LXR linux/drivers/gpu/drm/i915/gt/intel_timeline

   1/* SPDX-License-Identifier: MIT */
   2/*
   3 * Copyright © 2016 Intel Corporation
   4 */
   5
   6#ifndef __I915_TIMELINE_TYPES_H__
   7#define __I915_TIMELINE_TYPES_H__
   8
   9#include <linux/list.h>
  10#include <linux/kref.h>
  11#include <linux/mutex.h>
  12#include <linux/rcupdate.h>
  13#include <linux/types.h>
  14
  15#include "i915_active_types.h"
  16
  17struct i915_vma;
  18struct i915_syncmap;
  19struct intel_gt;
  20
  21struct intel_timeline {
  22        u64 fence_context;
  23        u32 seqno;
  24
  25        struct mutex mutex; /* protects the flow of requests */
  26
  27        /*
  28         * pin_count and active_count track essentially the same thing:
  29         * How many requests are in flight or may be under construction.
  30         *
  31         * We need two distinct counters so that we can assign different
  32         * lifetimes to the events for different use-cases. For example,
  33         * we want to permanently keep the timeline pinned for the kernel
  34         * context so that we can issue requests at any time without having
  35         * to acquire space in the GGTT. However, we want to keep tracking
  36         * the activity (to be able to detect when we become idle) along that
  37         * permanently pinned timeline and so end up requiring two counters.
  38         *
  39         * Note that the active_count is protected by the intel_timeline.mutex,
  40         * but the pin_count is protected by a combination of serialisation
  41         * from the intel_context caller plus internal atomicity.
  42         */
  43        atomic_t pin_count;
  44        atomic_t active_count;
  45
  46        void *hwsp_map;
  47        const u32 *hwsp_seqno;
  48        struct i915_vma *hwsp_ggtt;
  49        u32 hwsp_offset;
  50
  51        bool has_initial_breadcrumb;
  52
  53        /**
  54         * List of breadcrumbs associated with GPU requests currently
  55         * outstanding.
  56         */
  57        struct list_head requests;
  58
  59        /*
  60         * Contains an RCU guarded pointer to the last request. No reference is
  61         * held to the request, users must carefully acquire a reference to
  62         * the request using i915_active_fence_get(), or manage the RCU
  63         * protection themselves (cf the i915_active_fence API).
  64         */
  65        struct i915_active_fence last_request;
  66
  67        struct i915_active active;
  68
  69        /** A chain of completed timelines ready for early retirement. */
  70        struct intel_timeline *retire;
  71
  72        /**
  73         * We track the most recent seqno that we wait on in every context so
  74         * that we only have to emit a new await and dependency on a more
  75         * recent sync point. As the contexts may be executed out-of-order, we
  76         * have to track each individually and can not rely on an absolute
  77         * global_seqno. When we know that all tracked fences are completed
  78         * (i.e. when the driver is idle), we know that the syncmap is
  79         * redundant and we can discard it without loss of generality.
  80         */
  81        struct i915_syncmap *sync;
  82
  83        struct list_head link;
  84        struct intel_gt *gt;
  85
  86        struct list_head engine_link;
  87
  88        struct kref kref;
  89        struct rcu_head rcu;
  90};
  91
  92#endif /* __I915_TIMELINE_TYPES_H__ */
  93