arch/sparc/kernel/kgdb_32.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 #include <linux/sched.h>
   9
  10 #include <asm/kdebug.h>
  11 #include <asm/ptrace.h>
  12 #include <asm/irq.h>
  13 #include <asm/cacheflush.h>
  14
  15 #include "kernel.h"
  16 #include "entry.h"
  17
  18 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  19 {
  20         struct reg_window32 *win;
  21         int i;
  22
  23         gdb_regs[GDB_G0] = 0;
  24         for (i = 0; i < 15; i++)
  25                 gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
  26
  27         win = (struct reg_window32 *) regs->u_regs[UREG_FP];
  28         for (i = 0; i < 8; i++)
  29                 gdb_regs[GDB_L0 + i] = win->locals[i];
  30         for (i = 0; i < 8; i++)
  31                 gdb_regs[GDB_I0 + i] = win->ins[i];
  32
  33         for (i = GDB_F0; i <= GDB_F31; i++)
  34                 gdb_regs[i] = 0;
  35
  36         gdb_regs[GDB_Y] = regs->y;
  37         gdb_regs[GDB_PSR] = regs->psr;
  38         gdb_regs[GDB_WIM] = 0;
  39         gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  40         gdb_regs[GDB_PC] = regs->pc;
  41         gdb_regs[GDB_NPC] = regs->npc;
  42         gdb_regs[GDB_FSR] = 0;
  43         gdb_regs[GDB_CSR] = 0;
  44 }
  45
  46 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  47 {
  48         struct thread_info *t = task_thread_info(p);
  49         struct reg_window32 *win;
  50         int i;
  51
  52         for (i = GDB_G0; i < GDB_G6; i++)
  53                 gdb_regs[i] = 0;
  54         gdb_regs[GDB_G6] = (unsigned long) t;
  55         gdb_regs[GDB_G7] = 0;
  56         for (i = GDB_O0; i < GDB_SP; i++)
  57                 gdb_regs[i] = 0;
  58         gdb_regs[GDB_SP] = t->ksp;
  59         gdb_regs[GDB_O7] = 0;
  60
  61         win = (struct reg_window32 *) t->ksp;
  62         for (i = 0; i < 8; i++)
  63                 gdb_regs[GDB_L0 + i] = win->locals[i];
  64         for (i = 0; i < 8; i++)
  65                 gdb_regs[GDB_I0 + i] = win->ins[i];
  66
  67         for (i = GDB_F0; i <= GDB_F31; i++)
  68                 gdb_regs[i] = 0;
  69
  70         gdb_regs[GDB_Y] = 0;
  71
  72         gdb_regs[GDB_PSR] = t->kpsr;
  73         gdb_regs[GDB_WIM] = t->kwim;
  74         gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  75         gdb_regs[GDB_PC] = t->kpc;
  76         gdb_regs[GDB_NPC] = t->kpc + 4;
  77         gdb_regs[GDB_FSR] = 0;
  78         gdb_regs[GDB_CSR] = 0;
  79 }
  80
  81 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  82 {
  83         struct reg_window32 *win;
  84         int i;
  85
  86         for (i = 0; i < 15; i++)
  87                 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
  88
  89         /* If the PSR register is changing, we have to preserve
  90          * the CWP field, otherwise window save/restore explodes.
  91          */
  92         if (regs->psr != gdb_regs[GDB_PSR]) {
  93                 unsigned long cwp = regs->psr & PSR_CWP;
  94
  95                 regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp;
  96         }
  97
  98         regs->pc = gdb_regs[GDB_PC];
  99         regs->npc = gdb_regs[GDB_NPC];
 100         regs->y = gdb_regs[GDB_Y];
 101
 102         win = (struct reg_window32 *) regs->u_regs[UREG_FP];
 103         for (i = 0; i < 8; i++)
 104                 win->locals[i] = gdb_regs[GDB_L0 + i];
 105         for (i = 0; i < 8; i++)
 106                 win->ins[i] = gdb_regs[GDB_I0 + i];
 107 }
 108
 109 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 110                                char *remcomInBuffer, char *remcomOutBuffer,
 111                                struct pt_regs *linux_regs)
 112 {
 113         unsigned long addr;
 114         char *ptr;
 115
 116         switch (remcomInBuffer[0]) {
 117         case 'c':
 118                 /* try to read optional parameter, pc unchanged if no parm */
 119                 ptr = &remcomInBuffer[1];
 120                 if (kgdb_hex2long(&ptr, &addr)) {
 121                         linux_regs->pc = addr;
 122                         linux_regs->npc = addr + 4;
 123                 }
 124                 /* fallthru */
 125
 126         case 'D':
 127         case 'k':
 128                 if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) {
 129                         linux_regs->pc = linux_regs->npc;
 130                         linux_regs->npc += 4;
 131                 }
 132                 return 0;
 133         }
 134         return -1;
 135 }
 136
 137 asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs)
 138 {
 139         unsigned long flags;
 140
 141         if (user_mode(regs)) {
 142                 do_hw_interrupt(regs, trap_level);
 143                 return;
 144         }
 145
 146         flushw_all();
 147
 148         local_irq_save(flags);
 149         kgdb_handle_exception(trap_level, SIGTRAP, 0, regs);
 150         local_irq_restore(flags);
 151 }
 152
 153 int kgdb_arch_init(void)
 154 {
 155         return 0;
 156 }
 157
 158 void kgdb_arch_exit(void)
 159 {
 160 }
 161
 162 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
 163 {
 164         regs->pc = ip;
 165         regs->npc = regs->pc + 4;
 166 }
 167
 168 struct kgdb_arch arch_kgdb_ops = {
 169         /* Breakpoint instruction: ta 0x7d */
 170         .gdb_bpt_instr          = { 0x91, 0xd0, 0x20, 0x7d },
 171 };