1 files changed, 634 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
new file mode 100644
index 0000000000..a53b26178f
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -0,0 +1,634 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include "gem/i915_gem_context.h"
+#include "gem/i915_gem_pm.h"
+
+#include "i915_drv.h"
+#include "i915_trace.h"
+
+#include "intel_context.h"
+#include "intel_engine.h"
+#include "intel_engine_pm.h"
+#include "intel_ring.h"
+
+static struct kmem_cache *slab_ce;
+
+static struct intel_context *intel_context_alloc(void)
+{
+	return kmem_cache_zalloc(slab_ce, GFP_KERNEL);
+}
+
+static void rcu_context_free(struct rcu_head *rcu)
+{
+	struct intel_context *ce = container_of(rcu, typeof(*ce), rcu);
+
+	trace_intel_context_free(ce);
+	kmem_cache_free(slab_ce, ce);
+}
+
+void intel_context_free(struct intel_context *ce)
+{
+	call_rcu(&ce->rcu, rcu_context_free);
+}
+
+struct intel_context *
+intel_context_create(struct intel_engine_cs *engine)
+{
+	struct intel_context *ce;
+
+	ce = intel_context_alloc();
+	if (!ce)
+		return ERR_PTR(-ENOMEM);
+
+	intel_context_init(ce, engine);
+	trace_intel_context_create(ce);
+	return ce;
+}
+
+int intel_context_alloc_state(struct intel_context *ce)
+{
+	int err = 0;
+
+	if (mutex_lock_interruptible(&ce->pin_mutex))
+		return -EINTR;
+
+	if (!test_bit(CONTEXT_ALLOC_BIT, &ce->flags)) {
+		if (intel_context_is_banned(ce)) {
+			err = -EIO;
+			goto unlock;
+		}
+
+		err = ce->ops->alloc(ce);
+		if (unlikely(err))
+			goto unlock;
+
+		set_bit(CONTEXT_ALLOC_BIT, &ce->flags);
+	}
+
+unlock:
+	mutex_unlock(&ce->pin_mutex);
+	return err;
+}
+
+static int intel_context_active_acquire(struct intel_context *ce)
+{
+	int err;
+
+	__i915_active_acquire(&ce->active);
+
+	if (intel_context_is_barrier(ce) || intel_engine_uses_guc(ce->engine) ||
+	    intel_context_is_parallel(ce))
+		return 0;
+
+	/* Preallocate tracking nodes */
+	err = i915_active_acquire_preallocate_barrier(&ce->active,
+						      ce->engine);
+	if (err)
+		i915_active_release(&ce->active);
+
+	return err;
+}
+
+static void intel_context_active_release(struct intel_context *ce)
+{
+	/* Nodes preallocated in intel_context_active() */
+	i915_active_acquire_barrier(&ce->active);
+	i915_active_release(&ce->active);
+}
+
+static int __context_pin_state(struct i915_vma *vma, struct i915_gem_ww_ctx *ww)
+{
+	unsigned int bias = i915_ggtt_pin_bias(vma) | PIN_OFFSET_BIAS;
+	int err;
+
+	err = i915_ggtt_pin(vma, ww, 0, bias | PIN_HIGH);
+	if (err)
+		return err;
+
+	err = i915_active_acquire(&vma->active);
+	if (err)
+		goto err_unpin;
+
+	/*
+	 * And mark it as a globally pinned object to let the shrinker know
+	 * it cannot reclaim the object until we release it.
+	 */
+	i915_vma_make_unshrinkable(vma);
+	vma->obj->mm.dirty = true;
+
+	return 0;
+
+err_unpin:
+	i915_vma_unpin(vma);
+	return err;
+}
+
+static void __context_unpin_state(struct i915_vma *vma)
+{
+	i915_vma_make_shrinkable(vma);
+	i915_active_release(&vma->active);
+	__i915_vma_unpin(vma);
+}
+
+static int __ring_active(struct intel_ring *ring,
+			 struct i915_gem_ww_ctx *ww)
+{
+	int err;
+
+	err = intel_ring_pin(ring, ww);
+	if (err)
+		return err;
+
+	err = i915_active_acquire(&ring->vma->active);
+	if (err)
+		goto err_pin;
+
+	return 0;
+
+err_pin:
+	intel_ring_unpin(ring);
+	return err;
+}
+
+static void __ring_retire(struct intel_ring *ring)
+{
+	i915_active_release(&ring->vma->active);
+	intel_ring_unpin(ring);
+}
+
+static int intel_context_pre_pin(struct intel_context *ce,
+				 struct i915_gem_ww_ctx *ww)
+{
+	int err;
+
+	CE_TRACE(ce, "active\n");
+
+	err = __ring_active(ce->ring, ww);
+	if (err)
+		return err;
+
+	err = intel_timeline_pin(ce->timeline, ww);
+	if (err)
+		goto err_ring;
+
+	if (!ce->state)
+		return 0;
+
+	err = __context_pin_state(ce->state, ww);
+	if (err)
+		goto err_timeline;
+
+
+	return 0;
+
+err_timeline:
+	intel_timeline_unpin(ce->timeline);
+err_ring:
+	__ring_retire(ce->ring);
+	return err;
+}
+
+static void intel_context_post_unpin(struct intel_context *ce)
+{
+	if (ce->state)
+		__context_unpin_state(ce->state);
+
+	intel_timeline_unpin(ce->timeline);
+	__ring_retire(ce->ring);
+}
+
+int __intel_context_do_pin_ww(struct intel_context *ce,
+			      struct i915_gem_ww_ctx *ww)
+{
+	bool handoff = false;
+	void *vaddr;
+	int err = 0;
+
+	if (unlikely(!test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
+		err = intel_context_alloc_state(ce);
+		if (err)
+			return err;
+	}
+
+	/*
+	 * We always pin the context/ring/timeline here, to ensure a pin
+	 * refcount for __intel_context_active(), which prevent a lock
+	 * inversion of ce->pin_mutex vs dma_resv_lock().
+	 */
+
+	err = i915_gem_object_lock(ce->timeline->hwsp_ggtt->obj, ww);
+	if (!err)
+		err = i915_gem_object_lock(ce->ring->vma->obj, ww);
+	if (!err && ce->state)
+		err = i915_gem_object_lock(ce->state->obj, ww);
+	if (!err)
+		err = intel_context_pre_pin(ce, ww);
+	if (err)
+		return err;
+
+	err = ce->ops->pre_pin(ce, ww, &vaddr);
+	if (err)
+		goto err_ctx_unpin;
+
+	err = i915_active_acquire(&ce->active);
+	if (err)
+		goto err_post_unpin;
+
+	err = mutex_lock_interruptible(&ce->pin_mutex);
+	if (err)
+		goto err_release;
+
+	intel_engine_pm_might_get(ce->engine);
+
+	if (unlikely(intel_context_is_closed(ce))) {
+		err = -ENOENT;
+		goto err_unlock;
+	}
+
+	if (likely(!atomic_add_unless(&ce->pin_count, 1, 0))) {
+		err = intel_context_active_acquire(ce);
+		if (unlikely(err))
+			goto err_unlock;
+
+		err = ce->ops->pin(ce, vaddr);
+		if (err) {
+			intel_context_active_release(ce);
+			goto err_unlock;
+		}
+
+		CE_TRACE(ce, "pin ring:{start:%08x, head:%04x, tail:%04x}\n",
+			 i915_ggtt_offset(ce->ring->vma),
+			 ce->ring->head, ce->ring->tail);
+
+		handoff = true;
+		smp_mb__before_atomic(); /* flush pin before it is visible */
+		atomic_inc(&ce->pin_count);
+	}
+
+	GEM_BUG_ON(!intel_context_is_pinned(ce)); /* no overflow! */
+
+	trace_intel_context_do_pin(ce);
+
+err_unlock:
+	mutex_unlock(&ce->pin_mutex);
+err_release:
+	i915_active_release(&ce->active);
+err_post_unpin:
+	if (!handoff)
+		ce->ops->post_unpin(ce);
+err_ctx_unpin:
+	intel_context_post_unpin(ce);
+
+	/*
+	 * Unlock the hwsp_ggtt object since it's shared.
+	 * In principle we can unlock all the global state locked above
+	 * since it's pinned and doesn't need fencing, and will
+	 * thus remain resident until it is explicitly unpinned.
+	 */
+	i915_gem_ww_unlock_single(ce->timeline->hwsp_ggtt->obj);
+
+	return err;
+}
+
+int __intel_context_do_pin(struct intel_context *ce)
+{
+	struct i915_gem_ww_ctx ww;
+	int err;
+
+	i915_gem_ww_ctx_init(&ww, true);
+retry:
+	err = __intel_context_do_pin_ww(ce, &ww);
+	if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(&ww);
+		if (!err)
+			goto retry;
+	}
+	i915_gem_ww_ctx_fini(&ww);
+	return err;
+}
+
+void __intel_context_do_unpin(struct intel_context *ce, int sub)
+{
+	if (!atomic_sub_and_test(sub, &ce->pin_count))
+		return;
+
+	CE_TRACE(ce, "unpin\n");
+	ce->ops->unpin(ce);
+	ce->ops->post_unpin(ce);
+
+	/*
+	 * Once released, we may asynchronously drop the active reference.
+	 * As that may be the only reference keeping the context alive,
+	 * take an extra now so that it is not freed before we finish
+	 * dereferencing it.
+	 */
+	intel_context_get(ce);
+	intel_context_active_release(ce);
+	trace_intel_context_do_unpin(ce);
+	intel_context_put(ce);
+}
+
+static void __intel_context_retire(struct i915_active *active)
+{
+	struct intel_context *ce = container_of(active, typeof(*ce), active);
+
+	CE_TRACE(ce, "retire runtime: { total:%lluns, avg:%lluns }\n",
+		 intel_context_get_total_runtime_ns(ce),
+		 intel_context_get_avg_runtime_ns(ce));
+
+	set_bit(CONTEXT_VALID_BIT, &ce->flags);
+	intel_context_post_unpin(ce);
+	intel_context_put(ce);
+}
+
+static int __intel_context_active(struct i915_active *active)
+{
+	struct intel_context *ce = container_of(active, typeof(*ce), active);
+
+	intel_context_get(ce);
+
+	/* everything should already be activated by intel_context_pre_pin() */
+	GEM_WARN_ON(!i915_active_acquire_if_busy(&ce->ring->vma->active));
+	__intel_ring_pin(ce->ring);
+
+	__intel_timeline_pin(ce->timeline);
+
+	if (ce->state) {
+		GEM_WARN_ON(!i915_active_acquire_if_busy(&ce->state->active));
+		__i915_vma_pin(ce->state);
+		i915_vma_make_unshrinkable(ce->state);
+	}
+
+	return 0;
+}
+
+static int
+sw_fence_dummy_notify(struct i915_sw_fence *sf,
+		      enum i915_sw_fence_notify state)
+{
+	return NOTIFY_DONE;
+}
+
+void
+intel_context_init(struct intel_context *ce, struct intel_engine_cs *engine)
+{
+	GEM_BUG_ON(!engine->cops);
+	GEM_BUG_ON(!engine->gt->vm);
+
+	kref_init(&ce->ref);
+
+	ce->engine = engine;
+	ce->ops = engine->cops;
+	ce->sseu = engine->sseu;
+	ce->ring = NULL;
+	ce->ring_size = SZ_4K;
+
+	ewma_runtime_init(&ce->stats.runtime.avg);
+
+	ce->vm = i915_vm_get(engine->gt->vm);
+
+	/* NB ce->signal_link/lock is used under RCU */
+	spin_lock_init(&ce->signal_lock);
+	INIT_LIST_HEAD(&ce->signals);
+
+	mutex_init(&ce->pin_mutex);
+
+	spin_lock_init(&ce->guc_state.lock);
+	INIT_LIST_HEAD(&ce->guc_state.fences);
+	INIT_LIST_HEAD(&ce->guc_state.requests);
+
+	ce->guc_id.id = GUC_INVALID_CONTEXT_ID;
+	INIT_LIST_HEAD(&ce->guc_id.link);
+
+	INIT_LIST_HEAD(&ce->destroyed_link);
+
+	INIT_LIST_HEAD(&ce->parallel.child_list);
+
+	/*
+	 * Initialize fence to be complete as this is expected to be complete
+	 * unless there is a pending schedule disable outstanding.
+	 */
+	i915_sw_fence_init(&ce->guc_state.blocked,
+			   sw_fence_dummy_notify);
+	i915_sw_fence_commit(&ce->guc_state.blocked);
+
+	i915_active_init(&ce->active,
+			 __intel_context_active, __intel_context_retire, 0);
+}
+
+void intel_context_fini(struct intel_context *ce)
+{
+	struct intel_context *child, *next;
+
+	if (ce->timeline)
+		intel_timeline_put(ce->timeline);
+	i915_vm_put(ce->vm);
+
+	/* Need to put the creation ref for the children */
+	if (intel_context_is_parent(ce))
+		for_each_child_safe(ce, child, next)
+			intel_context_put(child);
+
+	mutex_destroy(&ce->pin_mutex);
+	i915_active_fini(&ce->active);
+	i915_sw_fence_fini(&ce->guc_state.blocked);
+}
+
+void i915_context_module_exit(void)
+{
+	kmem_cache_destroy(slab_ce);
+}
+
+int __init i915_context_module_init(void)
+{
+	slab_ce = KMEM_CACHE(intel_context, SLAB_HWCACHE_ALIGN);
+	if (!slab_ce)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void intel_context_enter_engine(struct intel_context *ce)
+{
+	intel_engine_pm_get(ce->engine);
+	intel_timeline_enter(ce->timeline);
+}
+
+void intel_context_exit_engine(struct intel_context *ce)
+{
+	intel_timeline_exit(ce->timeline);
+	intel_engine_pm_put(ce->engine);
+}
+
+int intel_context_prepare_remote_request(struct intel_context *ce,
+					 struct i915_request *rq)
+{
+	struct intel_timeline *tl = ce->timeline;
+	int err;
+
+	/* Only suitable for use in remotely modifying this context */
+	GEM_BUG_ON(rq->context == ce);
+
+	if (rcu_access_pointer(rq->timeline) != tl) { /* timeline sharing! */
+		/* Queue this switch after current activity by this context. */
+		err = i915_active_fence_set(&tl->last_request, rq);
+		if (err)
+			return err;
+	}
+
+	/*
+	 * Guarantee context image and the timeline remains pinned until the
+	 * modifying request is retired by setting the ce activity tracker.
+	 *
+	 * But we only need to take one pin on the account of it. Or in other
+	 * words transfer the pinned ce object to tracked active request.
+	 */
+	GEM_BUG_ON(i915_active_is_idle(&ce->active));
+	return i915_active_add_request(&ce->active, rq);
+}
+
+struct i915_request *intel_context_create_request(struct intel_context *ce)
+{
+	struct i915_gem_ww_ctx ww;
+	struct i915_request *rq;
+	int err;
+
+	i915_gem_ww_ctx_init(&ww, true);
+retry:
+	err = intel_context_pin_ww(ce, &ww);
+	if (!err) {
+		rq = i915_request_create(ce);
+		intel_context_unpin(ce);
+	} else if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(&ww);
+		if (!err)
+			goto retry;
+		rq = ERR_PTR(err);
+	} else {
+		rq = ERR_PTR(err);
+	}
+
+	i915_gem_ww_ctx_fini(&ww);
+
+	if (IS_ERR(rq))
+		return rq;
+
+	/*
+	 * timeline->mutex should be the inner lock, but is used as outer lock.
+	 * Hack around this to shut up lockdep in selftests..
+	 */
+	lockdep_unpin_lock(&ce->timeline->mutex, rq->cookie);
+	mutex_release(&ce->timeline->mutex.dep_map, _RET_IP_);
+	mutex_acquire(&ce->timeline->mutex.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
+	rq->cookie = lockdep_pin_lock(&ce->timeline->mutex);
+
+	return rq;
+}
+
+struct i915_request *intel_context_get_active_request(struct intel_context *ce)
+{
+	struct intel_context *parent = intel_context_to_parent(ce);
+	struct i915_request *rq, *active = NULL;
+	unsigned long flags;
+
+	GEM_BUG_ON(!intel_engine_uses_guc(ce->engine));
+
+	/*
+	 * We search the parent list to find an active request on the submitted
+	 * context. The parent list contains the requests for all the contexts
+	 * in the relationship so we have to do a compare of each request's
+	 * context.
+	 */
+	spin_lock_irqsave(&parent->guc_state.lock, flags);
+	list_for_each_entry_reverse(rq, &parent->guc_state.requests,
+				    sched.link) {
+		if (rq->context != ce)
+			continue;
+		if (i915_request_completed(rq))
+			break;
+
+		active = rq;
+	}
+	if (active)
+		active = i915_request_get_rcu(active);
+	spin_unlock_irqrestore(&parent->guc_state.lock, flags);
+
+	return active;
+}
+
+void intel_context_bind_parent_child(struct intel_context *parent,
+				     struct intel_context *child)
+{
+	/*
+	 * Callers responsibility to validate that this function is used
+	 * correctly but we use GEM_BUG_ON here ensure that they do.
+	 */
+	GEM_BUG_ON(intel_context_is_pinned(parent));
+	GEM_BUG_ON(intel_context_is_child(parent));
+	GEM_BUG_ON(intel_context_is_pinned(child));
+	GEM_BUG_ON(intel_context_is_child(child));
+	GEM_BUG_ON(intel_context_is_parent(child));
+
+	parent->parallel.child_index = parent->parallel.number_children++;
+	list_add_tail(&child->parallel.child_link,
+		      &parent->parallel.child_list);
+	child->parallel.parent = parent;
+}
+
+u64 intel_context_get_total_runtime_ns(struct intel_context *ce)
+{
+	u64 total, active;
+
+	if (ce->ops->update_stats)
+		ce->ops->update_stats(ce);
+
+	total = ce->stats.runtime.total;
+	if (ce->ops->flags & COPS_RUNTIME_CYCLES)
+		total *= ce->engine->gt->clock_period_ns;
+
+	active = READ_ONCE(ce->stats.active);
+	if (active)
+		active = intel_context_clock() - active;
+
+	return total + active;
+}
+
+u64 intel_context_get_avg_runtime_ns(struct intel_context *ce)
+{
+	u64 avg = ewma_runtime_read(&ce->stats.runtime.avg);
+
+	if (ce->ops->flags & COPS_RUNTIME_CYCLES)
+		avg *= ce->engine->gt->clock_period_ns;
+
+	return avg;
+}
+
+bool intel_context_ban(struct intel_context *ce, struct i915_request *rq)
+{
+	bool ret = intel_context_set_banned(ce);
+
+	trace_intel_context_ban(ce);
+
+	if (ce->ops->revoke)
+		ce->ops->revoke(ce, rq,
+				INTEL_CONTEXT_BANNED_PREEMPT_TIMEOUT_MS);
+
+	return ret;
+}
+
+bool intel_context_revoke(struct intel_context *ce)
+{
+	bool ret = intel_context_set_exiting(ce);
+
+	if (ce->ops->revoke)
+		ce->ops->revoke(ce, NULL, ce->engine->props.preempt_timeout_ms);
+
+	return ret;
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftest_context.c"
+#endif