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>
50 #include <linux/tboot.h>
51 #include <linux/stackprotector.h>
52 #include <linux/gfp.h>
59 #include <asm/trampoline.h>
62 #include <asm/pgtable.h>
63 #include <asm/tlbflush.h>
65 #include <asm/mwait.h>
67 #include <asm/io_apic.h>
68 #include <asm/setup.h>
69 #include <asm/uv/uv.h>
70 #include <linux/mc146818rtc.h>
72 #include <asm/smpboot_hooks.h>
73 #include <asm/i8259.h>
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))
92 * We need this for trampoline_base protection from concurrent accesses when
93 * off- and onlining cores wildly.
95 static DEFINE_MUTEX(x86_cpu_hotplug_driver_mutex);
97 void cpu_hotplug_driver_lock(void)
99 mutex_lock(&x86_cpu_hotplug_driver_mutex);
102 void cpu_hotplug_driver_unlock(void)
104 mutex_unlock(&x86_cpu_hotplug_driver_mutex);
107 ssize_t arch_cpu_probe(const char *buf, size_t count) { return -1; }
108 ssize_t arch_cpu_release(const char *buf, size_t count) { return -1; }
110 static struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
111 #define get_idle_for_cpu(x) (idle_thread_array[(x)])
112 #define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p))
115 /* Number of siblings per CPU package */
116 int smp_num_siblings = 1;
117 EXPORT_SYMBOL(smp_num_siblings);
119 /* Last level cache ID of each logical CPU */
120 DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
122 /* representing HT siblings of each logical CPU */
123 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
124 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
126 /* representing HT and core siblings of each logical CPU */
127 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
128 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
130 DEFINE_PER_CPU(cpumask_var_t, cpu_llc_shared_map);
132 /* Per CPU bogomips and other parameters */
133 DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
134 EXPORT_PER_CPU_SYMBOL(cpu_info);
136 atomic_t init_deasserted;
139 * Report back to the Boot Processor.
142 static void __cpuinit smp_callin(void)
145 unsigned long timeout;
148 * If waken up by an INIT in an 82489DX configuration
149 * we may get here before an INIT-deassert IPI reaches
150 * our local APIC. We have to wait for the IPI or we'll
151 * lock up on an APIC access.
153 if (apic->wait_for_init_deassert)
154 apic->wait_for_init_deassert(&init_deasserted);
157 * (This works even if the APIC is not enabled.)
159 phys_id = read_apic_id();
160 cpuid = smp_processor_id();
161 if (cpumask_test_cpu(cpuid, cpu_callin_mask)) {
162 panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__,
165 pr_debug("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
168 * STARTUP IPIs are fragile beasts as they might sometimes
169 * trigger some glue motherboard logic. Complete APIC bus
170 * silence for 1 second, this overestimates the time the
171 * boot CPU is spending to send the up to 2 STARTUP IPIs
172 * by a factor of two. This should be enough.
176 * Waiting 2s total for startup (udelay is not yet working)
178 timeout = jiffies + 2*HZ;
179 while (time_before(jiffies, timeout)) {
181 * Has the boot CPU finished it's STARTUP sequence?
183 if (cpumask_test_cpu(cpuid, cpu_callout_mask))
188 if (!time_before(jiffies, timeout)) {
189 panic("%s: CPU%d started up but did not get a callout!\n",
194 * the boot CPU has finished the init stage and is spinning
195 * on callin_map until we finish. We are free to set up this
196 * CPU, first the APIC. (this is probably redundant on most
200 pr_debug("CALLIN, before setup_local_APIC().\n");
201 if (apic->smp_callin_clear_local_apic)
202 apic->smp_callin_clear_local_apic();
204 end_local_APIC_setup();
207 * Need to setup vector mappings before we enable interrupts.
209 setup_vector_irq(smp_processor_id());
212 * Save our processor parameters. Note: this information
213 * is needed for clock calibration.
215 smp_store_cpu_info(cpuid);
219 * Update loops_per_jiffy in cpu_data. Previous call to
220 * smp_store_cpu_info() stored a value that is close but not as
221 * accurate as the value just calculated.
223 * Need to enable IRQs because it can take longer and then
224 * the NMI watchdog might kill us.
228 cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy;
230 pr_debug("Stack at about %p\n", &cpuid);
233 * This must be done before setting cpu_online_mask
234 * or calling notify_cpu_starting.
236 set_cpu_sibling_map(raw_smp_processor_id());
239 notify_cpu_starting(cpuid);
242 * Allow the master to continue.
244 cpumask_set_cpu(cpuid, cpu_callin_mask);
248 * Activate a secondary processor.
250 notrace static void __cpuinit start_secondary(void *unused)
253 * Don't put *anything* before cpu_init(), SMP booting is too
254 * fragile that we want to limit the things done here to the
255 * most necessary things.
262 /* switch away from the initial page table */
263 load_cr3(swapper_pg_dir);
267 /* otherwise gcc will move up smp_processor_id before the cpu_init */
270 * Check TSC synchronization with the BP:
272 check_tsc_sync_target();
275 * We need to hold call_lock, so there is no inconsistency
276 * between the time smp_call_function() determines number of
277 * IPI recipients, and the time when the determination is made
278 * for which cpus receive the IPI. Holding this
279 * lock helps us to not include this cpu in a currently in progress
280 * smp_call_function().
282 * We need to hold vector_lock so there the set of online cpus
283 * does not change while we are assigning vectors to cpus. Holding
284 * this lock ensures we don't half assign or remove an irq from a cpu.
288 set_cpu_online(smp_processor_id(), true);
289 unlock_vector_lock();
291 per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
292 x86_platform.nmi_init();
294 /* enable local interrupts */
297 /* to prevent fake stack check failure in clock setup */
298 boot_init_stack_canary();
300 x86_cpuinit.setup_percpu_clockev();
307 * The bootstrap kernel entry code has set these up. Save them for
311 void __cpuinit smp_store_cpu_info(int id)
313 struct cpuinfo_x86 *c = &cpu_data(id);
318 identify_secondary_cpu(c);
321 static void __cpuinit link_thread_siblings(int cpu1, int cpu2)
323 cpumask_set_cpu(cpu1, cpu_sibling_mask(cpu2));
324 cpumask_set_cpu(cpu2, cpu_sibling_mask(cpu1));
325 cpumask_set_cpu(cpu1, cpu_core_mask(cpu2));
326 cpumask_set_cpu(cpu2, cpu_core_mask(cpu1));
327 cpumask_set_cpu(cpu1, cpu_llc_shared_mask(cpu2));
328 cpumask_set_cpu(cpu2, cpu_llc_shared_mask(cpu1));
332 void __cpuinit set_cpu_sibling_map(int cpu)
335 struct cpuinfo_x86 *c = &cpu_data(cpu);
337 cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
339 if (smp_num_siblings > 1) {
340 for_each_cpu(i, cpu_sibling_setup_mask) {
341 struct cpuinfo_x86 *o = &cpu_data(i);
343 if (cpu_has(c, X86_FEATURE_TOPOEXT)) {
344 if (c->phys_proc_id == o->phys_proc_id &&
345 per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i) &&
346 c->compute_unit_id == o->compute_unit_id)
347 link_thread_siblings(cpu, i);
348 } else if (c->phys_proc_id == o->phys_proc_id &&
349 c->cpu_core_id == o->cpu_core_id) {
350 link_thread_siblings(cpu, i);
354 cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
357 cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu));
359 if (__this_cpu_read(cpu_info.x86_max_cores) == 1) {
360 cpumask_copy(cpu_core_mask(cpu), cpu_sibling_mask(cpu));
365 for_each_cpu(i, cpu_sibling_setup_mask) {
366 if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
367 per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
368 cpumask_set_cpu(i, cpu_llc_shared_mask(cpu));
369 cpumask_set_cpu(cpu, cpu_llc_shared_mask(i));
371 if (c->phys_proc_id == cpu_data(i).phys_proc_id) {
372 cpumask_set_cpu(i, cpu_core_mask(cpu));
373 cpumask_set_cpu(cpu, cpu_core_mask(i));
375 * Does this new cpu bringup a new core?
377 if (cpumask_weight(cpu_sibling_mask(cpu)) == 1) {
379 * for each core in package, increment
380 * the booted_cores for this new cpu
382 if (cpumask_first(cpu_sibling_mask(i)) == i)
385 * increment the core count for all
386 * the other cpus in this package
389 cpu_data(i).booted_cores++;
390 } else if (i != cpu && !c->booted_cores)
391 c->booted_cores = cpu_data(i).booted_cores;
396 /* maps the cpu to the sched domain representing multi-core */
397 const struct cpumask *cpu_coregroup_mask(int cpu)
399 struct cpuinfo_x86 *c = &cpu_data(cpu);
401 * For perf, we return last level cache shared map.
402 * And for power savings, we return cpu_core_map
404 if ((sched_mc_power_savings || sched_smt_power_savings) &&
405 !(cpu_has(c, X86_FEATURE_AMD_DCM)))
406 return cpu_core_mask(cpu);
408 return cpu_llc_shared_mask(cpu);
411 static void impress_friends(void)
414 unsigned long bogosum = 0;
416 * Allow the user to impress friends.
418 pr_debug("Before bogomips.\n");
419 for_each_possible_cpu(cpu)
420 if (cpumask_test_cpu(cpu, cpu_callout_mask))
421 bogosum += cpu_data(cpu).loops_per_jiffy;
423 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
426 (bogosum/(5000/HZ))%100);
428 pr_debug("Before bogocount - setting activated=1.\n");
431 void __inquire_remote_apic(int apicid)
433 unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
434 const char * const names[] = { "ID", "VERSION", "SPIV" };
438 printk(KERN_INFO "Inquiring remote APIC 0x%x...\n", apicid);
440 for (i = 0; i < ARRAY_SIZE(regs); i++) {
441 printk(KERN_INFO "... APIC 0x%x %s: ", apicid, names[i]);
446 status = safe_apic_wait_icr_idle();
449 "a previous APIC delivery may have failed\n");
451 apic_icr_write(APIC_DM_REMRD | regs[i], apicid);
456 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
457 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
460 case APIC_ICR_RR_VALID:
461 status = apic_read(APIC_RRR);
462 printk(KERN_CONT "%08x\n", status);
465 printk(KERN_CONT "failed\n");
471 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
472 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
473 * won't ... remember to clear down the APIC, etc later.
476 wakeup_secondary_cpu_via_nmi(int logical_apicid, unsigned long start_eip)
478 unsigned long send_status, accept_status = 0;
482 /* Boot on the stack */
483 /* Kick the second */
484 apic_icr_write(APIC_DM_NMI | apic->dest_logical, logical_apicid);
486 pr_debug("Waiting for send to finish...\n");
487 send_status = safe_apic_wait_icr_idle();
490 * Give the other CPU some time to accept the IPI.
493 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
494 maxlvt = lapic_get_maxlvt();
495 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
496 apic_write(APIC_ESR, 0);
497 accept_status = (apic_read(APIC_ESR) & 0xEF);
499 pr_debug("NMI sent.\n");
502 printk(KERN_ERR "APIC never delivered???\n");
504 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
506 return (send_status | accept_status);
510 wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
512 unsigned long send_status, accept_status = 0;
513 int maxlvt, num_starts, j;
515 maxlvt = lapic_get_maxlvt();
518 * Be paranoid about clearing APIC errors.
520 if (APIC_INTEGRATED(apic_version[phys_apicid])) {
521 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
522 apic_write(APIC_ESR, 0);
526 pr_debug("Asserting INIT.\n");
529 * Turn INIT on target chip
534 apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT,
537 pr_debug("Waiting for send to finish...\n");
538 send_status = safe_apic_wait_icr_idle();
542 pr_debug("Deasserting INIT.\n");
546 apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid);
548 pr_debug("Waiting for send to finish...\n");
549 send_status = safe_apic_wait_icr_idle();
552 atomic_set(&init_deasserted, 1);
555 * Should we send STARTUP IPIs ?
557 * Determine this based on the APIC version.
558 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
560 if (APIC_INTEGRATED(apic_version[phys_apicid]))
566 * Paravirt / VMI wants a startup IPI hook here to set up the
567 * target processor state.
569 startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
573 * Run STARTUP IPI loop.
575 pr_debug("#startup loops: %d.\n", num_starts);
577 for (j = 1; j <= num_starts; j++) {
578 pr_debug("Sending STARTUP #%d.\n", j);
579 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
580 apic_write(APIC_ESR, 0);
582 pr_debug("After apic_write.\n");
589 /* Boot on the stack */
590 /* Kick the second */
591 apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12),
595 * Give the other CPU some time to accept the IPI.
599 pr_debug("Startup point 1.\n");
601 pr_debug("Waiting for send to finish...\n");
602 send_status = safe_apic_wait_icr_idle();
605 * Give the other CPU some time to accept the IPI.
608 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
609 apic_write(APIC_ESR, 0);
610 accept_status = (apic_read(APIC_ESR) & 0xEF);
611 if (send_status || accept_status)
614 pr_debug("After Startup.\n");
617 printk(KERN_ERR "APIC never delivered???\n");
619 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
621 return (send_status | accept_status);
625 struct work_struct work;
626 struct task_struct *idle;
627 struct completion done;
631 static void __cpuinit do_fork_idle(struct work_struct *work)
633 struct create_idle *c_idle =
634 container_of(work, struct create_idle, work);
636 c_idle->idle = fork_idle(c_idle->cpu);
637 complete(&c_idle->done);
640 /* reduce the number of lines printed when booting a large cpu count system */
641 static void __cpuinit announce_cpu(int cpu, int apicid)
643 static int current_node = -1;
644 int node = early_cpu_to_node(cpu);
646 if (system_state == SYSTEM_BOOTING) {
647 if (node != current_node) {
648 if (current_node > (-1))
651 pr_info("Booting Node %3d, Processors ", node);
653 pr_cont(" #%d%s", cpu, cpu == (nr_cpu_ids - 1) ? " Ok.\n" : "");
656 pr_info("Booting Node %d Processor %d APIC 0x%x\n",
661 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
662 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
663 * Returns zero if CPU booted OK, else error code from
664 * ->wakeup_secondary_cpu.
666 static int __cpuinit do_boot_cpu(int apicid, int cpu)
668 unsigned long boot_error = 0;
669 unsigned long start_ip;
671 struct create_idle c_idle = {
673 .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
676 INIT_WORK_ONSTACK(&c_idle.work, do_fork_idle);
678 alternatives_smp_switch(1);
680 c_idle.idle = get_idle_for_cpu(cpu);
683 * We can't use kernel_thread since we must avoid to
684 * reschedule the child.
687 c_idle.idle->thread.sp = (unsigned long) (((struct pt_regs *)
688 (THREAD_SIZE + task_stack_page(c_idle.idle))) - 1);
689 init_idle(c_idle.idle, cpu);
693 schedule_work(&c_idle.work);
694 wait_for_completion(&c_idle.done);
696 if (IS_ERR(c_idle.idle)) {
697 printk("failed fork for CPU %d\n", cpu);
698 destroy_work_on_stack(&c_idle.work);
699 return PTR_ERR(c_idle.idle);
702 set_idle_for_cpu(cpu, c_idle.idle);
704 per_cpu(current_task, cpu) = c_idle.idle;
706 /* Stack for startup_32 can be just as for start_secondary onwards */
709 clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
710 initial_gs = per_cpu_offset(cpu);
711 per_cpu(kernel_stack, cpu) =
712 (unsigned long)task_stack_page(c_idle.idle) -
713 KERNEL_STACK_OFFSET + THREAD_SIZE;
715 early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
716 initial_code = (unsigned long)start_secondary;
717 stack_start = c_idle.idle->thread.sp;
719 /* start_ip had better be page-aligned! */
720 start_ip = trampoline_address();
722 /* So we see what's up */
723 announce_cpu(cpu, apicid);
726 * This grunge runs the startup process for
727 * the targeted processor.
730 printk(KERN_DEBUG "smpboot cpu %d: start_ip = %lx\n", cpu, start_ip);
732 atomic_set(&init_deasserted, 0);
734 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
736 pr_debug("Setting warm reset code and vector.\n");
738 smpboot_setup_warm_reset_vector(start_ip);
740 * Be paranoid about clearing APIC errors.
742 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
743 apic_write(APIC_ESR, 0);
749 * Kick the secondary CPU. Use the method in the APIC driver
750 * if it's defined - or use an INIT boot APIC message otherwise:
752 if (apic->wakeup_secondary_cpu)
753 boot_error = apic->wakeup_secondary_cpu(apicid, start_ip);
755 boot_error = wakeup_secondary_cpu_via_init(apicid, start_ip);
759 * allow APs to start initializing.
761 pr_debug("Before Callout %d.\n", cpu);
762 cpumask_set_cpu(cpu, cpu_callout_mask);
763 pr_debug("After Callout %d.\n", cpu);
766 * Wait 5s total for a response
768 for (timeout = 0; timeout < 50000; timeout++) {
769 if (cpumask_test_cpu(cpu, cpu_callin_mask))
770 break; /* It has booted */
773 * Allow other tasks to run while we wait for the
774 * AP to come online. This also gives a chance
775 * for the MTRR work(triggered by the AP coming online)
776 * to be completed in the stop machine context.
781 if (cpumask_test_cpu(cpu, cpu_callin_mask))
782 pr_debug("CPU%d: has booted.\n", cpu);
785 if (*(volatile u32 *)TRAMPOLINE_SYM(trampoline_status)
787 /* trampoline started but...? */
788 pr_err("CPU%d: Stuck ??\n", cpu);
790 /* trampoline code not run */
791 pr_err("CPU%d: Not responding.\n", cpu);
792 if (apic->inquire_remote_apic)
793 apic->inquire_remote_apic(apicid);
798 /* Try to put things back the way they were before ... */
799 numa_remove_cpu(cpu); /* was set by numa_add_cpu */
801 /* was set by do_boot_cpu() */
802 cpumask_clear_cpu(cpu, cpu_callout_mask);
804 /* was set by cpu_init() */
805 cpumask_clear_cpu(cpu, cpu_initialized_mask);
807 set_cpu_present(cpu, false);
808 per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
811 /* mark "stuck" area as not stuck */
812 *(volatile u32 *)TRAMPOLINE_SYM(trampoline_status) = 0;
814 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
816 * Cleanup possible dangling ends...
818 smpboot_restore_warm_reset_vector();
821 destroy_work_on_stack(&c_idle.work);
825 int __cpuinit native_cpu_up(unsigned int cpu)
827 int apicid = apic->cpu_present_to_apicid(cpu);
831 WARN_ON(irqs_disabled());
833 pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);
835 if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
836 !physid_isset(apicid, phys_cpu_present_map) ||
837 (!x2apic_mode && apicid >= 255)) {
838 printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
843 * Already booted CPU?
845 if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
846 pr_debug("do_boot_cpu %d Already started\n", cpu);
851 * Save current MTRR state in case it was changed since early boot
852 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
856 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
858 err = do_boot_cpu(apicid, cpu);
860 pr_debug("do_boot_cpu failed %d\n", err);
865 * Check TSC synchronization with the AP (keep irqs disabled
868 local_irq_save(flags);
869 check_tsc_sync_source(cpu);
870 local_irq_restore(flags);
872 while (!cpu_online(cpu)) {
874 touch_nmi_watchdog();
881 * arch_disable_smp_support() - disables SMP support for x86 at runtime
883 void arch_disable_smp_support(void)
885 disable_ioapic_support();
889 * Fall back to non SMP mode after errors.
891 * RED-PEN audit/test this more. I bet there is more state messed up here.
893 static __init void disable_smp(void)
895 init_cpu_present(cpumask_of(0));
896 init_cpu_possible(cpumask_of(0));
897 smpboot_clear_io_apic_irqs();
899 if (smp_found_config)
900 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
902 physid_set_mask_of_physid(0, &phys_cpu_present_map);
903 cpumask_set_cpu(0, cpu_sibling_mask(0));
904 cpumask_set_cpu(0, cpu_core_mask(0));
908 * Various sanity checks.
910 static int __init smp_sanity_check(unsigned max_cpus)
914 #if !defined(CONFIG_X86_BIGSMP) && defined(CONFIG_X86_32)
915 if (def_to_bigsmp && nr_cpu_ids > 8) {
920 "More than 8 CPUs detected - skipping them.\n"
921 "Use CONFIG_X86_BIGSMP.\n");
924 for_each_present_cpu(cpu) {
926 set_cpu_present(cpu, false);
931 for_each_possible_cpu(cpu) {
933 set_cpu_possible(cpu, false);
941 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
943 "weird, boot CPU (#%d) not listed by the BIOS.\n",
944 hard_smp_processor_id());
946 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
950 * If we couldn't find an SMP configuration at boot time,
951 * get out of here now!
953 if (!smp_found_config && !acpi_lapic) {
955 printk(KERN_NOTICE "SMP motherboard not detected.\n");
957 if (APIC_init_uniprocessor())
958 printk(KERN_NOTICE "Local APIC not detected."
959 " Using dummy APIC emulation.\n");
964 * Should not be necessary because the MP table should list the boot
965 * CPU too, but we do it for the sake of robustness anyway.
967 if (!apic->check_phys_apicid_present(boot_cpu_physical_apicid)) {
969 "weird, boot CPU (#%d) not listed by the BIOS.\n",
970 boot_cpu_physical_apicid);
971 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
976 * If we couldn't find a local APIC, then get out of here now!
978 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
981 pr_err("BIOS bug, local APIC #%d not detected!...\n",
982 boot_cpu_physical_apicid);
983 pr_err("... forcing use of dummy APIC emulation."
984 "(tell your hw vendor)\n");
986 smpboot_clear_io_apic();
987 disable_ioapic_support();
994 * If SMP should be disabled, then really disable it!
997 printk(KERN_INFO "SMP mode deactivated.\n");
998 smpboot_clear_io_apic();
1002 bsp_end_local_APIC_setup();
1009 static void __init smp_cpu_index_default(void)
1012 struct cpuinfo_x86 *c;
1014 for_each_possible_cpu(i) {
1016 /* mark all to hotplug */
1017 c->cpu_index = nr_cpu_ids;
1022 * Prepare for SMP bootup. The MP table or ACPI has been read
1023 * earlier. Just do some sanity checking here and enable APIC mode.
1025 void __init native_smp_prepare_cpus(unsigned int max_cpus)
1030 smp_cpu_index_default();
1033 * Setup boot CPU information
1035 smp_store_cpu_info(0); /* Final full version of the data */
1036 cpumask_copy(cpu_callin_mask, cpumask_of(0));
1039 current_thread_info()->cpu = 0; /* needed? */
1040 for_each_possible_cpu(i) {
1041 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
1042 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
1043 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
1045 set_cpu_sibling_map(0);
1048 if (smp_sanity_check(max_cpus) < 0) {
1049 printk(KERN_INFO "SMP disabled\n");
1054 default_setup_apic_routing();
1057 if (read_apic_id() != boot_cpu_physical_apicid) {
1058 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1059 read_apic_id(), boot_cpu_physical_apicid);
1060 /* Or can we switch back to PIC here? */
1067 * Switch from PIC to APIC mode.
1072 * Enable IO APIC before setting up error vector
1074 if (!skip_ioapic_setup && nr_ioapics)
1077 bsp_end_local_APIC_setup();
1079 if (apic->setup_portio_remap)
1080 apic->setup_portio_remap();
1082 smpboot_setup_io_apic();
1084 * Set up local APIC timer on boot CPU.
1087 printk(KERN_INFO "CPU%d: ", 0);
1088 print_cpu_info(&cpu_data(0));
1089 x86_init.timers.setup_percpu_clockev();
1094 set_mtrr_aps_delayed_init();
1099 void arch_disable_nonboot_cpus_begin(void)
1102 * Avoid the smp alternatives switch during the disable_nonboot_cpus().
1103 * In the suspend path, we will be back in the SMP mode shortly anyways.
1105 skip_smp_alternatives = true;
1108 void arch_disable_nonboot_cpus_end(void)
1110 skip_smp_alternatives = false;
1113 void arch_enable_nonboot_cpus_begin(void)
1115 set_mtrr_aps_delayed_init();
1118 void arch_enable_nonboot_cpus_end(void)
1124 * Early setup to make printk work.
1126 void __init native_smp_prepare_boot_cpu(void)
1128 int me = smp_processor_id();
1129 switch_to_new_gdt(me);
1130 /* already set me in cpu_online_mask in boot_cpu_init() */
1131 cpumask_set_cpu(me, cpu_callout_mask);
1132 per_cpu(cpu_state, me) = CPU_ONLINE;
1135 void __init native_smp_cpus_done(unsigned int max_cpus)
1137 pr_debug("Boot done.\n");
1141 #ifdef CONFIG_X86_IO_APIC
1142 setup_ioapic_dest();
1147 static int __initdata setup_possible_cpus = -1;
1148 static int __init _setup_possible_cpus(char *str)
1150 get_option(&str, &setup_possible_cpus);
1153 early_param("possible_cpus", _setup_possible_cpus);
1157 * cpu_possible_mask should be static, it cannot change as cpu's
1158 * are onlined, or offlined. The reason is per-cpu data-structures
1159 * are allocated by some modules at init time, and dont expect to
1160 * do this dynamically on cpu arrival/departure.
1161 * cpu_present_mask on the other hand can change dynamically.
1162 * In case when cpu_hotplug is not compiled, then we resort to current
1163 * behaviour, which is cpu_possible == cpu_present.
1166 * Three ways to find out the number of additional hotplug CPUs:
1167 * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
1168 * - The user can overwrite it with possible_cpus=NUM
1169 * - Otherwise don't reserve additional CPUs.
1170 * We do this because additional CPUs waste a lot of memory.
1173 __init void prefill_possible_map(void)
1177 /* no processor from mptable or madt */
1178 if (!num_processors)
1181 i = setup_max_cpus ?: 1;
1182 if (setup_possible_cpus == -1) {
1183 possible = num_processors;
1184 #ifdef CONFIG_HOTPLUG_CPU
1186 possible += disabled_cpus;
1192 possible = setup_possible_cpus;
1194 total_cpus = max_t(int, possible, num_processors + disabled_cpus);
1196 /* nr_cpu_ids could be reduced via nr_cpus= */
1197 if (possible > nr_cpu_ids) {
1199 "%d Processors exceeds NR_CPUS limit of %d\n",
1200 possible, nr_cpu_ids);
1201 possible = nr_cpu_ids;
1204 #ifdef CONFIG_HOTPLUG_CPU
1205 if (!setup_max_cpus)
1209 "%d Processors exceeds max_cpus limit of %u\n",
1210 possible, setup_max_cpus);
1214 printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
1215 possible, max_t(int, possible - num_processors, 0));
1217 for (i = 0; i < possible; i++)
1218 set_cpu_possible(i, true);
1219 for (; i < NR_CPUS; i++)
1220 set_cpu_possible(i, false);
1222 nr_cpu_ids = possible;
1225 #ifdef CONFIG_HOTPLUG_CPU
1227 static void remove_siblinginfo(int cpu)
1230 struct cpuinfo_x86 *c = &cpu_data(cpu);
1232 for_each_cpu(sibling, cpu_core_mask(cpu)) {
1233 cpumask_clear_cpu(cpu, cpu_core_mask(sibling));
1235 * last thread sibling in this cpu core going down
1237 if (cpumask_weight(cpu_sibling_mask(cpu)) == 1)
1238 cpu_data(sibling).booted_cores--;
1241 for_each_cpu(sibling, cpu_sibling_mask(cpu))
1242 cpumask_clear_cpu(cpu, cpu_sibling_mask(sibling));
1243 cpumask_clear(cpu_sibling_mask(cpu));
1244 cpumask_clear(cpu_core_mask(cpu));
1245 c->phys_proc_id = 0;
1247 cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
1250 static void __ref remove_cpu_from_maps(int cpu)
1252 set_cpu_online(cpu, false);
1253 cpumask_clear_cpu(cpu, cpu_callout_mask);
1254 cpumask_clear_cpu(cpu, cpu_callin_mask);
1255 /* was set by cpu_init() */
1256 cpumask_clear_cpu(cpu, cpu_initialized_mask);
1257 numa_remove_cpu(cpu);
1260 void cpu_disable_common(void)
1262 int cpu = smp_processor_id();
1264 remove_siblinginfo(cpu);
1266 /* It's now safe to remove this processor from the online map */
1268 remove_cpu_from_maps(cpu);
1269 unlock_vector_lock();
1273 int native_cpu_disable(void)
1275 int cpu = smp_processor_id();
1278 * Perhaps use cpufreq to drop frequency, but that could go
1279 * into generic code.
1281 * We won't take down the boot processor on i386 due to some
1282 * interrupts only being able to be serviced by the BSP.
1283 * Especially so if we're not using an IOAPIC -zwane
1290 cpu_disable_common();
1294 void native_cpu_die(unsigned int cpu)
1296 /* We don't do anything here: idle task is faking death itself. */
1299 for (i = 0; i < 10; i++) {
1300 /* They ack this in play_dead by setting CPU_DEAD */
1301 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
1302 if (system_state == SYSTEM_RUNNING)
1303 pr_info("CPU %u is now offline\n", cpu);
1305 if (1 == num_online_cpus())
1306 alternatives_smp_switch(0);
1311 pr_err("CPU %u didn't die...\n", cpu);
1314 void play_dead_common(void)
1317 reset_lazy_tlbstate();
1318 amd_e400_remove_cpu(raw_smp_processor_id());
1322 __this_cpu_write(cpu_state, CPU_DEAD);
1325 * With physical CPU hotplug, we should halt the cpu
1327 local_irq_disable();
1331 * We need to flush the caches before going to sleep, lest we have
1332 * dirty data in our caches when we come back up.
1334 static inline void mwait_play_dead(void)
1336 unsigned int eax, ebx, ecx, edx;
1337 unsigned int highest_cstate = 0;
1338 unsigned int highest_subcstate = 0;
1341 struct cpuinfo_x86 *c = __this_cpu_ptr(&cpu_info);
1343 if (!(this_cpu_has(X86_FEATURE_MWAIT) && mwait_usable(c)))
1345 if (!this_cpu_has(X86_FEATURE_CLFLSH))
1347 if (__this_cpu_read(cpu_info.cpuid_level) < CPUID_MWAIT_LEAF)
1350 eax = CPUID_MWAIT_LEAF;
1352 native_cpuid(&eax, &ebx, &ecx, &edx);
1355 * eax will be 0 if EDX enumeration is not valid.
1356 * Initialized below to cstate, sub_cstate value when EDX is valid.
1358 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED)) {
1361 edx >>= MWAIT_SUBSTATE_SIZE;
1362 for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
1363 if (edx & MWAIT_SUBSTATE_MASK) {
1365 highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
1368 eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
1369 (highest_subcstate - 1);
1373 * This should be a memory location in a cache line which is
1374 * unlikely to be touched by other processors. The actual
1375 * content is immaterial as it is not actually modified in any way.
1377 mwait_ptr = ¤t_thread_info()->flags;
1383 * The CLFLUSH is a workaround for erratum AAI65 for
1384 * the Xeon 7400 series. It's not clear it is actually
1385 * needed, but it should be harmless in either case.
1386 * The WBINVD is insufficient due to the spurious-wakeup
1387 * case where we return around the loop.
1390 __monitor(mwait_ptr, 0, 0);
1396 static inline void hlt_play_dead(void)
1398 if (__this_cpu_read(cpu_info.x86) >= 4)
1406 void native_play_dead(void)
1409 tboot_shutdown(TB_SHUTDOWN_WFS);
1411 mwait_play_dead(); /* Only returns on failure */
1415 #else /* ... !CONFIG_HOTPLUG_CPU */
1416 int native_cpu_disable(void)
1421 void native_cpu_die(unsigned int cpu)
1423 /* We said "no" in __cpu_disable */
1427 void native_play_dead(void)