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>
53 #include <linux/cpuidle.h>
60 #include <asm/realmode.h>
63 #include <asm/pgtable.h>
64 #include <asm/tlbflush.h>
66 #include <asm/mwait.h>
68 #include <asm/io_apic.h>
69 #include <asm/setup.h>
70 #include <asm/uv/uv.h>
71 #include <linux/mc146818rtc.h>
73 #include <asm/smpboot_hooks.h>
74 #include <asm/i8259.h>
76 #include <asm/realmode.h>
78 /* State of each CPU */
79 DEFINE_PER_CPU(int, cpu_state) = { 0 };
81 #ifdef CONFIG_HOTPLUG_CPU
83 * We need this for trampoline_base protection from concurrent accesses when
84 * off- and onlining cores wildly.
86 static DEFINE_MUTEX(x86_cpu_hotplug_driver_mutex);
88 void cpu_hotplug_driver_lock(void)
90 mutex_lock(&x86_cpu_hotplug_driver_mutex);
93 void cpu_hotplug_driver_unlock(void)
95 mutex_unlock(&x86_cpu_hotplug_driver_mutex);
98 ssize_t arch_cpu_probe(const char *buf, size_t count) { return -1; }
99 ssize_t arch_cpu_release(const char *buf, size_t count) { return -1; }
102 /* Number of siblings per CPU package */
103 int smp_num_siblings = 1;
104 EXPORT_SYMBOL(smp_num_siblings);
106 /* Last level cache ID of each logical CPU */
107 DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
109 /* representing HT siblings of each logical CPU */
110 DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map);
111 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
113 /* representing HT and core siblings of each logical CPU */
114 DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);
115 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
117 DEFINE_PER_CPU(cpumask_var_t, cpu_llc_shared_map);
119 /* Per CPU bogomips and other parameters */
120 DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
121 EXPORT_PER_CPU_SYMBOL(cpu_info);
123 atomic_t init_deasserted;
126 * Report back to the Boot Processor.
129 static void __cpuinit smp_callin(void)
132 unsigned long timeout;
135 * If waken up by an INIT in an 82489DX configuration
136 * we may get here before an INIT-deassert IPI reaches
137 * our local APIC. We have to wait for the IPI or we'll
138 * lock up on an APIC access.
140 if (apic->wait_for_init_deassert)
141 apic->wait_for_init_deassert(&init_deasserted);
144 * (This works even if the APIC is not enabled.)
146 phys_id = read_apic_id();
147 cpuid = smp_processor_id();
148 if (cpumask_test_cpu(cpuid, cpu_callin_mask)) {
149 panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__,
152 pr_debug("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
155 * STARTUP IPIs are fragile beasts as they might sometimes
156 * trigger some glue motherboard logic. Complete APIC bus
157 * silence for 1 second, this overestimates the time the
158 * boot CPU is spending to send the up to 2 STARTUP IPIs
159 * by a factor of two. This should be enough.
163 * Waiting 2s total for startup (udelay is not yet working)
165 timeout = jiffies + 2*HZ;
166 while (time_before(jiffies, timeout)) {
168 * Has the boot CPU finished it's STARTUP sequence?
170 if (cpumask_test_cpu(cpuid, cpu_callout_mask))
175 if (!time_before(jiffies, timeout)) {
176 panic("%s: CPU%d started up but did not get a callout!\n",
181 * the boot CPU has finished the init stage and is spinning
182 * on callin_map until we finish. We are free to set up this
183 * CPU, first the APIC. (this is probably redundant on most
187 pr_debug("CALLIN, before setup_local_APIC().\n");
188 if (apic->smp_callin_clear_local_apic)
189 apic->smp_callin_clear_local_apic();
191 end_local_APIC_setup();
194 * Need to setup vector mappings before we enable interrupts.
196 setup_vector_irq(smp_processor_id());
199 * Save our processor parameters. Note: this information
200 * is needed for clock calibration.
202 smp_store_cpu_info(cpuid);
206 * Update loops_per_jiffy in cpu_data. Previous call to
207 * smp_store_cpu_info() stored a value that is close but not as
208 * accurate as the value just calculated.
211 cpu_data(cpuid).loops_per_jiffy = loops_per_jiffy;
212 pr_debug("Stack at about %p\n", &cpuid);
215 * This must be done before setting cpu_online_mask
216 * or calling notify_cpu_starting.
218 set_cpu_sibling_map(raw_smp_processor_id());
221 notify_cpu_starting(cpuid);
224 * Allow the master to continue.
226 cpumask_set_cpu(cpuid, cpu_callin_mask);
230 * Activate a secondary processor.
232 notrace static void __cpuinit start_secondary(void *unused)
235 * Don't put *anything* before cpu_init(), SMP booting is too
236 * fragile that we want to limit the things done here to the
237 * most necessary things.
240 x86_cpuinit.early_percpu_clock_init();
245 /* switch away from the initial page table */
246 load_cr3(swapper_pg_dir);
250 /* otherwise gcc will move up smp_processor_id before the cpu_init */
253 * Check TSC synchronization with the BP:
255 check_tsc_sync_target();
258 * We need to hold call_lock, so there is no inconsistency
259 * between the time smp_call_function() determines number of
260 * IPI recipients, and the time when the determination is made
261 * for which cpus receive the IPI. Holding this
262 * lock helps us to not include this cpu in a currently in progress
263 * smp_call_function().
265 * We need to hold vector_lock so there the set of online cpus
266 * does not change while we are assigning vectors to cpus. Holding
267 * this lock ensures we don't half assign or remove an irq from a cpu.
271 set_cpu_online(smp_processor_id(), true);
272 unlock_vector_lock();
274 per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
275 x86_platform.nmi_init();
277 /* enable local interrupts */
280 /* to prevent fake stack check failure in clock setup */
281 boot_init_stack_canary();
283 x86_cpuinit.setup_percpu_clockev();
290 * The bootstrap kernel entry code has set these up. Save them for
294 void __cpuinit smp_store_cpu_info(int id)
296 struct cpuinfo_x86 *c = &cpu_data(id);
301 identify_secondary_cpu(c);
304 static bool __cpuinit
305 topology_sane(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o, const char *name)
307 int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
309 return !WARN_ONCE(cpu_to_node(cpu1) != cpu_to_node(cpu2),
310 "sched: CPU #%d's %s-sibling CPU #%d is not on the same node! "
311 "[node: %d != %d]. Ignoring dependency.\n",
312 cpu1, name, cpu2, cpu_to_node(cpu1), cpu_to_node(cpu2));
315 #define link_mask(_m, c1, c2) \
317 cpumask_set_cpu((c1), cpu_##_m##_mask(c2)); \
318 cpumask_set_cpu((c2), cpu_##_m##_mask(c1)); \
321 static bool __cpuinit match_smt(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
323 if (cpu_has(c, X86_FEATURE_TOPOEXT)) {
324 int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
326 if (c->phys_proc_id == o->phys_proc_id &&
327 per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2) &&
328 c->compute_unit_id == o->compute_unit_id)
329 return topology_sane(c, o, "smt");
331 } else if (c->phys_proc_id == o->phys_proc_id &&
332 c->cpu_core_id == o->cpu_core_id) {
333 return topology_sane(c, o, "smt");
339 static bool __cpuinit match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
341 int cpu1 = c->cpu_index, cpu2 = o->cpu_index;
343 if (per_cpu(cpu_llc_id, cpu1) != BAD_APICID &&
344 per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2))
345 return topology_sane(c, o, "llc");
350 static bool __cpuinit match_mc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
352 if (c->phys_proc_id == o->phys_proc_id)
353 return topology_sane(c, o, "mc");
358 void __cpuinit set_cpu_sibling_map(int cpu)
360 bool has_mc = boot_cpu_data.x86_max_cores > 1;
361 bool has_smt = smp_num_siblings > 1;
362 struct cpuinfo_x86 *c = &cpu_data(cpu);
363 struct cpuinfo_x86 *o;
366 cpumask_set_cpu(cpu, cpu_sibling_setup_mask);
368 if (!has_smt && !has_mc) {
369 cpumask_set_cpu(cpu, cpu_sibling_mask(cpu));
370 cpumask_set_cpu(cpu, cpu_llc_shared_mask(cpu));
371 cpumask_set_cpu(cpu, cpu_core_mask(cpu));
376 for_each_cpu(i, cpu_sibling_setup_mask) {
379 if ((i == cpu) || (has_smt && match_smt(c, o)))
380 link_mask(sibling, cpu, i);
382 if ((i == cpu) || (has_mc && match_llc(c, o)))
383 link_mask(llc_shared, cpu, i);
385 if ((i == cpu) || (has_mc && match_mc(c, o))) {
386 link_mask(core, cpu, i);
389 * Does this new cpu bringup a new core?
391 if (cpumask_weight(cpu_sibling_mask(cpu)) == 1) {
393 * for each core in package, increment
394 * the booted_cores for this new cpu
396 if (cpumask_first(cpu_sibling_mask(i)) == i)
399 * increment the core count for all
400 * the other cpus in this package
403 cpu_data(i).booted_cores++;
404 } else if (i != cpu && !c->booted_cores)
405 c->booted_cores = cpu_data(i).booted_cores;
410 /* maps the cpu to the sched domain representing multi-core */
411 const struct cpumask *cpu_coregroup_mask(int cpu)
413 return cpu_llc_shared_mask(cpu);
416 static void impress_friends(void)
419 unsigned long bogosum = 0;
421 * Allow the user to impress friends.
423 pr_debug("Before bogomips.\n");
424 for_each_possible_cpu(cpu)
425 if (cpumask_test_cpu(cpu, cpu_callout_mask))
426 bogosum += cpu_data(cpu).loops_per_jiffy;
428 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
431 (bogosum/(5000/HZ))%100);
433 pr_debug("Before bogocount - setting activated=1.\n");
436 void __inquire_remote_apic(int apicid)
438 unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
439 const char * const names[] = { "ID", "VERSION", "SPIV" };
443 printk(KERN_INFO "Inquiring remote APIC 0x%x...\n", apicid);
445 for (i = 0; i < ARRAY_SIZE(regs); i++) {
446 printk(KERN_INFO "... APIC 0x%x %s: ", apicid, names[i]);
451 status = safe_apic_wait_icr_idle();
454 "a previous APIC delivery may have failed\n");
456 apic_icr_write(APIC_DM_REMRD | regs[i], apicid);
461 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
462 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
465 case APIC_ICR_RR_VALID:
466 status = apic_read(APIC_RRR);
467 printk(KERN_CONT "%08x\n", status);
470 printk(KERN_CONT "failed\n");
476 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
477 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
478 * won't ... remember to clear down the APIC, etc later.
481 wakeup_secondary_cpu_via_nmi(int logical_apicid, unsigned long start_eip)
483 unsigned long send_status, accept_status = 0;
487 /* Boot on the stack */
488 /* Kick the second */
489 apic_icr_write(APIC_DM_NMI | apic->dest_logical, logical_apicid);
491 pr_debug("Waiting for send to finish...\n");
492 send_status = safe_apic_wait_icr_idle();
495 * Give the other CPU some time to accept the IPI.
498 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
499 maxlvt = lapic_get_maxlvt();
500 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
501 apic_write(APIC_ESR, 0);
502 accept_status = (apic_read(APIC_ESR) & 0xEF);
504 pr_debug("NMI sent.\n");
507 printk(KERN_ERR "APIC never delivered???\n");
509 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
511 return (send_status | accept_status);
515 wakeup_secondary_cpu_via_init(int phys_apicid, unsigned long start_eip)
517 unsigned long send_status, accept_status = 0;
518 int maxlvt, num_starts, j;
520 maxlvt = lapic_get_maxlvt();
523 * Be paranoid about clearing APIC errors.
525 if (APIC_INTEGRATED(apic_version[phys_apicid])) {
526 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
527 apic_write(APIC_ESR, 0);
531 pr_debug("Asserting INIT.\n");
534 * Turn INIT on target chip
539 apic_icr_write(APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT,
542 pr_debug("Waiting for send to finish...\n");
543 send_status = safe_apic_wait_icr_idle();
547 pr_debug("Deasserting INIT.\n");
551 apic_icr_write(APIC_INT_LEVELTRIG | APIC_DM_INIT, phys_apicid);
553 pr_debug("Waiting for send to finish...\n");
554 send_status = safe_apic_wait_icr_idle();
557 atomic_set(&init_deasserted, 1);
560 * Should we send STARTUP IPIs ?
562 * Determine this based on the APIC version.
563 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
565 if (APIC_INTEGRATED(apic_version[phys_apicid]))
571 * Paravirt / VMI wants a startup IPI hook here to set up the
572 * target processor state.
574 startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
578 * Run STARTUP IPI loop.
580 pr_debug("#startup loops: %d.\n", num_starts);
582 for (j = 1; j <= num_starts; j++) {
583 pr_debug("Sending STARTUP #%d.\n", j);
584 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
585 apic_write(APIC_ESR, 0);
587 pr_debug("After apic_write.\n");
594 /* Boot on the stack */
595 /* Kick the second */
596 apic_icr_write(APIC_DM_STARTUP | (start_eip >> 12),
600 * Give the other CPU some time to accept the IPI.
604 pr_debug("Startup point 1.\n");
606 pr_debug("Waiting for send to finish...\n");
607 send_status = safe_apic_wait_icr_idle();
610 * Give the other CPU some time to accept the IPI.
613 if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
614 apic_write(APIC_ESR, 0);
615 accept_status = (apic_read(APIC_ESR) & 0xEF);
616 if (send_status || accept_status)
619 pr_debug("After Startup.\n");
622 printk(KERN_ERR "APIC never delivered???\n");
624 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
626 return (send_status | accept_status);
629 /* reduce the number of lines printed when booting a large cpu count system */
630 static void __cpuinit announce_cpu(int cpu, int apicid)
632 static int current_node = -1;
633 int node = early_cpu_to_node(cpu);
635 if (system_state == SYSTEM_BOOTING) {
636 if (node != current_node) {
637 if (current_node > (-1))
640 pr_info("Booting Node %3d, Processors ", node);
642 pr_cont(" #%d%s", cpu, cpu == (nr_cpu_ids - 1) ? " Ok.\n" : "");
645 pr_info("Booting Node %d Processor %d APIC 0x%x\n",
650 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
651 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
652 * Returns zero if CPU booted OK, else error code from
653 * ->wakeup_secondary_cpu.
655 static int __cpuinit do_boot_cpu(int apicid, int cpu, struct task_struct *idle)
657 volatile u32 *trampoline_status =
658 (volatile u32 *) __va(real_mode_header->trampoline_status);
659 /* start_ip had better be page-aligned! */
660 unsigned long start_ip = real_mode_header->trampoline_start;
662 unsigned long boot_error = 0;
665 alternatives_smp_switch(1);
667 idle->thread.sp = (unsigned long) (((struct pt_regs *)
668 (THREAD_SIZE + task_stack_page(idle))) - 1);
669 per_cpu(current_task, cpu) = idle;
672 /* Stack for startup_32 can be just as for start_secondary onwards */
675 clear_tsk_thread_flag(idle, TIF_FORK);
676 initial_gs = per_cpu_offset(cpu);
677 per_cpu(kernel_stack, cpu) =
678 (unsigned long)task_stack_page(idle) -
679 KERNEL_STACK_OFFSET + THREAD_SIZE;
681 early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
682 initial_code = (unsigned long)start_secondary;
683 stack_start = idle->thread.sp;
685 /* So we see what's up */
686 announce_cpu(cpu, apicid);
689 * This grunge runs the startup process for
690 * the targeted processor.
693 atomic_set(&init_deasserted, 0);
695 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
697 pr_debug("Setting warm reset code and vector.\n");
699 smpboot_setup_warm_reset_vector(start_ip);
701 * Be paranoid about clearing APIC errors.
703 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
704 apic_write(APIC_ESR, 0);
710 * Kick the secondary CPU. Use the method in the APIC driver
711 * if it's defined - or use an INIT boot APIC message otherwise:
713 if (apic->wakeup_secondary_cpu)
714 boot_error = apic->wakeup_secondary_cpu(apicid, start_ip);
716 boot_error = wakeup_secondary_cpu_via_init(apicid, start_ip);
720 * allow APs to start initializing.
722 pr_debug("Before Callout %d.\n", cpu);
723 cpumask_set_cpu(cpu, cpu_callout_mask);
724 pr_debug("After Callout %d.\n", cpu);
727 * Wait 5s total for a response
729 for (timeout = 0; timeout < 50000; timeout++) {
730 if (cpumask_test_cpu(cpu, cpu_callin_mask))
731 break; /* It has booted */
734 * Allow other tasks to run while we wait for the
735 * AP to come online. This also gives a chance
736 * for the MTRR work(triggered by the AP coming online)
737 * to be completed in the stop machine context.
742 if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
743 print_cpu_msr(&cpu_data(cpu));
744 pr_debug("CPU%d: has booted.\n", cpu);
747 if (*trampoline_status == 0xA5A5A5A5)
748 /* trampoline started but...? */
749 pr_err("CPU%d: Stuck ??\n", cpu);
751 /* trampoline code not run */
752 pr_err("CPU%d: Not responding.\n", cpu);
753 if (apic->inquire_remote_apic)
754 apic->inquire_remote_apic(apicid);
759 /* Try to put things back the way they were before ... */
760 numa_remove_cpu(cpu); /* was set by numa_add_cpu */
762 /* was set by do_boot_cpu() */
763 cpumask_clear_cpu(cpu, cpu_callout_mask);
765 /* was set by cpu_init() */
766 cpumask_clear_cpu(cpu, cpu_initialized_mask);
768 set_cpu_present(cpu, false);
769 per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
772 /* mark "stuck" area as not stuck */
773 *trampoline_status = 0;
775 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
777 * Cleanup possible dangling ends...
779 smpboot_restore_warm_reset_vector();
784 int __cpuinit native_cpu_up(unsigned int cpu, struct task_struct *tidle)
786 int apicid = apic->cpu_present_to_apicid(cpu);
790 WARN_ON(irqs_disabled());
792 pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu);
794 if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
795 !physid_isset(apicid, phys_cpu_present_map) ||
796 !apic->apic_id_valid(apicid)) {
797 printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
802 * Already booted CPU?
804 if (cpumask_test_cpu(cpu, cpu_callin_mask)) {
805 pr_debug("do_boot_cpu %d Already started\n", cpu);
810 * Save current MTRR state in case it was changed since early boot
811 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
815 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
817 err = do_boot_cpu(apicid, cpu, tidle);
819 pr_debug("do_boot_cpu failed %d\n", err);
824 * Check TSC synchronization with the AP (keep irqs disabled
827 local_irq_save(flags);
828 check_tsc_sync_source(cpu);
829 local_irq_restore(flags);
831 while (!cpu_online(cpu)) {
833 touch_nmi_watchdog();
840 * arch_disable_smp_support() - disables SMP support for x86 at runtime
842 void arch_disable_smp_support(void)
844 disable_ioapic_support();
848 * Fall back to non SMP mode after errors.
850 * RED-PEN audit/test this more. I bet there is more state messed up here.
852 static __init void disable_smp(void)
854 init_cpu_present(cpumask_of(0));
855 init_cpu_possible(cpumask_of(0));
856 smpboot_clear_io_apic_irqs();
858 if (smp_found_config)
859 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
861 physid_set_mask_of_physid(0, &phys_cpu_present_map);
862 cpumask_set_cpu(0, cpu_sibling_mask(0));
863 cpumask_set_cpu(0, cpu_core_mask(0));
867 * Various sanity checks.
869 static int __init smp_sanity_check(unsigned max_cpus)
873 #if !defined(CONFIG_X86_BIGSMP) && defined(CONFIG_X86_32)
874 if (def_to_bigsmp && nr_cpu_ids > 8) {
879 "More than 8 CPUs detected - skipping them.\n"
880 "Use CONFIG_X86_BIGSMP.\n");
883 for_each_present_cpu(cpu) {
885 set_cpu_present(cpu, false);
890 for_each_possible_cpu(cpu) {
892 set_cpu_possible(cpu, false);
900 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
902 "weird, boot CPU (#%d) not listed by the BIOS.\n",
903 hard_smp_processor_id());
905 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
909 * If we couldn't find an SMP configuration at boot time,
910 * get out of here now!
912 if (!smp_found_config && !acpi_lapic) {
914 printk(KERN_NOTICE "SMP motherboard not detected.\n");
916 if (APIC_init_uniprocessor())
917 printk(KERN_NOTICE "Local APIC not detected."
918 " Using dummy APIC emulation.\n");
923 * Should not be necessary because the MP table should list the boot
924 * CPU too, but we do it for the sake of robustness anyway.
926 if (!apic->check_phys_apicid_present(boot_cpu_physical_apicid)) {
928 "weird, boot CPU (#%d) not listed by the BIOS.\n",
929 boot_cpu_physical_apicid);
930 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
935 * If we couldn't find a local APIC, then get out of here now!
937 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
940 pr_err("BIOS bug, local APIC #%d not detected!...\n",
941 boot_cpu_physical_apicid);
942 pr_err("... forcing use of dummy APIC emulation."
943 "(tell your hw vendor)\n");
945 smpboot_clear_io_apic();
946 disable_ioapic_support();
953 * If SMP should be disabled, then really disable it!
956 printk(KERN_INFO "SMP mode deactivated.\n");
957 smpboot_clear_io_apic();
961 bsp_end_local_APIC_setup();
968 static void __init smp_cpu_index_default(void)
971 struct cpuinfo_x86 *c;
973 for_each_possible_cpu(i) {
975 /* mark all to hotplug */
976 c->cpu_index = nr_cpu_ids;
981 * Prepare for SMP bootup. The MP table or ACPI has been read
982 * earlier. Just do some sanity checking here and enable APIC mode.
984 void __init native_smp_prepare_cpus(unsigned int max_cpus)
989 smp_cpu_index_default();
992 * Setup boot CPU information
994 smp_store_cpu_info(0); /* Final full version of the data */
995 cpumask_copy(cpu_callin_mask, cpumask_of(0));
998 current_thread_info()->cpu = 0; /* needed? */
999 for_each_possible_cpu(i) {
1000 zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
1001 zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
1002 zalloc_cpumask_var(&per_cpu(cpu_llc_shared_map, i), GFP_KERNEL);
1004 set_cpu_sibling_map(0);
1007 if (smp_sanity_check(max_cpus) < 0) {
1008 printk(KERN_INFO "SMP disabled\n");
1013 default_setup_apic_routing();
1016 if (read_apic_id() != boot_cpu_physical_apicid) {
1017 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1018 read_apic_id(), boot_cpu_physical_apicid);
1019 /* Or can we switch back to PIC here? */
1026 * Switch from PIC to APIC mode.
1031 * Enable IO APIC before setting up error vector
1033 if (!skip_ioapic_setup && nr_ioapics)
1036 bsp_end_local_APIC_setup();
1038 if (apic->setup_portio_remap)
1039 apic->setup_portio_remap();
1041 smpboot_setup_io_apic();
1043 * Set up local APIC timer on boot CPU.
1046 printk(KERN_INFO "CPU%d: ", 0);
1047 print_cpu_info(&cpu_data(0));
1048 x86_init.timers.setup_percpu_clockev();
1053 set_mtrr_aps_delayed_init();
1058 void arch_disable_nonboot_cpus_begin(void)
1061 * Avoid the smp alternatives switch during the disable_nonboot_cpus().
1062 * In the suspend path, we will be back in the SMP mode shortly anyways.
1064 skip_smp_alternatives = true;
1067 void arch_disable_nonboot_cpus_end(void)
1069 skip_smp_alternatives = false;
1072 void arch_enable_nonboot_cpus_begin(void)
1074 set_mtrr_aps_delayed_init();
1077 void arch_enable_nonboot_cpus_end(void)
1083 * Early setup to make printk work.
1085 void __init native_smp_prepare_boot_cpu(void)
1087 int me = smp_processor_id();
1088 switch_to_new_gdt(me);
1089 /* already set me in cpu_online_mask in boot_cpu_init() */
1090 cpumask_set_cpu(me, cpu_callout_mask);
1091 per_cpu(cpu_state, me) = CPU_ONLINE;
1094 void __init native_smp_cpus_done(unsigned int max_cpus)
1096 pr_debug("Boot done.\n");
1100 #ifdef CONFIG_X86_IO_APIC
1101 setup_ioapic_dest();
1106 static int __initdata setup_possible_cpus = -1;
1107 static int __init _setup_possible_cpus(char *str)
1109 get_option(&str, &setup_possible_cpus);
1112 early_param("possible_cpus", _setup_possible_cpus);
1116 * cpu_possible_mask should be static, it cannot change as cpu's
1117 * are onlined, or offlined. The reason is per-cpu data-structures
1118 * are allocated by some modules at init time, and dont expect to
1119 * do this dynamically on cpu arrival/departure.
1120 * cpu_present_mask on the other hand can change dynamically.
1121 * In case when cpu_hotplug is not compiled, then we resort to current
1122 * behaviour, which is cpu_possible == cpu_present.
1125 * Three ways to find out the number of additional hotplug CPUs:
1126 * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
1127 * - The user can overwrite it with possible_cpus=NUM
1128 * - Otherwise don't reserve additional CPUs.
1129 * We do this because additional CPUs waste a lot of memory.
1132 __init void prefill_possible_map(void)
1136 /* no processor from mptable or madt */
1137 if (!num_processors)
1140 i = setup_max_cpus ?: 1;
1141 if (setup_possible_cpus == -1) {
1142 possible = num_processors;
1143 #ifdef CONFIG_HOTPLUG_CPU
1145 possible += disabled_cpus;
1151 possible = setup_possible_cpus;
1153 total_cpus = max_t(int, possible, num_processors + disabled_cpus);
1155 /* nr_cpu_ids could be reduced via nr_cpus= */
1156 if (possible > nr_cpu_ids) {
1158 "%d Processors exceeds NR_CPUS limit of %d\n",
1159 possible, nr_cpu_ids);
1160 possible = nr_cpu_ids;
1163 #ifdef CONFIG_HOTPLUG_CPU
1164 if (!setup_max_cpus)
1168 "%d Processors exceeds max_cpus limit of %u\n",
1169 possible, setup_max_cpus);
1173 printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
1174 possible, max_t(int, possible - num_processors, 0));
1176 for (i = 0; i < possible; i++)
1177 set_cpu_possible(i, true);
1178 for (; i < NR_CPUS; i++)
1179 set_cpu_possible(i, false);
1181 nr_cpu_ids = possible;
1184 #ifdef CONFIG_HOTPLUG_CPU
1186 static void remove_siblinginfo(int cpu)
1189 struct cpuinfo_x86 *c = &cpu_data(cpu);
1191 for_each_cpu(sibling, cpu_core_mask(cpu)) {
1192 cpumask_clear_cpu(cpu, cpu_core_mask(sibling));
1194 * last thread sibling in this cpu core going down
1196 if (cpumask_weight(cpu_sibling_mask(cpu)) == 1)
1197 cpu_data(sibling).booted_cores--;
1200 for_each_cpu(sibling, cpu_sibling_mask(cpu))
1201 cpumask_clear_cpu(cpu, cpu_sibling_mask(sibling));
1202 cpumask_clear(cpu_sibling_mask(cpu));
1203 cpumask_clear(cpu_core_mask(cpu));
1204 c->phys_proc_id = 0;
1206 cpumask_clear_cpu(cpu, cpu_sibling_setup_mask);
1209 static void __ref remove_cpu_from_maps(int cpu)
1211 set_cpu_online(cpu, false);
1212 cpumask_clear_cpu(cpu, cpu_callout_mask);
1213 cpumask_clear_cpu(cpu, cpu_callin_mask);
1214 /* was set by cpu_init() */
1215 cpumask_clear_cpu(cpu, cpu_initialized_mask);
1216 numa_remove_cpu(cpu);
1219 void cpu_disable_common(void)
1221 int cpu = smp_processor_id();
1223 remove_siblinginfo(cpu);
1225 /* It's now safe to remove this processor from the online map */
1227 remove_cpu_from_maps(cpu);
1228 unlock_vector_lock();
1232 int native_cpu_disable(void)
1234 int cpu = smp_processor_id();
1237 * Perhaps use cpufreq to drop frequency, but that could go
1238 * into generic code.
1240 * We won't take down the boot processor on i386 due to some
1241 * interrupts only being able to be serviced by the BSP.
1242 * Especially so if we're not using an IOAPIC -zwane
1249 cpu_disable_common();
1253 void native_cpu_die(unsigned int cpu)
1255 /* We don't do anything here: idle task is faking death itself. */
1258 for (i = 0; i < 10; i++) {
1259 /* They ack this in play_dead by setting CPU_DEAD */
1260 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
1261 if (system_state == SYSTEM_RUNNING)
1262 pr_info("CPU %u is now offline\n", cpu);
1264 if (1 == num_online_cpus())
1265 alternatives_smp_switch(0);
1270 pr_err("CPU %u didn't die...\n", cpu);
1273 void play_dead_common(void)
1276 reset_lazy_tlbstate();
1277 amd_e400_remove_cpu(raw_smp_processor_id());
1281 __this_cpu_write(cpu_state, CPU_DEAD);
1284 * With physical CPU hotplug, we should halt the cpu
1286 local_irq_disable();
1290 * We need to flush the caches before going to sleep, lest we have
1291 * dirty data in our caches when we come back up.
1293 static inline void mwait_play_dead(void)
1295 unsigned int eax, ebx, ecx, edx;
1296 unsigned int highest_cstate = 0;
1297 unsigned int highest_subcstate = 0;
1300 struct cpuinfo_x86 *c = __this_cpu_ptr(&cpu_info);
1302 if (!(this_cpu_has(X86_FEATURE_MWAIT) && mwait_usable(c)))
1304 if (!this_cpu_has(X86_FEATURE_CLFLSH))
1306 if (__this_cpu_read(cpu_info.cpuid_level) < CPUID_MWAIT_LEAF)
1309 eax = CPUID_MWAIT_LEAF;
1311 native_cpuid(&eax, &ebx, &ecx, &edx);
1314 * eax will be 0 if EDX enumeration is not valid.
1315 * Initialized below to cstate, sub_cstate value when EDX is valid.
1317 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED)) {
1320 edx >>= MWAIT_SUBSTATE_SIZE;
1321 for (i = 0; i < 7 && edx; i++, edx >>= MWAIT_SUBSTATE_SIZE) {
1322 if (edx & MWAIT_SUBSTATE_MASK) {
1324 highest_subcstate = edx & MWAIT_SUBSTATE_MASK;
1327 eax = (highest_cstate << MWAIT_SUBSTATE_SIZE) |
1328 (highest_subcstate - 1);
1332 * This should be a memory location in a cache line which is
1333 * unlikely to be touched by other processors. The actual
1334 * content is immaterial as it is not actually modified in any way.
1336 mwait_ptr = ¤t_thread_info()->flags;
1342 * The CLFLUSH is a workaround for erratum AAI65 for
1343 * the Xeon 7400 series. It's not clear it is actually
1344 * needed, but it should be harmless in either case.
1345 * The WBINVD is insufficient due to the spurious-wakeup
1346 * case where we return around the loop.
1349 __monitor(mwait_ptr, 0, 0);
1355 static inline void hlt_play_dead(void)
1357 if (__this_cpu_read(cpu_info.x86) >= 4)
1365 void native_play_dead(void)
1368 tboot_shutdown(TB_SHUTDOWN_WFS);
1370 mwait_play_dead(); /* Only returns on failure */
1371 if (cpuidle_play_dead())
1375 #else /* ... !CONFIG_HOTPLUG_CPU */
1376 int native_cpu_disable(void)
1381 void native_cpu_die(unsigned int cpu)
1383 /* We said "no" in __cpu_disable */
1387 void native_play_dead(void)