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/cacheflush.h>
  11 #include <asm/kdebug.h>
  12 #include <asm/ptrace.h>
  13 #include <asm/irq.h>
  14
  15 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  16 {
  17         struct reg_window *win;
  18         int i;
  19
  20         gdb_regs[GDB_G0] = 0;
  21         for (i = 0; i < 15; i++)
  22                 gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
  23
  24         win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
  25         for (i = 0; i < 8; i++)
  26                 gdb_regs[GDB_L0 + i] = win->locals[i];
  27         for (i = 0; i < 8; i++)
  28                 gdb_regs[GDB_I0 + i] = win->ins[i];
  29
  30         for (i = GDB_F0; i <= GDB_F62; i++)
  31                 gdb_regs[i] = 0;
  32
  33         gdb_regs[GDB_PC] = regs->tpc;
  34         gdb_regs[GDB_NPC] = regs->tnpc;
  35         gdb_regs[GDB_STATE] = regs->tstate;
  36         gdb_regs[GDB_FSR] = 0;
  37         gdb_regs[GDB_FPRS] = 0;
  38         gdb_regs[GDB_Y] = regs->y;
  39 }
  40
  41 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  42 {
  43         struct thread_info *t = task_thread_info(p);
  44         extern unsigned int switch_to_pc;
  45         extern unsigned int ret_from_syscall;
  46         struct reg_window *win;
  47         unsigned long pc, cwp;
  48         int i;
  49
  50         for (i = GDB_G0; i < GDB_G6; i++)
  51                 gdb_regs[i] = 0;
  52         gdb_regs[GDB_G6] = (unsigned long) t;
  53         gdb_regs[GDB_G7] = (unsigned long) p;
  54         for (i = GDB_O0; i < GDB_SP; i++)
  55                 gdb_regs[i] = 0;
  56         gdb_regs[GDB_SP] = t->ksp;
  57         gdb_regs[GDB_O7] = 0;
  58
  59         win = (struct reg_window *) (t->ksp + STACK_BIAS);
  60         for (i = 0; i < 8; i++)
  61                 gdb_regs[GDB_L0 + i] = win->locals[i];
  62         for (i = 0; i < 8; i++)
  63                 gdb_regs[GDB_I0 + i] = win->ins[i];
  64
  65         for (i = GDB_F0; i <= GDB_F62; i++)
  66                 gdb_regs[i] = 0;
  67
  68         if (t->new_child)
  69                 pc = (unsigned long) &ret_from_syscall;
  70         else
  71                 pc = (unsigned long) &switch_to_pc;
  72
  73         gdb_regs[GDB_PC] = pc;
  74         gdb_regs[GDB_NPC] = pc + 4;
  75
  76         cwp = __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP];
  77
  78         gdb_regs[GDB_STATE] = (TSTATE_PRIV | TSTATE_IE | cwp);
  79         gdb_regs[GDB_FSR] = 0;
  80         gdb_regs[GDB_FPRS] = 0;
  81         gdb_regs[GDB_Y] = 0;
  82 }
  83
  84 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  85 {
  86         struct reg_window *win;
  87         int i;
  88
  89         for (i = 0; i < 15; i++)
  90                 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
  91
  92         /* If the TSTATE register is changing, we have to preserve
  93          * the CWP field, otherwise window save/restore explodes.
  94          */
  95         if (regs->tstate != gdb_regs[GDB_STATE]) {
  96                 unsigned long cwp = regs->tstate & TSTATE_CWP;
  97
  98                 regs->tstate = (gdb_regs[GDB_STATE] & ~TSTATE_CWP) | cwp;
  99         }
 100
 101         regs->tpc = gdb_regs[GDB_PC];
 102         regs->tnpc = gdb_regs[GDB_NPC];
 103         regs->y = gdb_regs[GDB_Y];
 104
 105         win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
 106         for (i = 0; i < 8; i++)
 107                 win->locals[i] = gdb_regs[GDB_L0 + i];
 108         for (i = 0; i < 8; i++)
 109                 win->ins[i] = gdb_regs[GDB_I0 + i];
 110 }
 111
 112 #ifdef CONFIG_SMP
 113 void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs)
 114 {
 115         unsigned long flags;
 116
 117         __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
 118                              "wrpr      %0, %1, %%pstate"
 119                              : "=r" (flags)
 120                              : "i" (PSTATE_IE));
 121
 122         flushw_all();
 123
 124         if (atomic_read(&kgdb_active) != -1)
 125                 kgdb_nmicallback(raw_smp_processor_id(), regs);
 126
 127         __asm__ __volatile__("wrpr      %0, 0, %%pstate"
 128                              : : "r" (flags));
 129 }
 130 #endif
 131
 132 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 133                                char *remcomInBuffer, char *remcomOutBuffer,
 134                                struct pt_regs *linux_regs)
 135 {
 136         unsigned long addr;
 137         char *ptr;
 138
 139         switch (remcomInBuffer[0]) {
 140         case 'c':
 141                 /* try to read optional parameter, pc unchanged if no parm */
 142                 ptr = &remcomInBuffer[1];
 143                 if (kgdb_hex2long(&ptr, &addr)) {
 144                         linux_regs->tpc = addr;
 145                         linux_regs->tnpc = addr + 4;
 146                 }
 147                 /* fallthru */
 148
 149         case 'D':
 150         case 'k':
 151                 if (linux_regs->tpc == (unsigned long) arch_kgdb_breakpoint) {
 152                         linux_regs->tpc = linux_regs->tnpc;
 153                         linux_regs->tnpc += 4;
 154                 }
 155                 return 0;
 156         }
 157         return -1;
 158 }
 159
 160 asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs)
 161 {
 162         unsigned long flags;
 163
 164         if (user_mode(regs)) {
 165                 bad_trap(regs, trap_level);
 166                 return;
 167         }
 168
 169         flushw_all();
 170
 171         local_irq_save(flags);
 172         kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
 173         local_irq_restore(flags);
 174 }
 175
 176 int kgdb_arch_init(void)
 177 {
 178         return 0;
 179 }
 180
 181 void kgdb_arch_exit(void)
 182 {
 183 }
 184
 185 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
 186 {
 187         regs->tpc = ip;
 188         regs->tnpc = regs->tpc + 4;
 189 }
 190
 191 struct kgdb_arch arch_kgdb_ops = {
 192         /* Breakpoint instruction: ta 0x72 */
 193         .gdb_bpt_instr          = { 0x91, 0xd0, 0x20, 0x72 },
 194 };