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flow.c

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  • panthor_sched.c 98.89 KiB
    // SPDX-License-Identifier: GPL-2.0 or MIT
    /* Copyright 2023 Collabora ltd. */
    
    #include <drm/drm_drv.h>
    #include <drm/drm_exec.h>
    #include <drm/drm_gem_shmem_helper.h>
    #include <drm/drm_managed.h>
    #include <drm/gpu_scheduler.h>
    #include <drm/panthor_drm.h>
    
    #include <linux/build_bug.h>
    #include <linux/clk.h>
    #include <linux/delay.h>
    #include <linux/dma-mapping.h>
    #include <linux/dma-resv.h>
    #include <linux/firmware.h>
    #include <linux/interrupt.h>
    #include <linux/io.h>
    #include <linux/iopoll.h>
    #include <linux/iosys-map.h>
    #include <linux/module.h>
    #include <linux/platform_device.h>
    #include <linux/pm_runtime.h>
    
    #include "panthor_devfreq.h"
    #include "panthor_device.h"
    #include "panthor_fw.h"
    #include "panthor_gem.h"
    #include "panthor_gpu.h"
    #include "panthor_heap.h"
    #include "panthor_mmu.h"
    #include "panthor_regs.h"
    #include "panthor_sched.h"
    
    /**
     * DOC: Scheduler
     *
     * Mali CSF hardware adopts a firmware-assisted scheduling model, where
     * the firmware takes care of scheduling aspects, to some extent.
     *
     * The scheduling happens at the scheduling group level, each group
     * contains 1 to N queues (N is FW/hardware dependent, and exposed
     * through the firmware interface). Each queue is assigned a command
     * stream ring buffer, which serves as a way to get jobs submitted to
     * the GPU, among other things.
     *
     * The firmware can schedule a maximum of M groups (M is FW/hardware
     * dependent, and exposed through the firmware interface). Passed
     * this maximum number of groups, the kernel must take care of
     * rotating the groups passed to the firmware so every group gets
     * a chance to have his queues scheduled for execution.
     *
     * The current implementation only supports with kernel-mode queues.
     * In other terms, userspace doesn't have access to the ring-buffer.
     * Instead, userspace passes indirect command stream buffers that are
     * called from the queue ring-buffer by the kernel using a pre-defined
     * sequence of command stream instructions to ensure the userspace driver
     * always gets consistent results (cache maintenance,
     * synchronization, ...).
     *
     * We rely on the drm_gpu_scheduler framework to deal with job
     * dependencies and submission. As any other driver dealing with a
     * FW-scheduler, we use the 1:1 entity:scheduler mode, such that each
     * entity has its own job scheduler. When a job is ready to be executed
     * (all its dependencies are met), it is pushed to the appropriate
     * queue ring-buffer, and the group is scheduled for execution if it
     * wasn't already active.
     *
     * Kernel-side group scheduling is timeslice-based. When we have less
     * groups than there are slots, the periodic tick is disabled and we
     * just let the FW schedule the active groups. When there are more
     * groups than slots, we let each group a chance to execute stuff for
     * a given amount of time, and then re-evaluate and pick new groups
     * to schedule. The group selection algorithm is based on
     * priority+round-robin.
     *
     * Even though user-mode queues is out of the scope right now, the
     * current design takes them into account by avoiding any guess on the
     * group/queue state that would be based on information we wouldn't have
     * if userspace was in charge of the ring-buffer. That's also one of the
     * reason we don't do 'cooperative' scheduling (encoding FW group slot
     * reservation as dma_fence that would be returned from the
     * drm_gpu_scheduler::prepare_job() hook, and treating group rotation as
     * a queue of waiters, ordered by job submission order). This approach
     * would work for kernel-mode queues, but would make user-mode queues a
     * lot more complicated to retrofit.
     */
    
    #define JOB_TIMEOUT_MS				5000
    
    #define MIN_CS_PER_CSG				8
    
    #define MIN_CSGS				3
    #define MAX_CSG_PRIO				0xf
    
    struct panthor_group;
    
    /**
     * struct panthor_csg_slot - Command stream group slot
     *
     * This represents a FW slot for a scheduling group.
     */
    struct panthor_csg_slot {
    	/** @group: Scheduling group bound to this slot. */
    	struct panthor_group *group;
    
    	/** @priority: Group priority. */
    	u8 priority;
    
    	/**
    	 * @idle: True if the group bound to this slot is idle.
    	 *
    	 * A group is idle when it has nothing waiting for execution on
    	 * all its queues, or when queues are blocked waiting for something
    	 * to happen (synchronization object).
    	 */
    	bool idle;
    };
    
    /**
     * enum panthor_csg_priority - Group priority
     */
    enum panthor_csg_priority {
    	/** @PANTHOR_CSG_PRIORITY_LOW: Low priority group. */
    	PANTHOR_CSG_PRIORITY_LOW = 0,
    
    	/** @PANTHOR_CSG_PRIORITY_MEDIUM: Medium priority group. */
    	PANTHOR_CSG_PRIORITY_MEDIUM,
    
    	/** @PANTHOR_CSG_PRIORITY_HIGH: High priority group. */
    	PANTHOR_CSG_PRIORITY_HIGH,
    
    	/**
    	 * @PANTHOR_CSG_PRIORITY_RT: Real-time priority group.
    	 *
    	 * Real-time priority allows one to preempt scheduling of other
    	 * non-real-time groups. When such a group becomes executable,
    	 * it will evict the group with the lowest non-rt priority if
    	 * there's no free group slot available.
    	 *
    	 * Currently not exposed to userspace.
    	 */
    	PANTHOR_CSG_PRIORITY_RT,
    
    	/** @PANTHOR_CSG_PRIORITY_COUNT: Number of priority levels. */
    	PANTHOR_CSG_PRIORITY_COUNT,
    };
    
    /**
     * struct panthor_scheduler - Object used to manage the scheduler
     */
    struct panthor_scheduler {
    	/** @ptdev: Device. */
    	struct panthor_device *ptdev;
    
    	/**
    	 * @wq: Workqueue used by our internal scheduler logic and
    	 * drm_gpu_scheduler.
    	 *
    	 * Used for the scheduler tick, group update or other kind of FW
    	 * event processing that can't be handled in the threaded interrupt
    	 * path. Also passed to the drm_gpu_scheduler instances embedded
    	 * in panthor_queue.
    	 */
    	struct workqueue_struct *wq;
    
    	/**
    	 * @heap_alloc_wq: Workqueue used to schedule tiler_oom works.
    	 *
    	 * We have a queue dedicated to heap chunk allocation works to avoid
    	 * blocking the rest of the scheduler if the allocation tries to
    	 * reclaim memory.
    	 */
    	struct workqueue_struct *heap_alloc_wq;
    
    	/** @tick_work: Work executed on a scheduling tick. */
    	struct delayed_work tick_work;
    
    	/**
    	 * @sync_upd_work: Work used to process synchronization object updates.
    	 *
    	 * We use this work to unblock queues/groups that were waiting on a
    	 * synchronization object.
    	 */
    	struct work_struct sync_upd_work;
    
    	/**
    	 * @fw_events_work: Work used to process FW events outside the interrupt path.
    	 *
    	 * Even if the interrupt is threaded, we need any event processing
    	 * that require taking the panthor_scheduler::lock to be processed
    	 * outside the interrupt path so we don't block the tick logic when
    	 * it calls panthor_fw_{csg,wait}_wait_acks(). Since most of the
    	 * event processing requires taking this lock, we just delegate all
    	 * FW event processing to the scheduler workqueue.
    	 */
    	struct work_struct fw_events_work;
    
    	/**
    	 * @fw_events: Bitmask encoding pending FW events.
    	 */
    	atomic_t fw_events;
    
    	/**
    	 * @resched_target: When the next tick should occur.
    	 *
    	 * Expressed in jiffies.
    	 */
    	u64 resched_target;
    
    	/**
    	 * @last_tick: When the last tick occurred.
    	 *
    	 * Expressed in jiffies.
    	 */
    	u64 last_tick;
    
    	/** @tick_period: Tick period in jiffies. */
    	u64 tick_period;
    
    	/**
    	 * @lock: Lock protecting access to all the scheduler fields.
    	 *
    	 * Should be taken in the tick work, the irq handler, and anywhere the @groups
    	 * fields are touched.
    	 */
    	struct mutex lock;
    
    	/** @groups: Various lists used to classify groups. */
    	struct {
    		/**
    		 * @runnable: Runnable group lists.
    		 *
    		 * When a group has queues that want to execute something,
    		 * its panthor_group::run_node should be inserted here.
    		 *
    		 * One list per-priority.
    		 */
    		struct list_head runnable[PANTHOR_CSG_PRIORITY_COUNT];
    
    		/**
    		 * @idle: Idle group lists.
    		 *
    		 * When all queues of a group are idle (either because they
    		 * have nothing to execute, or because they are blocked), the
    		 * panthor_group::run_node field should be inserted here.
    		 *
    		 * One list per-priority.
    		 */
    		struct list_head idle[PANTHOR_CSG_PRIORITY_COUNT];
    
    		/**
    		 * @waiting: List of groups whose queues are blocked on a
    		 * synchronization object.
    		 *
    		 * Insert panthor_group::wait_node here when a group is waiting
    		 * for synchronization objects to be signaled.
    		 *
    		 * This list is evaluated in the @sync_upd_work work.
    		 */
    		struct list_head waiting;
    	} groups;
    
    	/**
    	 * @csg_slots: FW command stream group slots.
    	 */
    	struct panthor_csg_slot csg_slots[MAX_CSGS];
    
    	/** @csg_slot_count: Number of command stream group slots exposed by the FW. */
    	u32 csg_slot_count;
    
    	/** @cs_slot_count: Number of command stream slot per group slot exposed by the FW. */
    	u32 cs_slot_count;
    
    	/** @as_slot_count: Number of address space slots supported by the MMU. */
    	u32 as_slot_count;
    
    	/** @used_csg_slot_count: Number of command stream group slot currently used. */
    	u32 used_csg_slot_count;
    
    	/** @sb_slot_count: Number of scoreboard slots. */
    	u32 sb_slot_count;
    
    	/**
    	 * @might_have_idle_groups: True if an active group might have become idle.
    	 *
    	 * This will force a tick, so other runnable groups can be scheduled if one
    	 * or more active groups became idle.
    	 */
    	bool might_have_idle_groups;
    
    	/** @pm: Power management related fields. */
    	struct {
    		/** @has_ref: True if the scheduler owns a runtime PM reference. */
    		bool has_ref;
    	} pm;
    
    	/** @reset: Reset related fields. */
    	struct {
    		/** @lock: Lock protecting the other reset fields. */
    		struct mutex lock;
    
    		/**
    		 * @in_progress: True if a reset is in progress.
    		 *
    		 * Set to true in panthor_sched_pre_reset() and back to false in
    		 * panthor_sched_post_reset().
    		 */
    		atomic_t in_progress;
    
    		/**
    		 * @stopped_groups: List containing all groups that were stopped
    		 * before a reset.
    		 *
    		 * Insert panthor_group::run_node in the pre_reset path.
    		 */
    		struct list_head stopped_groups;
    	} reset;
    };
    
    /**
     * struct panthor_syncobj_32b - 32-bit FW synchronization object
     */
    struct panthor_syncobj_32b {
    	/** @seqno: Sequence number. */
    	u32 seqno;
    
    	/**
    	 * @status: Status.
    	 *
    	 * Not zero on failure.
    	 */
    	u32 status;
    };
    
    /**
     * struct panthor_syncobj_64b - 64-bit FW synchronization object
     */
    struct panthor_syncobj_64b {
    	/** @seqno: Sequence number. */
    	u64 seqno;
    
    	/**
    	 * @status: Status.
    	 *
    	 * Not zero on failure.
    	 */
    	u32 status;
    
    	/** @pad: MBZ. */
    	u32 pad;
    };
    
    /**
     * struct panthor_queue - Execution queue
     */
    struct panthor_queue {
    	/** @scheduler: DRM scheduler used for this queue. */
    	struct drm_gpu_scheduler scheduler;
    
    	/** @entity: DRM scheduling entity used for this queue. */
    	struct drm_sched_entity entity;
    
    	/**
    	 * @remaining_time: Time remaining before the job timeout expires.
    	 *
    	 * The job timeout is suspended when the queue is not scheduled by the
    	 * FW. Every time we suspend the timer, we need to save the remaining
    	 * time so we can restore it later on.
    	 */
    	unsigned long remaining_time;
    
    	/** @timeout_suspended: True if the job timeout was suspended. */
    	bool timeout_suspended;
    
    	/**
    	 * @doorbell_id: Doorbell assigned to this queue.
    	 *
    	 * Right now, all groups share the same doorbell, and the doorbell ID
    	 * is assigned to group_slot + 1 when the group is assigned a slot. But
    	 * we might decide to provide fine grained doorbell assignment at some
    	 * point, so don't have to wake up all queues in a group every time one
    	 * of them is updated.
    	 */
    	u8 doorbell_id;
    
    	/**
    	 * @priority: Priority of the queue inside the group.
    	 *
    	 * Must be less than 16 (Only 4 bits available).
    	 */
    	u8 priority;
    #define CSF_MAX_QUEUE_PRIO	GENMASK(3, 0)
    
    	/** @ringbuf: Command stream ring-buffer. */
    	struct panthor_kernel_bo *ringbuf;
    
    	/** @iface: Firmware interface. */
    	struct {
    		/** @mem: FW memory allocated for this interface. */
    		struct panthor_kernel_bo *mem;
    
    		/** @input: Input interface. */
    		struct panthor_fw_ringbuf_input_iface *input;
    
    		/** @output: Output interface. */
    		const struct panthor_fw_ringbuf_output_iface *output;
    
    		/** @input_fw_va: FW virtual address of the input interface buffer. */
    		u32 input_fw_va;
    
    		/** @output_fw_va: FW virtual address of the output interface buffer. */
    		u32 output_fw_va;
    	} iface;
    
    	/**
    	 * @syncwait: Stores information about the synchronization object this
    	 * queue is waiting on.
    	 */
    	struct {
    		/** @gpu_va: GPU address of the synchronization object. */
    		u64 gpu_va;
    
    		/** @ref: Reference value to compare against. */
    		u64 ref;
    
    		/** @gt: True if this is a greater-than test. */
    		bool gt;
    
    		/** @sync64: True if this is a 64-bit sync object. */
    		bool sync64;
    
    		/** @bo: Buffer object holding the synchronization object. */
    		struct drm_gem_object *obj;
    
    		/** @offset: Offset of the synchronization object inside @bo. */
    		u64 offset;
    
    		/**
    		 * @kmap: Kernel mapping of the buffer object holding the
    		 * synchronization object.
    		 */
    		void *kmap;
    	} syncwait;
    
    	/** @fence_ctx: Fence context fields. */
    	struct {
    		/** @lock: Used to protect access to all fences allocated by this context. */
    		spinlock_t lock;
    
    		/**
    		 * @id: Fence context ID.
    		 *
    		 * Allocated with dma_fence_context_alloc().
    		 */
    		u64 id;
    
    		/** @seqno: Sequence number of the last initialized fence. */
    		atomic64_t seqno;
    
    		/**
    		 * @in_flight_jobs: List containing all in-flight jobs.
    		 *
    		 * Used to keep track and signal panthor_job::done_fence when the
    		 * synchronization object attached to the queue is signaled.
    		 */
    		struct list_head in_flight_jobs;
    	} fence_ctx;
    };
    
    /**
     * enum panthor_group_state - Scheduling group state.
     */
    enum panthor_group_state {
    	/** @PANTHOR_CS_GROUP_CREATED: Group was created, but not scheduled yet. */
    	PANTHOR_CS_GROUP_CREATED,
    
    	/** @PANTHOR_CS_GROUP_ACTIVE: Group is currently scheduled. */
    	PANTHOR_CS_GROUP_ACTIVE,
    
    	/**
    	 * @PANTHOR_CS_GROUP_SUSPENDED: Group was scheduled at least once, but is
    	 * inactive/suspended right now.
    	 */
    	PANTHOR_CS_GROUP_SUSPENDED,
    
    	/**
    	 * @PANTHOR_CS_GROUP_TERMINATED: Group was terminated.
    	 *
    	 * Can no longer be scheduled. The only allowed action is a destruction.
    	 */
    	PANTHOR_CS_GROUP_TERMINATED,
    
    	/**
    	 * @PANTHOR_CS_GROUP_UNKNOWN_STATE: Group is an unknown state.
    	 *
    	 * The FW returned an inconsistent state. The group is flagged unusable
    	 * and can no longer be scheduled. The only allowed action is a
    	 * destruction.
    	 *
    	 * When that happens, we also schedule a FW reset, to start from a fresh
    	 * state.
    	 */
    	PANTHOR_CS_GROUP_UNKNOWN_STATE,
    };
    
    /**
     * struct panthor_group - Scheduling group object
     */
    struct panthor_group {
    	/** @refcount: Reference count */
    	struct kref refcount;
    
    	/** @ptdev: Device. */
    	struct panthor_device *ptdev;
    
    	/** @vm: VM bound to the group. */
    	struct panthor_vm *vm;
    
    	/** @compute_core_mask: Mask of shader cores that can be used for compute jobs. */
    	u64 compute_core_mask;
    
    	/** @fragment_core_mask: Mask of shader cores that can be used for fragment jobs. */
    	u64 fragment_core_mask;
    
    	/** @tiler_core_mask: Mask of tiler cores that can be used for tiler jobs. */
    	u64 tiler_core_mask;
    
    	/** @max_compute_cores: Maximum number of shader cores used for compute jobs. */
    	u8 max_compute_cores;
    
    	/** @max_fragment_cores: Maximum number of shader cores used for fragment jobs. */
    	u8 max_fragment_cores;
    
    	/** @max_tiler_cores: Maximum number of tiler cores used for tiler jobs. */
    	u8 max_tiler_cores;
    
    	/** @priority: Group priority (check panthor_csg_priority). */
    	u8 priority;
    
    	/** @blocked_queues: Bitmask reflecting the blocked queues. */
    	u32 blocked_queues;
    
    	/** @idle_queues: Bitmask reflecting the idle queues. */
    	u32 idle_queues;
    
    	/** @fatal_lock: Lock used to protect access to fatal fields. */
    	spinlock_t fatal_lock;
    
    	/** @fatal_queues: Bitmask reflecting the queues that hit a fatal exception. */
    	u32 fatal_queues;
    
    	/** @tiler_oom: Mask of queues that have a tiler OOM event to process. */
    	atomic_t tiler_oom;
    
    	/** @queue_count: Number of queues in this group. */
    	u32 queue_count;
    
    	/** @queues: Queues owned by this group. */
    	struct panthor_queue *queues[MAX_CS_PER_CSG];
    
    	/**
    	 * @csg_id: ID of the FW group slot.
    	 *
    	 * -1 when the group is not scheduled/active.
    	 */
    	int csg_id;
    
    	/**
    	 * @destroyed: True when the group has been destroyed.
    	 *
    	 * If a group is destroyed it becomes useless: no further jobs can be submitted
    	 * to its queues. We simply wait for all references to be dropped so we can
    	 * release the group object.
    	 */
    	bool destroyed;
    
    	/**
    	 * @timedout: True when a timeout occurred on any of the queues owned by
    	 * this group.
    	 *
    	 * Timeouts can be reported by drm_sched or by the FW. In any case, any
    	 * timeout situation is unrecoverable, and the group becomes useless.
    	 * We simply wait for all references to be dropped so we can release the
    	 * group object.
    	 */
    	bool timedout;
    
    	/**
    	 * @syncobjs: Pool of per-queue synchronization objects.
    	 *
    	 * One sync object per queue. The position of the sync object is
    	 * determined by the queue index.
    	 */
    	struct panthor_kernel_bo *syncobjs;
    
    	/** @state: Group state. */
    	enum panthor_group_state state;
    
    	/**
    	 * @suspend_buf: Suspend buffer.
    	 *
    	 * Stores the state of the group and its queues when a group is suspended.
    	 * Used at resume time to restore the group in its previous state.
    	 *
    	 * The size of the suspend buffer is exposed through the FW interface.
    	 */
    	struct panthor_kernel_bo *suspend_buf;
    
    	/**
    	 * @protm_suspend_buf: Protection mode suspend buffer.
    	 *
    	 * Stores the state of the group and its queues when a group that's in
    	 * protection mode is suspended.
    	 *
    	 * Used at resume time to restore the group in its previous state.
    	 *
    	 * The size of the protection mode suspend buffer is exposed through the
    	 * FW interface.
    	 */
    	struct panthor_kernel_bo *protm_suspend_buf;
    
    	/** @sync_upd_work: Work used to check/signal job fences. */
    	struct work_struct sync_upd_work;
    
    	/** @tiler_oom_work: Work used to process tiler OOM events happening on this group. */
    	struct work_struct tiler_oom_work;
    
    	/** @term_work: Work used to finish the group termination procedure. */
    	struct work_struct term_work;
    
    	/**
    	 * @release_work: Work used to release group resources.
    	 *
    	 * We need to postpone the group release to avoid a deadlock when
    	 * the last ref is released in the tick work.
    	 */
    	struct work_struct release_work;
    
    	/**
    	 * @run_node: Node used to insert the group in the
    	 * panthor_group::groups::{runnable,idle} and
    	 * panthor_group::reset.stopped_groups lists.
    	 */
    	struct list_head run_node;
    
    	/**
    	 * @wait_node: Node used to insert the group in the
    	 * panthor_group::groups::waiting list.
    	 */
    	struct list_head wait_node;
    };
    
    /**
     * group_queue_work() - Queue a group work
     * @group: Group to queue the work for.
     * @wname: Work name.
     *
     * Grabs a ref and queue a work item to the scheduler workqueue. If
     * the work was already queued, we release the reference we grabbed.
     *
     * Work callbacks must release the reference we grabbed here.
     */
    #define group_queue_work(group, wname) \
    	do { \
    		group_get(group); \
    		if (!queue_work((group)->ptdev->scheduler->wq, &(group)->wname ## _work)) \
    			group_put(group); \
    	} while (0)
    
    /**
     * sched_queue_work() - Queue a scheduler work.
     * @sched: Scheduler object.
     * @wname: Work name.
     *
     * Conditionally queues a scheduler work if no reset is pending/in-progress.
     */
    #define sched_queue_work(sched, wname) \
    	do { \
    		if (!atomic_read(&(sched)->reset.in_progress) && \
    		    !panthor_device_reset_is_pending((sched)->ptdev)) \
    			queue_work((sched)->wq, &(sched)->wname ## _work); \
    	} while (0)
    
    /**
     * sched_queue_delayed_work() - Queue a scheduler delayed work.
     * @sched: Scheduler object.
     * @wname: Work name.
     * @delay: Work delay in jiffies.
     *
     * Conditionally queues a scheduler delayed work if no reset is
     * pending/in-progress.
     */
    #define sched_queue_delayed_work(sched, wname, delay) \
    	do { \
    		if (!atomic_read(&sched->reset.in_progress) && \
    		    !panthor_device_reset_is_pending((sched)->ptdev)) \
    			mod_delayed_work((sched)->wq, &(sched)->wname ## _work, delay); \
    	} while (0)
    
    /*
     * We currently set the maximum of groups per file to an arbitrary low value.
     * But this can be updated if we need more.
     */
    #define MAX_GROUPS_PER_POOL 128
    
    /**
     * struct panthor_group_pool - Group pool
     *
     * Each file get assigned a group pool.
     */
    struct panthor_group_pool {
    	/** @xa: Xarray used to manage group handles. */
    	struct xarray xa;
    };
    
    /**
     * struct panthor_job - Used to manage GPU job
     */
    struct panthor_job {
    	/** @base: Inherit from drm_sched_job. */
    	struct drm_sched_job base;
    
    	/** @refcount: Reference count. */
    	struct kref refcount;
    
    	/** @group: Group of the queue this job will be pushed to. */
    	struct panthor_group *group;
    
    	/** @queue_idx: Index of the queue inside @group. */
    	u32 queue_idx;
    
    	/** @call_info: Information about the userspace command stream call. */
    	struct {
    		/** @start: GPU address of the userspace command stream. */
    		u64 start;
    
    		/** @size: Size of the userspace command stream. */
    		u32 size;
    
    		/**
    		 * @latest_flush: Flush ID at the time the userspace command
    		 * stream was built.
    		 *
    		 * Needed for the flush reduction mechanism.
    		 */
    		u32 latest_flush;
    	} call_info;
    
    	/** @ringbuf: Position of this job is in the ring buffer. */
    	struct {
    		/** @start: Start offset. */
    		u64 start;
    
    		/** @end: End offset. */
    		u64 end;
    	} ringbuf;
    
    	/**
    	 * @node: Used to insert the job in the panthor_queue::fence_ctx::in_flight_jobs
    	 * list.
    	 */
    	struct list_head node;
    
    	/** @done_fence: Fence signaled when the job is finished or cancelled. */
    	struct dma_fence *done_fence;
    };
    
    static void
    panthor_queue_put_syncwait_obj(struct panthor_queue *queue)
    {
    	if (queue->syncwait.kmap) {
    		struct iosys_map map = IOSYS_MAP_INIT_VADDR(queue->syncwait.kmap);
    
    		drm_gem_vunmap_unlocked(queue->syncwait.obj, &map);
    		queue->syncwait.kmap = NULL;
    	}
    
    	drm_gem_object_put(queue->syncwait.obj);
    	queue->syncwait.obj = NULL;
    }
    
    static void *
    panthor_queue_get_syncwait_obj(struct panthor_group *group, struct panthor_queue *queue)
    {
    	struct panthor_device *ptdev = group->ptdev;
    	struct panthor_gem_object *bo;
    	struct iosys_map map;
    	int ret;
    
    	if (queue->syncwait.kmap)
    		return queue->syncwait.kmap + queue->syncwait.offset;
    
    	bo = panthor_vm_get_bo_for_va(group->vm,
    				      queue->syncwait.gpu_va,
    				      &queue->syncwait.offset);
    	if (drm_WARN_ON(&ptdev->base, IS_ERR_OR_NULL(bo)))
    		goto err_put_syncwait_obj;
    
    	queue->syncwait.obj = &bo->base.base;
    	ret = drm_gem_vmap_unlocked(queue->syncwait.obj, &map);
    	if (drm_WARN_ON(&ptdev->base, ret))
    		goto err_put_syncwait_obj;
    
    	queue->syncwait.kmap = map.vaddr;
    	if (drm_WARN_ON(&ptdev->base, !queue->syncwait.kmap))
    		goto err_put_syncwait_obj;
    
    	return queue->syncwait.kmap + queue->syncwait.offset;
    
    err_put_syncwait_obj:
    	panthor_queue_put_syncwait_obj(queue);
    	return NULL;
    }
    
    static void group_free_queue(struct panthor_group *group, struct panthor_queue *queue)
    {
    	if (IS_ERR_OR_NULL(queue))
    		return;
    
    	if (queue->entity.fence_context)
    		drm_sched_entity_destroy(&queue->entity);
    
    	if (queue->scheduler.ops)
    		drm_sched_fini(&queue->scheduler);
    
    	panthor_queue_put_syncwait_obj(queue);
    
    	panthor_kernel_bo_destroy(queue->ringbuf);
    	panthor_kernel_bo_destroy(queue->iface.mem);
    
    	kfree(queue);
    }
    
    static void group_release_work(struct work_struct *work)
    {
    	struct panthor_group *group = container_of(work,
    						   struct panthor_group,
    						   release_work);
    	u32 i;
    
    	for (i = 0; i < group->queue_count; i++)
    		group_free_queue(group, group->queues[i]);
    
    	panthor_kernel_bo_destroy(group->suspend_buf);
    	panthor_kernel_bo_destroy(group->protm_suspend_buf);
    	panthor_kernel_bo_destroy(group->syncobjs);
    
    	panthor_vm_put(group->vm);
    	kfree(group);
    }
    
    static void group_release(struct kref *kref)
    {
    	struct panthor_group *group = container_of(kref,
    						   struct panthor_group,
    						   refcount);
    	struct panthor_device *ptdev = group->ptdev;
    
    	drm_WARN_ON(&ptdev->base, group->csg_id >= 0);
    	drm_WARN_ON(&ptdev->base, !list_empty(&group->run_node));
    	drm_WARN_ON(&ptdev->base, !list_empty(&group->wait_node));
    
    	queue_work(panthor_cleanup_wq, &group->release_work);
    }
    
    static void group_put(struct panthor_group *group)
    {
    	if (group)
    		kref_put(&group->refcount, group_release);
    }
    
    static struct panthor_group *
    group_get(struct panthor_group *group)
    {
    	if (group)
    		kref_get(&group->refcount);
    
    	return group;
    }
    
    /**
     * group_bind_locked() - Bind a group to a group slot
     * @group: Group.
     * @csg_id: Slot.
     *
     * Return: 0 on success, a negative error code otherwise.
     */
    static int
    group_bind_locked(struct panthor_group *group, u32 csg_id)
    {
    	struct panthor_device *ptdev = group->ptdev;
    	struct panthor_csg_slot *csg_slot;
    	int ret;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	if (drm_WARN_ON(&ptdev->base, group->csg_id != -1 || csg_id >= MAX_CSGS ||
    			ptdev->scheduler->csg_slots[csg_id].group))
    		return -EINVAL;
    
    	ret = panthor_vm_active(group->vm);
    	if (ret)
    		return ret;
    
    	csg_slot = &ptdev->scheduler->csg_slots[csg_id];
    	group_get(group);
    	group->csg_id = csg_id;
    
    	/* Dummy doorbell allocation: doorbell is assigned to the group and
    	 * all queues use the same doorbell.
    	 *
    	 * TODO: Implement LRU-based doorbell assignment, so the most often
    	 * updated queues get their own doorbell, thus avoiding useless checks
    	 * on queues belonging to the same group that are rarely updated.
    	 */
    	for (u32 i = 0; i < group->queue_count; i++)
    		group->queues[i]->doorbell_id = csg_id + 1;
    
    	csg_slot->group = group;
    
    	return 0;
    }
    
    /**
     * group_unbind_locked() - Unbind a group from a slot.
     * @group: Group to unbind.
     *
     * Return: 0 on success, a negative error code otherwise.
     */
    static int
    group_unbind_locked(struct panthor_group *group)
    {
    	struct panthor_device *ptdev = group->ptdev;
    	struct panthor_csg_slot *slot;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	if (drm_WARN_ON(&ptdev->base, group->csg_id < 0 || group->csg_id >= MAX_CSGS))
    		return -EINVAL;
    
    	if (drm_WARN_ON(&ptdev->base, group->state == PANTHOR_CS_GROUP_ACTIVE))
    		return -EINVAL;
    
    	slot = &ptdev->scheduler->csg_slots[group->csg_id];
    	panthor_vm_idle(group->vm);
    	group->csg_id = -1;
    
    	/* Tiler OOM events will be re-issued next time the group is scheduled. */
    	atomic_set(&group->tiler_oom, 0);
    	cancel_work(&group->tiler_oom_work);
    
    	for (u32 i = 0; i < group->queue_count; i++)
    		group->queues[i]->doorbell_id = -1;
    
    	slot->group = NULL;
    
    	group_put(group);
    	return 0;
    }
    
    /**
     * cs_slot_prog_locked() - Program a queue slot
     * @ptdev: Device.
     * @csg_id: Group slot ID.
     * @cs_id: Queue slot ID.
     *
     * Program a queue slot with the queue information so things can start being
     * executed on this queue.
     *
     * The group slot must have a group bound to it already (group_bind_locked()).
     */
    static void
    cs_slot_prog_locked(struct panthor_device *ptdev, u32 csg_id, u32 cs_id)
    {
    	struct panthor_queue *queue = ptdev->scheduler->csg_slots[csg_id].group->queues[cs_id];
    	struct panthor_fw_cs_iface *cs_iface = panthor_fw_get_cs_iface(ptdev, csg_id, cs_id);
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	queue->iface.input->extract = queue->iface.output->extract;
    	drm_WARN_ON(&ptdev->base, queue->iface.input->insert < queue->iface.input->extract);
    
    	cs_iface->input->ringbuf_base = panthor_kernel_bo_gpuva(queue->ringbuf);
    	cs_iface->input->ringbuf_size = panthor_kernel_bo_size(queue->ringbuf);
    	cs_iface->input->ringbuf_input = queue->iface.input_fw_va;
    	cs_iface->input->ringbuf_output = queue->iface.output_fw_va;
    	cs_iface->input->config = CS_CONFIG_PRIORITY(queue->priority) |
    				  CS_CONFIG_DOORBELL(queue->doorbell_id);
    	cs_iface->input->ack_irq_mask = ~0;
    	panthor_fw_update_reqs(cs_iface, req,
    			       CS_IDLE_SYNC_WAIT |
    			       CS_IDLE_EMPTY |
    			       CS_STATE_START |
    			       CS_EXTRACT_EVENT,
    			       CS_IDLE_SYNC_WAIT |
    			       CS_IDLE_EMPTY |
    			       CS_STATE_MASK |
    			       CS_EXTRACT_EVENT);
    	if (queue->iface.input->insert != queue->iface.input->extract && queue->timeout_suspended) {
    		drm_sched_resume_timeout(&queue->scheduler, queue->remaining_time);
    		queue->timeout_suspended = false;
    	}
    }
    
    /**
     * cs_slot_reset_locked() - Reset a queue slot
     * @ptdev: Device.
     * @csg_id: Group slot.
     * @cs_id: Queue slot.
     *
     * Change the queue slot state to STOP and suspend the queue timeout if
     * the queue is not blocked.
     *
     * The group slot must have a group bound to it (group_bind_locked()).
     */
    static int
    cs_slot_reset_locked(struct panthor_device *ptdev, u32 csg_id, u32 cs_id)
    {
    	struct panthor_fw_cs_iface *cs_iface = panthor_fw_get_cs_iface(ptdev, csg_id, cs_id);
    	struct panthor_group *group = ptdev->scheduler->csg_slots[csg_id].group;
    	struct panthor_queue *queue = group->queues[cs_id];
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	panthor_fw_update_reqs(cs_iface, req,
    			       CS_STATE_STOP,
    			       CS_STATE_MASK);
    
    	/* If the queue is blocked, we want to keep the timeout running, so
    	 * we can detect unbounded waits and kill the group when that happens.
    	 */
    	if (!(group->blocked_queues & BIT(cs_id)) && !queue->timeout_suspended) {
    		queue->remaining_time = drm_sched_suspend_timeout(&queue->scheduler);
    		queue->timeout_suspended = true;
    		WARN_ON(queue->remaining_time > msecs_to_jiffies(JOB_TIMEOUT_MS));
    	}
    
    	return 0;
    }
    
    /**
     * csg_slot_sync_priority_locked() - Synchronize the group slot priority
     * @ptdev: Device.
     * @csg_id: Group slot ID.
     *
     * Group slot priority update happens asynchronously. When we receive a
     * %CSG_ENDPOINT_CONFIG, we know the update is effective, and can
     * reflect it to our panthor_csg_slot object.
     */
    static void
    csg_slot_sync_priority_locked(struct panthor_device *ptdev, u32 csg_id)
    {
    	struct panthor_csg_slot *csg_slot = &ptdev->scheduler->csg_slots[csg_id];
    	struct panthor_fw_csg_iface *csg_iface;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
    	csg_slot->priority = (csg_iface->input->endpoint_req & CSG_EP_REQ_PRIORITY_MASK) >> 28;
    }
    
    /**
     * cs_slot_sync_queue_state_locked() - Synchronize the queue slot priority
     * @ptdev: Device.
     * @csg_id: Group slot.
     * @cs_id: Queue slot.
     *
     * Queue state is updated on group suspend or STATUS_UPDATE event.
     */
    static void
    cs_slot_sync_queue_state_locked(struct panthor_device *ptdev, u32 csg_id, u32 cs_id)
    {
    	struct panthor_group *group = ptdev->scheduler->csg_slots[csg_id].group;
    	struct panthor_queue *queue = group->queues[cs_id];
    	struct panthor_fw_cs_iface *cs_iface =
    		panthor_fw_get_cs_iface(group->ptdev, csg_id, cs_id);
    
    	u32 status_wait_cond;
    
    	switch (cs_iface->output->status_blocked_reason) {
    	case CS_STATUS_BLOCKED_REASON_UNBLOCKED:
    		if (queue->iface.input->insert == queue->iface.output->extract &&
    		    cs_iface->output->status_scoreboards == 0)
    			group->idle_queues |= BIT(cs_id);
    		break;
    
    	case CS_STATUS_BLOCKED_REASON_SYNC_WAIT:
    		if (list_empty(&group->wait_node)) {
    			list_move_tail(&group->wait_node,
    				       &group->ptdev->scheduler->groups.waiting);
    		}
    		group->blocked_queues |= BIT(cs_id);
    		queue->syncwait.gpu_va = cs_iface->output->status_wait_sync_ptr;
    		queue->syncwait.ref = cs_iface->output->status_wait_sync_value;
    		status_wait_cond = cs_iface->output->status_wait & CS_STATUS_WAIT_SYNC_COND_MASK;
    		queue->syncwait.gt = status_wait_cond == CS_STATUS_WAIT_SYNC_COND_GT;
    		if (cs_iface->output->status_wait & CS_STATUS_WAIT_SYNC_64B) {
    			u64 sync_val_hi = cs_iface->output->status_wait_sync_value_hi;
    
    			queue->syncwait.sync64 = true;
    			queue->syncwait.ref |= sync_val_hi << 32;
    		} else {
    			queue->syncwait.sync64 = false;
    		}
    		break;
    
    	default:
    		/* Other reasons are not blocking. Consider the queue as runnable
    		 * in those cases.
    		 */
    		break;
    	}
    }
    
    static void
    csg_slot_sync_queues_state_locked(struct panthor_device *ptdev, u32 csg_id)
    {
    	struct panthor_csg_slot *csg_slot = &ptdev->scheduler->csg_slots[csg_id];
    	struct panthor_group *group = csg_slot->group;
    	u32 i;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	group->idle_queues = 0;
    	group->blocked_queues = 0;
    
    	for (i = 0; i < group->queue_count; i++) {
    		if (group->queues[i])
    			cs_slot_sync_queue_state_locked(ptdev, csg_id, i);
    	}
    }
    
    static void
    csg_slot_sync_state_locked(struct panthor_device *ptdev, u32 csg_id)
    {
    	struct panthor_csg_slot *csg_slot = &ptdev->scheduler->csg_slots[csg_id];
    	struct panthor_fw_csg_iface *csg_iface;
    	struct panthor_group *group;
    	enum panthor_group_state new_state, old_state;
    	u32 csg_state;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
    	group = csg_slot->group;
    
    	if (!group)
    		return;
    
    	old_state = group->state;
    	csg_state = csg_iface->output->ack & CSG_STATE_MASK;
    	switch (csg_state) {
    	case CSG_STATE_START:
    	case CSG_STATE_RESUME:
    		new_state = PANTHOR_CS_GROUP_ACTIVE;
    		break;
    	case CSG_STATE_TERMINATE:
    		new_state = PANTHOR_CS_GROUP_TERMINATED;
    		break;
    	case CSG_STATE_SUSPEND:
    		new_state = PANTHOR_CS_GROUP_SUSPENDED;
    		break;
    	default:
    		/* The unknown state might be caused by a FW state corruption,
    		 * which means the group metadata can't be trusted anymore, and
    		 * the SUSPEND operation might propagate the corruption to the
    		 * suspend buffers. Flag the group state as unknown to make
    		 * sure it's unusable after that point.
    		 */
    		drm_err(&ptdev->base, "Invalid state on CSG %d (state=%d)",
    			csg_id, csg_state);
    		new_state = PANTHOR_CS_GROUP_UNKNOWN_STATE;
    		break;
    	}
    
    	if (old_state == new_state)
    		return;
    
    	/* The unknown state might be caused by a FW issue, reset the FW to
    	 * take a fresh start.
    	 */
    	if (new_state == PANTHOR_CS_GROUP_UNKNOWN_STATE)
    		panthor_device_schedule_reset(ptdev);
    
    	if (new_state == PANTHOR_CS_GROUP_SUSPENDED)
    		csg_slot_sync_queues_state_locked(ptdev, csg_id);
    
    	if (old_state == PANTHOR_CS_GROUP_ACTIVE) {
    		u32 i;
    
    		/* Reset the queue slots so we start from a clean
    		 * state when starting/resuming a new group on this
    		 * CSG slot. No wait needed here, and no ringbell
    		 * either, since the CS slot will only be re-used
    		 * on the next CSG start operation.
    		 */
    		for (i = 0; i < group->queue_count; i++) {
    			if (group->queues[i])
    				cs_slot_reset_locked(ptdev, csg_id, i);
    		}
    	}
    
    	group->state = new_state;
    }
    
    static int
    csg_slot_prog_locked(struct panthor_device *ptdev, u32 csg_id, u32 priority)
    {
    	struct panthor_fw_csg_iface *csg_iface;
    	struct panthor_csg_slot *csg_slot;
    	struct panthor_group *group;
    	u32 queue_mask = 0, i;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	if (priority > MAX_CSG_PRIO)
    		return -EINVAL;
    
    	if (drm_WARN_ON(&ptdev->base, csg_id >= MAX_CSGS))
    		return -EINVAL;
    
    	csg_slot = &ptdev->scheduler->csg_slots[csg_id];
    	group = csg_slot->group;
    	if (!group || group->state == PANTHOR_CS_GROUP_ACTIVE)
    		return 0;
    
    	csg_iface = panthor_fw_get_csg_iface(group->ptdev, csg_id);
    
    	for (i = 0; i < group->queue_count; i++) {
    		if (group->queues[i]) {
    			cs_slot_prog_locked(ptdev, csg_id, i);
    			queue_mask |= BIT(i);
    		}
    	}
    
    	csg_iface->input->allow_compute = group->compute_core_mask;
    	csg_iface->input->allow_fragment = group->fragment_core_mask;
    	csg_iface->input->allow_other = group->tiler_core_mask;
    	csg_iface->input->endpoint_req = CSG_EP_REQ_COMPUTE(group->max_compute_cores) |
    					 CSG_EP_REQ_FRAGMENT(group->max_fragment_cores) |
    					 CSG_EP_REQ_TILER(group->max_tiler_cores) |
    					 CSG_EP_REQ_PRIORITY(priority);
    	csg_iface->input->config = panthor_vm_as(group->vm);
    
    	if (group->suspend_buf)
    		csg_iface->input->suspend_buf = panthor_kernel_bo_gpuva(group->suspend_buf);
    	else
    		csg_iface->input->suspend_buf = 0;
    
    	if (group->protm_suspend_buf) {
    		csg_iface->input->protm_suspend_buf =
    			panthor_kernel_bo_gpuva(group->protm_suspend_buf);
    	} else {
    		csg_iface->input->protm_suspend_buf = 0;
    	}
    
    	csg_iface->input->ack_irq_mask = ~0;
    	panthor_fw_toggle_reqs(csg_iface, doorbell_req, doorbell_ack, queue_mask);
    	return 0;
    }
    
    static void
    cs_slot_process_fatal_event_locked(struct panthor_device *ptdev,
    				   u32 csg_id, u32 cs_id)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_csg_slot *csg_slot = &sched->csg_slots[csg_id];
    	struct panthor_group *group = csg_slot->group;
    	struct panthor_fw_cs_iface *cs_iface;
    	u32 fatal;
    	u64 info;
    
    	lockdep_assert_held(&sched->lock);
    
    	cs_iface = panthor_fw_get_cs_iface(ptdev, csg_id, cs_id);
    	fatal = cs_iface->output->fatal;
    	info = cs_iface->output->fatal_info;
    
    	if (group)
    		group->fatal_queues |= BIT(cs_id);
    
    	if (CS_EXCEPTION_TYPE(fatal) == DRM_PANTHOR_EXCEPTION_CS_UNRECOVERABLE) {
    		/* If this exception is unrecoverable, queue a reset, and make
    		 * sure we stop scheduling groups until the reset has happened.
    		 */
    		panthor_device_schedule_reset(ptdev);
    		cancel_delayed_work(&sched->tick_work);
    	} else {
    		sched_queue_delayed_work(sched, tick, 0);
    	}
    
    	drm_warn(&ptdev->base,
    		 "CSG slot %d CS slot: %d\n"
    		 "CS_FATAL.EXCEPTION_TYPE: 0x%x (%s)\n"
    		 "CS_FATAL.EXCEPTION_DATA: 0x%x\n"
    		 "CS_FATAL_INFO.EXCEPTION_DATA: 0x%llx\n",
    		 csg_id, cs_id,
    		 (unsigned int)CS_EXCEPTION_TYPE(fatal),
    		 panthor_exception_name(ptdev, CS_EXCEPTION_TYPE(fatal)),
    		 (unsigned int)CS_EXCEPTION_DATA(fatal),
    		 info);
    }
    
    static void
    cs_slot_process_fault_event_locked(struct panthor_device *ptdev,
    				   u32 csg_id, u32 cs_id)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_csg_slot *csg_slot = &sched->csg_slots[csg_id];
    	struct panthor_group *group = csg_slot->group;
    	struct panthor_queue *queue = group && cs_id < group->queue_count ?
    				      group->queues[cs_id] : NULL;
    	struct panthor_fw_cs_iface *cs_iface;
    	u32 fault;
    	u64 info;
    
    	lockdep_assert_held(&sched->lock);
    
    	cs_iface = panthor_fw_get_cs_iface(ptdev, csg_id, cs_id);
    	fault = cs_iface->output->fault;
    	info = cs_iface->output->fault_info;
    
    	if (queue && CS_EXCEPTION_TYPE(fault) == DRM_PANTHOR_EXCEPTION_CS_INHERIT_FAULT) {
    		u64 cs_extract = queue->iface.output->extract;
    		struct panthor_job *job;
    
    		spin_lock(&queue->fence_ctx.lock);
    		list_for_each_entry(job, &queue->fence_ctx.in_flight_jobs, node) {
    			if (cs_extract >= job->ringbuf.end)
    				continue;
    
    			if (cs_extract < job->ringbuf.start)
    				break;
    
    			dma_fence_set_error(job->done_fence, -EINVAL);
    		}
    		spin_unlock(&queue->fence_ctx.lock);
    	}
    
    	drm_warn(&ptdev->base,
    		 "CSG slot %d CS slot: %d\n"
    		 "CS_FAULT.EXCEPTION_TYPE: 0x%x (%s)\n"
    		 "CS_FAULT.EXCEPTION_DATA: 0x%x\n"
    		 "CS_FAULT_INFO.EXCEPTION_DATA: 0x%llx\n",
    		 csg_id, cs_id,
    		 (unsigned int)CS_EXCEPTION_TYPE(fault),
    		 panthor_exception_name(ptdev, CS_EXCEPTION_TYPE(fault)),
    		 (unsigned int)CS_EXCEPTION_DATA(fault),
    		 info);
    }
    
    static int group_process_tiler_oom(struct panthor_group *group, u32 cs_id)
    {
    	struct panthor_device *ptdev = group->ptdev;
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	u32 renderpasses_in_flight, pending_frag_count;
    	struct panthor_heap_pool *heaps = NULL;
    	u64 heap_address, new_chunk_va = 0;
    	u32 vt_start, vt_end, frag_end;
    	int ret, csg_id;
    
    	mutex_lock(&sched->lock);
    	csg_id = group->csg_id;
    	if (csg_id >= 0) {
    		struct panthor_fw_cs_iface *cs_iface;
    
    		cs_iface = panthor_fw_get_cs_iface(ptdev, csg_id, cs_id);
    		heaps = panthor_vm_get_heap_pool(group->vm, false);
    		heap_address = cs_iface->output->heap_address;
    		vt_start = cs_iface->output->heap_vt_start;
    		vt_end = cs_iface->output->heap_vt_end;
    		frag_end = cs_iface->output->heap_frag_end;
    		renderpasses_in_flight = vt_start - frag_end;
    		pending_frag_count = vt_end - frag_end;
    	}
    	mutex_unlock(&sched->lock);
    
    	/* The group got scheduled out, we stop here. We will get a new tiler OOM event
    	 * when it's scheduled again.
    	 */
    	if (unlikely(csg_id < 0))
    		return 0;
    
    	if (IS_ERR(heaps) || frag_end > vt_end || vt_end >= vt_start) {
    		ret = -EINVAL;
    	} else {
    		/* We do the allocation without holding the scheduler lock to avoid
    		 * blocking the scheduling.
    		 */
    		ret = panthor_heap_grow(heaps, heap_address,
    					renderpasses_in_flight,
    					pending_frag_count, &new_chunk_va);
    	}
    
    	/* If the heap context doesn't have memory for us, we want to let the
    	 * FW try to reclaim memory by waiting for fragment jobs to land or by
    	 * executing the tiler OOM exception handler, which is supposed to
    	 * implement incremental rendering.
    	 */
    	if (ret && ret != -ENOMEM) {
    		drm_warn(&ptdev->base, "Failed to extend the tiler heap\n");
    		group->fatal_queues |= BIT(cs_id);
    		sched_queue_delayed_work(sched, tick, 0);
    		goto out_put_heap_pool;
    	}
    
    	mutex_lock(&sched->lock);
    	csg_id = group->csg_id;
    	if (csg_id >= 0) {
    		struct panthor_fw_csg_iface *csg_iface;
    		struct panthor_fw_cs_iface *cs_iface;
    
    		csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
    		cs_iface = panthor_fw_get_cs_iface(ptdev, csg_id, cs_id);
    
    		cs_iface->input->heap_start = new_chunk_va;
    		cs_iface->input->heap_end = new_chunk_va;
    		panthor_fw_update_reqs(cs_iface, req, cs_iface->output->ack, CS_TILER_OOM);
    		panthor_fw_toggle_reqs(csg_iface, doorbell_req, doorbell_ack, BIT(cs_id));
    		panthor_fw_ring_csg_doorbells(ptdev, BIT(csg_id));
    	}
    	mutex_unlock(&sched->lock);
    
    	/* We allocated a chunck, but couldn't link it to the heap
    	 * context because the group was scheduled out while we were
    	 * allocating memory. We need to return this chunk to the heap.
    	 */
    	if (unlikely(csg_id < 0 && new_chunk_va))
    		panthor_heap_return_chunk(heaps, heap_address, new_chunk_va);
    
    	ret = 0;
    
    out_put_heap_pool:
    	panthor_heap_pool_put(heaps);
    	return ret;
    }
    
    static void group_tiler_oom_work(struct work_struct *work)
    {
    	struct panthor_group *group =
    		container_of(work, struct panthor_group, tiler_oom_work);
    	u32 tiler_oom = atomic_xchg(&group->tiler_oom, 0);
    
    	while (tiler_oom) {
    		u32 cs_id = ffs(tiler_oom) - 1;
    
    		group_process_tiler_oom(group, cs_id);
    		tiler_oom &= ~BIT(cs_id);
    	}
    
    	group_put(group);
    }
    
    static void
    cs_slot_process_tiler_oom_event_locked(struct panthor_device *ptdev,
    				       u32 csg_id, u32 cs_id)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_csg_slot *csg_slot = &sched->csg_slots[csg_id];
    	struct panthor_group *group = csg_slot->group;
    
    	lockdep_assert_held(&sched->lock);
    
    	if (drm_WARN_ON(&ptdev->base, !group))
    		return;
    
    	atomic_or(BIT(cs_id), &group->tiler_oom);
    
    	/* We don't use group_queue_work() here because we want to queue the
    	 * work item to the heap_alloc_wq.
    	 */
    	group_get(group);
    	if (!queue_work(sched->heap_alloc_wq, &group->tiler_oom_work))
    		group_put(group);
    }
    
    static bool cs_slot_process_irq_locked(struct panthor_device *ptdev,
    				       u32 csg_id, u32 cs_id)
    {
    	struct panthor_fw_cs_iface *cs_iface;
    	u32 req, ack, events;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	cs_iface = panthor_fw_get_cs_iface(ptdev, csg_id, cs_id);
    	req = cs_iface->input->req;
    	ack = cs_iface->output->ack;
    	events = (req ^ ack) & CS_EVT_MASK;
    
    	if (events & CS_FATAL)
    		cs_slot_process_fatal_event_locked(ptdev, csg_id, cs_id);
    
    	if (events & CS_FAULT)
    		cs_slot_process_fault_event_locked(ptdev, csg_id, cs_id);
    
    	if (events & CS_TILER_OOM)
    		cs_slot_process_tiler_oom_event_locked(ptdev, csg_id, cs_id);
    
    	/* We don't acknowledge the TILER_OOM event since its handling is
    	 * deferred to a separate work.
    	 */
    	panthor_fw_update_reqs(cs_iface, req, ack, CS_FATAL | CS_FAULT);
    
    	return (events & (CS_FAULT | CS_TILER_OOM)) != 0;
    }
    
    static void csg_slot_sync_idle_state_locked(struct panthor_device *ptdev, u32 csg_id)
    {
    	struct panthor_csg_slot *csg_slot = &ptdev->scheduler->csg_slots[csg_id];
    	struct panthor_fw_csg_iface *csg_iface;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
    	csg_slot->idle = csg_iface->output->status_state & CSG_STATUS_STATE_IS_IDLE;
    }
    
    static void csg_slot_process_idle_event_locked(struct panthor_device *ptdev, u32 csg_id)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    
    	lockdep_assert_held(&sched->lock);
    
    	sched->might_have_idle_groups = true;
    
    	/* Schedule a tick so we can evict idle groups and schedule non-idle
    	 * ones. This will also update runtime PM and devfreq busy/idle states,
    	 * so the device can lower its frequency or get suspended.
    	 */
    	sched_queue_delayed_work(sched, tick, 0);
    }
    
    static void csg_slot_sync_update_locked(struct panthor_device *ptdev,
    					u32 csg_id)
    {
    	struct panthor_csg_slot *csg_slot = &ptdev->scheduler->csg_slots[csg_id];
    	struct panthor_group *group = csg_slot->group;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	if (group)
    		group_queue_work(group, sync_upd);
    
    	sched_queue_work(ptdev->scheduler, sync_upd);
    }
    
    static void
    csg_slot_process_progress_timer_event_locked(struct panthor_device *ptdev, u32 csg_id)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_csg_slot *csg_slot = &sched->csg_slots[csg_id];
    	struct panthor_group *group = csg_slot->group;
    
    	lockdep_assert_held(&sched->lock);
    
    	drm_warn(&ptdev->base, "CSG slot %d progress timeout\n", csg_id);
    
    	group = csg_slot->group;
    	if (!drm_WARN_ON(&ptdev->base, !group))
    		group->timedout = true;
    
    	sched_queue_delayed_work(sched, tick, 0);
    }
    
    static void sched_process_csg_irq_locked(struct panthor_device *ptdev, u32 csg_id)
    {
    	u32 req, ack, cs_irq_req, cs_irq_ack, cs_irqs, csg_events;
    	struct panthor_fw_csg_iface *csg_iface;
    	u32 ring_cs_db_mask = 0;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	if (drm_WARN_ON(&ptdev->base, csg_id >= ptdev->scheduler->csg_slot_count))
    		return;
    
    	csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
    	req = READ_ONCE(csg_iface->input->req);
    	ack = READ_ONCE(csg_iface->output->ack);
    	cs_irq_req = READ_ONCE(csg_iface->output->cs_irq_req);
    	cs_irq_ack = READ_ONCE(csg_iface->input->cs_irq_ack);
    	csg_events = (req ^ ack) & CSG_EVT_MASK;
    
    	/* There may not be any pending CSG/CS interrupts to process */
    	if (req == ack && cs_irq_req == cs_irq_ack)
    		return;
    
    	/* Immediately set IRQ_ACK bits to be same as the IRQ_REQ bits before
    	 * examining the CS_ACK & CS_REQ bits. This would ensure that Host
    	 * doesn't miss an interrupt for the CS in the race scenario where
    	 * whilst Host is servicing an interrupt for the CS, firmware sends
    	 * another interrupt for that CS.
    	 */
    	csg_iface->input->cs_irq_ack = cs_irq_req;
    
    	panthor_fw_update_reqs(csg_iface, req, ack,
    			       CSG_SYNC_UPDATE |
    			       CSG_IDLE |
    			       CSG_PROGRESS_TIMER_EVENT);
    
    	if (csg_events & CSG_IDLE)
    		csg_slot_process_idle_event_locked(ptdev, csg_id);
    
    	if (csg_events & CSG_PROGRESS_TIMER_EVENT)
    		csg_slot_process_progress_timer_event_locked(ptdev, csg_id);
    
    	cs_irqs = cs_irq_req ^ cs_irq_ack;
    	while (cs_irqs) {
    		u32 cs_id = ffs(cs_irqs) - 1;
    
    		if (cs_slot_process_irq_locked(ptdev, csg_id, cs_id))
    			ring_cs_db_mask |= BIT(cs_id);
    
    		cs_irqs &= ~BIT(cs_id);
    	}
    
    	if (csg_events & CSG_SYNC_UPDATE)
    		csg_slot_sync_update_locked(ptdev, csg_id);
    
    	if (ring_cs_db_mask)
    		panthor_fw_toggle_reqs(csg_iface, doorbell_req, doorbell_ack, ring_cs_db_mask);
    
    	panthor_fw_ring_csg_doorbells(ptdev, BIT(csg_id));
    }
    
    static void sched_process_idle_event_locked(struct panthor_device *ptdev)
    {
    	struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(ptdev);
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	/* Acknowledge the idle event and schedule a tick. */
    	panthor_fw_update_reqs(glb_iface, req, glb_iface->output->ack, GLB_IDLE);
    	sched_queue_delayed_work(ptdev->scheduler, tick, 0);
    }
    
    /**
     * sched_process_global_irq_locked() - Process the scheduling part of a global IRQ
     * @ptdev: Device.
     */
    static void sched_process_global_irq_locked(struct panthor_device *ptdev)
    {
    	struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(ptdev);
    	u32 req, ack, evts;
    
    	lockdep_assert_held(&ptdev->scheduler->lock);
    
    	req = READ_ONCE(glb_iface->input->req);
    	ack = READ_ONCE(glb_iface->output->ack);
    	evts = (req ^ ack) & GLB_EVT_MASK;
    
    	if (evts & GLB_IDLE)
    		sched_process_idle_event_locked(ptdev);
    }
    
    static void process_fw_events_work(struct work_struct *work)
    {
    	struct panthor_scheduler *sched = container_of(work, struct panthor_scheduler,
    						      fw_events_work);
    	u32 events = atomic_xchg(&sched->fw_events, 0);
    	struct panthor_device *ptdev = sched->ptdev;
    
    	mutex_lock(&sched->lock);
    
    	if (events & JOB_INT_GLOBAL_IF) {
    		sched_process_global_irq_locked(ptdev);
    		events &= ~JOB_INT_GLOBAL_IF;
    	}
    
    	while (events) {
    		u32 csg_id = ffs(events) - 1;
    
    		sched_process_csg_irq_locked(ptdev, csg_id);
    		events &= ~BIT(csg_id);
    	}
    
    	mutex_unlock(&sched->lock);
    }
    
    /**
     * panthor_sched_report_fw_events() - Report FW events to the scheduler.
     */
    void panthor_sched_report_fw_events(struct panthor_device *ptdev, u32 events)
    {
    	if (!ptdev->scheduler)
    		return;
    
    	atomic_or(events, &ptdev->scheduler->fw_events);
    	sched_queue_work(ptdev->scheduler, fw_events);
    }
    
    static const char *fence_get_driver_name(struct dma_fence *fence)
    {
    	return "panthor";
    }
    
    static const char *queue_fence_get_timeline_name(struct dma_fence *fence)
    {
    	return "queue-fence";
    }
    
    static const struct dma_fence_ops panthor_queue_fence_ops = {
    	.get_driver_name = fence_get_driver_name,
    	.get_timeline_name = queue_fence_get_timeline_name,
    };
    
    struct panthor_csg_slots_upd_ctx {
    	u32 update_mask;
    	u32 timedout_mask;
    	struct {
    		u32 value;
    		u32 mask;
    	} requests[MAX_CSGS];
    };
    
    static void csgs_upd_ctx_init(struct panthor_csg_slots_upd_ctx *ctx)
    {
    	memset(ctx, 0, sizeof(*ctx));
    }
    
    static void csgs_upd_ctx_queue_reqs(struct panthor_device *ptdev,
    				    struct panthor_csg_slots_upd_ctx *ctx,
    				    u32 csg_id, u32 value, u32 mask)
    {
    	if (drm_WARN_ON(&ptdev->base, !mask) ||
    	    drm_WARN_ON(&ptdev->base, csg_id >= ptdev->scheduler->csg_slot_count))
    		return;
    
    	ctx->requests[csg_id].value = (ctx->requests[csg_id].value & ~mask) | (value & mask);
    	ctx->requests[csg_id].mask |= mask;
    	ctx->update_mask |= BIT(csg_id);
    }
    
    static int csgs_upd_ctx_apply_locked(struct panthor_device *ptdev,
    				     struct panthor_csg_slots_upd_ctx *ctx)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	u32 update_slots = ctx->update_mask;
    
    	lockdep_assert_held(&sched->lock);
    
    	if (!ctx->update_mask)
    		return 0;
    
    	while (update_slots) {
    		struct panthor_fw_csg_iface *csg_iface;
    		u32 csg_id = ffs(update_slots) - 1;
    
    		update_slots &= ~BIT(csg_id);
    		csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
    		panthor_fw_update_reqs(csg_iface, req,
    				       ctx->requests[csg_id].value,
    				       ctx->requests[csg_id].mask);
    	}
    
    	panthor_fw_ring_csg_doorbells(ptdev, ctx->update_mask);
    
    	update_slots = ctx->update_mask;
    	while (update_slots) {
    		struct panthor_fw_csg_iface *csg_iface;
    		u32 csg_id = ffs(update_slots) - 1;
    		u32 req_mask = ctx->requests[csg_id].mask, acked;
    		int ret;
    
    		update_slots &= ~BIT(csg_id);
    		csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
    
    		ret = panthor_fw_csg_wait_acks(ptdev, csg_id, req_mask, &acked, 100);
    
    		if (acked & CSG_ENDPOINT_CONFIG)
    			csg_slot_sync_priority_locked(ptdev, csg_id);
    
    		if (acked & CSG_STATE_MASK)
    			csg_slot_sync_state_locked(ptdev, csg_id);
    
    		if (acked & CSG_STATUS_UPDATE) {
    			csg_slot_sync_queues_state_locked(ptdev, csg_id);
    			csg_slot_sync_idle_state_locked(ptdev, csg_id);
    		}
    
    		if (ret && acked != req_mask &&
    		    ((csg_iface->input->req ^ csg_iface->output->ack) & req_mask) != 0) {
    			drm_err(&ptdev->base, "CSG %d update request timedout", csg_id);
    			ctx->timedout_mask |= BIT(csg_id);
    		}
    	}
    
    	if (ctx->timedout_mask)
    		return -ETIMEDOUT;
    
    	return 0;
    }
    
    struct panthor_sched_tick_ctx {
    	struct list_head old_groups[PANTHOR_CSG_PRIORITY_COUNT];
    	struct list_head groups[PANTHOR_CSG_PRIORITY_COUNT];
    	u32 idle_group_count;
    	u32 group_count;
    	enum panthor_csg_priority min_priority;
    	struct panthor_vm *vms[MAX_CS_PER_CSG];
    	u32 as_count;
    	bool immediate_tick;
    	u32 csg_upd_failed_mask;
    };
    
    static bool
    tick_ctx_is_full(const struct panthor_scheduler *sched,
    		 const struct panthor_sched_tick_ctx *ctx)
    {
    	return ctx->group_count == sched->csg_slot_count;
    }
    
    static bool
    group_is_idle(struct panthor_group *group)
    {
    	struct panthor_device *ptdev = group->ptdev;
    	u32 inactive_queues;
    
    	if (group->csg_id >= 0)
    		return ptdev->scheduler->csg_slots[group->csg_id].idle;
    
    	inactive_queues = group->idle_queues | group->blocked_queues;
    	return hweight32(inactive_queues) == group->queue_count;
    }
    
    static bool
    group_can_run(struct panthor_group *group)
    {
    	return group->state != PANTHOR_CS_GROUP_TERMINATED &&
    	       group->state != PANTHOR_CS_GROUP_UNKNOWN_STATE &&
    	       !group->destroyed && group->fatal_queues == 0 &&
    	       !group->timedout;
    }
    
    static void
    tick_ctx_pick_groups_from_list(const struct panthor_scheduler *sched,
    			       struct panthor_sched_tick_ctx *ctx,
    			       struct list_head *queue,
    			       bool skip_idle_groups,
    			       bool owned_by_tick_ctx)
    {
    	struct panthor_group *group, *tmp;
    
    	if (tick_ctx_is_full(sched, ctx))
    		return;
    
    	list_for_each_entry_safe(group, tmp, queue, run_node) {
    		u32 i;
    
    		if (!group_can_run(group))
    			continue;
    
    		if (skip_idle_groups && group_is_idle(group))
    			continue;
    
    		for (i = 0; i < ctx->as_count; i++) {
    			if (ctx->vms[i] == group->vm)
    				break;
    		}
    
    		if (i == ctx->as_count && ctx->as_count == sched->as_slot_count)
    			continue;
    
    		if (!owned_by_tick_ctx)
    			group_get(group);
    
    		list_move_tail(&group->run_node, &ctx->groups[group->priority]);
    		ctx->group_count++;
    		if (group_is_idle(group))
    			ctx->idle_group_count++;
    
    		if (i == ctx->as_count)
    			ctx->vms[ctx->as_count++] = group->vm;
    
    		if (ctx->min_priority > group->priority)
    			ctx->min_priority = group->priority;
    
    		if (tick_ctx_is_full(sched, ctx))
    			return;
    	}
    }
    
    static void
    tick_ctx_insert_old_group(struct panthor_scheduler *sched,
    			  struct panthor_sched_tick_ctx *ctx,
    			  struct panthor_group *group,
    			  bool full_tick)
    {
    	struct panthor_csg_slot *csg_slot = &sched->csg_slots[group->csg_id];
    	struct panthor_group *other_group;
    
    	if (!full_tick) {
    		list_add_tail(&group->run_node, &ctx->old_groups[group->priority]);
    		return;
    	}
    
    	/* Rotate to make sure groups with lower CSG slot
    	 * priorities have a chance to get a higher CSG slot
    	 * priority next time they get picked. This priority
    	 * has an impact on resource request ordering, so it's
    	 * important to make sure we don't let one group starve
    	 * all other groups with the same group priority.
    	 */
    	list_for_each_entry(other_group,
    			    &ctx->old_groups[csg_slot->group->priority],
    			    run_node) {
    		struct panthor_csg_slot *other_csg_slot = &sched->csg_slots[other_group->csg_id];
    
    		if (other_csg_slot->priority > csg_slot->priority) {
    			list_add_tail(&csg_slot->group->run_node, &other_group->run_node);
    			return;
    		}
    	}
    
    	list_add_tail(&group->run_node, &ctx->old_groups[group->priority]);
    }
    
    static void
    tick_ctx_init(struct panthor_scheduler *sched,
    	      struct panthor_sched_tick_ctx *ctx,
    	      bool full_tick)
    {
    	struct panthor_device *ptdev = sched->ptdev;
    	struct panthor_csg_slots_upd_ctx upd_ctx;
    	int ret;
    	u32 i;
    
    	memset(ctx, 0, sizeof(*ctx));
    	csgs_upd_ctx_init(&upd_ctx);
    
    	ctx->min_priority = PANTHOR_CSG_PRIORITY_COUNT;
    	for (i = 0; i < ARRAY_SIZE(ctx->groups); i++) {
    		INIT_LIST_HEAD(&ctx->groups[i]);
    		INIT_LIST_HEAD(&ctx->old_groups[i]);
    	}
    
    	for (i = 0; i < sched->csg_slot_count; i++) {
    		struct panthor_csg_slot *csg_slot = &sched->csg_slots[i];
    		struct panthor_group *group = csg_slot->group;
    		struct panthor_fw_csg_iface *csg_iface;
    
    		if (!group)
    			continue;
    
    		csg_iface = panthor_fw_get_csg_iface(ptdev, i);
    		group_get(group);
    
    		/* If there was unhandled faults on the VM, force processing of
    		 * CSG IRQs, so we can flag the faulty queue.
    		 */
    		if (panthor_vm_has_unhandled_faults(group->vm)) {
    			sched_process_csg_irq_locked(ptdev, i);
    
    			/* No fatal fault reported, flag all queues as faulty. */
    			if (!group->fatal_queues)
    				group->fatal_queues |= GENMASK(group->queue_count - 1, 0);
    		}
    
    		tick_ctx_insert_old_group(sched, ctx, group, full_tick);
    		csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, i,
    					csg_iface->output->ack ^ CSG_STATUS_UPDATE,
    					CSG_STATUS_UPDATE);
    	}
    
    	ret = csgs_upd_ctx_apply_locked(ptdev, &upd_ctx);
    	if (ret) {
    		panthor_device_schedule_reset(ptdev);
    		ctx->csg_upd_failed_mask |= upd_ctx.timedout_mask;
    	}
    }
    
    #define NUM_INSTRS_PER_SLOT		16
    
    static void
    group_term_post_processing(struct panthor_group *group)
    {
    	struct panthor_job *job, *tmp;
    	LIST_HEAD(faulty_jobs);
    	bool cookie;
    	u32 i = 0;
    
    	if (drm_WARN_ON(&group->ptdev->base, group_can_run(group)))
    		return;
    
    	cookie = dma_fence_begin_signalling();
    	for (i = 0; i < group->queue_count; i++) {
    		struct panthor_queue *queue = group->queues[i];
    		struct panthor_syncobj_64b *syncobj;
    		int err;
    
    		if (group->fatal_queues & BIT(i))
    			err = -EINVAL;
    		else if (group->timedout)
    			err = -ETIMEDOUT;
    		else
    			err = -ECANCELED;
    
    		if (!queue)
    			continue;
    
    		spin_lock(&queue->fence_ctx.lock);
    		list_for_each_entry_safe(job, tmp, &queue->fence_ctx.in_flight_jobs, node) {
    			list_move_tail(&job->node, &faulty_jobs);
    			dma_fence_set_error(job->done_fence, err);
    			dma_fence_signal_locked(job->done_fence);
    		}
    		spin_unlock(&queue->fence_ctx.lock);
    
    		/* Manually update the syncobj seqno to unblock waiters. */
    		syncobj = group->syncobjs->kmap + (i * sizeof(*syncobj));
    		syncobj->status = ~0;
    		syncobj->seqno = atomic64_read(&queue->fence_ctx.seqno);
    		sched_queue_work(group->ptdev->scheduler, sync_upd);
    	}
    	dma_fence_end_signalling(cookie);
    
    	list_for_each_entry_safe(job, tmp, &faulty_jobs, node) {
    		list_del_init(&job->node);
    		panthor_job_put(&job->base);
    	}
    }
    
    static void group_term_work(struct work_struct *work)
    {
    	struct panthor_group *group =
    		container_of(work, struct panthor_group, term_work);
    
    	group_term_post_processing(group);
    	group_put(group);
    }
    
    static void
    tick_ctx_cleanup(struct panthor_scheduler *sched,
    		 struct panthor_sched_tick_ctx *ctx)
    {
    	struct panthor_group *group, *tmp;
    	u32 i;
    
    	for (i = 0; i < ARRAY_SIZE(ctx->old_groups); i++) {
    		list_for_each_entry_safe(group, tmp, &ctx->old_groups[i], run_node) {
    			/* If everything went fine, we should only have groups
    			 * to be terminated in the old_groups lists.
    			 */
    			drm_WARN_ON(&group->ptdev->base, !ctx->csg_upd_failed_mask &&
    				    group_can_run(group));
    
    			if (!group_can_run(group)) {
    				list_del_init(&group->run_node);
    				list_del_init(&group->wait_node);
    				group_queue_work(group, term);
    			} else if (group->csg_id >= 0) {
    				list_del_init(&group->run_node);
    			} else {
    				list_move(&group->run_node,
    					  group_is_idle(group) ?
    					  &sched->groups.idle[group->priority] :
    					  &sched->groups.runnable[group->priority]);
    			}
    			group_put(group);
    		}
    	}
    
    	for (i = 0; i < ARRAY_SIZE(ctx->groups); i++) {
    		/* If everything went fine, the groups to schedule lists should
    		 * be empty.
    		 */
    		drm_WARN_ON(&group->ptdev->base,
    			    !ctx->csg_upd_failed_mask && !list_empty(&ctx->groups[i]));
    
    		list_for_each_entry_safe(group, tmp, &ctx->groups[i], run_node) {
    			if (group->csg_id >= 0) {
    				list_del_init(&group->run_node);
    			} else {
    				list_move(&group->run_node,
    					  group_is_idle(group) ?
    					  &sched->groups.idle[group->priority] :
    					  &sched->groups.runnable[group->priority]);
    			}
    			group_put(group);
    		}
    	}
    }
    
    static void
    tick_ctx_apply(struct panthor_scheduler *sched, struct panthor_sched_tick_ctx *ctx)
    {
    	struct panthor_group *group, *tmp;
    	struct panthor_device *ptdev = sched->ptdev;
    	struct panthor_csg_slot *csg_slot;
    	int prio, new_csg_prio = MAX_CSG_PRIO, i;
    	u32 free_csg_slots = 0;
    	struct panthor_csg_slots_upd_ctx upd_ctx;
    	int ret;
    
    	csgs_upd_ctx_init(&upd_ctx);
    
    	for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) {
    		/* Suspend or terminate evicted groups. */
    		list_for_each_entry(group, &ctx->old_groups[prio], run_node) {
    			bool term = !group_can_run(group);
    			int csg_id = group->csg_id;
    
    			if (drm_WARN_ON(&ptdev->base, csg_id < 0))
    				continue;
    
    			csg_slot = &sched->csg_slots[csg_id];
    			csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
    						term ? CSG_STATE_TERMINATE : CSG_STATE_SUSPEND,
    						CSG_STATE_MASK);
    		}
    
    		/* Update priorities on already running groups. */
    		list_for_each_entry(group, &ctx->groups[prio], run_node) {
    			struct panthor_fw_csg_iface *csg_iface;
    			int csg_id = group->csg_id;
    
    			if (csg_id < 0) {
    				new_csg_prio--;
    				continue;
    			}
    
    			csg_slot = &sched->csg_slots[csg_id];
    			csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
    			if (csg_slot->priority == new_csg_prio) {
    				new_csg_prio--;
    				continue;
    			}
    
    			panthor_fw_update_reqs(csg_iface, endpoint_req,
    					       CSG_EP_REQ_PRIORITY(new_csg_prio),
    					       CSG_EP_REQ_PRIORITY_MASK);
    			csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
    						csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
    						CSG_ENDPOINT_CONFIG);
    			new_csg_prio--;
    		}
    	}
    
    	ret = csgs_upd_ctx_apply_locked(ptdev, &upd_ctx);
    	if (ret) {
    		panthor_device_schedule_reset(ptdev);
    		ctx->csg_upd_failed_mask |= upd_ctx.timedout_mask;
    		return;
    	}
    
    	/* Unbind evicted groups. */
    	for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) {
    		list_for_each_entry(group, &ctx->old_groups[prio], run_node) {
    			/* This group is gone. Process interrupts to clear
    			 * any pending interrupts before we start the new
    			 * group.
    			 */
    			if (group->csg_id >= 0)
    				sched_process_csg_irq_locked(ptdev, group->csg_id);
    
    			group_unbind_locked(group);
    		}
    	}
    
    	for (i = 0; i < sched->csg_slot_count; i++) {
    		if (!sched->csg_slots[i].group)
    			free_csg_slots |= BIT(i);
    	}
    
    	csgs_upd_ctx_init(&upd_ctx);
    	new_csg_prio = MAX_CSG_PRIO;
    
    	/* Start new groups. */
    	for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) {
    		list_for_each_entry(group, &ctx->groups[prio], run_node) {
    			int csg_id = group->csg_id;
    			struct panthor_fw_csg_iface *csg_iface;
    
    			if (csg_id >= 0) {
    				new_csg_prio--;
    				continue;
    			}
    
    			csg_id = ffs(free_csg_slots) - 1;
    			if (drm_WARN_ON(&ptdev->base, csg_id < 0))
    				break;
    
    			csg_iface = panthor_fw_get_csg_iface(ptdev, csg_id);
    			csg_slot = &sched->csg_slots[csg_id];
    			group_bind_locked(group, csg_id);
    			csg_slot_prog_locked(ptdev, csg_id, new_csg_prio--);
    			csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
    						group->state == PANTHOR_CS_GROUP_SUSPENDED ?
    						CSG_STATE_RESUME : CSG_STATE_START,
    						CSG_STATE_MASK);
    			csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
    						csg_iface->output->ack ^ CSG_ENDPOINT_CONFIG,
    						CSG_ENDPOINT_CONFIG);
    			free_csg_slots &= ~BIT(csg_id);
    		}
    	}
    
    	ret = csgs_upd_ctx_apply_locked(ptdev, &upd_ctx);
    	if (ret) {
    		panthor_device_schedule_reset(ptdev);
    		ctx->csg_upd_failed_mask |= upd_ctx.timedout_mask;
    		return;
    	}
    
    	for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) {
    		list_for_each_entry_safe(group, tmp, &ctx->groups[prio], run_node) {
    			list_del_init(&group->run_node);
    
    			/* If the group has been destroyed while we were
    			 * scheduling, ask for an immediate tick to
    			 * re-evaluate as soon as possible and get rid of
    			 * this dangling group.
    			 */
    			if (group->destroyed)
    				ctx->immediate_tick = true;
    			group_put(group);
    		}
    
    		/* Return evicted groups to the idle or run queues. Groups
    		 * that can no longer be run (because they've been destroyed
    		 * or experienced an unrecoverable error) will be scheduled
    		 * for destruction in tick_ctx_cleanup().
    		 */
    		list_for_each_entry_safe(group, tmp, &ctx->old_groups[prio], run_node) {
    			if (!group_can_run(group))
    				continue;
    
    			if (group_is_idle(group))
    				list_move_tail(&group->run_node, &sched->groups.idle[prio]);
    			else
    				list_move_tail(&group->run_node, &sched->groups.runnable[prio]);
    			group_put(group);
    		}
    	}
    
    	sched->used_csg_slot_count = ctx->group_count;
    	sched->might_have_idle_groups = ctx->idle_group_count > 0;
    }
    
    static u64
    tick_ctx_update_resched_target(struct panthor_scheduler *sched,
    			       const struct panthor_sched_tick_ctx *ctx)
    {
    	/* We had space left, no need to reschedule until some external event happens. */
    	if (!tick_ctx_is_full(sched, ctx))
    		goto no_tick;
    
    	/* If idle groups were scheduled, no need to wake up until some external
    	 * event happens (group unblocked, new job submitted, ...).
    	 */
    	if (ctx->idle_group_count)
    		goto no_tick;
    
    	if (drm_WARN_ON(&sched->ptdev->base, ctx->min_priority >= PANTHOR_CSG_PRIORITY_COUNT))
    		goto no_tick;
    
    	/* If there are groups of the same priority waiting, we need to
    	 * keep the scheduler ticking, otherwise, we'll just wait for
    	 * new groups with higher priority to be queued.
    	 */
    	if (!list_empty(&sched->groups.runnable[ctx->min_priority])) {
    		u64 resched_target = sched->last_tick + sched->tick_period;
    
    		if (time_before64(sched->resched_target, sched->last_tick) ||
    		    time_before64(resched_target, sched->resched_target))
    			sched->resched_target = resched_target;
    
    		return sched->resched_target - sched->last_tick;
    	}
    
    no_tick:
    	sched->resched_target = U64_MAX;
    	return U64_MAX;
    }
    
    static void tick_work(struct work_struct *work)
    {
    	struct panthor_scheduler *sched = container_of(work, struct panthor_scheduler,
    						      tick_work.work);
    	struct panthor_device *ptdev = sched->ptdev;
    	struct panthor_sched_tick_ctx ctx;
    	u64 remaining_jiffies = 0, resched_delay;
    	u64 now = get_jiffies_64();
    	int prio, ret, cookie;
    
    	if (!drm_dev_enter(&ptdev->base, &cookie))
    		return;
    
    	ret = pm_runtime_resume_and_get(ptdev->base.dev);
    	if (drm_WARN_ON(&ptdev->base, ret))
    		goto out_dev_exit;
    
    	if (time_before64(now, sched->resched_target))
    		remaining_jiffies = sched->resched_target - now;
    
    	mutex_lock(&sched->lock);
    	if (panthor_device_reset_is_pending(sched->ptdev))
    		goto out_unlock;
    
    	tick_ctx_init(sched, &ctx, remaining_jiffies != 0);
    	if (ctx.csg_upd_failed_mask)
    		goto out_cleanup_ctx;
    
    	if (remaining_jiffies) {
    		/* Scheduling forced in the middle of a tick. Only RT groups
    		 * can preempt non-RT ones. Currently running RT groups can't be
    		 * preempted.
    		 */
    		for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1;
    		     prio >= 0 && !tick_ctx_is_full(sched, &ctx);
    		     prio--) {
    			tick_ctx_pick_groups_from_list(sched, &ctx, &ctx.old_groups[prio],
    						       true, true);
    			if (prio == PANTHOR_CSG_PRIORITY_RT) {
    				tick_ctx_pick_groups_from_list(sched, &ctx,
    							       &sched->groups.runnable[prio],
    							       true, false);
    			}
    		}
    	}
    
    	/* First pick non-idle groups */
    	for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1;
    	     prio >= 0 && !tick_ctx_is_full(sched, &ctx);
    	     prio--) {
    		tick_ctx_pick_groups_from_list(sched, &ctx, &sched->groups.runnable[prio],
    					       true, false);
    		tick_ctx_pick_groups_from_list(sched, &ctx, &ctx.old_groups[prio], true, true);
    	}
    
    	/* If we have free CSG slots left, pick idle groups */
    	for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1;
    	     prio >= 0 && !tick_ctx_is_full(sched, &ctx);
    	     prio--) {
    		/* Check the old_group queue first to avoid reprogramming the slots */
    		tick_ctx_pick_groups_from_list(sched, &ctx, &ctx.old_groups[prio], false, true);
    		tick_ctx_pick_groups_from_list(sched, &ctx, &sched->groups.idle[prio],
    					       false, false);
    	}
    
    	tick_ctx_apply(sched, &ctx);
    	if (ctx.csg_upd_failed_mask)
    		goto out_cleanup_ctx;
    
    	if (ctx.idle_group_count == ctx.group_count) {
    		panthor_devfreq_record_idle(sched->ptdev);
    		if (sched->pm.has_ref) {
    			pm_runtime_put_autosuspend(ptdev->base.dev);
    			sched->pm.has_ref = false;
    		}
    	} else {
    		panthor_devfreq_record_busy(sched->ptdev);
    		if (!sched->pm.has_ref) {
    			pm_runtime_get(ptdev->base.dev);
    			sched->pm.has_ref = true;
    		}
    	}
    
    	sched->last_tick = now;
    	resched_delay = tick_ctx_update_resched_target(sched, &ctx);
    	if (ctx.immediate_tick)
    		resched_delay = 0;
    
    	if (resched_delay != U64_MAX)
    		sched_queue_delayed_work(sched, tick, resched_delay);
    
    out_cleanup_ctx:
    	tick_ctx_cleanup(sched, &ctx);
    
    out_unlock:
    	mutex_unlock(&sched->lock);
    	pm_runtime_mark_last_busy(ptdev->base.dev);
    	pm_runtime_put_autosuspend(ptdev->base.dev);
    
    out_dev_exit:
    	drm_dev_exit(cookie);
    }
    
    static int panthor_queue_eval_syncwait(struct panthor_group *group, u8 queue_idx)
    {
    	struct panthor_queue *queue = group->queues[queue_idx];
    	union {
    		struct panthor_syncobj_64b sync64;
    		struct panthor_syncobj_32b sync32;
    	} *syncobj;
    	bool result;
    	u64 value;
    
    	syncobj = panthor_queue_get_syncwait_obj(group, queue);
    	if (!syncobj)
    		return -EINVAL;
    
    	value = queue->syncwait.sync64 ?
    		syncobj->sync64.seqno :
    		syncobj->sync32.seqno;
    
    	if (queue->syncwait.gt)
    		result = value > queue->syncwait.ref;
    	else
    		result = value <= queue->syncwait.ref;
    
    	if (result)
    		panthor_queue_put_syncwait_obj(queue);
    
    	return result;
    }
    
    static void sync_upd_work(struct work_struct *work)
    {
    	struct panthor_scheduler *sched = container_of(work,
    						      struct panthor_scheduler,
    						      sync_upd_work);
    	struct panthor_group *group, *tmp;
    	bool immediate_tick = false;
    
    	mutex_lock(&sched->lock);
    	list_for_each_entry_safe(group, tmp, &sched->groups.waiting, wait_node) {
    		u32 tested_queues = group->blocked_queues;
    		u32 unblocked_queues = 0;
    
    		while (tested_queues) {
    			u32 cs_id = ffs(tested_queues) - 1;
    			int ret;
    
    			ret = panthor_queue_eval_syncwait(group, cs_id);
    			drm_WARN_ON(&group->ptdev->base, ret < 0);
    			if (ret)
    				unblocked_queues |= BIT(cs_id);
    
    			tested_queues &= ~BIT(cs_id);
    		}
    
    		if (unblocked_queues) {
    			group->blocked_queues &= ~unblocked_queues;
    
    			if (group->csg_id < 0) {
    				list_move(&group->run_node,
    					  &sched->groups.runnable[group->priority]);
    				if (group->priority == PANTHOR_CSG_PRIORITY_RT)
    					immediate_tick = true;
    			}
    		}
    
    		if (!group->blocked_queues)
    			list_del_init(&group->wait_node);
    	}
    	mutex_unlock(&sched->lock);
    
    	if (immediate_tick)
    		sched_queue_delayed_work(sched, tick, 0);
    }
    
    static void group_schedule_locked(struct panthor_group *group, u32 queue_mask)
    {
    	struct panthor_device *ptdev = group->ptdev;
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct list_head *queue = &sched->groups.runnable[group->priority];
    	u64 delay_jiffies = 0;
    	bool was_idle;
    	u64 now;
    
    	if (!group_can_run(group))
    		return;
    
    	/* All updated queues are blocked, no need to wake up the scheduler. */
    	if ((queue_mask & group->blocked_queues) == queue_mask)
    		return;
    
    	was_idle = group_is_idle(group);
    	group->idle_queues &= ~queue_mask;
    
    	/* Don't mess up with the lists if we're in a middle of a reset. */
    	if (atomic_read(&sched->reset.in_progress))
    		return;
    
    	if (was_idle && !group_is_idle(group))
    		list_move_tail(&group->run_node, queue);
    
    	/* RT groups are preemptive. */
    	if (group->priority == PANTHOR_CSG_PRIORITY_RT) {
    		sched_queue_delayed_work(sched, tick, 0);
    		return;
    	}
    
    	/* Some groups might be idle, force an immediate tick to
    	 * re-evaluate.
    	 */
    	if (sched->might_have_idle_groups) {
    		sched_queue_delayed_work(sched, tick, 0);
    		return;
    	}
    
    	/* Scheduler is ticking, nothing to do. */
    	if (sched->resched_target != U64_MAX) {
    		/* If there are free slots, force immediating ticking. */
    		if (sched->used_csg_slot_count < sched->csg_slot_count)
    			sched_queue_delayed_work(sched, tick, 0);
    
    		return;
    	}
    
    	/* Scheduler tick was off, recalculate the resched_target based on the
    	 * last tick event, and queue the scheduler work.
    	 */
    	now = get_jiffies_64();
    	sched->resched_target = sched->last_tick + sched->tick_period;
    	if (sched->used_csg_slot_count == sched->csg_slot_count &&
    	    time_before64(now, sched->resched_target))
    		delay_jiffies = min_t(unsigned long, sched->resched_target - now, ULONG_MAX);
    
    	sched_queue_delayed_work(sched, tick, delay_jiffies);
    }
    
    static void queue_stop(struct panthor_queue *queue,
    		       struct panthor_job *bad_job)
    {
    	drm_sched_stop(&queue->scheduler, bad_job ? &bad_job->base : NULL);
    }
    
    static void queue_start(struct panthor_queue *queue)
    {
    	struct panthor_job *job;
    
    	/* Re-assign the parent fences. */
    	list_for_each_entry(job, &queue->scheduler.pending_list, base.list)
    		job->base.s_fence->parent = dma_fence_get(job->done_fence);
    
    	drm_sched_start(&queue->scheduler, true);
    }
    
    static void panthor_group_stop(struct panthor_group *group)
    {
    	struct panthor_scheduler *sched = group->ptdev->scheduler;
    
    	lockdep_assert_held(&sched->reset.lock);
    
    	for (u32 i = 0; i < group->queue_count; i++)
    		queue_stop(group->queues[i], NULL);
    
    	group_get(group);
    	list_move_tail(&group->run_node, &sched->reset.stopped_groups);
    }
    
    static void panthor_group_start(struct panthor_group *group)
    {
    	struct panthor_scheduler *sched = group->ptdev->scheduler;
    
    	lockdep_assert_held(&group->ptdev->scheduler->reset.lock);
    
    	for (u32 i = 0; i < group->queue_count; i++)
    		queue_start(group->queues[i]);
    
    	if (group_can_run(group)) {
    		list_move_tail(&group->run_node,
    			       group_is_idle(group) ?
    			       &sched->groups.idle[group->priority] :
    			       &sched->groups.runnable[group->priority]);
    	} else {
    		list_del_init(&group->run_node);
    		list_del_init(&group->wait_node);
    		group_queue_work(group, term);
    	}
    
    	group_put(group);
    }
    
    static void panthor_sched_immediate_tick(struct panthor_device *ptdev)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    
    	sched_queue_delayed_work(sched, tick, 0);
    }
    
    /**
     * panthor_sched_report_mmu_fault() - Report MMU faults to the scheduler.
     */
    void panthor_sched_report_mmu_fault(struct panthor_device *ptdev)
    {
    	/* Force a tick to immediately kill faulty groups. */
    	if (ptdev->scheduler)
    		panthor_sched_immediate_tick(ptdev);
    }
    
    void panthor_sched_resume(struct panthor_device *ptdev)
    {
    	/* Force a tick to re-evaluate after a resume. */
    	panthor_sched_immediate_tick(ptdev);
    }
    
    void panthor_sched_suspend(struct panthor_device *ptdev)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_csg_slots_upd_ctx upd_ctx;
    	struct panthor_group *group;
    	u32 suspended_slots;
    	u32 i;
    
    	mutex_lock(&sched->lock);
    	csgs_upd_ctx_init(&upd_ctx);
    	for (i = 0; i < sched->csg_slot_count; i++) {
    		struct panthor_csg_slot *csg_slot = &sched->csg_slots[i];
    
    		if (csg_slot->group) {
    			csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, i,
    						group_can_run(csg_slot->group) ?
    						CSG_STATE_SUSPEND : CSG_STATE_TERMINATE,
    						CSG_STATE_MASK);
    		}
    	}
    
    	suspended_slots = upd_ctx.update_mask;
    
    	csgs_upd_ctx_apply_locked(ptdev, &upd_ctx);
    	suspended_slots &= ~upd_ctx.timedout_mask;
    
    	if (upd_ctx.timedout_mask) {
    		u32 slot_mask = upd_ctx.timedout_mask;
    
    		drm_err(&ptdev->base, "CSG suspend failed, escalating to termination");
    		csgs_upd_ctx_init(&upd_ctx);
    		while (slot_mask) {
    			u32 csg_id = ffs(slot_mask) - 1;
    
    			csgs_upd_ctx_queue_reqs(ptdev, &upd_ctx, csg_id,
    						CSG_STATE_TERMINATE,
    						CSG_STATE_MASK);
    			slot_mask &= ~BIT(csg_id);
    		}
    
    		csgs_upd_ctx_apply_locked(ptdev, &upd_ctx);
    
    		slot_mask = upd_ctx.timedout_mask;
    		while (slot_mask) {
    			u32 csg_id = ffs(slot_mask) - 1;
    			struct panthor_csg_slot *csg_slot = &sched->csg_slots[csg_id];
    
    			/* Terminate command timedout, but the soft-reset will
    			 * automatically terminate all active groups, so let's
    			 * force the state to halted here.
    			 */
    			if (csg_slot->group->state != PANTHOR_CS_GROUP_TERMINATED)
    				csg_slot->group->state = PANTHOR_CS_GROUP_TERMINATED;
    			slot_mask &= ~BIT(csg_id);
    		}
    	}
    
    	/* Flush L2 and LSC caches to make sure suspend state is up-to-date.
    	 * If the flush fails, flag all queues for termination.
    	 */
    	if (suspended_slots) {
    		bool flush_caches_failed = false;
    		u32 slot_mask = suspended_slots;
    
    		if (panthor_gpu_flush_caches(ptdev, CACHE_CLEAN, CACHE_CLEAN, 0))
    			flush_caches_failed = true;
    
    		while (slot_mask) {
    			u32 csg_id = ffs(slot_mask) - 1;
    			struct panthor_csg_slot *csg_slot = &sched->csg_slots[csg_id];
    
    			if (flush_caches_failed)
    				csg_slot->group->state = PANTHOR_CS_GROUP_TERMINATED;
    			else
    				csg_slot_sync_update_locked(ptdev, csg_id);
    
    			slot_mask &= ~BIT(csg_id);
    		}
    	}
    
    	for (i = 0; i < sched->csg_slot_count; i++) {
    		struct panthor_csg_slot *csg_slot = &sched->csg_slots[i];
    
    		group = csg_slot->group;
    		if (!group)
    			continue;
    
    		group_get(group);
    
    		if (group->csg_id >= 0)
    			sched_process_csg_irq_locked(ptdev, group->csg_id);
    
    		group_unbind_locked(group);
    
    		drm_WARN_ON(&group->ptdev->base, !list_empty(&group->run_node));
    
    		if (group_can_run(group)) {
    			list_add(&group->run_node,
    				 &sched->groups.idle[group->priority]);
    		} else {
    			/* We don't bother stopping the scheduler if the group is
    			 * faulty, the group termination work will finish the job.
    			 */
    			list_del_init(&group->wait_node);
    			group_queue_work(group, term);
    		}
    		group_put(group);
    	}
    	mutex_unlock(&sched->lock);
    }
    
    void panthor_sched_pre_reset(struct panthor_device *ptdev)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_group *group, *group_tmp;
    	u32 i;
    
    	mutex_lock(&sched->reset.lock);
    	atomic_set(&sched->reset.in_progress, true);
    
    	/* Cancel all scheduler works. Once this is done, these works can't be
    	 * scheduled again until the reset operation is complete.
    	 */
    	cancel_work_sync(&sched->sync_upd_work);
    	cancel_delayed_work_sync(&sched->tick_work);
    
    	panthor_sched_suspend(ptdev);
    
    	/* Stop all groups that might still accept jobs, so we don't get passed
    	 * new jobs while we're resetting.
    	 */
    	for (i = 0; i < ARRAY_SIZE(sched->groups.runnable); i++) {
    		/* All groups should be in the idle lists. */
    		drm_WARN_ON(&ptdev->base, !list_empty(&sched->groups.runnable[i]));
    		list_for_each_entry_safe(group, group_tmp, &sched->groups.runnable[i], run_node)
    			panthor_group_stop(group);
    	}
    
    	for (i = 0; i < ARRAY_SIZE(sched->groups.idle); i++) {
    		list_for_each_entry_safe(group, group_tmp, &sched->groups.idle[i], run_node)
    			panthor_group_stop(group);
    	}
    
    	mutex_unlock(&sched->reset.lock);
    }
    
    void panthor_sched_post_reset(struct panthor_device *ptdev, bool reset_failed)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_group *group, *group_tmp;
    
    	mutex_lock(&sched->reset.lock);
    
    	list_for_each_entry_safe(group, group_tmp, &sched->reset.stopped_groups, run_node) {
    		/* Consider all previously running group as terminated if the
    		 * reset failed.
    		 */
    		if (reset_failed)
    			group->state = PANTHOR_CS_GROUP_TERMINATED;
    
    		panthor_group_start(group);
    	}
    
    	/* We're done resetting the GPU, clear the reset.in_progress bit so we can
    	 * kick the scheduler.
    	 */
    	atomic_set(&sched->reset.in_progress, false);
    	mutex_unlock(&sched->reset.lock);
    
    	/* No need to queue a tick and update syncs if the reset failed. */
    	if (!reset_failed) {
    		sched_queue_delayed_work(sched, tick, 0);
    		sched_queue_work(sched, sync_upd);
    	}
    }
    
    static void group_sync_upd_work(struct work_struct *work)
    {
    	struct panthor_group *group =
    		container_of(work, struct panthor_group, sync_upd_work);
    	struct panthor_job *job, *job_tmp;
    	LIST_HEAD(done_jobs);
    	u32 queue_idx;
    	bool cookie;
    
    	cookie = dma_fence_begin_signalling();
    	for (queue_idx = 0; queue_idx < group->queue_count; queue_idx++) {
    		struct panthor_queue *queue = group->queues[queue_idx];
    		struct panthor_syncobj_64b *syncobj;
    
    		if (!queue)
    			continue;
    
    		syncobj = group->syncobjs->kmap + (queue_idx * sizeof(*syncobj));
    
    		spin_lock(&queue->fence_ctx.lock);
    		list_for_each_entry_safe(job, job_tmp, &queue->fence_ctx.in_flight_jobs, node) {
    			if (!job->call_info.size)
    				continue;
    
    			if (syncobj->seqno < job->done_fence->seqno)
    				break;
    
    			list_move_tail(&job->node, &done_jobs);
    			dma_fence_signal_locked(job->done_fence);
    		}
    		spin_unlock(&queue->fence_ctx.lock);
    	}
    	dma_fence_end_signalling(cookie);
    
    	list_for_each_entry_safe(job, job_tmp, &done_jobs, node) {
    		list_del_init(&job->node);
    		panthor_job_put(&job->base);
    	}
    
    	group_put(group);
    }
    
    static struct dma_fence *
    queue_run_job(struct drm_sched_job *sched_job)
    {
    	struct panthor_job *job = container_of(sched_job, struct panthor_job, base);
    	struct panthor_group *group = job->group;
    	struct panthor_queue *queue = group->queues[job->queue_idx];
    	struct panthor_device *ptdev = group->ptdev;
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	u32 ringbuf_size = panthor_kernel_bo_size(queue->ringbuf);
    	u32 ringbuf_insert = queue->iface.input->insert & (ringbuf_size - 1);
    	u64 addr_reg = ptdev->csif_info.cs_reg_count -
    		       ptdev->csif_info.unpreserved_cs_reg_count;
    	u64 val_reg = addr_reg + 2;
    	u64 sync_addr = panthor_kernel_bo_gpuva(group->syncobjs) +
    			job->queue_idx * sizeof(struct panthor_syncobj_64b);
    	u32 waitall_mask = GENMASK(sched->sb_slot_count - 1, 0);
    	struct dma_fence *done_fence;
    	int ret;
    
    	u64 call_instrs[NUM_INSTRS_PER_SLOT] = {
    		/* MOV32 rX+2, cs.latest_flush */
    		(2ull << 56) | (val_reg << 48) | job->call_info.latest_flush,
    
    		/* FLUSH_CACHE2.clean_inv_all.no_wait.signal(0) rX+2 */
    		(36ull << 56) | (0ull << 48) | (val_reg << 40) | (0 << 16) | 0x233,
    
    		/* MOV48 rX:rX+1, cs.start */
    		(1ull << 56) | (addr_reg << 48) | job->call_info.start,
    
    		/* MOV32 rX+2, cs.size */
    		(2ull << 56) | (val_reg << 48) | job->call_info.size,
    
    		/* WAIT(0) => waits for FLUSH_CACHE2 instruction */
    		(3ull << 56) | (1 << 16),
    
    		/* CALL rX:rX+1, rX+2 */
    		(32ull << 56) | (addr_reg << 40) | (val_reg << 32),
    
    		/* MOV48 rX:rX+1, sync_addr */
    		(1ull << 56) | (addr_reg << 48) | sync_addr,
    
    		/* MOV48 rX+2, #1 */
    		(1ull << 56) | (val_reg << 48) | 1,
    
    		/* WAIT(all) */
    		(3ull << 56) | (waitall_mask << 16),
    
    		/* SYNC_ADD64.system_scope.propage_err.nowait rX:rX+1, rX+2*/
    		(51ull << 56) | (0ull << 48) | (addr_reg << 40) | (val_reg << 32) | (0 << 16) | 1,
    
    		/* ERROR_BARRIER, so we can recover from faults at job
    		 * boundaries.
    		 */
    		(47ull << 56),
    	};
    
    	/* Need to be cacheline aligned to please the prefetcher. */
    	static_assert(sizeof(call_instrs) % 64 == 0,
    		      "call_instrs is not aligned on a cacheline");
    
    	/* Stream size is zero, nothing to do => return a NULL fence and let
    	 * drm_sched signal the parent.
    	 */
    	if (!job->call_info.size)
    		return NULL;
    
    	ret = pm_runtime_resume_and_get(ptdev->base.dev);
    	if (drm_WARN_ON(&ptdev->base, ret))
    		return ERR_PTR(ret);
    
    	mutex_lock(&sched->lock);
    	if (!group_can_run(group)) {
    		done_fence = ERR_PTR(-ECANCELED);
    		goto out_unlock;
    	}
    
    	dma_fence_init(job->done_fence,
    		       &panthor_queue_fence_ops,
    		       &queue->fence_ctx.lock,
    		       queue->fence_ctx.id,
    		       atomic64_inc_return(&queue->fence_ctx.seqno));
    
    	memcpy(queue->ringbuf->kmap + ringbuf_insert,
    	       call_instrs, sizeof(call_instrs));
    
    	panthor_job_get(&job->base);
    	spin_lock(&queue->fence_ctx.lock);
    	list_add_tail(&job->node, &queue->fence_ctx.in_flight_jobs);
    	spin_unlock(&queue->fence_ctx.lock);
    
    	job->ringbuf.start = queue->iface.input->insert;
    	job->ringbuf.end = job->ringbuf.start + sizeof(call_instrs);
    
    	/* Make sure the ring buffer is updated before the INSERT
    	 * register.
    	 */
    	wmb();
    
    	queue->iface.input->extract = queue->iface.output->extract;
    	queue->iface.input->insert = job->ringbuf.end;
    
    	if (group->csg_id < 0) {
    		/* If the queue is blocked, we want to keep the timeout running, so we
    		 * can detect unbounded waits and kill the group when that happens.
    		 * Otherwise, we suspend the timeout so the time we spend waiting for
    		 * a CSG slot is not counted.
    		 */
    		if (!(group->blocked_queues & BIT(job->queue_idx)) &&
    		    !queue->timeout_suspended) {
    			queue->remaining_time = drm_sched_suspend_timeout(&queue->scheduler);
    			queue->timeout_suspended = true;
    		}
    
    		group_schedule_locked(group, BIT(job->queue_idx));
    	} else {
    		gpu_write(ptdev, CSF_DOORBELL(queue->doorbell_id), 1);
    		if (!sched->pm.has_ref &&
    		    !(group->blocked_queues & BIT(job->queue_idx))) {
    			pm_runtime_get(ptdev->base.dev);
    			sched->pm.has_ref = true;
    		}
    		panthor_devfreq_record_busy(sched->ptdev);
    	}
    
    	done_fence = dma_fence_get(job->done_fence);
    
    out_unlock:
    	mutex_unlock(&sched->lock);
    	pm_runtime_mark_last_busy(ptdev->base.dev);
    	pm_runtime_put_autosuspend(ptdev->base.dev);
    
    	return done_fence;
    }
    
    static enum drm_gpu_sched_stat
    queue_timedout_job(struct drm_sched_job *sched_job)
    {
    	struct panthor_job *job = container_of(sched_job, struct panthor_job, base);
    	struct panthor_group *group = job->group;
    	struct panthor_device *ptdev = group->ptdev;
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_queue *queue = group->queues[job->queue_idx];
    
    	drm_warn(&ptdev->base, "job timeout\n");
    
    	drm_WARN_ON(&ptdev->base, atomic_read(&sched->reset.in_progress));
    
    	queue_stop(queue, job);
    
    	mutex_lock(&sched->lock);
    	group->timedout = true;
    	if (group->csg_id >= 0) {
    		sched_queue_delayed_work(ptdev->scheduler, tick, 0);
    	} else {
    		/* Remove from the run queues, so the scheduler can't
    		 * pick the group on the next tick.
    		 */
    		list_del_init(&group->run_node);
    		list_del_init(&group->wait_node);
    
    		group_queue_work(group, term);
    	}
    	mutex_unlock(&sched->lock);
    
    	queue_start(queue);
    
    	return DRM_GPU_SCHED_STAT_NOMINAL;
    }
    
    static void queue_free_job(struct drm_sched_job *sched_job)
    {
    	drm_sched_job_cleanup(sched_job);
    	panthor_job_put(sched_job);
    }
    
    static const struct drm_sched_backend_ops panthor_queue_sched_ops = {
    	.run_job = queue_run_job,
    	.timedout_job = queue_timedout_job,
    	.free_job = queue_free_job,
    };
    
    static struct panthor_queue *
    group_create_queue(struct panthor_group *group,
    		   const struct drm_panthor_queue_create *args)
    {
    	struct drm_gpu_scheduler *drm_sched;
    	struct panthor_queue *queue;
    	int ret;
    
    	if (args->pad[0] || args->pad[1] || args->pad[2])
    		return ERR_PTR(-EINVAL);
    
    	if (args->ringbuf_size < SZ_4K || args->ringbuf_size > SZ_64K ||
    	    !is_power_of_2(args->ringbuf_size))
    		return ERR_PTR(-EINVAL);
    
    	if (args->priority > CSF_MAX_QUEUE_PRIO)
    		return ERR_PTR(-EINVAL);
    
    	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
    	if (!queue)
    		return ERR_PTR(-ENOMEM);
    
    	queue->fence_ctx.id = dma_fence_context_alloc(1);
    	spin_lock_init(&queue->fence_ctx.lock);
    	INIT_LIST_HEAD(&queue->fence_ctx.in_flight_jobs);
    
    	queue->priority = args->priority;
    
    	queue->ringbuf = panthor_kernel_bo_create(group->ptdev, group->vm,
    						  args->ringbuf_size,
    						  DRM_PANTHOR_BO_NO_MMAP,
    						  DRM_PANTHOR_VM_BIND_OP_MAP_NOEXEC |
    						  DRM_PANTHOR_VM_BIND_OP_MAP_UNCACHED,
    						  PANTHOR_VM_KERNEL_AUTO_VA);
    	if (IS_ERR(queue->ringbuf)) {
    		ret = PTR_ERR(queue->ringbuf);
    		goto err_free_queue;
    	}
    
    	ret = panthor_kernel_bo_vmap(queue->ringbuf);
    	if (ret)
    		goto err_free_queue;
    
    	queue->iface.mem = panthor_fw_alloc_queue_iface_mem(group->ptdev,
    							    &queue->iface.input,
    							    &queue->iface.output,
    							    &queue->iface.input_fw_va,
    							    &queue->iface.output_fw_va);
    	if (IS_ERR(queue->iface.mem)) {
    		ret = PTR_ERR(queue->iface.mem);
    		goto err_free_queue;
    	}
    
    	ret = drm_sched_init(&queue->scheduler, &panthor_queue_sched_ops,
    			     group->ptdev->scheduler->wq, 1,
    			     args->ringbuf_size / (NUM_INSTRS_PER_SLOT * sizeof(u64)),
    			     0, msecs_to_jiffies(JOB_TIMEOUT_MS),
    			     group->ptdev->reset.wq,
    			     NULL, "panthor-queue", group->ptdev->base.dev);
    	if (ret)
    		goto err_free_queue;
    
    	drm_sched = &queue->scheduler;
    	ret = drm_sched_entity_init(&queue->entity, 0, &drm_sched, 1, NULL);
    
    	return queue;
    
    err_free_queue:
    	group_free_queue(group, queue);
    	return ERR_PTR(ret);
    }
    
    #define MAX_GROUPS_PER_POOL		128
    
    int panthor_group_create(struct panthor_file *pfile,
    			 const struct drm_panthor_group_create *group_args,
    			 const struct drm_panthor_queue_create *queue_args)
    {
    	struct panthor_device *ptdev = pfile->ptdev;
    	struct panthor_group_pool *gpool = pfile->groups;
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_fw_csg_iface *csg_iface = panthor_fw_get_csg_iface(ptdev, 0);
    	struct panthor_group *group = NULL;
    	u32 gid, i, suspend_size;
    	int ret;
    
    	if (group_args->pad)
    		return -EINVAL;
    
    	if (group_args->priority > PANTHOR_CSG_PRIORITY_HIGH)
    		return -EINVAL;
    
    	if ((group_args->compute_core_mask & ~ptdev->gpu_info.shader_present) ||
    	    (group_args->fragment_core_mask & ~ptdev->gpu_info.shader_present) ||
    	    (group_args->tiler_core_mask & ~ptdev->gpu_info.tiler_present))
    		return -EINVAL;
    
    	if (hweight64(group_args->compute_core_mask) < group_args->max_compute_cores ||
    	    hweight64(group_args->fragment_core_mask) < group_args->max_fragment_cores ||
    	    hweight64(group_args->tiler_core_mask) < group_args->max_tiler_cores)
    		return -EINVAL;
    
    	group = kzalloc(sizeof(*group), GFP_KERNEL);
    	if (!group)
    		return -ENOMEM;
    
    	spin_lock_init(&group->fatal_lock);
    	kref_init(&group->refcount);
    	group->state = PANTHOR_CS_GROUP_CREATED;
    	group->csg_id = -1;
    
    	group->ptdev = ptdev;
    	group->max_compute_cores = group_args->max_compute_cores;
    	group->compute_core_mask = group_args->compute_core_mask;
    	group->max_fragment_cores = group_args->max_fragment_cores;
    	group->fragment_core_mask = group_args->fragment_core_mask;
    	group->max_tiler_cores = group_args->max_tiler_cores;
    	group->tiler_core_mask = group_args->tiler_core_mask;
    	group->priority = group_args->priority;
    
    	INIT_LIST_HEAD(&group->wait_node);
    	INIT_LIST_HEAD(&group->run_node);
    	INIT_WORK(&group->term_work, group_term_work);
    	INIT_WORK(&group->sync_upd_work, group_sync_upd_work);
    	INIT_WORK(&group->tiler_oom_work, group_tiler_oom_work);
    	INIT_WORK(&group->release_work, group_release_work);
    
    	group->vm = panthor_vm_pool_get_vm(pfile->vms, group_args->vm_id);
    	if (!group->vm) {
    		ret = -EINVAL;
    		goto err_put_group;
    	}
    
    	suspend_size = csg_iface->control->suspend_size;
    	group->suspend_buf = panthor_fw_alloc_suspend_buf_mem(ptdev, suspend_size);
    	if (IS_ERR(group->suspend_buf)) {
    		ret = PTR_ERR(group->suspend_buf);
    		group->suspend_buf = NULL;
    		goto err_put_group;
    	}
    
    	suspend_size = csg_iface->control->protm_suspend_size;
    	group->protm_suspend_buf = panthor_fw_alloc_suspend_buf_mem(ptdev, suspend_size);
    	if (IS_ERR(group->protm_suspend_buf)) {
    		ret = PTR_ERR(group->protm_suspend_buf);
    		group->protm_suspend_buf = NULL;
    		goto err_put_group;
    	}
    
    	group->syncobjs = panthor_kernel_bo_create(ptdev, group->vm,
    						   group_args->queues.count *
    						   sizeof(struct panthor_syncobj_64b),
    						   DRM_PANTHOR_BO_NO_MMAP,
    						   DRM_PANTHOR_VM_BIND_OP_MAP_NOEXEC |
    						   DRM_PANTHOR_VM_BIND_OP_MAP_UNCACHED,
    						   PANTHOR_VM_KERNEL_AUTO_VA);
    	if (IS_ERR(group->syncobjs)) {
    		ret = PTR_ERR(group->syncobjs);
    		goto err_put_group;
    	}
    
    	ret = panthor_kernel_bo_vmap(group->syncobjs);
    	if (ret)
    		goto err_put_group;
    
    	memset(group->syncobjs->kmap, 0,
    	       group_args->queues.count * sizeof(struct panthor_syncobj_64b));
    
    	for (i = 0; i < group_args->queues.count; i++) {
    		group->queues[i] = group_create_queue(group, &queue_args[i]);
    		if (IS_ERR(group->queues[i])) {
    			ret = PTR_ERR(group->queues[i]);
    			group->queues[i] = NULL;
    			goto err_put_group;
    		}
    
    		group->queue_count++;
    	}
    
    	group->idle_queues = GENMASK(group->queue_count - 1, 0);
    
    	ret = xa_alloc(&gpool->xa, &gid, group, XA_LIMIT(1, MAX_GROUPS_PER_POOL), GFP_KERNEL);
    	if (ret)
    		goto err_put_group;
    
    	mutex_lock(&sched->reset.lock);
    	if (atomic_read(&sched->reset.in_progress)) {
    		panthor_group_stop(group);
    	} else {
    		mutex_lock(&sched->lock);
    		list_add_tail(&group->run_node,
    			      &sched->groups.idle[group->priority]);
    		mutex_unlock(&sched->lock);
    	}
    	mutex_unlock(&sched->reset.lock);
    
    	return gid;
    
    err_put_group:
    	group_put(group);
    	return ret;
    }
    
    int panthor_group_destroy(struct panthor_file *pfile, u32 group_handle)
    {
    	struct panthor_group_pool *gpool = pfile->groups;
    	struct panthor_device *ptdev = pfile->ptdev;
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_group *group;
    
    	group = xa_erase(&gpool->xa, group_handle);
    	if (!group)
    		return -EINVAL;
    
    	for (u32 i = 0; i < group->queue_count; i++) {
    		if (group->queues[i])
    			drm_sched_entity_destroy(&group->queues[i]->entity);
    	}
    
    	mutex_lock(&sched->reset.lock);
    	mutex_lock(&sched->lock);
    	group->destroyed = true;
    	if (group->csg_id >= 0) {
    		sched_queue_delayed_work(sched, tick, 0);
    	} else if (!atomic_read(&sched->reset.in_progress)) {
    		/* Remove from the run queues, so the scheduler can't
    		 * pick the group on the next tick.
    		 */
    		list_del_init(&group->run_node);
    		list_del_init(&group->wait_node);
    		group_queue_work(group, term);
    	}
    	mutex_unlock(&sched->lock);
    	mutex_unlock(&sched->reset.lock);
    
    	group_put(group);
    	return 0;
    }
    
    int panthor_group_get_state(struct panthor_file *pfile,
    			    struct drm_panthor_group_get_state *get_state)
    {
    	struct panthor_group_pool *gpool = pfile->groups;
    	struct panthor_device *ptdev = pfile->ptdev;
    	struct panthor_scheduler *sched = ptdev->scheduler;
    	struct panthor_group *group;
    
    	if (get_state->pad)
    		return -EINVAL;
    
    	group = group_get(xa_load(&gpool->xa, get_state->group_handle));
    	if (!group)
    		return -EINVAL;
    
    	memset(get_state, 0, sizeof(*get_state));
    
    	mutex_lock(&sched->lock);
    	if (group->timedout)
    		get_state->state |= DRM_PANTHOR_GROUP_STATE_TIMEDOUT;
    	if (group->fatal_queues) {
    		get_state->state |= DRM_PANTHOR_GROUP_STATE_FATAL_FAULT;
    		get_state->fatal_queues = group->fatal_queues;
    	}
    	mutex_unlock(&sched->lock);
    
    	group_put(group);
    	return 0;
    }
    
    int panthor_group_pool_create(struct panthor_file *pfile)
    {
    	struct panthor_group_pool *gpool;
    
    	gpool = kzalloc(sizeof(*gpool), GFP_KERNEL);
    	if (!gpool)
    		return -ENOMEM;
    
    	xa_init_flags(&gpool->xa, XA_FLAGS_ALLOC1);
    	pfile->groups = gpool;
    	return 0;
    }
    
    void panthor_group_pool_destroy(struct panthor_file *pfile)
    {
    	struct panthor_group_pool *gpool = pfile->groups;
    	struct panthor_group *group;
    	unsigned long i;
    
    	if (IS_ERR_OR_NULL(gpool))
    		return;
    
    	xa_for_each(&gpool->xa, i, group)
    		panthor_group_destroy(pfile, i);
    
    	xa_destroy(&gpool->xa);
    	kfree(gpool);
    	pfile->groups = NULL;
    }
    
    static void job_release(struct kref *ref)
    {
    	struct panthor_job *job = container_of(ref, struct panthor_job, refcount);
    
    	drm_WARN_ON(&job->group->ptdev->base, !list_empty(&job->node));
    
    	if (job->base.s_fence)
    		drm_sched_job_cleanup(&job->base);
    
    	if (job->done_fence && job->done_fence->ops)
    		dma_fence_put(job->done_fence);
    	else
    		dma_fence_free(job->done_fence);
    
    	group_put(job->group);
    
    	kfree(job);
    }
    
    struct drm_sched_job *panthor_job_get(struct drm_sched_job *sched_job)
    {
    	if (sched_job) {
    		struct panthor_job *job = container_of(sched_job, struct panthor_job, base);
    
    		kref_get(&job->refcount);
    	}
    
    	return sched_job;
    }
    
    void panthor_job_put(struct drm_sched_job *sched_job)
    {
    	struct panthor_job *job = container_of(sched_job, struct panthor_job, base);
    
    	if (sched_job)
    		kref_put(&job->refcount, job_release);
    }
    
    struct panthor_vm *panthor_job_vm(struct drm_sched_job *sched_job)
    {
    	struct panthor_job *job = container_of(sched_job, struct panthor_job, base);
    
    	return job->group->vm;
    }
    
    struct drm_sched_job *
    panthor_job_create(struct panthor_file *pfile,
    		   u16 group_handle,
    		   const struct drm_panthor_queue_submit *qsubmit)
    {
    	struct panthor_group_pool *gpool = pfile->groups;
    	struct panthor_job *job;
    	int ret;
    
    	if (qsubmit->pad)
    		return ERR_PTR(-EINVAL);
    
    	/* If stream_addr is zero, so stream_size should be. */
    	if ((qsubmit->stream_size == 0) != (qsubmit->stream_addr == 0))
    		return ERR_PTR(-EINVAL);
    
    	/* Make sure the address is aligned on 64-byte (cacheline) and the size is
    	 * aligned on 8-byte (instruction size).
    	 */
    	if ((qsubmit->stream_addr & 63) || (qsubmit->stream_size & 7))
    		return ERR_PTR(-EINVAL);
    
    	/* bits 24:30 must be zero. */
    	if (qsubmit->latest_flush & GENMASK(30, 24))
    		return ERR_PTR(-EINVAL);
    
    	job = kzalloc(sizeof(*job), GFP_KERNEL);
    	if (!job)
    		return ERR_PTR(-ENOMEM);
    
    	kref_init(&job->refcount);
    	job->queue_idx = qsubmit->queue_index;
    	job->call_info.size = qsubmit->stream_size;
    	job->call_info.start = qsubmit->stream_addr;
    	job->call_info.latest_flush = qsubmit->latest_flush;
    	INIT_LIST_HEAD(&job->node);
    
    	job->group = group_get(xa_load(&gpool->xa, group_handle));
    	if (!job->group) {
    		ret = -EINVAL;
    		goto err_put_job;
    	}
    
    	if (job->queue_idx >= job->group->queue_count ||
    	    !job->group->queues[job->queue_idx]) {
    		ret = -EINVAL;
    		goto err_put_job;
    	}
    
    	job->done_fence = kzalloc(sizeof(*job->done_fence), GFP_KERNEL);
    	if (!job->done_fence) {
    		ret = -ENOMEM;
    		goto err_put_job;
    	}
    
    	ret = drm_sched_job_init(&job->base,
    				 &job->group->queues[job->queue_idx]->entity,
    				 1, job->group);
    	if (ret)
    		goto err_put_job;
    
    	return &job->base;
    
    err_put_job:
    	panthor_job_put(&job->base);
    	return ERR_PTR(ret);
    }
    
    void panthor_job_update_resvs(struct drm_exec *exec, struct drm_sched_job *sched_job)
    {
    	struct panthor_job *job = container_of(sched_job, struct panthor_job, base);
    
    	/* Still not sure why we want USAGE_WRITE for external objects, since I
    	 * was assuming this would be handled through explicit syncs being imported
    	 * to external BOs with DMA_BUF_IOCTL_IMPORT_SYNC_FILE, but other drivers
    	 * seem to pass DMA_RESV_USAGE_WRITE, so there must be a good reason.
    	 */
    	panthor_vm_update_resvs(job->group->vm, exec, &sched_job->s_fence->finished,
    				DMA_RESV_USAGE_BOOKKEEP, DMA_RESV_USAGE_WRITE);
    }
    
    void panthor_sched_unplug(struct panthor_device *ptdev)
    {
    	struct panthor_scheduler *sched = ptdev->scheduler;
    
    	cancel_delayed_work_sync(&sched->tick_work);
    
    	mutex_lock(&sched->lock);
    	if (sched->pm.has_ref) {
    		pm_runtime_put(ptdev->base.dev);
    		sched->pm.has_ref = false;
    	}
    	mutex_unlock(&sched->lock);
    }
    
    static void panthor_sched_fini(struct drm_device *ddev, void *res)
    {
    	struct panthor_scheduler *sched = res;
    	int prio;
    
    	if (!sched || !sched->csg_slot_count)
    		return;
    
    	cancel_delayed_work_sync(&sched->tick_work);
    
    	if (sched->wq)
    		destroy_workqueue(sched->wq);
    
    	if (sched->heap_alloc_wq)
    		destroy_workqueue(sched->heap_alloc_wq);
    
    	for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) {
    		drm_WARN_ON(ddev, !list_empty(&sched->groups.runnable[prio]));
    		drm_WARN_ON(ddev, !list_empty(&sched->groups.idle[prio]));
    	}
    
    	drm_WARN_ON(ddev, !list_empty(&sched->groups.waiting));
    }
    
    int panthor_sched_init(struct panthor_device *ptdev)
    {
    	struct panthor_fw_global_iface *glb_iface = panthor_fw_get_glb_iface(ptdev);
    	struct panthor_fw_csg_iface *csg_iface = panthor_fw_get_csg_iface(ptdev, 0);
    	struct panthor_fw_cs_iface *cs_iface = panthor_fw_get_cs_iface(ptdev, 0, 0);
    	struct panthor_scheduler *sched;
    	u32 gpu_as_count, num_groups;
    	int prio, ret;
    
    	sched = drmm_kzalloc(&ptdev->base, sizeof(*sched), GFP_KERNEL);
    	if (!sched)
    		return -ENOMEM;
    
    	/* The highest bit in JOB_INT_* is reserved for globabl IRQs. That
    	 * leaves 31 bits for CSG IRQs, hence the MAX_CSGS clamp here.
    	 */
    	num_groups = min_t(u32, MAX_CSGS, glb_iface->control->group_num);
    
    	/* The FW-side scheduler might deadlock if two groups with the same
    	 * priority try to access a set of resources that overlaps, with part
    	 * of the resources being allocated to one group and the other part to
    	 * the other group, both groups waiting for the remaining resources to
    	 * be allocated. To avoid that, it is recommended to assign each CSG a
    	 * different priority. In theory we could allow several groups to have
    	 * the same CSG priority if they don't request the same resources, but
    	 * that makes the scheduling logic more complicated, so let's clamp
    	 * the number of CSG slots to MAX_CSG_PRIO + 1 for now.
    	 */
    	num_groups = min_t(u32, MAX_CSG_PRIO + 1, num_groups);
    
    	/* We need at least one AS for the MCU and one for the GPU contexts. */
    	gpu_as_count = hweight32(ptdev->gpu_info.as_present & GENMASK(31, 1));
    	if (!gpu_as_count) {
    		drm_err(&ptdev->base, "Not enough AS (%d, expected at least 2)",
    			gpu_as_count + 1);
    		return -EINVAL;
    	}
    
    	sched->ptdev = ptdev;
    	sched->sb_slot_count = CS_FEATURES_SCOREBOARDS(cs_iface->control->features);
    	sched->csg_slot_count = num_groups;
    	sched->cs_slot_count = csg_iface->control->stream_num;
    	sched->as_slot_count = gpu_as_count;
    	ptdev->csif_info.csg_slot_count = sched->csg_slot_count;
    	ptdev->csif_info.cs_slot_count = sched->cs_slot_count;
    	ptdev->csif_info.scoreboard_slot_count = sched->sb_slot_count;
    
    	sched->last_tick = 0;
    	sched->resched_target = U64_MAX;
    	sched->tick_period = msecs_to_jiffies(10);
    	INIT_DELAYED_WORK(&sched->tick_work, tick_work);
    	INIT_WORK(&sched->sync_upd_work, sync_upd_work);
    	INIT_WORK(&sched->fw_events_work, process_fw_events_work);
    
    	ret = drmm_mutex_init(&ptdev->base, &sched->lock);
    	if (ret)
    		return ret;
    
    	for (prio = PANTHOR_CSG_PRIORITY_COUNT - 1; prio >= 0; prio--) {
    		INIT_LIST_HEAD(&sched->groups.runnable[prio]);
    		INIT_LIST_HEAD(&sched->groups.idle[prio]);
    	}
    	INIT_LIST_HEAD(&sched->groups.waiting);
    
    	ret = drmm_mutex_init(&ptdev->base, &sched->reset.lock);
    	if (ret)
    		return ret;
    
    	INIT_LIST_HEAD(&sched->reset.stopped_groups);
    
    	/* sched->heap_alloc_wq will be used for heap chunk allocation on
    	 * tiler OOM events, which means we can't use the same workqueue for
    	 * the scheduler because works queued by the scheduler are in
    	 * the dma-signalling path. Allocate a dedicated heap_alloc_wq to
    	 * work around this limitation.
    	 *
    	 * FIXME: Ultimately, what we need is a failable/non-blocking GEM
    	 * allocation path that we can call when a heap OOM is reported. The
    	 * FW is smart enough to fall back on other methods if the kernel can't
    	 * allocate memory, and fail the tiling job if none of these
    	 * countermeasures worked.
    	 *
    	 * Set WQ_MEM_RECLAIM on sched->wq to unblock the situation when the
    	 * system is running out of memory.
    	 */
    	sched->heap_alloc_wq = alloc_workqueue("panthor-heap-alloc", WQ_UNBOUND, 0);
    	sched->wq = alloc_workqueue("panthor-csf-sched", WQ_MEM_RECLAIM | WQ_UNBOUND, 0);
    	if (!sched->wq || !sched->heap_alloc_wq) {
    		panthor_sched_fini(&ptdev->base, sched);
    		drm_err(&ptdev->base, "Failed to allocate the workqueues");
    		return -ENOMEM;
    	}
    
    	ret = drmm_add_action_or_reset(&ptdev->base, panthor_sched_fini, sched);
    	if (ret)
    		return ret;
    
    	ptdev->scheduler = sched;
    	return 0;
    }