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, 5 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index 30f1b371..f4ca5649 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -877,6 +877,9 @@ struct gk20a {
         atomic_t nonstall_ops;
         struct work_struct nonstall_fn_work;
         struct workqueue_struct *nonstall_work_queue;
+
+        bool is_fmodel;
+
         struct kref refcount;
 
         struct resource *reg_mem;
@@ -987,7 +990,7 @@ struct gk20a {
         bool global_profiler_reservation_held;
         int profiler_reservation_count;
 
-        void (*remove_support)(struct device *);
+        void (*remove_support)(struct gk20a *);
 
         u64 pg_ingating_time_us;
         u64 pg_ungating_time_us;
@@ -1455,7 +1458,7 @@ extern struct class nvgpu_class;
 
 int gk20a_pm_init(struct device *dev);
 int gk20a_pm_finalize_poweron(struct device *dev);
-void gk20a_remove_support(struct device *dev);
+void gk20a_remove_support(struct gk20a *g);
 
 static inline struct tsg_gk20a *tsg_gk20a_from_ch(struct channel_gk20a *ch)
 {