1/* 2 * PowerPC backend to the KGDB stub. 3 * 4 * 1998 (c) Michael AK Tesch (tesch@cs.wisc.edu) 5 * Copyright (C) 2003 Timesys Corporation. 6 * Copyright (C) 2004-2006 MontaVista Software, Inc. 7 * PPC64 Mods (C) 2005 Frank Rowand (frowand@mvista.com) 8 * PPC32 support restored by Vitaly Wool <vwool@ru.mvista.com> and 9 * Sergei Shtylyov <sshtylyov@ru.mvista.com> 10 * Copyright (C) 2007-2008 Wind River Systems, Inc. 11 * 12 * This file is licensed under the terms of the GNU General Public License 13 * version 2. This program as licensed "as is" without any warranty of any 14 * kind, whether express or implied. 15 */ 16 17#include <linux/kernel.h> 18#include <linux/init.h> 19#include <linux/kgdb.h> 20#include <linux/smp.h> 21#include <linux/signal.h> 22#include <linux/ptrace.h> 23#include <linux/kdebug.h> 24#include <asm/current.h> 25#include <asm/processor.h> 26#include <asm/machdep.h> 27 28/* 29 * This table contains the mapping between PowerPC hardware trap types, and 30 * signals, which are primarily what GDB understands. GDB and the kernel 31 * don't always agree on values, so we use constants taken from gdb-6.2. 32 */ 33static struct hard_trap_info 34{ 35 unsigned int tt; /* Trap type code for powerpc */ 36 unsigned char signo; /* Signal that we map this trap into */ 37} hard_trap_info[] = { 38 { 0x0100, 0x02 /* SIGINT */ }, /* system reset */ 39 { 0x0200, 0x0b /* SIGSEGV */ }, /* machine check */ 40 { 0x0300, 0x0b /* SIGSEGV */ }, /* data access */ 41 { 0x0400, 0x0b /* SIGSEGV */ }, /* instruction access */ 42 { 0x0500, 0x02 /* SIGINT */ }, /* external interrupt */ 43 { 0x0600, 0x0a /* SIGBUS */ }, /* alignment */ 44 { 0x0700, 0x05 /* SIGTRAP */ }, /* program check */ 45 { 0x0800, 0x08 /* SIGFPE */ }, /* fp unavailable */ 46 { 0x0900, 0x0e /* SIGALRM */ }, /* decrementer */ 47 { 0x0c00, 0x14 /* SIGCHLD */ }, /* system call */ 48#if defined(CONFIG_40x) || defined(CONFIG_BOOKE) 49 { 0x2002, 0x05 /* SIGTRAP */ }, /* debug */ 50#if defined(CONFIG_FSL_BOOKE) 51 { 0x2010, 0x08 /* SIGFPE */ }, /* spe unavailable */ 52 { 0x2020, 0x08 /* SIGFPE */ }, /* spe unavailable */ 53 { 0x2030, 0x08 /* SIGFPE */ }, /* spe fp data */ 54 { 0x2040, 0x08 /* SIGFPE */ }, /* spe fp data */ 55 { 0x2050, 0x08 /* SIGFPE */ }, /* spe fp round */ 56 { 0x2060, 0x0e /* SIGILL */ }, /* performance monitor */ 57 { 0x2900, 0x08 /* SIGFPE */ }, /* apu unavailable */ 58 { 0x3100, 0x0e /* SIGALRM */ }, /* fixed interval timer */ 59 { 0x3200, 0x02 /* SIGINT */ }, /* watchdog */ 60#else /* ! CONFIG_FSL_BOOKE */ 61 { 0x1000, 0x0e /* SIGALRM */ }, /* prog interval timer */ 62 { 0x1010, 0x0e /* SIGALRM */ }, /* fixed interval timer */ 63 { 0x1020, 0x02 /* SIGINT */ }, /* watchdog */ 64 { 0x2010, 0x08 /* SIGFPE */ }, /* fp unavailable */ 65 { 0x2020, 0x08 /* SIGFPE */ }, /* ap unavailable */ 66#endif 67#else /* ! (defined(CONFIG_40x) || defined(CONFIG_BOOKE)) */ 68 { 0x0d00, 0x05 /* SIGTRAP */ }, /* single-step */ 69#if defined(CONFIG_8xx) 70 { 0x1000, 0x04 /* SIGILL */ }, /* software emulation */ 71#else /* ! CONFIG_8xx */ 72 { 0x0f00, 0x04 /* SIGILL */ }, /* performance monitor */ 73 { 0x0f20, 0x08 /* SIGFPE */ }, /* altivec unavailable */ 74 { 0x1300, 0x05 /* SIGTRAP */ }, /* instruction address break */ 75#if defined(CONFIG_PPC64) 76 { 0x1200, 0x05 /* SIGILL */ }, /* system error */ 77 { 0x1500, 0x04 /* SIGILL */ }, /* soft patch */ 78 { 0x1600, 0x04 /* SIGILL */ }, /* maintenance */ 79 { 0x1700, 0x08 /* SIGFPE */ }, /* altivec assist */ 80 { 0x1800, 0x04 /* SIGILL */ }, /* thermal */ 81#else /* ! CONFIG_PPC64 */ 82 { 0x1400, 0x02 /* SIGINT */ }, /* SMI */ 83 { 0x1600, 0x08 /* SIGFPE */ }, /* altivec assist */ 84 { 0x1700, 0x04 /* SIGILL */ }, /* TAU */ 85 { 0x2000, 0x05 /* SIGTRAP */ }, /* run mode */ 86#endif 87#endif 88#endif 89 { 0x0000, 0x00 } /* Must be last */ 90}; 91 92static int computeSignal(unsigned int tt) 93{ 94 struct hard_trap_info *ht; 95 96 for (ht = hard_trap_info; ht->tt && ht->signo; ht++) 97 if (ht->tt == tt) 98 return ht->signo; 99 100 return SIGHUP; /* default for things we don't know about */ 101} 102 103static int kgdb_call_nmi_hook(struct pt_regs *regs) 104{ 105 kgdb_nmicallback(raw_smp_processor_id(), regs); 106 return 0; 107} 108 109#ifdef CONFIG_SMP 110void kgdb_roundup_cpus(unsigned long flags) 111{ 112 smp_send_debugger_break(MSG_ALL_BUT_SELF); 113} 114#endif 115 116/* KGDB functions to use existing PowerPC64 hooks. */ 117static int kgdb_debugger(struct pt_regs *regs) 118{ 119 return !kgdb_handle_exception(1, computeSignal(TRAP(regs)), 120 DIE_OOPS, regs); 121} 122 123static int kgdb_handle_breakpoint(struct pt_regs *regs) 124{ 125 if (user_mode(regs)) 126 return 0; 127 128 if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0) 129 return 0; 130 131 if (*(u32 *) (regs->nip) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr)) 132 regs->nip += BREAK_INSTR_SIZE; 133 134 return 1; 135} 136 137static int kgdb_singlestep(struct pt_regs *regs) 138{ 139 struct thread_info *thread_info, *exception_thread_info; 140 141 if (user_mode(regs)) 142 return 0; 143 144 thread_info = (struct thread_info *)(regs->gpr[1] & ~(THREAD_SIZE-1)); 145 exception_thread_info = current_thread_info(); 146 147 if (thread_info != exception_thread_info) 148 memcpy(exception_thread_info, thread_info, sizeof *thread_info); 149 150 kgdb_handle_exception(0, SIGTRAP, 0, regs); 151 152 if (thread_info != exception_thread_info) 153 memcpy(thread_info, exception_thread_info, sizeof *thread_info); 154 155 return 1; 156} 157 158static int kgdb_iabr_match(struct pt_regs *regs) 159{ 160 if (user_mode(regs)) 161 return 0; 162 163 if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0) 164 return 0; 165 return 1; 166} 167 168static int kgdb_dabr_match(struct pt_regs *regs) 169{ 170 if (user_mode(regs)) 171 return 0; 172 173 if (kgdb_handle_exception(0, computeSignal(TRAP(regs)), 0, regs) != 0) 174 return 0; 175 return 1; 176} 177 178#define PACK64(ptr, src) do { *(ptr++) = (src); } while (0) 179 180#define PACK32(ptr, src) do { \ 181 u32 *ptr32; \ 182 ptr32 = (u32 *)ptr; \ 183 *(ptr32++) = (src); \ 184 ptr = (unsigned long *)ptr32; \ 185 } while (0) 186 187 188void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) 189{ 190 unsigned long *ptr = gdb_regs; 191 int reg; 192 193 memset(gdb_regs, 0, NUMREGBYTES); 194 195 for (reg = 0; reg < 32; reg++) 196 PACK64(ptr, regs->gpr[reg]); 197 198#ifdef CONFIG_FSL_BOOKE 199#ifdef CONFIG_SPE 200 for (reg = 0; reg < 32; reg++) 201 PACK64(ptr, current->thread.evr[reg]); 202#else 203 ptr += 32; 204#endif 205#else 206 /* fp registers not used by kernel, leave zero */ 207 ptr += 32 * 8 / sizeof(long); 208#endif 209 210 PACK64(ptr, regs->nip); 211 PACK64(ptr, regs->msr); 212 PACK32(ptr, regs->ccr); 213 PACK64(ptr, regs->link); 214 PACK64(ptr, regs->ctr); 215 PACK32(ptr, regs->xer); 216 217 BUG_ON((unsigned long)ptr > 218 (unsigned long)(((void *)gdb_regs) + NUMREGBYTES)); 219} 220 221void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) 222{ 223 struct pt_regs *regs = (struct pt_regs *)(p->thread.ksp + 224 STACK_FRAME_OVERHEAD); 225 unsigned long *ptr = gdb_regs; 226 int reg; 227 228 memset(gdb_regs, 0, NUMREGBYTES); 229 230 /* Regs GPR0-2 */ 231 for (reg = 0; reg < 3; reg++) 232 PACK64(ptr, regs->gpr[reg]); 233 234 /* Regs GPR3-13 are caller saved, not in regs->gpr[] */ 235 ptr += 11; 236 237 /* Regs GPR14-31 */ 238 for (reg = 14; reg < 32; reg++) 239 PACK64(ptr, regs->gpr[reg]); 240 241#ifdef CONFIG_FSL_BOOKE 242#ifdef CONFIG_SPE 243 for (reg = 0; reg < 32; reg++) 244 PACK64(ptr, p->thread.evr[reg]); 245#else 246 ptr += 32; 247#endif 248#else 249 /* fp registers not used by kernel, leave zero */ 250 ptr += 32 * 8 / sizeof(long); 251#endif 252 253 PACK64(ptr, regs->nip); 254 PACK64(ptr, regs->msr); 255 PACK32(ptr, regs->ccr); 256 PACK64(ptr, regs->link); 257 PACK64(ptr, regs->ctr); 258 PACK32(ptr, regs->xer); 259 260 BUG_ON((unsigned long)ptr > 261 (unsigned long)(((void *)gdb_regs) + NUMREGBYTES)); 262} 263 264#define UNPACK64(dest, ptr) do { dest = *(ptr++); } while (0) 265 266#define UNPACK32(dest, ptr) do { \ 267 u32 *ptr32; \ 268 ptr32 = (u32 *)ptr; \ 269 dest = *(ptr32++); \ 270 ptr = (unsigned long *)ptr32; \ 271 } while (0) 272 273void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) 274{ 275 unsigned long *ptr = gdb_regs; 276 int reg; 277 278 for (reg = 0; reg < 32; reg++) 279 UNPACK64(regs->gpr[reg], ptr); 280 281#ifdef CONFIG_FSL_BOOKE 282#ifdef CONFIG_SPE 283 for (reg = 0; reg < 32; reg++) 284 UNPACK64(current->thread.evr[reg], ptr); 285#else 286 ptr += 32; 287#endif 288#else 289 /* fp registers not used by kernel, leave zero */ 290 ptr += 32 * 8 / sizeof(int); 291#endif 292 293 UNPACK64(regs->nip, ptr); 294 UNPACK64(regs->msr, ptr); 295 UNPACK32(regs->ccr, ptr); 296 UNPACK64(regs->link, ptr); 297 UNPACK64(regs->ctr, ptr); 298 UNPACK32(regs->xer, ptr); 299 300 BUG_ON((unsigned long)ptr > 301 (unsigned long)(((void *)gdb_regs) + NUMREGBYTES)); 302} 303 304void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) 305{ 306 regs->nip = pc; 307} 308 309/* 310 * This function does PowerPC specific procesing for interfacing to gdb. 311 */ 312int kgdb_arch_handle_exception(int vector, int signo, int err_code, 313 char *remcom_in_buffer, char *remcom_out_buffer, 314 struct pt_regs *linux_regs) 315{ 316 char *ptr = &remcom_in_buffer[1]; 317 unsigned long addr; 318 319 switch (remcom_in_buffer[0]) { 320 /* 321 * sAA..AA Step one instruction from AA..AA 322 * This will return an error to gdb .. 323 */ 324 case 's': 325 case 'c': 326 /* handle the optional parameter */ 327 if (kgdb_hex2long(&ptr, &addr)) 328 linux_regs->nip = addr; 329 330 atomic_set(&kgdb_cpu_doing_single_step, -1); 331 /* set the trace bit if we're stepping */ 332 if (remcom_in_buffer[0] == 's') { 333#ifdef CONFIG_PPC_ADV_DEBUG_REGS 334 mtspr(SPRN_DBCR0, 335 mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM); 336 linux_regs->msr |= MSR_DE; 337#else 338 linux_regs->msr |= MSR_SE; 339#endif 340 kgdb_single_step = 1; 341 atomic_set(&kgdb_cpu_doing_single_step, 342 raw_smp_processor_id()); 343 } 344 return 0; 345 } 346 347 return -1; 348} 349 350/* 351 * Global data 352 */ 353struct kgdb_arch arch_kgdb_ops = { 354 .gdb_bpt_instr = {0x7d, 0x82, 0x10, 0x08}, 355}; 356 357static int kgdb_not_implemented(struct pt_regs *regs) 358{ 359 return 0; 360} 361 362static void *old__debugger_ipi; 363static void *old__debugger; 364static void *old__debugger_bpt; 365static void *old__debugger_sstep; 366static void *old__debugger_iabr_match; 367static void *old__debugger_dabr_match; 368static void *old__debugger_fault_handler; 369 370int kgdb_arch_init(void) 371{ 372 old__debugger_ipi = __debugger_ipi; 373 old__debugger = __debugger; 374 old__debugger_bpt = __debugger_bpt; 375 old__debugger_sstep = __debugger_sstep; 376 old__debugger_iabr_match = __debugger_iabr_match; 377 old__debugger_dabr_match = __debugger_dabr_match; 378 old__debugger_fault_handler = __debugger_fault_handler; 379 380 __debugger_ipi = kgdb_call_nmi_hook; 381 __debugger = kgdb_debugger; 382 __debugger_bpt = kgdb_handle_breakpoint; 383 __debugger_sstep = kgdb_singlestep; 384 __debugger_iabr_match = kgdb_iabr_match; 385 __debugger_dabr_match = kgdb_dabr_match; 386 __debugger_fault_handler = kgdb_not_implemented; 387 388 return 0; 389} 390 391void kgdb_arch_exit(void) 392{ 393 __debugger_ipi = old__debugger_ipi; 394 __debugger = old__debugger; 395 __debugger_bpt = old__debugger_bpt; 396 __debugger_sstep = old__debugger_sstep; 397 __debugger_iabr_match = old__debugger_iabr_match; 398 __debugger_dabr_match = old__debugger_dabr_match; 399 __debugger_fault_handler = old__debugger_fault_handler; 400} 401