2 * x86 SMP booting functions
4 * (c) 1995 Alan Cox, Building #3 <alan@lxorguk.ukuu.org.uk>
5 * (c) 1998, 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
6 * Copyright 2001 Andi Kleen, SuSE Labs.
8 * Much of the core SMP work is based on previous work by Thomas Radke, to
9 * whom a great many thanks are extended.
11 * Thanks to Intel for making available several different Pentium,
12 * Pentium Pro and Pentium-II/Xeon MP machines.
13 * Original development of Linux SMP code supported by Caldera.
15 * This code is released under the GNU General Public License version 2 or
19 * Felix Koop : NR_CPUS used properly
20 * Jose Renau : Handle single CPU case.
21 * Alan Cox : By repeated request 8) - Total BogoMIPS report.
22 * Greg Wright : Fix for kernel stacks panic.
23 * Erich Boleyn : MP v1.4 and additional changes.
24 * Matthias Sattler : Changes for 2.1 kernel map.
25 * Michel Lespinasse : Changes for 2.1 kernel map.
26 * Michael Chastain : Change trampoline.S to gnu as.
27 * Alan Cox : Dumb bug: 'B' step PPro's are fine
28 * Ingo Molnar : Added APIC timers, based on code
30 * Ingo Molnar : various cleanups and rewrites
31 * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug.
32 * Maciej W. Rozycki : Bits for genuine 82489DX APICs
33 * Andi Kleen : Changed for SMP boot into long mode.
34 * Martin J. Bligh : Added support for multi-quad systems
35 * Dave Jones : Report invalid combinations of Athlon CPUs.
36 * Rusty Russell : Hacked into shape for new "hotplug" boot process.
37 * Andi Kleen : Converted to new state machine.
38 * Ashok Raj : CPU hotplug support
39 * Glauber Costa : i386 and x86_64 integration
42 #include <linux/init.h>
43 #include <linux/smp.h>
44 #include <linux/module.h>
45 #include <linux/sched.h>
46 #include <linux/percpu.h>
47 #include <linux/bootmem.h>
48 #include <linux/err.h>
49 #include <linux/nmi.h>
56 #include <asm/trampoline.h>
59 #include <asm/pgtable.h>
60 #include <asm/tlbflush.h>
64 #include <asm/setup.h>
65 #include <asm/uv/uv.h>
66 #include <linux/mc146818rtc.h>
68 #include <asm/smpboot_hooks.h>
71 u8 apicid_2_node[MAX_APICID];
72 static int low_mappings;
75 /* State of each CPU */
76 DEFINE_PER_CPU(int, cpu_state) = { 0 };
78 /* Store all idle threads, this can be reused instead of creating
79 * a new thread. Also avoids complicated thread destroy functionality
82 #ifdef CONFIG_HOTPLUG_CPU
84 * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
85 * removed after init for !CONFIG_HOTPLUG_CPU.
87 static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
88 #define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x))
89 #define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p))
91 static struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
92 #define get_idle_for_cpu(x) (idle_thread_array[(x)])
93 #define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p))
96 /* Number of siblings per CPU package */
97 int smp_num_siblings = 1;
98 EXPORT_SYMBOL(smp_num_siblings);
100 /* Last level cache ID of each logical CPU */
101 DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
103 /* representing HT siblings of each logical CPU */
104 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
105 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
107 /* representing HT and core siblings of each logical CPU */
108 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
109 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
111 /* Per CPU bogomips and other parameters */
112 DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
113 EXPORT_PER_CPU_SYMBOL(cpu_info);
115 atomic_t init_deasserted;
117 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_32)
118 /* which node each logical CPU is on */
119 int cpu_to_node_map[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = 0 };
120 EXPORT_SYMBOL(cpu_to_node_map);
122 /* set up a mapping between cpu and node. */
123 static void map_cpu_to_node(int cpu, int node)
125 printk(KERN_INFO "Mapping cpu %d to node %d\n", cpu, node);
126 cpumask_set_cpu(cpu, node_to_cpumask_map[node]);
127 cpu_to_node_map[cpu] = node;
130 /* undo a mapping between cpu and node. */
131 static void unmap_cpu_to_node(int cpu)
135 printk(KERN_INFO "Unmapping cpu %d from all nodes\n", cpu);
136 for (node = 0; node < MAX_NUMNODES; node++)
137 cpumask_clear_cpu(cpu, node_to_cpumask_map[node]);
138 cpu_to_node_map[cpu] = 0;
140 #else /* !(CONFIG_NUMA && CONFIG_X86_32) */
141 #define map_cpu_to_node(cpu, node) ({})
142 #define unmap_cpu_to_node(cpu) ({})
146 static int boot_cpu_logical_apicid;
148 u8 cpu_2_logical_apicid[NR_CPUS] __read_mostly =
149 { [0 ... NR_CPUS-1] = BAD_APICID };
151 static void map_cpu_to_logical_apicid(void)
153 int cpu = smp_processor_id();
154 int apicid = logical_smp_processor_id();
155 int node = apic->apicid_to_node(apicid);
157 if (!node_online(node))
158 node = first_online_node;
160 cpu_2_logical_apicid[cpu] = apicid;
161 map_cpu_to_node(cpu, node);
164 void numa_remove_cpu(int cpu)
166 cpu_2_logical_apicid[cpu] = BAD_APICID;
167 unmap_cpu_to_node(cpu);
170 #define map_cpu_to_logical_apicid() do {} while (0)
174 * Report back to the Boot Processor.
177 static void __cpuinit smp_callin(void)
180 unsigned long timeout;
183 * If waken up by an INIT in an 82489DX configuration
184 * we may get here before an INIT-deassert IPI reaches
185 * our local APIC. We have to wait for the IPI or we'll
186 * lock up on an APIC access.
188 if (apic->wait_for_init_deassert)
189 apic->wait_for_init_deassert(&init_deasserted);
192 * (This works even if the APIC is not enabled.)
194 phys_id = read_apic_id();
195 cpuid = smp_processor_id();
196 if (cpumask_test_cpu(cpuid, cpu_callin_mask)) {
197 panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__,
200 pr_debug("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
203 * STARTUP IPIs are fragile beasts as they might sometimes
204 * trigger some glue motherboard logic. Complete APIC bus
205 * silence for 1 second, this overestimates the time the
206 * boot CPU is spending to send the up to 2 STARTUP IPIs
207 * by a factor of two. This should be enough.
211 * Waiting 2s total for startup (udelay is not yet working)
213 timeout = jiffies + 2*HZ;
214 while (time_before(jiffies, timeout)) {
216 * Has the boot CPU finished it's STARTUP sequence?
218 if (cpumask_test_cpu(cpuid, cpu_callout_mask))
223 if (!time_before(jiffies, timeout)) {
224 panic("%s: CPU%d started up but did not get a callout!\n",
229 * the boot CPU has finished the init stage and is spinning
230 * on callin_map until we finish. We are free to set up this
231 * CPU, first the APIC. (this is probably redundant on most
235 pr_debug("CALLIN, before setup_local_APIC().\n");
236 if (apic->smp_callin_clear_local_apic)
237 apic->smp_callin_clear_local_apic();
239 end_local_APIC_setup();
240 map_cpu_to_logical_apicid();
242 notify_cpu_starting(cpuid);
246 * Need to enable IRQs because it can take longer and then
247 * the NMI watchdog might kill us.
252 pr_debug("Stack at about %p\n", &cpuid);
255 * Save our processor parameters
257 smp_store_cpu_info(cpuid);
260 * Allow the master to continue.
262 cpumask_set_cpu(cpuid, cpu_callin_mask);
266 * Activate a secondary processor.
268 notrace static void __cpuinit start_secondary(void *unused)
271 * Don't put *anything* before cpu_init(), SMP booting is too
272 * fragile that we want to limit the things done here to the
273 * most necessary things.
280 /* otherwise gcc will move up smp_processor_id before the cpu_init */
283 * Check TSC synchronization with the BP:
285 check_tsc_sync_target();
287 if (nmi_watchdog == NMI_IO_APIC) {
288 disable_8259A_irq(0);
289 enable_NMI_through_LVT0();
299 /* This must be done before setting cpu_online_mask */
300 set_cpu_sibling_map(raw_smp_processor_id());
304 * We need to hold call_lock, so there is no inconsistency
305 * between the time smp_call_function() determines number of
306 * IPI recipients, and the time when the determination is made
307 * for which cpus receive the IPI. Holding this
308 * lock helps us to not include this cpu in a currently in progress
309 * smp_call_function().
311 * We need to hold vector_lock so there the set of online cpus
312 * does not change while we are assigning vectors to cpus. Holding
313 * this lock ensures we don't half assign or remove an irq from a cpu.
317 __setup_vector_irq(smp_processor_id());
318 set_cpu_online(smp_processor_id(), true);
319 unlock_vector_lock();
321 per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
323 /* enable local interrupts */
326 setup_secondary_clock();
332 #ifdef CONFIG_CPUMASK_OFFSTACK
333 /* In this case, llc_shared_map is a pointer to a cpumask. */
334 static inline void copy_cpuinfo_x86(struct cpuinfo_x86 *dst,
335 const struct cpuinfo_x86 *src)
337 struct cpumask *llc = dst->llc_shared_map;
339 dst->llc_shared_map = llc;
342 static inline void copy_cpuinfo_x86(struct cpuinfo_x86 *dst,
343 const struct cpuinfo_x86 *src)
347 #endif /* CONFIG_CPUMASK_OFFSTACK */
350 * The bootstrap kernel entry code has set these up. Save them for
354 void __cpuinit smp_store_cpu_info(int id)
356 struct cpuinfo_x86 *c = &cpu_data(id);
358 copy_cpuinfo_x86(c, &boot_cpu_data);
361 identify_secondary_cpu(c);
365 void __cpuinit set_cpu_sibling_map(int cpu)
368 struct cpuinfo_x86 *c = &cpu_data(cpu);
370 cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
372 if (smp_num_siblings > 1) {
373 for_each_cpu(i, cpu_sibling_setup_mask) {
374 struct cpuinfo_x86 *o = &cpu_data(i);
376 if (c->phys_proc_id == o->phys_proc_id &&
377 c->cpu_core_id == o->cpu_core_id) {
378 cpumask_set_cpu(i, cpu_sibling_mask(cpu));
379 cpumask_set_cpu(cpu, cpu_sibling_mask(i));
380 cpumask_set_cpu(i, cpu_core_mask(cpu));
381 cpumask_set_cpu(cpu, cpu_core_mask(i));
382 cpumask_set_cpu(i, c->llc_shared_map);
383 cpumask_set_cpu(cpu, o->llc_shared_map);
387 cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
390 cpumask_set_cpu(cpu, c->llc_shared_map);
392 if (current_cpu_data.x86_max_cores == 1) {
393 cpumask_copy(cpu_core_mask(cpu), cpu_sibling_mask(cpu));
398 for_each_cpu(i, cpu_sibling_setup_mask) {
399 if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
400 per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
401 cpumask_set_cpu(i, c->llc_shared_map);
402 cpumask_set_cpu(cpu, cpu_data(i).llc_shared_map);
404 if (c->phys_proc_id == cpu_data(i).phys_proc_id) {
405 cpumask_set_cpu(i, cpu_core_mask(cpu));
406 cpumask_set_cpu(cpu, cpu_core_mask(i));
408 * Does this new cpu bringup a new core?
410 if (cpumask_weight(cpu_sibling_mask(cpu)) == 1) {
412 * for each core in package, increment
413 * the booted_cores for this new cpu
415 if (cpumask_first(cpu_sibling_mask(i)) == i)
418 * increment the core count for all
419 * the other cpus in this package
422 cpu_data(i).booted_cores++;
423 } else if (i != cpu && !c->booted_cores)
424 c->booted_cores = cpu_data(i).booted_cores;
429 /* maps the cpu to the sched domain representing multi-core */
430 const struct cpumask *cpu_coregroup_mask(int cpu)
432 struct cpuinfo_x86 *c = &cpu_data(cpu);
434 * For perf, we return last level cache shared map.
435 * And for power savings, we return cpu_core_map
437 if (sched_mc_power_savings || sched_smt_power_savings)
438 return cpu_core_mask(cpu);
440 return c->llc_shared_map;
443 static void impress_friends(void)
446 unsigned long bogosum = 0;
448 * Allow the user to impress friends.
450 pr_debug("Before bogomips.\n");
451 for_each_possible_cpu(cpu)
452 if (cpumask_test_cpu(cpu, cpu_callout_mask))
453 bogosum += cpu_data(cpu).loops_per_jiffy;
455 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
458 (bogosum/(5000/HZ))%100);
460 pr_debug("Before bogocount - setting activated=1.\n");
463 void __inquire_remote_apic(int apicid)
465 unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
466 char *names[] = { "ID", "VERSION", "SPIV" };
470 printk(KERN_INFO "Inquiring remote APIC 0x%x...\n", apicid);
472 for (i = 0; i < ARRAY_SIZE(regs); i++) {
473 printk(KERN_INFO "... APIC 0x%x %s: ", apicid, names[i]);
478 status = safe_apic_wait_icr_idle();
481 "a previous APIC delivery may have failed\n");
483 apic_icr_write(APIC_DM_REMRD | regs[i], apicid);
488 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
489 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
492 case APIC_ICR_RR_VALID:
493 status = apic_read(APIC_RRR);
494 printk(KERN_CONT "%08x\n", status);
497 printk(KERN_CONT "failed\n");
503 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
504 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
505 * won't ... remember to clear down the APIC, etc later.
508 wakeup_secondary_cpu_via_nmi(int logical_apicid, unsigned long start_eip)
510 unsigned long send_status, accept_status = 0;
514 /* Boot on the stack */
515 /* Kick the second */
516 apic_icr_write(APIC_DM_NMI | apic->dest_logical, logical_apicid);
518 pr_debug("Waiting for send to finish...\n");
519 send_status = safe_apic_wait_icr_idle();
522 * Give the other CPU some time to accept the IPI.
525 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
526 maxlvt = lapic_get_maxlvt();
527 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
528 apic_write(APIC_ESR, 0);
529 accept_status = (apic_read(APIC_ESR) & 0xEF);
531 pr_debug("NMI sent.\n");
534 printk(KERN_ERR "APIC never delivered???\n");
536 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
538 return (send_status | accept_status);
542 wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
544 unsigned long send_status, accept_status = 0;
545 int maxlvt, num_starts, j;
547 maxlvt = lapic_get_maxlvt();
550 * Be paranoid about clearing APIC errors.
552 if (APIC_INTEGRATED(apic_version[phys_apicid])) {
553 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
554 apic_write(APIC_ESR, 0);
558 pr_debug("Asserting INIT.\n");
561 * Turn INIT on target chip
566 apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT,
569 pr_debug("Waiting for send to finish...\n");
570 send_status = safe_apic_wait_icr_idle();
574 pr_debug("Deasserting INIT.\n");
578 apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid);
580 pr_debug("Waiting for send to finish...\n");
581 send_status = safe_apic_wait_icr_idle();
584 atomic_set(&init_deasserted, 1);
587 * Should we send STARTUP IPIs ?
589 * Determine this based on the APIC version.
590 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
592 if (APIC_INTEGRATED(apic_version[phys_apicid]))
598 * Paravirt / VMI wants a startup IPI hook here to set up the
599 * target processor state.
601 startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
602 (unsigned long)stack_start.sp);
605 * Run STARTUP IPI loop.
607 pr_debug("#startup loops: %d.\n", num_starts);
609 for (j = 1; j <= num_starts; j++) {
610 pr_debug("Sending STARTUP #%d.\n", j);
611 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
612 apic_write(APIC_ESR, 0);
614 pr_debug("After apic_write.\n");
621 /* Boot on the stack */
622 /* Kick the second */
623 apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12),
627 * Give the other CPU some time to accept the IPI.
631 pr_debug("Startup point 1.\n");
633 pr_debug("Waiting for send to finish...\n");
634 send_status = safe_apic_wait_icr_idle();
637 * Give the other CPU some time to accept the IPI.
640 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
641 apic_write(APIC_ESR, 0);
642 accept_status = (apic_read(APIC_ESR) & 0xEF);
643 if (send_status || accept_status)
646 pr_debug("After Startup.\n");
649 printk(KERN_ERR "APIC never delivered???\n");
651 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
653 return (send_status | accept_status);
657 struct work_struct work;
658 struct task_struct *idle;
659 struct completion done;
663 static void __cpuinit do_fork_idle(struct work_struct *work)
665 struct create_idle *c_idle =
666 container_of(work, struct create_idle, work);
668 c_idle->idle = fork_idle(c_idle->cpu);
669 complete(&c_idle->done);
673 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
674 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
675 * Returns zero if CPU booted OK, else error code from
676 * ->wakeup_secondary_cpu.
678 static int __cpuinit do_boot_cpu(int apicid, int cpu)
680 unsigned long boot_error = 0;
681 unsigned long start_ip;
683 struct create_idle c_idle = {
685 .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
688 INIT_WORK(&c_idle.work, do_fork_idle);
690 alternatives_smp_switch(1);
692 c_idle.idle = get_idle_for_cpu(cpu);
695 * We can't use kernel_thread since we must avoid to
696 * reschedule the child.
699 c_idle.idle->thread.sp = (unsigned long) (((struct pt_regs *)
700 (THREAD_SIZE + task_stack_page(c_idle.idle))) - 1);
701 init_idle(c_idle.idle, cpu);
705 if (!keventd_up() || current_is_keventd())
706 c_idle.work.func(&c_idle.work);
708 schedule_work(&c_idle.work);
709 wait_for_completion(&c_idle.done);
712 if (IS_ERR(c_idle.idle)) {
713 printk("failed fork for CPU %d\n", cpu);
714 return PTR_ERR(c_idle.idle);
717 set_idle_for_cpu(cpu, c_idle.idle);
719 per_cpu(current_task, cpu) = c_idle.idle;
721 /* Stack for startup_32 can be just as for start_secondary onwards */
724 clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
725 initial_gs = per_cpu_offset(cpu);
726 per_cpu(kernel_stack, cpu) =
727 (unsigned long)task_stack_page(c_idle.idle) -
728 KERNEL_STACK_OFFSET + THREAD_SIZE;
730 early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
731 initial_code = (unsigned long)start_secondary;
732 stack_start.sp = (void *) c_idle.idle->thread.sp;
734 /* start_ip had better be page-aligned! */
735 start_ip = setup_trampoline();
737 /* So we see what's up */
738 printk(KERN_INFO "Booting processor %d APIC 0x%x ip 0x%lx\n",
739 cpu, apicid, start_ip);
742 * This grunge runs the startup process for
743 * the targeted processor.
746 atomic_set(&init_deasserted, 0);
748 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
750 pr_debug("Setting warm reset code and vector.\n");
752 smpboot_setup_warm_reset_vector(start_ip);
754 * Be paranoid about clearing APIC errors.
756 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
757 apic_write(APIC_ESR, 0);
763 * Kick the secondary CPU. Use the method in the APIC driver
764 * if it's defined - or use an INIT boot APIC message otherwise:
766 if (apic->wakeup_secondary_cpu)
767 boot_error = apic->wakeup_secondary_cpu(apicid, start_ip);
769 boot_error = wakeup_secondary_cpu_via_init(apicid, start_ip);
773 * allow APs to start initializing.
775 pr_debug("Before Callout %d.\n", cpu);
776 cpumask_set_cpu(cpu, cpu_callout_mask);
777 pr_debug("After Callout %d.\n", cpu);
780 * Wait 5s total for a response
782 for (timeout = 0; timeout < 50000; timeout++) {
783 if (cpumask_test_cpu(cpu, cpu_callin_mask))
784 break; /* It has booted */
788 if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
789 /* number CPUs logically, starting from 1 (BSP is 0) */
791 printk(KERN_INFO "CPU%d: ", cpu);
792 print_cpu_info(&cpu_data(cpu));
793 pr_debug("CPU has booted.\n");
796 if (*((volatile unsigned char *)trampoline_base)
798 /* trampoline started but...? */
799 printk(KERN_ERR "Stuck ??\n");
801 /* trampoline code not run */
802 printk(KERN_ERR "Not responding.\n");
803 if (apic->inquire_remote_apic)
804 apic->inquire_remote_apic(apicid);
809 /* Try to put things back the way they were before ... */
810 numa_remove_cpu(cpu); /* was set by numa_add_cpu */
812 /* was set by do_boot_cpu() */
813 cpumask_clear_cpu(cpu, cpu_callout_mask);
815 /* was set by cpu_init() */
816 cpumask_clear_cpu(cpu, cpu_initialized_mask);
818 set_cpu_present(cpu, false);
819 per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
822 /* mark "stuck" area as not stuck */
823 *((volatile unsigned long *)trampoline_base) = 0;
825 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
827 * Cleanup possible dangling ends...
829 smpboot_restore_warm_reset_vector();
835 int __cpuinit native_cpu_up(unsigned int cpu)
837 int apicid = apic->cpu_present_to_apicid(cpu);
841 WARN_ON(irqs_disabled());
843 pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);
845 if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
846 !physid_isset(apicid, phys_cpu_present_map)) {
847 printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
852 * Already booted CPU?
854 if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
855 pr_debug("do_boot_cpu %d Already started\n", cpu);
860 * Save current MTRR state in case it was changed since early boot
861 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
865 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
868 /* init low mem mapping */
869 clone_pgd_range(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
870 min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
874 err = do_boot_cpu(apicid, cpu);
879 err = do_boot_cpu(apicid, cpu);
882 pr_debug("do_boot_cpu failed %d\n", err);
887 * Check TSC synchronization with the AP (keep irqs disabled
890 local_irq_save(flags);
891 check_tsc_sync_source(cpu);
892 local_irq_restore(flags);
894 while (!cpu_online(cpu)) {
896 touch_nmi_watchdog();
903 * Fall back to non SMP mode after errors.
905 * RED-PEN audit/test this more. I bet there is more state messed up here.
907 static __init void disable_smp(void)
909 init_cpu_present(cpumask_of(0));
910 init_cpu_possible(cpumask_of(0));
911 smpboot_clear_io_apic_irqs();
913 if (smp_found_config)
914 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
916 physid_set_mask_of_physid(0, &phys_cpu_present_map);
917 map_cpu_to_logical_apicid();
918 cpumask_set_cpu(0, cpu_sibling_mask(0));
919 cpumask_set_cpu(0, cpu_core_mask(0));
923 * Various sanity checks.
925 static int __init smp_sanity_check(unsigned max_cpus)
929 #if !defined(CONFIG_X86_BIGSMP) && defined(CONFIG_X86_32)
930 if (def_to_bigsmp && nr_cpu_ids > 8) {
935 "More than 8 CPUs detected - skipping them.\n"
936 "Use CONFIG_X86_BIGSMP.\n");
939 for_each_present_cpu(cpu) {
941 set_cpu_present(cpu, false);
946 for_each_possible_cpu(cpu) {
948 set_cpu_possible(cpu, false);
956 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
958 "weird, boot CPU (#%d) not listed by the BIOS.\n",
959 hard_smp_processor_id());
961 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
965 * If we couldn't find an SMP configuration at boot time,
966 * get out of here now!
968 if (!smp_found_config && !acpi_lapic) {
970 printk(KERN_NOTICE "SMP motherboard not detected.\n");
972 if (APIC_init_uniprocessor())
973 printk(KERN_NOTICE "Local APIC not detected."
974 " Using dummy APIC emulation.\n");
979 * Should not be necessary because the MP table should list the boot
980 * CPU too, but we do it for the sake of robustness anyway.
982 if (!apic->check_phys_apicid_present(boot_cpu_physical_apicid)) {
984 "weird, boot CPU (#%d) not listed by the BIOS.\n",
985 boot_cpu_physical_apicid);
986 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
991 * If we couldn't find a local APIC, then get out of here now!
993 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
996 pr_err("BIOS bug, local APIC #%d not detected!...\n",
997 boot_cpu_physical_apicid);
998 pr_err("... forcing use of dummy APIC emulation."
999 "(tell your hw vendor)\n");
1001 smpboot_clear_io_apic();
1002 arch_disable_smp_support();
1006 verify_local_APIC();
1009 * If SMP should be disabled, then really disable it!
1012 printk(KERN_INFO "SMP mode deactivated.\n");
1013 smpboot_clear_io_apic();
1015 localise_nmi_watchdog();
1019 end_local_APIC_setup();
1026 static void __init smp_cpu_index_default(void)
1029 struct cpuinfo_x86 *c;
1031 for_each_possible_cpu(i) {
1033 /* mark all to hotplug */
1034 c->cpu_index = nr_cpu_ids;
1039 * Prepare for SMP bootup. The MP table or ACPI has been read
1040 * earlier. Just do some sanity checking here and enable APIC mode.
1042 void __init native_smp_prepare_cpus(unsigned int max_cpus)
1047 smp_cpu_index_default();
1048 current_cpu_data = boot_cpu_data;
1049 cpumask_copy(cpu_callin_mask, cpumask_of(0));
1052 * Setup boot CPU information
1054 smp_store_cpu_info(0); /* Final full version of the data */
1055 #ifdef CONFIG_X86_32
1056 boot_cpu_logical_apicid = logical_smp_processor_id();
1058 current_thread_info()->cpu = 0; /* needed? */
1059 for_each_possible_cpu(i) {
1060 alloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
1061 alloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
1062 alloc_cpumask_var(&cpu_data(i).llc_shared_map, GFP_KERNEL);
1063 cpumask_clear(per_cpu(cpu_core_map, i));
1064 cpumask_clear(per_cpu(cpu_sibling_map, i));
1065 cpumask_clear(cpu_data(i).llc_shared_map);
1067 set_cpu_sibling_map(0);
1070 #ifdef CONFIG_X86_64
1071 default_setup_apic_routing();
1074 if (smp_sanity_check(max_cpus) < 0) {
1075 printk(KERN_INFO "SMP disabled\n");
1081 if (read_apic_id() != boot_cpu_physical_apicid) {
1082 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1083 read_apic_id(), boot_cpu_physical_apicid);
1084 /* Or can we switch back to PIC here? */
1091 * Switch from PIC to APIC mode.
1096 * Enable IO APIC before setting up error vector
1098 if (!skip_ioapic_setup && nr_ioapics)
1101 end_local_APIC_setup();
1103 map_cpu_to_logical_apicid();
1105 if (apic->setup_portio_remap)
1106 apic->setup_portio_remap();
1108 smpboot_setup_io_apic();
1110 * Set up local APIC timer on boot CPU.
1113 printk(KERN_INFO "CPU%d: ", 0);
1114 print_cpu_info(&cpu_data(0));
1123 * Early setup to make printk work.
1125 void __init native_smp_prepare_boot_cpu(void)
1127 int me = smp_processor_id();
1128 switch_to_new_gdt(me);
1129 /* already set me in cpu_online_mask in boot_cpu_init() */
1130 cpumask_set_cpu(me, cpu_callout_mask);
1131 per_cpu(cpu_state, me) = CPU_ONLINE;
1134 void __init native_smp_cpus_done(unsigned int max_cpus)
1136 pr_debug("Boot done.\n");
1139 #ifdef CONFIG_X86_IO_APIC
1140 setup_ioapic_dest();
1142 check_nmi_watchdog();
1145 static int __initdata setup_possible_cpus = -1;
1146 static int __init _setup_possible_cpus(char *str)
1148 get_option(&str, &setup_possible_cpus);
1151 early_param("possible_cpus", _setup_possible_cpus);
1155 * cpu_possible_mask should be static, it cannot change as cpu's
1156 * are onlined, or offlined. The reason is per-cpu data-structures
1157 * are allocated by some modules at init time, and dont expect to
1158 * do this dynamically on cpu arrival/departure.
1159 * cpu_present_mask on the other hand can change dynamically.
1160 * In case when cpu_hotplug is not compiled, then we resort to current
1161 * behaviour, which is cpu_possible == cpu_present.
1164 * Three ways to find out the number of additional hotplug CPUs:
1165 * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
1166 * - The user can overwrite it with possible_cpus=NUM
1167 * - Otherwise don't reserve additional CPUs.
1168 * We do this because additional CPUs waste a lot of memory.
1171 __init void prefill_possible_map(void)
1175 /* no processor from mptable or madt */
1176 if (!num_processors)
1179 if (setup_possible_cpus == -1)
1180 possible = num_processors + disabled_cpus;
1182 possible = setup_possible_cpus;
1184 total_cpus = max_t(int, possible, num_processors + disabled_cpus);
1186 if (possible > CONFIG_NR_CPUS) {
1188 "%d Processors exceeds NR_CPUS limit of %d\n",
1189 possible, CONFIG_NR_CPUS);
1190 possible = CONFIG_NR_CPUS;
1193 printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
1194 possible, max_t(int, possible - num_processors, 0));
1196 for (i = 0; i < possible; i++)
1197 set_cpu_possible(i, true);
1199 nr_cpu_ids = possible;
1202 #ifdef CONFIG_HOTPLUG_CPU
1204 static void remove_siblinginfo(int cpu)
1207 struct cpuinfo_x86 *c = &cpu_data(cpu);
1209 for_each_cpu(sibling, cpu_core_mask(cpu)) {
1210 cpumask_clear_cpu(cpu, cpu_core_mask(sibling));
1212 * last thread sibling in this cpu core going down
1214 if (cpumask_weight(cpu_sibling_mask(cpu)) == 1)
1215 cpu_data(sibling).booted_cores--;
1218 for_each_cpu(sibling, cpu_sibling_mask(cpu))
1219 cpumask_clear_cpu(cpu, cpu_sibling_mask(sibling));
1220 cpumask_clear(cpu_sibling_mask(cpu));
1221 cpumask_clear(cpu_core_mask(cpu));
1222 c->phys_proc_id = 0;
1224 cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
1227 static void __ref remove_cpu_from_maps(int cpu)
1229 set_cpu_online(cpu, false);
1230 cpumask_clear_cpu(cpu, cpu_callout_mask);
1231 cpumask_clear_cpu(cpu, cpu_callin_mask);
1232 /* was set by cpu_init() */
1233 cpumask_clear_cpu(cpu, cpu_initialized_mask);
1234 numa_remove_cpu(cpu);
1237 void cpu_disable_common(void)
1239 int cpu = smp_processor_id();
1242 * Allow any queued timer interrupts to get serviced
1243 * This is only a temporary solution until we cleanup
1244 * fixup_irqs as we do for IA64.
1249 local_irq_disable();
1250 remove_siblinginfo(cpu);
1252 /* It's now safe to remove this processor from the online map */
1254 remove_cpu_from_maps(cpu);
1255 unlock_vector_lock();
1259 int native_cpu_disable(void)
1261 int cpu = smp_processor_id();
1264 * Perhaps use cpufreq to drop frequency, but that could go
1265 * into generic code.
1267 * We won't take down the boot processor on i386 due to some
1268 * interrupts only being able to be serviced by the BSP.
1269 * Especially so if we're not using an IOAPIC -zwane
1274 if (nmi_watchdog == NMI_LOCAL_APIC)
1275 stop_apic_nmi_watchdog(NULL);
1278 cpu_disable_common();
1282 void native_cpu_die(unsigned int cpu)
1284 /* We don't do anything here: idle task is faking death itself. */
1287 for (i = 0; i < 10; i++) {
1288 /* They ack this in play_dead by setting CPU_DEAD */
1289 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
1290 printk(KERN_INFO "CPU %d is now offline\n", cpu);
1291 if (1 == num_online_cpus())
1292 alternatives_smp_switch(0);
1297 printk(KERN_ERR "CPU %u didn't die...\n", cpu);
1300 void play_dead_common(void)
1303 reset_lazy_tlbstate();
1304 irq_ctx_exit(raw_smp_processor_id());
1305 c1e_remove_cpu(raw_smp_processor_id());
1309 __get_cpu_var(cpu_state) = CPU_DEAD;
1312 * With physical CPU hotplug, we should halt the cpu
1314 local_irq_disable();
1317 void native_play_dead(void)
1323 #else /* ... !CONFIG_HOTPLUG_CPU */
1324 int native_cpu_disable(void)
1329 void native_cpu_die(unsigned int cpu)
1331 /* We said "no" in __cpu_disable */
1335 void native_play_dead(void)