2 * x86 SMP booting functions
4 * (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
5 * (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
7 * Much of the core SMP work is based on previous work by Thomas Radke, to
8 * whom a great many thanks are extended.
10 * Thanks to Intel for making available several different Pentium,
11 * Pentium Pro and Pentium-II/Xeon MP machines.
12 * Original development of Linux SMP code supported by Caldera.
14 * This code is released under the GNU General Public License version 2 or
18 * Felix Koop : NR_CPUS used properly
19 * Jose Renau : Handle single CPU case.
20 * Alan Cox : By repeated request 8) - Total BogoMIPS report.
21 * Greg Wright : Fix for kernel stacks panic.
22 * Erich Boleyn : MP v1.4 and additional changes.
23 * Matthias Sattler : Changes for 2.1 kernel map.
24 * Michel Lespinasse : Changes for 2.1 kernel map.
25 * Michael Chastain : Change trampoline.S to gnu as.
26 * Alan Cox : Dumb bug: 'B' step PPro's are fine
27 * Ingo Molnar : Added APIC timers, based on code
29 * Ingo Molnar : various cleanups and rewrites
30 * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug.
31 * Maciej W. Rozycki : Bits for genuine 82489DX APICs
32 * Martin J. Bligh : Added support for multi-quad systems
33 * Dave Jones : Report invalid combinations of Athlon CPUs.
34 * Rusty Russell : Hacked into shape for new "hotplug" boot process. */
36 #include <linux/module.h>
37 #include <linux/init.h>
38 #include <linux/kernel.h>
41 #include <linux/sched.h>
42 #include <linux/kernel_stat.h>
43 #include <linux/bootmem.h>
44 #include <linux/notifier.h>
45 #include <linux/cpu.h>
46 #include <linux/percpu.h>
47 #include <linux/nmi.h>
49 #include <linux/delay.h>
50 #include <linux/mc146818rtc.h>
51 #include <asm/tlbflush.h>
53 #include <asm/arch_hooks.h>
56 #include <mach_apic.h>
57 #include <mach_wakecpu.h>
58 #include <smpboot_hooks.h>
62 static cpumask_t smp_commenced_mask;
64 /* which logical CPU number maps to which CPU (physical APIC ID) */
65 u16 x86_cpu_to_apicid_init[NR_CPUS] __initdata =
66 { [0 ... NR_CPUS-1] = BAD_APICID };
67 void *x86_cpu_to_apicid_early_ptr;
68 DEFINE_PER_CPU(u16, x86_cpu_to_apicid) = BAD_APICID;
69 EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid);
71 u16 x86_bios_cpu_apicid_init[NR_CPUS] __initdata
72 = { [0 ... NR_CPUS-1] = BAD_APICID };
73 void *x86_bios_cpu_apicid_early_ptr;
74 DEFINE_PER_CPU(u16, x86_bios_cpu_apicid) = BAD_APICID;
75 EXPORT_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
77 u8 apicid_2_node[MAX_APICID];
79 static void map_cpu_to_logical_apicid(void);
81 /* State of each CPU. */
82 DEFINE_PER_CPU(int, cpu_state) = { 0 };
84 static atomic_t init_deasserted;
86 static void __cpuinit smp_callin(void)
89 unsigned long timeout;
92 * If waken up by an INIT in an 82489DX configuration
93 * we may get here before an INIT-deassert IPI reaches
94 * our local APIC. We have to wait for the IPI or we'll
95 * lock up on an APIC access.
97 wait_for_init_deassert(&init_deasserted);
100 * (This works even if the APIC is not enabled.)
102 phys_id = GET_APIC_ID(apic_read(APIC_ID));
103 cpuid = smp_processor_id();
104 if (cpu_isset(cpuid, cpu_callin_map)) {
105 printk("huh, phys CPU#%d, CPU#%d already present??\n",
109 Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
112 * STARTUP IPIs are fragile beasts as they might sometimes
113 * trigger some glue motherboard logic. Complete APIC bus
114 * silence for 1 second, this overestimates the time the
115 * boot CPU is spending to send the up to 2 STARTUP IPIs
116 * by a factor of two. This should be enough.
120 * Waiting 2s total for startup (udelay is not yet working)
122 timeout = jiffies + 2*HZ;
123 while (time_before(jiffies, timeout)) {
125 * Has the boot CPU finished it's STARTUP sequence?
127 if (cpu_isset(cpuid, cpu_callout_map))
132 if (!time_before(jiffies, timeout)) {
133 printk("BUG: CPU%d started up but did not get a callout!\n",
139 * the boot CPU has finished the init stage and is spinning
140 * on callin_map until we finish. We are free to set up this
141 * CPU, first the APIC. (this is probably redundant on most
145 Dprintk("CALLIN, before setup_local_APIC().\n");
146 smp_callin_clear_local_apic();
148 map_cpu_to_logical_apicid();
154 Dprintk("Stack at about %p\n",&cpuid);
157 * Save our processor parameters
159 smp_store_cpu_info(cpuid);
162 * Allow the master to continue.
164 cpu_set(cpuid, cpu_callin_map);
168 * Activate a secondary processor.
170 static void __cpuinit start_secondary(void *unused)
173 * Don't put *anything* before cpu_init(), SMP booting is too
174 * fragile that we want to limit the things done here to the
175 * most necessary things.
183 while (!cpu_isset(smp_processor_id(), smp_commenced_mask))
186 /* otherwise gcc will move up smp_processor_id before the cpu_init */
189 * Check TSC synchronization with the BP:
191 check_tsc_sync_target();
193 if (nmi_watchdog == NMI_IO_APIC) {
194 disable_8259A_irq(0);
195 enable_NMI_through_LVT0();
199 /* This must be done before setting cpu_online_map */
200 set_cpu_sibling_map(raw_smp_processor_id());
204 * We need to hold call_lock, so there is no inconsistency
205 * between the time smp_call_function() determines number of
206 * IPI recipients, and the time when the determination is made
207 * for which cpus receive the IPI. Holding this
208 * lock helps us to not include this cpu in a currently in progress
209 * smp_call_function().
211 lock_ipi_call_lock();
212 cpu_set(smp_processor_id(), cpu_online_map);
213 unlock_ipi_call_lock();
214 per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
216 setup_secondary_clock();
223 * Everything has been set up for the secondary
224 * CPUs - they just need to reload everything
225 * from the task structure
226 * This function must not return.
228 void __devinit initialize_secondary(void)
231 * We don't actually need to load the full TSS,
232 * basically just the stack pointer and the ip.
239 :"m" (current->thread.sp),"m" (current->thread.ip));
242 /* Static state in head.S used to set up a CPU */
250 /* which logical CPUs are on which nodes */
251 cpumask_t node_to_cpumask_map[MAX_NUMNODES] __read_mostly =
252 { [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE };
253 EXPORT_SYMBOL(node_to_cpumask_map);
254 /* which node each logical CPU is on */
255 int cpu_to_node_map[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = 0 };
256 EXPORT_SYMBOL(cpu_to_node_map);
258 /* set up a mapping between cpu and node. */
259 static inline void map_cpu_to_node(int cpu, int node)
261 printk("Mapping cpu %d to node %d\n", cpu, node);
262 cpu_set(cpu, node_to_cpumask_map[node]);
263 cpu_to_node_map[cpu] = node;
266 /* undo a mapping between cpu and node. */
267 static inline void unmap_cpu_to_node(int cpu)
271 printk("Unmapping cpu %d from all nodes\n", cpu);
272 for (node = 0; node < MAX_NUMNODES; node ++)
273 cpu_clear(cpu, node_to_cpumask_map[node]);
274 cpu_to_node_map[cpu] = 0;
276 #else /* !CONFIG_NUMA */
278 #define map_cpu_to_node(cpu, node) ({})
279 #define unmap_cpu_to_node(cpu) ({})
281 #endif /* CONFIG_NUMA */
283 u8 cpu_2_logical_apicid[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID };
285 static void map_cpu_to_logical_apicid(void)
287 int cpu = smp_processor_id();
288 int apicid = logical_smp_processor_id();
289 int node = apicid_to_node(apicid);
291 if (!node_online(node))
292 node = first_online_node;
294 cpu_2_logical_apicid[cpu] = apicid;
295 map_cpu_to_node(cpu, node);
298 static void unmap_cpu_to_logical_apicid(int cpu)
300 cpu_2_logical_apicid[cpu] = BAD_APICID;
301 unmap_cpu_to_node(cpu);
304 static inline void __inquire_remote_apic(int apicid)
306 unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
307 char *names[] = { "ID", "VERSION", "SPIV" };
311 printk(KERN_INFO "Inquiring remote APIC #%d...\n", apicid);
313 for (i = 0; i < ARRAY_SIZE(regs); i++) {
314 printk(KERN_INFO "... APIC #%d %s: ", apicid, names[i]);
319 status = safe_apic_wait_icr_idle();
322 "a previous APIC delivery may have failed\n");
324 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
325 apic_write_around(APIC_ICR, APIC_DM_REMRD | regs[i]);
330 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
331 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
334 case APIC_ICR_RR_VALID:
335 status = apic_read(APIC_RRR);
336 printk(KERN_CONT "%08x\n", status);
339 printk(KERN_CONT "failed\n");
344 #ifdef WAKE_SECONDARY_VIA_NMI
346 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
347 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
348 * won't ... remember to clear down the APIC, etc later.
351 wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
353 unsigned long send_status, accept_status = 0;
357 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid));
359 /* Boot on the stack */
360 /* Kick the second */
361 apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL);
363 Dprintk("Waiting for send to finish...\n");
364 send_status = safe_apic_wait_icr_idle();
367 * Give the other CPU some time to accept the IPI.
371 * Due to the Pentium erratum 3AP.
373 maxlvt = lapic_get_maxlvt();
375 apic_read_around(APIC_SPIV);
376 apic_write(APIC_ESR, 0);
378 accept_status = (apic_read(APIC_ESR) & 0xEF);
379 Dprintk("NMI sent.\n");
382 printk("APIC never delivered???\n");
384 printk("APIC delivery error (%lx).\n", accept_status);
386 return (send_status | accept_status);
388 #endif /* WAKE_SECONDARY_VIA_NMI */
390 #ifdef WAKE_SECONDARY_VIA_INIT
392 wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
394 unsigned long send_status, accept_status = 0;
395 int maxlvt, num_starts, j;
398 * Be paranoid about clearing APIC errors.
400 if (APIC_INTEGRATED(apic_version[phys_apicid])) {
401 apic_read_around(APIC_SPIV);
402 apic_write(APIC_ESR, 0);
406 Dprintk("Asserting INIT.\n");
409 * Turn INIT on target chip
411 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
416 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
419 Dprintk("Waiting for send to finish...\n");
420 send_status = safe_apic_wait_icr_idle();
424 Dprintk("Deasserting INIT.\n");
427 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
430 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
432 Dprintk("Waiting for send to finish...\n");
433 send_status = safe_apic_wait_icr_idle();
436 atomic_set(&init_deasserted, 1);
439 * Should we send STARTUP IPIs ?
441 * Determine this based on the APIC version.
442 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
444 if (APIC_INTEGRATED(apic_version[phys_apicid]))
450 * Paravirt / VMI wants a startup IPI hook here to set up the
451 * target processor state.
453 startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
454 (unsigned long) stack_start.sp);
457 * Run STARTUP IPI loop.
459 Dprintk("#startup loops: %d.\n", num_starts);
461 maxlvt = lapic_get_maxlvt();
463 for (j = 1; j <= num_starts; j++) {
464 Dprintk("Sending STARTUP #%d.\n",j);
465 apic_read_around(APIC_SPIV);
466 apic_write(APIC_ESR, 0);
468 Dprintk("After apic_write.\n");
475 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
477 /* Boot on the stack */
478 /* Kick the second */
479 apic_write_around(APIC_ICR, APIC_DM_STARTUP
480 | (start_eip >> 12));
483 * Give the other CPU some time to accept the IPI.
487 Dprintk("Startup point 1.\n");
489 Dprintk("Waiting for send to finish...\n");
490 send_status = safe_apic_wait_icr_idle();
493 * Give the other CPU some time to accept the IPI.
497 * Due to the Pentium erratum 3AP.
500 apic_read_around(APIC_SPIV);
501 apic_write(APIC_ESR, 0);
503 accept_status = (apic_read(APIC_ESR) & 0xEF);
504 if (send_status || accept_status)
507 Dprintk("After Startup.\n");
510 printk("APIC never delivered???\n");
512 printk("APIC delivery error (%lx).\n", accept_status);
514 return (send_status | accept_status);
516 #endif /* WAKE_SECONDARY_VIA_INIT */
518 extern cpumask_t cpu_initialized;
520 #ifdef CONFIG_HOTPLUG_CPU
521 static struct task_struct * __cpuinitdata cpu_idle_tasks[NR_CPUS];
522 static inline struct task_struct * __cpuinit alloc_idle_task(int cpu)
524 struct task_struct *idle;
526 if ((idle = cpu_idle_tasks[cpu]) != NULL) {
527 /* initialize thread_struct. we really want to avoid destroy
530 idle->thread.sp = (unsigned long)task_pt_regs(idle);
531 init_idle(idle, cpu);
534 idle = fork_idle(cpu);
537 cpu_idle_tasks[cpu] = idle;
541 #define alloc_idle_task(cpu) fork_idle(cpu)
544 static int __cpuinit do_boot_cpu(int apicid, int cpu)
546 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
547 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
548 * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu.
551 struct task_struct *idle;
552 unsigned long boot_error;
554 unsigned long start_eip;
555 unsigned short nmi_high = 0, nmi_low = 0;
558 * Save current MTRR state in case it was changed since early boot
559 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
564 * We can't use kernel_thread since we must avoid to
565 * reschedule the child.
567 idle = alloc_idle_task(cpu);
569 panic("failed fork for CPU %d", cpu);
572 per_cpu(current_task, cpu) = idle;
573 early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
575 idle->thread.ip = (unsigned long) start_secondary;
576 /* start_eip had better be page-aligned! */
577 start_eip = setup_trampoline();
579 alternatives_smp_switch(1);
581 /* So we see what's up */
582 printk("Booting processor %d/%d ip %lx\n", cpu, apicid, start_eip);
583 /* Stack for startup_32 can be just as for start_secondary onwards */
584 stack_start.sp = (void *) idle->thread.sp;
589 * This grunge runs the startup process for
590 * the targeted processor.
593 atomic_set(&init_deasserted, 0);
595 Dprintk("Setting warm reset code and vector.\n");
597 store_NMI_vector(&nmi_high, &nmi_low);
599 smpboot_setup_warm_reset_vector(start_eip);
602 * Starting actual IPI sequence...
604 boot_error = wakeup_secondary_cpu(apicid, start_eip);
608 * allow APs to start initializing.
610 Dprintk("Before Callout %d.\n", cpu);
611 cpu_set(cpu, cpu_callout_map);
612 Dprintk("After Callout %d.\n", cpu);
615 * Wait 5s total for a response
617 for (timeout = 0; timeout < 50000; timeout++) {
618 if (cpu_isset(cpu, cpu_callin_map))
619 break; /* It has booted */
623 if (cpu_isset(cpu, cpu_callin_map)) {
624 /* number CPUs logically, starting from 1 (BSP is 0) */
626 printk("CPU%d: ", cpu);
627 print_cpu_info(&cpu_data(cpu));
628 Dprintk("CPU has booted.\n");
631 if (*((volatile unsigned char *)trampoline_base)
633 /* trampoline started but...? */
634 printk("Stuck ??\n");
636 /* trampoline code not run */
637 printk("Not responding.\n");
638 inquire_remote_apic(apicid);
643 /* Try to put things back the way they were before ... */
644 unmap_cpu_to_logical_apicid(cpu);
645 cpu_clear(cpu, cpu_callout_map); /* was set here (do_boot_cpu()) */
646 cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
647 cpu_clear(cpu, cpu_possible_map);
648 per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
651 /* mark "stuck" area as not stuck */
652 *((volatile unsigned long *)trampoline_base) = 0;
657 #ifdef CONFIG_HOTPLUG_CPU
658 void cpu_exit_clear(void)
660 int cpu = raw_smp_processor_id();
667 cpu_clear(cpu, cpu_callout_map);
668 cpu_clear(cpu, cpu_callin_map);
670 cpu_clear(cpu, smp_commenced_mask);
671 unmap_cpu_to_logical_apicid(cpu);
674 struct warm_boot_cpu_info {
675 struct completion *complete;
676 struct work_struct task;
681 static void __cpuinit do_warm_boot_cpu(struct work_struct *work)
683 struct warm_boot_cpu_info *info =
684 container_of(work, struct warm_boot_cpu_info, task);
685 do_boot_cpu(info->apicid, info->cpu);
686 complete(info->complete);
689 static void __cpuinit __smp_prepare_cpu(int cpu)
691 DECLARE_COMPLETION_ONSTACK(done);
692 struct warm_boot_cpu_info info;
695 apicid = per_cpu(x86_cpu_to_apicid, cpu);
697 info.complete = &done;
698 info.apicid = apicid;
700 INIT_WORK(&info.task, do_warm_boot_cpu);
702 /* init low mem mapping */
703 clone_pgd_range(swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
704 min_t(unsigned long, KERNEL_PGD_PTRS, USER_PGD_PTRS));
706 if (!keventd_up() || current_is_keventd())
707 info.task.func(&info.task);
709 schedule_work(&info.task);
710 wait_for_completion(&done);
715 static int boot_cpu_logical_apicid;
716 /* Where the IO area was mapped on multiquad, always 0 otherwise */
718 #ifdef CONFIG_X86_NUMAQ
719 EXPORT_SYMBOL(xquad_portio);
722 static void __init disable_smp(void)
724 cpu_possible_map = cpumask_of_cpu(0);
725 cpu_present_map = cpumask_of_cpu(0);
726 smpboot_clear_io_apic_irqs();
727 phys_cpu_present_map = physid_mask_of_physid(0);
728 map_cpu_to_logical_apicid();
729 cpu_set(0, per_cpu(cpu_sibling_map, 0));
730 cpu_set(0, per_cpu(cpu_core_map, 0));
733 static int __init smp_sanity_check(unsigned max_cpus)
736 * If we couldn't find an SMP configuration at boot time,
737 * get out of here now!
739 if (!smp_found_config && !acpi_lapic) {
740 printk(KERN_NOTICE "SMP motherboard not detected.\n");
742 if (APIC_init_uniprocessor())
743 printk(KERN_NOTICE "Local APIC not detected."
744 " Using dummy APIC emulation.\n");
749 * Should not be necessary because the MP table should list the boot
750 * CPU too, but we do it for the sake of robustness anyway.
751 * Makes no sense to do this check in clustered apic mode, so skip it
753 if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
754 printk("weird, boot CPU (#%d) not listed by the BIOS.\n",
755 boot_cpu_physical_apicid);
756 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
760 * If we couldn't find a local APIC, then get out of here now!
762 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) && !cpu_has_apic) {
763 printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
764 boot_cpu_physical_apicid);
765 printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n");
772 * If SMP should be disabled, then really disable it!
775 smp_found_config = 0;
776 printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
778 if (nmi_watchdog == NMI_LOCAL_APIC) {
779 printk(KERN_INFO "activating minimal APIC for NMI watchdog use.\n");
789 * Cycle through the processors sending APIC IPIs to boot each.
791 static void __init smp_boot_cpus(unsigned int max_cpus)
793 int apicid, cpu, bit, kicked;
796 * Setup boot CPU information
798 smp_store_cpu_info(0); /* Final full version of the data */
799 printk(KERN_INFO "CPU%d: ", 0);
800 print_cpu_info(&cpu_data(0));
802 boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
803 boot_cpu_logical_apicid = logical_smp_processor_id();
805 current_thread_info()->cpu = 0;
807 set_cpu_sibling_map(0);
809 if (smp_sanity_check(max_cpus) < 0) {
810 printk(KERN_INFO "SMP disabled\n");
817 map_cpu_to_logical_apicid();
820 setup_portio_remap();
823 * Scan the CPU present map and fire up the other CPUs via do_boot_cpu
825 * In clustered apic mode, phys_cpu_present_map is a constructed thus:
826 * bits 0-3 are quad0, 4-7 are quad1, etc. A perverse twist on the
829 Dprintk("CPU present map: %lx\n", physids_coerce(phys_cpu_present_map));
832 for (bit = 0; kicked < NR_CPUS && bit < MAX_APICS; bit++) {
833 apicid = cpu_present_to_apicid(bit);
835 * Don't even attempt to start the boot CPU!
837 if ((apicid == boot_cpu_apicid) || (apicid == BAD_APICID))
840 if (!check_apicid_present(bit))
842 if (max_cpus <= cpus_weight(cpu_present_map))
844 /* Utterly temporary */
845 for (cpu = 0; cpu < NR_CPUS; cpu++)
846 if (per_cpu(x86_cpu_to_apicid, cpu) == apicid)
848 if (do_boot_cpu(apicid, cpu))
849 printk("CPU #%d not responding - cannot use it.\n",
855 smpboot_setup_io_apic();
860 /* These are wrappers to interface to the new boot process. Someone
861 who understands all this stuff should rewrite it properly. --RR 15/Jul/02 */
862 void __init native_smp_prepare_cpus(unsigned int max_cpus)
864 nmi_watchdog_default();
865 smp_commenced_mask = cpumask_of_cpu(0);
866 cpu_callin_map = cpumask_of_cpu(0);
868 smp_boot_cpus(max_cpus);
871 void __init native_smp_prepare_boot_cpu(void)
873 unsigned int cpu = smp_processor_id();
878 cpu_set(cpu, cpu_callout_map);
879 __get_cpu_var(cpu_state) = CPU_ONLINE;
882 int __cpuinit native_cpu_up(unsigned int cpu)
884 int apicid = cpu_present_to_apicid(cpu);
887 WARN_ON(irqs_disabled());
889 Dprintk("++++++++++++++++++++=_---CPU UP %u\n", cpu);
891 if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
892 !physid_isset(apicid, phys_cpu_present_map)) {
893 printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
897 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
898 #ifdef CONFIG_HOTPLUG_CPU
901 * We do warm boot only on cpus that had booted earlier
902 * Otherwise cold boot is all handled from smp_boot_cpus().
903 * cpu_callin_map is set during AP kickstart process. Its reset
904 * when a cpu is taken offline from cpu_exit_clear().
906 if (!cpu_isset(cpu, cpu_callin_map))
907 __smp_prepare_cpu(cpu);
910 /* In case one didn't come up */
911 if (!cpu_isset(cpu, cpu_callin_map)) {
912 printk(KERN_DEBUG "skipping cpu%d, didn't come online\n", cpu);
916 /* Unleash the CPU! */
917 cpu_set(cpu, smp_commenced_mask);
920 * Check TSC synchronization with the AP (keep irqs disabled
923 local_irq_save(flags);
924 check_tsc_sync_source(cpu);
925 local_irq_restore(flags);
927 while (!cpu_isset(cpu, cpu_online_map)) {
929 touch_nmi_watchdog();
935 extern void impress_friends(void);
936 extern void smp_checks(void);
938 void __init native_smp_cpus_done(unsigned int max_cpus)
941 * Cleanup possible dangling ends...
943 smpboot_restore_warm_reset_vector();
945 Dprintk("Boot done.\n");
949 #ifdef CONFIG_X86_IO_APIC
952 check_nmi_watchdog();