[PATCH v4 04/11] drm/xe/configfs: Use mutex from xe_configfs subsystem

[Michal Wajdeczko]

It should be sufficient to protect all configuration parameters
using single mutex already defined inside xe_configfs subsystem.

While around, also convert code to use guard/scoped_guard classes.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/xe/xe_configfs.c | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_configfs.c b/drivers/gpu/drm/xe/xe_configfs.c
index 6aa0531bcf76..e32517afae58 100644
--- a/drivers/gpu/drm/xe/xe_configfs.c
+++ b/drivers/gpu/drm/xe/xe_configfs.c
@@ -85,14 +85,15 @@
  *	rmdir /sys/kernel/config/xe/0000:03:00.0/
  */
 
+/*
+ * Use xe_configfs.su_mutex (also accessible from group.cg_subsys->su_mutex)
+ * to protect configuration data.
+ */
 struct xe_config_device {
 	struct config_group group;
 
 	bool survivability_mode;
 	u64 engines_allowed;
-
-	/* protects attributes */
-	struct mutex lock;
 };
 
 struct engine_info {
@@ -135,9 +136,8 @@ static ssize_t survivability_mode_store(struct config_item *item, const char *pa
 	if (ret)
 		return ret;
 
-	mutex_lock(&dev->lock);
-	dev->survivability_mode = survivability_mode;
-	mutex_unlock(&dev->lock);
+	scoped_guard(mutex, &item->ci_group->cg_subsys->su_mutex)
+		dev->survivability_mode = survivability_mode;
 
 	return len;
 }
@@ -219,9 +219,8 @@ static ssize_t engines_allowed_store(struct config_item *item, const char *page,
 		val |= mask;
 	}
 
-	mutex_lock(&dev->lock);
-	dev->engines_allowed = val;
-	mutex_unlock(&dev->lock);
+	scoped_guard(mutex, &item->ci_group->cg_subsys->su_mutex)
+		dev->engines_allowed = val;
 
 	return len;
 }
@@ -239,7 +238,6 @@ static void xe_config_device_release(struct config_item *item)
 {
 	struct xe_config_device *dev = to_xe_config_device(item);
 
-	mutex_destroy(&dev->lock);
 	kfree(dev);
 }
 
@@ -286,8 +284,6 @@ static struct config_group *xe_config_make_device_group(struct config_group *gro
 
 	config_group_init_type_name(&dev->group, name, &xe_config_device_type);
 
-	mutex_init(&dev->lock);
-
 	return &dev->group;
 }
 
@@ -311,12 +307,10 @@ static struct configfs_subsystem xe_configfs = {
 
 static struct xe_config_device *configfs_find_group(struct pci_dev *pdev)
 {
+	guard(mutex)(&xe_configfs.su_mutex);
 	struct config_item *item;
 
-	mutex_lock(&xe_configfs.su_mutex);
 	item = config_group_find_item(&xe_configfs.su_group, pci_name(pdev));
-	mutex_unlock(&xe_configfs.su_mutex);
-
 	if (!item)
 		return NULL;
 
@@ -360,9 +354,8 @@ void xe_configfs_clear_survivability_mode(struct pci_dev *pdev)
 	if (!dev)
 		return;
 
-	mutex_lock(&dev->lock);
-	dev->survivability_mode = 0;
-	mutex_unlock(&dev->lock);
+	scoped_guard(mutex, &xe_configfs.su_mutex)
+		dev->survivability_mode = 0;
 
 	config_item_put(&dev->group.cg_item);
 }
-- 
2.47.1