gpu: nvgpu: remove usage of xchg in clk arb code

With the removal of rcu locks and using spinlocks in place,
the usage of xchg for atomic pointer swap is unneccesary.
A few places already have barriers in place before changing
the pointer values, so a simple pointer assignment would do.

Jira VQRM-3741

Change-Id: I03296202b273b5175f166ab3e094c0e4de910eb8
Signed-off-by: Sourab Gupta <sourabg@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1709655
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/gpu/nvgpu/clk/clk_arb.c b/drivers/gpu/nvgpu/clk/clk_arb.c
index 456246bf..368bacc2 100644
--- a/drivers/gpu/nvgpu/clk/clk_arb.c
+++ b/drivers/gpu/nvgpu/clk/clk_arb.c
@@ -395,7 +395,7 @@ static int nvgpu_clk_arb_update_vf_table(struct nvgpu_clk_arb *arb)
 
         /* make table visible when all data has resolved in the tables */
         nvgpu_smp_wmb();
-        xchg(&arb->current_vf_table, table);
+        arb->current_vf_table = table;
 
 exit_vf_table:
 
@@ -800,7 +800,7 @@ static void nvgpu_clk_arb_run_arbiter_cb(struct nvgpu_clk_arb *arb)
                                         nvgpu_list_add(&dev->node, &arb->requests);
                                         nvgpu_spinlock_release(&arb->requests_lock);
                                 }
-                                xchg(&session->target, target);
+                                session->target = target;
                         }
                         nvgpu_spinlock_release(&session->session_lock);
 
@@ -933,7 +933,7 @@ static void nvgpu_clk_arb_run_arbiter_cb(struct nvgpu_clk_arb *arb)
 
         /* Make changes visible to other threads */
         nvgpu_smp_wmb();
-        xchg(&arb->actual, actual);
+        arb->actual = actual;
 
         status = nvgpu_lpwr_enable_pg(g, false);
         if (status < 0) {
@@ -988,7 +988,7 @@ static void nvgpu_clk_arb_run_arbiter_cb(struct nvgpu_clk_arb *arb)
         }
         /* commit changes before exchanging debug pointer */
         nvgpu_smp_wmb();
-        xchg(&arb->debug, debug);
+        arb->debug = debug;
 #endif
 
 exit_arb: