2 * x86 SMP booting functions
4 * (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
5 * (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
7 * Much of the core SMP work is based on previous work by Thomas Radke, to
8 * whom a great many thanks are extended.
10 * Thanks to Intel for making available several different Pentium,
11 * Pentium Pro and Pentium-II/Xeon MP machines.
12 * Original development of Linux SMP code supported by Caldera.
14 * This code is released under the GNU General Public License version 2 or
18 * Felix Koop : NR_CPUS used properly
19 * Jose Renau : Handle single CPU case.
20 * Alan Cox : By repeated request 8) - Total BogoMIPS report.
21 * Greg Wright : Fix for kernel stacks panic.
22 * Erich Boleyn : MP v1.4 and additional changes.
23 * Matthias Sattler : Changes for 2.1 kernel map.
24 * Michel Lespinasse : Changes for 2.1 kernel map.
25 * Michael Chastain : Change trampoline.S to gnu as.
26 * Alan Cox : Dumb bug: 'B' step PPro's are fine
27 * Ingo Molnar : Added APIC timers, based on code
29 * Ingo Molnar : various cleanups and rewrites
30 * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug.
31 * Maciej W. Rozycki : Bits for genuine 82489DX APICs
32 * Martin J. Bligh : Added support for multi-quad systems
33 * Dave Jones : Report invalid combinations of Athlon CPUs.
34 * Rusty Russell : Hacked into shape for new "hotplug" boot process. */
36 #include <linux/module.h>
37 #include <linux/config.h>
38 #include <linux/init.h>
39 #include <linux/kernel.h>
42 #include <linux/sched.h>
43 #include <linux/kernel_stat.h>
44 #include <linux/smp_lock.h>
45 #include <linux/irq.h>
46 #include <linux/bootmem.h>
48 #include <linux/delay.h>
49 #include <linux/mc146818rtc.h>
50 #include <asm/tlbflush.h>
52 #include <asm/arch_hooks.h>
54 #include <mach_apic.h>
55 #include <mach_wakecpu.h>
56 #include <smpboot_hooks.h>
58 /* Set if we find a B stepping CPU */
59 static int __initdata smp_b_stepping;
61 /* Number of siblings per CPU package */
62 int smp_num_siblings = 1;
63 int phys_proc_id[NR_CPUS]; /* Package ID of each logical CPU */
64 EXPORT_SYMBOL(phys_proc_id);
66 /* bitmap of online cpus */
67 cpumask_t cpu_online_map;
69 cpumask_t cpu_callin_map;
70 cpumask_t cpu_callout_map;
71 static cpumask_t smp_commenced_mask;
73 /* Per CPU bogomips and other parameters */
74 struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned;
76 u8 x86_cpu_to_apicid[NR_CPUS] =
77 { [0 ... NR_CPUS-1] = 0xff };
78 EXPORT_SYMBOL(x86_cpu_to_apicid);
80 /* Set when the idlers are all forked */
81 int smp_threads_ready;
84 * Trampoline 80x86 program as an array.
87 extern unsigned char trampoline_data [];
88 extern unsigned char trampoline_end [];
89 static unsigned char *trampoline_base;
90 static int trampoline_exec;
93 * Currently trivial. Write the real->protected mode
94 * bootstrap into the page concerned. The caller
95 * has made sure it's suitably aligned.
98 static unsigned long __init setup_trampoline(void)
100 memcpy(trampoline_base, trampoline_data, trampoline_end - trampoline_data);
101 return virt_to_phys(trampoline_base);
105 * We are called very early to get the low memory for the
106 * SMP bootup trampoline page.
108 void __init smp_alloc_memory(void)
110 trampoline_base = (void *) alloc_bootmem_low_pages(PAGE_SIZE);
112 * Has to be in very low memory so we can execute
115 if (__pa(trampoline_base) >= 0x9F000)
118 * Make the SMP trampoline executable:
120 trampoline_exec = set_kernel_exec((unsigned long)trampoline_base, 1);
124 * The bootstrap kernel entry code has set these up. Save them for
128 static void __init smp_store_cpu_info(int id)
130 struct cpuinfo_x86 *c = cpu_data + id;
136 * Mask B, Pentium, but not Pentium MMX
138 if (c->x86_vendor == X86_VENDOR_INTEL &&
140 c->x86_mask >= 1 && c->x86_mask <= 4 &&
143 * Remember we have B step Pentia with bugs
148 * Certain Athlons might work (for various values of 'work') in SMP
149 * but they are not certified as MP capable.
151 if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) {
153 /* Athlon 660/661 is valid. */
154 if ((c->x86_model==6) && ((c->x86_mask==0) || (c->x86_mask==1)))
157 /* Duron 670 is valid */
158 if ((c->x86_model==7) && (c->x86_mask==0))
162 * Athlon 662, Duron 671, and Athlon >model 7 have capability bit.
163 * It's worth noting that the A5 stepping (662) of some Athlon XP's
164 * have the MP bit set.
165 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for more.
167 if (((c->x86_model==6) && (c->x86_mask>=2)) ||
168 ((c->x86_model==7) && (c->x86_mask>=1)) ||
173 /* If we get here, it's not a certified SMP capable AMD system. */
174 tainted |= TAINT_UNSAFE_SMP;
182 * TSC synchronization.
184 * We first check whether all CPUs have their TSC's synchronized,
185 * then we print a warning if not, and always resync.
188 static atomic_t tsc_start_flag = ATOMIC_INIT(0);
189 static atomic_t tsc_count_start = ATOMIC_INIT(0);
190 static atomic_t tsc_count_stop = ATOMIC_INIT(0);
191 static unsigned long long tsc_values[NR_CPUS];
195 static void __init synchronize_tsc_bp (void)
198 unsigned long long t0;
199 unsigned long long sum, avg;
201 unsigned long one_usec;
204 printk(KERN_INFO "checking TSC synchronization across %u CPUs: ", num_booting_cpus());
206 /* convert from kcyc/sec to cyc/usec */
207 one_usec = cpu_khz / 1000;
209 atomic_set(&tsc_start_flag, 1);
213 * We loop a few times to get a primed instruction cache,
214 * then the last pass is more or less synchronized and
215 * the BP and APs set their cycle counters to zero all at
216 * once. This reduces the chance of having random offsets
217 * between the processors, and guarantees that the maximum
218 * delay between the cycle counters is never bigger than
219 * the latency of information-passing (cachelines) between
222 for (i = 0; i < NR_LOOPS; i++) {
224 * all APs synchronize but they loop on '== num_cpus'
226 while (atomic_read(&tsc_count_start) != num_booting_cpus()-1)
228 atomic_set(&tsc_count_stop, 0);
231 * this lets the APs save their current TSC:
233 atomic_inc(&tsc_count_start);
235 rdtscll(tsc_values[smp_processor_id()]);
237 * We clear the TSC in the last loop:
243 * Wait for all APs to leave the synchronization point:
245 while (atomic_read(&tsc_count_stop) != num_booting_cpus()-1)
247 atomic_set(&tsc_count_start, 0);
249 atomic_inc(&tsc_count_stop);
253 for (i = 0; i < NR_CPUS; i++) {
254 if (cpu_isset(i, cpu_callout_map)) {
260 do_div(avg, num_booting_cpus());
263 for (i = 0; i < NR_CPUS; i++) {
264 if (!cpu_isset(i, cpu_callout_map))
266 delta = tsc_values[i] - avg;
270 * We report bigger than 2 microseconds clock differences.
272 if (delta > 2*one_usec) {
279 do_div(realdelta, one_usec);
280 if (tsc_values[i] < avg)
281 realdelta = -realdelta;
283 printk(KERN_INFO "CPU#%d had %ld usecs TSC skew, fixed it up.\n", i, realdelta);
292 static void __init synchronize_tsc_ap (void)
297 * Not every cpu is online at the time
298 * this gets called, so we first wait for the BP to
299 * finish SMP initialization:
301 while (!atomic_read(&tsc_start_flag)) mb();
303 for (i = 0; i < NR_LOOPS; i++) {
304 atomic_inc(&tsc_count_start);
305 while (atomic_read(&tsc_count_start) != num_booting_cpus())
308 rdtscll(tsc_values[smp_processor_id()]);
312 atomic_inc(&tsc_count_stop);
313 while (atomic_read(&tsc_count_stop) != num_booting_cpus()) mb();
318 extern void calibrate_delay(void);
320 static atomic_t init_deasserted;
322 void __init smp_callin(void)
325 unsigned long timeout;
328 * If waken up by an INIT in an 82489DX configuration
329 * we may get here before an INIT-deassert IPI reaches
330 * our local APIC. We have to wait for the IPI or we'll
331 * lock up on an APIC access.
333 wait_for_init_deassert(&init_deasserted);
336 * (This works even if the APIC is not enabled.)
338 phys_id = GET_APIC_ID(apic_read(APIC_ID));
339 cpuid = smp_processor_id();
340 if (cpu_isset(cpuid, cpu_callin_map)) {
341 printk("huh, phys CPU#%d, CPU#%d already present??\n",
345 Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
348 * STARTUP IPIs are fragile beasts as they might sometimes
349 * trigger some glue motherboard logic. Complete APIC bus
350 * silence for 1 second, this overestimates the time the
351 * boot CPU is spending to send the up to 2 STARTUP IPIs
352 * by a factor of two. This should be enough.
356 * Waiting 2s total for startup (udelay is not yet working)
358 timeout = jiffies + 2*HZ;
359 while (time_before(jiffies, timeout)) {
361 * Has the boot CPU finished it's STARTUP sequence?
363 if (cpu_isset(cpuid, cpu_callout_map))
368 if (!time_before(jiffies, timeout)) {
369 printk("BUG: CPU%d started up but did not get a callout!\n",
375 * the boot CPU has finished the init stage and is spinning
376 * on callin_map until we finish. We are free to set up this
377 * CPU, first the APIC. (this is probably redundant on most
381 Dprintk("CALLIN, before setup_local_APIC().\n");
382 smp_callin_clear_local_apic();
384 map_cpu_to_logical_apicid();
390 Dprintk("Stack at about %p\n",&cpuid);
393 * Save our processor parameters
395 smp_store_cpu_info(cpuid);
397 disable_APIC_timer();
400 * Allow the master to continue.
402 cpu_set(cpuid, cpu_callin_map);
405 * Synchronize the TSC with the BP
407 if (cpu_has_tsc && cpu_khz)
408 synchronize_tsc_ap();
414 * Activate a secondary processor.
416 static void __init start_secondary(void *unused)
419 * Dont put anything before smp_callin(), SMP
420 * booting is too fragile that we want to limit the
421 * things done here to the most necessary things.
425 while (!cpu_isset(smp_processor_id(), smp_commenced_mask))
427 setup_secondary_APIC_clock();
428 if (nmi_watchdog == NMI_IO_APIC) {
429 disable_8259A_irq(0);
430 enable_NMI_through_LVT0(NULL);
435 * low-memory mappings have been cleared, flush them from
436 * the local TLBs too.
439 cpu_set(smp_processor_id(), cpu_online_map);
441 /* We can take interrupts now: we're officially "up". */
449 * Everything has been set up for the secondary
450 * CPUs - they just need to reload everything
451 * from the task structure
452 * This function must not return.
454 void __init initialize_secondary(void)
457 * We don't actually need to load the full TSS,
458 * basically just the stack pointer and the eip.
465 :"r" (current->thread.esp),"r" (current->thread.eip));
475 /* which logical CPUs are on which nodes */
476 cpumask_t node_2_cpu_mask[MAX_NUMNODES] =
477 { [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE };
478 /* which node each logical CPU is on */
479 int cpu_2_node[NR_CPUS] = { [0 ... NR_CPUS-1] = 0 };
480 EXPORT_SYMBOL(cpu_2_node);
482 /* set up a mapping between cpu and node. */
483 static inline void map_cpu_to_node(int cpu, int node)
485 printk("Mapping cpu %d to node %d\n", cpu, node);
486 cpu_set(cpu, node_2_cpu_mask[node]);
487 cpu_2_node[cpu] = node;
490 /* undo a mapping between cpu and node. */
491 static inline void unmap_cpu_to_node(int cpu)
495 printk("Unmapping cpu %d from all nodes\n", cpu);
496 for (node = 0; node < MAX_NUMNODES; node ++)
497 cpu_clear(cpu, node_2_cpu_mask[node]);
500 #else /* !CONFIG_NUMA */
502 #define map_cpu_to_node(cpu, node) ({})
503 #define unmap_cpu_to_node(cpu) ({})
505 #endif /* CONFIG_NUMA */
507 u8 cpu_2_logical_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
509 void map_cpu_to_logical_apicid(void)
511 int cpu = smp_processor_id();
512 int apicid = logical_smp_processor_id();
514 cpu_2_logical_apicid[cpu] = apicid;
515 map_cpu_to_node(cpu, apicid_to_node(apicid));
518 void unmap_cpu_to_logical_apicid(int cpu)
520 cpu_2_logical_apicid[cpu] = BAD_APICID;
521 unmap_cpu_to_node(cpu);
525 static inline void __inquire_remote_apic(int apicid)
527 int i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
528 char *names[] = { "ID", "VERSION", "SPIV" };
531 printk("Inquiring remote APIC #%d...\n", apicid);
533 for (i = 0; i < sizeof(regs) / sizeof(*regs); i++) {
534 printk("... APIC #%d %s: ", apicid, names[i]);
539 apic_wait_icr_idle();
541 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
542 apic_write_around(APIC_ICR, APIC_DM_REMRD | regs[i]);
547 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
548 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
551 case APIC_ICR_RR_VALID:
552 status = apic_read(APIC_RRR);
553 printk("%08x\n", status);
562 #ifdef WAKE_SECONDARY_VIA_NMI
564 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
565 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
566 * won't ... remember to clear down the APIC, etc later.
569 wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
571 unsigned long send_status = 0, accept_status = 0;
575 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid));
577 /* Boot on the stack */
578 /* Kick the second */
579 apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL);
581 Dprintk("Waiting for send to finish...\n");
586 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
587 } while (send_status && (timeout++ < 1000));
590 * Give the other CPU some time to accept the IPI.
594 * Due to the Pentium erratum 3AP.
596 maxlvt = get_maxlvt();
598 apic_read_around(APIC_SPIV);
599 apic_write(APIC_ESR, 0);
601 accept_status = (apic_read(APIC_ESR) & 0xEF);
602 Dprintk("NMI sent.\n");
605 printk("APIC never delivered???\n");
607 printk("APIC delivery error (%lx).\n", accept_status);
609 return (send_status | accept_status);
611 #endif /* WAKE_SECONDARY_VIA_NMI */
613 #ifdef WAKE_SECONDARY_VIA_INIT
615 wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
617 unsigned long send_status = 0, accept_status = 0;
618 int maxlvt, timeout, num_starts, j;
621 * Be paranoid about clearing APIC errors.
623 if (APIC_INTEGRATED(apic_version[phys_apicid])) {
624 apic_read_around(APIC_SPIV);
625 apic_write(APIC_ESR, 0);
629 Dprintk("Asserting INIT.\n");
632 * Turn INIT on target chip
634 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
639 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
642 Dprintk("Waiting for send to finish...\n");
647 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
648 } while (send_status && (timeout++ < 1000));
652 Dprintk("Deasserting INIT.\n");
655 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
658 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
660 Dprintk("Waiting for send to finish...\n");
665 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
666 } while (send_status && (timeout++ < 1000));
668 atomic_set(&init_deasserted, 1);
671 * Should we send STARTUP IPIs ?
673 * Determine this based on the APIC version.
674 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
676 if (APIC_INTEGRATED(apic_version[phys_apicid]))
682 * Run STARTUP IPI loop.
684 Dprintk("#startup loops: %d.\n", num_starts);
686 maxlvt = get_maxlvt();
688 for (j = 1; j <= num_starts; j++) {
689 Dprintk("Sending STARTUP #%d.\n",j);
690 apic_read_around(APIC_SPIV);
691 apic_write(APIC_ESR, 0);
693 Dprintk("After apic_write.\n");
700 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
702 /* Boot on the stack */
703 /* Kick the second */
704 apic_write_around(APIC_ICR, APIC_DM_STARTUP
705 | (start_eip >> 12));
708 * Give the other CPU some time to accept the IPI.
712 Dprintk("Startup point 1.\n");
714 Dprintk("Waiting for send to finish...\n");
719 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
720 } while (send_status && (timeout++ < 1000));
723 * Give the other CPU some time to accept the IPI.
727 * Due to the Pentium erratum 3AP.
730 apic_read_around(APIC_SPIV);
731 apic_write(APIC_ESR, 0);
733 accept_status = (apic_read(APIC_ESR) & 0xEF);
734 if (send_status || accept_status)
737 Dprintk("After Startup.\n");
740 printk("APIC never delivered???\n");
742 printk("APIC delivery error (%lx).\n", accept_status);
744 return (send_status | accept_status);
746 #endif /* WAKE_SECONDARY_VIA_INIT */
748 extern cpumask_t cpu_initialized;
750 static int __init do_boot_cpu(int apicid)
752 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
753 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
754 * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu.
757 struct task_struct *idle;
758 unsigned long boot_error;
760 unsigned long start_eip;
761 unsigned short nmi_high = 0, nmi_low = 0;
765 * We can't use kernel_thread since we must avoid to
766 * reschedule the child.
768 idle = fork_idle(cpu);
770 panic("failed fork for CPU %d", cpu);
771 idle->thread.eip = (unsigned long) start_secondary;
772 /* start_eip had better be page-aligned! */
773 start_eip = setup_trampoline();
775 /* So we see what's up */
776 printk("Booting processor %d/%d eip %lx\n", cpu, apicid, start_eip);
777 /* Stack for startup_32 can be just as for start_secondary onwards */
778 stack_start.esp = (void *) idle->thread.esp;
783 * This grunge runs the startup process for
784 * the targeted processor.
787 atomic_set(&init_deasserted, 0);
789 Dprintk("Setting warm reset code and vector.\n");
791 store_NMI_vector(&nmi_high, &nmi_low);
793 smpboot_setup_warm_reset_vector(start_eip);
796 * Starting actual IPI sequence...
798 boot_error = wakeup_secondary_cpu(apicid, start_eip);
802 * allow APs to start initializing.
804 Dprintk("Before Callout %d.\n", cpu);
805 cpu_set(cpu, cpu_callout_map);
806 Dprintk("After Callout %d.\n", cpu);
809 * Wait 5s total for a response
811 for (timeout = 0; timeout < 50000; timeout++) {
812 if (cpu_isset(cpu, cpu_callin_map))
813 break; /* It has booted */
817 if (cpu_isset(cpu, cpu_callin_map)) {
818 /* number CPUs logically, starting from 1 (BSP is 0) */
820 printk("CPU%d: ", cpu);
821 print_cpu_info(&cpu_data[cpu]);
822 Dprintk("CPU has booted.\n");
825 if (*((volatile unsigned char *)trampoline_base)
827 /* trampoline started but...? */
828 printk("Stuck ??\n");
830 /* trampoline code not run */
831 printk("Not responding.\n");
832 inquire_remote_apic(apicid);
835 x86_cpu_to_apicid[cpu] = apicid;
837 /* Try to put things back the way they were before ... */
838 unmap_cpu_to_logical_apicid(cpu);
839 cpu_clear(cpu, cpu_callout_map); /* was set here (do_boot_cpu()) */
840 cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
844 /* mark "stuck" area as not stuck */
845 *((volatile unsigned long *)trampoline_base) = 0;
850 cycles_t cacheflush_time;
851 unsigned long cache_decay_ticks;
853 static void smp_tune_scheduling (void)
855 unsigned long cachesize; /* kB */
856 unsigned long bandwidth = 350; /* MB/s */
858 * Rough estimation for SMP scheduling, this is the number of
859 * cycles it takes for a fully memory-limited process to flush
860 * the SMP-local cache.
862 * (For a P5 this pretty much means we will choose another idle
863 * CPU almost always at wakeup time (this is due to the small
864 * L1 cache), on PIIs it's around 50-100 usecs, depending on
870 * this basically disables processor-affinity
871 * scheduling on SMP without a TSC.
876 cachesize = boot_cpu_data.x86_cache_size;
877 if (cachesize == -1) {
878 cachesize = 16; /* Pentiums, 2x8kB cache */
882 cacheflush_time = (cpu_khz>>10) * (cachesize<<10) / bandwidth;
885 cache_decay_ticks = (long)cacheflush_time/cpu_khz + 1;
887 printk("per-CPU timeslice cutoff: %ld.%02ld usecs.\n",
888 (long)cacheflush_time/(cpu_khz/1000),
889 ((long)cacheflush_time*100/(cpu_khz/1000)) % 100);
890 printk("task migration cache decay timeout: %ld msecs.\n",
895 * Cycle through the processors sending APIC IPIs to boot each.
898 static int boot_cpu_logical_apicid;
899 /* Where the IO area was mapped on multiquad, always 0 otherwise */
902 cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
904 static void __init smp_boot_cpus(unsigned int max_cpus)
906 int apicid, cpu, bit, kicked;
907 unsigned long bogosum = 0;
910 * Setup boot CPU information
912 smp_store_cpu_info(0); /* Final full version of the data */
913 printk("CPU%d: ", 0);
914 print_cpu_info(&cpu_data[0]);
916 boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
917 boot_cpu_logical_apicid = logical_smp_processor_id();
918 x86_cpu_to_apicid[0] = boot_cpu_physical_apicid;
920 current_thread_info()->cpu = 0;
921 smp_tune_scheduling();
922 cpus_clear(cpu_sibling_map[0]);
923 cpu_set(0, cpu_sibling_map[0]);
926 * If we couldn't find an SMP configuration at boot time,
927 * get out of here now!
929 if (!smp_found_config && !acpi_lapic) {
930 printk(KERN_NOTICE "SMP motherboard not detected.\n");
931 smpboot_clear_io_apic_irqs();
932 phys_cpu_present_map = physid_mask_of_physid(0);
933 if (APIC_init_uniprocessor())
934 printk(KERN_NOTICE "Local APIC not detected."
935 " Using dummy APIC emulation.\n");
936 map_cpu_to_logical_apicid();
941 * Should not be necessary because the MP table should list the boot
942 * CPU too, but we do it for the sake of robustness anyway.
943 * Makes no sense to do this check in clustered apic mode, so skip it
945 if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
946 printk("weird, boot CPU (#%d) not listed by the BIOS.\n",
947 boot_cpu_physical_apicid);
948 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
952 * If we couldn't find a local APIC, then get out of here now!
954 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) && !cpu_has_apic) {
955 printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
956 boot_cpu_physical_apicid);
957 printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n");
958 smpboot_clear_io_apic_irqs();
959 phys_cpu_present_map = physid_mask_of_physid(0);
966 * If SMP should be disabled, then really disable it!
969 smp_found_config = 0;
970 printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
971 smpboot_clear_io_apic_irqs();
972 phys_cpu_present_map = physid_mask_of_physid(0);
978 map_cpu_to_logical_apicid();
981 setup_portio_remap();
984 * Scan the CPU present map and fire up the other CPUs via do_boot_cpu
986 * In clustered apic mode, phys_cpu_present_map is a constructed thus:
987 * bits 0-3 are quad0, 4-7 are quad1, etc. A perverse twist on the
990 Dprintk("CPU present map: %lx\n", physids_coerce(phys_cpu_present_map));
993 for (bit = 0; kicked < NR_CPUS && bit < MAX_APICS; bit++) {
994 apicid = cpu_present_to_apicid(bit);
996 * Don't even attempt to start the boot CPU!
998 if ((apicid == boot_cpu_apicid) || (apicid == BAD_APICID))
1001 if (!check_apicid_present(bit))
1003 if (max_cpus <= cpucount+1)
1006 if (do_boot_cpu(apicid))
1007 printk("CPU #%d not responding - cannot use it.\n",
1014 * Cleanup possible dangling ends...
1016 smpboot_restore_warm_reset_vector();
1019 * Allow the user to impress friends.
1021 Dprintk("Before bogomips.\n");
1022 for (cpu = 0; cpu < NR_CPUS; cpu++)
1023 if (cpu_isset(cpu, cpu_callout_map))
1024 bogosum += cpu_data[cpu].loops_per_jiffy;
1026 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
1028 bogosum/(500000/HZ),
1029 (bogosum/(5000/HZ))%100);
1031 Dprintk("Before bogocount - setting activated=1.\n");
1034 printk(KERN_WARNING "WARNING: SMP operation may be unreliable with B stepping processors.\n");
1037 * Don't taint if we are running SMP kernel on a single non-MP
1040 if (tainted & TAINT_UNSAFE_SMP) {
1042 printk (KERN_INFO "WARNING: This combination of AMD processors is not suitable for SMP.\n");
1044 tainted &= ~TAINT_UNSAFE_SMP;
1047 Dprintk("Boot done.\n");
1050 * construct cpu_sibling_map[], so that we can tell sibling CPUs
1053 for (cpu = 0; cpu < NR_CPUS; cpu++)
1054 cpus_clear(cpu_sibling_map[cpu]);
1056 for (cpu = 0; cpu < NR_CPUS; cpu++) {
1059 if (!cpu_isset(cpu, cpu_callout_map))
1062 if (smp_num_siblings > 1) {
1063 for (i = 0; i < NR_CPUS; i++) {
1064 if (!cpu_isset(i, cpu_callout_map))
1066 if (phys_proc_id[cpu] == phys_proc_id[i]) {
1068 cpu_set(i, cpu_sibling_map[cpu]);
1073 cpu_set(cpu, cpu_sibling_map[cpu]);
1076 if (siblings != smp_num_siblings)
1077 printk(KERN_WARNING "WARNING: %d siblings found for CPU%d, should be %d\n", siblings, cpu, smp_num_siblings);
1080 if (nmi_watchdog == NMI_LOCAL_APIC)
1081 check_nmi_watchdog();
1083 smpboot_setup_io_apic();
1085 setup_boot_APIC_clock();
1088 * Synchronize the TSC with the AP
1090 if (cpu_has_tsc && cpucount && cpu_khz)
1091 synchronize_tsc_bp();
1094 /* These are wrappers to interface to the new boot process. Someone
1095 who understands all this stuff should rewrite it properly. --RR 15/Jul/02 */
1096 void __init smp_prepare_cpus(unsigned int max_cpus)
1098 smp_boot_cpus(max_cpus);
1101 void __devinit smp_prepare_boot_cpu(void)
1103 cpu_set(smp_processor_id(), cpu_online_map);
1104 cpu_set(smp_processor_id(), cpu_callout_map);
1107 int __devinit __cpu_up(unsigned int cpu)
1109 /* This only works at boot for x86. See "rewrite" above. */
1110 if (cpu_isset(cpu, smp_commenced_mask)) {
1115 /* In case one didn't come up */
1116 if (!cpu_isset(cpu, cpu_callin_map)) {
1122 /* Unleash the CPU! */
1123 cpu_set(cpu, smp_commenced_mask);
1124 while (!cpu_isset(cpu, cpu_online_map))
1129 void __init smp_cpus_done(unsigned int max_cpus)
1131 #ifdef CONFIG_X86_IO_APIC
1132 setup_ioapic_dest();
1136 * Disable executability of the SMP trampoline:
1138 set_kernel_exec((unsigned long)trampoline_base, trampoline_exec);
1141 void __init smp_intr_init(void)
1144 * IRQ0 must be given a fixed assignment and initialized,
1145 * because it's used before the IO-APIC is set up.
1147 set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);
1150 * The reschedule interrupt is a CPU-to-CPU reschedule-helper
1151 * IPI, driven by wakeup.
1153 set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
1155 /* IPI for invalidation */
1156 set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
1158 /* IPI for generic function call */
1159 set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);