[Intel-gfx] [PATCH v2] drm/i915: Keep rings pinned while the context is active
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Wed Jun 19 16:26:05 UTC 2019
On 19/06/2019 16:39, Chris Wilson wrote:
> 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 GPU is no longer active.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.
>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110946
> Fixes: ce476c80b8bf ("drm/i915: Keep contexts pinned until after the next kernel context switch")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
> drivers/gpu/drm/i915/gt/intel_context.c | 27 ++++++++++++-------
> drivers/gpu/drm/i915/gt/intel_engine_types.h | 12 +++++++++
> drivers/gpu/drm/i915/gt/intel_lrc.c | 10 ++-----
> drivers/gpu/drm/i915/gt/intel_ringbuffer.c | 28 +++++++++++++-------
> drivers/gpu/drm/i915/gt/mock_engine.c | 1 +
> 5 files changed, 51 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
> index 2c454f227c2e..23120901c55f 100644
> --- a/drivers/gpu/drm/i915/gt/intel_context.c
> +++ b/drivers/gpu/drm/i915/gt/intel_context.c
> @@ -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)
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> index 868b220214f8..cc6b8eb0cda0 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> @@ -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;
> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
> index b42b5f158295..82b7ace62d97 100644
> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
> @@ -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:
> diff --git a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
> index c6023bc9452d..0d8aaaa089cc 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ringbuffer.c
> @@ -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--;
> diff --git a/drivers/gpu/drm/i915/gt/mock_engine.c b/drivers/gpu/drm/i915/gt/mock_engine.c
> index 086801b51441..486c6953dcb1 100644
> --- a/drivers/gpu/drm/i915/gt/mock_engine.c
> +++ b/drivers/gpu/drm/i915/gt/mock_engine.c
> @@ -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);
>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Regards,
Tvrtko
More information about the Intel-gfx
mailing list