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, 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/bug.h>
15 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/sched.h>
19 #include <linux/smp.h>
20 #include <linux/spinlock.h>
21 #include <linux/kallsyms.h>
22 #include <linux/bootmem.h>
23 #include <linux/interrupt.h>
25 #include <asm/bootinfo.h>
26 #include <asm/branch.h>
27 #include <asm/break.h>
31 #include <asm/mipsregs.h>
32 #include <asm/mipsmtregs.h>
33 #include <asm/module.h>
34 #include <asm/pgtable.h>
35 #include <asm/ptrace.h>
36 #include <asm/sections.h>
37 #include <asm/system.h>
38 #include <asm/tlbdebug.h>
39 #include <asm/traps.h>
40 #include <asm/uaccess.h>
41 #include <asm/mmu_context.h>
42 #include <asm/types.h>
43 #include <asm/stacktrace.h>
45 extern asmlinkage void handle_int(void);
46 extern asmlinkage void handle_tlbm(void);
47 extern asmlinkage void handle_tlbl(void);
48 extern asmlinkage void handle_tlbs(void);
49 extern asmlinkage void handle_adel(void);
50 extern asmlinkage void handle_ades(void);
51 extern asmlinkage void handle_ibe(void);
52 extern asmlinkage void handle_dbe(void);
53 extern asmlinkage void handle_sys(void);
54 extern asmlinkage void handle_bp(void);
55 extern asmlinkage void handle_ri(void);
56 extern asmlinkage void handle_ri_rdhwr_vivt(void);
57 extern asmlinkage void handle_ri_rdhwr(void);
58 extern asmlinkage void handle_cpu(void);
59 extern asmlinkage void handle_ov(void);
60 extern asmlinkage void handle_tr(void);
61 extern asmlinkage void handle_fpe(void);
62 extern asmlinkage void handle_mdmx(void);
63 extern asmlinkage void handle_watch(void);
64 extern asmlinkage void handle_mt(void);
65 extern asmlinkage void handle_dsp(void);
66 extern asmlinkage void handle_mcheck(void);
67 extern asmlinkage void handle_reserved(void);
69 extern int fpu_emulator_cop1Handler(struct pt_regs *xcp,
70 struct mips_fpu_struct *ctx, int has_fpu);
72 void (*board_be_init)(void);
73 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
74 void (*board_nmi_handler_setup)(void);
75 void (*board_ejtag_handler_setup)(void);
76 void (*board_bind_eic_interrupt)(int irq, int regset);
79 static void show_raw_backtrace(unsigned long reg29)
81 unsigned long *sp = (unsigned long *)reg29;
84 printk("Call Trace:");
85 #ifdef CONFIG_KALLSYMS
88 while (!kstack_end(sp)) {
90 if (__kernel_text_address(addr))
96 #ifdef CONFIG_KALLSYMS
98 static int __init set_raw_show_trace(char *str)
103 __setup("raw_show_trace", set_raw_show_trace);
106 static void show_backtrace(struct task_struct *task, struct pt_regs *regs)
108 unsigned long sp = regs->regs[29];
109 unsigned long ra = regs->regs[31];
110 unsigned long pc = regs->cp0_epc;
112 if (raw_show_trace || !__kernel_text_address(pc)) {
113 show_raw_backtrace(sp);
116 printk("Call Trace:\n");
119 pc = unwind_stack(task, &sp, pc, &ra);
125 * This routine abuses get_user()/put_user() to reference pointers
126 * with at least a bit of error checking ...
128 static void show_stacktrace(struct task_struct *task, struct pt_regs *regs)
130 const int field = 2 * sizeof(unsigned long);
133 unsigned long *sp = (unsigned long *)regs->regs[29];
137 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
138 if (i && ((i % (64 / field)) == 0))
145 if (__get_user(stackdata, sp++)) {
146 printk(" (Bad stack address)");
150 printk(" %0*lx", field, stackdata);
154 show_backtrace(task, regs);
157 void show_stack(struct task_struct *task, unsigned long *sp)
161 regs.regs[29] = (unsigned long)sp;
165 if (task && task != current) {
166 regs.regs[29] = task->thread.reg29;
168 regs.cp0_epc = task->thread.reg31;
170 prepare_frametrace(®s);
173 show_stacktrace(task, ®s);
177 * The architecture-independent dump_stack generator
179 void dump_stack(void)
183 prepare_frametrace(®s);
184 show_backtrace(current, ®s);
187 EXPORT_SYMBOL(dump_stack);
189 void show_code(unsigned int *pc)
195 for(i = -3 ; i < 6 ; i++) {
197 if (__get_user(insn, pc + i)) {
198 printk(" (Bad address in epc)\n");
201 printk("%c%08x%c", (i?' ':'<'), insn, (i?' ':'>'));
205 void show_regs(struct pt_regs *regs)
207 const int field = 2 * sizeof(unsigned long);
208 unsigned int cause = regs->cp0_cause;
211 printk("Cpu %d\n", smp_processor_id());
214 * Saved main processor registers
216 for (i = 0; i < 32; ) {
220 printk(" %0*lx", field, 0UL);
221 else if (i == 26 || i == 27)
222 printk(" %*s", field, "");
224 printk(" %0*lx", field, regs->regs[i]);
231 #ifdef CONFIG_CPU_HAS_SMARTMIPS
232 printk("Acx : %0*lx\n", field, regs->acx);
234 printk("Hi : %0*lx\n", field, regs->hi);
235 printk("Lo : %0*lx\n", field, regs->lo);
238 * Saved cp0 registers
240 printk("epc : %0*lx ", field, regs->cp0_epc);
241 print_symbol("%s ", regs->cp0_epc);
242 printk(" %s\n", print_tainted());
243 printk("ra : %0*lx ", field, regs->regs[31]);
244 print_symbol("%s\n", regs->regs[31]);
246 printk("Status: %08x ", (uint32_t) regs->cp0_status);
248 if (current_cpu_data.isa_level == MIPS_CPU_ISA_I) {
249 if (regs->cp0_status & ST0_KUO)
251 if (regs->cp0_status & ST0_IEO)
253 if (regs->cp0_status & ST0_KUP)
255 if (regs->cp0_status & ST0_IEP)
257 if (regs->cp0_status & ST0_KUC)
259 if (regs->cp0_status & ST0_IEC)
262 if (regs->cp0_status & ST0_KX)
264 if (regs->cp0_status & ST0_SX)
266 if (regs->cp0_status & ST0_UX)
268 switch (regs->cp0_status & ST0_KSU) {
273 printk("SUPERVISOR ");
282 if (regs->cp0_status & ST0_ERL)
284 if (regs->cp0_status & ST0_EXL)
286 if (regs->cp0_status & ST0_IE)
291 printk("Cause : %08x\n", cause);
293 cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
294 if (1 <= cause && cause <= 5)
295 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
297 printk("PrId : %08x\n", read_c0_prid());
300 void show_registers(struct pt_regs *regs)
304 printk("Process %s (pid: %d, threadinfo=%p, task=%p)\n",
305 current->comm, current->pid, current_thread_info(), current);
306 show_stacktrace(current, regs);
307 show_code((unsigned int *) regs->cp0_epc);
311 static DEFINE_SPINLOCK(die_lock);
313 void __noreturn die(const char * str, struct pt_regs * regs)
315 static int die_counter;
316 #ifdef CONFIG_MIPS_MT_SMTC
317 unsigned long dvpret = dvpe();
318 #endif /* CONFIG_MIPS_MT_SMTC */
321 spin_lock_irq(&die_lock);
323 #ifdef CONFIG_MIPS_MT_SMTC
324 mips_mt_regdump(dvpret);
325 #endif /* CONFIG_MIPS_MT_SMTC */
326 printk("%s[#%d]:\n", str, ++die_counter);
327 show_registers(regs);
328 spin_unlock_irq(&die_lock);
331 panic("Fatal exception in interrupt");
334 printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
336 panic("Fatal exception");
342 extern const struct exception_table_entry __start___dbe_table[];
343 extern const struct exception_table_entry __stop___dbe_table[];
346 " .section __dbe_table, \"a\"\n"
349 /* Given an address, look for it in the exception tables. */
350 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
352 const struct exception_table_entry *e;
354 e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
356 e = search_module_dbetables(addr);
360 asmlinkage void do_be(struct pt_regs *regs)
362 const int field = 2 * sizeof(unsigned long);
363 const struct exception_table_entry *fixup = NULL;
364 int data = regs->cp0_cause & 4;
365 int action = MIPS_BE_FATAL;
367 /* XXX For now. Fixme, this searches the wrong table ... */
368 if (data && !user_mode(regs))
369 fixup = search_dbe_tables(exception_epc(regs));
372 action = MIPS_BE_FIXUP;
374 if (board_be_handler)
375 action = board_be_handler(regs, fixup != 0);
378 case MIPS_BE_DISCARD:
382 regs->cp0_epc = fixup->nextinsn;
391 * Assume it would be too dangerous to continue ...
393 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
394 data ? "Data" : "Instruction",
395 field, regs->cp0_epc, field, regs->regs[31]);
396 die_if_kernel("Oops", regs);
397 force_sig(SIGBUS, current);
404 #define OPCODE 0xfc000000
405 #define BASE 0x03e00000
406 #define RT 0x001f0000
407 #define OFFSET 0x0000ffff
408 #define LL 0xc0000000
409 #define SC 0xe0000000
410 #define SPEC3 0x7c000000
411 #define RD 0x0000f800
412 #define FUNC 0x0000003f
413 #define RDHWR 0x0000003b
416 * The ll_bit is cleared by r*_switch.S
419 unsigned long ll_bit;
421 static struct task_struct *ll_task = NULL;
423 static inline void simulate_ll(struct pt_regs *regs, unsigned int opcode)
425 unsigned long value, __user *vaddr;
430 * analyse the ll instruction that just caused a ri exception
431 * and put the referenced address to addr.
434 /* sign extend offset */
435 offset = opcode & OFFSET;
439 vaddr = (unsigned long __user *)
440 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
442 if ((unsigned long)vaddr & 3) {
446 if (get_user(value, vaddr)) {
453 if (ll_task == NULL || ll_task == current) {
462 compute_return_epc(regs);
464 regs->regs[(opcode & RT) >> 16] = value;
469 force_sig(signal, current);
472 static inline void simulate_sc(struct pt_regs *regs, unsigned int opcode)
474 unsigned long __user *vaddr;
480 * analyse the sc instruction that just caused a ri exception
481 * and put the referenced address to addr.
484 /* sign extend offset */
485 offset = opcode & OFFSET;
489 vaddr = (unsigned long __user *)
490 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
491 reg = (opcode & RT) >> 16;
493 if ((unsigned long)vaddr & 3) {
500 if (ll_bit == 0 || ll_task != current) {
501 compute_return_epc(regs);
509 if (put_user(regs->regs[reg], vaddr)) {
514 compute_return_epc(regs);
520 force_sig(signal, current);
524 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
525 * opcodes are supposed to result in coprocessor unusable exceptions if
526 * executed on ll/sc-less processors. That's the theory. In practice a
527 * few processors such as NEC's VR4100 throw reserved instruction exceptions
528 * instead, so we're doing the emulation thing in both exception handlers.
530 static inline int simulate_llsc(struct pt_regs *regs)
534 if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
537 if ((opcode & OPCODE) == LL) {
538 simulate_ll(regs, opcode);
541 if ((opcode & OPCODE) == SC) {
542 simulate_sc(regs, opcode);
546 return -EFAULT; /* Strange things going on ... */
549 force_sig(SIGSEGV, current);
554 * Simulate trapping 'rdhwr' instructions to provide user accessible
555 * registers not implemented in hardware. The only current use of this
556 * is the thread area pointer.
558 static inline int simulate_rdhwr(struct pt_regs *regs)
560 struct thread_info *ti = task_thread_info(current);
563 if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
566 if (unlikely(compute_return_epc(regs)))
569 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
570 int rd = (opcode & RD) >> 11;
571 int rt = (opcode & RT) >> 16;
574 regs->regs[rt] = ti->tp_value;
585 force_sig(SIGSEGV, current);
589 asmlinkage void do_ov(struct pt_regs *regs)
593 die_if_kernel("Integer overflow", regs);
595 info.si_code = FPE_INTOVF;
596 info.si_signo = SIGFPE;
598 info.si_addr = (void __user *) regs->cp0_epc;
599 force_sig_info(SIGFPE, &info, current);
603 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
605 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
607 die_if_kernel("FP exception in kernel code", regs);
609 if (fcr31 & FPU_CSR_UNI_X) {
613 * Unimplemented operation exception. If we've got the full
614 * software emulator on-board, let's use it...
616 * Force FPU to dump state into task/thread context. We're
617 * moving a lot of data here for what is probably a single
618 * instruction, but the alternative is to pre-decode the FP
619 * register operands before invoking the emulator, which seems
620 * a bit extreme for what should be an infrequent event.
622 /* Ensure 'resume' not overwrite saved fp context again. */
625 /* Run the emulator */
626 sig = fpu_emulator_cop1Handler (regs, ¤t->thread.fpu, 1);
629 * We can't allow the emulated instruction to leave any of
630 * the cause bit set in $fcr31.
632 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
634 /* Restore the hardware register state */
635 own_fpu(1); /* Using the FPU again. */
637 /* If something went wrong, signal */
639 force_sig(sig, current);
644 force_sig(SIGFPE, current);
647 asmlinkage void do_bp(struct pt_regs *regs)
649 unsigned int opcode, bcode;
652 if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
656 * There is the ancient bug in the MIPS assemblers that the break
657 * code starts left to bit 16 instead to bit 6 in the opcode.
658 * Gas is bug-compatible, but not always, grrr...
659 * We handle both cases with a simple heuristics. --macro
661 bcode = ((opcode >> 6) & ((1 << 20) - 1));
662 if (bcode < (1 << 10))
666 * (A short test says that IRIX 5.3 sends SIGTRAP for all break
667 * insns, even for break codes that indicate arithmetic failures.
669 * But should we continue the brokenness??? --macro
672 case BRK_OVERFLOW << 10:
673 case BRK_DIVZERO << 10:
674 die_if_kernel("Break instruction in kernel code", regs);
675 if (bcode == (BRK_DIVZERO << 10))
676 info.si_code = FPE_INTDIV;
678 info.si_code = FPE_INTOVF;
679 info.si_signo = SIGFPE;
681 info.si_addr = (void __user *) regs->cp0_epc;
682 force_sig_info(SIGFPE, &info, current);
685 die("Kernel bug detected", regs);
688 die_if_kernel("Break instruction in kernel code", regs);
689 force_sig(SIGTRAP, current);
694 force_sig(SIGSEGV, current);
697 asmlinkage void do_tr(struct pt_regs *regs)
699 unsigned int opcode, tcode = 0;
702 if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
705 /* Immediate versions don't provide a code. */
706 if (!(opcode & OPCODE))
707 tcode = ((opcode >> 6) & ((1 << 10) - 1));
710 * (A short test says that IRIX 5.3 sends SIGTRAP for all trap
711 * insns, even for trap codes that indicate arithmetic failures.
713 * But should we continue the brokenness??? --macro
718 die_if_kernel("Trap instruction in kernel code", regs);
719 if (tcode == BRK_DIVZERO)
720 info.si_code = FPE_INTDIV;
722 info.si_code = FPE_INTOVF;
723 info.si_signo = SIGFPE;
725 info.si_addr = (void __user *) regs->cp0_epc;
726 force_sig_info(SIGFPE, &info, current);
729 die("Kernel bug detected", regs);
732 die_if_kernel("Trap instruction in kernel code", regs);
733 force_sig(SIGTRAP, current);
738 force_sig(SIGSEGV, current);
741 asmlinkage void do_ri(struct pt_regs *regs)
743 die_if_kernel("Reserved instruction in kernel code", regs);
746 if (!simulate_llsc(regs))
749 if (!simulate_rdhwr(regs))
752 force_sig(SIGILL, current);
756 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
757 * emulated more than some threshold number of instructions, force migration to
758 * a "CPU" that has FP support.
760 static void mt_ase_fp_affinity(void)
762 #ifdef CONFIG_MIPS_MT_FPAFF
763 if (mt_fpemul_threshold > 0 &&
764 ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
766 * If there's no FPU present, or if the application has already
767 * restricted the allowed set to exclude any CPUs with FPUs,
768 * we'll skip the procedure.
770 if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
773 cpus_and(tmask, current->thread.user_cpus_allowed,
775 set_cpus_allowed(current, tmask);
776 current->thread.mflags |= MF_FPUBOUND;
779 #endif /* CONFIG_MIPS_MT_FPAFF */
782 asmlinkage void do_cpu(struct pt_regs *regs)
786 die_if_kernel("do_cpu invoked from kernel context!", regs);
788 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
793 if (!simulate_llsc(regs))
796 if (!simulate_rdhwr(regs))
802 if (used_math()) /* Using the FPU again. */
804 else { /* First time FPU user. */
809 if (!raw_cpu_has_fpu) {
811 sig = fpu_emulator_cop1Handler(regs,
812 ¤t->thread.fpu, 0);
814 force_sig(sig, current);
816 mt_ase_fp_affinity();
826 force_sig(SIGILL, current);
829 asmlinkage void do_mdmx(struct pt_regs *regs)
831 force_sig(SIGILL, current);
834 asmlinkage void do_watch(struct pt_regs *regs)
837 * We use the watch exception where available to detect stack
842 panic("Caught WATCH exception - probably caused by stack overflow.");
845 asmlinkage void do_mcheck(struct pt_regs *regs)
847 const int field = 2 * sizeof(unsigned long);
848 int multi_match = regs->cp0_status & ST0_TS;
853 printk("Index : %0x\n", read_c0_index());
854 printk("Pagemask: %0x\n", read_c0_pagemask());
855 printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
856 printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
857 printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
862 show_code((unsigned int *) regs->cp0_epc);
865 * Some chips may have other causes of machine check (e.g. SB1
868 panic("Caught Machine Check exception - %scaused by multiple "
869 "matching entries in the TLB.",
870 (multi_match) ? "" : "not ");
873 asmlinkage void do_mt(struct pt_regs *regs)
877 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
878 >> VPECONTROL_EXCPT_SHIFT;
881 printk(KERN_DEBUG "Thread Underflow\n");
884 printk(KERN_DEBUG "Thread Overflow\n");
887 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
890 printk(KERN_DEBUG "Gating Storage Exception\n");
893 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
896 printk(KERN_DEBUG "Gating Storage Schedulier Exception\n");
899 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
903 die_if_kernel("MIPS MT Thread exception in kernel", regs);
905 force_sig(SIGILL, current);
909 asmlinkage void do_dsp(struct pt_regs *regs)
912 panic("Unexpected DSP exception\n");
914 force_sig(SIGILL, current);
917 asmlinkage void do_reserved(struct pt_regs *regs)
920 * Game over - no way to handle this if it ever occurs. Most probably
921 * caused by a new unknown cpu type or after another deadly
922 * hard/software error.
925 panic("Caught reserved exception %ld - should not happen.",
926 (regs->cp0_cause & 0x7f) >> 2);
930 * Some MIPS CPUs can enable/disable for cache parity detection, but do
933 static inline void parity_protection_init(void)
935 switch (current_cpu_data.cputype) {
939 write_c0_ecc(0x80000000);
940 back_to_back_c0_hazard();
941 /* Set the PE bit (bit 31) in the c0_errctl register. */
942 printk(KERN_INFO "Cache parity protection %sabled\n",
943 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
947 /* Clear the DE bit (bit 16) in the c0_status register. */
948 printk(KERN_INFO "Enable cache parity protection for "
949 "MIPS 20KC/25KF CPUs.\n");
950 clear_c0_status(ST0_DE);
957 asmlinkage void cache_parity_error(void)
959 const int field = 2 * sizeof(unsigned long);
960 unsigned int reg_val;
962 /* For the moment, report the problem and hang. */
963 printk("Cache error exception:\n");
964 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
965 reg_val = read_c0_cacheerr();
966 printk("c0_cacheerr == %08x\n", reg_val);
968 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
969 reg_val & (1<<30) ? "secondary" : "primary",
970 reg_val & (1<<31) ? "data" : "insn");
971 printk("Error bits: %s%s%s%s%s%s%s\n",
972 reg_val & (1<<29) ? "ED " : "",
973 reg_val & (1<<28) ? "ET " : "",
974 reg_val & (1<<26) ? "EE " : "",
975 reg_val & (1<<25) ? "EB " : "",
976 reg_val & (1<<24) ? "EI " : "",
977 reg_val & (1<<23) ? "E1 " : "",
978 reg_val & (1<<22) ? "E0 " : "");
979 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
981 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
982 if (reg_val & (1<<22))
983 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
985 if (reg_val & (1<<23))
986 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
989 panic("Can't handle the cache error!");
993 * SDBBP EJTAG debug exception handler.
994 * We skip the instruction and return to the next instruction.
996 void ejtag_exception_handler(struct pt_regs *regs)
998 const int field = 2 * sizeof(unsigned long);
999 unsigned long depc, old_epc;
1002 printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1003 depc = read_c0_depc();
1004 debug = read_c0_debug();
1005 printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1006 if (debug & 0x80000000) {
1008 * In branch delay slot.
1009 * We cheat a little bit here and use EPC to calculate the
1010 * debug return address (DEPC). EPC is restored after the
1013 old_epc = regs->cp0_epc;
1014 regs->cp0_epc = depc;
1015 __compute_return_epc(regs);
1016 depc = regs->cp0_epc;
1017 regs->cp0_epc = old_epc;
1020 write_c0_depc(depc);
1023 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1024 write_c0_debug(debug | 0x100);
1029 * NMI exception handler.
1031 void nmi_exception_handler(struct pt_regs *regs)
1033 #ifdef CONFIG_MIPS_MT_SMTC
1034 unsigned long dvpret = dvpe();
1036 printk("NMI taken!!!!\n");
1037 mips_mt_regdump(dvpret);
1040 printk("NMI taken!!!!\n");
1041 #endif /* CONFIG_MIPS_MT_SMTC */
1046 #define VECTORSPACING 0x100 /* for EI/VI mode */
1048 unsigned long ebase;
1049 unsigned long exception_handlers[32];
1050 unsigned long vi_handlers[64];
1053 * As a side effect of the way this is implemented we're limited
1054 * to interrupt handlers in the address range from
1055 * KSEG0 <= x < KSEG0 + 256mb on the Nevada. Oh well ...
1057 void *set_except_vector(int n, void *addr)
1059 unsigned long handler = (unsigned long) addr;
1060 unsigned long old_handler = exception_handlers[n];
1062 exception_handlers[n] = handler;
1063 if (n == 0 && cpu_has_divec) {
1064 *(volatile u32 *)(ebase + 0x200) = 0x08000000 |
1065 (0x03ffffff & (handler >> 2));
1066 flush_icache_range(ebase + 0x200, ebase + 0x204);
1068 return (void *)old_handler;
1071 #ifdef CONFIG_CPU_MIPSR2_SRS
1073 * MIPSR2 shadow register set allocation
1077 static struct shadow_registers {
1079 * Number of shadow register sets supported
1081 unsigned long sr_supported;
1083 * Bitmap of allocated shadow registers
1085 unsigned long sr_allocated;
1088 static void mips_srs_init(void)
1090 shadow_registers.sr_supported = ((read_c0_srsctl() >> 26) & 0x0f) + 1;
1091 printk(KERN_INFO "%ld MIPSR2 register sets available\n",
1092 shadow_registers.sr_supported);
1093 shadow_registers.sr_allocated = 1; /* Set 0 used by kernel */
1096 int mips_srs_max(void)
1098 return shadow_registers.sr_supported;
1101 int mips_srs_alloc(void)
1103 struct shadow_registers *sr = &shadow_registers;
1107 set = find_first_zero_bit(&sr->sr_allocated, sr->sr_supported);
1108 if (set >= sr->sr_supported)
1111 if (test_and_set_bit(set, &sr->sr_allocated))
1117 void mips_srs_free(int set)
1119 struct shadow_registers *sr = &shadow_registers;
1121 clear_bit(set, &sr->sr_allocated);
1124 static asmlinkage void do_default_vi(void)
1126 show_regs(get_irq_regs());
1127 panic("Caught unexpected vectored interrupt.");
1130 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1132 unsigned long handler;
1133 unsigned long old_handler = vi_handlers[n];
1137 if (!cpu_has_veic && !cpu_has_vint)
1141 handler = (unsigned long) do_default_vi;
1144 handler = (unsigned long) addr;
1145 vi_handlers[n] = (unsigned long) addr;
1147 b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1149 if (srs >= mips_srs_max())
1150 panic("Shadow register set %d not supported", srs);
1153 if (board_bind_eic_interrupt)
1154 board_bind_eic_interrupt (n, srs);
1155 } else if (cpu_has_vint) {
1156 /* SRSMap is only defined if shadow sets are implemented */
1157 if (mips_srs_max() > 1)
1158 change_c0_srsmap (0xf << n*4, srs << n*4);
1163 * If no shadow set is selected then use the default handler
1164 * that does normal register saving and a standard interrupt exit
1167 extern char except_vec_vi, except_vec_vi_lui;
1168 extern char except_vec_vi_ori, except_vec_vi_end;
1169 #ifdef CONFIG_MIPS_MT_SMTC
1171 * We need to provide the SMTC vectored interrupt handler
1172 * not only with the address of the handler, but with the
1173 * Status.IM bit to be masked before going there.
1175 extern char except_vec_vi_mori;
1176 const int mori_offset = &except_vec_vi_mori - &except_vec_vi;
1177 #endif /* CONFIG_MIPS_MT_SMTC */
1178 const int handler_len = &except_vec_vi_end - &except_vec_vi;
1179 const int lui_offset = &except_vec_vi_lui - &except_vec_vi;
1180 const int ori_offset = &except_vec_vi_ori - &except_vec_vi;
1182 if (handler_len > VECTORSPACING) {
1184 * Sigh... panicing won't help as the console
1185 * is probably not configured :(
1187 panic ("VECTORSPACING too small");
1190 memcpy (b, &except_vec_vi, handler_len);
1191 #ifdef CONFIG_MIPS_MT_SMTC
1192 BUG_ON(n > 7); /* Vector index %d exceeds SMTC maximum. */
1194 w = (u32 *)(b + mori_offset);
1195 *w = (*w & 0xffff0000) | (0x100 << n);
1196 #endif /* CONFIG_MIPS_MT_SMTC */
1197 w = (u32 *)(b + lui_offset);
1198 *w = (*w & 0xffff0000) | (((u32)handler >> 16) & 0xffff);
1199 w = (u32 *)(b + ori_offset);
1200 *w = (*w & 0xffff0000) | ((u32)handler & 0xffff);
1201 flush_icache_range((unsigned long)b, (unsigned long)(b+handler_len));
1205 * In other cases jump directly to the interrupt handler
1207 * It is the handlers responsibility to save registers if required
1208 * (eg hi/lo) and return from the exception using "eret"
1211 *w++ = 0x08000000 | (((u32)handler >> 2) & 0x03fffff); /* j handler */
1213 flush_icache_range((unsigned long)b, (unsigned long)(b+8));
1216 return (void *)old_handler;
1219 void *set_vi_handler(int n, vi_handler_t addr)
1221 return set_vi_srs_handler(n, addr, 0);
1226 static inline void mips_srs_init(void)
1230 #endif /* CONFIG_CPU_MIPSR2_SRS */
1233 * This is used by native signal handling
1235 asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
1236 asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
1238 extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
1239 extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
1241 extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
1242 extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
1245 static int smp_save_fp_context(struct sigcontext __user *sc)
1247 return raw_cpu_has_fpu
1248 ? _save_fp_context(sc)
1249 : fpu_emulator_save_context(sc);
1252 static int smp_restore_fp_context(struct sigcontext __user *sc)
1254 return raw_cpu_has_fpu
1255 ? _restore_fp_context(sc)
1256 : fpu_emulator_restore_context(sc);
1260 static inline void signal_init(void)
1263 /* For now just do the cpu_has_fpu check when the functions are invoked */
1264 save_fp_context = smp_save_fp_context;
1265 restore_fp_context = smp_restore_fp_context;
1268 save_fp_context = _save_fp_context;
1269 restore_fp_context = _restore_fp_context;
1271 save_fp_context = fpu_emulator_save_context;
1272 restore_fp_context = fpu_emulator_restore_context;
1277 #ifdef CONFIG_MIPS32_COMPAT
1280 * This is used by 32-bit signal stuff on the 64-bit kernel
1282 asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
1283 asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
1285 extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
1286 extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
1288 extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
1289 extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);
1291 static inline void signal32_init(void)
1294 save_fp_context32 = _save_fp_context32;
1295 restore_fp_context32 = _restore_fp_context32;
1297 save_fp_context32 = fpu_emulator_save_context32;
1298 restore_fp_context32 = fpu_emulator_restore_context32;
1303 extern void cpu_cache_init(void);
1304 extern void tlb_init(void);
1305 extern void flush_tlb_handlers(void);
1307 void __init per_cpu_trap_init(void)
1309 unsigned int cpu = smp_processor_id();
1310 unsigned int status_set = ST0_CU0;
1311 #ifdef CONFIG_MIPS_MT_SMTC
1312 int secondaryTC = 0;
1313 int bootTC = (cpu == 0);
1316 * Only do per_cpu_trap_init() for first TC of Each VPE.
1317 * Note that this hack assumes that the SMTC init code
1318 * assigns TCs consecutively and in ascending order.
1321 if (((read_c0_tcbind() & TCBIND_CURTC) != 0) &&
1322 ((read_c0_tcbind() & TCBIND_CURVPE) == cpu_data[cpu - 1].vpe_id))
1324 #endif /* CONFIG_MIPS_MT_SMTC */
1327 * Disable coprocessors and select 32-bit or 64-bit addressing
1328 * and the 16/32 or 32/32 FPR register model. Reset the BEV
1329 * flag that some firmware may have left set and the TS bit (for
1330 * IP27). Set XX for ISA IV code to work.
1333 status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
1335 if (current_cpu_data.isa_level == MIPS_CPU_ISA_IV)
1336 status_set |= ST0_XX;
1337 change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
1341 set_c0_status(ST0_MX);
1343 #ifdef CONFIG_CPU_MIPSR2
1344 if (cpu_has_mips_r2) {
1345 unsigned int enable = 0x0000000f;
1347 if (cpu_has_userlocal)
1348 enable |= (1 << 29);
1350 write_c0_hwrena(enable);
1354 #ifdef CONFIG_MIPS_MT_SMTC
1356 #endif /* CONFIG_MIPS_MT_SMTC */
1358 if (cpu_has_veic || cpu_has_vint) {
1359 write_c0_ebase (ebase);
1360 /* Setting vector spacing enables EI/VI mode */
1361 change_c0_intctl (0x3e0, VECTORSPACING);
1363 if (cpu_has_divec) {
1364 if (cpu_has_mipsmt) {
1365 unsigned int vpflags = dvpe();
1366 set_c0_cause(CAUSEF_IV);
1369 set_c0_cause(CAUSEF_IV);
1373 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
1375 * o read IntCtl.IPTI to determine the timer interrupt
1376 * o read IntCtl.IPPCI to determine the performance counter interrupt
1378 if (cpu_has_mips_r2) {
1379 cp0_compare_irq = (read_c0_intctl () >> 29) & 7;
1380 cp0_perfcount_irq = (read_c0_intctl () >> 26) & 7;
1381 if (cp0_perfcount_irq == cp0_compare_irq)
1382 cp0_perfcount_irq = -1;
1384 cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
1385 cp0_perfcount_irq = -1;
1388 #ifdef CONFIG_MIPS_MT_SMTC
1390 #endif /* CONFIG_MIPS_MT_SMTC */
1392 cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
1393 TLBMISS_HANDLER_SETUP();
1395 atomic_inc(&init_mm.mm_count);
1396 current->active_mm = &init_mm;
1397 BUG_ON(current->mm);
1398 enter_lazy_tlb(&init_mm, current);
1400 #ifdef CONFIG_MIPS_MT_SMTC
1402 #endif /* CONFIG_MIPS_MT_SMTC */
1405 #ifdef CONFIG_MIPS_MT_SMTC
1406 } else if (!secondaryTC) {
1408 * First TC in non-boot VPE must do subset of tlb_init()
1409 * for MMU countrol registers.
1411 write_c0_pagemask(PM_DEFAULT_MASK);
1414 #endif /* CONFIG_MIPS_MT_SMTC */
1417 /* Install CPU exception handler */
1418 void __init set_handler (unsigned long offset, void *addr, unsigned long size)
1420 memcpy((void *)(ebase + offset), addr, size);
1421 flush_icache_range(ebase + offset, ebase + offset + size);
1424 /* Install uncached CPU exception handler */
1425 void __init set_uncached_handler (unsigned long offset, void *addr, unsigned long size)
1428 unsigned long uncached_ebase = KSEG1ADDR(ebase);
1431 unsigned long uncached_ebase = TO_UNCAC(ebase);
1434 memcpy((void *)(uncached_ebase + offset), addr, size);
1437 static int __initdata rdhwr_noopt;
1438 static int __init set_rdhwr_noopt(char *str)
1444 __setup("rdhwr_noopt", set_rdhwr_noopt);
1446 void __init trap_init(void)
1448 extern char except_vec3_generic, except_vec3_r4000;
1449 extern char except_vec4;
1452 if (cpu_has_veic || cpu_has_vint)
1453 ebase = (unsigned long) alloc_bootmem_low_pages (0x200 + VECTORSPACING*64);
1459 per_cpu_trap_init();
1462 * Copy the generic exception handlers to their final destination.
1463 * This will be overriden later as suitable for a particular
1466 set_handler(0x180, &except_vec3_generic, 0x80);
1469 * Setup default vectors
1471 for (i = 0; i <= 31; i++)
1472 set_except_vector(i, handle_reserved);
1475 * Copy the EJTAG debug exception vector handler code to it's final
1478 if (cpu_has_ejtag && board_ejtag_handler_setup)
1479 board_ejtag_handler_setup ();
1482 * Only some CPUs have the watch exceptions.
1485 set_except_vector(23, handle_watch);
1488 * Initialise interrupt handlers
1490 if (cpu_has_veic || cpu_has_vint) {
1491 int nvec = cpu_has_veic ? 64 : 8;
1492 for (i = 0; i < nvec; i++)
1493 set_vi_handler(i, NULL);
1495 else if (cpu_has_divec)
1496 set_handler(0x200, &except_vec4, 0x8);
1499 * Some CPUs can enable/disable for cache parity detection, but does
1500 * it different ways.
1502 parity_protection_init();
1505 * The Data Bus Errors / Instruction Bus Errors are signaled
1506 * by external hardware. Therefore these two exceptions
1507 * may have board specific handlers.
1512 set_except_vector(0, handle_int);
1513 set_except_vector(1, handle_tlbm);
1514 set_except_vector(2, handle_tlbl);
1515 set_except_vector(3, handle_tlbs);
1517 set_except_vector(4, handle_adel);
1518 set_except_vector(5, handle_ades);
1520 set_except_vector(6, handle_ibe);
1521 set_except_vector(7, handle_dbe);
1523 set_except_vector(8, handle_sys);
1524 set_except_vector(9, handle_bp);
1525 set_except_vector(10, rdhwr_noopt ? handle_ri :
1526 (cpu_has_vtag_icache ?
1527 handle_ri_rdhwr_vivt : handle_ri_rdhwr));
1528 set_except_vector(11, handle_cpu);
1529 set_except_vector(12, handle_ov);
1530 set_except_vector(13, handle_tr);
1532 if (current_cpu_data.cputype == CPU_R6000 ||
1533 current_cpu_data.cputype == CPU_R6000A) {
1535 * The R6000 is the only R-series CPU that features a machine
1536 * check exception (similar to the R4000 cache error) and
1537 * unaligned ldc1/sdc1 exception. The handlers have not been
1538 * written yet. Well, anyway there is no R6000 machine on the
1539 * current list of targets for Linux/MIPS.
1540 * (Duh, crap, there is someone with a triple R6k machine)
1542 //set_except_vector(14, handle_mc);
1543 //set_except_vector(15, handle_ndc);
1547 if (board_nmi_handler_setup)
1548 board_nmi_handler_setup();
1550 if (cpu_has_fpu && !cpu_has_nofpuex)
1551 set_except_vector(15, handle_fpe);
1553 set_except_vector(22, handle_mdmx);
1556 set_except_vector(24, handle_mcheck);
1559 set_except_vector(25, handle_mt);
1561 set_except_vector(26, handle_dsp);
1564 /* Special exception: R4[04]00 uses also the divec space. */
1565 memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
1566 else if (cpu_has_4kex)
1567 memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
1569 memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
1572 #ifdef CONFIG_MIPS32_COMPAT
1576 flush_icache_range(ebase, ebase + 0x400);
1577 flush_tlb_handlers();