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
  38 static DEFINE_SPINLOCK(die_lock);
  39
  40 void 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 */
  54 asmlinkage 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
  61 void _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
  69 asmlinkage 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 }