Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 581 insertions, 0 deletions

diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
new file mode 100644
index 000000000..ca857ec9e
--- /dev/null
+++ b/include/drm/gpu_scheduler.h
@@ -0,0 +1,581 @@
+/*
+ * Copyright 2015 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#ifndef _DRM_GPU_SCHEDULER_H_
+#define _DRM_GPU_SCHEDULER_H_
+
+#include <drm/spsc_queue.h>
+#include <linux/dma-fence.h>
+#include <linux/completion.h>
+#include <linux/xarray.h>
+#include <linux/workqueue.h>
+
+#define MAX_WAIT_SCHED_ENTITY_Q_EMPTY msecs_to_jiffies(1000)
+
+/**
+ * DRM_SCHED_FENCE_DONT_PIPELINE - Prefent dependency pipelining
+ *
+ * Setting this flag on a scheduler fence prevents pipelining of jobs depending
+ * on this fence. In other words we always insert a full CPU round trip before
+ * dependen jobs are pushed to the hw queue.
+ */
+#define DRM_SCHED_FENCE_DONT_PIPELINE	DMA_FENCE_FLAG_USER_BITS
+
+enum dma_resv_usage;
+struct dma_resv;
+struct drm_gem_object;
+
+struct drm_gpu_scheduler;
+struct drm_sched_rq;
+
+/* These are often used as an (initial) index
+ * to an array, and as such should start at 0.
+ */
+enum drm_sched_priority {
+	DRM_SCHED_PRIORITY_MIN,
+	DRM_SCHED_PRIORITY_NORMAL,
+	DRM_SCHED_PRIORITY_HIGH,
+	DRM_SCHED_PRIORITY_KERNEL,
+
+	DRM_SCHED_PRIORITY_COUNT,
+	DRM_SCHED_PRIORITY_UNSET = -2
+};
+
+/* Used to chose between FIFO and RR jobs scheduling */
+extern int drm_sched_policy;
+
+#define DRM_SCHED_POLICY_RR    0
+#define DRM_SCHED_POLICY_FIFO  1
+
+/**
+ * struct drm_sched_entity - A wrapper around a job queue (typically
+ * attached to the DRM file_priv).
+ *
+ * Entities will emit jobs in order to their corresponding hardware
+ * ring, and the scheduler will alternate between entities based on
+ * scheduling policy.
+ */
+struct drm_sched_entity {
+	/**
+	 * @list:
+	 *
+	 * Used to append this struct to the list of entities in the runqueue
+	 * @rq under &drm_sched_rq.entities.
+	 *
+	 * Protected by &drm_sched_rq.lock of @rq.
+	 */
+	struct list_head		list;
+
+	/**
+	 * @rq:
+	 *
+	 * Runqueue on which this entity is currently scheduled.
+	 *
+	 * FIXME: Locking is very unclear for this. Writers are protected by
+	 * @rq_lock, but readers are generally lockless and seem to just race
+	 * with not even a READ_ONCE.
+	 */
+	struct drm_sched_rq		*rq;
+
+	/**
+	 * @sched_list:
+	 *
+	 * A list of schedulers (struct drm_gpu_scheduler).  Jobs from this entity can
+	 * be scheduled on any scheduler on this list.
+	 *
+	 * This can be modified by calling drm_sched_entity_modify_sched().
+	 * Locking is entirely up to the driver, see the above function for more
+	 * details.
+	 *
+	 * This will be set to NULL if &num_sched_list equals 1 and @rq has been
+	 * set already.
+	 *
+	 * FIXME: This means priority changes through
+	 * drm_sched_entity_set_priority() will be lost henceforth in this case.
+	 */
+	struct drm_gpu_scheduler        **sched_list;
+
+	/**
+	 * @num_sched_list:
+	 *
+	 * Number of drm_gpu_schedulers in the @sched_list.
+	 */
+	unsigned int                    num_sched_list;
+
+	/**
+	 * @priority:
+	 *
+	 * Priority of the entity. This can be modified by calling
+	 * drm_sched_entity_set_priority(). Protected by &rq_lock.
+	 */
+	enum drm_sched_priority         priority;
+
+	/**
+	 * @rq_lock:
+	 *
+	 * Lock to modify the runqueue to which this entity belongs.
+	 */
+	spinlock_t			rq_lock;
+
+	/**
+	 * @job_queue: the list of jobs of this entity.
+	 */
+	struct spsc_queue		job_queue;
+
+	/**
+	 * @fence_seq:
+	 *
+	 * A linearly increasing seqno incremented with each new
+	 * &drm_sched_fence which is part of the entity.
+	 *
+	 * FIXME: Callers of drm_sched_job_arm() need to ensure correct locking,
+	 * this doesn't need to be atomic.
+	 */
+	atomic_t			fence_seq;
+
+	/**
+	 * @fence_context:
+	 *
+	 * A unique context for all the fences which belong to this entity.  The
+	 * &drm_sched_fence.scheduled uses the fence_context but
+	 * &drm_sched_fence.finished uses fence_context + 1.
+	 */
+	uint64_t			fence_context;
+
+	/**
+	 * @dependency:
+	 *
+	 * The dependency fence of the job which is on the top of the job queue.
+	 */
+	struct dma_fence		*dependency;
+
+	/**
+	 * @cb:
+	 *
+	 * Callback for the dependency fence above.
+	 */
+	struct dma_fence_cb		cb;
+
+	/**
+	 * @guilty:
+	 *
+	 * Points to entities' guilty.
+	 */
+	atomic_t			*guilty;
+
+	/**
+	 * @last_scheduled:
+	 *
+	 * Points to the finished fence of the last scheduled job. Only written
+	 * by the scheduler thread, can be accessed locklessly from
+	 * drm_sched_job_arm() iff the queue is empty.
+	 */
+	struct dma_fence                *last_scheduled;
+
+	/**
+	 * @last_user: last group leader pushing a job into the entity.
+	 */
+	struct task_struct		*last_user;
+
+	/**
+	 * @stopped:
+	 *
+	 * Marks the enity as removed from rq and destined for
+	 * termination. This is set by calling drm_sched_entity_flush() and by
+	 * drm_sched_fini().
+	 */
+	bool 				stopped;
+
+	/**
+	 * @entity_idle:
+	 *
+	 * Signals when entity is not in use, used to sequence entity cleanup in
+	 * drm_sched_entity_fini().
+	 */
+	struct completion		entity_idle;
+
+	/**
+	 * @oldest_job_waiting:
+	 *
+	 * Marks earliest job waiting in SW queue
+	 */
+	ktime_t				oldest_job_waiting;
+
+	/**
+	 * @rb_tree_node:
+	 *
+	 * The node used to insert this entity into time based priority queue
+	 */
+	struct rb_node			rb_tree_node;
+
+};
+
+/**
+ * struct drm_sched_rq - queue of entities to be scheduled.
+ *
+ * @lock: to modify the entities list.
+ * @sched: the scheduler to which this rq belongs to.
+ * @entities: list of the entities to be scheduled.
+ * @current_entity: the entity which is to be scheduled.
+ * @rb_tree_root: root of time based priory queue of entities for FIFO scheduling
+ *
+ * Run queue is a set of entities scheduling command submissions for
+ * one specific ring. It implements the scheduling policy that selects
+ * the next entity to emit commands from.
+ */
+struct drm_sched_rq {
+	spinlock_t			lock;
+	struct drm_gpu_scheduler	*sched;
+	struct list_head		entities;
+	struct drm_sched_entity		*current_entity;
+	struct rb_root_cached		rb_tree_root;
+};
+
+/**
+ * struct drm_sched_fence - fences corresponding to the scheduling of a job.
+ */
+struct drm_sched_fence {
+        /**
+         * @scheduled: this fence is what will be signaled by the scheduler
+         * when the job is scheduled.
+         */
+	struct dma_fence		scheduled;
+
+        /**
+         * @finished: this fence is what will be signaled by the scheduler
+         * when the job is completed.
+         *
+         * When setting up an out fence for the job, you should use
+         * this, since it's available immediately upon
+         * drm_sched_job_init(), and the fence returned by the driver
+         * from run_job() won't be created until the dependencies have
+         * resolved.
+         */
+	struct dma_fence		finished;
+
+        /**
+         * @parent: the fence returned by &drm_sched_backend_ops.run_job
+         * when scheduling the job on hardware. We signal the
+         * &drm_sched_fence.finished fence once parent is signalled.
+         */
+	struct dma_fence		*parent;
+        /**
+         * @sched: the scheduler instance to which the job having this struct
+         * belongs to.
+         */
+	struct drm_gpu_scheduler	*sched;
+        /**
+         * @lock: the lock used by the scheduled and the finished fences.
+         */
+	spinlock_t			lock;
+        /**
+         * @owner: job owner for debugging
+         */
+	void				*owner;
+};
+
+struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
+
+/**
+ * struct drm_sched_job - A job to be run by an entity.
+ *
+ * @queue_node: used to append this struct to the queue of jobs in an entity.
+ * @list: a job participates in a "pending" and "done" lists.
+ * @sched: the scheduler instance on which this job is scheduled.
+ * @s_fence: contains the fences for the scheduling of job.
+ * @finish_cb: the callback for the finished fence.
+ * @work: Helper to reschdeule job kill to different context.
+ * @id: a unique id assigned to each job scheduled on the scheduler.
+ * @karma: increment on every hang caused by this job. If this exceeds the hang
+ *         limit of the scheduler then the job is marked guilty and will not
+ *         be scheduled further.
+ * @s_priority: the priority of the job.
+ * @entity: the entity to which this job belongs.
+ * @cb: the callback for the parent fence in s_fence.
+ *
+ * A job is created by the driver using drm_sched_job_init(), and
+ * should call drm_sched_entity_push_job() once it wants the scheduler
+ * to schedule the job.
+ */
+struct drm_sched_job {
+	struct spsc_node		queue_node;
+	struct list_head		list;
+	struct drm_gpu_scheduler	*sched;
+	struct drm_sched_fence		*s_fence;
+
+	/*
+	 * work is used only after finish_cb has been used and will not be
+	 * accessed anymore.
+	 */
+	union {
+		struct dma_fence_cb		finish_cb;
+		struct work_struct		work;
+	};
+
+	uint64_t			id;
+	atomic_t			karma;
+	enum drm_sched_priority		s_priority;
+	struct drm_sched_entity         *entity;
+	struct dma_fence_cb		cb;
+	/**
+	 * @dependencies:
+	 *
+	 * Contains the dependencies as struct dma_fence for this job, see
+	 * drm_sched_job_add_dependency() and
+	 * drm_sched_job_add_implicit_dependencies().
+	 */
+	struct xarray			dependencies;
+
+	/** @last_dependency: tracks @dependencies as they signal */
+	unsigned long			last_dependency;
+
+	/**
+	 * @submit_ts:
+	 *
+	 * When the job was pushed into the entity queue.
+	 */
+	ktime_t                         submit_ts;
+};
+
+static inline bool drm_sched_invalidate_job(struct drm_sched_job *s_job,
+					    int threshold)
+{
+	return s_job && atomic_inc_return(&s_job->karma) > threshold;
+}
+
+enum drm_gpu_sched_stat {
+	DRM_GPU_SCHED_STAT_NONE, /* Reserve 0 */
+	DRM_GPU_SCHED_STAT_NOMINAL,
+	DRM_GPU_SCHED_STAT_ENODEV,
+};
+
+/**
+ * struct drm_sched_backend_ops - Define the backend operations
+ *	called by the scheduler
+ *
+ * These functions should be implemented in the driver side.
+ */
+struct drm_sched_backend_ops {
+	/**
+	 * @prepare_job:
+	 *
+	 * Called when the scheduler is considering scheduling this job next, to
+	 * get another struct dma_fence for this job to block on.  Once it
+	 * returns NULL, run_job() may be called.
+	 *
+	 * Can be NULL if no additional preparation to the dependencies are
+	 * necessary. Skipped when jobs are killed instead of run.
+	 */
+	struct dma_fence *(*prepare_job)(struct drm_sched_job *sched_job,
+					 struct drm_sched_entity *s_entity);
+
+	/**
+         * @run_job: Called to execute the job once all of the dependencies
+         * have been resolved.  This may be called multiple times, if
+	 * timedout_job() has happened and drm_sched_job_recovery()
+	 * decides to try it again.
+	 */
+	struct dma_fence *(*run_job)(struct drm_sched_job *sched_job);
+
+	/**
+	 * @timedout_job: Called when a job has taken too long to execute,
+	 * to trigger GPU recovery.
+	 *
+	 * This method is called in a workqueue context.
+	 *
+	 * Drivers typically issue a reset to recover from GPU hangs, and this
+	 * procedure usually follows the following workflow:
+	 *
+	 * 1. Stop the scheduler using drm_sched_stop(). This will park the
+	 *    scheduler thread and cancel the timeout work, guaranteeing that
+	 *    nothing is queued while we reset the hardware queue
+	 * 2. Try to gracefully stop non-faulty jobs (optional)
+	 * 3. Issue a GPU reset (driver-specific)
+	 * 4. Re-submit jobs using drm_sched_resubmit_jobs()
+	 * 5. Restart the scheduler using drm_sched_start(). At that point, new
+	 *    jobs can be queued, and the scheduler thread is unblocked
+	 *
+	 * Note that some GPUs have distinct hardware queues but need to reset
+	 * the GPU globally, which requires extra synchronization between the
+	 * timeout handler of the different &drm_gpu_scheduler. One way to
+	 * achieve this synchronization is to create an ordered workqueue
+	 * (using alloc_ordered_workqueue()) at the driver level, and pass this
+	 * queue to drm_sched_init(), to guarantee that timeout handlers are
+	 * executed sequentially. The above workflow needs to be slightly
+	 * adjusted in that case:
+	 *
+	 * 1. Stop all schedulers impacted by the reset using drm_sched_stop()
+	 * 2. Try to gracefully stop non-faulty jobs on all queues impacted by
+	 *    the reset (optional)
+	 * 3. Issue a GPU reset on all faulty queues (driver-specific)
+	 * 4. Re-submit jobs on all schedulers impacted by the reset using
+	 *    drm_sched_resubmit_jobs()
+	 * 5. Restart all schedulers that were stopped in step #1 using
+	 *    drm_sched_start()
+	 *
+	 * Return DRM_GPU_SCHED_STAT_NOMINAL, when all is normal,
+	 * and the underlying driver has started or completed recovery.
+	 *
+	 * Return DRM_GPU_SCHED_STAT_ENODEV, if the device is no longer
+	 * available, i.e. has been unplugged.
+	 */
+	enum drm_gpu_sched_stat (*timedout_job)(struct drm_sched_job *sched_job);
+
+	/**
+         * @free_job: Called once the job's finished fence has been signaled
+         * and it's time to clean it up.
+	 */
+	void (*free_job)(struct drm_sched_job *sched_job);
+};
+
+/**
+ * struct drm_gpu_scheduler - scheduler instance-specific data
+ *
+ * @ops: backend operations provided by the driver.
+ * @hw_submission_limit: the max size of the hardware queue.
+ * @timeout: the time after which a job is removed from the scheduler.
+ * @name: name of the ring for which this scheduler is being used.
+ * @sched_rq: priority wise array of run queues.
+ * @wake_up_worker: the wait queue on which the scheduler sleeps until a job
+ *                  is ready to be scheduled.
+ * @job_scheduled: once @drm_sched_entity_do_release is called the scheduler
+ *                 waits on this wait queue until all the scheduled jobs are
+ *                 finished.
+ * @hw_rq_count: the number of jobs currently in the hardware queue.
+ * @job_id_count: used to assign unique id to the each job.
+ * @timeout_wq: workqueue used to queue @work_tdr
+ * @work_tdr: schedules a delayed call to @drm_sched_job_timedout after the
+ *            timeout interval is over.
+ * @thread: the kthread on which the scheduler which run.
+ * @pending_list: the list of jobs which are currently in the job queue.
+ * @job_list_lock: lock to protect the pending_list.
+ * @hang_limit: once the hangs by a job crosses this limit then it is marked
+ *              guilty and it will no longer be considered for scheduling.
+ * @score: score to help loadbalancer pick a idle sched
+ * @_score: score used when the driver doesn't provide one
+ * @ready: marks if the underlying HW is ready to work
+ * @free_guilty: A hit to time out handler to free the guilty job.
+ * @dev: system &struct device
+ *
+ * One scheduler is implemented for each hardware ring.
+ */
+struct drm_gpu_scheduler {
+	const struct drm_sched_backend_ops	*ops;
+	uint32_t			hw_submission_limit;
+	long				timeout;
+	const char			*name;
+	struct drm_sched_rq		sched_rq[DRM_SCHED_PRIORITY_COUNT];
+	wait_queue_head_t		wake_up_worker;
+	wait_queue_head_t		job_scheduled;
+	atomic_t			hw_rq_count;
+	atomic64_t			job_id_count;
+	struct workqueue_struct		*timeout_wq;
+	struct delayed_work		work_tdr;
+	struct task_struct		*thread;
+	struct list_head		pending_list;
+	spinlock_t			job_list_lock;
+	int				hang_limit;
+	atomic_t                        *score;
+	atomic_t                        _score;
+	bool				ready;
+	bool				free_guilty;
+	struct device			*dev;
+};
+
+int drm_sched_init(struct drm_gpu_scheduler *sched,
+		   const struct drm_sched_backend_ops *ops,
+		   uint32_t hw_submission, unsigned hang_limit,
+		   long timeout, struct workqueue_struct *timeout_wq,
+		   atomic_t *score, const char *name, struct device *dev);
+
+void drm_sched_fini(struct drm_gpu_scheduler *sched);
+int drm_sched_job_init(struct drm_sched_job *job,
+		       struct drm_sched_entity *entity,
+		       void *owner);
+void drm_sched_job_arm(struct drm_sched_job *job);
+int drm_sched_job_add_dependency(struct drm_sched_job *job,
+				 struct dma_fence *fence);
+int drm_sched_job_add_resv_dependencies(struct drm_sched_job *job,
+					struct dma_resv *resv,
+					enum dma_resv_usage usage);
+int drm_sched_job_add_implicit_dependencies(struct drm_sched_job *job,
+					    struct drm_gem_object *obj,
+					    bool write);
+
+
+void drm_sched_entity_modify_sched(struct drm_sched_entity *entity,
+				    struct drm_gpu_scheduler **sched_list,
+                                   unsigned int num_sched_list);
+
+void drm_sched_job_cleanup(struct drm_sched_job *job);
+void drm_sched_wakeup(struct drm_gpu_scheduler *sched);
+void drm_sched_stop(struct drm_gpu_scheduler *sched, struct drm_sched_job *bad);
+void drm_sched_start(struct drm_gpu_scheduler *sched, bool full_recovery);
+void drm_sched_resubmit_jobs(struct drm_gpu_scheduler *sched);
+void drm_sched_increase_karma(struct drm_sched_job *bad);
+void drm_sched_reset_karma(struct drm_sched_job *bad);
+void drm_sched_increase_karma_ext(struct drm_sched_job *bad, int type);
+bool drm_sched_dependency_optimized(struct dma_fence* fence,
+				    struct drm_sched_entity *entity);
+void drm_sched_fault(struct drm_gpu_scheduler *sched);
+void drm_sched_job_kickout(struct drm_sched_job *s_job);
+
+void drm_sched_rq_add_entity(struct drm_sched_rq *rq,
+			     struct drm_sched_entity *entity);
+void drm_sched_rq_remove_entity(struct drm_sched_rq *rq,
+				struct drm_sched_entity *entity);
+
+void drm_sched_rq_update_fifo(struct drm_sched_entity *entity, ktime_t ts);
+
+int drm_sched_entity_init(struct drm_sched_entity *entity,
+			  enum drm_sched_priority priority,
+			  struct drm_gpu_scheduler **sched_list,
+			  unsigned int num_sched_list,
+			  atomic_t *guilty);
+long drm_sched_entity_flush(struct drm_sched_entity *entity, long timeout);
+void drm_sched_entity_fini(struct drm_sched_entity *entity);
+void drm_sched_entity_destroy(struct drm_sched_entity *entity);
+void drm_sched_entity_select_rq(struct drm_sched_entity *entity);
+struct drm_sched_job *drm_sched_entity_pop_job(struct drm_sched_entity *entity);
+void drm_sched_entity_push_job(struct drm_sched_job *sched_job);
+void drm_sched_entity_set_priority(struct drm_sched_entity *entity,
+				   enum drm_sched_priority priority);
+bool drm_sched_entity_is_ready(struct drm_sched_entity *entity);
+
+struct drm_sched_fence *drm_sched_fence_alloc(
+	struct drm_sched_entity *s_entity, void *owner);
+void drm_sched_fence_init(struct drm_sched_fence *fence,
+			  struct drm_sched_entity *entity);
+void drm_sched_fence_free(struct drm_sched_fence *fence);
+
+void drm_sched_fence_scheduled(struct drm_sched_fence *fence);
+void drm_sched_fence_finished(struct drm_sched_fence *fence);
+
+unsigned long drm_sched_suspend_timeout(struct drm_gpu_scheduler *sched);
+void drm_sched_resume_timeout(struct drm_gpu_scheduler *sched,
+		                unsigned long remaining);
+struct drm_gpu_scheduler *
+drm_sched_pick_best(struct drm_gpu_scheduler **sched_list,
+		     unsigned int num_sched_list);
+
+#endif