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 #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 printk(KERN_WARNING "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 printk(KERN_WARNING "Exception %02x in %s mode, FSR=%08x PC=%08x " \ 83 "ESR=%08x\n", 84 type, user_mode(regs) ? "user" : "kernel", fsr, 85 (unsigned int) regs->pc, (unsigned int) regs->esr); 86 #endif 87 88 switch (type & 0x1F) { 89 case MICROBLAZE_ILL_OPCODE_EXCEPTION: 90 if (user_mode(regs)) { 91 pr_debug("Illegal opcode exception 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("Instruction bus error exception in user mode\n"); 102 _exception(SIGBUS, regs, BUS_ADRERR, addr); 103 return; 104 } 105 printk(KERN_WARNING "Instruction bus error exception " \ 106 "in kernel mode.\n"); 107 die("bus exception", regs, SIGBUS); 108 break; 109 case MICROBLAZE_DBUS_EXCEPTION: 110 if (user_mode(regs)) { 111 pr_debug("Data bus error exception in user mode\n"); 112 _exception(SIGBUS, regs, BUS_ADRERR, addr); 113 return; 114 } 115 printk(KERN_WARNING "Data bus error exception " \ 116 "in kernel mode.\n"); 117 die("bus exception", regs, SIGBUS); 118 break; 119 case MICROBLAZE_DIV_ZERO_EXCEPTION: 120 if (user_mode(regs)) { 121 pr_debug("Divide by zero exception in user mode\n"); 122 _exception(SIGFPE, regs, FPE_INTDIV, addr); 123 return; 124 } 125 printk(KERN_WARNING "Divide by zero exception " \ 126 "in kernel mode.\n"); 127 die("Divide by zero exception", regs, SIGBUS); 128 break; 129 case MICROBLAZE_FPU_EXCEPTION: 130 pr_debug("FPU exception\n"); 131 /* IEEE FP exception */ 132 /* I removed fsr variable and use code var for storing fsr */ 133 if (fsr & FSR_IO) 134 fsr = FPE_FLTINV; 135 else if (fsr & FSR_OF) 136 fsr = FPE_FLTOVF; 137 else if (fsr & FSR_UF) 138 fsr = FPE_FLTUND; 139 else if (fsr & FSR_DZ) 140 fsr = FPE_FLTDIV; 141 else if (fsr & FSR_DO) 142 fsr = FPE_FLTRES; 143 _exception(SIGFPE, regs, fsr, addr); 144 break; 145 146 #ifdef CONFIG_MMU 147 case MICROBLAZE_PRIVILEGED_EXCEPTION: 148 pr_debug("Privileged exception\n"); 149 _exception(SIGILL, regs, ILL_PRVOPC, addr); 150 break; 151 #endif 152 default: 153 /* FIXME what to do in unexpected exception */ 154 printk(KERN_WARNING "Unexpected exception %02x " 155 "PC=%08x in %s mode\n", type, (unsigned int) addr, 156 kernel_mode(regs) ? "kernel" : "user"); 157 } 158 return; 159 } 160