LXR linux/arch/microblaze/kernel/exceptions.c

   1/*
   2 * HW exception handling
   3 *
   4 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
   5 * Copyright (C) 2008 PetaLogix
   6 *
   7 * This file is subject to the terms and conditions of the GNU General
   8 * Public License.  See the file COPYING in the main directory of this
   9 * archive for more details.
  10 */
  11
  12/*
  13 * This file handles the architecture-dependent parts of hardware exceptions
  14 */
  15
  16#include <linux/export.h>
  17#include <linux/kernel.h>
  18#include <linux/signal.h>
  19#include <linux/sched.h>
  20#include <linux/sched/debug.h>
  21#include <linux/kallsyms.h>
  22
  23#include <asm/exceptions.h>
  24#include <asm/entry.h>          /* For KM CPU var */
  25#include <linux/uaccess.h>
  26#include <linux/errno.h>
  27#include <linux/ptrace.h>
  28#include <asm/current.h>
  29#include <asm/cacheflush.h>
  30
  31#define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
  32#define MICROBLAZE_IBUS_EXCEPTION       0x03
  33#define MICROBLAZE_DBUS_EXCEPTION       0x04
  34#define MICROBLAZE_DIV_ZERO_EXCEPTION   0x05
  35#define MICROBLAZE_FPU_EXCEPTION        0x06
  36#define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
  37
  38static DEFINE_SPINLOCK(die_lock);
  39
  40void die(const char *str, struct pt_regs *fp, long err)
  41{
  42        console_verbose();
  43        spin_lock_irq(&die_lock);
  44        pr_warn("Oops: %s, sig: %ld\n", str, err);
  45        show_regs(fp);
  46        spin_unlock_irq(&die_lock);
  47        /* do_exit() should take care of panic'ing from an interrupt
  48         * context so we don't handle it here
  49         */
  50        do_exit(err);
  51}
  52
  53/* for user application debugging */
  54asmlinkage void sw_exception(struct pt_regs *regs)
  55{
  56        _exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
  57        flush_dcache_range(regs->r16, regs->r16 + 0x4);
  58        flush_icache_range(regs->r16, regs->r16 + 0x4);
  59}
  60
  61void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
  62{
  63        if (kernel_mode(regs))
  64                die("Exception in kernel mode", regs, signr);
  65
  66        force_sig_fault(signr, code, (void __user *)addr);
  67}
  68
  69asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
  70                                                        int fsr, int addr)
  71{
  72#ifdef CONFIG_MMU
  73        addr = regs->pc;
  74#endif
  75
  76#if 0
  77        pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
  78                        type, user_mode(regs) ? "user" : "kernel", fsr,
  79                        (unsigned int) regs->pc, (unsigned int) regs->esr);
  80#endif
  81
  82        switch (type & 0x1F) {
  83        case MICROBLAZE_ILL_OPCODE_EXCEPTION:
  84                if (user_mode(regs)) {
  85                        pr_debug("Illegal opcode exception in user mode\n");
  86                        _exception(SIGILL, regs, ILL_ILLOPC, addr);
  87                        return;
  88                }
  89                pr_warn("Illegal opcode exception in kernel mode.\n");
  90                die("opcode exception", regs, SIGBUS);
  91                break;
  92        case MICROBLAZE_IBUS_EXCEPTION:
  93                if (user_mode(regs)) {
  94                        pr_debug("Instruction bus error exception in user mode\n");
  95                        _exception(SIGBUS, regs, BUS_ADRERR, addr);
  96                        return;
  97                }
  98                pr_warn("Instruction bus error exception in kernel mode.\n");
  99                die("bus exception", regs, SIGBUS);
 100                break;
 101        case MICROBLAZE_DBUS_EXCEPTION:
 102                if (user_mode(regs)) {
 103                        pr_debug("Data bus error exception in user mode\n");
 104                        _exception(SIGBUS, regs, BUS_ADRERR, addr);
 105                        return;
 106                }
 107                pr_warn("Data bus error exception in kernel mode.\n");
 108                die("bus exception", regs, SIGBUS);
 109                break;
 110        case MICROBLAZE_DIV_ZERO_EXCEPTION:
 111                if (user_mode(regs)) {
 112                        pr_debug("Divide by zero exception in user mode\n");
 113                        _exception(SIGFPE, regs, FPE_INTDIV, addr);
 114                        return;
 115                }
 116                pr_warn("Divide by zero exception in kernel mode.\n");
 117                die("Divide by zero exception", regs, SIGBUS);
 118                break;
 119        case MICROBLAZE_FPU_EXCEPTION:
 120                pr_debug("FPU exception\n");
 121                /* IEEE FP exception */
 122                /* I removed fsr variable and use code var for storing fsr */
 123                if (fsr & FSR_IO)
 124                        fsr = FPE_FLTINV;
 125                else if (fsr & FSR_OF)
 126                        fsr = FPE_FLTOVF;
 127                else if (fsr & FSR_UF)
 128                        fsr = FPE_FLTUND;
 129                else if (fsr & FSR_DZ)
 130                        fsr = FPE_FLTDIV;
 131                else if (fsr & FSR_DO)
 132                        fsr = FPE_FLTRES;
 133                _exception(SIGFPE, regs, fsr, addr);
 134                break;
 135
 136#ifdef CONFIG_MMU
 137        case MICROBLAZE_PRIVILEGED_EXCEPTION:
 138                pr_debug("Privileged exception\n");
 139                _exception(SIGILL, regs, ILL_PRVOPC, addr);
 140                break;
 141#endif
 142        default:
 143        /* FIXME what to do in unexpected exception */
 144                pr_warn("Unexpected exception %02x PC=%08x in %s mode\n",
 145                        type, (unsigned int) addr,
 146                        kernel_mode(regs) ? "kernel" : "user");
 147        }
 148        return;
 149}
 150