[PATCH 28/31] drm/i915: Move vma binding to vm exclusive fence, instead of relying on i915_active
Maarten Lankhorst
maarten.lankhorst at linux.intel.com
Wed Sep 22 14:48:58 UTC 2021
Instead of relying on the i915_active exclusive fence, use the exclusive
slot inside vm->_resv. As far as I can tell, only the lock part of the
reservation object is used by default, so there should be no shared fences.
Just in case there is, add a debug warning that we missed that part.
As i915_active kept the vma alive, just in case of a race add an extra
ref to i915_vma in the worker.
i915_active.excl is now unused, so remove all related infrastructure as
well.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
drivers/gpu/drm/i915/i915_active.c | 47 --------------------
drivers/gpu/drm/i915/i915_active.h | 19 --------
drivers/gpu/drm/i915/i915_active_types.h | 3 --
drivers/gpu/drm/i915/i915_vma.c | 43 ++++++++++--------
drivers/gpu/drm/i915/selftests/i915_active.c | 1 -
5 files changed, 24 insertions(+), 89 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_active.c b/drivers/gpu/drm/i915/i915_active.c
index ee2b3a375362..fa77d8284f1b 100644
--- a/drivers/gpu/drm/i915/i915_active.c
+++ b/drivers/gpu/drm/i915/i915_active.c
@@ -136,7 +136,6 @@ __active_retire(struct i915_active *ref)
if (!atomic_dec_and_lock_irqsave(&ref->count, &ref->tree_lock, flags))
return;
- GEM_BUG_ON(rcu_access_pointer(ref->excl.fence));
debug_active_deactivate(ref);
/* Even if we have not used the cache, we may still have a barrier */
@@ -223,13 +222,6 @@ node_retire(struct dma_fence *fence, struct dma_fence_cb *cb)
active_retire(container_of(cb, struct active_node, base.cb)->ref);
}
-static void
-excl_retire(struct dma_fence *fence, struct dma_fence_cb *cb)
-{
- if (active_fence_cb(fence, cb))
- active_retire(container_of(cb, struct i915_active, excl.cb));
-}
-
static struct active_node *__active_lookup(struct i915_active *ref, u64 idx)
{
struct active_node *it;
@@ -356,7 +348,6 @@ void __i915_active_init(struct i915_active *ref,
init_llist_head(&ref->preallocated_barriers);
atomic_set(&ref->count, 0);
__mutex_init(&ref->mutex, "i915_active", mkey);
- __i915_active_fence_init(&ref->excl, NULL, excl_retire);
INIT_WORK(&ref->work, active_work);
#if IS_ENABLED(CONFIG_LOCKDEP)
lockdep_init_map(&ref->work.lockdep_map, "i915_active.work", wkey, 0);
@@ -455,36 +446,6 @@ int i915_active_add_request(struct i915_active *ref, struct i915_request *rq)
return err;
}
-static struct dma_fence *
-__i915_active_set_fence(struct i915_active *ref,
- struct i915_active_fence *active,
- struct dma_fence *fence)
-{
- struct dma_fence *prev;
-
- if (replace_barrier(ref, active)) {
- RCU_INIT_POINTER(active->fence, fence);
- return NULL;
- }
-
- rcu_read_lock();
- prev = __i915_active_fence_set(active, fence);
- if (prev)
- prev = dma_fence_get_rcu(prev);
- else
- __i915_active_acquire(ref);
- rcu_read_unlock();
-
- return prev;
-}
-
-struct dma_fence *
-i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f)
-{
- /* We expect the caller to manage the exclusive timeline ordering */
- return __i915_active_set_fence(ref, &ref->excl, f);
-}
-
bool i915_active_acquire_if_busy(struct i915_active *ref)
{
debug_active_assert(ref);
@@ -585,7 +546,6 @@ static int flush_lazy_signals(struct i915_active *ref)
struct active_node *it, *n;
int err = 0;
- enable_signaling(&ref->excl);
rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node) {
err = flush_barrier(it); /* unconnected idle barrier? */
if (err)
@@ -697,13 +657,6 @@ static int await_active(struct i915_active *ref,
if (!i915_active_acquire_if_busy(ref))
return 0;
- if (flags & I915_ACTIVE_AWAIT_EXCL &&
- rcu_access_pointer(ref->excl.fence)) {
- err = __await_active(&ref->excl, fn, arg);
- if (err)
- goto out;
- }
-
if (flags & I915_ACTIVE_AWAIT_ACTIVE) {
struct active_node *it, *n;
diff --git a/drivers/gpu/drm/i915/i915_active.h b/drivers/gpu/drm/i915/i915_active.h
index 7eb44132183a..735a304457be 100644
--- a/drivers/gpu/drm/i915/i915_active.h
+++ b/drivers/gpu/drm/i915/i915_active.h
@@ -166,9 +166,6 @@ void __i915_active_init(struct i915_active *ref,
int i915_active_add_request(struct i915_active *ref, struct i915_request *rq);
-struct dma_fence *
-i915_active_set_exclusive(struct i915_active *ref, struct dma_fence *f);
-
int __i915_active_wait(struct i915_active *ref, int state);
static inline int i915_active_wait(struct i915_active *ref)
{
@@ -181,7 +178,6 @@ int i915_sw_fence_await_active(struct i915_sw_fence *fence,
int i915_request_await_active(struct i915_request *rq,
struct i915_active *ref,
unsigned int flags);
-#define I915_ACTIVE_AWAIT_EXCL BIT(0)
#define I915_ACTIVE_AWAIT_ACTIVE BIT(1)
#define I915_ACTIVE_AWAIT_BARRIER BIT(2)
@@ -217,21 +213,6 @@ struct i915_active *i915_active_create(void);
struct i915_active *i915_active_get(struct i915_active *ref);
void i915_active_put(struct i915_active *ref);
-static inline int __i915_request_await_exclusive(struct i915_request *rq,
- struct i915_active *active)
-{
- struct dma_fence *fence;
- int err = 0;
-
- fence = i915_active_fence_get(&active->excl);
- if (fence) {
- err = i915_request_await_dma_fence(rq, fence);
- dma_fence_put(fence);
- }
-
- return err;
-}
-
void i915_active_module_exit(void);
int i915_active_module_init(void);
diff --git a/drivers/gpu/drm/i915/i915_active_types.h b/drivers/gpu/drm/i915/i915_active_types.h
index c149f348a972..c3109602cf23 100644
--- a/drivers/gpu/drm/i915/i915_active_types.h
+++ b/drivers/gpu/drm/i915/i915_active_types.h
@@ -32,9 +32,6 @@ struct i915_active {
struct active_node *cache;
struct rb_root tree;
- /* Preallocated "exclusive" node */
- struct i915_active_fence excl;
-
unsigned long flags;
#define I915_ACTIVE_RETIRE_SLEEPS BIT(0)
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 1c2e72ea5e16..ae27c9749182 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -313,6 +313,8 @@ static void __vma_release(struct dma_fence_work *work)
}
i915_vm_free_pt_stash(vw->vm, &vw->stash);
+ if (vw->vma)
+ __i915_vma_put(vw->vma);
i915_vm_put(vw->vm);
}
@@ -338,18 +340,12 @@ struct i915_vma_work *i915_vma_work(void)
int i915_vma_wait_for_bind(struct i915_vma *vma)
{
+ struct dma_fence *fence = dma_resv_get_excl_unlocked(&vma->vm->_resv);
int err = 0;
- if (rcu_access_pointer(vma->active.excl.fence)) {
- struct dma_fence *fence;
-
- rcu_read_lock();
- fence = dma_fence_get_rcu_safe(&vma->active.excl.fence);
- rcu_read_unlock();
- if (fence) {
- err = dma_fence_wait(fence, MAX_SCHEDULE_TIMEOUT);
- dma_fence_put(fence);
- }
+ if (fence) {
+ err = dma_fence_wait(fence, true);
+ dma_fence_put(fence);
}
return err;
@@ -401,7 +397,7 @@ int i915_vma_bind(struct i915_vma *vma,
if (work) {
struct dma_fence *prev;
- work->vma = vma;
+ work->vma = __i915_vma_get(vma);
work->cache_level = cache_level;
work->flags = bind_flags;
@@ -410,17 +406,18 @@ int i915_vma_bind(struct i915_vma *vma,
* the pages (not the object itself). As we don't track that,
* yet, we have to use the exclusive fence instead.
*
- * Also note that we do not want to track the async vma as
- * part of the obj->resv->excl_fence as it only affects
- * execution and not content or object's backing store lifetime.
+ * Use the vm's exclusive fence for serialization.
*/
- prev = i915_active_set_exclusive(&vma->active, &work->base.dma);
- if (prev) {
+ prev = dma_resv_excl_fence(&vma->vm->_resv);
+ if (prev)
__i915_sw_fence_await_dma_fence(&work->base.chain,
prev,
&work->cb);
- dma_fence_put(prev);
- }
+
+ GEM_WARN_ON(dma_resv_shared_list(&vma->vm->_resv) &&
+ dma_resv_shared_list(&vma->vm->_resv)->shared_count);
+
+ dma_resv_add_excl_fence(&vma->vm->_resv, &work->base.dma);
work->base.dma.error = 0; /* enable the queue_work() */
@@ -1521,7 +1518,15 @@ void i915_vma_revoke_mmap(struct i915_vma *vma)
static int
__i915_request_await_bind(struct i915_request *rq, struct i915_vma *vma)
{
- return __i915_request_await_exclusive(rq, &vma->active);
+ struct dma_fence *fence = dma_resv_get_excl_unlocked(&vma->vm->_resv);
+ int ret;
+
+ if (!fence)
+ return 0;
+
+ ret = i915_request_await_dma_fence(rq, fence);
+ dma_fence_put(fence);
+ return ret;
}
static int __i915_vma_move_to_active(struct i915_vma *vma, struct i915_request *rq)
diff --git a/drivers/gpu/drm/i915/selftests/i915_active.c b/drivers/gpu/drm/i915/selftests/i915_active.c
index 61bf4560d8af..ddaf389b35e0 100644
--- a/drivers/gpu/drm/i915/selftests/i915_active.c
+++ b/drivers/gpu/drm/i915/selftests/i915_active.c
@@ -335,7 +335,6 @@ void i915_active_unlock_wait(struct i915_active *ref)
/* Wait for all active callbacks */
rcu_read_lock();
- active_flush(ref, &ref->excl);
rbtree_postorder_for_each_entry_safe(it, n, &ref->tree, node)
active_flush(ref, &it->base);
rcu_read_unlock();
--
2.33.0
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