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.
Suggested-by: Bas Nieuwenhuizen bas@basnieuwenhuizen.nl Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Bas Nieuwenhuizen bas@basnieuwenhuizen.nl --- drivers/dma-buf/sw_sync.c | 33 ++++++++++++++++++++------------- drivers/dma-buf/sync_debug.h | 2 ++ 2 files changed, 22 insertions(+), 13 deletions(-)
diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c index 807c82148062..5851bf7076d0 100644 --- a/drivers/dma-buf/sw_sync.c +++ b/drivers/dma-buf/sw_sync.c @@ -132,24 +132,32 @@ 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;
- 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(dma_fence_parent(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 +174,7 @@ 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 +258,13 @@ 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);
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.h b/drivers/dma-buf/sync_debug.h index 6176e52ba2d7..fd073fc32329 100644 --- a/drivers/dma-buf/sync_debug.h +++ b/drivers/dma-buf/sync_debug.h @@ -55,11 +55,13 @@ static inline struct sync_timeline *dma_fence_parent(struct dma_fence *fence) * @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 list_head link; struct rb_node node; + spinlock_t lock; };
extern const struct file_operations sw_sync_debugfs_fops;