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                 debugger(regs);
  63                 die("Exception in kernel mode", regs, signr);
  64         }
  65         info.si_signo = signr;
  66         info.si_errno = 0;
  67         info.si_code = code;
  68         info.si_addr = (void __user *) addr;
  69         force_sig_info(signr, &info, current);
  70 }
  71
  72 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
  73                                                         int fsr, int addr)
  74 {
  75 #ifdef CONFIG_MMU
  76         int code;
  77         addr = regs->pc;
  78 #endif
  79
  80 #if 0
  81         printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \
  82                                                         "ESR=%08x\n",
  83                         type, user_mode(regs) ? "user" : "kernel", fsr,
  84                         (unsigned int) regs->pc, (unsigned int) regs->esr);
  85 #endif
  86
  87         switch (type & 0x1F) {
  88         case MICROBLAZE_ILL_OPCODE_EXCEPTION:
  89                 if (user_mode(regs)) {
  90                         pr_debug(KERN_WARNING "Illegal opcode exception " \
  91                                                         "in user mode.\n");
  92                         _exception(SIGILL, regs, ILL_ILLOPC, addr);
  93                         return;
  94                 }
  95                 printk(KERN_WARNING "Illegal opcode exception " \
  96                                                         "in kernel mode.\n");
  97                 die("opcode exception", regs, SIGBUS);
  98                 break;
  99         case MICROBLAZE_IBUS_EXCEPTION:
 100                 if (user_mode(regs)) {
 101                         pr_debug(KERN_WARNING "Instruction bus error " \
 102                                                 "exception in user mode.\n");
 103                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 104                         return;
 105                 }
 106                 printk(KERN_WARNING "Instruction bus error exception " \
 107                                                         "in kernel mode.\n");
 108                 die("bus exception", regs, SIGBUS);
 109                 break;
 110         case MICROBLAZE_DBUS_EXCEPTION:
 111                 if (user_mode(regs)) {
 112                         pr_debug(KERN_WARNING "Data bus error exception " \
 113                                                         "in user mode.\n");
 114                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 115                         return;
 116                 }
 117                 printk(KERN_WARNING "Data bus error exception " \
 118                                                         "in kernel mode.\n");
 119                 die("bus exception", regs, SIGBUS);
 120                 break;
 121         case MICROBLAZE_DIV_ZERO_EXCEPTION:
 122                 if (user_mode(regs)) {
 123                         pr_debug(KERN_WARNING "Divide by zero exception " \
 124                                                         "in user mode\n");
 125                         _exception(SIGILL, regs, FPE_INTDIV, addr);
 126                         return;
 127                 }
 128                 printk(KERN_WARNING "Divide by zero exception " \
 129                                                         "in kernel mode.\n");
 130                 die("Divide by zero exception", regs, SIGBUS);
 131                 break;
 132         case MICROBLAZE_FPU_EXCEPTION:
 133                 pr_debug(KERN_WARNING "FPU exception\n");
 134                 /* IEEE FP exception */
 135                 /* I removed fsr variable and use code var for storing fsr */
 136                 if (fsr & FSR_IO)
 137                         fsr = FPE_FLTINV;
 138                 else if (fsr & FSR_OF)
 139                         fsr = FPE_FLTOVF;
 140                 else if (fsr & FSR_UF)
 141                         fsr = FPE_FLTUND;
 142                 else if (fsr & FSR_DZ)
 143                         fsr = FPE_FLTDIV;
 144                 else if (fsr & FSR_DO)
 145                         fsr = FPE_FLTRES;
 146                 _exception(SIGFPE, regs, fsr, addr);
 147                 break;
 148
 149 #ifdef CONFIG_MMU
 150         case MICROBLAZE_PRIVILEGED_EXCEPTION:
 151                 pr_debug(KERN_WARNING "Privileged exception\n");
 152                 /* "brk r0,r0" - used as debug breakpoint - old toolchain */
 153                 if (get_user(code, (unsigned long *)regs->pc) == 0
 154                         && code == 0x980c0000) {
 155                         _exception(SIGTRAP, regs, TRAP_BRKPT, addr);
 156                 } else {
 157                         _exception(SIGILL, regs, ILL_PRVOPC, addr);
 158                 }
 159                 break;
 160 #endif
 161         default:
 162         /* FIXME what to do in unexpected exception */
 163                 printk(KERN_WARNING "Unexpected exception %02x "
 164                         "PC=%08x in %s mode\n", type, (unsigned int) addr,
 165                         kernel_mode(regs) ? "kernel" : "user");
 166         }
 167         return;
 168 }