/* * 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 or * later. * * Fixes * Felix Koop : NR_CPUS used properly * Jose Renau : Handle single CPU case. * Alan Cox : By repeated request 8) - Total BogoMIPS 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. * Martin J. Bligh : Added support for multi-quad systems * Dave Jones : Report invalid combinations of Athlon CPUs. * Rusty Russell : Hacked into shape for new "hotplug" boot process. * Andi Kleen : Converted to new state machine. * Ashok Raj : CPU hotplug support * Glauber Costa : i386 and x86_64 integration */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_X86_32 u8 apicid_2_node[MAX_APICID]; static int low_mappings; #endif /* 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. */ #ifdef CONFIG_HOTPLUG_CPU /* * Needed only for CONFIG_HOTPLUG_CPU because __cpuinitdata is * removed after init for !CONFIG_HOTPLUG_CPU. */ static DEFINE_PER_CPU(struct task_struct *, idle_thread_array); #define get_idle_for_cpu(x) (per_cpu(idle_thread_array, x)) #define set_idle_for_cpu(x, p) (per_cpu(idle_thread_array, x) = (p)) #else 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)) #endif /* 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(u16, cpu_llc_id) = BAD_APICID; /* bitmap of online cpus */ cpumask_t cpu_online_map __read_mostly; EXPORT_SYMBOL(cpu_online_map); cpumask_t cpu_callin_map; cpumask_t cpu_callout_map; cpumask_t cpu_possible_map; EXPORT_SYMBOL(cpu_possible_map); /* 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); /* Per CPU bogomips and other parameters */ DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info); EXPORT_PER_CPU_SYMBOL(cpu_info); static atomic_t init_deasserted; static int boot_cpu_logical_apicid; /* representing cpus for which sibling maps can be computed */ static cpumask_t cpu_sibling_setup_map; /* Set if we find a B stepping CPU */ int __cpuinitdata smp_b_stepping; #if defined(CONFIG_NUMA) && defined(CONFIG_X86_32) /* which logical CPUs are on which nodes */ cpumask_t node_to_cpumask_map[MAX_NUMNODES] __read_mostly = { [0 ... MAX_NUMNODES-1] = CPU_MASK_NONE }; EXPORT_SYMBOL(node_to_cpumask_map); /* which node each logical CPU is on */ int cpu_to_node_map[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = 0 }; EXPORT_SYMBOL(cpu_to_node_map); /* set up a mapping between cpu and node. */ static void map_cpu_to_node(int cpu, int node) { printk(KERN_INFO "Mapping cpu %d to node %d\n", cpu, node); cpu_set(cpu, node_to_cpumask_map[node]); cpu_to_node_map[cpu] = node; } /* undo a mapping between cpu and node. */ static void unmap_cpu_to_node(int cpu) { int node; printk(KERN_INFO "Unmapping cpu %d from all nodes\n", cpu); for (node = 0; node < MAX_NUMNODES; node++) cpu_clear(cpu, node_to_cpumask_map[node]); cpu_to_node_map[cpu] = 0; } #else /* !(CONFIG_NUMA && CONFIG_X86_32) */ #define map_cpu_to_node(cpu, node) ({}) #define unmap_cpu_to_node(cpu) ({}) #endif #ifdef CONFIG_X86_32 u8 cpu_2_logical_apicid[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID }; static void map_cpu_to_logical_apicid(void) { int cpu = smp_processor_id(); int apicid = logical_smp_processor_id(); int node = apicid_to_node(apicid); if (!node_online(node)) node = first_online_node; cpu_2_logical_apicid[cpu] = apicid; map_cpu_to_node(cpu, node); } static void unmap_cpu_to_logical_apicid(int cpu) { cpu_2_logical_apicid[cpu] = BAD_APICID; unmap_cpu_to_node(cpu); } #else #define unmap_cpu_to_logical_apicid(cpu) do {} while (0) #define map_cpu_to_logical_apicid() do {} while (0) #endif /* * Report back to the Boot Processor. * Running on AP. */ static 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. */ wait_for_init_deassert(&init_deasserted); /* * (This works even if the APIC is not enabled.) */ phys_id = GET_APIC_ID(read_apic_id()); cpuid = smp_processor_id(); if (cpu_isset(cpuid, cpu_callin_map)) { panic("%s: phys CPU#%d, CPU#%d already present??\n", __func__, 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("%s: CPU%d started up but did not get a callout!\n", __func__, 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"); smp_callin_clear_local_apic(); setup_local_APIC(); end_local_APIC_setup(); map_cpu_to_logical_apicid(); /* * 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); } /* * Activate a secondary processor. */ static void __cpuinit start_secondary(void *unused) { /* * Don't put *anything* before cpu_init(), SMP booting is too * fragile that we want to limit the things done here to the * most necessary things. */ #ifdef CONFIG_VMI vmi_bringup(); #endif cpu_init(); preempt_disable(); smp_callin(); /* otherwise gcc will move up smp_processor_id before the cpu_init */ barrier(); /* * Check TSC synchronization with the BP: */ check_tsc_sync_target(); if (nmi_watchdog == NMI_IO_APIC) { disable_8259A_irq(0); enable_NMI_through_LVT0(); enable_8259A_irq(0); } #ifdef CONFIG_X86_32 while (low_mappings) cpu_relax(); __flush_tlb_all(); #endif /* This must be done before setting cpu_online_map */ set_cpu_sibling_map(raw_smp_processor_id()); wmb(); /* * 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. Holding this * lock helps us to not include this cpu in a currently in progress * smp_call_function(). */ lock_ipi_call_lock(); #ifdef CONFIG_X86_64 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); #endif 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(); } #ifdef CONFIG_X86_32 /* * Everything has been set up for the secondary * CPUs - they just need to reload everything * from the task structure * This function must not return. */ void __devinit initialize_secondary(void) { /* * We don't actually need to load the full TSS, * basically just the stack pointer and the ip. */ asm volatile( "movl %0,%%esp\n\t" "jmp *%1" : :"m" (current->thread.sp), "m" (current->thread.ip)); } #endif static void __cpuinit smp_apply_quirks(struct cpuinfo_x86 *c) { #ifdef CONFIG_X86_32 /* * Mask B, Pentium, but not Pentium MMX */ if (c->x86_vendor == X86_VENDOR_INTEL && c->x86 == 5 && c->x86_mask >= 1 && c->x86_mask <= 4 && c->x86_model <= 3) /* * Remember we have B step Pentia with bugs */ smp_b_stepping = 1; /* * Certain Athlons might work (for various values of 'work') in SMP * but they are not certified as MP capable. */ if ((c->x86_vendor == X86_VENDOR_AMD) && (c->x86 == 6)) { if (num_possible_cpus() == 1) goto valid_k7; /* Athlon 660/661 is valid. */ if ((c->x86_model == 6) && ((c->x86_mask == 0) || (c->x86_mask == 1))) goto valid_k7; /* Duron 670 is valid */ if ((c->x86_model == 7) && (c->x86_mask == 0)) goto valid_k7; /* * Athlon 662, Duron 671, and Athlon >model 7 have capability * bit. It's worth noting that the A5 stepping (662) of some * Athlon XP's have the MP bit set. * See http://www.heise.de/newsticker/data/jow-18.10.01-000 for * more. */ if (((c->x86_model == 6) && (c->x86_mask >= 2)) || ((c->x86_model == 7) && (c->x86_mask >= 1)) || (c->x86_model > 7)) if (cpu_has_mp) goto valid_k7; /* If we get here, not a certified SMP capable AMD system. */ add_taint(TAINT_UNSAFE_SMP); } valid_k7: ; #endif } static void __cpuinit smp_checks(void) { if (smp_b_stepping) printk(KERN_WARNING "WARNING: SMP operation may be unreliable" "with B stepping processors.\n"); /* * Don't taint if we are running SMP kernel on a single non-MP * approved Athlon */ if (tainted & TAINT_UNSAFE_SMP) { if (num_online_cpus()) printk(KERN_INFO "WARNING: This combination of AMD" "processors is not suitable for SMP.\n"); else tainted &= ~TAINT_UNSAFE_SMP; } } /* * The bootstrap kernel entry code has set these up. Save them for * a given CPU */ void __cpuinit smp_store_cpu_info(int id) { struct cpuinfo_x86 *c = &cpu_data(id); *c = boot_cpu_data; c->cpu_index = id; if (id != 0) identify_secondary_cpu(c); smp_apply_quirks(c); } void __cpuinit 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; } } } /* 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; } #ifdef CONFIG_X86_32 /* * We are called very early to get the low memory for the * SMP bootup trampoline page. */ void __init smp_alloc_memory(void) { trampoline_base = alloc_bootmem_low_pages(PAGE_SIZE); /* * Has to be in very low memory so we can execute * real-mode AP code. */ if (__pa(trampoline_base) >= 0x9F000) BUG(); } #endif static void impress_friends(void) { int cpu; unsigned long bogosum = 0; /* * Allow the user to impress friends. */ Dprintk("Before bogomips.\n"); for_each_possible_cpu(cpu) if (cpu_isset(cpu, cpu_callout_map)) bogosum += cpu_data(cpu).loops_per_jiffy; printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n", num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100); Dprintk("Before bogocount - setting activated=1.\n"); } static inline 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; u32 status; printk(KERN_INFO "Inquiring remote APIC #%d...\n", apicid); for (i = 0; i < ARRAY_SIZE(regs); i++) { printk(KERN_INFO "... APIC #%d %s: ", apicid, names[i]); /* * Wait for idle. */ status = safe_apic_wait_icr_idle(); if (status) printk(KERN_CONT "a previous APIC delivery may have failed\n"); apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid)); apic_write_around(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(KERN_CONT "%08x\n", status); break; default: printk(KERN_CONT "failed\n"); } } } #ifdef WAKE_SECONDARY_VIA_NMI /* * Poke the other CPU in the eye via NMI to wake it up. Remember that the normal * INIT, INIT, STARTUP sequence will reset the chip hard for us, and this * won't ... remember to clear down the APIC, etc later. */ static int __devinit wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip) { unsigned long send_status, accept_status = 0; int maxlvt; /* Target chip */ apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid)); /* Boot on the stack */ /* Kick the second */ apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL); 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. */ maxlvt = lapic_get_maxlvt(); if (maxlvt > 3) { apic_read_around(APIC_SPIV); apic_write(APIC_ESR, 0); } accept_status = (apic_read(APIC_ESR) & 0xEF); Dprintk("NMI sent.\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); } #endif /* WAKE_SECONDARY_VIA_NMI */ #ifdef WAKE_SECONDARY_VIA_INIT static int __devinit wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip) { unsigned long send_status, accept_status = 0; int maxlvt, num_starts, j; if (get_uv_system_type() == UV_NON_UNIQUE_APIC) { send_status = uv_wakeup_secondary(phys_apicid, start_eip); atomic_set(&init_deasserted, 1); return send_status; } /* * Be paranoid about clearing APIC errors. */ if (APIC_INTEGRATED(apic_version[phys_apicid])) { apic_read_around(APIC_SPIV); apic_write(APIC_ESR, 0); apic_read(APIC_ESR); } Dprintk("Asserting INIT.\n"); /* * Turn INIT on target chip */ apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid)); /* * Send IPI */ apic_write_around(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_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid)); /* Send IPI */ apic_write_around(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); /* * Should we send STARTUP IPIs ? * * Determine this based on the APIC version. * If we don't have an integrated APIC, don't send the STARTUP IPIs. */ if (APIC_INTEGRATED(apic_version[phys_apicid])) num_starts = 2; else num_starts = 0; /* * Paravirt / VMI wants a startup IPI hook here to set up the * target processor state. */ startup_ipi_hook(phys_apicid, (unsigned long) start_secondary, #ifdef CONFIG_X86_64 (unsigned long)init_rsp); #else (unsigned long)stack_start.sp); #endif /* * Run STARTUP IPI loop. */ Dprintk("#startup loops: %d.\n", num_starts); maxlvt = lapic_get_maxlvt(); for (j = 1; j <= num_starts; j++) { Dprintk("Sending STARTUP #%d.\n", j); apic_read_around(APIC_SPIV); apic_write(APIC_ESR, 0); apic_read(APIC_ESR); Dprintk("After apic_write.\n"); /* * STARTUP IPI */ /* Target chip */ apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid)); /* Boot on the stack */ /* Kick the second */ apic_write_around(APIC_ICR, APIC_DM_STARTUP | (start_eip >> 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_read_around(APIC_SPIV); 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); } #endif /* WAKE_SECONDARY_VIA_INIT */ struct create_idle { struct work_struct work; struct task_struct *idle; struct completion done; int cpu; }; static void __cpuinit 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); } /* * Allocate node local memory for the AP pda. * * Must be called after the _cpu_pda pointer table is initialized. */ static int __cpuinit get_local_pda(int cpu) { struct x8664_pda *oldpda, *newpda; unsigned long size = sizeof(struct x8664_pda); int node = cpu_to_node(cpu); if (cpu_pda(cpu) && !cpu_pda(cpu)->in_bootmem) return 0; oldpda = cpu_pda(cpu); newpda = kmalloc_node(size, GFP_ATOMIC, node); if (!newpda) { printk(KERN_ERR "Could not allocate node local PDA " "for CPU %d on node %d\n", cpu, node); if (oldpda) return 0; /* have a usable pda */ else return -1; } if (oldpda) { memcpy(newpda, oldpda, size); if (!after_bootmem) free_bootmem((unsigned long)oldpda, size); } newpda->in_bootmem = 0; cpu_pda(cpu) = newpda; return 0; } static int __cpuinit do_boot_cpu(int apicid, int cpu) /* * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad * (ie clustered apic addressing mode), this is a LOGICAL apic ID. * Returns zero if CPU booted OK, else error code from wakeup_secondary_cpu. */ { unsigned long boot_error = 0; int timeout; unsigned long start_ip; unsigned short nmi_high = 0, nmi_low = 0; struct create_idle c_idle = { .cpu = cpu, .done = COMPLETION_INITIALIZER_ONSTACK(c_idle.done), }; INIT_WORK(&c_idle.work, do_fork_idle); #ifdef CONFIG_X86_64 /* 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 > 0) { boot_error = get_local_pda(cpu); if (boot_error) goto restore_state; /* if can't get pda memory, can't start cpu */ } #endif alternatives_smp_switch(1); c_idle.idle = get_idle_for_cpu(cpu); /* * We can't use kernel_thread since we must avoid to * reschedule the child. */ if (c_idle.idle) { c_idle.idle->thread.sp = (unsigned long) (((struct pt_regs *) (THREAD_SIZE + task_stack_page(c_idle.idle))) - 1); init_idle(c_idle.idle, cpu); goto do_rest; } 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: #ifdef CONFIG_X86_32 per_cpu(current_task, cpu) = c_idle.idle; init_gdt(cpu); early_gdt_descr.address = (unsigned long)get_cpu_gdt_table(cpu); c_idle.idle->thread.ip = (unsigned long) start_secondary; /* Stack for startup_32 can be just as for start_secondary onwards */ stack_start.sp = (void *) c_idle.idle->thread.sp; irq_ctx_init(cpu); #else cpu_pda(cpu)->pcurrent = c_idle.idle; init_rsp = c_idle.idle->thread.sp; load_sp0(&per_cpu(init_tss, cpu), &c_idle.idle->thread); initial_code = (unsigned long)start_secondary; clear_tsk_thread_flag(c_idle.idle, TIF_FORK); #endif /* start_ip had better be page-aligned! */ start_ip = setup_trampoline(); /* So we see what's up */ printk(KERN_INFO "Booting processor %d/%d ip %lx\n", cpu, apicid, start_ip); /* * This grunge runs the startup process for * the targeted processor. */ atomic_set(&init_deasserted, 0); if (get_uv_system_type() != UV_NON_UNIQUE_APIC) { Dprintk("Setting warm reset code and vector.\n"); store_NMI_vector(&nmi_high, &nmi_low); smpboot_setup_warm_reset_vector(start_ip); /* * Be paranoid about clearing APIC errors. */ apic_write(APIC_ESR, 0); apic_read(APIC_ESR); } /* * Starting actual IPI sequence... */ boot_error = wakeup_secondary_cpu(apicid, start_ip); 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("OK.\n"); printk(KERN_INFO "CPU%d: ", cpu); print_cpu_info(&cpu_data(cpu)); Dprintk("CPU has booted.\n"); } else { boot_error = 1; if (*((volatile unsigned char *)trampoline_base) == 0xA5) /* trampoline started but...? */ printk(KERN_ERR "Stuck ??\n"); else /* trampoline code not run */ printk(KERN_ERR "Not responding.\n"); if (get_uv_system_type() != UV_NON_UNIQUE_APIC) inquire_remote_apic(apicid); } } restore_state: if (boot_error) { /* Try to put things back the way they were before ... */ unmap_cpu_to_logical_apicid(cpu); #ifdef CONFIG_X86_64 numa_remove_cpu(cpu); /* was set by numa_add_cpu */ #endif cpu_clear(cpu, cpu_callout_map); /* was set by do_boot_cpu() */ cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */ cpu_clear(cpu, cpu_present_map); per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID; } /* mark "stuck" area as not stuck */ *((volatile unsigned long *)trampoline_base) = 0; /* * Cleanup possible dangling ends... */ smpboot_restore_warm_reset_vector(); return boot_error; } int __cpuinit native_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_physical_apicid || !physid_isset(apicid, phys_cpu_present_map)) { printk(KERN_ERR "%s: bad cpu %d\n", __func__, 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; #ifdef CONFIG_X86_32 /* init low mem mapping */ clone_pgd_range(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY, min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY)); flush_tlb_all(); low_mappings = 1; err = do_boot_cpu(apicid, cpu); zap_low_mappings(); low_mappings = 0; #else err = do_boot_cpu(apicid, cpu); #endif if (err) { Dprintk("do_boot_cpu failed %d\n", err); return -EIO; } /* * Check TSC synchronization with the AP (keep irqs disabled * while doing so): */ local_irq_save(flags); check_tsc_sync_source(cpu); local_irq_restore(flags); while (!cpu_online(cpu)) { cpu_relax(); touch_nmi_watchdog(); } return 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); #ifdef CONFIG_X86_32 smpboot_clear_io_apic_irqs(); #endif 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); map_cpu_to_logical_apicid(); 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) { preempt_disable(); if (!physid_isset(hard_smp_processor_id(), phys_cpu_present_map)) { printk(KERN_WARNING "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 && !acpi_lapic) { preempt_enable(); 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 (!check_phys_apicid_present(boot_cpu_physical_apicid)) { 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); } preempt_enable(); /* * If we couldn't find a local APIC, then get out of here now! */ if (APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid]) && !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"); smpboot_clear_io_apic(); return -1; } verify_local_APIC(); /* * 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"); smpboot_clear_io_apic(); #ifdef CONFIG_X86_32 connect_bsp_APIC(); #endif setup_local_APIC(); end_local_APIC_setup(); return -1; } return 0; } static void __init smp_cpu_index_default(void) { int i; struct cpuinfo_x86 *c; for_each_possible_cpu(i) { 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) { preempt_disable(); nmi_watchdog_default(); smp_cpu_index_default(); current_cpu_data = boot_cpu_data; cpu_callin_map = cpumask_of_cpu(0); mb(); /* * Setup boot CPU information */ smp_store_cpu_info(0); /* Final full version of the data */ boot_cpu_logical_apicid = logical_smp_processor_id(); 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(); goto out; } preempt_disable(); if (GET_APIC_ID(read_apic_id()) != boot_cpu_physical_apicid) { panic("Boot APIC ID in local APIC unexpected (%d vs %d)", GET_APIC_ID(read_apic_id()), boot_cpu_physical_apicid); /* Or can we switch back to PIC here? */ } preempt_enable(); #ifdef CONFIG_X86_32 connect_bsp_APIC(); #endif /* * Switch from PIC to APIC mode. */ setup_local_APIC(); #ifdef CONFIG_X86_64 /* * Enable IO APIC before setting up error vector */ if (!skip_ioapic_setup && nr_ioapics) enable_IO_APIC(); #endif end_local_APIC_setup(); map_cpu_to_logical_apicid(); setup_portio_remap(); smpboot_setup_io_apic(); /* * Set up local APIC timer on boot CPU. */ printk(KERN_INFO "CPU%d: ", 0); print_cpu_info(&cpu_data(0)); setup_boot_clock(); out: preempt_enable(); } /* * Early setup to make printk work. */ void __init native_smp_prepare_boot_cpu(void) { int me = smp_processor_id(); #ifdef CONFIG_X86_32 init_gdt(me); switch_to_new_gdt(); #endif /* already set me in cpu_online_map in boot_cpu_init() */ cpu_set(me, cpu_callout_map); per_cpu(cpu_state, me) = CPU_ONLINE; } void __init native_smp_cpus_done(unsigned int max_cpus) { Dprintk("Boot done.\n"); impress_friends(); smp_checks(); #ifdef CONFIG_X86_IO_APIC setup_ioapic_dest(); #endif check_nmi_watchdog(); } #ifdef CONFIG_HOTPLUG_CPU # ifdef CONFIG_X86_32 void cpu_exit_clear(void) { int cpu = raw_smp_processor_id(); idle_task_exit(); cpu_uninit(); irq_ctx_exit(cpu); cpu_clear(cpu, cpu_callout_map); cpu_clear(cpu, cpu_callin_map); unmap_cpu_to_logical_apicid(cpu); } # endif /* CONFIG_X86_32 */ 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); } static int additional_cpus __initdata = -1; static __init int setup_additional_cpus(char *s) { return s && get_option(&s, &additional_cpus) ? 0 : -EINVAL; } early_param("additional_cpus", setup_additional_cpus); /* * 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); nr_cpu_ids = possible; } static void __ref remove_cpu_from_maps(int cpu) { cpu_clear(cpu, cpu_online_map); #ifdef CONFIG_X86_64 cpu_clear(cpu, cpu_callout_map); cpu_clear(cpu, cpu_callin_map); /* was set by cpu_init() */ clear_bit(cpu, (unsigned long *)&cpu_initialized); numa_remove_cpu(cpu); #endif } 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); /* It's now safe to remove this processor from the online map */ remove_cpu_from_maps(cpu); 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(KERN_INFO "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); } #else /* ... !CONFIG_HOTPLUG_CPU */ int __cpu_disable(void) { return -ENOSYS; } void __cpu_die(unsigned int cpu) { /* We said "no" in __cpu_disable */ BUG(); } #endif /* * If the BIOS enumerates physical processors before logical, * maxcpus=N at enumeration-time can be used to disable HT. */ static int __init parse_maxcpus(char *arg) { extern unsigned int maxcpus; maxcpus = simple_strtoul(arg, NULL, 0); return 0; } early_param("maxcpus", parse_maxcpus);