Rewind v3.13-rc3+ (78fd82238d0e5716) to v3.12

1 files changed, 0 insertions, 822 deletions

diff --git a/arch/arm/common/bL_switcher.c b/arch/arm/common/bL_switcher.c
deleted file mode 100644
index 5774b6e..0000000
--- a/arch/arm/common/bL_switcher.c
+++ /dev/null
@@ -1,822 +0,0 @@
-/*
- * arch/arm/common/bL_switcher.c -- big.LITTLE cluster switcher core driver
- *
- * Created by:	Nicolas Pitre, March 2012
- * Copyright:	(C) 2012-2013  Linaro Limited
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/atomic.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/cpu_pm.h>
-#include <linux/cpu.h>
-#include <linux/cpumask.h>
-#include <linux/kthread.h>
-#include <linux/wait.h>
-#include <linux/time.h>
-#include <linux/clockchips.h>
-#include <linux/hrtimer.h>
-#include <linux/tick.h>
-#include <linux/notifier.h>
-#include <linux/mm.h>
-#include <linux/mutex.h>
-#include <linux/smp.h>
-#include <linux/spinlock.h>
-#include <linux/string.h>
-#include <linux/sysfs.h>
-#include <linux/irqchip/arm-gic.h>
-#include <linux/moduleparam.h>
-
-#include <asm/smp_plat.h>
-#include <asm/cputype.h>
-#include <asm/suspend.h>
-#include <asm/mcpm.h>
-#include <asm/bL_switcher.h>
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/power_cpu_migrate.h>
-
-
-/*
- * Use our own MPIDR accessors as the generic ones in asm/cputype.h have
- * __attribute_const__ and we don't want the compiler to assume any
- * constness here as the value _does_ change along some code paths.
- */
-
-static int read_mpidr(void)
-{
-	unsigned int id;
-	asm volatile ("mrc p15, 0, %0, c0, c0, 5" : "=r" (id));
-	return id & MPIDR_HWID_BITMASK;
-}
-
-/*
- * Get a global nanosecond time stamp for tracing.
- */
-static s64 get_ns(void)
-{
-	struct timespec ts;
-	getnstimeofday(&ts);
-	return timespec_to_ns(&ts);
-}
-
-/*
- * bL switcher core code.
- */
-
-static void bL_do_switch(void *_arg)
-{
-	unsigned ib_mpidr, ib_cpu, ib_cluster;
-	long volatile handshake, **handshake_ptr = _arg;
-
-	pr_debug("%s\n", __func__);
-
-	ib_mpidr = cpu_logical_map(smp_processor_id());
-	ib_cpu = MPIDR_AFFINITY_LEVEL(ib_mpidr, 0);
-	ib_cluster = MPIDR_AFFINITY_LEVEL(ib_mpidr, 1);
-
-	/* Advertise our handshake location */
-	if (handshake_ptr) {
-		handshake = 0;
-		*handshake_ptr = &handshake;
-	} else
-		handshake = -1;
-
-	/*
-	 * Our state has been saved at this point.  Let's release our
-	 * inbound CPU.
-	 */
-	mcpm_set_entry_vector(ib_cpu, ib_cluster, cpu_resume);
-	sev();
-
-	/*
-	 * From this point, we must assume that our counterpart CPU might
-	 * have taken over in its parallel world already, as if execution
-	 * just returned from cpu_suspend().  It is therefore important to
-	 * be very careful not to make any change the other guy is not
-	 * expecting.  This is why we need stack isolation.
-	 *
-	 * Fancy under cover tasks could be performed here.  For now
-	 * we have none.
-	 */
-
-	/*
-	 * Let's wait until our inbound is alive.
-	 */
-	while (!handshake) {
-		wfe();
-		smp_mb();
-	}
-
-	/* Let's put ourself down. */
-	mcpm_cpu_power_down();
-
-	/* should never get here */
-	BUG();
-}
-
-/*
- * Stack isolation.  To ensure 'current' remains valid, we just use another
- * piece of our thread's stack space which should be fairly lightly used.
- * The selected area starts just above the thread_info structure located
- * at the very bottom of the stack, aligned to a cache line, and indexed
- * with the cluster number.
- */
-#define STACK_SIZE 512
-extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
-static int bL_switchpoint(unsigned long _arg)
-{
-	unsigned int mpidr = read_mpidr();
-	unsigned int clusterid = MPIDR_AFFINITY_LEVEL(mpidr, 1);
-	void *stack = current_thread_info() + 1;
-	stack = PTR_ALIGN(stack, L1_CACHE_BYTES);
-	stack += clusterid * STACK_SIZE + STACK_SIZE;
-	call_with_stack(bL_do_switch, (void *)_arg, stack);
-	BUG();
-}
-
-/*
- * Generic switcher interface
- */
-
-static unsigned int bL_gic_id[MAX_CPUS_PER_CLUSTER][MAX_NR_CLUSTERS];
-static int bL_switcher_cpu_pairing[NR_CPUS];
-
-/*
- * bL_switch_to - Switch to a specific cluster for the current CPU
- * @new_cluster_id: the ID of the cluster to switch to.
- *
- * This function must be called on the CPU to be switched.
- * Returns 0 on success, else a negative status code.
- */
-static int bL_switch_to(unsigned int new_cluster_id)
-{
-	unsigned int mpidr, this_cpu, that_cpu;
-	unsigned int ob_mpidr, ob_cpu, ob_cluster, ib_mpidr, ib_cpu, ib_cluster;
-	struct completion inbound_alive;
-	struct tick_device *tdev;
-	enum clock_event_mode tdev_mode;
-	long volatile *handshake_ptr;
-	int ipi_nr, ret;
-
-	this_cpu = smp_processor_id();
-	ob_mpidr = read_mpidr();
-	ob_cpu = MPIDR_AFFINITY_LEVEL(ob_mpidr, 0);
-	ob_cluster = MPIDR_AFFINITY_LEVEL(ob_mpidr, 1);
-	BUG_ON(cpu_logical_map(this_cpu) != ob_mpidr);
-
-	if (new_cluster_id == ob_cluster)
-		return 0;
-
-	that_cpu = bL_switcher_cpu_pairing[this_cpu];
-	ib_mpidr = cpu_logical_map(that_cpu);
-	ib_cpu = MPIDR_AFFINITY_LEVEL(ib_mpidr, 0);
-	ib_cluster = MPIDR_AFFINITY_LEVEL(ib_mpidr, 1);
-
-	pr_debug("before switch: CPU %d MPIDR %#x -> %#x\n",
-		 this_cpu, ob_mpidr, ib_mpidr);
-
-	this_cpu = smp_processor_id();
-
-	/* Close the gate for our entry vectors */
-	mcpm_set_entry_vector(ob_cpu, ob_cluster, NULL);
-	mcpm_set_entry_vector(ib_cpu, ib_cluster, NULL);
-
-	/* Install our "inbound alive" notifier. */
-	init_completion(&inbound_alive);
-	ipi_nr = register_ipi_completion(&inbound_alive, this_cpu);
-	ipi_nr |= ((1 << 16) << bL_gic_id[ob_cpu][ob_cluster]);
-	mcpm_set_early_poke(ib_cpu, ib_cluster, gic_get_sgir_physaddr(), ipi_nr);
-
-	/*
-	 * Let's wake up the inbound CPU now in case it requires some delay
-	 * to come online, but leave it gated in our entry vector code.
-	 */
-	ret = mcpm_cpu_power_up(ib_cpu, ib_cluster);
-	if (ret) {
-		pr_err("%s: mcpm_cpu_power_up() returned %d\n", __func__, ret);
-		return ret;
-	}
-
-	/*
-	 * Raise a SGI on the inbound CPU to make sure it doesn't stall
-	 * in a possible WFI, such as in bL_power_down().
-	 */
-	gic_send_sgi(bL_gic_id[ib_cpu][ib_cluster], 0);
-
-	/*
-	 * Wait for the inbound to come up.  This allows for other
-	 * tasks to be scheduled in the mean time.
-	 */
-	wait_for_completion(&inbound_alive);
-	mcpm_set_early_poke(ib_cpu, ib_cluster, 0, 0);
-
-	/*
-	 * From this point we are entering the switch critical zone
-	 * and can't take any interrupts anymore.
-	 */
-	local_irq_disable();
-	local_fiq_disable();
-	trace_cpu_migrate_begin(get_ns(), ob_mpidr);
-
-	/* redirect GIC's SGIs to our counterpart */
-	gic_migrate_target(bL_gic_id[ib_cpu][ib_cluster]);
-
-	tdev = tick_get_device(this_cpu);
-	if (tdev && !cpumask_equal(tdev->evtdev->cpumask, cpumask_of(this_cpu)))
-		tdev = NULL;
-	if (tdev) {
-		tdev_mode = tdev->evtdev->mode;
-		clockevents_set_mode(tdev->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
-	}
-
-	ret = cpu_pm_enter();
-
-	/* we can not tolerate errors at this point */
-	if (ret)
-		panic("%s: cpu_pm_enter() returned %d\n", __func__, ret);
-
-	/* Swap the physical CPUs in the logical map for this logical CPU. */
-	cpu_logical_map(this_cpu) = ib_mpidr;
-	cpu_logical_map(that_cpu) = ob_mpidr;
-
-	/* Let's do the actual CPU switch. */
-	ret = cpu_suspend((unsigned long)&handshake_ptr, bL_switchpoint);
-	if (ret > 0)
-		panic("%s: cpu_suspend() returned %d\n", __func__, ret);
-
-	/* We are executing on the inbound CPU at this point */
-	mpidr = read_mpidr();
-	pr_debug("after switch: CPU %d MPIDR %#x\n", this_cpu, mpidr);
-	BUG_ON(mpidr != ib_mpidr);
-
-	mcpm_cpu_powered_up();
-
-	ret = cpu_pm_exit();
-
-	if (tdev) {
-		clockevents_set_mode(tdev->evtdev, tdev_mode);
-		clockevents_program_event(tdev->evtdev,
-					  tdev->evtdev->next_event, 1);
-	}
-
-	trace_cpu_migrate_finish(get_ns(), ib_mpidr);
-	local_fiq_enable();
-	local_irq_enable();
-
-	*handshake_ptr = 1;
-	dsb_sev();
-
-	if (ret)
-		pr_err("%s exiting with error %d\n", __func__, ret);
-	return ret;
-}
-
-struct bL_thread {
-	spinlock_t lock;
-	struct task_struct *task;
-	wait_queue_head_t wq;
-	int wanted_cluster;
-	struct completion started;
-	bL_switch_completion_handler completer;
-	void *completer_cookie;
-};
-
-static struct bL_thread bL_threads[NR_CPUS];
-
-static int bL_switcher_thread(void *arg)
-{
-	struct bL_thread *t = arg;
-	struct sched_param param = { .sched_priority = 1 };
-	int cluster;
-	bL_switch_completion_handler completer;
-	void *completer_cookie;
-
-	sched_setscheduler_nocheck(current, SCHED_FIFO, &param);
-	complete(&t->started);
-
-	do {
-		if (signal_pending(current))
-			flush_signals(current);
-		wait_event_interruptible(t->wq,
-				t->wanted_cluster != -1 ||
-				kthread_should_stop());
-
-		spin_lock(&t->lock);
-		cluster = t->wanted_cluster;
-		completer = t->completer;
-		completer_cookie = t->completer_cookie;
-		t->wanted_cluster = -1;
-		t->completer = NULL;
-		spin_unlock(&t->lock);
-
-		if (cluster != -1) {
-			bL_switch_to(cluster);
-
-			if (completer)
-				completer(completer_cookie);
-		}
-	} while (!kthread_should_stop());
-
-	return 0;
-}
-
-static struct task_struct *bL_switcher_thread_create(int cpu, void *arg)
-{
-	struct task_struct *task;
-
-	task = kthread_create_on_node(bL_switcher_thread, arg,
-				      cpu_to_node(cpu), "kswitcher_%d", cpu);
-	if (!IS_ERR(task)) {
-		kthread_bind(task, cpu);
-		wake_up_process(task);
-	} else
-		pr_err("%s failed for CPU %d\n", __func__, cpu);
-	return task;
-}
-
-/*
- * bL_switch_request_cb - Switch to a specific cluster for the given CPU,
- *      with completion notification via a callback
- *
- * @cpu: the CPU to switch
- * @new_cluster_id: the ID of the cluster to switch to.
- * @completer: switch completion callback.  if non-NULL,
- *	@completer(@completer_cookie) will be called on completion of
- *	the switch, in non-atomic context.
- * @completer_cookie: opaque context argument for @completer.
- *
- * This function causes a cluster switch on the given CPU by waking up
- * the appropriate switcher thread.  This function may or may not return
- * before the switch has occurred.
- *
- * If a @completer callback function is supplied, it will be called when
- * the switch is complete.  This can be used to determine asynchronously
- * when the switch is complete, regardless of when bL_switch_request()
- * returns.  When @completer is supplied, no new switch request is permitted
- * for the affected CPU until after the switch is complete, and @completer
- * has returned.
- */
-int bL_switch_request_cb(unsigned int cpu, unsigned int new_cluster_id,
-			 bL_switch_completion_handler completer,
-			 void *completer_cookie)
-{
-	struct bL_thread *t;
-
-	if (cpu >= ARRAY_SIZE(bL_threads)) {
-		pr_err("%s: cpu %d out of bounds\n", __func__, cpu);
-		return -EINVAL;
-	}
-
-	t = &bL_threads[cpu];
-
-	if (IS_ERR(t->task))
-		return PTR_ERR(t->task);
-	if (!t->task)
-		return -ESRCH;
-
-	spin_lock(&t->lock);
-	if (t->completer) {
-		spin_unlock(&t->lock);
-		return -EBUSY;
-	}
-	t->completer = completer;
-	t->completer_cookie = completer_cookie;
-	t->wanted_cluster = new_cluster_id;
-	spin_unlock(&t->lock);
-	wake_up(&t->wq);
-	return 0;
-}
-EXPORT_SYMBOL_GPL(bL_switch_request_cb);
-
-/*
- * Activation and configuration code.
- */
-
-static DEFINE_MUTEX(bL_switcher_activation_lock);
-static BLOCKING_NOTIFIER_HEAD(bL_activation_notifier);
-static unsigned int bL_switcher_active;
-static unsigned int bL_switcher_cpu_original_cluster[NR_CPUS];
-static cpumask_t bL_switcher_removed_logical_cpus;
-
-int bL_switcher_register_notifier(struct notifier_block *nb)
-{
-	return blocking_notifier_chain_register(&bL_activation_notifier, nb);
-}
-EXPORT_SYMBOL_GPL(bL_switcher_register_notifier);
-
-int bL_switcher_unregister_notifier(struct notifier_block *nb)
-{
-	return blocking_notifier_chain_unregister(&bL_activation_notifier, nb);
-}
-EXPORT_SYMBOL_GPL(bL_switcher_unregister_notifier);
-
-static int bL_activation_notify(unsigned long val)
-{
-	int ret;
-
-	ret = blocking_notifier_call_chain(&bL_activation_notifier, val, NULL);
-	if (ret & NOTIFY_STOP_MASK)
-		pr_err("%s: notifier chain failed with status 0x%x\n",
-			__func__, ret);
-	return notifier_to_errno(ret);
-}
-
-static void bL_switcher_restore_cpus(void)
-{
-	int i;
-
-	for_each_cpu(i, &bL_switcher_removed_logical_cpus)
-		cpu_up(i);
-}
-
-static int bL_switcher_halve_cpus(void)
-{
-	int i, j, cluster_0, gic_id, ret;
-	unsigned int cpu, cluster, mask;
-	cpumask_t available_cpus;
-
-	/* First pass to validate what we have */
-	mask = 0;
-	for_each_online_cpu(i) {
-		cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 0);
-		cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
-		if (cluster >= 2) {
-			pr_err("%s: only dual cluster systems are supported\n", __func__);
-			return -EINVAL;
-		}
-		if (WARN_ON(cpu >= MAX_CPUS_PER_CLUSTER))
-			return -EINVAL;
-		mask |= (1 << cluster);
-	}
-	if (mask != 3) {
-		pr_err("%s: no CPU pairing possible\n", __func__);
-		return -EINVAL;
-	}
-
-	/*
-	 * Now let's do the pairing.  We match each CPU with another CPU
-	 * from a different cluster.  To get a uniform scheduling behavior
-	 * without fiddling with CPU topology and compute capacity data,
-	 * we'll use logical CPUs initially belonging to the same cluster.
-	 */
-	memset(bL_switcher_cpu_pairing, -1, sizeof(bL_switcher_cpu_pairing));
-	cpumask_copy(&available_cpus, cpu_online_mask);
-	cluster_0 = -1;
-	for_each_cpu(i, &available_cpus) {
-		int match = -1;
-		cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
-		if (cluster_0 == -1)
-			cluster_0 = cluster;
-		if (cluster != cluster_0)
-			continue;
-		cpumask_clear_cpu(i, &available_cpus);
-		for_each_cpu(j, &available_cpus) {
-			cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(j), 1);
-			/*
-			 * Let's remember the last match to create "odd"
-			 * pairings on purpose in order for other code not
-			 * to assume any relation between physical and
-			 * logical CPU numbers.
-			 */
-			if (cluster != cluster_0)
-				match = j;
-		}
-		if (match != -1) {
-			bL_switcher_cpu_pairing[i] = match;
-			cpumask_clear_cpu(match, &available_cpus);
-			pr_info("CPU%d paired with CPU%d\n", i, match);
-		}
-	}
-
-	/*
-	 * Now we disable the unwanted CPUs i.e. everything that has no
-	 * pairing information (that includes the pairing counterparts).
-	 */
-	cpumask_clear(&bL_switcher_removed_logical_cpus);
-	for_each_online_cpu(i) {
-		cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 0);
-		cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(i), 1);
-
-		/* Let's take note of the GIC ID for this CPU */
-		gic_id = gic_get_cpu_id(i);
-		if (gic_id < 0) {
-			pr_err("%s: bad GIC ID for CPU %d\n", __func__, i);
-			bL_switcher_restore_cpus();
-			return -EINVAL;
-		}
-		bL_gic_id[cpu][cluster] = gic_id;
-		pr_info("GIC ID for CPU %u cluster %u is %u\n",
-			cpu, cluster, gic_id);
-
-		if (bL_switcher_cpu_pairing[i] != -1) {
-			bL_switcher_cpu_original_cluster[i] = cluster;
-			continue;
-		}
-
-		ret = cpu_down(i);
-		if (ret) {
-			bL_switcher_restore_cpus();
-			return ret;
-		}
-		cpumask_set_cpu(i, &bL_switcher_removed_logical_cpus);
-	}
-
-	return 0;
-}
-
-/* Determine the logical CPU a given physical CPU is grouped on. */
-int bL_switcher_get_logical_index(u32 mpidr)
-{
-	int cpu;
-
-	if (!bL_switcher_active)
-		return -EUNATCH;
-
-	mpidr &= MPIDR_HWID_BITMASK;
-	for_each_online_cpu(cpu) {
-		int pairing = bL_switcher_cpu_pairing[cpu];
-		if (pairing == -1)
-			continue;
-		if ((mpidr == cpu_logical_map(cpu)) ||
-		    (mpidr == cpu_logical_map(pairing)))
-			return cpu;
-	}
-	return -EINVAL;
-}
-
-static void bL_switcher_trace_trigger_cpu(void *__always_unused info)
-{
-	trace_cpu_migrate_current(get_ns(), read_mpidr());
-}
-
-int bL_switcher_trace_trigger(void)
-{
-	int ret;
-
-	preempt_disable();
-
-	bL_switcher_trace_trigger_cpu(NULL);
-	ret = smp_call_function(bL_switcher_trace_trigger_cpu, NULL, true);
-
-	preempt_enable();
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(bL_switcher_trace_trigger);
-
-static int bL_switcher_enable(void)
-{
-	int cpu, ret;
-
-	mutex_lock(&bL_switcher_activation_lock);
-	lock_device_hotplug();
-	if (bL_switcher_active) {
-		unlock_device_hotplug();
-		mutex_unlock(&bL_switcher_activation_lock);
-		return 0;
-	}
-
-	pr_info("big.LITTLE switcher initializing\n");
-
-	ret = bL_activation_notify(BL_NOTIFY_PRE_ENABLE);
-	if (ret)
-		goto error;
-
-	ret = bL_switcher_halve_cpus();
-	if (ret)
-		goto error;
-
-	bL_switcher_trace_trigger();
-
-	for_each_online_cpu(cpu) {
-		struct bL_thread *t = &bL_threads[cpu];
-		spin_lock_init(&t->lock);
-		init_waitqueue_head(&t->wq);
-		init_completion(&t->started);
-		t->wanted_cluster = -1;
-		t->task = bL_switcher_thread_create(cpu, t);
-	}
-
-	bL_switcher_active = 1;
-	bL_activation_notify(BL_NOTIFY_POST_ENABLE);
-	pr_info("big.LITTLE switcher initialized\n");
-	goto out;
-
-error:
-	pr_warn("big.LITTLE switcher initialization failed\n");
-	bL_activation_notify(BL_NOTIFY_POST_DISABLE);
-
-out:
-	unlock_device_hotplug();
-	mutex_unlock(&bL_switcher_activation_lock);
-	return ret;
-}
-
-#ifdef CONFIG_SYSFS
-
-static void bL_switcher_disable(void)
-{
-	unsigned int cpu, cluster;
-	struct bL_thread *t;
-	struct task_struct *task;
-
-	mutex_lock(&bL_switcher_activation_lock);
-	lock_device_hotplug();
-
-	if (!bL_switcher_active)
-		goto out;
-
-	if (bL_activation_notify(BL_NOTIFY_PRE_DISABLE) != 0) {
-		bL_activation_notify(BL_NOTIFY_POST_ENABLE);
-		goto out;
-	}
-
-	bL_switcher_active = 0;
-
-	/*
-	 * To deactivate the switcher, we must shut down the switcher
-	 * threads to prevent any other requests from being accepted.
-	 * Then, if the final cluster for given logical CPU is not the
-	 * same as the original one, we'll recreate a switcher thread
-	 * just for the purpose of switching the CPU back without any
-	 * possibility for interference from external requests.
-	 */
-	for_each_online_cpu(cpu) {
-		t = &bL_threads[cpu];
-		task = t->task;
-		t->task = NULL;
-		if (!task || IS_ERR(task))
-			continue;
-		kthread_stop(task);
-		/* no more switch may happen on this CPU at this point */
-		cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
-		if (cluster == bL_switcher_cpu_original_cluster[cpu])
-			continue;
-		init_completion(&t->started);
-		t->wanted_cluster = bL_switcher_cpu_original_cluster[cpu];
-		task = bL_switcher_thread_create(cpu, t);
-		if (!IS_ERR(task)) {
-			wait_for_completion(&t->started);
-			kthread_stop(task);
-			cluster = MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
-			if (cluster == bL_switcher_cpu_original_cluster[cpu])
-				continue;
-		}
-		/* If execution gets here, we're in trouble. */
-		pr_crit("%s: unable to restore original cluster for CPU %d\n",
-			__func__, cpu);
-		pr_crit("%s: CPU %d can't be restored\n",
-			__func__, bL_switcher_cpu_pairing[cpu]);
-		cpumask_clear_cpu(bL_switcher_cpu_pairing[cpu],
-				  &bL_switcher_removed_logical_cpus);
-	}
-
-	bL_switcher_restore_cpus();
-	bL_switcher_trace_trigger();
-
-	bL_activation_notify(BL_NOTIFY_POST_DISABLE);
-
-out:
-	unlock_device_hotplug();
-	mutex_unlock(&bL_switcher_activation_lock);
-}
-
-static ssize_t bL_switcher_active_show(struct kobject *kobj,
-		struct kobj_attribute *attr, char *buf)
-{
-	return sprintf(buf, "%u\n", bL_switcher_active);
-}
-
-static ssize_t bL_switcher_active_store(struct kobject *kobj,
-		struct kobj_attribute *attr, const char *buf, size_t count)
-{
-	int ret;
-
-	switch (buf[0]) {
-	case '0':
-		bL_switcher_disable();
-		ret = 0;
-		break;
-	case '1':
-		ret = bL_switcher_enable();
-		break;
-	default:
-		ret = -EINVAL;
-	}
-
-	return (ret >= 0) ? count : ret;
-}
-
-static ssize_t bL_switcher_trace_trigger_store(struct kobject *kobj,
-		struct kobj_attribute *attr, const char *buf, size_t count)
-{
-	int ret = bL_switcher_trace_trigger();
-
-	return ret ? ret : count;
-}
-
-static struct kobj_attribute bL_switcher_active_attr =
-	__ATTR(active, 0644, bL_switcher_active_show, bL_switcher_active_store);
-
-static struct kobj_attribute bL_switcher_trace_trigger_attr =
-	__ATTR(trace_trigger, 0200, NULL, bL_switcher_trace_trigger_store);
-
-static struct attribute *bL_switcher_attrs[] = {
-	&bL_switcher_active_attr.attr,
-	&bL_switcher_trace_trigger_attr.attr,
-	NULL,
-};
-
-static struct attribute_group bL_switcher_attr_group = {
-	.attrs = bL_switcher_attrs,
-};
-
-static struct kobject *bL_switcher_kobj;
-
-static int __init bL_switcher_sysfs_init(void)
-{
-	int ret;
-
-	bL_switcher_kobj = kobject_create_and_add("bL_switcher", kernel_kobj);
-	if (!bL_switcher_kobj)
-		return -ENOMEM;
-	ret = sysfs_create_group(bL_switcher_kobj, &bL_switcher_attr_group);
-	if (ret)
-		kobject_put(bL_switcher_kobj);
-	return ret;
-}
-
-#endif  /* CONFIG_SYSFS */
-
-bool bL_switcher_get_enabled(void)
-{
-	mutex_lock(&bL_switcher_activation_lock);
-
-	return bL_switcher_active;
-}
-EXPORT_SYMBOL_GPL(bL_switcher_get_enabled);
-
-void bL_switcher_put_enabled(void)
-{
-	mutex_unlock(&bL_switcher_activation_lock);
-}
-EXPORT_SYMBOL_GPL(bL_switcher_put_enabled);
-
-/*
- * Veto any CPU hotplug operation on those CPUs we've removed
- * while the switcher is active.
- * We're just not ready to deal with that given the trickery involved.
- */
-static int bL_switcher_hotplug_callback(struct notifier_block *nfb,
-					unsigned long action, void *hcpu)
-{
-	if (bL_switcher_active) {
-		int pairing = bL_switcher_cpu_pairing[(unsigned long)hcpu];
-		switch (action & 0xf) {
-		case CPU_UP_PREPARE:
-		case CPU_DOWN_PREPARE:
-			if (pairing == -1)
-				return NOTIFY_BAD;
-		}
-	}
-	return NOTIFY_DONE;
-}
-
-static bool no_bL_switcher;
-core_param(no_bL_switcher, no_bL_switcher, bool, 0644);
-
-static int __init bL_switcher_init(void)
-{
-	int ret;
-
-	if (MAX_NR_CLUSTERS != 2) {
-		pr_err("%s: only dual cluster systems are supported\n", __func__);
-		return -EINVAL;
-	}
-
-	cpu_notifier(bL_switcher_hotplug_callback, 0);
-
-	if (!no_bL_switcher) {
-		ret = bL_switcher_enable();
-		if (ret)
-			return ret;
-	}
-
-#ifdef CONFIG_SYSFS
-	ret = bL_switcher_sysfs_init();
-	if (ret)
-		pr_err("%s: unable to create sysfs entry\n", __func__);
-#endif
-
-	return 0;
-}
-
-late_initcall(bL_switcher_init);