arch/h8300/kernel/kgdb.c

   1 /*
   2  * H8/300 KGDB support
   3  *
   4  * Copyright (C) 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10
  11 #include <linux/ptrace.h>
  12 #include <linux/kgdb.h>
  13 #include <linux/kdebug.h>
  14 #include <linux/io.h>
  15
  16 struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
  17         { "er0", GDB_SIZEOF_REG, offsetof(struct pt_regs, er0) },
  18         { "er1", GDB_SIZEOF_REG, offsetof(struct pt_regs, er1) },
  19         { "er2", GDB_SIZEOF_REG, offsetof(struct pt_regs, er2) },
  20         { "er3", GDB_SIZEOF_REG, offsetof(struct pt_regs, er3) },
  21         { "er4", GDB_SIZEOF_REG, offsetof(struct pt_regs, er4) },
  22         { "er5", GDB_SIZEOF_REG, offsetof(struct pt_regs, er5) },
  23         { "er6", GDB_SIZEOF_REG, offsetof(struct pt_regs, er6) },
  24         { "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, sp) },
  25         { "ccr", GDB_SIZEOF_REG, offsetof(struct pt_regs, ccr) },
  26         { "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, pc) },
  27         { "cycles", GDB_SIZEOF_REG, -1 },
  28 #if defined(CONFIG_CPU_H8S)
  29         { "exr", GDB_SIZEOF_REG, offsetof(struct pt_regs, exr) },
  30 #endif
  31         { "tick", GDB_SIZEOF_REG, -1 },
  32         { "inst", GDB_SIZEOF_REG, -1 },
  33 };
  34
  35 char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
  36 {
  37         if (regno >= DBG_MAX_REG_NUM || regno < 0)
  38                 return NULL;
  39
  40         switch (regno) {
  41         case GDB_CCR:
  42 #if defined(CONFIG_CPU_H8S)
  43         case GDB_EXR:
  44 #endif
  45                 *(u32 *)mem = *(u16 *)((void *)regs +
  46                                        dbg_reg_def[regno].offset);
  47                 break;
  48         default:
  49                 if (dbg_reg_def[regno].offset >= 0)
  50                         memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
  51                                dbg_reg_def[regno].size);
  52                 else
  53                         memset(mem, 0, dbg_reg_def[regno].size);
  54                 break;
  55         }
  56         return dbg_reg_def[regno].name;
  57 }
  58
  59 int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
  60 {
  61         if (regno >= DBG_MAX_REG_NUM || regno < 0)
  62                 return -EINVAL;
  63
  64         switch (regno) {
  65         case GDB_CCR:
  66 #if defined(CONFIG_CPU_H8S)
  67         case GDB_EXR:
  68 #endif
  69                 *(u16 *)((void *)regs +
  70                          dbg_reg_def[regno].offset) = *(u32 *)mem;
  71                 break;
  72         default:
  73                 memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
  74                        dbg_reg_def[regno].size);
  75         }
  76         return 0;
  77 }
  78
  79 asmlinkage void h8300_kgdb_trap(struct pt_regs *regs)
  80 {
  81         regs->pc &= 0x00ffffff;
  82         if (kgdb_handle_exception(10, SIGTRAP, 0, regs))
  83                 return;
  84         if (*(u16 *)(regs->pc) == *(u16 *)&arch_kgdb_ops.gdb_bpt_instr)
  85                 regs->pc += BREAK_INSTR_SIZE;
  86         regs->pc |= regs->ccr << 24;
  87 }
  88
  89 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  90 {
  91         memset((char *)gdb_regs, 0, NUMREGBYTES);
  92         gdb_regs[GDB_SP] = p->thread.ksp;
  93         gdb_regs[GDB_PC] = KSTK_EIP(p);
  94 }
  95
  96 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
  97 {
  98         regs->pc = pc;
  99 }
 100
 101 int kgdb_arch_handle_exception(int vector, int signo, int err_code,
 102                                 char *remcom_in_buffer, char *remcom_out_buffer,
 103                                 struct pt_regs *regs)
 104 {
 105         char *ptr;
 106         unsigned long addr;
 107
 108         switch (remcom_in_buffer[0]) {
 109         case 's':
 110         case 'c':
 111                 /* handle the optional parameters */
 112                 ptr = &remcom_in_buffer[1];
 113                 if (kgdb_hex2long(&ptr, &addr))
 114                         regs->pc = addr;
 115
 116                 return 0;
 117         }
 118
 119         return -1; /* this means that we do not want to exit from the handler */
 120 }
 121
 122 int kgdb_arch_init(void)
 123 {
 124         return 0;
 125 }
 126
 127 void kgdb_arch_exit(void)
 128 {
 129         /* Nothing to do */
 130 }
 131
 132 const struct kgdb_arch arch_kgdb_ops = {
 133         /* Breakpoint instruction: trapa #2 */
 134         .gdb_bpt_instr = { 0x57, 0x20 },
 135 };