arch/sparc/kernel/kgdb.c

   1 /* kgdb.c: KGDB support for 32-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
   9 #include <asm/kdebug.h>
  10 #include <asm/ptrace.h>
  11 #include <asm/irq.h>
  12
  13 extern unsigned long trapbase;
  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];
  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_F31; i++)
  31                 gdb_regs[i] = 0;
  32
  33         gdb_regs[GDB_Y] = regs->y;
  34         gdb_regs[GDB_PSR] = regs->psr;
  35         gdb_regs[GDB_WIM] = 0;
  36         gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  37         gdb_regs[GDB_PC] = regs->pc;
  38         gdb_regs[GDB_NPC] = regs->npc;
  39         gdb_regs[GDB_FSR] = 0;
  40         gdb_regs[GDB_CSR] = 0;
  41 }
  42
  43 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  44 {
  45         struct thread_info *t = task_thread_info(p);
  46         struct reg_window *win;
  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] = 0;
  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;
  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_F31; i++)
  65                 gdb_regs[i] = 0;
  66
  67         gdb_regs[GDB_Y] = 0;
  68
  69         gdb_regs[GDB_PSR] = t->kpsr;
  70         gdb_regs[GDB_WIM] = t->kwim;
  71         gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  72         gdb_regs[GDB_PC] = t->kpc;
  73         gdb_regs[GDB_NPC] = t->kpc + 4;
  74         gdb_regs[GDB_FSR] = 0;
  75         gdb_regs[GDB_CSR] = 0;
  76 }
  77
  78 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  79 {
  80         struct reg_window *win;
  81         int i;
  82
  83         for (i = 0; i < 15; i++)
  84                 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
  85
  86         /* If the PSR register is changing, we have to preserve
  87          * the CWP field, otherwise window save/restore explodes.
  88          */
  89         if (regs->psr != gdb_regs[GDB_PSR]) {
  90                 unsigned long cwp = regs->psr & PSR_CWP;
  91
  92                 regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp;
  93         }
  94
  95         regs->pc = gdb_regs[GDB_PC];
  96         regs->npc = gdb_regs[GDB_NPC];
  97         regs->y = gdb_regs[GDB_Y];
  98
  99         win = (struct reg_window *) regs->u_regs[UREG_FP];
 100         for (i = 0; i < 8; i++)
 101                 win->locals[i] = gdb_regs[GDB_L0 + i];
 102         for (i = 0; i < 8; i++)
 103                 win->ins[i] = gdb_regs[GDB_I0 + i];
 104 }
 105
 106 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 107                                char *remcomInBuffer, char *remcomOutBuffer,
 108                                struct pt_regs *linux_regs)
 109 {
 110         unsigned long addr;
 111         char *ptr;
 112
 113         switch (remcomInBuffer[0]) {
 114         case 'c':
 115                 /* try to read optional parameter, pc unchanged if no parm */
 116                 ptr = &remcomInBuffer[1];
 117                 if (kgdb_hex2long(&ptr, &addr)) {
 118                         linux_regs->pc = addr;
 119                         linux_regs->npc = addr + 4;
 120                 }
 121                 /* fallthru */
 122
 123         case 'D':
 124         case 'k':
 125                 if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) {
 126                         linux_regs->pc = linux_regs->npc;
 127                         linux_regs->npc += 4;
 128                 }
 129                 return 0;
 130         }
 131         return -1;
 132 }
 133
 134 extern void do_hw_interrupt(struct pt_regs *regs, unsigned long type);
 135
 136 asmlinkage void kgdb_trap(struct pt_regs *regs)
 137 {
 138         unsigned long flags;
 139
 140         if (user_mode(regs)) {
 141                 do_hw_interrupt(regs, 0xfd);
 142                 return;
 143         }
 144
 145         flushw_all();
 146
 147         local_irq_save(flags);
 148         kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
 149         local_irq_restore(flags);
 150 }
 151
 152 int kgdb_arch_init(void)
 153 {
 154         return 0;
 155 }
 156
 157 void kgdb_arch_exit(void)
 158 {
 159 }
 160
 161 struct kgdb_arch arch_kgdb_ops = {
 162         /* Breakpoint instruction: ta 0x7d */
 163         .gdb_bpt_instr          = { 0x91, 0xd0, 0x20, 0x7d },
 164 };