Commit 09c5ab38 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Keep rings pinned while the context is active 

Remember to keep the rings pinned as well as the context image until the
GPU is no longer active.

v2: Introduce a ring->pin_count primarily to hide the
mock_ring that doesn't fit into the normal GGTT vma picture.

v3: Order is important in teardown, ringbuffer submission needs to drop
the pin count on the engine->kernel_context before it can gleefully free
its ring.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110946


Fixes: ce476c80 ("drm/i915: Keep contexts pinned until after the next kernel context switch")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190619170135.15281-1-chris@chris-wilson.co.uk
parent bdeb18db

drivers/gpu/drm/i915/gt/intel_context.c

+18 −9
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ static void intel_context_retire(struct i915_active *active) 
	if (ce->state)

		__context_unpin_state(ce->state);



	intel_ring_unpin(ce->ring);

	intel_context_put(ce);

}
@@ -160,27 +161,35 @@ int intel_context_active_acquire(struct intel_context *ce, unsigned long flags) 


	intel_context_get(ce);



	err = intel_ring_pin(ce->ring);

	if (err)

		goto err_put;



	if (!ce->state)

		return 0;



	err = __context_pin_state(ce->state, flags);

	if (err) {

		i915_active_cancel(&ce->active);

		intel_context_put(ce);

		return err;

	}

	if (err)

		goto err_ring;



	/* Preallocate tracking nodes */

	if (!i915_gem_context_is_kernel(ce->gem_context)) {

		err = i915_active_acquire_preallocate_barrier(&ce->active,

							      ce->engine);

		if (err) {

			i915_active_release(&ce->active);

			return err;

		}

		if (err)

			goto err_state;

	}



	return 0;



err_state:

	__context_unpin_state(ce->state);

err_ring:

	intel_ring_unpin(ce->ring);

err_put:

	intel_context_put(ce);

	i915_active_cancel(&ce->active);

	return err;

}



void intel_context_active_release(struct intel_context *ce)

drivers/gpu/drm/i915/gt/intel_engine_types.h

+12 −0
Original line number Diff line number Diff line
@@ -70,6 +70,18 @@ struct intel_ring { 
	struct list_head request_list;

	struct list_head active_link;



	/*

	 * 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;

drivers/gpu/drm/i915/gt/intel_lrc.c

+2 −8
Original line number Diff line number Diff line
@@ -1414,6 +1414,7 @@ static void execlists_context_destroy(struct kref *kref) 
{

	struct intel_context *ce = container_of(kref, typeof(*ce), ref);



	GEM_BUG_ON(!i915_active_is_idle(&ce->active));

	GEM_BUG_ON(intel_context_is_pinned(ce));



	if (ce->state)
@@ -1426,7 +1427,6 @@ static void execlists_context_unpin(struct intel_context *ce) 
{

	i915_gem_context_unpin_hw_id(ce->gem_context);

	i915_gem_object_unpin_map(ce->state->obj);

	intel_ring_unpin(ce->ring);

}



static void
@@ -1478,13 +1478,9 @@ __execlists_context_pin(struct intel_context *ce, 
		goto unpin_active;

	}



	ret = intel_ring_pin(ce->ring);

	if (ret)

		goto unpin_map;



	ret = i915_gem_context_pin_hw_id(ce->gem_context);

	if (ret)

		goto unpin_ring;

		goto unpin_map;



	ce->lrc_desc = lrc_descriptor(ce, engine);

	ce->lrc_reg_state = vaddr + LRC_STATE_PN * PAGE_SIZE;
@@ -1492,8 +1488,6 @@ __execlists_context_pin(struct intel_context *ce, 


	return 0;



unpin_ring:

	intel_ring_unpin(ce->ring);

unpin_map:

	i915_gem_object_unpin_map(ce->state->obj);

unpin_active:

drivers/gpu/drm/i915/gt/intel_ringbuffer.c

+20 −11
Original line number Diff line number Diff line
@@ -1149,16 +1149,16 @@ i915_emit_bb_start(struct i915_request *rq, 
int intel_ring_pin(struct intel_ring *ring)

{

	struct i915_vma *vma = ring->vma;

	enum i915_map_type map = i915_coherent_map_type(vma->vm->i915);

	unsigned int flags;

	void *addr;

	int ret;



	GEM_BUG_ON(ring->vaddr);

	if (atomic_fetch_inc(&ring->pin_count))

		return 0;



	ret = i915_timeline_pin(ring->timeline);

	if (ret)

		return ret;

		goto err_unpin;



	flags = PIN_GLOBAL;
@@ -1172,26 +1172,31 @@ int intel_ring_pin(struct intel_ring *ring) 


	ret = i915_vma_pin(vma, 0, 0, flags);

	if (unlikely(ret))

		goto unpin_timeline;

		goto err_timeline;



	if (i915_vma_is_map_and_fenceable(vma))

		addr = (void __force *)i915_vma_pin_iomap(vma);

	else

		addr = i915_gem_object_pin_map(vma->obj, map);

		addr = i915_gem_object_pin_map(vma->obj,

					       i915_coherent_map_type(vma->vm->i915));

	if (IS_ERR(addr)) {

		ret = PTR_ERR(addr);

		goto unpin_ring;

		goto err_ring;

	}



	vma->obj->pin_global++;



	GEM_BUG_ON(ring->vaddr);

	ring->vaddr = addr;



	return 0;



unpin_ring:

err_ring:

	i915_vma_unpin(vma);

unpin_timeline:

err_timeline:

	i915_timeline_unpin(ring->timeline);

err_unpin:

	atomic_dec(&ring->pin_count);

	return ret;

}
@@ -1207,16 +1212,19 @@ void intel_ring_reset(struct intel_ring *ring, u32 tail) 


void intel_ring_unpin(struct intel_ring *ring)

{

	GEM_BUG_ON(!ring->vma);

	GEM_BUG_ON(!ring->vaddr);

	if (!atomic_dec_and_test(&ring->pin_count))

		return;



	/* Discard any unused bytes beyond that submitted to hw. */

	intel_ring_reset(ring, ring->tail);



	GEM_BUG_ON(!ring->vma);

	if (i915_vma_is_map_and_fenceable(ring->vma))

		i915_vma_unpin_iomap(ring->vma);

	else

		i915_gem_object_unpin_map(ring->vma->obj);



	GEM_BUG_ON(!ring->vaddr);

	ring->vaddr = NULL;



	ring->vma->obj->pin_global--;
@@ -2081,10 +2089,11 @@ static void ring_destroy(struct intel_engine_cs *engine) 
	WARN_ON(INTEL_GEN(dev_priv) > 2 &&

		(ENGINE_READ(engine, RING_MI_MODE) & MODE_IDLE) == 0);



	intel_engine_cleanup_common(engine);



	intel_ring_unpin(engine->buffer);

	intel_ring_put(engine->buffer);



	intel_engine_cleanup_common(engine);

	kfree(engine);

}

drivers/gpu/drm/i915/gt/mock_engine.c

+1 −0
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ static struct intel_ring *mock_ring(struct intel_engine_cs *engine) 
	ring->base.effective_size = sz;

	ring->base.vaddr = (void *)(ring + 1);

	ring->base.timeline = &ring->timeline;

	atomic_set(&ring->base.pin_count, 1);



	INIT_LIST_HEAD(&ring->base.request_list);

	intel_ring_update_space(&ring->base);

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