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 33 #include <asm/cpu.h> 34 #include <asm/delay.h> 35 #include <asm/elf.h> 36 #include <asm/irq.h> 37 #include <asm/kexec.h> 38 #include <asm/pgalloc.h> 39 #include <asm/processor.h> 40 #include <asm/sal.h> 41 #include <asm/switch_to.h> 42 #include <asm/tlbflush.h> 43 #include <asm/uaccess.h> 44 #include <asm/unwind.h> 45 #include <asm/user.h> 46 47 #include "entry.h" 48 49 #ifdef CONFIG_PERFMON 50 # include <asm/perfmon.h> 51 #endif 52 53 #include "sigframe.h" 54 55 void (*ia64_mark_idle)(int); 56 57 unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE; 58 EXPORT_SYMBOL(boot_option_idle_override); 59 void (*pm_idle) (void); 60 EXPORT_SYMBOL(pm_idle); 61 void (*pm_power_off) (void); 62 EXPORT_SYMBOL(pm_power_off); 63 64 void 65 ia64_do_show_stack (struct unw_frame_info *info, void *arg) 66 { 67 unsigned long ip, sp, bsp; 68 char buf[128]; /* don't make it so big that it overflows the stack! */ 69 70 printk("\nCall Trace:\n"); 71 do { 72 unw_get_ip(info, &ip); 73 if (ip == 0) 74 break; 75 76 unw_get_sp(info, &sp); 77 unw_get_bsp(info, &bsp); 78 snprintf(buf, sizeof(buf), 79 " [<%016lx>] %%s\n" 80 " sp=%016lx bsp=%016lx\n", 81 ip, sp, bsp); 82 print_symbol(buf, ip); 83 } while (unw_unwind(info) >= 0); 84 } 85 86 void 87 show_stack (struct task_struct *task, unsigned long *sp) 88 { 89 if (!task) 90 unw_init_running(ia64_do_show_stack, NULL); 91 else { 92 struct unw_frame_info info; 93 94 unw_init_from_blocked_task(&info, task); 95 ia64_do_show_stack(&info, NULL); 96 } 97 } 98 99 void 100 dump_stack (void) 101 { 102 show_stack(NULL, NULL); 103 } 104 105 EXPORT_SYMBOL(dump_stack); 106 107 void 108 show_regs (struct pt_regs *regs) 109 { 110 unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri; 111 112 print_modules(); 113 printk("\nPid: %d, CPU %d, comm: %20s\n", task_pid_nr(current), 114 smp_processor_id(), current->comm); 115 printk("psr : %016lx ifs : %016lx ip : [<%016lx>] %s (%s)\n", 116 regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(), 117 init_utsname()->release); 118 print_symbol("ip is at %s\n", ip); 119 printk("unat: %016lx pfs : %016lx rsc : %016lx\n", 120 regs->ar_unat, regs->ar_pfs, regs->ar_rsc); 121 printk("rnat: %016lx bsps: %016lx pr : %016lx\n", 122 regs->ar_rnat, regs->ar_bspstore, regs->pr); 123 printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n", 124 regs->loadrs, regs->ar_ccv, regs->ar_fpsr); 125 printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd); 126 printk("b0 : %016lx b6 : %016lx b7 : %016lx\n", regs->b0, regs->b6, regs->b7); 127 printk("f6 : %05lx%016lx f7 : %05lx%016lx\n", 128 regs->f6.u.bits[1], regs->f6.u.bits[0], 129 regs->f7.u.bits[1], regs->f7.u.bits[0]); 130 printk("f8 : %05lx%016lx f9 : %05lx%016lx\n", 131 regs->f8.u.bits[1], regs->f8.u.bits[0], 132 regs->f9.u.bits[1], regs->f9.u.bits[0]); 133 printk("f10 : %05lx%016lx f11 : %05lx%016lx\n", 134 regs->f10.u.bits[1], regs->f10.u.bits[0], 135 regs->f11.u.bits[1], regs->f11.u.bits[0]); 136 137 printk("r1 : %016lx r2 : %016lx r3 : %016lx\n", regs->r1, regs->r2, regs->r3); 138 printk("r8 : %016lx r9 : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10); 139 printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13); 140 printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16); 141 printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19); 142 printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22); 143 printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25); 144 printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28); 145 printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31); 146 147 if (user_mode(regs)) { 148 /* print the stacked registers */ 149 unsigned long val, *bsp, ndirty; 150 int i, sof, is_nat = 0; 151 152 sof = regs->cr_ifs & 0x7f; /* size of frame */ 153 ndirty = (regs->loadrs >> 19); 154 bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty); 155 for (i = 0; i < sof; ++i) { 156 get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i)); 157 printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val, 158 ((i == sof - 1) || (i % 3) == 2) ? "\n" : " "); 159 } 160 } else 161 show_stack(NULL, NULL); 162 } 163 164 /* local support for deprecated console_print */ 165 void 166 console_print(const char *s) 167 { 168 printk(KERN_EMERG "%s", s); 169 } 170 171 void 172 do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall) 173 { 174 if (fsys_mode(current, &scr->pt)) { 175 /* 176 * defer signal-handling etc. until we return to 177 * privilege-level 0. 178 */ 179 if (!ia64_psr(&scr->pt)->lp) 180 ia64_psr(&scr->pt)->lp = 1; 181 return; 182 } 183 184 #ifdef CONFIG_PERFMON 185 if (current->thread.pfm_needs_checking) 186 /* 187 * Note: pfm_handle_work() allow us to call it with interrupts 188 * disabled, and may enable interrupts within the function. 189 */ 190 pfm_handle_work(); 191 #endif 192 193 /* deal with pending signal delivery */ 194 if (test_thread_flag(TIF_SIGPENDING)) { 195 local_irq_enable(); /* force interrupt enable */ 196 ia64_do_signal(scr, in_syscall); 197 } 198 199 if (test_thread_flag(TIF_NOTIFY_RESUME)) { 200 clear_thread_flag(TIF_NOTIFY_RESUME); 201 tracehook_notify_resume(&scr->pt); 202 } 203 204 /* copy user rbs to kernel rbs */ 205 if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) { 206 local_irq_enable(); /* force interrupt enable */ 207 ia64_sync_krbs(); 208 } 209 210 local_irq_disable(); /* force interrupt disable */ 211 } 212 213 static int pal_halt = 1; 214 static int can_do_pal_halt = 1; 215 216 static int __init nohalt_setup(char * str) 217 { 218 pal_halt = can_do_pal_halt = 0; 219 return 1; 220 } 221 __setup("nohalt", nohalt_setup); 222 223 void 224 update_pal_halt_status(int status) 225 { 226 can_do_pal_halt = pal_halt && status; 227 } 228 229 /* 230 * We use this if we don't have any better idle routine.. 231 */ 232 void 233 default_idle (void) 234 { 235 local_irq_enable(); 236 while (!need_resched()) { 237 if (can_do_pal_halt) { 238 local_irq_disable(); 239 if (!need_resched()) { 240 safe_halt(); 241 } 242 local_irq_enable(); 243 } else 244 cpu_relax(); 245 } 246 } 247 248 #ifdef CONFIG_HOTPLUG_CPU 249 /* We don't actually take CPU down, just spin without interrupts. */ 250 static inline void play_dead(void) 251 { 252 unsigned int this_cpu = smp_processor_id(); 253 254 /* Ack it */ 255 __get_cpu_var(cpu_state) = CPU_DEAD; 256 257 max_xtp(); 258 local_irq_disable(); 259 idle_task_exit(); 260 ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]); 261 /* 262 * The above is a point of no-return, the processor is 263 * expected to be in SAL loop now. 264 */ 265 BUG(); 266 } 267 #else 268 static inline void play_dead(void) 269 { 270 BUG(); 271 } 272 #endif /* CONFIG_HOTPLUG_CPU */ 273 274 void __attribute__((noreturn)) 275 cpu_idle (void) 276 { 277 void (*mark_idle)(int) = ia64_mark_idle; 278 int cpu = smp_processor_id(); 279 280 /* endless idle loop with no priority at all */ 281 while (1) { 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 idle = pm_idle; 303 if (!idle) 304 idle = default_idle; 305 (*idle)(); 306 if (mark_idle) 307 (*mark_idle)(0); 308 #ifdef CONFIG_SMP 309 normal_xtp(); 310 #endif 311 } 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, struct pt_regs *regs) 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 int retval = 0; 400 401 #ifdef CONFIG_SMP 402 /* 403 * For SMP idle threads, fork_by_hand() calls do_fork with 404 * NULL regs. 405 */ 406 if (!regs) 407 return 0; 408 #endif 409 410 stack = ((struct switch_stack *) regs) - 1; 411 412 child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1; 413 child_stack = (struct switch_stack *) child_ptregs - 1; 414 415 /* copy parent's switch_stack & pt_regs to child: */ 416 memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack)); 417 418 rbs = (unsigned long) current + IA64_RBS_OFFSET; 419 child_rbs = (unsigned long) p + IA64_RBS_OFFSET; 420 rbs_size = stack->ar_bspstore - rbs; 421 422 /* copy the parent's register backing store to the child: */ 423 memcpy((void *) child_rbs, (void *) rbs, rbs_size); 424 425 if (likely(user_mode(child_ptregs))) { 426 if (clone_flags & CLONE_SETTLS) 427 child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */ 428 if (user_stack_base) { 429 child_ptregs->r12 = user_stack_base + user_stack_size - 16; 430 child_ptregs->ar_bspstore = user_stack_base; 431 child_ptregs->ar_rnat = 0; 432 child_ptregs->loadrs = 0; 433 } 434 } else { 435 /* 436 * Note: we simply preserve the relative position of 437 * the stack pointer here. There is no need to 438 * allocate a scratch area here, since that will have 439 * been taken care of by the caller of sys_clone() 440 * already. 441 */ 442 child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */ 443 child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */ 444 } 445 child_stack->ar_bspstore = child_rbs + rbs_size; 446 child_stack->b0 = (unsigned long) &ia64_ret_from_clone; 447 448 /* copy parts of thread_struct: */ 449 p->thread.ksp = (unsigned long) child_stack - 16; 450 451 /* stop some PSR bits from being inherited. 452 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve() 453 * therefore we must specify them explicitly here and not include them in 454 * IA64_PSR_BITS_TO_CLEAR. 455 */ 456 child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET) 457 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP)); 458 459 /* 460 * NOTE: The calling convention considers all floating point 461 * registers in the high partition (fph) to be scratch. Since 462 * the only way to get to this point is through a system call, 463 * we know that the values in fph are all dead. Hence, there 464 * is no need to inherit the fph state from the parent to the 465 * child and all we have to do is to make sure that 466 * IA64_THREAD_FPH_VALID is cleared in the child. 467 * 468 * XXX We could push this optimization a bit further by 469 * clearing IA64_THREAD_FPH_VALID on ANY system call. 470 * However, it's not clear this is worth doing. Also, it 471 * would be a slight deviation from the normal Linux system 472 * call behavior where scratch registers are preserved across 473 * system calls (unless used by the system call itself). 474 */ 475 # define THREAD_FLAGS_TO_CLEAR (IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \ 476 | IA64_THREAD_PM_VALID) 477 # define THREAD_FLAGS_TO_SET 0 478 p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR) 479 | THREAD_FLAGS_TO_SET); 480 ia64_drop_fpu(p); /* don't pick up stale state from a CPU's fph */ 481 482 #ifdef CONFIG_PERFMON 483 if (current->thread.pfm_context) 484 pfm_inherit(p, child_ptregs); 485 #endif 486 return retval; 487 } 488 489 static void 490 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg) 491 { 492 unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm; 493 unsigned long uninitialized_var(ip); /* GCC be quiet */ 494 elf_greg_t *dst = arg; 495 struct pt_regs *pt; 496 char nat; 497 int i; 498 499 memset(dst, 0, sizeof(elf_gregset_t)); /* don't leak any kernel bits to user-level */ 500 501 if (unw_unwind_to_user(info) < 0) 502 return; 503 504 unw_get_sp(info, &sp); 505 pt = (struct pt_regs *) (sp + 16); 506 507 urbs_end = ia64_get_user_rbs_end(task, pt, &cfm); 508 509 if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0) 510 return; 511 512 ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end), 513 &ar_rnat); 514 515 /* 516 * coredump format: 517 * r0-r31 518 * NaT bits (for r0-r31; bit N == 1 iff rN is a NaT) 519 * predicate registers (p0-p63) 520 * b0-b7 521 * ip cfm user-mask 522 * ar.rsc ar.bsp ar.bspstore ar.rnat 523 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec 524 */ 525 526 /* r0 is zero */ 527 for (i = 1, mask = (1UL << i); i < 32; ++i) { 528 unw_get_gr(info, i, &dst[i], &nat); 529 if (nat) 530 nat_bits |= mask; 531 mask <<= 1; 532 } 533 dst[32] = nat_bits; 534 unw_get_pr(info, &dst[33]); 535 536 for (i = 0; i < 8; ++i) 537 unw_get_br(info, i, &dst[34 + i]); 538 539 unw_get_rp(info, &ip); 540 dst[42] = ip + ia64_psr(pt)->ri; 541 dst[43] = cfm; 542 dst[44] = pt->cr_ipsr & IA64_PSR_UM; 543 544 unw_get_ar(info, UNW_AR_RSC, &dst[45]); 545 /* 546 * For bsp and bspstore, unw_get_ar() would return the kernel 547 * addresses, but we need the user-level addresses instead: 548 */ 549 dst[46] = urbs_end; /* note: by convention PT_AR_BSP points to the end of the urbs! */ 550 dst[47] = pt->ar_bspstore; 551 dst[48] = ar_rnat; 552 unw_get_ar(info, UNW_AR_CCV, &dst[49]); 553 unw_get_ar(info, UNW_AR_UNAT, &dst[50]); 554 unw_get_ar(info, UNW_AR_FPSR, &dst[51]); 555 dst[52] = pt->ar_pfs; /* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */ 556 unw_get_ar(info, UNW_AR_LC, &dst[53]); 557 unw_get_ar(info, UNW_AR_EC, &dst[54]); 558 unw_get_ar(info, UNW_AR_CSD, &dst[55]); 559 unw_get_ar(info, UNW_AR_SSD, &dst[56]); 560 } 561 562 void 563 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg) 564 { 565 elf_fpreg_t *dst = arg; 566 int i; 567 568 memset(dst, 0, sizeof(elf_fpregset_t)); /* don't leak any "random" bits */ 569 570 if (unw_unwind_to_user(info) < 0) 571 return; 572 573 /* f0 is 0.0, f1 is 1.0 */ 574 575 for (i = 2; i < 32; ++i) 576 unw_get_fr(info, i, dst + i); 577 578 ia64_flush_fph(task); 579 if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0) 580 memcpy(dst + 32, task->thread.fph, 96*16); 581 } 582 583 void 584 do_copy_regs (struct unw_frame_info *info, void *arg) 585 { 586 do_copy_task_regs(current, info, arg); 587 } 588 589 void 590 do_dump_fpu (struct unw_frame_info *info, void *arg) 591 { 592 do_dump_task_fpu(current, info, arg); 593 } 594 595 void 596 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst) 597 { 598 unw_init_running(do_copy_regs, dst); 599 } 600 601 int 602 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst) 603 { 604 unw_init_running(do_dump_fpu, dst); 605 return 1; /* f0-f31 are always valid so we always return 1 */ 606 } 607 608 long 609 sys_execve (const char __user *filename, 610 const char __user *const __user *argv, 611 const char __user *const __user *envp, 612 struct pt_regs *regs) 613 { 614 char *fname; 615 int error; 616 617 fname = getname(filename); 618 error = PTR_ERR(fname); 619 if (IS_ERR(fname)) 620 goto out; 621 error = do_execve(fname, argv, envp, regs); 622 putname(fname); 623 out: 624 return error; 625 } 626 627 pid_t 628 kernel_thread (int (*fn)(void *), void *arg, unsigned long flags) 629 { 630 extern void start_kernel_thread (void); 631 unsigned long *helper_fptr = (unsigned long *) &start_kernel_thread; 632 struct { 633 struct switch_stack sw; 634 struct pt_regs pt; 635 } regs; 636 637 memset(®s, 0, sizeof(regs)); 638 regs.pt.cr_iip = helper_fptr[0]; /* set entry point (IP) */ 639 regs.pt.r1 = helper_fptr[1]; /* set GP */ 640 regs.pt.r9 = (unsigned long) fn; /* 1st argument */ 641 regs.pt.r11 = (unsigned long) arg; /* 2nd argument */ 642 /* Preserve PSR bits, except for bits 32-34 and 37-45, which we can't read. */ 643 regs.pt.cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN; 644 regs.pt.cr_ifs = 1UL << 63; /* mark as valid, empty frame */ 645 regs.sw.ar_fpsr = regs.pt.ar_fpsr = ia64_getreg(_IA64_REG_AR_FPSR); 646 regs.sw.ar_bspstore = (unsigned long) current + IA64_RBS_OFFSET; 647 regs.sw.pr = (1 << PRED_KERNEL_STACK); 648 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s.pt, 0, NULL, NULL); 649 } 650 EXPORT_SYMBOL(kernel_thread); 651 652 /* This gets called from kernel_thread() via ia64_invoke_thread_helper(). */ 653 int 654 kernel_thread_helper (int (*fn)(void *), void *arg) 655 { 656 return (*fn)(arg); 657 } 658 659 /* 660 * Flush thread state. This is called when a thread does an execve(). 661 */ 662 void 663 flush_thread (void) 664 { 665 /* drop floating-point and debug-register state if it exists: */ 666 current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID); 667 ia64_drop_fpu(current); 668 } 669 670 /* 671 * Clean up state associated with current thread. This is called when 672 * the thread calls exit(). 673 */ 674 void 675 exit_thread (void) 676 { 677 678 ia64_drop_fpu(current); 679 #ifdef CONFIG_PERFMON 680 /* if needed, stop monitoring and flush state to perfmon context */ 681 if (current->thread.pfm_context) 682 pfm_exit_thread(current); 683 684 /* free debug register resources */ 685 if (current->thread.flags & IA64_THREAD_DBG_VALID) 686 pfm_release_debug_registers(current); 687 #endif 688 } 689 690 unsigned long 691 get_wchan (struct task_struct *p) 692 { 693 struct unw_frame_info info; 694 unsigned long ip; 695 int count = 0; 696 697 if (!p || p == current || p->state == TASK_RUNNING) 698 return 0; 699 700 /* 701 * Note: p may not be a blocked task (it could be current or 702 * another process running on some other CPU. Rather than 703 * trying to determine if p is really blocked, we just assume 704 * it's blocked and rely on the unwind routines to fail 705 * gracefully if the process wasn't really blocked after all. 706 * --davidm 99/12/15 707 */ 708 unw_init_from_blocked_task(&info, p); 709 do { 710 if (p->state == TASK_RUNNING) 711 return 0; 712 if (unw_unwind(&info) < 0) 713 return 0; 714 unw_get_ip(&info, &ip); 715 if (!in_sched_functions(ip)) 716 return ip; 717 } while (count++ < 16); 718 return 0; 719 } 720 721 void 722 cpu_halt (void) 723 { 724 pal_power_mgmt_info_u_t power_info[8]; 725 unsigned long min_power; 726 int i, min_power_state; 727 728 if (ia64_pal_halt_info(power_info) != 0) 729 return; 730 731 min_power_state = 0; 732 min_power = power_info[0].pal_power_mgmt_info_s.power_consumption; 733 for (i = 1; i < 8; ++i) 734 if (power_info[i].pal_power_mgmt_info_s.im 735 && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) { 736 min_power = power_info[i].pal_power_mgmt_info_s.power_consumption; 737 min_power_state = i; 738 } 739 740 while (1) 741 ia64_pal_halt(min_power_state); 742 } 743 744 void machine_shutdown(void) 745 { 746 #ifdef CONFIG_HOTPLUG_CPU 747 int cpu; 748 749 for_each_online_cpu(cpu) { 750 if (cpu != smp_processor_id()) 751 cpu_down(cpu); 752 } 753 #endif 754 #ifdef CONFIG_KEXEC 755 kexec_disable_iosapic(); 756 #endif 757 } 758 759 void 760 machine_restart (char *restart_cmd) 761 { 762 (void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0); 763 (*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL); 764 } 765 766 void 767 machine_halt (void) 768 { 769 (void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0); 770 cpu_halt(); 771 } 772 773 void 774 machine_power_off (void) 775 { 776 if (pm_power_off) 777 pm_power_off(); 778 machine_halt(); 779 } 780 781