Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
dma-buf/dma-fence: Add dma_fence_check_and_signal()
The overwhelming majority of users of dma_fence signaling functions
don't care about whether the fence had already been signaled by someone
else. Therefore, the return code shall be removed from those functions.
For the few users who rely on the check, a new, specialized function
shall be provided.
Add dma_fence_check_and_signal(), which signals a fence if it had not
yet been signaled, and informs the user about that.
Add a counter part, dma_fence_check_and_signal_locked(), which doesn't
take the spinlock.
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patch.msgid.link/20251201105011.19386-4-phasta@kernel.org
+46
+44
drivers/dma-buf/dma-fence.c
+44
drivers/dma-buf/dma-fence.c
···
444
444
EXPORT_SYMBOL(dma_fence_signal_locked);
445
445
446
446
/**
447
+
* dma_fence_check_and_signal_locked - signal the fence if it's not yet signaled
448
+
* @fence: the fence to check and signal
449
+
*
450
+
* Checks whether a fence was signaled and signals it if it was not yet signaled.
451
+
*
452
+
* Unlike dma_fence_check_and_signal(), this function must be called with
453
+
* &struct dma_fence.lock being held.
454
+
*
455
+
* Return: true if fence has been signaled already, false otherwise.
456
+
*/
457
+
bool dma_fence_check_and_signal_locked(struct dma_fence *fence)
458
+
{
459
+
bool ret;
460
+
461
+
ret = dma_fence_test_signaled_flag(fence);
462
+
dma_fence_signal_locked(fence);
463
+
464
+
return ret;
465
+
}
466
+
EXPORT_SYMBOL(dma_fence_check_and_signal_locked);
467
+
468
+
/**
469
+
* dma_fence_check_and_signal - signal the fence if it's not yet signaled
470
+
* @fence: the fence to check and signal
471
+
*
472
+
* Checks whether a fence was signaled and signals it if it was not yet signaled.
473
+
* All this is done in a race-free manner.
474
+
*
475
+
* Return: true if fence has been signaled already, false otherwise.
476
+
*/
477
+
bool dma_fence_check_and_signal(struct dma_fence *fence)
478
+
{
479
+
unsigned long flags;
480
+
bool ret;
481
+
482
+
spin_lock_irqsave(fence->lock, flags);
483
+
ret = dma_fence_check_and_signal_locked(fence);
484
+
spin_unlock_irqrestore(fence->lock, flags);
485
+
486
+
return ret;
487
+
}
488
+
EXPORT_SYMBOL(dma_fence_check_and_signal);
489
+
490
+
/**
447
491
* dma_fence_signal - signal completion of a fence
448
492
* @fence: the fence to signal
449
493
*
+2
include/linux/dma-fence.h
+2
include/linux/dma-fence.h
···
365
365
#endif
366
366
367
367
int dma_fence_signal(struct dma_fence *fence);
368
+
bool dma_fence_check_and_signal(struct dma_fence *fence);
369
+
bool dma_fence_check_and_signal_locked(struct dma_fence *fence);
368
370
int dma_fence_signal_locked(struct dma_fence *fence);
369
371
int dma_fence_signal_timestamp(struct dma_fence *fence, ktime_t timestamp);
370
372
int dma_fence_signal_timestamp_locked(struct dma_fence *fence,