gpu: nvgpu: expose deterministic submit support

Add these bits in the gpu characteristics flags:

NVGPU_GPU_FLAGS_SUPPORT_DETERMINISTIC_SUBMIT_NO_JOBTRACKING - fast
submits with no in-kernel job tracking are supported.

NVGPU_GPU_FLAGS_SUPPORT_DETERMINISTIC_SUBMIT_FULL - deterministic
submits also with job tracking and num_inflight_jobs set are supported.

Either of these may get disabled if the particular channel or submit
still requires features that block these.

Make gk20a_channel_sync_needs_sync_framework() take a gk20a pointer
instead of a channel pointer so that it can be called without a channel.
It does not need any per-channel data.

Bug 20029130
Bug 200274674

Change-Id: I5f82510b6d39b53bcf6f1006dd83bdd9053963a0
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/1456845
Signed-off-by: Debarshi Dutta <ddutta@nvidia.com>
(cherry picked from commit ee9733e587 in
dev-kernel)
Reviewed-on: https://git-master.nvidia.com/r/1558993
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bibek Basu <bbasu@nvidia.com>

drivers/gpu/nvgpu/gk20a/channel_gk20a.c

@@ -3106,7 +3106,7 @@ int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
 			return -EINVAL;
 
 		need_sync_framework = force_need_sync_fence ||
-			gk20a_channel_sync_needs_sync_framework(c) ||
+			gk20a_channel_sync_needs_sync_framework(g) ||
 			(flags & NVGPU_SUBMIT_GPFIFO_FLAGS_SYNC_FENCE &&
 			(flags & NVGPU_SUBMIT_GPFIFO_FLAGS_FENCE_WAIT ||
 			 flags & NVGPU_SUBMIT_GPFIFO_FLAGS_FENCE_GET));

drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c

@@ -979,10 +979,10 @@ struct gk20a_channel_sync *gk20a_channel_sync_create(struct channel_gk20a *c)
 	return gk20a_channel_semaphore_create(c);
 }
 
-bool gk20a_channel_sync_needs_sync_framework(struct channel_gk20a *c)
+bool gk20a_channel_sync_needs_sync_framework(struct gk20a *g)
 {
 #ifdef CONFIG_TEGRA_GK20A
-	if (gk20a_platform_has_syncpoints(c->g->dev))
+	if (gk20a_platform_has_syncpoints(g->dev))
 		return false;
 #endif
 	return true;

drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.h

@@ -101,7 +101,7 @@ struct gk20a_channel_sync {
 
 void gk20a_channel_sync_destroy(struct gk20a_channel_sync *sync);
 struct gk20a_channel_sync *gk20a_channel_sync_create(struct channel_gk20a *c);
-bool gk20a_channel_sync_needs_sync_framework(struct channel_gk20a *c);
+bool gk20a_channel_sync_needs_sync_framework(struct gk20a *g);
 
 #ifdef CONFIG_SYNC
 void gk20a_channel_cancel_pending_sema_waits(struct gk20a *g);

drivers/gpu/nvgpu/gk20a/gk20a.c

@@ -2207,6 +2207,25 @@ int gk20a_init_gpu_characteristics(struct gk20a *g)
 	    gk20a_platform_has_syncpoints(g->dev))
 		gpu->flags |= NVGPU_GPU_FLAGS_HAS_SYNCPOINTS;
 
+	/*
+	 * Railgating needs job tracking which prevents fast submits. They're
+	 * supported otherwise, provided that the user doesn't request anything
+	 * that depends on job tracking. (Here, fast means strictly no
+	 * metadata, just the gpfifo contents are copied and gp_put updated).
+	 */
+	if (!platform->can_railgate)
+		gpu->flags |= NVGPU_GPU_FLAGS_SUPPORT_DETERMINISTIC_SUBMIT_NO_JOBTRACKING;
+
+	/*
+	 * Railgating and sync framework require deferred job cleanup which
+	 * prevents deterministic submits. They're supported otherwise,
+	 * provided that the user doesn't request anything that depends on
+	 * deferred cleanup.
+	 */
+	if (!platform->can_railgate
+	    && !gk20a_channel_sync_needs_sync_framework(g))
+		gpu->flags |= NVGPU_GPU_FLAGS_SUPPORT_DETERMINISTIC_SUBMIT_FULL;
+
 	gpu->flags |= NVGPU_GPU_FLAGS_SUPPORT_USERSPACE_MANAGED_AS;
 	gpu->flags |= NVGPU_GPU_FLAGS_SUPPORT_TSG;
 	gpu->flags |= NVGPU_GPU_FLAGS_SUPPORT_MAP_COMPBITS;

include/uapi/linux/nvgpu.h

@@ -137,6 +137,10 @@ struct nvgpu_gpu_zbc_query_table_args {
 #define NVGPU_GPU_FLAGS_SUPPORT_FECS_CTXSW_TRACE	(1ULL << 16)
 /* NVGPU_AS_IOCTL_MAP_BUFFER_COMPBITS is available */
 #define NVGPU_GPU_FLAGS_SUPPORT_MAP_COMPBITS		(1ULL << 17)
+/* Fast deterministic submits with no job tracking are supported */
+#define NVGPU_GPU_FLAGS_SUPPORT_DETERMINISTIC_SUBMIT_NO_JOBTRACKING (1ULL << 18)
+/* Deterministic submits are supported even with job tracking */
+#define NVGPU_GPU_FLAGS_SUPPORT_DETERMINISTIC_SUBMIT_FULL (1ULL << 19)
 /* NVGPU_SUBMIT_GPFIFO_FLAGS_RESCHEDULE_RUNLIST is available */
 #define NVGPU_GPU_FLAGS_SUPPORT_RESCHEDULE_RUNLIST	(1ULL << 21)
 
@@ -1350,8 +1354,22 @@ struct nvgpu_alloc_gpfifo_args {
 struct nvgpu_alloc_gpfifo_ex_args {
 	__u32 num_entries;
 	__u32 num_inflight_jobs;
-#define NVGPU_ALLOC_GPFIFO_EX_FLAGS_VPR_ENABLED		(1 << 0) /* set owner channel of this gpfifo as a vpr channel */
+/* Set owner channel of this gpfifo as a vpr channel. */
-#define NVGPU_ALLOC_GPFIFO_EX_FLAGS_DETERMINISTIC	(1 << 1) /* channel shall exhibit deterministic behavior in the submit path */
+#define NVGPU_ALLOC_GPFIFO_EX_FLAGS_VPR_ENABLED		(1 << 0)
+/*
+ * Channel shall exhibit deterministic behavior in the submit path.
+ *
+ * With this flag, any submits with in-kernel job tracking also require that
+ * num_inflight_jobs is nonzero, and additionally that
+ * NVGPU_GPU_FLAGS_SUPPORT_DETERMINISTIC_SUBMIT_FULL is found in gpu
+ * characteristics.flags.
+ *
+ * Note that fast submits (with no in-kernel job tracking) are also
+ * deterministic and are supported if the characteristics flags contain
+ * NVGPU_GPU_FLAGS_SUPPORT_DETERMINISTIC_SUBMIT_NO_JOBTRACKING; this flag or
+ * num_inflight_jobs are not necessary in that case.
+ */
+#define NVGPU_ALLOC_GPFIFO_EX_FLAGS_DETERMINISTIC	(1 << 1)
 	__u32 flags;
 	__u32 reserved[5];
 };