gpu: nvgpu: add deterministic submit flag

This change adds a new ioctl flag,
NVGPU_SUBMIT_GPFIFO_FLAGS_DETERMINISTIC, which indicates that a
gpfifo submission must exhibit deterministic behavior within the
kernel.

For submissions that require job tracking and also set
this flag, we require the channel to have previously
pre-allocated job tracking resources.

Bug 1795076

Change-Id: I0496a2513c6c683fcda161b32db9e7ee6712d45c
Signed-off-by: Sachit Kadle <skadle@nvidia.com>
Reviewed-on: http://git-master/r/1210527
(cherry picked from commit 0a36a0ce3a6cbe398931993e742fc928f7b2c0aa)
Reviewed-on: http://git-master/r/1223935
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index cc3bbbd2..b846054d 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -2628,6 +2628,15 @@ int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
                         !skip_buffer_refcounting;
 
         if (need_job_tracking) {
+                /*
+                 * If the submit is to have deterministic latency and
+                 * job tracking is required, the channel must have
+                 * pre-allocated resources. Otherwise, we fail the submit here
+                 */
+                if ((flags & NVGPU_SUBMIT_GPFIFO_FLAGS_DETERMINISTIC) &&
+                                !channel_gk20a_is_prealloc_enabled(c))
+                        return -EINVAL;
+
                 /* gk20a_channel_update releases this ref. */
                 err = gk20a_busy(g->dev);
                 if (err) {