arch/csky/kernel/traps.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/sched.h>
   5 #include <linux/signal.h>
   6 #include <linux/kernel.h>
   7 #include <linux/mm.h>
   8 #include <linux/module.h>
   9 #include <linux/user.h>
  10 #include <linux/string.h>
  11 #include <linux/linkage.h>
  12 #include <linux/init.h>
  13 #include <linux/ptrace.h>
  14 #include <linux/kallsyms.h>
  15 #include <linux/rtc.h>
  16 #include <linux/uaccess.h>
  17
  18 #include <asm/setup.h>
  19 #include <asm/traps.h>
  20 #include <asm/pgalloc.h>
  21 #include <asm/siginfo.h>
  22
  23 #include <asm/mmu_context.h>
  24
  25 #ifdef CONFIG_CPU_HAS_FPU
  26 #include <abi/fpu.h>
  27 #endif
  28
  29 /* Defined in entry.S */
  30 asmlinkage void csky_trap(void);
  31
  32 asmlinkage void csky_systemcall(void);
  33 asmlinkage void csky_cmpxchg(void);
  34 asmlinkage void csky_get_tls(void);
  35 asmlinkage void csky_irq(void);
  36
  37 asmlinkage void csky_tlbinvalidl(void);
  38 asmlinkage void csky_tlbinvalids(void);
  39 asmlinkage void csky_tlbmodified(void);
  40
  41 /* Defined in head.S */
  42 asmlinkage void _start_smp_secondary(void);
  43
  44 void __init pre_trap_init(void)
  45 {
  46         int i;
  47
  48         mtcr("vbr", vec_base);
  49
  50         for (i = 1; i < 128; i++)
  51                 VEC_INIT(i, csky_trap);
  52 }
  53
  54 void __init trap_init(void)
  55 {
  56         VEC_INIT(VEC_AUTOVEC, csky_irq);
  57
  58         /* setup trap0 trap2 trap3 */
  59         VEC_INIT(VEC_TRAP0, csky_systemcall);
  60         VEC_INIT(VEC_TRAP2, csky_cmpxchg);
  61         VEC_INIT(VEC_TRAP3, csky_get_tls);
  62
  63         /* setup MMU TLB exception */
  64         VEC_INIT(VEC_TLBINVALIDL, csky_tlbinvalidl);
  65         VEC_INIT(VEC_TLBINVALIDS, csky_tlbinvalids);
  66         VEC_INIT(VEC_TLBMODIFIED, csky_tlbmodified);
  67
  68 #ifdef CONFIG_CPU_HAS_FPU
  69         init_fpu();
  70 #endif
  71
  72 #ifdef CONFIG_SMP
  73         mtcr("cr<28, 0>", virt_to_phys(vec_base));
  74
  75         VEC_INIT(VEC_RESET, (void *)virt_to_phys(_start_smp_secondary));
  76 #endif
  77 }
  78
  79 void die_if_kernel(char *str, struct pt_regs *regs, int nr)
  80 {
  81         if (user_mode(regs))
  82                 return;
  83
  84         console_verbose();
  85         pr_err("%s: %08x\n", str, nr);
  86         show_regs(regs);
  87         add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
  88         do_exit(SIGSEGV);
  89 }
  90
  91 void buserr(struct pt_regs *regs)
  92 {
  93 #ifdef CONFIG_CPU_CK810
  94         static unsigned long prev_pc;
  95
  96         if ((regs->pc == prev_pc) && prev_pc != 0) {
  97                 prev_pc = 0;
  98         } else {
  99                 prev_pc = regs->pc;
 100                 return;
 101         }
 102 #endif
 103
 104         die_if_kernel("Kernel mode BUS error", regs, 0);
 105
 106         pr_err("User mode Bus Error\n");
 107         show_regs(regs);
 108
 109         force_sig_fault(SIGSEGV, 0, (void __user *)regs->pc);
 110 }
 111
 112 #define USR_BKPT 0x1464
 113 asmlinkage void trap_c(struct pt_regs *regs)
 114 {
 115         int sig;
 116         unsigned long vector;
 117         siginfo_t info;
 118
 119         vector = (mfcr("psr") >> 16) & 0xff;
 120
 121         switch (vector) {
 122         case VEC_ZERODIV:
 123                 die_if_kernel("Kernel mode ZERO DIV", regs, vector);
 124                 sig = SIGFPE;
 125                 break;
 126         /* ptrace */
 127         case VEC_TRACE:
 128                 info.si_code = TRAP_TRACE;
 129                 sig = SIGTRAP;
 130                 break;
 131         case VEC_ILLEGAL:
 132                 die_if_kernel("Kernel mode ILLEGAL", regs, vector);
 133 #ifndef CONFIG_CPU_NO_USER_BKPT
 134                 if (*(uint16_t *)instruction_pointer(regs) != USR_BKPT)
 135 #endif
 136                 {
 137                         sig = SIGILL;
 138                         break;
 139                 }
 140         /* gdbserver  breakpoint */
 141         case VEC_TRAP1:
 142         /* jtagserver breakpoint */
 143         case VEC_BREAKPOINT:
 144                 die_if_kernel("Kernel mode BKPT", regs, vector);
 145                 info.si_code = TRAP_BRKPT;
 146                 sig = SIGTRAP;
 147                 break;
 148         case VEC_ACCESS:
 149                 return buserr(regs);
 150 #ifdef CONFIG_CPU_NEED_SOFTALIGN
 151         case VEC_ALIGN:
 152                 return csky_alignment(regs);
 153 #endif
 154 #ifdef CONFIG_CPU_HAS_FPU
 155         case VEC_FPE:
 156                 die_if_kernel("Kernel mode FPE", regs, vector);
 157                 return fpu_fpe(regs);
 158         case VEC_PRIV:
 159                 die_if_kernel("Kernel mode PRIV", regs, vector);
 160                 if (fpu_libc_helper(regs))
 161                         return;
 162 #endif
 163         default:
 164                 sig = SIGSEGV;
 165                 break;
 166         }
 167         send_sig(sig, current, 0);
 168 }