arch/ia64/kernel/process.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
ia64_do_show_stack
show_stack
show_regs
console_print
do_notify_resume_user
nohalt_setup
play_dead
play_dead
arch_cpu_idle_dead
arch_cpu_idle
ia64_save_extra
ia64_load_extra
copy_thread
do_copy_task_regs
do_dump_task_fpu
do_copy_regs
do_dump_fpu
ia64_elf_core_copy_regs
dump_fpu
flush_thread
exit_thread
get_wchan
cpu_halt
machine_shutdown
machine_restart
machine_halt
machine_power_off
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Architecture-specific setup.
   4  *
   5  * Copyright (C) 1998-2003 Hewlett-Packard Co
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>
   7  * 04/11/17 Ashok Raj   <ashok.raj@intel.com> Added CPU Hotplug Support
   8  *
   9  * 2005-10-07 Keith Owens <kaos@sgi.com>
  10  *            Add notify_die() hooks.
  11  */
  12 #include <linux/cpu.h>
  13 #include <linux/pm.h>
  14 #include <linux/elf.h>
  15 #include <linux/errno.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/sched/debug.h>
  24 #include <linux/sched/hotplug.h>
  25 #include <linux/sched/task.h>
  26 #include <linux/sched/task_stack.h>
  27 #include <linux/stddef.h>
  28 #include <linux/thread_info.h>
  29 #include <linux/unistd.h>
  30 #include <linux/efi.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/delay.h>
  33 #include <linux/kdebug.h>
  34 #include <linux/utsname.h>
  35 #include <linux/tracehook.h>
  36 #include <linux/rcupdate.h>
  37 
  38 #include <asm/cpu.h>
  39 #include <asm/delay.h>
  40 #include <asm/elf.h>
  41 #include <asm/irq.h>
  42 #include <asm/kexec.h>
  43 #include <asm/pgalloc.h>
  44 #include <asm/processor.h>
  45 #include <asm/sal.h>
  46 #include <asm/switch_to.h>
  47 #include <asm/tlbflush.h>
  48 #include <linux/uaccess.h>
  49 #include <asm/unwind.h>
  50 #include <asm/user.h>
  51 
  52 #include "entry.h"
  53 
  54 #ifdef CONFIG_PERFMON
  55 # include <asm/perfmon.h>
  56 #endif
  57 
  58 #include "sigframe.h"
  59 
  60 void (*ia64_mark_idle)(int);
  61 
  62 unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
  63 EXPORT_SYMBOL(boot_option_idle_override);
  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 
  72         printk("\nCall Trace:\n");
  73         do {
  74                 unw_get_ip(info, &ip);
  75                 if (ip == 0)
  76                         break;
  77 
  78                 unw_get_sp(info, &sp);
  79                 unw_get_bsp(info, &bsp);
  80                 printk(" [<%016lx>] %pS\n"
  81                          "                                sp=%016lx bsp=%016lx\n",
  82                          ip, (void *)ip, sp, bsp);
  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 show_regs (struct pt_regs *regs)
 101 {
 102         unsigned long ip = regs->cr_iip + ia64_psr(regs)->ri;
 103 
 104         print_modules();
 105         printk("\n");
 106         show_regs_print_info(KERN_DEFAULT);
 107         printk("psr : %016lx ifs : %016lx ip  : [<%016lx>]    %s (%s)\n",
 108                regs->cr_ipsr, regs->cr_ifs, ip, print_tainted(),
 109                init_utsname()->release);
 110         printk("ip is at %pS\n", (void *)ip);
 111         printk("unat: %016lx pfs : %016lx rsc : %016lx\n",
 112                regs->ar_unat, regs->ar_pfs, regs->ar_rsc);
 113         printk("rnat: %016lx bsps: %016lx pr  : %016lx\n",
 114                regs->ar_rnat, regs->ar_bspstore, regs->pr);
 115         printk("ldrs: %016lx ccv : %016lx fpsr: %016lx\n",
 116                regs->loadrs, regs->ar_ccv, regs->ar_fpsr);
 117         printk("csd : %016lx ssd : %016lx\n", regs->ar_csd, regs->ar_ssd);
 118         printk("b0  : %016lx b6  : %016lx b7  : %016lx\n", regs->b0, regs->b6, regs->b7);
 119         printk("f6  : %05lx%016lx f7  : %05lx%016lx\n",
 120                regs->f6.u.bits[1], regs->f6.u.bits[0],
 121                regs->f7.u.bits[1], regs->f7.u.bits[0]);
 122         printk("f8  : %05lx%016lx f9  : %05lx%016lx\n",
 123                regs->f8.u.bits[1], regs->f8.u.bits[0],
 124                regs->f9.u.bits[1], regs->f9.u.bits[0]);
 125         printk("f10 : %05lx%016lx f11 : %05lx%016lx\n",
 126                regs->f10.u.bits[1], regs->f10.u.bits[0],
 127                regs->f11.u.bits[1], regs->f11.u.bits[0]);
 128 
 129         printk("r1  : %016lx r2  : %016lx r3  : %016lx\n", regs->r1, regs->r2, regs->r3);
 130         printk("r8  : %016lx r9  : %016lx r10 : %016lx\n", regs->r8, regs->r9, regs->r10);
 131         printk("r11 : %016lx r12 : %016lx r13 : %016lx\n", regs->r11, regs->r12, regs->r13);
 132         printk("r14 : %016lx r15 : %016lx r16 : %016lx\n", regs->r14, regs->r15, regs->r16);
 133         printk("r17 : %016lx r18 : %016lx r19 : %016lx\n", regs->r17, regs->r18, regs->r19);
 134         printk("r20 : %016lx r21 : %016lx r22 : %016lx\n", regs->r20, regs->r21, regs->r22);
 135         printk("r23 : %016lx r24 : %016lx r25 : %016lx\n", regs->r23, regs->r24, regs->r25);
 136         printk("r26 : %016lx r27 : %016lx r28 : %016lx\n", regs->r26, regs->r27, regs->r28);
 137         printk("r29 : %016lx r30 : %016lx r31 : %016lx\n", regs->r29, regs->r30, regs->r31);
 138 
 139         if (user_mode(regs)) {
 140                 /* print the stacked registers */
 141                 unsigned long val, *bsp, ndirty;
 142                 int i, sof, is_nat = 0;
 143 
 144                 sof = regs->cr_ifs & 0x7f;      /* size of frame */
 145                 ndirty = (regs->loadrs >> 19);
 146                 bsp = ia64_rse_skip_regs((unsigned long *) regs->ar_bspstore, ndirty);
 147                 for (i = 0; i < sof; ++i) {
 148                         get_user(val, (unsigned long __user *) ia64_rse_skip_regs(bsp, i));
 149                         printk("r%-3u:%c%016lx%s", 32 + i, is_nat ? '*' : ' ', val,
 150                                ((i == sof - 1) || (i % 3) == 2) ? "\n" : " ");
 151                 }
 152         } else
 153                 show_stack(NULL, NULL);
 154 }
 155 
 156 /* local support for deprecated console_print */
 157 void
 158 console_print(const char *s)
 159 {
 160         printk(KERN_EMERG "%s", s);
 161 }
 162 
 163 void
 164 do_notify_resume_user(sigset_t *unused, struct sigscratch *scr, long in_syscall)
 165 {
 166         if (fsys_mode(current, &scr->pt)) {
 167                 /*
 168                  * defer signal-handling etc. until we return to
 169                  * privilege-level 0.
 170                  */
 171                 if (!ia64_psr(&scr->pt)->lp)
 172                         ia64_psr(&scr->pt)->lp = 1;
 173                 return;
 174         }
 175 
 176 #ifdef CONFIG_PERFMON
 177         if (current->thread.pfm_needs_checking)
 178                 /*
 179                  * Note: pfm_handle_work() allow us to call it with interrupts
 180                  * disabled, and may enable interrupts within the function.
 181                  */
 182                 pfm_handle_work();
 183 #endif
 184 
 185         /* deal with pending signal delivery */
 186         if (test_thread_flag(TIF_SIGPENDING)) {
 187                 local_irq_enable();     /* force interrupt enable */
 188                 ia64_do_signal(scr, in_syscall);
 189         }
 190 
 191         if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) {
 192                 local_irq_enable();     /* force interrupt enable */
 193                 tracehook_notify_resume(&scr->pt);
 194         }
 195 
 196         /* copy user rbs to kernel rbs */
 197         if (unlikely(test_thread_flag(TIF_RESTORE_RSE))) {
 198                 local_irq_enable();     /* force interrupt enable */
 199                 ia64_sync_krbs();
 200         }
 201 
 202         local_irq_disable();    /* force interrupt disable */
 203 }
 204 
 205 static int __init nohalt_setup(char * str)
 206 {
 207         cpu_idle_poll_ctrl(true);
 208         return 1;
 209 }
 210 __setup("nohalt", nohalt_setup);
 211 
 212 #ifdef CONFIG_HOTPLUG_CPU
 213 /* We don't actually take CPU down, just spin without interrupts. */
 214 static inline void play_dead(void)
 215 {
 216         unsigned int this_cpu = smp_processor_id();
 217 
 218         /* Ack it */
 219         __this_cpu_write(cpu_state, CPU_DEAD);
 220 
 221         max_xtp();
 222         local_irq_disable();
 223         idle_task_exit();
 224         ia64_jump_to_sal(&sal_boot_rendez_state[this_cpu]);
 225         /*
 226          * The above is a point of no-return, the processor is
 227          * expected to be in SAL loop now.
 228          */
 229         BUG();
 230 }
 231 #else
 232 static inline void play_dead(void)
 233 {
 234         BUG();
 235 }
 236 #endif /* CONFIG_HOTPLUG_CPU */
 237 
 238 void arch_cpu_idle_dead(void)
 239 {
 240         play_dead();
 241 }
 242 
 243 void arch_cpu_idle(void)
 244 {
 245         void (*mark_idle)(int) = ia64_mark_idle;
 246 
 247 #ifdef CONFIG_SMP
 248         min_xtp();
 249 #endif
 250         rmb();
 251         if (mark_idle)
 252                 (*mark_idle)(1);
 253 
 254         safe_halt();
 255 
 256         if (mark_idle)
 257                 (*mark_idle)(0);
 258 #ifdef CONFIG_SMP
 259         normal_xtp();
 260 #endif
 261 }
 262 
 263 void
 264 ia64_save_extra (struct task_struct *task)
 265 {
 266 #ifdef CONFIG_PERFMON
 267         unsigned long info;
 268 #endif
 269 
 270         if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
 271                 ia64_save_debug_regs(&task->thread.dbr[0]);
 272 
 273 #ifdef CONFIG_PERFMON
 274         if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
 275                 pfm_save_regs(task);
 276 
 277         info = __this_cpu_read(pfm_syst_info);
 278         if (info & PFM_CPUINFO_SYST_WIDE)
 279                 pfm_syst_wide_update_task(task, info, 0);
 280 #endif
 281 }
 282 
 283 void
 284 ia64_load_extra (struct task_struct *task)
 285 {
 286 #ifdef CONFIG_PERFMON
 287         unsigned long info;
 288 #endif
 289 
 290         if ((task->thread.flags & IA64_THREAD_DBG_VALID) != 0)
 291                 ia64_load_debug_regs(&task->thread.dbr[0]);
 292 
 293 #ifdef CONFIG_PERFMON
 294         if ((task->thread.flags & IA64_THREAD_PM_VALID) != 0)
 295                 pfm_load_regs(task);
 296 
 297         info = __this_cpu_read(pfm_syst_info);
 298         if (info & PFM_CPUINFO_SYST_WIDE) 
 299                 pfm_syst_wide_update_task(task, info, 1);
 300 #endif
 301 }
 302 
 303 /*
 304  * Copy the state of an ia-64 thread.
 305  *
 306  * We get here through the following  call chain:
 307  *
 308  *      from user-level:        from kernel:
 309  *
 310  *      <clone syscall>         <some kernel call frames>
 311  *      sys_clone                  :
 312  *      do_fork                 do_fork
 313  *      copy_thread             copy_thread
 314  *
 315  * This means that the stack layout is as follows:
 316  *
 317  *      +---------------------+ (highest addr)
 318  *      |   struct pt_regs    |
 319  *      +---------------------+
 320  *      | struct switch_stack |
 321  *      +---------------------+
 322  *      |                     |
 323  *      |    memory stack     |
 324  *      |                     | <-- sp (lowest addr)
 325  *      +---------------------+
 326  *
 327  * Observe that we copy the unat values that are in pt_regs and switch_stack.  Spilling an
 328  * integer to address X causes bit N in ar.unat to be set to the NaT bit of the register,
 329  * with N=(X & 0x1ff)/8.  Thus, copying the unat value preserves the NaT bits ONLY if the
 330  * pt_regs structure in the parent is congruent to that of the child, modulo 512.  Since
 331  * the stack is page aligned and the page size is at least 4KB, this is always the case,
 332  * so there is nothing to worry about.
 333  */
 334 int
 335 copy_thread(unsigned long clone_flags,
 336              unsigned long user_stack_base, unsigned long user_stack_size,
 337              struct task_struct *p)
 338 {
 339         extern char ia64_ret_from_clone;
 340         struct switch_stack *child_stack, *stack;
 341         unsigned long rbs, child_rbs, rbs_size;
 342         struct pt_regs *child_ptregs;
 343         struct pt_regs *regs = current_pt_regs();
 344         int retval = 0;
 345 
 346         child_ptregs = (struct pt_regs *) ((unsigned long) p + IA64_STK_OFFSET) - 1;
 347         child_stack = (struct switch_stack *) child_ptregs - 1;
 348 
 349         rbs = (unsigned long) current + IA64_RBS_OFFSET;
 350         child_rbs = (unsigned long) p + IA64_RBS_OFFSET;
 351 
 352         /* copy parts of thread_struct: */
 353         p->thread.ksp = (unsigned long) child_stack - 16;
 354 
 355         /*
 356          * NOTE: The calling convention considers all floating point
 357          * registers in the high partition (fph) to be scratch.  Since
 358          * the only way to get to this point is through a system call,
 359          * we know that the values in fph are all dead.  Hence, there
 360          * is no need to inherit the fph state from the parent to the
 361          * child and all we have to do is to make sure that
 362          * IA64_THREAD_FPH_VALID is cleared in the child.
 363          *
 364          * XXX We could push this optimization a bit further by
 365          * clearing IA64_THREAD_FPH_VALID on ANY system call.
 366          * However, it's not clear this is worth doing.  Also, it
 367          * would be a slight deviation from the normal Linux system
 368          * call behavior where scratch registers are preserved across
 369          * system calls (unless used by the system call itself).
 370          */
 371 #       define THREAD_FLAGS_TO_CLEAR    (IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID \
 372                                          | IA64_THREAD_PM_VALID)
 373 #       define THREAD_FLAGS_TO_SET      0
 374         p->thread.flags = ((current->thread.flags & ~THREAD_FLAGS_TO_CLEAR)
 375                            | THREAD_FLAGS_TO_SET);
 376 
 377         ia64_drop_fpu(p);       /* don't pick up stale state from a CPU's fph */
 378 
 379         if (unlikely(p->flags & PF_KTHREAD)) {
 380                 if (unlikely(!user_stack_base)) {
 381                         /* fork_idle() called us */
 382                         return 0;
 383                 }
 384                 memset(child_stack, 0, sizeof(*child_ptregs) + sizeof(*child_stack));
 385                 child_stack->r4 = user_stack_base;      /* payload */
 386                 child_stack->r5 = user_stack_size;      /* argument */
 387                 /*
 388                  * Preserve PSR bits, except for bits 32-34 and 37-45,
 389                  * which we can't read.
 390                  */
 391                 child_ptregs->cr_ipsr = ia64_getreg(_IA64_REG_PSR) | IA64_PSR_BN;
 392                 /* mark as valid, empty frame */
 393                 child_ptregs->cr_ifs = 1UL << 63;
 394                 child_stack->ar_fpsr = child_ptregs->ar_fpsr
 395                         = ia64_getreg(_IA64_REG_AR_FPSR);
 396                 child_stack->pr = (1 << PRED_KERNEL_STACK);
 397                 child_stack->ar_bspstore = child_rbs;
 398                 child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
 399 
 400                 /* stop some PSR bits from being inherited.
 401                  * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
 402                  * therefore we must specify them explicitly here and not include them in
 403                  * IA64_PSR_BITS_TO_CLEAR.
 404                  */
 405                 child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
 406                                  & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
 407 
 408                 return 0;
 409         }
 410         stack = ((struct switch_stack *) regs) - 1;
 411         /* copy parent's switch_stack & pt_regs to child: */
 412         memcpy(child_stack, stack, sizeof(*child_ptregs) + sizeof(*child_stack));
 413 
 414         /* copy the parent's register backing store to the child: */
 415         rbs_size = stack->ar_bspstore - rbs;
 416         memcpy((void *) child_rbs, (void *) rbs, rbs_size);
 417         if (clone_flags & CLONE_SETTLS)
 418                 child_ptregs->r13 = regs->r16;  /* see sys_clone2() in entry.S */
 419         if (user_stack_base) {
 420                 child_ptregs->r12 = user_stack_base + user_stack_size - 16;
 421                 child_ptregs->ar_bspstore = user_stack_base;
 422                 child_ptregs->ar_rnat = 0;
 423                 child_ptregs->loadrs = 0;
 424         }
 425         child_stack->ar_bspstore = child_rbs + rbs_size;
 426         child_stack->b0 = (unsigned long) &ia64_ret_from_clone;
 427 
 428         /* stop some PSR bits from being inherited.
 429          * the psr.up/psr.pp bits must be cleared on fork but inherited on execve()
 430          * therefore we must specify them explicitly here and not include them in
 431          * IA64_PSR_BITS_TO_CLEAR.
 432          */
 433         child_ptregs->cr_ipsr = ((child_ptregs->cr_ipsr | IA64_PSR_BITS_TO_SET)
 434                                  & ~(IA64_PSR_BITS_TO_CLEAR | IA64_PSR_PP | IA64_PSR_UP));
 435 
 436 #ifdef CONFIG_PERFMON
 437         if (current->thread.pfm_context)
 438                 pfm_inherit(p, child_ptregs);
 439 #endif
 440         return retval;
 441 }
 442 
 443 static void
 444 do_copy_task_regs (struct task_struct *task, struct unw_frame_info *info, void *arg)
 445 {
 446         unsigned long mask, sp, nat_bits = 0, ar_rnat, urbs_end, cfm;
 447         unsigned long uninitialized_var(ip);    /* GCC be quiet */
 448         elf_greg_t *dst = arg;
 449         struct pt_regs *pt;
 450         char nat;
 451         int i;
 452 
 453         memset(dst, 0, sizeof(elf_gregset_t));  /* don't leak any kernel bits to user-level */
 454 
 455         if (unw_unwind_to_user(info) < 0)
 456                 return;
 457 
 458         unw_get_sp(info, &sp);
 459         pt = (struct pt_regs *) (sp + 16);
 460 
 461         urbs_end = ia64_get_user_rbs_end(task, pt, &cfm);
 462 
 463         if (ia64_sync_user_rbs(task, info->sw, pt->ar_bspstore, urbs_end) < 0)
 464                 return;
 465 
 466         ia64_peek(task, info->sw, urbs_end, (long) ia64_rse_rnat_addr((long *) urbs_end),
 467                   &ar_rnat);
 468 
 469         /*
 470          * coredump format:
 471          *      r0-r31
 472          *      NaT bits (for r0-r31; bit N == 1 iff rN is a NaT)
 473          *      predicate registers (p0-p63)
 474          *      b0-b7
 475          *      ip cfm user-mask
 476          *      ar.rsc ar.bsp ar.bspstore ar.rnat
 477          *      ar.ccv ar.unat ar.fpsr ar.pfs ar.lc ar.ec
 478          */
 479 
 480         /* r0 is zero */
 481         for (i = 1, mask = (1UL << i); i < 32; ++i) {
 482                 unw_get_gr(info, i, &dst[i], &nat);
 483                 if (nat)
 484                         nat_bits |= mask;
 485                 mask <<= 1;
 486         }
 487         dst[32] = nat_bits;
 488         unw_get_pr(info, &dst[33]);
 489 
 490         for (i = 0; i < 8; ++i)
 491                 unw_get_br(info, i, &dst[34 + i]);
 492 
 493         unw_get_rp(info, &ip);
 494         dst[42] = ip + ia64_psr(pt)->ri;
 495         dst[43] = cfm;
 496         dst[44] = pt->cr_ipsr & IA64_PSR_UM;
 497 
 498         unw_get_ar(info, UNW_AR_RSC, &dst[45]);
 499         /*
 500          * For bsp and bspstore, unw_get_ar() would return the kernel
 501          * addresses, but we need the user-level addresses instead:
 502          */
 503         dst[46] = urbs_end;     /* note: by convention PT_AR_BSP points to the end of the urbs! */
 504         dst[47] = pt->ar_bspstore;
 505         dst[48] = ar_rnat;
 506         unw_get_ar(info, UNW_AR_CCV, &dst[49]);
 507         unw_get_ar(info, UNW_AR_UNAT, &dst[50]);
 508         unw_get_ar(info, UNW_AR_FPSR, &dst[51]);
 509         dst[52] = pt->ar_pfs;   /* UNW_AR_PFS is == to pt->cr_ifs for interrupt frames */
 510         unw_get_ar(info, UNW_AR_LC, &dst[53]);
 511         unw_get_ar(info, UNW_AR_EC, &dst[54]);
 512         unw_get_ar(info, UNW_AR_CSD, &dst[55]);
 513         unw_get_ar(info, UNW_AR_SSD, &dst[56]);
 514 }
 515 
 516 void
 517 do_dump_task_fpu (struct task_struct *task, struct unw_frame_info *info, void *arg)
 518 {
 519         elf_fpreg_t *dst = arg;
 520         int i;
 521 
 522         memset(dst, 0, sizeof(elf_fpregset_t)); /* don't leak any "random" bits */
 523 
 524         if (unw_unwind_to_user(info) < 0)
 525                 return;
 526 
 527         /* f0 is 0.0, f1 is 1.0 */
 528 
 529         for (i = 2; i < 32; ++i)
 530                 unw_get_fr(info, i, dst + i);
 531 
 532         ia64_flush_fph(task);
 533         if ((task->thread.flags & IA64_THREAD_FPH_VALID) != 0)
 534                 memcpy(dst + 32, task->thread.fph, 96*16);
 535 }
 536 
 537 void
 538 do_copy_regs (struct unw_frame_info *info, void *arg)
 539 {
 540         do_copy_task_regs(current, info, arg);
 541 }
 542 
 543 void
 544 do_dump_fpu (struct unw_frame_info *info, void *arg)
 545 {
 546         do_dump_task_fpu(current, info, arg);
 547 }
 548 
 549 void
 550 ia64_elf_core_copy_regs (struct pt_regs *pt, elf_gregset_t dst)
 551 {
 552         unw_init_running(do_copy_regs, dst);
 553 }
 554 
 555 int
 556 dump_fpu (struct pt_regs *pt, elf_fpregset_t dst)
 557 {
 558         unw_init_running(do_dump_fpu, dst);
 559         return 1;       /* f0-f31 are always valid so we always return 1 */
 560 }
 561 
 562 /*
 563  * Flush thread state.  This is called when a thread does an execve().
 564  */
 565 void
 566 flush_thread (void)
 567 {
 568         /* drop floating-point and debug-register state if it exists: */
 569         current->thread.flags &= ~(IA64_THREAD_FPH_VALID | IA64_THREAD_DBG_VALID);
 570         ia64_drop_fpu(current);
 571 }
 572 
 573 /*
 574  * Clean up state associated with a thread.  This is called when
 575  * the thread calls exit().
 576  */
 577 void
 578 exit_thread (struct task_struct *tsk)
 579 {
 580 
 581         ia64_drop_fpu(tsk);
 582 #ifdef CONFIG_PERFMON
 583        /* if needed, stop monitoring and flush state to perfmon context */
 584         if (tsk->thread.pfm_context)
 585                 pfm_exit_thread(tsk);
 586 
 587         /* free debug register resources */
 588         if (tsk->thread.flags & IA64_THREAD_DBG_VALID)
 589                 pfm_release_debug_registers(tsk);
 590 #endif
 591 }
 592 
 593 unsigned long
 594 get_wchan (struct task_struct *p)
 595 {
 596         struct unw_frame_info info;
 597         unsigned long ip;
 598         int count = 0;
 599 
 600         if (!p || p == current || p->state == TASK_RUNNING)
 601                 return 0;
 602 
 603         /*
 604          * Note: p may not be a blocked task (it could be current or
 605          * another process running on some other CPU.  Rather than
 606          * trying to determine if p is really blocked, we just assume
 607          * it's blocked and rely on the unwind routines to fail
 608          * gracefully if the process wasn't really blocked after all.
 609          * --davidm 99/12/15
 610          */
 611         unw_init_from_blocked_task(&info, p);
 612         do {
 613                 if (p->state == TASK_RUNNING)
 614                         return 0;
 615                 if (unw_unwind(&info) < 0)
 616                         return 0;
 617                 unw_get_ip(&info, &ip);
 618                 if (!in_sched_functions(ip))
 619                         return ip;
 620         } while (count++ < 16);
 621         return 0;
 622 }
 623 
 624 void
 625 cpu_halt (void)
 626 {
 627         pal_power_mgmt_info_u_t power_info[8];
 628         unsigned long min_power;
 629         int i, min_power_state;
 630 
 631         if (ia64_pal_halt_info(power_info) != 0)
 632                 return;
 633 
 634         min_power_state = 0;
 635         min_power = power_info[0].pal_power_mgmt_info_s.power_consumption;
 636         for (i = 1; i < 8; ++i)
 637                 if (power_info[i].pal_power_mgmt_info_s.im
 638                     && power_info[i].pal_power_mgmt_info_s.power_consumption < min_power) {
 639                         min_power = power_info[i].pal_power_mgmt_info_s.power_consumption;
 640                         min_power_state = i;
 641                 }
 642 
 643         while (1)
 644                 ia64_pal_halt(min_power_state);
 645 }
 646 
 647 void machine_shutdown(void)
 648 {
 649 #ifdef CONFIG_HOTPLUG_CPU
 650         int cpu;
 651 
 652         for_each_online_cpu(cpu) {
 653                 if (cpu != smp_processor_id())
 654                         cpu_down(cpu);
 655         }
 656 #endif
 657 #ifdef CONFIG_KEXEC
 658         kexec_disable_iosapic();
 659 #endif
 660 }
 661 
 662 void
 663 machine_restart (char *restart_cmd)
 664 {
 665         (void) notify_die(DIE_MACHINE_RESTART, restart_cmd, NULL, 0, 0, 0);
 666         efi_reboot(REBOOT_WARM, NULL);
 667 }
 668 
 669 void
 670 machine_halt (void)
 671 {
 672         (void) notify_die(DIE_MACHINE_HALT, "", NULL, 0, 0, 0);
 673         cpu_halt();
 674 }
 675 
 676 void
 677 machine_power_off (void)
 678 {
 679         if (pm_power_off)
 680                 pm_power_off();
 681         machine_halt();
 682 }
 683
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root/arch/ia64/kernel/process.c

DEFINITIONS
