[RFC PATCH 5/6] drm/nouveau: Add new callback for scheduler teardown

[Philipp Stanner]

There is a new callback for always tearing the scheduler down in a
leak-free, deadlock-free manner.

Port Nouveau as its first user by providing the scheduler with a
callback that ensures the fence context gets killed in drm_sched_fini().

Signed-off-by: Philipp Stanner <pha...@kernel.org>
---
 drivers/gpu/drm/nouveau/nouveau_fence.c | 15 +++++++++++++++
 drivers/gpu/drm/nouveau/nouveau_fence.h |  1 +
 drivers/gpu/drm/nouveau/nouveau_sched.c | 15 ++++++++++++++-
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c 
b/drivers/gpu/drm/nouveau/nouveau_fence.c
index 869d4335c0f4..1c30ce686c6a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fence.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
@@ -240,6 +240,21 @@ nouveau_fence_emit(struct nouveau_fence *fence)
        return ret;
 }
 
+void
+nouveau_fence_cancel(struct nouveau_fence *fence)
+{
+       struct nouveau_fence_chan *fctx = nouveau_fctx(fence);
+       unsigned long flags;
+
+       spin_lock_irqsave(&fctx->lock, flags);
+       if (!dma_fence_is_signaled(&fence->base)) {
+               dma_fence_set_error(&fence->base, -ECANCELED);
+               if (nouveau_fence_signal(fence))
+                       nvif_event_block(&fctx->event);
+       }
+       spin_unlock_irqrestore(&fctx->lock, flags);
+}
+
 bool
 nouveau_fence_done(struct nouveau_fence *fence)
 {
diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.h 
b/drivers/gpu/drm/nouveau/nouveau_fence.h
index c3595c2197b5..4d8f78cd6ebc 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fence.h
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.h
@@ -29,6 +29,7 @@ void nouveau_fence_unref(struct nouveau_fence **);
 
 int  nouveau_fence_emit(struct nouveau_fence *);
 bool nouveau_fence_done(struct nouveau_fence *);
+void nouveau_fence_cancel(struct nouveau_fence *fence);
 int  nouveau_fence_wait(struct nouveau_fence *, bool lazy, bool intr);
 int  nouveau_fence_sync(struct nouveau_bo *, struct nouveau_channel *, bool 
exclusive, bool intr);
 
diff --git a/drivers/gpu/drm/nouveau/nouveau_sched.c 
b/drivers/gpu/drm/nouveau/nouveau_sched.c
index 460a5fb02412..2ec62059c351 100644
--- a/drivers/gpu/drm/nouveau/nouveau_sched.c
+++ b/drivers/gpu/drm/nouveau/nouveau_sched.c
@@ -11,6 +11,7 @@
 #include "nouveau_exec.h"
 #include "nouveau_abi16.h"
 #include "nouveau_sched.h"
+#include "nouveau_chan.h"
 
 #define NOUVEAU_SCHED_JOB_TIMEOUT_MS           10000
 
@@ -393,10 +394,23 @@ nouveau_sched_free_job(struct drm_sched_job *sched_job)
        nouveau_job_fini(job);
 }
 
+static void
+nouveau_sched_cancel_job(struct drm_sched_job *sched_job)
+{
+       struct nouveau_fence *fence;
+       struct nouveau_job *job;
+
+       job = to_nouveau_job(sched_job);
+       fence = to_nouveau_fence(job->done_fence);
+
+       nouveau_fence_cancel(fence);
+}
+
 static const struct drm_sched_backend_ops nouveau_sched_ops = {
        .run_job = nouveau_sched_run_job,
        .timedout_job = nouveau_sched_timedout_job,
        .free_job = nouveau_sched_free_job,
+       .cancel_job = nouveau_sched_cancel_job,
 };
 
 static int
@@ -482,7 +496,6 @@ nouveau_sched_create(struct nouveau_sched **psched, struct 
nouveau_drm *drm,
        return 0;
 }
 
-
 static void
 nouveau_sched_fini(struct nouveau_sched *sched)
 {
-- 
2.49.0