diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/dma-fence.h | 31 | ||||
| -rw-r--r-- | include/trace/events/dma_fence.h | 38 |
2 files changed, 56 insertions, 13 deletions
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 10a849cb2d3f..64639e104110 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -378,15 +378,28 @@ bool dma_fence_remove_callback(struct dma_fence *fence, struct dma_fence_cb *cb); void dma_fence_enable_sw_signaling(struct dma_fence *fence); -static inline const char *dma_fence_driver_name(struct dma_fence *fence) -{ - return fence->ops->get_driver_name(fence); -} - -static inline const char *dma_fence_timeline_name(struct dma_fence *fence) -{ - return fence->ops->get_timeline_name(fence); -} +/** + * DOC: Safe external access to driver provided object members + * + * All data not stored directly in the dma-fence object, such as the + * &dma_fence.lock and memory potentially accessed by functions in the + * &dma_fence.ops table, MUST NOT be accessed after the fence has been signalled + * because after that point drivers are allowed to free it. + * + * All code accessing that data via the dma-fence API (or directly, which is + * discouraged), MUST make sure to contain the complete access within a + * &rcu_read_lock and &rcu_read_unlock pair. + * + * Some dma-fence API handles this automatically, while other, as for example + * &dma_fence_driver_name and &dma_fence_timeline_name, leave that + * responsibility to the caller. + * + * To enable this scheme to work drivers MUST ensure a RCU grace period elapses + * between signalling the fence and freeing the said data. + * + */ +const char __rcu *dma_fence_driver_name(struct dma_fence *fence); +const char __rcu *dma_fence_timeline_name(struct dma_fence *fence); /** * dma_fence_is_signaled_locked - Return an indication if the fence diff --git a/include/trace/events/dma_fence.h b/include/trace/events/dma_fence.h index 84c83074ee81..4814a65b68dc 100644 --- a/include/trace/events/dma_fence.h +++ b/include/trace/events/dma_fence.h @@ -34,14 +34,44 @@ DECLARE_EVENT_CLASS(dma_fence, __entry->seqno) ); -DEFINE_EVENT(dma_fence, dma_fence_emit, +/* + * Safe only for call sites which are guaranteed to not race with fence + * signaling,holding the fence->lock and having checked for not signaled, or the + * signaling path itself. + */ +DECLARE_EVENT_CLASS(dma_fence_unsignaled, + + TP_PROTO(struct dma_fence *fence), + + TP_ARGS(fence), + + TP_STRUCT__entry( + __string(driver, fence->ops->get_driver_name(fence)) + __string(timeline, fence->ops->get_timeline_name(fence)) + __field(unsigned int, context) + __field(unsigned int, seqno) + ), + + TP_fast_assign( + __assign_str(driver); + __assign_str(timeline); + __entry->context = fence->context; + __entry->seqno = fence->seqno; + ), + + TP_printk("driver=%s timeline=%s context=%u seqno=%u", + __get_str(driver), __get_str(timeline), __entry->context, + __entry->seqno) +); + +DEFINE_EVENT(dma_fence_unsignaled, dma_fence_emit, TP_PROTO(struct dma_fence *fence), TP_ARGS(fence) ); -DEFINE_EVENT(dma_fence, dma_fence_init, +DEFINE_EVENT(dma_fence_unsignaled, dma_fence_init, TP_PROTO(struct dma_fence *fence), @@ -55,14 +85,14 @@ DEFINE_EVENT(dma_fence, dma_fence_destroy, TP_ARGS(fence) ); -DEFINE_EVENT(dma_fence, dma_fence_enable_signal, +DEFINE_EVENT(dma_fence_unsignaled, dma_fence_enable_signal, TP_PROTO(struct dma_fence *fence), TP_ARGS(fence) ); -DEFINE_EVENT(dma_fence, dma_fence_signaled, +DEFINE_EVENT(dma_fence_unsignaled, dma_fence_signaled, TP_PROTO(struct dma_fence *fence), |