smpboot.c

xen虚拟机源代码安装包

	int timeout;
#ifndef XEN
	struct create_idle c_idle = {
		.cpu	= cpu,
		.done	= COMPLETION_INITIALIZER(c_idle.done),
	};
	DECLARE_WORK(work, do_fork_idle, &c_idle);

 	c_idle.idle = get_idle_for_cpu(cpu);
 	if (c_idle.idle) {
		init_idle(c_idle.idle, cpu);
 		goto do_rest;
	}

	/*
	 * We can't use kernel_thread since we must avoid to reschedule the child.
	 */
	if (!keventd_up() || current_is_keventd())
		work.func(work.data);
	else {
		schedule_work(&work);
		wait_for_completion(&c_idle.done);
	}

	if (IS_ERR(c_idle.idle))
		panic("failed fork for CPU %d", cpu);

	set_idle_for_cpu(cpu, c_idle.idle);

do_rest:
	task_for_booting_cpu = c_idle.idle;
#else
	struct vcpu *v;

	v = alloc_idle_vcpu(cpu);
	BUG_ON(v == NULL);

	//printf ("do_boot_cpu: cpu=%d, domain=%p, vcpu=%p\n", cpu, idle, v);

	task_for_booting_cpu = (task_t *)v;

	/* Set cpu number.  */
	get_thread_info(v)->cpu = cpu;
#endif

	Dprintk("Sending wakeup vector %lu to AP 0x%x/0x%x.\n", ap_wakeup_vector, cpu, sapicid);

	set_brendez_area(cpu);
	platform_send_ipi(cpu, ap_wakeup_vector, IA64_IPI_DM_INT, 0);

	/*
	 * Wait 10s total for the AP to start
	 */
	Dprintk("Waiting on callin_map ...");
	for (timeout = 0; timeout < 100000; timeout++) {
		if (cpu_isset(cpu, cpu_callin_map))
			break;  /* It has booted */
		udelay(100);
	}
	Dprintk("\n");

	if (!cpu_isset(cpu, cpu_callin_map)) {
		printk(KERN_ERR "Processor 0x%x/0x%x is stuck.\n", cpu, sapicid);
		ia64_cpu_to_sapicid[cpu] = -1;
		cpu_clear(cpu, cpu_online_map);  /* was set in smp_callin() */
		return -EINVAL;
	}
	return 0;
}

#ifndef XEN
static int __init
decay (char *str)
{
	int ticks;
	get_option (&str, &ticks);
	return 1;
}

__setup("decay=", decay);
#endif

/*
 * Initialize the logical CPU number to SAPICID mapping
 */
void __init
smp_build_cpu_map (void)
{
	int sapicid, cpu, i;
	int boot_cpu_id = hard_smp_processor_id();

	for (cpu = 0; cpu < NR_CPUS; cpu++) {
		ia64_cpu_to_sapicid[cpu] = -1;
#ifndef XEN
#ifdef CONFIG_HOTPLUG_CPU
		cpu_set(cpu, cpu_possible_map);
#endif
#endif
	}

	ia64_cpu_to_sapicid[0] = boot_cpu_id;
	cpus_clear(cpu_present_map);
	cpu_set(0, cpu_present_map);
	cpu_set(0, cpu_possible_map);
	for (cpu = 1, i = 0; i < smp_boot_data.cpu_count; i++) {
		sapicid = smp_boot_data.cpu_phys_id[i];
		if (sapicid == boot_cpu_id)
			continue;
		cpu_set(cpu, cpu_present_map);
		cpu_set(cpu, cpu_possible_map);
		ia64_cpu_to_sapicid[cpu] = sapicid;
		cpu++;
	}
}

/*
 * Cycle through the APs sending Wakeup IPIs to boot each.
 */
void __init
smp_prepare_cpus (unsigned int max_cpus)
{
	int boot_cpu_id = hard_smp_processor_id();

	/*
	 * Initialize the per-CPU profiling counter/multiplier
	 */

	smp_setup_percpu_timer();

	/*
	 * We have the boot CPU online for sure.
	 */
	cpu_set(0, cpu_online_map);
	cpu_set(0, cpu_callin_map);

	local_cpu_data->loops_per_jiffy = loops_per_jiffy;
	ia64_cpu_to_sapicid[0] = boot_cpu_id;

	printk(KERN_INFO "Boot processor id 0x%x/0x%x\n", 0, boot_cpu_id);

	current_thread_info()->cpu = 0;

	/*
	 * If SMP should be disabled, then really disable it!
	 */
	if (!max_cpus) {
		printk(KERN_INFO "SMP mode deactivated.\n");
		cpus_clear(cpu_online_map);
		cpus_clear(cpu_present_map);
		cpus_clear(cpu_possible_map);
		cpu_set(0, cpu_online_map);
		cpu_set(0, cpu_present_map);
		cpu_set(0, cpu_possible_map);
		return;
	}
}

void __devinit smp_prepare_boot_cpu(void)
{
	cpu_set(smp_processor_id(), cpu_online_map);
	cpu_set(smp_processor_id(), cpu_callin_map);
	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
}

/*
 * mt_info[] is a temporary store for all info returned by
 * PAL_LOGICAL_TO_PHYSICAL, to be copied into cpuinfo_ia64 when the
 * specific cpu comes.
 */
static struct {
	__u32   socket_id;
	__u16   core_id;
	__u16   thread_id;
	__u16   proc_fixed_addr;
	__u8    valid;
} mt_info[NR_CPUS] __devinitdata;

#if defined(XEN) && !defined(CONFIG_HOTPLUG_CPU)
static inline void
remove_from_mtinfo(int cpu)
{
	int i;

	for_each_cpu(i)
		if (mt_info[i].valid &&  mt_info[i].socket_id ==
		    				cpu_data(cpu)->socket_id)
			mt_info[i].valid = 0;
}

static inline void
clear_cpu_sibling_map(int cpu)
{
	int i;

	for_each_cpu_mask(i, cpu_sibling_map[cpu])
		cpu_clear(cpu, cpu_sibling_map[i]);
	for_each_cpu_mask(i, cpu_core_map[cpu])
		cpu_clear(cpu, cpu_core_map[i]);

	cpus_clear(cpu_sibling_map[cpu]);
	cpus_clear(cpu_core_map[cpu]);
}

static void
remove_siblinginfo(int cpu)
{
	int last = 0;

	if (cpu_data(cpu)->threads_per_core == 1 &&
	    cpu_data(cpu)->cores_per_socket == 1) {
		cpu_clear(cpu, cpu_core_map[cpu]);
		cpu_clear(cpu, cpu_sibling_map[cpu]);
		return;
	}

	last = (cpus_weight(cpu_core_map[cpu]) == 1 ? 1 : 0);

	/* remove it from all sibling map's */
	clear_cpu_sibling_map(cpu);

	/* if this cpu is the last in the core group, remove all its info 
	 * from mt_info structure
	 */
	if (last)
		remove_from_mtinfo(cpu);
}

extern void fixup_irqs(void);
/* must be called with cpucontrol mutex held */
int __cpu_disable(void)
{
	int cpu = smp_processor_id();

	/*
	 * dont permit boot processor for now
	 */
	if (cpu == 0)
		return -EBUSY;

	remove_siblinginfo(cpu);
	cpu_clear(cpu, cpu_online_map);
#ifndef XEN
	fixup_irqs();
#endif
	local_flush_tlb_all();
	cpu_clear(cpu, cpu_callin_map);
	return 0;
}
#else /* !CONFIG_HOTPLUG_CPU */
int __cpu_disable(void)
{
	return -ENOSYS;
}
#endif /* CONFIG_HOTPLUG_CPU */

#ifdef CONFIG_HOTPLUG_CPU
void __cpu_die(unsigned int cpu)
{
	unsigned int i;

	for (i = 0; i < 100; 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);
			return;
		}
#ifdef XEN
		udelay(100 * 1000);
#else
		msleep(100);
#endif
	}
 	printk(KERN_ERR "CPU %u didn't die...\n", cpu);
}
#else /* !CONFIG_HOTPLUG_CPU */
void __cpu_die(unsigned int cpu)
{
	/* We said "no" in __cpu_disable */
	BUG();
}
#endif /* CONFIG_HOTPLUG_CPU */

void
smp_cpus_done (unsigned int dummy)
{
	int cpu;
	unsigned long bogosum = 0;

	/*
	 * Allow the user to impress friends.
	 */

	for (cpu = 0; cpu < NR_CPUS; cpu++)
		if (cpu_online(cpu))
			bogosum += cpu_data(cpu)->loops_per_jiffy;

	printk(KERN_INFO "Total of %d processors activated (%lu.%02lu BogoMIPS).\n",
	       (int)num_online_cpus(), bogosum/(500000/HZ), (bogosum/(5000/HZ))%100);
}

static inline void __devinit
set_cpu_sibling_map(int cpu)
{
	int i;

	for_each_online_cpu(i) {
		if ((cpu_data(cpu)->socket_id == cpu_data(i)->socket_id)) {
			cpu_set(i, cpu_core_map[cpu]);
			cpu_set(cpu, cpu_core_map[i]);
			if (cpu_data(cpu)->core_id == cpu_data(i)->core_id) {
				cpu_set(i, cpu_sibling_map[cpu]);
				cpu_set(cpu, cpu_sibling_map[i]);
			}
		}
	}
}

int __devinit
__cpu_up (unsigned int cpu)
{
	int ret;
	int sapicid;

	sapicid = ia64_cpu_to_sapicid[cpu];
	if (sapicid == -1)
		return -EINVAL;

	/*
	 * Already booted cpu? not valid anymore since we dont
	 * do idle loop tightspin anymore.
	 */
	if (cpu_isset(cpu, cpu_callin_map))
		return -EINVAL;

	per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
	/* Processor goes to start_secondary(), sets online flag */
	ret = do_boot_cpu(sapicid, cpu);
	if (ret < 0)
		return ret;

	if (cpu_data(cpu)->threads_per_core == 1 &&
	    cpu_data(cpu)->cores_per_socket == 1) {
		cpu_set(cpu, cpu_sibling_map[cpu]);
		cpu_set(cpu, cpu_core_map[cpu]);
		return 0;
	}

	set_cpu_sibling_map(cpu);

	return 0;
}

/*
 * Assume that CPU's have been discovered by some platform-dependent interface.  For
 * SoftSDV/Lion, that would be ACPI.
 *
 * Setup of the IPI irq handler is done in irq.c:init_IRQ_SMP().
 */
void __init
init_smp_config(void)
{
	struct fptr {
		unsigned long fp;
		unsigned long gp;
	} *ap_startup;
	long sal_ret;

	/* Tell SAL where to drop the AP's.  */
	ap_startup = (struct fptr *) start_ap;
	sal_ret = ia64_sal_set_vectors(SAL_VECTOR_OS_BOOT_RENDEZ,
				       ia64_tpa(ap_startup->fp), ia64_tpa(ap_startup->gp), 0, 0, 0, 0);
	if (sal_ret < 0)
		printk(KERN_ERR "SMP: Can't set SAL AP Boot Rendezvous: %s\n",
		       ia64_sal_strerror(sal_ret));
}

static inline int __devinit
check_for_mtinfo_index(void)
{
	int i;
	
	for_each_cpu(i)
		if (!mt_info[i].valid)
			return i;

	return -1;
}

/*
 * Search the mt_info to find out if this socket's cid/tid information is
 * cached or not. If the socket exists, fill in the core_id and thread_id 
 * in cpuinfo
 */
static int __devinit
check_for_new_socket(__u16 logical_address, struct cpuinfo_ia64 *c)
{
	int i;
	__u32 sid = c->socket_id;

	for_each_cpu(i) {
		if (mt_info[i].valid && mt_info[i].proc_fixed_addr == logical_address
		    && mt_info[i].socket_id == sid) {
			c->core_id = mt_info[i].core_id;
			c->thread_id = mt_info[i].thread_id;
			return 1; /* not a new socket */
		}
	}
	return 0;
}

/*
 * identify_siblings(cpu) gets called from identify_cpu. This populates the 
 * information related to logical execution units in per_cpu_data structure.
 */
void __devinit
identify_siblings(struct cpuinfo_ia64 *c)
{
	s64 status;
	u16 pltid;
	u64 proc_fixed_addr;
	int count, i;
	pal_logical_to_physical_t info;

	if (smp_num_cpucores == 1 && smp_num_siblings == 1)
		return;

	if ((status = ia64_pal_logical_to_phys(0, &info)) != PAL_STATUS_SUCCESS) {
		printk(KERN_ERR "ia64_pal_logical_to_phys failed with %ld\n",
		       status);
		return;
	}
	if ((status = ia64_sal_physical_id_info(&pltid)) != PAL_STATUS_SUCCESS) {
		printk(KERN_ERR "ia64_sal_pltid failed with %ld\n", status);
		return;
	}
	if ((status = ia64_pal_fixed_addr(&proc_fixed_addr)) != PAL_STATUS_SUCCESS) {
		printk(KERN_ERR "ia64_pal_fixed_addr failed with %ld\n", status);
		return;
	}

	c->socket_id =  (pltid << 8) | info.overview_ppid;
	c->cores_per_socket = info.overview_cpp;
	c->threads_per_core = info.overview_tpc;
	count = c->num_log = info.overview_num_log;

	/* If the thread and core id information is already cached, then
	 * we will simply update cpu_info and return. Otherwise, we will
	 * do the PAL calls and cache core and thread id's of all the siblings.
	 */
	if (check_for_new_socket(proc_fixed_addr, c))
		return;

	for (i = 0; i < count; i++) {
		int index;

		if (i && (status = ia64_pal_logical_to_phys(i, &info))
			  != PAL_STATUS_SUCCESS) {
                	printk(KERN_ERR "ia64_pal_logical_to_phys failed"
					" with %ld\n", status);
                	return;
		}
		if (info.log2_la == proc_fixed_addr) {
			c->core_id = info.log1_cid;
			c->thread_id = info.log1_tid;
		}

		index = check_for_mtinfo_index();
		/* We will not do the mt_info caching optimization in this case.
		 */
		if (index < 0)
			continue;

		mt_info[index].valid = 1;
		mt_info[index].socket_id = c->socket_id;
		mt_info[index].core_id = info.log1_cid;
		mt_info[index].thread_id = info.log1_tid;
		mt_info[index].proc_fixed_addr = info.log2_la;
	}
}
#endif /* CONFIG_SMP ifdef XEN */