1 /* 2 * Architecture-specific setup. 3 * 4 * Copyright (C) 1998-2003 Hewlett-Packard Co 5 * David Mosberger-Tang <davidm@hpl.hp.com> 6 * 04/11/17 Ashok Raj <ashok.raj@intel.com> Added CPU Hotplug Support 7 * 8 * 2005-10-07 Keith Owens <kaos@sgi.com> 9 * Add notify_die() hooks. 10 */ 11 #include <linux/cpu.h> 12 #include <linux/pm.h> 13 #include <linux/elf.h> 14 #include <linux/errno.h> 15 #include <linux/kallsyms.h> 16 #include <linux/kernel.h> 17 #include <linux/mm.h> 18 #include <linux/slab.h> 19 #include <linux/module.h> 20 #include <linux/notifier.h> 21 #include <linux/personality.h> 22 #include <linux/sched.h> 23 #include <linux/stddef.h> 24 #include <linux/thread_info.h> 25 #include <linux/unistd.h> 26 #include <linux/efi.h> 27 #include <linux/interrupt.h> 28 #include <linux/delay.h> 29 #include <linux/kdebug.h> 30 #include <linux/utsname.h> 31 #include <linux/tracehook.h> 32 #include <linux/rcupdate.h> 33 34 #include <asm/cpu.h> 35 #include <asm/delay.h> 36 #include <asm/elf.h> 37 #include <asm/irq.h> 38 #include <asm/kexec.h> 39 #include <asm/pgalloc.h> 40 #include <asm/processor.h> 41 #include <asm/sal.h> 42 #include <asm/switch_to.h> 43 #include <asm/tlbflush.h> 44 #include <asm/uaccess.h> 45 #include <asm/unwind.h> 46 #include <asm/user.h> 47 48 #include "entry.h" 49 50 #ifdef CONFIG_PERFMON 51 # include <asm/perfmon.h> 52 #endif 53 54 #include "sigframe.h" 55 56 void (*ia64_mark_idle)(int); 57 58 unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE; 59 EXPORT_SYMBOL(boot_option_idle_override); 60 void (*pm_power_off) (void); 61 EXPORT_SYMBOL(pm_power_off); 62 63 void 64 ia64_do_show_stack (struct unw_frame_info *info, void *arg) 65 { 66 unsigned long ip, sp, bsp; 67 char buf[128]; /* don't make it so big that it overflows the stack! */ 68 69 printk("\nCall Trace:\n"); 70 do { 71 unw_get_ip(info, &ip); 72 if (ip == 0) 73 break; 74 75 unw_get_sp(info, &sp); 76 unw_get_bsp(info, &bsp); 77 snprintf(buf, sizeof(buf), 78 " [<%016lx>] %%s\n" 79 " sp=%016lx bsp=%016lx\n", 80 ip, sp, bsp); 81 print_symbol(buf, ip); 82 } while (unw_unwind(info) >= 0); 83 } 84 85 void 86 show_stack (struct task_struct *task, unsigned long *sp) 87 { 88 if (!task) 89 unw_init_running(ia64_do_show_stack, NULL); 90 else { 91 struct unw_frame_info info; 92 93 unw_init_from_blocked_task(&info, task); 94 ia64_do_show_stack(&info, NULL); 95 } 96 } 97 98 void 99 dump_stack (void) 100 { 101 show_stack(NULL, NULL); 102 } 103 104 EXPORT_SYMBOL(dump_stack); 105 106 void 107 show_regs (struct pt_regs *regs) 108 { 109 unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri; 110 111 print_modules(); 112 printk("\nPid: %d, CPU %d, comm: %20s\n", task_pid_nr(current), 113 smp_processor_id(), current->comm); 114 printk("psr : %016lx ifs : %016lx ip : [<%016lx>] %s (%s)\n", 115 regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(), 116 init_utsname()->release); 117 print_symbol("ip is at %s\n", ip); 118 printk("unat: %016lx pfs : %016lx rsc : %016lx\n", 119 regs->ar_unat, regs->ar_pfs, regs->ar_rsc); 120 printk("rnat: %016lx bsps: %016lx pr : %016lx\n", 121 regs->ar_rnat, regs->ar_bspstore, regs->pr); 122 printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n", 123 regs->loadrs, regs->ar_ccv, regs->ar_fpsr); 124 printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd); 125 printk("b0 : %016lx b6 : %016lx b7 : %016lx\n", regs->b0, regs->b6, regs->b7); 126 printk("f6 : %05lx%016lx f7 : %05lx%016lx\n", 127 regs->f6.u.bits[1], regs->f6.u.bits[0], 128 regs->f7.u.bits[1], regs->f7.u.bits[0]); 129 printk("f8 : %05lx%016lx f9 : %05lx%016lx\n", 130 regs->f8.u.bits[1], regs->f8.u.bits[0], 131 regs->f9.u.bits[1], regs->f9.u.bits[0]); 132 printk("f10 : %05lx%016lx f11 : %05lx%016lx\n", 133 regs->f10.u.bits[1], regs->f10.u.bits[0], 134 regs->f11.u.bits[1], regs->f11.u.bits[0]); 135 136 printk("r1 : %016lx r2 : %016lx r3 : %016lx\n", regs->r1, regs->r2, regs->r3); 137 printk("r8 : %016lx r9 : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10); 138 printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13); 139 printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16); 140 printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19); 141 printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22); 142 printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25); 143 printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28); 144 printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31); 145 146 if (user_mode(regs)) { 147 /* print the stacked registers */ 148 unsigned long val, *bsp, ndirty; 149 int i, sof, is_nat = 0; 150 151 sof = regs->cr_ifs & 0x7f; /* size of frame */ 152 ndirty = (regs->loadrs >> 19); 153 bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty); 154 for (i = 0; i < sof; ++i) { 155 get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i)); 156 printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val, 157 ((i == sof - 1) || (i % 3) == 2) ? "\n" : " "); 158 } 159 } else 160 show_stack(NULL, NULL); 161 } 162 163 /* local support for deprecated console_print */ 164 void 165 console_print(const char *s) 166 { 167 printk(KERN_EMERG "%s", s); 168 } 169 170 void 171 do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall) 172 { 173 if (fsys_mode(current, &scr->pt)) { 174 /* 175 * defer signal-handling etc. until we return to 176 * privilege-level 0. 177 */ 178 if (!ia64_psr(&scr->pt)->lp) 179 ia64_psr(&scr->pt)->lp = 1; 180 return; 181 } 182 183 #ifdef CONFIG_PERFMON 184 if (current->thread.pfm_needs_checking) 185 /* 186 * Note: pfm_handle_work() allow us to call it with interrupts 187 * disabled, and may enable interrupts within the function. 188 */ 189 pfm_handle_work(); 190 #endif 191 192 /* deal with pending signal delivery */ 193 if (test_thread_flag(TIF_SIGPENDING)) { 194 local_irq_enable(); /* force interrupt enable */ 195 ia64_do_signal(scr, in_syscall); 196 } 197 198 if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) { 199 local_irq_enable(); /* force interrupt enable */ 200 tracehook_notify_resume(&scr->pt); 201 } 202 203 /* copy user rbs to kernel rbs */ 204 if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) { 205 local_irq_enable(); /* force interrupt enable */ 206 ia64_sync_krbs(); 207 } 208 209 local_irq_disable(); /* force interrupt disable */ 210 } 211 212 static int pal_halt = 1; 213 static int can_do_pal_halt = 1; 214 215 static int __init nohalt_setup(char * str) 216 { 217 pal_halt = can_do_pal_halt = 0; 218 return 1; 219 } 220 __setup("nohalt", nohalt_setup); 221 222 void 223 update_pal_halt_status(int status) 224 { 225 can_do_pal_halt = pal_halt && status; 226 } 227 228 /* 229 * We use this if we don't have any better idle routine.. 230 */ 231 void 232 default_idle (void) 233 { 234 local_irq_enable(); 235 while (!need_resched()) { 236 if (can_do_pal_halt) { 237 local_irq_disable(); 238 if (!need_resched()) { 239 safe_halt(); 240 } 241 local_irq_enable(); 242 } else 243 cpu_relax(); 244 } 245 } 246 247 #ifdef CONFIG_HOTPLUG_CPU 248 /* We don't actually take CPU down, just spin without interrupts. */ 249 static inline void play_dead(void) 250 { 251 unsigned int this_cpu = smp_processor_id(); 252 253 /* Ack it */ 254 __get_cpu_var(cpu_state) = CPU_DEAD; 255 256 max_xtp(); 257 local_irq_disable(); 258 idle_task_exit(); 259 ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]); 260 /* 261 * The above is a point of no-return, the processor is 262 * expected to be in SAL loop now. 263 */ 264 BUG(); 265 } 266 #else 267 static inline void play_dead(void) 268 { 269 BUG(); 270 } 271 #endif /* CONFIG_HOTPLUG_CPU */ 272 273 void __attribute__((noreturn)) 274 cpu_idle (void) 275 { 276 void (*mark_idle)(int) = ia64_mark_idle; 277 int cpu = smp_processor_id(); 278 279 /* endless idle loop with no priority at all */ 280 while (1) { 281 rcu_idle_enter(); 282 if (can_do_pal_halt) { 283 current_thread_info()->status &= ~TS_POLLING; 284 /* 285 * TS_POLLING-cleared state must be visible before we 286 * test NEED_RESCHED: 287 */ 288 smp_mb(); 289 } else { 290 current_thread_info()->status |= TS_POLLING; 291 } 292 293 if (!need_resched()) { 294 void (*idle)(void); 295 #ifdef CONFIG_SMP 296 min_xtp(); 297 #endif 298 rmb(); 299 if (mark_idle) 300 (*mark_idle)(1); 301 302 if (!idle) 303 idle = default_idle; 304 (*idle)(); 305 if (mark_idle) 306 (*mark_idle)(0); 307 #ifdef CONFIG_SMP 308 normal_xtp(); 309 #endif 310 } 311 rcu_idle_exit(); 312 schedule_preempt_disabled(); 313 check_pgt_cache(); 314 if (cpu_is_offline(cpu)) 315 play_dead(); 316 } 317 } 318 319 void 320 ia64_save_extra (struct task_struct *task) 321 { 322 #ifdef CONFIG_PERFMON 323 unsigned long info; 324 #endif 325 326 if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0) 327 ia64_save_debug_regs(&task->thread.dbr[0]); 328 329 #ifdef CONFIG_PERFMON 330 if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0) 331 pfm_save_regs(task); 332 333 info = __get_cpu_var(pfm_syst_info); 334 if (info & PFM_CPUINFO_SYST_WIDE) 335 pfm_syst_wide_update_task(task, info, 0); 336 #endif 337 } 338 339 void 340 ia64_load_extra (struct task_struct *task) 341 { 342 #ifdef CONFIG_PERFMON 343 unsigned long info; 344 #endif 345 346 if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0) 347 ia64_load_debug_regs(&task->thread.dbr[0]); 348 349 #ifdef CONFIG_PERFMON 350 if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0) 351 pfm_load_regs(task); 352 353 info = __get_cpu_var(pfm_syst_info); 354 if (info & PFM_CPUINFO_SYST_WIDE) 355 pfm_syst_wide_update_task(task, info, 1); 356 #endif 357 } 358 359 /* 360 * Copy the state of an ia-64 thread. 361 * 362 * We get here through the following call chain: 363 * 364 * from user-level: from kernel: 365 * 366 * <clone syscall> <some kernel call frames> 367 * sys_clone : 368 * do_fork do_fork 369 * copy_thread copy_thread 370 * 371 * This means that the stack layout is as follows: 372 * 373 * +---------------------+ (highest addr) 374 * | struct pt_regs | 375 * +---------------------+ 376 * | struct switch_stack | 377 * +---------------------+ 378 * | | 379 * | memory stack | 380 * | | <-- sp (lowest addr) 381 * +---------------------+ 382 * 383 * Observe that we copy the unat values that are in pt_regs and switch_stack. Spilling an 384 * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register, 385 * with N=(X & 0x1ff)/8. Thus, copying the unat value preserves the NaT bits ONLY if the 386 * pt_regs structure in the parent is congruent to that of the child, modulo 512. Since 387 * the stack is page aligned and the page size is at least 4KB, this is always the case, 388 * so there is nothing to worry about. 389 */ 390 int 391 copy_thread(unsigned long clone_flags, 392 unsigned long user_stack_base, unsigned long user_stack_size, 393 struct task_struct *p) 394 { 395 extern char ia64_ret_from_clone; 396 struct switch_stack *child_stack, *stack; 397 unsigned long rbs, child_rbs, rbs_size; 398 struct pt_regs *child_ptregs; 399 struct pt_regs *regs = current_pt_regs(); 400 int retval = 0; 401 402 child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1; 403 child_stack = (struct switch_stack *) child_ptregs - 1; 404 405 rbs = (unsigned long) current + IA64_RBS_OFFSET; 406 child_rbs = (unsigned long) p + IA64_RBS_OFFSET; 407 408 /* copy parts of thread_struct: */ 409 p->thread.ksp = (unsigned long) child_stack - 16; 410 411 /* 412 * NOTE: The calling convention considers all floating point 413 * registers in the high partition (fph) to be scratch. Since 414 * the only way to get to this point is through a system call, 415 * we know that the values in fph are all dead. Hence, there 416 * is no need to inherit the fph state from the parent to the 417 * child and all we have to do is to make sure that 418 * IA64_THREAD_FPH_VALID is cleared in the child. 419 * 420 * XXX We could push this optimization a bit further by 421 * clearing IA64_THREAD_FPH_VALID on ANY system call. 422 * However, it's not clear this is worth doing. Also, it 423 * would be a slight deviation from the normal Linux system 424 * call behavior where scratch registers are preserved across 425 * system calls (unless used by the system call itself). 426 */ 427 # define THREAD_FLAGS_TO_CLEAR (IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \ 428 | IA64_THREAD_PM_VALID) 429 # define THREAD_FLAGS_TO_SET 0 430 p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR) 431 | THREAD_FLAGS_TO_SET); 432 433 ia64_drop_fpu(p); /* don't pick up stale state from a CPU's fph */ 434 435 if (unlikely(p->flags & PF_KTHREAD)) { 436 if (unlikely(!user_stack_base)) { 437 /* fork_idle() called us */ 438 return 0; 439 } 440 memset(child_stack, 0, sizeof(*child_ptregs) + sizeof(*child_stack)); 441 child_stack->r4 = user_stack_base; /* payload */ 442 child_stack->r5 = user_stack_size; /* argument */ 443 /* 444 * Preserve PSR bits, except for bits 32-34 and 37-45, 445 * which we can't read. 446 */ 447 child_ptregs->cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN; 448 /* mark as valid, empty frame */ 449 child_ptregs->cr_ifs = 1UL << 63; 450 child_stack->ar_fpsr = child_ptregs->ar_fpsr 451 = ia64_getreg(_IA64_REG_AR_FPSR); 452 child_stack->pr = (1 << PRED_KERNEL_STACK); 453 child_stack->ar_bspstore = child_rbs; 454 child_stack->b0 = (unsigned long) &ia64_ret_from_clone; 455 456 /* stop some PSR bits from being inherited. 457 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve() 458 * therefore we must specify them explicitly here and not include them in 459 * IA64_PSR_BITS_TO_CLEAR. 460 */ 461 child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET) 462 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP)); 463 464 return 0; 465 } 466 stack = ((struct switch_stack *) regs) - 1; 467 /* copy parent's switch_stack & pt_regs to child: */ 468 memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack)); 469 470 /* copy the parent's register backing store to the child: */ 471 rbs_size = stack->ar_bspstore - rbs; 472 memcpy((void *) child_rbs, (void *) rbs, rbs_size); 473 if (clone_flags & CLONE_SETTLS) 474 child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */ 475 if (user_stack_base) { 476 child_ptregs->r12 = user_stack_base + user_stack_size - 16; 477 child_ptregs->ar_bspstore = user_stack_base; 478 child_ptregs->ar_rnat = 0; 479 child_ptregs->loadrs = 0; 480 } 481 child_stack->ar_bspstore = child_rbs + rbs_size; 482 child_stack->b0 = (unsigned long) &ia64_ret_from_clone; 483 484 /* stop some PSR bits from being inherited. 485 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve() 486 * therefore we must specify them explicitly here and not include them in 487 * IA64_PSR_BITS_TO_CLEAR. 488 */ 489 child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET) 490 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP)); 491 492 #ifdef CONFIG_PERFMON 493 if (current->thread.pfm_context) 494 pfm_inherit(p, child_ptregs); 495 #endif 496 return retval; 497 } 498 499 static void 500 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg) 501 { 502 unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm; 503 unsigned long uninitialized_var(ip); /* GCC be quiet */ 504 elf_greg_t *dst = arg; 505 struct pt_regs *pt; 506 char nat; 507 int i; 508 509 memset(dst, 0, sizeof(elf_gregset_t)); /* don't leak any kernel bits to user-level */ 510 511 if (unw_unwind_to_user(info) < 0) 512 return; 513 514 unw_get_sp(info, &sp); 515 pt = (struct pt_regs *) (sp + 16); 516 517 urbs_end = ia64_get_user_rbs_end(task, pt, &cfm); 518 519 if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0) 520 return; 521 522 ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end), 523 &ar_rnat); 524 525 /* 526 * coredump format: 527 * r0-r31 528 * NaT bits (for r0-r31; bit N == 1 iff rN is a NaT) 529 * predicate registers (p0-p63) 530 * b0-b7 531 * ip cfm user-mask 532 * ar.rsc ar.bsp ar.bspstore ar.rnat 533 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec 534 */ 535 536 /* r0 is zero */ 537 for (i = 1, mask = (1UL << i); i < 32; ++i) { 538 unw_get_gr(info, i, &dst[i], &nat); 539 if (nat) 540 nat_bits |= mask; 541 mask <<= 1; 542 } 543 dst[32] = nat_bits; 544 unw_get_pr(info, &dst[33]); 545 546 for (i = 0; i < 8; ++i) 547 unw_get_br(info, i, &dst[34 + i]); 548 549 unw_get_rp(info, &ip); 550 dst[42] = ip + ia64_psr(pt)->ri; 551 dst[43] = cfm; 552 dst[44] = pt->cr_ipsr & IA64_PSR_UM; 553 554 unw_get_ar(info, UNW_AR_RSC, &dst[45]); 555 /* 556 * For bsp and bspstore, unw_get_ar() would return the kernel 557 * addresses, but we need the user-level addresses instead: 558 */ 559 dst[46] = urbs_end; /* note: by convention PT_AR_BSP points to the end of the urbs! */ 560 dst[47] = pt->ar_bspstore; 561 dst[48] = ar_rnat; 562 unw_get_ar(info, UNW_AR_CCV, &dst[49]); 563 unw_get_ar(info, UNW_AR_UNAT, &dst[50]); 564 unw_get_ar(info, UNW_AR_FPSR, &dst[51]); 565 dst[52] = pt->ar_pfs; /* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */ 566 unw_get_ar(info, UNW_AR_LC, &dst[53]); 567 unw_get_ar(info, UNW_AR_EC, &dst[54]); 568 unw_get_ar(info, UNW_AR_CSD, &dst[55]); 569 unw_get_ar(info, UNW_AR_SSD, &dst[56]); 570 } 571 572 void 573 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg) 574 { 575 elf_fpreg_t *dst = arg; 576 int i; 577 578 memset(dst, 0, sizeof(elf_fpregset_t)); /* don't leak any "random" bits */ 579 580 if (unw_unwind_to_user(info) < 0) 581 return; 582 583 /* f0 is 0.0, f1 is 1.0 */ 584 585 for (i = 2; i < 32; ++i) 586 unw_get_fr(info, i, dst + i); 587 588 ia64_flush_fph(task); 589 if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0) 590 memcpy(dst + 32, task->thread.fph, 96*16); 591 } 592 593 void 594 do_copy_regs (struct unw_frame_info *info, void *arg) 595 { 596 do_copy_task_regs(current, info, arg); 597 } 598 599 void 600 do_dump_fpu (struct unw_frame_info *info, void *arg) 601 { 602 do_dump_task_fpu(current, info, arg); 603 } 604 605 void 606 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst) 607 { 608 unw_init_running(do_copy_regs, dst); 609 } 610 611 int 612 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst) 613 { 614 unw_init_running(do_dump_fpu, dst); 615 return 1; /* f0-f31 are always valid so we always return 1 */ 616 } 617 618 /* 619 * Flush thread state. This is called when a thread does an execve(). 620 */ 621 void 622 flush_thread (void) 623 { 624 /* drop floating-point and debug-register state if it exists: */ 625 current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID); 626 ia64_drop_fpu(current); 627 } 628 629 /* 630 * Clean up state associated with current thread. This is called when 631 * the thread calls exit(). 632 */ 633 void 634 exit_thread (void) 635 { 636 637 ia64_drop_fpu(current); 638 #ifdef CONFIG_PERFMON 639 /* if needed, stop monitoring and flush state to perfmon context */ 640 if (current->thread.pfm_context) 641 pfm_exit_thread(current); 642 643 /* free debug register resources */ 644 if (current->thread.flags & IA64_THREAD_DBG_VALID) 645 pfm_release_debug_registers(current); 646 #endif 647 } 648 649 unsigned long 650 get_wchan (struct task_struct *p) 651 { 652 struct unw_frame_info info; 653 unsigned long ip; 654 int count = 0; 655 656 if (!p || p == current || p->state == TASK_RUNNING) 657 return 0; 658 659 /* 660 * Note: p may not be a blocked task (it could be current or 661 * another process running on some other CPU. Rather than 662 * trying to determine if p is really blocked, we just assume 663 * it's blocked and rely on the unwind routines to fail 664 * gracefully if the process wasn't really blocked after all. 665 * --davidm 99/12/15 666 */ 667 unw_init_from_blocked_task(&info, p); 668 do { 669 if (p->state == TASK_RUNNING) 670 return 0; 671 if (unw_unwind(&info) < 0) 672 return 0; 673 unw_get_ip(&info, &ip); 674 if (!in_sched_functions(ip)) 675 return ip; 676 } while (count++ < 16); 677 return 0; 678 } 679 680 void 681 cpu_halt (void) 682 { 683 pal_power_mgmt_info_u_t power_info[8]; 684 unsigned long min_power; 685 int i, min_power_state; 686 687 if (ia64_pal_halt_info(power_info) != 0) 688 return; 689 690 min_power_state = 0; 691 min_power = power_info[0].pal_power_mgmt_info_s.power_consumption; 692 for (i = 1; i < 8; ++i) 693 if (power_info[i].pal_power_mgmt_info_s.im 694 && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) { 695 min_power = power_info[i].pal_power_mgmt_info_s.power_consumption; 696 min_power_state = i; 697 } 698 699 while (1) 700 ia64_pal_halt(min_power_state); 701 } 702 703 void machine_shutdown(void) 704 { 705 #ifdef CONFIG_HOTPLUG_CPU 706 int cpu; 707 708 for_each_online_cpu(cpu) { 709 if (cpu != smp_processor_id()) 710 cpu_down(cpu); 711 } 712 #endif 713 #ifdef CONFIG_KEXEC 714 kexec_disable_iosapic(); 715 #endif 716 } 717 718 void 719 machine_restart (char *restart_cmd) 720 { 721 (void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0); 722 (*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL); 723 } 724 725 void 726 machine_halt (void) 727 { 728 (void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0); 729 cpu_halt(); 730 } 731 732 void 733 machine_power_off (void) 734 { 735 if (pm_power_off) 736 pm_power_off(); 737 machine_halt(); 738 } 739 740