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         addr = regs->pc;
  73
  74 #if 0
  75         pr_warn("Exception %02x in %s mode, FSR=%08x PC=%08x ESR=%08x\n",
  76                         type, user_mode(regs) ? "user" : "kernel", fsr,
  77                         (unsigned int) regs->pc, (unsigned int) regs->esr);
  78 #endif
  79
  80         switch (type & 0x1F) {
  81         case MICROBLAZE_ILL_OPCODE_EXCEPTION:
  82                 if (user_mode(regs)) {
  83                         pr_debug("Illegal opcode exception in user mode\n");
  84                         _exception(SIGILL, regs, ILL_ILLOPC, addr);
  85                         return;
  86                 }
  87                 pr_warn("Illegal opcode exception in kernel mode.\n");
  88                 die("opcode exception", regs, SIGBUS);
  89                 break;
  90         case MICROBLAZE_IBUS_EXCEPTION:
  91                 if (user_mode(regs)) {
  92                         pr_debug("Instruction bus error exception in user mode\n");
  93                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
  94                         return;
  95                 }
  96                 pr_warn("Instruction bus error exception in kernel mode.\n");
  97                 die("bus exception", regs, SIGBUS);
  98                 break;
  99         case MICROBLAZE_DBUS_EXCEPTION:
 100                 if (user_mode(regs)) {
 101                         pr_debug("Data bus error exception in user mode\n");
 102                         _exception(SIGBUS, regs, BUS_ADRERR, addr);
 103                         return;
 104                 }
 105                 pr_warn("Data bus error exception in kernel mode.\n");
 106                 die("bus exception", regs, SIGBUS);
 107                 break;
 108         case MICROBLAZE_DIV_ZERO_EXCEPTION:
 109                 if (user_mode(regs)) {
 110                         pr_debug("Divide by zero exception in user mode\n");
 111                         _exception(SIGFPE, regs, FPE_INTDIV, addr);
 112                         return;
 113                 }
 114                 pr_warn("Divide by zero exception in kernel mode.\n");
 115                 die("Divide by zero exception", regs, SIGBUS);
 116                 break;
 117         case MICROBLAZE_FPU_EXCEPTION:
 118                 pr_debug("FPU exception\n");
 119                 /* IEEE FP exception */
 120                 /* I removed fsr variable and use code var for storing fsr */
 121                 if (fsr & FSR_IO)
 122                         fsr = FPE_FLTINV;
 123                 else if (fsr & FSR_OF)
 124                         fsr = FPE_FLTOVF;
 125                 else if (fsr & FSR_UF)
 126                         fsr = FPE_FLTUND;
 127                 else if (fsr & FSR_DZ)
 128                         fsr = FPE_FLTDIV;
 129                 else if (fsr & FSR_DO)
 130                         fsr = FPE_FLTRES;
 131                 _exception(SIGFPE, regs, fsr, addr);
 132                 break;
 133         case MICROBLAZE_PRIVILEGED_EXCEPTION:
 134                 pr_debug("Privileged exception\n");
 135                 _exception(SIGILL, regs, ILL_PRVOPC, addr);
 136                 break;
 137         default:
 138         /* FIXME what to do in unexpected exception */
 139                 pr_warn("Unexpected exception %02x PC=%08x in %s mode\n",
 140                         type, (unsigned int) addr,
 141                         kernel_mode(regs) ? "kernel" : "user");
 142         }
 143         return;
 144 }