diff options
| -rw-r--r-- | drivers/dma-buf/dma-fence.c | 36 | ||||
| -rw-r--r-- | include/linux/dma-fence.h | 1 |
2 files changed, 36 insertions, 1 deletions
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -30,13 +30,16 @@ EXPORT_TRACEPOINT_SYMBOL(dma_fence_emit); EXPORT_TRACEPOINT_SYMBOL(dma_fence_enable_signal); +static DEFINE_SPINLOCK(dma_fence_stub_lock); +static struct dma_fence dma_fence_stub; + /* * fence context counter: each execution context should have its own * fence context, this allows checking if fences belong to the same * context or not. One device can have multiple separate contexts, * and they're used if some engine can run independently of another. */ -static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1); /** * DOC: DMA fences overview @@ -68,6 +71,37 @@ static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); * &dma_buf.resv pointer. */ +static const char *dma_fence_stub_get_name(struct dma_fence *fence) +{ + return "stub"; +} + +static const struct dma_fence_ops dma_fence_stub_ops = { + .get_driver_name = dma_fence_stub_get_name, + .get_timeline_name = dma_fence_stub_get_name, +}; + +/** + * dma_fence_get_stub - return a signaled fence + * + * Return a stub fence which is already signaled. + */ +struct dma_fence *dma_fence_get_stub(void) +{ + spin_lock(&dma_fence_stub_lock); + if (!dma_fence_stub.ops) { + dma_fence_init(&dma_fence_stub, + &dma_fence_stub_ops, + &dma_fence_stub_lock, + 0, 0); + dma_fence_signal_locked(&dma_fence_stub); + } + spin_unlock(&dma_fence_stub_lock); + + return dma_fence_get(&dma_fence_stub); +} +EXPORT_SYMBOL(dma_fence_get_stub); + /** * dma_fence_context_alloc - allocate an array of fence contexts * @num: amount of contexts to allocate diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 02dba8cd033d..999e4b104410 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -541,6 +541,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) return ret < 0 ? ret : 0; } +struct dma_fence *dma_fence_get_stub(void); u64 dma_fence_context_alloc(unsigned num); #define DMA_FENCE_TRACE(f, fmt, args...) \ |