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 #include <asm/irq_regs.h>
  13
  14 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  15 {
  16         gdb_regs[BFIN_R0] = regs->r0;
  17         gdb_regs[BFIN_R1] = regs->r1;
  18         gdb_regs[BFIN_R2] = regs->r2;
  19         gdb_regs[BFIN_R3] = regs->r3;
  20         gdb_regs[BFIN_R4] = regs->r4;
  21         gdb_regs[BFIN_R5] = regs->r5;
  22         gdb_regs[BFIN_R6] = regs->r6;
  23         gdb_regs[BFIN_R7] = regs->r7;
  24         gdb_regs[BFIN_P0] = regs->p0;
  25         gdb_regs[BFIN_P1] = regs->p1;
  26         gdb_regs[BFIN_P2] = regs->p2;
  27         gdb_regs[BFIN_P3] = regs->p3;
  28         gdb_regs[BFIN_P4] = regs->p4;
  29         gdb_regs[BFIN_P5] = regs->p5;
  30         gdb_regs[BFIN_SP] = regs->reserved;
  31         gdb_regs[BFIN_FP] = regs->fp;
  32         gdb_regs[BFIN_I0] = regs->i0;
  33         gdb_regs[BFIN_I1] = regs->i1;
  34         gdb_regs[BFIN_I2] = regs->i2;
  35         gdb_regs[BFIN_I3] = regs->i3;
  36         gdb_regs[BFIN_M0] = regs->m0;
  37         gdb_regs[BFIN_M1] = regs->m1;
  38         gdb_regs[BFIN_M2] = regs->m2;
  39         gdb_regs[BFIN_M3] = regs->m3;
  40         gdb_regs[BFIN_B0] = regs->b0;
  41         gdb_regs[BFIN_B1] = regs->b1;
  42         gdb_regs[BFIN_B2] = regs->b2;
  43         gdb_regs[BFIN_B3] = regs->b3;
  44         gdb_regs[BFIN_L0] = regs->l0;
  45         gdb_regs[BFIN_L1] = regs->l1;
  46         gdb_regs[BFIN_L2] = regs->l2;
  47         gdb_regs[BFIN_L3] = regs->l3;
  48         gdb_regs[BFIN_A0_DOT_X] = regs->a0x;
  49         gdb_regs[BFIN_A0_DOT_W] = regs->a0w;
  50         gdb_regs[BFIN_A1_DOT_X] = regs->a1x;
  51         gdb_regs[BFIN_A1_DOT_W] = regs->a1w;
  52         gdb_regs[BFIN_ASTAT] = regs->astat;
  53         gdb_regs[BFIN_RETS] = regs->rets;
  54         gdb_regs[BFIN_LC0] = regs->lc0;
  55         gdb_regs[BFIN_LT0] = regs->lt0;
  56         gdb_regs[BFIN_LB0] = regs->lb0;
  57         gdb_regs[BFIN_LC1] = regs->lc1;
  58         gdb_regs[BFIN_LT1] = regs->lt1;
  59         gdb_regs[BFIN_LB1] = regs->lb1;
  60         gdb_regs[BFIN_CYCLES] = 0;
  61         gdb_regs[BFIN_CYCLES2] = 0;
  62         gdb_regs[BFIN_USP] = regs->usp;
  63         gdb_regs[BFIN_SEQSTAT] = regs->seqstat;
  64         gdb_regs[BFIN_SYSCFG] = regs->syscfg;
  65         gdb_regs[BFIN_RETI] = regs->pc;
  66         gdb_regs[BFIN_RETX] = regs->retx;
  67         gdb_regs[BFIN_RETN] = regs->retn;
  68         gdb_regs[BFIN_RETE] = regs->rete;
  69         gdb_regs[BFIN_PC] = regs->pc;
  70         gdb_regs[BFIN_CC] = (regs->astat >> 5) & 1;
  71         gdb_regs[BFIN_EXTRA1] = 0;
  72         gdb_regs[BFIN_EXTRA2] = 0;
  73         gdb_regs[BFIN_EXTRA3] = 0;
  74         gdb_regs[BFIN_IPEND] = regs->ipend;
  75 }
  76
  77 /*
  78  * Extracts ebp, esp and eip values understandable by gdb from the values
  79  * saved by switch_to.
  80  * thread.esp points to ebp. flags and ebp are pushed in switch_to hence esp
  81  * prior to entering switch_to is 8 greater than the value that is saved.
  82  * If switch_to changes, change following code appropriately.
  83  */
  84 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  85 {
  86         gdb_regs[BFIN_SP] = p->thread.ksp;
  87         gdb_regs[BFIN_PC] = p->thread.pc;
  88         gdb_regs[BFIN_SEQSTAT] = p->thread.seqstat;
  89 }
  90
  91 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  92 {
  93         regs->r0 = gdb_regs[BFIN_R0];
  94         regs->r1 = gdb_regs[BFIN_R1];
  95         regs->r2 = gdb_regs[BFIN_R2];
  96         regs->r3 = gdb_regs[BFIN_R3];
  97         regs->r4 = gdb_regs[BFIN_R4];
  98         regs->r5 = gdb_regs[BFIN_R5];
  99         regs->r6 = gdb_regs[BFIN_R6];
 100         regs->r7 = gdb_regs[BFIN_R7];
 101         regs->p0 = gdb_regs[BFIN_P0];
 102         regs->p1 = gdb_regs[BFIN_P1];
 103         regs->p2 = gdb_regs[BFIN_P2];
 104         regs->p3 = gdb_regs[BFIN_P3];
 105         regs->p4 = gdb_regs[BFIN_P4];
 106         regs->p5 = gdb_regs[BFIN_P5];
 107         regs->fp = gdb_regs[BFIN_FP];
 108         regs->i0 = gdb_regs[BFIN_I0];
 109         regs->i1 = gdb_regs[BFIN_I1];
 110         regs->i2 = gdb_regs[BFIN_I2];
 111         regs->i3 = gdb_regs[BFIN_I3];
 112         regs->m0 = gdb_regs[BFIN_M0];
 113         regs->m1 = gdb_regs[BFIN_M1];
 114         regs->m2 = gdb_regs[BFIN_M2];
 115         regs->m3 = gdb_regs[BFIN_M3];
 116         regs->b0 = gdb_regs[BFIN_B0];
 117         regs->b1 = gdb_regs[BFIN_B1];
 118         regs->b2 = gdb_regs[BFIN_B2];
 119         regs->b3 = gdb_regs[BFIN_B3];
 120         regs->l0 = gdb_regs[BFIN_L0];
 121         regs->l1 = gdb_regs[BFIN_L1];
 122         regs->l2 = gdb_regs[BFIN_L2];
 123         regs->l3 = gdb_regs[BFIN_L3];
 124         regs->a0x = gdb_regs[BFIN_A0_DOT_X];
 125         regs->a0w = gdb_regs[BFIN_A0_DOT_W];
 126         regs->a1x = gdb_regs[BFIN_A1_DOT_X];
 127         regs->a1w = gdb_regs[BFIN_A1_DOT_W];
 128         regs->rets = gdb_regs[BFIN_RETS];
 129         regs->lc0 = gdb_regs[BFIN_LC0];
 130         regs->lt0 = gdb_regs[BFIN_LT0];
 131         regs->lb0 = gdb_regs[BFIN_LB0];
 132         regs->lc1 = gdb_regs[BFIN_LC1];
 133         regs->lt1 = gdb_regs[BFIN_LT1];
 134         regs->lb1 = gdb_regs[BFIN_LB1];
 135         regs->usp = gdb_regs[BFIN_USP];
 136         regs->syscfg = gdb_regs[BFIN_SYSCFG];
 137         regs->retx = gdb_regs[BFIN_RETX];
 138         regs->retn = gdb_regs[BFIN_RETN];
 139         regs->rete = gdb_regs[BFIN_RETE];
 140         regs->pc = gdb_regs[BFIN_PC];
 141
 142 #if 0                           /* can't change these */
 143         regs->astat = gdb_regs[BFIN_ASTAT];
 144         regs->seqstat = gdb_regs[BFIN_SEQSTAT];
 145         regs->ipend = gdb_regs[BFIN_IPEND];
 146 #endif
 147 }
 148
 149 static struct hw_breakpoint {
 150         unsigned int occupied:1;
 151         unsigned int skip:1;
 152         unsigned int enabled:1;
 153         unsigned int type:1;
 154         unsigned int dataacc:2;
 155         unsigned short count;
 156         unsigned int addr;
 157 } breakinfo[HW_WATCHPOINT_NUM];
 158
 159 static int bfin_set_hw_break(unsigned long addr, int len, enum kgdb_bptype type)
 160 {
 161         int breakno;
 162         int bfin_type;
 163         int dataacc = 0;
 164
 165         switch (type) {
 166         case BP_HARDWARE_BREAKPOINT:
 167                 bfin_type = TYPE_INST_WATCHPOINT;
 168                 break;
 169         case BP_WRITE_WATCHPOINT:
 170                 dataacc = 1;
 171                 bfin_type = TYPE_DATA_WATCHPOINT;
 172                 break;
 173         case BP_READ_WATCHPOINT:
 174                 dataacc = 2;
 175                 bfin_type = TYPE_DATA_WATCHPOINT;
 176                 break;
 177         case BP_ACCESS_WATCHPOINT:
 178                 dataacc = 3;
 179                 bfin_type = TYPE_DATA_WATCHPOINT;
 180                 break;
 181         default:
 182                 return -ENOSPC;
 183         }
 184
 185         /* Because hardware data watchpoint impelemented in current
 186          * Blackfin can not trigger an exception event as the hardware
 187          * instrction watchpoint does, we ignaore all data watch point here.
 188          * They can be turned on easily after future blackfin design
 189          * supports this feature.
 190          */
 191         for (breakno = 0; breakno < HW_INST_WATCHPOINT_NUM; breakno++)
 192                 if (bfin_type == breakinfo[breakno].type
 193                         && !breakinfo[breakno].occupied) {
 194                         breakinfo[breakno].occupied = 1;
 195                         breakinfo[breakno].skip = 0;
 196                         breakinfo[breakno].enabled = 1;
 197                         breakinfo[breakno].addr = addr;
 198                         breakinfo[breakno].dataacc = dataacc;
 199                         breakinfo[breakno].count = 0;
 200                         return 0;
 201                 }
 202
 203         return -ENOSPC;
 204 }
 205
 206 static int bfin_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype type)
 207 {
 208         int breakno;
 209         int bfin_type;
 210
 211         switch (type) {
 212         case BP_HARDWARE_BREAKPOINT:
 213                 bfin_type = TYPE_INST_WATCHPOINT;
 214                 break;
 215         case BP_WRITE_WATCHPOINT:
 216         case BP_READ_WATCHPOINT:
 217         case BP_ACCESS_WATCHPOINT:
 218                 bfin_type = TYPE_DATA_WATCHPOINT;
 219                 break;
 220         default:
 221                 return 0;
 222         }
 223         for (breakno = 0; breakno < HW_WATCHPOINT_NUM; breakno++)
 224                 if (bfin_type == breakinfo[breakno].type
 225                         && breakinfo[breakno].occupied
 226                         && breakinfo[breakno].addr == addr) {
 227                         breakinfo[breakno].occupied = 0;
 228                         breakinfo[breakno].enabled = 0;
 229                 }
 230
 231         return 0;
 232 }
 233
 234 static void bfin_remove_all_hw_break(void)
 235 {
 236         int breakno;
 237
 238         memset(breakinfo, 0, sizeof(struct hw_breakpoint)*HW_WATCHPOINT_NUM);
 239
 240         for (breakno = 0; breakno < HW_INST_WATCHPOINT_NUM; breakno++)
 241                 breakinfo[breakno].type = TYPE_INST_WATCHPOINT;
 242         for (; breakno < HW_WATCHPOINT_NUM; breakno++)
 243                 breakinfo[breakno].type = TYPE_DATA_WATCHPOINT;
 244 }
 245
 246 static void bfin_correct_hw_break(void)
 247 {
 248         int breakno;
 249         unsigned int wpiactl = 0;
 250         unsigned int wpdactl = 0;
 251         int enable_wp = 0;
 252
 253         for (breakno = 0; breakno < HW_WATCHPOINT_NUM; breakno++)
 254                 if (breakinfo[breakno].enabled) {
 255                         enable_wp = 1;
 256
 257                         switch (breakno) {
 258                         case 0:
 259                                 wpiactl |= WPIAEN0|WPICNTEN0;
 260                                 bfin_write_WPIA0(breakinfo[breakno].addr);
 261                                 bfin_write_WPIACNT0(breakinfo[breakno].count
 262                                         + breakinfo->skip);
 263                                 break;
 264                         case 1:
 265                                 wpiactl |= WPIAEN1|WPICNTEN1;
 266                                 bfin_write_WPIA1(breakinfo[breakno].addr);
 267                                 bfin_write_WPIACNT1(breakinfo[breakno].count
 268                                         + breakinfo->skip);
 269                                 break;
 270                         case 2:
 271                                 wpiactl |= WPIAEN2|WPICNTEN2;
 272                                 bfin_write_WPIA2(breakinfo[breakno].addr);
 273                                 bfin_write_WPIACNT2(breakinfo[breakno].count
 274                                         + breakinfo->skip);
 275                                 break;
 276                         case 3:
 277                                 wpiactl |= WPIAEN3|WPICNTEN3;
 278                                 bfin_write_WPIA3(breakinfo[breakno].addr);
 279                                 bfin_write_WPIACNT3(breakinfo[breakno].count
 280                                         + breakinfo->skip);
 281                                 break;
 282                         case 4:
 283                                 wpiactl |= WPIAEN4|WPICNTEN4;
 284                                 bfin_write_WPIA4(breakinfo[breakno].addr);
 285                                 bfin_write_WPIACNT4(breakinfo[breakno].count
 286                                         + breakinfo->skip);
 287                                 break;
 288                         case 5:
 289                                 wpiactl |= WPIAEN5|WPICNTEN5;
 290                                 bfin_write_WPIA5(breakinfo[breakno].addr);
 291                                 bfin_write_WPIACNT5(breakinfo[breakno].count
 292                                         + breakinfo->skip);
 293                                 break;
 294                         case 6:
 295                                 wpdactl |= WPDAEN0|WPDCNTEN0|WPDSRC0;
 296                                 wpdactl |= breakinfo[breakno].dataacc
 297                                         << WPDACC0_OFFSET;
 298                                 bfin_write_WPDA0(breakinfo[breakno].addr);
 299                                 bfin_write_WPDACNT0(breakinfo[breakno].count
 300                                         + breakinfo->skip);
 301                                 break;
 302                         case 7:
 303                                 wpdactl |= WPDAEN1|WPDCNTEN1|WPDSRC1;
 304                                 wpdactl |= breakinfo[breakno].dataacc
 305                                         << WPDACC1_OFFSET;
 306                                 bfin_write_WPDA1(breakinfo[breakno].addr);
 307                                 bfin_write_WPDACNT1(breakinfo[breakno].count
 308                                         + breakinfo->skip);
 309                                 break;
 310                         }
 311                 }
 312
 313         /* Should enable WPPWR bit first before set any other
 314          * WPIACTL and WPDACTL bits */
 315         if (enable_wp) {
 316                 bfin_write_WPIACTL(WPPWR);
 317                 CSYNC();
 318                 bfin_write_WPIACTL(wpiactl|WPPWR);
 319                 bfin_write_WPDACTL(wpdactl);
 320                 CSYNC();
 321         }
 322 }
 323
 324 static void bfin_disable_hw_debug(struct pt_regs *regs)
 325 {
 326         /* Disable hardware debugging while we are in kgdb */
 327         bfin_write_WPIACTL(0);
 328         bfin_write_WPDACTL(0);
 329         CSYNC();
 330 }
 331
 332 #ifdef CONFIG_SMP
 333 void kgdb_passive_cpu_callback(void *info)
 334 {
 335         kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
 336 }
 337
 338 void kgdb_roundup_cpus(unsigned long flags)
 339 {
 340         unsigned int cpu;
 341
 342         for (cpu = cpumask_first(cpu_online_mask); cpu < nr_cpu_ids;
 343                 cpu = cpumask_next(cpu, cpu_online_mask))
 344                 smp_call_function_single(cpu, kgdb_passive_cpu_callback,
 345                                          NULL, 0);
 346 }
 347
 348 void kgdb_roundup_cpu(int cpu, unsigned long flags)
 349 {
 350         smp_call_function_single(cpu, kgdb_passive_cpu_callback, NULL, 0);
 351 }
 352 #endif
 353
 354 #ifdef CONFIG_IPIPE
 355 static unsigned long kgdb_arch_imask;
 356 #endif
 357
 358 int kgdb_arch_handle_exception(int vector, int signo,
 359                                int err_code, char *remcom_in_buffer,
 360                                char *remcom_out_buffer,
 361                                struct pt_regs *regs)
 362 {
 363         long addr;
 364         char *ptr;
 365         int newPC;
 366         int i;
 367
 368         switch (remcom_in_buffer[0]) {
 369         case 'c':
 370         case 's':
 371                 if (kgdb_contthread && kgdb_contthread != current) {
 372                         strcpy(remcom_out_buffer, "E00");
 373                         break;
 374                 }
 375
 376                 kgdb_contthread = NULL;
 377
 378                 /* try to read optional parameter, pc unchanged if no parm */
 379                 ptr = &remcom_in_buffer[1];
 380                 if (kgdb_hex2long(&ptr, &addr)) {
 381                         regs->retx = addr;
 382                 }
 383                 newPC = regs->retx;
 384
 385                 /* clear the trace bit */
 386                 regs->syscfg &= 0xfffffffe;
 387
 388                 /* set the trace bit if we're stepping */
 389                 if (remcom_in_buffer[0] == 's') {
 390                         regs->syscfg |= 0x1;
 391                         kgdb_single_step = regs->ipend;
 392                         kgdb_single_step >>= 6;
 393                         for (i = 10; i > 0; i--, kgdb_single_step >>= 1)
 394                                 if (kgdb_single_step & 1)
 395                                         break;
 396                         /* i indicate event priority of current stopped instruction
 397                          * user space instruction is 0, IVG15 is 1, IVTMR is 10.
 398                          * kgdb_single_step > 0 means in single step mode
 399                          */
 400                         kgdb_single_step = i + 1;
 401
 402                         preempt_disable();
 403 #ifdef CONFIG_IPIPE
 404                         kgdb_arch_imask = cpu_pda[raw_smp_processor_id()].ex_imask;
 405                         cpu_pda[raw_smp_processor_id()].ex_imask = 0;
 406 #endif
 407                 }
 408
 409                 bfin_correct_hw_break();
 410
 411                 return 0;
 412         }                       /* switch */
 413         return -1;              /* this means that we do not want to exit from the handler */
 414 }
 415
 416 struct kgdb_arch arch_kgdb_ops = {
 417         .gdb_bpt_instr = {0xa1},
 418         .flags = KGDB_HW_BREAKPOINT,
 419         .set_hw_breakpoint = bfin_set_hw_break,
 420         .remove_hw_breakpoint = bfin_remove_hw_break,
 421         .disable_hw_break = bfin_disable_hw_debug,
 422         .remove_all_hw_break = bfin_remove_all_hw_break,
 423         .correct_hw_break = bfin_correct_hw_break,
 424 };
 425
 426 #define IN_MEM(addr, size, l1_addr, l1_size) \
 427 ({ \
 428         unsigned long __addr = (unsigned long)(addr); \
 429         (l1_size && __addr >= l1_addr && __addr + (size) <= l1_addr + l1_size); \
 430 })
 431 #define ASYNC_BANK_SIZE \
 432         (ASYNC_BANK0_SIZE + ASYNC_BANK1_SIZE + \
 433          ASYNC_BANK2_SIZE + ASYNC_BANK3_SIZE)
 434
 435 int kgdb_validate_break_address(unsigned long addr)
 436 {
 437         int cpu = raw_smp_processor_id();
 438
 439         if (addr >= 0x1000 && (addr + BREAK_INSTR_SIZE) <= physical_mem_end)
 440                 return 0;
 441         if (IN_MEM(addr, BREAK_INSTR_SIZE, ASYNC_BANK0_BASE, ASYNC_BANK_SIZE))
 442                 return 0;
 443         if (cpu == 0 && IN_MEM(addr, BREAK_INSTR_SIZE, L1_CODE_START, L1_CODE_LENGTH))
 444                 return 0;
 445 #ifdef CONFIG_SMP
 446         else if (cpu == 1 && IN_MEM(addr, BREAK_INSTR_SIZE, COREB_L1_CODE_START, L1_CODE_LENGTH))
 447                 return 0;
 448 #endif
 449         if (IN_MEM(addr, BREAK_INSTR_SIZE, L2_START, L2_LENGTH))
 450                 return 0;
 451
 452         return -EFAULT;
 453 }
 454
 455 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
 456 {
 457         regs->retx = ip;
 458 }
 459
 460 int kgdb_arch_init(void)
 461 {
 462         kgdb_single_step = 0;
 463 #ifdef CONFIG_IPIPE
 464         kgdb_arch_imask = 0;
 465 #endif
 466
 467         bfin_remove_all_hw_break();
 468         return 0;
 469 }
 470
 471 void kgdb_arch_exit(void)
 472 {
 473 }