gpu: nvgpu: protect clk_arb init with mutex.

g->clk_arb is currently initialized as a part of gk20a_finalize_poweron().
Any subsequent call to gk20a_finalize_poweron reinitializes the clk_arb
and leading to memory leaks. This is resolved by protecting the
g->clk_arb initialization with a mutex clk_arb_enable_lock in struct
gk20a. We skip initializing the g->clk_arb if its not NULL.

Bug 2061372

Change-Id: I59158e0a5e4c827fdbd6d9ea2d04c78d0986347a
Signed-off-by: Debarshi Dutta <ddutta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1811650
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

2 files changed, 3 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/driver_common.c b/drivers/gpu/nvgpu/os/linux/driver_common.c
index 16af2cb0..b81cc90c 100644
--- a/drivers/gpu/nvgpu/os/linux/driver_common.c
+++ b/drivers/gpu/nvgpu/os/linux/driver_common.c
@@ -65,6 +65,7 @@ static void nvgpu_init_vars(struct gk20a *g)
         nvgpu_mutex_init(&g->poweroff_lock);
         nvgpu_mutex_init(&g->ctxsw_disable_lock);
         nvgpu_mutex_init(&g->tpc_pg_lock);
+        nvgpu_mutex_init(&g->clk_arb_enable_lock);
 
         l->regs_saved = l->regs;
         l->bar1_saved = l->bar1;
diff --git a/drivers/gpu/nvgpu/os/linux/module.c b/drivers/gpu/nvgpu/os/linux/module.c
index cb501683..d226ceeb 100644
--- a/drivers/gpu/nvgpu/os/linux/module.c
+++ b/drivers/gpu/nvgpu/os/linux/module.c
@@ -1310,6 +1310,8 @@ int nvgpu_remove(struct device *dev, struct class *class)
         if (platform->remove)
                 platform->remove(dev);
 
+        nvgpu_mutex_destroy(&g->clk_arb_enable_lock);
+
         nvgpu_log_fn(g, "removed");
 
         return err;