@@ -30,6 +30,13 @@
EXPORT_TRACEPOINT_SYMBOL(dma_fence_emit);
EXPORT_TRACEPOINT_SYMBOL(dma_fence_enable_signal);
+
+#ifdef CONFIG_LOCKDEP_CROSSRELEASE
+struct lockdep_map_cross dma_fence_wait_map =
+ STATIC_CROSS_LOCKDEP_MAP_INIT("dma_fence_signal", &dma_fence_wait_map);
+EXPORT_SYMBOL(dma_fence_wait_map);
+#endif
+
/*
* fence context counter: each execution context should have its own
* fence context, this allows checking if fences belong to the same
@@ -106,6 +113,8 @@ int dma_fence_signal_locked(struct dma_fence *fence)
lockdep_assert_held(fence->lock);
+ dma_fence_wait_release_commit();
+
if (WARN_ON(!fence))
return -EINVAL;
@@ -153,6 +162,8 @@ int dma_fence_signal(struct dma_fence *fence)
if (test_and_set_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags))
return -EINVAL;
+ dma_fence_wait_release_commit();
+
fence->timestamp = ktime_get();
set_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags);
trace_dma_fence_signaled(fence);
@@ -197,12 +208,15 @@ dma_fence_wait_timeout(struct dma_fence *fence, bool intr, signed long timeout)
if (WARN_ON(timeout < 0))
return -EINVAL;
+ dma_fence_wait_acquire();
trace_dma_fence_wait_start(fence);
if (fence->ops->wait)
ret = fence->ops->wait(fence, intr, timeout);
else
ret = dma_fence_default_wait(fence, intr, timeout);
trace_dma_fence_wait_end(fence);
+ dma_fence_wait_release();
+
return ret;
}
EXPORT_SYMBOL(dma_fence_wait_timeout);
@@ -34,6 +34,34 @@ struct dma_fence;
struct dma_fence_ops;
struct dma_fence_cb;
+#ifdef CONFIG_LOCKDEP_CROSSRELEASE
+#include <linux/lockdep.h>
+extern struct lockdep_map_cross dma_fence_wait_map;
+
+static inline void dma_fence_wait_acquire(void)
+{
+ lock_acquire_exclusive(&dma_fence_wait_map.map, 0, 0, NULL, _RET_IP_);
+}
+static inline void dma_fence_wait_release(void)
+{
+ lock_release(&dma_fence_wait_map.map, 0, _RET_IP_);
+}
+static inline void dma_fence_wait_release_commit(void)
+{
+ lock_commit_crosslock(&dma_fence_wait_map.map);
+}
+#else
+static inline void dma_fence_wait_acquire(void) {}
+static inline void dma_fence_wait_release(void) {}
+static inline void dma_fence_wait_release_commit(void) {}
+#endif
+
+static inline void dma_fence_might_wait(void)
+{
+ dma_fence_wait_acquire();
+ dma_fence_wait_release();
+}
+
/**
* struct dma_fence - software synchronization primitive
* @refcount: refcount for this fence
dma-fence is a completion on steriods, which also allows hardware to directly sync work among each another. It's supposed to be deadlock free, so let's try to make sure that holds at least for the cpu-only interactions and waits. It's a bit much #ifdef, but I figured for the single case it's not worth it to pull it all out. Also, the single global lockdep map is intentional: dma_fences are supposed to be shared, we need all drivers to be compatible to each another in their locking hierarchy. v2: - handle #idef mess cleaner - also annotate dma_fence_signal() v3: - Add a dma_fence_might_wait() function to annotate fastpaths - Put it all into headers for other code to use Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> --- drivers/dma-buf/dma-fence.c | 14 ++++++++++++++ include/linux/dma-fence.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+)