gpu: nvgpu: support tuning per-ch deterministic opts

Add a new ioctl NVGPU_GPU_IOCTL_SET_DETERMINISTIC_OPTS to adjust
deterministic options on a per-channel basis. Currently, the only
supported option is to relax the no-railgating requirement on open
deterministic channels. This also disallows submits on such channels,
until the railgate option is reset.

Bug 200327089

Change-Id: If4f0f51fd1d40ad7407d13638150d7402479aff0
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1554563
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/channel.c b/drivers/gpu/nvgpu/common/linux/channel.c
index 716c5820..c295336f 100644
--- a/drivers/gpu/nvgpu/common/linux/channel.c
+++ b/drivers/gpu/nvgpu/common/linux/channel.c
@@ -537,6 +537,17 @@ int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
         if (c->deterministic)
                 nvgpu_rwsem_down_read(&g->deterministic_busy);
 
+        if (c->deterministic && c->deterministic_railgate_allowed) {
+                /*
+                 * Nope - this channel has dropped its own power ref. As
+                 * deterministic submits don't hold power on per each submitted
+                 * job like normal ones do, the GPU might railgate any time now
+                 * and thus submit is disallowed.
+                 */
+                err = -EINVAL;
+                goto clean_up;
+        }
+
         trace_gk20a_channel_submit_gpfifo(g->name,
                                           c->chid,
                                           num_entries,