oolong/mali_kbase_pm.c

/*
 *
 * (C) COPYRIGHT 2010-2015 ARM Limited. All rights reserved.
 *
 * This program is free software and is provided to you under the terms of the
 * GNU General Public License version 2 as published by the Free Software
 * Foundation, and any use by you of this program is subject to the terms
 * of such GNU licence.
 *
 * A copy of the licence is included with the program, and can also be obtained
 * from Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301, USA.
 *
 */

/**
 * @file mali_kbase_pm.c
 * Base kernel power management APIs
 */
#include <mali_kbase.h>
#include <mali_midg_regmap.h>
#include <mali_kbase_config_defaults.h>
#include <mali_kbase_instr.h>

#include <mali_kbase_pm.h>

int kbase_pm_powerup(struct kbase_device *kbdev, unsigned int flags)
{
	return kbase_hwaccess_pm_powerup(kbdev, flags);
}

void kbase_pm_halt(struct kbase_device *kbdev)
{
	kbase_hwaccess_pm_halt(kbdev);
}

void kbase_pm_context_active(struct kbase_device *kbdev)
{
	(void)kbase_pm_context_active_handle_suspend(kbdev, KBASE_PM_SUSPEND_HANDLER_NOT_POSSIBLE);
}

int kbase_pm_context_active_handle_suspend(struct kbase_device *kbdev, enum kbase_pm_suspend_handler suspend_handler)
{
	struct kbasep_js_device_data *js_devdata = &kbdev->js_data;
	int c;
	int old_count;

	KBASE_DEBUG_ASSERT(kbdev != NULL);

	/* Trace timeline information about how long it took to handle the decision
	 * to powerup. Sometimes the event might be missed due to reading the count
	 * outside of mutex, but this is necessary to get the trace timing
	 * correct. */
	old_count = kbdev->pm.active_count;
	if (old_count == 0)
		kbase_timeline_pm_send_event(kbdev, KBASE_TIMELINE_PM_EVENT_GPU_ACTIVE);

	mutex_lock(&js_devdata->runpool_mutex);
	mutex_lock(&kbdev->pm.lock);
	if (kbase_pm_is_suspending(kbdev)) {
		switch (suspend_handler) {
		case KBASE_PM_SUSPEND_HANDLER_DONT_REACTIVATE:
			if (kbdev->pm.active_count != 0)
				break;
			/* FALLTHROUGH */
		case KBASE_PM_SUSPEND_HANDLER_DONT_INCREASE:
			mutex_unlock(&kbdev->pm.lock);
			mutex_unlock(&js_devdata->runpool_mutex);
			if (old_count == 0)
				kbase_timeline_pm_handle_event(kbdev, KBASE_TIMELINE_PM_EVENT_GPU_ACTIVE);
			return 1;

		case KBASE_PM_SUSPEND_HANDLER_NOT_POSSIBLE:
			/* FALLTHROUGH */
		default:
			KBASE_DEBUG_ASSERT_MSG(false, "unreachable");
			break;
		}
	}
	c = ++kbdev->pm.active_count;
	KBASE_TIMELINE_CONTEXT_ACTIVE(kbdev, c);
	KBASE_TRACE_ADD_REFCOUNT(kbdev, PM_CONTEXT_ACTIVE, NULL, NULL, 0u, c);

	/* Trace the event being handled */
	if (old_count == 0)
		kbase_timeline_pm_handle_event(kbdev, KBASE_TIMELINE_PM_EVENT_GPU_ACTIVE);

	if (c == 1)
		/* First context active: Power on the GPU and any cores requested by
		 * the policy */
		kbase_hwaccess_pm_gpu_active(kbdev);

	mutex_unlock(&kbdev->pm.lock);
	mutex_unlock(&js_devdata->runpool_mutex);

	return 0;
}

void kbase_pm_context_idle(struct kbase_device *kbdev)
{
	struct kbasep_js_device_data *js_devdata = &kbdev->js_data;
	int c;
	int old_count;

	KBASE_DEBUG_ASSERT(kbdev != NULL);

	/* Trace timeline information about how long it took to handle the decision
	 * to powerdown. Sometimes the event might be missed due to reading the
	 * count outside of mutex, but this is necessary to get the trace timing
	 * correct. */
	old_count = kbdev->pm.active_count;
	if (old_count == 0)
		kbase_timeline_pm_send_event(kbdev, KBASE_TIMELINE_PM_EVENT_GPU_IDLE);

	mutex_lock(&js_devdata->runpool_mutex);
	mutex_lock(&kbdev->pm.lock);

	c = --kbdev->pm.active_count;
	KBASE_TIMELINE_CONTEXT_ACTIVE(kbdev, c);
	KBASE_TRACE_ADD_REFCOUNT(kbdev, PM_CONTEXT_IDLE, NULL, NULL, 0u, c);

	KBASE_DEBUG_ASSERT(c >= 0);

	/* Trace the event being handled */
	if (old_count == 0)
		kbase_timeline_pm_handle_event(kbdev, KBASE_TIMELINE_PM_EVENT_GPU_IDLE);

	if (c == 0) {
		/* Last context has gone idle */
		kbase_hwaccess_pm_gpu_idle(kbdev);

		/* Wake up anyone waiting for this to become 0 (e.g. suspend). The
		 * waiters must synchronize with us by locking the pm.lock after
		 * waiting */
		wake_up(&kbdev->pm.zero_active_count_wait);
	}

	mutex_unlock(&kbdev->pm.lock);
	mutex_unlock(&js_devdata->runpool_mutex);
}

void kbase_pm_suspend(struct kbase_device *kbdev)
{
	KBASE_DEBUG_ASSERT(kbdev);

	mutex_lock(&kbdev->pm.lock);
	KBASE_DEBUG_ASSERT(!kbase_pm_is_suspending(kbdev));
	kbdev->pm.suspending = true;
	mutex_unlock(&kbdev->pm.lock);

	/* From now on, the active count will drop towards zero. Sometimes, it'll
	 * go up briefly before going down again. However, once it reaches zero it
	 * will stay there - guaranteeing that we've idled all pm references */

	/* Suspend job scheduler and associated components, so that it releases all
	 * the PM active count references */
	kbasep_js_suspend(kbdev);

	/* Suspend any counter collection that might be happening */
	kbase_instr_hwcnt_suspend(kbdev);

	/* Wait for the active count to reach zero. This is not the same as
	 * waiting for a power down, since not all policies power down when this
	 * reaches zero. */
	wait_event(kbdev->pm.zero_active_count_wait, kbdev->pm.active_count == 0);

	/* NOTE: We synchronize with anything that was just finishing a
	 * kbase_pm_context_idle() call by locking the pm.lock below */

	kbase_hwaccess_pm_suspend(kbdev);
}

void kbase_pm_resume(struct kbase_device *kbdev)
{
	/* MUST happen before any pm_context_active calls occur */
	kbase_hwaccess_pm_resume(kbdev);

	/* Initial active call, to power on the GPU/cores if needed */
	kbase_pm_context_active(kbdev);

	/* Re-enable instrumentation, if it was previously disabled */
	kbase_instr_hwcnt_resume(kbdev);

	/* Resume any blocked atoms (which may cause contexts to be scheduled in
	 * and dependent atoms to run) */
	kbase_resume_suspended_soft_jobs(kbdev);

	/* Resume the Job Scheduler and associated components, and start running
	 * atoms */
	kbasep_js_resume(kbdev);

	/* Matching idle call, to power off the GPU/cores if we didn't actually
	 * need it and the policy doesn't want it on */
	kbase_pm_context_idle(kbdev);
}