[PATCH] drm/scheduler: Unwrap job dependencies

[Rob Clark]

From: Rob Clark <robdcl...@chromium.org>

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 <robdcl...@chromium.org>
---
 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