2 * x86 SMP booting functions
4 * (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
5 * (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
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>
63 #include <asm/genapic.h>
64 #include <linux/mc146818rtc.h>
66 #include <mach_apic.h>
67 #include <mach_wakecpu.h>
68 #include <smpboot_hooks.h>
71 * FIXME: For x86_64, those are defined in other files. But moving them here,
72 * would make the setup areas dependent on smp, which is a loss. When we
73 * integrate apic between arches, we can probably do a better job, but
74 * right now, they'll stay here -- glommer
77 /* which logical CPU number maps to which CPU (physical APIC ID) */
78 u16 x86_cpu_to_apicid_init[NR_CPUS] __initdata =
79 { [0 ... NR_CPUS-1] = BAD_APICID };
80 void *x86_cpu_to_apicid_early_ptr;
82 u16 x86_bios_cpu_apicid_init[NR_CPUS] __initdata
83 = { [0 ... NR_CPUS-1] = BAD_APICID };
84 void *x86_bios_cpu_apicid_early_ptr;
87 u8 apicid_2_node[MAX_APICID];
88 static int low_mappings;
91 /* State of each CPU */
92 DEFINE_PER_CPU(int, cpu_state) = { 0 };
94 /* Store all idle threads, this can be reused instead of creating
95 * a new thread. Also avoids complicated thread destroy functionality
98 #ifdef CONFIG_HOTPLUG_CPU
100 * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
101 * removed after init for !CONFIG_HOTPLUG_CPU.
103 static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
104 #define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x))
105 #define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p))
107 struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
108 #define get_idle_for_cpu(x) (idle_thread_array[(x)])
109 #define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p))
112 /* Number of siblings per CPU package */
113 int smp_num_siblings = 1;
114 EXPORT_SYMBOL(smp_num_siblings);
116 /* Last level cache ID of each logical CPU */
117 DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
119 /* bitmap of online cpus */
120 cpumask_t cpu_online_map __read_mostly;
121 EXPORT_SYMBOL(cpu_online_map);
123 cpumask_t cpu_callin_map;
124 cpumask_t cpu_callout_map;
125 cpumask_t cpu_possible_map;
126 EXPORT_SYMBOL(cpu_possible_map);
128 /* representing HT siblings of each logical CPU */
129 DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
130 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
132 /* representing HT and core siblings of each logical CPU */
133 DEFINE_PER_CPU(cpumask_t, cpu_core_map);
134 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
136 /* Per CPU bogomips and other parameters */
137 DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
138 EXPORT_PER_CPU_SYMBOL(cpu_info);
140 static atomic_t init_deasserted;
142 static int boot_cpu_logical_apicid;
144 /* representing cpus for which sibling maps can be computed */
145 static cpumask_t cpu_sibling_setup_map;
147 /* Set if we find a B stepping CPU */
148 int __cpuinitdata smp_b_stepping;
150 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_32)
152 /* which logical CPUs are on which nodes */
153 cpumask_t node_to_cpumask_map[MAX_NUMNODES] __read_mostly =
154 { [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE };
155 EXPORT_SYMBOL(node_to_cpumask_map);
156 /* which node each logical CPU is on */
157 int cpu_to_node_map[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = 0 };
158 EXPORT_SYMBOL(cpu_to_node_map);
160 /* set up a mapping between cpu and node. */
161 static void map_cpu_to_node(int cpu, int node)
163 printk(KERN_INFO "Mapping cpu %d to node %d\n", cpu, node);
164 cpu_set(cpu, node_to_cpumask_map[node]);
165 cpu_to_node_map[cpu] = node;
168 /* undo a mapping between cpu and node. */
169 static void unmap_cpu_to_node(int cpu)
173 printk(KERN_INFO "Unmapping cpu %d from all nodes\n", cpu);
174 for (node = 0; node < MAX_NUMNODES; node++)
175 cpu_clear(cpu, node_to_cpumask_map[node]);
176 cpu_to_node_map[cpu] = 0;
178 #else /* !(CONFIG_NUMA && CONFIG_X86_32) */
179 #define map_cpu_to_node(cpu, node) ({})
180 #define unmap_cpu_to_node(cpu) ({})
184 u8 cpu_2_logical_apicid[NR_CPUS] __read_mostly =
185 { [0 ... NR_CPUS-1] = BAD_APICID };
187 static void map_cpu_to_logical_apicid(void)
189 int cpu = smp_processor_id();
190 int apicid = logical_smp_processor_id();
191 int node = apicid_to_node(apicid);
193 if (!node_online(node))
194 node = first_online_node;
196 cpu_2_logical_apicid[cpu] = apicid;
197 map_cpu_to_node(cpu, node);
200 static void unmap_cpu_to_logical_apicid(int cpu)
202 cpu_2_logical_apicid[cpu] = BAD_APICID;
203 unmap_cpu_to_node(cpu);
206 #define unmap_cpu_to_logical_apicid(cpu) do {} while (0)
207 #define map_cpu_to_logical_apicid() do {} while (0)
211 * Report back to the Boot Processor.
214 static void __cpuinit smp_callin(void)
217 unsigned long timeout;
220 * If waken up by an INIT in an 82489DX configuration
221 * we may get here before an INIT-deassert IPI reaches
222 * our local APIC. We have to wait for the IPI or we'll
223 * lock up on an APIC access.
225 wait_for_init_deassert(&init_deasserted);
228 * (This works even if the APIC is not enabled.)
230 phys_id = GET_APIC_ID(read_apic_id());
231 cpuid = smp_processor_id();
232 if (cpu_isset(cpuid, cpu_callin_map)) {
233 panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__,
236 Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
239 * STARTUP IPIs are fragile beasts as they might sometimes
240 * trigger some glue motherboard logic. Complete APIC bus
241 * silence for 1 second, this overestimates the time the
242 * boot CPU is spending to send the up to 2 STARTUP IPIs
243 * by a factor of two. This should be enough.
247 * Waiting 2s total for startup (udelay is not yet working)
249 timeout = jiffies + 2*HZ;
250 while (time_before(jiffies, timeout)) {
252 * Has the boot CPU finished it's STARTUP sequence?
254 if (cpu_isset(cpuid, cpu_callout_map))
259 if (!time_before(jiffies, timeout)) {
260 panic("%s: CPU%d started up but did not get a callout!\n",
265 * the boot CPU has finished the init stage and is spinning
266 * on callin_map until we finish. We are free to set up this
267 * CPU, first the APIC. (this is probably redundant on most
271 Dprintk("CALLIN, before setup_local_APIC().\n");
272 smp_callin_clear_local_apic();
274 end_local_APIC_setup();
275 map_cpu_to_logical_apicid();
280 * Need to enable IRQs because it can take longer and then
281 * the NMI watchdog might kill us.
286 Dprintk("Stack at about %p\n", &cpuid);
289 * Save our processor parameters
291 smp_store_cpu_info(cpuid);
294 * Allow the master to continue.
296 cpu_set(cpuid, cpu_callin_map);
300 * Activate a secondary processor.
302 static void __cpuinit start_secondary(void *unused)
305 * Don't put *anything* before cpu_init(), SMP booting is too
306 * fragile that we want to limit the things done here to the
307 * most necessary things.
316 /* otherwise gcc will move up smp_processor_id before the cpu_init */
319 * Check TSC synchronization with the BP:
321 check_tsc_sync_target();
323 if (nmi_watchdog == NMI_IO_APIC) {
324 disable_8259A_irq(0);
325 enable_NMI_through_LVT0();
335 /* This must be done before setting cpu_online_map */
336 set_cpu_sibling_map(raw_smp_processor_id());
340 * We need to hold call_lock, so there is no inconsistency
341 * between the time smp_call_function() determines number of
342 * IPI recipients, and the time when the determination is made
343 * for which cpus receive the IPI. Holding this
344 * lock helps us to not include this cpu in a currently in progress
345 * smp_call_function().
347 lock_ipi_call_lock();
349 spin_lock(&vector_lock);
351 /* Setup the per cpu irq handling data structures */
352 __setup_vector_irq(smp_processor_id());
354 * Allow the master to continue.
356 spin_unlock(&vector_lock);
358 cpu_set(smp_processor_id(), cpu_online_map);
359 unlock_ipi_call_lock();
360 per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
362 setup_secondary_clock();
370 * Everything has been set up for the secondary
371 * CPUs - they just need to reload everything
372 * from the task structure
373 * This function must not return.
375 void __devinit initialize_secondary(void)
378 * We don't actually need to load the full TSS,
379 * basically just the stack pointer and the ip.
386 :"m" (current->thread.sp), "m" (current->thread.ip));
390 static void __cpuinit smp_apply_quirks(struct cpuinfo_x86 *c)
394 * Mask B, Pentium, but not Pentium MMX
396 if (c->x86_vendor == X86_VENDOR_INTEL &&
398 c->x86_mask >= 1 && c->x86_mask <= 4 &&
401 * Remember we have B step Pentia with bugs
406 * Certain Athlons might work (for various values of 'work') in SMP
407 * but they are not certified as MP capable.
409 if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) {
411 if (num_possible_cpus() == 1)
414 /* Athlon 660/661 is valid. */
415 if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
419 /* Duron 670 is valid */
420 if ((c->x86_model == 7) && (c->x86_mask == 0))
424 * Athlon 662, Duron 671, and Athlon >model 7 have capability
425 * bit. It's worth noting that the A5 stepping (662) of some
426 * Athlon XP's have the MP bit set.
427 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
430 if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
431 ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
436 /* If we get here, not a certified SMP capable AMD system. */
437 add_taint(TAINT_UNSAFE_SMP);
445 static void __cpuinit smp_checks(void)
448 printk(KERN_WARNING "WARNING: SMP operation may be unreliable"
449 "with B stepping processors.\n");
452 * Don't taint if we are running SMP kernel on a single non-MP
455 if (tainted & TAINT_UNSAFE_SMP) {
456 if (num_online_cpus())
457 printk(KERN_INFO "WARNING: This combination of AMD"
458 "processors is not suitable for SMP.\n");
460 tainted &= ~TAINT_UNSAFE_SMP;
465 * The bootstrap kernel entry code has set these up. Save them for
469 void __cpuinit smp_store_cpu_info(int id)
471 struct cpuinfo_x86 *c = &cpu_data(id);
476 identify_secondary_cpu(c);
481 void __cpuinit set_cpu_sibling_map(int cpu)
484 struct cpuinfo_x86 *c = &cpu_data(cpu);
486 cpu_set(cpu, cpu_sibling_setup_map);
488 if (smp_num_siblings > 1) {
489 for_each_cpu_mask(i, cpu_sibling_setup_map) {
490 if (c->phys_proc_id == cpu_data(i).phys_proc_id &&
491 c->cpu_core_id == cpu_data(i).cpu_core_id) {
492 cpu_set(i, per_cpu(cpu_sibling_map, cpu));
493 cpu_set(cpu, per_cpu(cpu_sibling_map, i));
494 cpu_set(i, per_cpu(cpu_core_map, cpu));
495 cpu_set(cpu, per_cpu(cpu_core_map, i));
496 cpu_set(i, c->llc_shared_map);
497 cpu_set(cpu, cpu_data(i).llc_shared_map);
501 cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
504 cpu_set(cpu, c->llc_shared_map);
506 if (current_cpu_data.x86_max_cores == 1) {
507 per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
512 for_each_cpu_mask(i, cpu_sibling_setup_map) {
513 if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
514 per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
515 cpu_set(i, c->llc_shared_map);
516 cpu_set(cpu, cpu_data(i).llc_shared_map);
518 if (c->phys_proc_id == cpu_data(i).phys_proc_id) {
519 cpu_set(i, per_cpu(cpu_core_map, cpu));
520 cpu_set(cpu, per_cpu(cpu_core_map, i));
522 * Does this new cpu bringup a new core?
524 if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) {
526 * for each core in package, increment
527 * the booted_cores for this new cpu
529 if (first_cpu(per_cpu(cpu_sibling_map, i)) == i)
532 * increment the core count for all
533 * the other cpus in this package
536 cpu_data(i).booted_cores++;
537 } else if (i != cpu && !c->booted_cores)
538 c->booted_cores = cpu_data(i).booted_cores;
543 /* maps the cpu to the sched domain representing multi-core */
544 cpumask_t cpu_coregroup_map(int cpu)
546 struct cpuinfo_x86 *c = &cpu_data(cpu);
548 * For perf, we return last level cache shared map.
549 * And for power savings, we return cpu_core_map
551 if (sched_mc_power_savings || sched_smt_power_savings)
552 return per_cpu(cpu_core_map, cpu);
554 return c->llc_shared_map;
557 static void impress_friends(void)
560 unsigned long bogosum = 0;
562 * Allow the user to impress friends.
564 Dprintk("Before bogomips.\n");
565 for_each_possible_cpu(cpu)
566 if (cpu_isset(cpu, cpu_callout_map))
567 bogosum += cpu_data(cpu).loops_per_jiffy;
569 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
572 (bogosum/(5000/HZ))%100);
574 Dprintk("Before bogocount - setting activated=1.\n");
577 static inline void __inquire_remote_apic(int apicid)
579 unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
580 char *names[] = { "ID", "VERSION", "SPIV" };
584 printk(KERN_INFO "Inquiring remote APIC #%d...\n", apicid);
586 for (i = 0; i < ARRAY_SIZE(regs); i++) {
587 printk(KERN_INFO "... APIC #%d %s: ", apicid, names[i]);
592 status = safe_apic_wait_icr_idle();
595 "a previous APIC delivery may have failed\n");
597 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
598 apic_write_around(APIC_ICR, APIC_DM_REMRD | regs[i]);
603 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
604 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
607 case APIC_ICR_RR_VALID:
608 status = apic_read(APIC_RRR);
609 printk(KERN_CONT "%08x\n", status);
612 printk(KERN_CONT "failed\n");
617 #ifdef WAKE_SECONDARY_VIA_NMI
619 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
620 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
621 * won't ... remember to clear down the APIC, etc later.
624 wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
626 unsigned long send_status, accept_status = 0;
630 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid));
632 /* Boot on the stack */
633 /* Kick the second */
634 apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL);
636 Dprintk("Waiting for send to finish...\n");
637 send_status = safe_apic_wait_icr_idle();
640 * Give the other CPU some time to accept the IPI.
644 * Due to the Pentium erratum 3AP.
646 maxlvt = lapic_get_maxlvt();
648 apic_read_around(APIC_SPIV);
649 apic_write(APIC_ESR, 0);
651 accept_status = (apic_read(APIC_ESR) & 0xEF);
652 Dprintk("NMI sent.\n");
655 printk(KERN_ERR "APIC never delivered???\n");
657 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
659 return (send_status | accept_status);
661 #endif /* WAKE_SECONDARY_VIA_NMI */
663 #ifdef WAKE_SECONDARY_VIA_INIT
665 wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
667 unsigned long send_status, accept_status = 0;
668 int maxlvt, num_starts, j;
670 if (get_uv_system_type() == UV_NON_UNIQUE_APIC) {
671 send_status = uv_wakeup_secondary(phys_apicid, start_eip);
672 atomic_set(&init_deasserted, 1);
677 * Be paranoid about clearing APIC errors.
679 if (APIC_INTEGRATED(apic_version[phys_apicid])) {
680 apic_read_around(APIC_SPIV);
681 apic_write(APIC_ESR, 0);
685 Dprintk("Asserting INIT.\n");
688 * Turn INIT on target chip
690 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
695 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
698 Dprintk("Waiting for send to finish...\n");
699 send_status = safe_apic_wait_icr_idle();
703 Dprintk("Deasserting INIT.\n");
706 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
709 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
711 Dprintk("Waiting for send to finish...\n");
712 send_status = safe_apic_wait_icr_idle();
715 atomic_set(&init_deasserted, 1);
718 * Should we send STARTUP IPIs ?
720 * Determine this based on the APIC version.
721 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
723 if (APIC_INTEGRATED(apic_version[phys_apicid]))
729 * Paravirt / VMI wants a startup IPI hook here to set up the
730 * target processor state.
732 startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
734 (unsigned long)init_rsp);
736 (unsigned long)stack_start.sp);
740 * Run STARTUP IPI loop.
742 Dprintk("#startup loops: %d.\n", num_starts);
744 maxlvt = lapic_get_maxlvt();
746 for (j = 1; j <= num_starts; j++) {
747 Dprintk("Sending STARTUP #%d.\n", j);
748 apic_read_around(APIC_SPIV);
749 apic_write(APIC_ESR, 0);
751 Dprintk("After apic_write.\n");
758 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
760 /* Boot on the stack */
761 /* Kick the second */
762 apic_write_around(APIC_ICR, APIC_DM_STARTUP
763 | (start_eip >> 12));
766 * Give the other CPU some time to accept the IPI.
770 Dprintk("Startup point 1.\n");
772 Dprintk("Waiting for send to finish...\n");
773 send_status = safe_apic_wait_icr_idle();
776 * Give the other CPU some time to accept the IPI.
780 * Due to the Pentium erratum 3AP.
783 apic_read_around(APIC_SPIV);
784 apic_write(APIC_ESR, 0);
786 accept_status = (apic_read(APIC_ESR) & 0xEF);
787 if (send_status || accept_status)
790 Dprintk("After Startup.\n");
793 printk(KERN_ERR "APIC never delivered???\n");
795 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
797 return (send_status | accept_status);
799 #endif /* WAKE_SECONDARY_VIA_INIT */
802 struct work_struct work;
803 struct task_struct *idle;
804 struct completion done;
808 static void __cpuinit do_fork_idle(struct work_struct *work)
810 struct create_idle *c_idle =
811 container_of(work, struct create_idle, work);
813 c_idle->idle = fork_idle(c_idle->cpu);
814 complete(&c_idle->done);
817 static int __cpuinit do_boot_cpu(int apicid, int cpu)
819 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
820 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
821 * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu.
824 unsigned long boot_error = 0;
826 unsigned long start_ip;
827 unsigned short nmi_high = 0, nmi_low = 0;
828 struct create_idle c_idle = {
830 .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
832 INIT_WORK(&c_idle.work, do_fork_idle);
834 /* allocate memory for gdts of secondary cpus. Hotplug is considered */
835 if (!cpu_gdt_descr[cpu].address &&
836 !(cpu_gdt_descr[cpu].address = get_zeroed_page(GFP_KERNEL))) {
837 printk(KERN_ERR "Failed to allocate GDT for CPU %d\n", cpu);
841 /* Allocate node local memory for AP pdas */
842 if (cpu_pda(cpu) == &boot_cpu_pda[cpu]) {
843 struct x8664_pda *newpda, *pda;
844 int node = cpu_to_node(cpu);
846 newpda = kmalloc_node(sizeof(struct x8664_pda), GFP_ATOMIC,
849 memcpy(newpda, pda, sizeof(struct x8664_pda));
850 cpu_pda(cpu) = newpda;
853 "Could not allocate node local PDA for CPU %d on node %d\n",
858 alternatives_smp_switch(1);
860 c_idle.idle = get_idle_for_cpu(cpu);
863 * We can't use kernel_thread since we must avoid to
864 * reschedule the child.
867 c_idle.idle->thread.sp = (unsigned long) (((struct pt_regs *)
868 (THREAD_SIZE + task_stack_page(c_idle.idle))) - 1);
869 init_idle(c_idle.idle, cpu);
873 if (!keventd_up() || current_is_keventd())
874 c_idle.work.func(&c_idle.work);
876 schedule_work(&c_idle.work);
877 wait_for_completion(&c_idle.done);
880 if (IS_ERR(c_idle.idle)) {
881 printk("failed fork for CPU %d\n", cpu);
882 return PTR_ERR(c_idle.idle);
885 set_idle_for_cpu(cpu, c_idle.idle);
888 per_cpu(current_task, cpu) = c_idle.idle;
890 early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
891 c_idle.idle->thread.ip = (unsigned long) start_secondary;
892 /* Stack for startup_32 can be just as for start_secondary onwards */
893 stack_start.sp = (void *) c_idle.idle->thread.sp;
896 cpu_pda(cpu)->pcurrent = c_idle.idle;
897 init_rsp = c_idle.idle->thread.sp;
898 load_sp0(&per_cpu(init_tss, cpu), &c_idle.idle->thread);
899 initial_code = (unsigned long)start_secondary;
900 clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
903 /* start_ip had better be page-aligned! */
904 start_ip = setup_trampoline();
906 /* So we see what's up */
907 printk(KERN_INFO "Booting processor %d/%d ip %lx\n",
908 cpu, apicid, start_ip);
911 * This grunge runs the startup process for
912 * the targeted processor.
915 atomic_set(&init_deasserted, 0);
917 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
919 Dprintk("Setting warm reset code and vector.\n");
921 store_NMI_vector(&nmi_high, &nmi_low);
923 smpboot_setup_warm_reset_vector(start_ip);
925 * Be paranoid about clearing APIC errors.
927 apic_write(APIC_ESR, 0);
932 * Starting actual IPI sequence...
934 boot_error = wakeup_secondary_cpu(apicid, start_ip);
938 * allow APs to start initializing.
940 Dprintk("Before Callout %d.\n", cpu);
941 cpu_set(cpu, cpu_callout_map);
942 Dprintk("After Callout %d.\n", cpu);
945 * Wait 5s total for a response
947 for (timeout = 0; timeout < 50000; timeout++) {
948 if (cpu_isset(cpu, cpu_callin_map))
949 break; /* It has booted */
953 if (cpu_isset(cpu, cpu_callin_map)) {
954 /* number CPUs logically, starting from 1 (BSP is 0) */
956 printk(KERN_INFO "CPU%d: ", cpu);
957 print_cpu_info(&cpu_data(cpu));
958 Dprintk("CPU has booted.\n");
961 if (*((volatile unsigned char *)trampoline_base)
963 /* trampoline started but...? */
964 printk(KERN_ERR "Stuck ??\n");
966 /* trampoline code not run */
967 printk(KERN_ERR "Not responding.\n");
968 if (get_uv_system_type() != UV_NON_UNIQUE_APIC)
969 inquire_remote_apic(apicid);
974 /* Try to put things back the way they were before ... */
975 unmap_cpu_to_logical_apicid(cpu);
977 clear_node_cpumask(cpu); /* was set by numa_add_cpu */
979 cpu_clear(cpu, cpu_callout_map); /* was set by do_boot_cpu() */
980 cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
981 cpu_clear(cpu, cpu_present_map);
982 per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
985 /* mark "stuck" area as not stuck */
986 *((volatile unsigned long *)trampoline_base) = 0;
989 * Cleanup possible dangling ends...
991 smpboot_restore_warm_reset_vector();
996 int __cpuinit native_cpu_up(unsigned int cpu)
998 int apicid = cpu_present_to_apicid(cpu);
1002 WARN_ON(irqs_disabled());
1004 Dprintk("++++++++++++++++++++=_---CPU UP %u\n", cpu);
1006 if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
1007 !physid_isset(apicid, phys_cpu_present_map)) {
1008 printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
1013 * Already booted CPU?
1015 if (cpu_isset(cpu, cpu_callin_map)) {
1016 Dprintk("do_boot_cpu %d Already started\n", cpu);
1021 * Save current MTRR state in case it was changed since early boot
1022 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
1026 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
1028 #ifdef CONFIG_X86_32
1029 /* init low mem mapping */
1030 clone_pgd_range(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
1031 min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
1035 err = do_boot_cpu(apicid, cpu);
1040 err = do_boot_cpu(apicid, cpu);
1043 Dprintk("do_boot_cpu failed %d\n", err);
1048 * Check TSC synchronization with the AP (keep irqs disabled
1051 local_irq_save(flags);
1052 check_tsc_sync_source(cpu);
1053 local_irq_restore(flags);
1055 while (!cpu_online(cpu)) {
1057 touch_nmi_watchdog();
1064 * Fall back to non SMP mode after errors.
1066 * RED-PEN audit/test this more. I bet there is more state messed up here.
1068 static __init void disable_smp(void)
1070 cpu_present_map = cpumask_of_cpu(0);
1071 cpu_possible_map = cpumask_of_cpu(0);
1072 #ifdef CONFIG_X86_32
1073 smpboot_clear_io_apic_irqs();
1075 if (smp_found_config)
1076 phys_cpu_present_map =
1077 physid_mask_of_physid(boot_cpu_physical_apicid);
1079 phys_cpu_present_map = physid_mask_of_physid(0);
1080 map_cpu_to_logical_apicid();
1081 cpu_set(0, per_cpu(cpu_sibling_map, 0));
1082 cpu_set(0, per_cpu(cpu_core_map, 0));
1086 * Various sanity checks.
1088 static int __init smp_sanity_check(unsigned max_cpus)
1091 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
1092 printk(KERN_WARNING "weird, boot CPU (#%d) not listed"
1093 "by the BIOS.\n", hard_smp_processor_id());
1094 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1098 * If we couldn't find an SMP configuration at boot time,
1099 * get out of here now!
1101 if (!smp_found_config && !acpi_lapic) {
1103 printk(KERN_NOTICE "SMP motherboard not detected.\n");
1105 if (APIC_init_uniprocessor())
1106 printk(KERN_NOTICE "Local APIC not detected."
1107 " Using dummy APIC emulation.\n");
1112 * Should not be necessary because the MP table should list the boot
1113 * CPU too, but we do it for the sake of robustness anyway.
1115 if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
1117 "weird, boot CPU (#%d) not listed by the BIOS.\n",
1118 boot_cpu_physical_apicid);
1119 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1124 * If we couldn't find a local APIC, then get out of here now!
1126 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
1128 printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
1129 boot_cpu_physical_apicid);
1130 printk(KERN_ERR "... forcing use of dummy APIC emulation."
1131 "(tell your hw vendor)\n");
1132 smpboot_clear_io_apic();
1136 verify_local_APIC();
1139 * If SMP should be disabled, then really disable it!
1142 printk(KERN_INFO "SMP mode deactivated.\n");
1143 smpboot_clear_io_apic();
1145 localise_nmi_watchdog();
1147 #ifdef CONFIG_X86_32
1151 end_local_APIC_setup();
1158 static void __init smp_cpu_index_default(void)
1161 struct cpuinfo_x86 *c;
1163 for_each_possible_cpu(i) {
1165 /* mark all to hotplug */
1166 c->cpu_index = NR_CPUS;
1171 * Prepare for SMP bootup. The MP table or ACPI has been read
1172 * earlier. Just do some sanity checking here and enable APIC mode.
1174 void __init native_smp_prepare_cpus(unsigned int max_cpus)
1177 nmi_watchdog_default();
1178 smp_cpu_index_default();
1179 current_cpu_data = boot_cpu_data;
1180 cpu_callin_map = cpumask_of_cpu(0);
1183 * Setup boot CPU information
1185 smp_store_cpu_info(0); /* Final full version of the data */
1186 boot_cpu_logical_apicid = logical_smp_processor_id();
1187 current_thread_info()->cpu = 0; /* needed? */
1188 set_cpu_sibling_map(0);
1190 if (smp_sanity_check(max_cpus) < 0) {
1191 printk(KERN_INFO "SMP disabled\n");
1197 if (GET_APIC_ID(read_apic_id()) != boot_cpu_physical_apicid) {
1198 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1199 GET_APIC_ID(read_apic_id()), boot_cpu_physical_apicid);
1200 /* Or can we switch back to PIC here? */
1204 #ifdef CONFIG_X86_32
1208 * Switch from PIC to APIC mode.
1212 #ifdef CONFIG_X86_64
1214 * Enable IO APIC before setting up error vector
1216 if (!skip_ioapic_setup && nr_ioapics)
1219 end_local_APIC_setup();
1221 map_cpu_to_logical_apicid();
1223 setup_portio_remap();
1225 smpboot_setup_io_apic();
1227 * Set up local APIC timer on boot CPU.
1230 printk(KERN_INFO "CPU%d: ", 0);
1231 print_cpu_info(&cpu_data(0));
1237 * Early setup to make printk work.
1239 void __init native_smp_prepare_boot_cpu(void)
1241 int me = smp_processor_id();
1242 #ifdef CONFIG_X86_32
1244 switch_to_new_gdt();
1246 /* already set me in cpu_online_map in boot_cpu_init() */
1247 cpu_set(me, cpu_callout_map);
1248 per_cpu(cpu_state, me) = CPU_ONLINE;
1251 void __init native_smp_cpus_done(unsigned int max_cpus)
1253 Dprintk("Boot done.\n");
1257 #ifdef CONFIG_X86_IO_APIC
1258 setup_ioapic_dest();
1260 check_nmi_watchdog();
1263 #ifdef CONFIG_HOTPLUG_CPU
1265 # ifdef CONFIG_X86_32
1266 void cpu_exit_clear(void)
1268 int cpu = raw_smp_processor_id();
1275 cpu_clear(cpu, cpu_callout_map);
1276 cpu_clear(cpu, cpu_callin_map);
1278 unmap_cpu_to_logical_apicid(cpu);
1280 # endif /* CONFIG_X86_32 */
1282 static void remove_siblinginfo(int cpu)
1285 struct cpuinfo_x86 *c = &cpu_data(cpu);
1287 for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) {
1288 cpu_clear(cpu, per_cpu(cpu_core_map, sibling));
1290 * last thread sibling in this cpu core going down
1292 if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1)
1293 cpu_data(sibling).booted_cores--;
1296 for_each_cpu_mask(sibling, per_cpu(cpu_sibling_map, cpu))
1297 cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling));
1298 cpus_clear(per_cpu(cpu_sibling_map, cpu));
1299 cpus_clear(per_cpu(cpu_core_map, cpu));
1300 c->phys_proc_id = 0;
1302 cpu_clear(cpu, cpu_sibling_setup_map);
1305 static int additional_cpus __initdata = -1;
1307 static __init int setup_additional_cpus(char *s)
1309 return s && get_option(&s, &additional_cpus) ? 0 : -EINVAL;
1311 early_param("additional_cpus", setup_additional_cpus);
1314 * cpu_possible_map should be static, it cannot change as cpu's
1315 * are onlined, or offlined. The reason is per-cpu data-structures
1316 * are allocated by some modules at init time, and dont expect to
1317 * do this dynamically on cpu arrival/departure.
1318 * cpu_present_map on the other hand can change dynamically.
1319 * In case when cpu_hotplug is not compiled, then we resort to current
1320 * behaviour, which is cpu_possible == cpu_present.
1323 * Three ways to find out the number of additional hotplug CPUs:
1324 * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
1325 * - The user can overwrite it with additional_cpus=NUM
1326 * - Otherwise don't reserve additional CPUs.
1327 * We do this because additional CPUs waste a lot of memory.
1330 __init void prefill_possible_map(void)
1335 if (additional_cpus == -1) {
1336 if (disabled_cpus > 0)
1337 additional_cpus = disabled_cpus;
1339 additional_cpus = 0;
1341 possible = num_processors + additional_cpus;
1342 if (possible > NR_CPUS)
1345 printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
1346 possible, max_t(int, possible - num_processors, 0));
1348 for (i = 0; i < possible; i++)
1349 cpu_set(i, cpu_possible_map);
1352 static void __ref remove_cpu_from_maps(int cpu)
1354 cpu_clear(cpu, cpu_online_map);
1355 #ifdef CONFIG_X86_64
1356 cpu_clear(cpu, cpu_callout_map);
1357 cpu_clear(cpu, cpu_callin_map);
1358 /* was set by cpu_init() */
1359 clear_bit(cpu, (unsigned long *)&cpu_initialized);
1360 clear_node_cpumask(cpu);
1364 int __cpu_disable(void)
1366 int cpu = smp_processor_id();
1369 * Perhaps use cpufreq to drop frequency, but that could go
1370 * into generic code.
1372 * We won't take down the boot processor on i386 due to some
1373 * interrupts only being able to be serviced by the BSP.
1374 * Especially so if we're not using an IOAPIC -zwane
1379 if (nmi_watchdog == NMI_LOCAL_APIC)
1380 stop_apic_nmi_watchdog(NULL);
1385 * Allow any queued timer interrupts to get serviced
1386 * This is only a temporary solution until we cleanup
1387 * fixup_irqs as we do for IA64.
1392 local_irq_disable();
1393 remove_siblinginfo(cpu);
1395 /* It's now safe to remove this processor from the online map */
1396 remove_cpu_from_maps(cpu);
1397 fixup_irqs(cpu_online_map);
1401 void __cpu_die(unsigned int cpu)
1403 /* We don't do anything here: idle task is faking death itself. */
1406 for (i = 0; i < 10; i++) {
1407 /* They ack this in play_dead by setting CPU_DEAD */
1408 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
1409 printk(KERN_INFO "CPU %d is now offline\n", cpu);
1410 if (1 == num_online_cpus())
1411 alternatives_smp_switch(0);
1416 printk(KERN_ERR "CPU %u didn't die...\n", cpu);
1418 #else /* ... !CONFIG_HOTPLUG_CPU */
1419 int __cpu_disable(void)
1424 void __cpu_die(unsigned int cpu)
1426 /* We said "no" in __cpu_disable */
1432 * If the BIOS enumerates physical processors before logical,
1433 * maxcpus=N at enumeration-time can be used to disable HT.
1435 static int __init parse_maxcpus(char *arg)
1437 extern unsigned int maxcpus;
1439 maxcpus = simple_strtoul(arg, NULL, 0);
1442 early_param("maxcpus", parse_maxcpus);