smpboot.c 35.8 KB
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/*
 *	x86 SMP booting functions
 *
 *	(c) 1995 Alan Cox, Building #3 <alan@redhat.com>
 *	(c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
 *	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
 */

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#include <linux/init.h>
#include <linux/smp.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/percpu.h>
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#include <linux/bootmem.h>
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#include <linux/err.h>
#include <linux/nmi.h>
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#include <asm/acpi.h>
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#include <asm/desc.h>
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#include <asm/nmi.h>
#include <asm/irq.h>
#include <asm/smp.h>
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#include <asm/trampoline.h>
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#include <asm/cpu.h>
#include <asm/numa.h>
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#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/mtrr.h>
#include <asm/nmi.h>
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#include <asm/vmi.h>
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#include <asm/genapic.h>
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#include <linux/mc146818rtc.h>
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#include <mach_apic.h>
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#include <mach_wakecpu.h>
#include <smpboot_hooks.h>

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/*
 * FIXME: For x86_64, those are defined in other files. But moving them here,
 * would make the setup areas dependent on smp, which is a loss. When we
 * integrate apic between arches, we can probably do a better job, but
 * right now, they'll stay here -- glommer
 */
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/* which logical CPU number maps to which CPU (physical APIC ID) */
u16 x86_cpu_to_apicid_init[NR_CPUS] __initdata =
			{ [0 ... NR_CPUS-1] = BAD_APICID };
void *x86_cpu_to_apicid_early_ptr;

u16 x86_bios_cpu_apicid_init[NR_CPUS] __initdata
				= { [0 ... NR_CPUS-1] = BAD_APICID };
void *x86_bios_cpu_apicid_early_ptr;
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#ifdef CONFIG_X86_32
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u8 apicid_2_node[MAX_APICID];
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static int low_mappings;
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#endif

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/* State of each CPU */
DEFINE_PER_CPU(int, cpu_state) = { 0 };

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/* 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
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/* 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);
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static atomic_t init_deasserted;

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static int boot_cpu_logical_apicid;

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/* representing cpus for which sibling maps can be computed */
static cpumask_t cpu_sibling_setup_map;

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/* Set if we find a B stepping CPU */
int __cpuinitdata smp_b_stepping;

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#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 };

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static void map_cpu_to_logical_apicid(void)
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{
	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);
}

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static void unmap_cpu_to_logical_apicid(int cpu)
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{
	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

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/*
 * Report back to the Boot Processor.
 * Running on AP.
 */
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static void __cpuinit smp_callin(void)
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{
	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.)
	 */
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	phys_id = GET_APIC_ID(read_apic_id());
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	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);
}

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/*
 * Activate a secondary processor.
 */
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static void __cpuinit start_secondary(void *unused)
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{
	/*
	 * 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);
	}

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#ifdef CONFIG_X86_32
	while (low_mappings)
		cpu_relax();
	__flush_tlb_all();
#endif

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	/* 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
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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
}

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static void __cpuinit smp_checks(void)
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{
	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) {
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		if (num_online_cpus())
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			printk(KERN_INFO "WARNING: This combination of AMD"
				"processors is not suitable for SMP.\n");
		else
			tainted &= ~TAINT_UNSAFE_SMP;
	}
}

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/*
 * 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);
}


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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;
		}
	}
}

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/* 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;
}

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#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
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static void impress_friends(void)
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{
	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",
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		num_online_cpus(),
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		bogosum/(500000/HZ),
		(bogosum/(5000/HZ))%100);

	Dprintk("Before bogocount - setting activated=1.\n");
}

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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;

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	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;
	}

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	/*
	 * 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);
}

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_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);
	}
#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);

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	if (get_uv_system_type() != UV_NON_UNIQUE_APIC) {
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		Dprintk("Setting warm reset code and vector.\n");
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		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);
	}
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	/*
	 * 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");
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			if (get_uv_system_type() != UV_NON_UNIQUE_APIC)
				inquire_remote_apic(apicid);
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		}
	}

	if (boot_error) {
		/* Try to put things back the way they were before ... */
		unmap_cpu_to_logical_apicid(cpu);
#ifdef CONFIG_X86_64
		clear_node_cpumask(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_possible_map);
		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;

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	/*
	 * Cleanup possible dangling ends...
	 */
	smpboot_restore_warm_reset_vector();

1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048
	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 */
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	clone_pgd_range(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
1050
		min_t(unsigned long, KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
1051
	flush_tlb_all();
1052
	low_mappings = 1;
1053 1054

	err = do_boot_cpu(apicid, cpu);
1055 1056 1057 1058 1059 1060 1061

	zap_low_mappings();
	low_mappings = 0;
#else
	err = do_boot_cpu(apicid, cpu);
#endif
	if (err) {
1062
		Dprintk("do_boot_cpu failed %d\n", err);
1063
		return -EIO;
1064 1065 1066 1067 1068 1069 1070 1071 1072 1073
	}

	/*
	 * 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);

1074
	while (!cpu_online(cpu)) {
1075 1076 1077 1078 1079 1080 1081
		cpu_relax();
		touch_nmi_watchdog();
	}

	return 0;
}

1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108
/*
 * 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)
{
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	preempt_disable();
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	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) {
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		preempt_enable();
1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139
		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);
	}
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	preempt_enable();
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	/*
	 * 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
1165
		connect_bsp_APIC();
1166
#endif
1167 1168
		setup_local_APIC();
		end_local_APIC_setup();
1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179
		return -1;
	}

	return 0;
}

static void __init smp_cpu_index_default(void)
{
	int i;
	struct cpuinfo_x86 *c;

1180
	for_each_possible_cpu(i) {
1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211
		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;
	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();
		return;
	}

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	preempt_disable();
1213
	if (GET_APIC_ID(read_apic_id()) != boot_cpu_physical_apicid) {
1214
		panic("Boot APIC ID in local APIC unexpected (%d vs %d)",
1215
		     GET_APIC_ID(read_apic_id()), boot_cpu_physical_apicid);
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		/* Or can we switch back to PIC here? */
	}
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	preempt_enable();
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#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();
}
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/*
 * 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;
}

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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();
}

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#ifdef CONFIG_HOTPLUG_CPU
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#  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 */

I
Ingo Molnar 已提交
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static void remove_siblinginfo(int cpu)
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{
	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);
}
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A
Adrian Bunk 已提交
1319
static int additional_cpus __initdata = -1;
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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);
}
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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);
	clear_node_cpumask(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();
}
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#endif

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/*
 * 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);