arch/blackfin/kernel/kgdb.c

   1 /*
   2  * arch/blackfin/kernel/kgdb.c - Blackfin kgdb pieces
   3  *
   4  * Copyright 2005-2008 Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8
   9 #include <linux/ptrace.h>               /* for linux pt_regs struct */
  10 #include <linux/kgdb.h>
  11 #include <linux/uaccess.h>
  12
  13 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  14 {
  15         gdb_regs[BFIN_R0] = regs->r0;
  16         gdb_regs[BFIN_R1] = regs->r1;
  17         gdb_regs[BFIN_R2] = regs->r2;
  18         gdb_regs[BFIN_R3] = regs->r3;
  19         gdb_regs[BFIN_R4] = regs->r4;
  20         gdb_regs[BFIN_R5] = regs->r5;
  21         gdb_regs[BFIN_R6] = regs->r6;
  22         gdb_regs[BFIN_R7] = regs->r7;
  23         gdb_regs[BFIN_P0] = regs->p0;
  24         gdb_regs[BFIN_P1] = regs->p1;
  25         gdb_regs[BFIN_P2] = regs->p2;
  26         gdb_regs[BFIN_P3] = regs->p3;
  27         gdb_regs[BFIN_P4] = regs->p4;
  28         gdb_regs[BFIN_P5] = regs->p5;
  29         gdb_regs[BFIN_SP] = regs->reserved;
  30         gdb_regs[BFIN_FP] = regs->fp;
  31         gdb_regs[BFIN_I0] = regs->i0;
  32         gdb_regs[BFIN_I1] = regs->i1;
  33         gdb_regs[BFIN_I2] = regs->i2;
  34         gdb_regs[BFIN_I3] = regs->i3;
  35         gdb_regs[BFIN_M0] = regs->m0;
  36         gdb_regs[BFIN_M1] = regs->m1;
  37         gdb_regs[BFIN_M2] = regs->m2;
  38         gdb_regs[BFIN_M3] = regs->m3;
  39         gdb_regs[BFIN_B0] = regs->b0;
  40         gdb_regs[BFIN_B1] = regs->b1;
  41         gdb_regs[BFIN_B2] = regs->b2;
  42         gdb_regs[BFIN_B3] = regs->b3;
  43         gdb_regs[BFIN_L0] = regs->l0;
  44         gdb_regs[BFIN_L1] = regs->l1;
  45         gdb_regs[BFIN_L2] = regs->l2;
  46         gdb_regs[BFIN_L3] = regs->l3;
  47         gdb_regs[BFIN_A0_DOT_X] = regs->a0x;
  48         gdb_regs[BFIN_A0_DOT_W] = regs->a0w;
  49         gdb_regs[BFIN_A1_DOT_X] = regs->a1x;
  50         gdb_regs[BFIN_A1_DOT_W] = regs->a1w;
  51         gdb_regs[BFIN_ASTAT] = regs->astat;
  52         gdb_regs[BFIN_RETS] = regs->rets;
  53         gdb_regs[BFIN_LC0] = regs->lc0;
  54         gdb_regs[BFIN_LT0] = regs->lt0;
  55         gdb_regs[BFIN_LB0] = regs->lb0;
  56         gdb_regs[BFIN_LC1] = regs->lc1;
  57         gdb_regs[BFIN_LT1] = regs->lt1;
  58         gdb_regs[BFIN_LB1] = regs->lb1;
  59         gdb_regs[BFIN_CYCLES] = 0;
  60         gdb_regs[BFIN_CYCLES2] = 0;
  61         gdb_regs[BFIN_USP] = regs->usp;
  62         gdb_regs[BFIN_SEQSTAT] = regs->seqstat;
  63         gdb_regs[BFIN_SYSCFG] = regs->syscfg;
  64         gdb_regs[BFIN_RETI] = regs->pc;
  65         gdb_regs[BFIN_RETX] = regs->retx;
  66         gdb_regs[BFIN_RETN] = regs->retn;
  67         gdb_regs[BFIN_RETE] = regs->rete;
  68         gdb_regs[BFIN_PC] = regs->pc;
  69         gdb_regs[BFIN_CC] = (regs->astat >> 5) & 1;
  70         gdb_regs[BFIN_EXTRA1] = 0;
  71         gdb_regs[BFIN_EXTRA2] = 0;
  72         gdb_regs[BFIN_EXTRA3] = 0;
  73         gdb_regs[BFIN_IPEND] = regs->ipend;
  74 }
  75
  76 /*
  77  * Extracts ebp, esp and eip values understandable by gdb from the values
  78  * saved by switch_to.
  79  * thread.esp points to ebp. flags and ebp are pushed in switch_to hence esp
  80  * prior to entering switch_to is 8 greater than the value that is saved.
  81  * If switch_to changes, change following code appropriately.
  82  */
  83 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  84 {
  85         gdb_regs[BFIN_SP] = p->thread.ksp;
  86         gdb_regs[BFIN_PC] = p->thread.pc;
  87         gdb_regs[BFIN_SEQSTAT] = p->thread.seqstat;
  88 }
  89
  90 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  91 {
  92         regs->r0 = gdb_regs[BFIN_R0];
  93         regs->r1 = gdb_regs[BFIN_R1];
  94         regs->r2 = gdb_regs[BFIN_R2];
  95         regs->r3 = gdb_regs[BFIN_R3];
  96         regs->r4 = gdb_regs[BFIN_R4];
  97         regs->r5 = gdb_regs[BFIN_R5];
  98         regs->r6 = gdb_regs[BFIN_R6];
  99         regs->r7 = gdb_regs[BFIN_R7];
 100         regs->p0 = gdb_regs[BFIN_P0];
 101         regs->p1 = gdb_regs[BFIN_P1];
 102         regs->p2 = gdb_regs[BFIN_P2];
 103         regs->p3 = gdb_regs[BFIN_P3];
 104         regs->p4 = gdb_regs[BFIN_P4];
 105         regs->p5 = gdb_regs[BFIN_P5];
 106         regs->fp = gdb_regs[BFIN_FP];
 107         regs->i0 = gdb_regs[BFIN_I0];
 108         regs->i1 = gdb_regs[BFIN_I1];
 109         regs->i2 = gdb_regs[BFIN_I2];
 110         regs->i3 = gdb_regs[BFIN_I3];
 111         regs->m0 = gdb_regs[BFIN_M0];
 112         regs->m1 = gdb_regs[BFIN_M1];
 113         regs->m2 = gdb_regs[BFIN_M2];
 114         regs->m3 = gdb_regs[BFIN_M3];
 115         regs->b0 = gdb_regs[BFIN_B0];
 116         regs->b1 = gdb_regs[BFIN_B1];
 117         regs->b2 = gdb_regs[BFIN_B2];
 118         regs->b3 = gdb_regs[BFIN_B3];
 119         regs->l0 = gdb_regs[BFIN_L0];
 120         regs->l1 = gdb_regs[BFIN_L1];
 121         regs->l2 = gdb_regs[BFIN_L2];
 122         regs->l3 = gdb_regs[BFIN_L3];
 123         regs->a0x = gdb_regs[BFIN_A0_DOT_X];
 124         regs->a0w = gdb_regs[BFIN_A0_DOT_W];
 125         regs->a1x = gdb_regs[BFIN_A1_DOT_X];
 126         regs->a1w = gdb_regs[BFIN_A1_DOT_W];
 127         regs->rets = gdb_regs[BFIN_RETS];
 128         regs->lc0 = gdb_regs[BFIN_LC0];
 129         regs->lt0 = gdb_regs[BFIN_LT0];
 130         regs->lb0 = gdb_regs[BFIN_LB0];
 131         regs->lc1 = gdb_regs[BFIN_LC1];
 132         regs->lt1 = gdb_regs[BFIN_LT1];
 133         regs->lb1 = gdb_regs[BFIN_LB1];
 134         regs->usp = gdb_regs[BFIN_USP];
 135         regs->syscfg = gdb_regs[BFIN_SYSCFG];
 136         regs->retx = gdb_regs[BFIN_RETX];
 137         regs->retn = gdb_regs[BFIN_RETN];
 138         regs->rete = gdb_regs[BFIN_RETE];
 139         regs->pc = gdb_regs[BFIN_PC];
 140
 141 #if 0                           /* can't change these */
 142         regs->astat = gdb_regs[BFIN_ASTAT];
 143         regs->seqstat = gdb_regs[BFIN_SEQSTAT];
 144         regs->ipend = gdb_regs[BFIN_IPEND];
 145 #endif
 146 }
 147
 148 static struct hw_breakpoint {
 149         unsigned int occupied:1;
 150         unsigned int skip:1;
 151         unsigned int enabled:1;
 152         unsigned int type:1;
 153         unsigned int dataacc:2;
 154         unsigned short count;
 155         unsigned int addr;
 156 } breakinfo[HW_WATCHPOINT_NUM];
 157
 158 static int bfin_set_hw_break(unsigned long addr, int len, enum kgdb_bptype type)
 159 {
 160         int breakno;
 161         int bfin_type;
 162         int dataacc = 0;
 163
 164         switch (type) {
 165         case BP_HARDWARE_BREAKPOINT:
 166                 bfin_type = TYPE_INST_WATCHPOINT;
 167                 break;
 168         case BP_WRITE_WATCHPOINT:
 169                 dataacc = 1;
 170                 bfin_type = TYPE_DATA_WATCHPOINT;
 171                 break;
 172         case BP_READ_WATCHPOINT:
 173                 dataacc = 2;
 174                 bfin_type = TYPE_DATA_WATCHPOINT;
 175                 break;
 176         case BP_ACCESS_WATCHPOINT:
 177                 dataacc = 3;
 178                 bfin_type = TYPE_DATA_WATCHPOINT;
 179                 break;
 180         default:
 181                 return -ENOSPC;
 182         }
 183
 184         /* Becasue hardware data watchpoint impelemented in current
 185          * Blackfin can not trigger an exception event as the hardware
 186          * instrction watchpoint does, we ignaore all data watch point here.
 187          * They can be turned on easily after future blackfin design
 188          * supports this feature.
 189          */
 190         for (breakno = 0; breakno < HW_INST_WATCHPOINT_NUM; breakno++)
 191                 if (bfin_type == breakinfo[breakno].type
 192                         && !breakinfo[breakno].occupied) {
 193                         breakinfo[breakno].occupied = 1;
 194                         breakinfo[breakno].skip = 0;
 195                         breakinfo[breakno].enabled = 1;
 196                         breakinfo[breakno].addr = addr;
 197                         breakinfo[breakno].dataacc = dataacc;
 198                         breakinfo[breakno].count = 0;
 199                         return 0;
 200                 }
 201
 202         return -ENOSPC;
 203 }
 204
 205 static int bfin_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype type)
 206 {
 207         int breakno;
 208         int bfin_type;
 209
 210         switch (type) {
 211         case BP_HARDWARE_BREAKPOINT:
 212                 bfin_type = TYPE_INST_WATCHPOINT;
 213                 break;
 214         case BP_WRITE_WATCHPOINT:
 215         case BP_READ_WATCHPOINT:
 216         case BP_ACCESS_WATCHPOINT:
 217                 bfin_type = TYPE_DATA_WATCHPOINT;
 218                 break;
 219         default:
 220                 return 0;
 221         }
 222         for (breakno = 0; breakno < HW_WATCHPOINT_NUM; breakno++)
 223                 if (bfin_type == breakinfo[breakno].type
 224                         && breakinfo[breakno].occupied
 225                         && breakinfo[breakno].addr == addr) {
 226                         breakinfo[breakno].occupied = 0;
 227                         breakinfo[breakno].enabled = 0;
 228                 }
 229
 230         return 0;
 231 }
 232
 233 static void bfin_remove_all_hw_break(void)
 234 {
 235         int breakno;
 236
 237         memset(breakinfo, 0, sizeof(struct hw_breakpoint)*HW_WATCHPOINT_NUM);
 238
 239         for (breakno = 0; breakno < HW_INST_WATCHPOINT_NUM; breakno++)
 240                 breakinfo[breakno].type = TYPE_INST_WATCHPOINT;
 241         for (; breakno < HW_WATCHPOINT_NUM; breakno++)
 242                 breakinfo[breakno].type = TYPE_DATA_WATCHPOINT;
 243 }
 244
 245 static void bfin_correct_hw_break(void)
 246 {
 247         int breakno;
 248         unsigned int wpiactl = 0;
 249         unsigned int wpdactl = 0;
 250         int enable_wp = 0;
 251
 252         for (breakno = 0; breakno < HW_WATCHPOINT_NUM; breakno++)
 253                 if (breakinfo[breakno].enabled) {
 254                         enable_wp = 1;
 255
 256                         switch (breakno) {
 257                         case 0:
 258                                 wpiactl |= WPIAEN0|WPICNTEN0;
 259                                 bfin_write_WPIA0(breakinfo[breakno].addr);
 260                                 bfin_write_WPIACNT0(breakinfo[breakno].count
 261                                         + breakinfo->skip);
 262                                 break;
 263                         case 1:
 264                                 wpiactl |= WPIAEN1|WPICNTEN1;
 265                                 bfin_write_WPIA1(breakinfo[breakno].addr);
 266                                 bfin_write_WPIACNT1(breakinfo[breakno].count
 267                                         + breakinfo->skip);
 268                                 break;
 269                         case 2:
 270                                 wpiactl |= WPIAEN2|WPICNTEN2;
 271                                 bfin_write_WPIA2(breakinfo[breakno].addr);
 272                                 bfin_write_WPIACNT2(breakinfo[breakno].count
 273                                         + breakinfo->skip);
 274                                 break;
 275                         case 3:
 276                                 wpiactl |= WPIAEN3|WPICNTEN3;
 277                                 bfin_write_WPIA3(breakinfo[breakno].addr);
 278                                 bfin_write_WPIACNT3(breakinfo[breakno].count
 279                                         + breakinfo->skip);
 280                                 break;
 281                         case 4:
 282                                 wpiactl |= WPIAEN4|WPICNTEN4;
 283                                 bfin_write_WPIA4(breakinfo[breakno].addr);
 284                                 bfin_write_WPIACNT4(breakinfo[breakno].count
 285                                         + breakinfo->skip);
 286                                 break;
 287                         case 5:
 288                                 wpiactl |= WPIAEN5|WPICNTEN5;
 289                                 bfin_write_WPIA5(breakinfo[breakno].addr);
 290                                 bfin_write_WPIACNT5(breakinfo[breakno].count
 291                                         + breakinfo->skip);
 292                                 break;
 293                         case 6:
 294                                 wpdactl |= WPDAEN0|WPDCNTEN0|WPDSRC0;
 295                                 wpdactl |= breakinfo[breakno].dataacc
 296                                         << WPDACC0_OFFSET;
 297                                 bfin_write_WPDA0(breakinfo[breakno].addr);
 298                                 bfin_write_WPDACNT0(breakinfo[breakno].count
 299                                         + breakinfo->skip);
 300                                 break;
 301                         case 7:
 302                                 wpdactl |= WPDAEN1|WPDCNTEN1|WPDSRC1;
 303                                 wpdactl |= breakinfo[breakno].dataacc
 304                                         << WPDACC1_OFFSET;
 305                                 bfin_write_WPDA1(breakinfo[breakno].addr);
 306                                 bfin_write_WPDACNT1(breakinfo[breakno].count
 307                                         + breakinfo->skip);
 308                                 break;
 309                         }
 310                 }
 311
 312         /* Should enable WPPWR bit first before set any other
 313          * WPIACTL and WPDACTL bits */
 314         if (enable_wp) {
 315                 bfin_write_WPIACTL(WPPWR);
 316                 CSYNC();
 317                 bfin_write_WPIACTL(wpiactl|WPPWR);
 318                 bfin_write_WPDACTL(wpdactl);
 319                 CSYNC();
 320         }
 321 }
 322
 323 void kgdb_disable_hw_debug(struct pt_regs *regs)
 324 {
 325         /* Disable hardware debugging while we are in kgdb */
 326         bfin_write_WPIACTL(0);
 327         bfin_write_WPDACTL(0);
 328         CSYNC();
 329 }
 330
 331 #ifdef CONFIG_SMP
 332 void kgdb_passive_cpu_callback(void *info)
 333 {
 334         kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
 335 }
 336
 337 void kgdb_roundup_cpus(unsigned long flags)
 338 {
 339         smp_call_function(kgdb_passive_cpu_callback, NULL, 0);
 340 }
 341
 342 void kgdb_roundup_cpu(int cpu, unsigned long flags)
 343 {
 344         smp_call_function_single(cpu, kgdb_passive_cpu_callback, NULL, 0);
 345 }
 346 #endif
 347
 348 int kgdb_arch_handle_exception(int vector, int signo,
 349                                int err_code, char *remcom_in_buffer,
 350                                char *remcom_out_buffer,
 351                                struct pt_regs *regs)
 352 {
 353         long addr;
 354         char *ptr;
 355         int newPC;
 356         int i;
 357
 358         switch (remcom_in_buffer[0]) {
 359         case 'c':
 360         case 's':
 361                 if (kgdb_contthread && kgdb_contthread != current) {
 362                         strcpy(remcom_out_buffer, "E00");
 363                         break;
 364                 }
 365
 366                 kgdb_contthread = NULL;
 367
 368                 /* try to read optional parameter, pc unchanged if no parm */
 369                 ptr = &remcom_in_buffer[1];
 370                 if (kgdb_hex2long(&ptr, &addr)) {
 371                         regs->retx = addr;
 372                 }
 373                 newPC = regs->retx;
 374
 375                 /* clear the trace bit */
 376                 regs->syscfg &= 0xfffffffe;
 377
 378                 /* set the trace bit if we're stepping */
 379                 if (remcom_in_buffer[0] == 's') {
 380                         regs->syscfg |= 0x1;
 381                         kgdb_single_step = regs->ipend;
 382                         kgdb_single_step >>= 6;
 383                         for (i = 10; i > 0; i--, kgdb_single_step >>= 1)
 384                                 if (kgdb_single_step & 1)
 385                                         break;
 386                         /* i indicate event priority of current stopped instruction
 387                          * user space instruction is 0, IVG15 is 1, IVTMR is 10.
 388                          * kgdb_single_step > 0 means in single step mode
 389                          */
 390                         kgdb_single_step = i + 1;
 391                 }
 392
 393                 bfin_correct_hw_break();
 394
 395                 return 0;
 396         }                       /* switch */
 397         return -1;              /* this means that we do not want to exit from the handler */
 398 }
 399
 400 struct kgdb_arch arch_kgdb_ops = {
 401         .gdb_bpt_instr = {0xa1},
 402 #ifdef CONFIG_SMP
 403         .flags = KGDB_HW_BREAKPOINT|KGDB_THR_PROC_SWAP,
 404 #else
 405         .flags = KGDB_HW_BREAKPOINT,
 406 #endif
 407         .set_hw_breakpoint = bfin_set_hw_break,
 408         .remove_hw_breakpoint = bfin_remove_hw_break,
 409         .remove_all_hw_break = bfin_remove_all_hw_break,
 410         .correct_hw_break = bfin_correct_hw_break,
 411 };
 412
 413 #define IN_MEM(addr, size, l1_addr, l1_size) \
 414 ({ \
 415         unsigned long __addr = (unsigned long)(addr); \
 416         (l1_size && __addr >= l1_addr && __addr + (size) <= l1_addr + l1_size); \
 417 })
 418 #define ASYNC_BANK_SIZE \
 419         (ASYNC_BANK0_SIZE + ASYNC_BANK1_SIZE + \
 420          ASYNC_BANK2_SIZE + ASYNC_BANK3_SIZE)
 421
 422 int kgdb_validate_break_address(unsigned long addr)
 423 {
 424         int cpu = raw_smp_processor_id();
 425
 426         if (addr >= 0x1000 && (addr + BREAK_INSTR_SIZE) <= physical_mem_end)
 427                 return 0;
 428         if (IN_MEM(addr, BREAK_INSTR_SIZE, ASYNC_BANK0_BASE, ASYNC_BANK_SIZE))
 429                 return 0;
 430         if (cpu == 0 && IN_MEM(addr, BREAK_INSTR_SIZE, L1_CODE_START, L1_CODE_LENGTH))
 431                 return 0;
 432 #ifdef CONFIG_SMP
 433         else if (cpu == 1 && IN_MEM(addr, BREAK_INSTR_SIZE, COREB_L1_CODE_START, L1_CODE_LENGTH))
 434                 return 0;
 435 #endif
 436         if (IN_MEM(addr, BREAK_INSTR_SIZE, L2_START, L2_LENGTH))
 437                 return 0;
 438
 439         return -EFAULT;
 440 }
 441
 442 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
 443 {
 444         regs->retx = ip;
 445 }
 446
 447 int kgdb_arch_init(void)
 448 {
 449         kgdb_single_step = 0;
 450
 451         bfin_remove_all_hw_break();
 452         return 0;
 453 }
 454
 455 void kgdb_arch_exit(void)
 456 {
 457 }