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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
cb3c8b90
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
768d9505
GC
128/* representing cpus for which sibling maps can be computed */
129static cpumask_t cpu_sibling_setup_map;
130
1d89a7f0
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
a4928cff 184static void unmap_cpu_to_logical_apicid(int cpu)
7cc3959e
GOC
185{
186 cpu_2_logical_apicid[cpu] = BAD_APICID;
187 unmap_cpu_to_node(cpu);
188}
189#else
190#define unmap_cpu_to_logical_apicid(cpu) do {} while (0)
191#define map_cpu_to_logical_apicid() do {} while (0)
192#endif
193
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GOC
194/*
195 * Report back to the Boot Processor.
196 * Running on AP.
197 */
a4928cff 198static void __cpuinit smp_callin(void)
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GOC
199{
200 int cpuid, phys_id;
201 unsigned long timeout;
202
203 /*
204 * If waken up by an INIT in an 82489DX configuration
205 * we may get here before an INIT-deassert IPI reaches
206 * our local APIC. We have to wait for the IPI or we'll
207 * lock up on an APIC access.
208 */
209 wait_for_init_deassert(&init_deasserted);
210
211 /*
212 * (This works even if the APIC is not enabled.)
213 */
05f2d12c 214 phys_id = GET_APIC_ID(read_apic_id());
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GOC
215 cpuid = smp_processor_id();
216 if (cpu_isset(cpuid, cpu_callin_map)) {
217 panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__,
218 phys_id, cpuid);
219 }
220 Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
221
222 /*
223 * STARTUP IPIs are fragile beasts as they might sometimes
224 * trigger some glue motherboard logic. Complete APIC bus
225 * silence for 1 second, this overestimates the time the
226 * boot CPU is spending to send the up to 2 STARTUP IPIs
227 * by a factor of two. This should be enough.
228 */
229
230 /*
231 * Waiting 2s total for startup (udelay is not yet working)
232 */
233 timeout = jiffies + 2*HZ;
234 while (time_before(jiffies, timeout)) {
235 /*
236 * Has the boot CPU finished it's STARTUP sequence?
237 */
238 if (cpu_isset(cpuid, cpu_callout_map))
239 break;
240 cpu_relax();
241 }
242
243 if (!time_before(jiffies, timeout)) {
244 panic("%s: CPU%d started up but did not get a callout!\n",
245 __func__, cpuid);
246 }
247
248 /*
249 * the boot CPU has finished the init stage and is spinning
250 * on callin_map until we finish. We are free to set up this
251 * CPU, first the APIC. (this is probably redundant on most
252 * boards)
253 */
254
255 Dprintk("CALLIN, before setup_local_APIC().\n");
256 smp_callin_clear_local_apic();
257 setup_local_APIC();
258 end_local_APIC_setup();
259 map_cpu_to_logical_apicid();
260
261 /*
262 * Get our bogomips.
263 *
264 * Need to enable IRQs because it can take longer and then
265 * the NMI watchdog might kill us.
266 */
267 local_irq_enable();
268 calibrate_delay();
269 local_irq_disable();
270 Dprintk("Stack at about %p\n", &cpuid);
271
272 /*
273 * Save our processor parameters
274 */
275 smp_store_cpu_info(cpuid);
276
277 /*
278 * Allow the master to continue.
279 */
280 cpu_set(cpuid, cpu_callin_map);
281}
282
bbc2ff6a
GOC
283/*
284 * Activate a secondary processor.
285 */
dbe55f47 286static void __cpuinit start_secondary(void *unused)
bbc2ff6a
GOC
287{
288 /*
289 * Don't put *anything* before cpu_init(), SMP booting is too
290 * fragile that we want to limit the things done here to the
291 * most necessary things.
292 */
293#ifdef CONFIG_VMI
294 vmi_bringup();
295#endif
296 cpu_init();
297 preempt_disable();
298 smp_callin();
299
300 /* otherwise gcc will move up smp_processor_id before the cpu_init */
301 barrier();
302 /*
303 * Check TSC synchronization with the BP:
304 */
305 check_tsc_sync_target();
306
307 if (nmi_watchdog == NMI_IO_APIC) {
308 disable_8259A_irq(0);
309 enable_NMI_through_LVT0();
310 enable_8259A_irq(0);
311 }
312
61165d7a
HD
313#ifdef CONFIG_X86_32
314 while (low_mappings)
315 cpu_relax();
316 __flush_tlb_all();
317#endif
318
bbc2ff6a
GOC
319 /* This must be done before setting cpu_online_map */
320 set_cpu_sibling_map(raw_smp_processor_id());
321 wmb();
322
323 /*
324 * We need to hold call_lock, so there is no inconsistency
325 * between the time smp_call_function() determines number of
326 * IPI recipients, and the time when the determination is made
327 * for which cpus receive the IPI. Holding this
328 * lock helps us to not include this cpu in a currently in progress
329 * smp_call_function().
330 */
331 lock_ipi_call_lock();
3fde6900
GC
332#ifdef CONFIG_X86_IO_APIC
333 setup_vector_irq(smp_processor_id());
bbc2ff6a
GOC
334#endif
335 cpu_set(smp_processor_id(), cpu_online_map);
336 unlock_ipi_call_lock();
337 per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
338
339 setup_secondary_clock();
340
341 wmb();
342 cpu_idle();
343}
344
1d89a7f0
GOC
345static void __cpuinit smp_apply_quirks(struct cpuinfo_x86 *c)
346{
1d89a7f0
GOC
347 /*
348 * Mask B, Pentium, but not Pentium MMX
349 */
350 if (c->x86_vendor == X86_VENDOR_INTEL &&
351 c->x86 == 5 &&
352 c->x86_mask >= 1 && c->x86_mask <= 4 &&
353 c->x86_model <= 3)
354 /*
355 * Remember we have B step Pentia with bugs
356 */
357 smp_b_stepping = 1;
358
359 /*
360 * Certain Athlons might work (for various values of 'work') in SMP
361 * but they are not certified as MP capable.
362 */
363 if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) {
364
365 if (num_possible_cpus() == 1)
366 goto valid_k7;
367
368 /* Athlon 660/661 is valid. */
369 if ((c->x86_model == 6) && ((c->x86_mask == 0) ||
370 (c->x86_mask == 1)))
371 goto valid_k7;
372
373 /* Duron 670 is valid */
374 if ((c->x86_model == 7) && (c->x86_mask == 0))
375 goto valid_k7;
376
377 /*
378 * Athlon 662, Duron 671, and Athlon >model 7 have capability
379 * bit. It's worth noting that the A5 stepping (662) of some
380 * Athlon XP's have the MP bit set.
381 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for
382 * more.
383 */
384 if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
385 ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
386 (c->x86_model > 7))
387 if (cpu_has_mp)
388 goto valid_k7;
389
390 /* If we get here, not a certified SMP capable AMD system. */
391 add_taint(TAINT_UNSAFE_SMP);
392 }
393
394valid_k7:
395 ;
1d89a7f0
GOC
396}
397
a4928cff 398static void __cpuinit smp_checks(void)
693d4b8a
GOC
399{
400 if (smp_b_stepping)
401 printk(KERN_WARNING "WARNING: SMP operation may be unreliable"
402 "with B stepping processors.\n");
403
404 /*
405 * Don't taint if we are running SMP kernel on a single non-MP
406 * approved Athlon
407 */
408 if (tainted & TAINT_UNSAFE_SMP) {
f68e00a3 409 if (num_online_cpus())
693d4b8a
GOC
410 printk(KERN_INFO "WARNING: This combination of AMD"
411 "processors is not suitable for SMP.\n");
412 else
413 tainted &= ~TAINT_UNSAFE_SMP;
414 }
415}
416
1d89a7f0
GOC
417/*
418 * The bootstrap kernel entry code has set these up. Save them for
419 * a given CPU
420 */
421
422void __cpuinit smp_store_cpu_info(int id)
423{
424 struct cpuinfo_x86 *c = &cpu_data(id);
425
426 *c = boot_cpu_data;
427 c->cpu_index = id;
428 if (id != 0)
429 identify_secondary_cpu(c);
430 smp_apply_quirks(c);
431}
432
433
768d9505
GC
434void __cpuinit set_cpu_sibling_map(int cpu)
435{
436 int i;
437 struct cpuinfo_x86 *c = &cpu_data(cpu);
438
439 cpu_set(cpu, cpu_sibling_setup_map);
440
441 if (smp_num_siblings > 1) {
442 for_each_cpu_mask(i, cpu_sibling_setup_map) {
443 if (c->phys_proc_id == cpu_data(i).phys_proc_id &&
444 c->cpu_core_id == cpu_data(i).cpu_core_id) {
445 cpu_set(i, per_cpu(cpu_sibling_map, cpu));
446 cpu_set(cpu, per_cpu(cpu_sibling_map, i));
447 cpu_set(i, per_cpu(cpu_core_map, cpu));
448 cpu_set(cpu, per_cpu(cpu_core_map, i));
449 cpu_set(i, c->llc_shared_map);
450 cpu_set(cpu, cpu_data(i).llc_shared_map);
451 }
452 }
453 } else {
454 cpu_set(cpu, per_cpu(cpu_sibling_map, cpu));
455 }
456
457 cpu_set(cpu, c->llc_shared_map);
458
459 if (current_cpu_data.x86_max_cores == 1) {
460 per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu);
461 c->booted_cores = 1;
462 return;
463 }
464
465 for_each_cpu_mask(i, cpu_sibling_setup_map) {
466 if (per_cpu(cpu_llc_id, cpu) != BAD_APICID &&
467 per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) {
468 cpu_set(i, c->llc_shared_map);
469 cpu_set(cpu, cpu_data(i).llc_shared_map);
470 }
471 if (c->phys_proc_id == cpu_data(i).phys_proc_id) {
472 cpu_set(i, per_cpu(cpu_core_map, cpu));
473 cpu_set(cpu, per_cpu(cpu_core_map, i));
474 /*
475 * Does this new cpu bringup a new core?
476 */
477 if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) {
478 /*
479 * for each core in package, increment
480 * the booted_cores for this new cpu
481 */
482 if (first_cpu(per_cpu(cpu_sibling_map, i)) == i)
483 c->booted_cores++;
484 /*
485 * increment the core count for all
486 * the other cpus in this package
487 */
488 if (i != cpu)
489 cpu_data(i).booted_cores++;
490 } else if (i != cpu && !c->booted_cores)
491 c->booted_cores = cpu_data(i).booted_cores;
492 }
493 }
494}
495
70708a18
GC
496/* maps the cpu to the sched domain representing multi-core */
497cpumask_t cpu_coregroup_map(int cpu)
498{
499 struct cpuinfo_x86 *c = &cpu_data(cpu);
500 /*
501 * For perf, we return last level cache shared map.
502 * And for power savings, we return cpu_core_map
503 */
504 if (sched_mc_power_savings || sched_smt_power_savings)
505 return per_cpu(cpu_core_map, cpu);
506 else
507 return c->llc_shared_map;
508}
509
a4928cff 510static void impress_friends(void)
904541e2
GOC
511{
512 int cpu;
513 unsigned long bogosum = 0;
514 /*
515 * Allow the user to impress friends.
516 */
517 Dprintk("Before bogomips.\n");
518 for_each_possible_cpu(cpu)
519 if (cpu_isset(cpu, cpu_callout_map))
520 bogosum += cpu_data(cpu).loops_per_jiffy;
521 printk(KERN_INFO
522 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
f68e00a3 523 num_online_cpus(),
904541e2
GOC
524 bogosum/(500000/HZ),
525 (bogosum/(5000/HZ))%100);
526
527 Dprintk("Before bogocount - setting activated=1.\n");
528}
529
cb3c8b90
GOC
530static inline void __inquire_remote_apic(int apicid)
531{
532 unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
533 char *names[] = { "ID", "VERSION", "SPIV" };
534 int timeout;
535 u32 status;
536
537 printk(KERN_INFO "Inquiring remote APIC #%d...\n", apicid);
538
539 for (i = 0; i < ARRAY_SIZE(regs); i++) {
540 printk(KERN_INFO "... APIC #%d %s: ", apicid, names[i]);
541
542 /*
543 * Wait for idle.
544 */
545 status = safe_apic_wait_icr_idle();
546 if (status)
547 printk(KERN_CONT
548 "a previous APIC delivery may have failed\n");
549
550 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
551 apic_write_around(APIC_ICR, APIC_DM_REMRD | regs[i]);
552
553 timeout = 0;
554 do {
555 udelay(100);
556 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
557 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
558
559 switch (status) {
560 case APIC_ICR_RR_VALID:
561 status = apic_read(APIC_RRR);
562 printk(KERN_CONT "%08x\n", status);
563 break;
564 default:
565 printk(KERN_CONT "failed\n");
566 }
567 }
568}
569
570#ifdef WAKE_SECONDARY_VIA_NMI
571/*
572 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
573 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
574 * won't ... remember to clear down the APIC, etc later.
575 */
576static int __devinit
577wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
578{
579 unsigned long send_status, accept_status = 0;
580 int maxlvt;
581
582 /* Target chip */
583 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid));
584
585 /* Boot on the stack */
586 /* Kick the second */
587 apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL);
588
589 Dprintk("Waiting for send to finish...\n");
590 send_status = safe_apic_wait_icr_idle();
591
592 /*
593 * Give the other CPU some time to accept the IPI.
594 */
595 udelay(200);
596 /*
597 * Due to the Pentium erratum 3AP.
598 */
599 maxlvt = lapic_get_maxlvt();
600 if (maxlvt > 3) {
601 apic_read_around(APIC_SPIV);
602 apic_write(APIC_ESR, 0);
603 }
604 accept_status = (apic_read(APIC_ESR) & 0xEF);
605 Dprintk("NMI sent.\n");
606
607 if (send_status)
608 printk(KERN_ERR "APIC never delivered???\n");
609 if (accept_status)
610 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
611
612 return (send_status | accept_status);
613}
614#endif /* WAKE_SECONDARY_VIA_NMI */
615
cb3c8b90
GOC
616#ifdef WAKE_SECONDARY_VIA_INIT
617static int __devinit
618wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
619{
620 unsigned long send_status, accept_status = 0;
621 int maxlvt, num_starts, j;
622
34d05591
JS
623 if (get_uv_system_type() == UV_NON_UNIQUE_APIC) {
624 send_status = uv_wakeup_secondary(phys_apicid, start_eip);
625 atomic_set(&init_deasserted, 1);
626 return send_status;
627 }
628
cb3c8b90
GOC
629 /*
630 * Be paranoid about clearing APIC errors.
631 */
632 if (APIC_INTEGRATED(apic_version[phys_apicid])) {
633 apic_read_around(APIC_SPIV);
634 apic_write(APIC_ESR, 0);
635 apic_read(APIC_ESR);
636 }
637
638 Dprintk("Asserting INIT.\n");
639
640 /*
641 * Turn INIT on target chip
642 */
643 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
644
645 /*
646 * Send IPI
647 */
648 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
649 | APIC_DM_INIT);
650
651 Dprintk("Waiting for send to finish...\n");
652 send_status = safe_apic_wait_icr_idle();
653
654 mdelay(10);
655
656 Dprintk("Deasserting INIT.\n");
657
658 /* Target chip */
659 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
660
661 /* Send IPI */
662 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
663
664 Dprintk("Waiting for send to finish...\n");
665 send_status = safe_apic_wait_icr_idle();
666
667 mb();
668 atomic_set(&init_deasserted, 1);
669
670 /*
671 * Should we send STARTUP IPIs ?
672 *
673 * Determine this based on the APIC version.
674 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
675 */
676 if (APIC_INTEGRATED(apic_version[phys_apicid]))
677 num_starts = 2;
678 else
679 num_starts = 0;
680
681 /*
682 * Paravirt / VMI wants a startup IPI hook here to set up the
683 * target processor state.
684 */
685 startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
cb3c8b90 686 (unsigned long)stack_start.sp);
cb3c8b90
GOC
687
688 /*
689 * Run STARTUP IPI loop.
690 */
691 Dprintk("#startup loops: %d.\n", num_starts);
692
693 maxlvt = lapic_get_maxlvt();
694
695 for (j = 1; j <= num_starts; j++) {
696 Dprintk("Sending STARTUP #%d.\n", j);
697 apic_read_around(APIC_SPIV);
698 apic_write(APIC_ESR, 0);
699 apic_read(APIC_ESR);
700 Dprintk("After apic_write.\n");
701
702 /*
703 * STARTUP IPI
704 */
705
706 /* Target chip */
707 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
708
709 /* Boot on the stack */
710 /* Kick the second */
711 apic_write_around(APIC_ICR, APIC_DM_STARTUP
712 | (start_eip >> 12));
713
714 /*
715 * Give the other CPU some time to accept the IPI.
716 */
717 udelay(300);
718
719 Dprintk("Startup point 1.\n");
720
721 Dprintk("Waiting for send to finish...\n");
722 send_status = safe_apic_wait_icr_idle();
723
724 /*
725 * Give the other CPU some time to accept the IPI.
726 */
727 udelay(200);
728 /*
729 * Due to the Pentium erratum 3AP.
730 */
731 if (maxlvt > 3) {
732 apic_read_around(APIC_SPIV);
733 apic_write(APIC_ESR, 0);
734 }
735 accept_status = (apic_read(APIC_ESR) & 0xEF);
736 if (send_status || accept_status)
737 break;
738 }
739 Dprintk("After Startup.\n");
740
741 if (send_status)
742 printk(KERN_ERR "APIC never delivered???\n");
743 if (accept_status)
744 printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status);
745
746 return (send_status | accept_status);
747}
748#endif /* WAKE_SECONDARY_VIA_INIT */
749
750struct create_idle {
751 struct work_struct work;
752 struct task_struct *idle;
753 struct completion done;
754 int cpu;
755};
756
757static void __cpuinit do_fork_idle(struct work_struct *work)
758{
759 struct create_idle *c_idle =
760 container_of(work, struct create_idle, work);
761
762 c_idle->idle = fork_idle(c_idle->cpu);
763 complete(&c_idle->done);
764}
765
f307d25e 766#ifdef CONFIG_X86_64
3461b0af
MT
767/*
768 * Allocate node local memory for the AP pda.
769 *
770 * Must be called after the _cpu_pda pointer table is initialized.
771 */
772static int __cpuinit get_local_pda(int cpu)
773{
774 struct x8664_pda *oldpda, *newpda;
775 unsigned long size = sizeof(struct x8664_pda);
776 int node = cpu_to_node(cpu);
777
778 if (cpu_pda(cpu) && !cpu_pda(cpu)->in_bootmem)
779 return 0;
780
781 oldpda = cpu_pda(cpu);
782 newpda = kmalloc_node(size, GFP_ATOMIC, node);
783 if (!newpda) {
784 printk(KERN_ERR "Could not allocate node local PDA "
785 "for CPU %d on node %d\n", cpu, node);
786
787 if (oldpda)
788 return 0; /* have a usable pda */
789 else
790 return -1;
791 }
792
793 if (oldpda) {
794 memcpy(newpda, oldpda, size);
795 if (!after_bootmem)
796 free_bootmem((unsigned long)oldpda, size);
797 }
798
799 newpda->in_bootmem = 0;
800 cpu_pda(cpu) = newpda;
801 return 0;
802}
f307d25e 803#endif /* CONFIG_X86_64 */
3461b0af 804
cb3c8b90
GOC
805static int __cpuinit do_boot_cpu(int apicid, int cpu)
806/*
807 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
808 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
809 * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu.
810 */
811{
812 unsigned long boot_error = 0;
813 int timeout;
814 unsigned long start_ip;
815 unsigned short nmi_high = 0, nmi_low = 0;
816 struct create_idle c_idle = {
817 .cpu = cpu,
818 .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done),
819 };
820 INIT_WORK(&c_idle.work, do_fork_idle);
cb3c8b90 821
a939098a 822#ifdef CONFIG_X86_64
cb3c8b90 823 /* Allocate node local memory for AP pdas */
3461b0af
MT
824 if (cpu > 0) {
825 boot_error = get_local_pda(cpu);
826 if (boot_error)
827 goto restore_state;
828 /* if can't get pda memory, can't start cpu */
cb3c8b90
GOC
829 }
830#endif
831
832 alternatives_smp_switch(1);
833
834 c_idle.idle = get_idle_for_cpu(cpu);
835
836 /*
837 * We can't use kernel_thread since we must avoid to
838 * reschedule the child.
839 */
840 if (c_idle.idle) {
841 c_idle.idle->thread.sp = (unsigned long) (((struct pt_regs *)
842 (THREAD_SIZE + task_stack_page(c_idle.idle))) - 1);
843 init_idle(c_idle.idle, cpu);
844 goto do_rest;
845 }
846
847 if (!keventd_up() || current_is_keventd())
848 c_idle.work.func(&c_idle.work);
849 else {
850 schedule_work(&c_idle.work);
851 wait_for_completion(&c_idle.done);
852 }
853
854 if (IS_ERR(c_idle.idle)) {
855 printk("failed fork for CPU %d\n", cpu);
856 return PTR_ERR(c_idle.idle);
857 }
858
859 set_idle_for_cpu(cpu, c_idle.idle);
860do_rest:
861#ifdef CONFIG_X86_32
862 per_cpu(current_task, cpu) = c_idle.idle;
863 init_gdt(cpu);
cb3c8b90 864 /* Stack for startup_32 can be just as for start_secondary onwards */
cb3c8b90
GOC
865 irq_ctx_init(cpu);
866#else
867 cpu_pda(cpu)->pcurrent = c_idle.idle;
cb3c8b90 868 load_sp0(&per_cpu(init_tss, cpu), &c_idle.idle->thread);
cb3c8b90
GOC
869 clear_tsk_thread_flag(c_idle.idle, TIF_FORK);
870#endif
a939098a 871 early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu);
3e970473 872 initial_code = (unsigned long)start_secondary;
9cf4f298 873 stack_start.sp = (void *) c_idle.idle->thread.sp;
cb3c8b90
GOC
874
875 /* start_ip had better be page-aligned! */
876 start_ip = setup_trampoline();
877
878 /* So we see what's up */
879 printk(KERN_INFO "Booting processor %d/%d ip %lx\n",
880 cpu, apicid, start_ip);
881
882 /*
883 * This grunge runs the startup process for
884 * the targeted processor.
885 */
886
887 atomic_set(&init_deasserted, 0);
888
34d05591 889 if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
cb3c8b90 890
34d05591 891 Dprintk("Setting warm reset code and vector.\n");
cb3c8b90 892
34d05591
JS
893 store_NMI_vector(&nmi_high, &nmi_low);
894
895 smpboot_setup_warm_reset_vector(start_ip);
896 /*
897 * Be paranoid about clearing APIC errors.
898 */
899 apic_write(APIC_ESR, 0);
900 apic_read(APIC_ESR);
901 }
cb3c8b90 902
cb3c8b90
GOC
903 /*
904 * Starting actual IPI sequence...
905 */
906 boot_error = wakeup_secondary_cpu(apicid, start_ip);
907
908 if (!boot_error) {
909 /*
910 * allow APs to start initializing.
911 */
912 Dprintk("Before Callout %d.\n", cpu);
913 cpu_set(cpu, cpu_callout_map);
914 Dprintk("After Callout %d.\n", cpu);
915
916 /*
917 * Wait 5s total for a response
918 */
919 for (timeout = 0; timeout < 50000; timeout++) {
920 if (cpu_isset(cpu, cpu_callin_map))
921 break; /* It has booted */
922 udelay(100);
923 }
924
925 if (cpu_isset(cpu, cpu_callin_map)) {
926 /* number CPUs logically, starting from 1 (BSP is 0) */
927 Dprintk("OK.\n");
928 printk(KERN_INFO "CPU%d: ", cpu);
929 print_cpu_info(&cpu_data(cpu));
930 Dprintk("CPU has booted.\n");
931 } else {
932 boot_error = 1;
933 if (*((volatile unsigned char *)trampoline_base)
934 == 0xA5)
935 /* trampoline started but...? */
936 printk(KERN_ERR "Stuck ??\n");
937 else
938 /* trampoline code not run */
939 printk(KERN_ERR "Not responding.\n");
34d05591
JS
940 if (get_uv_system_type() != UV_NON_UNIQUE_APIC)
941 inquire_remote_apic(apicid);
cb3c8b90
GOC
942 }
943 }
944
3461b0af
MT
945restore_state:
946
cb3c8b90
GOC
947 if (boot_error) {
948 /* Try to put things back the way they were before ... */
949 unmap_cpu_to_logical_apicid(cpu);
950#ifdef CONFIG_X86_64
23ca4bba 951 numa_remove_cpu(cpu); /* was set by numa_add_cpu */
cb3c8b90
GOC
952#endif
953 cpu_clear(cpu, cpu_callout_map); /* was set by do_boot_cpu() */
954 cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
cb3c8b90
GOC
955 cpu_clear(cpu, cpu_present_map);
956 per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
957 }
958
959 /* mark "stuck" area as not stuck */
960 *((volatile unsigned long *)trampoline_base) = 0;
961
63d38198
AK
962 /*
963 * Cleanup possible dangling ends...
964 */
965 smpboot_restore_warm_reset_vector();
966
cb3c8b90
GOC
967 return boot_error;
968}
969
970int __cpuinit native_cpu_up(unsigned int cpu)
971{
972 int apicid = cpu_present_to_apicid(cpu);
973 unsigned long flags;
974 int err;
975
976 WARN_ON(irqs_disabled());
977
978 Dprintk("++++++++++++++++++++=_---CPU UP %u\n", cpu);
979
980 if (apicid == BAD_APICID || apicid == boot_cpu_physical_apicid ||
981 !physid_isset(apicid, phys_cpu_present_map)) {
982 printk(KERN_ERR "%s: bad cpu %d\n", __func__, cpu);
983 return -EINVAL;
984 }
985
986 /*
987 * Already booted CPU?
988 */
989 if (cpu_isset(cpu, cpu_callin_map)) {
990 Dprintk("do_boot_cpu %d Already started\n", cpu);
991 return -ENOSYS;
992 }
993
994 /*
995 * Save current MTRR state in case it was changed since early boot
996 * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync:
997 */
998 mtrr_save_state();
999
1000 per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
1001
1002#ifdef CONFIG_X86_32
1003 /* init low mem mapping */
68db065c 1004 clone_pgd_range(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
61165d7a 1005 min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
cb3c8b90 1006 flush_tlb_all();
61165d7a 1007 low_mappings = 1;
cb3c8b90
GOC
1008
1009 err = do_boot_cpu(apicid, cpu);
61165d7a
HD
1010
1011 zap_low_mappings();
1012 low_mappings = 0;
1013#else
1014 err = do_boot_cpu(apicid, cpu);
1015#endif
1016 if (err) {
cb3c8b90 1017 Dprintk("do_boot_cpu failed %d\n", err);
61165d7a 1018 return -EIO;
cb3c8b90
GOC
1019 }
1020
1021 /*
1022 * Check TSC synchronization with the AP (keep irqs disabled
1023 * while doing so):
1024 */
1025 local_irq_save(flags);
1026 check_tsc_sync_source(cpu);
1027 local_irq_restore(flags);
1028
7c04e64a 1029 while (!cpu_online(cpu)) {
cb3c8b90
GOC
1030 cpu_relax();
1031 touch_nmi_watchdog();
1032 }
1033
1034 return 0;
1035}
1036
8aef135c
GOC
1037/*
1038 * Fall back to non SMP mode after errors.
1039 *
1040 * RED-PEN audit/test this more. I bet there is more state messed up here.
1041 */
1042static __init void disable_smp(void)
1043{
1044 cpu_present_map = cpumask_of_cpu(0);
1045 cpu_possible_map = cpumask_of_cpu(0);
8aef135c 1046 smpboot_clear_io_apic_irqs();
0f385d1d 1047
8aef135c 1048 if (smp_found_config)
b6df1b8b 1049 physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
8aef135c 1050 else
b6df1b8b 1051 physid_set_mask_of_physid(0, &phys_cpu_present_map);
8aef135c
GOC
1052 map_cpu_to_logical_apicid();
1053 cpu_set(0, per_cpu(cpu_sibling_map, 0));
1054 cpu_set(0, per_cpu(cpu_core_map, 0));
1055}
1056
1057/*
1058 * Various sanity checks.
1059 */
1060static int __init smp_sanity_check(unsigned max_cpus)
1061{
ac23d4ee 1062 preempt_disable();
8aef135c
GOC
1063 if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) {
1064 printk(KERN_WARNING "weird, boot CPU (#%d) not listed"
1065 "by the BIOS.\n", hard_smp_processor_id());
1066 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1067 }
1068
1069 /*
1070 * If we couldn't find an SMP configuration at boot time,
1071 * get out of here now!
1072 */
1073 if (!smp_found_config && !acpi_lapic) {
ac23d4ee 1074 preempt_enable();
8aef135c
GOC
1075 printk(KERN_NOTICE "SMP motherboard not detected.\n");
1076 disable_smp();
1077 if (APIC_init_uniprocessor())
1078 printk(KERN_NOTICE "Local APIC not detected."
1079 " Using dummy APIC emulation.\n");
1080 return -1;
1081 }
1082
1083 /*
1084 * Should not be necessary because the MP table should list the boot
1085 * CPU too, but we do it for the sake of robustness anyway.
1086 */
1087 if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
1088 printk(KERN_NOTICE
1089 "weird, boot CPU (#%d) not listed by the BIOS.\n",
1090 boot_cpu_physical_apicid);
1091 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
1092 }
ac23d4ee 1093 preempt_enable();
8aef135c
GOC
1094
1095 /*
1096 * If we couldn't find a local APIC, then get out of here now!
1097 */
1098 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) &&
1099 !cpu_has_apic) {
1100 printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
1101 boot_cpu_physical_apicid);
1102 printk(KERN_ERR "... forcing use of dummy APIC emulation."
1103 "(tell your hw vendor)\n");
1104 smpboot_clear_io_apic();
1105 return -1;
1106 }
1107
1108 verify_local_APIC();
1109
1110 /*
1111 * If SMP should be disabled, then really disable it!
1112 */
1113 if (!max_cpus) {
73d08e63 1114 printk(KERN_INFO "SMP mode deactivated.\n");
8aef135c 1115 smpboot_clear_io_apic();
d54db1ac
MR
1116
1117 localise_nmi_watchdog();
1118
8aef135c 1119#ifdef CONFIG_X86_32
e90955c2 1120 connect_bsp_APIC();
8aef135c 1121#endif
e90955c2
JB
1122 setup_local_APIC();
1123 end_local_APIC_setup();
8aef135c
GOC
1124 return -1;
1125 }
1126
1127 return 0;
1128}
1129
1130static void __init smp_cpu_index_default(void)
1131{
1132 int i;
1133 struct cpuinfo_x86 *c;
1134
7c04e64a 1135 for_each_possible_cpu(i) {
8aef135c
GOC
1136 c = &cpu_data(i);
1137 /* mark all to hotplug */
1138 c->cpu_index = NR_CPUS;
1139 }
1140}
1141
1142/*
1143 * Prepare for SMP bootup. The MP table or ACPI has been read
1144 * earlier. Just do some sanity checking here and enable APIC mode.
1145 */
1146void __init native_smp_prepare_cpus(unsigned int max_cpus)
1147{
deef3250 1148 preempt_disable();
8aef135c
GOC
1149 nmi_watchdog_default();
1150 smp_cpu_index_default();
1151 current_cpu_data = boot_cpu_data;
1152 cpu_callin_map = cpumask_of_cpu(0);
1153 mb();
1154 /*
1155 * Setup boot CPU information
1156 */
1157 smp_store_cpu_info(0); /* Final full version of the data */
1158 boot_cpu_logical_apicid = logical_smp_processor_id();
1159 current_thread_info()->cpu = 0; /* needed? */
1160 set_cpu_sibling_map(0);
1161
1162 if (smp_sanity_check(max_cpus) < 0) {
1163 printk(KERN_INFO "SMP disabled\n");
1164 disable_smp();
deef3250 1165 goto out;
8aef135c
GOC
1166 }
1167
ac23d4ee 1168 preempt_disable();
05f2d12c 1169 if (GET_APIC_ID(read_apic_id()) != boot_cpu_physical_apicid) {
8aef135c 1170 panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
05f2d12c 1171 GET_APIC_ID(read_apic_id()), boot_cpu_physical_apicid);
8aef135c
GOC
1172 /* Or can we switch back to PIC here? */
1173 }
ac23d4ee 1174 preempt_enable();
8aef135c
GOC
1175
1176#ifdef CONFIG_X86_32
1177 connect_bsp_APIC();
1178#endif
1179 /*
1180 * Switch from PIC to APIC mode.
1181 */
1182 setup_local_APIC();
1183
1184#ifdef CONFIG_X86_64
1185 /*
1186 * Enable IO APIC before setting up error vector
1187 */
1188 if (!skip_ioapic_setup && nr_ioapics)
1189 enable_IO_APIC();
1190#endif
1191 end_local_APIC_setup();
1192
1193 map_cpu_to_logical_apicid();
1194
1195 setup_portio_remap();
1196
1197 smpboot_setup_io_apic();
1198 /*
1199 * Set up local APIC timer on boot CPU.
1200 */
1201
1202 printk(KERN_INFO "CPU%d: ", 0);
1203 print_cpu_info(&cpu_data(0));
1204 setup_boot_clock();
deef3250
IM
1205out:
1206 preempt_enable();
8aef135c 1207}
a8db8453
GOC
1208/*
1209 * Early setup to make printk work.
1210 */
1211void __init native_smp_prepare_boot_cpu(void)
1212{
1213 int me = smp_processor_id();
1214#ifdef CONFIG_X86_32
1215 init_gdt(me);
a8db8453 1216#endif
a939098a 1217 switch_to_new_gdt();
a8db8453
GOC
1218 /* already set me in cpu_online_map in boot_cpu_init() */
1219 cpu_set(me, cpu_callout_map);
1220 per_cpu(cpu_state, me) = CPU_ONLINE;
1221}
1222
83f7eb9c
GOC
1223void __init native_smp_cpus_done(unsigned int max_cpus)
1224{
83f7eb9c
GOC
1225 Dprintk("Boot done.\n");
1226
1227 impress_friends();
1228 smp_checks();
1229#ifdef CONFIG_X86_IO_APIC
1230 setup_ioapic_dest();
1231#endif
1232 check_nmi_watchdog();
83f7eb9c
GOC
1233}
1234
68a1c3f8 1235#ifdef CONFIG_HOTPLUG_CPU
2cd9fb71
GOC
1236
1237# ifdef CONFIG_X86_32
1238void cpu_exit_clear(void)
1239{
1240 int cpu = raw_smp_processor_id();
1241
1242 idle_task_exit();
1243
1244 cpu_uninit();
1245 irq_ctx_exit(cpu);
1246
1247 cpu_clear(cpu, cpu_callout_map);
1248 cpu_clear(cpu, cpu_callin_map);
1249
1250 unmap_cpu_to_logical_apicid(cpu);
1251}
1252# endif /* CONFIG_X86_32 */
1253
a4928cff 1254static void remove_siblinginfo(int cpu)
768d9505
GC
1255{
1256 int sibling;
1257 struct cpuinfo_x86 *c = &cpu_data(cpu);
1258
1259 for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) {
1260 cpu_clear(cpu, per_cpu(cpu_core_map, sibling));
1261 /*/
1262 * last thread sibling in this cpu core going down
1263 */
1264 if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1)
1265 cpu_data(sibling).booted_cores--;
1266 }
1267
1268 for_each_cpu_mask(sibling, per_cpu(cpu_sibling_map, cpu))
1269 cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling));
1270 cpus_clear(per_cpu(cpu_sibling_map, cpu));
1271 cpus_clear(per_cpu(cpu_core_map, cpu));
1272 c->phys_proc_id = 0;
1273 c->cpu_core_id = 0;
1274 cpu_clear(cpu, cpu_sibling_setup_map);
1275}
68a1c3f8 1276
c5562fae 1277static int additional_cpus __initdata = -1;
68a1c3f8
GC
1278
1279static __init int setup_additional_cpus(char *s)
1280{
1281 return s && get_option(&s, &additional_cpus) ? 0 : -EINVAL;
1282}
1283early_param("additional_cpus", setup_additional_cpus);
1284
1285/*
1286 * cpu_possible_map should be static, it cannot change as cpu's
1287 * are onlined, or offlined. The reason is per-cpu data-structures
1288 * are allocated by some modules at init time, and dont expect to
1289 * do this dynamically on cpu arrival/departure.
1290 * cpu_present_map on the other hand can change dynamically.
1291 * In case when cpu_hotplug is not compiled, then we resort to current
1292 * behaviour, which is cpu_possible == cpu_present.
1293 * - Ashok Raj
1294 *
1295 * Three ways to find out the number of additional hotplug CPUs:
1296 * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
1297 * - The user can overwrite it with additional_cpus=NUM
1298 * - Otherwise don't reserve additional CPUs.
1299 * We do this because additional CPUs waste a lot of memory.
1300 * -AK
1301 */
1302__init void prefill_possible_map(void)
1303{
1304 int i;
1305 int possible;
1306
1307 if (additional_cpus == -1) {
1308 if (disabled_cpus > 0)
1309 additional_cpus = disabled_cpus;
1310 else
1311 additional_cpus = 0;
1312 }
1313 possible = num_processors + additional_cpus;
1314 if (possible > NR_CPUS)
1315 possible = NR_CPUS;
1316
1317 printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
1318 possible, max_t(int, possible - num_processors, 0));
1319
1320 for (i = 0; i < possible; i++)
1321 cpu_set(i, cpu_possible_map);
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1322
1323 nr_cpu_ids = possible;
68a1c3f8 1324}
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1325
1326static void __ref remove_cpu_from_maps(int cpu)
1327{
1328 cpu_clear(cpu, cpu_online_map);
1329#ifdef CONFIG_X86_64
1330 cpu_clear(cpu, cpu_callout_map);
1331 cpu_clear(cpu, cpu_callin_map);
1332 /* was set by cpu_init() */
1333 clear_bit(cpu, (unsigned long *)&cpu_initialized);
23ca4bba 1334 numa_remove_cpu(cpu);
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GC
1335#endif
1336}
1337
1338int __cpu_disable(void)
1339{
1340 int cpu = smp_processor_id();
1341
1342 /*
1343 * Perhaps use cpufreq to drop frequency, but that could go
1344 * into generic code.
1345 *
1346 * We won't take down the boot processor on i386 due to some
1347 * interrupts only being able to be serviced by the BSP.
1348 * Especially so if we're not using an IOAPIC -zwane
1349 */
1350 if (cpu == 0)
1351 return -EBUSY;
1352
1353 if (nmi_watchdog == NMI_LOCAL_APIC)
1354 stop_apic_nmi_watchdog(NULL);
1355 clear_local_APIC();
1356
1357 /*
1358 * HACK:
1359 * Allow any queued timer interrupts to get serviced
1360 * This is only a temporary solution until we cleanup
1361 * fixup_irqs as we do for IA64.
1362 */
1363 local_irq_enable();
1364 mdelay(1);
1365
1366 local_irq_disable();
1367 remove_siblinginfo(cpu);
1368
1369 /* It's now safe to remove this processor from the online map */
1370 remove_cpu_from_maps(cpu);
1371 fixup_irqs(cpu_online_map);
1372 return 0;
1373}
1374
1375void __cpu_die(unsigned int cpu)
1376{
1377 /* We don't do anything here: idle task is faking death itself. */
1378 unsigned int i;
1379
1380 for (i = 0; i < 10; i++) {
1381 /* They ack this in play_dead by setting CPU_DEAD */
1382 if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
1383 printk(KERN_INFO "CPU %d is now offline\n", cpu);
1384 if (1 == num_online_cpus())
1385 alternatives_smp_switch(0);
1386 return;
1387 }
1388 msleep(100);
1389 }
1390 printk(KERN_ERR "CPU %u didn't die...\n", cpu);
1391}
1392#else /* ... !CONFIG_HOTPLUG_CPU */
1393int __cpu_disable(void)
1394{
1395 return -ENOSYS;
1396}
1397
1398void __cpu_die(unsigned int cpu)
1399{
1400 /* We said "no" in __cpu_disable */
1401 BUG();
1402}
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1403#endif
1404
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1405/*
1406 * If the BIOS enumerates physical processors before logical,
1407 * maxcpus=N at enumeration-time can be used to disable HT.
1408 */
1409static int __init parse_maxcpus(char *arg)
1410{
1411 extern unsigned int maxcpus;
1412
1413 maxcpus = simple_strtoul(arg, NULL, 0);
1414 return 0;
1415}
1416early_param("maxcpus", parse_maxcpus);