Some driver use fence->ops to test if a fence was initialized or not. The problem is that this utilizes internal behavior of the dma_fence implementation.
So better abstract that into a function.
v2: use a flag instead of testing fence->ops, rename the function, move to the beginning of the patch set.
Signed-off-by: Christian König christian.koenig@amd.com --- drivers/dma-buf/dma-fence.c | 2 +- drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 13 +++++++------ drivers/gpu/drm/qxl/qxl_release.c | 2 +- include/linux/dma-fence.h | 15 +++++++++++++++ 4 files changed, 24 insertions(+), 8 deletions(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 21c5c30b4f34..c9a036b0d592 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -1054,7 +1054,7 @@ __dma_fence_init(struct dma_fence *fence, const struct dma_fence_ops *ops, fence->lock = lock; fence->context = context; fence->seqno = seqno; - fence->flags = flags; + fence->flags = flags | BIT(DMA_FENCE_FLAG_INITIALIZED_BIT); fence->error = 0;
trace_dma_fence_init(fence); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c index 0a0dcbf0798d..d1e74d0050c7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c @@ -278,9 +278,10 @@ void amdgpu_job_free_resources(struct amdgpu_job *job) unsigned i;
/* Check if any fences were initialized */ - if (job->base.s_fence && job->base.s_fence->finished.ops) + if (job->base.s_fence && + dma_fence_was_initialized(&job->base.s_fence->finished)) f = &job->base.s_fence->finished; - else if (job->hw_fence && job->hw_fence->base.ops) + else if (dma_fence_was_initialized(&job->hw_fence->base)) f = &job->hw_fence->base; else f = NULL; @@ -297,11 +298,11 @@ static void amdgpu_job_free_cb(struct drm_sched_job *s_job)
amdgpu_sync_free(&job->explicit_sync);
- if (job->hw_fence->base.ops) + if (dma_fence_was_initialized(&job->hw_fence->base)) dma_fence_put(&job->hw_fence->base); else kfree(job->hw_fence); - if (job->hw_vm_fence->base.ops) + if (dma_fence_was_initialized(&job->hw_vm_fence->base)) dma_fence_put(&job->hw_vm_fence->base); else kfree(job->hw_vm_fence); @@ -335,11 +336,11 @@ void amdgpu_job_free(struct amdgpu_job *job) if (job->gang_submit != &job->base.s_fence->scheduled) dma_fence_put(job->gang_submit);
- if (job->hw_fence->base.ops) + if (dma_fence_was_initialized(&job->hw_fence->base)) dma_fence_put(&job->hw_fence->base); else kfree(job->hw_fence); - if (job->hw_vm_fence->base.ops) + if (dma_fence_was_initialized(&job->hw_vm_fence->base)) dma_fence_put(&job->hw_vm_fence->base); else kfree(job->hw_vm_fence); diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c index 7b3c9a6016db..06b0b2aa7953 100644 --- a/drivers/gpu/drm/qxl/qxl_release.c +++ b/drivers/gpu/drm/qxl/qxl_release.c @@ -146,7 +146,7 @@ qxl_release_free(struct qxl_device *qdev, idr_remove(&qdev->release_idr, release->id); spin_unlock(&qdev->release_idr_lock);
- if (release->base.ops) { + if (dma_fence_was_initialized(&release->base)) { WARN_ON(list_empty(&release->bos)); qxl_release_free_list(release);
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index d4c92fd35092..9c4d25289239 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -48,6 +48,7 @@ struct seq_file; * atomic ops (bit_*), so taking the spinlock will not be needed most * of the time. * + * DMA_FENCE_FLAG_INITIALIZED_BIT - fence was initialized * DMA_FENCE_FLAG_SIGNALED_BIT - fence is already signaled * DMA_FENCE_FLAG_TIMESTAMP_BIT - timestamp recorded for fence signaling * DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT - enable_signaling might have been called @@ -98,6 +99,7 @@ struct dma_fence { };
enum dma_fence_flag_bits { + DMA_FENCE_FLAG_INITIALIZED_BIT, DMA_FENCE_FLAG_SEQNO64_BIT, DMA_FENCE_FLAG_SIGNALED_BIT, DMA_FENCE_FLAG_TIMESTAMP_BIT, @@ -263,6 +265,19 @@ void dma_fence_release(struct kref *kref); void dma_fence_free(struct dma_fence *fence); void dma_fence_describe(struct dma_fence *fence, struct seq_file *seq);
+/** + * dma_fence_was_initialized - test if fence was initialized + * @fence: fence to test + * + * Return: True if fence was ever initialized, false otherwise. Works correctly + * only when memory backing the fence structure is zero initialized on + * allocation. + */ +static inline bool dma_fence_was_initialized(struct dma_fence *fence) +{ + return fence && test_bit(DMA_FENCE_FLAG_INITIALIZED_BIT, &fence->flags); +} + /** * dma_fence_put - decreases refcount of the fence * @fence: fence to reduce refcount of