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/kernel.h>
  17 #include <linux/signal.h>
  18 #include <linux/sched.h>
  19 #include <linux/kallsyms.h>
  20 #include <linux/module.h>
  21
  22 #include <asm/exceptions.h>
  23 #include <asm/entry.h>          /* For KM CPU var */
  24 #include <linux/uaccess.h>
  25 #include <linux/errno.h>
  26 #include <linux/ptrace.h>
  27 #include <asm/current.h>
  28
  29 #define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
  30 #define MICROBLAZE_IBUS_EXCEPTION       0x03
  31 #define MICROBLAZE_DBUS_EXCEPTION       0x04
  32 #define MICROBLAZE_DIV_ZERO_EXCEPTION   0x05
  33 #define MICROBLAZE_FPU_EXCEPTION        0x06
  34 #define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
  35
  36 static DEFINE_SPINLOCK(die_lock);
  37
  38 void die(const char *str, struct pt_regs *fp, long err)
  39 {
  40         console_verbose();
  41         spin_lock_irq(&die_lock);
  42         printk(KERN_WARNING "Oops: %s, sig: %ld\n", str, err);
  43         show_regs(fp);
  44         spin_unlock_irq(&die_lock);
  45         /* do_exit() should take care of panic'ing from an interrupt
  46          * context so we don't handle it here
  47          */
  48         do_exit(err);
  49 }
  50
  51 /* for user application debugging */
  52 void sw_exception(struct pt_regs *regs)
  53 {
  54         _exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
  55 }
  56
  57 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
  58 {
  59         siginfo_t info;
  60
  61         if (kernel_mode(regs)) {
  62                 die("Exception in kernel mode", regs, signr);
  63         }
  64         info.si_signo = signr;
  65         info.si_errno = 0;
  66         info.si_code = code;
  67         info.si_addr = (void __user *) addr;
  68         force_sig_info(signr, &info, current);
  69 }
  70
  71 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
  72                                                         int fsr, int addr)
  73 {
  74 #ifdef CONFIG_MMU
  75         int code;
  76         addr = regs->pc;
  77 #endif
  78
  79 #if 0
  80         printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \
  81                                                         "ESR=%08x\n",
  82                         type, user_mode(regs) ? "user" : "kernel", fsr,
  83                         (unsigned int) regs->pc, (unsigned int) regs->esr);
  84 #endif
  85
  86         switch (type & 0x1F) {
  87         case MICROBLAZE_ILL_OPCODE_EXCEPTION:
  88                 if (user_mode(regs)) {
  89                         pr_debug("Illegal opcode exception in user mode\n");
  90                         _exception(SIGILL, regs, ILL_ILLOPC, addr);
  91                         return;
  92                 }
  93                 printk(KERN_WARNING "Illegal opcode exception " \
  94                                                         "in kernel mode.\n");
  95                 die("opcode exception", regs, SIGBUS);
  96                 break;
  97         case MICROBLAZE_IBUS_EXCEPTION:
  98                 if (user_mode(regs)) {
  99                         pr_debug("Instruction bus error exception in user mode\n");
 100                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 101                         return;
 102                 }
 103                 printk(KERN_WARNING "Instruction bus error exception " \
 104                                                         "in kernel mode.\n");
 105                 die("bus exception", regs, SIGBUS);
 106                 break;
 107         case MICROBLAZE_DBUS_EXCEPTION:
 108                 if (user_mode(regs)) {
 109                         pr_debug("Data bus error exception in user mode\n");
 110                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 111                         return;
 112                 }
 113                 printk(KERN_WARNING "Data bus error exception " \
 114                                                         "in kernel mode.\n");
 115                 die("bus exception", regs, SIGBUS);
 116                 break;
 117         case MICROBLAZE_DIV_ZERO_EXCEPTION:
 118                 if (user_mode(regs)) {
 119                         pr_debug("Divide by zero exception in user mode\n");
 120                         _exception(SIGILL, regs, FPE_INTDIV, addr);
 121                         return;
 122                 }
 123                 printk(KERN_WARNING "Divide by zero exception " \
 124                                                         "in kernel mode.\n");
 125                 die("Divide by zero exception", regs, SIGBUS);
 126                 break;
 127         case MICROBLAZE_FPU_EXCEPTION:
 128                 pr_debug("FPU exception\n");
 129                 /* IEEE FP exception */
 130                 /* I removed fsr variable and use code var for storing fsr */
 131                 if (fsr & FSR_IO)
 132                         fsr = FPE_FLTINV;
 133                 else if (fsr & FSR_OF)
 134                         fsr = FPE_FLTOVF;
 135                 else if (fsr & FSR_UF)
 136                         fsr = FPE_FLTUND;
 137                 else if (fsr & FSR_DZ)
 138                         fsr = FPE_FLTDIV;
 139                 else if (fsr & FSR_DO)
 140                         fsr = FPE_FLTRES;
 141                 _exception(SIGFPE, regs, fsr, addr);
 142                 break;
 143
 144 #ifdef CONFIG_MMU
 145         case MICROBLAZE_PRIVILEGED_EXCEPTION:
 146                 pr_debug("Privileged exception\n");
 147                 /* "brk r0,r0" - used as debug breakpoint - old toolchain */
 148                 if (get_user(code, (unsigned long *)regs->pc) == 0
 149                         && code == 0x980c0000) {
 150                         _exception(SIGTRAP, regs, TRAP_BRKPT, addr);
 151                 } else {
 152                         _exception(SIGILL, regs, ILL_PRVOPC, addr);
 153                 }
 154                 break;
 155 #endif
 156         default:
 157         /* FIXME what to do in unexpected exception */
 158                 printk(KERN_WARNING "Unexpected exception %02x "
 159                         "PC=%08x in %s mode\n", type, (unsigned int) addr,
 160                         kernel_mode(regs) ? "kernel" : "user");
 161         }
 162         return;
 163 }