C++ cpumask_empty函数代码示例

void irq_move_masked_irq(struct irq_data *idata)
{
	struct irq_desc *desc = irq_data_to_desc(idata);
	struct irq_chip *chip = desc->irq_data.chip;

	if (likely(!irqd_is_setaffinity_pending(&desc->irq_data)))
		return;

	irqd_clr_move_pending(&desc->irq_data);

	/*
	 * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
	 */
	if (irqd_is_per_cpu(&desc->irq_data)) {
		WARN_ON(1);
		return;
	}

	if (unlikely(cpumask_empty(desc->pending_mask)))
		return;

	if (!chip->irq_set_affinity)
		return;

	assert_raw_spin_locked(&desc->lock);

	/*
	 * If there was a valid mask to work with, please
	 * do the disable, re-program, enable sequence.
	 * This is *not* particularly important for level triggered
	 * but in a edge trigger case, we might be setting rte
	 * when an active trigger is coming in. This could
	 * cause some ioapics to mal-function.
	 * Being paranoid i guess!
	 *
	 * For correct operation this depends on the caller
	 * masking the irqs.
	 */
	if (cpumask_any_and(desc->pending_mask, cpu_online_mask) < nr_cpu_ids)
		irq_do_set_affinity(&desc->irq_data, desc->pending_mask, false);

	cpumask_clear(desc->pending_mask);
}

/*
 * Remove a CPU from broadcasting
 */
void tick_shutdown_broadcast(unsigned int *cpup)
{
	struct clock_event_device *bc;
	unsigned long flags;
	unsigned int cpu = *cpup;

	raw_spin_lock_irqsave(&tick_broadcast_lock, flags);

	bc = tick_broadcast_device.evtdev;
	cpumask_clear_cpu(cpu, tick_broadcast_mask);
	cpumask_clear_cpu(cpu, tick_broadcast_on);

	if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC) {
		if (bc && cpumask_empty(tick_broadcast_mask))
			clockevents_shutdown(bc);
	}

	raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}

void _percpu_write_lock(percpu_rwlock_t **per_cpudata,
                percpu_rwlock_t *percpu_rwlock)
{
    unsigned int cpu;
    cpumask_t *rwlock_readers = &this_cpu(percpu_rwlock_readers);

    /* Validate the correct per_cpudata variable has been provided. */
    _percpu_rwlock_owner_check(per_cpudata, percpu_rwlock);

    /*
     * First take the write lock to protect against other writers or slow
     * path readers.
     */
    write_lock(&percpu_rwlock->rwlock);

    /* Now set the global variable so that readers start using read_lock. */
    percpu_rwlock->writer_activating = 1;
    smp_mb();

    /* Using a per cpu cpumask is only safe if there is no nesting. */
    ASSERT(!in_irq());
    cpumask_copy(rwlock_readers, &cpu_online_map);

    /* Check if there are any percpu readers in progress on this rwlock. */
    for ( ; ; )
    {
        for_each_cpu(cpu, rwlock_readers)
        {
            /*
             * Remove any percpu readers not contending on this rwlock
             * from our check mask.
             */
            if ( per_cpu_ptr(per_cpudata, cpu) != percpu_rwlock )
                __cpumask_clear_cpu(cpu, rwlock_readers);
        }
        /* Check if we've cleared all percpu readers from check mask. */
        if ( cpumask_empty(rwlock_readers) )
            break;
        /* Give the coherency fabric a break. */
        cpu_relax();
    };
}

void flush_area_mask(const cpumask_t *mask, const void *va, unsigned int flags)
{
    ASSERT(local_irq_is_enabled());

    if ( cpumask_test_cpu(smp_processor_id(), mask) )
        flush_area_local(va, flags);

    if ( !cpumask_subset(mask, cpumask_of(smp_processor_id())) )
    {
        spin_lock(&flush_lock);
        cpumask_and(&flush_cpumask, mask, &cpu_online_map);
        cpumask_clear_cpu(smp_processor_id(), &flush_cpumask);
        flush_va      = va;
        flush_flags   = flags;
        send_IPI_mask(&flush_cpumask, INVALIDATE_TLB_VECTOR);
        while ( !cpumask_empty(&flush_cpumask) )
            cpu_relax();
        spin_unlock(&flush_lock);
    }
}

/*
 * Broadcast the event to the cpus, which are set in the mask (mangled).
 */
static bool tick_do_broadcast(struct cpumask *mask)
{
	int cpu = smp_processor_id();
	struct tick_device *td;
	bool local = false;

	/*
	 * Check, if the current cpu is in the mask
	 */
	if (cpumask_test_cpu(cpu, mask)) {
		struct clock_event_device *bc = tick_broadcast_device.evtdev;

		cpumask_clear_cpu(cpu, mask);
		/*
		 * We only run the local handler, if the broadcast
		 * device is not hrtimer based. Otherwise we run into
		 * a hrtimer recursion.
		 *
		 * local timer_interrupt()
		 *   local_handler()
		 *     expire_hrtimers()
		 *       bc_handler()
		 *         local_handler()
		 *	     expire_hrtimers()
		 */
		local = !(bc->features & CLOCK_EVT_FEAT_HRTIMER);
	}

	if (!cpumask_empty(mask)) {
		/*
		 * It might be necessary to actually check whether the devices
		 * have different broadcast functions. For now, just use the
		 * one of the first device. This works as long as we have this
		 * misfeature only on x86 (lapic)
		 */
		td = &per_cpu(tick_cpu_device, cpumask_first(mask));
		td->evtdev->broadcast(mask);
	}
	return local;
}

/* On return cpumask will be altered to indicate CPUs changed.
 * CPUs with states changed will be set in the mask,
 * CPUs with status unchanged will be unset in the mask. */
static int rtas_cpu_state_change_mask(enum rtas_cpu_state state,
				cpumask_var_t cpus)
{
	int cpu;
	int cpuret = 0;
	int ret = 0;

	if (cpumask_empty(cpus))
		return 0;

	for_each_cpu(cpu, cpus) {
		switch (state) {
		case DOWN:
			cpuret = cpu_down(cpu);
			break;
		case UP:
			cpuret = cpu_up(cpu);
			break;
		}
		if (cpuret) {
			pr_debug("%s: cpu_%s for cpu#%d returned %d.\n",
					__func__,
					((state == UP) ? "up" : "down"),
					cpu, cpuret);
			if (!ret)
				ret = cpuret;
			if (state == UP) {
				/* clear bits for unchanged cpus, return */
				cpumask_shift_right(cpus, cpus, cpu);
				cpumask_shift_left(cpus, cpus, cpu);
				break;
			} else {
				/* clear bit for unchanged cpu, continue */
				cpumask_clear_cpu(cpu, cpus);
			}
		}
	}

	return ret;
}

static u32 get_cur_val(const cpumask_t *mask)
{
    struct cpufreq_policy *policy;
    struct processor_performance *perf;
    struct drv_cmd cmd;
    unsigned int cpu = smp_processor_id();

    if (unlikely(cpumask_empty(mask)))
        return 0;

    if (!cpumask_test_cpu(cpu, mask))
        cpu = cpumask_first(mask);
    if (cpu >= nr_cpu_ids || !cpu_online(cpu))
        return 0;

    policy = per_cpu(cpufreq_cpu_policy, cpu);
    if (!policy || !cpufreq_drv_data[policy->cpu])
        return 0;    

    switch (cpufreq_drv_data[policy->cpu]->arch_cpu_flags) {
    case SYSTEM_INTEL_MSR_CAPABLE:
        cmd.type = SYSTEM_INTEL_MSR_CAPABLE;
        cmd.addr.msr.reg = MSR_IA32_PERF_STATUS;
        break;
    case SYSTEM_IO_CAPABLE:
        cmd.type = SYSTEM_IO_CAPABLE;
        perf = cpufreq_drv_data[policy->cpu]->acpi_data;
        cmd.addr.io.port = perf->control_register.address;
        cmd.addr.io.bit_width = perf->control_register.bit_width;
        break;
    default:
        return 0;
    }

    cmd.mask = cpumask_of(cpu);

    drv_read(&cmd);
    return cmd.val;
}

void __ref enable_nonboot_cpus(void)
{
	int cpu, error;
#if defined (CONFIG_MACH_APQ8064_OMEGA) || defined (CONFIG_MACH_APQ8064_OMEGAR)
	static int first = 0;

	if (!first) {
		init_timer(&boost_freq_timer);
		first = 1;
	}
	if (timer_pending(&boost_freq_timer))
		del_timer(&boost_freq_timer);
	boost_freq_timer.function = boost_freq_timer_cb;
	boost_freq_timer.expires =
		jiffies + msecs_to_jiffies(BOOST_FREQ_TIME_MS);
	add_timer(&boost_freq_timer);
	boost_freq = 1;
#endif

	/* Allow everyone to use the CPU hotplug again */
	cpu_maps_update_begin();
	cpu_hotplug_disabled = 0;
	if (cpumask_empty(frozen_cpus))
		goto out;

	printk(KERN_INFO "Enabling non-boot CPUs ...\n");

	arch_enable_nonboot_cpus_begin();

	for_each_cpu(cpu, frozen_cpus) {
		error = _cpu_up(cpu, 1);
		if (!error) {
			printk(KERN_INFO "CPU%d is up\n", cpu);
			continue;
		}
		printk(KERN_WARNING "Error taking CPU%d up: %d\n", cpu, error);
	}

/* This gets called just before system reboots */
void opal_flash_term_callback(void)
{
	struct cpumask mask;

	if (update_flash_data.status != FLASH_IMG_READY)
		return;

	pr_alert("FLASH: Flashing new firmware\n");
	pr_alert("FLASH: Image is %u bytes\n", image_data.size);
	pr_alert("FLASH: Performing flash and reboot/shutdown\n");
	pr_alert("FLASH: This will take several minutes. Do not power off!\n");

	/* Small delay to help getting the above message out */
	msleep(500);

	/* Return secondary CPUs to firmware */
	cpumask_copy(&mask, cpu_online_mask);
	cpumask_clear_cpu(smp_processor_id(), &mask);
	if (!cpumask_empty(&mask))
		smp_call_function_many(&mask,
				       flash_return_cpu, NULL, false);
	/* Hard disable interrupts */
	hard_irq_disable();
}

static int __bind_irq_vector(int irq, int vector, cpumask_t domain)
{
	cpumask_t mask;
	int cpu;
	struct irq_cfg *cfg = &irq_cfg[irq];

	BUG_ON((unsigned)irq >= NR_IRQS);
	BUG_ON((unsigned)vector >= IA64_NUM_VECTORS);

	cpumask_and(&mask, &domain, cpu_online_mask);
	if (cpumask_empty(&mask))
		return -EINVAL;
	if ((cfg->vector == vector) && cpumask_equal(&cfg->domain, &domain))
		return 0;
	if (cfg->vector != IRQ_VECTOR_UNASSIGNED)
		return -EBUSY;
	for_each_cpu(cpu, &mask)
		per_cpu(vector_irq, cpu)[vector] = irq;
	cfg->vector = vector;
	cfg->domain = domain;
	irq_status[irq] = IRQ_USED;
	cpumask_or(&vector_table[vector], &vector_table[vector], &domain);
	return 0;
}

void __init arch_get_hmp_domains(struct list_head *hmp_domains_list)
{
	struct hmp_domain *domain;

	arch_get_fast_and_slow_cpus(&hmp_fast_cpu_mask, &hmp_slow_cpu_mask);

	/*
	 * Initialize hmp_domains
	 * Must be ordered with respect to compute capacity.
	 * Fastest domain at head of list.
	 */
	if(!cpumask_empty(&hmp_slow_cpu_mask)) {
		domain = (struct hmp_domain *)
			kmalloc(sizeof(struct hmp_domain), GFP_KERNEL);
		cpumask_copy(&domain->possible_cpus, &hmp_slow_cpu_mask);
		cpumask_and(&domain->cpus, cpu_online_mask, &domain->possible_cpus);
		list_add(&domain->hmp_domains, hmp_domains_list);
	}
	domain = (struct hmp_domain *)
		kmalloc(sizeof(struct hmp_domain), GFP_KERNEL);
	cpumask_copy(&domain->possible_cpus, &hmp_fast_cpu_mask);
	cpumask_and(&domain->cpus, cpu_online_mask, &domain->possible_cpus);
	list_add(&domain->hmp_domains, hmp_domains_list);
}

void __ref enable_nonboot_cpus(void)
{
	int cpu, error;

	/* Allow everyone to use the CPU hotplug again */
	cpu_maps_update_begin();
	cpu_hotplug_disabled = 0;
	if (cpumask_empty(frozen_cpus))
		goto out;

	pr_info("Enabling non-boot CPUs ...\n");

	arch_enable_nonboot_cpus_begin();

	for_each_cpu(cpu, frozen_cpus) {
		trace_suspend_resume(TPS("CPU_ON"), cpu, true);
		error = _cpu_up(cpu, 1);
		trace_suspend_resume(TPS("CPU_ON"), cpu, false);
		if (!error) {
			pr_info("CPU%d is up\n", cpu);
			continue;
		}
		pr_warn("Error taking CPU%d up: %d\n", cpu, error);
	}

/*
 * Handle oneshot mode broadcasting
 */
static void tick_handle_oneshot_broadcast(struct clock_event_device *dev)
{
	struct tick_device *td;
	ktime_t now, next_event;
	int cpu, next_cpu = 0;
	bool bc_local;

	raw_spin_lock(&tick_broadcast_lock);
	dev->next_event = KTIME_MAX;
	next_event = KTIME_MAX;
	cpumask_clear(tmpmask);
	now = ktime_get();
	/* Find all expired events */
	for_each_cpu(cpu, tick_broadcast_oneshot_mask) {
		/*
		 * Required for !SMP because for_each_cpu() reports
		 * unconditionally CPU0 as set on UP kernels.
		 */
		if (!IS_ENABLED(CONFIG_SMP) &&
		    cpumask_empty(tick_broadcast_oneshot_mask))
			break;

		td = &per_cpu(tick_cpu_device, cpu);
		if (td->evtdev->next_event <= now) {
			cpumask_set_cpu(cpu, tmpmask);
			/*
			 * Mark the remote cpu in the pending mask, so
			 * it can avoid reprogramming the cpu local
			 * timer in tick_broadcast_oneshot_control().
			 */
			cpumask_set_cpu(cpu, tick_broadcast_pending_mask);
		} else if (td->evtdev->next_event < next_event) {
			next_event = td->evtdev->next_event;
			next_cpu = cpu;
		}
	}

	/*
	 * Remove the current cpu from the pending mask. The event is
	 * delivered immediately in tick_do_broadcast() !
	 */
	cpumask_clear_cpu(smp_processor_id(), tick_broadcast_pending_mask);

	/* Take care of enforced broadcast requests */
	cpumask_or(tmpmask, tmpmask, tick_broadcast_force_mask);
	cpumask_clear(tick_broadcast_force_mask);

	/*
	 * Sanity check. Catch the case where we try to broadcast to
	 * offline cpus.
	 */
	if (WARN_ON_ONCE(!cpumask_subset(tmpmask, cpu_online_mask)))
		cpumask_and(tmpmask, tmpmask, cpu_online_mask);

	/*
	 * Wakeup the cpus which have an expired event.
	 */
	bc_local = tick_do_broadcast(tmpmask);

	/*
	 * Two reasons for reprogram:
	 *
	 * - The global event did not expire any CPU local
	 * events. This happens in dyntick mode, as the maximum PIT
	 * delta is quite small.
	 *
	 * - There are pending events on sleeping CPUs which were not
	 * in the event mask
	 */
	if (next_event != KTIME_MAX)
		tick_broadcast_set_event(dev, next_cpu, next_event);

	raw_spin_unlock(&tick_broadcast_lock);

	if (bc_local) {
		td = this_cpu_ptr(&tick_cpu_device);
		td->evtdev->event_handler(td->evtdev);
	}
}

/**
 * tick_broadcast_control - Enable/disable or force broadcast mode
 * @mode:	The selected broadcast mode
 *
 * Called when the system enters a state where affected tick devices
 * might stop. Note: TICK_BROADCAST_FORCE cannot be undone.
 */
void tick_broadcast_control(enum tick_broadcast_mode mode)
{
	struct clock_event_device *bc, *dev;
	struct tick_device *td;
	int cpu, bc_stopped;
	unsigned long flags;

	/* Protects also the local clockevent device. */
	raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
	td = this_cpu_ptr(&tick_cpu_device);
	dev = td->evtdev;

	/*
	 * Is the device not affected by the powerstate ?
	 */
	if (!dev || !(dev->features & CLOCK_EVT_FEAT_C3STOP))
		goto out;

	if (!tick_device_is_functional(dev))
		goto out;

	cpu = smp_processor_id();
	bc = tick_broadcast_device.evtdev;
	bc_stopped = cpumask_empty(tick_broadcast_mask);

	switch (mode) {
	case TICK_BROADCAST_FORCE:
		tick_broadcast_forced = 1;
	case TICK_BROADCAST_ON:
		cpumask_set_cpu(cpu, tick_broadcast_on);
		if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_mask)) {
			/*
			 * Only shutdown the cpu local device, if:
			 *
			 * - the broadcast device exists
			 * - the broadcast device is not a hrtimer based one
			 * - the broadcast device is in periodic mode to
			 *   avoid a hickup during switch to oneshot mode
			 */
			if (bc && !(bc->features & CLOCK_EVT_FEAT_HRTIMER) &&
			    tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
				clockevents_shutdown(dev);
		}
		break;

	case TICK_BROADCAST_OFF:
		if (tick_broadcast_forced)
			break;
		cpumask_clear_cpu(cpu, tick_broadcast_on);
		if (cpumask_test_and_clear_cpu(cpu, tick_broadcast_mask)) {
			if (tick_broadcast_device.mode ==
			    TICKDEV_MODE_PERIODIC)
				tick_setup_periodic(dev, 0);
		}
		break;
	}

	if (bc) {
		if (cpumask_empty(tick_broadcast_mask)) {
			if (!bc_stopped)
				clockevents_shutdown(bc);
		} else if (bc_stopped) {
			if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
				tick_broadcast_start_periodic(bc);
			else
				tick_broadcast_setup_oneshot(bc);
		}
	}
out:
	raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}

/*
 * Check, if the device is disfunctional and a place holder, which
 * needs to be handled by the broadcast device.
 */
int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
{
	struct clock_event_device *bc = tick_broadcast_device.evtdev;
	unsigned long flags;
	int ret = 0;

	raw_spin_lock_irqsave(&tick_broadcast_lock, flags);

	/*
	 * Devices might be registered with both periodic and oneshot
	 * mode disabled. This signals, that the device needs to be
	 * operated from the broadcast device and is a placeholder for
	 * the cpu local device.
	 */
	if (!tick_device_is_functional(dev)) {
		dev->event_handler = tick_handle_periodic;
		tick_device_setup_broadcast_func(dev);
		cpumask_set_cpu(cpu, tick_broadcast_mask);
		if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
			tick_broadcast_start_periodic(bc);
		else
			tick_broadcast_setup_oneshot(bc);
		ret = 1;
	} else {
		/*
		 * Clear the broadcast bit for this cpu if the
		 * device is not power state affected.
		 */
		if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
			cpumask_clear_cpu(cpu, tick_broadcast_mask);
		else
			tick_device_setup_broadcast_func(dev);

		/*
		 * Clear the broadcast bit if the CPU is not in
		 * periodic broadcast on state.
		 */
		if (!cpumask_test_cpu(cpu, tick_broadcast_on))
			cpumask_clear_cpu(cpu, tick_broadcast_mask);

		switch (tick_broadcast_device.mode) {
		case TICKDEV_MODE_ONESHOT:
			/*
			 * If the system is in oneshot mode we can
			 * unconditionally clear the oneshot mask bit,
			 * because the CPU is running and therefore
			 * not in an idle state which causes the power
			 * state affected device to stop. Let the
			 * caller initialize the device.
			 */
			tick_broadcast_clear_oneshot(cpu);
			ret = 0;
			break;

		case TICKDEV_MODE_PERIODIC:
			/*
			 * If the system is in periodic mode, check
			 * whether the broadcast device can be
			 * switched off now.
			 */
			if (cpumask_empty(tick_broadcast_mask) && bc)
				clockevents_shutdown(bc);
			/*
			 * If we kept the cpu in the broadcast mask,
			 * tell the caller to leave the per cpu device
			 * in shutdown state. The periodic interrupt
			 * is delivered by the broadcast device, if
			 * the broadcast device exists and is not
			 * hrtimer based.
			 */
			if (bc && !(bc->features & CLOCK_EVT_FEAT_HRTIMER))
				ret = cpumask_test_cpu(cpu, tick_broadcast_mask);
			break;
		default:
			break;
		}
	}
	raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
	return ret;
}