mm: page_alloc: do not treat a zone that cannot be used for dirty pages as "full"
[linux/fpc-iii.git] / arch / mips / kernel / traps.c
blob81e6ae0220bc2f58dc7b19002db40fc5dbb102b3
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.
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) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
12 * Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc. All rights reserved.
14 #include <linux/bug.h>
15 #include <linux/compiler.h>
16 #include <linux/context_tracking.h>
17 #include <linux/kexec.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/mm.h>
22 #include <linux/sched.h>
23 #include <linux/smp.h>
24 #include <linux/spinlock.h>
25 #include <linux/kallsyms.h>
26 #include <linux/bootmem.h>
27 #include <linux/interrupt.h>
28 #include <linux/ptrace.h>
29 #include <linux/kgdb.h>
30 #include <linux/kdebug.h>
31 #include <linux/kprobes.h>
32 #include <linux/notifier.h>
33 #include <linux/kdb.h>
34 #include <linux/irq.h>
35 #include <linux/perf_event.h>
37 #include <asm/bootinfo.h>
38 #include <asm/branch.h>
39 #include <asm/break.h>
40 #include <asm/cop2.h>
41 #include <asm/cpu.h>
42 #include <asm/cpu-type.h>
43 #include <asm/dsp.h>
44 #include <asm/fpu.h>
45 #include <asm/fpu_emulator.h>
46 #include <asm/idle.h>
47 #include <asm/mipsregs.h>
48 #include <asm/mipsmtregs.h>
49 #include <asm/module.h>
50 #include <asm/pgtable.h>
51 #include <asm/ptrace.h>
52 #include <asm/sections.h>
53 #include <asm/tlbdebug.h>
54 #include <asm/traps.h>
55 #include <asm/uaccess.h>
56 #include <asm/watch.h>
57 #include <asm/mmu_context.h>
58 #include <asm/types.h>
59 #include <asm/stacktrace.h>
60 #include <asm/uasm.h>
62 extern void check_wait(void);
63 extern asmlinkage void rollback_handle_int(void);
64 extern asmlinkage void handle_int(void);
65 extern u32 handle_tlbl[];
66 extern u32 handle_tlbs[];
67 extern u32 handle_tlbm[];
68 extern asmlinkage void handle_adel(void);
69 extern asmlinkage void handle_ades(void);
70 extern asmlinkage void handle_ibe(void);
71 extern asmlinkage void handle_dbe(void);
72 extern asmlinkage void handle_sys(void);
73 extern asmlinkage void handle_bp(void);
74 extern asmlinkage void handle_ri(void);
75 extern asmlinkage void handle_ri_rdhwr_vivt(void);
76 extern asmlinkage void handle_ri_rdhwr(void);
77 extern asmlinkage void handle_cpu(void);
78 extern asmlinkage void handle_ov(void);
79 extern asmlinkage void handle_tr(void);
80 extern asmlinkage void handle_fpe(void);
81 extern asmlinkage void handle_ftlb(void);
82 extern asmlinkage void handle_mdmx(void);
83 extern asmlinkage void handle_watch(void);
84 extern asmlinkage void handle_mt(void);
85 extern asmlinkage void handle_dsp(void);
86 extern asmlinkage void handle_mcheck(void);
87 extern asmlinkage void handle_reserved(void);
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 void (*board_ebase_setup)(void);
95 void(*board_cache_error_setup)(void);
97 static void show_raw_backtrace(unsigned long reg29)
99 unsigned long *sp = (unsigned long *)(reg29 & ~3);
100 unsigned long addr;
102 printk("Call Trace:");
103 #ifdef CONFIG_KALLSYMS
104 printk("\n");
105 #endif
106 while (!kstack_end(sp)) {
107 unsigned long __user *p =
108 (unsigned long __user *)(unsigned long)sp++;
109 if (__get_user(addr, p)) {
110 printk(" (Bad stack address)");
111 break;
113 if (__kernel_text_address(addr))
114 print_ip_sym(addr);
116 printk("\n");
119 #ifdef CONFIG_KALLSYMS
120 int raw_show_trace;
121 static int __init set_raw_show_trace(char *str)
123 raw_show_trace = 1;
124 return 1;
126 __setup("raw_show_trace", set_raw_show_trace);
127 #endif
129 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
131 unsigned long sp = regs->regs[29];
132 unsigned long ra = regs->regs[31];
133 unsigned long pc = regs->cp0_epc;
135 if (!task)
136 task = current;
138 if (raw_show_trace || !__kernel_text_address(pc)) {
139 show_raw_backtrace(sp);
140 return;
142 printk("Call Trace:\n");
143 do {
144 print_ip_sym(pc);
145 pc = unwind_stack(task, &sp, pc, &ra);
146 } while (pc);
147 printk("\n");
151 * This routine abuses get_user()/put_user() to reference pointers
152 * with at least a bit of error checking ...
154 static void show_stacktrace(struct task_struct *task,
155 const struct pt_regs *regs)
157 const int field = 2 * sizeof(unsigned long);
158 long stackdata;
159 int i;
160 unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
162 printk("Stack :");
163 i = 0;
164 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
165 if (i && ((i % (64 / field)) == 0))
166 printk("\n ");
167 if (i > 39) {
168 printk(" ...");
169 break;
172 if (__get_user(stackdata, sp++)) {
173 printk(" (Bad stack address)");
174 break;
177 printk(" %0*lx", field, stackdata);
178 i++;
180 printk("\n");
181 show_backtrace(task, regs);
184 void show_stack(struct task_struct *task, unsigned long *sp)
186 struct pt_regs regs;
187 if (sp) {
188 regs.regs[29] = (unsigned long)sp;
189 regs.regs[31] = 0;
190 regs.cp0_epc = 0;
191 } else {
192 if (task && task != current) {
193 regs.regs[29] = task->thread.reg29;
194 regs.regs[31] = 0;
195 regs.cp0_epc = task->thread.reg31;
196 #ifdef CONFIG_KGDB_KDB
197 } else if (atomic_read(&kgdb_active) != -1 &&
198 kdb_current_regs) {
199 memcpy(&regs, kdb_current_regs, sizeof(regs));
200 #endif /* CONFIG_KGDB_KDB */
201 } else {
202 prepare_frametrace(&regs);
205 show_stacktrace(task, &regs);
208 static void show_code(unsigned int __user *pc)
210 long i;
211 unsigned short __user *pc16 = NULL;
213 printk("\nCode:");
215 if ((unsigned long)pc & 1)
216 pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
217 for(i = -3 ; i < 6 ; i++) {
218 unsigned int insn;
219 if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
220 printk(" (Bad address in epc)\n");
221 break;
223 printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
227 static void __show_regs(const struct pt_regs *regs)
229 const int field = 2 * sizeof(unsigned long);
230 unsigned int cause = regs->cp0_cause;
231 int i;
233 show_regs_print_info(KERN_DEFAULT);
236 * Saved main processor registers
238 for (i = 0; i < 32; ) {
239 if ((i % 4) == 0)
240 printk("$%2d :", i);
241 if (i == 0)
242 printk(" %0*lx", field, 0UL);
243 else if (i == 26 || i == 27)
244 printk(" %*s", field, "");
245 else
246 printk(" %0*lx", field, regs->regs[i]);
248 i++;
249 if ((i % 4) == 0)
250 printk("\n");
253 #ifdef CONFIG_CPU_HAS_SMARTMIPS
254 printk("Acx : %0*lx\n", field, regs->acx);
255 #endif
256 printk("Hi : %0*lx\n", field, regs->hi);
257 printk("Lo : %0*lx\n", field, regs->lo);
260 * Saved cp0 registers
262 printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
263 (void *) regs->cp0_epc);
264 printk(" %s\n", print_tainted());
265 printk("ra : %0*lx %pS\n", field, regs->regs[31],
266 (void *) regs->regs[31]);
268 printk("Status: %08x ", (uint32_t) regs->cp0_status);
270 if (cpu_has_3kex) {
271 if (regs->cp0_status & ST0_KUO)
272 printk("KUo ");
273 if (regs->cp0_status & ST0_IEO)
274 printk("IEo ");
275 if (regs->cp0_status & ST0_KUP)
276 printk("KUp ");
277 if (regs->cp0_status & ST0_IEP)
278 printk("IEp ");
279 if (regs->cp0_status & ST0_KUC)
280 printk("KUc ");
281 if (regs->cp0_status & ST0_IEC)
282 printk("IEc ");
283 } else if (cpu_has_4kex) {
284 if (regs->cp0_status & ST0_KX)
285 printk("KX ");
286 if (regs->cp0_status & ST0_SX)
287 printk("SX ");
288 if (regs->cp0_status & ST0_UX)
289 printk("UX ");
290 switch (regs->cp0_status & ST0_KSU) {
291 case KSU_USER:
292 printk("USER ");
293 break;
294 case KSU_SUPERVISOR:
295 printk("SUPERVISOR ");
296 break;
297 case KSU_KERNEL:
298 printk("KERNEL ");
299 break;
300 default:
301 printk("BAD_MODE ");
302 break;
304 if (regs->cp0_status & ST0_ERL)
305 printk("ERL ");
306 if (regs->cp0_status & ST0_EXL)
307 printk("EXL ");
308 if (regs->cp0_status & ST0_IE)
309 printk("IE ");
311 printk("\n");
313 printk("Cause : %08x\n", cause);
315 cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
316 if (1 <= cause && cause <= 5)
317 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
319 printk("PrId : %08x (%s)\n", read_c0_prid(),
320 cpu_name_string());
324 * FIXME: really the generic show_regs should take a const pointer argument.
326 void show_regs(struct pt_regs *regs)
328 __show_regs((struct pt_regs *)regs);
331 void show_registers(struct pt_regs *regs)
333 const int field = 2 * sizeof(unsigned long);
334 mm_segment_t old_fs = get_fs();
336 __show_regs(regs);
337 print_modules();
338 printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
339 current->comm, current->pid, current_thread_info(), current,
340 field, current_thread_info()->tp_value);
341 if (cpu_has_userlocal) {
342 unsigned long tls;
344 tls = read_c0_userlocal();
345 if (tls != current_thread_info()->tp_value)
346 printk("*HwTLS: %0*lx\n", field, tls);
349 if (!user_mode(regs))
350 /* Necessary for getting the correct stack content */
351 set_fs(KERNEL_DS);
352 show_stacktrace(current, regs);
353 show_code((unsigned int __user *) regs->cp0_epc);
354 printk("\n");
355 set_fs(old_fs);
358 static int regs_to_trapnr(struct pt_regs *regs)
360 return (regs->cp0_cause >> 2) & 0x1f;
363 static DEFINE_RAW_SPINLOCK(die_lock);
365 void __noreturn die(const char *str, struct pt_regs *regs)
367 static int die_counter;
368 int sig = SIGSEGV;
369 #ifdef CONFIG_MIPS_MT_SMTC
370 unsigned long dvpret;
371 #endif /* CONFIG_MIPS_MT_SMTC */
373 oops_enter();
375 if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs),
376 SIGSEGV) == NOTIFY_STOP)
377 sig = 0;
379 console_verbose();
380 raw_spin_lock_irq(&die_lock);
381 #ifdef CONFIG_MIPS_MT_SMTC
382 dvpret = dvpe();
383 #endif /* CONFIG_MIPS_MT_SMTC */
384 bust_spinlocks(1);
385 #ifdef CONFIG_MIPS_MT_SMTC
386 mips_mt_regdump(dvpret);
387 #endif /* CONFIG_MIPS_MT_SMTC */
389 printk("%s[#%d]:\n", str, ++die_counter);
390 show_registers(regs);
391 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
392 raw_spin_unlock_irq(&die_lock);
394 oops_exit();
396 if (in_interrupt())
397 panic("Fatal exception in interrupt");
399 if (panic_on_oops) {
400 printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
401 ssleep(5);
402 panic("Fatal exception");
405 if (regs && kexec_should_crash(current))
406 crash_kexec(regs);
408 do_exit(sig);
411 extern struct exception_table_entry __start___dbe_table[];
412 extern struct exception_table_entry __stop___dbe_table[];
414 __asm__(
415 " .section __dbe_table, \"a\"\n"
416 " .previous \n");
418 /* Given an address, look for it in the exception tables. */
419 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
421 const struct exception_table_entry *e;
423 e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
424 if (!e)
425 e = search_module_dbetables(addr);
426 return e;
429 asmlinkage void do_be(struct pt_regs *regs)
431 const int field = 2 * sizeof(unsigned long);
432 const struct exception_table_entry *fixup = NULL;
433 int data = regs->cp0_cause & 4;
434 int action = MIPS_BE_FATAL;
435 enum ctx_state prev_state;
437 prev_state = exception_enter();
438 /* XXX For now. Fixme, this searches the wrong table ... */
439 if (data && !user_mode(regs))
440 fixup = search_dbe_tables(exception_epc(regs));
442 if (fixup)
443 action = MIPS_BE_FIXUP;
445 if (board_be_handler)
446 action = board_be_handler(regs, fixup != NULL);
448 switch (action) {
449 case MIPS_BE_DISCARD:
450 goto out;
451 case MIPS_BE_FIXUP:
452 if (fixup) {
453 regs->cp0_epc = fixup->nextinsn;
454 goto out;
456 break;
457 default:
458 break;
462 * Assume it would be too dangerous to continue ...
464 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
465 data ? "Data" : "Instruction",
466 field, regs->cp0_epc, field, regs->regs[31]);
467 if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs),
468 SIGBUS) == NOTIFY_STOP)
469 goto out;
471 die_if_kernel("Oops", regs);
472 force_sig(SIGBUS, current);
474 out:
475 exception_exit(prev_state);
479 * ll/sc, rdhwr, sync emulation
482 #define OPCODE 0xfc000000
483 #define BASE 0x03e00000
484 #define RT 0x001f0000
485 #define OFFSET 0x0000ffff
486 #define LL 0xc0000000
487 #define SC 0xe0000000
488 #define SPEC0 0x00000000
489 #define SPEC3 0x7c000000
490 #define RD 0x0000f800
491 #define FUNC 0x0000003f
492 #define SYNC 0x0000000f
493 #define RDHWR 0x0000003b
495 /* microMIPS definitions */
496 #define MM_POOL32A_FUNC 0xfc00ffff
497 #define MM_RDHWR 0x00006b3c
498 #define MM_RS 0x001f0000
499 #define MM_RT 0x03e00000
502 * The ll_bit is cleared by r*_switch.S
505 unsigned int ll_bit;
506 struct task_struct *ll_task;
508 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
510 unsigned long value, __user *vaddr;
511 long offset;
514 * analyse the ll instruction that just caused a ri exception
515 * and put the referenced address to addr.
518 /* sign extend offset */
519 offset = opcode & OFFSET;
520 offset <<= 16;
521 offset >>= 16;
523 vaddr = (unsigned long __user *)
524 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
526 if ((unsigned long)vaddr & 3)
527 return SIGBUS;
528 if (get_user(value, vaddr))
529 return SIGSEGV;
531 preempt_disable();
533 if (ll_task == NULL || ll_task == current) {
534 ll_bit = 1;
535 } else {
536 ll_bit = 0;
538 ll_task = current;
540 preempt_enable();
542 regs->regs[(opcode & RT) >> 16] = value;
544 return 0;
547 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
549 unsigned long __user *vaddr;
550 unsigned long reg;
551 long offset;
554 * analyse the sc instruction that just caused a ri exception
555 * and put the referenced address to addr.
558 /* sign extend offset */
559 offset = opcode & OFFSET;
560 offset <<= 16;
561 offset >>= 16;
563 vaddr = (unsigned long __user *)
564 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
565 reg = (opcode & RT) >> 16;
567 if ((unsigned long)vaddr & 3)
568 return SIGBUS;
570 preempt_disable();
572 if (ll_bit == 0 || ll_task != current) {
573 regs->regs[reg] = 0;
574 preempt_enable();
575 return 0;
578 preempt_enable();
580 if (put_user(regs->regs[reg], vaddr))
581 return SIGSEGV;
583 regs->regs[reg] = 1;
585 return 0;
589 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
590 * opcodes are supposed to result in coprocessor unusable exceptions if
591 * executed on ll/sc-less processors. That's the theory. In practice a
592 * few processors such as NEC's VR4100 throw reserved instruction exceptions
593 * instead, so we're doing the emulation thing in both exception handlers.
595 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
597 if ((opcode & OPCODE) == LL) {
598 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
599 1, regs, 0);
600 return simulate_ll(regs, opcode);
602 if ((opcode & OPCODE) == SC) {
603 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
604 1, regs, 0);
605 return simulate_sc(regs, opcode);
608 return -1; /* Must be something else ... */
612 * Simulate trapping 'rdhwr' instructions to provide user accessible
613 * registers not implemented in hardware.
615 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
617 struct thread_info *ti = task_thread_info(current);
619 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
620 1, regs, 0);
621 switch (rd) {
622 case 0: /* CPU number */
623 regs->regs[rt] = smp_processor_id();
624 return 0;
625 case 1: /* SYNCI length */
626 regs->regs[rt] = min(current_cpu_data.dcache.linesz,
627 current_cpu_data.icache.linesz);
628 return 0;
629 case 2: /* Read count register */
630 regs->regs[rt] = read_c0_count();
631 return 0;
632 case 3: /* Count register resolution */
633 switch (current_cpu_type()) {
634 case CPU_20KC:
635 case CPU_25KF:
636 regs->regs[rt] = 1;
637 break;
638 default:
639 regs->regs[rt] = 2;
641 return 0;
642 case 29:
643 regs->regs[rt] = ti->tp_value;
644 return 0;
645 default:
646 return -1;
650 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
652 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
653 int rd = (opcode & RD) >> 11;
654 int rt = (opcode & RT) >> 16;
656 simulate_rdhwr(regs, rd, rt);
657 return 0;
660 /* Not ours. */
661 return -1;
664 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode)
666 if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
667 int rd = (opcode & MM_RS) >> 16;
668 int rt = (opcode & MM_RT) >> 21;
669 simulate_rdhwr(regs, rd, rt);
670 return 0;
673 /* Not ours. */
674 return -1;
677 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
679 if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
680 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
681 1, regs, 0);
682 return 0;
685 return -1; /* Must be something else ... */
688 asmlinkage void do_ov(struct pt_regs *regs)
690 enum ctx_state prev_state;
691 siginfo_t info;
693 prev_state = exception_enter();
694 die_if_kernel("Integer overflow", regs);
696 info.si_code = FPE_INTOVF;
697 info.si_signo = SIGFPE;
698 info.si_errno = 0;
699 info.si_addr = (void __user *) regs->cp0_epc;
700 force_sig_info(SIGFPE, &info, current);
701 exception_exit(prev_state);
704 int process_fpemu_return(int sig, void __user *fault_addr)
706 if (sig == SIGSEGV || sig == SIGBUS) {
707 struct siginfo si = {0};
708 si.si_addr = fault_addr;
709 si.si_signo = sig;
710 if (sig == SIGSEGV) {
711 if (find_vma(current->mm, (unsigned long)fault_addr))
712 si.si_code = SEGV_ACCERR;
713 else
714 si.si_code = SEGV_MAPERR;
715 } else {
716 si.si_code = BUS_ADRERR;
718 force_sig_info(sig, &si, current);
719 return 1;
720 } else if (sig) {
721 force_sig(sig, current);
722 return 1;
723 } else {
724 return 0;
729 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
731 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
733 enum ctx_state prev_state;
734 siginfo_t info = {0};
736 prev_state = exception_enter();
737 if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs),
738 SIGFPE) == NOTIFY_STOP)
739 goto out;
740 die_if_kernel("FP exception in kernel code", regs);
742 if (fcr31 & FPU_CSR_UNI_X) {
743 int sig;
744 void __user *fault_addr = NULL;
747 * Unimplemented operation exception. If we've got the full
748 * software emulator on-board, let's use it...
750 * Force FPU to dump state into task/thread context. We're
751 * moving a lot of data here for what is probably a single
752 * instruction, but the alternative is to pre-decode the FP
753 * register operands before invoking the emulator, which seems
754 * a bit extreme for what should be an infrequent event.
756 /* Ensure 'resume' not overwrite saved fp context again. */
757 lose_fpu(1);
759 /* Run the emulator */
760 sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
761 &fault_addr);
764 * We can't allow the emulated instruction to leave any of
765 * the cause bit set in $fcr31.
767 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
769 /* Restore the hardware register state */
770 own_fpu(1); /* Using the FPU again. */
772 /* If something went wrong, signal */
773 process_fpemu_return(sig, fault_addr);
775 goto out;
776 } else if (fcr31 & FPU_CSR_INV_X)
777 info.si_code = FPE_FLTINV;
778 else if (fcr31 & FPU_CSR_DIV_X)
779 info.si_code = FPE_FLTDIV;
780 else if (fcr31 & FPU_CSR_OVF_X)
781 info.si_code = FPE_FLTOVF;
782 else if (fcr31 & FPU_CSR_UDF_X)
783 info.si_code = FPE_FLTUND;
784 else if (fcr31 & FPU_CSR_INE_X)
785 info.si_code = FPE_FLTRES;
786 else
787 info.si_code = __SI_FAULT;
788 info.si_signo = SIGFPE;
789 info.si_errno = 0;
790 info.si_addr = (void __user *) regs->cp0_epc;
791 force_sig_info(SIGFPE, &info, current);
793 out:
794 exception_exit(prev_state);
797 static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
798 const char *str)
800 siginfo_t info;
801 char b[40];
803 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
804 if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
805 return;
806 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
808 if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs),
809 SIGTRAP) == NOTIFY_STOP)
810 return;
813 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
814 * insns, even for trap and break codes that indicate arithmetic
815 * failures. Weird ...
816 * But should we continue the brokenness??? --macro
818 switch (code) {
819 case BRK_OVERFLOW:
820 case BRK_DIVZERO:
821 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
822 die_if_kernel(b, regs);
823 if (code == BRK_DIVZERO)
824 info.si_code = FPE_INTDIV;
825 else
826 info.si_code = FPE_INTOVF;
827 info.si_signo = SIGFPE;
828 info.si_errno = 0;
829 info.si_addr = (void __user *) regs->cp0_epc;
830 force_sig_info(SIGFPE, &info, current);
831 break;
832 case BRK_BUG:
833 die_if_kernel("Kernel bug detected", regs);
834 force_sig(SIGTRAP, current);
835 break;
836 case BRK_MEMU:
838 * Address errors may be deliberately induced by the FPU
839 * emulator to retake control of the CPU after executing the
840 * instruction in the delay slot of an emulated branch.
842 * Terminate if exception was recognized as a delay slot return
843 * otherwise handle as normal.
845 if (do_dsemulret(regs))
846 return;
848 die_if_kernel("Math emu break/trap", regs);
849 force_sig(SIGTRAP, current);
850 break;
851 default:
852 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
853 die_if_kernel(b, regs);
854 force_sig(SIGTRAP, current);
858 asmlinkage void do_bp(struct pt_regs *regs)
860 unsigned int opcode, bcode;
861 enum ctx_state prev_state;
862 unsigned long epc;
863 u16 instr[2];
865 prev_state = exception_enter();
866 if (get_isa16_mode(regs->cp0_epc)) {
867 /* Calculate EPC. */
868 epc = exception_epc(regs);
869 if (cpu_has_mmips) {
870 if ((__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)) ||
871 (__get_user(instr[1], (u16 __user *)msk_isa16_mode(epc + 2)))))
872 goto out_sigsegv;
873 opcode = (instr[0] << 16) | instr[1];
874 } else {
875 /* MIPS16e mode */
876 if (__get_user(instr[0], (u16 __user *)msk_isa16_mode(epc)))
877 goto out_sigsegv;
878 bcode = (instr[0] >> 6) & 0x3f;
879 do_trap_or_bp(regs, bcode, "Break");
880 goto out;
882 } else {
883 if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
884 goto out_sigsegv;
888 * There is the ancient bug in the MIPS assemblers that the break
889 * code starts left to bit 16 instead to bit 6 in the opcode.
890 * Gas is bug-compatible, but not always, grrr...
891 * We handle both cases with a simple heuristics. --macro
893 bcode = ((opcode >> 6) & ((1 << 20) - 1));
894 if (bcode >= (1 << 10))
895 bcode >>= 10;
898 * notify the kprobe handlers, if instruction is likely to
899 * pertain to them.
901 switch (bcode) {
902 case BRK_KPROBE_BP:
903 if (notify_die(DIE_BREAK, "debug", regs, bcode,
904 regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
905 goto out;
906 else
907 break;
908 case BRK_KPROBE_SSTEPBP:
909 if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
910 regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
911 goto out;
912 else
913 break;
914 default:
915 break;
918 do_trap_or_bp(regs, bcode, "Break");
920 out:
921 exception_exit(prev_state);
922 return;
924 out_sigsegv:
925 force_sig(SIGSEGV, current);
926 goto out;
929 asmlinkage void do_tr(struct pt_regs *regs)
931 u32 opcode, tcode = 0;
932 enum ctx_state prev_state;
933 u16 instr[2];
934 unsigned long epc = msk_isa16_mode(exception_epc(regs));
936 prev_state = exception_enter();
937 if (get_isa16_mode(regs->cp0_epc)) {
938 if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
939 __get_user(instr[1], (u16 __user *)(epc + 2)))
940 goto out_sigsegv;
941 opcode = (instr[0] << 16) | instr[1];
942 /* Immediate versions don't provide a code. */
943 if (!(opcode & OPCODE))
944 tcode = (opcode >> 12) & ((1 << 4) - 1);
945 } else {
946 if (__get_user(opcode, (u32 __user *)epc))
947 goto out_sigsegv;
948 /* Immediate versions don't provide a code. */
949 if (!(opcode & OPCODE))
950 tcode = (opcode >> 6) & ((1 << 10) - 1);
953 do_trap_or_bp(regs, tcode, "Trap");
955 out:
956 exception_exit(prev_state);
957 return;
959 out_sigsegv:
960 force_sig(SIGSEGV, current);
961 goto out;
964 asmlinkage void do_ri(struct pt_regs *regs)
966 unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
967 unsigned long old_epc = regs->cp0_epc;
968 unsigned long old31 = regs->regs[31];
969 enum ctx_state prev_state;
970 unsigned int opcode = 0;
971 int status = -1;
973 prev_state = exception_enter();
974 if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs),
975 SIGILL) == NOTIFY_STOP)
976 goto out;
978 die_if_kernel("Reserved instruction in kernel code", regs);
980 if (unlikely(compute_return_epc(regs) < 0))
981 goto out;
983 if (get_isa16_mode(regs->cp0_epc)) {
984 unsigned short mmop[2] = { 0 };
986 if (unlikely(get_user(mmop[0], epc) < 0))
987 status = SIGSEGV;
988 if (unlikely(get_user(mmop[1], epc) < 0))
989 status = SIGSEGV;
990 opcode = (mmop[0] << 16) | mmop[1];
992 if (status < 0)
993 status = simulate_rdhwr_mm(regs, opcode);
994 } else {
995 if (unlikely(get_user(opcode, epc) < 0))
996 status = SIGSEGV;
998 if (!cpu_has_llsc && status < 0)
999 status = simulate_llsc(regs, opcode);
1001 if (status < 0)
1002 status = simulate_rdhwr_normal(regs, opcode);
1004 if (status < 0)
1005 status = simulate_sync(regs, opcode);
1008 if (status < 0)
1009 status = SIGILL;
1011 if (unlikely(status > 0)) {
1012 regs->cp0_epc = old_epc; /* Undo skip-over. */
1013 regs->regs[31] = old31;
1014 force_sig(status, current);
1017 out:
1018 exception_exit(prev_state);
1022 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1023 * emulated more than some threshold number of instructions, force migration to
1024 * a "CPU" that has FP support.
1026 static void mt_ase_fp_affinity(void)
1028 #ifdef CONFIG_MIPS_MT_FPAFF
1029 if (mt_fpemul_threshold > 0 &&
1030 ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1032 * If there's no FPU present, or if the application has already
1033 * restricted the allowed set to exclude any CPUs with FPUs,
1034 * we'll skip the procedure.
1036 if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
1037 cpumask_t tmask;
1039 current->thread.user_cpus_allowed
1040 = current->cpus_allowed;
1041 cpus_and(tmask, current->cpus_allowed,
1042 mt_fpu_cpumask);
1043 set_cpus_allowed_ptr(current, &tmask);
1044 set_thread_flag(TIF_FPUBOUND);
1047 #endif /* CONFIG_MIPS_MT_FPAFF */
1051 * No lock; only written during early bootup by CPU 0.
1053 static RAW_NOTIFIER_HEAD(cu2_chain);
1055 int __ref register_cu2_notifier(struct notifier_block *nb)
1057 return raw_notifier_chain_register(&cu2_chain, nb);
1060 int cu2_notifier_call_chain(unsigned long val, void *v)
1062 return raw_notifier_call_chain(&cu2_chain, val, v);
1065 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1066 void *data)
1068 struct pt_regs *regs = data;
1070 die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1071 "instruction", regs);
1072 force_sig(SIGILL, current);
1074 return NOTIFY_OK;
1077 asmlinkage void do_cpu(struct pt_regs *regs)
1079 enum ctx_state prev_state;
1080 unsigned int __user *epc;
1081 unsigned long old_epc, old31;
1082 unsigned int opcode;
1083 unsigned int cpid;
1084 int status, err;
1085 unsigned long __maybe_unused flags;
1087 prev_state = exception_enter();
1088 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1090 if (cpid != 2)
1091 die_if_kernel("do_cpu invoked from kernel context!", regs);
1093 switch (cpid) {
1094 case 0:
1095 epc = (unsigned int __user *)exception_epc(regs);
1096 old_epc = regs->cp0_epc;
1097 old31 = regs->regs[31];
1098 opcode = 0;
1099 status = -1;
1101 if (unlikely(compute_return_epc(regs) < 0))
1102 goto out;
1104 if (get_isa16_mode(regs->cp0_epc)) {
1105 unsigned short mmop[2] = { 0 };
1107 if (unlikely(get_user(mmop[0], epc) < 0))
1108 status = SIGSEGV;
1109 if (unlikely(get_user(mmop[1], epc) < 0))
1110 status = SIGSEGV;
1111 opcode = (mmop[0] << 16) | mmop[1];
1113 if (status < 0)
1114 status = simulate_rdhwr_mm(regs, opcode);
1115 } else {
1116 if (unlikely(get_user(opcode, epc) < 0))
1117 status = SIGSEGV;
1119 if (!cpu_has_llsc && status < 0)
1120 status = simulate_llsc(regs, opcode);
1122 if (status < 0)
1123 status = simulate_rdhwr_normal(regs, opcode);
1126 if (status < 0)
1127 status = SIGILL;
1129 if (unlikely(status > 0)) {
1130 regs->cp0_epc = old_epc; /* Undo skip-over. */
1131 regs->regs[31] = old31;
1132 force_sig(status, current);
1135 goto out;
1137 case 3:
1139 * Old (MIPS I and MIPS II) processors will set this code
1140 * for COP1X opcode instructions that replaced the original
1141 * COP3 space. We don't limit COP1 space instructions in
1142 * the emulator according to the CPU ISA, so we want to
1143 * treat COP1X instructions consistently regardless of which
1144 * code the CPU chose. Therefore we redirect this trap to
1145 * the FP emulator too.
1147 * Then some newer FPU-less processors use this code
1148 * erroneously too, so they are covered by this choice
1149 * as well.
1151 if (raw_cpu_has_fpu)
1152 break;
1153 /* Fall through. */
1155 case 1:
1156 if (used_math()) /* Using the FPU again. */
1157 err = own_fpu(1);
1158 else { /* First time FPU user. */
1159 err = init_fpu();
1160 set_used_math();
1163 if (!raw_cpu_has_fpu || err) {
1164 int sig;
1165 void __user *fault_addr = NULL;
1166 sig = fpu_emulator_cop1Handler(regs,
1167 &current->thread.fpu,
1168 0, &fault_addr);
1169 if (!process_fpemu_return(sig, fault_addr) && !err)
1170 mt_ase_fp_affinity();
1173 goto out;
1175 case 2:
1176 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1177 goto out;
1180 force_sig(SIGILL, current);
1182 out:
1183 exception_exit(prev_state);
1186 asmlinkage void do_mdmx(struct pt_regs *regs)
1188 enum ctx_state prev_state;
1190 prev_state = exception_enter();
1191 force_sig(SIGILL, current);
1192 exception_exit(prev_state);
1196 * Called with interrupts disabled.
1198 asmlinkage void do_watch(struct pt_regs *regs)
1200 enum ctx_state prev_state;
1201 u32 cause;
1203 prev_state = exception_enter();
1205 * Clear WP (bit 22) bit of cause register so we don't loop
1206 * forever.
1208 cause = read_c0_cause();
1209 cause &= ~(1 << 22);
1210 write_c0_cause(cause);
1213 * If the current thread has the watch registers loaded, save
1214 * their values and send SIGTRAP. Otherwise another thread
1215 * left the registers set, clear them and continue.
1217 if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1218 mips_read_watch_registers();
1219 local_irq_enable();
1220 force_sig(SIGTRAP, current);
1221 } else {
1222 mips_clear_watch_registers();
1223 local_irq_enable();
1225 exception_exit(prev_state);
1228 asmlinkage void do_mcheck(struct pt_regs *regs)
1230 const int field = 2 * sizeof(unsigned long);
1231 int multi_match = regs->cp0_status & ST0_TS;
1232 enum ctx_state prev_state;
1234 prev_state = exception_enter();
1235 show_regs(regs);
1237 if (multi_match) {
1238 printk("Index : %0x\n", read_c0_index());
1239 printk("Pagemask: %0x\n", read_c0_pagemask());
1240 printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
1241 printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1242 printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1243 printk("\n");
1244 dump_tlb_all();
1247 show_code((unsigned int __user *) regs->cp0_epc);
1250 * Some chips may have other causes of machine check (e.g. SB1
1251 * graduation timer)
1253 panic("Caught Machine Check exception - %scaused by multiple "
1254 "matching entries in the TLB.",
1255 (multi_match) ? "" : "not ");
1258 asmlinkage void do_mt(struct pt_regs *regs)
1260 int subcode;
1262 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1263 >> VPECONTROL_EXCPT_SHIFT;
1264 switch (subcode) {
1265 case 0:
1266 printk(KERN_DEBUG "Thread Underflow\n");
1267 break;
1268 case 1:
1269 printk(KERN_DEBUG "Thread Overflow\n");
1270 break;
1271 case 2:
1272 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1273 break;
1274 case 3:
1275 printk(KERN_DEBUG "Gating Storage Exception\n");
1276 break;
1277 case 4:
1278 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1279 break;
1280 case 5:
1281 printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1282 break;
1283 default:
1284 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1285 subcode);
1286 break;
1288 die_if_kernel("MIPS MT Thread exception in kernel", regs);
1290 force_sig(SIGILL, current);
1294 asmlinkage void do_dsp(struct pt_regs *regs)
1296 if (cpu_has_dsp)
1297 panic("Unexpected DSP exception");
1299 force_sig(SIGILL, current);
1302 asmlinkage void do_reserved(struct pt_regs *regs)
1305 * Game over - no way to handle this if it ever occurs. Most probably
1306 * caused by a new unknown cpu type or after another deadly
1307 * hard/software error.
1309 show_regs(regs);
1310 panic("Caught reserved exception %ld - should not happen.",
1311 (regs->cp0_cause & 0x7f) >> 2);
1314 static int __initdata l1parity = 1;
1315 static int __init nol1parity(char *s)
1317 l1parity = 0;
1318 return 1;
1320 __setup("nol1par", nol1parity);
1321 static int __initdata l2parity = 1;
1322 static int __init nol2parity(char *s)
1324 l2parity = 0;
1325 return 1;
1327 __setup("nol2par", nol2parity);
1330 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1331 * it different ways.
1333 static inline void parity_protection_init(void)
1335 switch (current_cpu_type()) {
1336 case CPU_24K:
1337 case CPU_34K:
1338 case CPU_74K:
1339 case CPU_1004K:
1340 case CPU_INTERAPTIV:
1341 case CPU_PROAPTIV:
1343 #define ERRCTL_PE 0x80000000
1344 #define ERRCTL_L2P 0x00800000
1345 unsigned long errctl;
1346 unsigned int l1parity_present, l2parity_present;
1348 errctl = read_c0_ecc();
1349 errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1351 /* probe L1 parity support */
1352 write_c0_ecc(errctl | ERRCTL_PE);
1353 back_to_back_c0_hazard();
1354 l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1356 /* probe L2 parity support */
1357 write_c0_ecc(errctl|ERRCTL_L2P);
1358 back_to_back_c0_hazard();
1359 l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1361 if (l1parity_present && l2parity_present) {
1362 if (l1parity)
1363 errctl |= ERRCTL_PE;
1364 if (l1parity ^ l2parity)
1365 errctl |= ERRCTL_L2P;
1366 } else if (l1parity_present) {
1367 if (l1parity)
1368 errctl |= ERRCTL_PE;
1369 } else if (l2parity_present) {
1370 if (l2parity)
1371 errctl |= ERRCTL_L2P;
1372 } else {
1373 /* No parity available */
1376 printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1378 write_c0_ecc(errctl);
1379 back_to_back_c0_hazard();
1380 errctl = read_c0_ecc();
1381 printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1383 if (l1parity_present)
1384 printk(KERN_INFO "Cache parity protection %sabled\n",
1385 (errctl & ERRCTL_PE) ? "en" : "dis");
1387 if (l2parity_present) {
1388 if (l1parity_present && l1parity)
1389 errctl ^= ERRCTL_L2P;
1390 printk(KERN_INFO "L2 cache parity protection %sabled\n",
1391 (errctl & ERRCTL_L2P) ? "en" : "dis");
1394 break;
1396 case CPU_5KC:
1397 case CPU_5KE:
1398 case CPU_LOONGSON1:
1399 write_c0_ecc(0x80000000);
1400 back_to_back_c0_hazard();
1401 /* Set the PE bit (bit 31) in the c0_errctl register. */
1402 printk(KERN_INFO "Cache parity protection %sabled\n",
1403 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1404 break;
1405 case CPU_20KC:
1406 case CPU_25KF:
1407 /* Clear the DE bit (bit 16) in the c0_status register. */
1408 printk(KERN_INFO "Enable cache parity protection for "
1409 "MIPS 20KC/25KF CPUs.\n");
1410 clear_c0_status(ST0_DE);
1411 break;
1412 default:
1413 break;
1417 asmlinkage void cache_parity_error(void)
1419 const int field = 2 * sizeof(unsigned long);
1420 unsigned int reg_val;
1422 /* For the moment, report the problem and hang. */
1423 printk("Cache error exception:\n");
1424 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1425 reg_val = read_c0_cacheerr();
1426 printk("c0_cacheerr == %08x\n", reg_val);
1428 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1429 reg_val & (1<<30) ? "secondary" : "primary",
1430 reg_val & (1<<31) ? "data" : "insn");
1431 if (cpu_has_mips_r2 &&
1432 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1433 pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1434 reg_val & (1<<29) ? "ED " : "",
1435 reg_val & (1<<28) ? "ET " : "",
1436 reg_val & (1<<27) ? "ES " : "",
1437 reg_val & (1<<26) ? "EE " : "",
1438 reg_val & (1<<25) ? "EB " : "",
1439 reg_val & (1<<24) ? "EI " : "",
1440 reg_val & (1<<23) ? "E1 " : "",
1441 reg_val & (1<<22) ? "E0 " : "");
1442 } else {
1443 pr_err("Error bits: %s%s%s%s%s%s%s\n",
1444 reg_val & (1<<29) ? "ED " : "",
1445 reg_val & (1<<28) ? "ET " : "",
1446 reg_val & (1<<26) ? "EE " : "",
1447 reg_val & (1<<25) ? "EB " : "",
1448 reg_val & (1<<24) ? "EI " : "",
1449 reg_val & (1<<23) ? "E1 " : "",
1450 reg_val & (1<<22) ? "E0 " : "");
1452 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1454 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1455 if (reg_val & (1<<22))
1456 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1458 if (reg_val & (1<<23))
1459 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1460 #endif
1462 panic("Can't handle the cache error!");
1465 asmlinkage void do_ftlb(void)
1467 const int field = 2 * sizeof(unsigned long);
1468 unsigned int reg_val;
1470 /* For the moment, report the problem and hang. */
1471 if (cpu_has_mips_r2 &&
1472 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1473 pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1474 read_c0_ecc());
1475 pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1476 reg_val = read_c0_cacheerr();
1477 pr_err("c0_cacheerr == %08x\n", reg_val);
1479 if ((reg_val & 0xc0000000) == 0xc0000000) {
1480 pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1481 } else {
1482 pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1483 reg_val & (1<<30) ? "secondary" : "primary",
1484 reg_val & (1<<31) ? "data" : "insn");
1486 } else {
1487 pr_err("FTLB error exception\n");
1489 /* Just print the cacheerr bits for now */
1490 cache_parity_error();
1494 * SDBBP EJTAG debug exception handler.
1495 * We skip the instruction and return to the next instruction.
1497 void ejtag_exception_handler(struct pt_regs *regs)
1499 const int field = 2 * sizeof(unsigned long);
1500 unsigned long depc, old_epc, old_ra;
1501 unsigned int debug;
1503 printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1504 depc = read_c0_depc();
1505 debug = read_c0_debug();
1506 printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1507 if (debug & 0x80000000) {
1509 * In branch delay slot.
1510 * We cheat a little bit here and use EPC to calculate the
1511 * debug return address (DEPC). EPC is restored after the
1512 * calculation.
1514 old_epc = regs->cp0_epc;
1515 old_ra = regs->regs[31];
1516 regs->cp0_epc = depc;
1517 compute_return_epc(regs);
1518 depc = regs->cp0_epc;
1519 regs->cp0_epc = old_epc;
1520 regs->regs[31] = old_ra;
1521 } else
1522 depc += 4;
1523 write_c0_depc(depc);
1525 #if 0
1526 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1527 write_c0_debug(debug | 0x100);
1528 #endif
1532 * NMI exception handler.
1533 * No lock; only written during early bootup by CPU 0.
1535 static RAW_NOTIFIER_HEAD(nmi_chain);
1537 int register_nmi_notifier(struct notifier_block *nb)
1539 return raw_notifier_chain_register(&nmi_chain, nb);
1542 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1544 char str[100];
1546 raw_notifier_call_chain(&nmi_chain, 0, regs);
1547 bust_spinlocks(1);
1548 snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1549 smp_processor_id(), regs->cp0_epc);
1550 regs->cp0_epc = read_c0_errorepc();
1551 die(str, regs);
1554 #define VECTORSPACING 0x100 /* for EI/VI mode */
1556 unsigned long ebase;
1557 unsigned long exception_handlers[32];
1558 unsigned long vi_handlers[64];
1560 void __init *set_except_vector(int n, void *addr)
1562 unsigned long handler = (unsigned long) addr;
1563 unsigned long old_handler;
1565 #ifdef CONFIG_CPU_MICROMIPS
1567 * Only the TLB handlers are cache aligned with an even
1568 * address. All other handlers are on an odd address and
1569 * require no modification. Otherwise, MIPS32 mode will
1570 * be entered when handling any TLB exceptions. That
1571 * would be bad...since we must stay in microMIPS mode.
1573 if (!(handler & 0x1))
1574 handler |= 1;
1575 #endif
1576 old_handler = xchg(&exception_handlers[n], handler);
1578 if (n == 0 && cpu_has_divec) {
1579 #ifdef CONFIG_CPU_MICROMIPS
1580 unsigned long jump_mask = ~((1 << 27) - 1);
1581 #else
1582 unsigned long jump_mask = ~((1 << 28) - 1);
1583 #endif
1584 u32 *buf = (u32 *)(ebase + 0x200);
1585 unsigned int k0 = 26;
1586 if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1587 uasm_i_j(&buf, handler & ~jump_mask);
1588 uasm_i_nop(&buf);
1589 } else {
1590 UASM_i_LA(&buf, k0, handler);
1591 uasm_i_jr(&buf, k0);
1592 uasm_i_nop(&buf);
1594 local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1596 return (void *)old_handler;
1599 static void do_default_vi(void)
1601 show_regs(get_irq_regs());
1602 panic("Caught unexpected vectored interrupt.");
1605 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1607 unsigned long handler;
1608 unsigned long old_handler = vi_handlers[n];
1609 int srssets = current_cpu_data.srsets;
1610 u16 *h;
1611 unsigned char *b;
1613 BUG_ON(!cpu_has_veic && !cpu_has_vint);
1615 if (addr == NULL) {
1616 handler = (unsigned long) do_default_vi;
1617 srs = 0;
1618 } else
1619 handler = (unsigned long) addr;
1620 vi_handlers[n] = handler;
1622 b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1624 if (srs >= srssets)
1625 panic("Shadow register set %d not supported", srs);
1627 if (cpu_has_veic) {
1628 if (board_bind_eic_interrupt)
1629 board_bind_eic_interrupt(n, srs);
1630 } else if (cpu_has_vint) {
1631 /* SRSMap is only defined if shadow sets are implemented */
1632 if (srssets > 1)
1633 change_c0_srsmap(0xf << n*4, srs << n*4);
1636 if (srs == 0) {
1638 * If no shadow set is selected then use the default handler
1639 * that does normal register saving and standard interrupt exit
1641 extern char except_vec_vi, except_vec_vi_lui;
1642 extern char except_vec_vi_ori, except_vec_vi_end;
1643 extern char rollback_except_vec_vi;
1644 char *vec_start = using_rollback_handler() ?
1645 &rollback_except_vec_vi : &except_vec_vi;
1646 #ifdef CONFIG_MIPS_MT_SMTC
1648 * We need to provide the SMTC vectored interrupt handler
1649 * not only with the address of the handler, but with the
1650 * Status.IM bit to be masked before going there.
1652 extern char except_vec_vi_mori;
1653 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1654 const int mori_offset = &except_vec_vi_mori - vec_start + 2;
1655 #else
1656 const int mori_offset = &except_vec_vi_mori - vec_start;
1657 #endif
1658 #endif /* CONFIG_MIPS_MT_SMTC */
1659 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1660 const int lui_offset = &except_vec_vi_lui - vec_start + 2;
1661 const int ori_offset = &except_vec_vi_ori - vec_start + 2;
1662 #else
1663 const int lui_offset = &except_vec_vi_lui - vec_start;
1664 const int ori_offset = &except_vec_vi_ori - vec_start;
1665 #endif
1666 const int handler_len = &except_vec_vi_end - vec_start;
1668 if (handler_len > VECTORSPACING) {
1670 * Sigh... panicing won't help as the console
1671 * is probably not configured :(
1673 panic("VECTORSPACING too small");
1676 set_handler(((unsigned long)b - ebase), vec_start,
1677 #ifdef CONFIG_CPU_MICROMIPS
1678 (handler_len - 1));
1679 #else
1680 handler_len);
1681 #endif
1682 #ifdef CONFIG_MIPS_MT_SMTC
1683 BUG_ON(n > 7); /* Vector index %d exceeds SMTC maximum. */
1685 h = (u16 *)(b + mori_offset);
1686 *h = (0x100 << n);
1687 #endif /* CONFIG_MIPS_MT_SMTC */
1688 h = (u16 *)(b + lui_offset);
1689 *h = (handler >> 16) & 0xffff;
1690 h = (u16 *)(b + ori_offset);
1691 *h = (handler & 0xffff);
1692 local_flush_icache_range((unsigned long)b,
1693 (unsigned long)(b+handler_len));
1695 else {
1697 * In other cases jump directly to the interrupt handler. It
1698 * is the handler's responsibility to save registers if required
1699 * (eg hi/lo) and return from the exception using "eret".
1701 u32 insn;
1703 h = (u16 *)b;
1704 /* j handler */
1705 #ifdef CONFIG_CPU_MICROMIPS
1706 insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
1707 #else
1708 insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
1709 #endif
1710 h[0] = (insn >> 16) & 0xffff;
1711 h[1] = insn & 0xffff;
1712 h[2] = 0;
1713 h[3] = 0;
1714 local_flush_icache_range((unsigned long)b,
1715 (unsigned long)(b+8));
1718 return (void *)old_handler;
1721 void *set_vi_handler(int n, vi_handler_t addr)
1723 return set_vi_srs_handler(n, addr, 0);
1726 extern void tlb_init(void);
1729 * Timer interrupt
1731 int cp0_compare_irq;
1732 EXPORT_SYMBOL_GPL(cp0_compare_irq);
1733 int cp0_compare_irq_shift;
1736 * Performance counter IRQ or -1 if shared with timer
1738 int cp0_perfcount_irq;
1739 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
1741 static int noulri;
1743 static int __init ulri_disable(char *s)
1745 pr_info("Disabling ulri\n");
1746 noulri = 1;
1748 return 1;
1750 __setup("noulri", ulri_disable);
1752 void per_cpu_trap_init(bool is_boot_cpu)
1754 unsigned int cpu = smp_processor_id();
1755 unsigned int status_set = ST0_CU0;
1756 unsigned int hwrena = cpu_hwrena_impl_bits;
1757 #ifdef CONFIG_MIPS_MT_SMTC
1758 int secondaryTC = 0;
1759 int bootTC = (cpu == 0);
1762 * Only do per_cpu_trap_init() for first TC of Each VPE.
1763 * Note that this hack assumes that the SMTC init code
1764 * assigns TCs consecutively and in ascending order.
1767 if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1768 ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1769 secondaryTC = 1;
1770 #endif /* CONFIG_MIPS_MT_SMTC */
1773 * Disable coprocessors and select 32-bit or 64-bit addressing
1774 * and the 16/32 or 32/32 FPR register model. Reset the BEV
1775 * flag that some firmware may have left set and the TS bit (for
1776 * IP27). Set XX for ISA IV code to work.
1778 #ifdef CONFIG_64BIT
1779 status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1780 #endif
1781 if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
1782 status_set |= ST0_XX;
1783 if (cpu_has_dsp)
1784 status_set |= ST0_MX;
1786 change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1787 status_set);
1789 if (cpu_has_mips_r2)
1790 hwrena |= 0x0000000f;
1792 if (!noulri && cpu_has_userlocal)
1793 hwrena |= (1 << 29);
1795 if (hwrena)
1796 write_c0_hwrena(hwrena);
1798 #ifdef CONFIG_MIPS_MT_SMTC
1799 if (!secondaryTC) {
1800 #endif /* CONFIG_MIPS_MT_SMTC */
1802 if (cpu_has_veic || cpu_has_vint) {
1803 unsigned long sr = set_c0_status(ST0_BEV);
1804 write_c0_ebase(ebase);
1805 write_c0_status(sr);
1806 /* Setting vector spacing enables EI/VI mode */
1807 change_c0_intctl(0x3e0, VECTORSPACING);
1809 if (cpu_has_divec) {
1810 if (cpu_has_mipsmt) {
1811 unsigned int vpflags = dvpe();
1812 set_c0_cause(CAUSEF_IV);
1813 evpe(vpflags);
1814 } else
1815 set_c0_cause(CAUSEF_IV);
1819 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1821 * o read IntCtl.IPTI to determine the timer interrupt
1822 * o read IntCtl.IPPCI to determine the performance counter interrupt
1824 if (cpu_has_mips_r2) {
1825 cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
1826 cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
1827 cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
1828 if (cp0_perfcount_irq == cp0_compare_irq)
1829 cp0_perfcount_irq = -1;
1830 } else {
1831 cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1832 cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
1833 cp0_perfcount_irq = -1;
1836 #ifdef CONFIG_MIPS_MT_SMTC
1838 #endif /* CONFIG_MIPS_MT_SMTC */
1840 if (!cpu_data[cpu].asid_cache)
1841 cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1843 atomic_inc(&init_mm.mm_count);
1844 current->active_mm = &init_mm;
1845 BUG_ON(current->mm);
1846 enter_lazy_tlb(&init_mm, current);
1848 #ifdef CONFIG_MIPS_MT_SMTC
1849 if (bootTC) {
1850 #endif /* CONFIG_MIPS_MT_SMTC */
1851 /* Boot CPU's cache setup in setup_arch(). */
1852 if (!is_boot_cpu)
1853 cpu_cache_init();
1854 tlb_init();
1855 #ifdef CONFIG_MIPS_MT_SMTC
1856 } else if (!secondaryTC) {
1858 * First TC in non-boot VPE must do subset of tlb_init()
1859 * for MMU countrol registers.
1861 write_c0_pagemask(PM_DEFAULT_MASK);
1862 write_c0_wired(0);
1864 #endif /* CONFIG_MIPS_MT_SMTC */
1865 TLBMISS_HANDLER_SETUP();
1868 /* Install CPU exception handler */
1869 void set_handler(unsigned long offset, void *addr, unsigned long size)
1871 #ifdef CONFIG_CPU_MICROMIPS
1872 memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
1873 #else
1874 memcpy((void *)(ebase + offset), addr, size);
1875 #endif
1876 local_flush_icache_range(ebase + offset, ebase + offset + size);
1879 static char panic_null_cerr[] =
1880 "Trying to set NULL cache error exception handler";
1883 * Install uncached CPU exception handler.
1884 * This is suitable only for the cache error exception which is the only
1885 * exception handler that is being run uncached.
1887 void set_uncached_handler(unsigned long offset, void *addr,
1888 unsigned long size)
1890 unsigned long uncached_ebase = CKSEG1ADDR(ebase);
1892 if (!addr)
1893 panic(panic_null_cerr);
1895 memcpy((void *)(uncached_ebase + offset), addr, size);
1898 static int __initdata rdhwr_noopt;
1899 static int __init set_rdhwr_noopt(char *str)
1901 rdhwr_noopt = 1;
1902 return 1;
1905 __setup("rdhwr_noopt", set_rdhwr_noopt);
1907 void __init trap_init(void)
1909 extern char except_vec3_generic;
1910 extern char except_vec4;
1911 extern char except_vec3_r4000;
1912 unsigned long i;
1914 check_wait();
1916 #if defined(CONFIG_KGDB)
1917 if (kgdb_early_setup)
1918 return; /* Already done */
1919 #endif
1921 if (cpu_has_veic || cpu_has_vint) {
1922 unsigned long size = 0x200 + VECTORSPACING*64;
1923 ebase = (unsigned long)
1924 __alloc_bootmem(size, 1 << fls(size), 0);
1925 } else {
1926 #ifdef CONFIG_KVM_GUEST
1927 #define KVM_GUEST_KSEG0 0x40000000
1928 ebase = KVM_GUEST_KSEG0;
1929 #else
1930 ebase = CKSEG0;
1931 #endif
1932 if (cpu_has_mips_r2)
1933 ebase += (read_c0_ebase() & 0x3ffff000);
1936 if (cpu_has_mmips) {
1937 unsigned int config3 = read_c0_config3();
1939 if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
1940 write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
1941 else
1942 write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
1945 if (board_ebase_setup)
1946 board_ebase_setup();
1947 per_cpu_trap_init(true);
1950 * Copy the generic exception handlers to their final destination.
1951 * This will be overriden later as suitable for a particular
1952 * configuration.
1954 set_handler(0x180, &except_vec3_generic, 0x80);
1957 * Setup default vectors
1959 for (i = 0; i <= 31; i++)
1960 set_except_vector(i, handle_reserved);
1963 * Copy the EJTAG debug exception vector handler code to it's final
1964 * destination.
1966 if (cpu_has_ejtag && board_ejtag_handler_setup)
1967 board_ejtag_handler_setup();
1970 * Only some CPUs have the watch exceptions.
1972 if (cpu_has_watch)
1973 set_except_vector(23, handle_watch);
1976 * Initialise interrupt handlers
1978 if (cpu_has_veic || cpu_has_vint) {
1979 int nvec = cpu_has_veic ? 64 : 8;
1980 for (i = 0; i < nvec; i++)
1981 set_vi_handler(i, NULL);
1983 else if (cpu_has_divec)
1984 set_handler(0x200, &except_vec4, 0x8);
1987 * Some CPUs can enable/disable for cache parity detection, but does
1988 * it different ways.
1990 parity_protection_init();
1993 * The Data Bus Errors / Instruction Bus Errors are signaled
1994 * by external hardware. Therefore these two exceptions
1995 * may have board specific handlers.
1997 if (board_be_init)
1998 board_be_init();
2000 set_except_vector(0, using_rollback_handler() ? rollback_handle_int
2001 : handle_int);
2002 set_except_vector(1, handle_tlbm);
2003 set_except_vector(2, handle_tlbl);
2004 set_except_vector(3, handle_tlbs);
2006 set_except_vector(4, handle_adel);
2007 set_except_vector(5, handle_ades);
2009 set_except_vector(6, handle_ibe);
2010 set_except_vector(7, handle_dbe);
2012 set_except_vector(8, handle_sys);
2013 set_except_vector(9, handle_bp);
2014 set_except_vector(10, rdhwr_noopt ? handle_ri :
2015 (cpu_has_vtag_icache ?
2016 handle_ri_rdhwr_vivt : handle_ri_rdhwr));
2017 set_except_vector(11, handle_cpu);
2018 set_except_vector(12, handle_ov);
2019 set_except_vector(13, handle_tr);
2021 if (current_cpu_type() == CPU_R6000 ||
2022 current_cpu_type() == CPU_R6000A) {
2024 * The R6000 is the only R-series CPU that features a machine
2025 * check exception (similar to the R4000 cache error) and
2026 * unaligned ldc1/sdc1 exception. The handlers have not been
2027 * written yet. Well, anyway there is no R6000 machine on the
2028 * current list of targets for Linux/MIPS.
2029 * (Duh, crap, there is someone with a triple R6k machine)
2031 //set_except_vector(14, handle_mc);
2032 //set_except_vector(15, handle_ndc);
2036 if (board_nmi_handler_setup)
2037 board_nmi_handler_setup();
2039 if (cpu_has_fpu && !cpu_has_nofpuex)
2040 set_except_vector(15, handle_fpe);
2042 set_except_vector(16, handle_ftlb);
2043 set_except_vector(22, handle_mdmx);
2045 if (cpu_has_mcheck)
2046 set_except_vector(24, handle_mcheck);
2048 if (cpu_has_mipsmt)
2049 set_except_vector(25, handle_mt);
2051 set_except_vector(26, handle_dsp);
2053 if (board_cache_error_setup)
2054 board_cache_error_setup();
2056 if (cpu_has_vce)
2057 /* Special exception: R4[04]00 uses also the divec space. */
2058 set_handler(0x180, &except_vec3_r4000, 0x100);
2059 else if (cpu_has_4kex)
2060 set_handler(0x180, &except_vec3_generic, 0x80);
2061 else
2062 set_handler(0x080, &except_vec3_generic, 0x80);
2064 local_flush_icache_range(ebase, ebase + 0x400);
2066 sort_extable(__start___dbe_table, __stop___dbe_table);
2068 cu2_notifier(default_cu2_call, 0x80000000); /* Run last */