* SPDX-License-Identifier: MIT
 * Copyright © 2019 Intel Corporation


#include <linux/hashtable.h>
#include <linux/irq_work.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/llist.h>
#include <linux/rbtree.h>
#include <linux/timer.h>
#include <linux/types.h>

#include "i915_gem.h"
#include "i915_pmu.h"
#include "i915_priolist_types.h"
#include "i915_selftest.h"
#include "intel_engine_pool_types.h"
#include "intel_sseu.h"
#include "intel_timeline_types.h"
#include "intel_wakeref.h"
#include "intel_workarounds_types.h"

/* Legacy HW Engine ID */

#define RCS0_HW		0
#define VCS0_HW		1
#define BCS0_HW		2
#define VECS0_HW	3
#define VCS1_HW		4
#define VCS2_HW		6
#define VCS3_HW		7
#define VECS1_HW	12

/* Gen11+ HW Engine class + instance */
#define RENDER_CLASS		0
#define OTHER_CLASS		4

#define I915_MAX_SLICES	3
#define I915_MAX_SUBSLICES 8

#define I915_CMD_HASH_ORDER 9

struct dma_fence;
struct drm_i915_gem_object;
struct drm_i915_reg_table;
struct i915_gem_context;
struct i915_request;
struct i915_sched_attr;
struct intel_gt;
struct intel_uncore;

typedef u8 intel_engine_mask_t;
#define ALL_ENGINES ((intel_engine_mask_t)~0ul)

struct intel_hw_status_page {
	struct i915_vma *vma;
	u32 *addr;

struct intel_instdone {
	u32 instdone;
	/* The following exist only in the RCS engine */
	u32 slice_common;
	u32 sampler[I915_MAX_SLICES][I915_MAX_SUBSLICES];
	u32 row[I915_MAX_SLICES][I915_MAX_SUBSLICES];

struct intel_engine_hangcheck {
	u64 acthd;
	u32 last_ring;
	u32 last_head;
	unsigned long action_timestamp;
	struct intel_instdone instdone;

struct intel_ring {
	struct kref ref;
	struct i915_vma *vma;
	void *vaddr;

	 * As we have two types of rings, one global to the engine used
	 * by ringbuffer submission and those that are exclusive to a
	 * context used by execlists, we have to play safe and allow
	 * atomic updates to the pin_count. However, the actual pinning
	 * of the context is either done during initialisation for
	 * ringbuffer submission or serialised as part of the context
	 * pinning for execlists, and so we do not need a mutex ourselves
	 * to serialise intel_ring_pin/intel_ring_unpin.
	atomic_t pin_count;

	u32 head;
	u32 tail;
	u32 emit;

	u32 space;
	u32 size;
	u32 effective_size;

 * we use a single page to load ctx workarounds so all of these
 * values are referred in terms of dwords
 * struct i915_wa_ctx_bb:
 *  offset: specifies batch starting position, also helpful in case
 *    if we want to have multiple batches at different offsets based on
 *    some criteria. It is not a requirement at the moment but provides
 *    an option for future use.
 *  size: size of the batch in DWORDS
struct i915_ctx_workarounds {
	struct i915_wa_ctx_bb {
		u32 offset;
		u32 size;
	} indirect_ctx, per_ctx;
	struct i915_vma *vma;

#define I915_MAX_VCS	4
#define I915_MAX_VECS	2

 * Engine IDs definitions.
 * Keep instances of the same type engine together.
enum intel_engine_id {
	RCS0 = 0,
#define _VCS(n) (VCS0 + (n))
#define _VECS(n) (VECS0 + (n))

struct st_preempt_hang {
	struct completion completion;
	unsigned int count;
	bool inject_hang;

 * struct intel_engine_execlists - execlist submission queue and port state
 * The struct intel_engine_execlists represents the combined logical state of
 * driver and the hardware state for execlist mode of submission.
struct intel_engine_execlists {
	 * @tasklet: softirq tasklet for bottom handler
	struct tasklet_struct tasklet;

	 * @timer: kick the current context if its timeslice expires
	struct timer_list timer;

	 * @default_priolist: priority list for I915_PRIORITY_NORMAL
	struct i915_priolist default_priolist;

	 * @no_priolist: priority lists disabled
	bool no_priolist;

	 * @submit_reg: gen-specific execlist submission register
	 * set to the ExecList Submission Port (elsp) register pre-Gen11 and to
	 * the ExecList Submission Queue Contents register array for Gen11+
	u32 __iomem *submit_reg;

	 * @ctrl_reg: the enhanced execlists control register, used to load the
	 * submit queue on the HW and to request preemptions to idle
	u32 __iomem *ctrl_reg;

	 * @active: the currently known context executing on HW
	struct i915_request * const *active;
	 * @inflight: the set of contexts submitted and acknowleged by HW
	 * The set of inflight contexts is managed by reading CS events
	 * from the HW. On a context-switch event (not preemption), we
	 * know the HW has transitioned from port0 to port1, and we
	 * advance our inflight/active tracking accordingly.
	struct i915_request *inflight[EXECLIST_MAX_PORTS + 1 /* sentinel */];
	 * @pending: the next set of contexts submitted to ELSP
	 * We store the array of contexts that we submit to HW (via ELSP) and
	 * promote them to the inflight array once HW has signaled the
	 * preemption or idle-to-active event.
	struct i915_request *pending[EXECLIST_MAX_PORTS + 1];

	 * @port_mask: number of execlist ports - 1
	unsigned int port_mask;

	 * @switch_priority_hint: Second context priority.
	 * We submit multiple contexts to the HW simultaneously and would
	 * like to occasionally switch between them to emulate timeslicing.
	 * To know when timeslicing is suitable, we track the priority of
	 * the context submitted second.
	int switch_priority_hint;

	 * @queue_priority_hint: Highest pending priority.
	 * When we add requests into the queue, or adjust the priority of
	 * executing requests, we compute the maximum priority of those
	 * pending requests. We can then use this value to determine if
	 * we need to preempt the executing requests to service the queue.
	 * However, since the we may have recorded the priority of an inflight
	 * request we wanted to preempt but since completed, at the time of
	 * dequeuing the priority hint may no longer may match the highest
	 * available request priority.
	int queue_priority_hint;

	 * @queue: queue of requests, in priority lists
	struct rb_root_cached queue;
	struct rb_root_cached virtual;

	 * @csb_write: control register for Context Switch buffer
	 * Note this register may be either mmio or HWSP shadow.
	u32 *csb_write;

	 * @csb_status: status array for Context Switch buffer
	 * Note these register may be either mmio or HWSP shadow.
	u32 *csb_status;

	 * @csb_size: context status buffer FIFO size
	u8 csb_size;

	 * @csb_head: context status buffer head
	u8 csb_head;

	I915_SELFTEST_DECLARE(struct st_preempt_hang preempt_hang;)


struct intel_engine_cs {
	struct drm_i915_private *i915;
	struct intel_gt *gt;
	struct intel_uncore *uncore;

	enum intel_engine_id id;
	enum intel_engine_id legacy_idx;

	unsigned int hw_id;
	unsigned int guc_id;

	intel_engine_mask_t mask;

	u8 class;
	u8 instance;

	u8 uabi_class;
	u8 uabi_instance;

	u32 context_size;
	u32 mmio_base;

	u32 uabi_capabilities;

	struct rb_node uabi_node;

	struct intel_sseu sseu;

	struct {
		spinlock_t lock;
		struct list_head requests;
	} active;

	struct llist_head barrier_tasks;

	struct intel_context *kernel_context; /* pinned */

	intel_engine_mask_t saturated; /* submitting semaphores too late? */

	unsigned long serial;

	unsigned long wakeref_serial;
	struct intel_wakeref wakeref;
	struct drm_i915_gem_object *default_state;
	void *pinned_default_state;

	struct {
		struct intel_ring *ring;
		struct intel_timeline *timeline;
	} legacy;

	/* Rather than have every client wait upon all user interrupts,
	 * with the herd waking after every interrupt and each doing the
	 * heavyweight seqno dance, we delegate the task (of being the
	 * bottom-half of the user interrupt) to the first client. After
	 * every interrupt, we wake up one client, who does the heavyweight
	 * coherent seqno read and either goes back to sleep (if incomplete),
	 * or wakes up all the completed clients in parallel, before then
	 * transferring the bottom-half status to the next client in the queue.
	 * Compared to walking the entire list of waiters in a single dedicated
	 * bottom-half, we reduce the latency of the first waiter by avoiding
	 * a context switch, but incur additional coherent seqno reads when
	 * following the chain of request breadcrumbs. Since it is most likely
	 * that we have a single client waiting on each seqno, then reducing
	 * the overhead of waking that client is much preferred.
	struct intel_breadcrumbs {
		spinlock_t irq_lock;
		struct list_head signalers;

		struct irq_work irq_work; /* for use from inside irq_lock */

		unsigned int irq_enabled;

		bool irq_armed;
	} breadcrumbs;

	struct intel_engine_pmu {
		 * @enable: Bitmask of enable sample events on this engine.
		 * Bits correspond to sample event types, for instance
		 * I915_SAMPLE_QUEUED is bit 0 etc.
		u32 enable;
		 * @enable_count: Reference count for the enabled samplers.
		 * Index number corresponds to @enum drm_i915_pmu_engine_sample.
		unsigned int enable_count[I915_ENGINE_SAMPLE_COUNT];
		 * @sample: Counter values for sampling events.
		 * Our internal timer stores the current counters in this field.
		 * Index number corresponds to @enum drm_i915_pmu_engine_sample.
		struct i915_pmu_sample sample[I915_ENGINE_SAMPLE_COUNT];
	} pmu;

	 * A pool of objects to use as shadow copies of client batch buffers
	 * when the command parser is enabled. Prevents the client from
	 * modifying the batch contents after software parsing.
	struct intel_engine_pool pool;

	struct intel_hw_status_page status_page;
	struct i915_ctx_workarounds wa_ctx;
	struct i915_wa_list ctx_wa_list;
	struct i915_wa_list wa_list;
	struct i915_wa_list whitelist;

	u32             irq_keep_mask; /* always keep these interrupts */
	u32		irq_enable_mask; /* bitmask to enable ring interrupt */
	void		(*irq_enable)(struct intel_engine_cs *engine);
	void		(*irq_disable)(struct intel_engine_cs *engine);

	int		(*resume)(struct intel_engine_cs *engine);

	struct {
		void (*prepare)(struct intel_engine_cs *engine);
		void (*reset)(struct intel_engine_cs *engine, bool stalled);
		void (*finish)(struct intel_engine_cs *engine);
	} reset;

	void		(*park)(struct intel_engine_cs *engine);
	void		(*unpark)(struct intel_engine_cs *engine);

	void		(*set_default_submission)(struct intel_engine_cs *engine);

	const struct intel_context_ops *cops;

	int		(*request_alloc)(struct i915_request *rq);

	int		(*emit_flush)(struct i915_request *request, u32 mode);
#define EMIT_FLUSH	BIT(1)
	int		(*emit_bb_start)(struct i915_request *rq,
					 u64 offset, u32 length,
					 unsigned int dispatch_flags);
	int		 (*emit_init_breadcrumb)(struct i915_request *rq);
	u32		*(*emit_fini_breadcrumb)(struct i915_request *rq,
						 u32 *cs);
	unsigned int	emit_fini_breadcrumb_dw;

	/* Pass the request to the hardware queue (e.g. directly into
	 * the legacy ringbuffer or to the end of an execlist).
	 * This is called from an atomic context with irqs disabled; must
	 * be irq safe.
	void		(*submit_request)(struct i915_request *rq);

	 * Called on signaling of a SUBMIT_FENCE, passing along the signaling
	 * request down to the bonded pairs.
	void            (*bond_execute)(struct i915_request *rq,
					struct dma_fence *signal);

	 * Call when the priority on a request has changed and it and its
	 * dependencies may need rescheduling. Note the request itself may
	 * not be ready to run!
	void		(*schedule)(struct i915_request *request,
				    const struct i915_sched_attr *attr);

	 * Cancel all requests on the hardware, or queued for execution.
	 * This should only cancel the ready requests that have been
	 * submitted to the engine (via the engine->submit_request callback).
	 * This is called when marking the device as wedged.
	void		(*cancel_requests)(struct intel_engine_cs *engine);

	void		(*destroy)(struct intel_engine_cs *engine);

	struct intel_engine_execlists execlists;

	/* status_notifier: list of callbacks for context-switch changes */
	struct atomic_notifier_head context_status_notifier;

	struct intel_engine_hangcheck hangcheck;

#define I915_ENGINE_IS_VIRTUAL       BIT(5)
	unsigned int flags;

	 * Table of commands the command parser needs to know about
	 * for this engine.

	 * Table of registers allowed in commands that read/write registers.
	const struct drm_i915_reg_table *reg_tables;
	int reg_table_count;

	 * Returns the bitmask for the length field of the specified command.
	 * Return 0 for an unrecognized/invalid command.
	 * If the command parser finds an entry for a command in the engine's
	 * cmd_tables, it gets the command's length based on the table entry.
	 * If not, it calls this function to determine the per-engine length
	 * field encoding for the command (i.e. different opcode ranges use
	 * certain bits to encode the command length in the header).
	u32 (*get_cmd_length_mask)(u32 cmd_header);

	struct {
		 * @lock: Lock protecting the below fields.
		seqlock_t lock;
		 * @enabled: Reference count indicating number of listeners.
		unsigned int enabled;
		 * @active: Number of contexts currently scheduled in.
		unsigned int active;
		 * @enabled_at: Timestamp when busy stats were enabled.
		ktime_t enabled_at;
		 * @start: Timestamp of the last idle to active transition.
		 * Idle is defined as active == 0, active is active > 0.
		ktime_t start;
		 * @total: Total time this engine was busy.
		 * Accumulated time not counting the most recent block in cases
		 * where engine is currently busy (active > 0).
		ktime_t total;
	} stats;

static inline bool
intel_engine_needs_cmd_parser(const struct intel_engine_cs *engine)
	return engine->flags & I915_ENGINE_NEEDS_CMD_PARSER;

static inline bool
intel_engine_supports_stats(const struct intel_engine_cs *engine)
	return engine->flags & I915_ENGINE_SUPPORTS_STATS;

static inline bool
intel_engine_has_preemption(const struct intel_engine_cs *engine)
	return engine->flags & I915_ENGINE_HAS_PREEMPTION;

static inline bool
intel_engine_has_semaphores(const struct intel_engine_cs *engine)
	return engine->flags & I915_ENGINE_HAS_SEMAPHORES;

static inline bool
intel_engine_needs_breadcrumb_tasklet(const struct intel_engine_cs *engine)
	return engine->flags & I915_ENGINE_NEEDS_BREADCRUMB_TASKLET;

static inline bool
intel_engine_is_virtual(const struct intel_engine_cs *engine)
	return engine->flags & I915_ENGINE_IS_VIRTUAL;

#define instdone_slice_mask(dev_priv__) \
	(IS_GEN(dev_priv__, 7) ? \
	 1 : RUNTIME_INFO(dev_priv__)->sseu.slice_mask)

#define instdone_subslice_mask(dev_priv__) \
	(IS_GEN(dev_priv__, 7) ? \
	 1 : RUNTIME_INFO(dev_priv__)->sseu.subslice_mask[0])

#define for_each_instdone_slice_subslice(dev_priv__, slice__, subslice__) \
	for ((slice__) = 0, (subslice__) = 0; \
	     (slice__) < I915_MAX_SLICES; \
	     (subslice__) = ((subslice__) + 1) < I915_MAX_SUBSLICES ? (subslice__) + 1 : 0, \
	       (slice__) += ((subslice__) == 0)) \
		for_each_if((BIT(slice__) & instdone_slice_mask(dev_priv__)) && \
			    (BIT(subslice__) & instdone_subslice_mask(dev_priv__)))

#endif /* __INTEL_ENGINE_TYPES_H__ */