Many drivers have a trivial implementation for ->enable_signaling. Let's make it optional by assuming that signalling is already available when the callback isn't present.
Reviewed-by: Christian König christian.koenig@amd.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com 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 --- drivers/dma-buf/dma-fence.c | 13 ++++++++++++- include/linux/dma-fence.h | 3 ++- 2 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 4edb9fd3cf47..7b5b40d6b70e 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -181,6 +181,13 @@ void dma_fence_release(struct kref *kref) } EXPORT_SYMBOL(dma_fence_release);
+/** + * dma_fence_free - default release function for &dma_fence. + * @fence: fence to release + * + * This is the default implementation for &dma_fence_ops.release. It calls + * kfree_rcu() on @fence. + */ void dma_fence_free(struct dma_fence *fence) { kfree_rcu(fence, rcu); @@ -560,7 +567,7 @@ dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, spinlock_t *lock, u64 context, unsigned seqno) { BUG_ON(!lock); - BUG_ON(!ops || !ops->wait || !ops->enable_signaling || + BUG_ON(!ops || !ops->wait || !ops->get_driver_name || !ops->get_timeline_name);
kref_init(&fence->refcount); @@ -572,6 +579,10 @@ dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, fence->flags = 0UL; fence->error = 0;
+ if (!ops->enable_signaling) + set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, + &fence->flags); + trace_dma_fence_init(fence); } EXPORT_SYMBOL(dma_fence_init); diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 111aefe1c956..c053d19e1e24 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -166,7 +166,8 @@ struct dma_fence_ops { * released when the fence is signalled (through e.g. the interrupt * handler). * - * This callback is mandatory. + * This callback is optional. If this callback is not present, then the + * driver must always have signaling enabled. */ bool (*enable_signaling)(struct dma_fence *fence);
Quoting Daniel Vetter (2018-05-03 15:25:50)
@@ -560,7 +567,7 @@ dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, spinlock_t *lock, u64 context, unsigned seqno) { BUG_ON(!lock);
BUG_ON(!ops || !ops->wait || !ops->enable_signaling ||
BUG_ON(!ops || !ops->wait || !ops->get_driver_name || !ops->get_timeline_name);
One thing I was wondering about (following the discussion of rhashtable on lwn) was inlining this function and passing dma_fence_ops by value. And seeing if that eliminates the branch and makes smaller code (probably not, mostly idling wondering about that technique) and kills off the BUGs (can then be BUILD_BUG_ON). -Chris
Many drivers have a trivial implementation for ->enable_signaling. Let's make it optional by assuming that signalling is already available when the callback isn't present.
v2: Don't do the trick to set the ENABLE_SIGNAL_BIT unconditionally, it results in an expensive spinlock take for everyone. Instead just check if the callback is present. Suggested by Maarten.
Also move misplaced kerneldoc hunk to the right patch.
Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Reviewed-by: Christian König christian.koenig@amd.com (v1) Signed-off-by: Daniel Vetter daniel.vetter@intel.com 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 --- drivers/dma-buf/dma-fence.c | 9 +++++---- include/linux/dma-fence.h | 3 ++- 2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 4edb9fd3cf47..dd01a1720be9 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -200,7 +200,8 @@ void dma_fence_enable_sw_signaling(struct dma_fence *fence)
if (!test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags) && - !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) { + !test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) && + fence->ops->enable_signaling) { trace_dma_fence_enable_signal(fence);
spin_lock_irqsave(fence->lock, flags); @@ -260,7 +261,7 @@ int dma_fence_add_callback(struct dma_fence *fence, struct dma_fence_cb *cb,
if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) ret = -ENOENT; - else if (!was_set) { + else if (!was_set && fence->ops->enable_signaling) { trace_dma_fence_enable_signal(fence);
if (!fence->ops->enable_signaling(fence)) { @@ -388,7 +389,7 @@ dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout) if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) goto out;
- if (!was_set) { + if (!was_set && fence->ops->enable_signaling) { trace_dma_fence_enable_signal(fence);
if (!fence->ops->enable_signaling(fence)) { @@ -560,7 +561,7 @@ dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, spinlock_t *lock, u64 context, unsigned seqno) { BUG_ON(!lock); - BUG_ON(!ops || !ops->wait || !ops->enable_signaling || + BUG_ON(!ops || !ops->wait || !ops->get_driver_name || !ops->get_timeline_name);
kref_init(&fence->refcount); diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 111aefe1c956..c053d19e1e24 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -166,7 +166,8 @@ struct dma_fence_ops { * released when the fence is signalled (through e.g. the interrupt * handler). * - * This callback is mandatory. + * This callback is optional. If this callback is not present, then the + * driver must always have signaling enabled. */ bool (*enable_signaling)(struct dma_fence *fence);
Op 04-05-18 om 16:10 schreef Daniel Vetter:
Many drivers have a trivial implementation for ->enable_signaling. Let's make it optional by assuming that signalling is already available when the callback isn't present.
v2: Don't do the trick to set the ENABLE_SIGNAL_BIT unconditionally, it results in an expensive spinlock take for everyone. Instead just check if the callback is present. Suggested by Maarten.
Also move misplaced kerneldoc hunk to the right patch.
Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Reviewed-by: Christian König christian.koenig@amd.com (v1) Signed-off-by: Daniel Vetter daniel.vetter@intel.com 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
drivers/dma-buf/dma-fence.c | 9 +++++---- include/linux/dma-fence.h | 3 ++- 2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 4edb9fd3cf47..dd01a1720be9 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -200,7 +200,8 @@ void dma_fence_enable_sw_signaling(struct dma_fence *fence) if (!test_and_set_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &fence->flags) &&
!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) {
!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) &&fence->ops->enable_signaling) {spin_lock_irqsave(fence->lock, flags); @@ -260,7 +261,7 @@ int dma_fence_add_callback(struct dma_fence *fence, struct dma_fence_cb *cb, if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) ret = -ENOENT;
- else if (!was_set) {
- else if (!was_set && fence->ops->enable_signaling) { trace_dma_fence_enable_signal(fence);
if (!fence->ops->enable_signaling(fence)) { @@ -388,7 +389,7 @@ dma_fence_default_wait(struct dma_fence *fence, bool intr, signed long timeout) if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags)) goto out;
- if (!was_set) {
- if (!was_set && fence->ops->enable_signaling) { trace_dma_fence_enable_signal(fence);
if (!fence->ops->enable_signaling(fence)) { @@ -560,7 +561,7 @@ dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, spinlock_t *lock, u64 context, unsigned seqno) { BUG_ON(!lock);
- BUG_ON(!ops || !ops->wait || !ops->enable_signaling ||
- BUG_ON(!ops || !ops->wait || !ops->get_driver_name || !ops->get_timeline_name);
kref_init(&fence->refcount); diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 111aefe1c956..c053d19e1e24 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -166,7 +166,8 @@ struct dma_fence_ops { * released when the fence is signalled (through e.g. the interrupt * handler). *
* This callback is mandatory.
* This callback is optional. If this callback is not present, then the* driver must always have signaling enabled.
Much better. :)
Reviewed-by: Maarten Lankhorst maarten.lankhorst@linux.intel.com
linaro-mm-sig@lists.linaro.org
-
Chris Wilson -
Daniel Vetter -
Maarten Lankhorst