arch/sparc/kernel/kgdb_64.c

   1 /* kgdb.c: KGDB support for 64-bit sparc.
   2  *
   3  * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
   4  */
   5
   6 #include <linux/kgdb.h>
   7 #include <linux/kdebug.h>
   8 #include <linux/ftrace.h>
   9
  10 #include <asm/kdebug.h>
  11 #include <asm/ptrace.h>
  12 #include <asm/irq.h>
  13
  14 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  15 {
  16         struct reg_window *win;
  17         int i;
  18
  19         gdb_regs[GDB_G0] = 0;
  20         for (i = 0; i < 15; i++)
  21                 gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
  22
  23         win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
  24         for (i = 0; i < 8; i++)
  25                 gdb_regs[GDB_L0 + i] = win->locals[i];
  26         for (i = 0; i < 8; i++)
  27                 gdb_regs[GDB_I0 + i] = win->ins[i];
  28
  29         for (i = GDB_F0; i <= GDB_F62; i++)
  30                 gdb_regs[i] = 0;
  31
  32         gdb_regs[GDB_PC] = regs->tpc;
  33         gdb_regs[GDB_NPC] = regs->tnpc;
  34         gdb_regs[GDB_STATE] = regs->tstate;
  35         gdb_regs[GDB_FSR] = 0;
  36         gdb_regs[GDB_FPRS] = 0;
  37         gdb_regs[GDB_Y] = regs->y;
  38 }
  39
  40 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  41 {
  42         struct thread_info *t = task_thread_info(p);
  43         extern unsigned int switch_to_pc;
  44         extern unsigned int ret_from_syscall;
  45         struct reg_window *win;
  46         unsigned long pc, cwp;
  47         int i;
  48
  49         for (i = GDB_G0; i < GDB_G6; i++)
  50                 gdb_regs[i] = 0;
  51         gdb_regs[GDB_G6] = (unsigned long) t;
  52         gdb_regs[GDB_G7] = (unsigned long) p;
  53         for (i = GDB_O0; i < GDB_SP; i++)
  54                 gdb_regs[i] = 0;
  55         gdb_regs[GDB_SP] = t->ksp;
  56         gdb_regs[GDB_O7] = 0;
  57
  58         win = (struct reg_window *) (t->ksp + STACK_BIAS);
  59         for (i = 0; i < 8; i++)
  60                 gdb_regs[GDB_L0 + i] = win->locals[i];
  61         for (i = 0; i < 8; i++)
  62                 gdb_regs[GDB_I0 + i] = win->ins[i];
  63
  64         for (i = GDB_F0; i <= GDB_F62; i++)
  65                 gdb_regs[i] = 0;
  66
  67         if (t->new_child)
  68                 pc = (unsigned long) &ret_from_syscall;
  69         else
  70                 pc = (unsigned long) &switch_to_pc;
  71
  72         gdb_regs[GDB_PC] = pc;
  73         gdb_regs[GDB_NPC] = pc + 4;
  74
  75         cwp = __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP];
  76
  77         gdb_regs[GDB_STATE] = (TSTATE_PRIV | TSTATE_IE | cwp);
  78         gdb_regs[GDB_FSR] = 0;
  79         gdb_regs[GDB_FPRS] = 0;
  80         gdb_regs[GDB_Y] = 0;
  81 }
  82
  83 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  84 {
  85         struct reg_window *win;
  86         int i;
  87
  88         for (i = 0; i < 15; i++)
  89                 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
  90
  91         /* If the TSTATE register is changing, we have to preserve
  92          * the CWP field, otherwise window save/restore explodes.
  93          */
  94         if (regs->tstate != gdb_regs[GDB_STATE]) {
  95                 unsigned long cwp = regs->tstate & TSTATE_CWP;
  96
  97                 regs->tstate = (gdb_regs[GDB_STATE] & ~TSTATE_CWP) | cwp;
  98         }
  99
 100         regs->tpc = gdb_regs[GDB_PC];
 101         regs->tnpc = gdb_regs[GDB_NPC];
 102         regs->y = gdb_regs[GDB_Y];
 103
 104         win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
 105         for (i = 0; i < 8; i++)
 106                 win->locals[i] = gdb_regs[GDB_L0 + i];
 107         for (i = 0; i < 8; i++)
 108                 win->ins[i] = gdb_regs[GDB_I0 + i];
 109 }
 110
 111 #ifdef CONFIG_SMP
 112 void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs)
 113 {
 114         unsigned long flags;
 115
 116         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 117                              "wrpr      %0, %1, %%pstate"
 118                              : "=r" (flags)
 119                              : "i" (PSTATE_IE));
 120
 121         flushw_all();
 122
 123         if (atomic_read(&kgdb_active) != -1)
 124                 kgdb_nmicallback(raw_smp_processor_id(), regs);
 125
 126         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 127                              : : "r" (flags));
 128 }
 129 #endif
 130
 131 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 132                                char *remcomInBuffer, char *remcomOutBuffer,
 133                                struct pt_regs *linux_regs)
 134 {
 135         unsigned long addr;
 136         char *ptr;
 137
 138         switch (remcomInBuffer[0]) {
 139         case 'c':
 140                 /* try to read optional parameter, pc unchanged if no parm */
 141                 ptr = &remcomInBuffer[1];
 142                 if (kgdb_hex2long(&ptr, &addr)) {
 143                         linux_regs->tpc = addr;
 144                         linux_regs->tnpc = addr + 4;
 145                 }
 146                 /* fallthru */
 147
 148         case 'D':
 149         case 'k':
 150                 if (linux_regs->tpc == (unsigned long) arch_kgdb_breakpoint) {
 151                         linux_regs->tpc = linux_regs->tnpc;
 152                         linux_regs->tnpc += 4;
 153                 }
 154                 return 0;
 155         }
 156         return -1;
 157 }
 158
 159 asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs)
 160 {
 161         unsigned long flags;
 162
 163         if (user_mode(regs)) {
 164                 bad_trap(regs, trap_level);
 165                 return;
 166         }
 167
 168         flushw_all();
 169
 170         local_irq_save(flags);
 171         kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
 172         local_irq_restore(flags);
 173 }
 174
 175 int kgdb_arch_init(void)
 176 {
 177         return 0;
 178 }
 179
 180 void kgdb_arch_exit(void)
 181 {
 182 }
 183
 184 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
 185 {
 186         regs->tpc = ip;
 187         regs->tnpc = regs->tpc + 4;
 188 }
 189
 190 struct kgdb_arch arch_kgdb_ops = {
 191         /* Breakpoint instruction: ta 0x72 */
 192         .gdb_bpt_instr          = { 0x91, 0xd0, 0x20, 0x72 },
 193 };