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>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/clk/clk_arb.c b/drivers/gpu/nvgpu/clk/clk_arb.c
index 983a82f9..8543196b 100644
--- a/drivers/gpu/nvgpu/clk/clk_arb.c
+++ b/drivers/gpu/nvgpu/clk/clk_arb.c
@@ -750,12 +750,20 @@ error_check:
 
 int nvgpu_clk_arb_init_arbiter(struct gk20a *g)
 {
+        int err = 0;
+
         if (!g->ops.clk.support_clk_freq_controller ||
                 !g->ops.clk_arb.get_arbiter_clk_domains) {
                 return 0;
         }
 
-        return g->ops.clk_arb.arbiter_clk_init(g);
+        nvgpu_mutex_acquire(&g->clk_arb_enable_lock);
+
+        err = g->ops.clk_arb.arbiter_clk_init(g);
+
+        nvgpu_mutex_release(&g->clk_arb_enable_lock);
+
+        return err;
 }
 
 void nvgpu_clk_arb_send_thermal_alarm(struct gk20a *g)
@@ -783,10 +791,14 @@ void nvgpu_clk_arb_cleanup_arbiter(struct gk20a *g)
 {
         struct nvgpu_clk_arb *arb = g->clk_arb;
 
+        nvgpu_mutex_acquire(&g->clk_arb_enable_lock);
+
         if (arb) {
                 nvgpu_clk_arb_worker_deinit(g);
                 g->ops.clk_arb.clk_arb_cleanup(g->clk_arb);
         }
+
+        nvgpu_mutex_release(&g->clk_arb_enable_lock);
 }
 
 int nvgpu_clk_arb_init_session(struct gk20a *g,