/* * x86 SMP booting functions * * (c) 1995 Alan Cox, Building #3 * (c) 1998, 1999, 2000 Ingo Molnar * Copyright 2001 Andi Kleen, SuSE Labs. * * Much of the core SMP work is based on previous work by Thomas Radke, to * whom a great many thanks are extended. * * Thanks to Intel for making available several different Pentium, * Pentium Pro and Pentium-II/Xeon MP machines. * Original development of Linux SMP code supported by Caldera. * * This code is released under the GNU General Public License version 2 * * Fixes * Felix Koop : NR_CPUS used properly * Jose Renau : Handle single CPU case. * Alan Cox : By repeated request 8) - Total BogoMIP report. * Greg Wright : Fix for kernel stacks panic. * Erich Boleyn : MP v1.4 and additional changes. * Matthias Sattler : Changes for 2.1 kernel map. * Michel Lespinasse : Changes for 2.1 kernel map. * Michael Chastain : Change trampoline.S to gnu as. * Alan Cox : Dumb bug: 'B' step PPro's are fine * Ingo Molnar : Added APIC timers, based on code * from Jose Renau * Ingo Molnar : various cleanups and rewrites * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug. * Maciej W. Rozycki : Bits for genuine 82489DX APICs * Andi Kleen : Changed for SMP boot into long mode. * Rusty Russell : Hacked into shape for new "hotplug" boot process. * Andi Kleen : Converted to new state machine. * Various cleanups. * Probably mostly hotplug CPU ready now. * Ashok Raj : CPU hotplug support */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Set when the idlers are all forked */ int smp_threads_ready; /* State of each CPU */ DEFINE_PER_CPU(int, cpu_state) = { 0 }; extern void smp_callin(void); /* * Setup code on secondary processor (after comming out of the trampoline) */ void __cpuinit start_secondary(void) { /* * Dont put anything before smp_callin(), SMP * booting is too fragile that we want to limit the * things done here to the most necessary things. */ cpu_init(); preempt_disable(); smp_callin(); /* otherwise gcc will move up the smp_processor_id before the cpu_init */ barrier(); /* * Check TSC sync first: */ check_tsc_sync_target(); if (nmi_watchdog == NMI_IO_APIC) { disable_8259A_irq(0); enable_NMI_through_LVT0(); enable_8259A_irq(0); } /* * The sibling maps must be set before turing the online map on for * this cpu */ set_cpu_sibling_map(smp_processor_id()); /* * We need to hold call_lock, so there is no inconsistency * between the time smp_call_function() determines number of * IPI recipients, and the time when the determination is made * for which cpus receive the IPI in genapic_flat.c. Holding this * lock helps us to not include this cpu in a currently in progress * smp_call_function(). */ lock_ipi_call_lock(); spin_lock(&vector_lock); /* Setup the per cpu irq handling data structures */ __setup_vector_irq(smp_processor_id()); /* * Allow the master to continue. */ spin_unlock(&vector_lock); cpu_set(smp_processor_id(), cpu_online_map); unlock_ipi_call_lock(); per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; setup_secondary_clock(); wmb(); cpu_idle(); } cycles_t cacheflush_time; unsigned long cache_decay_ticks; /* * Fall back to non SMP mode after errors. * * RED-PEN audit/test this more. I bet there is more state messed up here. */ static __init void disable_smp(void) { cpu_present_map = cpumask_of_cpu(0); cpu_possible_map = cpumask_of_cpu(0); if (smp_found_config) phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid); else phys_cpu_present_map = physid_mask_of_physid(0); cpu_set(0, per_cpu(cpu_sibling_map, 0)); cpu_set(0, per_cpu(cpu_core_map, 0)); } /* * Various sanity checks. */ static int __init smp_sanity_check(unsigned max_cpus) { if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) { printk("weird, boot CPU (#%d) not listed by the BIOS.\n", hard_smp_processor_id()); physid_set(hard_smp_processor_id(), phys_cpu_present_map); } /* * If we couldn't find an SMP configuration at boot time, * get out of here now! */ if (!smp_found_config) { printk(KERN_NOTICE "SMP motherboard not detected.\n"); disable_smp(); if (APIC_init_uniprocessor()) printk(KERN_NOTICE "Local APIC not detected." " Using dummy APIC emulation.\n"); return -1; } /* * Should not be necessary because the MP table should list the boot * CPU too, but we do it for the sake of robustness anyway. */ if (!physid_isset(boot_cpu_physical_apicid, phys_cpu_present_map)) { printk(KERN_NOTICE "weird, boot CPU (#%d) not listed by the BIOS.\n", boot_cpu_physical_apicid); physid_set(hard_smp_processor_id(), phys_cpu_present_map); } /* * If we couldn't find a local APIC, then get out of here now! */ if (!cpu_has_apic) { printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n", boot_cpu_physical_apicid); printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n"); nr_ioapics = 0; return -1; } /* * If SMP should be disabled, then really disable it! */ if (!max_cpus) { printk(KERN_INFO "SMP mode deactivated, forcing use of dummy APIC emulation.\n"); nr_ioapics = 0; return -1; } return 0; } static void __init smp_cpu_index_default(void) { int i; struct cpuinfo_x86 *c; for_each_cpu_mask(i, cpu_possible_map) { c = &cpu_data(i); /* mark all to hotplug */ c->cpu_index = NR_CPUS; } } /* * Prepare for SMP bootup. The MP table or ACPI has been read * earlier. Just do some sanity checking here and enable APIC mode. */ void __init native_smp_prepare_cpus(unsigned int max_cpus) { nmi_watchdog_default(); smp_cpu_index_default(); current_cpu_data = boot_cpu_data; current_thread_info()->cpu = 0; /* needed? */ set_cpu_sibling_map(0); if (smp_sanity_check(max_cpus) < 0) { printk(KERN_INFO "SMP disabled\n"); disable_smp(); return; } /* * Switch from PIC to APIC mode. */ setup_local_APIC(); /* * Enable IO APIC before setting up error vector */ if (!skip_ioapic_setup && nr_ioapics) enable_IO_APIC(); end_local_APIC_setup(); if (GET_APIC_ID(apic_read(APIC_ID)) != boot_cpu_physical_apicid) { panic("Boot APIC ID in local APIC unexpected (%d vs %d)", GET_APIC_ID(apic_read(APIC_ID)), boot_cpu_physical_apicid); /* Or can we switch back to PIC here? */ } /* * Now start the IO-APICs */ if (!skip_ioapic_setup && nr_ioapics) setup_IO_APIC(); else nr_ioapics = 0; /* * Set up local APIC timer on boot CPU. */ setup_boot_clock(); printk(KERN_INFO "CPU%d: ", 0); print_cpu_info(&cpu_data(0)); } /* * Early setup to make printk work. */ void __init native_smp_prepare_boot_cpu(void) { int me = smp_processor_id(); /* already set me in cpu_online_map in boot_cpu_init() */ cpu_set(me, cpu_callout_map); per_cpu(cpu_state, me) = CPU_ONLINE; } extern void impress_friends(void); extern void smp_checks(void); /* * Finish the SMP boot. */ void __init native_smp_cpus_done(unsigned int max_cpus) { smpboot_restore_warm_reset_vector(); Dprintk("Boot done.\n"); impress_friends(); smp_checks(); setup_ioapic_dest(); check_nmi_watchdog(); }