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) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
12 * Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc. All rights reserved.
13 * Copyright (C) 2014, Imagination Technologies Ltd.
15 #include <linux/bitops.h>
16 #include <linux/bug.h>
17 #include <linux/compiler.h>
18 #include <linux/context_tracking.h>
19 #include <linux/cpu_pm.h>
20 #include <linux/kexec.h>
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/extable.h>
26 #include <linux/sched.h>
27 #include <linux/smp.h>
28 #include <linux/spinlock.h>
29 #include <linux/kallsyms.h>
30 #include <linux/bootmem.h>
31 #include <linux/interrupt.h>
32 #include <linux/ptrace.h>
33 #include <linux/kgdb.h>
34 #include <linux/kdebug.h>
35 #include <linux/kprobes.h>
36 #include <linux/notifier.h>
37 #include <linux/kdb.h>
38 #include <linux/irq.h>
39 #include <linux/perf_event.h>
41 #include <asm/addrspace.h>
42 #include <asm/bootinfo.h>
43 #include <asm/branch.h>
44 #include <asm/break.h>
47 #include <asm/cpu-type.h>
50 #include <asm/fpu_emulator.h>
52 #include <asm/mips-cm.h>
53 #include <asm/mips-r2-to-r6-emul.h>
54 #include <asm/mipsregs.h>
55 #include <asm/mipsmtregs.h>
56 #include <asm/module.h>
58 #include <asm/pgtable.h>
59 #include <asm/ptrace.h>
60 #include <asm/sections.h>
61 #include <asm/siginfo.h>
62 #include <asm/tlbdebug.h>
63 #include <asm/traps.h>
64 #include <asm/uaccess.h>
65 #include <asm/watch.h>
66 #include <asm/mmu_context.h>
67 #include <asm/types.h>
68 #include <asm/stacktrace.h>
71 extern void check_wait(void);
72 extern asmlinkage void rollback_handle_int(void);
73 extern asmlinkage void handle_int(void);
74 extern u32 handle_tlbl[];
75 extern u32 handle_tlbs[];
76 extern u32 handle_tlbm[];
77 extern asmlinkage void handle_adel(void);
78 extern asmlinkage void handle_ades(void);
79 extern asmlinkage void handle_ibe(void);
80 extern asmlinkage void handle_dbe(void);
81 extern asmlinkage void handle_sys(void);
82 extern asmlinkage void handle_bp(void);
83 extern asmlinkage void handle_ri(void);
84 extern asmlinkage void handle_ri_rdhwr_vivt(void);
85 extern asmlinkage void handle_ri_rdhwr(void);
86 extern asmlinkage void handle_cpu(void);
87 extern asmlinkage void handle_ov(void);
88 extern asmlinkage void handle_tr(void);
89 extern asmlinkage void handle_msa_fpe(void);
90 extern asmlinkage void handle_fpe(void);
91 extern asmlinkage void handle_ftlb(void);
92 extern asmlinkage void handle_msa(void);
93 extern asmlinkage void handle_mdmx(void);
94 extern asmlinkage void handle_watch(void);
95 extern asmlinkage void handle_mt(void);
96 extern asmlinkage void handle_dsp(void);
97 extern asmlinkage void handle_mcheck(void);
98 extern asmlinkage void handle_reserved(void);
99 extern void tlb_do_page_fault_0(void);
101 void (*board_be_init)(void);
102 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
103 void (*board_nmi_handler_setup)(void);
104 void (*board_ejtag_handler_setup)(void);
105 void (*board_bind_eic_interrupt)(int irq, int regset);
106 void (*board_ebase_setup)(void);
107 void(*board_cache_error_setup)(void);
109 static void show_raw_backtrace(unsigned long reg29)
111 unsigned long *sp = (unsigned long *)(reg29 & ~3);
114 printk("Call Trace:");
115 #ifdef CONFIG_KALLSYMS
118 while (!kstack_end(sp)) {
119 unsigned long __user *p =
120 (unsigned long __user *)(unsigned long)sp++;
121 if (__get_user(addr, p)) {
122 printk(" (Bad stack address)");
125 if (__kernel_text_address(addr))
131 #ifdef CONFIG_KALLSYMS
133 static int __init set_raw_show_trace(char *str)
138 __setup("raw_show_trace", set_raw_show_trace);
141 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
143 unsigned long sp = regs->regs[29];
144 unsigned long ra = regs->regs[31];
145 unsigned long pc = regs->cp0_epc;
150 if (raw_show_trace || user_mode(regs) || !__kernel_text_address(pc)) {
151 show_raw_backtrace(sp);
154 printk("Call Trace:\n");
157 pc = unwind_stack(task, &sp, pc, &ra);
163 * This routine abuses get_user()/put_user() to reference pointers
164 * with at least a bit of error checking ...
166 static void show_stacktrace(struct task_struct *task,
167 const struct pt_regs *regs)
169 const int field = 2 * sizeof(unsigned long);
172 unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
176 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
177 if (i && ((i % (64 / field)) == 0)) {
186 if (__get_user(stackdata, sp++)) {
187 pr_cont(" (Bad stack address)");
191 pr_cont(" %0*lx", field, stackdata);
195 show_backtrace(task, regs);
198 void show_stack(struct task_struct *task, unsigned long *sp)
201 mm_segment_t old_fs = get_fs();
203 regs.regs[29] = (unsigned long)sp;
207 if (task && task != current) {
208 regs.regs[29] = task->thread.reg29;
210 regs.cp0_epc = task->thread.reg31;
211 #ifdef CONFIG_KGDB_KDB
212 } else if (atomic_read(&kgdb_active) != -1 &&
214 memcpy(®s, kdb_current_regs, sizeof(regs));
215 #endif /* CONFIG_KGDB_KDB */
217 prepare_frametrace(®s);
221 * show_stack() deals exclusively with kernel mode, so be sure to access
222 * the stack in the kernel (not user) address space.
225 show_stacktrace(task, ®s);
229 static void show_code(unsigned int __user *pc)
232 unsigned short __user *pc16 = NULL;
236 if ((unsigned long)pc & 1)
237 pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
238 for(i = -3 ; i < 6 ; i++) {
240 if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
241 printk(" (Bad address in epc)\n");
244 printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
248 static void __show_regs(const struct pt_regs *regs)
250 const int field = 2 * sizeof(unsigned long);
251 unsigned int cause = regs->cp0_cause;
252 unsigned int exccode;
255 show_regs_print_info(KERN_DEFAULT);
258 * Saved main processor registers
260 for (i = 0; i < 32; ) {
264 printk(" %0*lx", field, 0UL);
265 else if (i == 26 || i == 27)
266 printk(" %*s", field, "");
268 printk(" %0*lx", field, regs->regs[i]);
275 #ifdef CONFIG_CPU_HAS_SMARTMIPS
276 printk("Acx : %0*lx\n", field, regs->acx);
278 printk("Hi : %0*lx\n", field, regs->hi);
279 printk("Lo : %0*lx\n", field, regs->lo);
282 * Saved cp0 registers
284 printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
285 (void *) regs->cp0_epc);
286 printk("ra : %0*lx %pS\n", field, regs->regs[31],
287 (void *) regs->regs[31]);
289 printk("Status: %08x ", (uint32_t) regs->cp0_status);
292 if (regs->cp0_status & ST0_KUO)
294 if (regs->cp0_status & ST0_IEO)
296 if (regs->cp0_status & ST0_KUP)
298 if (regs->cp0_status & ST0_IEP)
300 if (regs->cp0_status & ST0_KUC)
302 if (regs->cp0_status & ST0_IEC)
304 } else if (cpu_has_4kex) {
305 if (regs->cp0_status & ST0_KX)
307 if (regs->cp0_status & ST0_SX)
309 if (regs->cp0_status & ST0_UX)
311 switch (regs->cp0_status & ST0_KSU) {
316 printk("SUPERVISOR ");
325 if (regs->cp0_status & ST0_ERL)
327 if (regs->cp0_status & ST0_EXL)
329 if (regs->cp0_status & ST0_IE)
334 exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
335 printk("Cause : %08x (ExcCode %02x)\n", cause, exccode);
337 if (1 <= exccode && exccode <= 5)
338 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
340 printk("PrId : %08x (%s)\n", read_c0_prid(),
345 * FIXME: really the generic show_regs should take a const pointer argument.
347 void show_regs(struct pt_regs *regs)
349 __show_regs((struct pt_regs *)regs);
352 void show_registers(struct pt_regs *regs)
354 const int field = 2 * sizeof(unsigned long);
355 mm_segment_t old_fs = get_fs();
359 printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
360 current->comm, current->pid, current_thread_info(), current,
361 field, current_thread_info()->tp_value);
362 if (cpu_has_userlocal) {
365 tls = read_c0_userlocal();
366 if (tls != current_thread_info()->tp_value)
367 printk("*HwTLS: %0*lx\n", field, tls);
370 if (!user_mode(regs))
371 /* Necessary for getting the correct stack content */
373 show_stacktrace(current, regs);
374 show_code((unsigned int __user *) regs->cp0_epc);
379 static DEFINE_RAW_SPINLOCK(die_lock);
381 void __noreturn die(const char *str, struct pt_regs *regs)
383 static int die_counter;
388 if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
389 SIGSEGV) == NOTIFY_STOP)
393 raw_spin_lock_irq(&die_lock);
396 printk("%s[#%d]:\n", str, ++die_counter);
397 show_registers(regs);
398 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
399 raw_spin_unlock_irq(&die_lock);
404 panic("Fatal exception in interrupt");
407 panic("Fatal exception");
409 if (regs && kexec_should_crash(current))
415 extern struct exception_table_entry __start___dbe_table[];
416 extern struct exception_table_entry __stop___dbe_table[];
419 " .section __dbe_table, \"a\"\n"
422 /* Given an address, look for it in the exception tables. */
423 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
425 const struct exception_table_entry *e;
427 e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
429 e = search_module_dbetables(addr);
433 asmlinkage void do_be(struct pt_regs *regs)
435 const int field = 2 * sizeof(unsigned long);
436 const struct exception_table_entry *fixup = NULL;
437 int data = regs->cp0_cause & 4;
438 int action = MIPS_BE_FATAL;
439 enum ctx_state prev_state;
441 prev_state = exception_enter();
442 /* XXX For now. Fixme, this searches the wrong table ... */
443 if (data && !user_mode(regs))
444 fixup = search_dbe_tables(exception_epc(regs));
447 action = MIPS_BE_FIXUP;
449 if (board_be_handler)
450 action = board_be_handler(regs, fixup != NULL);
452 mips_cm_error_report();
455 case MIPS_BE_DISCARD:
459 regs->cp0_epc = fixup->nextinsn;
468 * Assume it would be too dangerous to continue ...
470 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
471 data ? "Data" : "Instruction",
472 field, regs->cp0_epc, field, regs->regs[31]);
473 if (notify_die(DIE_OOPS, "bus error", regs, 0, current->thread.trap_nr,
474 SIGBUS) == NOTIFY_STOP)
477 die_if_kernel("Oops", regs);
478 force_sig(SIGBUS, current);
481 exception_exit(prev_state);
485 * ll/sc, rdhwr, sync emulation
488 #define OPCODE 0xfc000000
489 #define BASE 0x03e00000
490 #define RT 0x001f0000
491 #define OFFSET 0x0000ffff
492 #define LL 0xc0000000
493 #define SC 0xe0000000
494 #define SPEC0 0x00000000
495 #define SPEC3 0x7c000000
496 #define RD 0x0000f800
497 #define FUNC 0x0000003f
498 #define SYNC 0x0000000f
499 #define RDHWR 0x0000003b
501 /* microMIPS definitions */
502 #define MM_POOL32A_FUNC 0xfc00ffff
503 #define MM_RDHWR 0x00006b3c
504 #define MM_RS 0x001f0000
505 #define MM_RT 0x03e00000
508 * The ll_bit is cleared by r*_switch.S
512 struct task_struct *ll_task;
514 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
516 unsigned long value, __user *vaddr;
520 * analyse the ll instruction that just caused a ri exception
521 * and put the referenced address to addr.
524 /* sign extend offset */
525 offset = opcode & OFFSET;
529 vaddr = (unsigned long __user *)
530 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
532 if ((unsigned long)vaddr & 3)
534 if (get_user(value, vaddr))
539 if (ll_task == NULL || ll_task == current) {
548 regs->regs[(opcode & RT) >> 16] = value;
553 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
555 unsigned long __user *vaddr;
560 * analyse the sc instruction that just caused a ri exception
561 * and put the referenced address to addr.
564 /* sign extend offset */
565 offset = opcode & OFFSET;
569 vaddr = (unsigned long __user *)
570 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
571 reg = (opcode & RT) >> 16;
573 if ((unsigned long)vaddr & 3)
578 if (ll_bit == 0 || ll_task != current) {
586 if (put_user(regs->regs[reg], vaddr))
595 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
596 * opcodes are supposed to result in coprocessor unusable exceptions if
597 * executed on ll/sc-less processors. That's the theory. In practice a
598 * few processors such as NEC's VR4100 throw reserved instruction exceptions
599 * instead, so we're doing the emulation thing in both exception handlers.
601 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
603 if ((opcode & OPCODE) == LL) {
604 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
606 return simulate_ll(regs, opcode);
608 if ((opcode & OPCODE) == SC) {
609 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
611 return simulate_sc(regs, opcode);
614 return -1; /* Must be something else ... */
618 * Simulate trapping 'rdhwr' instructions to provide user accessible
619 * registers not implemented in hardware.
621 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
623 struct thread_info *ti = task_thread_info(current);
625 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
628 case MIPS_HWR_CPUNUM: /* CPU number */
629 regs->regs[rt] = smp_processor_id();
631 case MIPS_HWR_SYNCISTEP: /* SYNCI length */
632 regs->regs[rt] = min(current_cpu_data.dcache.linesz,
633 current_cpu_data.icache.linesz);
635 case MIPS_HWR_CC: /* Read count register */
636 regs->regs[rt] = read_c0_count();
638 case MIPS_HWR_CCRES: /* Count register resolution */
639 switch (current_cpu_type()) {
648 case MIPS_HWR_ULR: /* Read UserLocal register */
649 regs->regs[rt] = ti->tp_value;
656 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
658 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
659 int rd = (opcode & RD) >> 11;
660 int rt = (opcode & RT) >> 16;
662 simulate_rdhwr(regs, rd, rt);
670 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned int opcode)
672 if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
673 int rd = (opcode & MM_RS) >> 16;
674 int rt = (opcode & MM_RT) >> 21;
675 simulate_rdhwr(regs, rd, rt);
683 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
685 if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
686 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
691 return -1; /* Must be something else ... */
694 asmlinkage void do_ov(struct pt_regs *regs)
696 enum ctx_state prev_state;
699 .si_code = FPE_INTOVF,
700 .si_addr = (void __user *)regs->cp0_epc,
703 prev_state = exception_enter();
704 die_if_kernel("Integer overflow", regs);
706 force_sig_info(SIGFPE, &info, current);
707 exception_exit(prev_state);
710 int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
712 struct siginfo si = { 0 };
713 struct vm_area_struct *vma;
720 si.si_addr = fault_addr;
723 * Inexact can happen together with Overflow or Underflow.
724 * Respect the mask to deliver the correct exception.
726 fcr31 &= (fcr31 & FPU_CSR_ALL_E) <<
727 (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E));
728 if (fcr31 & FPU_CSR_INV_X)
729 si.si_code = FPE_FLTINV;
730 else if (fcr31 & FPU_CSR_DIV_X)
731 si.si_code = FPE_FLTDIV;
732 else if (fcr31 & FPU_CSR_OVF_X)
733 si.si_code = FPE_FLTOVF;
734 else if (fcr31 & FPU_CSR_UDF_X)
735 si.si_code = FPE_FLTUND;
736 else if (fcr31 & FPU_CSR_INE_X)
737 si.si_code = FPE_FLTRES;
739 si.si_code = __SI_FAULT;
740 force_sig_info(sig, &si, current);
744 si.si_addr = fault_addr;
746 si.si_code = BUS_ADRERR;
747 force_sig_info(sig, &si, current);
751 si.si_addr = fault_addr;
753 down_read(¤t->mm->mmap_sem);
754 vma = find_vma(current->mm, (unsigned long)fault_addr);
755 if (vma && (vma->vm_start <= (unsigned long)fault_addr))
756 si.si_code = SEGV_ACCERR;
758 si.si_code = SEGV_MAPERR;
759 up_read(¤t->mm->mmap_sem);
760 force_sig_info(sig, &si, current);
764 force_sig(sig, current);
769 static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
770 unsigned long old_epc, unsigned long old_ra)
772 union mips_instruction inst = { .word = opcode };
773 void __user *fault_addr;
777 /* If it's obviously not an FP instruction, skip it */
778 switch (inst.i_format.opcode) {
792 * do_ri skipped over the instruction via compute_return_epc, undo
793 * that for the FPU emulator.
795 regs->cp0_epc = old_epc;
796 regs->regs[31] = old_ra;
798 /* Save the FP context to struct thread_struct */
801 /* Run the emulator */
802 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1,
804 fcr31 = current->thread.fpu.fcr31;
807 * We can't allow the emulated instruction to leave any of
808 * the cause bits set in $fcr31.
810 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
812 /* Restore the hardware register state */
815 /* Send a signal if required. */
816 process_fpemu_return(sig, fault_addr, fcr31);
822 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
824 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
826 enum ctx_state prev_state;
827 void __user *fault_addr;
830 prev_state = exception_enter();
831 if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
832 SIGFPE) == NOTIFY_STOP)
835 /* Clear FCSR.Cause before enabling interrupts */
836 write_32bit_cp1_register(CP1_STATUS, fcr31 & ~FPU_CSR_ALL_X);
839 die_if_kernel("FP exception in kernel code", regs);
841 if (fcr31 & FPU_CSR_UNI_X) {
843 * Unimplemented operation exception. If we've got the full
844 * software emulator on-board, let's use it...
846 * Force FPU to dump state into task/thread context. We're
847 * moving a lot of data here for what is probably a single
848 * instruction, but the alternative is to pre-decode the FP
849 * register operands before invoking the emulator, which seems
850 * a bit extreme for what should be an infrequent event.
852 /* Ensure 'resume' not overwrite saved fp context again. */
855 /* Run the emulator */
856 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1,
858 fcr31 = current->thread.fpu.fcr31;
861 * We can't allow the emulated instruction to leave any of
862 * the cause bits set in $fcr31.
864 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
866 /* Restore the hardware register state */
867 own_fpu(1); /* Using the FPU again. */
870 fault_addr = (void __user *) regs->cp0_epc;
873 /* Send a signal if required. */
874 process_fpemu_return(sig, fault_addr, fcr31);
877 exception_exit(prev_state);
880 void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code,
883 siginfo_t info = { 0 };
886 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
887 if (kgdb_ll_trap(DIE_TRAP, str, regs, code, current->thread.trap_nr,
888 SIGTRAP) == NOTIFY_STOP)
890 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
892 if (notify_die(DIE_TRAP, str, regs, code, current->thread.trap_nr,
893 SIGTRAP) == NOTIFY_STOP)
897 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
898 * insns, even for trap and break codes that indicate arithmetic
899 * failures. Weird ...
900 * But should we continue the brokenness??? --macro
905 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
906 die_if_kernel(b, regs);
907 if (code == BRK_DIVZERO)
908 info.si_code = FPE_INTDIV;
910 info.si_code = FPE_INTOVF;
911 info.si_signo = SIGFPE;
912 info.si_addr = (void __user *) regs->cp0_epc;
913 force_sig_info(SIGFPE, &info, current);
916 die_if_kernel("Kernel bug detected", regs);
917 force_sig(SIGTRAP, current);
921 * This breakpoint code is used by the FPU emulator to retake
922 * control of the CPU after executing the instruction from the
923 * delay slot of an emulated branch.
925 * Terminate if exception was recognized as a delay slot return
926 * otherwise handle as normal.
928 if (do_dsemulret(regs))
931 die_if_kernel("Math emu break/trap", regs);
932 force_sig(SIGTRAP, current);
935 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
936 die_if_kernel(b, regs);
938 info.si_signo = SIGTRAP;
939 info.si_code = si_code;
940 force_sig_info(SIGTRAP, &info, current);
942 force_sig(SIGTRAP, current);
947 asmlinkage void do_bp(struct pt_regs *regs)
949 unsigned long epc = msk_isa16_mode(exception_epc(regs));
950 unsigned int opcode, bcode;
951 enum ctx_state prev_state;
955 if (!user_mode(regs))
958 prev_state = exception_enter();
959 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
960 if (get_isa16_mode(regs->cp0_epc)) {
963 if (__get_user(instr[0], (u16 __user *)epc))
966 if (!cpu_has_mmips) {
968 bcode = (instr[0] >> 5) & 0x3f;
969 } else if (mm_insn_16bit(instr[0])) {
970 /* 16-bit microMIPS BREAK */
971 bcode = instr[0] & 0xf;
973 /* 32-bit microMIPS BREAK */
974 if (__get_user(instr[1], (u16 __user *)(epc + 2)))
976 opcode = (instr[0] << 16) | instr[1];
977 bcode = (opcode >> 6) & ((1 << 20) - 1);
980 if (__get_user(opcode, (unsigned int __user *)epc))
982 bcode = (opcode >> 6) & ((1 << 20) - 1);
986 * There is the ancient bug in the MIPS assemblers that the break
987 * code starts left to bit 16 instead to bit 6 in the opcode.
988 * Gas is bug-compatible, but not always, grrr...
989 * We handle both cases with a simple heuristics. --macro
991 if (bcode >= (1 << 10))
992 bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10);
995 * notify the kprobe handlers, if instruction is likely to
1000 if (notify_die(DIE_UPROBE, "uprobe", regs, bcode,
1001 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1005 case BRK_UPROBE_XOL:
1006 if (notify_die(DIE_UPROBE_XOL, "uprobe_xol", regs, bcode,
1007 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1012 if (notify_die(DIE_BREAK, "debug", regs, bcode,
1013 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1017 case BRK_KPROBE_SSTEPBP:
1018 if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
1019 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1027 do_trap_or_bp(regs, bcode, TRAP_BRKPT, "Break");
1031 exception_exit(prev_state);
1035 force_sig(SIGSEGV, current);
1039 asmlinkage void do_tr(struct pt_regs *regs)
1041 u32 opcode, tcode = 0;
1042 enum ctx_state prev_state;
1045 unsigned long epc = msk_isa16_mode(exception_epc(regs));
1048 if (!user_mode(regs))
1051 prev_state = exception_enter();
1052 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1053 if (get_isa16_mode(regs->cp0_epc)) {
1054 if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
1055 __get_user(instr[1], (u16 __user *)(epc + 2)))
1057 opcode = (instr[0] << 16) | instr[1];
1058 /* Immediate versions don't provide a code. */
1059 if (!(opcode & OPCODE))
1060 tcode = (opcode >> 12) & ((1 << 4) - 1);
1062 if (__get_user(opcode, (u32 __user *)epc))
1064 /* Immediate versions don't provide a code. */
1065 if (!(opcode & OPCODE))
1066 tcode = (opcode >> 6) & ((1 << 10) - 1);
1069 do_trap_or_bp(regs, tcode, 0, "Trap");
1073 exception_exit(prev_state);
1077 force_sig(SIGSEGV, current);
1081 asmlinkage void do_ri(struct pt_regs *regs)
1083 unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
1084 unsigned long old_epc = regs->cp0_epc;
1085 unsigned long old31 = regs->regs[31];
1086 enum ctx_state prev_state;
1087 unsigned int opcode = 0;
1091 * Avoid any kernel code. Just emulate the R2 instruction
1092 * as quickly as possible.
1094 if (mipsr2_emulation && cpu_has_mips_r6 &&
1095 likely(user_mode(regs)) &&
1096 likely(get_user(opcode, epc) >= 0)) {
1097 unsigned long fcr31 = 0;
1099 status = mipsr2_decoder(regs, opcode, &fcr31);
1103 task_thread_info(current)->r2_emul_return = 1;
1108 process_fpemu_return(status,
1109 ¤t->thread.cp0_baduaddr,
1111 task_thread_info(current)->r2_emul_return = 1;
1118 prev_state = exception_enter();
1119 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1121 if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
1122 SIGILL) == NOTIFY_STOP)
1125 die_if_kernel("Reserved instruction in kernel code", regs);
1127 if (unlikely(compute_return_epc(regs) < 0))
1130 if (!get_isa16_mode(regs->cp0_epc)) {
1131 if (unlikely(get_user(opcode, epc) < 0))
1134 if (!cpu_has_llsc && status < 0)
1135 status = simulate_llsc(regs, opcode);
1138 status = simulate_rdhwr_normal(regs, opcode);
1141 status = simulate_sync(regs, opcode);
1144 status = simulate_fp(regs, opcode, old_epc, old31);
1145 } else if (cpu_has_mmips) {
1146 unsigned short mmop[2] = { 0 };
1148 if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
1150 if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
1153 opcode = (opcode << 16) | mmop[1];
1156 status = simulate_rdhwr_mm(regs, opcode);
1162 if (unlikely(status > 0)) {
1163 regs->cp0_epc = old_epc; /* Undo skip-over. */
1164 regs->regs[31] = old31;
1165 force_sig(status, current);
1169 exception_exit(prev_state);
1173 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1174 * emulated more than some threshold number of instructions, force migration to
1175 * a "CPU" that has FP support.
1177 static void mt_ase_fp_affinity(void)
1179 #ifdef CONFIG_MIPS_MT_FPAFF
1180 if (mt_fpemul_threshold > 0 &&
1181 ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1183 * If there's no FPU present, or if the application has already
1184 * restricted the allowed set to exclude any CPUs with FPUs,
1185 * we'll skip the procedure.
1187 if (cpumask_intersects(¤t->cpus_allowed, &mt_fpu_cpumask)) {
1190 current->thread.user_cpus_allowed
1191 = current->cpus_allowed;
1192 cpumask_and(&tmask, ¤t->cpus_allowed,
1194 set_cpus_allowed_ptr(current, &tmask);
1195 set_thread_flag(TIF_FPUBOUND);
1198 #endif /* CONFIG_MIPS_MT_FPAFF */
1202 * No lock; only written during early bootup by CPU 0.
1204 static RAW_NOTIFIER_HEAD(cu2_chain);
1206 int __ref register_cu2_notifier(struct notifier_block *nb)
1208 return raw_notifier_chain_register(&cu2_chain, nb);
1211 int cu2_notifier_call_chain(unsigned long val, void *v)
1213 return raw_notifier_call_chain(&cu2_chain, val, v);
1216 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1219 struct pt_regs *regs = data;
1221 die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1222 "instruction", regs);
1223 force_sig(SIGILL, current);
1228 static int wait_on_fp_mode_switch(atomic_t *p)
1231 * The FP mode for this task is currently being switched. That may
1232 * involve modifications to the format of this tasks FP context which
1233 * make it unsafe to proceed with execution for the moment. Instead,
1234 * schedule some other task.
1240 static int enable_restore_fp_context(int msa)
1242 int err, was_fpu_owner, prior_msa;
1245 * If an FP mode switch is currently underway, wait for it to
1246 * complete before proceeding.
1248 wait_on_atomic_t(¤t->mm->context.fp_mode_switching,
1249 wait_on_fp_mode_switch, TASK_KILLABLE);
1252 /* First time FP context user. */
1258 set_thread_flag(TIF_USEDMSA);
1259 set_thread_flag(TIF_MSA_CTX_LIVE);
1268 * This task has formerly used the FP context.
1270 * If this thread has no live MSA vector context then we can simply
1271 * restore the scalar FP context. If it has live MSA vector context
1272 * (that is, it has or may have used MSA since last performing a
1273 * function call) then we'll need to restore the vector context. This
1274 * applies even if we're currently only executing a scalar FP
1275 * instruction. This is because if we were to later execute an MSA
1276 * instruction then we'd either have to:
1278 * - Restore the vector context & clobber any registers modified by
1279 * scalar FP instructions between now & then.
1283 * - Not restore the vector context & lose the most significant bits
1284 * of all vector registers.
1286 * Neither of those options is acceptable. We cannot restore the least
1287 * significant bits of the registers now & only restore the most
1288 * significant bits later because the most significant bits of any
1289 * vector registers whose aliased FP register is modified now will have
1290 * been zeroed. We'd have no way to know that when restoring the vector
1291 * context & thus may load an outdated value for the most significant
1292 * bits of a vector register.
1294 if (!msa && !thread_msa_context_live())
1298 * This task is using or has previously used MSA. Thus we require
1299 * that Status.FR == 1.
1302 was_fpu_owner = is_fpu_owner();
1303 err = own_fpu_inatomic(0);
1308 write_msa_csr(current->thread.fpu.msacsr);
1309 set_thread_flag(TIF_USEDMSA);
1312 * If this is the first time that the task is using MSA and it has
1313 * previously used scalar FP in this time slice then we already nave
1314 * FP context which we shouldn't clobber. We do however need to clear
1315 * the upper 64b of each vector register so that this task has no
1316 * opportunity to see data left behind by another.
1318 prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
1319 if (!prior_msa && was_fpu_owner) {
1327 * Restore the least significant 64b of each vector register
1328 * from the existing scalar FP context.
1330 _restore_fp(current);
1333 * The task has not formerly used MSA, so clear the upper 64b
1334 * of each vector register such that it cannot see data left
1335 * behind by another task.
1339 /* We need to restore the vector context. */
1340 restore_msa(current);
1342 /* Restore the scalar FP control & status register */
1344 write_32bit_cp1_register(CP1_STATUS,
1345 current->thread.fpu.fcr31);
1354 asmlinkage void do_cpu(struct pt_regs *regs)
1356 enum ctx_state prev_state;
1357 unsigned int __user *epc;
1358 unsigned long old_epc, old31;
1359 void __user *fault_addr;
1360 unsigned int opcode;
1361 unsigned long fcr31;
1366 prev_state = exception_enter();
1367 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1370 die_if_kernel("do_cpu invoked from kernel context!", regs);
1374 epc = (unsigned int __user *)exception_epc(regs);
1375 old_epc = regs->cp0_epc;
1376 old31 = regs->regs[31];
1380 if (unlikely(compute_return_epc(regs) < 0))
1383 if (!get_isa16_mode(regs->cp0_epc)) {
1384 if (unlikely(get_user(opcode, epc) < 0))
1387 if (!cpu_has_llsc && status < 0)
1388 status = simulate_llsc(regs, opcode);
1394 if (unlikely(status > 0)) {
1395 regs->cp0_epc = old_epc; /* Undo skip-over. */
1396 regs->regs[31] = old31;
1397 force_sig(status, current);
1404 * The COP3 opcode space and consequently the CP0.Status.CU3
1405 * bit and the CP0.Cause.CE=3 encoding have been removed as
1406 * of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs
1407 * up the space has been reused for COP1X instructions, that
1408 * are enabled by the CP0.Status.CU1 bit and consequently
1409 * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
1410 * exceptions. Some FPU-less processors that implement one
1411 * of these ISAs however use this code erroneously for COP1X
1412 * instructions. Therefore we redirect this trap to the FP
1415 if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
1416 force_sig(SIGILL, current);
1422 err = enable_restore_fp_context(0);
1424 if (raw_cpu_has_fpu && !err)
1427 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 0,
1429 fcr31 = current->thread.fpu.fcr31;
1432 * We can't allow the emulated instruction to leave
1433 * any of the cause bits set in $fcr31.
1435 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
1437 /* Send a signal if required. */
1438 if (!process_fpemu_return(sig, fault_addr, fcr31) && !err)
1439 mt_ase_fp_affinity();
1444 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1448 exception_exit(prev_state);
1451 asmlinkage void do_msa_fpe(struct pt_regs *regs, unsigned int msacsr)
1453 enum ctx_state prev_state;
1455 prev_state = exception_enter();
1456 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1457 if (notify_die(DIE_MSAFP, "MSA FP exception", regs, 0,
1458 current->thread.trap_nr, SIGFPE) == NOTIFY_STOP)
1461 /* Clear MSACSR.Cause before enabling interrupts */
1462 write_msa_csr(msacsr & ~MSA_CSR_CAUSEF);
1465 die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
1466 force_sig(SIGFPE, current);
1468 exception_exit(prev_state);
1471 asmlinkage void do_msa(struct pt_regs *regs)
1473 enum ctx_state prev_state;
1476 prev_state = exception_enter();
1478 if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
1479 force_sig(SIGILL, current);
1483 die_if_kernel("do_msa invoked from kernel context!", regs);
1485 err = enable_restore_fp_context(1);
1487 force_sig(SIGILL, current);
1489 exception_exit(prev_state);
1492 asmlinkage void do_mdmx(struct pt_regs *regs)
1494 enum ctx_state prev_state;
1496 prev_state = exception_enter();
1497 force_sig(SIGILL, current);
1498 exception_exit(prev_state);
1502 * Called with interrupts disabled.
1504 asmlinkage void do_watch(struct pt_regs *regs)
1506 siginfo_t info = { .si_signo = SIGTRAP, .si_code = TRAP_HWBKPT };
1507 enum ctx_state prev_state;
1509 prev_state = exception_enter();
1511 * Clear WP (bit 22) bit of cause register so we don't loop
1514 clear_c0_cause(CAUSEF_WP);
1517 * If the current thread has the watch registers loaded, save
1518 * their values and send SIGTRAP. Otherwise another thread
1519 * left the registers set, clear them and continue.
1521 if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1522 mips_read_watch_registers();
1524 force_sig_info(SIGTRAP, &info, current);
1526 mips_clear_watch_registers();
1529 exception_exit(prev_state);
1532 asmlinkage void do_mcheck(struct pt_regs *regs)
1534 int multi_match = regs->cp0_status & ST0_TS;
1535 enum ctx_state prev_state;
1536 mm_segment_t old_fs = get_fs();
1538 prev_state = exception_enter();
1547 if (!user_mode(regs))
1550 show_code((unsigned int __user *) regs->cp0_epc);
1555 * Some chips may have other causes of machine check (e.g. SB1
1558 panic("Caught Machine Check exception - %scaused by multiple "
1559 "matching entries in the TLB.",
1560 (multi_match) ? "" : "not ");
1563 asmlinkage void do_mt(struct pt_regs *regs)
1567 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1568 >> VPECONTROL_EXCPT_SHIFT;
1571 printk(KERN_DEBUG "Thread Underflow\n");
1574 printk(KERN_DEBUG "Thread Overflow\n");
1577 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1580 printk(KERN_DEBUG "Gating Storage Exception\n");
1583 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1586 printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1589 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1593 die_if_kernel("MIPS MT Thread exception in kernel", regs);
1595 force_sig(SIGILL, current);
1599 asmlinkage void do_dsp(struct pt_regs *regs)
1602 panic("Unexpected DSP exception");
1604 force_sig(SIGILL, current);
1607 asmlinkage void do_reserved(struct pt_regs *regs)
1610 * Game over - no way to handle this if it ever occurs. Most probably
1611 * caused by a new unknown cpu type or after another deadly
1612 * hard/software error.
1615 panic("Caught reserved exception %ld - should not happen.",
1616 (regs->cp0_cause & 0x7f) >> 2);
1619 static int __initdata l1parity = 1;
1620 static int __init nol1parity(char *s)
1625 __setup("nol1par", nol1parity);
1626 static int __initdata l2parity = 1;
1627 static int __init nol2parity(char *s)
1632 __setup("nol2par", nol2parity);
1635 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1636 * it different ways.
1638 static inline void parity_protection_init(void)
1640 switch (current_cpu_type()) {
1646 case CPU_INTERAPTIV:
1649 case CPU_QEMU_GENERIC:
1653 #define ERRCTL_PE 0x80000000
1654 #define ERRCTL_L2P 0x00800000
1655 unsigned long errctl;
1656 unsigned int l1parity_present, l2parity_present;
1658 errctl = read_c0_ecc();
1659 errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1661 /* probe L1 parity support */
1662 write_c0_ecc(errctl | ERRCTL_PE);
1663 back_to_back_c0_hazard();
1664 l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1666 /* probe L2 parity support */
1667 write_c0_ecc(errctl|ERRCTL_L2P);
1668 back_to_back_c0_hazard();
1669 l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1671 if (l1parity_present && l2parity_present) {
1673 errctl |= ERRCTL_PE;
1674 if (l1parity ^ l2parity)
1675 errctl |= ERRCTL_L2P;
1676 } else if (l1parity_present) {
1678 errctl |= ERRCTL_PE;
1679 } else if (l2parity_present) {
1681 errctl |= ERRCTL_L2P;
1683 /* No parity available */
1686 printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1688 write_c0_ecc(errctl);
1689 back_to_back_c0_hazard();
1690 errctl = read_c0_ecc();
1691 printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1693 if (l1parity_present)
1694 printk(KERN_INFO "Cache parity protection %sabled\n",
1695 (errctl & ERRCTL_PE) ? "en" : "dis");
1697 if (l2parity_present) {
1698 if (l1parity_present && l1parity)
1699 errctl ^= ERRCTL_L2P;
1700 printk(KERN_INFO "L2 cache parity protection %sabled\n",
1701 (errctl & ERRCTL_L2P) ? "en" : "dis");
1709 write_c0_ecc(0x80000000);
1710 back_to_back_c0_hazard();
1711 /* Set the PE bit (bit 31) in the c0_errctl register. */
1712 printk(KERN_INFO "Cache parity protection %sabled\n",
1713 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1717 /* Clear the DE bit (bit 16) in the c0_status register. */
1718 printk(KERN_INFO "Enable cache parity protection for "
1719 "MIPS 20KC/25KF CPUs.\n");
1720 clear_c0_status(ST0_DE);
1727 asmlinkage void cache_parity_error(void)
1729 const int field = 2 * sizeof(unsigned long);
1730 unsigned int reg_val;
1732 /* For the moment, report the problem and hang. */
1733 printk("Cache error exception:\n");
1734 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1735 reg_val = read_c0_cacheerr();
1736 printk("c0_cacheerr == %08x\n", reg_val);
1738 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1739 reg_val & (1<<30) ? "secondary" : "primary",
1740 reg_val & (1<<31) ? "data" : "insn");
1741 if ((cpu_has_mips_r2_r6) &&
1742 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1743 pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1744 reg_val & (1<<29) ? "ED " : "",
1745 reg_val & (1<<28) ? "ET " : "",
1746 reg_val & (1<<27) ? "ES " : "",
1747 reg_val & (1<<26) ? "EE " : "",
1748 reg_val & (1<<25) ? "EB " : "",
1749 reg_val & (1<<24) ? "EI " : "",
1750 reg_val & (1<<23) ? "E1 " : "",
1751 reg_val & (1<<22) ? "E0 " : "");
1753 pr_err("Error bits: %s%s%s%s%s%s%s\n",
1754 reg_val & (1<<29) ? "ED " : "",
1755 reg_val & (1<<28) ? "ET " : "",
1756 reg_val & (1<<26) ? "EE " : "",
1757 reg_val & (1<<25) ? "EB " : "",
1758 reg_val & (1<<24) ? "EI " : "",
1759 reg_val & (1<<23) ? "E1 " : "",
1760 reg_val & (1<<22) ? "E0 " : "");
1762 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1764 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1765 if (reg_val & (1<<22))
1766 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1768 if (reg_val & (1<<23))
1769 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1772 panic("Can't handle the cache error!");
1775 asmlinkage void do_ftlb(void)
1777 const int field = 2 * sizeof(unsigned long);
1778 unsigned int reg_val;
1780 /* For the moment, report the problem and hang. */
1781 if ((cpu_has_mips_r2_r6) &&
1782 (((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS) ||
1783 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_LOONGSON))) {
1784 pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1786 pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1787 reg_val = read_c0_cacheerr();
1788 pr_err("c0_cacheerr == %08x\n", reg_val);
1790 if ((reg_val & 0xc0000000) == 0xc0000000) {
1791 pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1793 pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1794 reg_val & (1<<30) ? "secondary" : "primary",
1795 reg_val & (1<<31) ? "data" : "insn");
1798 pr_err("FTLB error exception\n");
1800 /* Just print the cacheerr bits for now */
1801 cache_parity_error();
1805 * SDBBP EJTAG debug exception handler.
1806 * We skip the instruction and return to the next instruction.
1808 void ejtag_exception_handler(struct pt_regs *regs)
1810 const int field = 2 * sizeof(unsigned long);
1811 unsigned long depc, old_epc, old_ra;
1814 printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1815 depc = read_c0_depc();
1816 debug = read_c0_debug();
1817 printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1818 if (debug & 0x80000000) {
1820 * In branch delay slot.
1821 * We cheat a little bit here and use EPC to calculate the
1822 * debug return address (DEPC). EPC is restored after the
1825 old_epc = regs->cp0_epc;
1826 old_ra = regs->regs[31];
1827 regs->cp0_epc = depc;
1828 compute_return_epc(regs);
1829 depc = regs->cp0_epc;
1830 regs->cp0_epc = old_epc;
1831 regs->regs[31] = old_ra;
1834 write_c0_depc(depc);
1837 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1838 write_c0_debug(debug | 0x100);
1843 * NMI exception handler.
1844 * No lock; only written during early bootup by CPU 0.
1846 static RAW_NOTIFIER_HEAD(nmi_chain);
1848 int register_nmi_notifier(struct notifier_block *nb)
1850 return raw_notifier_chain_register(&nmi_chain, nb);
1853 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1858 raw_notifier_call_chain(&nmi_chain, 0, regs);
1860 snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1861 smp_processor_id(), regs->cp0_epc);
1862 regs->cp0_epc = read_c0_errorepc();
1867 #define VECTORSPACING 0x100 /* for EI/VI mode */
1869 unsigned long ebase;
1870 EXPORT_SYMBOL_GPL(ebase);
1871 unsigned long exception_handlers[32];
1872 unsigned long vi_handlers[64];
1874 void __init *set_except_vector(int n, void *addr)
1876 unsigned long handler = (unsigned long) addr;
1877 unsigned long old_handler;
1879 #ifdef CONFIG_CPU_MICROMIPS
1881 * Only the TLB handlers are cache aligned with an even
1882 * address. All other handlers are on an odd address and
1883 * require no modification. Otherwise, MIPS32 mode will
1884 * be entered when handling any TLB exceptions. That
1885 * would be bad...since we must stay in microMIPS mode.
1887 if (!(handler & 0x1))
1890 old_handler = xchg(&exception_handlers[n], handler);
1892 if (n == 0 && cpu_has_divec) {
1893 #ifdef CONFIG_CPU_MICROMIPS
1894 unsigned long jump_mask = ~((1 << 27) - 1);
1896 unsigned long jump_mask = ~((1 << 28) - 1);
1898 u32 *buf = (u32 *)(ebase + 0x200);
1899 unsigned int k0 = 26;
1900 if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1901 uasm_i_j(&buf, handler & ~jump_mask);
1904 UASM_i_LA(&buf, k0, handler);
1905 uasm_i_jr(&buf, k0);
1908 local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1910 return (void *)old_handler;
1913 static void do_default_vi(void)
1915 show_regs(get_irq_regs());
1916 panic("Caught unexpected vectored interrupt.");
1919 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1921 unsigned long handler;
1922 unsigned long old_handler = vi_handlers[n];
1923 int srssets = current_cpu_data.srsets;
1927 BUG_ON(!cpu_has_veic && !cpu_has_vint);
1930 handler = (unsigned long) do_default_vi;
1933 handler = (unsigned long) addr;
1934 vi_handlers[n] = handler;
1936 b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1939 panic("Shadow register set %d not supported", srs);
1942 if (board_bind_eic_interrupt)
1943 board_bind_eic_interrupt(n, srs);
1944 } else if (cpu_has_vint) {
1945 /* SRSMap is only defined if shadow sets are implemented */
1947 change_c0_srsmap(0xf << n*4, srs << n*4);
1952 * If no shadow set is selected then use the default handler
1953 * that does normal register saving and standard interrupt exit
1955 extern char except_vec_vi, except_vec_vi_lui;
1956 extern char except_vec_vi_ori, except_vec_vi_end;
1957 extern char rollback_except_vec_vi;
1958 char *vec_start = using_rollback_handler() ?
1959 &rollback_except_vec_vi : &except_vec_vi;
1960 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1961 const int lui_offset = &except_vec_vi_lui - vec_start + 2;
1962 const int ori_offset = &except_vec_vi_ori - vec_start + 2;
1964 const int lui_offset = &except_vec_vi_lui - vec_start;
1965 const int ori_offset = &except_vec_vi_ori - vec_start;
1967 const int handler_len = &except_vec_vi_end - vec_start;
1969 if (handler_len > VECTORSPACING) {
1971 * Sigh... panicing won't help as the console
1972 * is probably not configured :(
1974 panic("VECTORSPACING too small");
1977 set_handler(((unsigned long)b - ebase), vec_start,
1978 #ifdef CONFIG_CPU_MICROMIPS
1983 h = (u16 *)(b + lui_offset);
1984 *h = (handler >> 16) & 0xffff;
1985 h = (u16 *)(b + ori_offset);
1986 *h = (handler & 0xffff);
1987 local_flush_icache_range((unsigned long)b,
1988 (unsigned long)(b+handler_len));
1992 * In other cases jump directly to the interrupt handler. It
1993 * is the handler's responsibility to save registers if required
1994 * (eg hi/lo) and return from the exception using "eret".
2000 #ifdef CONFIG_CPU_MICROMIPS
2001 insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
2003 insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
2005 h[0] = (insn >> 16) & 0xffff;
2006 h[1] = insn & 0xffff;
2009 local_flush_icache_range((unsigned long)b,
2010 (unsigned long)(b+8));
2013 return (void *)old_handler;
2016 void *set_vi_handler(int n, vi_handler_t addr)
2018 return set_vi_srs_handler(n, addr, 0);
2021 extern void tlb_init(void);
2026 int cp0_compare_irq;
2027 EXPORT_SYMBOL_GPL(cp0_compare_irq);
2028 int cp0_compare_irq_shift;
2031 * Performance counter IRQ or -1 if shared with timer
2033 int cp0_perfcount_irq;
2034 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
2037 * Fast debug channel IRQ or -1 if not present
2040 EXPORT_SYMBOL_GPL(cp0_fdc_irq);
2044 static int __init ulri_disable(char *s)
2046 pr_info("Disabling ulri\n");
2051 __setup("noulri", ulri_disable);
2053 /* configure STATUS register */
2054 static void configure_status(void)
2057 * Disable coprocessors and select 32-bit or 64-bit addressing
2058 * and the 16/32 or 32/32 FPR register model. Reset the BEV
2059 * flag that some firmware may have left set and the TS bit (for
2060 * IP27). Set XX for ISA IV code to work.
2062 unsigned int status_set = ST0_CU0;
2064 status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
2066 if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
2067 status_set |= ST0_XX;
2069 status_set |= ST0_MX;
2071 change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
2075 unsigned int hwrena;
2076 EXPORT_SYMBOL_GPL(hwrena);
2078 /* configure HWRENA register */
2079 static void configure_hwrena(void)
2081 hwrena = cpu_hwrena_impl_bits;
2083 if (cpu_has_mips_r2_r6)
2084 hwrena |= MIPS_HWRENA_CPUNUM |
2085 MIPS_HWRENA_SYNCISTEP |
2089 if (!noulri && cpu_has_userlocal)
2090 hwrena |= MIPS_HWRENA_ULR;
2093 write_c0_hwrena(hwrena);
2096 static void configure_exception_vector(void)
2098 if (cpu_has_veic || cpu_has_vint) {
2099 unsigned long sr = set_c0_status(ST0_BEV);
2100 /* If available, use WG to set top bits of EBASE */
2101 if (cpu_has_ebase_wg) {
2103 write_c0_ebase_64(ebase | MIPS_EBASE_WG);
2105 write_c0_ebase(ebase | MIPS_EBASE_WG);
2108 write_c0_ebase(ebase);
2109 write_c0_status(sr);
2110 /* Setting vector spacing enables EI/VI mode */
2111 change_c0_intctl(0x3e0, VECTORSPACING);
2113 if (cpu_has_divec) {
2114 if (cpu_has_mipsmt) {
2115 unsigned int vpflags = dvpe();
2116 set_c0_cause(CAUSEF_IV);
2119 set_c0_cause(CAUSEF_IV);
2123 void per_cpu_trap_init(bool is_boot_cpu)
2125 unsigned int cpu = smp_processor_id();
2130 configure_exception_vector();
2133 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
2135 * o read IntCtl.IPTI to determine the timer interrupt
2136 * o read IntCtl.IPPCI to determine the performance counter interrupt
2137 * o read IntCtl.IPFDC to determine the fast debug channel interrupt
2139 if (cpu_has_mips_r2_r6) {
2141 * We shouldn't trust a secondary core has a sane EBASE register
2142 * so use the one calculated by the boot CPU.
2145 /* If available, use WG to set top bits of EBASE */
2146 if (cpu_has_ebase_wg) {
2148 write_c0_ebase_64(ebase | MIPS_EBASE_WG);
2150 write_c0_ebase(ebase | MIPS_EBASE_WG);
2153 write_c0_ebase(ebase);
2156 cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
2157 cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
2158 cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
2159 cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7;
2164 cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
2165 cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
2166 cp0_perfcount_irq = -1;
2170 if (!cpu_data[cpu].asid_cache)
2171 cpu_data[cpu].asid_cache = asid_first_version(cpu);
2173 atomic_inc(&init_mm.mm_count);
2174 current->active_mm = &init_mm;
2175 BUG_ON(current->mm);
2176 enter_lazy_tlb(&init_mm, current);
2178 /* Boot CPU's cache setup in setup_arch(). */
2182 TLBMISS_HANDLER_SETUP();
2185 /* Install CPU exception handler */
2186 void set_handler(unsigned long offset, void *addr, unsigned long size)
2188 #ifdef CONFIG_CPU_MICROMIPS
2189 memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
2191 memcpy((void *)(ebase + offset), addr, size);
2193 local_flush_icache_range(ebase + offset, ebase + offset + size);
2196 static char panic_null_cerr[] =
2197 "Trying to set NULL cache error exception handler";
2200 * Install uncached CPU exception handler.
2201 * This is suitable only for the cache error exception which is the only
2202 * exception handler that is being run uncached.
2204 void set_uncached_handler(unsigned long offset, void *addr,
2207 unsigned long uncached_ebase = CKSEG1ADDR(ebase);
2210 panic(panic_null_cerr);
2212 memcpy((void *)(uncached_ebase + offset), addr, size);
2215 static int __initdata rdhwr_noopt;
2216 static int __init set_rdhwr_noopt(char *str)
2222 __setup("rdhwr_noopt", set_rdhwr_noopt);
2224 void __init trap_init(void)
2226 extern char except_vec3_generic;
2227 extern char except_vec4;
2228 extern char except_vec3_r4000;
2233 if (cpu_has_veic || cpu_has_vint) {
2234 unsigned long size = 0x200 + VECTORSPACING*64;
2235 phys_addr_t ebase_pa;
2237 ebase = (unsigned long)
2238 __alloc_bootmem(size, 1 << fls(size), 0);
2241 * Try to ensure ebase resides in KSeg0 if possible.
2243 * It shouldn't generally be in XKPhys on MIPS64 to avoid
2244 * hitting a poorly defined exception base for Cache Errors.
2245 * The allocation is likely to be in the low 512MB of physical,
2246 * in which case we should be able to convert to KSeg0.
2248 * EVA is special though as it allows segments to be rearranged
2249 * and to become uncached during cache error handling.
2251 ebase_pa = __pa(ebase);
2252 if (!IS_ENABLED(CONFIG_EVA) && !WARN_ON(ebase_pa >= 0x20000000))
2253 ebase = CKSEG0ADDR(ebase_pa);
2257 if (cpu_has_mips_r2_r6) {
2258 if (cpu_has_ebase_wg) {
2260 ebase = (read_c0_ebase_64() & ~0xfff);
2262 ebase = (read_c0_ebase() & ~0xfff);
2265 ebase += (read_c0_ebase() & 0x3ffff000);
2270 if (cpu_has_mmips) {
2271 unsigned int config3 = read_c0_config3();
2273 if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
2274 write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
2276 write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
2279 if (board_ebase_setup)
2280 board_ebase_setup();
2281 per_cpu_trap_init(true);
2284 * Copy the generic exception handlers to their final destination.
2285 * This will be overridden later as suitable for a particular
2288 set_handler(0x180, &except_vec3_generic, 0x80);
2291 * Setup default vectors
2293 for (i = 0; i <= 31; i++)
2294 set_except_vector(i, handle_reserved);
2297 * Copy the EJTAG debug exception vector handler code to it's final
2300 if (cpu_has_ejtag && board_ejtag_handler_setup)
2301 board_ejtag_handler_setup();
2304 * Only some CPUs have the watch exceptions.
2307 set_except_vector(EXCCODE_WATCH, handle_watch);
2310 * Initialise interrupt handlers
2312 if (cpu_has_veic || cpu_has_vint) {
2313 int nvec = cpu_has_veic ? 64 : 8;
2314 for (i = 0; i < nvec; i++)
2315 set_vi_handler(i, NULL);
2317 else if (cpu_has_divec)
2318 set_handler(0x200, &except_vec4, 0x8);
2321 * Some CPUs can enable/disable for cache parity detection, but does
2322 * it different ways.
2324 parity_protection_init();
2327 * The Data Bus Errors / Instruction Bus Errors are signaled
2328 * by external hardware. Therefore these two exceptions
2329 * may have board specific handlers.
2334 set_except_vector(EXCCODE_INT, using_rollback_handler() ?
2335 rollback_handle_int : handle_int);
2336 set_except_vector(EXCCODE_MOD, handle_tlbm);
2337 set_except_vector(EXCCODE_TLBL, handle_tlbl);
2338 set_except_vector(EXCCODE_TLBS, handle_tlbs);
2340 set_except_vector(EXCCODE_ADEL, handle_adel);
2341 set_except_vector(EXCCODE_ADES, handle_ades);
2343 set_except_vector(EXCCODE_IBE, handle_ibe);
2344 set_except_vector(EXCCODE_DBE, handle_dbe);
2346 set_except_vector(EXCCODE_SYS, handle_sys);
2347 set_except_vector(EXCCODE_BP, handle_bp);
2348 set_except_vector(EXCCODE_RI, rdhwr_noopt ? handle_ri :
2349 (cpu_has_vtag_icache ?
2350 handle_ri_rdhwr_vivt : handle_ri_rdhwr));
2351 set_except_vector(EXCCODE_CPU, handle_cpu);
2352 set_except_vector(EXCCODE_OV, handle_ov);
2353 set_except_vector(EXCCODE_TR, handle_tr);
2354 set_except_vector(EXCCODE_MSAFPE, handle_msa_fpe);
2356 if (current_cpu_type() == CPU_R6000 ||
2357 current_cpu_type() == CPU_R6000A) {
2359 * The R6000 is the only R-series CPU that features a machine
2360 * check exception (similar to the R4000 cache error) and
2361 * unaligned ldc1/sdc1 exception. The handlers have not been
2362 * written yet. Well, anyway there is no R6000 machine on the
2363 * current list of targets for Linux/MIPS.
2364 * (Duh, crap, there is someone with a triple R6k machine)
2366 //set_except_vector(14, handle_mc);
2367 //set_except_vector(15, handle_ndc);
2371 if (board_nmi_handler_setup)
2372 board_nmi_handler_setup();
2374 if (cpu_has_fpu && !cpu_has_nofpuex)
2375 set_except_vector(EXCCODE_FPE, handle_fpe);
2377 set_except_vector(MIPS_EXCCODE_TLBPAR, handle_ftlb);
2379 if (cpu_has_rixiex) {
2380 set_except_vector(EXCCODE_TLBRI, tlb_do_page_fault_0);
2381 set_except_vector(EXCCODE_TLBXI, tlb_do_page_fault_0);
2384 set_except_vector(EXCCODE_MSADIS, handle_msa);
2385 set_except_vector(EXCCODE_MDMX, handle_mdmx);
2388 set_except_vector(EXCCODE_MCHECK, handle_mcheck);
2391 set_except_vector(EXCCODE_THREAD, handle_mt);
2393 set_except_vector(EXCCODE_DSPDIS, handle_dsp);
2395 if (board_cache_error_setup)
2396 board_cache_error_setup();
2399 /* Special exception: R4[04]00 uses also the divec space. */
2400 set_handler(0x180, &except_vec3_r4000, 0x100);
2401 else if (cpu_has_4kex)
2402 set_handler(0x180, &except_vec3_generic, 0x80);
2404 set_handler(0x080, &except_vec3_generic, 0x80);
2406 local_flush_icache_range(ebase, ebase + 0x400);
2408 sort_extable(__start___dbe_table, __stop___dbe_table);
2410 cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
2413 static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
2417 case CPU_PM_ENTER_FAILED:
2421 configure_exception_vector();
2423 /* Restore register with CPU number for TLB handlers */
2424 TLBMISS_HANDLER_RESTORE();
2432 static struct notifier_block trap_pm_notifier_block = {
2433 .notifier_call = trap_pm_notifier,
2436 static int __init trap_pm_init(void)
2438 return cpu_pm_register_notifier(&trap_pm_notifier_block);
2440 arch_initcall(trap_pm_init);