Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfashe...
[linux-2.6-block.git] / arch / x86 / kernel / smpboot.c
CommitLineData
4cedb334
GOC
1/*
2 * x86 SMP booting functions
3 *
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.
7 *
8 * Much of the core SMP work is based on previous work by Thomas Radke, to
9 * whom a great many thanks are extended.
10 *
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.
14 *
15 * This code is released under the GNU General Public License version 2 or
16 * later.
17 *
18 * Fixes
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
29 * from Jose Renau
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
40 */
41
68a1c3f8
GC
42#include <linux/init.h>
43#include <linux/smp.h>
a355352b 44#include <linux/module.h>
70708a18 45#include <linux/sched.h>
69c18c15 46#include <linux/percpu.h>
91718e8d 47#include <linux/bootmem.h>
cb3c8b90
GOC
48#include <linux/err.h>
49#include <linux/nmi.h>
69c18c15 50
8aef135c 51#include <asm/acpi.h>
cb3c8b90 52#include <asm/desc.h>
69c18c15
GC
53#include <asm/nmi.h>
54#include <asm/irq.h>
55#include <asm/smp.h>
e44b7b75 56#include <asm/trampoline.h>
69c18c15
GC
57#include <asm/cpu.h>
58#include <asm/numa.h>
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GOC
59#include <asm/pgtable.h>
60#include <asm/tlbflush.h>
61#include <asm/mtrr.h>
bbc2ff6a 62#include <asm/vmi.h>
34d05591 63#include <asm/genapic.h>
cb3c8b90 64#include <linux/mc146818rtc.h>
68a1c3f8 65
f6bc4029 66#include <mach_apic.h>
cb3c8b90
GOC
67#include <mach_wakecpu.h>
68#include <smpboot_hooks.h>
69
16ecf7a4 70#ifdef CONFIG_X86_32
4cedb334 71u8 apicid_2_node[MAX_APICID];
61165d7a 72static int low_mappings;
acbb6734
GOC
73#endif
74
a8db8453
GOC
75/* State of each CPU */
76DEFINE_PER_CPU(int, cpu_state) = { 0 };
77
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GOC
78/* Store all idle threads, this can be reused instead of creating
79* a new thread. Also avoids complicated thread destroy functionality
80* for idle threads.
81*/
82#ifdef CONFIG_HOTPLUG_CPU
83/*
84 * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is
85 * removed after init for !CONFIG_HOTPLUG_CPU.
86 */
87static DEFINE_PER_CPU(struct task_struct *, idle_thread_array);
88#define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x))
89#define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p))
90#else
91struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ;
92#define get_idle_for_cpu(x) (idle_thread_array[(x)])
93#define set_idle_for_cpu(x, p) (idle_thread_array[(x)] = (p))
94#endif
f6bc4029 95
a355352b
GC
96/* Number of siblings per CPU package */
97int smp_num_siblings = 1;
98EXPORT_SYMBOL(smp_num_siblings);
99
100/* Last level cache ID of each logical CPU */
101DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
102
103/* bitmap of online cpus */
104cpumask_t cpu_online_map __read_mostly;
105EXPORT_SYMBOL(cpu_online_map);
106
107cpumask_t cpu_callin_map;
108cpumask_t cpu_callout_map;
109cpumask_t cpu_possible_map;
110EXPORT_SYMBOL(cpu_possible_map);
111
112/* representing HT siblings of each logical CPU */
113DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
114EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
115
116/* representing HT and core siblings of each logical CPU */
117DEFINE_PER_CPU(cpumask_t, cpu_core_map);
118EXPORT_PER_CPU_SYMBOL(cpu_core_map);
119
120/* Per CPU bogomips and other parameters */
121DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
122EXPORT_PER_CPU_SYMBOL(cpu_info);
768d9505 123
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124static atomic_t init_deasserted;
125
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GOC
126static int boot_cpu_logical_apicid;
127
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GC
128/* representing cpus for which sibling maps can be computed */
129static cpumask_t cpu_sibling_setup_map;
130
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GOC
131/* Set if we find a B stepping CPU */
132int __cpuinitdata smp_b_stepping;
1d89a7f0 133
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GOC
134#if defined(CONFIG_NUMA) && defined(CONFIG_X86_32)
135
136/* which logical CPUs are on which nodes */
137cpumask_t node_to_cpumask_map[MAX_NUMNODES] __read_mostly =
138 { [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE };
139EXPORT_SYMBOL(node_to_cpumask_map);
140/* which node each logical CPU is on */
141int cpu_to_node_map[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = 0 };
142EXPORT_SYMBOL(cpu_to_node_map);
143
144/* set up a mapping between cpu and node. */
145static void map_cpu_to_node(int cpu, int node)
146{
147 printk(KERN_INFO "Mapping cpu %d to node %d\n", cpu, node);
148 cpu_set(cpu, node_to_cpumask_map[node]);
149 cpu_to_node_map[cpu] = node;
150}
151
152/* undo a mapping between cpu and node. */
153static void unmap_cpu_to_node(int cpu)
154{
155 int node;
156
157 printk(KERN_INFO "Unmapping cpu %d from all nodes\n", cpu);
158 for (node = 0; node < MAX_NUMNODES; node++)
159 cpu_clear(cpu, node_to_cpumask_map[node]);
160 cpu_to_node_map[cpu] = 0;
161}
162#else /* !(CONFIG_NUMA && CONFIG_X86_32) */
163#define map_cpu_to_node(cpu, node) ({})
164#define unmap_cpu_to_node(cpu) ({})
165#endif
166
167#ifdef CONFIG_X86_32
168u8 cpu_2_logical_apicid[NR_CPUS] __read_mostly =
169 { [0 ... NR_CPUS-1] = BAD_APICID };
170
a4928cff 171static void map_cpu_to_logical_apicid(void)
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GOC
172{
173 int cpu = smp_processor_id();
174 int apicid = logical_smp_processor_id();
175 int node = apicid_to_node(apicid);
176
177 if (!node_online(node))
178 node = first_online_node;
179
180 cpu_2_logical_apicid[cpu] = apicid;
181 map_cpu_to_node(cpu, node);
182}
183
1481a3dd 184void numa_remove_cpu(int cpu)
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GOC
185{
186 cpu_2_logical_apicid[cpu] = BAD_APICID;
187 unmap_cpu_to_node(cpu);
188}
189#else
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GOC
190#define map_cpu_to_logical_apicid() do {} while (0)
191#endif
192
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GOC
193/*
194 * Report back to the Boot Processor.
195 * Running on AP.
196 */
a4928cff 197static void __cpuinit smp_callin(void)
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GOC
198{
199 int cpuid, phys_id;
200 unsigned long timeout;
201
202 /*
203 * If waken up by an INIT in an 82489DX configuration
204 * we may get here before an INIT-deassert IPI reaches
205 * our local APIC. We have to wait for the IPI or we'll
206 * lock up on an APIC access.
207 */
208 wait_for_init_deassert(&init_deasserted);
209
210 /*
211 * (This works even if the APIC is not enabled.)
212 */
05f2d12c 213 phys_id = GET_APIC_ID(read_apic_id());
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GOC
214 cpuid = smp_processor_id();
215 if (cpu_isset(cpuid, cpu_callin_map)) {
216 panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__,
217 phys_id, cpuid);
218 }
219 Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
220
221 /*
222 * STARTUP IPIs are fragile beasts as they might sometimes
223 * trigger some glue motherboard logic. Complete APIC bus
224 * silence for 1 second, this overestimates the time the
225 * boot CPU is spending to send the up to 2 STARTUP IPIs
226 * by a factor of two. This should be enough.
227 */
228
229 /*
230 * Waiting 2s total for startup (udelay is not yet working)
231 */
232 timeout = jiffies + 2*HZ;
233 while (time_before(jiffies, timeout)) {
234 /*
235 * Has the boot CPU finished it's STARTUP sequence?
236 */
237 if (cpu_isset(cpuid, cpu_callout_map))
238 break;
239 cpu_relax();
240 }
241
242 if (!time_before(jiffies, timeout)) {
243 panic("%s: CPU%d started up but did not get a callout!\n",
244 __func__, cpuid);
245 }
246
247 /*
248 * the boot CPU has finished the init stage and is spinning
249 * on callin_map until we finish. We are free to set up this
250 * CPU, first the APIC. (this is probably redundant on most
251 * boards)
252 */
253
254 Dprintk("CALLIN, before setup_local_APIC().\n");
255 smp_callin_clear_local_apic();
256 setup_local_APIC();
257 end_local_APIC_setup();
258 map_cpu_to_logical_apicid();
259
260 /*
261 * Get our bogomips.
262 *
263 * Need to enable IRQs because it can take longer and then
264 * the NMI watchdog might kill us.
265 */
266 local_irq_enable();
267 calibrate_delay();
268 local_irq_disable();
269 Dprintk("Stack at about %p\n", &cpuid);
270
271 /*
272 * Save our processor parameters
273 */
274 smp_store_cpu_info(cpuid);
275
276 /*
277 * Allow the master to continue.
278 */
279 cpu_set(cpuid, cpu_callin_map);
280}
281
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282/*
283 * Activate a secondary processor.
284 */
dbe55f47 285static void __cpuinit start_secondary(void *unused)
bbc2ff6a
GOC
286{
287 /*
288 * Don't put *anything* before cpu_init(), SMP booting is too
289 * fragile that we want to limit the things done here to the
290 * most necessary things.
291 */
292#ifdef CONFIG_VMI
293 vmi_bringup();
294#endif
295 cpu_init();
296 preempt_disable();
297 smp_callin();
298
299 /* otherwise gcc will move up smp_processor_id before the cpu_init */
300 barrier();
301 /*
302 * Check TSC synchronization with the BP:
303 */
304 check_tsc_sync_target();
305
306 if (nmi_watchdog == NMI_IO_APIC) {
307 disable_8259A_irq(0);
308 enable_NMI_through_LVT0();
309 enable_8259A_irq(0);
310 }
311
61165d7a
HD
312#ifdef CONFIG_X86_32
313 while (low_mappings)
314 cpu_relax();
315 __flush_tlb_all();
316#endif
317
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GOC
318 /* This must be done before setting cpu_online_map */
319 set_cpu_sibling_map(raw_smp_processor_id());
320 wmb();
321
322 /*
323 * We need to hold call_lock, so there is no inconsistency
324 * between the time smp_call_function() determines number of
325 * IPI recipients, and the time when the determination is made
326 * for which cpus receive the IPI. Holding this
327 * lock helps us to not include this cpu in a currently in progress
328 * smp_call_function().
329 */
3b16cf87 330 ipi_call_lock_irq();
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GC
331#ifdef CONFIG_X86_IO_APIC
332 setup_vector_irq(smp_processor_id());
bbc2ff6a
GOC
333#endif
334 cpu_set(smp_processor_id(), cpu_online_map);
3b16cf87 335 ipi_call_unlock_irq();
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GOC
336 per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
337
338 setup_secondary_clock();
339
340 wmb();
341 cpu_idle();
342}
343
1d89a7f0
GOC
344static void __cpuinit smp_apply_quirks(struct cpuinfo_x86 *c)
345{
1d89a7f0
GOC
346 /*
347 * Mask B, Pentium, but not Pentium MMX
348 */
349 if (c->x86_vendor == X86_VENDOR_INTEL &&
350 c->x86 == 5 &&
351 c->x86_mask >= 1 && c->x86_mask <= 4 &&
352 c->x86_model <= 3)
353 /*
354 * Remember we have B step Pentia with bugs
355 */
356 smp_b_stepping = 1;
357
358 /*
359 * Certain Athlons might work (for various values of 'work') in SMP
360 * but they are not certified as MP capable.
361 */
362 if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) {
363
364 if (num_possible_cpus() == 1)
365 goto valid_k7;
366
367 /* Athlon 660/661 is valid. */
368 if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
369 (c->x86_mask == 1)))
370 goto valid_k7;
371
372 /* Duron 670 is valid */
373 if ((c->x86_model == 7) && (c->x86_mask == 0))
374 goto valid_k7;
375
376 /*
377 * Athlon 662, Duron 671, and Athlon >model 7 have capability
378 * bit. It's worth noting that the A5 stepping (662) of some
379 * Athlon XP's have the MP bit set.
380 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
381 * more.
382 */
383 if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
384 ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
385 (c->x86_model > 7))
386 if (cpu_has_mp)
387 goto valid_k7;
388
389 /* If we get here, not a certified SMP capable AMD system. */
390 add_taint(TAINT_UNSAFE_SMP);
391 }
392
393valid_k7:
394 ;
1d89a7f0
GOC
395}
396
a4928cff 397static void __cpuinit smp_checks(void)
693d4b8a
GOC
398{
399 if (smp_b_stepping)
400 printk(KERN_WARNING "WARNING: SMP operation may be unreliable"
401 "with B stepping processors.\n");
402
403 /*
404 * Don't taint if we are running SMP kernel on a single non-MP
405 * approved Athlon
406 */
407 if (tainted & TAINT_UNSAFE_SMP) {
f68e00a3 408 if (num_online_cpus())
693d4b8a
GOC
409 printk(KERN_INFO "WARNING: This combination of AMD"
410 "processors is not suitable for SMP.\n");
411 else
412 tainted &= ~TAINT_UNSAFE_SMP;
413 }
414}
415
1d89a7f0
GOC
416/*
417 * The bootstrap kernel entry code has set these up. Save them for
418 * a given CPU
419 */
420
421void __cpuinit smp_store_cpu_info(int id)
422{
423 struct cpuinfo_x86 *c = &cpu_data(id);
424
425 *c = boot_cpu_data;
426 c->cpu_index = id;
427 if (id != 0)
428 identify_secondary_cpu(c);
429 smp_apply_quirks(c);
430}
431
432
768d9505
GC
433void __cpuinit set_cpu_sibling_map(int cpu)
434{
435 int i;
436 struct cpuinfo_x86 *c = &cpu_data(cpu);
437
438 cpu_set(cpu, cpu_sibling_setup_map);
439
440 if (smp_num_siblings > 1) {
441 for_each_cpu_mask(i, cpu_sibling_setup_map) {
442 if (c->phys_proc_id == cpu_data(i).phys_proc_id &&
443 c->cpu_core_id == cpu_data(i).cpu_core_id) {
444 cpu_set(i, per_cpu(cpu_sibling_map, cpu));
445 cpu_set(cpu, per_cpu(cpu_sibling_map, i));
446 cpu_set(i, per_cpu(cpu_core_map, cpu));
447 cpu_set(cpu, per_cpu(cpu_core_map, i));
448 cpu_set(i, c->llc_shared_map);
449 cpu_set(cpu, cpu_data(i).llc_shared_map);
450 }
451 }
452 } else {
453 cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
454 }
455
456 cpu_set(cpu, c->llc_shared_map);
457
458 if (current_cpu_data.x86_max_cores == 1) {
459 per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
460 c->booted_cores = 1;
461 return;
462 }
463
464 for_each_cpu_mask(i, cpu_sibling_setup_map) {
465 if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
466 per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
467 cpu_set(i, c->llc_shared_map);
468 cpu_set(cpu, cpu_data(i).llc_shared_map);
469 }
470 if (c->phys_proc_id == cpu_data(i).phys_proc_id) {
471 cpu_set(i, per_cpu(cpu_core_map, cpu));
472 cpu_set(cpu, per_cpu(cpu_core_map, i));
473 /*
474 * Does this new cpu bringup a new core?
475 */
476 if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) {
477 /*
478 * for each core in package, increment
479 * the booted_cores for this new cpu
480 */
481 if (first_cpu(per_cpu(cpu_sibling_map, i)) == i)
482 c->booted_cores++;
483 /*
484 * increment the core count for all
485 * the other cpus in this package
486 */
487 if (i != cpu)
488 cpu_data(i).booted_cores++;
489 } else if (i != cpu && !c->booted_cores)
490 c->booted_cores = cpu_data(i).booted_cores;
491 }
492 }
493}
494
70708a18
GC
495/* maps the cpu to the sched domain representing multi-core */
496cpumask_t cpu_coregroup_map(int cpu)
497{
498 struct cpuinfo_x86 *c = &cpu_data(cpu);
499 /*
500 * For perf, we return last level cache shared map.
501 * And for power savings, we return cpu_core_map
502 */
503 if (sched_mc_power_savings || sched_smt_power_savings)
504 return per_cpu(cpu_core_map, cpu);
505 else
506 return c->llc_shared_map;
507}
508
a4928cff 509static void impress_friends(void)
904541e2
GOC
510{
511 int cpu;
512 unsigned long bogosum = 0;
513 /*
514 * Allow the user to impress friends.
515 */
516 Dprintk("Before bogomips.\n");
517 for_each_possible_cpu(cpu)
518 if (cpu_isset(cpu, cpu_callout_map))
519 bogosum += cpu_data(cpu).loops_per_jiffy;
520 printk(KERN_INFO
521 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
f68e00a3 522 num_online_cpus(),
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GOC
523 bogosum/(500000/HZ),
524 (bogosum/(5000/HZ))%100);
525
526 Dprintk("Before bogocount - setting activated=1.\n");
527}
528
cb3c8b90
GOC
529static inline void __inquire_remote_apic(int apicid)
530{
531 unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
532 char *names[] = { "ID", "VERSION", "SPIV" };
533 int timeout;
534 u32 status;
535
536 printk(KERN_INFO "Inquiring remote APIC #%d...\n", apicid);
537
538 for (i = 0; i < ARRAY_SIZE(regs); i++) {
539 printk(KERN_INFO "... APIC #%d %s: ", apicid, names[i]);
540
541 /*
542 * Wait for idle.
543 */
544 status = safe_apic_wait_icr_idle();
545 if (status)
546 printk(KERN_CONT
547 "a previous APIC delivery may have failed\n");
548
549 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
550 apic_write_around(APIC_ICR, APIC_DM_REMRD | regs[i]);
551
552 timeout = 0;
553 do {
554 udelay(100);
555 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
556 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
557
558 switch (status) {
559 case APIC_ICR_RR_VALID:
560 status = apic_read(APIC_RRR);
561 printk(KERN_CONT "%08x\n", status);
562 break;
563 default:
564 printk(KERN_CONT "failed\n");
565 }
566 }
567}
568
569#ifdef WAKE_SECONDARY_VIA_NMI
570/*
571 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
572 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
573 * won't ... remember to clear down the APIC, etc later.
574 */
575static int __devinit
576wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
577{
578 unsigned long send_status, accept_status = 0;
579 int maxlvt;
580
581 /* Target chip */
582 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid));
583
584 /* Boot on the stack */
585 /* Kick the second */
586 apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL);
587
588 Dprintk("Waiting for send to finish...\n");
589 send_status = safe_apic_wait_icr_idle();
590
591 /*
592 * Give the other CPU some time to accept the IPI.
593 */
594 udelay(200);
595 /*
596 * Due to the Pentium erratum 3AP.
597 */
598 maxlvt = lapic_get_maxlvt();
599 if (maxlvt > 3) {
600 apic_read_around(APIC_SPIV);
601 apic_write(APIC_ESR, 0);
602 }
603 accept_status = (apic_read(APIC_ESR) & 0xEF);
604 Dprintk("NMI sent.\n");
605
606 if (send_status)
607 printk(KERN_ERR "APIC never delivered???\n");
608 if (accept_status)
609 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
610
611 return (send_status | accept_status);
612}
613#endif /* WAKE_SECONDARY_VIA_NMI */
614
cb3c8b90
GOC
615#ifdef WAKE_SECONDARY_VIA_INIT
616static int __devinit
617wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
618{
619 unsigned long send_status, accept_status = 0;
620 int maxlvt, num_starts, j;
621
34d05591
JS
622 if (get_uv_system_type() == UV_NON_UNIQUE_APIC) {
623 send_status = uv_wakeup_secondary(phys_apicid, start_eip);
624 atomic_set(&init_deasserted, 1);
625 return send_status;
626 }
627
cb3c8b90
GOC
628 /*
629 * Be paranoid about clearing APIC errors.
630 */
631 if (APIC_INTEGRATED(apic_version[phys_apicid])) {
632 apic_read_around(APIC_SPIV);
633 apic_write(APIC_ESR, 0);
634 apic_read(APIC_ESR);
635 }
636
637 Dprintk("Asserting INIT.\n");
638
639 /*
640 * Turn INIT on target chip
641 */
642 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
643
644 /*
645 * Send IPI
646 */
647 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
648 | APIC_DM_INIT);
649
650 Dprintk("Waiting for send to finish...\n");
651 send_status = safe_apic_wait_icr_idle();
652
653 mdelay(10);
654
655 Dprintk("Deasserting INIT.\n");
656
657 /* Target chip */
658 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
659
660 /* Send IPI */
661 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
662
663 Dprintk("Waiting for send to finish...\n");
664 send_status = safe_apic_wait_icr_idle();
665
666 mb();
667 atomic_set(&init_deasserted, 1);
668
669 /*
670 * Should we send STARTUP IPIs ?
671 *
672 * Determine this based on the APIC version.
673 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
674 */
675 if (APIC_INTEGRATED(apic_version[phys_apicid]))
676 num_starts = 2;
677 else
678 num_starts = 0;
679
680 /*
681 * Paravirt / VMI wants a startup IPI hook here to set up the
682 * target processor state.
683 */
684 startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
cb3c8b90 685 (unsigned long)stack_start.sp);
cb3c8b90
GOC
686
687 /*
688 * Run STARTUP IPI loop.
689 */
690 Dprintk("#startup loops: %d.\n", num_starts);
691
692 maxlvt = lapic_get_maxlvt();
693
694 for (j = 1; j <= num_starts; j++) {
695 Dprintk("Sending STARTUP #%d.\n", j);
696 apic_read_around(APIC_SPIV);
697 apic_write(APIC_ESR, 0);
698 apic_read(APIC_ESR);
699 Dprintk("After apic_write.\n");
700
701 /*
702 * STARTUP IPI
703 */
704
705 /* Target chip */
706 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
707
708 /* Boot on the stack */
709 /* Kick the second */
710 apic_write_around(APIC_ICR, APIC_DM_STARTUP
711 | (start_eip >> 12));
712
713 /*
714 * Give the other CPU some time to accept the IPI.
715 */
716 udelay(300);
717
718 Dprintk("Startup point 1.\n");
719
720 Dprintk("Waiting for send to finish...\n");
721 send_status = safe_apic_wait_icr_idle();
722
723 /*
724 * Give the other CPU some time to accept the IPI.
725 */
726 udelay(200);
727 /*
728 * Due to the Pentium erratum 3AP.
729 */
730 if (maxlvt > 3) {
731 apic_read_around(APIC_SPIV);
732 apic_write(APIC_ESR, 0);
733 }
734 accept_status = (apic_read(APIC_ESR) & 0xEF);
735 if (send_status || accept_status)
736 break;
737 }
738 Dprintk("After Startup.\n");
739
740 if (send_status)
741 printk(KERN_ERR "APIC never delivered???\n");
742 if (accept_status)
743 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
744
745 return (send_status | accept_status);
746}
747#endif /* WAKE_SECONDARY_VIA_INIT */
748
749struct create_idle {
750 struct work_struct work;
751 struct task_struct *idle;
752 struct completion done;
753 int cpu;
754};
755
756static void __cpuinit do_fork_idle(struct work_struct *work)
757{
758 struct create_idle *c_idle =
759 container_of(work, struct create_idle, work);
760
761 c_idle->idle = fork_idle(c_idle->cpu);
762 complete(&c_idle->done);
763}
764
f307d25e 765#ifdef CONFIG_X86_64
3461b0af
MT
766/*
767 * Allocate node local memory for the AP pda.
768 *
769 * Must be called after the _cpu_pda pointer table is initialized.
770 */
771static int __cpuinit get_local_pda(int cpu)
772{
773 struct x8664_pda *oldpda, *newpda;
774 unsigned long size = sizeof(struct x8664_pda);
775 int node = cpu_to_node(cpu);
776
777 if (cpu_pda(cpu) && !cpu_pda(cpu)->in_bootmem)
778 return 0;
779
780 oldpda = cpu_pda(cpu);
781 newpda = kmalloc_node(size, GFP_ATOMIC, node);
782 if (!newpda) {
783 printk(KERN_ERR "Could not allocate node local PDA "
784 "for CPU %d on node %d\n", cpu, node);
785
786 if (oldpda)
787 return 0; /* have a usable pda */
788 else
789 return -1;
790 }
791
792 if (oldpda) {
793 memcpy(newpda, oldpda, size);
794 if (!after_bootmem)
795 free_bootmem((unsigned long)oldpda, size);
796 }
797
798 newpda->in_bootmem = 0;
799 cpu_pda(cpu) = newpda;
800 return 0;
801}
f307d25e 802#endif /* CONFIG_X86_64 */
3461b0af 803
cb3c8b90
GOC
804static int __cpuinit do_boot_cpu(int apicid, int cpu)
805/*
806 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
807 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
808 * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu.
809 */
810{
811 unsigned long boot_error = 0;
812 int timeout;
813 unsigned long start_ip;
814 unsigned short nmi_high = 0, nmi_low = 0;
815 struct create_idle c_idle = {
816 .cpu = cpu,
817 .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
818 };
819 INIT_WORK(&c_idle.work, do_fork_idle);
cb3c8b90 820
a939098a 821#ifdef CONFIG_X86_64
cb3c8b90 822 /* Allocate node local memory for AP pdas */
3461b0af
MT
823 if (cpu > 0) {
824 boot_error = get_local_pda(cpu);
825 if (boot_error)
826 goto restore_state;
827 /* if can't get pda memory, can't start cpu */
cb3c8b90
GOC
828 }
829#endif
830
831 alternatives_smp_switch(1);
832
833 c_idle.idle = get_idle_for_cpu(cpu);
834
835 /*
836 * We can't use kernel_thread since we must avoid to
837 * reschedule the child.
838 */
839 if (c_idle.idle) {
840 c_idle.idle->thread.sp = (unsigned long) (((struct pt_regs *)
841 (THREAD_SIZE + task_stack_page(c_idle.idle))) - 1);
842 init_idle(c_idle.idle, cpu);
843 goto do_rest;
844 }
845
846 if (!keventd_up() || current_is_keventd())
847 c_idle.work.func(&c_idle.work);
848 else {
849 schedule_work(&c_idle.work);
850 wait_for_completion(&c_idle.done);
851 }
852
853 if (IS_ERR(c_idle.idle)) {
854 printk("failed fork for CPU %d\n", cpu);
855 return PTR_ERR(c_idle.idle);
856 }
857
858 set_idle_for_cpu(cpu, c_idle.idle);
859do_rest:
860#ifdef CONFIG_X86_32
861 per_cpu(current_task, cpu) = c_idle.idle;
862 init_gdt(cpu);
cb3c8b90 863 /* Stack for startup_32 can be just as for start_secondary onwards */
cb3c8b90
GOC
864 irq_ctx_init(cpu);
865#else
866 cpu_pda(cpu)->pcurrent = c_idle.idle;
cb3c8b90
GOC
867 clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
868#endif
a939098a 869 early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
3e970473 870 initial_code = (unsigned long)start_secondary;
9cf4f298 871 stack_start.sp = (void *) c_idle.idle->thread.sp;
cb3c8b90
GOC
872
873 /* start_ip had better be page-aligned! */
874 start_ip = setup_trampoline();
875
876 /* So we see what's up */
877 printk(KERN_INFO "Booting processor %d/%d ip %lx\n",
878 cpu, apicid, start_ip);
879
880 /*
881 * This grunge runs the startup process for
882 * the targeted processor.
883 */
884
885 atomic_set(&init_deasserted, 0);
886
34d05591 887 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
cb3c8b90 888
34d05591 889 Dprintk("Setting warm reset code and vector.\n");
cb3c8b90 890
34d05591
JS
891 store_NMI_vector(&nmi_high, &nmi_low);
892
893 smpboot_setup_warm_reset_vector(start_ip);
894 /*
895 * Be paranoid about clearing APIC errors.
896 */
897 apic_write(APIC_ESR, 0);
898 apic_read(APIC_ESR);
899 }
cb3c8b90 900
cb3c8b90
GOC
901 /*
902 * Starting actual IPI sequence...
903 */
904 boot_error = wakeup_secondary_cpu(apicid, start_ip);
905
906 if (!boot_error) {
907 /*
908 * allow APs to start initializing.
909 */
910 Dprintk("Before Callout %d.\n", cpu);
911 cpu_set(cpu, cpu_callout_map);
912 Dprintk("After Callout %d.\n", cpu);
913
914 /*
915 * Wait 5s total for a response
916 */
917 for (timeout = 0; timeout < 50000; timeout++) {
918 if (cpu_isset(cpu, cpu_callin_map))
919 break; /* It has booted */
920 udelay(100);
921 }
922
923 if (cpu_isset(cpu, cpu_callin_map)) {
924 /* number CPUs logically, starting from 1 (BSP is 0) */
925 Dprintk("OK.\n");
926 printk(KERN_INFO "CPU%d: ", cpu);
927 print_cpu_info(&cpu_data(cpu));
928 Dprintk("CPU has booted.\n");
929 } else {
930 boot_error = 1;
931 if (*((volatile unsigned char *)trampoline_base)
932 == 0xA5)
933 /* trampoline started but...? */
934 printk(KERN_ERR "Stuck ??\n");
935 else
936 /* trampoline code not run */
937 printk(KERN_ERR "Not responding.\n");
34d05591
JS
938 if (get_uv_system_type() != UV_NON_UNIQUE_APIC)
939 inquire_remote_apic(apicid);
cb3c8b90
GOC
940 }
941 }
6f585e01 942#ifdef CONFIG_X86_64
3461b0af 943restore_state:
6f585e01 944#endif
cb3c8b90
GOC
945 if (boot_error) {
946 /* Try to put things back the way they were before ... */
23ca4bba 947 numa_remove_cpu(cpu); /* was set by numa_add_cpu */
cb3c8b90
GOC
948 cpu_clear(cpu, cpu_callout_map); /* was set by do_boot_cpu() */
949 cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
cb3c8b90
GOC
950 cpu_clear(cpu, cpu_present_map);
951 per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
952 }
953
954 /* mark "stuck" area as not stuck */
955 *((volatile unsigned long *)trampoline_base) = 0;
956
63d38198
AK
957 /*
958 * Cleanup possible dangling ends...
959 */
960 smpboot_restore_warm_reset_vector();
961
cb3c8b90
GOC
962 return boot_error;
963}
964
965int __cpuinit native_cpu_up(unsigned int cpu)
966{
967 int apicid = cpu_present_to_apicid(cpu);
968 unsigned long flags;
969 int err;
970
971 WARN_ON(irqs_disabled());
972
973 Dprintk("++++++++++++++++++++=_---CPU UP %u\n", cpu);
974
975 if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
976 !physid_isset(apicid, phys_cpu_present_map)) {
977 printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
978 return -EINVAL;
979 }
980
981 /*
982 * Already booted CPU?
983 */
984 if (cpu_isset(cpu, cpu_callin_map)) {
985 Dprintk("do_boot_cpu %d Already started\n", cpu);
986 return -ENOSYS;
987 }
988
989 /*
990 * Save current MTRR state in case it was changed since early boot
991 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
992 */
993 mtrr_save_state();
994
995 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
996
997#ifdef CONFIG_X86_32
998 /* init low mem mapping */
68db065c 999 clone_pgd_range(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
61165d7a 1000 min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
cb3c8b90 1001 flush_tlb_all();
61165d7a 1002 low_mappings = 1;
cb3c8b90
GOC
1003
1004 err = do_boot_cpu(apicid, cpu);
61165d7a
HD
1005
1006 zap_low_mappings();
1007 low_mappings = 0;
1008#else
1009 err = do_boot_cpu(apicid, cpu);
1010#endif
1011 if (err) {
cb3c8b90 1012 Dprintk("do_boot_cpu failed %d\n", err);
61165d7a 1013 return -EIO;
cb3c8b90
GOC
1014 }
1015
1016 /*
1017 * Check TSC synchronization with the AP (keep irqs disabled
1018 * while doing so):
1019 */
1020 local_irq_save(flags);
1021 check_tsc_sync_source(cpu);
1022 local_irq_restore(flags);
1023
7c04e64a 1024 while (!cpu_online(cpu)) {
cb3c8b90
GOC
1025 cpu_relax();
1026 touch_nmi_watchdog();
1027 }
1028
1029 return 0;
1030}
1031
8aef135c
GOC
1032/*
1033 * Fall back to non SMP mode after errors.
1034 *
1035 * RED-PEN audit/test this more. I bet there is more state messed up here.
1036 */
1037static __init void disable_smp(void)
1038{
1039 cpu_present_map = cpumask_of_cpu(0);
1040 cpu_possible_map = cpumask_of_cpu(0);
8aef135c 1041 smpboot_clear_io_apic_irqs();
0f385d1d 1042
8aef135c 1043 if (smp_found_config)
b6df1b8b 1044 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
8aef135c 1045 else
b6df1b8b 1046 physid_set_mask_of_physid(0, &phys_cpu_present_map);
8aef135c
GOC
1047 map_cpu_to_logical_apicid();
1048 cpu_set(0, per_cpu(cpu_sibling_map, 0));
1049 cpu_set(0, per_cpu(cpu_core_map, 0));
1050}
1051
1052/*
1053 * Various sanity checks.
1054 */
1055static int __init smp_sanity_check(unsigned max_cpus)
1056{
ac23d4ee 1057 preempt_disable();
8aef135c
GOC
1058 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
1059 printk(KERN_WARNING "weird, boot CPU (#%d) not listed"
1060 "by the BIOS.\n", hard_smp_processor_id());
1061 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1062 }
1063
1064 /*
1065 * If we couldn't find an SMP configuration at boot time,
1066 * get out of here now!
1067 */
1068 if (!smp_found_config && !acpi_lapic) {
ac23d4ee 1069 preempt_enable();
8aef135c
GOC
1070 printk(KERN_NOTICE "SMP motherboard not detected.\n");
1071 disable_smp();
1072 if (APIC_init_uniprocessor())
1073 printk(KERN_NOTICE "Local APIC not detected."
1074 " Using dummy APIC emulation.\n");
1075 return -1;
1076 }
1077
1078 /*
1079 * Should not be necessary because the MP table should list the boot
1080 * CPU too, but we do it for the sake of robustness anyway.
1081 */
1082 if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
1083 printk(KERN_NOTICE
1084 "weird, boot CPU (#%d) not listed by the BIOS.\n",
1085 boot_cpu_physical_apicid);
1086 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1087 }
ac23d4ee 1088 preempt_enable();
8aef135c
GOC
1089
1090 /*
1091 * If we couldn't find a local APIC, then get out of here now!
1092 */
1093 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
1094 !cpu_has_apic) {
1095 printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
1096 boot_cpu_physical_apicid);
1097 printk(KERN_ERR "... forcing use of dummy APIC emulation."
1098 "(tell your hw vendor)\n");
1099 smpboot_clear_io_apic();
1100 return -1;
1101 }
1102
1103 verify_local_APIC();
1104
1105 /*
1106 * If SMP should be disabled, then really disable it!
1107 */
1108 if (!max_cpus) {
73d08e63 1109 printk(KERN_INFO "SMP mode deactivated.\n");
8aef135c 1110 smpboot_clear_io_apic();
d54db1ac
MR
1111
1112 localise_nmi_watchdog();
1113
e90955c2 1114 connect_bsp_APIC();
e90955c2
JB
1115 setup_local_APIC();
1116 end_local_APIC_setup();
8aef135c
GOC
1117 return -1;
1118 }
1119
1120 return 0;
1121}
1122
1123static void __init smp_cpu_index_default(void)
1124{
1125 int i;
1126 struct cpuinfo_x86 *c;
1127
7c04e64a 1128 for_each_possible_cpu(i) {
8aef135c
GOC
1129 c = &cpu_data(i);
1130 /* mark all to hotplug */
1131 c->cpu_index = NR_CPUS;
1132 }
1133}
1134
1135/*
1136 * Prepare for SMP bootup. The MP table or ACPI has been read
1137 * earlier. Just do some sanity checking here and enable APIC mode.
1138 */
1139void __init native_smp_prepare_cpus(unsigned int max_cpus)
1140{
deef3250 1141 preempt_disable();
8aef135c
GOC
1142 smp_cpu_index_default();
1143 current_cpu_data = boot_cpu_data;
1144 cpu_callin_map = cpumask_of_cpu(0);
1145 mb();
1146 /*
1147 * Setup boot CPU information
1148 */
1149 smp_store_cpu_info(0); /* Final full version of the data */
1150 boot_cpu_logical_apicid = logical_smp_processor_id();
1151 current_thread_info()->cpu = 0; /* needed? */
1152 set_cpu_sibling_map(0);
1153
1154 if (smp_sanity_check(max_cpus) < 0) {
1155 printk(KERN_INFO "SMP disabled\n");
1156 disable_smp();
deef3250 1157 goto out;
8aef135c
GOC
1158 }
1159
ac23d4ee 1160 preempt_disable();
05f2d12c 1161 if (GET_APIC_ID(read_apic_id()) != boot_cpu_physical_apicid) {
8aef135c 1162 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
05f2d12c 1163 GET_APIC_ID(read_apic_id()), boot_cpu_physical_apicid);
8aef135c
GOC
1164 /* Or can we switch back to PIC here? */
1165 }
ac23d4ee 1166 preempt_enable();
8aef135c 1167
8aef135c 1168 connect_bsp_APIC();
b5841765 1169
8aef135c
GOC
1170 /*
1171 * Switch from PIC to APIC mode.
1172 */
1173 setup_local_APIC();
1174
1175#ifdef CONFIG_X86_64
1176 /*
1177 * Enable IO APIC before setting up error vector
1178 */
1179 if (!skip_ioapic_setup && nr_ioapics)
1180 enable_IO_APIC();
1181#endif
1182 end_local_APIC_setup();
1183
1184 map_cpu_to_logical_apicid();
1185
1186 setup_portio_remap();
1187
1188 smpboot_setup_io_apic();
1189 /*
1190 * Set up local APIC timer on boot CPU.
1191 */
1192
1193 printk(KERN_INFO "CPU%d: ", 0);
1194 print_cpu_info(&cpu_data(0));
1195 setup_boot_clock();
deef3250
IM
1196out:
1197 preempt_enable();
8aef135c 1198}
a8db8453
GOC
1199/*
1200 * Early setup to make printk work.
1201 */
1202void __init native_smp_prepare_boot_cpu(void)
1203{
1204 int me = smp_processor_id();
1205#ifdef CONFIG_X86_32
1206 init_gdt(me);
a8db8453 1207#endif
a939098a 1208 switch_to_new_gdt();
a8db8453
GOC
1209 /* already set me in cpu_online_map in boot_cpu_init() */
1210 cpu_set(me, cpu_callout_map);
1211 per_cpu(cpu_state, me) = CPU_ONLINE;
1212}
1213
83f7eb9c
GOC
1214void __init native_smp_cpus_done(unsigned int max_cpus)
1215{
83f7eb9c
GOC
1216 Dprintk("Boot done.\n");
1217
1218 impress_friends();
1219 smp_checks();
1220#ifdef CONFIG_X86_IO_APIC
1221 setup_ioapic_dest();
1222#endif
1223 check_nmi_watchdog();
83f7eb9c
GOC
1224}
1225
68a1c3f8 1226#ifdef CONFIG_HOTPLUG_CPU
2cd9fb71 1227
a4928cff 1228static void remove_siblinginfo(int cpu)
768d9505
GC
1229{
1230 int sibling;
1231 struct cpuinfo_x86 *c = &cpu_data(cpu);
1232
1233 for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) {
1234 cpu_clear(cpu, per_cpu(cpu_core_map, sibling));
1235 /*/
1236 * last thread sibling in this cpu core going down
1237 */
1238 if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1)
1239 cpu_data(sibling).booted_cores--;
1240 }
1241
1242 for_each_cpu_mask(sibling, per_cpu(cpu_sibling_map, cpu))
1243 cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling));
1244 cpus_clear(per_cpu(cpu_sibling_map, cpu));
1245 cpus_clear(per_cpu(cpu_core_map, cpu));
1246 c->phys_proc_id = 0;
1247 c->cpu_core_id = 0;
1248 cpu_clear(cpu, cpu_sibling_setup_map);
1249}
68a1c3f8 1250
c5562fae 1251static int additional_cpus __initdata = -1;
68a1c3f8
GC
1252
1253static __init int setup_additional_cpus(char *s)
1254{
1255 return s && get_option(&s, &additional_cpus) ? 0 : -EINVAL;
1256}
1257early_param("additional_cpus", setup_additional_cpus);
1258
1259/*
1260 * cpu_possible_map should be static, it cannot change as cpu's
1261 * are onlined, or offlined. The reason is per-cpu data-structures
1262 * are allocated by some modules at init time, and dont expect to
1263 * do this dynamically on cpu arrival/departure.
1264 * cpu_present_map on the other hand can change dynamically.
1265 * In case when cpu_hotplug is not compiled, then we resort to current
1266 * behaviour, which is cpu_possible == cpu_present.
1267 * - Ashok Raj
1268 *
1269 * Three ways to find out the number of additional hotplug CPUs:
1270 * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
1271 * - The user can overwrite it with additional_cpus=NUM
1272 * - Otherwise don't reserve additional CPUs.
1273 * We do this because additional CPUs waste a lot of memory.
1274 * -AK
1275 */
1276__init void prefill_possible_map(void)
1277{
1278 int i;
1279 int possible;
1280
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1281 /* no processor from mptable or madt */
1282 if (!num_processors)
1283 num_processors = 1;
1284
1285#ifdef CONFIG_HOTPLUG_CPU
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1286 if (additional_cpus == -1) {
1287 if (disabled_cpus > 0)
1288 additional_cpus = disabled_cpus;
1289 else
1290 additional_cpus = 0;
1291 }
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1292#else
1293 additional_cpus = 0;
1294#endif
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GC
1295 possible = num_processors + additional_cpus;
1296 if (possible > NR_CPUS)
1297 possible = NR_CPUS;
1298
1299 printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
1300 possible, max_t(int, possible - num_processors, 0));
1301
1302 for (i = 0; i < possible; i++)
1303 cpu_set(i, cpu_possible_map);
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1304
1305 nr_cpu_ids = possible;
68a1c3f8 1306}
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1307
1308static void __ref remove_cpu_from_maps(int cpu)
1309{
1310 cpu_clear(cpu, cpu_online_map);
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1311 cpu_clear(cpu, cpu_callout_map);
1312 cpu_clear(cpu, cpu_callin_map);
1313 /* was set by cpu_init() */
1314 clear_bit(cpu, (unsigned long *)&cpu_initialized);
23ca4bba 1315 numa_remove_cpu(cpu);
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1316}
1317
1318int __cpu_disable(void)
1319{
1320 int cpu = smp_processor_id();
1321
1322 /*
1323 * Perhaps use cpufreq to drop frequency, but that could go
1324 * into generic code.
1325 *
1326 * We won't take down the boot processor on i386 due to some
1327 * interrupts only being able to be serviced by the BSP.
1328 * Especially so if we're not using an IOAPIC -zwane
1329 */
1330 if (cpu == 0)
1331 return -EBUSY;
1332
1333 if (nmi_watchdog == NMI_LOCAL_APIC)
1334 stop_apic_nmi_watchdog(NULL);
1335 clear_local_APIC();
1336
1337 /*
1338 * HACK:
1339 * Allow any queued timer interrupts to get serviced
1340 * This is only a temporary solution until we cleanup
1341 * fixup_irqs as we do for IA64.
1342 */
1343 local_irq_enable();
1344 mdelay(1);
1345
1346 local_irq_disable();
1347 remove_siblinginfo(cpu);
1348
1349 /* It's now safe to remove this processor from the online map */
1350 remove_cpu_from_maps(cpu);
1351 fixup_irqs(cpu_online_map);
1352 return 0;
1353}
1354
1355void __cpu_die(unsigned int cpu)
1356{
1357 /* We don't do anything here: idle task is faking death itself. */
1358 unsigned int i;
1359
1360 for (i = 0; i < 10; i++) {
1361 /* They ack this in play_dead by setting CPU_DEAD */
1362 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
1363 printk(KERN_INFO "CPU %d is now offline\n", cpu);
1364 if (1 == num_online_cpus())
1365 alternatives_smp_switch(0);
1366 return;
1367 }
1368 msleep(100);
1369 }
1370 printk(KERN_ERR "CPU %u didn't die...\n", cpu);
1371}
1372#else /* ... !CONFIG_HOTPLUG_CPU */
1373int __cpu_disable(void)
1374{
1375 return -ENOSYS;
1376}
1377
1378void __cpu_die(unsigned int cpu)
1379{
1380 /* We said "no" in __cpu_disable */
1381 BUG();
1382}
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1383#endif
1384
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1385/*
1386 * If the BIOS enumerates physical processors before logical,
1387 * maxcpus=N at enumeration-time can be used to disable HT.
1388 */
1389static int __init parse_maxcpus(char *arg)
1390{
1391 extern unsigned int maxcpus;
1392
1393 maxcpus = simple_strtoul(arg, NULL, 0);
1394 return 0;
1395}
1396early_param("maxcpus", parse_maxcpus);