Since we decouple the sync_pt from the timeline tree upon release, in
order to allow releasing the sync_pt from a signal callback we need to
separate the sync_pt signaling lock from the timeline tree lock.
v2: Mark up the unlocked read of the current timeline value.
v3: Store a timeline pointer in the sync_pt as we cannot use the common
fence->lock trick to find our parent anymore.
Suggested-by: Bas Nieuwenhuizen <bas@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Bas Nieuwenhuizen <bas@xxxxxxxxxxxxxxxxxxx>
---
drivers/dma-buf/sw_sync.c | 40 +++++++++++++++++++++---------------
drivers/dma-buf/sync_debug.c | 2 +-
drivers/dma-buf/sync_debug.h | 13 +++++++-----
3 files changed, 32 insertions(+), 23 deletions(-)
diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
index 807c82148062..17a5c1a3b7ce 100644
--- a/drivers/dma-buf/sw_sync.c
+++ b/drivers/dma-buf/sw_sync.c
@@ -123,33 +123,39 @@ static const char *timeline_fence_get_driver_name(struct dma_fence *fence)
static const char *timeline_fence_get_timeline_name(struct dma_fence *fence)
{
- struct sync_timeline *parent = dma_fence_parent(fence);
-
- return parent->name;
+ return sync_timeline(fence)->name;
}
static void timeline_fence_release(struct dma_fence *fence)
{
struct sync_pt *pt = dma_fence_to_sync_pt(fence);
- struct sync_timeline *parent = dma_fence_parent(fence);
- unsigned long flags;
+ struct sync_timeline *parent = pt->timeline;
- spin_lock_irqsave(fence->lock, flags);
if (!list_empty(&pt->link)) {
- list_del(&pt->link);
- rb_erase(&pt->node, &parent->pt_tree);
+ unsigned long flags;
+
+ spin_lock_irqsave(&parent->lock, flags);
+ if (!list_empty(&pt->link)) {
+ list_del(&pt->link);
+ rb_erase(&pt->node, &parent->pt_tree);
+ }
+ spin_unlock_irqrestore(&parent->lock, flags);
}
- spin_unlock_irqrestore(fence->lock, flags);
sync_timeline_put(parent);
dma_fence_free(fence);
}
-static bool timeline_fence_signaled(struct dma_fence *fence)
+static int timeline_value(struct dma_fence *fence)
{
- struct sync_timeline *parent = dma_fence_parent(fence);
+ return READ_ONCE(sync_timeline(fence)->value);
+}
- return !__dma_fence_is_later(fence->seqno, parent->value, fence->ops);
+static bool timeline_fence_signaled(struct dma_fence *fence)
+{
+ return !__dma_fence_is_later(fence->seqno,
+ timeline_value(fence),
+ fence->ops);
}
static bool timeline_fence_enable_signaling(struct dma_fence *fence)
@@ -166,9 +172,7 @@ static void timeline_fence_value_str(struct dma_fence *fence,
static void timeline_fence_timeline_value_str(struct dma_fence *fence,
char *str, int size)
{
- struct sync_timeline *parent = dma_fence_parent(fence);
-
- snprintf(str, size, "%d", parent->value);
+ snprintf(str, size, "%d", timeline_value(fence));
}
static const struct dma_fence_ops timeline_fence_ops = {
@@ -252,12 +256,14 @@ static struct sync_pt *sync_pt_create(struct sync_timeline *obj,
return NULL;
sync_timeline_get(obj);
- dma_fence_init(&pt->base, &timeline_fence_ops, &obj->lock,
+ spin_lock_init(&pt->lock);
+ dma_fence_init(&pt->base, &timeline_fence_ops, &pt->lock,
obj->context, value);
INIT_LIST_HEAD(&pt->link);
+ pt->timeline = obj;
spin_lock_irq(&obj->lock);
- if (!dma_fence_is_signaled_locked(&pt->base)) {
+ if (!dma_fence_is_signaled(&pt->base)) {
struct rb_node **p = &obj->pt_tree.rb_node;
struct rb_node *parent = NULL;
diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c
index 101394f16930..2188ee17e889 100644
--- a/drivers/dma-buf/sync_debug.c
+++ b/drivers/dma-buf/sync_debug.c
@@ -65,7 +65,7 @@ static const char *sync_status_str(int status)
static void sync_print_fence(struct seq_file *s,
struct dma_fence *fence, bool show)
{
- struct sync_timeline *parent = dma_fence_parent(fence);
+ struct sync_timeline *parent = sync_timeline(fence);
int status;
status = dma_fence_get_status_locked(fence);
diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h
index 6176e52ba2d7..56589dae2159 100644
--- a/drivers/dma-buf/sync_debug.h
+++ b/drivers/dma-buf/sync_debug.h
@@ -45,23 +45,26 @@ struct sync_timeline {
struct list_head sync_timeline_list;
};
-static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence)
-{
- return container_of(fence->lock, struct sync_timeline, lock);
-}
-
/**
* struct sync_pt - sync_pt object
* @base: base fence object
* @link: link on the sync timeline's list
* @node: node in the sync timeline's tree
+ * @lock: fence signaling lock
*/
struct sync_pt {
struct dma_fence base;
+ struct sync_timeline *timeline;
struct list_head link;
struct rb_node node;
+ spinlock_t lock;
};
+static inline struct sync_timeline *sync_timeline(struct dma_fence *fence)
+{
+ return container_of(fence, struct sync_pt, base)->timeline;
+}
+
extern const struct file_operations sw_sync_debugfs_fops;
void sync_timeline_debug_add(struct sync_timeline *obj);
--
2.20.1
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