Forgo the struct_mutex serialisation for i915_active, and interpose its
own mutex handling for active/retire.
This is a multi-layered sleight-of-hand. First, we had to ensure that no
active/retire callbacks accidentally inverted the mutex ordering rules,
nor assumed that they were themselves serialised by struct_mutex. More
challenging though, is the rule over updating elements of the active
rbtree. Instead of the whole i915_active now being serialised by
struct_mutex, allocations/rotations of the tree are serialised by the
i915_active.mutex and individual nodes are serialised by the caller
using the i915_timeline.mutex (we need to use nested spinlocks to
interact with the dma_fence callback lists).
The pain point here is that instead of a single mutex around execbuf, we
now have to take a mutex for active tracker (one for each vma, context,
etc) and a couple of spinlocks for each fence update. The improvement in
fine grained locking allowing for multiple concurrent clients
(eventually!) should be worth it in typical loads.
v2: Add some comments that barely elucidate anything :(
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
---
.../gpu/drm/i915/display/intel_frontbuffer.c | 2 +-
drivers/gpu/drm/i915/display/intel_overlay.c | 3 +-
drivers/gpu/drm/i915/gem/i915_gem_context.c | 4 +-
.../gpu/drm/i915/gem/i915_gem_object_types.h | 1 +
drivers/gpu/drm/i915/gem/i915_gem_pm.c | 9 +-
drivers/gpu/drm/i915/gt/intel_context.c | 4 +-
drivers/gpu/drm/i915/gt/intel_engine_pool.c | 2 +-
drivers/gpu/drm/i915/gt/intel_reset.c | 10 +-
drivers/gpu/drm/i915/gt/intel_timeline.c | 7 +-
.../gpu/drm/i915/gt/intel_timeline_types.h | 9 +-
drivers/gpu/drm/i915/gt/selftest_context.c | 16 +-
drivers/gpu/drm/i915/gt/selftest_lrc.c | 10 +-
.../gpu/drm/i915/gt/selftests/mock_timeline.c | 2 +-
drivers/gpu/drm/i915/gvt/scheduler.c | 3 -
drivers/gpu/drm/i915/i915_active.c | 322 +++++++++---------
drivers/gpu/drm/i915/i915_active.h | 319 ++++-------------
drivers/gpu/drm/i915/i915_active_types.h | 23 +-
drivers/gpu/drm/i915/i915_gem.c | 42 ++-
drivers/gpu/drm/i915/i915_gem_gtt.c | 3 +-
drivers/gpu/drm/i915/i915_gpu_error.c | 4 +-
drivers/gpu/drm/i915/i915_request.c | 38 +--
drivers/gpu/drm/i915/i915_request.h | 1 -
drivers/gpu/drm/i915/i915_vma.c | 4 +-
drivers/gpu/drm/i915/selftests/i915_active.c | 32 +-
24 files changed, 298 insertions(+), 572 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_frontbuffer.c b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
index 6428b8dd70d3..84b164f31895 100644
--- a/drivers/gpu/drm/i915/display/intel_frontbuffer.c
+++ b/drivers/gpu/drm/i915/display/intel_frontbuffer.c
@@ -257,7 +257,7 @@ intel_frontbuffer_get(struct drm_i915_gem_object *obj)
front->obj = obj;
kref_init(&front->ref);
atomic_set(&front->bits, 0);
- i915_active_init(i915, &front->write,
+ i915_active_init(&front->write,
frontbuffer_active,
i915_active_may_sleep(frontbuffer_retire));
diff --git a/drivers/gpu/drm/i915/display/intel_overlay.c b/drivers/gpu/drm/i915/display/intel_overlay.c
index 3f4ac1ee7668..e12e1a753af0 100644
--- a/drivers/gpu/drm/i915/display/intel_overlay.c
+++ b/drivers/gpu/drm/i915/display/intel_overlay.c
@@ -1360,8 +1360,7 @@ void intel_overlay_setup(struct drm_i915_private *dev_priv)
overlay->contrast = 75;
overlay->saturation = 146;
- i915_active_init(dev_priv,
- &overlay->last_flip,
+ i915_active_init(&overlay->last_flip,
NULL, intel_overlay_last_flip_retire);
ret = get_registers(overlay, OVERLAY_NEEDS_PHYSICAL(dev_priv));
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index 4cd7d2ecf1d5..9d85aab68d34 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -868,20 +868,18 @@ static int context_barrier_task(struct i915_gem_context *ctx,
void (*task)(void *data),
void *data)
{
- struct drm_i915_private *i915 = ctx->i915;
struct context_barrier_task *cb;
struct i915_gem_engines_iter it;
struct intel_context *ce;
int err = 0;
- lockdep_assert_held(&i915->drm.struct_mutex);
GEM_BUG_ON(!task);
cb = kmalloc(sizeof(*cb), GFP_KERNEL);
if (!cb)
return -ENOMEM;
- i915_active_init(i915, &cb->base, NULL, cb_retire);
+ i915_active_init(&cb->base, NULL, cb_retire);
err = i915_active_acquire(&cb->base);
if (err) {
kfree(cb);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index e1aab2fd1cd9..c00b4f077f9e 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -8,6 +8,7 @@
#define __I915_GEM_OBJECT_TYPES_H__
#include <drm/drm_gem.h>
+#include <uapi/drm/i915_drm.h>
#include "i915_active.h"
#include "i915_selftest.h"
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pm.c b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
index cca192ecff8b..0a4115c6c275 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
@@ -16,14 +16,11 @@ static void call_idle_barriers(struct intel_engine_cs *engine)
struct llist_node *node, *next;
llist_for_each_safe(node, next, llist_del_all(&engine->barrier_tasks)) {
- struct i915_active_request *active =
+ struct dma_fence_cb *cb =
container_of((struct list_head *)node,
- typeof(*active), link);
+ typeof(*cb), node);
- INIT_LIST_HEAD(&active->link);
- RCU_INIT_POINTER(active->request, NULL);
-
- active->retire(active, NULL);
+ cb->func(NULL, cb);
}
}
diff --git a/drivers/gpu/drm/i915/gt/intel_context.c b/drivers/gpu/drm/i915/gt/intel_context.c
index 06fabdf205cf..35a40c2820a2 100644
--- a/drivers/gpu/drm/i915/gt/intel_context.c
+++ b/drivers/gpu/drm/i915/gt/intel_context.c
@@ -240,7 +240,7 @@ intel_context_init(struct intel_context *ce,
mutex_init(&ce->pin_mutex);
- i915_active_init(ctx->i915, &ce->active,
+ i915_active_init(&ce->active,
__intel_context_active, __intel_context_retire);
}
@@ -307,7 +307,7 @@ int intel_context_prepare_remote_request(struct intel_context *ce,
return err;
/* Queue this switch after current activity by this context. */
- err = i915_active_request_set(&tl->last_request, rq);
+ err = i915_active_fence_set(&tl->last_request, rq);
mutex_unlock(&tl->mutex);
if (err)
return err;
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pool.c b/drivers/gpu/drm/i915/gt/intel_engine_pool.c
index 81fab101fdb4..3cdbd5f8b5be 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_pool.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_pool.c
@@ -95,7 +95,7 @@ node_create(struct intel_engine_pool *pool, size_t sz)
return ERR_PTR(-ENOMEM);
node->pool = pool;
- i915_active_init(engine->i915, &node->active, pool_active, pool_retire);
+ i915_active_init(&node->active, pool_active, pool_retire);
obj = i915_gem_object_create_internal(engine->i915, sz);
if (IS_ERR(obj)) {
diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
index e189897e8797..055496f0825f 100644
--- a/drivers/gpu/drm/i915/gt/intel_reset.c
+++ b/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -844,10 +844,10 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt)
*/
spin_lock_irqsave(&timelines->lock, flags);
list_for_each_entry(tl, &timelines->active_list, link) {
- struct i915_request *rq;
+ struct dma_fence *fence;
- rq = i915_active_request_get_unlocked(&tl->last_request);
- if (!rq)
+ fence = i915_active_fence_get(&tl->last_request);
+ if (!fence)
continue;
spin_unlock_irqrestore(&timelines->lock, flags);
@@ -859,8 +859,8 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt)
* (I915_FENCE_TIMEOUT) so this wait should not be unbounded
* in the worst case.
*/
- dma_fence_default_wait(&rq->fence, false, MAX_SCHEDULE_TIMEOUT);
- i915_request_put(rq);
+ dma_fence_default_wait(fence, false, MAX_SCHEDULE_TIMEOUT);
+ dma_fence_put(fence);
/* Restart iteration after droping lock */
spin_lock_irqsave(&timelines->lock, flags);
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c
index 653f60e78392..0f959694303c 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline.c
+++ b/drivers/gpu/drm/i915/gt/intel_timeline.c
@@ -178,8 +178,7 @@ cacheline_alloc(struct intel_timeline_hwsp *hwsp, unsigned int cacheline)
cl->hwsp = hwsp;
cl->vaddr = page_pack_bits(vaddr, cacheline);
- i915_active_init(hwsp->gt->i915, &cl->active,
- __cacheline_active, __cacheline_retire);
+ i915_active_init(&cl->active, __cacheline_active, __cacheline_retire);
return cl;
}
@@ -255,7 +254,7 @@ int intel_timeline_init(struct intel_timeline *timeline,
mutex_init(&timeline->mutex);
- INIT_ACTIVE_REQUEST(&timeline->last_request, &timeline->mutex);
+ INIT_ACTIVE_FENCE(&timeline->last_request, &timeline->mutex);
INIT_LIST_HEAD(&timeline->requests);
i915_syncmap_init(&timeline->sync);
@@ -443,7 +442,7 @@ __intel_timeline_get_seqno(struct intel_timeline *tl,
* free it after the current request is retired, which ensures that
* all writes into the cacheline from previous requests are complete.
*/
- err = i915_active_ref(&tl->hwsp_cacheline->active, tl, rq);
+ err = i915_active_ref(&tl->hwsp_cacheline->active, tl, &rq->fence);
if (err)
goto err_cacheline;
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline_types.h b/drivers/gpu/drm/i915/gt/intel_timeline_types.h
index c668c4c50e75..98d9ee166379 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_timeline_types.h
@@ -58,12 +58,13 @@ struct intel_timeline {
*/
struct list_head requests;
- /* Contains an RCU guarded pointer to the last request. No reference is
+ /*
+ * Contains an RCU guarded pointer to the last request. No reference is
* held to the request, users must carefully acquire a reference to
- * the request using i915_active_request_get_request_rcu(), or hold the
- * struct_mutex.
+ * the request using i915_active_fence_get(), or manage the RCU
+ * protection themselves (cf the i915_active_fence API).
*/
- struct i915_active_request last_request;
+ struct i915_active_fence last_request;
/**
* We track the most recent seqno that we wait on in every context so
diff --git a/drivers/gpu/drm/i915/gt/selftest_context.c b/drivers/gpu/drm/i915/gt/selftest_context.c
index 4ce1e25433d2..e6bcbe7ab5e1 100644
--- a/drivers/gpu/drm/i915/gt/selftest_context.c
+++ b/drivers/gpu/drm/i915/gt/selftest_context.c
@@ -47,24 +47,20 @@ static int context_sync(struct intel_context *ce)
mutex_lock(&tl->mutex);
do {
- struct i915_request *rq;
+ struct dma_fence *fence;
long timeout;
- rcu_read_lock();
- rq = rcu_dereference(tl->last_request.request);
- if (rq)
- rq = i915_request_get_rcu(rq);
- rcu_read_unlock();
- if (!rq)
+ fence = i915_active_fence_get(&tl->last_request);
+ if (!fence)
break;
- timeout = i915_request_wait(rq, 0, HZ / 10);
+ timeout = dma_fence_wait_timeout(fence, false, HZ / 10);
if (timeout < 0)
err = timeout;
else
- i915_request_retire_upto(rq);
+ i915_request_retire_upto(to_request(fence));
- i915_request_put(rq);
+ dma_fence_put(fence);
} while (!err);
mutex_unlock(&tl->mutex);
diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index e7bc2dbbb2a5..dd25636abc5b 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -1172,9 +1172,13 @@ static struct i915_request *dummy_request(struct intel_engine_cs *engine)
if (!rq)
return NULL;
- INIT_LIST_HEAD(&rq->active_list);
rq->engine = engine;
+ spin_lock_init(&rq->lock);
+ INIT_LIST_HEAD(&rq->fence.cb_list);
+ rq->fence.lock = &rq->lock;
+ rq->fence.ops = &i915_fence_ops;
+
i915_sched_node_init(&rq->sched);
/* mark this request as permanently incomplete */
@@ -1267,8 +1271,8 @@ static int live_suppress_wait_preempt(void *arg)
}
/* Disable NEWCLIENT promotion */
- __i915_active_request_set(&i915_request_timeline(rq[i])->last_request,
- dummy);
+ __i915_active_fence_set(&i915_request_timeline(rq[i])->last_request,
+ &dummy->fence);
i915_request_add(rq[i]);
}
diff --git a/drivers/gpu/drm/i915/gt/selftests/mock_timeline.c b/drivers/gpu/drm/i915/gt/selftests/mock_timeline.c
index 598170efcaf6..2a77c051f36a 100644
--- a/drivers/gpu/drm/i915/gt/selftests/mock_timeline.c
+++ b/drivers/gpu/drm/i915/gt/selftests/mock_timeline.c
@@ -15,7 +15,7 @@ void mock_timeline_init(struct intel_timeline *timeline, u64 context)
mutex_init(&timeline->mutex);
- INIT_ACTIVE_REQUEST(&timeline->last_request, &timeline->mutex);
+ INIT_ACTIVE_FENCE(&timeline->last_request, &timeline->mutex);
INIT_LIST_HEAD(&timeline->requests);
i915_syncmap_init(&timeline->sync);
diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
index 6c79d16b381e..03f567084548 100644
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -385,11 +385,8 @@ intel_gvt_workload_req_alloc(struct intel_vgpu_workload *workload)
{
struct intel_vgpu *vgpu = workload->vgpu;
struct intel_vgpu_submission *s = &vgpu->submission;
- struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
struct i915_request *rq;
- lockdep_assert_held(&dev_priv->drm.struct_mutex);
-
if (workload->req)
return 0;
diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index 7ca066688b98..023652ded4be 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -12,8 +12,6 @@
#include "i915_active.h"
#include "i915_globals.h"
-#define BKL(ref) (&(ref)->i915->drm.struct_mutex)
-
/*
* Active refs memory management
*
@@ -27,35 +25,35 @@ static struct i915_global_active {
} global;
struct active_node {
- struct i915_active_request base;
+ struct i915_active_fence base;
struct i915_active *ref;
struct rb_node node;
u64 timeline;
};
static inline struct active_node *
-node_from_active(struct i915_active_request *active)
+node_from_active(struct i915_active_fence *active)
{
return container_of(active, struct active_node, base);
}
#define take_preallocated_barriers(x) llist_del_all(&(x)->preallocated_barriers)
-static inline bool is_barrier(const struct i915_active_request *active)
+static inline bool is_barrier(const struct i915_active_fence *active)
{
- return IS_ERR(rcu_access_pointer(active->request));
+ return IS_ERR(rcu_access_pointer(active->fence));
}
static inline struct llist_node *barrier_to_ll(struct active_node *node)
{
GEM_BUG_ON(!is_barrier(&node->base));
- return (struct llist_node *)&node->base.link;
+ return (struct llist_node *)&node->base.cb.node;
}
static inline struct intel_engine_cs *
__barrier_to_engine(struct active_node *node)
{
- return (struct intel_engine_cs *)READ_ONCE(node->base.link.prev);
+ return (struct intel_engine_cs *)READ_ONCE(node->base.cb.node.prev);
}
static inline struct intel_engine_cs *
@@ -68,7 +66,7 @@ barrier_to_engine(struct active_node *node)
static inline struct active_node *barrier_from_ll(struct llist_node *x)
{
return container_of((struct list_head *)x,
- struct active_node, base.link);
+ struct active_node, base.cb.node);
}
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) && IS_ENABLED(CONFIG_DEBUG_OBJECTS)
@@ -147,15 +145,18 @@ __active_retire(struct i915_active *ref)
if (!retire)
return;
- GEM_BUG_ON(rcu_access_pointer(ref->excl));
+ GEM_BUG_ON(rcu_access_pointer(ref->excl.fence));
rbtree_postorder_for_each_entry_safe(it, n, &root, node) {
- GEM_BUG_ON(i915_active_request_isset(&it->base));
+ GEM_BUG_ON(i915_active_fence_isset(&it->base));
kmem_cache_free(global.slab_cache, it);
}
/* After the final retire, the entire struct may be freed */
if (ref->retire)
ref->retire(ref);
+
+ /* ... except if you wait on it, you must manage your own references! */
+ wake_up_var(ref);
}
static void
@@ -189,12 +190,20 @@ active_retire(struct i915_active *ref)
}
static void
-node_retire(struct i915_active_request *base, struct i915_request *rq)
+node_retire(struct dma_fence *fence, struct dma_fence_cb *cb)
{
- active_retire(node_from_active(base)->ref);
+ i915_active_fence_cb(fence, cb);
+ active_retire(container_of(cb, struct active_node, base.cb)->ref);
}
-static struct i915_active_request *
+static void
+excl_retire(struct dma_fence *fence, struct dma_fence_cb *cb)
+{
+ i915_active_fence_cb(fence, cb);
+ active_retire(container_of(cb, struct i915_active, excl.cb));
+}
+
+static struct i915_active_fence *
active_instance(struct i915_active *ref, struct intel_timeline *tl)
{
struct active_node *node, *prealloc;
@@ -238,7 +247,7 @@ active_instance(struct i915_active *ref, struct intel_timeline *tl)
}
node = prealloc;
- i915_active_request_init(&node->base, &tl->mutex, NULL, node_retire);
+ __i915_active_fence_init(&node->base, &tl->mutex, NULL, node_retire);
node->ref = ref;
node->timeline = idx;
@@ -253,8 +262,7 @@ active_instance(struct i915_active *ref, struct intel_timeline *tl)
return &node->base;
}
-void __i915_active_init(struct drm_i915_private *i915,
- struct i915_active *ref,
+void __i915_active_init(struct i915_active *ref,
int (*active)(struct i915_active *ref),
void (*retire)(struct i915_active *ref),
struct lock_class_key *key)
@@ -263,19 +271,18 @@ void __i915_active_init(struct drm_i915_private *i915,
debug_active_init(ref);
- ref->i915 = i915;
ref->flags = 0;
ref->active = active;
ref->retire = ptr_unpack_bits(retire, &bits, 2);
if (bits & I915_ACTIVE_MAY_SLEEP)
ref->flags |= I915_ACTIVE_RETIRE_SLEEPS;
- ref->excl = NULL;
ref->tree = RB_ROOT;
ref->cache = NULL;
init_llist_head(&ref->preallocated_barriers);
atomic_set(&ref->count, 0);
__mutex_init(&ref->mutex, "i915_active", key);
+ __i915_active_fence_init(&ref->excl, &ref->mutex, NULL, excl_retire);
INIT_WORK(&ref->work, active_work);
}
@@ -329,9 +336,9 @@ __active_del_barrier(struct i915_active *ref, struct active_node *node)
int i915_active_ref(struct i915_active *ref,
struct intel_timeline *tl,
- struct i915_request *rq)
+ struct dma_fence *fence)
{
- struct i915_active_request *active;
+ struct i915_active_fence *active;
int err;
lockdep_assert_held(&tl->mutex);
@@ -354,66 +361,44 @@ int i915_active_ref(struct i915_active *ref,
* request that we want to emit on the kernel_context.
*/
__active_del_barrier(ref, node_from_active(active));
- RCU_INIT_POINTER(active->request, NULL);
- INIT_LIST_HEAD(&active->link);
- } else {
- if (!i915_active_request_isset(active))
- atomic_inc(&ref->count);
+ RCU_INIT_POINTER(active->fence, NULL);
+ atomic_dec(&ref->count);
}
- GEM_BUG_ON(!atomic_read(&ref->count));
- __i915_active_request_set(active, rq);
+ if (!__i915_active_fence_set(active, fence))
+ atomic_inc(&ref->count);
out:
i915_active_release(ref);
return err;
}
-static void excl_cb(struct dma_fence *f, struct dma_fence_cb *cb)
-{
- struct i915_active *ref = container_of(cb, typeof(*ref), excl_cb);
-
- RCU_INIT_POINTER(ref->excl, NULL);
- dma_fence_put(f);
-
- active_retire(ref);
-}
-
void i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f)
{
/* We expect the caller to manage the exclusive timeline ordering */
GEM_BUG_ON(i915_active_is_idle(ref));
- dma_fence_get(f);
-
- rcu_read_lock();
- if (rcu_access_pointer(ref->excl)) {
- struct dma_fence *old;
-
- old = dma_fence_get_rcu_safe(&ref->excl);
- if (old) {
- if (dma_fence_remove_callback(old, &ref->excl_cb))
- atomic_dec(&ref->count);
- dma_fence_put(old);
- }
- }
- rcu_read_unlock();
-
- atomic_inc(&ref->count);
- rcu_assign_pointer(ref->excl, f);
+ /*
+ * As we don't know which mutex the caller is using, we told a small
+ * lie to the debug code that it is using the i915_active.mutex;
+ * and now we must stick to that lie.
+ */
+ mutex_acquire(&ref->mutex.dep_map, 0, 0, _THIS_IP_);
+ if (!__i915_active_fence_set(&ref->excl, f))
+ atomic_inc(&ref->count);
+ mutex_release(&ref->mutex.dep_map, 0, _THIS_IP_);
+}
- if (dma_fence_add_callback(f, &ref->excl_cb, excl_cb)) {
- RCU_INIT_POINTER(ref->excl, NULL);
- atomic_dec(&ref->count);
- dma_fence_put(f);
- }
+bool i915_active_acquire_if_busy(struct i915_active *ref)
+{
+ debug_active_assert(ref);
+ return atomic_add_unless(&ref->count, 1, 0);
}
int i915_active_acquire(struct i915_active *ref)
{
int err;
- debug_active_assert(ref);
- if (atomic_add_unless(&ref->count, 1, 0))
+ if (i915_active_acquire_if_busy(ref))
return 0;
err = mutex_lock_interruptible(&ref->mutex);
@@ -438,121 +423,57 @@ void i915_active_release(struct i915_active *ref)
active_retire(ref);
}
-static void __active_ungrab(struct i915_active *ref)
-{
- clear_and_wake_up_bit(I915_ACTIVE_GRAB_BIT, &ref->flags);
-}
-
-bool i915_active_trygrab(struct i915_active *ref)
+static void enable_signaling(struct i915_active_fence *active)
{
- debug_active_assert(ref);
-
- if (test_and_set_bit(I915_ACTIVE_GRAB_BIT, &ref->flags))
- return false;
-
- if (!atomic_add_unless(&ref->count, 1, 0)) {
- __active_ungrab(ref);
- return false;
- }
+ struct dma_fence *fence;
- return true;
-}
-
-void i915_active_ungrab(struct i915_active *ref)
-{
- GEM_BUG_ON(!test_bit(I915_ACTIVE_GRAB_BIT, &ref->flags));
-
- active_retire(ref);
- __active_ungrab(ref);
-}
-
-static int excl_wait(struct i915_active *ref)
-{
- struct dma_fence *old;
- int err = 0;
-
- if (!rcu_access_pointer(ref->excl))
- return 0;
-
- rcu_read_lock();
- old = dma_fence_get_rcu_safe(&ref->excl);
- rcu_read_unlock();
- if (old) {
- err = dma_fence_wait(old, true);
- dma_fence_put(old);
- }
+ fence = i915_active_fence_get(active);
+ if (!fence)
+ return;
- return err;
+ dma_fence_enable_sw_signaling(fence);
+ dma_fence_put(fence);
}
int i915_active_wait(struct i915_active *ref)
{
struct active_node *it, *n;
- int err;
+ int err = 0;
might_sleep();
- might_lock(&ref->mutex);
-
- if (i915_active_is_idle(ref))
- return 0;
-
- err = mutex_lock_interruptible(&ref->mutex);
- if (err)
- return err;
- if (!atomic_add_unless(&ref->count, 1, 0)) {
- mutex_unlock(&ref->mutex);
+ if (!i915_active_acquire_if_busy(ref))
return 0;
- }
-
- err = excl_wait(ref);
- if (err)
- goto out;
+ /* Flush lazy signals */
+ enable_signaling(&ref->excl);
rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
- if (is_barrier(&it->base)) { /* unconnected idle-barrier */
- err = -EBUSY;
- break;
- }
+ if (is_barrier(&it->base)) /* unconnected idle barrier */
+ continue;
- err = i915_active_request_retire(&it->base, BKL(ref));
- if (err)
- break;
+ enable_signaling(&it->base);
}
+ /* Any fence added after the wait begins will not be auto-signaled */
-out:
- __active_retire(ref);
+ i915_active_release(ref);
if (err)
return err;
- if (wait_on_bit(&ref->flags, I915_ACTIVE_GRAB_BIT, TASK_KILLABLE))
+ if (wait_var_event_interruptible(ref, i915_active_is_idle(ref)))
return -EINTR;
- flush_work(&ref->work);
- if (!i915_active_is_idle(ref))
- return -EBUSY;
-
return 0;
}
-int i915_request_await_active_request(struct i915_request *rq,
- struct i915_active_request *active)
-{
- struct i915_request *barrier =
- i915_active_request_raw(active, &rq->i915->drm.struct_mutex);
-
- return barrier ? i915_request_await_dma_fence(rq, &barrier->fence) : 0;
-}
-
int i915_request_await_active(struct i915_request *rq, struct i915_active *ref)
{
int err = 0;
- if (rcu_access_pointer(ref->excl)) {
+ if (rcu_access_pointer(ref->excl.fence)) {
struct dma_fence *fence;
rcu_read_lock();
- fence = dma_fence_get_rcu_safe(&ref->excl);
+ fence = dma_fence_get_rcu_safe(&ref->excl.fence);
rcu_read_unlock();
if (fence) {
err = i915_request_await_dma_fence(rq, fence);
@@ -578,7 +499,7 @@ void i915_active_fini(struct i915_active *ref)
static inline bool is_idle_barrier(struct active_node *node, u64 idx)
{
- return node->timeline == idx && !i915_active_request_isset(&node->base);
+ return node->timeline == idx && !i915_active_fence_isset(&node->base);
}
static struct active_node *reuse_idle_barrier(struct i915_active *ref, u64 idx)
@@ -698,13 +619,13 @@ int i915_active_acquire_preallocate_barrier(struct i915_active *ref,
node->base.lock =
&engine->kernel_context->timeline->mutex;
#endif
- RCU_INIT_POINTER(node->base.request, NULL);
- node->base.retire = node_retire;
+ RCU_INIT_POINTER(node->base.fence, NULL);
+ node->base.cb.func = node_retire;
node->timeline = idx;
node->ref = ref;
}
- if (!i915_active_request_isset(&node->base)) {
+ if (!i915_active_fence_isset(&node->base)) {
/*
* Mark this as being *our* unconnected proto-node.
*
@@ -714,8 +635,8 @@ int i915_active_acquire_preallocate_barrier(struct i915_active *ref,
* and then we can use the rb_node and list pointers
* for our tracking of the pending barrier.
*/
- RCU_INIT_POINTER(node->base.request, ERR_PTR(-EAGAIN));
- node->base.link.prev = (void *)engine;
+ RCU_INIT_POINTER(node->base.fence, ERR_PTR(-EAGAIN));
+ node->base.cb.node.prev = (void *)engine;
atomic_inc(&ref->count);
}
@@ -782,44 +703,113 @@ void i915_request_add_active_barriers(struct i915_request *rq)
{
struct intel_engine_cs *engine = rq->engine;
struct llist_node *node, *next;
+ unsigned long flags;
GEM_BUG_ON(intel_engine_is_virtual(engine));
GEM_BUG_ON(i915_request_timeline(rq) != engine->kernel_context->timeline);
+ node = llist_del_all(&engine->barrier_tasks);
+ if (!node)
+ return;
/*
* Attach the list of proto-fences to the in-flight request such
* that the parent i915_active will be released when this request
* is retired.
*/
- llist_for_each_safe(node, next, llist_del_all(&engine->barrier_tasks)) {
- RCU_INIT_POINTER(barrier_from_ll(node)->base.request, rq);
+ spin_lock_irqsave(&rq->lock, flags);
+ llist_for_each_safe(node, next, node) {
+ RCU_INIT_POINTER(barrier_from_ll(node)->base.fence, &rq->fence);
smp_wmb(); /* serialise with reuse_idle_barrier */
- list_add_tail((struct list_head *)node, &rq->active_list);
+ list_add_tail((struct list_head *)node, &rq->fence.cb_list);
+ }
+ spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
+#define active_is_held(active) lockdep_is_held((active)->lock)
+#else
+#define active_is_held(active) true
+#endif
+
+/*
+ * __i915_active_fence_set: Update the last active fence along its timeline
+ * @active: the active tracker
+ * @fence: the new fence (under construction)
+ *
+ * Records the new @fence as the last active fence along its timeline in
+ * this active tracker, moving the tracking callbacks from the previous
+ * fence onto this one. Returns the previous fence (if not already completed),
+ * which the caller must ensure is executed before the new fence. To ensure
+ * that the order of fences within the timeline of the i915_active_fence is
+ * maintained, it must be locked by the caller.
+ */
+struct dma_fence *
+__i915_active_fence_set(struct i915_active_fence *active,
+ struct dma_fence *fence)
+{
+ struct dma_fence *prev;
+ unsigned long flags;
+
+ /* NB: must be serialised by an outer timeline mutex (active->lock) */
+ spin_lock_irqsave(fence->lock, flags);
+ GEM_BUG_ON(test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags));
+
+ prev = rcu_dereference_protected(active->fence, active_is_held(active));
+ if (prev) {
+ GEM_BUG_ON(prev == fence);
+ spin_lock_nested(prev->lock, SINGLE_DEPTH_NESTING);
+ __list_del_entry(&active->cb.node);
+ spin_unlock(prev->lock); /* serialise with prev->cb_list */
+
+ /*
+ * active->fence is reset by the callback from inside
+ * interrupt context. We need to serialise our list
+ * manipulation with the fence->lock to prevent the prev
+ * being lost inside an interrupt (it can't be replaced as
+ * no other caller is allowed to enter __i915_active_fence_set
+ * as we hold the timeline lock). After serialising with
+ * the callback, we need to double check which ran first,
+ * our list_del() [decoupling prev from the callback] or
+ * the callback...
+ */
+ prev = rcu_access_pointer(active->fence);
}
+
+ rcu_assign_pointer(active->fence, fence);
+ list_add_tail(&active->cb.node, &fence->cb_list);
+
+ spin_unlock_irqrestore(fence->lock, flags);
+
+ return prev;
}
-int i915_active_request_set(struct i915_active_request *active,
- struct i915_request *rq)
+int i915_active_fence_set(struct i915_active_fence *active,
+ struct i915_request *rq)
{
- int err;
+ struct dma_fence *fence;
+ int err = 0;
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
lockdep_assert_held(active->lock);
#endif
- /* Must maintain ordering wrt previous active requests */
- err = i915_request_await_active_request(rq, active);
- if (err)
- return err;
+ /* Must maintain timeline ordering wrt previous active requests */
+ rcu_read_lock();
+ fence = __i915_active_fence_set(active, &rq->fence);
+ if (fence) /* but the previous fence may not belong to that timeline! */
+ fence = dma_fence_get_rcu(fence);
+ rcu_read_unlock();
+ if (fence) {
+ err = i915_request_await_dma_fence(rq, fence);
+ dma_fence_put(fence);
+ }
- __i915_active_request_set(active, rq);
- return 0;
+ return err;
}
-void i915_active_retire_noop(struct i915_active_request *active,
- struct i915_request *request)
+void i915_active_noop(struct dma_fence *fence, struct dma_fence_cb *cb)
{
- /* Space left intentionally blank */
+ i915_active_fence_cb(fence, cb);
}
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
diff --git a/drivers/gpu/drm/i915/i915_active.h b/drivers/gpu/drm/i915/i915_active.h
index 90034f61b7c2..4f52fe6146d2 100644
--- a/drivers/gpu/drm/i915/i915_active.h
+++ b/drivers/gpu/drm/i915/i915_active.h
@@ -12,6 +12,10 @@
#include "i915_active_types.h"
#include "i915_request.h"
+struct i915_request;
+struct intel_engine_cs;
+struct intel_timeline;
+
/*
* We treat requests as fences. This is not be to confused with our
* "fence registers" but pipeline synchronisation objects ala GL_ARB_sync.
@@ -28,308 +32,108 @@
* write access so that we can perform concurrent read operations between
* the CPU and GPU engines, as well as waiting for all rendering to
* complete, or waiting for the last GPU user of a "fence register". The
- * object then embeds a #i915_active_request to track the most recent (in
+ * object then embeds a #i915_active_fence to track the most recent (in
* retirement order) request relevant for the desired mode of access.
- * The #i915_active_request is updated with i915_active_request_set() to
+ * The #i915_active_fence is updated with i915_active_fence_set() to
* track the most recent fence request, typically this is done as part of
* i915_vma_move_to_active().
*
- * When the #i915_active_request completes (is retired), it will
+ * When the #i915_active_fence completes (is retired), it will
* signal its completion to the owner through a callback as well as mark
- * itself as idle (i915_active_request.request == NULL). The owner
+ * itself as idle (i915_active_fence.request == NULL). The owner
* can then perform any action, such as delayed freeing of an active
* resource including itself.
*/
-void i915_active_retire_noop(struct i915_active_request *active,
- struct i915_request *request);
+void i915_active_noop(struct dma_fence *fence, struct dma_fence_cb *cb);
/**
- * i915_active_request_init - prepares the activity tracker for use
+ * __i915_active_fence_init - prepares the activity tracker for use
* @active - the active tracker
- * @rq - initial request to track, can be NULL
+ * @fence - initial fence to track, can be NULL
* @func - a callback when then the tracker is retired (becomes idle),
* can be NULL
*
- * i915_active_request_init() prepares the embedded @active struct for use as
- * an activity tracker, that is for tracking the last known active request
- * associated with it. When the last request becomes idle, when it is retired
+ * i915_active_fence_init() prepares the embedded @active struct for use as
+ * an activity tracker, that is for tracking the last known active fence
+ * associated with it. When the last fence becomes idle, when it is retired
* after completion, the optional callback @func is invoked.
*/
static inline void
-i915_active_request_init(struct i915_active_request *active,
+__i915_active_fence_init(struct i915_active_fence *active,
struct mutex *lock,
- struct i915_request *rq,
- i915_active_retire_fn retire)
+ void *fence,
+ dma_fence_func_t fn)
{
- RCU_INIT_POINTER(active->request, rq);
- INIT_LIST_HEAD(&active->link);
- active->retire = retire ?: i915_active_retire_noop;
+ RCU_INIT_POINTER(active->fence, fence);
+ active->cb.func = fn ?: i915_active_noop;
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
active->lock = lock;
#endif
}
-#define INIT_ACTIVE_REQUEST(name, lock) \
- i915_active_request_init((name), (lock), NULL, NULL)
-
-/**
- * i915_active_request_set - updates the tracker to watch the current request
- * @active - the active tracker
- * @request - the request to watch
- *
- * __i915_active_request_set() watches the given @request for completion. Whilst
- * that @request is busy, the @active reports busy. When that @request is
- * retired, the @active tracker is updated to report idle.
- */
-static inline void
-__i915_active_request_set(struct i915_active_request *active,
- struct i915_request *request)
-{
-#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
- lockdep_assert_held(active->lock);
-#endif
- list_move(&active->link, &request->active_list);
- rcu_assign_pointer(active->request, request);
-}
+#define INIT_ACTIVE_FENCE(A, LOCK) \
+ __i915_active_fence_init((A), (LOCK), NULL, NULL)
-int __must_check
-i915_active_request_set(struct i915_active_request *active,
- struct i915_request *rq);
+struct dma_fence *
+__i915_active_fence_set(struct i915_active_fence *active,
+ struct dma_fence *fence);
/**
- * i915_active_request_raw - return the active request
+ * i915_active_fence_set - updates the tracker to watch the current fence
* @active - the active tracker
+ * @rq - the request to watch
*
- * i915_active_request_raw() returns the current request being tracked, or NULL.
- * It does not obtain a reference on the request for the caller, so the caller
- * must hold struct_mutex.
+ * i915_active_fence_set() watches the given @rq for completion. While
+ * that @rq is busy, the @active reports busy. When that @rq is signaled
+ * (or else retired) the @active tracker is updated to report idle.
*/
-static inline struct i915_request *
-i915_active_request_raw(const struct i915_active_request *active,
- struct mutex *mutex)
-{
- return rcu_dereference_protected(active->request,
- lockdep_is_held(mutex));
-}
-
-/**
- * i915_active_request_peek - report the active request being monitored
- * @active - the active tracker
- *
- * i915_active_request_peek() returns the current request being tracked if
- * still active, or NULL. It does not obtain a reference on the request
- * for the caller, so the caller must hold struct_mutex.
- */
-static inline struct i915_request *
-i915_active_request_peek(const struct i915_active_request *active,
- struct mutex *mutex)
-{
- struct i915_request *request;
-
- request = i915_active_request_raw(active, mutex);
- if (!request || i915_request_completed(request))
- return NULL;
-
- return request;
-}
-
-/**
- * i915_active_request_get - return a reference to the active request
- * @active - the active tracker
- *
- * i915_active_request_get() returns a reference to the active request, or NULL
- * if the active tracker is idle. The caller must hold struct_mutex.
- */
-static inline struct i915_request *
-i915_active_request_get(const struct i915_active_request *active,
- struct mutex *mutex)
-{
- return i915_request_get(i915_active_request_peek(active, mutex));
-}
-
-/**
- * __i915_active_request_get_rcu - return a reference to the active request
- * @active - the active tracker
- *
- * __i915_active_request_get() returns a reference to the active request,
- * or NULL if the active tracker is idle. The caller must hold the RCU read
- * lock, but the returned pointer is safe to use outside of RCU.
- */
-static inline struct i915_request *
-__i915_active_request_get_rcu(const struct i915_active_request *active)
-{
- /*
- * Performing a lockless retrieval of the active request is super
- * tricky. SLAB_TYPESAFE_BY_RCU merely guarantees that the backing
- * slab of request objects will not be freed whilst we hold the
- * RCU read lock. It does not guarantee that the request itself
- * will not be freed and then *reused*. Viz,
- *
- * Thread A Thread B
- *
- * rq = active.request
- * retire(rq) -> free(rq);
- * (rq is now first on the slab freelist)
- * active.request = NULL
- *
- * rq = new submission on a new object
- * ref(rq)
- *
- * To prevent the request from being reused whilst the caller
- * uses it, we take a reference like normal. Whilst acquiring
- * the reference we check that it is not in a destroyed state
- * (refcnt == 0). That prevents the request being reallocated
- * whilst the caller holds on to it. To check that the request
- * was not reallocated as we acquired the reference we have to
- * check that our request remains the active request across
- * the lookup, in the same manner as a seqlock. The visibility
- * of the pointer versus the reference counting is controlled
- * by using RCU barriers (rcu_dereference and rcu_assign_pointer).
- *
- * In the middle of all that, we inspect whether the request is
- * complete. Retiring is lazy so the request may be completed long
- * before the active tracker is updated. Querying whether the
- * request is complete is far cheaper (as it involves no locked
- * instructions setting cachelines to exclusive) than acquiring
- * the reference, so we do it first. The RCU read lock ensures the
- * pointer dereference is valid, but does not ensure that the
- * seqno nor HWS is the right one! However, if the request was
- * reallocated, that means the active tracker's request was complete.
- * If the new request is also complete, then both are and we can
- * just report the active tracker is idle. If the new request is
- * incomplete, then we acquire a reference on it and check that
- * it remained the active request.
- *
- * It is then imperative that we do not zero the request on
- * reallocation, so that we can chase the dangling pointers!
- * See i915_request_alloc().
- */
- do {
- struct i915_request *request;
-
- request = rcu_dereference(active->request);
- if (!request || i915_request_completed(request))
- return NULL;
-
- /*
- * An especially silly compiler could decide to recompute the
- * result of i915_request_completed, more specifically
- * re-emit the load for request->fence.seqno. A race would catch
- * a later seqno value, which could flip the result from true to
- * false. Which means part of the instructions below might not
- * be executed, while later on instructions are executed. Due to
- * barriers within the refcounting the inconsistency can't reach
- * past the call to i915_request_get_rcu, but not executing
- * that while still executing i915_request_put() creates
- * havoc enough. Prevent this with a compiler barrier.
- */
- barrier();
-
- request = i915_request_get_rcu(request);
-
- /*
- * What stops the following rcu_access_pointer() from occurring
- * before the above i915_request_get_rcu()? If we were
- * to read the value before pausing to get the reference to
- * the request, we may not notice a change in the active
- * tracker.
- *
- * The rcu_access_pointer() is a mere compiler barrier, which
- * means both the CPU and compiler are free to perform the
- * memory read without constraint. The compiler only has to
- * ensure that any operations after the rcu_access_pointer()
- * occur afterwards in program order. This means the read may
- * be performed earlier by an out-of-order CPU, or adventurous
- * compiler.
- *
- * The atomic operation at the heart of
- * i915_request_get_rcu(), see dma_fence_get_rcu(), is
- * atomic_inc_not_zero() which is only a full memory barrier
- * when successful. That is, if i915_request_get_rcu()
- * returns the request (and so with the reference counted
- * incremented) then the following read for rcu_access_pointer()
- * must occur after the atomic operation and so confirm
- * that this request is the one currently being tracked.
- *
- * The corresponding write barrier is part of
- * rcu_assign_pointer().
- */
- if (!request || request == rcu_access_pointer(active->request))
- return rcu_pointer_handoff(request);
-
- i915_request_put(request);
- } while (1);
-}
-
+int __must_check
+i915_active_fence_set(struct i915_active_fence *active,
+ struct i915_request *rq);
/**
- * i915_active_request_get_unlocked - return a reference to the active request
+ * i915_active_fence_get - return a reference to the active fence
* @active - the active tracker
*
- * i915_active_request_get_unlocked() returns a reference to the active request,
+ * i915_active_fence_get() returns a reference to the active fence,
* or NULL if the active tracker is idle. The reference is obtained under RCU,
* so no locking is required by the caller.
*
- * The reference should be freed with i915_request_put().
+ * The reference should be freed with dma_fence_put().
*/
-static inline struct i915_request *
-i915_active_request_get_unlocked(const struct i915_active_request *active)
+static inline struct dma_fence *
+i915_active_fence_get(struct i915_active_fence *active)
{
- struct i915_request *request;
+ struct dma_fence *fence;
rcu_read_lock();
- request = __i915_active_request_get_rcu(active);
+ fence = dma_fence_get_rcu_safe(&active->fence);
rcu_read_unlock();
- return request;
+ return fence;
}
/**
- * i915_active_request_isset - report whether the active tracker is assigned
+ * i915_active_fence_isset - report whether the active tracker is assigned
* @active - the active tracker
*
- * i915_active_request_isset() returns true if the active tracker is currently
- * assigned to a request. Due to the lazy retiring, that request may be idle
+ * i915_active_fence_isset() returns true if the active tracker is currently
+ * assigned to a fence. Due to the lazy retiring, that fence may be idle
* and this may report stale information.
*/
static inline bool
-i915_active_request_isset(const struct i915_active_request *active)
+i915_active_fence_isset(const struct i915_active_fence *active)
{
- return rcu_access_pointer(active->request);
+ return rcu_access_pointer(active->fence);
}
-/**
- * i915_active_request_retire - waits until the request is retired
- * @active - the active request on which to wait
- *
- * i915_active_request_retire() waits until the request is completed,
- * and then ensures that at least the retirement handler for this
- * @active tracker is called before returning. If the @active
- * tracker is idle, the function returns immediately.
- */
-static inline int __must_check
-i915_active_request_retire(struct i915_active_request *active,
- struct mutex *mutex)
+static inline void
+i915_active_fence_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
{
- struct i915_request *request;
- long ret;
-
- request = i915_active_request_raw(active, mutex);
- if (!request)
- return 0;
-
- ret = i915_request_wait(request,
- I915_WAIT_INTERRUPTIBLE,
- MAX_SCHEDULE_TIMEOUT);
- if (ret < 0)
- return ret;
+ struct i915_active_fence *active =
+ container_of(cb, typeof(*active), cb);
- list_del_init(&active->link);
- RCU_INIT_POINTER(active->request, NULL);
-
- active->retire(active, request);
-
- return 0;
+ RCU_INIT_POINTER(active->fence, NULL);
}
/*
@@ -358,47 +162,40 @@ i915_active_request_retire(struct i915_active_request *active,
* synchronisation.
*/
-void __i915_active_init(struct drm_i915_private *i915,
- struct i915_active *ref,
+void __i915_active_init(struct i915_active *ref,
int (*active)(struct i915_active *ref),
void (*retire)(struct i915_active *ref),
struct lock_class_key *key);
-#define i915_active_init(i915, ref, active, retire) do { \
+#define i915_active_init(ref, active, retire) do { \
static struct lock_class_key __key; \
\
- __i915_active_init(i915, ref, active, retire, &__key); \
+ __i915_active_init(ref, active, retire, &__key); \
} while (0)
int i915_active_ref(struct i915_active *ref,
struct intel_timeline *tl,
- struct i915_request *rq);
+ struct dma_fence *fence);
static inline int
i915_active_add_request(struct i915_active *ref, struct i915_request *rq)
{
- return i915_active_ref(ref, i915_request_timeline(rq), rq);
+ return i915_active_ref(ref, i915_request_timeline(rq), &rq->fence);
}
void i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f);
static inline bool i915_active_has_exclusive(struct i915_active *ref)
{
- return rcu_access_pointer(ref->excl);
+ return rcu_access_pointer(ref->excl.fence);
}
int i915_active_wait(struct i915_active *ref);
-int i915_request_await_active(struct i915_request *rq,
- struct i915_active *ref);
-int i915_request_await_active_request(struct i915_request *rq,
- struct i915_active_request *active);
+int i915_request_await_active(struct i915_request *rq, struct i915_active *ref);
int i915_active_acquire(struct i915_active *ref);
+bool i915_active_acquire_if_busy(struct i915_active *ref);
void i915_active_release(struct i915_active *ref);
-void __i915_active_release_nested(struct i915_active *ref, int subclass);
-
-bool i915_active_trygrab(struct i915_active *ref);
-void i915_active_ungrab(struct i915_active *ref);
static inline bool
i915_active_is_idle(const struct i915_active *ref)
diff --git a/drivers/gpu/drm/i915/i915_active_types.h b/drivers/gpu/drm/i915/i915_active_types.h
index 021167f0004d..d89a74c142c6 100644
--- a/drivers/gpu/drm/i915/i915_active_types.h
+++ b/drivers/gpu/drm/i915/i915_active_types.h
@@ -17,17 +17,9 @@
#include "i915_utils.h"
-struct drm_i915_private;
-struct i915_active_request;
-struct i915_request;
-
-typedef void (*i915_active_retire_fn)(struct i915_active_request *,
- struct i915_request *);
-
-struct i915_active_request {
- struct i915_request __rcu *request;
- struct list_head link;
- i915_active_retire_fn retire;
+struct i915_active_fence {
+ struct dma_fence __rcu *fence;
+ struct dma_fence_cb cb;
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
/*
* Incorporeal!
@@ -53,20 +45,17 @@ struct active_node;
#define i915_active_may_sleep(fn) ptr_pack_bits(&(fn), I915_ACTIVE_MAY_SLEEP, 2)
struct i915_active {
- struct drm_i915_private *i915;
+ atomic_t count;
+ struct mutex mutex;
struct active_node *cache;
struct rb_root tree;
- struct mutex mutex;
- atomic_t count;
/* Preallocated "exclusive" node */
- struct dma_fence __rcu *excl;
- struct dma_fence_cb excl_cb;
+ struct i915_active_fence excl;
unsigned long flags;
#define I915_ACTIVE_RETIRE_SLEEPS BIT(0)
-#define I915_ACTIVE_GRAB_BIT 1
int (*active)(struct i915_active *ref);
void (*retire)(struct i915_active *ref);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f50058cf8ab8..64890627d638 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -892,28 +892,38 @@ wait_for_timelines(struct intel_gt *gt, unsigned int wait, long timeout)
spin_lock_irqsave(&timelines->lock, flags);
list_for_each_entry(tl, &timelines->active_list, link) {
- struct i915_request *rq;
+ struct dma_fence *fence;
- rq = i915_active_request_get_unlocked(&tl->last_request);
- if (!rq)
+ fence = i915_active_fence_get(&tl->last_request);
+ if (!fence)
continue;
spin_unlock_irqrestore(&timelines->lock, flags);
- /*
- * "Race-to-idle".
- *
- * Switching to the kernel context is often used a synchronous
- * step prior to idling, e.g. in suspend for flushing all
- * current operations to memory before sleeping. These we
- * want to complete as quickly as possible to avoid prolonged
- * stalls, so allow the gpu to boost to maximum clocks.
- */
- if (wait & I915_WAIT_FOR_IDLE_BOOST)
- gen6_rps_boost(rq);
+ if (!dma_fence_is_i915(fence)) {
+ timeout = dma_fence_wait_timeout(fence,
+ flags & I915_WAIT_INTERRUPTIBLE,
+ timeout);
+ } else {
+ struct i915_request *rq = to_request(fence);
+
+ /*
+ * "Race-to-idle".
+ *
+ * Switching to the kernel context is often used as
+ * a synchronous step prior to idling, e.g. in suspend
+ * for flushing all current operations to memory before
+ * sleeping. These we want to complete as quickly as
+ * possible to avoid prolonged stalls, so allow the gpu
+ * to boost to maximum clocks.
+ */
+ if (flags & I915_WAIT_FOR_IDLE_BOOST)
+ gen6_rps_boost(rq);
+
+ timeout = i915_request_wait(rq, flags, timeout);
+ }
- timeout = i915_request_wait(rq, wait, timeout);
- i915_request_put(rq);
+ dma_fence_put(fence);
if (timeout < 0)
return timeout;
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 55cebf256d03..7462d87f7a48 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1861,7 +1861,6 @@ static const struct i915_vma_ops pd_vma_ops = {
static struct i915_vma *pd_vma_create(struct gen6_ppgtt *ppgtt, int size)
{
- struct drm_i915_private *i915 = ppgtt->base.vm.i915;
struct i915_ggtt *ggtt = ppgtt->base.vm.gt->ggtt;
struct i915_vma *vma;
@@ -1872,7 +1871,7 @@ static struct i915_vma *pd_vma_create(struct gen6_ppgtt *ppgtt, int size)
if (!vma)
return ERR_PTR(-ENOMEM);
- i915_active_init(i915, &vma->active, NULL, NULL);
+ i915_active_init(&vma->active, NULL, NULL);
mutex_init(&vma->pages_mutex);
vma->vm = i915_vm_get(&ggtt->vm);
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 6384a06aa5bf..a28ee754b7b4 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -1299,7 +1299,7 @@ capture_vma(struct capture_vma *next,
if (!c)
return next;
- if (!i915_active_trygrab(&vma->active)) {
+ if (!i915_active_acquire_if_busy(&vma->active)) {
kfree(c);
return next;
}
@@ -1439,7 +1439,7 @@ gem_record_rings(struct i915_gpu_state *error, struct compress *compress)
*this->slot =
i915_error_object_create(i915, vma, compress);
- i915_active_ungrab(&vma->active);
+ i915_active_release(&vma->active);
i915_vma_put(vma);
capture = this->next;
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index a8916412759b..4ffe62a42186 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -218,8 +218,6 @@ static void remove_from_engine(struct i915_request *rq)
static bool i915_request_retire(struct i915_request *rq)
{
- struct i915_active_request *active, *next;
-
if (!i915_request_completed(rq))
return false;
@@ -244,35 +242,6 @@ static bool i915_request_retire(struct i915_request *rq)
&i915_request_timeline(rq)->requests));
rq->ring->head = rq->postfix;
- /*
- * Walk through the active list, calling retire on each. This allows
- * objects to track their GPU activity and mark themselves as idle
- * when their *last* active request is completed (updating state
- * tracking lists for eviction, active references for GEM, etc).
- *
- * As the ->retire() may free the node, we decouple it first and
- * pass along the auxiliary information (to avoid dereferencing
- * the node after the callback).
- */
- list_for_each_entry_safe(active, next, &rq->active_list, link) {
- /*
- * In microbenchmarks or focusing upon time inside the kernel,
- * we may spend an inordinate amount of time simply handling
- * the retirement of requests and processing their callbacks.
- * Of which, this loop itself is particularly hot due to the
- * cache misses when jumping around the list of
- * i915_active_request. So we try to keep this loop as
- * streamlined as possible and also prefetch the next
- * i915_active_request to try and hide the likely cache miss.
- */
- prefetchw(next);
-
- INIT_LIST_HEAD(&active->link);
- RCU_INIT_POINTER(active->request, NULL);
-
- active->retire(active, rq);
- }
-
local_irq_disable();
/*
@@ -704,7 +673,6 @@ __i915_request_create(struct intel_context *ce, gfp_t gfp)
rq->flags = 0;
rq->execution_mask = ALL_ENGINES;
- INIT_LIST_HEAD(&rq->active_list);
INIT_LIST_HEAD(&rq->execute_cb);
/*
@@ -743,7 +711,6 @@ __i915_request_create(struct intel_context *ce, gfp_t gfp)
ce->ring->emit = rq->head;
/* Make sure we didn't add ourselves to external state before freeing */
- GEM_BUG_ON(!list_empty(&rq->active_list));
GEM_BUG_ON(!list_empty(&rq->sched.signalers_list));
GEM_BUG_ON(!list_empty(&rq->sched.waiters_list));
@@ -1174,8 +1141,8 @@ __i915_request_add_to_timeline(struct i915_request *rq)
* precludes optimising to use semaphores serialisation of a single
* timeline across engines.
*/
- prev = rcu_dereference_protected(timeline->last_request.request,
- lockdep_is_held(&timeline->mutex));
+ prev = to_request(__i915_active_fence_set(&timeline->last_request,
+ &rq->fence));
if (prev && !i915_request_completed(prev)) {
if (is_power_of_2(prev->engine->mask | rq->engine->mask))
i915_sw_fence_await_sw_fence(&rq->submit,
@@ -1200,7 +1167,6 @@ __i915_request_add_to_timeline(struct i915_request *rq)
* us, the timeline will hold its seqno which is later than ours.
*/
GEM_BUG_ON(timeline->seqno != rq->fence.seqno);
- __i915_active_request_set(&timeline->last_request, rq);
return prev;
}
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index ec5bb4c2e5ae..91a885c36c6b 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -211,7 +211,6 @@ struct i915_request {
* on the active_list (of their final request).
*/
struct i915_capture_list *capture_list;
- struct list_head active_list;
/** Time at which this request was emitted, in jiffies. */
unsigned long emitted_jiffies;
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index e191247c7c5f..9fdcd4e2c799 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -120,8 +120,7 @@ vma_create(struct drm_i915_gem_object *obj,
vma->size = obj->base.size;
vma->display_alignment = I915_GTT_MIN_ALIGNMENT;
- i915_active_init(vm->i915, &vma->active,
- __i915_vma_active, __i915_vma_retire);
+ i915_active_init(&vma->active, __i915_vma_active, __i915_vma_retire);
/* Declare ourselves safe for use inside shrinkers */
if (IS_ENABLED(CONFIG_LOCKDEP)) {
@@ -1148,6 +1147,7 @@ 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;
diff --git a/drivers/gpu/drm/i915/selftests/i915_active.c b/drivers/gpu/drm/i915/selftests/i915_active.c
index a41785822ed9..2cc71bcf884f 100644
--- a/drivers/gpu/drm/i915/selftests/i915_active.c
+++ b/drivers/gpu/drm/i915/selftests/i915_active.c
@@ -68,7 +68,7 @@ static struct live_active *__live_alloc(struct drm_i915_private *i915)
return NULL;
kref_init(&active->ref);
- i915_active_init(i915, &active->base, __live_active, __live_retire);
+ i915_active_init(&active->base, __live_active, __live_retire);
return active;
}
@@ -146,19 +146,13 @@ static int live_active_wait(void *arg)
{
struct drm_i915_private *i915 = arg;
struct live_active *active;
- intel_wakeref_t wakeref;
int err = 0;
/* Check that we get a callback when requests retire upon waiting */
- mutex_lock(&i915->drm.struct_mutex);
- wakeref = intel_runtime_pm_get(&i915->runtime_pm);
-
active = __live_active_setup(i915);
- if (IS_ERR(active)) {
- err = PTR_ERR(active);
- goto err;
- }
+ if (IS_ERR(active))
+ return PTR_ERR(active);
i915_active_wait(&active->base);
if (!READ_ONCE(active->retired)) {
@@ -168,11 +162,9 @@ static int live_active_wait(void *arg)
__live_put(active);
+ mutex_lock(&i915->drm.struct_mutex);
if (igt_flush_test(i915, I915_WAIT_LOCKED))
err = -EIO;
-
-err:
- intel_runtime_pm_put(&i915->runtime_pm, wakeref);
mutex_unlock(&i915->drm.struct_mutex);
return err;
@@ -182,23 +174,19 @@ static int live_active_retire(void *arg)
{
struct drm_i915_private *i915 = arg;
struct live_active *active;
- intel_wakeref_t wakeref;
int err = 0;
/* Check that we get a callback when requests are indirectly retired */
- mutex_lock(&i915->drm.struct_mutex);
- wakeref = intel_runtime_pm_get(&i915->runtime_pm);
-
active = __live_active_setup(i915);
- if (IS_ERR(active)) {
- err = PTR_ERR(active);
- goto err;
- }
+ if (IS_ERR(active))
+ return PTR_ERR(active);
/* waits for & retires all requests */
+ mutex_lock(&i915->drm.struct_mutex);
if (igt_flush_test(i915, I915_WAIT_LOCKED))
err = -EIO;
+ mutex_unlock(&i915->drm.struct_mutex);
if (!READ_ONCE(active->retired)) {
pr_err("i915_active not retired after flushing!\n");
@@ -207,10 +195,6 @@ static int live_active_retire(void *arg)
__live_put(active);
-err:
- intel_runtime_pm_put(&i915->runtime_pm, wakeref);
- mutex_unlock(&i915->drm.struct_mutex);
-
return err;
}
--
2.23.0
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