[Intel-gfx] [PATCH 14/24] drm/i915: Rework intel_context pinning to do everything outside of pin_mutex
Maarten Lankhorst
maarten.lankhorst at linux.intel.com
Mon Aug 10 10:30:53 UTC 2020
Instead of doing everything inside of pin_mutex, we move all pinning
outside. Because i915_active has its own reference counting and
pinning is also having the same issues vs mutexes, we make sure
everything is pinned first, so the pinning in i915_active only needs
to bump refcounts. This allows us to take pin refcounts correctly
all the time.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
drivers/gpu/drm/i915/gt/intel_context.c | 232 +++++++++++-------
drivers/gpu/drm/i915/gt/intel_context_types.h | 4 +-
drivers/gpu/drm/i915/gt/intel_lrc.c | 34 ++-
.../gpu/drm/i915/gt/intel_ring_submission.c | 13 +-
drivers/gpu/drm/i915/gt/mock_engine.c | 13 +-
5 files changed, 190 insertions(+), 106 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 52db2bde44a3..efe9a7a89ede 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -93,79 +93,6 @@ static void intel_context_active_release(struct intel_context *ce)
i915_active_release(&ce->active);
}
-int __intel_context_do_pin(struct intel_context *ce)
-{
- int err;
-
- if (unlikely(!test_bit(CONTEXT_ALLOC_BIT, &ce->flags))) {
- err = intel_context_alloc_state(ce);
- if (err)
- return err;
- }
-
- err = i915_active_acquire(&ce->active);
- if (err)
- return err;
-
- if (mutex_lock_interruptible(&ce->pin_mutex)) {
- err = -EINTR;
- goto out_release;
- }
-
- if (unlikely(intel_context_is_closed(ce))) {
- err = -ENOENT;
- goto out_unlock;
- }
-
- if (likely(!atomic_add_unless(&ce->pin_count, 1, 0))) {
- err = intel_context_active_acquire(ce);
- if (unlikely(err))
- goto out_unlock;
-
- err = ce->ops->pin(ce);
- if (unlikely(err))
- goto err_active;
-
- CE_TRACE(ce, "pin ring:{start:%08x, head:%04x, tail:%04x}\n",
- i915_ggtt_offset(ce->ring->vma),
- ce->ring->head, ce->ring->tail);
-
- 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! */
- GEM_BUG_ON(i915_active_is_idle(&ce->active));
- goto out_unlock;
-
-err_active:
- intel_context_active_release(ce);
-out_unlock:
- mutex_unlock(&ce->pin_mutex);
-out_release:
- i915_active_release(&ce->active);
- return err;
-}
-
-void intel_context_unpin(struct intel_context *ce)
-{
- if (!atomic_dec_and_test(&ce->pin_count))
- return;
-
- CE_TRACE(ce, "unpin\n");
- ce->ops->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);
- intel_context_put(ce);
-}
-
static int __context_pin_state(struct i915_vma *vma)
{
unsigned int bias = i915_ggtt_pin_bias(vma) | PIN_OFFSET_BIAS;
@@ -225,6 +152,138 @@ static void __ring_retire(struct intel_ring *ring)
intel_ring_unpin(ring);
}
+static int intel_context_pre_pin(struct intel_context *ce)
+{
+ int err;
+
+ CE_TRACE(ce, "active\n");
+
+ err = __ring_active(ce->ring);
+ if (err)
+ return err;
+
+ err = intel_timeline_pin(ce->timeline);
+ if (err)
+ goto err_ring;
+
+ if (!ce->state)
+ return 0;
+
+ err = __context_pin_state(ce->state);
+ 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(struct intel_context *ce)
+{
+ 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 = intel_context_pre_pin(ce);
+ if (err)
+ return err;
+
+ err = i915_active_acquire(&ce->active);
+ if (err)
+ goto err_ctx_unpin;
+
+ err = ce->ops->pre_pin(ce, &vaddr);
+ if (err)
+ goto err_release;
+
+ err = mutex_lock_interruptible(&ce->pin_mutex);
+ if (err)
+ goto err_post_unpin;
+
+ 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! */
+
+err_unlock:
+ mutex_unlock(&ce->pin_mutex);
+err_post_unpin:
+ if (!handoff)
+ ce->ops->post_unpin(ce);
+err_release:
+ i915_active_release(&ce->active);
+err_ctx_unpin:
+ intel_context_post_unpin(ce);
+ return err;
+}
+
+void intel_context_unpin(struct intel_context *ce)
+{
+ if (!atomic_dec_and_test(&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);
+ intel_context_put(ce);
+}
+
__i915_active_call
static void __intel_context_retire(struct i915_active *active)
{
@@ -235,12 +294,7 @@ static void __intel_context_retire(struct i915_active *active)
intel_context_get_avg_runtime_ns(ce));
set_bit(CONTEXT_VALID_BIT, &ce->flags);
- if (ce->state)
- __context_unpin_state(ce->state);
-
- intel_timeline_unpin(ce->timeline);
- __ring_retire(ce->ring);
-
+ intel_context_post_unpin(ce);
intel_context_put(ce);
}
@@ -249,29 +303,25 @@ static int __intel_context_active(struct i915_active *active)
struct intel_context *ce = container_of(active, typeof(*ce), active);
int err;
- CE_TRACE(ce, "active\n");
-
intel_context_get(ce);
+ /* everything should already be activated by intel_context_pre_pin() */
err = __ring_active(ce->ring);
- if (err)
+ if (GEM_WARN_ON(err))
goto err_put;
err = intel_timeline_pin(ce->timeline);
- if (err)
+ if (GEM_WARN_ON(err))
goto err_ring;
- if (!ce->state)
- return 0;
-
- err = __context_pin_state(ce->state);
- if (err)
- goto err_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;
-err_timeline:
- intel_timeline_unpin(ce->timeline);
err_ring:
__ring_retire(ce->ring);
err_put:
diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h
index 4954b0df4864..ca8e05b4d3ef 100644
--- a/drivers/gpu/drm/i915/gt/intel_context_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_context_types.h
@@ -30,8 +30,10 @@ struct intel_ring;
struct intel_context_ops {
int (*alloc)(struct intel_context *ce);
- int (*pin)(struct intel_context *ce);
+ int (*pre_pin)(struct intel_context *ce, void **vaddr);
+ int (*pin)(struct intel_context *ce, void *vaddr);
void (*unpin)(struct intel_context *ce);
+ void (*post_unpin)(struct intel_context *ce);
void (*enter)(struct intel_context *ce);
void (*exit)(struct intel_context *ce);
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 417f6b0c6c61..f4390559a3d5 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -3303,7 +3303,10 @@ static void execlists_context_unpin(struct intel_context *ce)
{
check_redzone((void *)ce->lrc_reg_state - LRC_STATE_OFFSET,
ce->engine);
+}
+static void execlists_context_post_unpin(struct intel_context *ce)
+{
i915_gem_object_unpin_map(ce->state->obj);
}
@@ -3465,20 +3468,23 @@ __execlists_update_reg_state(const struct intel_context *ce,
}
static int
-__execlists_context_pin(struct intel_context *ce,
- struct intel_engine_cs *engine)
+execlists_context_pre_pin(struct intel_context *ce, void **vaddr)
{
- void *vaddr;
-
GEM_BUG_ON(!ce->state);
GEM_BUG_ON(!i915_vma_is_pinned(ce->state));
- vaddr = i915_gem_object_pin_map(ce->state->obj,
- i915_coherent_map_type(engine->i915) |
+ *vaddr = i915_gem_object_pin_map(ce->state->obj,
+ i915_coherent_map_type(ce->engine->i915) |
I915_MAP_OVERRIDE);
- if (IS_ERR(vaddr))
- return PTR_ERR(vaddr);
+ return PTR_ERR_OR_ZERO(*vaddr);
+}
+
+static int
+__execlists_context_pin(struct intel_context *ce,
+ struct intel_engine_cs *engine,
+ void *vaddr)
+{
ce->lrc.lrca = lrc_descriptor(ce, engine) | CTX_DESC_FORCE_RESTORE;
ce->lrc_reg_state = vaddr + LRC_STATE_OFFSET;
__execlists_update_reg_state(ce, engine, ce->ring->tail);
@@ -3486,9 +3492,9 @@ __execlists_context_pin(struct intel_context *ce,
return 0;
}
-static int execlists_context_pin(struct intel_context *ce)
+static int execlists_context_pin(struct intel_context *ce, void *vaddr)
{
- return __execlists_context_pin(ce, ce->engine);
+ return __execlists_context_pin(ce, ce->engine, vaddr);
}
static int execlists_context_alloc(struct intel_context *ce)
@@ -3514,8 +3520,10 @@ static void execlists_context_reset(struct intel_context *ce)
static const struct intel_context_ops execlists_context_ops = {
.alloc = execlists_context_alloc,
+ .pre_pin = execlists_context_pre_pin,
.pin = execlists_context_pin,
.unpin = execlists_context_unpin,
+ .post_unpin = execlists_context_post_unpin,
.enter = intel_context_enter_engine,
.exit = intel_context_exit_engine,
@@ -5454,12 +5462,12 @@ static int virtual_context_alloc(struct intel_context *ce)
return __execlists_context_alloc(ce, ve->siblings[0]);
}
-static int virtual_context_pin(struct intel_context *ce)
+static int virtual_context_pin(struct intel_context *ce, void *vaddr)
{
struct virtual_engine *ve = container_of(ce, typeof(*ve), context);
/* Note: we must use a real engine class for setting up reg state */
- return __execlists_context_pin(ce, ve->siblings[0]);
+ return __execlists_context_pin(ce, ve->siblings[0], vaddr);
}
static void virtual_context_enter(struct intel_context *ce)
@@ -5487,8 +5495,10 @@ static void virtual_context_exit(struct intel_context *ce)
static const struct intel_context_ops virtual_context_ops = {
.alloc = virtual_context_alloc,
+ .pre_pin = execlists_context_pre_pin,
.pin = virtual_context_pin,
.unpin = execlists_context_unpin,
+ .post_unpin = execlists_context_post_unpin,
.enter = virtual_context_enter,
.exit = virtual_context_exit,
diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c
index a3b10f3c83eb..93cf72cfd318 100644
--- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c
@@ -499,6 +499,10 @@ static void __context_unpin_ppgtt(struct intel_context *ce)
}
static void ring_context_unpin(struct intel_context *ce)
+{
+}
+
+static void ring_context_post_unpin(struct intel_context *ce)
{
__context_unpin_ppgtt(ce);
}
@@ -587,11 +591,16 @@ static int ring_context_alloc(struct intel_context *ce)
return 0;
}
-static int ring_context_pin(struct intel_context *ce)
+static int ring_context_pre_pin(struct intel_context *ce, void **unused)
{
return __context_pin_ppgtt(ce);
}
+static int ring_context_pin(struct intel_context *ce, void *unused)
+{
+ return 0;
+}
+
static void ring_context_reset(struct intel_context *ce)
{
intel_ring_reset(ce->ring, ce->ring->emit);
@@ -600,8 +609,10 @@ static void ring_context_reset(struct intel_context *ce)
static const struct intel_context_ops ring_context_ops = {
.alloc = ring_context_alloc,
+ .pre_pin = ring_context_pre_pin,
.pin = ring_context_pin,
.unpin = ring_context_unpin,
+ .post_unpin = ring_context_post_unpin,
.enter = intel_context_enter_engine,
.exit = intel_context_exit_engine,
diff --git a/drivers/gpu/drm/i915/gt/mock_engine.c b/drivers/gpu/drm/i915/gt/mock_engine.c
index 79764305b8ec..c8e631222f23 100644
--- a/drivers/gpu/drm/i915/gt/mock_engine.c
+++ b/drivers/gpu/drm/i915/gt/mock_engine.c
@@ -131,6 +131,10 @@ static void mock_context_unpin(struct intel_context *ce)
{
}
+static void mock_context_post_unpin(struct intel_context *ce)
+{
+}
+
static void mock_context_destroy(struct kref *ref)
{
struct intel_context *ce = container_of(ref, typeof(*ce), ref);
@@ -163,7 +167,12 @@ static int mock_context_alloc(struct intel_context *ce)
return 0;
}
-static int mock_context_pin(struct intel_context *ce)
+static int mock_context_pre_pin(struct intel_context *ce, void **unused)
+{
+ return 0;
+}
+
+static int mock_context_pin(struct intel_context *ce, void *unused)
{
return 0;
}
@@ -175,8 +184,10 @@ static void mock_context_reset(struct intel_context *ce)
static const struct intel_context_ops mock_context_ops = {
.alloc = mock_context_alloc,
+ .pre_pin = mock_context_pre_pin,
.pin = mock_context_pin,
.unpin = mock_context_unpin,
+ .post_unpin = mock_context_post_unpin,
.enter = intel_context_enter_engine,
.exit = intel_context_exit_engine,
--
2.28.0
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