gpu: nvgpu: implement sync refcounting

We currently free sync when we find job list empty
If aggressive_sync is set to true, we try to free
sync during channel unbind() call

But we rarely free sync from channel_unbind() call
since freeing it when job list is empty is
aggressive enough

Hence remove sync free code from channel_unbind()

Implement refcounting for sync:
- get a refcount while submitting a job (and
  allocate sync if it is not allocated already)
- put a refcount while freeing the job
- if refcount==0 and if aggressive_sync_destroy is
  set, free the sync
- if aggressive_sync_destroy is not set, we will
  free the sync during channel close time

Bug 200187553

Change-Id: I74e24adb15dc26a375ebca1fdd017b3ad6d57b61
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1120410
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
index 025b000e..b47c1010 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
@@ -356,6 +356,7 @@ gk20a_channel_syncpt_create(struct channel_gk20a *c)
 
         nvhost_syncpt_set_min_eq_max_ext(sp->host1x_pdev, sp->id);
 
+        atomic_set(&sp->ops.refcount, 0);
         sp->ops.wait_syncpt             = gk20a_channel_syncpt_wait_syncpt;
         sp->ops.wait_fd                 = gk20a_channel_syncpt_wait_fd;
         sp->ops.incr                    = gk20a_channel_syncpt_incr;
@@ -711,6 +712,7 @@ gk20a_channel_semaphore_create(struct channel_gk20a *c)
         if (!sema->timeline)
                 goto clean_up;
 #endif
+        atomic_set(&sema->ops.refcount, 0);
         sema->ops.wait_syncpt   = gk20a_channel_semaphore_wait_syncpt;
         sema->ops.wait_fd       = gk20a_channel_semaphore_wait_fd;
         sema->ops.incr          = gk20a_channel_semaphore_incr;
@@ -727,6 +729,11 @@ clean_up:
         return NULL;
 }
 
+void gk20a_channel_sync_destroy(struct gk20a_channel_sync *sync)
+{
+        sync->destroy(sync);
+}
+
 struct gk20a_channel_sync *gk20a_channel_sync_create(struct channel_gk20a *c)
 {
 #ifdef CONFIG_TEGRA_GK20A