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
6 * Copyright (C) 1994 - 1999, 2000, 01 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 Maciej W. Rozycki
14 #include <linux/config.h>
15 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/smp.h>
20 #include <linux/smp_lock.h>
21 #include <linux/spinlock.h>
22 #include <linux/kallsyms.h>
24 #include <asm/bootinfo.h>
25 #include <asm/branch.h>
28 #include <asm/module.h>
29 #include <asm/pgtable.h>
30 #include <asm/ptrace.h>
31 #include <asm/sections.h>
32 #include <asm/system.h>
33 #include <asm/tlbdebug.h>
34 #include <asm/traps.h>
35 #include <asm/uaccess.h>
36 #include <asm/mmu_context.h>
37 #include <asm/watch.h>
38 #include <asm/types.h>
40 extern asmlinkage void __xtlb_mod(void);
41 extern asmlinkage void __xtlb_tlbl(void);
42 extern asmlinkage void __xtlb_tlbs(void);
43 extern asmlinkage void handle_adel(void);
44 extern asmlinkage void handle_ades(void);
45 extern asmlinkage void handle_ibe(void);
46 extern asmlinkage void handle_dbe(void);
47 extern asmlinkage void handle_sys(void);
48 extern asmlinkage void handle_bp(void);
49 extern asmlinkage void handle_ri(void);
50 extern asmlinkage void handle_cpu(void);
51 extern asmlinkage void handle_ov(void);
52 extern asmlinkage void handle_tr(void);
53 extern asmlinkage void handle_fpe(void);
54 extern asmlinkage void handle_mdmx(void);
55 extern asmlinkage void handle_watch(void);
56 extern asmlinkage void handle_mcheck(void);
57 extern asmlinkage void handle_reserved(void);
59 extern int fpu_emulator_cop1Handler(int xcptno, struct pt_regs *xcp,
60 struct mips_fpu_soft_struct *ctx);
62 void (*board_be_init)(void);
63 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
66 * These constant is for searching for possible module text segments.
67 * MODULE_RANGE is a guess of how much space is likely to be vmalloced.
69 #define MODULE_RANGE (8*1024*1024)
72 * This routine abuses get_user()/put_user() to reference pointers
73 * with at least a bit of error checking ...
75 void show_stack(struct task_struct *task, unsigned long *sp)
77 const int field = 2 * sizeof(unsigned long);
81 sp = sp ? sp : (unsigned long *) &sp;
85 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
86 if (i && ((i % (64 / sizeof(unsigned long))) == 0))
93 if (__get_user(stackdata, sp++)) {
94 printk(" (Bad stack address)");
98 printk(" %0*lx", field, stackdata);
104 void show_trace(struct task_struct *task, unsigned long *stack)
106 const int field = 2 * sizeof(unsigned long);
110 stack = (unsigned long*)&stack;
112 printk("Call Trace:");
113 #ifdef CONFIG_KALLSYMS
116 while (((long) stack & (THREAD_SIZE-1)) != 0) {
118 if (kernel_text_address(addr)) {
119 printk(" [<%0*lx>] ", field, addr);
120 print_symbol("%s\n", addr);
126 void show_trace_task(struct task_struct *tsk)
128 show_trace(tsk, (long *)tsk->thread.reg29);
132 * The architecture-independent dump_stack generator
134 void dump_stack(void)
138 show_trace(current, &stack);
141 void show_code(unsigned int *pc)
147 for(i = -3 ; i < 6 ; i++) {
149 if (__get_user(insn, pc + i)) {
150 printk(" (Bad address in epc)\n");
153 printk("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
157 void show_regs(struct pt_regs *regs)
159 const int field = 2 * sizeof(unsigned long);
162 printk("Cpu %d\n", smp_processor_id());
165 * Saved main processor registers
167 for (i = 0; i < 32; i++) {
171 printk(" %0*lx", field, 0UL);
172 else if (i == 26 || i == 27)
173 printk(" %*s", field, "");
175 printk(" %0*lx", field, regs->regs[i]);
182 printk("Hi : %0*lx\n", field, regs->hi);
183 printk("Lo : %0*lx\n", field, regs->lo);
186 * Saved cp0 registers
188 printk("epc : %0*lx %s\n", field, regs->cp0_epc, print_tainted());
189 printk("Status: %0*lx\n", field, regs->cp0_status);
190 printk("Cause : %0*lx\n", field, regs->cp0_cause);
192 if (regs->cp0_status & ST0_KX)
194 if (regs->cp0_status & ST0_SX)
196 if (regs->cp0_status & ST0_UX)
198 switch (regs->cp0_status & ST0_KSU) {
203 printk("SUPERVISOR ");
212 if (regs->cp0_status & ST0_ERL)
214 if (regs->cp0_status & ST0_EXL)
216 if (regs->cp0_status & ST0_IE)
220 void show_registers(struct pt_regs *regs)
222 const int field = 2 * sizeof(unsigned long);
225 printk("Process %s (pid: %d, stackpage=%0*lx)\n",
226 current->comm, current->pid, field, (unsigned long) current);
227 show_stack(current, (long *) regs->regs[29]);
228 show_trace(current, (long *) regs->regs[29]);
229 show_code((unsigned int *) regs->cp0_epc);
233 static spinlock_t die_lock = SPIN_LOCK_UNLOCKED;
235 void __die(const char * str, struct pt_regs * regs, const char * file,
236 const char * func, unsigned long line)
238 static int die_counter;
241 spin_lock_irq(&die_lock);
244 printk(" in %s:%s, line %ld", file, func, line);
245 printk("[#%d]:\n", ++die_counter);
246 show_registers(regs);
247 spin_unlock_irq(&die_lock);
251 void __die_if_kernel(const char * str, struct pt_regs * regs,
252 const char * file, const char * func, unsigned long line)
254 if (!user_mode(regs))
255 __die(str, regs, file, func, line);
258 extern const struct exception_table_entry __start___dbe_table[];
259 extern const struct exception_table_entry __stop___dbe_table[];
261 void __declare_dbe_table(void)
263 __asm__ __volatile__(
264 ".section\t__dbe_table,\"a\"\n\t"
269 asmlinkage void do_be(struct pt_regs *regs)
271 const int field = 2 * sizeof(unsigned long);
272 const struct exception_table_entry *fixup = NULL;
273 int data = regs->cp0_cause & 4;
274 int action = MIPS_BE_FATAL;
276 /* XXX For now. Fixme, this searches the wrong table ... */
277 if (data && !user_mode(regs))
278 fixup = search_exception_tables(regs->cp0_epc);
281 action = MIPS_BE_FIXUP;
283 if (board_be_handler)
284 action = board_be_handler(regs, fixup != 0);
287 case MIPS_BE_DISCARD:
291 regs->cp0_epc = fixup->nextinsn;
300 * Assume it would be too dangerous to continue ...
302 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
303 data ? "Data" : "Instruction",
304 field, regs->cp0_epc, field, regs->regs[31]);
305 die_if_kernel("Oops", regs);
306 force_sig(SIGBUS, current);
309 static inline int get_insn_opcode(struct pt_regs *regs, unsigned int *opcode)
313 epc = (unsigned int *) regs->cp0_epc +
314 ((regs->cp0_cause & CAUSEF_BD) != 0);
315 if (!get_user(*opcode, epc))
318 force_sig(SIGSEGV, current);
326 #define OPCODE 0xfc000000
327 #define BASE 0x03e00000
328 #define RT 0x001f0000
329 #define OFFSET 0x0000ffff
330 #define LL 0xc0000000
331 #define SC 0xe0000000
334 * The ll_bit is cleared by r*_switch.S
337 unsigned long ll_bit;
339 static struct task_struct *ll_task = NULL;
341 static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
343 unsigned long value, *vaddr;
348 * analyse the ll instruction that just caused a ri exception
349 * and put the referenced address to addr.
352 /* sign extend offset */
353 offset = opcode & OFFSET;
357 vaddr = (unsigned long *)((long)(regs->regs[(opcode & BASE) >> 21]) + offset);
359 if ((unsigned long)vaddr & 3) {
363 if (get_user(value, vaddr)) {
368 if (ll_task == NULL || ll_task == current) {
375 regs->regs[(opcode & RT) >> 16] = value;
377 compute_return_epc(regs);
381 force_sig(signal, current);
384 static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
386 unsigned long *vaddr, reg;
391 * analyse the sc instruction that just caused a ri exception
392 * and put the referenced address to addr.
395 /* sign extend offset */
396 offset = opcode & OFFSET;
400 vaddr = (unsigned long *)((long)(regs->regs[(opcode & BASE) >> 21]) + offset);
401 reg = (opcode & RT) >> 16;
403 if ((unsigned long)vaddr & 3) {
407 if (ll_bit == 0 || ll_task != current) {
409 compute_return_epc(regs);
413 if (put_user(regs->regs[reg], vaddr)) {
420 compute_return_epc(regs);
424 force_sig(signal, current);
428 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
429 * opcodes are supposed to result in coprocessor unusable exceptions if
430 * executed on ll/sc-less processors. That's the theory. In practice a
431 * few processors such as NEC's VR4100 throw reserved instruction exceptions
432 * instead, so we're doing the emulation thing in both exception handlers.
434 static inline int simulate_llsc(struct pt_regs *regs)
438 if (unlikely(get_insn_opcode(regs, &opcode)))
441 if ((opcode & OPCODE) == LL) {
442 simulate_ll(regs, opcode);
445 if ((opcode & OPCODE) == SC) {
446 simulate_sc(regs, opcode);
450 return -EFAULT; /* Strange things going on ... */
453 asmlinkage void do_ov(struct pt_regs *regs)
457 info.si_code = FPE_INTOVF;
458 info.si_signo = SIGFPE;
460 info.si_addr = (void *)regs->cp0_epc;
461 force_sig_info(SIGFPE, &info, current);
465 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
467 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
469 if (fcr31 & FPU_CSR_UNI_X) {
473 * Unimplemented operation exception. If we've got the full
474 * software emulator on-board, let's use it...
476 * Force FPU to dump state into task/thread context. We're
477 * moving a lot of data here for what is probably a single
478 * instruction, but the alternative is to pre-decode the FP
479 * register operands before invoking the emulator, which seems
480 * a bit extreme for what should be an infrequent event.
484 /* Run the emulator */
485 sig = fpu_emulator_cop1Handler (0, regs,
486 ¤t->thread.fpu.soft);
489 * We can't allow the emulated instruction to leave any of
490 * the cause bit set in $fcr31.
492 current->thread.fpu.soft.sr &= ~FPU_CSR_ALL_X;
494 /* Restore the hardware register state */
497 /* If something went wrong, signal */
499 force_sig(sig, current);
504 force_sig(SIGFPE, current);
507 asmlinkage void do_bp(struct pt_regs *regs)
509 unsigned int opcode, bcode;
512 die_if_kernel("Break instruction in kernel code", regs);
514 if (get_insn_opcode(regs, &opcode))
518 * There is the ancient bug in the MIPS assemblers that the break
519 * code starts left to bit 16 instead to bit 6 in the opcode.
520 * Gas is bug-compatible ...
522 bcode = ((opcode >> 16) & ((1 << 20) - 1));
525 * (A short test says that IRIX 5.3 sends SIGTRAP for all break
526 * insns, even for break codes that indicate arithmetic failures.
528 * But should we continue the brokenness??? --macro
534 info.si_code = FPE_INTDIV;
536 info.si_code = FPE_INTOVF;
537 info.si_signo = SIGFPE;
539 info.si_addr = (void *)regs->cp0_epc;
540 force_sig_info(SIGFPE, &info, current);
543 force_sig(SIGTRAP, current);
547 asmlinkage void do_tr(struct pt_regs *regs)
549 unsigned int opcode, tcode = 0;
552 die_if_kernel("Trap instruction in kernel code", regs);
554 if (get_insn_opcode(regs, &opcode))
557 /* Immediate versions don't provide a code. */
558 if (!(opcode & OPCODE))
559 tcode = ((opcode >> 6) & ((1 << 20) - 1));
562 * (A short test says that IRIX 5.3 sends SIGTRAP for all trap
563 * insns, even for trap codes that indicate arithmetic failures.
565 * But should we continue the brokenness??? --macro
571 info.si_code = FPE_INTDIV;
573 info.si_code = FPE_INTOVF;
574 info.si_signo = SIGFPE;
576 info.si_addr = (void *)regs->cp0_epc;
577 force_sig_info(SIGFPE, &info, current);
580 force_sig(SIGTRAP, current);
584 asmlinkage void do_ri(struct pt_regs *regs)
586 die_if_kernel("Reserved instruction in kernel code", regs);
589 if (!simulate_llsc(regs))
592 force_sig(SIGILL, current);
595 asmlinkage void do_cpu(struct pt_regs *regs)
599 die_if_kernel("do_cpu invoked from kernel context!", regs);
601 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
608 if (!simulate_llsc(regs))
614 if (current->used_math) { /* Using the FPU again. */
616 } else { /* First time FPU user. */
618 current->used_math = 1;
622 int sig = fpu_emulator_cop1Handler(0, regs,
623 ¤t->thread.fpu.soft);
625 force_sig(sig, current);
635 force_sig(SIGILL, current);
638 asmlinkage void do_mdmx(struct pt_regs *regs)
640 force_sig(SIGILL, current);
643 asmlinkage void do_watch(struct pt_regs *regs)
646 * We use the watch exception where available to detect stack
651 panic("Caught WATCH exception - probably caused by stack overflow.");
654 asmlinkage void do_mcheck(struct pt_regs *regs)
659 * Some chips may have other causes of machine check (e.g. SB1
662 panic("Caught Machine Check exception - %scaused by multiple "
663 "matching entries in the TLB.",
664 (regs->cp0_status & ST0_TS) ? "" : "not ");
667 asmlinkage void do_reserved(struct pt_regs *regs)
670 * Game over - no way to handle this if it ever occurs. Most probably
671 * caused by a new unknown cpu type or after another deadly
672 * hard/software error.
675 panic("Caught reserved exception %ld - should not happen.",
676 (regs->cp0_cause & 0x7f) >> 2);
680 * Some MIPS CPUs can enable/disable for cache parity detection, but do
683 static inline void parity_protection_init(void)
685 switch (current_cpu_data.cputype) {
687 /* Set the PE bit (bit 31) in the c0_ecc register. */
688 printk(KERN_INFO "Enable the cache parity protection for "
690 write_c0_ecc(read_c0_ecc() | 0x80000000);
697 asmlinkage void cache_parity_error(void)
699 const int field = 2 * sizeof(unsigned long);
700 unsigned int reg_val;
702 /* For the moment, report the problem and hang. */
703 printk("Cache error exception:\n");
704 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
705 reg_val = read_c0_cacheerr();
706 printk("c0_cacheerr == %08x\n", reg_val);
708 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
709 reg_val & (1<<30) ? "secondary" : "primary",
710 reg_val & (1<<31) ? "data" : "insn");
711 printk("Error bits: %s%s%s%s%s%s%s\n",
712 reg_val & (1<<29) ? "ED " : "",
713 reg_val & (1<<28) ? "ET " : "",
714 reg_val & (1<<26) ? "EE " : "",
715 reg_val & (1<<25) ? "EB " : "",
716 reg_val & (1<<24) ? "EI " : "",
717 reg_val & (1<<23) ? "E1 " : "",
718 reg_val & (1<<22) ? "E0 " : "");
719 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
721 #if defined(CONFIG_CPU_MIPS32) || defined (CONFIG_CPU_MIPS64)
722 if (reg_val & (1<<22))
723 printk("DErrAddr0: 0x%08x\n", read_c0_derraddr0());
725 if (reg_val & (1<<23))
726 printk("DErrAddr1: 0x%08x\n", read_c0_derraddr1());
729 panic("Can't handle the cache error!");
733 * SDBBP EJTAG debug exception handler.
734 * We skip the instruction and return to the next instruction.
736 void ejtag_exception_handler(struct pt_regs *regs)
738 const int field = 2 * sizeof(unsigned long);
739 unsigned long depc, old_epc;
742 printk("SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
743 depc = read_c0_depc();
744 debug = read_c0_debug();
745 printk("c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
746 if (debug & 0x80000000) {
748 * In branch delay slot.
749 * We cheat a little bit here and use EPC to calculate the
750 * debug return address (DEPC). EPC is restored after the
753 old_epc = regs->cp0_epc;
754 regs->cp0_epc = depc;
755 __compute_return_epc(regs);
756 depc = regs->cp0_epc;
757 regs->cp0_epc = old_epc;
763 printk("\n\n----- Enable EJTAG single stepping ----\n\n");
764 write_c0_debug(debug | 0x100);
769 * NMI exception handler.
771 void nmi_exception_handler(struct pt_regs *regs)
773 printk("NMI taken!!!!\n");
778 unsigned long exception_handlers[32];
781 * As a side effect of the way this is implemented we're limited
782 * to interrupt handlers in the address range from
783 * KSEG0 <= x < KSEG0 + 256mb on the Nevada. Oh well ...
785 void *set_except_vector(int n, void *addr)
787 unsigned long handler = (unsigned long) addr;
788 unsigned long old_handler = exception_handlers[n];
790 exception_handlers[n] = handler;
791 if (n == 0 && cpu_has_divec) {
792 *(volatile u32 *)(KSEG0+0x200) = 0x08000000 |
793 (0x03ffffff & (handler >> 2));
794 flush_icache_range(KSEG0+0x200, KSEG0 + 0x204);
796 return (void *)old_handler;
799 asmlinkage int (*save_fp_context)(struct sigcontext *sc);
800 asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
802 extern asmlinkage int _save_fp_context(struct sigcontext *sc);
803 extern asmlinkage int _restore_fp_context(struct sigcontext *sc);
805 extern asmlinkage int fpu_emulator_save_context(struct sigcontext *sc);
806 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext *sc);
808 void __init per_cpu_trap_init(void)
810 unsigned int cpu = smp_processor_id();
812 /* Some firmware leaves the BEV flag set, clear it. */
813 clear_c0_status(ST0_CU1|ST0_CU2|ST0_CU3|ST0_BEV);
814 set_c0_status(ST0_CU0|ST0_FR|ST0_KX|ST0_SX|ST0_UX);
817 * Some MIPS CPUs have a dedicated interrupt vector which reduces the
818 * interrupt processing overhead. Use it where available.
821 set_c0_cause(CAUSEF_IV);
823 cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
824 write_c0_context(((long)(&pgd_current[cpu])) << 23);
828 void __init trap_init(void)
830 extern char except_vec0_generic;
831 extern char except_vec3_generic, except_vec3_r4000;
832 extern char except_vec_ejtag_debug;
833 extern char except_vec4;
838 /* Copy the generic exception handlers to their final destination. */
839 memcpy((void *) KSEG0 , &except_vec0_generic, 0x80);
840 memcpy((void *)(KSEG0 + 0x180), &except_vec3_generic, 0x80);
843 * Setup default vectors
845 for (i = 0; i <= 31; i++)
846 set_except_vector(i, handle_reserved);
849 * Copy the EJTAG debug exception vector handler code to it's final
853 memcpy((void *)(KSEG0 + 0x300), &except_vec_ejtag_debug, 0x80);
856 * Only some CPUs have the watch exceptions or a dedicated
860 set_except_vector(23, handle_watch);
863 * Some MIPS CPUs have a dedicated interrupt vector which reduces the
864 * interrupt processing overhead. Use it where available.
867 memcpy((void *)(KSEG0 + 0x200), &except_vec4, 0x8);
870 * Some CPUs can enable/disable for cache parity detection, but does
873 parity_protection_init();
876 * The Data Bus Errors / Instruction Bus Errors are signaled
877 * by external hardware. Therefore these two exceptions
878 * may have board specific handlers.
883 set_except_vector(1, __xtlb_mod);
884 set_except_vector(2, __xtlb_tlbl);
885 set_except_vector(3, __xtlb_tlbs);
886 set_except_vector(4, handle_adel);
887 set_except_vector(5, handle_ades);
889 set_except_vector(6, handle_ibe);
890 set_except_vector(7, handle_dbe);
892 set_except_vector(8, handle_sys);
893 set_except_vector(9, handle_bp);
894 set_except_vector(10, handle_ri);
895 set_except_vector(11, handle_cpu);
896 set_except_vector(12, handle_ov);
897 set_except_vector(13, handle_tr);
898 set_except_vector(22, handle_mdmx);
900 if (cpu_has_fpu && !cpu_has_nofpuex)
901 set_except_vector(15, handle_fpe);
904 set_except_vector(24, handle_mcheck);
907 memcpy((void *)(KSEG0 + 0x180), &except_vec3_r4000, 0x100);
908 else if (cpu_has_4kex)
909 memcpy((void *)(KSEG0 + 0x180), &except_vec3_generic, 0x80);
911 memcpy((void *)(KSEG0 + 0x080), &except_vec3_generic, 0x80);
913 if (current_cpu_data.cputype == CPU_R6000 ||
914 current_cpu_data.cputype == CPU_R6000A) {
916 * The R6000 is the only R-series CPU that features a machine
917 * check exception (similar to the R4000 cache error) and
918 * unaligned ldc1/sdc1 exception. The handlers have not been
919 * written yet. Well, anyway there is no R6000 machine on the
920 * current list of targets for Linux/MIPS.
921 * (Duh, crap, there is someone with a tripple R6k machine)
923 //set_except_vector(14, handle_mc);
924 //set_except_vector(15, handle_ndc);
928 save_fp_context = _save_fp_context;
929 restore_fp_context = _restore_fp_context;
931 save_fp_context = fpu_emulator_save_context;
932 restore_fp_context = fpu_emulator_restore_context;
935 flush_icache_range(KSEG0, KSEG0 + 0x400);
937 if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
938 set_c0_status(ST0_XX);
940 atomic_inc(&init_mm.mm_count); /* XXX UP? */
941 current->active_mm = &init_mm;