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 extern unsigned long trapbase;
  16
  17 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  18 {
  19         struct reg_window32 *win;
  20         int i;
  21
  22         gdb_regs[GDB_G0] = 0;
  23         for (i = 0; i < 15; i++)
  24                 gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
  25
  26         win = (struct reg_window32 *) regs->u_regs[UREG_FP];
  27         for (i = 0; i < 8; i++)
  28                 gdb_regs[GDB_L0 + i] = win->locals[i];
  29         for (i = 0; i < 8; i++)
  30                 gdb_regs[GDB_I0 + i] = win->ins[i];
  31
  32         for (i = GDB_F0; i <= GDB_F31; i++)
  33                 gdb_regs[i] = 0;
  34
  35         gdb_regs[GDB_Y] = regs->y;
  36         gdb_regs[GDB_PSR] = regs->psr;
  37         gdb_regs[GDB_WIM] = 0;
  38         gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  39         gdb_regs[GDB_PC] = regs->pc;
  40         gdb_regs[GDB_NPC] = regs->npc;
  41         gdb_regs[GDB_FSR] = 0;
  42         gdb_regs[GDB_CSR] = 0;
  43 }
  44
  45 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  46 {
  47         struct thread_info *t = task_thread_info(p);
  48         struct reg_window32 *win;
  49         int i;
  50
  51         for (i = GDB_G0; i < GDB_G6; i++)
  52                 gdb_regs[i] = 0;
  53         gdb_regs[GDB_G6] = (unsigned long) t;
  54         gdb_regs[GDB_G7] = 0;
  55         for (i = GDB_O0; i < GDB_SP; i++)
  56                 gdb_regs[i] = 0;
  57         gdb_regs[GDB_SP] = t->ksp;
  58         gdb_regs[GDB_O7] = 0;
  59
  60         win = (struct reg_window32 *) t->ksp;
  61         for (i = 0; i < 8; i++)
  62                 gdb_regs[GDB_L0 + i] = win->locals[i];
  63         for (i = 0; i < 8; i++)
  64                 gdb_regs[GDB_I0 + i] = win->ins[i];
  65
  66         for (i = GDB_F0; i <= GDB_F31; i++)
  67                 gdb_regs[i] = 0;
  68
  69         gdb_regs[GDB_Y] = 0;
  70
  71         gdb_regs[GDB_PSR] = t->kpsr;
  72         gdb_regs[GDB_WIM] = t->kwim;
  73         gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  74         gdb_regs[GDB_PC] = t->kpc;
  75         gdb_regs[GDB_NPC] = t->kpc + 4;
  76         gdb_regs[GDB_FSR] = 0;
  77         gdb_regs[GDB_CSR] = 0;
  78 }
  79
  80 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  81 {
  82         struct reg_window32 *win;
  83         int i;
  84
  85         for (i = 0; i < 15; i++)
  86                 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
  87
  88         /* If the PSR register is changing, we have to preserve
  89          * the CWP field, otherwise window save/restore explodes.
  90          */
  91         if (regs->psr != gdb_regs[GDB_PSR]) {
  92                 unsigned long cwp = regs->psr & PSR_CWP;
  93
  94                 regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp;
  95         }
  96
  97         regs->pc = gdb_regs[GDB_PC];
  98         regs->npc = gdb_regs[GDB_NPC];
  99         regs->y = gdb_regs[GDB_Y];
 100
 101         win = (struct reg_window32 *) regs->u_regs[UREG_FP];
 102         for (i = 0; i < 8; i++)
 103                 win->locals[i] = gdb_regs[GDB_L0 + i];
 104         for (i = 0; i < 8; i++)
 105                 win->ins[i] = gdb_regs[GDB_I0 + i];
 106 }
 107
 108 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 109                                char *remcomInBuffer, char *remcomOutBuffer,
 110                                struct pt_regs *linux_regs)
 111 {
 112         unsigned long addr;
 113         char *ptr;
 114
 115         switch (remcomInBuffer[0]) {
 116         case 'c':
 117                 /* try to read optional parameter, pc unchanged if no parm */
 118                 ptr = &remcomInBuffer[1];
 119                 if (kgdb_hex2long(&ptr, &addr)) {
 120                         linux_regs->pc = addr;
 121                         linux_regs->npc = addr + 4;
 122                 }
 123                 /* fallthru */
 124
 125         case 'D':
 126         case 'k':
 127                 if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) {
 128                         linux_regs->pc = linux_regs->npc;
 129                         linux_regs->npc += 4;
 130                 }
 131                 return 0;
 132         }
 133         return -1;
 134 }
 135
 136 extern void do_hw_interrupt(struct pt_regs *regs, unsigned long type);
 137
 138 asmlinkage void kgdb_trap(struct pt_regs *regs)
 139 {
 140         unsigned long flags;
 141
 142         if (user_mode(regs)) {
 143                 do_hw_interrupt(regs, 0xfd);
 144                 return;
 145         }
 146
 147         flushw_all();
 148
 149         local_irq_save(flags);
 150         kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
 151         local_irq_restore(flags);
 152 }
 153
 154 int kgdb_arch_init(void)
 155 {
 156         return 0;
 157 }
 158
 159 void kgdb_arch_exit(void)
 160 {
 161 }
 162
 163 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
 164 {
 165         regs->pc = ip;
 166         regs->npc = regs->pc + 4;
 167 }
 168
 169 struct kgdb_arch arch_kgdb_ops = {
 170         /* Breakpoint instruction: ta 0x7d */
 171         .gdb_bpt_instr          = { 0x91, 0xd0, 0x20, 0x7d },
 172 };