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);
81 * Trampoline 80x86 program as an array.
84 extern unsigned char trampoline_data [];
85 extern unsigned char trampoline_end [];
86 static unsigned char *trampoline_base;
87 static int trampoline_exec;
89 static void map_cpu_to_logical_apicid(void);
92 * Currently trivial. Write the real->protected mode
93 * bootstrap into the page concerned. The caller
94 * has made sure it's suitably aligned.
97 static unsigned long __init setup_trampoline(void)
99 memcpy(trampoline_base, trampoline_data, trampoline_end - trampoline_data);
100 return virt_to_phys(trampoline_base);
104 * We are called very early to get the low memory for the
105 * SMP bootup trampoline page.
107 void __init smp_alloc_memory(void)
109 trampoline_base = (void *) alloc_bootmem_low_pages(PAGE_SIZE);
111 * Has to be in very low memory so we can execute
114 if (__pa(trampoline_base) >= 0x9F000)
117 * Make the SMP trampoline executable:
119 trampoline_exec = set_kernel_exec((unsigned long)trampoline_base, 1);
123 * The bootstrap kernel entry code has set these up. Save them for
127 static void __init smp_store_cpu_info(int id)
129 struct cpuinfo_x86 *c = cpu_data + id;
135 * Mask B, Pentium, but not Pentium MMX
137 if (c->x86_vendor == X86_VENDOR_INTEL &&
139 c->x86_mask >= 1 && c->x86_mask <= 4 &&
142 * Remember we have B step Pentia with bugs
147 * Certain Athlons might work (for various values of 'work') in SMP
148 * but they are not certified as MP capable.
150 if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) {
152 /* Athlon 660/661 is valid. */
153 if ((c->x86_model==6) && ((c->x86_mask==0) || (c->x86_mask==1)))
156 /* Duron 670 is valid */
157 if ((c->x86_model==7) && (c->x86_mask==0))
161 * Athlon 662, Duron 671, and Athlon >model 7 have capability bit.
162 * It's worth noting that the A5 stepping (662) of some Athlon XP's
163 * have the MP bit set.
164 * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for more.
166 if (((c->x86_model==6) && (c->x86_mask>=2)) ||
167 ((c->x86_model==7) && (c->x86_mask>=1)) ||
172 /* If we get here, it's not a certified SMP capable AMD system. */
173 tainted |= TAINT_UNSAFE_SMP;
181 * TSC synchronization.
183 * We first check whether all CPUs have their TSC's synchronized,
184 * then we print a warning if not, and always resync.
187 static atomic_t tsc_start_flag = ATOMIC_INIT(0);
188 static atomic_t tsc_count_start = ATOMIC_INIT(0);
189 static atomic_t tsc_count_stop = ATOMIC_INIT(0);
190 static unsigned long long tsc_values[NR_CPUS];
194 static void __init synchronize_tsc_bp (void)
197 unsigned long long t0;
198 unsigned long long sum, avg;
200 unsigned long one_usec;
203 printk(KERN_INFO "checking TSC synchronization across %u CPUs: ", num_booting_cpus());
205 /* convert from kcyc/sec to cyc/usec */
206 one_usec = cpu_khz / 1000;
208 atomic_set(&tsc_start_flag, 1);
212 * We loop a few times to get a primed instruction cache,
213 * then the last pass is more or less synchronized and
214 * the BP and APs set their cycle counters to zero all at
215 * once. This reduces the chance of having random offsets
216 * between the processors, and guarantees that the maximum
217 * delay between the cycle counters is never bigger than
218 * the latency of information-passing (cachelines) between
221 for (i = 0; i < NR_LOOPS; i++) {
223 * all APs synchronize but they loop on '== num_cpus'
225 while (atomic_read(&tsc_count_start) != num_booting_cpus()-1)
227 atomic_set(&tsc_count_stop, 0);
230 * this lets the APs save their current TSC:
232 atomic_inc(&tsc_count_start);
234 rdtscll(tsc_values[smp_processor_id()]);
236 * We clear the TSC in the last loop:
242 * Wait for all APs to leave the synchronization point:
244 while (atomic_read(&tsc_count_stop) != num_booting_cpus()-1)
246 atomic_set(&tsc_count_start, 0);
248 atomic_inc(&tsc_count_stop);
252 for (i = 0; i < NR_CPUS; i++) {
253 if (cpu_isset(i, cpu_callout_map)) {
259 do_div(avg, num_booting_cpus());
262 for (i = 0; i < NR_CPUS; i++) {
263 if (!cpu_isset(i, cpu_callout_map))
265 delta = tsc_values[i] - avg;
269 * We report bigger than 2 microseconds clock differences.
271 if (delta > 2*one_usec) {
278 do_div(realdelta, one_usec);
279 if (tsc_values[i] < avg)
280 realdelta = -realdelta;
282 printk(KERN_INFO "CPU#%d had %ld usecs TSC skew, fixed it up.\n", i, realdelta);
291 static void __init synchronize_tsc_ap (void)
296 * Not every cpu is online at the time
297 * this gets called, so we first wait for the BP to
298 * finish SMP initialization:
300 while (!atomic_read(&tsc_start_flag)) mb();
302 for (i = 0; i < NR_LOOPS; i++) {
303 atomic_inc(&tsc_count_start);
304 while (atomic_read(&tsc_count_start) != num_booting_cpus())
307 rdtscll(tsc_values[smp_processor_id()]);
311 atomic_inc(&tsc_count_stop);
312 while (atomic_read(&tsc_count_stop) != num_booting_cpus()) mb();
317 extern void calibrate_delay(void);
319 static atomic_t init_deasserted;
321 static void __init smp_callin(void)
324 unsigned long timeout;
327 * If waken up by an INIT in an 82489DX configuration
328 * we may get here before an INIT-deassert IPI reaches
329 * our local APIC. We have to wait for the IPI or we'll
330 * lock up on an APIC access.
332 wait_for_init_deassert(&init_deasserted);
335 * (This works even if the APIC is not enabled.)
337 phys_id = GET_APIC_ID(apic_read(APIC_ID));
338 cpuid = smp_processor_id();
339 if (cpu_isset(cpuid, cpu_callin_map)) {
340 printk("huh, phys CPU#%d, CPU#%d already present??\n",
344 Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id);
347 * STARTUP IPIs are fragile beasts as they might sometimes
348 * trigger some glue motherboard logic. Complete APIC bus
349 * silence for 1 second, this overestimates the time the
350 * boot CPU is spending to send the up to 2 STARTUP IPIs
351 * by a factor of two. This should be enough.
355 * Waiting 2s total for startup (udelay is not yet working)
357 timeout = jiffies + 2*HZ;
358 while (time_before(jiffies, timeout)) {
360 * Has the boot CPU finished it's STARTUP sequence?
362 if (cpu_isset(cpuid, cpu_callout_map))
367 if (!time_before(jiffies, timeout)) {
368 printk("BUG: CPU%d started up but did not get a callout!\n",
374 * the boot CPU has finished the init stage and is spinning
375 * on callin_map until we finish. We are free to set up this
376 * CPU, first the APIC. (this is probably redundant on most
380 Dprintk("CALLIN, before setup_local_APIC().\n");
381 smp_callin_clear_local_apic();
383 map_cpu_to_logical_apicid();
389 Dprintk("Stack at about %p\n",&cpuid);
392 * Save our processor parameters
394 smp_store_cpu_info(cpuid);
396 disable_APIC_timer();
399 * Allow the master to continue.
401 cpu_set(cpuid, cpu_callin_map);
404 * Synchronize the TSC with the BP
406 if (cpu_has_tsc && cpu_khz)
407 synchronize_tsc_ap();
413 * Activate a secondary processor.
415 static void __init start_secondary(void *unused)
418 * Dont put anything before smp_callin(), SMP
419 * booting is too fragile that we want to limit the
420 * things done here to the most necessary things.
424 while (!cpu_isset(smp_processor_id(), smp_commenced_mask))
426 setup_secondary_APIC_clock();
427 if (nmi_watchdog == NMI_IO_APIC) {
428 disable_8259A_irq(0);
429 enable_NMI_through_LVT0(NULL);
434 * low-memory mappings have been cleared, flush them from
435 * the local TLBs too.
438 cpu_set(smp_processor_id(), cpu_online_map);
440 /* We can take interrupts now: we're officially "up". */
448 * Everything has been set up for the secondary
449 * CPUs - they just need to reload everything
450 * from the task structure
451 * This function must not return.
453 void __init initialize_secondary(void)
456 * We don't actually need to load the full TSS,
457 * basically just the stack pointer and the eip.
464 :"r" (current->thread.esp),"r" (current->thread.eip));
474 /* which logical CPUs are on which nodes */
475 cpumask_t node_2_cpu_mask[MAX_NUMNODES] =
476 { [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE };
477 /* which node each logical CPU is on */
478 int cpu_2_node[NR_CPUS] = { [0 ... NR_CPUS-1] = 0 };
479 EXPORT_SYMBOL(cpu_2_node);
481 /* set up a mapping between cpu and node. */
482 static inline void map_cpu_to_node(int cpu, int node)
484 printk("Mapping cpu %d to node %d\n", cpu, node);
485 cpu_set(cpu, node_2_cpu_mask[node]);
486 cpu_2_node[cpu] = node;
489 /* undo a mapping between cpu and node. */
490 static inline void unmap_cpu_to_node(int cpu)
494 printk("Unmapping cpu %d from all nodes\n", cpu);
495 for (node = 0; node < MAX_NUMNODES; node ++)
496 cpu_clear(cpu, node_2_cpu_mask[node]);
499 #else /* !CONFIG_NUMA */
501 #define map_cpu_to_node(cpu, node) ({})
502 #define unmap_cpu_to_node(cpu) ({})
504 #endif /* CONFIG_NUMA */
506 u8 cpu_2_logical_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
508 static void map_cpu_to_logical_apicid(void)
510 int cpu = smp_processor_id();
511 int apicid = logical_smp_processor_id();
513 cpu_2_logical_apicid[cpu] = apicid;
514 map_cpu_to_node(cpu, apicid_to_node(apicid));
517 static void unmap_cpu_to_logical_apicid(int cpu)
519 cpu_2_logical_apicid[cpu] = BAD_APICID;
520 unmap_cpu_to_node(cpu);
524 static inline void __inquire_remote_apic(int apicid)
526 int i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 };
527 char *names[] = { "ID", "VERSION", "SPIV" };
530 printk("Inquiring remote APIC #%d...\n", apicid);
532 for (i = 0; i < sizeof(regs) / sizeof(*regs); i++) {
533 printk("... APIC #%d %s: ", apicid, names[i]);
538 apic_wait_icr_idle();
540 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
541 apic_write_around(APIC_ICR, APIC_DM_REMRD | regs[i]);
546 status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK;
547 } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000);
550 case APIC_ICR_RR_VALID:
551 status = apic_read(APIC_RRR);
552 printk("%08x\n", status);
561 #ifdef WAKE_SECONDARY_VIA_NMI
563 * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal
564 * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this
565 * won't ... remember to clear down the APIC, etc later.
568 wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
570 unsigned long send_status = 0, accept_status = 0;
574 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid));
576 /* Boot on the stack */
577 /* Kick the second */
578 apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL);
580 Dprintk("Waiting for send to finish...\n");
585 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
586 } while (send_status && (timeout++ < 1000));
589 * Give the other CPU some time to accept the IPI.
593 * Due to the Pentium erratum 3AP.
595 maxlvt = get_maxlvt();
597 apic_read_around(APIC_SPIV);
598 apic_write(APIC_ESR, 0);
600 accept_status = (apic_read(APIC_ESR) & 0xEF);
601 Dprintk("NMI sent.\n");
604 printk("APIC never delivered???\n");
606 printk("APIC delivery error (%lx).\n", accept_status);
608 return (send_status | accept_status);
610 #endif /* WAKE_SECONDARY_VIA_NMI */
612 #ifdef WAKE_SECONDARY_VIA_INIT
614 wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
616 unsigned long send_status = 0, accept_status = 0;
617 int maxlvt, timeout, num_starts, j;
620 * Be paranoid about clearing APIC errors.
622 if (APIC_INTEGRATED(apic_version[phys_apicid])) {
623 apic_read_around(APIC_SPIV);
624 apic_write(APIC_ESR, 0);
628 Dprintk("Asserting INIT.\n");
631 * Turn INIT on target chip
633 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
638 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
641 Dprintk("Waiting for send to finish...\n");
646 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
647 } while (send_status && (timeout++ < 1000));
651 Dprintk("Deasserting INIT.\n");
654 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
657 apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
659 Dprintk("Waiting for send to finish...\n");
664 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
665 } while (send_status && (timeout++ < 1000));
667 atomic_set(&init_deasserted, 1);
670 * Should we send STARTUP IPIs ?
672 * Determine this based on the APIC version.
673 * If we don't have an integrated APIC, don't send the STARTUP IPIs.
675 if (APIC_INTEGRATED(apic_version[phys_apicid]))
681 * Run STARTUP IPI loop.
683 Dprintk("#startup loops: %d.\n", num_starts);
685 maxlvt = get_maxlvt();
687 for (j = 1; j <= num_starts; j++) {
688 Dprintk("Sending STARTUP #%d.\n",j);
689 apic_read_around(APIC_SPIV);
690 apic_write(APIC_ESR, 0);
692 Dprintk("After apic_write.\n");
699 apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
701 /* Boot on the stack */
702 /* Kick the second */
703 apic_write_around(APIC_ICR, APIC_DM_STARTUP
704 | (start_eip >> 12));
707 * Give the other CPU some time to accept the IPI.
711 Dprintk("Startup point 1.\n");
713 Dprintk("Waiting for send to finish...\n");
718 send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
719 } while (send_status && (timeout++ < 1000));
722 * Give the other CPU some time to accept the IPI.
726 * Due to the Pentium erratum 3AP.
729 apic_read_around(APIC_SPIV);
730 apic_write(APIC_ESR, 0);
732 accept_status = (apic_read(APIC_ESR) & 0xEF);
733 if (send_status || accept_status)
736 Dprintk("After Startup.\n");
739 printk("APIC never delivered???\n");
741 printk("APIC delivery error (%lx).\n", accept_status);
743 return (send_status | accept_status);
745 #endif /* WAKE_SECONDARY_VIA_INIT */
747 extern cpumask_t cpu_initialized;
749 static int __init do_boot_cpu(int apicid)
751 * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad
752 * (ie clustered apic addressing mode), this is a LOGICAL apic ID.
753 * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu.
756 struct task_struct *idle;
757 unsigned long boot_error;
759 unsigned long start_eip;
760 unsigned short nmi_high = 0, nmi_low = 0;
764 * We can't use kernel_thread since we must avoid to
765 * reschedule the child.
767 idle = fork_idle(cpu);
769 panic("failed fork for CPU %d", cpu);
770 idle->thread.eip = (unsigned long) start_secondary;
771 /* start_eip had better be page-aligned! */
772 start_eip = setup_trampoline();
774 /* So we see what's up */
775 printk("Booting processor %d/%d eip %lx\n", cpu, apicid, start_eip);
776 /* Stack for startup_32 can be just as for start_secondary onwards */
777 stack_start.esp = (void *) idle->thread.esp;
782 * This grunge runs the startup process for
783 * the targeted processor.
786 atomic_set(&init_deasserted, 0);
788 Dprintk("Setting warm reset code and vector.\n");
790 store_NMI_vector(&nmi_high, &nmi_low);
792 smpboot_setup_warm_reset_vector(start_eip);
795 * Starting actual IPI sequence...
797 boot_error = wakeup_secondary_cpu(apicid, start_eip);
801 * allow APs to start initializing.
803 Dprintk("Before Callout %d.\n", cpu);
804 cpu_set(cpu, cpu_callout_map);
805 Dprintk("After Callout %d.\n", cpu);
808 * Wait 5s total for a response
810 for (timeout = 0; timeout < 50000; timeout++) {
811 if (cpu_isset(cpu, cpu_callin_map))
812 break; /* It has booted */
816 if (cpu_isset(cpu, cpu_callin_map)) {
817 /* number CPUs logically, starting from 1 (BSP is 0) */
819 printk("CPU%d: ", cpu);
820 print_cpu_info(&cpu_data[cpu]);
821 Dprintk("CPU has booted.\n");
824 if (*((volatile unsigned char *)trampoline_base)
826 /* trampoline started but...? */
827 printk("Stuck ??\n");
829 /* trampoline code not run */
830 printk("Not responding.\n");
831 inquire_remote_apic(apicid);
834 x86_cpu_to_apicid[cpu] = apicid;
836 /* Try to put things back the way they were before ... */
837 unmap_cpu_to_logical_apicid(cpu);
838 cpu_clear(cpu, cpu_callout_map); /* was set here (do_boot_cpu()) */
839 cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
843 /* mark "stuck" area as not stuck */
844 *((volatile unsigned long *)trampoline_base) = 0;
849 static void smp_tune_scheduling (void)
851 unsigned long cachesize; /* kB */
852 unsigned long bandwidth = 350; /* MB/s */
854 * Rough estimation for SMP scheduling, this is the number of
855 * cycles it takes for a fully memory-limited process to flush
856 * the SMP-local cache.
858 * (For a P5 this pretty much means we will choose another idle
859 * CPU almost always at wakeup time (this is due to the small
860 * L1 cache), on PIIs it's around 50-100 usecs, depending on
866 * this basically disables processor-affinity
867 * scheduling on SMP without a TSC.
871 cachesize = boot_cpu_data.x86_cache_size;
872 if (cachesize == -1) {
873 cachesize = 16; /* Pentiums, 2x8kB cache */
880 * Cycle through the processors sending APIC IPIs to boot each.
883 static int boot_cpu_logical_apicid;
884 /* Where the IO area was mapped on multiquad, always 0 otherwise */
887 cpumask_t cpu_sibling_map[NR_CPUS] __cacheline_aligned;
889 static void __init smp_boot_cpus(unsigned int max_cpus)
891 int apicid, cpu, bit, kicked;
892 unsigned long bogosum = 0;
895 * Setup boot CPU information
897 smp_store_cpu_info(0); /* Final full version of the data */
898 printk("CPU%d: ", 0);
899 print_cpu_info(&cpu_data[0]);
901 boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
902 boot_cpu_logical_apicid = logical_smp_processor_id();
903 x86_cpu_to_apicid[0] = boot_cpu_physical_apicid;
905 current_thread_info()->cpu = 0;
906 smp_tune_scheduling();
907 cpus_clear(cpu_sibling_map[0]);
908 cpu_set(0, cpu_sibling_map[0]);
911 * If we couldn't find an SMP configuration at boot time,
912 * get out of here now!
914 if (!smp_found_config && !acpi_lapic) {
915 printk(KERN_NOTICE "SMP motherboard not detected.\n");
916 smpboot_clear_io_apic_irqs();
917 phys_cpu_present_map = physid_mask_of_physid(0);
918 if (APIC_init_uniprocessor())
919 printk(KERN_NOTICE "Local APIC not detected."
920 " Using dummy APIC emulation.\n");
921 map_cpu_to_logical_apicid();
926 * Should not be necessary because the MP table should list the boot
927 * CPU too, but we do it for the sake of robustness anyway.
928 * Makes no sense to do this check in clustered apic mode, so skip it
930 if (!check_phys_apicid_present(boot_cpu_physical_apicid)) {
931 printk("weird, boot CPU (#%d) not listed by the BIOS.\n",
932 boot_cpu_physical_apicid);
933 physid_set(hard_smp_processor_id(), phys_cpu_present_map);
937 * If we couldn't find a local APIC, then get out of here now!
939 if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) && !cpu_has_apic) {
940 printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
941 boot_cpu_physical_apicid);
942 printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n");
943 smpboot_clear_io_apic_irqs();
944 phys_cpu_present_map = physid_mask_of_physid(0);
951 * If SMP should be disabled, then really disable it!
954 smp_found_config = 0;
955 printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n");
956 smpboot_clear_io_apic_irqs();
957 phys_cpu_present_map = physid_mask_of_physid(0);
963 map_cpu_to_logical_apicid();
966 setup_portio_remap();
969 * Scan the CPU present map and fire up the other CPUs via do_boot_cpu
971 * In clustered apic mode, phys_cpu_present_map is a constructed thus:
972 * bits 0-3 are quad0, 4-7 are quad1, etc. A perverse twist on the
975 Dprintk("CPU present map: %lx\n", physids_coerce(phys_cpu_present_map));
978 for (bit = 0; kicked < NR_CPUS && bit < MAX_APICS; bit++) {
979 apicid = cpu_present_to_apicid(bit);
981 * Don't even attempt to start the boot CPU!
983 if ((apicid == boot_cpu_apicid) || (apicid == BAD_APICID))
986 if (!check_apicid_present(bit))
988 if (max_cpus <= cpucount+1)
991 if (do_boot_cpu(apicid))
992 printk("CPU #%d not responding - cannot use it.\n",
999 * Cleanup possible dangling ends...
1001 smpboot_restore_warm_reset_vector();
1004 * Allow the user to impress friends.
1006 Dprintk("Before bogomips.\n");
1007 for (cpu = 0; cpu < NR_CPUS; cpu++)
1008 if (cpu_isset(cpu, cpu_callout_map))
1009 bogosum += cpu_data[cpu].loops_per_jiffy;
1011 "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
1013 bogosum/(500000/HZ),
1014 (bogosum/(5000/HZ))%100);
1016 Dprintk("Before bogocount - setting activated=1.\n");
1019 printk(KERN_WARNING "WARNING: SMP operation may be unreliable with B stepping processors.\n");
1022 * Don't taint if we are running SMP kernel on a single non-MP
1025 if (tainted & TAINT_UNSAFE_SMP) {
1027 printk (KERN_INFO "WARNING: This combination of AMD processors is not suitable for SMP.\n");
1029 tainted &= ~TAINT_UNSAFE_SMP;
1032 Dprintk("Boot done.\n");
1035 * construct cpu_sibling_map[], so that we can tell sibling CPUs
1038 for (cpu = 0; cpu < NR_CPUS; cpu++)
1039 cpus_clear(cpu_sibling_map[cpu]);
1041 for (cpu = 0; cpu < NR_CPUS; cpu++) {
1044 if (!cpu_isset(cpu, cpu_callout_map))
1047 if (smp_num_siblings > 1) {
1048 for (i = 0; i < NR_CPUS; i++) {
1049 if (!cpu_isset(i, cpu_callout_map))
1051 if (phys_proc_id[cpu] == phys_proc_id[i]) {
1053 cpu_set(i, cpu_sibling_map[cpu]);
1058 cpu_set(cpu, cpu_sibling_map[cpu]);
1061 if (siblings != smp_num_siblings)
1062 printk(KERN_WARNING "WARNING: %d siblings found for CPU%d, should be %d\n", siblings, cpu, smp_num_siblings);
1065 if (nmi_watchdog == NMI_LOCAL_APIC)
1066 check_nmi_watchdog();
1068 smpboot_setup_io_apic();
1070 setup_boot_APIC_clock();
1073 * Synchronize the TSC with the AP
1075 if (cpu_has_tsc && cpucount && cpu_khz)
1076 synchronize_tsc_bp();
1079 /* These are wrappers to interface to the new boot process. Someone
1080 who understands all this stuff should rewrite it properly. --RR 15/Jul/02 */
1081 void __init smp_prepare_cpus(unsigned int max_cpus)
1083 smp_boot_cpus(max_cpus);
1086 void __devinit smp_prepare_boot_cpu(void)
1088 cpu_set(smp_processor_id(), cpu_online_map);
1089 cpu_set(smp_processor_id(), cpu_callout_map);
1092 int __devinit __cpu_up(unsigned int cpu)
1094 /* This only works at boot for x86. See "rewrite" above. */
1095 if (cpu_isset(cpu, smp_commenced_mask)) {
1100 /* In case one didn't come up */
1101 if (!cpu_isset(cpu, cpu_callin_map)) {
1107 /* Unleash the CPU! */
1108 cpu_set(cpu, smp_commenced_mask);
1109 while (!cpu_isset(cpu, cpu_online_map))
1114 void __init smp_cpus_done(unsigned int max_cpus)
1116 #ifdef CONFIG_X86_IO_APIC
1117 setup_ioapic_dest();
1121 * Disable executability of the SMP trampoline:
1123 set_kernel_exec((unsigned long)trampoline_base, trampoline_exec);
1126 void __init smp_intr_init(void)
1129 * IRQ0 must be given a fixed assignment and initialized,
1130 * because it's used before the IO-APIC is set up.
1132 set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);
1135 * The reschedule interrupt is a CPU-to-CPU reschedule-helper
1136 * IPI, driven by wakeup.
1138 set_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);
1140 /* IPI for invalidation */
1141 set_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);
1143 /* IPI for generic function call */
1144 set_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);