path: root/drivers/gpu/arm/t6xx/kbase/src/common/mali_kbase_js.h

/*
 *
 * (C) COPYRIGHT 2011-2013 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_js.h
 * Job Scheduler APIs.
 */

#ifndef _KBASE_JS_H_
#define _KBASE_JS_H_

#include <malisw/mali_malisw.h>

#include "mali_kbase_js_defs.h"
#include "mali_kbase_js_policy.h"
#include "mali_kbase_defs.h"

#include "mali_kbase_js_ctx_attr.h"

/**
 * @addtogroup base_api
 * @{
 */

/**
 * @addtogroup base_kbase_api
 * @{
 */

/**
 * @addtogroup kbase_js Job Scheduler Internal APIs
 * @{
 *
 * These APIs are Internal to KBase and are available for use by the
 * @ref kbase_js_policy "Job Scheduler Policy APIs"
 */

/**
 * @brief Initialize the Job Scheduler
 *
 * The kbasep_js_device_data sub-structure of \a kbdev must be zero
 * initialized before passing to the kbasep_js_devdata_init() function. This is
 * to give efficient error path code.
 */
mali_error kbasep_js_devdata_init(kbase_device * const kbdev);

/**
 * @brief Halt the Job Scheduler.
 *
 * It is safe to call this on \a kbdev even if it the kbasep_js_device_data
 * sub-structure was never initialized/failed initialization, to give efficient
 * error-path code.
 *
 * For this to work, the kbasep_js_device_data sub-structure of \a kbdev must
 * be zero initialized before passing to the kbasep_js_devdata_init()
 * function. This is to give efficient error path code.
 *
 * It is a Programming Error to call this whilst there are still kbase_context
 * structures registered with this scheduler.
 *
 */
void kbasep_js_devdata_halt(kbase_device *kbdev);

/**
 * @brief Terminate the Job Scheduler
 *
 * It is safe to call this on \a kbdev even if it the kbasep_js_device_data
 * sub-structure was never initialized/failed initialization, to give efficient
 * error-path code.
 *
 * For this to work, the kbasep_js_device_data sub-structure of \a kbdev must
 * be zero initialized before passing to the kbasep_js_devdata_init()
 * function. This is to give efficient error path code.
 *
 * It is a Programming Error to call this whilst there are still kbase_context
 * structures registered with this scheduler.
 */
void kbasep_js_devdata_term(kbase_device *kbdev);

/**
 * @brief Initialize the Scheduling Component of a kbase_context on the Job Scheduler.
 *
 * This effectively registers a kbase_context with a Job Scheduler.
 *
 * It does not register any jobs owned by the kbase_context with the scheduler.
 * Those must be separately registered by kbasep_js_add_job().
 *
 * The kbase_context must be zero intitialized before passing to the
 * kbase_js_init() function. This is to give efficient error path code.
 */
mali_error kbasep_js_kctx_init(kbase_context * const kctx);

/**
 * @brief Terminate the Scheduling Component of a kbase_context on the Job Scheduler
 *
 * This effectively de-registers a kbase_context from its Job Scheduler
 *
 * It is safe to call this on a kbase_context that has never had or failed
 * initialization of its jctx.sched_info member, to give efficient error-path
 * code.
 *
 * For this to work, the kbase_context must be zero intitialized before passing
 * to the kbase_js_init() function.
 *
 * It is a Programming Error to call this whilst there are still jobs
 * registered with this context.
 */
void kbasep_js_kctx_term(kbase_context *kctx);

/**
 * @brief Add a job chain to the Job Scheduler, and take necessary actions to
 * schedule the context/run the job.
 *
 * This atomically does the following:
 * - Update the numbers of jobs information
 * - Add the job to the run pool if necessary (part of init_job)
 *
 * Once this is done, then an appropriate action is taken:
 * - If the ctx is scheduled, it attempts to start the next job (which might be
 * this added job)
 * - Otherwise, and if this is the first job on the context, it enqueues it on
 * the Policy Queue
 *
 * The Policy's Queue can be updated by this in the following ways:
 * - In the above case that this is the first job on the context
 * - If the job is high priority and the context is not scheduled, then it
 * could cause the Policy to schedule out a low-priority context, allowing
 * this context to be scheduled in.
 *
 * If the context is already scheduled on the RunPool, then adding a job to it
 * is guarenteed not to update the Policy Queue. And so, the caller is
 * guarenteed to not need to try scheduling a context from the Run Pool - it
 * can safely assert that the result is MALI_FALSE.
 *
 * It is a programming error to have more than U32_MAX jobs in flight at a time.
 *
 * The following locking conditions are made on the caller:
 * - it must \em not hold kbasep_js_kctx_info::ctx::jsctx_mutex.
 * - it must \em not hold kbasep_js_device_data::runpool_irq::lock (as this will be
 * obtained internally)
 * - it must \em not hold kbasep_js_device_data::runpool_mutex (as this will be
 * obtained internally)
 * - it must \em not hold kbasep_jd_device_data::queue_mutex (again, it's used internally).
 *
 * @return MALI_TRUE indicates that the Policy Queue was updated, and so the
 * caller will need to try scheduling a context onto the Run Pool.
 * @return MALI_FALSE indicates that no updates were made to the Policy Queue,
 * so no further action is required from the caller. This is \b always returned
 * when the context is currently scheduled.
 */
mali_bool kbasep_js_add_job(kbase_context *kctx, kbase_jd_atom *atom);

/**
 * @brief Remove a job chain from the Job Scheduler, except for its 'retained state'.
 *
 * Completely removing a job requires several calls:
 * - kbasep_js_copy_atom_retained_state(), to capture the 'retained state' of
 *   the atom
 * - kbasep_js_remove_job(), to partially remove the atom from the Job Scheduler
 * - kbasep_js_runpool_release_ctx_and_katom_retained_state(), to release the
 *   remaining state held as part of the job having been run.
 *
 * In the common case of atoms completing normally, this set of actions is more optimal for spinlock purposes than having kbasep_js_remove_job() handle all of the actions.
 *
 * In the case of cancelling atoms, it is easier to call kbasep_js_remove_cancelled_job(), which handles all the necessary actions.
 *
 * It is a programming error to call this when:
 * - \a atom is not a job belonging to kctx.
 * - \a atom has already been removed from the Job Scheduler.
 * - \a atom is still in the runpool:
 *  - it has not been removed with kbasep_js_policy_dequeue_job()
 *  - or, it has not been removed with kbasep_js_policy_dequeue_job_irq()
 *
 * Do not use this for removing jobs being killed by kbase_jd_cancel() - use
 * kbasep_js_remove_cancelled_job() instead.
 *
 * The following locking conditions are made on the caller:
 * - it must hold kbasep_js_kctx_info::ctx::jsctx_mutex.
 *
 */
void kbasep_js_remove_job(kbase_device *kbdev, kbase_context *kctx, kbase_jd_atom *atom);

/**
 * @brief Completely remove a job chain from the Job Scheduler, in the case
 * where the job chain was cancelled.
 *
 * This is a variant of kbasep_js_remove_job() that takes care of removing all
 * of the retained state too. This is generally useful for cancelled atoms,
 * which need not be handled in an optimal way.
 *
 * It is a programming error to call this when:
 * - \a atom is not a job belonging to kctx.
 * - \a atom has already been removed from the Job Scheduler.
 * - \a atom is still in the runpool:
 *  - it is not being killed with kbasep_jd_cancel()
 *  - or, it has not been removed with kbasep_js_policy_dequeue_job()
 *  - or, it has not been removed with kbasep_js_policy_dequeue_job_irq()
 *
 * The following locking conditions are made on the caller:
 * - it must hold kbasep_js_kctx_info::ctx::jsctx_mutex.
 * - it must \em not hold the kbasep_js_device_data::runpool_irq::lock, (as this will be
 * obtained internally)
 * - it must \em not hold kbasep_js_device_data::runpool_mutex (as this could be
 * obtained internally)
 */
void kbasep_js_remove_cancelled_job(kbase_device *kbdev, kbase_context *kctx, kbase_jd_atom *katom);

/**
 * @brief Refcount a context as being busy, preventing it from being scheduled
 * out.
 *
 * @note This function can safely be called from IRQ context.
 *
 * The following locking conditions are made on the caller:
 * - it must \em not hold the kbasep_js_device_data::runpool_irq::lock, because
 * it will be used internally.
 *
 * @return value != MALI_FALSE if the retain succeeded, and the context will not be scheduled out.
 * @return MALI_FALSE if the retain failed (because the context is being/has been scheduled out).
 */
mali_bool kbasep_js_runpool_retain_ctx(kbase_device *kbdev, kbase_context *kctx);

/**
 * @brief Refcount a context as being busy, preventing it from being scheduled
 * out.
 *
 * @note This function can safely be called from IRQ context.
 *
 * The following locks must be held by the caller:
 * - kbasep_js_device_data::runpool_irq::lock
 *
 * @return value != MALI_FALSE if the retain succeeded, and the context will not be scheduled out.
 * @return MALI_FALSE if the retain failed (because the context is being/has been scheduled out).
 */
mali_bool kbasep_js_runpool_retain_ctx_nolock(kbase_device *kbdev, kbase_context *kctx);

/**
 * @brief Lookup a context in the Run Pool based upon its current address space
 * and ensure that is stays scheduled in.
 *
 * The context is refcounted as being busy to prevent it from scheduling
 * out. It must be released with kbasep_js_runpool_release_ctx() when it is no
 * longer required to stay scheduled in.
 *
 * @note This function can safely be called from IRQ context.
 *
 * The following locking conditions are made on the caller:
 * - it must \em not hold the kbasep_js_device_data::runpoool_irq::lock, because
 * it will be used internally.
 *
 * @return a valid kbase_context on success, which has been refcounted as being busy.
 * @return NULL on failure, indicating that no context was found in \a as_nr
 */
kbase_context *kbasep_js_runpool_lookup_ctx(kbase_device *kbdev, int as_nr);

/**
 * @brief Handling the requeuing/killing of a context that was evicted from the
 * policy queue or runpool.
 *
 * This should be used whenever handing off a context that has been evicted
 * from the policy queue or the runpool:
 * - If the context is not dying and has jobs, it gets re-added to the policy
 * queue
 * - Otherwise, it is not added
 *
 * In addition, if the context is dying the jobs are killed asynchronously.
 *
 * In all cases, the Power Manager active reference is released
 * (kbase_pm_context_idle()) whenever the has_pm_ref parameter is true.  \a
 * has_pm_ref must be set to false whenever the context was not previously in
 * the runpool and does not hold a Power Manager active refcount. Note that
 * contexts in a rollback of kbasep_js_try_schedule_head_ctx() might have an
 * active refcount even though they weren't in the runpool.
 *
 * The following locking conditions are made on the caller:
 * - it must hold kbasep_js_kctx_info::ctx::jsctx_mutex.
 * - it must \em not hold kbasep_jd_device_data::queue_mutex (as this will be
 * obtained internally)
 */
void kbasep_js_runpool_requeue_or_kill_ctx(kbase_device *kbdev, kbase_context *kctx, mali_bool has_pm_ref);

/**
 * @brief Release a refcount of a context being busy, allowing it to be
 * scheduled out.
 *
 * When the refcount reaches zero and the context \em might be scheduled out
 * (depending on whether the Scheudling Policy has deemed it so, or if it has run
 * out of jobs).
 *
 * If the context does get scheduled out, then The following actions will be
 * taken as part of deschduling a context:
 * - For the context being descheduled:
 *  - If the context is in the processing of dying (all the jobs are being
 * removed from it), then descheduling also kills off any jobs remaining in the
 * context.
 *  - If the context is not dying, and any jobs remain after descheduling the
 * context then it is re-enqueued to the Policy's Queue.
 *  - Otherwise, the context is still known to the scheduler, but remains absent
 * from the Policy Queue until a job is next added to it.
 *  - In all descheduling cases, the Power Manager active reference (obtained
 * during kbasep_js_try_schedule_head_ctx()) is released (kbase_pm_context_idle()).
 *
 * Whilst the context is being descheduled, this also handles actions that
 * cause more atoms to be run:
 * - Attempt submitting atoms when the Context Attributes on the Runpool have
 * changed. This is because the context being scheduled out could mean that
 * there are more opportunities to run atoms.
 * - Attempt submitting to a slot that was previously blocked due to affinity
 * restrictions. This is usually only necessary when releasing a context
 * happens as part of completing a previous job, but is harmless nonetheless.
 * - Attempt scheduling in a new context (if one is available), and if necessary,
 * running a job from that new context.
 *
 * Unlike retaining a context in the runpool, this function \b cannot be called
 * from IRQ context.
 *
 * It is a programming error to call this on a \a kctx that is not currently
 * scheduled, or that already has a zero refcount.
 *
 * The following locking conditions are made on the caller:
 * - it must \em not hold the kbasep_js_device_data::runpool_irq::lock, because
 * it will be used internally.
 * - it must \em not hold kbasep_js_kctx_info::ctx::jsctx_mutex.
 * - it must \em not hold kbasep_js_device_data::runpool_mutex (as this will be
 * obtained internally)
 * - it must \em not hold the kbase_device::as[n].transaction_mutex (as this will be obtained internally)
 * - it must \em not hold kbasep_jd_device_data::queue_mutex (as this will be
 * obtained internally)
 *
 */
void kbasep_js_runpool_release_ctx(kbase_device *kbdev, kbase_context *kctx);

/**
 * @brief Variant of kbasep_js_runpool_release_ctx() that handles additional
 * actions from completing an atom.
 *
 * This is usually called as part of completing an atom and releasing the
 * refcount on the context held by the atom.
 *
 * Therefore, the extra actions carried out are part of handling actions queued
 * on a completed atom, namely:
 * - Releasing the atom's context attributes
 * - Retrying the submission on a particular slot, because we couldn't submit
 * on that slot from an IRQ handler.
 *
 * The locking conditions of this function are the same as those for
 * kbasep_js_runpool_release_ctx()
 */
void kbasep_js_runpool_release_ctx_and_katom_retained_state(kbase_device *kbdev, kbase_context *kctx, kbasep_js_atom_retained_state *katom_retained_state);

/**
 * @brief Try to submit the next job on a \b particular slot whilst in IRQ
 * context, and whilst the caller already holds the runpool IRQ spinlock.
 *
 * \a *submit_count will be checked against
 * KBASE_JS_MAX_JOB_SUBMIT_PER_SLOT_PER_IRQ to see whether too many jobs have
 * been submitted. This is to prevent the IRQ handler looping over lots of GPU
 * NULL jobs, which may complete whilst the IRQ handler is still processing. \a
 * submit_count itself should point to kbase_device::slot_submit_count_irq[ \a js ],
 * which is initialized to zero on entry to the IRQ handler.
 *
 * The following locks must be held by the caller:
 * - kbasep_js_device_data::runpool_irq::lock
 *
 * @return truthful (i.e. != MALI_FALSE) if too many jobs were submitted from
 * IRQ. Therefore, this indicates that submission should be retried from a
 * work-queue, by using
 * kbasep_js_try_run_next_job_on_slot_nolock()/kbase_js_try_run_jobs_on_slot().
 * @return MALI_FALSE if submission had no problems: the GPU is either already
 * full of jobs in the HEAD and NEXT registers, or we were able to get enough
 * jobs from the Run Pool to fill the GPU's HEAD and NEXT registers.
 */
mali_bool kbasep_js_try_run_next_job_on_slot_irq_nolock(kbase_device *kbdev, int js, s8 *submit_count);

/**
 * @brief Try to submit the next job on a particular slot, outside of IRQ context
 *
 * This obtains the Job Slot lock for the duration of the call only.
 *
 * Unlike kbasep_js_try_run_next_job_on_slot_irq_nolock(), there is no limit on
 * submission, because eventually IRQ_THROTTLE will kick in to prevent us
 * getting stuck in a loop of submitting GPU NULL jobs. This is because the IRQ
 * handler will be delayed, and so this function will eventually fill up the
 * space in our software 'submitted' slot (kbase_jm_slot::submitted).
 *
 * In addition, there's no return value - we'll run the maintenence functions
 * on the Policy's Run Pool, but if there's nothing there after that, then the
 * Run Pool is truely empty, and so no more action need be taken.
 *
 * The following locking conditions are made on the caller:
 * - it must hold kbasep_js_device_data::runpool_mutex
 * - it must hold kbasep_js_device_data::runpool_irq::lock
 *
 * This must only be called whilst the GPU is powered - for example, when
 * kbdev->jsdata.nr_user_contexts_running > 0.
 *
 * @note The caller \em might be holding one of the
 * kbasep_js_kctx_info::ctx::jsctx_mutex locks.
 *
 */
void kbasep_js_try_run_next_job_on_slot_nolock(kbase_device *kbdev, int js);

/**
 * @brief Try to submit the next job for each slot in the system, outside of IRQ context
 *
 * This will internally call kbasep_js_try_run_next_job_on_slot_nolock(), so similar
 * locking conditions on the caller are required.
 *
 * The following locking conditions are made on the caller:
 * - it must hold kbasep_js_device_data::runpool_mutex
 * - it must hold kbasep_js_device_data::runpool_irq::lock
 *
 * @note The caller \em might be holding one of the
 * kbasep_js_kctx_info::ctx::jsctx_mutex locks.
 *
 */
void kbasep_js_try_run_next_job_nolock(kbase_device *kbdev);

/**
 * @brief Try to schedule the next context onto the Run Pool
 *
 * This checks whether there's space in the Run Pool to accommodate a new
 * context. If so, it attempts to dequeue a context from the Policy Queue, and
 * submit this to the Run Pool.
 *
 * If the scheduling succeeds, then it also makes a call to
 * kbasep_js_try_run_next_job_nolock(), in case the new context has jobs
 * matching the job slot requirements, but no other currently scheduled context
 * has such jobs.
 *
 * Whilst attempting to obtain a context from the policy queue, or add a
 * context to the runpool, this function takes a Power Manager active
 * reference. If for any reason a context cannot be added to the runpool, any
 * reference obtained is released once the context is safely back in the policy
 * queue. If no context was available on the policy queue, any reference
 * obtained is released too.
 *
 * Only if the context gets placed in the runpool does the Power Manager active
 * reference stay held (and is effectively now owned by the
 * context/runpool). It is only released once the context is removed
 * completely, or added back to the policy queue
 * (e.g. kbasep_js_runpool_release_ctx(),
 * kbasep_js_runpool_requeue_or_kill_ctx(), etc)
 *
 * If any of these actions fail (Run Pool Full, Policy Queue empty, can't get
 * PM active reference due to a suspend, etc) then any actions taken are rolled
 * back and the function just returns normally.
 *
 * The following locking conditions are made on the caller:
 * - it must \em not hold the kbasep_js_device_data::runpool_irq::lock, because
 * it will be used internally.
 * - it must \em not hold kbasep_js_device_data::runpool_mutex (as this will be
 * obtained internally)
 * - it must \em not hold the kbase_device::as[n].transaction_mutex (as this will be obtained internally)
 * - it must \em not hold kbasep_jd_device_data::queue_mutex (again, it's used internally).
 * - it must \em not hold kbasep_js_kctx_info::ctx::jsctx_mutex, because it will
 * be used internally.
 *
 */
void kbasep_js_try_schedule_head_ctx(kbase_device *kbdev);

/**
 * @brief Schedule in a privileged context
 *
 * This schedules a context in regardless of the context priority.
 * If the runpool is full, a context will be forced out of the runpool and the function will wait
 * for the new context to be scheduled in.
 * The context will be kept scheduled in (and the corresponding address space reserved) until
 * kbasep_js_release_privileged_ctx is called).
 *
 * The following locking conditions are made on the caller:
 * - it must \em not hold the kbasep_js_device_data::runpool_irq::lock, because
 * it will be used internally.
 * - it must \em not hold kbasep_js_device_data::runpool_mutex (as this will be
 * obtained internally)
 * - it must \em not hold the kbase_device::as[n].transaction_mutex (as this will be obtained internally)
 * - it must \em not hold kbasep_jd_device_data::queue_mutex (again, it's used internally).
 * - it must \em not hold kbasep_js_kctx_info::ctx::jsctx_mutex, because it will
 * be used internally.
 *
 */
void kbasep_js_schedule_privileged_ctx(kbase_device *kbdev, kbase_context *kctx);

/**
 * @brief Release a privileged context, allowing it to be scheduled out.
 *
 * See kbasep_js_runpool_release_ctx for potential side effects.
 *
 * The following locking conditions are made on the caller:
 * - it must \em not hold the kbasep_js_device_data::runpool_irq::lock, because
 * it will be used internally.
 * - it must \em not hold kbasep_js_kctx_info::ctx::jsctx_mutex.
 * - it must \em not hold kbasep_js_device_data::runpool_mutex (as this will be
 * obtained internally)
 * - it must \em not hold the kbase_device::as[n].transaction_mutex (as this will be obtained internally)
 *
 */
void kbasep_js_release_privileged_ctx(kbase_device *kbdev, kbase_context *kctx);

/**
 * @brief Handle the Job Scheduler component for the IRQ of a job finishing
 *
 * This does the following:
 * -# Releases resources held by the atom
 * -# if \a end_timestamp != NULL, updates the runpool's notion of time spent by a running ctx
 * -# determines whether a context should be marked for scheduling out
 * -# examines done_code to determine whether to submit the next job on the slot
 * (picking from all ctxs in the runpool)
 *
 * In addition, if submission didn't happen (the submit-from-IRQ function
 * failed or done_code didn't specify to start new jobs), then this sets a
 * message on katom that submission needs to be retried from the worker thread.
 *
 * Normally, the time calculated from end_timestamp is rounded up to the
 * minimum time precision. Therefore, to ensure the job is recorded as not
 * spending any time, then set end_timestamp to NULL. For example, this is necessary when
 * evicting jobs from JSn_HEAD_NEXT (because they didn't actually run).
 *
 * NOTE: It's possible to move the steps (2) and (3) (inc calculating job's time
 * used) into the worker (outside of IRQ context), but this may allow a context
 * to use up to twice as much timeslice as is allowed by the policy. For
 * policies that order by time spent, this is not a problem for overall
 * 'fairness', but can still increase latency between contexts.
 *
 * The following locking conditions are made on the caller:
 * - it must hold kbasep_js_device_data::runpoool_irq::lock
 */
void kbasep_js_job_done_slot_irq(kbase_jd_atom *katom, int slot_nr,
                                 ktime_t *end_timestamp,
                                 kbasep_js_atom_done_code done_code);

/**
 * @brief Try to submit the next job on each slot
 *
 * The following locks may be used:
 * - kbasep_js_device_data::runpool_mutex
 * - kbasep_js_device_data::runpool_irq::lock
 */
void kbase_js_try_run_jobs(kbase_device *kbdev);

/**
 * @brief Try to submit the next job on a specfic slot
 *
 * The following locking conditions are made on the caller:
 *
 * - it must \em not hold kbasep_js_device_data::runpool_mutex (as this will be
 * obtained internally)
 * - it must \em not hold kbasep_js_device_data::runpool_irq::lock (as this
 * will be obtained internally)
 *
 */
void kbase_js_try_run_jobs_on_slot(kbase_device *kbdev, int js);

/**
 * @brief Handle releasing cores for power management and affinity management,
 * ensuring that cores are powered down and affinity tracking is updated.
 *
 * This must only be called on an atom that is not currently running, and has
 * not been re-queued onto the context (and so does not need locking)
 *
 * This function enters at the following @ref kbase_atom_coreref_state states:
 * - NO_CORES_REQUESTED
 * - WAITING_FOR_REQUESTED_CORES
 * - RECHECK_AFFINITY
 * - READY
 *
 * It transitions the above states back to NO_CORES_REQUESTED by the end of the
 * function call (possibly via intermediate states).
 *
 * No locks need be held by the caller, since this takes the necessary Power
 * Management locks itself. The runpool_irq.lock is not taken (the work that
 * requires it is handled by kbase_js_affinity_submit_to_blocked_slots() ).
 *
 * @note The corresponding kbasep_js_job_check_ref_cores() is private to the
 * Job Scheduler, and is called automatically when running the next job.
 */
void kbasep_js_job_check_deref_cores(kbase_device *kbdev, struct kbase_jd_atom *katom);

/**
 * @brief Suspend the job scheduler during a Power Management Suspend event.
 *
 * Causes all contexts to be removed from the runpool, and prevents any
 * contexts from (re)entering the runpool.
 *
 * This does not handle suspending the one privileged context: the caller must
 * instead do this by by suspending the GPU HW Counter Instrumentation.
 *
 * This will eventually cause all Power Management active references held by
 * contexts on the runpool to be released, without running any more atoms.
 *
 * The caller must then wait for all Power Mangement active refcount to become
 * zero before completing the suspend.
 *
 * The emptying mechanism may take some time to complete, since it can wait for
 * jobs to complete naturally instead of forcing them to end quickly. However,
 * this is bounded by the Job Scheduling Policy's Job Timeouts. Hence, this
 * function is guaranteed to complete in a finite time whenever the Job
 * Scheduling Policy implements Job Timeouts (such as those done by CFS).
 */
void kbasep_js_suspend(kbase_device *kbdev);

/**
 * @brief Resume the Job Scheduler after a Power Management Resume event.
 *
 * This restores the actions from kbasep_js_suspend():
 * - Schedules contexts back into the runpool
 * - Resumes running atoms on the GPU
 */
void kbasep_js_resume(kbase_device *kbdev);


/*
 * Helpers follow
 */

/**
 * @brief Check that a context is allowed to submit jobs on this policy
 *
 * The purpose of this abstraction is to hide the underlying data size, and wrap up
 * the long repeated line of code.
 *
 * As with any mali_bool, never test the return value with MALI_TRUE.
 *
 * The caller must hold kbasep_js_device_data::runpool_irq::lock.
 */
static INLINE mali_bool kbasep_js_is_submit_allowed(kbasep_js_device_data *js_devdata, kbase_context *kctx)
{
	u16 test_bit;

	/* Ensure context really is scheduled in */
	KBASE_DEBUG_ASSERT(kctx->as_nr != KBASEP_AS_NR_INVALID);
	KBASE_DEBUG_ASSERT(kctx->jctx.sched_info.ctx.is_scheduled != MALI_FALSE);

	test_bit = (u16) (1u << kctx->as_nr);

	return (mali_bool) (js_devdata->runpool_irq.submit_allowed & test_bit);
}

/**
 * @brief Allow a context to submit jobs on this policy
 *
 * The purpose of this abstraction is to hide the underlying data size, and wrap up
 * the long repeated line of code.
 *
 * The caller must hold kbasep_js_device_data::runpool_irq::lock.
 */
static INLINE void kbasep_js_set_submit_allowed(kbasep_js_device_data *js_devdata, kbase_context *kctx)
{
	u16 set_bit;

	/* Ensure context really is scheduled in */
	KBASE_DEBUG_ASSERT(kctx->as_nr != KBASEP_AS_NR_INVALID);
	KBASE_DEBUG_ASSERT(kctx->jctx.sched_info.ctx.is_scheduled != MALI_FALSE);

	set_bit = (u16) (1u << kctx->as_nr);

	KBASE_DEBUG_PRINT_INFO(KBASE_JM, "JS: Setting Submit Allowed on %p (as=%d)", kctx, kctx->as_nr);

	js_devdata->runpool_irq.submit_allowed |= set_bit;
}

/**
 * @brief Prevent a context from submitting more jobs on this policy
 *
 * The purpose of this abstraction is to hide the underlying data size, and wrap up
 * the long repeated line of code.
 *
 * The caller must hold kbasep_js_device_data::runpool_irq::lock.
 */
static INLINE void kbasep_js_clear_submit_allowed(kbasep_js_device_data *js_devdata, kbase_context *kctx)
{
	u16 clear_bit;
	u16 clear_mask;

	/* Ensure context really is scheduled in */
	KBASE_DEBUG_ASSERT(kctx->as_nr != KBASEP_AS_NR_INVALID);
	KBASE_DEBUG_ASSERT(kctx->jctx.sched_info.ctx.is_scheduled != MALI_FALSE);

	clear_bit = (u16) (1u << kctx->as_nr);
	clear_mask = ~clear_bit;

	KBASE_DEBUG_PRINT_INFO(KBASE_JM, "JS: Clearing Submit Allowed on %p (as=%d)", kctx, kctx->as_nr);

	js_devdata->runpool_irq.submit_allowed &= clear_mask;
}

/**
 * @brief Manage the 'retry_submit_on_slot' part of a kbase_jd_atom
 */
static INLINE void kbasep_js_clear_job_retry_submit(kbase_jd_atom *atom)
{
	atom->retry_submit_on_slot = KBASEP_JS_RETRY_SUBMIT_SLOT_INVALID;
}

/**
 * Mark a slot as requiring resubmission by carrying that information on a
 * completing atom.
 *
 * @note This can ASSERT in debug builds if the submit slot has been set to
 * something other than the current value for @a js. This is because you might
 * be unintentionally stopping more jobs being submitted on the old submit
 * slot, and that might cause a scheduling-hang.
 *
 * @note If you can guarantee that the atoms for the original slot will be
 * submitted on some other slot, then call kbasep_js_clear_job_retry_submit()
 * first to silence the ASSERT.
 */
static INLINE void kbasep_js_set_job_retry_submit_slot(kbase_jd_atom *atom, int js)
{
	KBASE_DEBUG_ASSERT(0 <= js && js <= BASE_JM_MAX_NR_SLOTS);
	KBASE_DEBUG_ASSERT(atom->retry_submit_on_slot == KBASEP_JS_RETRY_SUBMIT_SLOT_INVALID
	                   || atom->retry_submit_on_slot == js);

	atom->retry_submit_on_slot = js;
}

/**
 * Create an initial 'invalid' atom retained state, that requires no
 * atom-related work to be done on releasing with
 * kbasep_js_runpool_release_ctx_and_katom_retained_state()
 */
static INLINE void kbasep_js_atom_retained_state_init_invalid(kbasep_js_atom_retained_state *retained_state)
{
	retained_state->event_code = BASE_JD_EVENT_NOT_STARTED;
	retained_state->core_req = KBASEP_JS_ATOM_RETAINED_STATE_CORE_REQ_INVALID;
	retained_state->retry_submit_on_slot = KBASEP_JS_RETRY_SUBMIT_SLOT_INVALID;
}

/**
 * Copy atom state that can be made available after jd_done_nolock() is called
 * on that atom.
 */
static INLINE void kbasep_js_atom_retained_state_copy(kbasep_js_atom_retained_state *retained_state, const kbase_jd_atom *katom)
{
	retained_state->event_code = katom->event_code;
	retained_state->core_req = katom->core_req;
	retained_state->retry_submit_on_slot = katom->retry_submit_on_slot;
}

/**
 * @brief Determine whether an atom has finished (given its retained state),
 * and so should be given back to userspace/removed from the system.
 *
 * Reasons for an atom not finishing include:
 * - Being soft-stopped (and so, the atom should be resubmitted sometime later)
 *
 * @param[in] katom_retained_state the retained state of the atom to check
 * @return    MALI_FALSE if the atom has not finished
 * @return    !=MALI_FALSE if the atom has finished
 */
static INLINE mali_bool kbasep_js_has_atom_finished(const kbasep_js_atom_retained_state *katom_retained_state)
{
	return (mali_bool) (katom_retained_state->event_code != BASE_JD_EVENT_STOPPED && katom_retained_state->event_code != BASE_JD_EVENT_REMOVED_FROM_NEXT);
}

/**
 * @brief Determine whether a kbasep_js_atom_retained_state is valid
 *
 * An invalid kbasep_js_atom_retained_state is allowed, and indicates that the
 * code should just ignore it.
 *
 * @param[in] katom_retained_state the atom's retained state to check
 * @return    MALI_FALSE if the retained state is invalid, and can be ignored
 * @return    !=MALI_FALSE if the retained state is valid
 */
static INLINE mali_bool kbasep_js_atom_retained_state_is_valid(const kbasep_js_atom_retained_state *katom_retained_state)
{
	return (mali_bool) (katom_retained_state->core_req != KBASEP_JS_ATOM_RETAINED_STATE_CORE_REQ_INVALID);
}

static INLINE mali_bool kbasep_js_get_atom_retry_submit_slot(const kbasep_js_atom_retained_state *katom_retained_state, int *res)
{
	int js = katom_retained_state->retry_submit_on_slot;
	*res = js;
	return (mali_bool) (js >= 0);
}

#if KBASE_DEBUG_DISABLE_ASSERTS == 0
/**
 * Debug Check the refcount of a context. Only use within ASSERTs
 *
 * Obtains kbasep_js_device_data::runpool_irq::lock
 *
 * @return negative value if the context is not scheduled in
 * @return current refcount of the context if it is scheduled in. The refcount
 * is not guarenteed to be kept constant.
 */
static INLINE int kbasep_js_debug_check_ctx_refcount(kbase_device *kbdev, kbase_context *kctx)
{
	unsigned long flags;
	kbasep_js_device_data *js_devdata;
	int result = -1;
	int as_nr;

	KBASE_DEBUG_ASSERT(kbdev != NULL);
	KBASE_DEBUG_ASSERT(kctx != NULL);
	js_devdata = &kbdev->js_data;

	spin_lock_irqsave(&js_devdata->runpool_irq.lock, flags);
	as_nr = kctx->as_nr;
	if (as_nr != KBASEP_AS_NR_INVALID)
		result = js_devdata->runpool_irq.per_as_data[as_nr].as_busy_refcount;

	spin_unlock_irqrestore(&js_devdata->runpool_irq.lock, flags);

	return result;
}
#endif				/* KBASE_DEBUG_DISABLE_ASSERTS == 0 */

/**
 * @brief Variant of kbasep_js_runpool_lookup_ctx() that can be used when the
 * context is guarenteed to be already previously retained.
 *
 * It is a programming error to supply the \a as_nr of a context that has not
 * been previously retained/has a busy refcount of zero. The only exception is
 * when there is no ctx in \a as_nr (NULL returned).
 *
 * The following locking conditions are made on the caller:
 * - it must \em not hold the kbasep_js_device_data::runpoool_irq::lock, because
 * it will be used internally.
 *
 * @return a valid kbase_context on success, with a refcount that is guarenteed
 * to be non-zero and unmodified by this function.
 * @return NULL on failure, indicating that no context was found in \a as_nr
 */
static INLINE kbase_context *kbasep_js_runpool_lookup_ctx_noretain(kbase_device *kbdev, int as_nr)
{
	unsigned long flags;
	kbasep_js_device_data *js_devdata;
	kbase_context *found_kctx;
	kbasep_js_per_as_data *js_per_as_data;

	KBASE_DEBUG_ASSERT(kbdev != NULL);
	KBASE_DEBUG_ASSERT(0 <= as_nr && as_nr < BASE_MAX_NR_AS);
	js_devdata = &kbdev->js_data;
	js_per_as_data = &js_devdata->runpool_irq.per_as_data[as_nr];

	spin_lock_irqsave(&js_devdata->runpool_irq.lock, flags);

	found_kctx = js_per_as_data->kctx;
	KBASE_DEBUG_ASSERT(found_kctx == NULL || js_per_as_data->as_busy_refcount > 0);

	spin_unlock_irqrestore(&js_devdata->runpool_irq.lock, flags);

	return found_kctx;
}

/**
 * This will provide a conversion from time (us) to ticks of the gpu clock
 * based on the minimum available gpu frequency.
 * This is usually good to compute best/worst case (where the use of current
 * frequency is not valid due to DVFS).
 * e.g.: when you need the number of cycles to guarantee you won't wait for
 * longer than 'us' time (you might have a shorter wait).
 */
static INLINE u32 kbasep_js_convert_us_to_gpu_ticks_min_freq(kbase_device *kbdev, u32 us)
{
	u32 gpu_freq = kbdev->gpu_props.props.core_props.gpu_freq_khz_min;
	KBASE_DEBUG_ASSERT(0 != gpu_freq);
	return us * (gpu_freq / 1000);
}

/**
 * This will provide a conversion from time (us) to ticks of the gpu clock
 * based on the maximum available gpu frequency.
 * This is usually good to compute best/worst case (where the use of current
 * frequency is not valid due to DVFS).
 * e.g.: When you need the number of cycles to guarantee you'll wait at least
 * 'us' amount of time (but you might wait longer).
 */
static INLINE u32 kbasep_js_convert_us_to_gpu_ticks_max_freq(kbase_device *kbdev, u32 us)
{
	u32 gpu_freq = kbdev->gpu_props.props.core_props.gpu_freq_khz_max;
	KBASE_DEBUG_ASSERT(0 != gpu_freq);
	return us * (u32) (gpu_freq / 1000);
}

/**
 * This will provide a conversion from ticks of the gpu clock to time (us)
 * based on the minimum available gpu frequency.
 * This is usually good to compute best/worst case (where the use of current
 * frequency is not valid due to DVFS).
 * e.g.: When you need to know the worst-case wait that 'ticks' cycles will
 * take (you guarantee that you won't wait any longer than this, but it may
 * be shorter).
 */
static INLINE u32 kbasep_js_convert_gpu_ticks_to_us_min_freq(kbase_device *kbdev, u32 ticks)
{
	u32 gpu_freq = kbdev->gpu_props.props.core_props.gpu_freq_khz_min;
	KBASE_DEBUG_ASSERT(0 != gpu_freq);
	return ticks / gpu_freq * 1000;
}

/**
 * This will provide a conversion from ticks of the gpu clock to time (us)
 * based on the maximum available gpu frequency.
 * This is usually good to compute best/worst case (where the use of current
 * frequency is not valid due to DVFS).
 * e.g.: When you need to know the best-case wait for 'tick' cycles (you
 * guarantee to be waiting for at least this long, but it may be longer).
 */
static INLINE u32 kbasep_js_convert_gpu_ticks_to_us_max_freq(kbase_device *kbdev, u32 ticks)
{
	u32 gpu_freq = kbdev->gpu_props.props.core_props.gpu_freq_khz_max;
	KBASE_DEBUG_ASSERT(0 != gpu_freq);
	return ticks / gpu_freq * 1000;
}

	  /** @} *//* end group kbase_js */
	  /** @} *//* end group base_kbase_api */
	  /** @} *//* end group base_api */

#endif				/* _KBASE_JS_H_ */