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/tlbflush.h> 42 #include <asm/uaccess.h> 43 #include <asm/unwind.h> 44 #include <asm/user.h> 45 46 #include "entry.h" 47 48 #ifdef CONFIG_PERFMON 49 # include <asm/perfmon.h> 50 #endif 51 52 #include "sigframe.h" 53 54 void (*ia64_mark_idle)(int); 55 56 unsigned long boot_option_idle_override = 0; 57 EXPORT_SYMBOL(boot_option_idle_override); 58 unsigned long idle_halt; 59 EXPORT_SYMBOL(idle_halt); 60 unsigned long idle_nomwait; 61 EXPORT_SYMBOL(idle_nomwait); 62 void (*pm_idle) (void); 63 EXPORT_SYMBOL(pm_idle); 64 void (*pm_power_off) (void); 65 EXPORT_SYMBOL(pm_power_off); 66 67 void 68 ia64_do_show_stack (struct unw_frame_info *info, void *arg) 69 { 70 unsigned long ip, sp, bsp; 71 char buf[128]; /* don't make it so big that it overflows the stack! */ 72 73 printk("\nCall Trace:\n"); 74 do { 75 unw_get_ip(info, &ip); 76 if (ip == 0) 77 break; 78 79 unw_get_sp(info, &sp); 80 unw_get_bsp(info, &bsp); 81 snprintf(buf, sizeof(buf), 82 " [<%016lx>] %%s\n" 83 " sp=%016lx bsp=%016lx\n", 84 ip, sp, bsp); 85 print_symbol(buf, ip); 86 } while (unw_unwind(info) >= 0); 87 } 88 89 void 90 show_stack (struct task_struct *task, unsigned long *sp) 91 { 92 if (!task) 93 unw_init_running(ia64_do_show_stack, NULL); 94 else { 95 struct unw_frame_info info; 96 97 unw_init_from_blocked_task(&info, task); 98 ia64_do_show_stack(&info, NULL); 99 } 100 } 101 102 void 103 dump_stack (void) 104 { 105 show_stack(NULL, NULL); 106 } 107 108 EXPORT_SYMBOL(dump_stack); 109 110 void 111 show_regs (struct pt_regs *regs) 112 { 113 unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri; 114 115 print_modules(); 116 printk("\nPid: %d, CPU %d, comm: %20s\n", task_pid_nr(current), 117 smp_processor_id(), current->comm); 118 printk("psr : %016lx ifs : %016lx ip : [<%016lx>] %s (%s)\n", 119 regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(), 120 init_utsname()->release); 121 print_symbol("ip is at %s\n", ip); 122 printk("unat: %016lx pfs : %016lx rsc : %016lx\n", 123 regs->ar_unat, regs->ar_pfs, regs->ar_rsc); 124 printk("rnat: %016lx bsps: %016lx pr : %016lx\n", 125 regs->ar_rnat, regs->ar_bspstore, regs->pr); 126 printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n", 127 regs->loadrs, regs->ar_ccv, regs->ar_fpsr); 128 printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd); 129 printk("b0 : %016lx b6 : %016lx b7 : %016lx\n", regs->b0, regs->b6, regs->b7); 130 printk("f6 : %05lx%016lx f7 : %05lx%016lx\n", 131 regs->f6.u.bits[1], regs->f6.u.bits[0], 132 regs->f7.u.bits[1], regs->f7.u.bits[0]); 133 printk("f8 : %05lx%016lx f9 : %05lx%016lx\n", 134 regs->f8.u.bits[1], regs->f8.u.bits[0], 135 regs->f9.u.bits[1], regs->f9.u.bits[0]); 136 printk("f10 : %05lx%016lx f11 : %05lx%016lx\n", 137 regs->f10.u.bits[1], regs->f10.u.bits[0], 138 regs->f11.u.bits[1], regs->f11.u.bits[0]); 139 140 printk("r1 : %016lx r2 : %016lx r3 : %016lx\n", regs->r1, regs->r2, regs->r3); 141 printk("r8 : %016lx r9 : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10); 142 printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13); 143 printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16); 144 printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19); 145 printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22); 146 printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25); 147 printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28); 148 printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31); 149 150 if (user_mode(regs)) { 151 /* print the stacked registers */ 152 unsigned long val, *bsp, ndirty; 153 int i, sof, is_nat = 0; 154 155 sof = regs->cr_ifs & 0x7f; /* size of frame */ 156 ndirty = (regs->loadrs >> 19); 157 bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty); 158 for (i = 0; i < sof; ++i) { 159 get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i)); 160 printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val, 161 ((i == sof - 1) || (i % 3) == 2) ? "\n" : " "); 162 } 163 } else 164 show_stack(NULL, NULL); 165 } 166 167 /* local support for deprecated console_print */ 168 void 169 console_print(const char *s) 170 { 171 printk(KERN_EMERG "%s", s); 172 } 173 174 void 175 do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall) 176 { 177 if (fsys_mode(current, &scr->pt)) { 178 /* 179 * defer signal-handling etc. until we return to 180 * privilege-level 0. 181 */ 182 if (!ia64_psr(&scr->pt)->lp) 183 ia64_psr(&scr->pt)->lp = 1; 184 return; 185 } 186 187 #ifdef CONFIG_PERFMON 188 if (current->thread.pfm_needs_checking) 189 /* 190 * Note: pfm_handle_work() allow us to call it with interrupts 191 * disabled, and may enable interrupts within the function. 192 */ 193 pfm_handle_work(); 194 #endif 195 196 /* deal with pending signal delivery */ 197 if (test_thread_flag(TIF_SIGPENDING)) { 198 local_irq_enable(); /* force interrupt enable */ 199 ia64_do_signal(scr, in_syscall); 200 } 201 202 if (test_thread_flag(TIF_NOTIFY_RESUME)) { 203 clear_thread_flag(TIF_NOTIFY_RESUME); 204 tracehook_notify_resume(&scr->pt); 205 if (current->replacement_session_keyring) 206 key_replace_session_keyring(); 207 } 208 209 /* copy user rbs to kernel rbs */ 210 if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) { 211 local_irq_enable(); /* force interrupt enable */ 212 ia64_sync_krbs(); 213 } 214 215 local_irq_disable(); /* force interrupt disable */ 216 } 217 218 static int pal_halt = 1; 219 static int can_do_pal_halt = 1; 220 221 static int __init nohalt_setup(char * str) 222 { 223 pal_halt = can_do_pal_halt = 0; 224 return 1; 225 } 226 __setup("nohalt", nohalt_setup); 227 228 void 229 update_pal_halt_status(int status) 230 { 231 can_do_pal_halt = pal_halt && status; 232 } 233 234 /* 235 * We use this if we don't have any better idle routine.. 236 */ 237 void 238 default_idle (void) 239 { 240 local_irq_enable(); 241 while (!need_resched()) { 242 if (can_do_pal_halt) { 243 local_irq_disable(); 244 if (!need_resched()) { 245 safe_halt(); 246 } 247 local_irq_enable(); 248 } else 249 cpu_relax(); 250 } 251 } 252 253 #ifdef CONFIG_HOTPLUG_CPU 254 /* We don't actually take CPU down, just spin without interrupts. */ 255 static inline void play_dead(void) 256 { 257 unsigned int this_cpu = smp_processor_id(); 258 259 /* Ack it */ 260 __get_cpu_var(cpu_state) = CPU_DEAD; 261 262 max_xtp(); 263 local_irq_disable(); 264 idle_task_exit(); 265 ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]); 266 /* 267 * The above is a point of no-return, the processor is 268 * expected to be in SAL loop now. 269 */ 270 BUG(); 271 } 272 #else 273 static inline void play_dead(void) 274 { 275 BUG(); 276 } 277 #endif /* CONFIG_HOTPLUG_CPU */ 278 279 static void do_nothing(void *unused) 280 { 281 } 282 283 /* 284 * cpu_idle_wait - Used to ensure that all the CPUs discard old value of 285 * pm_idle and update to new pm_idle value. Required while changing pm_idle 286 * handler on SMP systems. 287 * 288 * Caller must have changed pm_idle to the new value before the call. Old 289 * pm_idle value will not be used by any CPU after the return of this function. 290 */ 291 void cpu_idle_wait(void) 292 { 293 smp_mb(); 294 /* kick all the CPUs so that they exit out of pm_idle */ 295 smp_call_function(do_nothing, NULL, 1); 296 } 297 EXPORT_SYMBOL_GPL(cpu_idle_wait); 298 299 void __attribute__((noreturn)) 300 cpu_idle (void) 301 { 302 void (*mark_idle)(int) = ia64_mark_idle; 303 int cpu = smp_processor_id(); 304 305 /* endless idle loop with no priority at all */ 306 while (1) { 307 if (can_do_pal_halt) { 308 current_thread_info()->status &= ~TS_POLLING; 309 /* 310 * TS_POLLING-cleared state must be visible before we 311 * test NEED_RESCHED: 312 */ 313 smp_mb(); 314 } else { 315 current_thread_info()->status |= TS_POLLING; 316 } 317 318 if (!need_resched()) { 319 void (*idle)(void); 320 #ifdef CONFIG_SMP 321 min_xtp(); 322 #endif 323 rmb(); 324 if (mark_idle) 325 (*mark_idle)(1); 326 327 idle = pm_idle; 328 if (!idle) 329 idle = default_idle; 330 (*idle)(); 331 if (mark_idle) 332 (*mark_idle)(0); 333 #ifdef CONFIG_SMP 334 normal_xtp(); 335 #endif 336 } 337 preempt_enable_no_resched(); 338 schedule(); 339 preempt_disable(); 340 check_pgt_cache(); 341 if (cpu_is_offline(cpu)) 342 play_dead(); 343 } 344 } 345 346 void 347 ia64_save_extra (struct task_struct *task) 348 { 349 #ifdef CONFIG_PERFMON 350 unsigned long info; 351 #endif 352 353 if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0) 354 ia64_save_debug_regs(&task->thread.dbr[0]); 355 356 #ifdef CONFIG_PERFMON 357 if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0) 358 pfm_save_regs(task); 359 360 info = __get_cpu_var(pfm_syst_info); 361 if (info & PFM_CPUINFO_SYST_WIDE) 362 pfm_syst_wide_update_task(task, info, 0); 363 #endif 364 } 365 366 void 367 ia64_load_extra (struct task_struct *task) 368 { 369 #ifdef CONFIG_PERFMON 370 unsigned long info; 371 #endif 372 373 if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0) 374 ia64_load_debug_regs(&task->thread.dbr[0]); 375 376 #ifdef CONFIG_PERFMON 377 if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0) 378 pfm_load_regs(task); 379 380 info = __get_cpu_var(pfm_syst_info); 381 if (info & PFM_CPUINFO_SYST_WIDE) 382 pfm_syst_wide_update_task(task, info, 1); 383 #endif 384 } 385 386 /* 387 * Copy the state of an ia-64 thread. 388 * 389 * We get here through the following call chain: 390 * 391 * from user-level: from kernel: 392 * 393 * <clone syscall> <some kernel call frames> 394 * sys_clone : 395 * do_fork do_fork 396 * copy_thread copy_thread 397 * 398 * This means that the stack layout is as follows: 399 * 400 * +---------------------+ (highest addr) 401 * | struct pt_regs | 402 * +---------------------+ 403 * | struct switch_stack | 404 * +---------------------+ 405 * | | 406 * | memory stack | 407 * | | <-- sp (lowest addr) 408 * +---------------------+ 409 * 410 * Observe that we copy the unat values that are in pt_regs and switch_stack. Spilling an 411 * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register, 412 * with N=(X & 0x1ff)/8. Thus, copying the unat value preserves the NaT bits ONLY if the 413 * pt_regs structure in the parent is congruent to that of the child, modulo 512. Since 414 * the stack is page aligned and the page size is at least 4KB, this is always the case, 415 * so there is nothing to worry about. 416 */ 417 int 418 copy_thread(unsigned long clone_flags, 419 unsigned long user_stack_base, unsigned long user_stack_size, 420 struct task_struct *p, struct pt_regs *regs) 421 { 422 extern char ia64_ret_from_clone; 423 struct switch_stack *child_stack, *stack; 424 unsigned long rbs, child_rbs, rbs_size; 425 struct pt_regs *child_ptregs; 426 int retval = 0; 427 428 #ifdef CONFIG_SMP 429 /* 430 * For SMP idle threads, fork_by_hand() calls do_fork with 431 * NULL regs. 432 */ 433 if (!regs) 434 return 0; 435 #endif 436 437 stack = ((struct switch_stack *) regs) - 1; 438 439 child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1; 440 child_stack = (struct switch_stack *) child_ptregs - 1; 441 442 /* copy parent's switch_stack & pt_regs to child: */ 443 memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack)); 444 445 rbs = (unsigned long) current + IA64_RBS_OFFSET; 446 child_rbs = (unsigned long) p + IA64_RBS_OFFSET; 447 rbs_size = stack->ar_bspstore - rbs; 448 449 /* copy the parent's register backing store to the child: */ 450 memcpy((void *) child_rbs, (void *) rbs, rbs_size); 451 452 if (likely(user_mode(child_ptregs))) { 453 if (clone_flags & CLONE_SETTLS) 454 child_ptregs->r13 = regs->r16; /* see sys_clone2() in entry.S */ 455 if (user_stack_base) { 456 child_ptregs->r12 = user_stack_base + user_stack_size - 16; 457 child_ptregs->ar_bspstore = user_stack_base; 458 child_ptregs->ar_rnat = 0; 459 child_ptregs->loadrs = 0; 460 } 461 } else { 462 /* 463 * Note: we simply preserve the relative position of 464 * the stack pointer here. There is no need to 465 * allocate a scratch area here, since that will have 466 * been taken care of by the caller of sys_clone() 467 * already. 468 */ 469 child_ptregs->r12 = (unsigned long) child_ptregs - 16; /* kernel sp */ 470 child_ptregs->r13 = (unsigned long) p; /* set `current' pointer */ 471 } 472 child_stack->ar_bspstore = child_rbs + rbs_size; 473 child_stack->b0 = (unsigned long) &ia64_ret_from_clone; 474 475 /* copy parts of thread_struct: */ 476 p->thread.ksp = (unsigned long) child_stack - 16; 477 478 /* stop some PSR bits from being inherited. 479 * the psr.up/psr.pp bits must be cleared on fork but inherited on execve() 480 * therefore we must specify them explicitly here and not include them in 481 * IA64_PSR_BITS_TO_CLEAR. 482 */ 483 child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET) 484 & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP)); 485 486 /* 487 * NOTE: The calling convention considers all floating point 488 * registers in the high partition (fph) to be scratch. Since 489 * the only way to get to this point is through a system call, 490 * we know that the values in fph are all dead. Hence, there 491 * is no need to inherit the fph state from the parent to the 492 * child and all we have to do is to make sure that 493 * IA64_THREAD_FPH_VALID is cleared in the child. 494 * 495 * XXX We could push this optimization a bit further by 496 * clearing IA64_THREAD_FPH_VALID on ANY system call. 497 * However, it's not clear this is worth doing. Also, it 498 * would be a slight deviation from the normal Linux system 499 * call behavior where scratch registers are preserved across 500 * system calls (unless used by the system call itself). 501 */ 502 # define THREAD_FLAGS_TO_CLEAR (IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \ 503 | IA64_THREAD_PM_VALID) 504 # define THREAD_FLAGS_TO_SET 0 505 p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR) 506 | THREAD_FLAGS_TO_SET); 507 ia64_drop_fpu(p); /* don't pick up stale state from a CPU's fph */ 508 509 #ifdef CONFIG_PERFMON 510 if (current->thread.pfm_context) 511 pfm_inherit(p, child_ptregs); 512 #endif 513 return retval; 514 } 515 516 static void 517 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg) 518 { 519 unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm; 520 unsigned long uninitialized_var(ip); /* GCC be quiet */ 521 elf_greg_t *dst = arg; 522 struct pt_regs *pt; 523 char nat; 524 int i; 525 526 memset(dst, 0, sizeof(elf_gregset_t)); /* don't leak any kernel bits to user-level */ 527 528 if (unw_unwind_to_user(info) < 0) 529 return; 530 531 unw_get_sp(info, &sp); 532 pt = (struct pt_regs *) (sp + 16); 533 534 urbs_end = ia64_get_user_rbs_end(task, pt, &cfm); 535 536 if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0) 537 return; 538 539 ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end), 540 &ar_rnat); 541 542 /* 543 * coredump format: 544 * r0-r31 545 * NaT bits (for r0-r31; bit N == 1 iff rN is a NaT) 546 * predicate registers (p0-p63) 547 * b0-b7 548 * ip cfm user-mask 549 * ar.rsc ar.bsp ar.bspstore ar.rnat 550 * ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec 551 */ 552 553 /* r0 is zero */ 554 for (i = 1, mask = (1UL << i); i < 32; ++i) { 555 unw_get_gr(info, i, &dst[i], &nat); 556 if (nat) 557 nat_bits |= mask; 558 mask <<= 1; 559 } 560 dst[32] = nat_bits; 561 unw_get_pr(info, &dst[33]); 562 563 for (i = 0; i < 8; ++i) 564 unw_get_br(info, i, &dst[34 + i]); 565 566 unw_get_rp(info, &ip); 567 dst[42] = ip + ia64_psr(pt)->ri; 568 dst[43] = cfm; 569 dst[44] = pt->cr_ipsr & IA64_PSR_UM; 570 571 unw_get_ar(info, UNW_AR_RSC, &dst[45]); 572 /* 573 * For bsp and bspstore, unw_get_ar() would return the kernel 574 * addresses, but we need the user-level addresses instead: 575 */ 576 dst[46] = urbs_end; /* note: by convention PT_AR_BSP points to the end of the urbs! */ 577 dst[47] = pt->ar_bspstore; 578 dst[48] = ar_rnat; 579 unw_get_ar(info, UNW_AR_CCV, &dst[49]); 580 unw_get_ar(info, UNW_AR_UNAT, &dst[50]); 581 unw_get_ar(info, UNW_AR_FPSR, &dst[51]); 582 dst[52] = pt->ar_pfs; /* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */ 583 unw_get_ar(info, UNW_AR_LC, &dst[53]); 584 unw_get_ar(info, UNW_AR_EC, &dst[54]); 585 unw_get_ar(info, UNW_AR_CSD, &dst[55]); 586 unw_get_ar(info, UNW_AR_SSD, &dst[56]); 587 } 588 589 void 590 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg) 591 { 592 elf_fpreg_t *dst = arg; 593 int i; 594 595 memset(dst, 0, sizeof(elf_fpregset_t)); /* don't leak any "random" bits */ 596 597 if (unw_unwind_to_user(info) < 0) 598 return; 599 600 /* f0 is 0.0, f1 is 1.0 */ 601 602 for (i = 2; i < 32; ++i) 603 unw_get_fr(info, i, dst + i); 604 605 ia64_flush_fph(task); 606 if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0) 607 memcpy(dst + 32, task->thread.fph, 96*16); 608 } 609 610 void 611 do_copy_regs (struct unw_frame_info *info, void *arg) 612 { 613 do_copy_task_regs(current, info, arg); 614 } 615 616 void 617 do_dump_fpu (struct unw_frame_info *info, void *arg) 618 { 619 do_dump_task_fpu(current, info, arg); 620 } 621 622 void 623 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst) 624 { 625 unw_init_running(do_copy_regs, dst); 626 } 627 628 int 629 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst) 630 { 631 unw_init_running(do_dump_fpu, dst); 632 return 1; /* f0-f31 are always valid so we always return 1 */ 633 } 634 635 long 636 sys_execve (const char __user *filename, 637 const char __user *const __user *argv, 638 const char __user *const __user *envp, 639 struct pt_regs *regs) 640 { 641 char *fname; 642 int error; 643 644 fname = getname(filename); 645 error = PTR_ERR(fname); 646 if (IS_ERR(fname)) 647 goto out; 648 error = do_execve(fname, argv, envp, regs); 649 putname(fname); 650 out: 651 return error; 652 } 653 654 pid_t 655 kernel_thread (int (*fn)(void *), void *arg, unsigned long flags) 656 { 657 extern void start_kernel_thread (void); 658 unsigned long *helper_fptr = (unsigned long *) &start_kernel_thread; 659 struct { 660 struct switch_stack sw; 661 struct pt_regs pt; 662 } regs; 663 664 memset(®s, 0, sizeof(regs)); 665 regs.pt.cr_iip = helper_fptr[0]; /* set entry point (IP) */ 666 regs.pt.r1 = helper_fptr[1]; /* set GP */ 667 regs.pt.r9 = (unsigned long) fn; /* 1st argument */ 668 regs.pt.r11 = (unsigned long) arg; /* 2nd argument */ 669 /* Preserve PSR bits, except for bits 32-34 and 37-45, which we can't read. */ 670 regs.pt.cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN; 671 regs.pt.cr_ifs = 1UL << 63; /* mark as valid, empty frame */ 672 regs.sw.ar_fpsr = regs.pt.ar_fpsr = ia64_getreg(_IA64_REG_AR_FPSR); 673 regs.sw.ar_bspstore = (unsigned long) current + IA64_RBS_OFFSET; 674 regs.sw.pr = (1 << PRED_KERNEL_STACK); 675 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s.pt, 0, NULL, NULL); 676 } 677 EXPORT_SYMBOL(kernel_thread); 678 679 /* This gets called from kernel_thread() via ia64_invoke_thread_helper(). */ 680 int 681 kernel_thread_helper (int (*fn)(void *), void *arg) 682 { 683 return (*fn)(arg); 684 } 685 686 /* 687 * Flush thread state. This is called when a thread does an execve(). 688 */ 689 void 690 flush_thread (void) 691 { 692 /* drop floating-point and debug-register state if it exists: */ 693 current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID); 694 ia64_drop_fpu(current); 695 } 696 697 /* 698 * Clean up state associated with current thread. This is called when 699 * the thread calls exit(). 700 */ 701 void 702 exit_thread (void) 703 { 704 705 ia64_drop_fpu(current); 706 #ifdef CONFIG_PERFMON 707 /* if needed, stop monitoring and flush state to perfmon context */ 708 if (current->thread.pfm_context) 709 pfm_exit_thread(current); 710 711 /* free debug register resources */ 712 if (current->thread.flags & IA64_THREAD_DBG_VALID) 713 pfm_release_debug_registers(current); 714 #endif 715 } 716 717 unsigned long 718 get_wchan (struct task_struct *p) 719 { 720 struct unw_frame_info info; 721 unsigned long ip; 722 int count = 0; 723 724 if (!p || p == current || p->state == TASK_RUNNING) 725 return 0; 726 727 /* 728 * Note: p may not be a blocked task (it could be current or 729 * another process running on some other CPU. Rather than 730 * trying to determine if p is really blocked, we just assume 731 * it's blocked and rely on the unwind routines to fail 732 * gracefully if the process wasn't really blocked after all. 733 * --davidm 99/12/15 734 */ 735 unw_init_from_blocked_task(&info, p); 736 do { 737 if (p->state == TASK_RUNNING) 738 return 0; 739 if (unw_unwind(&info) < 0) 740 return 0; 741 unw_get_ip(&info, &ip); 742 if (!in_sched_functions(ip)) 743 return ip; 744 } while (count++ < 16); 745 return 0; 746 } 747 748 void 749 cpu_halt (void) 750 { 751 pal_power_mgmt_info_u_t power_info[8]; 752 unsigned long min_power; 753 int i, min_power_state; 754 755 if (ia64_pal_halt_info(power_info) != 0) 756 return; 757 758 min_power_state = 0; 759 min_power = power_info[0].pal_power_mgmt_info_s.power_consumption; 760 for (i = 1; i < 8; ++i) 761 if (power_info[i].pal_power_mgmt_info_s.im 762 && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) { 763 min_power = power_info[i].pal_power_mgmt_info_s.power_consumption; 764 min_power_state = i; 765 } 766 767 while (1) 768 ia64_pal_halt(min_power_state); 769 } 770 771 void machine_shutdown(void) 772 { 773 #ifdef CONFIG_HOTPLUG_CPU 774 int cpu; 775 776 for_each_online_cpu(cpu) { 777 if (cpu != smp_processor_id()) 778 cpu_down(cpu); 779 } 780 #endif 781 #ifdef CONFIG_KEXEC 782 kexec_disable_iosapic(); 783 #endif 784 } 785 786 void 787 machine_restart (char *restart_cmd) 788 { 789 (void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0); 790 (*efi.reset_system)(EFI_RESET_WARM, 0, 0, NULL); 791 } 792 793 void 794 machine_halt (void) 795 { 796 (void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0); 797 cpu_halt(); 798 } 799 800 void 801 machine_power_off (void) 802 { 803 if (pm_power_off) 804 pm_power_off(); 805 machine_halt(); 806 } 807 808