arch/h8300/platform/h8300h/ptrace_h8300h.c

   1 /*
   2  *  linux/arch/h8300/platform/h8300h/ptrace_h8300h.c
   3  *    ptrace cpu depend helper functions
   4  *
   5  *  Yoshinori Sato <ysato@users.sourceforge.jp>
   6  *
   7  * This file is subject to the terms and conditions of the GNU General
   8  * Public License.  See the file COPYING in the main directory of
   9  * this archive for more details.
  10  */
  11
  12 #include <linux/linkage.h>
  13 #include <linux/sched.h>
  14 #include <asm/ptrace.h>
  15
  16 #define CCR_MASK 0x6f    /* mode/imask not set */
  17 #define BREAKINST 0x5730 /* trapa #3 */
  18
  19 /* Mapping from PT_xxx to the stack offset at which the register is
  20    saved.  Notice that usp has no stack-slot and needs to be treated
  21    specially (see get_reg/put_reg below). */
  22 static const int h8300_register_offset[] = {
  23         PT_REG(er1), PT_REG(er2), PT_REG(er3), PT_REG(er4),
  24         PT_REG(er5), PT_REG(er6), PT_REG(er0), PT_REG(orig_er0),
  25         PT_REG(ccr), PT_REG(pc)
  26 };
  27
  28 /* read register */
  29 long h8300_get_reg(struct task_struct *task, int regno)
  30 {
  31         switch (regno) {
  32         case PT_USP:
  33                 return task->thread.usp + sizeof(long)*2;
  34         case PT_CCR:
  35             return *(unsigned short *)(task->thread.esp0 + h8300_register_offset[regno]);
  36         default:
  37             return *(unsigned long *)(task->thread.esp0 + h8300_register_offset[regno]);
  38         }
  39 }
  40
  41 /* write register */
  42 int h8300_put_reg(struct task_struct *task, int regno, unsigned long data)
  43 {
  44         unsigned short oldccr;
  45         switch (regno) {
  46         case PT_USP:
  47                 task->thread.usp = data - sizeof(long)*2;
  48         case PT_CCR:
  49                 oldccr = *(unsigned short *)(task->thread.esp0 + h8300_register_offset[regno]);
  50                 oldccr &= ~CCR_MASK;
  51                 data &= CCR_MASK;
  52                 data |= oldccr;
  53                 *(unsigned short *)(task->thread.esp0 + h8300_register_offset[regno]) = data;
  54                 break;
  55         default:
  56                 *(unsigned long *)(task->thread.esp0 + h8300_register_offset[regno]) = data;
  57                 break;
  58         }
  59         return 0;
  60 }
  61
  62 /* disable singlestep */
  63 void h8300_disable_trace(struct task_struct *child)
  64 {
  65         if((long)child->thread.breakinfo.addr != -1L) {
  66                 *child->thread.breakinfo.addr = child->thread.breakinfo.inst;
  67                 child->thread.breakinfo.addr = (unsigned short *)-1L;
  68         }
  69 }
  70
  71 /* calculate next pc */
  72 enum jump_type {none,    /* normal instruction */
  73                 jabs,    /* absolute address jump */
  74                 ind,     /* indirect address jump */
  75                 ret,     /* return to subrutine */
  76                 reg,     /* register indexed jump */
  77                 relb,    /* pc relative jump (byte offset) */
  78                 relw,    /* pc relative jump (word offset) */
  79                };
  80
  81 /* opcode decode table define
  82    ptn: opcode pattern
  83    msk: opcode bitmask
  84    len: instruction length (<0 next table index)
  85    jmp: jump operation mode */
  86 struct optable {
  87         unsigned char bitpattern;
  88         unsigned char bitmask;
  89         signed char length;
  90         signed char type;
  91 } __attribute__((aligned(1),packed));
  92
  93 #define OPTABLE(ptn,msk,len,jmp)   \
  94         {                          \
  95                 .bitpattern = ptn, \
  96                 .bitmask    = msk, \
  97                 .length     = len, \
  98                 .type       = jmp, \
  99         }
 100
 101 static const struct optable optable_0[] = {
 102         OPTABLE(0x00,0xff, 1,none), /* 0x00 */
 103         OPTABLE(0x01,0xff,-1,none), /* 0x01 */
 104         OPTABLE(0x02,0xfe, 1,none), /* 0x02-0x03 */
 105         OPTABLE(0x04,0xee, 1,none), /* 0x04-0x05/0x14-0x15 */
 106         OPTABLE(0x06,0xfe, 1,none), /* 0x06-0x07 */
 107         OPTABLE(0x08,0xea, 1,none), /* 0x08-0x09/0x0c-0x0d/0x18-0x19/0x1c-0x1d */
 108         OPTABLE(0x0a,0xee, 1,none), /* 0x0a-0x0b/0x1a-0x1b */
 109         OPTABLE(0x0e,0xee, 1,none), /* 0x0e-0x0f/0x1e-0x1f */
 110         OPTABLE(0x10,0xfc, 1,none), /* 0x10-0x13 */
 111         OPTABLE(0x16,0xfe, 1,none), /* 0x16-0x17 */
 112         OPTABLE(0x20,0xe0, 1,none), /* 0x20-0x3f */
 113         OPTABLE(0x40,0xf0, 1,relb), /* 0x40-0x4f */
 114         OPTABLE(0x50,0xfc, 1,none), /* 0x50-0x53 */
 115         OPTABLE(0x54,0xfd, 1,ret ), /* 0x54/0x56 */
 116         OPTABLE(0x55,0xff, 1,relb), /* 0x55 */
 117         OPTABLE(0x57,0xff, 1,none), /* 0x57 */
 118         OPTABLE(0x58,0xfb, 2,relw), /* 0x58/0x5c */
 119         OPTABLE(0x59,0xfb, 1,reg ), /* 0x59/0x5b */
 120         OPTABLE(0x5a,0xfb, 2,jabs), /* 0x5a/0x5e */
 121         OPTABLE(0x5b,0xfb, 2,ind ), /* 0x5b/0x5f */
 122         OPTABLE(0x60,0xe8, 1,none), /* 0x60-0x67/0x70-0x77 */
 123         OPTABLE(0x68,0xfa, 1,none), /* 0x68-0x69/0x6c-0x6d */
 124         OPTABLE(0x6a,0xfe,-2,none), /* 0x6a-0x6b */
 125         OPTABLE(0x6e,0xfe, 2,none), /* 0x6e-0x6f */
 126         OPTABLE(0x78,0xff, 4,none), /* 0x78 */
 127         OPTABLE(0x79,0xff, 2,none), /* 0x79 */
 128         OPTABLE(0x7a,0xff, 3,none), /* 0x7a */
 129         OPTABLE(0x7b,0xff, 2,none), /* 0x7b */
 130         OPTABLE(0x7c,0xfc, 2,none), /* 0x7c-0x7f */
 131         OPTABLE(0x80,0x80, 1,none), /* 0x80-0xff */
 132 };
 133
 134 static const struct optable optable_1[] = {
 135         OPTABLE(0x00,0xff,-3,none), /* 0x0100 */
 136         OPTABLE(0x40,0xf0,-3,none), /* 0x0140-0x14f */
 137         OPTABLE(0x80,0xf0, 1,none), /* 0x0180-0x018f */
 138         OPTABLE(0xc0,0xc0, 2,none), /* 0x01c0-0x01ff */
 139 };
 140
 141 static const struct optable optable_2[] = {
 142         OPTABLE(0x00,0x20, 2,none), /* 0x6a0?/0x6a8?/0x6b0?/0x6b8? */
 143         OPTABLE(0x20,0x20, 3,none), /* 0x6a2?/0x6aa?/0x6b2?/0x6ba? */
 144 };
 145
 146 static const struct optable optable_3[] = {
 147         OPTABLE(0x69,0xfb, 2,none), /* 0x010069/0x01006d/014069/0x01406d */
 148         OPTABLE(0x6b,0xff,-4,none), /* 0x01006b/0x01406b */
 149         OPTABLE(0x6f,0xff, 3,none), /* 0x01006f/0x01406f */
 150         OPTABLE(0x78,0xff, 5,none), /* 0x010078/0x014078 */
 151 };
 152
 153 static const struct optable optable_4[] = {
 154         OPTABLE(0x00,0x78, 3,none), /* 0x0100690?/0x01006d0?/0140690/0x01406d0?/0x0100698?/0x01006d8?/0140698?/0x01406d8? */
 155         OPTABLE(0x20,0x78, 4,none), /* 0x0100692?/0x01006d2?/0140692/0x01406d2?/0x010069a?/0x01006da?/014069a?/0x01406da? */
 156 };
 157
 158 static const struct optables_list {
 159         const struct optable *ptr;
 160         int size;
 161 } optables[] = {
 162 #define OPTABLES(no)                                                   \
 163         {                                                              \
 164                 .ptr  = optable_##no,                                  \
 165                 .size = sizeof(optable_##no) / sizeof(struct optable), \
 166         }
 167         OPTABLES(0),
 168         OPTABLES(1),
 169         OPTABLES(2),
 170         OPTABLES(3),
 171         OPTABLES(4),
 172
 173 };
 174
 175 const unsigned char condmask[] = {
 176         0x00,0x40,0x01,0x04,0x02,0x08,0x10,0x20
 177 };
 178
 179 static int isbranch(struct task_struct *task,int reson)
 180 {
 181         unsigned char cond = h8300_get_reg(task, PT_CCR);
 182         /* encode complex conditions */
 183         /* B4: N^V
 184            B5: Z|(N^V)
 185            B6: C|Z */
 186         __asm__("bld #3,%w0\n\t"
 187                 "bxor #1,%w0\n\t"
 188                 "bst #4,%w0\n\t"
 189                 "bor #2,%w0\n\t"
 190                 "bst #5,%w0\n\t"
 191                 "bld #2,%w0\n\t"
 192                 "bor #0,%w0\n\t"
 193                 "bst #6,%w0\n\t"
 194                 :"=&r"(cond)::"cc");
 195         cond &= condmask[reson >> 1];
 196         if (!(reson & 1))
 197                 return cond == 0;
 198         else
 199                 return cond != 0;
 200 }
 201
 202 static unsigned short *getnextpc(struct task_struct *child, unsigned short *pc)
 203 {
 204         const struct optable *op;
 205         unsigned char *fetch_p;
 206         unsigned char inst;
 207         unsigned long addr;
 208         unsigned long *sp;
 209         int op_len,regno;
 210         op = optables[0].ptr;
 211         op_len = optables[0].size;
 212         fetch_p = (unsigned char *)pc;
 213         inst = *fetch_p++;
 214         do {
 215                 if ((inst & op->bitmask) == op->bitpattern) {
 216                         if (op->length < 0) {
 217                                 op = optables[-op->length].ptr;
 218                                 op_len = optables[-op->length].size + 1;
 219                                 inst = *fetch_p++;
 220                         } else {
 221                                 switch (op->type) {
 222                                 case none:
 223                                         return pc + op->length;
 224                                 case jabs:
 225                                         addr = *(unsigned long *)pc;
 226                                         return (unsigned short *)(addr & 0x00ffffff);
 227                                 case ind:
 228                                         addr = *pc & 0xff;
 229                                         return (unsigned short *)(*(unsigned long *)addr);
 230                                 case ret:
 231                                         sp = (unsigned long *)h8300_get_reg(child, PT_USP);
 232                                         /* user stack frames
 233                                            |   er0  | temporary saved
 234                                            +--------+
 235                                            |   exp  | exception stack frames
 236                                            +--------+
 237                                            | ret pc | userspace return address
 238                                         */
 239                                         return (unsigned short *)(*(sp+2) & 0x00ffffff);
 240                                 case reg:
 241                                         regno = (*pc >> 4) & 0x07;
 242                                         if (regno == 0)
 243                                                 addr = h8300_get_reg(child, PT_ER0);
 244                                         else
 245                                                 addr = h8300_get_reg(child, regno-1+PT_ER1);
 246                                         return (unsigned short *)addr;
 247                                 case relb:
 248                                         if (inst == 0x55 || isbranch(child,inst & 0x0f))
 249                                                 pc = (unsigned short *)((unsigned long)pc +
 250                                                                        ((signed char)(*fetch_p)));
 251                                         return pc+1; /* skip myself */
 252                                 case relw:
 253                                         if (inst == 0x5c || isbranch(child,(*fetch_p & 0xf0) >> 4))
 254                                                 pc = (unsigned short *)((unsigned long)pc +
 255                                                                        ((signed short)(*(pc+1))));
 256                                         return pc+2; /* skip myself */
 257                                 }
 258                         }
 259                 } else
 260                         op++;
 261         } while(--op_len > 0);
 262         return NULL;
 263 }
 264
 265 /* Set breakpoint(s) to simulate a single step from the current PC.  */
 266
 267 void h8300_enable_trace(struct task_struct *child)
 268 {
 269         unsigned short *nextpc;
 270         nextpc = getnextpc(child,(unsigned short *)h8300_get_reg(child, PT_PC));
 271         child->thread.breakinfo.addr = nextpc;
 272         child->thread.breakinfo.inst = *nextpc;
 273         *nextpc = BREAKINST;
 274 }
 275
 276 asmlinkage void trace_trap(unsigned long bp)
 277 {
 278         if ((unsigned long)current->thread.breakinfo.addr == bp) {
 279                 h8300_disable_trace(current);
 280                 force_sig(SIGTRAP,current);
 281         } else
 282                 force_sig(SIGILL,current);
 283 }
 284