drivers: soc: ti: knav_qmss_queue: Pass lockdep expression to RCU lists

inst->handles is traversed using list_for_each_entry_rcu
outside an RCU read-side critical section but under the protection
of knav_dev_lock.

Hence, add corresponding lockdep expression to silence false-positive
lockdep warnings, and harden RCU lists.

Add macro for the corresponding lockdep expression.

Link: https://lore.kernel.org/r/20200118042433.4968-1-frextrite@gmail.com
Signed-off-by: Amol Grover <frextrite@gmail.com>
Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

diff --git a/drivers/soc/ti/knav_qmss_queue.c b/drivers/soc/ti/knav_qmss_queue.c
index 1ccc9064e1eb5e051d9ccdb4ae0ff0c0d92e40f0..37f3db6c041c2299723f2a1a3f4bb4d8cdb658ea 100644 (file)
--- a/drivers/soc/ti/knav_qmss_queue.c
+++ b/drivers/soc/ti/knav_qmss_queue.c
@@ -25,6 +25,8 @@
 
 static struct knav_device *kdev;
 static DEFINE_MUTEX(knav_dev_lock);
+#define knav_dev_lock_held() \
+       lockdep_is_held(&knav_dev_lock)
 
 /* Queue manager register indices in DTS */
 #define KNAV_QUEUE_PEEK_REG_INDEX      0
@@ -52,8 +54,9 @@ static DEFINE_MUTEX(knav_dev_lock);
 #define knav_queue_idx_to_inst(kdev, idx)                      \
        (kdev->instances + (idx << kdev->inst_shift))
 
-#define for_each_handle_rcu(qh, inst)                  \
-       list_for_each_entry_rcu(qh, &inst->handles, list)
+#define for_each_handle_rcu(qh, inst)                          \
+       list_for_each_entry_rcu(qh, &inst->handles, list,       \
+                               knav_dev_lock_held())
 
 #define for_each_instance(idx, inst, kdev)             \
        for (idx = 0, inst = kdev->instances;           \