/* * 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 /* Number of siblings per CPU package */ int smp_num_siblings = 1; EXPORT_SYMBOL(smp_num_siblings); /* Last level cache ID of each logical CPU */ DEFINE_PER_CPU(u8, cpu_llc_id) = BAD_APICID; /* Bitmask of currently online CPUs */ cpumask_t cpu_online_map __read_mostly; EXPORT_SYMBOL(cpu_online_map); /* * Private maps to synchronize booting between AP and BP. * Probably not needed anymore, but it makes for easier debugging. -AK */ cpumask_t cpu_callin_map; cpumask_t cpu_callout_map; EXPORT_SYMBOL(cpu_callout_map); cpumask_t cpu_possible_map; EXPORT_SYMBOL(cpu_possible_map); /* Per CPU bogomips and other parameters */ DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info); EXPORT_PER_CPU_SYMBOL(cpu_info); /* Set when the idlers are all forked */ int smp_threads_ready; /* representing HT siblings of each logical CPU */ DEFINE_PER_CPU(cpumask_t, cpu_sibling_map); EXPORT_PER_CPU_SYMBOL(cpu_sibling_map); /* representing HT and core siblings of each logical CPU */ DEFINE_PER_CPU(cpumask_t, cpu_core_map); EXPORT_PER_CPU_SYMBOL(cpu_core_map); /* * Trampoline 80x86 program as an array. */ extern const unsigned char trampoline_data[]; extern const unsigned char trampoline_end[]; /* State of each CPU */ DEFINE_PER_CPU(int, cpu_state) = { 0 }; /* * Store all idle threads, this can be reused instead of creating * a new thread. Also avoids complicated thread destroy functionality * for idle threads. */ struct task_struct *idle_thread_array[NR_CPUS] __cpuinitdata ; #define get_idle_for_cpu(x) (idle_thread_array[(x)]) #define set_idle_for_cpu(x,p) (idle_thread_array[(x)] = (p)) /* * Currently trivial. Write the real->protected mode * bootstrap into the page concerned. The caller * has made sure it's suitably aligned. */ static unsigned long __cpuinit setup_trampoline(void) { void *tramp = __va(SMP_TRAMPOLINE_BASE); memcpy(tramp, trampoline_data, trampoline_end - trampoline_data); return virt_to_phys(tramp); } /* * The bootstrap kernel entry code has set these up. Save them for * a given CPU */ static void __cpuinit smp_store_cpu_info(int id) { struct cpuinfo_x86 *c = &cpu_data(id); *c = boot_cpu_data; c->cpu_index = id; identify_cpu(c); print_cpu_info(c); } static atomic_t init_deasserted __cpuinitdata; /* * Report back to the Boot Processor. * Running on AP. */ void __cpuinit smp_callin(void) { int cpuid, phys_id; unsigned long timeout; /* * If waken up by an INIT in an 82489DX configuration * we may get here before an INIT-deassert IPI reaches * our local APIC. We have to wait for the IPI or we'll * lock up on an APIC access. */ while (!atomic_read(&init_deasserted)) cpu_relax(); /* * (This works even if the APIC is not enabled.) */ phys_id = GET_APIC_ID(apic_read(APIC_ID)); cpuid = smp_processor_id(); if (cpu_isset(cpuid, cpu_callin_map)) { panic("smp_callin: phys CPU#%d, CPU#%d already present??\n", phys_id, cpuid); } Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpuid, phys_id); /* * STARTUP IPIs are fragile beasts as they might sometimes * trigger some glue motherboard logic. Complete APIC bus * silence for 1 second, this overestimates the time the * boot CPU is spending to send the up to 2 STARTUP IPIs * by a factor of two. This should be enough. */ /* * Waiting 2s total for startup (udelay is not yet working) */ timeout = jiffies + 2*HZ; while (time_before(jiffies, timeout)) { /* * Has the boot CPU finished it's STARTUP sequence? */ if (cpu_isset(cpuid, cpu_callout_map)) break; cpu_relax(); } if (!time_before(jiffies, timeout)) { panic("smp_callin: CPU%d started up but did not get a callout!\n", cpuid); } /* * the boot CPU has finished the init stage and is spinning * on callin_map until we finish. We are free to set up this * CPU, first the APIC. (this is probably redundant on most * boards) */ Dprintk("CALLIN, before setup_local_APIC().\n"); setup_local_APIC(); /* * Get our bogomips. * * Need to enable IRQs because it can take longer and then * the NMI watchdog might kill us. */ local_irq_enable(); calibrate_delay(); local_irq_disable(); Dprintk("Stack at about %p\n",&cpuid); /* * Save our processor parameters */ smp_store_cpu_info(cpuid); /* * Allow the master to continue. */ cpu_set(cpuid, cpu_callin_map); } /* maps the cpu to the sched domain representing multi-core */ cpumask_t cpu_coregroup_map(int cpu) { struct cpuinfo_x86 *c = &cpu_data(cpu); /* * For perf, we return last level cache shared map. * And for power savings, we return cpu_core_map */ if (sched_mc_power_savings || sched_smt_power_savings) return per_cpu(cpu_core_map, cpu); else return c->llc_shared_map; } /* representing cpus for which sibling maps can be computed */ static cpumask_t cpu_sibling_setup_map; static inline void set_cpu_sibling_map(int cpu) { int i; struct cpuinfo_x86 *c = &cpu_data(cpu); cpu_set(cpu, cpu_sibling_setup_map); if (smp_num_siblings > 1) { for_each_cpu_mask(i, cpu_sibling_setup_map) { if (c->phys_proc_id == cpu_data(i).phys_proc_id && c->cpu_core_id == cpu_data(i).cpu_core_id) { cpu_set(i, per_cpu(cpu_sibling_map, cpu)); cpu_set(cpu, per_cpu(cpu_sibling_map, i)); cpu_set(i, per_cpu(cpu_core_map, cpu)); cpu_set(cpu, per_cpu(cpu_core_map, i)); cpu_set(i, c->llc_shared_map); cpu_set(cpu, cpu_data(i).llc_shared_map); } } } else { cpu_set(cpu, per_cpu(cpu_sibling_map, cpu)); } cpu_set(cpu, c->llc_shared_map); if (current_cpu_data.x86_max_cores == 1) { per_cpu(cpu_core_map, cpu) = per_cpu(cpu_sibling_map, cpu); c->booted_cores = 1; return; } for_each_cpu_mask(i, cpu_sibling_setup_map) { if (per_cpu(cpu_llc_id, cpu) != BAD_APICID && per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) { cpu_set(i, c->llc_shared_map); cpu_set(cpu, cpu_data(i).llc_shared_map); } if (c->phys_proc_id == cpu_data(i).phys_proc_id) { cpu_set(i, per_cpu(cpu_core_map, cpu)); cpu_set(cpu, per_cpu(cpu_core_map, i)); /* * Does this new cpu bringup a new core? */ if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) { /* * for each core in package, increment * the booted_cores for this new cpu */ if (first_cpu(per_cpu(cpu_sibling_map, i)) == i) c->booted_cores++; /* * increment the core count for all * the other cpus in this package */ if (i != cpu) cpu_data(i).booted_cores++; } else if (i != cpu && !c->booted_cores) c->booted_cores = cpu_data(i).booted_cores; } } } /* * 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(NULL); 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 receipients, 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. */ cpu_set(smp_processor_id(), cpu_online_map); per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE; spin_unlock(&vector_lock); unlock_ipi_call_lock(); setup_secondary_APIC_clock(); cpu_idle(); } extern volatile unsigned long init_rsp; extern void (*initial_code)(void); #ifdef APIC_DEBUG static void inquire_remote_apic(int apicid) { unsigned i, regs[] = { APIC_ID >> 4, APIC_LVR >> 4, APIC_SPIV >> 4 }; char *names[] = { "ID", "VERSION", "SPIV" }; int timeout; unsigned int status; printk(KERN_INFO "Inquiring remote APIC #%d...\n", apicid); for (i = 0; i < sizeof(regs) / sizeof(*regs); i++) { printk("... APIC #%d %s: ", apicid, names[i]); /* * Wait for idle. */ status = safe_apic_wait_icr_idle(); if (status) printk("a previous APIC delivery may have failed\n"); apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(apicid)); apic_write(APIC_ICR, APIC_DM_REMRD | regs[i]); timeout = 0; do { udelay(100); status = apic_read(APIC_ICR) & APIC_ICR_RR_MASK; } while (status == APIC_ICR_RR_INPROG && timeout++ < 1000); switch (status) { case APIC_ICR_RR_VALID: status = apic_read(APIC_RRR); printk("%08x\n", status); break; default: printk("failed\n"); } } } #endif /* * Kick the secondary to wake up. */ static int __cpuinit wakeup_secondary_via_INIT(int phys_apicid, unsigned int start_rip) { unsigned long send_status, accept_status = 0; int maxlvt, num_starts, j; Dprintk("Asserting INIT.\n"); /* * Turn INIT on target chip */ apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid)); /* * Send IPI */ apic_write(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT); Dprintk("Waiting for send to finish...\n"); send_status = safe_apic_wait_icr_idle(); mdelay(10); Dprintk("Deasserting INIT.\n"); /* Target chip */ apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid)); /* Send IPI */ apic_write(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT); Dprintk("Waiting for send to finish...\n"); send_status = safe_apic_wait_icr_idle(); mb(); atomic_set(&init_deasserted, 1); num_starts = 2; /* * Run STARTUP IPI loop. */ Dprintk("#startup loops: %d.\n", num_starts); maxlvt = get_maxlvt(); for (j = 1; j <= num_starts; j++) { Dprintk("Sending STARTUP #%d.\n",j); apic_write(APIC_ESR, 0); apic_read(APIC_ESR); Dprintk("After apic_write.\n"); /* * STARTUP IPI */ /* Target chip */ apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid)); /* Boot on the stack */ /* Kick the second */ apic_write(APIC_ICR, APIC_DM_STARTUP | (start_rip >> 12)); /* * Give the other CPU some time to accept the IPI. */ udelay(300); Dprintk("Startup point 1.\n"); Dprintk("Waiting for send to finish...\n"); send_status = safe_apic_wait_icr_idle(); /* * Give the other CPU some time to accept the IPI. */ udelay(200); /* * Due to the Pentium erratum 3AP. */ if (maxlvt > 3) { apic_write(APIC_ESR, 0); } accept_status = (apic_read(APIC_ESR) & 0xEF); if (send_status || accept_status) break; } Dprintk("After Startup.\n"); if (send_status) printk(KERN_ERR "APIC never delivered???\n"); if (accept_status) printk(KERN_ERR "APIC delivery error (%lx).\n", accept_status); return (send_status | accept_status); } struct create_idle { struct work_struct work; struct task_struct *idle; struct completion done; int cpu; }; void do_fork_idle(struct work_struct *work) { struct create_idle *c_idle = container_of(work, struct create_idle, work); c_idle->idle = fork_idle(c_idle->cpu); complete(&c_idle->done); } /* * Boot one CPU. */ static int __cpuinit do_boot_cpu(int cpu, int apicid) { unsigned long boot_error; int timeout; unsigned long start_rip; struct create_idle c_idle = { .work = __WORK_INITIALIZER(c_idle.work, do_fork_idle), .cpu = cpu, .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done), }; /* allocate memory for gdts of secondary cpus. Hotplug is considered */ if (!cpu_gdt_descr[cpu].address && !(cpu_gdt_descr[cpu].address = get_zeroed_page(GFP_KERNEL))) { printk(KERN_ERR "Failed to allocate GDT for CPU %d\n", cpu); return -1; } /* Allocate node local memory for AP pdas */ if (cpu_pda(cpu) == &boot_cpu_pda[cpu]) { struct x8664_pda *newpda, *pda; int node = cpu_to_node(cpu); pda = cpu_pda(cpu); newpda = kmalloc_node(sizeof (struct x8664_pda), GFP_ATOMIC, node); if (newpda) { memcpy(newpda, pda, sizeof (struct x8664_pda)); cpu_pda(cpu) = newpda; } else printk(KERN_ERR "Could not allocate node local PDA for CPU %d on node %d\n", cpu, node); } alternatives_smp_switch(1); c_idle.idle = get_idle_for_cpu(cpu); if (c_idle.idle) { c_idle.idle->thread.rsp = (unsigned long) (((struct pt_regs *) (THREAD_SIZE + task_stack_page(c_idle.idle))) - 1); init_idle(c_idle.idle, cpu); goto do_rest; } /* * During cold boot process, keventd thread is not spun up yet. * When we do cpu hot-add, we create idle threads on the fly, we should * not acquire any attributes from the calling context. Hence the clean * way to create kernel_threads() is to do that from keventd(). * We do the current_is_keventd() due to the fact that ACPI notifier * was also queuing to keventd() and when the caller is already running * in context of keventd(), we would end up with locking up the keventd * thread. */ if (!keventd_up() || current_is_keventd()) c_idle.work.func(&c_idle.work); else { schedule_work(&c_idle.work); wait_for_completion(&c_idle.done); } if (IS_ERR(c_idle.idle)) { printk("failed fork for CPU %d\n", cpu); return PTR_ERR(c_idle.idle); } set_idle_for_cpu(cpu, c_idle.idle); do_rest: cpu_pda(cpu)->pcurrent = c_idle.idle; start_rip = setup_trampoline(); init_rsp = c_idle.idle->thread.rsp; per_cpu(init_tss,cpu).rsp0 = init_rsp; initial_code = start_secondary; clear_tsk_thread_flag(c_idle.idle, TIF_FORK); printk(KERN_INFO "Booting processor %d/%d APIC 0x%x\n", cpu, cpus_weight(cpu_present_map), apicid); /* * This grunge runs the startup process for * the targeted processor. */ atomic_set(&init_deasserted, 0); Dprintk("Setting warm reset code and vector.\n"); CMOS_WRITE(0xa, 0xf); local_flush_tlb(); Dprintk("1.\n"); *((volatile unsigned short *) phys_to_virt(0x469)) = start_rip >> 4; Dprintk("2.\n"); *((volatile unsigned short *) phys_to_virt(0x467)) = start_rip & 0xf; Dprintk("3.\n"); /* * Be paranoid about clearing APIC errors. */ apic_write(APIC_ESR, 0); apic_read(APIC_ESR); /* * Status is now clean */ boot_error = 0; /* * Starting actual IPI sequence... */ boot_error = wakeup_secondary_via_INIT(apicid, start_rip); if (!boot_error) { /* * allow APs to start initializing. */ Dprintk("Before Callout %d.\n", cpu); cpu_set(cpu, cpu_callout_map); Dprintk("After Callout %d.\n", cpu); /* * Wait 5s total for a response */ for (timeout = 0; timeout < 50000; timeout++) { if (cpu_isset(cpu, cpu_callin_map)) break; /* It has booted */ udelay(100); } if (cpu_isset(cpu, cpu_callin_map)) { /* number CPUs logically, starting from 1 (BSP is 0) */ Dprintk("CPU has booted.\n"); } else { boot_error = 1; if (*((volatile unsigned char *)phys_to_virt(SMP_TRAMPOLINE_BASE)) == 0xA5) /* trampoline started but...? */ printk("Stuck ??\n"); else /* trampoline code not run */ printk("Not responding.\n"); #ifdef APIC_DEBUG inquire_remote_apic(apicid); #endif } } if (boot_error) { cpu_clear(cpu, cpu_callout_map); /* was set here (do_boot_cpu()) */ clear_bit(cpu, &cpu_initialized); /* was set by cpu_init() */ clear_node_cpumask(cpu); /* was set by numa_add_cpu */ cpu_clear(cpu, cpu_present_map); cpu_clear(cpu, cpu_possible_map); per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID; return -EIO; } return 0; } cycles_t cacheflush_time; unsigned long cache_decay_ticks; /* * Cleanup possible dangling ends... */ static __cpuinit void smp_cleanup_boot(void) { /* * Paranoid: Set warm reset code and vector here back * to default values. */ CMOS_WRITE(0, 0xf); /* * Reset trampoline flag */ *((volatile int *) phys_to_virt(0x467)) = 0; } /* * 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_id); 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)); } #ifdef CONFIG_HOTPLUG_CPU int additional_cpus __initdata = -1; /* * cpu_possible_map should be static, it cannot change as cpu's * are onlined, or offlined. The reason is per-cpu data-structures * are allocated by some modules at init time, and dont expect to * do this dynamically on cpu arrival/departure. * cpu_present_map on the other hand can change dynamically. * In case when cpu_hotplug is not compiled, then we resort to current * behaviour, which is cpu_possible == cpu_present. * - Ashok Raj * * Three ways to find out the number of additional hotplug CPUs: * - If the BIOS specified disabled CPUs in ACPI/mptables use that. * - The user can overwrite it with additional_cpus=NUM * - Otherwise don't reserve additional CPUs. * We do this because additional CPUs waste a lot of memory. * -AK */ __init void prefill_possible_map(void) { int i; int possible; if (additional_cpus == -1) { if (disabled_cpus > 0) additional_cpus = disabled_cpus; else additional_cpus = 0; } possible = num_processors + additional_cpus; if (possible > NR_CPUS) possible = NR_CPUS; printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n", possible, max_t(int, possible - num_processors, 0)); for (i = 0; i < possible; i++) cpu_set(i, cpu_possible_map); } #endif /* * 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_id, phys_cpu_present_map)) { printk(KERN_NOTICE "weird, boot CPU (#%d) not listed by the BIOS.\n", boot_cpu_id); 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_id); 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; } /* * Copy apicid's found by MP_processor_info from initial array to the per cpu * data area. The x86_cpu_to_apicid_init array is then expendable and the * x86_cpu_to_apicid_ptr is zeroed indicating that the static array is no * longer available. */ void __init smp_set_apicids(void) { int cpu; for_each_cpu_mask(cpu, cpu_possible_map) { if (per_cpu_offset(cpu)) per_cpu(x86_cpu_to_apicid, cpu) = x86_cpu_to_apicid_init[cpu]; } /* indicate the static array will be going away soon */ x86_cpu_to_apicid_ptr = NULL; } /* * 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 smp_prepare_cpus(unsigned int max_cpus) { nmi_watchdog_default(); current_cpu_data = boot_cpu_data; current_thread_info()->cpu = 0; /* needed? */ smp_set_apicids(); 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(); if (GET_APIC_ID(apic_read(APIC_ID)) != boot_cpu_id) { panic("Boot APIC ID in local APIC unexpected (%d vs %d)", GET_APIC_ID(apic_read(APIC_ID)), boot_cpu_id); /* 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_APIC_clock(); } /* * Early setup to make printk work. */ void __init smp_prepare_boot_cpu(void) { int me = smp_processor_id(); cpu_set(me, cpu_online_map); cpu_set(me, cpu_callout_map); per_cpu(cpu_state, me) = CPU_ONLINE; } /* * Entry point to boot a CPU. */ int __cpuinit __cpu_up(unsigned int cpu) { int apicid = cpu_present_to_apicid(cpu); unsigned long flags; int err; WARN_ON(irqs_disabled()); Dprintk("++++++++++++++++++++=_---CPU UP %u\n", cpu); if (apicid == BAD_APICID || apicid == boot_cpu_id || !physid_isset(apicid, phys_cpu_present_map)) { printk("__cpu_up: bad cpu %d\n", cpu); return -EINVAL; } /* * Already booted CPU? */ if (cpu_isset(cpu, cpu_callin_map)) { Dprintk("do_boot_cpu %d Already started\n", cpu); return -ENOSYS; } /* * Save current MTRR state in case it was changed since early boot * (e.g. by the ACPI SMI) to initialize new CPUs with MTRRs in sync: */ mtrr_save_state(); per_cpu(cpu_state, cpu) = CPU_UP_PREPARE; /* Boot it! */ err = do_boot_cpu(cpu, apicid); if (err < 0) { Dprintk("do_boot_cpu failed %d\n", err); return err; } /* Unleash the CPU! */ Dprintk("waiting for cpu %d\n", cpu); /* * Make sure and check TSC sync: */ local_irq_save(flags); check_tsc_sync_source(cpu); local_irq_restore(flags); while (!cpu_isset(cpu, cpu_online_map)) cpu_relax(); err = 0; return err; } /* * Finish the SMP boot. */ void __init smp_cpus_done(unsigned int max_cpus) { smp_cleanup_boot(); setup_ioapic_dest(); check_nmi_watchdog(); } #ifdef CONFIG_HOTPLUG_CPU static void remove_siblinginfo(int cpu) { int sibling; struct cpuinfo_x86 *c = &cpu_data(cpu); for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) { cpu_clear(cpu, per_cpu(cpu_core_map, sibling)); /* * last thread sibling in this cpu core going down */ if (cpus_weight(per_cpu(cpu_sibling_map, cpu)) == 1) cpu_data(sibling).booted_cores--; } for_each_cpu_mask(sibling, per_cpu(cpu_sibling_map, cpu)) cpu_clear(cpu, per_cpu(cpu_sibling_map, sibling)); cpus_clear(per_cpu(cpu_sibling_map, cpu)); cpus_clear(per_cpu(cpu_core_map, cpu)); c->phys_proc_id = 0; c->cpu_core_id = 0; cpu_clear(cpu, cpu_sibling_setup_map); } void remove_cpu_from_maps(void) { int cpu = smp_processor_id(); cpu_clear(cpu, cpu_callout_map); cpu_clear(cpu, cpu_callin_map); clear_bit(cpu, &cpu_initialized); /* was set by cpu_init() */ clear_node_cpumask(cpu); } int __cpu_disable(void) { int cpu = smp_processor_id(); /* * Perhaps use cpufreq to drop frequency, but that could go * into generic code. * * We won't take down the boot processor on i386 due to some * interrupts only being able to be serviced by the BSP. * Especially so if we're not using an IOAPIC -zwane */ if (cpu == 0) return -EBUSY; if (nmi_watchdog == NMI_LOCAL_APIC) stop_apic_nmi_watchdog(NULL); clear_local_APIC(); /* * HACK: * Allow any queued timer interrupts to get serviced * This is only a temporary solution until we cleanup * fixup_irqs as we do for IA64. */ local_irq_enable(); mdelay(1); local_irq_disable(); remove_siblinginfo(cpu); spin_lock(&vector_lock); /* It's now safe to remove this processor from the online map */ cpu_clear(cpu, cpu_online_map); spin_unlock(&vector_lock); remove_cpu_from_maps(); fixup_irqs(cpu_online_map); return 0; } void __cpu_die(unsigned int cpu) { /* We don't do anything here: idle task is faking death itself. */ unsigned int i; for (i = 0; i < 10; i++) { /* They ack this in play_dead by setting CPU_DEAD */ if (per_cpu(cpu_state, cpu) == CPU_DEAD) { printk ("CPU %d is now offline\n", cpu); if (1 == num_online_cpus()) alternatives_smp_switch(0); return; } msleep(100); } printk(KERN_ERR "CPU %u didn't die...\n", cpu); } static __init int setup_additional_cpus(char *s) { return s && get_option(&s, &additional_cpus) ? 0 : -EINVAL; } early_param("additional_cpus", setup_additional_cpus); #else /* ... !CONFIG_HOTPLUG_CPU */ int __cpu_disable(void) { return -ENOSYS; } void __cpu_die(unsigned int cpu) { /* We said "no" in __cpu_disable */ BUG(); } #endif /* CONFIG_HOTPLUG_CPU */