmlinkage void handle_mt(void);
81 extern asmlinkage void handle_dsp(void);
82 extern asmlinkage void handle_mcheck(void);
83 extern asmlinkage void handle_reserved(void);
84 
85 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
86 				    struct mips_fpu_struct *ctx, int has_fpu,
87 				    void *__user *fault_addr);
88 
89 void (*board_be_init)(void);
90 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
91 void (*board_nmi_handler_setup)(void);
92 void (*board_ejtag_handler_setup)(void);
93 void (*board_bind_eic_interrupt)(int irq, int regset);
94 
95 
show_raw_backtrace(unsigned long reg29)96 static void show_raw_backtrace(unsigned long reg29)
97 {
98 	unsigned long *sp = (unsigned long *)(reg29 & ~3);
99 	unsigned long addr;
100 
101 	printk("Call Trace:");
102 #ifdef CONFIG_KALLSYMS
103 	printk("\n");
104 #endif
105 	while (!kstack_end(sp)) {
106 		unsigned long __user *p =
107 			(unsigned long __user *)(unsigned long)sp++;
108 		if (__get_user(addr, p)) {
109 			printk(" (Bad stack address)");
110 			break;
111 		}
112 		if (__kernel_text_address(addr))
113 			print_ip_sym(addr);
114 	}
115 	printk("\n");
116 }
117 
118 #ifdef CONFIG_KALLSYMS
119 int raw_show_trace;
set_raw_show_trace(char * str)120 static int __init set_raw_show_trace(char *str)
121 {
122 	raw_show_trace = 1;
123 	return 1;
124 }
125 __setup("raw_show_trace", set_raw_show_trace);
126 #endif
127 
show_backtrace(struct task_struct * task,const struct pt_regs * regs)128 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
129 {
130 	unsigned long sp = regs->regs[29];
131 	unsigned long ra = regs->regs[31];
132 	unsigned long pc = regs->cp0_epc;
133 
134 	if (raw_show_trace || !__kernel_text_address(pc)) {
135 		show_raw_backtrace(sp);
136 		return;
137 	}
138 	printk("Call Trace:\n");
139 	do {
140 		print_ip_sym(pc);
141 		pc = unwind_stack(task, &sp, pc, &ra);
142 	} while (pc);
143 	printk("\n");
144 }
145 
146 /*
147  * This routine abuses get_user()/put_user() to reference pointers
148  * with at least a bit of error checking ...
149  */
show_stacktrace(struct task_struct * task,const struct pt_regs * regs)150 static void show_stacktrace(struct task_struct *task,
151 	const struct pt_regs *regs)
152 {
153 	const int field = 2 * sizeof(unsigned long);
154 	long stackdata;
155 	int i;
156 	unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
157 
158 	printk("Stack :");
159 	i = 0;
160 	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
161 		if (i && ((i % (64 / field)) == 0))
162 			printk("\n       ");
163 		if (i > 39) {
164 			printk(" ...");
165 			break;
166 		}
167 
168 		if (__get_user(stackdata, sp++)) {
169 			printk(" (Bad stack address)");
170 			break;
171 		}
172 
173 		printk(" %0*lx", field, stackdata);
174 		i++;
175 	}
176 	printk("\n");
177 	show_backtrace(task, regs);
178 }
179 
show_stack(struct task_struct * task,unsigned long * sp)180 void show_stack(struct task_struct *task, unsigned long *sp)
181 {
182 	struct pt_regs regs;
183 	if (sp) {
184 		regs.regs[29] = (unsigned long)sp;
185 		regs.regs[31] = 0;
186 		regs.cp0_epc = 0;
187 	} else {
188 		if (task && task != current) {
189 			regs.regs[29] = task->thread.reg29;
190 			regs.regs[31] = 0;
191 			regs.cp0_epc = task->thread.reg31;
192 #ifdef CONFIG_KGDB_KDB
193 		} else if (atomic_read(&kgdb_active) != -1 &&
194 			   kdb_current_regs) {
195 			memcpy(&regs, kdb_current_regs, sizeof(regs));
196 #endif /* CONFIG_KGDB_KDB */
197 		} else {
198 			prepare_frametrace(&regs);
199 		}
200 	}
201 	show_stacktrace(task, &regs);
202 }
203 
204 /*
205  * The architecture-independent dump_stack generator
206  */
dump_stack(void)207 void dump_stack(void)
208 {
209 	struct pt_regs regs;
210 
211 	prepare_frametrace(&regs);
212 	show_backtrace(current, &regs);
213 }
214 
215 EXPORT_SYMBOL(dump_stack);
216 
show_code(unsigned int __user * pc)217 static void show_code(unsigned int __user *pc)
218 {
219 	long i;
220 	unsigned short __user *pc16 = NULL;
221 
222 	printk("\nCode:");
223 
224 	if ((unsigned long)pc & 1)
225 		pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
226 	for(i = -3 ; i < 6 ; i++) {
227 		unsigned int insn;
228 		if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
229 			printk(" (Bad address in epc)\n");
230 			break;
231 		}
232 		printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
233 	}
234 }
235 
__show_regs(const struct pt_regs * regs)236 static void __show_regs(const struct pt_regs *regs)
237 {
238 	const int field = 2 * sizeof(unsigned long);
239 	unsigned int cause = regs->cp0_cause;
240 	int i;
241 
242 	printk("Cpu %d\n", smp_processor_id());
243 
244 	/*
245 	 * Saved main processor registers
246 	 */
247 	for (i = 0; i < 32; ) {
248 		if ((i % 4) == 0)
249 			printk("$%2d   :", i);
250 		if (i == 0)
251 			printk(" %0*lx", field, 0UL);
252 		else if (i == 26 || i == 27)
253 			printk(" %*s", field, "");
254 		else
255 			printk(" %0*lx", field, regs->regs[i]);
256 
257 		i++;
258 		if ((i % 4) == 0)
259 			printk("\n");
260 	}
261 
262 #ifdef CONFIG_CPU_HAS_SMARTMIPS
263 	printk("Acx    : %0*lx\n", field, regs->acx);
264 #endif
265 	printk("Hi    : %0*lx\n", field, regs->hi);
266 	printk("Lo    : %0*lx\n", field, regs->lo);
267 
268 	/*
269 	 * Saved cp0 registers
270 	 */
271 	printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
272 	       (void *) regs->cp0_epc);
273 	printk("    %s\n", print_tainted());
274 	printk("ra    : %0*lx %pS\n", field, regs->regs[31],
275 	       (void *) regs->regs[31]);
276 
277 	printk("Status: %08x    ", (uint32_t) regs->cp0_status);
278 
279 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
280 		if (regs->cp0_status & ST0_KUO)
281 			printk("KUo ");
282 		if (regs->cp0_status & ST0_IEO)
283 			printk("IEo ");
284 		if (regs->cp0_status & ST0_KUP)
285 			printk("KUp ");
286 		if (regs->cp0_status & ST0_IEP)
287 			printk("IEp ");
288 		if (regs->cp0_status & ST0_KUC)
289 			printk("KUc ");
290 		if (regs->cp0_status & ST0_IEC)
291 			printk("IEc ");
292 	} else {
293 		if (regs->cp0_status & ST0_KX)
294 			printk("KX ");
295 		if (regs->cp0_status & ST0_SX)
296 			printk("SX ");
297 		if (regs->cp0_status & ST0_UX)
298 			printk("UX ");
299 		switch (regs->cp0_status & ST0_KSU) {
300 		case KSU_USER:
301 			printk("USER ");
302 			break;
303 		case KSU_SUPERVISOR:
304 			printk("SUPERVISOR ");
305 			break;
306 		case KSU_KERNEL:
307 			printk("KERNEL ");
308 			break;
309 		default:
310 			printk("BAD_MODE ");
311 			break;
312 		}
313 		if (regs->cp0_status & ST0_ERL)
314 			printk("ERL ");
315 		if (regs->cp0_status & ST0_EXL)
316 			printk("EXL ");
317 		if (regs->cp0_status & ST0_IE)
318 			printk("IE ");
319 	}
320 	printk("\n");
321 
322 	printk("Cause : %08x\n", cause);
323 
324 	cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
325 	if (1 <= cause && cause <= 5)
326 		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
327 
328 	printk("PrId  : %08x (%s)\n", read_c0_prid(),
329 	       cpu_name_string());
330 }
331 
332 /*
333  * FIXME: really the generic show_regs should take a const pointer argument.
334  */
show_regs(struct pt_regs * regs)335 void show_regs(struct pt_regs *regs)
336 {
337 	__show_regs((struct pt_regs *)regs);
338 }
339 
show_registers(struct pt_regs * regs)340 void show_registers(struct pt_regs *regs)
341 {
342 	const int field = 2 * sizeof(unsigned long);
343 
344 	__show_regs(regs);
345 	print_modules();
346 	printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
347 	       current->comm, current->pid, current_thread_info(), current,
348 	      field, current_thread_info()->tp_value);
349 	if (cpu_has_userlocal) {
350 		unsigned long tls;
351 
352 		tls = read_c0_userlocal();
353 		if (tls != current_thread_info()->tp_value)
354 			printk("*HwTLS: %0*lx\n", field, tls);
355 	}
356 
357 	show_stacktrace(current, regs);
358 	show_code((unsigned int __user *) regs->cp0_epc);
359 	printk("\n");
360 }
361 
regs_to_trapnr(struct pt_regs * regs)362 static int regs_to_trapnr(struct pt_regs *regs)
363 {
364 	return (regs->cp0_cause >> 2) & 0x1f;
365 }
366 
367 static DEFINE_SPINLOCK(die_lock);
368 
die(const char * str,struct pt_regs * regs)369 void __noreturn die(const char *str, struct pt_regs *regs)
370 {
371 	static int die_counter;
372 	int sig = SIGSEGV;
373 #ifdef CONFIG_MIPS_MT_SMTC
374 	unsigned long dvpret = dvpe();
375 #endif /* CONFIG_MIPS_MT_SMTC */
376 
377 	if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV) == NOTIFY_STOP)
378 		sig = 0;
379 
380 	console_verbose();
381 	spin_lock_irq(&die_lock);
382 	bust_spinlocks(1);
383 #ifdef CONFIG_MIPS_MT_SMTC
384 	mips_mt_regdump(dvpret);
385 #endif /* CONFIG_MIPS_MT_SMTC */
386 
387 	printk("%s[#%d]:\n", str, ++die_counter);
388 	show_registers(regs);
389 	add_taint(TAINT_DIE);
390 	spin_unlock_irq(&die_lock);
391 
392 	if (in_interrupt())
393 		panic("Fatal exception in interrupt");
394 
395 	if (panic_on_oops) {
396 		printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
397 		ssleep(5);
398 		panic("Fatal exception");
399 	}
400 
401 	do_exit(sig);
402 }
403 
404 extern struct exception_table_entry __start___dbe_table[];
405 extern struct exception_table_entry __stop___dbe_table[];
406 
407 __asm__(
408 "	.section	__dbe_table, \"a\"\n"
409 "	.previous			\n");
410 
411 /* Given an address, look for it in the exception tables. */
search_dbe_tables(unsigned long addr)412 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
413 {
414 	const struct exception_table_entry *e;
415 
416 	e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
417 	if (!e)
418 		e = search_module_dbetables(addr);
419 	return e;
420 }
421 
do_be(struct pt_regs * regs)422 asmlinkage void do_be(struct pt_regs *regs)
423 {
424 	const int field = 2 * sizeof(unsigned long);
425 	const struct exception_table_entry *fixup = NULL;
426 	int data = regs->cp0_cause & 4;
427 	int action = MIPS_BE_FATAL;
428 
429 	/* XXX For now.  Fixme, this searches the wrong table ...  */
430 	if (data && !user_mode(regs))
431 		fixup = search_dbe_tables(exception_epc(regs));
432 
433 	if (fixup)
434 		action = MIPS_BE_FIXUP;
435 
436 	if (board_be_handler)
437 		action = board_be_handler(regs, fixup != NULL);
438 
439 	switch (action) {
440 	case MIPS_BE_DISCARD:
441 		return;
442 	case MIPS_BE_FIXUP:
443 		if (fixup) {
444 			regs->cp0_epc = fixup->nextinsn;
445 			return;
446 		}
447 		break;
448 	default:
449 		break;
450 	}
451 
452 	/*
453 	 * Assume it would be too dangerous to continue ...
454 	 */
455 	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
456 	       data ? "Data" : "Instruction",
457 	       field, regs->cp0_epc, field, regs->regs[31]);
458 	if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs), SIGBUS)
459 	    == NOTIFY_STOP)
460 		return;
461 
462 	die_if_kernel("Oops", regs);
463 	force_sig(SIGBUS, current);
464 }
465 
466 /*
467  * ll/sc, rdhwr, sync emulation
468  */
469 
470 #define OPCODE 0xfc000000
471 #define BASE   0x03e00000
472 #define RT     0x001f0000
473 #define OFFSET 0x0000ffff
474 #define LL     0xc0000000
475 #define SC     0xe0000000
476 #define SPEC0  0x00000000
477 #define SPEC3  0x7c000000
478 #define RD     0x0000f800
479 #define FUNC   0x0000003f
480 #define SYNC   0x0000000f
481 #define RDHWR  0x0000003b
482 
483 /*
484  * The ll_bit is cleared by r*_switch.S
485  */
486 
487 unsigned int ll_bit;
488 struct task_struct *ll_task;
489 
simulate_ll(struct pt_regs * regs,unsigned int opcode)490 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
491 {
492 	unsigned long value, __user *vaddr;
493 	long offset;
494 
495 	/*
496 	 * analyse the ll instruction that just caused a ri exception
497 	 * and put the referenced address to addr.
498 	 */
499 
500 	/* sign extend offset */
501 	offset = opcode & OFFSET;
502 	offset <<= 16;
503 	offset >>= 16;
504 
505 	vaddr = (unsigned long __user *)
506 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
507 
508 	if ((unsigned long)vaddr & 3)
509 		return SIGBUS;
510 	if (get_user(value, vaddr))
511 		return SIGSEGV;
512 
513 	preempt_disable();
514 
515 	if (ll_task == NULL || ll_task == current) {
516 		ll_bit = 1;
517 	} else {
518 		ll_bit = 0;
519 	}
520 	ll_task = current;
521 
522 	preempt_enable();
523 
524 	regs->regs[(opcode & RT) >> 16] = value;
525 
526 	return 0;
527 }
528 
simulate_sc(struct pt_regs * regs,unsigned int opcode)529 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
530 {
531 	unsigned long __user *vaddr;
532 	unsigned long reg;
533 	long offset;
534 
535 	/*
536 	 * analyse the sc instruction that just caused a ri exception
537 	 * and put the referenced address to addr.
538 	 */
539 
540 	/* sign extend offset */
541 	offset = opcode & OFFSET;
542 	offset <<= 16;
543 	offset >>= 16;
544 
545 	vaddr = (unsigned long __user *)
546 	        ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
547 	reg = (opcode & RT) >> 16;
548 
549 	if ((unsigned long)vaddr & 3)
550 		return SIGBUS;
551 
552 	preempt_disable();
553 
554 	if (ll_bit == 0 || ll_task != current) {
555 		regs->regs[reg] = 0;
556 		preempt_enable();
557 		return 0;
558 	}
559 
560 	preempt_enable();
561 
562 	if (put_user(regs->regs[reg], vaddr))
563 		return SIGSEGV;
564 
565 	regs->regs[reg] = 1;
566 
567 	return 0;
568 }
569 
570 /*
571  * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
572  * opcodes are supposed to result in coprocessor unusable exceptions if
573  * executed on ll/sc-less processors.  That's the theory.  In practice a
574  * few processors such as NEC's VR4100 throw reserved instruction exceptions
575  * instead, so we're doing the emulation thing in both exception handlers.
576  */
simulate_llsc(struct pt_regs * regs,unsigned int opcode)577 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
578 {
579 	if ((opcode & OPCODE) == LL) {
580 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
581 				1, 0, regs, 0);
582 		return simulate_ll(regs, opcode);
583 	}
584 	if ((opcode & OPCODE) == SC) {
585 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
586 				1, 0, regs, 0);
587 		return simulate_sc(regs, opcode);
588 	}
589 
590 	return -1;			/* Must be something else ... */
591 }
592 
593 /*
594  * Simulate trapping 'rdhwr' instructions to provide user accessible
595  * registers not implemented in hardware.
596  */
simulate_rdhwr(struct pt_regs * regs,unsigned int opcode)597 static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
598 {
599 	struct thread_info *ti = task_thread_info(current);
600 
601 	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
602 		int rd = (opcode & RD) >> 11;
603 		int rt = (opcode & RT) >> 16;
604 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
605 				1, 0, regs, 0);
606 		switch (rd) {
607 		case 0:		/* CPU number */
608 			regs->regs[rt] = smp_processor_id();
609 			return 0;
610 		case 1:		/* SYNCI length */
611 			regs->regs[rt] = min(current_cpu_data.dcache.linesz,
612 					     current_cpu_data.icache.linesz);
613 			return 0;
614 		case 2:		/* Read count register */
615 			regs->regs[rt] = read_c0_count();
616 			return 0;
617 		case 3:		/* Count register resolution */
618 			switch (current_cpu_data.cputype) {
619 			case CPU_20KC:
620 			case CPU_25KF:
621 				regs->regs[rt] = 1;
622 				break;
623 			default:
624 				regs->regs[rt] = 2;
625 			}
626 			return 0;
627 		case 29:
628 			regs->regs[rt] = ti->tp_value;
629 			return 0;
630 		default:
631 			return -1;
632 		}
633 	}
634 
635 	/* Not ours.  */
636 	return -1;
637 }
638 
simulate_sync(struct pt_regs * regs,unsigned int opcode)639 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
640 {
641 	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
642 		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
643 				1, 0, regs, 0);
644 		return 0;
645 	}
646 
647 	return -1;			/* Must be something else ... */
648 }
649 
do_ov(struct pt_regs * regs)650 asmlinkage void do_ov(struct pt_regs *regs)
651 {
652 	siginfo_t info;
653 
654 	die_if_kernel("Integer overflow", regs);
655 
656 	info.si_code = FPE_INTOVF;
657 	info.si_signo = SIGFPE;
658 	info.si_errno = 0;
659 	info.si_addr = (void __user *) regs->cp0_epc;
660 	force_sig_info(SIGFPE, &info, current);
661 }
662 
process_fpemu_return(int sig,void __user * fault_addr)663 static int process_fpemu_return(int sig, void __user *fault_addr)
664 {
665 	if (sig == SIGSEGV || sig == SIGBUS) {
666 		struct siginfo si = {0};
667 		si.si_addr = fault_addr;
668 		si.si_signo = sig;
669 		if (sig == SIGSEGV) {
670 			if (find_vma(current->mm, (unsigned long)fault_addr))
671 				si.si_code = SEGV_ACCERR;
672 			else
673 				si.si_code = SEGV_MAPERR;
674 		} else {
675 			si.si_code = BUS_ADRERR;
676 		}
677 		force_sig_info(sig, &si, current);
678 		return 1;
679 	} else if (sig) {
680 		force_sig(sig, current);
681 		return 1;
682 	} else {
683 		return 0;
684 	}
685 }
686 
687 /*
688  * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
689  */
do_fpe(struct pt_regs * regs,unsigned long fcr31)690 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
691 {
692 	siginfo_t info = {0};
693 
694 	if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs), SIGFPE)
695 	    == NOTIFY_STOP)
696 		return;
697 	die_if_kernel("FP exception in kernel code", regs);
698 
699 	if (fcr31 & FPU_CSR_UNI_X) {
700 		int sig;
701 		void __user *fault_addr = NULL;
702 
703 		/*
704 		 * Unimplemented operation exception.  If we've got the full
705 		 * software emulator on-board, let's use it...
706 		 *
707 		 * Force FPU to dump state into task/thread context.  We're
708 		 * moving a lot of data here for what is probably a single
709 		 * instruction, but the alternative is to pre-decode the FP
710 		 * register operands before invoking the emulator, which seems
711 		 * a bit extreme for what should be an infrequent event.
712 		 */
713 		/* Ensure 'resume' not overwrite saved fp context again. */
714 		lose_fpu(1);
715 
716 		/* Run the emulator */
717 		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
718 					       &fault_addr);
719 
720 		/*
721 		 * We can't allow the emulated instruction to leave any of
722 		 * the cause bit set in $fcr31.
723 		 */
724 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
725 
726 		/* Restore the hardware register state */
727 		own_fpu(1);	/* Using the FPU again.  */
728 
729 		/* If something went wrong, signal */
730 		process_fpemu_return(sig, fault_addr);
731 
732 		return;
733 	} else if (fcr31 & FPU_CSR_INV_X)
734 		info.si_code = FPE_FLTINV;
735 	else if (fcr31 & FPU_CSR_DIV_X)
736 		info.si_code = FPE_FLTDIV;
737 	else if (fcr31 & FPU_CSR_OVF_X)
738 		info.si_code = FPE_FLTOVF;
739 	else if (fcr31 & FPU_CSR_UDF_X)
740 		info.si_code = FPE_FLTUND;
741 	else if (fcr31 & FPU_CSR_INE_X)
742 		info.si_code = FPE_FLTRES;
743 	else
744 		info.si_code = __SI_FAULT;
745 	info.si_signo = SIGFPE;
746 	info.si_errno = 0;
747 	info.si_addr = (void __user *) regs->cp0_epc;
748 	force_sig_info(SIGFPE, &info, current);
749 }
750 
do_trap_or_bp(struct pt_regs * regs,unsigned int code,const char * str)751 static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
752 	const char *str)
753 {
754 	siginfo_t info;
755 	char b[40];
756 
757 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
758 	if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
759 		return;
760 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
761 
762 	if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
763 		return;
764 
765 	/*
766 	 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
767 	 * insns, even for trap and break codes that indicate arithmetic
768 	 * failures.  Weird ...
769 	 * But should we continue the brokenness???  --macro
770 	 */
771 	switch (code) {
772 	case BRK_OVERFLOW:
773 	case BRK_DIVZERO:
774 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
775 		die_if_kernel(b, regs);
776 		if (code == BRK_DIVZERO)
777 			info.si_code = FPE_INTDIV;
778 		else
779 			info.si_code = FPE_INTOVF;
780 		info.si_signo = SIGFPE;
781 		info.si_errno = 0;
782 		info.si_addr = (void __user *) regs->cp0_epc;
783 		force_sig_info(SIGFPE, &info, current);
784 		break;
785 	case BRK_BUG:
786 		die_if_kernel("Kernel bug detected", regs);
787 		force_sig(SIGTRAP, current);
788 		break;
789 	case BRK_MEMU:
790 		/*
791 		 * Address errors may be deliberately induced by the FPU
792 		 * emulator to retake control of the CPU after executing the
793 		 * instruction in the delay slot of an emulated branch.
794 		 *
795 		 * Terminate if exception was recognized as a delay slot return
796 		 * otherwise handle as normal.
797 		 */
798 		if (do_dsemulret(regs))
799 			return;
800 
801 		die_if_kernel("Math emu break/trap", regs);
802 		force_sig(SIGTRAP, current);
803 		break;
804 	default:
805 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
806 		die_if_kernel(b, regs);
807 		force_sig(SIGTRAP, current);
808 	}
809 }
810 
do_bp(struct pt_regs * regs)811 asmlinkage void do_bp(struct pt_regs *regs)
812 {
813 	unsigned int opcode, bcode;
814 
815 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
816 		goto out_sigsegv;
817 
818 	/*
819 	 * There is the ancient bug in the MIPS assemblers that the break
820 	 * code starts left to bit 16 instead to bit 6 in the opcode.
821 	 * Gas is bug-compatible, but not always, grrr...
822 	 * We handle both cases with a simple heuristics.  --macro
823 	 */
824 	bcode = ((opcode >> 6) & ((1 << 20) - 1));
825 	if (bcode >= (1 << 10))
826 		bcode >>= 10;
827 
828 	/*
829 	 * notify the kprobe handlers, if instruction is likely to
830 	 * pertain to them.
831 	 */
832 	switch (bcode) {
833 	case BRK_KPROBE_BP:
834 		if (notify_die(DIE_BREAK, "debug", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
835 			return;
836 		else
837 			break;
838 	case BRK_KPROBE_SSTEPBP:
839 		if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
840 			return;
841 		else
842 			break;
843 	default:
844 		break;
845 	}
846 
847 	do_trap_or_bp(regs, bcode, "Break");
848 	return;
849 
850 out_sigsegv:
851 	force_sig(SIGSEGV, current);
852 }
853 
do_tr(struct pt_regs * regs)854 asmlinkage void do_tr(struct pt_regs *regs)
855 {
856 	unsigned int opcode, tcode = 0;
857 
858 	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
859 		goto out_sigsegv;
860 
861 	/* Immediate versions don't provide a code.  */
862 	if (!(opcode & OPCODE))
863 		tcode = ((opcode >> 6) & ((1 << 10) - 1));
864 
865 	do_trap_or_bp(regs, tcode, "Trap");
866 	return;
867 
868 out_sigsegv:
869 	force_sig(SIGSEGV, current);
870 }
871 
do_ri(struct pt_regs * regs)872 asmlinkage void do_ri(struct pt_regs *regs)
873 {
874 	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
875 	unsigned long old_epc = regs->cp0_epc;
876 	unsigned int opcode = 0;
877 	int status = -1;
878 
879 	if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs), SIGILL)
880 	    == NOTIFY_STOP)
881 		return;
882 
883 	die_if_kernel("Reserved instruction in kernel code", regs);
884 
885 	if (unlikely(compute_return_epc(regs) < 0))
886 		return;
887 
888 	if (unlikely(get_user(opcode, epc) < 0))
889 		status = SIGSEGV;
890 
891 	if (!cpu_has_llsc && status < 0)
892 		status = simulate_llsc(regs, opcode);
893 
894 	if (status < 0)
895 		status = simulate_rdhwr(regs, opcode);
896 
897 	if (status < 0)
898 		status = simulate_sync(regs, opcode);
899 
900 	if (status < 0)
901 		status = SIGILL;
902 
903 	if (unlikely(status > 0)) {
904 		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
905 		force_sig(status, current);
906 	}
907 }
908 
909 /*
910  * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
911  * emulated more than some threshold number of instructions, force migration to
912  * a "CPU" that has FP support.
913  */
mt_ase_fp_affinity(void)914 static void mt_ase_fp_affinity(void)
915 {
916 #ifdef CONFIG_MIPS_MT_FPAFF
917 	if (mt_fpemul_threshold > 0 &&
918 	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
919 		/*
920 		 * If there's no FPU present, or if the application has already
921 		 * restricted the allowed set to exclude any CPUs with FPUs,
922 		 * we'll skip the procedure.
923 		 */
924 		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
925 			cpumask_t tmask;
926 
927 			current->thread.user_cpus_allowed
928 				= current->cpus_allowed;
929 			cpus_and(tmask, current->cpus_allowed,
930 				mt_fpu_cpumask);
931 			set_cpus_allowed_ptr(current, &tmask);
932 			set_thread_flag(TIF_FPUBOUND);
933 		}
934 	}
935 #endif /* CONFIG_MIPS_MT_FPAFF */
936 }
937 
938 /*
939  * No lock; only written during early bootup by CPU 0.
940  */
941 static RAW_NOTIFIER_HEAD(cu2_chain);
942 
register_cu2_notifier(struct notifier_block * nb)943 int __ref register_cu2_notifier(struct notifier_block *nb)
944 {
945 	return raw_notifier_chain_register(&cu2_chain, nb);
946 }
947 
cu2_notifier_call_chain(unsigned long val,void * v)948 int cu2_notifier_call_chain(unsigned long val, void *v)
949 {
950 	return raw_notifier_call_chain(&cu2_chain, val, v);
951 }
952 
default_cu2_call(struct notifier_block * nfb,unsigned long action,void * data)953 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
954         void *data)
955 {
956 	struct pt_regs *regs = data;
957 
958 	switch (action) {
959 	default:
960 		die_if_kernel("Unhandled kernel unaligned access or invalid "
961 			      "instruction", regs);
962 		/* Fall through  */
963 
964 	case CU2_EXCEPTION:
965 		force_sig(SIGILL, current);
966 	}
967 
968 	return NOTIFY_OK;
969 }
970 
do_cpu(struct pt_regs * regs)971 asmlinkage void do_cpu(struct pt_regs *regs)
972 {
973 	unsigned int __user *epc;
974 	unsigned long old_epc;
975 	unsigned int opcode;
976 	unsigned int cpid;
977 	int status;
978 	unsigned long __maybe_unused flags;
979 
980 	die_if_kernel("do_cpu invoked from kernel context!", regs);
981 
982 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
983 
984 	switch (cpid) {
985 	case 0:
986 		epc = (unsigned int __user *)exception_epc(regs);
987 		old_epc = regs->cp0_epc;
988 		opcode = 0;
989 		status = -1;
990 
991 		if (unlikely(compute_return_epc(regs) < 0))
992 			return;
993 
994 		if (unlikely(get_user(opcode, epc) < 0))
995 			status = SIGSEGV;
996 
997 		if (!cpu_has_llsc && status < 0)
998 			status = simulate_llsc(regs, opcode);
999 
1000 		if (status < 0)
1001 			status = simulate_rdhwr(regs, opcode);
1002 
1003 		if (status < 0)
1004 			status = SIGILL;
1005 
1006 		if (unlikely(status > 0)) {
1007 			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
1008 			force_sig(status, current);
1009 		}
1010 
1011 		return;
1012 
1013 	case 1:
1014 		if (used_math())	/* Using the FPU again.  */
1015 			own_fpu(1);
1016 		else {			/* First time FPU user.  */
1017 			init_fpu();
1018 			set_used_math();
1019 		}
1020 
1021 		if (!raw_cpu_has_fpu) {
1022 			int sig;
1023 			void __user *fault_addr = NULL;
1024 			sig = fpu_emulator_cop1Handler(regs,
1025 						       &current->thread.fpu,
1026 						       0, &fault_addr);
1027 			if (!process_fpemu_return(sig, fault_addr))
1028 				mt_ase_fp_affinity();
1029 		}
1030 
1031 		return;
1032 
1033 	case 2:
1034 		raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1035 		return;
1036 
1037 	case 3:
1038 		break;
1039 	}
1040 
1041 	force_sig(SIGILL, current);
1042 }
1043 
do_mdmx(struct pt_regs * regs)1044 asmlinkage void do_mdmx(struct pt_regs *regs)
1045 {
1046 	force_sig(SIGILL, current);
1047 }
1048 
1049 /*
1050  * Called with interrupts disabled.
1051  */
do_watch(struct pt_regs * regs)1052 asmlinkage void do_watch(struct pt_regs *regs)
1053 {
1054 	u32 cause;
1055 
1056 	/*
1057 	 * Clear WP (bit 22) bit of cause register so we don't loop
1058 	 * forever.
1059 	 */
1060 	cause = read_c0_cause();
1061 	cause &= ~(1 << 22);
1062 	write_c0_cause(cause);
1063 
1064 	/*
1065 	 * If the current thread has the watch registers loaded, save
1066 	 * their values and send SIGTRAP.  Otherwise another thread
1067 	 * left the registers set, clear them and continue.
1068 	 */
1069 	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1070 		mips_read_watch_registers();
1071 		local_irq_enable();
1072 		force_sig(SIGTRAP, current);
1073 	} else {
1074 		mips_clear_watch_registers();
1075 		local_irq_enable();
1076 	}
1077 }
1078 
do_mcheck(struct pt_regs * regs)1079 asmlinkage void do_mcheck(struct pt_regs *regs)
1080 {
1081 	const int field = 2 * sizeof(unsigned long);
1082 	int multi_match = regs->cp0_status & ST0_TS;
1083 
1084 	show_regs(regs);
1085 
1086 	if (multi_match) {
1087 		printk("Index   : %0x\n", read_c0_index());
1088 		printk("Pagemask: %0x\n", read_c0_pagemask());
1089 		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
1090 		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1091 		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1092 		printk("\n");
1093 		dump_tlb_all();
1094 	}
1095 
1096 	show_code((unsigned int __user *) regs->cp0_epc);
1097 
1098 	/*
1099 	 * Some chips may have other causes of machine check (e.g. SB1
1100 	 * graduation timer)
1101 	 */
1102 	panic("Caught Machine Check exception - %scaused by multiple "
1103 	      "matching entries in the TLB.",
1104 	      (multi_match) ? "" : "not ");
1105 }
1106 
do_mt(struct pt_regs * regs)1107 asmlinkage void do_mt(struct pt_regs *regs)
1108 {
1109 	int subcode;
1110 
1111 	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1112 			>> VPECONTROL_EXCPT_SHIFT;
1113 	switch (subcode) {
1114 	case 0:
1115 		printk(KERN_DEBUG "Thread Underflow\n");
1116 		break;
1117 	case 1:
1118 		printk(KERN_DEBUG "Thread Overflow\n");
1119 		break;
1120 	case 2:
1121 		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1122 		break;
1123 	case 3:
1124 		printk(KERN_DEBUG "Gating Storage Exception\n");
1125 		break;
1126 	case 4:
1127 		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1128 		break;
1129 	case 5:
1130 		printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
1131 		break;
1132 	default:
1133 		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1134 			subcode);
1135 		break;
1136 	}
1137 	die_if_kernel("MIPS MT Thread exception in kernel", regs);
1138 
1139 	force_sig(SIGILL, current);
1140 }
1141 
1142 
do_dsp(struct pt_regs * regs)1143 asmlinkage void do_dsp(struct pt_regs *regs)
1144 {
1145 	if (cpu_has_dsp)
1146 		panic("Unexpected DSP exception\n");
1147 
1148 	force_sig(SIGILL, current);
1149 }
1150 
do_reserved(struct pt_regs * regs)1151 asmlinkage void do_reserved(struct pt_regs *regs)
1152 {
1153 	/*
1154 	 * Game over - no way to handle this if it ever occurs.  Most probably
1155 	 * caused by a new unknown cpu type or after another deadly
1156 	 * hard/software error.
1157 	 */
1158 	show_regs(regs);
1159 	panic("Caught reserved exception %ld - should not happen.",
1160 	      (regs->cp0_cause & 0x7f) >> 2);
1161 }
1162 
1163 static int __initdata l1parity = 1;
nol1parity(char * s)1164 static int __init nol1parity(char *s)
1165 {
1166 	l1parity = 0;
1167 	return 1;
1168 }
1169 __setup("nol1par", nol1parity);
1170 static int __initdata l2parity = 1;
nol2parity(char * s)1171 static int __init nol2parity(char *s)
1172 {
1173 	l2parity = 0;
1174 	return 1;
1175 }
1176 __setup("nol2par", nol2parity);
1177 
1178 /*
1179  * Some MIPS CPUs can enable/disable for cache parity detection, but do
1180  * it different ways.
1181  */
parity_protection_init(void)1182 static inline void parity_protection_init(void)
1183 {
1184 	switch (current_cpu_type()) {
1185 	case CPU_24K:
1186 	case CPU_34K:
1187 	case CPU_74K:
1188 	case CPU_1004K:
1189 		{
1190 #define ERRCTL_PE	0x80000000
1191 #define ERRCTL_L2P	0x00800000
1192 			unsigned long errctl;
1193 			unsigned int l1parity_present, l2parity_present;
1194 
1195 			errctl = read_c0_ecc();
1196 			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1197 
1198 			/* probe L1 parity support */
1199 			write_c0_ecc(errctl | ERRCTL_PE);
1200 			back_to_back_c0_hazard();
1201 			l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1202 
1203 			/* probe L2 parity support */
1204 			write_c0_ecc(errctl|ERRCTL_L2P);
1205 			back_to_back_c0_hazard();
1206 			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1207 
1208 			if (l1parity_present && l2parity_present) {
1209 				if (l1parity)
1210 					errctl |= ERRCTL_PE;
1211 				if (l1parity ^ l2parity)
1212 					errctl |= ERRCTL_L2P;
1213 			} else if (l1parity_present) {
1214 				if (l1parity)
1215 					errctl |= ERRCTL_PE;
1216 			} else if (l2parity_present) {
1217 				if (l2parity)
1218 					errctl |= ERRCTL_L2P;
1219 			} else {
1220 				/* No parity available */
1221 			}
1222 
1223 			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1224 
1225 			write_c0_ecc(errctl);
1226 			back_to_back_c0_hazard();
1227 			errctl = read_c0_ecc();
1228 			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1229 
1230 			if (l1parity_present)
1231 				printk(KERN_INFO "Cache parity protection %sabled\n",
1232 				       (errctl & ERRCTL_PE) ? "en" : "dis");
1233 
1234 			if (l2parity_present) {
1235 				if (l1parity_present && l1parity)
1236 					errctl ^= ERRCTL_L2P;
1237 				printk(KERN_INFO "L2 cache parity protection %sabled\n",
1238 				       (errctl & ERRCTL_L2P) ? "en" : "dis");
1239 			}
1240 		}
1241 		break;
1242 
1243 	case CPU_5KC:
1244 		write_c0_ecc(0x80000000);
1245 		back_to_back_c0_hazard();
1246 		/* Set the PE bit (bit 31) in the c0_errctl register. */
1247 		printk(KERN_INFO "Cache parity protection %sabled\n",
1248 		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1249 		break;
1250 	case CPU_20KC:
1251 	case CPU_25KF:
1252 		/* Clear the DE bit (bit 16) in the c0_status register. */
1253 		printk(KERN_INFO "Enable cache parity protection for "
1254 		       "MIPS 20KC/25KF CPUs.\n");
1255 		clear_c0_status(ST0_DE);
1256 		break;
1257 	default:
1258 		break;
1259 	}
1260 }
1261 
cache_parity_error(void)1262 asmlinkage void cache_parity_error(void)
1263 {
1264 	const int field = 2 * sizeof(unsigned long);
1265 	unsigned int reg_val;
1266 
1267 	/* For the moment, report the problem and hang. */
1268 	printk("Cache error exception:\n");
1269 	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1270 	reg_val = read_c0_cacheerr();
1271 	printk("c0_cacheerr == %08x\n", reg_val);
1272 
1273 	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1274 	       reg_val & (1<<30) ? "secondary" : "primary",
1275 	       reg_val & (1<<31) ? "data" : "insn");
1276 	printk("Error bits: %s%s%s%s%s%s%s\n",
1277 	       reg_val & (1<<29) ? "ED " : "",
1278 	       reg_val & (1<<28) ? "ET " : "",
1279 	       reg_val & (1<<26) ? "EE " : "",
1280 	       reg_val & (1<<25) ? "EB " : "",
1281 	       reg_val & (1<<24) ? "EI " : "",
1282 	       reg_val & (1<<23) ? "E1 " : "",
1283 	       reg_val & (1<<22) ? "E0 " : "");
1284 	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1285 
1286 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1287 	if (reg_val & (1<<22))
1288 		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1289 
1290 	if (reg_val & (1<<23))
1291 		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1292 #endif
1293 
1294 	panic("Can't handle the cache error!");
1295 }
1296 
1297 /*
1298  * SDBBP EJTAG debug exception handler.
1299  * We skip the instruction and return to the next instruction.
1300  */
ejtag_exception_handler(struct pt_regs * regs)1301 void ejtag_exception_handler(struct pt_regs *regs)
1302 {
1303 	const int field = 2 * sizeof(unsigned long);
1304 	unsigned long depc, old_epc;
1305 	unsigned int debug;
1306 
1307 	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1308 	depc = read_c0_depc();
1309 	debug = read_c0_debug();
1310 	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1311 	if (debug & 0x80000000) {
1312 		/*
1313 		 * In branch delay slot.
1314 		 * We cheat a little bit here and use EPC to calculate the
1315 		 * debug return address (DEPC). EPC is restored after the
1316 		 * calculation.
1317 		 */
1318 		old_epc = regs->cp0_epc;
1319 		regs->cp0_epc = depc;
1320 		__compute_return_epc(regs);
1321 		depc = regs->cp0_epc;
1322 		regs->cp0_epc = old_epc;
1323 	} else
1324 		depc += 4;
1325 	write_c0_depc(depc);
1326 
1327 #if 0
1328 	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1329 	write_c0_debug(debug | 0x100);
1330 #endif
1331 }
1332 
1333 /*
1334  * NMI exception handler.
1335  */
nmi_exception_handler(struct pt_regs * regs)1336 NORET_TYPE void ATTRIB_NORET nmi_exception_handler(struct pt_regs *regs)
1337 {
1338 	bust_spinlocks(1);
1339 	printk("NMI taken!!!!\n");
1340 	die("NMI", regs);
1341 }
1342 
1343 #define VECTORSPACING 0x100	/* for EI/VI mode */
1344 
1345 unsigned long ebase;
1346 unsigned long exception_handlers[32];
1347 unsigned long vi_handlers[64];
1348 
set_except_vector(int n,void * addr)1349 void __init *set_except_vector(int n, void *addr)
1350 {
1351 	unsigned long handler = (unsigned long) addr;
1352 	unsigned long old_handler = exception_handlers[n];
1353 
1354 	exception_handlers[n] = handler;
1355 	if (n == 0 && cpu_has_divec) {
1356 		unsigned long jump_mask = ~((1 << 28) - 1);
1357 		u32 *buf = (u32 *)(ebase + 0x200);
1358 		unsigned int k0 = 26;
1359 		if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1360 			uasm_i_j(&buf, handler & ~jump_mask);
1361 			uasm_i_nop(&buf);
1362 		} else {
1363 			UASM_i_LA(&buf, k0, handler);
1364 			uasm_i_jr(&buf, k0);
1365 			uasm_i_nop(&buf);
1366 		}
1367 		local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1368 	}
1369 	return (void *)old_handler;
1370 }
1371 
do_default_vi(void)1372 static asmlinkage void do_default_vi(void)
1373 {
1374 	show_regs(get_irq_regs());
1375 	panic("Caught unexpected vectored interrupt.");
1376 }
1377 
set_vi_srs_handler(int n,vi_handler_t addr,int srs)1378 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1379 {
1380 	unsigned long handler;
1381 	unsigned long old_handler = vi_handlers[n];
1382 	int srssets = current_cpu_data.srsets;
1383 	u32 *w;
1384 	unsigned char *b;
1385 
1386 	BUG_ON(!cpu_has_veic && !cpu_has_vint);
1387 
1388 	if (addr == NULL) {
1389 		handler = (unsigned long) do_default_vi;
1390 		srs = 0;
1391 	} else
1392 		handler = (unsigned long) addr;
1393 	vi_handlers[n] = (unsigned long) addr;
1394 
1395 	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1396 
1397 	if (srs >= srssets)
1398 		panic("Shadow register set %d not supported", srs);
1399 
1400 	if (cpu_has_veic) {
1401 		if (board_bind_eic_interrupt)
1402 			board_bind_eic_interrupt(n, srs);
1403 	} else if (cpu_has_vint) {
1404 		/* SRSMap is only defined if shadow sets are implemented */
1405 		if (srssets > 1)
1406 			change_c0_srsmap(0xf << n*4, srs << n*4);
1407 	}
1408 
1409 	if (srs == 0) {
1410 		/*
1411 		 * If no shadow set is selected then use the default handler
1412 		 * that does normal register saving and a standard interrupt exit
1413 		 */
1414 
1415 		extern char except_vec_vi, except_vec_vi_lui;
1416 		extern char except_vec_vi_ori, except_vec_vi_end;
1417 		extern char rollback_except_vec_vi;
1418 		char *vec_start = (cpu_wait == r4k_wait) ?
1419 			&rollback_except_vec_vi : &except_vec_vi;
1420 #ifdef CONFIG_MIPS_MT_SMTC
1421 		/*
1422 		 * We need to provide the SMTC vectored interrupt handler
1423 		 * not only with the address of the handler, but with the
1424 		 * Status.IM bit to be masked before going there.
1425 		 */
1426 		extern char except_vec_vi_mori;
1427 		const int mori_offset = &except_vec_vi_mori - vec_start;
1428 #endif /* CONFIG_MIPS_MT_SMTC */
1429 		const int handler_len = &except_vec_vi_end - vec_start;
1430 		const int lui_offset = &except_vec_vi_lui - vec_start;
1431 		const int ori_offset = &except_vec_vi_ori - vec_start;
1432 
1433 		if (handler_len > VECTORSPACING) {
1434 			/*
1435 			 * Sigh... panicing won't help as the console
1436 			 * is probably not configured :(
1437 			 */
1438 			panic("VECTORSPACING too small");
1439 		}
1440 
1441 		memcpy(b, vec_start, handler_len);
1442 #ifdef CONFIG_MIPS_MT_SMTC
1443 		BUG_ON(n > 7);	/* Vector index %d exceeds SMTC maximum. */
1444 
1445 		w = (u32 *)(b + mori_offset);
1446 		*w = (*w & 0xffff0000) | (0x100 << n);
1447 #endif /* CONFIG_MIPS_MT_SMTC */
1448 		w = (u32 *)(b + lui_offset);
1449 		*w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1450 		w = (u32 *)(b + ori_offset);
1451 		*w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1452 		local_flush_icache_range((unsigned long)b,
1453 					 (unsigned long)(b+handler_len));
1454 	}
1455 	else {
1456 		/*
1457 		 * In other cases jump directly to the interrupt handler
1458 		 *
1459 		 * It is the handlers responsibility to save registers if required
1460 		 * (eg hi/lo) and return from the exception using "eret"
1461 		 */
1462 		w = (u32 *)b;
1463 		*w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1464 		*w = 0;
1465 		local_flush_icache_range((unsigned long)b,
1466 					 (unsigned long)(b+8));
1467 	}
1468 
1469 	return (void *)old_handler;
1470 }
1471 
set_vi_handler(int n,vi_handler_t addr)1472 void *set_vi_handler(int n, vi_handler_t addr)
1473 {
1474 	return set_vi_srs_handler(n, addr, 0);
1475 }
1476 
1477 extern void cpu_cache_init(void);
1478 extern void tlb_init(void);
1479 extern void flush_tlb_handlers(void);
1480 
1481 /*
1482  * Timer interrupt
1483  */
1484 int cp0_compare_irq;
1485 int cp0_compare_irq_shift;
1486 
1487 /*
1488  * Performance counter IRQ or -1 if shared with timer
1489  */
1490 int cp0_perfcount_irq;
1491 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1492 
1493 static int __cpuinitdata noulri;
1494 
ulri_disable(char * s)1495 static int __init ulri_disable(char *s)
1496 {
1497 	pr_info("Disabling ulri\n");
1498 	noulri = 1;
1499 
1500 	return 1;
1501 }
1502 __setup("noulri", ulri_disable);
1503 
per_cpu_trap_init(void)1504 void __cpuinit per_cpu_trap_init(void)
1505 {
1506 	unsigned int cpu = smp_processor_id();
1507 	unsigned int status_set = ST0_CU0;
1508 	unsigned int hwrena = cpu_hwrena_impl_bits;
1509 #ifdef CONFIG_MIPS_MT_SMTC
1510 	int secondaryTC = 0;
1511 	int bootTC = (cpu == 0);
1512 
1513 	/*
1514 	 * Only do per_cpu_trap_init() for first TC of Each VPE.
1515 	 * Note that this hack assumes that the SMTC init code
1516 	 * assigns TCs consecutively and in ascending order.
1517 	 */
1518 
1519 	if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1520 	    ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1521 		secondaryTC = 1;
1522 #endif /* CONFIG_MIPS_MT_SMTC */
1523 
1524 	/*
1525 	 * Disable coprocessors and select 32-bit or 64-bit addressing
1526 	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
1527 	 * flag that some firmware may have left set and the TS bit (for
1528 	 * IP27).  Set XX for ISA IV code to work.
1529 	 */
1530 #ifdef CONFIG_64BIT
1531 	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1532 #endif
1533 	if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1534 		status_set |= ST0_XX;
1535 	if (cpu_has_dsp)
1536 		status_set |= ST0_MX;
1537 
1538 	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1539 			 status_set);
1540 
1541 	if (cpu_has_mips_r2)
1542 		hwrena |= 0x0000000f;
1543 
1544 	if (!noulri && cpu_has_userlocal)
1545 		hwrena |= (1 << 29);
1546 
1547 	if (hwrena)
1548 		write_c0_hwrena(hwrena);
1549 
1550 #ifdef CONFIG_MIPS_MT_SMTC
1551 	if (!secondaryTC) {
1552 #endif /* CONFIG_MIPS_MT_SMTC */
1553 
1554 	if (cpu_has_veic || cpu_has_vint) {
1555 		unsigned long sr = set_c0_status(ST0_BEV);
1556 		write_c0_ebase(ebase);
1557 		write_c0_status(sr);
1558 		/* Setting vector spacing enables EI/VI mode  */
1559 		change_c0_intctl(0x3e0, VECTORSPACING);
1560 	}
1561 	if (cpu_has_divec) {
1562 		if (cpu_has_mipsmt) {
1563 			unsigned int vpflags = dvpe();
1564 			set_c0_cause(CAUSEF_IV);
1565 			evpe(vpflags);
1566 		} else
1567 			set_c0_cause(CAUSEF_IV);
1568 	}
1569 
1570 	/*
1571 	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1572 	 *
1573 	 *  o read IntCtl.IPTI to determine the timer interrupt
1574 	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
1575 	 */
1576 	if (cpu_has_mips_r2) {
1577 		cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
1578 		cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
1579 		cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
1580 		if (cp0_perfcount_irq == cp0_compare_irq)
1581 			cp0_perfcount_irq = -1;
1582 	} else {
1583 		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1584 		cp0_compare_irq_shift = cp0_compare_irq;
1585 		cp0_perfcount_irq = -1;
1586 	}
1587 
1588 #ifdef CONFIG_MIPS_MT_SMTC
1589 	}
1590 #endif /* CONFIG_MIPS_MT_SMTC */
1591 
1592 	cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1593 
1594 	atomic_inc(&init_mm.mm_count);
1595 	current->active_mm = &init_mm;
1596 	BUG_ON(current->mm);
1597 	enter_lazy_tlb(&init_mm, current);
1598 
1599 #ifdef CONFIG_MIPS_MT_SMTC
1600 	if (bootTC) {
1601 #endif /* CONFIG_MIPS_MT_SMTC */
1602 		cpu_cache_init();
1603 		tlb_init();
1604 #ifdef CONFIG_MIPS_MT_SMTC
1605 	} else if (!secondaryTC) {
1606 		/*
1607 		 * First TC in non-boot VPE must do subset of tlb_init()
1608 		 * for MMU countrol registers.
1609 		 */
1610 		write_c0_pagemask(PM_DEFAULT_MASK);
1611 		write_c0_wired(0);
1612 	}
1613 #endif /* CONFIG_MIPS_MT_SMTC */
1614 	TLBMISS_HANDLER_SETUP();
1615 }
1616 
1617 /* Install CPU exception handler */
set_handler(unsigned long offset,void * addr,unsigned long size)1618 void __init set_handler(unsigned long offset, void *addr, unsigned long size)
1619 {
1620 	memcpy((void *)(ebase + offset), addr, size);
1621 	local_flush_icache_range(ebase + offset, ebase + offset + size);
1622 }
1623 
1624 static char panic_null_cerr[] __cpuinitdata =
1625 	"Trying to set NULL cache error exception handler";
1626 
1627 /*
1628  * Install uncached CPU exception handler.
1629  * This is suitable only for the cache error exception which is the only
1630  * exception handler that is being run uncached.
1631  */
set_uncached_handler(unsigned long offset,void * addr,unsigned long size)1632 void __cpuinit set_uncached_handler(unsigned long offset, void *addr,
1633 	unsigned long size)
1634 {
1635 	unsigned long uncached_ebase = CKSEG1ADDR(ebase);
1636 
1637 	if (!addr)
1638 		panic(panic_null_cerr);
1639 
1640 	memcpy((void *)(uncached_ebase + offset), addr, size);
1641 }
1642 
1643 static int __initdata rdhwr_noopt;
set_rdhwr_noopt(char * str)1644 static int __init set_rdhwr_noopt(char *str)
1645 {
1646 	rdhwr_noopt = 1;
1647 	return 1;
1648 }
1649 
1650 __setup("rdhwr_noopt", set_rdhwr_noopt);
1651 
trap_init(void)1652 void __init trap_init(void)
1653 {
1654 	extern char except_vec3_generic, except_vec3_r4000;
1655 	extern char except_vec4;
1656 	unsigned long i;
1657 	int rollback;
1658 
1659 	check_wait();
1660 	rollback = (cpu_wait == r4k_wait);
1661 
1662 #if defined(CONFIG_KGDB)
1663 	if (kgdb_early_setup)
1664 		return;	/* Already done */
1665 #endif
1666 
1667 	if (cpu_has_veic || cpu_has_vint) {
1668 		unsigned long size = 0x200 + VECTORSPACING*64;
1669 		ebase = (unsigned long)
1670 			__alloc_bootmem(size, 1 << fls(size), 0);
1671 	} else {
1672 		ebase = CKSEG0;
1673 		if (cpu_has_mips_r2)
1674 			ebase += (read_c0_ebase() & 0x3ffff000);
1675 	}
1676 
1677 	per_cpu_trap_init();
1678 
1679 	/*
1680 	 * Copy the generic exception handlers to their final destination.
1681 	 * This will be overriden later as suitable for a particular
1682 	 * configuration.
1683 	 */
1684 	set_handler(0x180, &except_vec3_generic, 0x80);
1685 
1686 	/*
1687 	 * Setup default vectors
1688 	 */
1689 	for (i = 0; i <= 31; i++)
1690 		set_except_vector(i, handle_reserved);
1691 
1692 	/*
1693 	 * Copy the EJTAG debug exception vector handler code to it's final
1694 	 * destination.
1695 	 */
1696 	if (cpu_has_ejtag && board_ejtag_handler_setup)
1697 		board_ejtag_handler_setup();
1698 
1699 	/*
1700 	 * Only some CPUs have the watch exceptions.
1701 	 */
1702 	if (cpu_has_watch)
1703 		set_except_vector(23, handle_watch);
1704 
1705 	/*
1706 	 * Initialise interrupt handlers
1707 	 */
1708 	if (cpu_has_veic || cpu_has_vint) {
1709 		int nvec = cpu_has_veic ? 64 : 8;
1710 		for (i = 0; i < nvec; i++)
1711 			set_vi_handler(i, NULL);
1712 	}
1713 	else if (cpu_has_divec)
1714 		set_handler(0x200, &except_vec4, 0x8);
1715 
1716 	/*
1717 	 * Some CPUs can enable/disable for cache parity detection, but does
1718 	 * it different ways.
1719 	 */
1720 	parity_protection_init();
1721 
1722 	/*
1723 	 * The Data Bus Errors / Instruction Bus Errors are signaled
1724 	 * by external hardware.  Therefore these two exceptions
1725 	 * may have board specific handlers.
1726 	 */
1727 	if (board_be_init)
1728 		board_be_init();
1729 
1730 	set_except_vector(0, rollback ? rollback_handle_int : handle_int);
1731 	set_except_vector(1, handle_tlbm);
1732 	set_except_vector(2, handle_tlbl);
1733 	set_except_vector(3, handle_tlbs);
1734 
1735 	set_except_vector(4, handle_adel);
1736 	set_except_vector(5, handle_ades);
1737 
1738 	set_except_vector(6, handle_ibe);
1739 	set_except_vector(7, handle_dbe);
1740 
1741 	set_except_vector(8, handle_sys);
1742 	set_except_vector(9, handle_bp);
1743 	set_except_vector(10, rdhwr_noopt ? handle_ri :
1744 			  (cpu_has_vtag_icache ?
1745 			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1746 	set_except_vector(11, handle_cpu);
1747 	set_except_vector(12, handle_ov);
1748 	set_except_vector(13, handle_tr);
1749 
1750 	if (current_cpu_type() == CPU_R6000 ||
1751 	    current_cpu_type() == CPU_R6000A) {
1752 		/*
1753 		 * The R6000 is the only R-series CPU that features a machine
1754 		 * check exception (similar to the R4000 cache error) and
1755 		 * unaligned ldc1/sdc1 exception.  The handlers have not been
1756 		 * written yet.  Well, anyway there is no R6000 machine on the
1757 		 * current list of targets for Linux/MIPS.
1758 		 * (Duh, crap, there is someone with a triple R6k machine)
1759 		 */
1760 		//set_except_vector(14, handle_mc);
1761 		//set_except_vector(15, handle_ndc);
1762 	}
1763 
1764 
1765 	if (board_nmi_handler_setup)
1766 		board_nmi_handler_setup();
1767 
1768 	if (cpu_has_fpu && !cpu_has_nofpuex)
1769 		set_except_vector(15, handle_fpe);
1770 
1771 	set_except_vector(22, handle_mdmx);
1772 
1773 	if (cpu_has_mcheck)
1774 		set_except_vector(24, handle_mcheck);
1775 
1776 	if (cpu_has_mipsmt)
1777 		set_except_vector(25, handle_mt);
1778 
1779 	set_except_vector(26, handle_dsp);
1780 
1781 	if (cpu_has_vce)
1782 		/* Special exception: R4[04]00 uses also the divec space. */
1783 		memcpy((void *)(ebase + 0x180), &except_vec3_r4000, 0x100);
1784 	else if (cpu_has_4kex)
1785 		memcpy((void *)(ebase + 0x180), &except_vec3_generic, 0x80);
1786 	else
1787 		memcpy((void *)(ebase + 0x080), &except_vec3_generic, 0x80);
1788 
1789 	local_flush_icache_range(ebase, ebase + 0x400);
1790 	flush_tlb_handlers();
1791 
1792 	sort_extable(__start___dbe_table, __stop___dbe_table);
1793 
1794 	cu2_notifier(default_cu2_call, 0x80000000);	/* Run last  */
1795 }
1796