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/setup.h>
68 #include <asm/uv/uv.h>
69 #include <linux/mc146818rtc.h>
71 #include <asm/smpboot_hooks.h>
72 #include <asm/i8259.h>
75 u8 apicid_2_node
[MAX_APICID
];
78 /* State of each CPU */
79 DEFINE_PER_CPU(int, cpu_state
) = { 0 };
81 /* Store all idle threads, this can be reused instead of creating
82 * a new thread. Also avoids complicated thread destroy functionality
85 #ifdef CONFIG_HOTPLUG_CPU
87 * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
88 * removed after init for !CONFIG_HOTPLUG_CPU.
90 static DEFINE_PER_CPU(struct task_struct
*, idle_thread_array
);
91 #define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x))
92 #define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p))
95 * We need this for trampoline_base protection from concurrent accesses when
96 * off- and onlining cores wildly.
98 static DEFINE_MUTEX(x86_cpu_hotplug_driver_mutex
);
100 void cpu_hotplug_driver_lock(void)
102 mutex_lock(&x86_cpu_hotplug_driver_mutex
);
105 void cpu_hotplug_driver_unlock(void)
107 mutex_unlock(&x86_cpu_hotplug_driver_mutex
);
110 ssize_t
arch_cpu_probe(const char *buf
, size_t count
) { return -1; }
111 ssize_t
arch_cpu_release(const char *buf
, size_t count
) { return -1; }
113 static struct task_struct
*idle_thread_array
[NR_CPUS
] __cpuinitdata
;
114 #define get_idle_for_cpu(x) (idle_thread_array[(x)])
115 #define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p))
118 /* Number of siblings per CPU package */
119 int smp_num_siblings
= 1;
120 EXPORT_SYMBOL(smp_num_siblings
);
122 /* Last level cache ID of each logical CPU */
123 DEFINE_PER_CPU(u16
, cpu_llc_id
) = BAD_APICID
;
125 /* representing HT siblings of each logical CPU */
126 DEFINE_PER_CPU(cpumask_var_t
, cpu_sibling_map
);
127 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map
);
129 /* representing HT and core siblings of each logical CPU */
130 DEFINE_PER_CPU(cpumask_var_t
, cpu_core_map
);
131 EXPORT_PER_CPU_SYMBOL(cpu_core_map
);
133 /* Per CPU bogomips and other parameters */
134 DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86
, cpu_info
);
135 EXPORT_PER_CPU_SYMBOL(cpu_info
);
137 atomic_t init_deasserted
;
139 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_32)
140 /* which node each logical CPU is on */
141 int cpu_to_node_map
[NR_CPUS
] __read_mostly
= { [0 ... NR_CPUS
-1] = 0 };
142 EXPORT_SYMBOL(cpu_to_node_map
);
144 /* set up a mapping between cpu and node. */
145 static void map_cpu_to_node(int cpu
, int node
)
147 printk(KERN_INFO
"Mapping cpu %d to node %d\n", cpu
, node
);
148 cpumask_set_cpu(cpu
, node_to_cpumask_map
[node
]);
149 cpu_to_node_map
[cpu
] = node
;
152 /* undo a mapping between cpu and node. */
153 static void unmap_cpu_to_node(int cpu
)
157 printk(KERN_INFO
"Unmapping cpu %d from all nodes\n", cpu
);
158 for (node
= 0; node
< MAX_NUMNODES
; node
++)
159 cpumask_clear_cpu(cpu
, node_to_cpumask_map
[node
]);
160 cpu_to_node_map
[cpu
] = 0;
162 #else /* !(CONFIG_NUMA && CONFIG_X86_32) */
163 #define map_cpu_to_node(cpu, node) ({})
164 #define unmap_cpu_to_node(cpu) ({})
168 static int boot_cpu_logical_apicid
;
170 u8 cpu_2_logical_apicid
[NR_CPUS
] __read_mostly
=
171 { [0 ... NR_CPUS
-1] = BAD_APICID
};
173 static void map_cpu_to_logical_apicid(void)
175 int cpu
= smp_processor_id();
176 int apicid
= logical_smp_processor_id();
177 int node
= apic
->apicid_to_node(apicid
);
179 if (!node_online(node
))
180 node
= first_online_node
;
182 cpu_2_logical_apicid
[cpu
] = apicid
;
183 map_cpu_to_node(cpu
, node
);
186 void numa_remove_cpu(int cpu
)
188 cpu_2_logical_apicid
[cpu
] = BAD_APICID
;
189 unmap_cpu_to_node(cpu
);
192 #define map_cpu_to_logical_apicid() do {} while (0)
196 * Report back to the Boot Processor.
199 static void __cpuinit
smp_callin(void)
202 unsigned long timeout
;
205 * If waken up by an INIT in an 82489DX configuration
206 * we may get here before an INIT-deassert IPI reaches
207 * our local APIC. We have to wait for the IPI or we'll
208 * lock up on an APIC access.
210 if (apic
->wait_for_init_deassert
)
211 apic
->wait_for_init_deassert(&init_deasserted
);
214 * (This works even if the APIC is not enabled.)
216 phys_id
= read_apic_id();
217 cpuid
= smp_processor_id();
218 if (cpumask_test_cpu(cpuid
, cpu_callin_mask
)) {
219 panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__
,
222 pr_debug("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid
, phys_id
);
225 * STARTUP IPIs are fragile beasts as they might sometimes
226 * trigger some glue motherboard logic. Complete APIC bus
227 * silence for 1 second, this overestimates the time the
228 * boot CPU is spending to send the up to 2 STARTUP IPIs
229 * by a factor of two. This should be enough.
233 * Waiting 2s total for startup (udelay is not yet working)
235 timeout
= jiffies
+ 2*HZ
;
236 while (time_before(jiffies
, timeout
)) {
238 * Has the boot CPU finished it's STARTUP sequence?
240 if (cpumask_test_cpu(cpuid
, cpu_callout_mask
))
245 if (!time_before(jiffies
, timeout
)) {
246 panic("%s: CPU%d started up but did not get a callout!\n",
251 * the boot CPU has finished the init stage and is spinning
252 * on callin_map until we finish. We are free to set up this
253 * CPU, first the APIC. (this is probably redundant on most
257 pr_debug("CALLIN, before setup_local_APIC().\n");
258 if (apic
->smp_callin_clear_local_apic
)
259 apic
->smp_callin_clear_local_apic();
261 end_local_APIC_setup();
262 map_cpu_to_logical_apicid();
265 * Need to setup vector mappings before we enable interrupts.
267 setup_vector_irq(smp_processor_id());
271 * Need to enable IRQs because it can take longer and then
272 * the NMI watchdog might kill us.
277 pr_debug("Stack at about %p\n", &cpuid
);
280 * Save our processor parameters
282 smp_store_cpu_info(cpuid
);
285 * This must be done before setting cpu_online_mask
286 * or calling notify_cpu_starting.
288 set_cpu_sibling_map(raw_smp_processor_id());
291 notify_cpu_starting(cpuid
);
294 * Allow the master to continue.
296 cpumask_set_cpu(cpuid
, cpu_callin_mask
);
300 * Activate a secondary processor.
302 notrace
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.
314 /* switch away from the initial page table */
315 load_cr3(swapper_pg_dir
);
319 /* otherwise gcc will move up smp_processor_id before the cpu_init */
322 * Check TSC synchronization with the BP:
324 check_tsc_sync_target();
327 * We need to hold call_lock, so there is no inconsistency
328 * between the time smp_call_function() determines number of
329 * IPI recipients, and the time when the determination is made
330 * for which cpus receive the IPI. Holding this
331 * lock helps us to not include this cpu in a currently in progress
332 * smp_call_function().
334 * We need to hold vector_lock so there the set of online cpus
335 * does not change while we are assigning vectors to cpus. Holding
336 * this lock ensures we don't half assign or remove an irq from a cpu.
340 set_cpu_online(smp_processor_id(), true);
341 unlock_vector_lock();
343 per_cpu(cpu_state
, smp_processor_id()) = CPU_ONLINE
;
344 x86_platform
.nmi_init();
346 /* enable local interrupts */
349 /* to prevent fake stack check failure in clock setup */
350 boot_init_stack_canary();
352 x86_cpuinit
.setup_percpu_clockev();
358 #ifdef CONFIG_CPUMASK_OFFSTACK
359 /* In this case, llc_shared_map is a pointer to a cpumask. */
360 static inline void copy_cpuinfo_x86(struct cpuinfo_x86
*dst
,
361 const struct cpuinfo_x86
*src
)
363 struct cpumask
*llc
= dst
->llc_shared_map
;
365 dst
->llc_shared_map
= llc
;
368 static inline void copy_cpuinfo_x86(struct cpuinfo_x86
*dst
,
369 const struct cpuinfo_x86
*src
)
373 #endif /* CONFIG_CPUMASK_OFFSTACK */
376 * The bootstrap kernel entry code has set these up. Save them for
380 void __cpuinit
smp_store_cpu_info(int id
)
382 struct cpuinfo_x86
*c
= &cpu_data(id
);
384 copy_cpuinfo_x86(c
, &boot_cpu_data
);
387 identify_secondary_cpu(c
);
390 static void __cpuinit
link_thread_siblings(int cpu1
, int cpu2
)
392 struct cpuinfo_x86
*c1
= &cpu_data(cpu1
);
393 struct cpuinfo_x86
*c2
= &cpu_data(cpu2
);
395 cpumask_set_cpu(cpu1
, cpu_sibling_mask(cpu2
));
396 cpumask_set_cpu(cpu2
, cpu_sibling_mask(cpu1
));
397 cpumask_set_cpu(cpu1
, cpu_core_mask(cpu2
));
398 cpumask_set_cpu(cpu2
, cpu_core_mask(cpu1
));
399 cpumask_set_cpu(cpu1
, c2
->llc_shared_map
);
400 cpumask_set_cpu(cpu2
, c1
->llc_shared_map
);
404 void __cpuinit
set_cpu_sibling_map(int cpu
)
407 struct cpuinfo_x86
*c
= &cpu_data(cpu
);
409 cpumask_set_cpu(cpu
, cpu_sibling_setup_mask
);
411 if (smp_num_siblings
> 1) {
412 for_each_cpu(i
, cpu_sibling_setup_mask
) {
413 struct cpuinfo_x86
*o
= &cpu_data(i
);
415 if (cpu_has(c
, X86_FEATURE_TOPOEXT
)) {
416 if (c
->phys_proc_id
== o
->phys_proc_id
&&
417 c
->compute_unit_id
== o
->compute_unit_id
)
418 link_thread_siblings(cpu
, i
);
419 } else if (c
->phys_proc_id
== o
->phys_proc_id
&&
420 c
->cpu_core_id
== o
->cpu_core_id
) {
421 link_thread_siblings(cpu
, i
);
425 cpumask_set_cpu(cpu
, cpu_sibling_mask(cpu
));
428 cpumask_set_cpu(cpu
, c
->llc_shared_map
);
430 if (__this_cpu_read(cpu_info
.x86_max_cores
) == 1) {
431 cpumask_copy(cpu_core_mask(cpu
), cpu_sibling_mask(cpu
));
436 for_each_cpu(i
, cpu_sibling_setup_mask
) {
437 if (per_cpu(cpu_llc_id
, cpu
) != BAD_APICID
&&
438 per_cpu(cpu_llc_id
, cpu
) == per_cpu(cpu_llc_id
, i
)) {
439 cpumask_set_cpu(i
, c
->llc_shared_map
);
440 cpumask_set_cpu(cpu
, cpu_data(i
).llc_shared_map
);
442 if (c
->phys_proc_id
== cpu_data(i
).phys_proc_id
) {
443 cpumask_set_cpu(i
, cpu_core_mask(cpu
));
444 cpumask_set_cpu(cpu
, cpu_core_mask(i
));
446 * Does this new cpu bringup a new core?
448 if (cpumask_weight(cpu_sibling_mask(cpu
)) == 1) {
450 * for each core in package, increment
451 * the booted_cores for this new cpu
453 if (cpumask_first(cpu_sibling_mask(i
)) == i
)
456 * increment the core count for all
457 * the other cpus in this package
460 cpu_data(i
).booted_cores
++;
461 } else if (i
!= cpu
&& !c
->booted_cores
)
462 c
->booted_cores
= cpu_data(i
).booted_cores
;
467 /* maps the cpu to the sched domain representing multi-core */
468 const struct cpumask
*cpu_coregroup_mask(int cpu
)
470 struct cpuinfo_x86
*c
= &cpu_data(cpu
);
472 * For perf, we return last level cache shared map.
473 * And for power savings, we return cpu_core_map
475 if ((sched_mc_power_savings
|| sched_smt_power_savings
) &&
476 !(cpu_has(c
, X86_FEATURE_AMD_DCM
)))
477 return cpu_core_mask(cpu
);
479 return c
->llc_shared_map
;
482 static void impress_friends(void)
485 unsigned long bogosum
= 0;
487 * Allow the user to impress friends.
489 pr_debug("Before bogomips.\n");
490 for_each_possible_cpu(cpu
)
491 if (cpumask_test_cpu(cpu
, cpu_callout_mask
))
492 bogosum
+= cpu_data(cpu
).loops_per_jiffy
;
494 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
497 (bogosum
/(5000/HZ
))%100);
499 pr_debug("Before bogocount - setting activated=1.\n");
502 void __inquire_remote_apic(int apicid
)
504 unsigned i
, regs
[] = { APIC_ID
>> 4, APIC_LVR
>> 4, APIC_SPIV
>> 4 };
505 char *names
[] = { "ID", "VERSION", "SPIV" };
509 printk(KERN_INFO
"Inquiring remote APIC 0x%x...\n", apicid
);
511 for (i
= 0; i
< ARRAY_SIZE(regs
); i
++) {
512 printk(KERN_INFO
"... APIC 0x%x %s: ", apicid
, names
[i
]);
517 status
= safe_apic_wait_icr_idle();
520 "a previous APIC delivery may have failed\n");
522 apic_icr_write(APIC_DM_REMRD
| regs
[i
], apicid
);
527 status
= apic_read(APIC_ICR
) & APIC_ICR_RR_MASK
;
528 } while (status
== APIC_ICR_RR_INPROG
&& timeout
++ < 1000);
531 case APIC_ICR_RR_VALID
:
532 status
= apic_read(APIC_RRR
);
533 printk(KERN_CONT
"%08x\n", status
);
536 printk(KERN_CONT
"failed\n");
542 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
543 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
544 * won't ... remember to clear down the APIC, etc later.
547 wakeup_secondary_cpu_via_nmi(int logical_apicid
, unsigned long start_eip
)
549 unsigned long send_status
, accept_status
= 0;
553 /* Boot on the stack */
554 /* Kick the second */
555 apic_icr_write(APIC_DM_NMI
| apic
->dest_logical
, logical_apicid
);
557 pr_debug("Waiting for send to finish...\n");
558 send_status
= safe_apic_wait_icr_idle();
561 * Give the other CPU some time to accept the IPI.
564 if (APIC_INTEGRATED(apic_version
[boot_cpu_physical_apicid
])) {
565 maxlvt
= lapic_get_maxlvt();
566 if (maxlvt
> 3) /* Due to the Pentium erratum 3AP. */
567 apic_write(APIC_ESR
, 0);
568 accept_status
= (apic_read(APIC_ESR
) & 0xEF);
570 pr_debug("NMI sent.\n");
573 printk(KERN_ERR
"APIC never delivered???\n");
575 printk(KERN_ERR
"APIC delivery error (%lx).\n", accept_status
);
577 return (send_status
| accept_status
);
581 wakeup_secondary_cpu_via_init(int phys_apicid
, unsigned long start_eip
)
583 unsigned long send_status
, accept_status
= 0;
584 int maxlvt
, num_starts
, j
;
586 maxlvt
= lapic_get_maxlvt();
589 * Be paranoid about clearing APIC errors.
591 if (APIC_INTEGRATED(apic_version
[phys_apicid
])) {
592 if (maxlvt
> 3) /* Due to the Pentium erratum 3AP. */
593 apic_write(APIC_ESR
, 0);
597 pr_debug("Asserting INIT.\n");
600 * Turn INIT on target chip
605 apic_icr_write(APIC_INT_LEVELTRIG
| APIC_INT_ASSERT
| APIC_DM_INIT
,
608 pr_debug("Waiting for send to finish...\n");
609 send_status
= safe_apic_wait_icr_idle();
613 pr_debug("Deasserting INIT.\n");
617 apic_icr_write(APIC_INT_LEVELTRIG
| APIC_DM_INIT
, phys_apicid
);
619 pr_debug("Waiting for send to finish...\n");
620 send_status
= safe_apic_wait_icr_idle();
623 atomic_set(&init_deasserted
, 1);
626 * Should we send STARTUP IPIs ?
628 * Determine this based on the APIC version.
629 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
631 if (APIC_INTEGRATED(apic_version
[phys_apicid
]))
637 * Paravirt / VMI wants a startup IPI hook here to set up the
638 * target processor state.
640 startup_ipi_hook(phys_apicid
, (unsigned long) start_secondary
,
641 (unsigned long)stack_start
.sp
);
644 * Run STARTUP IPI loop.
646 pr_debug("#startup loops: %d.\n", num_starts
);
648 for (j
= 1; j
<= num_starts
; j
++) {
649 pr_debug("Sending STARTUP #%d.\n", j
);
650 if (maxlvt
> 3) /* Due to the Pentium erratum 3AP. */
651 apic_write(APIC_ESR
, 0);
653 pr_debug("After apic_write.\n");
660 /* Boot on the stack */
661 /* Kick the second */
662 apic_icr_write(APIC_DM_STARTUP
| (start_eip
>> 12),
666 * Give the other CPU some time to accept the IPI.
670 pr_debug("Startup point 1.\n");
672 pr_debug("Waiting for send to finish...\n");
673 send_status
= safe_apic_wait_icr_idle();
676 * Give the other CPU some time to accept the IPI.
679 if (maxlvt
> 3) /* Due to the Pentium erratum 3AP. */
680 apic_write(APIC_ESR
, 0);
681 accept_status
= (apic_read(APIC_ESR
) & 0xEF);
682 if (send_status
|| accept_status
)
685 pr_debug("After Startup.\n");
688 printk(KERN_ERR
"APIC never delivered???\n");
690 printk(KERN_ERR
"APIC delivery error (%lx).\n", accept_status
);
692 return (send_status
| accept_status
);
696 struct work_struct work
;
697 struct task_struct
*idle
;
698 struct completion done
;
702 static void __cpuinit
do_fork_idle(struct work_struct
*work
)
704 struct create_idle
*c_idle
=
705 container_of(work
, struct create_idle
, work
);
707 c_idle
->idle
= fork_idle(c_idle
->cpu
);
708 complete(&c_idle
->done
);
711 /* reduce the number of lines printed when booting a large cpu count system */
712 static void __cpuinit
announce_cpu(int cpu
, int apicid
)
714 static int current_node
= -1;
715 int node
= early_cpu_to_node(cpu
);
717 if (system_state
== SYSTEM_BOOTING
) {
718 if (node
!= current_node
) {
719 if (current_node
> (-1))
722 pr_info("Booting Node %3d, Processors ", node
);
724 pr_cont(" #%d%s", cpu
, cpu
== (nr_cpu_ids
- 1) ? " Ok.\n" : "");
727 pr_info("Booting Node %d Processor %d APIC 0x%x\n",
732 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
733 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
734 * Returns zero if CPU booted OK, else error code from
735 * ->wakeup_secondary_cpu.
737 static int __cpuinit
do_boot_cpu(int apicid
, int cpu
)
739 unsigned long boot_error
= 0;
740 unsigned long start_ip
;
742 struct create_idle c_idle
= {
744 .done
= COMPLETION_INITIALIZER_ONSTACK(c_idle
.done
),
747 INIT_WORK_ONSTACK(&c_idle
.work
, do_fork_idle
);
749 alternatives_smp_switch(1);
751 c_idle
.idle
= get_idle_for_cpu(cpu
);
754 * We can't use kernel_thread since we must avoid to
755 * reschedule the child.
758 c_idle
.idle
->thread
.sp
= (unsigned long) (((struct pt_regs
*)
759 (THREAD_SIZE
+ task_stack_page(c_idle
.idle
))) - 1);
760 init_idle(c_idle
.idle
, cpu
);
764 schedule_work(&c_idle
.work
);
765 wait_for_completion(&c_idle
.done
);
767 if (IS_ERR(c_idle
.idle
)) {
768 printk("failed fork for CPU %d\n", cpu
);
769 destroy_work_on_stack(&c_idle
.work
);
770 return PTR_ERR(c_idle
.idle
);
773 set_idle_for_cpu(cpu
, c_idle
.idle
);
775 per_cpu(current_task
, cpu
) = c_idle
.idle
;
777 /* Stack for startup_32 can be just as for start_secondary onwards */
780 clear_tsk_thread_flag(c_idle
.idle
, TIF_FORK
);
781 initial_gs
= per_cpu_offset(cpu
);
782 per_cpu(kernel_stack
, cpu
) =
783 (unsigned long)task_stack_page(c_idle
.idle
) -
784 KERNEL_STACK_OFFSET
+ THREAD_SIZE
;
786 early_gdt_descr
.address
= (unsigned long)get_cpu_gdt_table(cpu
);
787 initial_code
= (unsigned long)start_secondary
;
788 stack_start
.sp
= (void *) c_idle
.idle
->thread
.sp
;
790 /* start_ip had better be page-aligned! */
791 start_ip
= setup_trampoline();
793 /* So we see what's up */
794 announce_cpu(cpu
, apicid
);
797 * This grunge runs the startup process for
798 * the targeted processor.
801 atomic_set(&init_deasserted
, 0);
803 if (get_uv_system_type() != UV_NON_UNIQUE_APIC
) {
805 pr_debug("Setting warm reset code and vector.\n");
807 smpboot_setup_warm_reset_vector(start_ip
);
809 * Be paranoid about clearing APIC errors.
811 if (APIC_INTEGRATED(apic_version
[boot_cpu_physical_apicid
])) {
812 apic_write(APIC_ESR
, 0);
818 * Kick the secondary CPU. Use the method in the APIC driver
819 * if it's defined - or use an INIT boot APIC message otherwise:
821 if (apic
->wakeup_secondary_cpu
)
822 boot_error
= apic
->wakeup_secondary_cpu(apicid
, start_ip
);
824 boot_error
= wakeup_secondary_cpu_via_init(apicid
, start_ip
);
828 * allow APs to start initializing.
830 pr_debug("Before Callout %d.\n", cpu
);
831 cpumask_set_cpu(cpu
, cpu_callout_mask
);
832 pr_debug("After Callout %d.\n", cpu
);
835 * Wait 5s total for a response
837 for (timeout
= 0; timeout
< 50000; timeout
++) {
838 if (cpumask_test_cpu(cpu
, cpu_callin_mask
))
839 break; /* It has booted */
842 * Allow other tasks to run while we wait for the
843 * AP to come online. This also gives a chance
844 * for the MTRR work(triggered by the AP coming online)
845 * to be completed in the stop machine context.
850 if (cpumask_test_cpu(cpu
, cpu_callin_mask
))
851 pr_debug("CPU%d: has booted.\n", cpu
);
854 if (*((volatile unsigned char *)trampoline_base
)
856 /* trampoline started but...? */
857 pr_err("CPU%d: Stuck ??\n", cpu
);
859 /* trampoline code not run */
860 pr_err("CPU%d: Not responding.\n", cpu
);
861 if (apic
->inquire_remote_apic
)
862 apic
->inquire_remote_apic(apicid
);
867 /* Try to put things back the way they were before ... */
868 numa_remove_cpu(cpu
); /* was set by numa_add_cpu */
870 /* was set by do_boot_cpu() */
871 cpumask_clear_cpu(cpu
, cpu_callout_mask
);
873 /* was set by cpu_init() */
874 cpumask_clear_cpu(cpu
, cpu_initialized_mask
);
876 set_cpu_present(cpu
, false);
877 per_cpu(x86_cpu_to_apicid
, cpu
) = BAD_APICID
;
880 /* mark "stuck" area as not stuck */
881 *((volatile unsigned long *)trampoline_base
) = 0;
883 if (get_uv_system_type() != UV_NON_UNIQUE_APIC
) {
885 * Cleanup possible dangling ends...
887 smpboot_restore_warm_reset_vector();
890 destroy_work_on_stack(&c_idle
.work
);
894 int __cpuinit
native_cpu_up(unsigned int cpu
)
896 int apicid
= apic
->cpu_present_to_apicid(cpu
);
900 WARN_ON(irqs_disabled());
902 pr_debug("++++++++++++++++++++=_---CPU UP %u\n", cpu
);
904 if (apicid
== BAD_APICID
|| apicid
== boot_cpu_physical_apicid
||
905 !physid_isset(apicid
, phys_cpu_present_map
)) {
906 printk(KERN_ERR
"%s: bad cpu %d\n", __func__
, cpu
);
911 * Already booted CPU?
913 if (cpumask_test_cpu(cpu
, cpu_callin_mask
)) {
914 pr_debug("do_boot_cpu %d Already started\n", cpu
);
919 * Save current MTRR state in case it was changed since early boot
920 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
924 per_cpu(cpu_state
, cpu
) = CPU_UP_PREPARE
;
926 err
= do_boot_cpu(apicid
, cpu
);
928 pr_debug("do_boot_cpu failed %d\n", err
);
933 * Check TSC synchronization with the AP (keep irqs disabled
936 local_irq_save(flags
);
937 check_tsc_sync_source(cpu
);
938 local_irq_restore(flags
);
940 while (!cpu_online(cpu
)) {
942 touch_nmi_watchdog();
949 * Fall back to non SMP mode after errors.
951 * RED-PEN audit/test this more. I bet there is more state messed up here.
953 static __init
void disable_smp(void)
955 init_cpu_present(cpumask_of(0));
956 init_cpu_possible(cpumask_of(0));
957 smpboot_clear_io_apic_irqs();
959 if (smp_found_config
)
960 physid_set_mask_of_physid(boot_cpu_physical_apicid
, &phys_cpu_present_map
);
962 physid_set_mask_of_physid(0, &phys_cpu_present_map
);
963 map_cpu_to_logical_apicid();
964 cpumask_set_cpu(0, cpu_sibling_mask(0));
965 cpumask_set_cpu(0, cpu_core_mask(0));
969 * Various sanity checks.
971 static int __init
smp_sanity_check(unsigned max_cpus
)
975 #if !defined(CONFIG_X86_BIGSMP) && defined(CONFIG_X86_32)
976 if (def_to_bigsmp
&& nr_cpu_ids
> 8) {
981 "More than 8 CPUs detected - skipping them.\n"
982 "Use CONFIG_X86_BIGSMP.\n");
985 for_each_present_cpu(cpu
) {
987 set_cpu_present(cpu
, false);
992 for_each_possible_cpu(cpu
) {
994 set_cpu_possible(cpu
, false);
1002 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map
)) {
1004 "weird, boot CPU (#%d) not listed by the BIOS.\n",
1005 hard_smp_processor_id());
1007 physid_set(hard_smp_processor_id(), phys_cpu_present_map
);
1011 * If we couldn't find an SMP configuration at boot time,
1012 * get out of here now!
1014 if (!smp_found_config
&& !acpi_lapic
) {
1016 printk(KERN_NOTICE
"SMP motherboard not detected.\n");
1018 if (APIC_init_uniprocessor())
1019 printk(KERN_NOTICE
"Local APIC not detected."
1020 " Using dummy APIC emulation.\n");
1025 * Should not be necessary because the MP table should list the boot
1026 * CPU too, but we do it for the sake of robustness anyway.
1028 if (!apic
->check_phys_apicid_present(boot_cpu_physical_apicid
)) {
1030 "weird, boot CPU (#%d) not listed by the BIOS.\n",
1031 boot_cpu_physical_apicid
);
1032 physid_set(hard_smp_processor_id(), phys_cpu_present_map
);
1037 * If we couldn't find a local APIC, then get out of here now!
1039 if (APIC_INTEGRATED(apic_version
[boot_cpu_physical_apicid
]) &&
1041 if (!disable_apic
) {
1042 pr_err("BIOS bug, local APIC #%d not detected!...\n",
1043 boot_cpu_physical_apicid
);
1044 pr_err("... forcing use of dummy APIC emulation."
1045 "(tell your hw vendor)\n");
1047 smpboot_clear_io_apic();
1048 arch_disable_smp_support();
1052 verify_local_APIC();
1055 * If SMP should be disabled, then really disable it!
1058 printk(KERN_INFO
"SMP mode deactivated.\n");
1059 smpboot_clear_io_apic();
1063 end_local_APIC_setup();
1070 static void __init
smp_cpu_index_default(void)
1073 struct cpuinfo_x86
*c
;
1075 for_each_possible_cpu(i
) {
1077 /* mark all to hotplug */
1078 c
->cpu_index
= nr_cpu_ids
;
1083 * Prepare for SMP bootup. The MP table or ACPI has been read
1084 * earlier. Just do some sanity checking here and enable APIC mode.
1086 void __init
native_smp_prepare_cpus(unsigned int max_cpus
)
1091 smp_cpu_index_default();
1092 memcpy(__this_cpu_ptr(&cpu_info
), &boot_cpu_data
, sizeof(cpu_info
));
1093 cpumask_copy(cpu_callin_mask
, cpumask_of(0));
1096 * Setup boot CPU information
1098 smp_store_cpu_info(0); /* Final full version of the data */
1099 #ifdef CONFIG_X86_32
1100 boot_cpu_logical_apicid
= logical_smp_processor_id();
1102 current_thread_info()->cpu
= 0; /* needed? */
1103 for_each_possible_cpu(i
) {
1104 zalloc_cpumask_var(&per_cpu(cpu_sibling_map
, i
), GFP_KERNEL
);
1105 zalloc_cpumask_var(&per_cpu(cpu_core_map
, i
), GFP_KERNEL
);
1106 zalloc_cpumask_var(&cpu_data(i
).llc_shared_map
, GFP_KERNEL
);
1108 set_cpu_sibling_map(0);
1111 if (smp_sanity_check(max_cpus
) < 0) {
1112 printk(KERN_INFO
"SMP disabled\n");
1117 default_setup_apic_routing();
1120 if (read_apic_id() != boot_cpu_physical_apicid
) {
1121 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1122 read_apic_id(), boot_cpu_physical_apicid
);
1123 /* Or can we switch back to PIC here? */
1130 * Switch from PIC to APIC mode.
1135 * Enable IO APIC before setting up error vector
1137 if (!skip_ioapic_setup
&& nr_ioapics
)
1140 end_local_APIC_setup();
1142 map_cpu_to_logical_apicid();
1144 if (apic
->setup_portio_remap
)
1145 apic
->setup_portio_remap();
1147 smpboot_setup_io_apic();
1149 * Set up local APIC timer on boot CPU.
1152 printk(KERN_INFO
"CPU%d: ", 0);
1153 print_cpu_info(&cpu_data(0));
1154 x86_init
.timers
.setup_percpu_clockev();
1159 set_mtrr_aps_delayed_init();
1164 void arch_disable_nonboot_cpus_begin(void)
1167 * Avoid the smp alternatives switch during the disable_nonboot_cpus().
1168 * In the suspend path, we will be back in the SMP mode shortly anyways.
1170 skip_smp_alternatives
= true;
1173 void arch_disable_nonboot_cpus_end(void)
1175 skip_smp_alternatives
= false;
1178 void arch_enable_nonboot_cpus_begin(void)
1180 set_mtrr_aps_delayed_init();
1183 void arch_enable_nonboot_cpus_end(void)
1189 * Early setup to make printk work.
1191 void __init
native_smp_prepare_boot_cpu(void)
1193 int me
= smp_processor_id();
1194 switch_to_new_gdt(me
);
1195 /* already set me in cpu_online_mask in boot_cpu_init() */
1196 cpumask_set_cpu(me
, cpu_callout_mask
);
1197 per_cpu(cpu_state
, me
) = CPU_ONLINE
;
1200 void __init
native_smp_cpus_done(unsigned int max_cpus
)
1202 pr_debug("Boot done.\n");
1205 #ifdef CONFIG_X86_IO_APIC
1206 setup_ioapic_dest();
1211 static int __initdata setup_possible_cpus
= -1;
1212 static int __init
_setup_possible_cpus(char *str
)
1214 get_option(&str
, &setup_possible_cpus
);
1217 early_param("possible_cpus", _setup_possible_cpus
);
1221 * cpu_possible_mask should be static, it cannot change as cpu's
1222 * are onlined, or offlined. The reason is per-cpu data-structures
1223 * are allocated by some modules at init time, and dont expect to
1224 * do this dynamically on cpu arrival/departure.
1225 * cpu_present_mask on the other hand can change dynamically.
1226 * In case when cpu_hotplug is not compiled, then we resort to current
1227 * behaviour, which is cpu_possible == cpu_present.
1230 * Three ways to find out the number of additional hotplug CPUs:
1231 * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
1232 * - The user can overwrite it with possible_cpus=NUM
1233 * - Otherwise don't reserve additional CPUs.
1234 * We do this because additional CPUs waste a lot of memory.
1237 __init
void prefill_possible_map(void)
1241 /* no processor from mptable or madt */
1242 if (!num_processors
)
1245 i
= setup_max_cpus
?: 1;
1246 if (setup_possible_cpus
== -1) {
1247 possible
= num_processors
;
1248 #ifdef CONFIG_HOTPLUG_CPU
1250 possible
+= disabled_cpus
;
1256 possible
= setup_possible_cpus
;
1258 total_cpus
= max_t(int, possible
, num_processors
+ disabled_cpus
);
1260 /* nr_cpu_ids could be reduced via nr_cpus= */
1261 if (possible
> nr_cpu_ids
) {
1263 "%d Processors exceeds NR_CPUS limit of %d\n",
1264 possible
, nr_cpu_ids
);
1265 possible
= nr_cpu_ids
;
1268 #ifdef CONFIG_HOTPLUG_CPU
1269 if (!setup_max_cpus
)
1273 "%d Processors exceeds max_cpus limit of %u\n",
1274 possible
, setup_max_cpus
);
1278 printk(KERN_INFO
"SMP: Allowing %d CPUs, %d hotplug CPUs\n",
1279 possible
, max_t(int, possible
- num_processors
, 0));
1281 for (i
= 0; i
< possible
; i
++)
1282 set_cpu_possible(i
, true);
1283 for (; i
< NR_CPUS
; i
++)
1284 set_cpu_possible(i
, false);
1286 nr_cpu_ids
= possible
;
1289 #ifdef CONFIG_HOTPLUG_CPU
1291 static void remove_siblinginfo(int cpu
)
1294 struct cpuinfo_x86
*c
= &cpu_data(cpu
);
1296 for_each_cpu(sibling
, cpu_core_mask(cpu
)) {
1297 cpumask_clear_cpu(cpu
, cpu_core_mask(sibling
));
1299 * last thread sibling in this cpu core going down
1301 if (cpumask_weight(cpu_sibling_mask(cpu
)) == 1)
1302 cpu_data(sibling
).booted_cores
--;
1305 for_each_cpu(sibling
, cpu_sibling_mask(cpu
))
1306 cpumask_clear_cpu(cpu
, cpu_sibling_mask(sibling
));
1307 cpumask_clear(cpu_sibling_mask(cpu
));
1308 cpumask_clear(cpu_core_mask(cpu
));
1309 c
->phys_proc_id
= 0;
1311 cpumask_clear_cpu(cpu
, cpu_sibling_setup_mask
);
1314 static void __ref
remove_cpu_from_maps(int cpu
)
1316 set_cpu_online(cpu
, false);
1317 cpumask_clear_cpu(cpu
, cpu_callout_mask
);
1318 cpumask_clear_cpu(cpu
, cpu_callin_mask
);
1319 /* was set by cpu_init() */
1320 cpumask_clear_cpu(cpu
, cpu_initialized_mask
);
1321 numa_remove_cpu(cpu
);
1324 void cpu_disable_common(void)
1326 int cpu
= smp_processor_id();
1328 remove_siblinginfo(cpu
);
1330 /* It's now safe to remove this processor from the online map */
1332 remove_cpu_from_maps(cpu
);
1333 unlock_vector_lock();
1337 int native_cpu_disable(void)
1339 int cpu
= smp_processor_id();
1342 * Perhaps use cpufreq to drop frequency, but that could go
1343 * into generic code.
1345 * We won't take down the boot processor on i386 due to some
1346 * interrupts only being able to be serviced by the BSP.
1347 * Especially so if we're not using an IOAPIC -zwane
1354 cpu_disable_common();
1358 void native_cpu_die(unsigned int cpu
)
1360 /* We don't do anything here: idle task is faking death itself. */
1363 for (i
= 0; i
< 10; i
++) {
1364 /* They ack this in play_dead by setting CPU_DEAD */
1365 if (per_cpu(cpu_state
, cpu
) == CPU_DEAD
) {
1366 if (system_state
== SYSTEM_RUNNING
)
1367 pr_info("CPU %u is now offline\n", cpu
);
1369 if (1 == num_online_cpus())
1370 alternatives_smp_switch(0);
1375 pr_err("CPU %u didn't die...\n", cpu
);
1378 void play_dead_common(void)
1381 reset_lazy_tlbstate();
1382 c1e_remove_cpu(raw_smp_processor_id());
1386 __this_cpu_write(cpu_state
, CPU_DEAD
);
1389 * With physical CPU hotplug, we should halt the cpu
1391 local_irq_disable();
1395 * We need to flush the caches before going to sleep, lest we have
1396 * dirty data in our caches when we come back up.
1398 static inline void mwait_play_dead(void)
1400 unsigned int eax
, ebx
, ecx
, edx
;
1401 unsigned int highest_cstate
= 0;
1402 unsigned int highest_subcstate
= 0;
1405 struct cpuinfo_x86
*c
= __this_cpu_ptr(&cpu_info
);
1407 if (!(cpu_has(c
, X86_FEATURE_MWAIT
) && mwait_usable(c
)))
1409 if (!cpu_has(__this_cpu_ptr(&cpu_info
), X86_FEATURE_CLFLSH
))
1411 if (__this_cpu_read(cpu_info
.cpuid_level
) < CPUID_MWAIT_LEAF
)
1414 eax
= CPUID_MWAIT_LEAF
;
1416 native_cpuid(&eax
, &ebx
, &ecx
, &edx
);
1419 * eax will be 0 if EDX enumeration is not valid.
1420 * Initialized below to cstate, sub_cstate value when EDX is valid.
1422 if (!(ecx
& CPUID5_ECX_EXTENSIONS_SUPPORTED
)) {
1425 edx
>>= MWAIT_SUBSTATE_SIZE
;
1426 for (i
= 0; i
< 7 && edx
; i
++, edx
>>= MWAIT_SUBSTATE_SIZE
) {
1427 if (edx
& MWAIT_SUBSTATE_MASK
) {
1429 highest_subcstate
= edx
& MWAIT_SUBSTATE_MASK
;
1432 eax
= (highest_cstate
<< MWAIT_SUBSTATE_SIZE
) |
1433 (highest_subcstate
- 1);
1437 * This should be a memory location in a cache line which is
1438 * unlikely to be touched by other processors. The actual
1439 * content is immaterial as it is not actually modified in any way.
1441 mwait_ptr
= ¤t_thread_info()->flags
;
1447 * The CLFLUSH is a workaround for erratum AAI65 for
1448 * the Xeon 7400 series. It's not clear it is actually
1449 * needed, but it should be harmless in either case.
1450 * The WBINVD is insufficient due to the spurious-wakeup
1451 * case where we return around the loop.
1454 __monitor(mwait_ptr
, 0, 0);
1460 static inline void hlt_play_dead(void)
1462 if (__this_cpu_read(cpu_info
.x86
) >= 4)
1470 void native_play_dead(void)
1473 tboot_shutdown(TB_SHUTDOWN_WFS
);
1475 mwait_play_dead(); /* Only returns on failure */
1479 #else /* ... !CONFIG_HOTPLUG_CPU */
1480 int native_cpu_disable(void)
1485 void native_cpu_die(unsigned int cpu
)
1487 /* We said "no" in __cpu_disable */
1491 void native_play_dead(void)