/*
 *
 * (C) COPYRIGHT 2014-2015 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.
 *
 */


/*
 * HW access job manager common APIs
 */

#ifndef _KBASE_HWACCESS_JM_H_
#define _KBASE_HWACCESS_JM_H_

/**
 * kbase_backend_run_atom() - Run an atom on the GPU
 * @kbdev:	Device pointer
 * @atom:	Atom to run
 *
 * Caller must hold the HW access lock
 */
void kbase_backend_run_atom(struct kbase_device *kbdev,
				struct kbase_jd_atom *katom);

/**
 * kbase_backend_find_free_address_space() - Find a free address space.
 * @kbdev:	Device pointer
 * @kctx:	Context pointer
 *
 * If no address spaces are currently free, then this function can evict an
 * idle context from the runpool, freeing up the address space it was using.
 *
 * The address space is marked as in use. The caller must either assign a
 * context using kbase_gpu_use_ctx(), or release it using
 * kbase_gpu_release_free_address_space()
 *
 * Return: Number of free address space, or KBASEP_AS_NR_INVALID if none
 *	   available
 */
int kbase_backend_find_free_address_space(struct kbase_device *kbdev,
						struct kbase_context *kctx);

/**
 * kbase_backend_release_free_address_space() - Release an address space.
 * @kbdev:	Device pointer
 * @as_nr:	Address space to release
 *
 * The address space must have been returned by
 * kbase_gpu_find_free_address_space().
 */
void kbase_backend_release_free_address_space(struct kbase_device *kbdev,
						int as_nr);

/**
 * kbase_backend_use_ctx() - Activate a currently unscheduled context, using the
 *			     provided address space.
 * @kbdev:	Device pointer
 * @kctx:	Context pointer. May be NULL
 * @as_nr:	Free address space to use
 *
 * kbase_gpu_next_job() will pull atoms from the active context.
 *
 * Return: true if successful, false if ASID not assigned. If kctx->as_pending
 *         is true then ASID assignment will complete at some point in the
 *         future and will re-start scheduling, otherwise no ASIDs are available
 */
bool kbase_backend_use_ctx(struct kbase_device *kbdev,
				struct kbase_context *kctx,
				int as_nr);

/**
 * kbase_backend_use_ctx_sched() - Activate a context.
 * @kbdev:	Device pointer
 * @kctx:	Context pointer
 *
 * kbase_gpu_next_job() will pull atoms from the active context.
 *
 * The context must already be scheduled and assigned to an address space. If
 * the context is not scheduled, then kbase_gpu_use_ctx() should be used
 * instead.
 *
 * Caller must hold runpool_irq.lock
 *
 * Return: true if context is now active, false otherwise (ie if context does
 *	   not have an address space assigned)
 */
bool kbase_backend_use_ctx_sched(struct kbase_device *kbdev,
					struct kbase_context *kctx);

/**
 * kbase_backend_release_ctx_irq - Release a context from the GPU. This will
 *                                 de-assign the assigned address space.
 * @kbdev: Device pointer
 * @kctx:  Context pointer
 *
 * Caller must hold as->transaction_mutex and runpool_irq.lock
 */
void kbase_backend_release_ctx_irq(struct kbase_device *kbdev,
				struct kbase_context *kctx);

/**
 * kbase_backend_release_ctx_noirq - Release a context from the GPU. This will
 *                                   de-assign the assigned address space.
 * @kbdev: Device pointer
 * @kctx:  Context pointer
 *
 * Caller must hold as->transaction_mutex
 *
 * This function must perform any operations that could not be performed in IRQ
 * context by kbase_backend_release_ctx_irq().
 */
void kbase_backend_release_ctx_noirq(struct kbase_device *kbdev,
						struct kbase_context *kctx);

/**
 * kbase_backend_complete_wq() - Perform backend-specific actions required on
 *				 completing an atom.
 * @kbdev:	Device pointer
 * @katom:	Pointer to the atom to complete
 *
 * This function should only be called from kbase_jd_done_worker() or
 * js_return_worker().
 *
 * Return: true if atom has completed, false if atom should be re-submitted
 */
void kbase_backend_complete_wq(struct kbase_device *kbdev,
				struct kbase_jd_atom *katom);

/**
 * kbase_backend_complete_wq_post_sched - Perform backend-specific actions
 *                                        required on completing an atom, after
 *                                        any scheduling has taken place.
 * @kbdev:         Device pointer
 * @core_req:      Core requirements of atom
 * @affinity:      Affinity of atom
 * @coreref_state: Coreref state of atom
 *
 * This function should only be called from kbase_jd_done_worker() or
 * js_return_worker().
 */
void kbase_backend_complete_wq_post_sched(struct kbase_device *kbdev,
		base_jd_core_req core_req, u64 affinity,
		enum kbase_atom_coreref_state coreref_state);

/**
 * kbase_backend_reset() - The GPU is being reset. Cancel all jobs on the GPU
 *			   and remove any others from the ringbuffers.
 * @kbdev:		Device pointer
 * @end_timestamp:	Timestamp of reset
 */
void kbase_backend_reset(struct kbase_device *kbdev, ktime_t *end_timestamp);

/**
 * kbase_backend_inspect_head() - Return the atom currently at the head of slot
 *				  @js
 * @kbdev:	Device pointer
 * @js:		Job slot to inspect
 *
 * Return : Atom currently at the head of slot @js, or NULL
 */
struct kbase_jd_atom *kbase_backend_inspect_head(struct kbase_device *kbdev,
					int js);

/**
 * kbase_backend_inspect_tail - Return the atom currently at the tail of slot
 *                              @js
 * @kbdev: Device pointer
 * @js:    Job slot to inspect
 *
 * Return : Atom currently at the head of slot @js, or NULL
 */
struct kbase_jd_atom *kbase_backend_inspect_tail(struct kbase_device *kbdev,
					int js);

/**
 * kbase_backend_nr_atoms_on_slot() - Return the number of atoms currently on a
 *				      slot.
 * @kbdev:	Device pointer
 * @js:		Job slot to inspect
 *
 * Return : Number of atoms currently on slot
 */
int kbase_backend_nr_atoms_on_slot(struct kbase_device *kbdev, int js);

/**
 * kbase_backend_nr_atoms_submitted() - Return the number of atoms on a slot
 *					that are currently on the GPU.
 * @kbdev:	Device pointer
 * @js:		Job slot to inspect
 *
 * Return : Number of atoms currently on slot @js that are currently on the GPU.
 */
int kbase_backend_nr_atoms_submitted(struct kbase_device *kbdev, int js);

/**
 * kbase_backend_ctx_count_changed() - Number of contexts ready to submit jobs
 *				       has changed.
 * @kbdev:	Device pointer
 *
 * Perform any required backend-specific actions (eg starting/stopping
 * scheduling timers).
 */
void kbase_backend_ctx_count_changed(struct kbase_device *kbdev);

/**
 * kbase_backend_slot_free() - Return the number of jobs that can be currently
 *			       submitted to slot @js.
 * @kbdev:	Device pointer
 * @js:		Job slot to inspect
 *
 * Return : Number of jobs that can be submitted.
 */
int kbase_backend_slot_free(struct kbase_device *kbdev, int js);

/**
 * kbase_job_check_enter_disjoint - potentially leave disjoint state
 * @kbdev: kbase device
 * @target_katom: atom which is finishing
 *
 * Work out whether to leave disjoint state when finishing an atom that was
 * originated by kbase_job_check_enter_disjoint().
 */
void kbase_job_check_leave_disjoint(struct kbase_device *kbdev,
		struct kbase_jd_atom *target_katom);

/**
 * kbase_backend_jm_kill_jobs_from_kctx - Kill all jobs that are currently
 *                                        running from a context
 * @kctx: Context pointer
 *
 * This is used in response to a page fault to remove all jobs from the faulting
 * context from the hardware.
 */
void kbase_backend_jm_kill_jobs_from_kctx(struct kbase_context *kctx);

/**
 * kbase_jm_wait_for_zero_jobs - Wait for context to have zero jobs running, and
 *                               to be descheduled.
 * @kctx: Context pointer
 *
 * This should be called following kbase_js_zap_context(), to ensure the context
 * can be safely destroyed.
 */
void kbase_jm_wait_for_zero_jobs(struct kbase_context *kctx);

/**
 * kbase_backend_get_current_flush_id - Return the current flush ID
 *
 * @kbdev: Device pointer
 *
 * Return: the current flush ID to be recorded for each job chain
 */
u32 kbase_backend_get_current_flush_id(struct kbase_device *kbdev);

#if KBASE_GPU_RESET_EN
/**
 * kbase_prepare_to_reset_gpu - Prepare for resetting the GPU.
 * @kbdev: Device pointer
 *
 * This function just soft-stops all the slots to ensure that as many jobs as
 * possible are saved.
 *
 * Return: a boolean which should be interpreted as follows:
 * - true  - Prepared for reset, kbase_reset_gpu should be called.
 * - false - Another thread is performing a reset, kbase_reset_gpu should
 *                not be called.
 */
bool kbase_prepare_to_reset_gpu(struct kbase_device *kbdev);

/**
 * kbase_reset_gpu - Reset the GPU
 * @kbdev: Device pointer
 *
 * This function should be called after kbase_prepare_to_reset_gpu if it returns
 * true. It should never be called without a corresponding call to
 * kbase_prepare_to_reset_gpu.
 *
 * After this function is called (or not called if kbase_prepare_to_reset_gpu
 * returned false), the caller should wait for kbdev->reset_waitq to be
 * signalled to know when the reset has completed.
 */
void kbase_reset_gpu(struct kbase_device *kbdev);

/**
 * kbase_prepare_to_reset_gpu_locked - Prepare for resetting the GPU.
 * @kbdev: Device pointer
 *
 * This function just soft-stops all the slots to ensure that as many jobs as
 * possible are saved.
 *
 * Return: a boolean which should be interpreted as follows:
 * - true  - Prepared for reset, kbase_reset_gpu should be called.
 * - false - Another thread is performing a reset, kbase_reset_gpu should
 *                not be called.
 */
bool kbase_prepare_to_reset_gpu_locked(struct kbase_device *kbdev);

/**
 * kbase_reset_gpu_locked - Reset the GPU
 * @kbdev: Device pointer
 *
 * This function should be called after kbase_prepare_to_reset_gpu if it
 * returns true. It should never be called without a corresponding call to
 * kbase_prepare_to_reset_gpu.
 *
 * After this function is called (or not called if kbase_prepare_to_reset_gpu
 * returned false), the caller should wait for kbdev->reset_waitq to be
 * signalled to know when the reset has completed.
 */
void kbase_reset_gpu_locked(struct kbase_device *kbdev);
#endif

/**
 * kbase_job_slot_hardstop - Hard-stop the specified job slot
 * @kctx:         The kbase context that contains the job(s) that should
 *                be hard-stopped
 * @js:           The job slot to hard-stop
 * @target_katom: The job that should be hard-stopped (or NULL for all
 *                jobs from the context)
 * Context:
 *   The job slot lock must be held when calling this function.
 */
void kbase_job_slot_hardstop(struct kbase_context *kctx, int js,
				struct kbase_jd_atom *target_katom);

#endif /* _KBASE_HWACCESS_JM_H_ */