gpu: host1x: Use different lock classes for each client

BugLink: https://bugs.launchpad.net/bugs/1926993
[ Upstream commit a24f98176d1efae2c37d3438c57a624d530d9c33 ]

To avoid false lockdep warnings, give each client lock a different
lock class, passed from the initialization site by macro.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c
index 347fb962b6c936ecb25f59807b1a673c385262ed..68a766ff0e9d2479ce3a594410098cfd9f3dccfc 100644 (file)
--- a/drivers/gpu/host1x/bus.c
+++ b/drivers/gpu/host1x/bus.c
@@ -705,8 +705,9 @@ void host1x_driver_unregister(struct host1x_driver *driver)
 EXPORT_SYMBOL(host1x_driver_unregister);
 
 /**
- * host1x_client_register() - register a host1x client
+ * __host1x_client_register() - register a host1x client
  * @client: host1x client
+ * @key: lock class key for the client-specific mutex
  *
  * Registers a host1x client with each host1x controller instance. Note that
  * each client will only match their parent host1x controller and will only be
@@ -715,13 +716,14 @@ EXPORT_SYMBOL(host1x_driver_unregister);
  * device and call host1x_device_init(), which will in turn call each client's
  * &host1x_client_ops.init implementation.
  */
-int host1x_client_register(struct host1x_client *client)
+int __host1x_client_register(struct host1x_client *client,
+                            struct lock_class_key *key)
 {
        struct host1x *host1x;
        int err;
 
        INIT_LIST_HEAD(&client->list);
-       mutex_init(&client->lock);
+       __mutex_init(&client->lock, "host1x client lock", key);
        client->usecount = 0;
 
        mutex_lock(&devices_lock);
@@ -742,7 +744,7 @@ int host1x_client_register(struct host1x_client *client)
 
        return 0;
 }
-EXPORT_SYMBOL(host1x_client_register);
+EXPORT_SYMBOL(__host1x_client_register);
 
 /**
  * host1x_client_unregister() - unregister a host1x client

diff --git a/include/linux/host1x.h b/include/linux/host1x.h
index ce59a6a6a0087e6ab71de2200076d2189b64a2d0..9eb77c87a83b0a23d453267a1873af249a22ddcd 100644 (file)
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -320,7 +320,14 @@ static inline struct host1x_device *to_host1x_device(struct device *dev)
 int host1x_device_init(struct host1x_device *device);
 int host1x_device_exit(struct host1x_device *device);
 
-int host1x_client_register(struct host1x_client *client);
+int __host1x_client_register(struct host1x_client *client,
+                            struct lock_class_key *key);
+#define host1x_client_register(class) \
+       ({ \
+               static struct lock_class_key __key; \
+               __host1x_client_register(class, &__key); \
+       })
+
 int host1x_client_unregister(struct host1x_client *client);
 
 int host1x_client_suspend(struct host1x_client *client);