/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (C) 1994 - 1999, 2000, 01, 06 Ralf Baechle * Copyright (C) 1995, 1996 Paul M. Antoine * Copyright (C) 1998 Ulf Carlsson * Copyright (C) 1999 Silicon Graphics, Inc. * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com * Copyright (C) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki * Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc. All rights reserved. * Copyright (C) 2014, Imagination Technologies Ltd. */ #include <linux/bitops.h> #include <linux/bug.h> #include <linux/compiler.h> #include <linux/context_tracking.h> #include <linux/cpu_pm.h> #include <linux/kexec.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/mm.h> #include <linux/sched.h> #include <linux/smp.h> #include <linux/spinlock.h> #include <linux/kallsyms.h> #include <linux/bootmem.h> #include <linux/interrupt.h> #include <linux/ptrace.h> #include <linux/kgdb.h> #include <linux/kdebug.h> #include <linux/kprobes.h> #include <linux/notifier.h> #include <linux/kdb.h> #include <linux/irq.h> #include <linux/perf_event.h> #include <asm/bootinfo.h> #include <asm/branch.h> #include <asm/break.h> #include <asm/cop2.h> #include <asm/cpu.h> #include <asm/cpu-type.h> #include <asm/dsp.h> #include <asm/fpu.h> #include <asm/fpu_emulator.h> #include <asm/idle.h> #include <asm/mips-r2-to-r6-emul.h> #include <asm/mipsregs.h> #include <asm/mipsmtregs.h> #include <asm/module.h> #include <asm/msa.h> #include <asm/pgtable.h> #include <asm/ptrace.h> #include <asm/sections.h> #include <asm/tlbdebug.h> #include <asm/traps.h> #include <asm/uaccess.h> #include <asm/watch.h> #include <asm/mmu_context.h> #include <asm/types.h> #include <asm/stacktrace.h> #include <asm/uasm.h> extern void check_wait(void); extern asmlinkage void rollback_handle_int(void); extern asmlinkage void handle_int(void); extern u32 handle_tlbl[]; extern u32 handle_tlbs[]; extern u32 handle_tlbm[]; extern asmlinkage void handle_adel(void); extern asmlinkage void handle_ades(void); extern asmlinkage void handle_ibe(void); extern asmlinkage void handle_dbe(void); extern asmlinkage void handle_sys(void); extern asmlinkage void handle_bp(void); extern asmlinkage void handle_ri(void); extern asmlinkage void handle_ri_rdhwr_vivt(void); extern asmlinkage void handle_ri_rdhwr(void); extern asmlinkage void handle_cpu(void); extern asmlinkage void handle_ov(void); extern asmlinkage void handle_tr(void); extern asmlinkage void handle_msa_fpe(void); extern asmlinkage void handle_fpe(void); extern asmlinkage void handle_ftlb(void); extern asmlinkage void handle_msa(void); extern asmlinkage void handle_mdmx(void); extern asmlinkage void handle_watch(void); extern asmlinkage void handle_mt(void); extern asmlinkage void handle_dsp(void); extern asmlinkage void handle_mcheck(void); extern asmlinkage void handle_reserved(void); extern void tlb_do_page_fault_0(void); void (*board_be_init)(void); int (*board_be_handler)(struct pt_regs *regs, int is_fixup); void (*board_nmi_handler_setup)(void); void (*board_ejtag_handler_setup)(void); void (*board_bind_eic_interrupt)(int irq, int regset); void (*board_ebase_setup)(void); void(*board_cache_error_setup)(void); static void show_raw_backtrace(unsigned long reg29) { unsigned long *sp = (unsigned long *)(reg29 & ~3); unsigned long addr; printk("Call Trace:"); #ifdef CONFIG_KALLSYMS printk("\n"); #endif while (!kstack_end(sp)) { unsigned long __user *p = (unsigned long __user *)(unsigned long)sp++; if (__get_user(addr, p)) { printk(" (Bad stack address)"); break; } if (__kernel_text_address(addr)) print_ip_sym(addr); } printk("\n"); } #ifdef CONFIG_KALLSYMS int raw_show_trace; static int __init set_raw_show_trace(char *str) { raw_show_trace = 1; return 1; } __setup("raw_show_trace", set_raw_show_trace); #endif static void show_backtrace(struct task_struct *task, const struct pt_regs *regs) { unsigned long sp = regs->regs[29]; unsigned long ra = regs->regs[31]; unsigned long pc = regs->cp0_epc; if (!task) task = current; if (raw_show_trace || !__kernel_text_address(pc)) { show_raw_backtrace(sp); return; } printk("Call Trace:\n"); do { print_ip_sym(pc); pc = unwind_stack(task, &sp, pc, &ra); } while (pc); printk("\n"); } /* * This routine abuses get_user()/put_user() to reference pointers * with at least a bit of error checking ... */ static void show_stacktrace(struct task_struct *task, const struct pt_regs *regs) { const int field = 2 * sizeof(unsigned long); long stackdata; int i; unsigned long __user *sp = (unsigned long __user *)regs->regs[29]; printk("Stack :"); i = 0; while ((unsigned long) sp & (PAGE_SIZE - 1)) { if (i && ((i % (64 / field)) == 0)) printk("\n "); if (i > 39) { printk(" ..."); break; } if (__get_user(stackdata, sp++)) { printk(" (Bad stack address)"); break; } printk(" %0*lx", field, stackdata); i++; } printk("\n"); show_backtrace(task, regs); } void show_stack(struct task_struct *task, unsigned long *sp) { struct pt_regs regs; if (sp) { regs.regs[29] = (unsigned long)sp; regs.regs[31] = 0; regs.cp0_epc = 0; } else { if (task && task != current) { regs.regs[29] = task->thread.reg29; regs.regs[31] = 0; regs.cp0_epc = task->thread.reg31; #ifdef CONFIG_KGDB_KDB } else if (atomic_read(&kgdb_active) != -1 && kdb_current_regs) { memcpy(®s, kdb_current_regs, sizeof(regs)); #endif /* CONFIG_KGDB_KDB */ } else { prepare_frametrace(®s); } } show_stacktrace(task, ®s); } static void show_code(unsigned int __user *pc) { long i; unsigned short __user *pc16 = NULL; printk("\nCode:"); if ((unsigned long)pc & 1) pc16 = (unsigned short __user *)((unsigned long)pc & ~1); for(i = -3 ; i < 6 ; i++) { unsigned int insn; if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) { printk(" (Bad address in epc)\n"); break; } printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>')); } } static void __show_regs(const struct pt_regs *regs) { const int field = 2 * sizeof(unsigned long); unsigned int cause = regs->cp0_cause; unsigned int exccode; int i; show_regs_print_info(KERN_DEFAULT); /* * Saved main processor registers */ for (i = 0; i < 32; ) { if ((i % 4) == 0) printk("$%2d :", i); if (i == 0) printk(" %0*lx", field, 0UL); else if (i == 26 || i == 27) printk(" %*s", field, ""); else printk(" %0*lx", field, regs->regs[i]); i++; if ((i % 4) == 0) printk("\n"); } #ifdef CONFIG_CPU_HAS_SMARTMIPS printk("Acx : %0*lx\n", field, regs->acx); #endif printk("Hi : %0*lx\n", field, regs->hi); printk("Lo : %0*lx\n", field, regs->lo); /* * Saved cp0 registers */ printk("epc : %0*lx %pS\n", field, regs->cp0_epc, (void *) regs->cp0_epc); printk("ra : %0*lx %pS\n", field, regs->regs[31], (void *) regs->regs[31]); printk("Status: %08x ", (uint32_t) regs->cp0_status); if (cpu_has_3kex) { if (regs->cp0_status & ST0_KUO) printk("KUo "); if (regs->cp0_status & ST0_IEO) printk("IEo "); if (regs->cp0_status & ST0_KUP) printk("KUp "); if (regs->cp0_status & ST0_IEP) printk("IEp "); if (regs->cp0_status & ST0_KUC) printk("KUc "); if (regs->cp0_status & ST0_IEC) printk("IEc "); } else if (cpu_has_4kex) { if (regs->cp0_status & ST0_KX) printk("KX "); if (regs->cp0_status & ST0_SX) printk("SX "); if (regs->cp0_status & ST0_UX) printk("UX "); switch (regs->cp0_status & ST0_KSU) { case KSU_USER: printk("USER "); break; case KSU_SUPERVISOR: printk("SUPERVISOR "); break; case KSU_KERNEL: printk("KERNEL "); break; default: printk("BAD_MODE "); break; } if (regs->cp0_status & ST0_ERL) printk("ERL "); if (regs->cp0_status & ST0_EXL) printk("EXL "); if (regs->cp0_status & ST0_IE) printk("IE "); } printk("\n"); exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE; printk("Cause : %08x (ExcCode %02x)\n", cause, exccode); if (1 <= exccode && exccode <= 5) printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr); printk("PrId : %08x (%s)\n", read_c0_prid(), cpu_name_string()); } /* * FIXME: really the generic show_regs should take a const pointer argument. */ void show_regs(struct pt_regs *regs) { __show_regs((struct pt_regs *)regs); } void show_registers(struct pt_regs *regs) { const int field = 2 * sizeof(unsigned long); mm_segment_t old_fs = get_fs(); __show_regs(regs); print_modules(); printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n", current->comm, current->pid, current_thread_info(), current, field, current_thread_info()->tp_value); if (cpu_has_userlocal) { unsigned long tls; tls = read_c0_userlocal(); if (tls != current_thread_info()->tp_value) printk("*HwTLS: %0*lx\n", field, tls); } if (!user_mode(regs)) /* Necessary for getting the correct stack content */ set_fs(KERNEL_DS); show_stacktrace(current, regs); show_code((unsigned int __user *) regs->cp0_epc); printk("\n"); set_fs(old_fs); } static int regs_to_trapnr(struct pt_regs *regs) { return (regs->cp0_cause >> 2) & 0x1f; } static DEFINE_RAW_SPINLOCK(die_lock); void __noreturn die(const char *str, struct pt_regs *regs) { static int die_counter; int sig = SIGSEGV; oops_enter(); if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs), SIGSEGV) == NOTIFY_STOP) sig = 0; console_verbose(); raw_spin_lock_irq(&die_lock); bust_spinlocks(1); printk("%s[#%d]:\n", str, ++die_counter); show_registers(regs); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); raw_spin_unlock_irq(&die_lock); oops_exit(); if (in_interrupt()) panic("Fatal exception in interrupt"); if (panic_on_oops) { printk(KERN_EMERG "Fatal exception: panic in 5 seconds"); ssleep(5); panic("Fatal exception"); } if (regs && kexec_should_crash(current)) crash_kexec(regs); do_exit(sig); } extern struct exception_table_entry __start___dbe_table[]; extern struct exception_table_entry __stop___dbe_table[]; __asm__( " .section __dbe_table, \"a\"\n" " .previous \n"); /* Given an address, look for it in the exception tables. */ static const struct exception_table_entry *search_dbe_tables(unsigned long addr) { const struct exception_table_entry *e; e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr); if (!e) e = search_module_dbetables(addr); return e; } asmlinkage void do_be(struct pt_regs *regs) { const int field = 2 * sizeof(unsigned long); const struct exception_table_entry *fixup = NULL; int data = regs->cp0_cause & 4; int action = MIPS_BE_FATAL; enum ctx_state prev_state; prev_state = exception_enter(); /* XXX For now. Fixme, this searches the wrong table ... */ if (data && !user_mode(regs)) fixup = search_dbe_tables(exception_epc(regs)); if (fixup) action = MIPS_BE_FIXUP; if (board_be_handler) action = board_be_handler(regs, fixup != NULL); switch (action) { case MIPS_BE_DISCARD: goto out; case MIPS_BE_FIXUP: if (fixup) { regs->cp0_epc = fixup->nextinsn; goto out; } break; default: break; } /* * Assume it would be too dangerous to continue ... */ printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n", data ? "Data" : "Instruction", field, regs->cp0_epc, field, regs->regs[31]); if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs), SIGBUS) == NOTIFY_STOP) goto out; die_if_kernel("Oops", regs); force_sig(SIGBUS, current); out: exception_exit(prev_state); } /* * ll/sc, rdhwr, sync emulation */ #define OPCODE 0xfc000000 #define BASE 0x03e00000 #define RT 0x001f0000 #define OFFSET 0x0000ffff #define LL 0xc0000000 #define SC 0xe0000000 #define SPEC0 0x00000000 #define SPEC3 0x7c000000 #define RD 0x0000f800 #define FUNC 0x0000003f #define SYNC 0x0000000f #define RDHWR 0x0000003b /* microMIPS definitions */ #define MM_POOL32A_FUNC 0xfc00ffff #define MM_RDHWR 0x00006b3c #define MM_RS 0x001f0000 #define MM_RT 0x03e00000 /* * The ll_bit is cleared by r*_switch.S */ unsigned int ll_bit; struct task_struct *ll_task; static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode) { unsigned long value, __user *vaddr; long offset; /* * analyse the ll instruction that just caused a ri exception * and put the referenced address to addr. */ /* sign extend offset */ offset = opcode & OFFSET; offset <<= 16; offset >>= 16; vaddr = (unsigned long __user *) ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset); if ((unsigned long)vaddr & 3) return SIGBUS; if (get_user(value, vaddr)) return SIGSEGV; preempt_disable(); if (ll_task == NULL || ll_task == current) { ll_bit = 1; } else { ll_bit = 0; } ll_task = current; preempt_enable(); regs->regs[(opcode & RT) >> 16] = value; return 0; } static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode) { unsigned long __user *vaddr; unsigned long reg; long offset; /* * analyse the sc instruction that just caused a ri exception * and put the referenced address to addr. */ /* sign extend offset */ offset = opcode & OFFSET; offset <<= 16; offset >>= 16; vaddr = (unsigned long __user *) ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset); reg = (opcode & RT) >> 16; if ((unsigned long)vaddr & 3) return SIGBUS; preempt_disable(); if (ll_bit == 0 || ll_task != current) { regs->regs[reg] = 0; preempt_enable(); return 0; } preempt_enable(); if (put_user(regs->regs[reg], vaddr)) return SIGSEGV; regs->regs[reg] = 1; return 0; } /* * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both * opcodes are supposed to result in coprocessor unusable exceptions if * executed on ll/sc-less processors. That's the theory. In practice a * few processors such as NEC's VR4100 throw reserved instruction exceptions * instead, so we're doing the emulation thing in both exception handlers. */ static int simulate_llsc(struct pt_regs *regs, unsigned int opcode) { if ((opcode & OPCODE) == LL) { perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0); return simulate_ll(regs, opcode); } if ((opcode & OPCODE) == SC) { perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0); return simulate_sc(regs, opcode); } return -1; /* Must be something else ... */ } /* * Simulate trapping 'rdhwr' instructions to provide user accessible * registers not implemented in hardware. */ static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt) { struct thread_info *ti = task_thread_info(current); perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0); switch (rd) { case 0: /* CPU number */ regs->regs[rt] = smp_processor_id(); return 0; case 1: /* SYNCI length */ regs->regs[rt] = min(current_cpu_data.dcache.linesz, current_cpu_data.icache.linesz); return 0; case 2: /* Read count register */ regs->regs[rt] = read_c0_count(); return 0; case 3: /* Count register resolution */ switch (current_cpu_type()) { case CPU_20KC: case CPU_25KF: regs->regs[rt] = 1; break; default: regs->regs[rt] = 2; } return 0; case 29: regs->regs[rt] = ti->tp_value; return 0; default: return -1; } } static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode) { if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) { int rd = (opcode & RD) >> 11; int rt = (opcode & RT) >> 16; simulate_rdhwr(regs, rd, rt); return 0; } /* Not ours. */ return -1; } static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode) { if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) { int rd = (opcode & MM_RS) >> 16; int rt = (opcode & MM_RT) >> 21; simulate_rdhwr(regs, rd, rt); return 0; } /* Not ours. */ return -1; } static int simulate_sync(struct pt_regs *regs, unsigned int opcode) { if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) { perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0); return 0; } return -1; /* Must be something else ... */ } asmlinkage void do_ov(struct pt_regs *regs) { enum ctx_state prev_state; siginfo_t info; prev_state = exception_enter(); die_if_kernel("Integer overflow", regs); info.si_code = FPE_INTOVF; info.si_signo = SIGFPE; info.si_errno = 0; info.si_addr = (void __user *) regs->cp0_epc; force_sig_info(SIGFPE, &info, current); exception_exit(prev_state); } int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31) { struct siginfo si = { 0 }; switch (sig) { case 0: return 0; case SIGFPE: si.si_addr = fault_addr; si.si_signo = sig; /* * Inexact can happen together with Overflow or Underflow. * Respect the mask to deliver the correct exception. */ fcr31 &= (fcr31 & FPU_CSR_ALL_E) << (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E)); if (fcr31 & FPU_CSR_INV_X) si.si_code = FPE_FLTINV; else if (fcr31 & FPU_CSR_DIV_X) si.si_code = FPE_FLTDIV; else if (fcr31 & FPU_CSR_OVF_X) si.si_code = FPE_FLTOVF; else if (fcr31 & FPU_CSR_UDF_X) si.si_code = FPE_FLTUND; else if (fcr31 & FPU_CSR_INE_X) si.si_code = FPE_FLTRES; else si.si_code = __SI_FAULT; force_sig_info(sig, &si, current); return 1; case SIGBUS: si.si_addr = fault_addr; si.si_signo = sig; si.si_code = BUS_ADRERR; force_sig_info(sig, &si, current); return 1; case SIGSEGV: si.si_addr = fault_addr; si.si_signo = sig; down_read(¤t->mm->mmap_sem); if (find_vma(current->mm, (unsigned long)fault_addr)) si.si_code = SEGV_ACCERR; else si.si_code = SEGV_MAPERR; up_read(¤t->mm->mmap_sem); force_sig_info(sig, &si, current); return 1; default: force_sig(sig, current); return 1; } } static int simulate_fp(struct pt_regs *regs, unsigned int opcode, unsigned long old_epc, unsigned long old_ra) { union mips_instruction inst = { .word = opcode }; void __user *fault_addr; unsigned long fcr31; int sig; /* If it's obviously not an FP instruction, skip it */ switch (inst.i_format.opcode) { case cop1_op: case cop1x_op: case lwc1_op: case ldc1_op: case swc1_op: case sdc1_op: break; default: return -1; } /* * do_ri skipped over the instruction via compute_return_epc, undo * that for the FPU emulator. */ regs->cp0_epc = old_epc; regs->regs[31] = old_ra; /* Save the FP context to struct thread_struct */ lose_fpu(1); /* Run the emulator */ sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1, &fault_addr); fcr31 = current->thread.fpu.fcr31; /* * We can't allow the emulated instruction to leave any of * the cause bits set in $fcr31. */ current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X; /* Restore the hardware register state */ own_fpu(1); /* Send a signal if required. */ process_fpemu_return(sig, fault_addr, fcr31); return 0; } /* * XXX Delayed fp exceptions when doing a lazy ctx switch XXX */ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31) { enum ctx_state prev_state; void __user *fault_addr; int sig; prev_state = exception_enter(); if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs), SIGFPE) == NOTIFY_STOP) goto out; /* Clear FCSR.Cause before enabling interrupts */ write_32bit_cp1_register(CP1_STATUS, fcr31 & ~FPU_CSR_ALL_X); local_irq_enable(); die_if_kernel("FP exception in kernel code", regs); if (fcr31 & FPU_CSR_UNI_X) { /* * Unimplemented operation exception. If we've got the full * software emulator on-board, let's use it... * * Force FPU to dump state into task/thread context. We're * moving a lot of data here for what is probably a single * instruction, but the alternative is to pre-decode the FP * register operands before invoking the emulator, which seems * a bit extreme for what should be an infrequent event. */ /* Ensure 'resume' not overwrite saved fp context again. */ lose_fpu(1); /* Run the emulator */ sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1, &fault_addr); fcr31 = current->thread.fpu.fcr31; /* * We can't allow the emulated instruction to leave any of * the cause bits set in $fcr31. */ current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X; /* Restore the hardware register state */ own_fpu(1); /* Using the FPU again. */ } else { sig = SIGFPE; fault_addr = (void __user *) regs->cp0_epc; } /* Send a signal if required. */ process_fpemu_return(sig, fault_addr, fcr31); out: exception_exit(prev_state); } void do_trap_or_bp(struct pt_regs *regs, unsigned int code, const char *str) { siginfo_t info; char b[40]; #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP) return; #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP) return; /* * A short test says that IRIX 5.3 sends SIGTRAP for all trap * insns, even for trap and break codes that indicate arithmetic * failures. Weird ... * But should we continue the brokenness??? --macro */ switch (code) { case BRK_OVERFLOW: case BRK_DIVZERO: scnprintf(b, sizeof(b), "%s instruction in kernel code", str); die_if_kernel(b, regs); if (code == BRK_DIVZERO) info.si_code = FPE_INTDIV; else info.si_code = FPE_INTOVF; info.si_signo = SIGFPE; info.si_errno = 0; info.si_addr = (void __user *) regs->cp0_epc; force_sig_info(SIGFPE, &info, current); break; case BRK_BUG: die_if_kernel("Kernel bug detected", regs); force_sig(SIGTRAP, current); break; case BRK_MEMU: /* * This breakpoint code is used by the FPU emulator to retake * control of the CPU after executing the instruction from the * delay slot of an emulated branch. * * Terminate if exception was recognized as a delay slot return * otherwise handle as normal. */ if (do_dsemulret(regs)) return; die_if_kernel("Math emu break/trap", regs); force_sig(SIGTRAP, current); break; default: scnprintf(b, sizeof(b), "%s instruction in kernel code", str); die_if_kernel(b, regs); force_sig(SIGTRAP, current); } } asmlinkage void do_bp(struct pt_regs *regs) { unsigned long epc = msk_isa16_mode(exception_epc(regs)); unsigned int opcode, bcode; enum ctx_state prev_state; mm_segment_t seg; seg = get_fs(); if (!user_mode(regs)) set_fs(KERNEL_DS); prev_state = exception_enter(); if (get_isa16_mode(regs->cp0_epc)) { u16 instr[2]; if (__get_user(instr[0], (u16 __user *)epc)) goto out_sigsegv; if (!cpu_has_mmips) { /* MIPS16e mode */ bcode = (instr[0] >> 5) & 0x3f; } else if (mm_insn_16bit(instr[0])) { /* 16-bit microMIPS BREAK */ bcode = instr[0] & 0xf; } else { /* 32-bit microMIPS BREAK */ if (__get_user(instr[1], (u16 __user *)(epc + 2))) goto out_sigsegv; opcode = (instr[0] << 16) | instr[1]; bcode = (opcode >> 6) & ((1 << 20) - 1); } } else { if (__get_user(opcode, (unsigned int __user *)epc)) goto out_sigsegv; bcode = (opcode >> 6) & ((1 << 20) - 1); } /* * There is the ancient bug in the MIPS assemblers that the break * code starts left to bit 16 instead to bit 6 in the opcode. * Gas is bug-compatible, but not always, grrr... * We handle both cases with a simple heuristics. --macro */ if (bcode >= (1 << 10)) bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10); /* * notify the kprobe handlers, if instruction is likely to * pertain to them. */ switch (bcode) { case BRK_KPROBE_BP: if (notify_die(DIE_BREAK, "debug", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP) goto out; else break; case BRK_KPROBE_SSTEPBP: if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP) goto out; else break; default: break; } do_trap_or_bp(regs, bcode, "Break"); out: set_fs(seg); exception_exit(prev_state); return; out_sigsegv: force_sig(SIGSEGV, current); goto out; } asmlinkage void do_tr(struct pt_regs *regs) { u32 opcode, tcode = 0; enum ctx_state prev_state; u16 instr[2]; mm_segment_t seg; unsigned long epc = msk_isa16_mode(exception_epc(regs)); seg = get_fs(); if (!user_mode(regs)) set_fs(get_ds()); prev_state = exception_enter(); if (get_isa16_mode(regs->cp0_epc)) { if (__get_user(instr[0], (u16 __user *)(epc + 0)) || __get_user(instr[1], (u16 __user *)(epc + 2))) goto out_sigsegv; opcode = (instr[0] << 16) | instr[1]; /* Immediate versions don't provide a code. */ if (!(opcode & OPCODE)) tcode = (opcode >> 12) & ((1 << 4) - 1); } else { if (__get_user(opcode, (u32 __user *)epc)) goto out_sigsegv; /* Immediate versions don't provide a code. */ if (!(opcode & OPCODE)) tcode = (opcode >> 6) & ((1 << 10) - 1); } do_trap_or_bp(regs, tcode, "Trap"); out: set_fs(seg); exception_exit(prev_state); return; out_sigsegv: force_sig(SIGSEGV, current); goto out; } asmlinkage void do_ri(struct pt_regs *regs) { unsigned int __user *epc = (unsigned int __user *)exception_epc(regs); unsigned long old_epc = regs->cp0_epc; unsigned long old31 = regs->regs[31]; enum ctx_state prev_state; unsigned int opcode = 0; int status = -1; /* * Avoid any kernel code. Just emulate the R2 instruction * as quickly as possible. */ if (mipsr2_emulation && cpu_has_mips_r6 && likely(user_mode(regs)) && likely(get_user(opcode, epc) >= 0)) { unsigned long fcr31 = 0; status = mipsr2_decoder(regs, opcode, &fcr31); switch (status) { case 0: case SIGEMT: task_thread_info(current)->r2_emul_return = 1; return; case SIGILL: goto no_r2_instr; default: process_fpemu_return(status, ¤t->thread.cp0_baduaddr, fcr31); task_thread_info(current)->r2_emul_return = 1; return; } } no_r2_instr: prev_state = exception_enter(); if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs), SIGILL) == NOTIFY_STOP) goto out; die_if_kernel("Reserved instruction in kernel code", regs); if (unlikely(compute_return_epc(regs) < 0)) goto out; if (get_isa16_mode(regs->cp0_epc)) { unsigned short mmop[2] = { 0 }; if (unlikely(get_user(mmop[0], epc) < 0)) status = SIGSEGV; if (unlikely(get_user(mmop[1], epc) < 0)) status = SIGSEGV; opcode = (mmop[0] << 16) | mmop[1]; if (status < 0) status = simulate_rdhwr_mm(regs, opcode); } else { if (unlikely(get_user(opcode, epc) < 0)) status = SIGSEGV; if (!cpu_has_llsc && status < 0) status = simulate_llsc(regs, opcode); if (status < 0) status = simulate_rdhwr_normal(regs, opcode); if (status < 0) status = simulate_sync(regs, opcode); if (status < 0) status = simulate_fp(regs, opcode, old_epc, old31); } if (status < 0) status = SIGILL; if (unlikely(status > 0)) { regs->cp0_epc = old_epc; /* Undo skip-over. */ regs->regs[31] = old31; force_sig(status, current); } out: exception_exit(prev_state); } /* * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've * emulated more than some threshold number of instructions, force migration to * a "CPU" that has FP support. */ static void mt_ase_fp_affinity(void) { #ifdef CONFIG_MIPS_MT_FPAFF if (mt_fpemul_threshold > 0 && ((current->thread.emulated_fp++ > mt_fpemul_threshold))) { /* * If there's no FPU present, or if the application has already * restricted the allowed set to exclude any CPUs with FPUs, * we'll skip the procedure. */ if (cpumask_intersects(¤t->cpus_allowed, &mt_fpu_cpumask)) { cpumask_t tmask; current->thread.user_cpus_allowed = current->cpus_allowed; cpumask_and(&tmask, ¤t->cpus_allowed, &mt_fpu_cpumask); set_cpus_allowed_ptr(current, &tmask); set_thread_flag(TIF_FPUBOUND); } } #endif /* CONFIG_MIPS_MT_FPAFF */ } /* * No lock; only written during early bootup by CPU 0. */ static RAW_NOTIFIER_HEAD(cu2_chain); int __ref register_cu2_notifier(struct notifier_block *nb) { return raw_notifier_chain_register(&cu2_chain, nb); } int cu2_notifier_call_chain(unsigned long val, void *v) { return raw_notifier_call_chain(&cu2_chain, val, v); } static int default_cu2_call(struct notifier_block *nfb, unsigned long action, void *data) { struct pt_regs *regs = data; die_if_kernel("COP2: Unhandled kernel unaligned access or invalid " "instruction", regs); force_sig(SIGILL, current); return NOTIFY_OK; } static int wait_on_fp_mode_switch(atomic_t *p) { /* * The FP mode for this task is currently being switched. That may * involve modifications to the format of this tasks FP context which * make it unsafe to proceed with execution for the moment. Instead, * schedule some other task. */ schedule(); return 0; } static int enable_restore_fp_context(int msa) { int err, was_fpu_owner, prior_msa; /* * If an FP mode switch is currently underway, wait for it to * complete before proceeding. */ wait_on_atomic_t(¤t->mm->context.fp_mode_switching, wait_on_fp_mode_switch, TASK_KILLABLE); if (!used_math()) { /* First time FP context user. */ preempt_disable(); err = init_fpu(); if (msa && !err) { enable_msa(); _init_msa_upper(); set_thread_flag(TIF_USEDMSA); set_thread_flag(TIF_MSA_CTX_LIVE); } preempt_enable(); if (!err) set_used_math(); return err; } /* * This task has formerly used the FP context. * * If this thread has no live MSA vector context then we can simply * restore the scalar FP context. If it has live MSA vector context * (that is, it has or may have used MSA since last performing a * function call) then we'll need to restore the vector context. This * applies even if we're currently only executing a scalar FP * instruction. This is because if we were to later execute an MSA * instruction then we'd either have to: * * - Restore the vector context & clobber any registers modified by * scalar FP instructions between now & then. * * or * * - Not restore the vector context & lose the most significant bits * of all vector registers. * * Neither of those options is acceptable. We cannot restore the least * significant bits of the registers now & only restore the most * significant bits later because the most significant bits of any * vector registers whose aliased FP register is modified now will have * been zeroed. We'd have no way to know that when restoring the vector * context & thus may load an outdated value for the most significant * bits of a vector register. */ if (!msa && !thread_msa_context_live()) return own_fpu(1); /* * This task is using or has previously used MSA. Thus we require * that Status.FR == 1. */ preempt_disable(); was_fpu_owner = is_fpu_owner(); err = own_fpu_inatomic(0); if (err) goto out; enable_msa(); write_msa_csr(current->thread.fpu.msacsr); set_thread_flag(TIF_USEDMSA); /* * If this is the first time that the task is using MSA and it has * previously used scalar FP in this time slice then we already nave * FP context which we shouldn't clobber. We do however need to clear * the upper 64b of each vector register so that this task has no * opportunity to see data left behind by another. */ prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE); if (!prior_msa && was_fpu_owner) { _init_msa_upper(); goto out; } if (!prior_msa) { /* * Restore the least significant 64b of each vector register * from the existing scalar FP context. */ _restore_fp(current); /* * The task has not formerly used MSA, so clear the upper 64b * of each vector register such that it cannot see data left * behind by another task. */ _init_msa_upper(); } else { /* We need to restore the vector context. */ restore_msa(current); /* Restore the scalar FP control & status register */ if (!was_fpu_owner) write_32bit_cp1_register(CP1_STATUS, current->thread.fpu.fcr31); } out: preempt_enable(); return 0; } asmlinkage void do_cpu(struct pt_regs *regs) { enum ctx_state prev_state; unsigned int __user *epc; unsigned long old_epc, old31; void __user *fault_addr; unsigned int opcode; unsigned long fcr31; unsigned int cpid; int status, err; unsigned long __maybe_unused flags; int sig; prev_state = exception_enter(); cpid = (regs->cp0_cause >> CAUSEB_CE) & 3; if (cpid != 2) die_if_kernel("do_cpu invoked from kernel context!", regs); switch (cpid) { case 0: epc = (unsigned int __user *)exception_epc(regs); old_epc = regs->cp0_epc; old31 = regs->regs[31]; opcode = 0; status = -1; if (unlikely(compute_return_epc(regs) < 0)) break; if (get_isa16_mode(regs->cp0_epc)) { unsigned short mmop[2] = { 0 }; if (unlikely(get_user(mmop[0], epc) < 0)) status = SIGSEGV; if (unlikely(get_user(mmop[1], epc) < 0)) status = SIGSEGV; opcode = (mmop[0] << 16) | mmop[1]; if (status < 0) status = simulate_rdhwr_mm(regs, opcode); } else { if (unlikely(get_user(opcode, epc) < 0)) status = SIGSEGV; if (!cpu_has_llsc && status < 0) status = simulate_llsc(regs, opcode); if (status < 0) status = simulate_rdhwr_normal(regs, opcode); } if (status < 0) status = SIGILL; if (unlikely(status > 0)) { regs->cp0_epc = old_epc; /* Undo skip-over. */ regs->regs[31] = old31; force_sig(status, current); } break; case 3: /* * The COP3 opcode space and consequently the CP0.Status.CU3 * bit and the CP0.Cause.CE=3 encoding have been removed as * of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs * up the space has been reused for COP1X instructions, that * are enabled by the CP0.Status.CU1 bit and consequently * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable * exceptions. Some FPU-less processors that implement one * of these ISAs however use this code erroneously for COP1X * instructions. Therefore we redirect this trap to the FP * emulator too. */ if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) { force_sig(SIGILL, current); break; } /* Fall through. */ case 1: err = enable_restore_fp_context(0); if (raw_cpu_has_fpu && !err) break; sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 0, &fault_addr); fcr31 = current->thread.fpu.fcr31; /* * We can't allow the emulated instruction to leave * any of the cause bits set in $fcr31. */ current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X; /* Send a signal if required. */ if (!process_fpemu_return(sig, fault_addr, fcr31) && !err) mt_ase_fp_affinity(); break; case 2: raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs); break; } exception_exit(prev_state); } asmlinkage void do_msa_fpe(struct pt_regs *regs, unsigned int msacsr) { enum ctx_state prev_state; prev_state = exception_enter(); if (notify_die(DIE_MSAFP, "MSA FP exception", regs, 0, regs_to_trapnr(regs), SIGFPE) == NOTIFY_STOP) goto out; /* Clear MSACSR.Cause before enabling interrupts */ write_msa_csr(msacsr & ~MSA_CSR_CAUSEF); local_irq_enable(); die_if_kernel("do_msa_fpe invoked from kernel context!", regs); force_sig(SIGFPE, current); out: exception_exit(prev_state); } asmlinkage void do_msa(struct pt_regs *regs) { enum ctx_state prev_state; int err; prev_state = exception_enter(); if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) { force_sig(SIGILL, current); goto out; } die_if_kernel("do_msa invoked from kernel context!", regs); err = enable_restore_fp_context(1); if (err) force_sig(SIGILL, current); out: exception_exit(prev_state); } asmlinkage void do_mdmx(struct pt_regs *regs) { enum ctx_state prev_state; prev_state = exception_enter(); force_sig(SIGILL, current); exception_exit(prev_state); } /* * Called with interrupts disabled. */ asmlinkage void do_watch(struct pt_regs *regs) { enum ctx_state prev_state; u32 cause; prev_state = exception_enter(); /* * Clear WP (bit 22) bit of cause register so we don't loop * forever. */ cause = read_c0_cause(); cause &= ~(1 << 22); write_c0_cause(cause); /* * If the current thread has the watch registers loaded, save * their values and send SIGTRAP. Otherwise another thread * left the registers set, clear them and continue. */ if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) { mips_read_watch_registers(); local_irq_enable(); force_sig(SIGTRAP, current); } else { mips_clear_watch_registers(); local_irq_enable(); } exception_exit(prev_state); } asmlinkage void do_mcheck(struct pt_regs *regs) { const int field = 2 * sizeof(unsigned long); int multi_match = regs->cp0_status & ST0_TS; enum ctx_state prev_state; prev_state = exception_enter(); show_regs(regs); if (multi_match) { pr_err("Index : %0x\n", read_c0_index()); pr_err("Pagemask: %0x\n", read_c0_pagemask()); pr_err("EntryHi : %0*lx\n", field, read_c0_entryhi()); pr_err("EntryLo0: %0*lx\n", field, read_c0_entrylo0()); pr_err("EntryLo1: %0*lx\n", field, read_c0_entrylo1()); pr_err("Wired : %0x\n", read_c0_wired()); pr_err("Pagegrain: %0x\n", read_c0_pagegrain()); if (cpu_has_htw) { pr_err("PWField : %0*lx\n", field, read_c0_pwfield()); pr_err("PWSize : %0*lx\n", field, read_c0_pwsize()); pr_err("PWCtl : %0x\n", read_c0_pwctl()); } pr_err("\n"); dump_tlb_all(); } show_code((unsigned int __user *) regs->cp0_epc); /* * Some chips may have other causes of machine check (e.g. SB1 * graduation timer) */ panic("Caught Machine Check exception - %scaused by multiple " "matching entries in the TLB.", (multi_match) ? "" : "not "); } asmlinkage void do_mt(struct pt_regs *regs) { int subcode; subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT) >> VPECONTROL_EXCPT_SHIFT; switch (subcode) { case 0: printk(KERN_DEBUG "Thread Underflow\n"); break; case 1: printk(KERN_DEBUG "Thread Overflow\n"); break; case 2: printk(KERN_DEBUG "Invalid YIELD Qualifier\n"); break; case 3: printk(KERN_DEBUG "Gating Storage Exception\n"); break; case 4: printk(KERN_DEBUG "YIELD Scheduler Exception\n"); break; case 5: printk(KERN_DEBUG "Gating Storage Scheduler Exception\n"); break; default: printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n", subcode); break; } die_if_kernel("MIPS MT Thread exception in kernel", regs); force_sig(SIGILL, current); } asmlinkage void do_dsp(struct pt_regs *regs) { if (cpu_has_dsp) panic("Unexpected DSP exception"); force_sig(SIGILL, current); } asmlinkage void do_reserved(struct pt_regs *regs) { /* * Game over - no way to handle this if it ever occurs. Most probably * caused by a new unknown cpu type or after another deadly * hard/software error. */ show_regs(regs); panic("Caught reserved exception %ld - should not happen.", (regs->cp0_cause & 0x7f) >> 2); } static int __initdata l1parity = 1; static int __init nol1parity(char *s) { l1parity = 0; return 1; } __setup("nol1par", nol1parity); static int __initdata l2parity = 1; static int __init nol2parity(char *s) { l2parity = 0; return 1; } __setup("nol2par", nol2parity); /* * Some MIPS CPUs can enable/disable for cache parity detection, but do * it different ways. */ static inline void parity_protection_init(void) { switch (current_cpu_type()) { case CPU_24K: case CPU_34K: case CPU_74K: case CPU_1004K: case CPU_1074K: case CPU_INTERAPTIV: case CPU_PROAPTIV: case CPU_P5600: case CPU_QEMU_GENERIC: { #define ERRCTL_PE 0x80000000 #define ERRCTL_L2P 0x00800000 unsigned long errctl; unsigned int l1parity_present, l2parity_present; errctl = read_c0_ecc(); errctl &= ~(ERRCTL_PE|ERRCTL_L2P); /* probe L1 parity support */ write_c0_ecc(errctl | ERRCTL_PE); back_to_back_c0_hazard(); l1parity_present = (read_c0_ecc() & ERRCTL_PE); /* probe L2 parity support */ write_c0_ecc(errctl|ERRCTL_L2P); back_to_back_c0_hazard(); l2parity_present = (read_c0_ecc() & ERRCTL_L2P); if (l1parity_present && l2parity_present) { if (l1parity) errctl |= ERRCTL_PE; if (l1parity ^ l2parity) errctl |= ERRCTL_L2P; } else if (l1parity_present) { if (l1parity) errctl |= ERRCTL_PE; } else if (l2parity_present) { if (l2parity) errctl |= ERRCTL_L2P; } else { /* No parity available */ } printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl); write_c0_ecc(errctl); back_to_back_c0_hazard(); errctl = read_c0_ecc(); printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl); if (l1parity_present) printk(KERN_INFO "Cache parity protection %sabled\n", (errctl & ERRCTL_PE) ? "en" : "dis"); if (l2parity_present) { if (l1parity_present && l1parity) errctl ^= ERRCTL_L2P; printk(KERN_INFO "L2 cache parity protection %sabled\n", (errctl & ERRCTL_L2P) ? "en" : "dis"); } } break; case CPU_5KC: case CPU_5KE: case CPU_LOONGSON1: write_c0_ecc(0x80000000); back_to_back_c0_hazard(); /* Set the PE bit (bit 31) in the c0_errctl register. */ printk(KERN_INFO "Cache parity protection %sabled\n", (read_c0_ecc() & 0x80000000) ? "en" : "dis"); break; case CPU_20KC: case CPU_25KF: /* Clear the DE bit (bit 16) in the c0_status register. */ printk(KERN_INFO "Enable cache parity protection for " "MIPS 20KC/25KF CPUs.\n"); clear_c0_status(ST0_DE); break; default: break; } } asmlinkage void cache_parity_error(void) { const int field = 2 * sizeof(unsigned long); unsigned int reg_val; /* For the moment, report the problem and hang. */ printk("Cache error exception:\n"); printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc()); reg_val = read_c0_cacheerr(); printk("c0_cacheerr == %08x\n", reg_val); printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n", reg_val & (1<<30) ? "secondary" : "primary", reg_val & (1<<31) ? "data" : "insn"); if ((cpu_has_mips_r2_r6) && ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) { pr_err("Error bits: %s%s%s%s%s%s%s%s\n", reg_val & (1<<29) ? "ED " : "", reg_val & (1<<28) ? "ET " : "", reg_val & (1<<27) ? "ES " : "", reg_val & (1<<26) ? "EE " : "", reg_val & (1<<25) ? "EB " : "", reg_val & (1<<24) ? "EI " : "", reg_val & (1<<23) ? "E1 " : "", reg_val & (1<<22) ? "E0 " : ""); } else { pr_err("Error bits: %s%s%s%s%s%s%s\n", reg_val & (1<<29) ? "ED " : "", reg_val & (1<<28) ? "ET " : "", reg_val & (1<<26) ? "EE " : "", reg_val & (1<<25) ? "EB " : "", reg_val & (1<<24) ? "EI " : "", reg_val & (1<<23) ? "E1 " : "", reg_val & (1<<22) ? "E0 " : ""); } printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1)); #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64) if (reg_val & (1<<22)) printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0()); if (reg_val & (1<<23)) printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1()); #endif panic("Can't handle the cache error!"); } asmlinkage void do_ftlb(void) { const int field = 2 * sizeof(unsigned long); unsigned int reg_val; /* For the moment, report the problem and hang. */ if ((cpu_has_mips_r2_r6) && ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) { pr_err("FTLB error exception, cp0_ecc=0x%08x:\n", read_c0_ecc()); pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc()); reg_val = read_c0_cacheerr(); pr_err("c0_cacheerr == %08x\n", reg_val); if ((reg_val & 0xc0000000) == 0xc0000000) { pr_err("Decoded c0_cacheerr: FTLB parity error\n"); } else { pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n", reg_val & (1<<30) ? "secondary" : "primary", reg_val & (1<<31) ? "data" : "insn"); } } else { pr_err("FTLB error exception\n"); } /* Just print the cacheerr bits for now */ cache_parity_error(); } /* * SDBBP EJTAG debug exception handler. * We skip the instruction and return to the next instruction. */ void ejtag_exception_handler(struct pt_regs *regs) { const int field = 2 * sizeof(unsigned long); unsigned long depc, old_epc, old_ra; unsigned int debug; printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n"); depc = read_c0_depc(); debug = read_c0_debug(); printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug); if (debug & 0x80000000) { /* * In branch delay slot. * We cheat a little bit here and use EPC to calculate the * debug return address (DEPC). EPC is restored after the * calculation. */ old_epc = regs->cp0_epc; old_ra = regs->regs[31]; regs->cp0_epc = depc; compute_return_epc(regs); depc = regs->cp0_epc; regs->cp0_epc = old_epc; regs->regs[31] = old_ra; } else depc += 4; write_c0_depc(depc); #if 0 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n"); write_c0_debug(debug | 0x100); #endif } /* * NMI exception handler. * No lock; only written during early bootup by CPU 0. */ static RAW_NOTIFIER_HEAD(nmi_chain); int register_nmi_notifier(struct notifier_block *nb) { return raw_notifier_chain_register(&nmi_chain, nb); } void __noreturn nmi_exception_handler(struct pt_regs *regs) { char str[100]; raw_notifier_call_chain(&nmi_chain, 0, regs); bust_spinlocks(1); snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n", smp_processor_id(), regs->cp0_epc); regs->cp0_epc = read_c0_errorepc(); die(str, regs); } #define VECTORSPACING 0x100 /* for EI/VI mode */ unsigned long ebase; unsigned long exception_handlers[32]; unsigned long vi_handlers[64]; void __init *set_except_vector(int n, void *addr) { unsigned long handler = (unsigned long) addr; unsigned long old_handler; #ifdef CONFIG_CPU_MICROMIPS /* * Only the TLB handlers are cache aligned with an even * address. All other handlers are on an odd address and * require no modification. Otherwise, MIPS32 mode will * be entered when handling any TLB exceptions. That * would be bad...since we must stay in microMIPS mode. */ if (!(handler & 0x1)) handler |= 1; #endif old_handler = xchg(&exception_handlers[n], handler); if (n == 0 && cpu_has_divec) { #ifdef CONFIG_CPU_MICROMIPS unsigned long jump_mask = ~((1 << 27) - 1); #else unsigned long jump_mask = ~((1 << 28) - 1); #endif u32 *buf = (u32 *)(ebase + 0x200); unsigned int k0 = 26; if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) { uasm_i_j(&buf, handler & ~jump_mask); uasm_i_nop(&buf); } else { UASM_i_LA(&buf, k0, handler); uasm_i_jr(&buf, k0); uasm_i_nop(&buf); } local_flush_icache_range(ebase + 0x200, (unsigned long)buf); } return (void *)old_handler; } static void do_default_vi(void) { show_regs(get_irq_regs()); panic("Caught unexpected vectored interrupt."); } static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs) { unsigned long handler; unsigned long old_handler = vi_handlers[n]; int srssets = current_cpu_data.srsets; u16 *h; unsigned char *b; BUG_ON(!cpu_has_veic && !cpu_has_vint); if (addr == NULL) { handler = (unsigned long) do_default_vi; srs = 0; } else handler = (unsigned long) addr; vi_handlers[n] = handler; b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING); if (srs >= srssets) panic("Shadow register set %d not supported", srs); if (cpu_has_veic) { if (board_bind_eic_interrupt) board_bind_eic_interrupt(n, srs); } else if (cpu_has_vint) { /* SRSMap is only defined if shadow sets are implemented */ if (srssets > 1) change_c0_srsmap(0xf << n*4, srs << n*4); } if (srs == 0) { /* * If no shadow set is selected then use the default handler * that does normal register saving and standard interrupt exit */ extern char except_vec_vi, except_vec_vi_lui; extern char except_vec_vi_ori, except_vec_vi_end; extern char rollback_except_vec_vi; char *vec_start = using_rollback_handler() ? &rollback_except_vec_vi : &except_vec_vi; #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN) const int lui_offset = &except_vec_vi_lui - vec_start + 2; const int ori_offset = &except_vec_vi_ori - vec_start + 2; #else const int lui_offset = &except_vec_vi_lui - vec_start; const int ori_offset = &except_vec_vi_ori - vec_start; #endif const int handler_len = &except_vec_vi_end - vec_start; if (handler_len > VECTORSPACING) { /* * Sigh... panicing won't help as the console * is probably not configured :( */ panic("VECTORSPACING too small"); } set_handler(((unsigned long)b - ebase), vec_start, #ifdef CONFIG_CPU_MICROMIPS (handler_len - 1)); #else handler_len); #endif h = (u16 *)(b + lui_offset); *h = (handler >> 16) & 0xffff; h = (u16 *)(b + ori_offset); *h = (handler & 0xffff); local_flush_icache_range((unsigned long)b, (unsigned long)(b+handler_len)); } else { /* * In other cases jump directly to the interrupt handler. It * is the handler's responsibility to save registers if required * (eg hi/lo) and return from the exception using "eret". */ u32 insn; h = (u16 *)b; /* j handler */ #ifdef CONFIG_CPU_MICROMIPS insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1); #else insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2); #endif h[0] = (insn >> 16) & 0xffff; h[1] = insn & 0xffff; h[2] = 0; h[3] = 0; local_flush_icache_range((unsigned long)b, (unsigned long)(b+8)); } return (void *)old_handler; } void *set_vi_handler(int n, vi_handler_t addr) { return set_vi_srs_handler(n, addr, 0); } extern void tlb_init(void); /* * Timer interrupt */ int cp0_compare_irq; EXPORT_SYMBOL_GPL(cp0_compare_irq); int cp0_compare_irq_shift; /* * Performance counter IRQ or -1 if shared with timer */ int cp0_perfcount_irq; EXPORT_SYMBOL_GPL(cp0_perfcount_irq); /* * Fast debug channel IRQ or -1 if not present */ int cp0_fdc_irq; EXPORT_SYMBOL_GPL(cp0_fdc_irq); static int noulri; static int __init ulri_disable(char *s) { pr_info("Disabling ulri\n"); noulri = 1; return 1; } __setup("noulri", ulri_disable); /* configure STATUS register */ static void configure_status(void) { /* * Disable coprocessors and select 32-bit or 64-bit addressing * and the 16/32 or 32/32 FPR register model. Reset the BEV * flag that some firmware may have left set and the TS bit (for * IP27). Set XX for ISA IV code to work. */ unsigned int status_set = ST0_CU0; #ifdef CONFIG_64BIT status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX; #endif if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV) status_set |= ST0_XX; if (cpu_has_dsp) status_set |= ST0_MX; change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX, status_set); } /* configure HWRENA register */ static void configure_hwrena(void) { unsigned int hwrena = cpu_hwrena_impl_bits; if (cpu_has_mips_r2_r6) hwrena |= 0x0000000f; if (!noulri && cpu_has_userlocal) hwrena |= (1 << 29); if (hwrena) write_c0_hwrena(hwrena); } static void configure_exception_vector(void) { if (cpu_has_veic || cpu_has_vint) { unsigned long sr = set_c0_status(ST0_BEV); write_c0_ebase(ebase); write_c0_status(sr); /* Setting vector spacing enables EI/VI mode */ change_c0_intctl(0x3e0, VECTORSPACING); } if (cpu_has_divec) { if (cpu_has_mipsmt) { unsigned int vpflags = dvpe(); set_c0_cause(CAUSEF_IV); evpe(vpflags); } else set_c0_cause(CAUSEF_IV); } } void per_cpu_trap_init(bool is_boot_cpu) { unsigned int cpu = smp_processor_id(); configure_status(); configure_hwrena(); configure_exception_vector(); /* * Before R2 both interrupt numbers were fixed to 7, so on R2 only: * * o read IntCtl.IPTI to determine the timer interrupt * o read IntCtl.IPPCI to determine the performance counter interrupt * o read IntCtl.IPFDC to determine the fast debug channel interrupt */ if (cpu_has_mips_r2_r6) { cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP; cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7; cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7; cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7; if (!cp0_fdc_irq) cp0_fdc_irq = -1; } else { cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ; cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ; cp0_perfcount_irq = -1; cp0_fdc_irq = -1; } if (!cpu_data[cpu].asid_cache) cpu_data[cpu].asid_cache = ASID_FIRST_VERSION; atomic_inc(&init_mm.mm_count); current->active_mm = &init_mm; BUG_ON(current->mm); enter_lazy_tlb(&init_mm, current); /* Boot CPU's cache setup in setup_arch(). */ if (!is_boot_cpu) cpu_cache_init(); tlb_init(); TLBMISS_HANDLER_SETUP(); } /* Install CPU exception handler */ void set_handler(unsigned long offset, void *addr, unsigned long size) { #ifdef CONFIG_CPU_MICROMIPS memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size); #else memcpy((void *)(ebase + offset), addr, size); #endif local_flush_icache_range(ebase + offset, ebase + offset + size); } static char panic_null_cerr[] = "Trying to set NULL cache error exception handler"; /* * Install uncached CPU exception handler. * This is suitable only for the cache error exception which is the only * exception handler that is being run uncached. */ void set_uncached_handler(unsigned long offset, void *addr, unsigned long size) { unsigned long uncached_ebase = CKSEG1ADDR(ebase); if (!addr) panic(panic_null_cerr); memcpy((void *)(uncached_ebase + offset), addr, size); } static int __initdata rdhwr_noopt; static int __init set_rdhwr_noopt(char *str) { rdhwr_noopt = 1; return 1; } __setup("rdhwr_noopt", set_rdhwr_noopt); void __init trap_init(void) { extern char except_vec3_generic; extern char except_vec4; extern char except_vec3_r4000; unsigned long i; check_wait(); if (cpu_has_veic || cpu_has_vint) { unsigned long size = 0x200 + VECTORSPACING*64; ebase = (unsigned long) __alloc_bootmem(size, 1 << fls(size), 0); } else { #ifdef CONFIG_KVM_GUEST #define KVM_GUEST_KSEG0 0x40000000 ebase = KVM_GUEST_KSEG0; #else ebase = CKSEG0; #endif if (cpu_has_mips_r2_r6) ebase += (read_c0_ebase() & 0x3ffff000); } if (cpu_has_mmips) { unsigned int config3 = read_c0_config3(); if (IS_ENABLED(CONFIG_CPU_MICROMIPS)) write_c0_config3(config3 | MIPS_CONF3_ISA_OE); else write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE); } if (board_ebase_setup) board_ebase_setup(); per_cpu_trap_init(true); /* * Copy the generic exception handlers to their final destination. * This will be overriden later as suitable for a particular * configuration. */ set_handler(0x180, &except_vec3_generic, 0x80); /* * Setup default vectors */ for (i = 0; i <= 31; i++) set_except_vector(i, handle_reserved); /* * Copy the EJTAG debug exception vector handler code to it's final * destination. */ if (cpu_has_ejtag && board_ejtag_handler_setup) board_ejtag_handler_setup(); /* * Only some CPUs have the watch exceptions. */ if (cpu_has_watch) set_except_vector(23, handle_watch); /* * Initialise interrupt handlers */ if (cpu_has_veic || cpu_has_vint) { int nvec = cpu_has_veic ? 64 : 8; for (i = 0; i < nvec; i++) set_vi_handler(i, NULL); } else if (cpu_has_divec) set_handler(0x200, &except_vec4, 0x8); /* * Some CPUs can enable/disable for cache parity detection, but does * it different ways. */ parity_protection_init(); /* * The Data Bus Errors / Instruction Bus Errors are signaled * by external hardware. Therefore these two exceptions * may have board specific handlers. */ if (board_be_init) board_be_init(); set_except_vector(0, using_rollback_handler() ? rollback_handle_int : handle_int); set_except_vector(1, handle_tlbm); set_except_vector(2, handle_tlbl); set_except_vector(3, handle_tlbs); set_except_vector(4, handle_adel); set_except_vector(5, handle_ades); set_except_vector(6, handle_ibe); set_except_vector(7, handle_dbe); set_except_vector(8, handle_sys); set_except_vector(9, handle_bp); set_except_vector(10, rdhwr_noopt ? handle_ri : (cpu_has_vtag_icache ? handle_ri_rdhwr_vivt : handle_ri_rdhwr)); set_except_vector(11, handle_cpu); set_except_vector(12, handle_ov); set_except_vector(13, handle_tr); set_except_vector(14, handle_msa_fpe); if (current_cpu_type() == CPU_R6000 || current_cpu_type() == CPU_R6000A) { /* * The R6000 is the only R-series CPU that features a machine * check exception (similar to the R4000 cache error) and * unaligned ldc1/sdc1 exception. The handlers have not been * written yet. Well, anyway there is no R6000 machine on the * current list of targets for Linux/MIPS. * (Duh, crap, there is someone with a triple R6k machine) */ //set_except_vector(14, handle_mc); //set_except_vector(15, handle_ndc); } if (board_nmi_handler_setup) board_nmi_handler_setup(); if (cpu_has_fpu && !cpu_has_nofpuex) set_except_vector(15, handle_fpe); set_except_vector(16, handle_ftlb); if (cpu_has_rixiex) { set_except_vector(19, tlb_do_page_fault_0); set_except_vector(20, tlb_do_page_fault_0); } set_except_vector(21, handle_msa); set_except_vector(22, handle_mdmx); if (cpu_has_mcheck) set_except_vector(24, handle_mcheck); if (cpu_has_mipsmt) set_except_vector(25, handle_mt); set_except_vector(26, handle_dsp); if (board_cache_error_setup) board_cache_error_setup(); if (cpu_has_vce) /* Special exception: R4[04]00 uses also the divec space. */ set_handler(0x180, &except_vec3_r4000, 0x100); else if (cpu_has_4kex) set_handler(0x180, &except_vec3_generic, 0x80); else set_handler(0x080, &except_vec3_generic, 0x80); local_flush_icache_range(ebase, ebase + 0x400); sort_extable(__start___dbe_table, __stop___dbe_table); cu2_notifier(default_cu2_call, 0x80000000); /* Run last */ } static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd, void *v) { switch (cmd) { case CPU_PM_ENTER_FAILED: case CPU_PM_EXIT: configure_status(); configure_hwrena(); configure_exception_vector(); /* Restore register with CPU number for TLB handlers */ TLBMISS_HANDLER_RESTORE(); break; } return NOTIFY_OK; } static struct notifier_block trap_pm_notifier_block = { .notifier_call = trap_pm_notifier, }; static int __init trap_pm_init(void) { return cpu_pm_register_notifier(&trap_pm_notifier_block); } arch_initcall(trap_pm_init);