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-r2-to-r6-emul.h>
53 #include <asm/mipsregs.h>
54 #include <asm/mipsmtregs.h>
55 #include <asm/module.h>
57 #include <asm/pgtable.h>
58 #include <asm/ptrace.h>
59 #include <asm/sections.h>
60 #include <asm/siginfo.h>
61 #include <asm/tlbdebug.h>
62 #include <asm/traps.h>
63 #include <asm/uaccess.h>
64 #include <asm/watch.h>
65 #include <asm/mmu_context.h>
66 #include <asm/types.h>
67 #include <asm/stacktrace.h>
70 extern void check_wait(void);
71 extern asmlinkage void rollback_handle_int(void);
72 extern asmlinkage void handle_int(void);
73 extern u32 handle_tlbl[];
74 extern u32 handle_tlbs[];
75 extern u32 handle_tlbm[];
76 extern asmlinkage void handle_adel(void);
77 extern asmlinkage void handle_ades(void);
78 extern asmlinkage void handle_ibe(void);
79 extern asmlinkage void handle_dbe(void);
80 extern asmlinkage void handle_sys(void);
81 extern asmlinkage void handle_bp(void);
82 extern asmlinkage void handle_ri(void);
83 extern asmlinkage void handle_ri_rdhwr_vivt(void);
84 extern asmlinkage void handle_ri_rdhwr(void);
85 extern asmlinkage void handle_cpu(void);
86 extern asmlinkage void handle_ov(void);
87 extern asmlinkage void handle_tr(void);
88 extern asmlinkage void handle_msa_fpe(void);
89 extern asmlinkage void handle_fpe(void);
90 extern asmlinkage void handle_ftlb(void);
91 extern asmlinkage void handle_msa(void);
92 extern asmlinkage void handle_mdmx(void);
93 extern asmlinkage void handle_watch(void);
94 extern asmlinkage void handle_mt(void);
95 extern asmlinkage void handle_dsp(void);
96 extern asmlinkage void handle_mcheck(void);
97 extern asmlinkage void handle_reserved(void);
98 extern void tlb_do_page_fault_0(void);
100 void (*board_be_init)(void);
101 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
102 void (*board_nmi_handler_setup)(void);
103 void (*board_ejtag_handler_setup)(void);
104 void (*board_bind_eic_interrupt)(int irq, int regset);
105 void (*board_ebase_setup)(void);
106 void(*board_cache_error_setup)(void);
108 static void show_raw_backtrace(unsigned long reg29)
110 unsigned long *sp = (unsigned long *)(reg29 & ~3);
113 printk("Call Trace:");
114 #ifdef CONFIG_KALLSYMS
117 while (!kstack_end(sp)) {
118 unsigned long __user *p =
119 (unsigned long __user *)(unsigned long)sp++;
120 if (__get_user(addr, p)) {
121 printk(" (Bad stack address)");
124 if (__kernel_text_address(addr))
130 #ifdef CONFIG_KALLSYMS
132 static int __init set_raw_show_trace(char *str)
137 __setup("raw_show_trace", set_raw_show_trace);
140 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
142 unsigned long sp = regs->regs[29];
143 unsigned long ra = regs->regs[31];
144 unsigned long pc = regs->cp0_epc;
149 if (raw_show_trace || user_mode(regs) || !__kernel_text_address(pc)) {
150 show_raw_backtrace(sp);
153 printk("Call Trace:\n");
156 pc = unwind_stack(task, &sp, pc, &ra);
162 * This routine abuses get_user()/put_user() to reference pointers
163 * with at least a bit of error checking ...
165 static void show_stacktrace(struct task_struct *task,
166 const struct pt_regs *regs)
168 const int field = 2 * sizeof(unsigned long);
171 unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
175 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
176 if (i && ((i % (64 / field)) == 0))
183 if (__get_user(stackdata, sp++)) {
184 printk(" (Bad stack address)");
188 printk(" %0*lx", field, stackdata);
192 show_backtrace(task, regs);
195 void show_stack(struct task_struct *task, unsigned long *sp)
198 mm_segment_t old_fs = get_fs();
200 regs.regs[29] = (unsigned long)sp;
204 if (task && task != current) {
205 regs.regs[29] = task->thread.reg29;
207 regs.cp0_epc = task->thread.reg31;
208 #ifdef CONFIG_KGDB_KDB
209 } else if (atomic_read(&kgdb_active) != -1 &&
211 memcpy(®s, kdb_current_regs, sizeof(regs));
212 #endif /* CONFIG_KGDB_KDB */
214 prepare_frametrace(®s);
218 * show_stack() deals exclusively with kernel mode, so be sure to access
219 * the stack in the kernel (not user) address space.
222 show_stacktrace(task, ®s);
226 static void show_code(unsigned int __user *pc)
229 unsigned short __user *pc16 = NULL;
233 if ((unsigned long)pc & 1)
234 pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
235 for(i = -3 ; i < 6 ; i++) {
237 if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
238 printk(" (Bad address in epc)\n");
241 printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
245 static void __show_regs(const struct pt_regs *regs)
247 const int field = 2 * sizeof(unsigned long);
248 unsigned int cause = regs->cp0_cause;
249 unsigned int exccode;
252 show_regs_print_info(KERN_DEFAULT);
255 * Saved main processor registers
257 for (i = 0; i < 32; ) {
261 printk(" %0*lx", field, 0UL);
262 else if (i == 26 || i == 27)
263 printk(" %*s", field, "");
265 printk(" %0*lx", field, regs->regs[i]);
272 #ifdef CONFIG_CPU_HAS_SMARTMIPS
273 printk("Acx : %0*lx\n", field, regs->acx);
275 printk("Hi : %0*lx\n", field, regs->hi);
276 printk("Lo : %0*lx\n", field, regs->lo);
279 * Saved cp0 registers
281 printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
282 (void *) regs->cp0_epc);
283 printk("ra : %0*lx %pS\n", field, regs->regs[31],
284 (void *) regs->regs[31]);
286 printk("Status: %08x ", (uint32_t) regs->cp0_status);
289 if (regs->cp0_status & ST0_KUO)
291 if (regs->cp0_status & ST0_IEO)
293 if (regs->cp0_status & ST0_KUP)
295 if (regs->cp0_status & ST0_IEP)
297 if (regs->cp0_status & ST0_KUC)
299 if (regs->cp0_status & ST0_IEC)
301 } else if (cpu_has_4kex) {
302 if (regs->cp0_status & ST0_KX)
304 if (regs->cp0_status & ST0_SX)
306 if (regs->cp0_status & ST0_UX)
308 switch (regs->cp0_status & ST0_KSU) {
313 printk("SUPERVISOR ");
322 if (regs->cp0_status & ST0_ERL)
324 if (regs->cp0_status & ST0_EXL)
326 if (regs->cp0_status & ST0_IE)
331 exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
332 printk("Cause : %08x (ExcCode %02x)\n", cause, exccode);
334 if (1 <= exccode && exccode <= 5)
335 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
337 printk("PrId : %08x (%s)\n", read_c0_prid(),
342 * FIXME: really the generic show_regs should take a const pointer argument.
344 void show_regs(struct pt_regs *regs)
346 __show_regs((struct pt_regs *)regs);
349 void show_registers(struct pt_regs *regs)
351 const int field = 2 * sizeof(unsigned long);
352 mm_segment_t old_fs = get_fs();
356 printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
357 current->comm, current->pid, current_thread_info(), current,
358 field, current_thread_info()->tp_value);
359 if (cpu_has_userlocal) {
362 tls = read_c0_userlocal();
363 if (tls != current_thread_info()->tp_value)
364 printk("*HwTLS: %0*lx\n", field, tls);
367 if (!user_mode(regs))
368 /* Necessary for getting the correct stack content */
370 show_stacktrace(current, regs);
371 show_code((unsigned int __user *) regs->cp0_epc);
376 static DEFINE_RAW_SPINLOCK(die_lock);
378 void __noreturn die(const char *str, struct pt_regs *regs)
380 static int die_counter;
385 if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
386 SIGSEGV) == NOTIFY_STOP)
390 raw_spin_lock_irq(&die_lock);
393 printk("%s[#%d]:\n", str, ++die_counter);
394 show_registers(regs);
395 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
396 raw_spin_unlock_irq(&die_lock);
401 panic("Fatal exception in interrupt");
404 panic("Fatal exception");
406 if (regs && kexec_should_crash(current))
412 extern struct exception_table_entry __start___dbe_table[];
413 extern struct exception_table_entry __stop___dbe_table[];
416 " .section __dbe_table, \"a\"\n"
419 /* Given an address, look for it in the exception tables. */
420 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
422 const struct exception_table_entry *e;
424 e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
426 e = search_module_dbetables(addr);
430 asmlinkage void do_be(struct pt_regs *regs)
432 const int field = 2 * sizeof(unsigned long);
433 const struct exception_table_entry *fixup = NULL;
434 int data = regs->cp0_cause & 4;
435 int action = MIPS_BE_FATAL;
436 enum ctx_state prev_state;
438 prev_state = exception_enter();
439 /* XXX For now. Fixme, this searches the wrong table ... */
440 if (data && !user_mode(regs))
441 fixup = search_dbe_tables(exception_epc(regs));
444 action = MIPS_BE_FIXUP;
446 if (board_be_handler)
447 action = board_be_handler(regs, fixup != NULL);
450 case MIPS_BE_DISCARD:
454 regs->cp0_epc = fixup->nextinsn;
463 * Assume it would be too dangerous to continue ...
465 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
466 data ? "Data" : "Instruction",
467 field, regs->cp0_epc, field, regs->regs[31]);
468 if (notify_die(DIE_OOPS, "bus error", regs, 0, current->thread.trap_nr,
469 SIGBUS) == NOTIFY_STOP)
472 die_if_kernel("Oops", regs);
473 force_sig(SIGBUS, current);
476 exception_exit(prev_state);
480 * ll/sc, rdhwr, sync emulation
483 #define OPCODE 0xfc000000
484 #define BASE 0x03e00000
485 #define RT 0x001f0000
486 #define OFFSET 0x0000ffff
487 #define LL 0xc0000000
488 #define SC 0xe0000000
489 #define SPEC0 0x00000000
490 #define SPEC3 0x7c000000
491 #define RD 0x0000f800
492 #define FUNC 0x0000003f
493 #define SYNC 0x0000000f
494 #define RDHWR 0x0000003b
496 /* microMIPS definitions */
497 #define MM_POOL32A_FUNC 0xfc00ffff
498 #define MM_RDHWR 0x00006b3c
499 #define MM_RS 0x001f0000
500 #define MM_RT 0x03e00000
503 * The ll_bit is cleared by r*_switch.S
507 struct task_struct *ll_task;
509 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
511 unsigned long value, __user *vaddr;
515 * analyse the ll instruction that just caused a ri exception
516 * and put the referenced address to addr.
519 /* sign extend offset */
520 offset = opcode & OFFSET;
524 vaddr = (unsigned long __user *)
525 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
527 if ((unsigned long)vaddr & 3)
529 if (get_user(value, vaddr))
534 if (ll_task == NULL || ll_task == current) {
543 regs->regs[(opcode & RT) >> 16] = value;
548 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
550 unsigned long __user *vaddr;
555 * analyse the sc instruction that just caused a ri exception
556 * and put the referenced address to addr.
559 /* sign extend offset */
560 offset = opcode & OFFSET;
564 vaddr = (unsigned long __user *)
565 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
566 reg = (opcode & RT) >> 16;
568 if ((unsigned long)vaddr & 3)
573 if (ll_bit == 0 || ll_task != current) {
581 if (put_user(regs->regs[reg], vaddr))
590 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
591 * opcodes are supposed to result in coprocessor unusable exceptions if
592 * executed on ll/sc-less processors. That's the theory. In practice a
593 * few processors such as NEC's VR4100 throw reserved instruction exceptions
594 * instead, so we're doing the emulation thing in both exception handlers.
596 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
598 if ((opcode & OPCODE) == LL) {
599 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
601 return simulate_ll(regs, opcode);
603 if ((opcode & OPCODE) == SC) {
604 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
606 return simulate_sc(regs, opcode);
609 return -1; /* Must be something else ... */
613 * Simulate trapping 'rdhwr' instructions to provide user accessible
614 * registers not implemented in hardware.
616 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
618 struct thread_info *ti = task_thread_info(current);
620 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
623 case MIPS_HWR_CPUNUM: /* CPU number */
624 regs->regs[rt] = smp_processor_id();
626 case MIPS_HWR_SYNCISTEP: /* SYNCI length */
627 regs->regs[rt] = min(current_cpu_data.dcache.linesz,
628 current_cpu_data.icache.linesz);
630 case MIPS_HWR_CC: /* Read count register */
631 regs->regs[rt] = read_c0_count();
633 case MIPS_HWR_CCRES: /* Count register resolution */
634 switch (current_cpu_type()) {
643 case MIPS_HWR_ULR: /* Read UserLocal register */
644 regs->regs[rt] = ti->tp_value;
651 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
653 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
654 int rd = (opcode & RD) >> 11;
655 int rt = (opcode & RT) >> 16;
657 simulate_rdhwr(regs, rd, rt);
665 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned int opcode)
667 if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
668 int rd = (opcode & MM_RS) >> 16;
669 int rt = (opcode & MM_RT) >> 21;
670 simulate_rdhwr(regs, rd, rt);
678 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
680 if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
681 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
686 return -1; /* Must be something else ... */
689 asmlinkage void do_ov(struct pt_regs *regs)
691 enum ctx_state prev_state;
694 .si_code = FPE_INTOVF,
695 .si_addr = (void __user *)regs->cp0_epc,
698 prev_state = exception_enter();
699 die_if_kernel("Integer overflow", regs);
701 force_sig_info(SIGFPE, &info, current);
702 exception_exit(prev_state);
705 int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
707 struct siginfo si = { 0 };
708 struct vm_area_struct *vma;
715 si.si_addr = fault_addr;
718 * Inexact can happen together with Overflow or Underflow.
719 * Respect the mask to deliver the correct exception.
721 fcr31 &= (fcr31 & FPU_CSR_ALL_E) <<
722 (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E));
723 if (fcr31 & FPU_CSR_INV_X)
724 si.si_code = FPE_FLTINV;
725 else if (fcr31 & FPU_CSR_DIV_X)
726 si.si_code = FPE_FLTDIV;
727 else if (fcr31 & FPU_CSR_OVF_X)
728 si.si_code = FPE_FLTOVF;
729 else if (fcr31 & FPU_CSR_UDF_X)
730 si.si_code = FPE_FLTUND;
731 else if (fcr31 & FPU_CSR_INE_X)
732 si.si_code = FPE_FLTRES;
734 si.si_code = __SI_FAULT;
735 force_sig_info(sig, &si, current);
739 si.si_addr = fault_addr;
741 si.si_code = BUS_ADRERR;
742 force_sig_info(sig, &si, current);
746 si.si_addr = fault_addr;
748 down_read(¤t->mm->mmap_sem);
749 vma = find_vma(current->mm, (unsigned long)fault_addr);
750 if (vma && (vma->vm_start <= (unsigned long)fault_addr))
751 si.si_code = SEGV_ACCERR;
753 si.si_code = SEGV_MAPERR;
754 up_read(¤t->mm->mmap_sem);
755 force_sig_info(sig, &si, current);
759 force_sig(sig, current);
764 static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
765 unsigned long old_epc, unsigned long old_ra)
767 union mips_instruction inst = { .word = opcode };
768 void __user *fault_addr;
772 /* If it's obviously not an FP instruction, skip it */
773 switch (inst.i_format.opcode) {
787 * do_ri skipped over the instruction via compute_return_epc, undo
788 * that for the FPU emulator.
790 regs->cp0_epc = old_epc;
791 regs->regs[31] = old_ra;
793 /* Save the FP context to struct thread_struct */
796 /* Run the emulator */
797 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1,
799 fcr31 = current->thread.fpu.fcr31;
802 * We can't allow the emulated instruction to leave any of
803 * the cause bits set in $fcr31.
805 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
807 /* Restore the hardware register state */
810 /* Send a signal if required. */
811 process_fpemu_return(sig, fault_addr, fcr31);
817 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
819 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
821 enum ctx_state prev_state;
822 void __user *fault_addr;
825 prev_state = exception_enter();
826 if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
827 SIGFPE) == NOTIFY_STOP)
830 /* Clear FCSR.Cause before enabling interrupts */
831 write_32bit_cp1_register(CP1_STATUS, fcr31 & ~FPU_CSR_ALL_X);
834 die_if_kernel("FP exception in kernel code", regs);
836 if (fcr31 & FPU_CSR_UNI_X) {
838 * Unimplemented operation exception. If we've got the full
839 * software emulator on-board, let's use it...
841 * Force FPU to dump state into task/thread context. We're
842 * moving a lot of data here for what is probably a single
843 * instruction, but the alternative is to pre-decode the FP
844 * register operands before invoking the emulator, which seems
845 * a bit extreme for what should be an infrequent event.
847 /* Ensure 'resume' not overwrite saved fp context again. */
850 /* Run the emulator */
851 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1,
853 fcr31 = current->thread.fpu.fcr31;
856 * We can't allow the emulated instruction to leave any of
857 * the cause bits set in $fcr31.
859 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
861 /* Restore the hardware register state */
862 own_fpu(1); /* Using the FPU again. */
865 fault_addr = (void __user *) regs->cp0_epc;
868 /* Send a signal if required. */
869 process_fpemu_return(sig, fault_addr, fcr31);
872 exception_exit(prev_state);
875 void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code,
878 siginfo_t info = { 0 };
881 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
882 if (kgdb_ll_trap(DIE_TRAP, str, regs, code, current->thread.trap_nr,
883 SIGTRAP) == NOTIFY_STOP)
885 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
887 if (notify_die(DIE_TRAP, str, regs, code, current->thread.trap_nr,
888 SIGTRAP) == NOTIFY_STOP)
892 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
893 * insns, even for trap and break codes that indicate arithmetic
894 * failures. Weird ...
895 * But should we continue the brokenness??? --macro
900 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
901 die_if_kernel(b, regs);
902 if (code == BRK_DIVZERO)
903 info.si_code = FPE_INTDIV;
905 info.si_code = FPE_INTOVF;
906 info.si_signo = SIGFPE;
907 info.si_addr = (void __user *) regs->cp0_epc;
908 force_sig_info(SIGFPE, &info, current);
911 die_if_kernel("Kernel bug detected", regs);
912 force_sig(SIGTRAP, current);
916 * This breakpoint code is used by the FPU emulator to retake
917 * control of the CPU after executing the instruction from the
918 * delay slot of an emulated branch.
920 * Terminate if exception was recognized as a delay slot return
921 * otherwise handle as normal.
923 if (do_dsemulret(regs))
926 die_if_kernel("Math emu break/trap", regs);
927 force_sig(SIGTRAP, current);
930 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
931 die_if_kernel(b, regs);
933 info.si_signo = SIGTRAP;
934 info.si_code = si_code;
935 force_sig_info(SIGTRAP, &info, current);
937 force_sig(SIGTRAP, current);
942 asmlinkage void do_bp(struct pt_regs *regs)
944 unsigned long epc = msk_isa16_mode(exception_epc(regs));
945 unsigned int opcode, bcode;
946 enum ctx_state prev_state;
950 if (!user_mode(regs))
953 prev_state = exception_enter();
954 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
955 if (get_isa16_mode(regs->cp0_epc)) {
958 if (__get_user(instr[0], (u16 __user *)epc))
961 if (!cpu_has_mmips) {
963 bcode = (instr[0] >> 5) & 0x3f;
964 } else if (mm_insn_16bit(instr[0])) {
965 /* 16-bit microMIPS BREAK */
966 bcode = instr[0] & 0xf;
968 /* 32-bit microMIPS BREAK */
969 if (__get_user(instr[1], (u16 __user *)(epc + 2)))
971 opcode = (instr[0] << 16) | instr[1];
972 bcode = (opcode >> 6) & ((1 << 20) - 1);
975 if (__get_user(opcode, (unsigned int __user *)epc))
977 bcode = (opcode >> 6) & ((1 << 20) - 1);
981 * There is the ancient bug in the MIPS assemblers that the break
982 * code starts left to bit 16 instead to bit 6 in the opcode.
983 * Gas is bug-compatible, but not always, grrr...
984 * We handle both cases with a simple heuristics. --macro
986 if (bcode >= (1 << 10))
987 bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10);
990 * notify the kprobe handlers, if instruction is likely to
995 if (notify_die(DIE_UPROBE, "uprobe", regs, bcode,
996 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1000 case BRK_UPROBE_XOL:
1001 if (notify_die(DIE_UPROBE_XOL, "uprobe_xol", regs, bcode,
1002 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1007 if (notify_die(DIE_BREAK, "debug", regs, bcode,
1008 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1012 case BRK_KPROBE_SSTEPBP:
1013 if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
1014 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1022 do_trap_or_bp(regs, bcode, TRAP_BRKPT, "Break");
1026 exception_exit(prev_state);
1030 force_sig(SIGSEGV, current);
1034 asmlinkage void do_tr(struct pt_regs *regs)
1036 u32 opcode, tcode = 0;
1037 enum ctx_state prev_state;
1040 unsigned long epc = msk_isa16_mode(exception_epc(regs));
1043 if (!user_mode(regs))
1046 prev_state = exception_enter();
1047 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1048 if (get_isa16_mode(regs->cp0_epc)) {
1049 if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
1050 __get_user(instr[1], (u16 __user *)(epc + 2)))
1052 opcode = (instr[0] << 16) | instr[1];
1053 /* Immediate versions don't provide a code. */
1054 if (!(opcode & OPCODE))
1055 tcode = (opcode >> 12) & ((1 << 4) - 1);
1057 if (__get_user(opcode, (u32 __user *)epc))
1059 /* Immediate versions don't provide a code. */
1060 if (!(opcode & OPCODE))
1061 tcode = (opcode >> 6) & ((1 << 10) - 1);
1064 do_trap_or_bp(regs, tcode, 0, "Trap");
1068 exception_exit(prev_state);
1072 force_sig(SIGSEGV, current);
1076 asmlinkage void do_ri(struct pt_regs *regs)
1078 unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
1079 unsigned long old_epc = regs->cp0_epc;
1080 unsigned long old31 = regs->regs[31];
1081 enum ctx_state prev_state;
1082 unsigned int opcode = 0;
1086 * Avoid any kernel code. Just emulate the R2 instruction
1087 * as quickly as possible.
1089 if (mipsr2_emulation && cpu_has_mips_r6 &&
1090 likely(user_mode(regs)) &&
1091 likely(get_user(opcode, epc) >= 0)) {
1092 unsigned long fcr31 = 0;
1094 status = mipsr2_decoder(regs, opcode, &fcr31);
1098 task_thread_info(current)->r2_emul_return = 1;
1103 process_fpemu_return(status,
1104 ¤t->thread.cp0_baduaddr,
1106 task_thread_info(current)->r2_emul_return = 1;
1113 prev_state = exception_enter();
1114 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1116 if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
1117 SIGILL) == NOTIFY_STOP)
1120 die_if_kernel("Reserved instruction in kernel code", regs);
1122 if (unlikely(compute_return_epc(regs) < 0))
1125 if (!get_isa16_mode(regs->cp0_epc)) {
1126 if (unlikely(get_user(opcode, epc) < 0))
1129 if (!cpu_has_llsc && status < 0)
1130 status = simulate_llsc(regs, opcode);
1133 status = simulate_rdhwr_normal(regs, opcode);
1136 status = simulate_sync(regs, opcode);
1139 status = simulate_fp(regs, opcode, old_epc, old31);
1140 } else if (cpu_has_mmips) {
1141 unsigned short mmop[2] = { 0 };
1143 if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
1145 if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
1148 opcode = (opcode << 16) | mmop[1];
1151 status = simulate_rdhwr_mm(regs, opcode);
1157 if (unlikely(status > 0)) {
1158 regs->cp0_epc = old_epc; /* Undo skip-over. */
1159 regs->regs[31] = old31;
1160 force_sig(status, current);
1164 exception_exit(prev_state);
1168 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1169 * emulated more than some threshold number of instructions, force migration to
1170 * a "CPU" that has FP support.
1172 static void mt_ase_fp_affinity(void)
1174 #ifdef CONFIG_MIPS_MT_FPAFF
1175 if (mt_fpemul_threshold > 0 &&
1176 ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1178 * If there's no FPU present, or if the application has already
1179 * restricted the allowed set to exclude any CPUs with FPUs,
1180 * we'll skip the procedure.
1182 if (cpumask_intersects(¤t->cpus_allowed, &mt_fpu_cpumask)) {
1185 current->thread.user_cpus_allowed
1186 = current->cpus_allowed;
1187 cpumask_and(&tmask, ¤t->cpus_allowed,
1189 set_cpus_allowed_ptr(current, &tmask);
1190 set_thread_flag(TIF_FPUBOUND);
1193 #endif /* CONFIG_MIPS_MT_FPAFF */
1197 * No lock; only written during early bootup by CPU 0.
1199 static RAW_NOTIFIER_HEAD(cu2_chain);
1201 int __ref register_cu2_notifier(struct notifier_block *nb)
1203 return raw_notifier_chain_register(&cu2_chain, nb);
1206 int cu2_notifier_call_chain(unsigned long val, void *v)
1208 return raw_notifier_call_chain(&cu2_chain, val, v);
1211 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1214 struct pt_regs *regs = data;
1216 die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1217 "instruction", regs);
1218 force_sig(SIGILL, current);
1223 static int wait_on_fp_mode_switch(atomic_t *p)
1226 * The FP mode for this task is currently being switched. That may
1227 * involve modifications to the format of this tasks FP context which
1228 * make it unsafe to proceed with execution for the moment. Instead,
1229 * schedule some other task.
1235 static int enable_restore_fp_context(int msa)
1237 int err, was_fpu_owner, prior_msa;
1240 * If an FP mode switch is currently underway, wait for it to
1241 * complete before proceeding.
1243 wait_on_atomic_t(¤t->mm->context.fp_mode_switching,
1244 wait_on_fp_mode_switch, TASK_KILLABLE);
1247 /* First time FP context user. */
1253 set_thread_flag(TIF_USEDMSA);
1254 set_thread_flag(TIF_MSA_CTX_LIVE);
1263 * This task has formerly used the FP context.
1265 * If this thread has no live MSA vector context then we can simply
1266 * restore the scalar FP context. If it has live MSA vector context
1267 * (that is, it has or may have used MSA since last performing a
1268 * function call) then we'll need to restore the vector context. This
1269 * applies even if we're currently only executing a scalar FP
1270 * instruction. This is because if we were to later execute an MSA
1271 * instruction then we'd either have to:
1273 * - Restore the vector context & clobber any registers modified by
1274 * scalar FP instructions between now & then.
1278 * - Not restore the vector context & lose the most significant bits
1279 * of all vector registers.
1281 * Neither of those options is acceptable. We cannot restore the least
1282 * significant bits of the registers now & only restore the most
1283 * significant bits later because the most significant bits of any
1284 * vector registers whose aliased FP register is modified now will have
1285 * been zeroed. We'd have no way to know that when restoring the vector
1286 * context & thus may load an outdated value for the most significant
1287 * bits of a vector register.
1289 if (!msa && !thread_msa_context_live())
1293 * This task is using or has previously used MSA. Thus we require
1294 * that Status.FR == 1.
1297 was_fpu_owner = is_fpu_owner();
1298 err = own_fpu_inatomic(0);
1303 write_msa_csr(current->thread.fpu.msacsr);
1304 set_thread_flag(TIF_USEDMSA);
1307 * If this is the first time that the task is using MSA and it has
1308 * previously used scalar FP in this time slice then we already nave
1309 * FP context which we shouldn't clobber. We do however need to clear
1310 * the upper 64b of each vector register so that this task has no
1311 * opportunity to see data left behind by another.
1313 prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
1314 if (!prior_msa && was_fpu_owner) {
1322 * Restore the least significant 64b of each vector register
1323 * from the existing scalar FP context.
1325 _restore_fp(current);
1328 * The task has not formerly used MSA, so clear the upper 64b
1329 * of each vector register such that it cannot see data left
1330 * behind by another task.
1334 /* We need to restore the vector context. */
1335 restore_msa(current);
1337 /* Restore the scalar FP control & status register */
1339 write_32bit_cp1_register(CP1_STATUS,
1340 current->thread.fpu.fcr31);
1349 asmlinkage void do_cpu(struct pt_regs *regs)
1351 enum ctx_state prev_state;
1352 unsigned int __user *epc;
1353 unsigned long old_epc, old31;
1354 void __user *fault_addr;
1355 unsigned int opcode;
1356 unsigned long fcr31;
1361 prev_state = exception_enter();
1362 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1365 die_if_kernel("do_cpu invoked from kernel context!", regs);
1369 epc = (unsigned int __user *)exception_epc(regs);
1370 old_epc = regs->cp0_epc;
1371 old31 = regs->regs[31];
1375 if (unlikely(compute_return_epc(regs) < 0))
1378 if (!get_isa16_mode(regs->cp0_epc)) {
1379 if (unlikely(get_user(opcode, epc) < 0))
1382 if (!cpu_has_llsc && status < 0)
1383 status = simulate_llsc(regs, opcode);
1389 if (unlikely(status > 0)) {
1390 regs->cp0_epc = old_epc; /* Undo skip-over. */
1391 regs->regs[31] = old31;
1392 force_sig(status, current);
1399 * The COP3 opcode space and consequently the CP0.Status.CU3
1400 * bit and the CP0.Cause.CE=3 encoding have been removed as
1401 * of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs
1402 * up the space has been reused for COP1X instructions, that
1403 * are enabled by the CP0.Status.CU1 bit and consequently
1404 * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
1405 * exceptions. Some FPU-less processors that implement one
1406 * of these ISAs however use this code erroneously for COP1X
1407 * instructions. Therefore we redirect this trap to the FP
1410 if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
1411 force_sig(SIGILL, current);
1417 err = enable_restore_fp_context(0);
1419 if (raw_cpu_has_fpu && !err)
1422 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 0,
1424 fcr31 = current->thread.fpu.fcr31;
1427 * We can't allow the emulated instruction to leave
1428 * any of the cause bits set in $fcr31.
1430 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
1432 /* Send a signal if required. */
1433 if (!process_fpemu_return(sig, fault_addr, fcr31) && !err)
1434 mt_ase_fp_affinity();
1439 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1443 exception_exit(prev_state);
1446 asmlinkage void do_msa_fpe(struct pt_regs *regs, unsigned int msacsr)
1448 enum ctx_state prev_state;
1450 prev_state = exception_enter();
1451 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1452 if (notify_die(DIE_MSAFP, "MSA FP exception", regs, 0,
1453 current->thread.trap_nr, SIGFPE) == NOTIFY_STOP)
1456 /* Clear MSACSR.Cause before enabling interrupts */
1457 write_msa_csr(msacsr & ~MSA_CSR_CAUSEF);
1460 die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
1461 force_sig(SIGFPE, current);
1463 exception_exit(prev_state);
1466 asmlinkage void do_msa(struct pt_regs *regs)
1468 enum ctx_state prev_state;
1471 prev_state = exception_enter();
1473 if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
1474 force_sig(SIGILL, current);
1478 die_if_kernel("do_msa invoked from kernel context!", regs);
1480 err = enable_restore_fp_context(1);
1482 force_sig(SIGILL, current);
1484 exception_exit(prev_state);
1487 asmlinkage void do_mdmx(struct pt_regs *regs)
1489 enum ctx_state prev_state;
1491 prev_state = exception_enter();
1492 force_sig(SIGILL, current);
1493 exception_exit(prev_state);
1497 * Called with interrupts disabled.
1499 asmlinkage void do_watch(struct pt_regs *regs)
1501 siginfo_t info = { .si_signo = SIGTRAP, .si_code = TRAP_HWBKPT };
1502 enum ctx_state prev_state;
1504 prev_state = exception_enter();
1506 * Clear WP (bit 22) bit of cause register so we don't loop
1509 clear_c0_cause(CAUSEF_WP);
1512 * If the current thread has the watch registers loaded, save
1513 * their values and send SIGTRAP. Otherwise another thread
1514 * left the registers set, clear them and continue.
1516 if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1517 mips_read_watch_registers();
1519 force_sig_info(SIGTRAP, &info, current);
1521 mips_clear_watch_registers();
1524 exception_exit(prev_state);
1527 asmlinkage void do_mcheck(struct pt_regs *regs)
1529 int multi_match = regs->cp0_status & ST0_TS;
1530 enum ctx_state prev_state;
1531 mm_segment_t old_fs = get_fs();
1533 prev_state = exception_enter();
1542 if (!user_mode(regs))
1545 show_code((unsigned int __user *) regs->cp0_epc);
1550 * Some chips may have other causes of machine check (e.g. SB1
1553 panic("Caught Machine Check exception - %scaused by multiple "
1554 "matching entries in the TLB.",
1555 (multi_match) ? "" : "not ");
1558 asmlinkage void do_mt(struct pt_regs *regs)
1562 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1563 >> VPECONTROL_EXCPT_SHIFT;
1566 printk(KERN_DEBUG "Thread Underflow\n");
1569 printk(KERN_DEBUG "Thread Overflow\n");
1572 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1575 printk(KERN_DEBUG "Gating Storage Exception\n");
1578 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1581 printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1584 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1588 die_if_kernel("MIPS MT Thread exception in kernel", regs);
1590 force_sig(SIGILL, current);
1594 asmlinkage void do_dsp(struct pt_regs *regs)
1597 panic("Unexpected DSP exception");
1599 force_sig(SIGILL, current);
1602 asmlinkage void do_reserved(struct pt_regs *regs)
1605 * Game over - no way to handle this if it ever occurs. Most probably
1606 * caused by a new unknown cpu type or after another deadly
1607 * hard/software error.
1610 panic("Caught reserved exception %ld - should not happen.",
1611 (regs->cp0_cause & 0x7f) >> 2);
1614 static int __initdata l1parity = 1;
1615 static int __init nol1parity(char *s)
1620 __setup("nol1par", nol1parity);
1621 static int __initdata l2parity = 1;
1622 static int __init nol2parity(char *s)
1627 __setup("nol2par", nol2parity);
1630 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1631 * it different ways.
1633 static inline void parity_protection_init(void)
1635 switch (current_cpu_type()) {
1641 case CPU_INTERAPTIV:
1644 case CPU_QEMU_GENERIC:
1648 #define ERRCTL_PE 0x80000000
1649 #define ERRCTL_L2P 0x00800000
1650 unsigned long errctl;
1651 unsigned int l1parity_present, l2parity_present;
1653 errctl = read_c0_ecc();
1654 errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1656 /* probe L1 parity support */
1657 write_c0_ecc(errctl | ERRCTL_PE);
1658 back_to_back_c0_hazard();
1659 l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1661 /* probe L2 parity support */
1662 write_c0_ecc(errctl|ERRCTL_L2P);
1663 back_to_back_c0_hazard();
1664 l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1666 if (l1parity_present && l2parity_present) {
1668 errctl |= ERRCTL_PE;
1669 if (l1parity ^ l2parity)
1670 errctl |= ERRCTL_L2P;
1671 } else if (l1parity_present) {
1673 errctl |= ERRCTL_PE;
1674 } else if (l2parity_present) {
1676 errctl |= ERRCTL_L2P;
1678 /* No parity available */
1681 printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1683 write_c0_ecc(errctl);
1684 back_to_back_c0_hazard();
1685 errctl = read_c0_ecc();
1686 printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1688 if (l1parity_present)
1689 printk(KERN_INFO "Cache parity protection %sabled\n",
1690 (errctl & ERRCTL_PE) ? "en" : "dis");
1692 if (l2parity_present) {
1693 if (l1parity_present && l1parity)
1694 errctl ^= ERRCTL_L2P;
1695 printk(KERN_INFO "L2 cache parity protection %sabled\n",
1696 (errctl & ERRCTL_L2P) ? "en" : "dis");
1704 write_c0_ecc(0x80000000);
1705 back_to_back_c0_hazard();
1706 /* Set the PE bit (bit 31) in the c0_errctl register. */
1707 printk(KERN_INFO "Cache parity protection %sabled\n",
1708 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1712 /* Clear the DE bit (bit 16) in the c0_status register. */
1713 printk(KERN_INFO "Enable cache parity protection for "
1714 "MIPS 20KC/25KF CPUs.\n");
1715 clear_c0_status(ST0_DE);
1722 asmlinkage void cache_parity_error(void)
1724 const int field = 2 * sizeof(unsigned long);
1725 unsigned int reg_val;
1727 /* For the moment, report the problem and hang. */
1728 printk("Cache error exception:\n");
1729 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1730 reg_val = read_c0_cacheerr();
1731 printk("c0_cacheerr == %08x\n", reg_val);
1733 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1734 reg_val & (1<<30) ? "secondary" : "primary",
1735 reg_val & (1<<31) ? "data" : "insn");
1736 if ((cpu_has_mips_r2_r6) &&
1737 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1738 pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1739 reg_val & (1<<29) ? "ED " : "",
1740 reg_val & (1<<28) ? "ET " : "",
1741 reg_val & (1<<27) ? "ES " : "",
1742 reg_val & (1<<26) ? "EE " : "",
1743 reg_val & (1<<25) ? "EB " : "",
1744 reg_val & (1<<24) ? "EI " : "",
1745 reg_val & (1<<23) ? "E1 " : "",
1746 reg_val & (1<<22) ? "E0 " : "");
1748 pr_err("Error bits: %s%s%s%s%s%s%s\n",
1749 reg_val & (1<<29) ? "ED " : "",
1750 reg_val & (1<<28) ? "ET " : "",
1751 reg_val & (1<<26) ? "EE " : "",
1752 reg_val & (1<<25) ? "EB " : "",
1753 reg_val & (1<<24) ? "EI " : "",
1754 reg_val & (1<<23) ? "E1 " : "",
1755 reg_val & (1<<22) ? "E0 " : "");
1757 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1759 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1760 if (reg_val & (1<<22))
1761 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1763 if (reg_val & (1<<23))
1764 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1767 panic("Can't handle the cache error!");
1770 asmlinkage void do_ftlb(void)
1772 const int field = 2 * sizeof(unsigned long);
1773 unsigned int reg_val;
1775 /* For the moment, report the problem and hang. */
1776 if ((cpu_has_mips_r2_r6) &&
1777 (((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS) ||
1778 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_LOONGSON))) {
1779 pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1781 pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1782 reg_val = read_c0_cacheerr();
1783 pr_err("c0_cacheerr == %08x\n", reg_val);
1785 if ((reg_val & 0xc0000000) == 0xc0000000) {
1786 pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1788 pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1789 reg_val & (1<<30) ? "secondary" : "primary",
1790 reg_val & (1<<31) ? "data" : "insn");
1793 pr_err("FTLB error exception\n");
1795 /* Just print the cacheerr bits for now */
1796 cache_parity_error();
1800 * SDBBP EJTAG debug exception handler.
1801 * We skip the instruction and return to the next instruction.
1803 void ejtag_exception_handler(struct pt_regs *regs)
1805 const int field = 2 * sizeof(unsigned long);
1806 unsigned long depc, old_epc, old_ra;
1809 printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1810 depc = read_c0_depc();
1811 debug = read_c0_debug();
1812 printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1813 if (debug & 0x80000000) {
1815 * In branch delay slot.
1816 * We cheat a little bit here and use EPC to calculate the
1817 * debug return address (DEPC). EPC is restored after the
1820 old_epc = regs->cp0_epc;
1821 old_ra = regs->regs[31];
1822 regs->cp0_epc = depc;
1823 compute_return_epc(regs);
1824 depc = regs->cp0_epc;
1825 regs->cp0_epc = old_epc;
1826 regs->regs[31] = old_ra;
1829 write_c0_depc(depc);
1832 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1833 write_c0_debug(debug | 0x100);
1838 * NMI exception handler.
1839 * No lock; only written during early bootup by CPU 0.
1841 static RAW_NOTIFIER_HEAD(nmi_chain);
1843 int register_nmi_notifier(struct notifier_block *nb)
1845 return raw_notifier_chain_register(&nmi_chain, nb);
1848 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1853 raw_notifier_call_chain(&nmi_chain, 0, regs);
1855 snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1856 smp_processor_id(), regs->cp0_epc);
1857 regs->cp0_epc = read_c0_errorepc();
1862 #define VECTORSPACING 0x100 /* for EI/VI mode */
1864 unsigned long ebase;
1865 EXPORT_SYMBOL_GPL(ebase);
1866 unsigned long exception_handlers[32];
1867 unsigned long vi_handlers[64];
1869 void __init *set_except_vector(int n, void *addr)
1871 unsigned long handler = (unsigned long) addr;
1872 unsigned long old_handler;
1874 #ifdef CONFIG_CPU_MICROMIPS
1876 * Only the TLB handlers are cache aligned with an even
1877 * address. All other handlers are on an odd address and
1878 * require no modification. Otherwise, MIPS32 mode will
1879 * be entered when handling any TLB exceptions. That
1880 * would be bad...since we must stay in microMIPS mode.
1882 if (!(handler & 0x1))
1885 old_handler = xchg(&exception_handlers[n], handler);
1887 if (n == 0 && cpu_has_divec) {
1888 #ifdef CONFIG_CPU_MICROMIPS
1889 unsigned long jump_mask = ~((1 << 27) - 1);
1891 unsigned long jump_mask = ~((1 << 28) - 1);
1893 u32 *buf = (u32 *)(ebase + 0x200);
1894 unsigned int k0 = 26;
1895 if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1896 uasm_i_j(&buf, handler & ~jump_mask);
1899 UASM_i_LA(&buf, k0, handler);
1900 uasm_i_jr(&buf, k0);
1903 local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1905 return (void *)old_handler;
1908 static void do_default_vi(void)
1910 show_regs(get_irq_regs());
1911 panic("Caught unexpected vectored interrupt.");
1914 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1916 unsigned long handler;
1917 unsigned long old_handler = vi_handlers[n];
1918 int srssets = current_cpu_data.srsets;
1922 BUG_ON(!cpu_has_veic && !cpu_has_vint);
1925 handler = (unsigned long) do_default_vi;
1928 handler = (unsigned long) addr;
1929 vi_handlers[n] = handler;
1931 b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1934 panic("Shadow register set %d not supported", srs);
1937 if (board_bind_eic_interrupt)
1938 board_bind_eic_interrupt(n, srs);
1939 } else if (cpu_has_vint) {
1940 /* SRSMap is only defined if shadow sets are implemented */
1942 change_c0_srsmap(0xf << n*4, srs << n*4);
1947 * If no shadow set is selected then use the default handler
1948 * that does normal register saving and standard interrupt exit
1950 extern char except_vec_vi, except_vec_vi_lui;
1951 extern char except_vec_vi_ori, except_vec_vi_end;
1952 extern char rollback_except_vec_vi;
1953 char *vec_start = using_rollback_handler() ?
1954 &rollback_except_vec_vi : &except_vec_vi;
1955 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1956 const int lui_offset = &except_vec_vi_lui - vec_start + 2;
1957 const int ori_offset = &except_vec_vi_ori - vec_start + 2;
1959 const int lui_offset = &except_vec_vi_lui - vec_start;
1960 const int ori_offset = &except_vec_vi_ori - vec_start;
1962 const int handler_len = &except_vec_vi_end - vec_start;
1964 if (handler_len > VECTORSPACING) {
1966 * Sigh... panicing won't help as the console
1967 * is probably not configured :(
1969 panic("VECTORSPACING too small");
1972 set_handler(((unsigned long)b - ebase), vec_start,
1973 #ifdef CONFIG_CPU_MICROMIPS
1978 h = (u16 *)(b + lui_offset);
1979 *h = (handler >> 16) & 0xffff;
1980 h = (u16 *)(b + ori_offset);
1981 *h = (handler & 0xffff);
1982 local_flush_icache_range((unsigned long)b,
1983 (unsigned long)(b+handler_len));
1987 * In other cases jump directly to the interrupt handler. It
1988 * is the handler's responsibility to save registers if required
1989 * (eg hi/lo) and return from the exception using "eret".
1995 #ifdef CONFIG_CPU_MICROMIPS
1996 insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
1998 insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
2000 h[0] = (insn >> 16) & 0xffff;
2001 h[1] = insn & 0xffff;
2004 local_flush_icache_range((unsigned long)b,
2005 (unsigned long)(b+8));
2008 return (void *)old_handler;
2011 void *set_vi_handler(int n, vi_handler_t addr)
2013 return set_vi_srs_handler(n, addr, 0);
2016 extern void tlb_init(void);
2021 int cp0_compare_irq;
2022 EXPORT_SYMBOL_GPL(cp0_compare_irq);
2023 int cp0_compare_irq_shift;
2026 * Performance counter IRQ or -1 if shared with timer
2028 int cp0_perfcount_irq;
2029 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
2032 * Fast debug channel IRQ or -1 if not present
2035 EXPORT_SYMBOL_GPL(cp0_fdc_irq);
2039 static int __init ulri_disable(char *s)
2041 pr_info("Disabling ulri\n");
2046 __setup("noulri", ulri_disable);
2048 /* configure STATUS register */
2049 static void configure_status(void)
2052 * Disable coprocessors and select 32-bit or 64-bit addressing
2053 * and the 16/32 or 32/32 FPR register model. Reset the BEV
2054 * flag that some firmware may have left set and the TS bit (for
2055 * IP27). Set XX for ISA IV code to work.
2057 unsigned int status_set = ST0_CU0;
2059 status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
2061 if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
2062 status_set |= ST0_XX;
2064 status_set |= ST0_MX;
2066 change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
2070 unsigned int hwrena;
2071 EXPORT_SYMBOL_GPL(hwrena);
2073 /* configure HWRENA register */
2074 static void configure_hwrena(void)
2076 hwrena = cpu_hwrena_impl_bits;
2078 if (cpu_has_mips_r2_r6)
2079 hwrena |= MIPS_HWRENA_CPUNUM |
2080 MIPS_HWRENA_SYNCISTEP |
2084 if (!noulri && cpu_has_userlocal)
2085 hwrena |= MIPS_HWRENA_ULR;
2088 write_c0_hwrena(hwrena);
2091 static void configure_exception_vector(void)
2093 if (cpu_has_veic || cpu_has_vint) {
2094 unsigned long sr = set_c0_status(ST0_BEV);
2095 write_c0_ebase(ebase);
2096 write_c0_status(sr);
2097 /* Setting vector spacing enables EI/VI mode */
2098 change_c0_intctl(0x3e0, VECTORSPACING);
2100 if (cpu_has_divec) {
2101 if (cpu_has_mipsmt) {
2102 unsigned int vpflags = dvpe();
2103 set_c0_cause(CAUSEF_IV);
2106 set_c0_cause(CAUSEF_IV);
2110 void per_cpu_trap_init(bool is_boot_cpu)
2112 unsigned int cpu = smp_processor_id();
2117 configure_exception_vector();
2120 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
2122 * o read IntCtl.IPTI to determine the timer interrupt
2123 * o read IntCtl.IPPCI to determine the performance counter interrupt
2124 * o read IntCtl.IPFDC to determine the fast debug channel interrupt
2126 if (cpu_has_mips_r2_r6) {
2128 * We shouldn't trust a secondary core has a sane EBASE register
2129 * so use the one calculated by the boot CPU.
2132 write_c0_ebase(ebase);
2134 cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
2135 cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
2136 cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
2137 cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7;
2142 cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
2143 cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
2144 cp0_perfcount_irq = -1;
2148 if (!cpu_data[cpu].asid_cache)
2149 cpu_data[cpu].asid_cache = asid_first_version(cpu);
2151 atomic_inc(&init_mm.mm_count);
2152 current->active_mm = &init_mm;
2153 BUG_ON(current->mm);
2154 enter_lazy_tlb(&init_mm, current);
2156 /* Boot CPU's cache setup in setup_arch(). */
2160 TLBMISS_HANDLER_SETUP();
2163 /* Install CPU exception handler */
2164 void set_handler(unsigned long offset, void *addr, unsigned long size)
2166 #ifdef CONFIG_CPU_MICROMIPS
2167 memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
2169 memcpy((void *)(ebase + offset), addr, size);
2171 local_flush_icache_range(ebase + offset, ebase + offset + size);
2174 static char panic_null_cerr[] =
2175 "Trying to set NULL cache error exception handler";
2178 * Install uncached CPU exception handler.
2179 * This is suitable only for the cache error exception which is the only
2180 * exception handler that is being run uncached.
2182 void set_uncached_handler(unsigned long offset, void *addr,
2185 unsigned long uncached_ebase = CKSEG1ADDR(ebase);
2188 panic(panic_null_cerr);
2190 memcpy((void *)(uncached_ebase + offset), addr, size);
2193 static int __initdata rdhwr_noopt;
2194 static int __init set_rdhwr_noopt(char *str)
2200 __setup("rdhwr_noopt", set_rdhwr_noopt);
2202 void __init trap_init(void)
2204 extern char except_vec3_generic;
2205 extern char except_vec4;
2206 extern char except_vec3_r4000;
2211 if (cpu_has_veic || cpu_has_vint) {
2212 unsigned long size = 0x200 + VECTORSPACING*64;
2213 phys_addr_t ebase_pa;
2215 ebase = (unsigned long)
2216 __alloc_bootmem(size, 1 << fls(size), 0);
2219 * Try to ensure ebase resides in KSeg0 if possible.
2221 * It shouldn't generally be in XKPhys on MIPS64 to avoid
2222 * hitting a poorly defined exception base for Cache Errors.
2223 * The allocation is likely to be in the low 512MB of physical,
2224 * in which case we should be able to convert to KSeg0.
2226 * EVA is special though as it allows segments to be rearranged
2227 * and to become uncached during cache error handling.
2229 ebase_pa = __pa(ebase);
2230 if (!IS_ENABLED(CONFIG_EVA) && !WARN_ON(ebase_pa >= 0x20000000))
2231 ebase = CKSEG0ADDR(ebase_pa);
2235 if (cpu_has_mips_r2_r6) {
2236 if (cpu_has_ebase_wg) {
2238 ebase = (read_c0_ebase_64() & ~0xfff);
2240 ebase = (read_c0_ebase() & ~0xfff);
2243 ebase += (read_c0_ebase() & 0x3ffff000);
2248 if (cpu_has_mmips) {
2249 unsigned int config3 = read_c0_config3();
2251 if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
2252 write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
2254 write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
2257 if (board_ebase_setup)
2258 board_ebase_setup();
2259 per_cpu_trap_init(true);
2262 * Copy the generic exception handlers to their final destination.
2263 * This will be overridden later as suitable for a particular
2266 set_handler(0x180, &except_vec3_generic, 0x80);
2269 * Setup default vectors
2271 for (i = 0; i <= 31; i++)
2272 set_except_vector(i, handle_reserved);
2275 * Copy the EJTAG debug exception vector handler code to it's final
2278 if (cpu_has_ejtag && board_ejtag_handler_setup)
2279 board_ejtag_handler_setup();
2282 * Only some CPUs have the watch exceptions.
2285 set_except_vector(EXCCODE_WATCH, handle_watch);
2288 * Initialise interrupt handlers
2290 if (cpu_has_veic || cpu_has_vint) {
2291 int nvec = cpu_has_veic ? 64 : 8;
2292 for (i = 0; i < nvec; i++)
2293 set_vi_handler(i, NULL);
2295 else if (cpu_has_divec)
2296 set_handler(0x200, &except_vec4, 0x8);
2299 * Some CPUs can enable/disable for cache parity detection, but does
2300 * it different ways.
2302 parity_protection_init();
2305 * The Data Bus Errors / Instruction Bus Errors are signaled
2306 * by external hardware. Therefore these two exceptions
2307 * may have board specific handlers.
2312 set_except_vector(EXCCODE_INT, using_rollback_handler() ?
2313 rollback_handle_int : handle_int);
2314 set_except_vector(EXCCODE_MOD, handle_tlbm);
2315 set_except_vector(EXCCODE_TLBL, handle_tlbl);
2316 set_except_vector(EXCCODE_TLBS, handle_tlbs);
2318 set_except_vector(EXCCODE_ADEL, handle_adel);
2319 set_except_vector(EXCCODE_ADES, handle_ades);
2321 set_except_vector(EXCCODE_IBE, handle_ibe);
2322 set_except_vector(EXCCODE_DBE, handle_dbe);
2324 set_except_vector(EXCCODE_SYS, handle_sys);
2325 set_except_vector(EXCCODE_BP, handle_bp);
2326 set_except_vector(EXCCODE_RI, rdhwr_noopt ? handle_ri :
2327 (cpu_has_vtag_icache ?
2328 handle_ri_rdhwr_vivt : handle_ri_rdhwr));
2329 set_except_vector(EXCCODE_CPU, handle_cpu);
2330 set_except_vector(EXCCODE_OV, handle_ov);
2331 set_except_vector(EXCCODE_TR, handle_tr);
2332 set_except_vector(EXCCODE_MSAFPE, handle_msa_fpe);
2334 if (current_cpu_type() == CPU_R6000 ||
2335 current_cpu_type() == CPU_R6000A) {
2337 * The R6000 is the only R-series CPU that features a machine
2338 * check exception (similar to the R4000 cache error) and
2339 * unaligned ldc1/sdc1 exception. The handlers have not been
2340 * written yet. Well, anyway there is no R6000 machine on the
2341 * current list of targets for Linux/MIPS.
2342 * (Duh, crap, there is someone with a triple R6k machine)
2344 //set_except_vector(14, handle_mc);
2345 //set_except_vector(15, handle_ndc);
2349 if (board_nmi_handler_setup)
2350 board_nmi_handler_setup();
2352 if (cpu_has_fpu && !cpu_has_nofpuex)
2353 set_except_vector(EXCCODE_FPE, handle_fpe);
2355 set_except_vector(MIPS_EXCCODE_TLBPAR, handle_ftlb);
2357 if (cpu_has_rixiex) {
2358 set_except_vector(EXCCODE_TLBRI, tlb_do_page_fault_0);
2359 set_except_vector(EXCCODE_TLBXI, tlb_do_page_fault_0);
2362 set_except_vector(EXCCODE_MSADIS, handle_msa);
2363 set_except_vector(EXCCODE_MDMX, handle_mdmx);
2366 set_except_vector(EXCCODE_MCHECK, handle_mcheck);
2369 set_except_vector(EXCCODE_THREAD, handle_mt);
2371 set_except_vector(EXCCODE_DSPDIS, handle_dsp);
2373 if (board_cache_error_setup)
2374 board_cache_error_setup();
2377 /* Special exception: R4[04]00 uses also the divec space. */
2378 set_handler(0x180, &except_vec3_r4000, 0x100);
2379 else if (cpu_has_4kex)
2380 set_handler(0x180, &except_vec3_generic, 0x80);
2382 set_handler(0x080, &except_vec3_generic, 0x80);
2384 local_flush_icache_range(ebase, ebase + 0x400);
2386 sort_extable(__start___dbe_table, __stop___dbe_table);
2388 cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
2391 static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
2395 case CPU_PM_ENTER_FAILED:
2399 configure_exception_vector();
2401 /* Restore register with CPU number for TLB handlers */
2402 TLBMISS_HANDLER_RESTORE();
2410 static struct notifier_block trap_pm_notifier_block = {
2411 .notifier_call = trap_pm_notifier,
2414 static int __init trap_pm_init(void)
2416 return cpu_pm_register_notifier(&trap_pm_notifier_block);
2418 arch_initcall(trap_pm_init);