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/kallsyms.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 #include <asm/cacheflush.h>
  29
  30 #define MICROBLAZE_ILL_OPCODE_EXCEPTION 0x02
  31 #define MICROBLAZE_IBUS_EXCEPTION       0x03
  32 #define MICROBLAZE_DBUS_EXCEPTION       0x04
  33 #define MICROBLAZE_DIV_ZERO_EXCEPTION   0x05
  34 #define MICROBLAZE_FPU_EXCEPTION        0x06
  35 #define MICROBLAZE_PRIVILEGED_EXCEPTION 0x07
  36
  37 static DEFINE_SPINLOCK(die_lock);
  38
  39 void die(const char *str, struct pt_regs *fp, long err)
  40 {
  41         console_verbose();
  42         spin_lock_irq(&die_lock);
  43         pr_warn("Oops: %s, sig: %ld\n", str, err);
  44         show_regs(fp);
  45         spin_unlock_irq(&die_lock);
  46         /* do_exit() should take care of panic'ing from an interrupt
  47          * context so we don't handle it here
  48          */
  49         do_exit(err);
  50 }
  51
  52 /* for user application debugging */
  53 asmlinkage void sw_exception(struct pt_regs *regs)
  54 {
  55         _exception(SIGTRAP, regs, TRAP_BRKPT, regs->r16);
  56         flush_dcache_range(regs->r16, regs->r16 + 0x4);
  57         flush_icache_range(regs->r16, regs->r16 + 0x4);
  58 }
  59
  60 void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
  61 {
  62         siginfo_t info;
  63
  64         if (kernel_mode(regs))
  65                 die("Exception in kernel mode", regs, signr);
  66
  67         info.si_signo = signr;
  68         info.si_errno = 0;
  69         info.si_code = code;
  70         info.si_addr = (void __user *) addr;
  71         force_sig_info(signr, &info, current);
  72 }
  73
  74 asmlinkage void full_exception(struct pt_regs *regs, unsigned int type,
  75                                                         int fsr, int addr)
  76 {
  77 #ifdef CONFIG_MMU
  78         addr = regs->pc;
  79 #endif
  80
  81 #if 0
  82         pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x 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("Illegal opcode exception in user mode\n");
  91                         _exception(SIGILL, regs, ILL_ILLOPC, addr);
  92                         return;
  93                 }
  94                 pr_warn("Illegal opcode exception 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                 pr_warn("Instruction bus error exception in kernel mode.\n");
 104                 die("bus exception", regs, SIGBUS);
 105                 break;
 106         case MICROBLAZE_DBUS_EXCEPTION:
 107                 if (user_mode(regs)) {
 108                         pr_debug("Data bus error exception in user mode\n");
 109                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 110                         return;
 111                 }
 112                 pr_warn("Data bus error exception in kernel mode.\n");
 113                 die("bus exception", regs, SIGBUS);
 114                 break;
 115         case MICROBLAZE_DIV_ZERO_EXCEPTION:
 116                 if (user_mode(regs)) {
 117                         pr_debug("Divide by zero exception in user mode\n");
 118                         _exception(SIGFPE, regs, FPE_INTDIV, addr);
 119                         return;
 120                 }
 121                 pr_warn("Divide by zero exception in kernel mode.\n");
 122                 die("Divide by zero exception", regs, SIGBUS);
 123                 break;
 124         case MICROBLAZE_FPU_EXCEPTION:
 125                 pr_debug("FPU exception\n");
 126                 /* IEEE FP exception */
 127                 /* I removed fsr variable and use code var for storing fsr */
 128                 if (fsr & FSR_IO)
 129                         fsr = FPE_FLTINV;
 130                 else if (fsr & FSR_OF)
 131                         fsr = FPE_FLTOVF;
 132                 else if (fsr & FSR_UF)
 133                         fsr = FPE_FLTUND;
 134                 else if (fsr & FSR_DZ)
 135                         fsr = FPE_FLTDIV;
 136                 else if (fsr & FSR_DO)
 137                         fsr = FPE_FLTRES;
 138                 _exception(SIGFPE, regs, fsr, addr);
 139                 break;
 140
 141 #ifdef CONFIG_MMU
 142         case MICROBLAZE_PRIVILEGED_EXCEPTION:
 143                 pr_debug("Privileged exception\n");
 144                 _exception(SIGILL, regs, ILL_PRVOPC, addr);
 145                 break;
 146 #endif
 147         default:
 148         /* FIXME what to do in unexpected exception */
 149                 pr_warn("Unexpected exception %02x PC=%08x in %s mode\n",
 150                         type, (unsigned int) addr,
 151                         kernel_mode(regs) ? "kernel" : "user");
 152         }
 153         return;
 154 }