As we need to use a mutex to serialise i915_active activation
(because we want to allow the callback to sleep), we need to push the
i915_active.retire into a worker callback in case we get need to retire
from an atomic context.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 1 +
drivers/gpu/drm/i915/gt/intel_context.c | 1 +
drivers/gpu/drm/i915/i915_active.c | 72 ++++++++++++++++-----
drivers/gpu/drm/i915/i915_active_types.h | 12 ++++
drivers/gpu/drm/i915/i915_timeline.c | 1 +
drivers/gpu/drm/i915/i915_vma.c | 3 +-
6 files changed, 74 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 911f3564972d..55b8f0e04846 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -891,6 +891,7 @@ struct context_barrier_task {
void *data;
};
+__i915_active_call
static void cb_retire(struct i915_active *base)
{
struct context_barrier_task *cb = container_of(base, typeof(*cb), base);
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 20c708ae6dc0..70d3b2568227 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -123,6 +123,7 @@ static void __context_unpin_state(struct i915_vma *vma)
__i915_vma_unpin(vma);
}
+__i915_active_call
static void __intel_context_retire(struct i915_active *active)
{
struct intel_context *ce = container_of(active, typeof(*ce), active);
diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index 3070fccbc08b..710805605bb3 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -97,18 +97,14 @@ static void debug_active_assert(struct i915_active *ref)
#endif
static void
-active_retire(struct i915_active *ref)
+__active_retire(struct i915_active *ref)
{
struct active_node *it, *n;
struct rb_root root;
bool retire = false;
- GEM_BUG_ON(!atomic_read(&ref->count));
- if (atomic_add_unless(&ref->count, -1, 1))
- return;
-
- /* One active may be flushed from inside the acquire of another */
- mutex_lock_nested(&ref->mutex, SINGLE_DEPTH_NESTING);
+ lockdep_assert_held(&ref->mutex);
+ GEM_BUG_ON(i915_active_is_idle(ref));
/* return the unused nodes to our slabcache -- flushing the allocator */
if (atomic_dec_and_test(&ref->count)) {
@@ -131,6 +127,36 @@ active_retire(struct i915_active *ref)
}
}
+static void
+active_work(struct work_struct *wrk)
+{
+ struct i915_active *ref = container_of(wrk, typeof(*ref), work);
+
+ GEM_BUG_ON(!atomic_read(&ref->count));
+ if (atomic_add_unless(&ref->count, -1, 1))
+ return;
+
+ mutex_lock(&ref->mutex);
+ __active_retire(ref);
+}
+
+static void
+active_retire(struct i915_active *ref)
+{
+ GEM_BUG_ON(!atomic_read(&ref->count));
+ if (atomic_add_unless(&ref->count, -1, 1))
+ return;
+
+ /* If we are inside interrupt context (fence signaling), defer */
+ if (ref->flags & I915_ACTIVE_RETIRE_SLEEPS ||
+ !mutex_trylock(&ref->mutex)) {
+ queue_work(system_unbound_wq, &ref->work);
+ return;
+ }
+
+ __active_retire(ref);
+}
+
static void
node_retire(struct i915_active_request *base, struct i915_request *rq)
{
@@ -200,16 +226,24 @@ void __i915_active_init(struct drm_i915_private *i915,
void (*retire)(struct i915_active *ref),
struct lock_class_key *key)
{
+ unsigned long bits;
+
debug_active_init(ref);
ref->i915 = i915;
+
+ ref->flags = 0;
ref->active = active;
- ref->retire = retire;
+ ref->retire = ptr_unpack_bits(retire, &bits, 2);
+ if (bits & I915_ACTIVE_MAY_SLEEP)
+ ref->flags |= I915_ACTIVE_RETIRE_SLEEPS;
+
ref->tree = RB_ROOT;
ref->cache = NULL;
init_llist_head(&ref->barriers);
atomic_set(&ref->count, 0);
__mutex_init(&ref->mutex, "i915_active", key);
+ INIT_WORK(&ref->work, active_work);
}
int i915_active_ref(struct i915_active *ref,
@@ -282,8 +316,10 @@ int i915_active_wait(struct i915_active *ref)
if (err)
return err;
- if (!atomic_add_unless(&ref->count, 1, 0))
- goto unlock;
+ if (!atomic_add_unless(&ref->count, 1, 0)) {
+ mutex_unlock(&ref->mutex);
+ return 0;
+ }
rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
err = i915_active_request_retire(&it->base, BKL(ref));
@@ -291,10 +327,15 @@ int i915_active_wait(struct i915_active *ref)
break;
}
- active_retire(ref);
-unlock:
- mutex_unlock(&ref->mutex);
- return err;
+ __active_retire(ref);
+ if (err)
+ return err;
+
+ flush_work(&ref->work);
+ if (!i915_active_is_idle(ref))
+ return -EBUSY;
+
+ return 0;
}
int i915_request_await_active_request(struct i915_request *rq,
@@ -335,8 +376,9 @@ int i915_request_await_active(struct i915_request *rq, struct i915_active *ref)
void i915_active_fini(struct i915_active *ref)
{
debug_active_fini(ref);
- GEM_BUG_ON(!RB_EMPTY_ROOT(&ref->tree));
GEM_BUG_ON(atomic_read(&ref->count));
+ GEM_BUG_ON(work_pending(&ref->work));
+ GEM_BUG_ON(!RB_EMPTY_ROOT(&ref->tree));
mutex_destroy(&ref->mutex);
}
#endif
diff --git a/drivers/gpu/drm/i915/i915_active_types.h b/drivers/gpu/drm/i915/i915_active_types.h
index 5b0a3024ce24..a3a5ec3e4163 100644
--- a/drivers/gpu/drm/i915/i915_active_types.h
+++ b/drivers/gpu/drm/i915/i915_active_types.h
@@ -12,6 +12,9 @@
#include <linux/mutex.h>
#include <linux/rbtree.h>
#include <linux/rcupdate.h>
+#include <linux/workqueue.h>
+
+#include "i915_utils.h"
struct drm_i915_private;
struct i915_active_request;
@@ -28,6 +31,11 @@ struct i915_active_request {
struct active_node;
+#define I915_ACTIVE_MAY_SLEEP BIT(0)
+
+#define __i915_active_call __aligned(4)
+#define i915_active_may_sleep(fn) ptr_pack_bits(&(fn), I915_ACTIVE_MAY_SLEEP, 2)
+
struct i915_active {
struct drm_i915_private *i915;
@@ -38,6 +46,10 @@ struct i915_active {
int (*active)(struct i915_active *ref);
void (*retire)(struct i915_active *ref);
+ unsigned long flags;
+#define I915_ACTIVE_RETIRE_SLEEPS BIT(0)
+
+ struct work_struct work;
struct llist_head barriers;
};
diff --git a/drivers/gpu/drm/i915/i915_timeline.c b/drivers/gpu/drm/i915/i915_timeline.c
index 3ea1b881a4ae..0f4ca9478ae5 100644
--- a/drivers/gpu/drm/i915/i915_timeline.c
+++ b/drivers/gpu/drm/i915/i915_timeline.c
@@ -138,6 +138,7 @@ static void __idle_cacheline_free(struct i915_timeline_cacheline *cl)
kfree(cl);
}
+__i915_active_call
static void __cacheline_retire(struct i915_active *active)
{
struct i915_timeline_cacheline *cl =
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index ece5392c4f05..f694bfa54e0d 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -88,6 +88,7 @@ static int __i915_vma_active(struct i915_active *ref)
return 0;
}
+__i915_active_call
static void __i915_vma_retire(struct i915_active *ref)
{
i915_vma_put(active_to_vma(ref));
@@ -976,13 +977,13 @@ int i915_vma_unbind(struct i915_vma *vma)
if (ret)
return ret;
}
- GEM_BUG_ON(i915_vma_is_active(vma));
if (i915_vma_is_pinned(vma)) {
vma_print_allocator(vma, "is pinned");
return -EBUSY;
}
+ GEM_BUG_ON(i915_vma_is_active(vma));
if (!drm_mm_node_allocated(&vma->node))
return 0;
--
2.20.1
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