[PATCH] drm/scheduler: Unwrap job dependencies

From: Rob Clark
Date: Tue Dec 05 2023 - 14:02:43 EST


From: Rob Clark <robdclark@xxxxxxxxxxxx>

Container fences have burner contexts, which makes the trick to store at
most one fence per context somewhat useless if we don't unwrap array or
chain fences.

Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
drivers/gpu/drm/scheduler/sched_main.c | 47 ++++++++++++++++++--------
1 file changed, 32 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index 9762464e3f99..16b550949c57 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -52,6 +52,7 @@
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/completion.h>
+#include <linux/dma-fence-unwrap.h>
#include <linux/dma-resv.h>
#include <uapi/linux/sched/types.h>

@@ -684,27 +685,14 @@ void drm_sched_job_arm(struct drm_sched_job *job)
}
EXPORT_SYMBOL(drm_sched_job_arm);

-/**
- * drm_sched_job_add_dependency - adds the fence as a job dependency
- * @job: scheduler job to add the dependencies to
- * @fence: the dma_fence to add to the list of dependencies.
- *
- * Note that @fence is consumed in both the success and error cases.
- *
- * Returns:
- * 0 on success, or an error on failing to expand the array.
- */
-int drm_sched_job_add_dependency(struct drm_sched_job *job,
- struct dma_fence *fence)
+static int drm_sched_job_add_single_dependency(struct drm_sched_job *job,
+ struct dma_fence *fence)
{
struct dma_fence *entry;
unsigned long index;
u32 id = 0;
int ret;

- if (!fence)
- return 0;
-
/* Deduplicate if we already depend on a fence from the same context.
* This lets the size of the array of deps scale with the number of
* engines involved, rather than the number of BOs.
@@ -728,6 +716,35 @@ int drm_sched_job_add_dependency(struct drm_sched_job *job,

return ret;
}
+
+/**
+ * drm_sched_job_add_dependency - adds the fence as a job dependency
+ * @job: scheduler job to add the dependencies to
+ * @fence: the dma_fence to add to the list of dependencies.
+ *
+ * Note that @fence is consumed in both the success and error cases.
+ *
+ * Returns:
+ * 0 on success, or an error on failing to expand the array.
+ */
+int drm_sched_job_add_dependency(struct drm_sched_job *job,
+ struct dma_fence *fence)
+{
+ struct dma_fence_unwrap iter;
+ struct dma_fence *f;
+ int ret = 0;
+
+ dma_fence_unwrap_for_each (f, &iter, fence) {
+ dma_fence_get(f);
+ ret = drm_sched_job_add_single_dependency(job, f);
+ if (ret)
+ break;
+ }
+
+ dma_fence_put(fence);
+
+ return ret;
+}
EXPORT_SYMBOL(drm_sched_job_add_dependency);

/**
--
2.42.0