gpu: nvgpu: refactor teardown to support unbind

This change refactors the teardown in remove to ensure that it is
possible to unload the driver while leaving fds open. This is achieved
by making sure that the SW state is kept alive till all fds are closed
and by checking that subsequent calls to ioctls after the teardown fail.

Normally, this would be achieved ny calls into gk20a_busy(), but in
kickoff we dont call into that to reduce latency, so we need to check
the driver status directly, and also in some of the functions
as we need to make sure the ioctl does not dereference the device or
platform struct

bug 200277762
JIRA: EVLR-1023

Change-Id: I163e47a08c29d4d5b3ab79f0eb531ef234f40bde
Signed-off-by: David Nieto <dmartineznie@nvidia.com>
Reviewed-on: http://git-master/r/1320219
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
Reviewed-by: Shreshtha Sahu <ssahu@nvidia.com>
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/ce2_gk20a.h b/drivers/gpu/nvgpu/gk20a/ce2_gk20a.h
index 5cdd233e..7ecf130f 100644
--- a/drivers/gpu/nvgpu/gk20a/ce2_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/ce2_gk20a.h
@@ -144,9 +144,12 @@ int gk20a_ce_execute_ops(struct device *dev,
                 struct gk20a_fence *gk20a_fence_in,
                 u32 submit_flags,
                 struct gk20a_fence **gk20a_fence_out);
+void gk20a_ce_delete_context_priv(struct gk20a *g,
+                u32 ce_ctx_id);
 void gk20a_ce_delete_context(struct device *dev,
                 u32 ce_ctx_id);
 
+
 #ifdef CONFIG_DEBUG_FS
 /* CE app debugfs api */
 void gk20a_ce_debugfs_init(struct device *dev);