[MIPS] Less noise on multithreading exceptions.
[linux-2.6/cjktty.git] / arch / mips / kernel / traps.c
blob7cbcbd9a95408560c0dbe01e67c7f421780467d1
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) 2000, 01 MIPS Technologies, Inc.
12 * Copyright (C) 2002, 2003, 2004, 2005 Maciej W. Rozycki
14 #include <linux/init.h>
15 #include <linux/mm.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/smp.h>
19 #include <linux/smp_lock.h>
20 #include <linux/spinlock.h>
21 #include <linux/kallsyms.h>
22 #include <linux/bootmem.h>
24 #include <asm/bootinfo.h>
25 #include <asm/branch.h>
26 #include <asm/break.h>
27 #include <asm/cpu.h>
28 #include <asm/dsp.h>
29 #include <asm/fpu.h>
30 #include <asm/mipsregs.h>
31 #include <asm/mipsmtregs.h>
32 #include <asm/module.h>
33 #include <asm/pgtable.h>
34 #include <asm/ptrace.h>
35 #include <asm/sections.h>
36 #include <asm/system.h>
37 #include <asm/tlbdebug.h>
38 #include <asm/traps.h>
39 #include <asm/uaccess.h>
40 #include <asm/mmu_context.h>
41 #include <asm/watch.h>
42 #include <asm/types.h>
44 extern asmlinkage void handle_int(void);
45 extern asmlinkage void handle_tlbm(void);
46 extern asmlinkage void handle_tlbl(void);
47 extern asmlinkage void handle_tlbs(void);
48 extern asmlinkage void handle_adel(void);
49 extern asmlinkage void handle_ades(void);
50 extern asmlinkage void handle_ibe(void);
51 extern asmlinkage void handle_dbe(void);
52 extern asmlinkage void handle_sys(void);
53 extern asmlinkage void handle_bp(void);
54 extern asmlinkage void handle_ri(void);
55 extern asmlinkage void handle_cpu(void);
56 extern asmlinkage void handle_ov(void);
57 extern asmlinkage void handle_tr(void);
58 extern asmlinkage void handle_fpe(void);
59 extern asmlinkage void handle_mdmx(void);
60 extern asmlinkage void handle_watch(void);
61 extern asmlinkage void handle_mt(void);
62 extern asmlinkage void handle_dsp(void);
63 extern asmlinkage void handle_mcheck(void);
64 extern asmlinkage void handle_reserved(void);
66 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
67 struct mips_fpu_struct *ctx);
69 void (*board_be_init)(void);
70 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
71 void (*board_nmi_handler_setup)(void);
72 void (*board_ejtag_handler_setup)(void);
73 void (*board_bind_eic_interrupt)(int irq, int regset);
76 * These constant is for searching for possible module text segments.
77 * MODULE_RANGE is a guess of how much space is likely to be vmalloced.
79 #define MODULE_RANGE (8*1024*1024)
82 * This routine abuses get_user()/put_user() to reference pointers
83 * with at least a bit of error checking ...
85 void show_stack(struct task_struct *task, unsigned long *sp)
87 const int field = 2 * sizeof(unsigned long);
88 long stackdata;
89 int i;
91 if (!sp) {
92 if (task && task != current)
93 sp = (unsigned long *) task->thread.reg29;
94 else
95 sp = (unsigned long *) &sp;
98 printk("Stack :");
99 i = 0;
100 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
101 if (i && ((i % (64 / field)) == 0))
102 printk("\n ");
103 if (i > 39) {
104 printk(" ...");
105 break;
108 if (__get_user(stackdata, sp++)) {
109 printk(" (Bad stack address)");
110 break;
113 printk(" %0*lx", field, stackdata);
114 i++;
116 printk("\n");
119 void show_trace(struct task_struct *task, unsigned long *stack)
121 const int field = 2 * sizeof(unsigned long);
122 unsigned long addr;
124 if (!stack) {
125 if (task && task != current)
126 stack = (unsigned long *) task->thread.reg29;
127 else
128 stack = (unsigned long *) &stack;
131 printk("Call Trace:");
132 #ifdef CONFIG_KALLSYMS
133 printk("\n");
134 #endif
135 while (!kstack_end(stack)) {
136 addr = *stack++;
137 if (__kernel_text_address(addr)) {
138 printk(" [<%0*lx>] ", field, addr);
139 print_symbol("%s\n", addr);
142 printk("\n");
146 * The architecture-independent dump_stack generator
148 void dump_stack(void)
150 unsigned long stack;
152 show_trace(current, &stack);
155 EXPORT_SYMBOL(dump_stack);
157 void show_code(unsigned int *pc)
159 long i;
161 printk("\nCode:");
163 for(i = -3 ; i < 6 ; i++) {
164 unsigned int insn;
165 if (__get_user(insn, pc + i)) {
166 printk(" (Bad address in epc)\n");
167 break;
169 printk("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
173 void show_regs(struct pt_regs *regs)
175 const int field = 2 * sizeof(unsigned long);
176 unsigned int cause = regs->cp0_cause;
177 int i;
179 printk("Cpu %d\n", smp_processor_id());
182 * Saved main processor registers
184 for (i = 0; i < 32; ) {
185 if ((i % 4) == 0)
186 printk("$%2d :", i);
187 if (i == 0)
188 printk(" %0*lx", field, 0UL);
189 else if (i == 26 || i == 27)
190 printk(" %*s", field, "");
191 else
192 printk(" %0*lx", field, regs->regs[i]);
194 i++;
195 if ((i % 4) == 0)
196 printk("\n");
199 printk("Hi : %0*lx\n", field, regs->hi);
200 printk("Lo : %0*lx\n", field, regs->lo);
203 * Saved cp0 registers
205 printk("epc : %0*lx ", field, regs->cp0_epc);
206 print_symbol("%s ", regs->cp0_epc);
207 printk(" %s\n", print_tainted());
208 printk("ra : %0*lx ", field, regs->regs[31]);
209 print_symbol("%s\n", regs->regs[31]);
211 printk("Status: %08x ", (uint32_t) regs->cp0_status);
213 if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
214 if (regs->cp0_status & ST0_KUO)
215 printk("KUo ");
216 if (regs->cp0_status & ST0_IEO)
217 printk("IEo ");
218 if (regs->cp0_status & ST0_KUP)
219 printk("KUp ");
220 if (regs->cp0_status & ST0_IEP)
221 printk("IEp ");
222 if (regs->cp0_status & ST0_KUC)
223 printk("KUc ");
224 if (regs->cp0_status & ST0_IEC)
225 printk("IEc ");
226 } else {
227 if (regs->cp0_status & ST0_KX)
228 printk("KX ");
229 if (regs->cp0_status & ST0_SX)
230 printk("SX ");
231 if (regs->cp0_status & ST0_UX)
232 printk("UX ");
233 switch (regs->cp0_status & ST0_KSU) {
234 case KSU_USER:
235 printk("USER ");
236 break;
237 case KSU_SUPERVISOR:
238 printk("SUPERVISOR ");
239 break;
240 case KSU_KERNEL:
241 printk("KERNEL ");
242 break;
243 default:
244 printk("BAD_MODE ");
245 break;
247 if (regs->cp0_status & ST0_ERL)
248 printk("ERL ");
249 if (regs->cp0_status & ST0_EXL)
250 printk("EXL ");
251 if (regs->cp0_status & ST0_IE)
252 printk("IE ");
254 printk("\n");
256 printk("Cause : %08x\n", cause);
258 cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
259 if (1 <= cause && cause <= 5)
260 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
262 printk("PrId : %08x\n", read_c0_prid());
265 void show_registers(struct pt_regs *regs)
267 show_regs(regs);
268 print_modules();
269 printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
270 current->comm, current->pid, current_thread_info(), current);
271 show_stack(current, (long *) regs->regs[29]);
272 show_trace(current, (long *) regs->regs[29]);
273 show_code((unsigned int *) regs->cp0_epc);
274 printk("\n");
277 static DEFINE_SPINLOCK(die_lock);
279 NORET_TYPE void ATTRIB_NORET die(const char * str, struct pt_regs * regs)
281 static int die_counter;
282 #ifdef CONFIG_MIPS_MT_SMTC
283 unsigned long dvpret = dvpe();
284 #endif /* CONFIG_MIPS_MT_SMTC */
286 console_verbose();
287 spin_lock_irq(&die_lock);
288 bust_spinlocks(1);
289 #ifdef CONFIG_MIPS_MT_SMTC
290 mips_mt_regdump(dvpret);
291 #endif /* CONFIG_MIPS_MT_SMTC */
292 printk("%s[#%d]:\n", str, ++die_counter);
293 show_registers(regs);
294 spin_unlock_irq(&die_lock);
295 do_exit(SIGSEGV);
298 extern const struct exception_table_entry __start___dbe_table[];
299 extern const struct exception_table_entry __stop___dbe_table[];
301 void __declare_dbe_table(void)
303 __asm__ __volatile__(
304 ".section\t__dbe_table,\"a\"\n\t"
305 ".previous"
309 /* Given an address, look for it in the exception tables. */
310 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
312 const struct exception_table_entry *e;
314 e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
315 if (!e)
316 e = search_module_dbetables(addr);
317 return e;
320 asmlinkage void do_be(struct pt_regs *regs)
322 const int field = 2 * sizeof(unsigned long);
323 const struct exception_table_entry *fixup = NULL;
324 int data = regs->cp0_cause & 4;
325 int action = MIPS_BE_FATAL;
327 /* XXX For now. Fixme, this searches the wrong table ... */
328 if (data && !user_mode(regs))
329 fixup = search_dbe_tables(exception_epc(regs));
331 if (fixup)
332 action = MIPS_BE_FIXUP;
334 if (board_be_handler)
335 action = board_be_handler(regs, fixup != 0);
337 switch (action) {
338 case MIPS_BE_DISCARD:
339 return;
340 case MIPS_BE_FIXUP:
341 if (fixup) {
342 regs->cp0_epc = fixup->nextinsn;
343 return;
345 break;
346 default:
347 break;
351 * Assume it would be too dangerous to continue ...
353 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
354 data ? "Data" : "Instruction",
355 field, regs->cp0_epc, field, regs->regs[31]);
356 die_if_kernel("Oops", regs);
357 force_sig(SIGBUS, current);
360 static inline int get_insn_opcode(struct pt_regs *regs, unsigned int *opcode)
362 unsigned int __user *epc;
364 epc = (unsigned int __user *) regs->cp0_epc +
365 ((regs->cp0_cause & CAUSEF_BD) != 0);
366 if (!get_user(*opcode, epc))
367 return 0;
369 force_sig(SIGSEGV, current);
370 return 1;
374 * ll/sc emulation
377 #define OPCODE 0xfc000000
378 #define BASE 0x03e00000
379 #define RT 0x001f0000
380 #define OFFSET 0x0000ffff
381 #define LL 0xc0000000
382 #define SC 0xe0000000
383 #define SPEC3 0x7c000000
384 #define RD 0x0000f800
385 #define FUNC 0x0000003f
386 #define RDHWR 0x0000003b
389 * The ll_bit is cleared by r*_switch.S
392 unsigned long ll_bit;
394 static struct task_struct *ll_task = NULL;
396 static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
398 unsigned long value, __user *vaddr;
399 long offset;
400 int signal = 0;
403 * analyse the ll instruction that just caused a ri exception
404 * and put the referenced address to addr.
407 /* sign extend offset */
408 offset = opcode & OFFSET;
409 offset <<= 16;
410 offset >>= 16;
412 vaddr = (unsigned long __user *)
413 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
415 if ((unsigned long)vaddr & 3) {
416 signal = SIGBUS;
417 goto sig;
419 if (get_user(value, vaddr)) {
420 signal = SIGSEGV;
421 goto sig;
424 preempt_disable();
426 if (ll_task == NULL || ll_task == current) {
427 ll_bit = 1;
428 } else {
429 ll_bit = 0;
431 ll_task = current;
433 preempt_enable();
435 compute_return_epc(regs);
437 regs->regs[(opcode & RT) >> 16] = value;
439 return;
441 sig:
442 force_sig(signal, current);
445 static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
447 unsigned long __user *vaddr;
448 unsigned long reg;
449 long offset;
450 int signal = 0;
453 * analyse the sc instruction that just caused a ri exception
454 * and put the referenced address to addr.
457 /* sign extend offset */
458 offset = opcode & OFFSET;
459 offset <<= 16;
460 offset >>= 16;
462 vaddr = (unsigned long __user *)
463 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
464 reg = (opcode & RT) >> 16;
466 if ((unsigned long)vaddr & 3) {
467 signal = SIGBUS;
468 goto sig;
471 preempt_disable();
473 if (ll_bit == 0 || ll_task != current) {
474 compute_return_epc(regs);
475 regs->regs[reg] = 0;
476 preempt_enable();
477 return;
480 preempt_enable();
482 if (put_user(regs->regs[reg], vaddr)) {
483 signal = SIGSEGV;
484 goto sig;
487 compute_return_epc(regs);
488 regs->regs[reg] = 1;
490 return;
492 sig:
493 force_sig(signal, current);
497 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
498 * opcodes are supposed to result in coprocessor unusable exceptions if
499 * executed on ll/sc-less processors. That's the theory. In practice a
500 * few processors such as NEC's VR4100 throw reserved instruction exceptions
501 * instead, so we're doing the emulation thing in both exception handlers.
503 static inline int simulate_llsc(struct pt_regs *regs)
505 unsigned int opcode;
507 if (unlikely(get_insn_opcode(regs, &opcode)))
508 return -EFAULT;
510 if ((opcode & OPCODE) == LL) {
511 simulate_ll(regs, opcode);
512 return 0;
514 if ((opcode & OPCODE) == SC) {
515 simulate_sc(regs, opcode);
516 return 0;
519 return -EFAULT; /* Strange things going on ... */
523 * Simulate trapping 'rdhwr' instructions to provide user accessible
524 * registers not implemented in hardware. The only current use of this
525 * is the thread area pointer.
527 static inline int simulate_rdhwr(struct pt_regs *regs)
529 struct thread_info *ti = task_thread_info(current);
530 unsigned int opcode;
532 if (unlikely(get_insn_opcode(regs, &opcode)))
533 return -EFAULT;
535 if (unlikely(compute_return_epc(regs)))
536 return -EFAULT;
538 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
539 int rd = (opcode & RD) >> 11;
540 int rt = (opcode & RT) >> 16;
541 switch (rd) {
542 case 29:
543 regs->regs[rt] = ti->tp_value;
544 return 0;
545 default:
546 return -EFAULT;
550 /* Not ours. */
551 return -EFAULT;
554 asmlinkage void do_ov(struct pt_regs *regs)
556 siginfo_t info;
558 die_if_kernel("Integer overflow", regs);
560 info.si_code = FPE_INTOVF;
561 info.si_signo = SIGFPE;
562 info.si_errno = 0;
563 info.si_addr = (void __user *) regs->cp0_epc;
564 force_sig_info(SIGFPE, &info, current);
568 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
570 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
572 if (fcr31 & FPU_CSR_UNI_X) {
573 int sig;
575 preempt_disable();
577 #ifdef CONFIG_PREEMPT
578 if (!is_fpu_owner()) {
579 /* We might lose fpu before disabling preempt... */
580 own_fpu();
581 BUG_ON(!used_math());
582 restore_fp(current);
584 #endif
586 * Unimplemented operation exception. If we've got the full
587 * software emulator on-board, let's use it...
589 * Force FPU to dump state into task/thread context. We're
590 * moving a lot of data here for what is probably a single
591 * instruction, but the alternative is to pre-decode the FP
592 * register operands before invoking the emulator, which seems
593 * a bit extreme for what should be an infrequent event.
595 save_fp(current);
596 /* Ensure 'resume' not overwrite saved fp context again. */
597 lose_fpu();
599 preempt_enable();
601 /* Run the emulator */
602 sig = fpu_emulator_cop1Handler (regs, &current->thread.fpu);
604 preempt_disable();
606 own_fpu(); /* Using the FPU again. */
608 * We can't allow the emulated instruction to leave any of
609 * the cause bit set in $fcr31.
611 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
613 /* Restore the hardware register state */
614 restore_fp(current);
616 preempt_enable();
618 /* If something went wrong, signal */
619 if (sig)
620 force_sig(sig, current);
622 return;
625 force_sig(SIGFPE, current);
628 asmlinkage void do_bp(struct pt_regs *regs)
630 unsigned int opcode, bcode;
631 siginfo_t info;
633 die_if_kernel("Break instruction in kernel code", regs);
635 if (get_insn_opcode(regs, &opcode))
636 return;
639 * There is the ancient bug in the MIPS assemblers that the break
640 * code starts left to bit 16 instead to bit 6 in the opcode.
641 * Gas is bug-compatible, but not always, grrr...
642 * We handle both cases with a simple heuristics. --macro
644 bcode = ((opcode >> 6) & ((1 << 20) - 1));
645 if (bcode < (1 << 10))
646 bcode <<= 10;
649 * (A short test says that IRIX 5.3 sends SIGTRAP for all break
650 * insns, even for break codes that indicate arithmetic failures.
651 * Weird ...)
652 * But should we continue the brokenness??? --macro
654 switch (bcode) {
655 case BRK_OVERFLOW << 10:
656 case BRK_DIVZERO << 10:
657 if (bcode == (BRK_DIVZERO << 10))
658 info.si_code = FPE_INTDIV;
659 else
660 info.si_code = FPE_INTOVF;
661 info.si_signo = SIGFPE;
662 info.si_errno = 0;
663 info.si_addr = (void __user *) regs->cp0_epc;
664 force_sig_info(SIGFPE, &info, current);
665 break;
666 default:
667 force_sig(SIGTRAP, current);
671 asmlinkage void do_tr(struct pt_regs *regs)
673 unsigned int opcode, tcode = 0;
674 siginfo_t info;
676 die_if_kernel("Trap instruction in kernel code", regs);
678 if (get_insn_opcode(regs, &opcode))
679 return;
681 /* Immediate versions don't provide a code. */
682 if (!(opcode & OPCODE))
683 tcode = ((opcode >> 6) & ((1 << 10) - 1));
686 * (A short test says that IRIX 5.3 sends SIGTRAP for all trap
687 * insns, even for trap codes that indicate arithmetic failures.
688 * Weird ...)
689 * But should we continue the brokenness??? --macro
691 switch (tcode) {
692 case BRK_OVERFLOW:
693 case BRK_DIVZERO:
694 if (tcode == BRK_DIVZERO)
695 info.si_code = FPE_INTDIV;
696 else
697 info.si_code = FPE_INTOVF;
698 info.si_signo = SIGFPE;
699 info.si_errno = 0;
700 info.si_addr = (void __user *) regs->cp0_epc;
701 force_sig_info(SIGFPE, &info, current);
702 break;
703 default:
704 force_sig(SIGTRAP, current);
708 asmlinkage void do_ri(struct pt_regs *regs)
710 die_if_kernel("Reserved instruction in kernel code", regs);
712 if (!cpu_has_llsc)
713 if (!simulate_llsc(regs))
714 return;
716 if (!simulate_rdhwr(regs))
717 return;
719 force_sig(SIGILL, current);
722 asmlinkage void do_cpu(struct pt_regs *regs)
724 unsigned int cpid;
726 die_if_kernel("do_cpu invoked from kernel context!", regs);
728 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
730 switch (cpid) {
731 case 0:
732 if (!cpu_has_llsc)
733 if (!simulate_llsc(regs))
734 return;
736 if (!simulate_rdhwr(regs))
737 return;
739 break;
741 case 1:
742 preempt_disable();
744 own_fpu();
745 if (used_math()) { /* Using the FPU again. */
746 restore_fp(current);
747 } else { /* First time FPU user. */
748 init_fpu();
749 set_used_math();
752 preempt_enable();
754 if (!cpu_has_fpu) {
755 int sig = fpu_emulator_cop1Handler(regs,
756 &current->thread.fpu);
757 if (sig)
758 force_sig(sig, current);
759 #ifdef CONFIG_MIPS_MT_FPAFF
760 else {
762 * MIPS MT processors may have fewer FPU contexts
763 * than CPU threads. If we've emulated more than
764 * some threshold number of instructions, force
765 * migration to a "CPU" that has FP support.
767 if(mt_fpemul_threshold > 0
768 && ((current->thread.emulated_fp++
769 > mt_fpemul_threshold))) {
771 * If there's no FPU present, or if the
772 * application has already restricted
773 * the allowed set to exclude any CPUs
774 * with FPUs, we'll skip the procedure.
776 if (cpus_intersects(current->cpus_allowed,
777 mt_fpu_cpumask)) {
778 cpumask_t tmask;
780 cpus_and(tmask,
781 current->thread.user_cpus_allowed,
782 mt_fpu_cpumask);
783 set_cpus_allowed(current, tmask);
784 current->thread.mflags |= MF_FPUBOUND;
788 #endif /* CONFIG_MIPS_MT_FPAFF */
791 return;
793 case 2:
794 case 3:
795 die_if_kernel("do_cpu invoked from kernel context!", regs);
796 break;
799 force_sig(SIGILL, current);
802 asmlinkage void do_mdmx(struct pt_regs *regs)
804 force_sig(SIGILL, current);
807 asmlinkage void do_watch(struct pt_regs *regs)
810 * We use the watch exception where available to detect stack
811 * overflows.
813 dump_tlb_all();
814 show_regs(regs);
815 panic("Caught WATCH exception - probably caused by stack overflow.");
818 asmlinkage void do_mcheck(struct pt_regs *regs)
820 const int field = 2 * sizeof(unsigned long);
821 int multi_match = regs->cp0_status & ST0_TS;
823 show_regs(regs);
825 if (multi_match) {
826 printk("Index : %0x\n", read_c0_index());
827 printk("Pagemask: %0x\n", read_c0_pagemask());
828 printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
829 printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
830 printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
831 printk("\n");
832 dump_tlb_all();
835 show_code((unsigned int *) regs->cp0_epc);
838 * Some chips may have other causes of machine check (e.g. SB1
839 * graduation timer)
841 panic("Caught Machine Check exception - %scaused by multiple "
842 "matching entries in the TLB.",
843 (multi_match) ? "" : "not ");
846 asmlinkage void do_mt(struct pt_regs *regs)
848 int subcode;
850 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
851 >> VPECONTROL_EXCPT_SHIFT;
852 switch (subcode) {
853 case 0:
854 printk(KERN_DEBUG "Thread Underflow\n");
855 break;
856 case 1:
857 printk(KERN_DEBUG "Thread Overflow\n");
858 break;
859 case 2:
860 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
861 break;
862 case 3:
863 printk(KERN_DEBUG "Gating Storage Exception\n");
864 break;
865 case 4:
866 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
867 break;
868 case 5:
869 printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
870 break;
871 default:
872 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
873 subcode);
874 break;
876 die_if_kernel("MIPS MT Thread exception in kernel", regs);
878 force_sig(SIGILL, current);
882 asmlinkage void do_dsp(struct pt_regs *regs)
884 if (cpu_has_dsp)
885 panic("Unexpected DSP exception\n");
887 force_sig(SIGILL, current);
890 asmlinkage void do_reserved(struct pt_regs *regs)
893 * Game over - no way to handle this if it ever occurs. Most probably
894 * caused by a new unknown cpu type or after another deadly
895 * hard/software error.
897 show_regs(regs);
898 panic("Caught reserved exception %ld - should not happen.",
899 (regs->cp0_cause & 0x7f) >> 2);
902 asmlinkage void do_default_vi(struct pt_regs *regs)
904 show_regs(regs);
905 panic("Caught unexpected vectored interrupt.");
909 * Some MIPS CPUs can enable/disable for cache parity detection, but do
910 * it different ways.
912 static inline void parity_protection_init(void)
914 switch (current_cpu_data.cputype) {
915 case CPU_24K:
916 case CPU_34K:
917 case CPU_5KC:
918 write_c0_ecc(0x80000000);
919 back_to_back_c0_hazard();
920 /* Set the PE bit (bit 31) in the c0_errctl register. */
921 printk(KERN_INFO "Cache parity protection %sabled\n",
922 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
923 break;
924 case CPU_20KC:
925 case CPU_25KF:
926 /* Clear the DE bit (bit 16) in the c0_status register. */
927 printk(KERN_INFO "Enable cache parity protection for "
928 "MIPS 20KC/25KF CPUs.\n");
929 clear_c0_status(ST0_DE);
930 break;
931 default:
932 break;
936 asmlinkage void cache_parity_error(void)
938 const int field = 2 * sizeof(unsigned long);
939 unsigned int reg_val;
941 /* For the moment, report the problem and hang. */
942 printk("Cache error exception:\n");
943 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
944 reg_val = read_c0_cacheerr();
945 printk("c0_cacheerr == %08x\n", reg_val);
947 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
948 reg_val & (1<<30) ? "secondary" : "primary",
949 reg_val & (1<<31) ? "data" : "insn");
950 printk("Error bits: %s%s%s%s%s%s%s\n",
951 reg_val & (1<<29) ? "ED " : "",
952 reg_val & (1<<28) ? "ET " : "",
953 reg_val & (1<<26) ? "EE " : "",
954 reg_val & (1<<25) ? "EB " : "",
955 reg_val & (1<<24) ? "EI " : "",
956 reg_val & (1<<23) ? "E1 " : "",
957 reg_val & (1<<22) ? "E0 " : "");
958 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
960 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
961 if (reg_val & (1<<22))
962 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
964 if (reg_val & (1<<23))
965 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
966 #endif
968 panic("Can't handle the cache error!");
972 * SDBBP EJTAG debug exception handler.
973 * We skip the instruction and return to the next instruction.
975 void ejtag_exception_handler(struct pt_regs *regs)
977 const int field = 2 * sizeof(unsigned long);
978 unsigned long depc, old_epc;
979 unsigned int debug;
981 printk("SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
982 depc = read_c0_depc();
983 debug = read_c0_debug();
984 printk("c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
985 if (debug & 0x80000000) {
987 * In branch delay slot.
988 * We cheat a little bit here and use EPC to calculate the
989 * debug return address (DEPC). EPC is restored after the
990 * calculation.
992 old_epc = regs->cp0_epc;
993 regs->cp0_epc = depc;
994 __compute_return_epc(regs);
995 depc = regs->cp0_epc;
996 regs->cp0_epc = old_epc;
997 } else
998 depc += 4;
999 write_c0_depc(depc);
1001 #if 0
1002 printk("\n\n----- Enable EJTAG single stepping ----\n\n");
1003 write_c0_debug(debug | 0x100);
1004 #endif
1008 * NMI exception handler.
1010 void nmi_exception_handler(struct pt_regs *regs)
1012 #ifdef CONFIG_MIPS_MT_SMTC
1013 unsigned long dvpret = dvpe();
1014 bust_spinlocks(1);
1015 printk("NMI taken!!!!\n");
1016 mips_mt_regdump(dvpret);
1017 #else
1018 bust_spinlocks(1);
1019 printk("NMI taken!!!!\n");
1020 #endif /* CONFIG_MIPS_MT_SMTC */
1021 die("NMI", regs);
1022 while(1) ;
1025 #define VECTORSPACING 0x100 /* for EI/VI mode */
1027 unsigned long ebase;
1028 unsigned long exception_handlers[32];
1029 unsigned long vi_handlers[64];
1032 * As a side effect of the way this is implemented we're limited
1033 * to interrupt handlers in the address range from
1034 * KSEG0 <= x < KSEG0 + 256mb on the Nevada. Oh well ...
1036 void *set_except_vector(int n, void *addr)
1038 unsigned long handler = (unsigned long) addr;
1039 unsigned long old_handler = exception_handlers[n];
1041 exception_handlers[n] = handler;
1042 if (n == 0 && cpu_has_divec) {
1043 *(volatile u32 *)(ebase + 0x200) = 0x08000000 |
1044 (0x03ffffff & (handler >> 2));
1045 flush_icache_range(ebase + 0x200, ebase + 0x204);
1047 return (void *)old_handler;
1050 #ifdef CONFIG_CPU_MIPSR2_SRS
1052 * MIPSR2 shadow register set allocation
1053 * FIXME: SMP...
1056 static struct shadow_registers {
1058 * Number of shadow register sets supported
1060 unsigned long sr_supported;
1062 * Bitmap of allocated shadow registers
1064 unsigned long sr_allocated;
1065 } shadow_registers;
1067 static void mips_srs_init(void)
1069 shadow_registers.sr_supported = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1070 printk(KERN_INFO "%d MIPSR2 register sets available\n",
1071 shadow_registers.sr_supported);
1072 shadow_registers.sr_allocated = 1; /* Set 0 used by kernel */
1075 int mips_srs_max(void)
1077 return shadow_registers.sr_supported;
1080 int mips_srs_alloc(void)
1082 struct shadow_registers *sr = &shadow_registers;
1083 int set;
1085 again:
1086 set = find_first_zero_bit(&sr->sr_allocated, sr->sr_supported);
1087 if (set >= sr->sr_supported)
1088 return -1;
1090 if (test_and_set_bit(set, &sr->sr_allocated))
1091 goto again;
1093 return set;
1096 void mips_srs_free(int set)
1098 struct shadow_registers *sr = &shadow_registers;
1100 clear_bit(set, &sr->sr_allocated);
1103 static void *set_vi_srs_handler(int n, void *addr, int srs)
1105 unsigned long handler;
1106 unsigned long old_handler = vi_handlers[n];
1107 u32 *w;
1108 unsigned char *b;
1110 if (!cpu_has_veic && !cpu_has_vint)
1111 BUG();
1113 if (addr == NULL) {
1114 handler = (unsigned long) do_default_vi;
1115 srs = 0;
1116 } else
1117 handler = (unsigned long) addr;
1118 vi_handlers[n] = (unsigned long) addr;
1120 b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1122 if (srs >= mips_srs_max())
1123 panic("Shadow register set %d not supported", srs);
1125 if (cpu_has_veic) {
1126 if (board_bind_eic_interrupt)
1127 board_bind_eic_interrupt (n, srs);
1128 } else if (cpu_has_vint) {
1129 /* SRSMap is only defined if shadow sets are implemented */
1130 if (mips_srs_max() > 1)
1131 change_c0_srsmap (0xf << n*4, srs << n*4);
1134 if (srs == 0) {
1136 * If no shadow set is selected then use the default handler
1137 * that does normal register saving and a standard interrupt exit
1140 extern char except_vec_vi, except_vec_vi_lui;
1141 extern char except_vec_vi_ori, except_vec_vi_end;
1142 #ifdef CONFIG_MIPS_MT_SMTC
1144 * We need to provide the SMTC vectored interrupt handler
1145 * not only with the address of the handler, but with the
1146 * Status.IM bit to be masked before going there.
1148 extern char except_vec_vi_mori;
1149 const int mori_offset = &except_vec_vi_mori - &except_vec_vi;
1150 #endif /* CONFIG_MIPS_MT_SMTC */
1151 const int handler_len = &except_vec_vi_end - &except_vec_vi;
1152 const int lui_offset = &except_vec_vi_lui - &except_vec_vi;
1153 const int ori_offset = &except_vec_vi_ori - &except_vec_vi;
1155 if (handler_len > VECTORSPACING) {
1157 * Sigh... panicing won't help as the console
1158 * is probably not configured :(
1160 panic ("VECTORSPACING too small");
1163 memcpy (b, &except_vec_vi, handler_len);
1164 #ifdef CONFIG_MIPS_MT_SMTC
1165 if (n > 7)
1166 printk("Vector index %d exceeds SMTC maximum\n", n);
1167 w = (u32 *)(b + mori_offset);
1168 *w = (*w & 0xffff0000) | (0x100 << n);
1169 #endif /* CONFIG_MIPS_MT_SMTC */
1170 w = (u32 *)(b + lui_offset);
1171 *w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1172 w = (u32 *)(b + ori_offset);
1173 *w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1174 flush_icache_range((unsigned long)b, (unsigned long)(b+handler_len));
1176 else {
1178 * In other cases jump directly to the interrupt handler
1180 * It is the handlers responsibility to save registers if required
1181 * (eg hi/lo) and return from the exception using "eret"
1183 w = (u32 *)b;
1184 *w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1185 *w = 0;
1186 flush_icache_range((unsigned long)b, (unsigned long)(b+8));
1189 return (void *)old_handler;
1192 void *set_vi_handler(int n, void *addr)
1194 return set_vi_srs_handler(n, addr, 0);
1197 #else
1199 static inline void mips_srs_init(void)
1203 #endif /* CONFIG_CPU_MIPSR2_SRS */
1206 * This is used by native signal handling
1208 asmlinkage int (*save_fp_context)(struct sigcontext *sc);
1209 asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
1211 extern asmlinkage int _save_fp_context(struct sigcontext *sc);
1212 extern asmlinkage int _restore_fp_context(struct sigcontext *sc);
1214 extern asmlinkage int fpu_emulator_save_context(struct sigcontext *sc);
1215 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext *sc);
1217 #ifdef CONFIG_SMP
1218 static int smp_save_fp_context(struct sigcontext *sc)
1220 return cpu_has_fpu
1221 ? _save_fp_context(sc)
1222 : fpu_emulator_save_context(sc);
1225 static int smp_restore_fp_context(struct sigcontext *sc)
1227 return cpu_has_fpu
1228 ? _restore_fp_context(sc)
1229 : fpu_emulator_restore_context(sc);
1231 #endif
1233 static inline void signal_init(void)
1235 #ifdef CONFIG_SMP
1236 /* For now just do the cpu_has_fpu check when the functions are invoked */
1237 save_fp_context = smp_save_fp_context;
1238 restore_fp_context = smp_restore_fp_context;
1239 #else
1240 if (cpu_has_fpu) {
1241 save_fp_context = _save_fp_context;
1242 restore_fp_context = _restore_fp_context;
1243 } else {
1244 save_fp_context = fpu_emulator_save_context;
1245 restore_fp_context = fpu_emulator_restore_context;
1247 #endif
1250 #ifdef CONFIG_MIPS32_COMPAT
1253 * This is used by 32-bit signal stuff on the 64-bit kernel
1255 asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
1256 asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
1258 extern asmlinkage int _save_fp_context32(struct sigcontext32 *sc);
1259 extern asmlinkage int _restore_fp_context32(struct sigcontext32 *sc);
1261 extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 *sc);
1262 extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 *sc);
1264 static inline void signal32_init(void)
1266 if (cpu_has_fpu) {
1267 save_fp_context32 = _save_fp_context32;
1268 restore_fp_context32 = _restore_fp_context32;
1269 } else {
1270 save_fp_context32 = fpu_emulator_save_context32;
1271 restore_fp_context32 = fpu_emulator_restore_context32;
1274 #endif
1276 extern void cpu_cache_init(void);
1277 extern void tlb_init(void);
1278 extern void flush_tlb_handlers(void);
1280 void __init per_cpu_trap_init(void)
1282 unsigned int cpu = smp_processor_id();
1283 unsigned int status_set = ST0_CU0;
1284 #ifdef CONFIG_MIPS_MT_SMTC
1285 int secondaryTC = 0;
1286 int bootTC = (cpu == 0);
1289 * Only do per_cpu_trap_init() for first TC of Each VPE.
1290 * Note that this hack assumes that the SMTC init code
1291 * assigns TCs consecutively and in ascending order.
1294 if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1295 ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1296 secondaryTC = 1;
1297 #endif /* CONFIG_MIPS_MT_SMTC */
1300 * Disable coprocessors and select 32-bit or 64-bit addressing
1301 * and the 16/32 or 32/32 FPR register model. Reset the BEV
1302 * flag that some firmware may have left set and the TS bit (for
1303 * IP27). Set XX for ISA IV code to work.
1305 #ifdef CONFIG_64BIT
1306 status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1307 #endif
1308 if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1309 status_set |= ST0_XX;
1310 change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1311 status_set);
1313 if (cpu_has_dsp)
1314 set_c0_status(ST0_MX);
1316 #ifdef CONFIG_CPU_MIPSR2
1317 write_c0_hwrena (0x0000000f); /* Allow rdhwr to all registers */
1318 #endif
1320 #ifdef CONFIG_MIPS_MT_SMTC
1321 if (!secondaryTC) {
1322 #endif /* CONFIG_MIPS_MT_SMTC */
1325 * Interrupt handling.
1327 if (cpu_has_veic || cpu_has_vint) {
1328 write_c0_ebase (ebase);
1329 /* Setting vector spacing enables EI/VI mode */
1330 change_c0_intctl (0x3e0, VECTORSPACING);
1332 if (cpu_has_divec) {
1333 if (cpu_has_mipsmt) {
1334 unsigned int vpflags = dvpe();
1335 set_c0_cause(CAUSEF_IV);
1336 evpe(vpflags);
1337 } else
1338 set_c0_cause(CAUSEF_IV);
1340 #ifdef CONFIG_MIPS_MT_SMTC
1342 #endif /* CONFIG_MIPS_MT_SMTC */
1344 cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1345 TLBMISS_HANDLER_SETUP();
1347 atomic_inc(&init_mm.mm_count);
1348 current->active_mm = &init_mm;
1349 BUG_ON(current->mm);
1350 enter_lazy_tlb(&init_mm, current);
1352 #ifdef CONFIG_MIPS_MT_SMTC
1353 if (bootTC) {
1354 #endif /* CONFIG_MIPS_MT_SMTC */
1355 cpu_cache_init();
1356 tlb_init();
1357 #ifdef CONFIG_MIPS_MT_SMTC
1359 #endif /* CONFIG_MIPS_MT_SMTC */
1362 /* Install CPU exception handler */
1363 void __init set_handler (unsigned long offset, void *addr, unsigned long size)
1365 memcpy((void *)(ebase + offset), addr, size);
1366 flush_icache_range(ebase + offset, ebase + offset + size);
1369 /* Install uncached CPU exception handler */
1370 void __init set_uncached_handler (unsigned long offset, void *addr, unsigned long size)
1372 #ifdef CONFIG_32BIT
1373 unsigned long uncached_ebase = KSEG1ADDR(ebase);
1374 #endif
1375 #ifdef CONFIG_64BIT
1376 unsigned long uncached_ebase = TO_UNCAC(ebase);
1377 #endif
1379 memcpy((void *)(uncached_ebase + offset), addr, size);
1382 void __init trap_init(void)
1384 extern char except_vec3_generic, except_vec3_r4000;
1385 extern char except_vec4;
1386 unsigned long i;
1388 if (cpu_has_veic || cpu_has_vint)
1389 ebase = (unsigned long) alloc_bootmem_low_pages (0x200 + VECTORSPACING*64);
1390 else
1391 ebase = CAC_BASE;
1393 mips_srs_init();
1395 per_cpu_trap_init();
1398 * Copy the generic exception handlers to their final destination.
1399 * This will be overriden later as suitable for a particular
1400 * configuration.
1402 set_handler(0x180, &except_vec3_generic, 0x80);
1405 * Setup default vectors
1407 for (i = 0; i <= 31; i++)
1408 set_except_vector(i, handle_reserved);
1411 * Copy the EJTAG debug exception vector handler code to it's final
1412 * destination.
1414 if (cpu_has_ejtag && board_ejtag_handler_setup)
1415 board_ejtag_handler_setup ();
1418 * Only some CPUs have the watch exceptions.
1420 if (cpu_has_watch)
1421 set_except_vector(23, handle_watch);
1424 * Initialise interrupt handlers
1426 if (cpu_has_veic || cpu_has_vint) {
1427 int nvec = cpu_has_veic ? 64 : 8;
1428 for (i = 0; i < nvec; i++)
1429 set_vi_handler(i, NULL);
1431 else if (cpu_has_divec)
1432 set_handler(0x200, &except_vec4, 0x8);
1435 * Some CPUs can enable/disable for cache parity detection, but does
1436 * it different ways.
1438 parity_protection_init();
1441 * The Data Bus Errors / Instruction Bus Errors are signaled
1442 * by external hardware. Therefore these two exceptions
1443 * may have board specific handlers.
1445 if (board_be_init)
1446 board_be_init();
1448 set_except_vector(0, handle_int);
1449 set_except_vector(1, handle_tlbm);
1450 set_except_vector(2, handle_tlbl);
1451 set_except_vector(3, handle_tlbs);
1453 set_except_vector(4, handle_adel);
1454 set_except_vector(5, handle_ades);
1456 set_except_vector(6, handle_ibe);
1457 set_except_vector(7, handle_dbe);
1459 set_except_vector(8, handle_sys);
1460 set_except_vector(9, handle_bp);
1461 set_except_vector(10, handle_ri);
1462 set_except_vector(11, handle_cpu);
1463 set_except_vector(12, handle_ov);
1464 set_except_vector(13, handle_tr);
1466 if (current_cpu_data.cputype == CPU_R6000 ||
1467 current_cpu_data.cputype == CPU_R6000A) {
1469 * The R6000 is the only R-series CPU that features a machine
1470 * check exception (similar to the R4000 cache error) and
1471 * unaligned ldc1/sdc1 exception. The handlers have not been
1472 * written yet. Well, anyway there is no R6000 machine on the
1473 * current list of targets for Linux/MIPS.
1474 * (Duh, crap, there is someone with a triple R6k machine)
1476 //set_except_vector(14, handle_mc);
1477 //set_except_vector(15, handle_ndc);
1481 if (board_nmi_handler_setup)
1482 board_nmi_handler_setup();
1484 if (cpu_has_fpu && !cpu_has_nofpuex)
1485 set_except_vector(15, handle_fpe);
1487 set_except_vector(22, handle_mdmx);
1489 if (cpu_has_mcheck)
1490 set_except_vector(24, handle_mcheck);
1492 if (cpu_has_mipsmt)
1493 set_except_vector(25, handle_mt);
1495 if (cpu_has_dsp)
1496 set_except_vector(26, handle_dsp);
1498 if (cpu_has_vce)
1499 /* Special exception: R4[04]00 uses also the divec space. */
1500 memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
1501 else if (cpu_has_4kex)
1502 memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
1503 else
1504 memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
1506 signal_init();
1507 #ifdef CONFIG_MIPS32_COMPAT
1508 signal32_init();
1509 #endif
1511 flush_icache_range(ebase, ebase + 0x400);
1512 flush_tlb_handlers();