driver core: Add device_link_test() for testing device link flags

To avoid coding mistakes like the one fixed by commit 3860cbe23963 ("PM:
sleep: Fix bit masking operation"), introduce device_link_test() for
testing device link flags and use it where applicable.

No intentional functional impact.

Signed-off-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/2793309.mvXUDI8C0e@rjwysocki.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 45 insertions, 41 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index cbc0099d8ef2..3809baed42f3 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -460,9 +460,9 @@ static ssize_t auto_remove_on_show(struct device *dev,
 	struct device_link *link = to_devlink(dev);
 	const char *output;
 
-	if (link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
+	if (device_link_test(link, DL_FLAG_AUTOREMOVE_SUPPLIER))
 		output = "supplier unbind";
-	else if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER)
+	else if (device_link_test(link, DL_FLAG_AUTOREMOVE_CONSUMER))
 		output = "consumer unbind";
 	else
 		output = "never";
@@ -476,7 +476,7 @@ static ssize_t runtime_pm_show(struct device *dev,
 {
 	struct device_link *link = to_devlink(dev);
 
-	return sysfs_emit(buf, "%d\n", !!(link->flags & DL_FLAG_PM_RUNTIME));
+	return sysfs_emit(buf, "%d\n", device_link_test(link, DL_FLAG_PM_RUNTIME));
 }
 static DEVICE_ATTR_RO(runtime_pm);
 
@@ -485,8 +485,7 @@ static ssize_t sync_state_only_show(struct device *dev,
 {
 	struct device_link *link = to_devlink(dev);
 
-	return sysfs_emit(buf, "%d\n",
-			  !!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
+	return sysfs_emit(buf, "%d\n", device_link_test(link, DL_FLAG_SYNC_STATE_ONLY));
 }
 static DEVICE_ATTR_RO(sync_state_only);
 
@@ -792,12 +791,12 @@ struct device_link *device_link_add(struct device *consumer,
 		if (link->consumer != consumer)
 			continue;
 
-		if (link->flags & DL_FLAG_INFERRED &&
+		if (device_link_test(link, DL_FLAG_INFERRED) &&
 		    !(flags & DL_FLAG_INFERRED))
 			link->flags &= ~DL_FLAG_INFERRED;
 
 		if (flags & DL_FLAG_PM_RUNTIME) {
-			if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
+			if (!device_link_test(link, DL_FLAG_PM_RUNTIME)) {
 				pm_runtime_new_link(consumer);
 				link->flags |= DL_FLAG_PM_RUNTIME;
 			}
@@ -807,8 +806,8 @@ struct device_link *device_link_add(struct device *consumer,
 
 		if (flags & DL_FLAG_STATELESS) {
 			kref_get(&link->kref);
-			if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
-			    !(link->flags & DL_FLAG_STATELESS)) {
+			if (device_link_test(link, DL_FLAG_SYNC_STATE_ONLY) &&
+			    !device_link_test(link, DL_FLAG_STATELESS)) {
 				link->flags |= DL_FLAG_STATELESS;
 				goto reorder;
 			} else {
@@ -823,7 +822,7 @@ struct device_link *device_link_add(struct device *consumer,
 		 * update the existing link to stay around longer.
 		 */
 		if (flags & DL_FLAG_AUTOREMOVE_SUPPLIER) {
-			if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
+			if (device_link_test(link, DL_FLAG_AUTOREMOVE_CONSUMER)) {
 				link->flags &= ~DL_FLAG_AUTOREMOVE_CONSUMER;
 				link->flags |= DL_FLAG_AUTOREMOVE_SUPPLIER;
 			}
@@ -831,12 +830,12 @@ struct device_link *device_link_add(struct device *consumer,
 			link->flags &= ~(DL_FLAG_AUTOREMOVE_CONSUMER |
 					 DL_FLAG_AUTOREMOVE_SUPPLIER);
 		}
-		if (!(link->flags & DL_FLAG_MANAGED)) {
+		if (!device_link_test(link, DL_FLAG_MANAGED)) {
 			kref_get(&link->kref);
 			link->flags |= DL_FLAG_MANAGED;
 			device_link_init_status(link, consumer, supplier);
 		}
-		if (link->flags & DL_FLAG_SYNC_STATE_ONLY &&
+		if (device_link_test(link, DL_FLAG_SYNC_STATE_ONLY) &&
 		    !(flags & DL_FLAG_SYNC_STATE_ONLY)) {
 			link->flags &= ~DL_FLAG_SYNC_STATE_ONLY;
 			goto reorder;
@@ -940,7 +939,7 @@ static void __device_link_del(struct kref *kref)
 
 static void device_link_put_kref(struct device_link *link)
 {
-	if (link->flags & DL_FLAG_STATELESS)
+	if (device_link_test(link, DL_FLAG_STATELESS))
 		kref_put(&link->kref, __device_link_del);
 	else if (!device_is_registered(link->consumer))
 		__device_link_del(&link->kref);
@@ -1004,7 +1003,7 @@ static void device_links_missing_supplier(struct device *dev)
 		if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
 			WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
 		} else {
-			WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
+			WARN_ON(!device_link_test(link, DL_FLAG_SYNC_STATE_ONLY));
 			WRITE_ONCE(link->status, DL_STATE_DORMANT);
 		}
 	}
@@ -1072,14 +1071,14 @@ int device_links_check_suppliers(struct device *dev)
 	device_links_write_lock();
 
 	list_for_each_entry(link, &dev->links.suppliers, c_node) {
-		if (!(link->flags & DL_FLAG_MANAGED))
+		if (!device_link_test(link, DL_FLAG_MANAGED))
 			continue;
 
 		if (link->status != DL_STATE_AVAILABLE &&
-		    !(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
+		    !device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)) {
 
 			if (dev_is_best_effort(dev) &&
-			    link->flags & DL_FLAG_INFERRED &&
+			    device_link_test(link, DL_FLAG_INFERRED) &&
 			    !link->supplier->can_match) {
 				ret = -EAGAIN;
 				continue;
@@ -1128,7 +1127,7 @@ static void __device_links_queue_sync_state(struct device *dev,
 		return;
 
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
-		if (!(link->flags & DL_FLAG_MANAGED))
+		if (!device_link_test(link, DL_FLAG_MANAGED))
 			continue;
 		if (link->status != DL_STATE_ACTIVE)
 			return;
@@ -1268,7 +1267,7 @@ void device_links_force_bind(struct device *dev)
 	device_links_write_lock();
 
 	list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
-		if (!(link->flags & DL_FLAG_MANAGED))
+		if (!device_link_test(link, DL_FLAG_MANAGED))
 			continue;
 
 		if (link->status != DL_STATE_AVAILABLE) {
@@ -1329,7 +1328,7 @@ void device_links_driver_bound(struct device *dev)
 	device_links_write_lock();
 
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
-		if (!(link->flags & DL_FLAG_MANAGED))
+		if (!device_link_test(link, DL_FLAG_MANAGED))
 			continue;
 
 		/*
@@ -1345,7 +1344,7 @@ void device_links_driver_bound(struct device *dev)
 		WARN_ON(link->status != DL_STATE_DORMANT);
 		WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
 
-		if (link->flags & DL_FLAG_AUTOPROBE_CONSUMER)
+		if (device_link_test(link, DL_FLAG_AUTOPROBE_CONSUMER))
 			driver_deferred_probe_add(link->consumer);
 	}
 
@@ -1357,11 +1356,11 @@ void device_links_driver_bound(struct device *dev)
 	list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
 		struct device *supplier;
 
-		if (!(link->flags & DL_FLAG_MANAGED))
+		if (!device_link_test(link, DL_FLAG_MANAGED))
 			continue;
 
 		supplier = link->supplier;
-		if (link->flags & DL_FLAG_SYNC_STATE_ONLY) {
+		if (device_link_test(link, DL_FLAG_SYNC_STATE_ONLY)) {
 			/*
 			 * When DL_FLAG_SYNC_STATE_ONLY is set, it means no
 			 * other DL_MANAGED_LINK_FLAGS have been set. So, it's
@@ -1369,7 +1368,7 @@ void device_links_driver_bound(struct device *dev)
 			 */
 			device_link_drop_managed(link);
 		} else if (dev_is_best_effort(dev) &&
-			   link->flags & DL_FLAG_INFERRED &&
+			   device_link_test(link, DL_FLAG_INFERRED) &&
 			   link->status != DL_STATE_CONSUMER_PROBE &&
 			   !link->supplier->can_match) {
 			/*
@@ -1421,10 +1420,10 @@ static void __device_links_no_driver(struct device *dev)
 	struct device_link *link, *ln;
 
 	list_for_each_entry_safe_reverse(link, ln, &dev->links.suppliers, c_node) {
-		if (!(link->flags & DL_FLAG_MANAGED))
+		if (!device_link_test(link, DL_FLAG_MANAGED))
 			continue;
 
-		if (link->flags & DL_FLAG_AUTOREMOVE_CONSUMER) {
+		if (device_link_test(link, DL_FLAG_AUTOREMOVE_CONSUMER)) {
 			device_link_drop_managed(link);
 			continue;
 		}
@@ -1436,7 +1435,7 @@ static void __device_links_no_driver(struct device *dev)
 		if (link->supplier->links.status == DL_DEV_DRIVER_BOUND) {
 			WRITE_ONCE(link->status, DL_STATE_AVAILABLE);
 		} else {
-			WARN_ON(!(link->flags & DL_FLAG_SYNC_STATE_ONLY));
+			WARN_ON(!device_link_test(link, DL_FLAG_SYNC_STATE_ONLY));
 			WRITE_ONCE(link->status, DL_STATE_DORMANT);
 		}
 	}
@@ -1461,7 +1460,7 @@ void device_links_no_driver(struct device *dev)
 	device_links_write_lock();
 
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
-		if (!(link->flags & DL_FLAG_MANAGED))
+		if (!device_link_test(link, DL_FLAG_MANAGED))
 			continue;
 
 		/*
@@ -1498,10 +1497,10 @@ void device_links_driver_cleanup(struct device *dev)
 	device_links_write_lock();
 
 	list_for_each_entry_safe(link, ln, &dev->links.consumers, s_node) {
-		if (!(link->flags & DL_FLAG_MANAGED))
+		if (!device_link_test(link, DL_FLAG_MANAGED))
 			continue;
 
-		WARN_ON(link->flags & DL_FLAG_AUTOREMOVE_CONSUMER);
+		WARN_ON(device_link_test(link, DL_FLAG_AUTOREMOVE_CONSUMER));
 		WARN_ON(link->status != DL_STATE_SUPPLIER_UNBIND);
 
 		/*
@@ -1510,7 +1509,7 @@ void device_links_driver_cleanup(struct device *dev)
 		 * has moved to DL_STATE_SUPPLIER_UNBIND.
 		 */
 		if (link->status == DL_STATE_SUPPLIER_UNBIND &&
-		    link->flags & DL_FLAG_AUTOREMOVE_SUPPLIER)
+		    device_link_test(link, DL_FLAG_AUTOREMOVE_SUPPLIER))
 			device_link_drop_managed(link);
 
 		WRITE_ONCE(link->status, DL_STATE_DORMANT);
@@ -1544,7 +1543,7 @@ bool device_links_busy(struct device *dev)
 	device_links_write_lock();
 
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
-		if (!(link->flags & DL_FLAG_MANAGED))
+		if (!device_link_test(link, DL_FLAG_MANAGED))
 			continue;
 
 		if (link->status == DL_STATE_CONSUMER_PROBE
@@ -1586,8 +1585,8 @@ void device_links_unbind_consumers(struct device *dev)
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
 		enum device_link_state status;
 
-		if (!(link->flags & DL_FLAG_MANAGED) ||
-		    link->flags & DL_FLAG_SYNC_STATE_ONLY)
+		if (!device_link_test(link, DL_FLAG_MANAGED) ||
+		    device_link_test(link, DL_FLAG_SYNC_STATE_ONLY))
 			continue;
 
 		status = link->status;
@@ -1743,7 +1742,7 @@ static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
 
 static void fw_devlink_relax_link(struct device_link *link)
 {
-	if (!(link->flags & DL_FLAG_INFERRED))
+	if (!device_link_test(link, DL_FLAG_INFERRED))
 		return;
 
 	if (device_link_flag_is_sync_state_only(link->flags))
@@ -1779,7 +1778,7 @@ static int fw_devlink_dev_sync_state(struct device *dev, void *data)
 	struct device_link *link = to_devlink(dev);
 	struct device *sup = link->supplier;
 
-	if (!(link->flags & DL_FLAG_MANAGED) ||
+	if (!device_link_test(link, DL_FLAG_MANAGED) ||
 	    link->status == DL_STATE_ACTIVE || sup->state_synced ||
 	    !dev_has_sync_state(sup))
 		return 0;
@@ -2063,7 +2062,7 @@ static bool __fw_devlink_relax_cycles(struct fwnode_handle *con_handle,
 		 * such due to a cycle.
 		 */
 		if (device_link_flag_is_sync_state_only(dev_link->flags) &&
-		    !(dev_link->flags & DL_FLAG_CYCLE))
+		    !device_link_test(dev_link, DL_FLAG_CYCLE))
 			continue;
 
 		if (__fw_devlink_relax_cycles(con_handle,
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index eebe699fdf4f..6c6f8ded6877 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1998,7 +1998,7 @@ static bool device_prepare_smart_suspend(struct device *dev)
 	idx = device_links_read_lock();
 
 	list_for_each_entry_rcu_locked(link, &dev->links.suppliers, c_node) {
-		if (!(link->flags & DL_FLAG_PM_RUNTIME))
+		if (!device_link_test(link, DL_FLAG_PM_RUNTIME))
 			continue;
 
 		if (!dev_pm_smart_suspend(link->supplier) &&
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index c55a7c70bc1a..c67e7a6b8ed0 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -290,7 +290,7 @@ static int rpm_get_suppliers(struct device *dev)
 				device_links_read_lock_held()) {
 		int retval;
 
-		if (!(link->flags & DL_FLAG_PM_RUNTIME))
+		if (!device_link_test(link, DL_FLAG_PM_RUNTIME))
 			continue;
 
 		retval = pm_runtime_get_sync(link->supplier);
@@ -1879,7 +1879,7 @@ void pm_runtime_get_suppliers(struct device *dev)
 
 	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
 				device_links_read_lock_held())
-		if (link->flags & DL_FLAG_PM_RUNTIME) {
+		if (device_link_test(link, DL_FLAG_PM_RUNTIME)) {
 			link->supplier_preactivated = true;
 			pm_runtime_get_sync(link->supplier);
 		}
@@ -1933,7 +1933,7 @@ static void pm_runtime_drop_link_count(struct device *dev)
  */
 void pm_runtime_drop_link(struct device_link *link)
 {
-	if (!(link->flags & DL_FLAG_PM_RUNTIME))
+	if (!device_link_test(link, DL_FLAG_PM_RUNTIME))
 		return;
 
 	pm_runtime_drop_link_count(link->consumer);
diff --git a/include/linux/device.h b/include/linux/device.h
index 4940db137fff..afdd4f7c0d94 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -1162,6 +1162,11 @@ void device_links_supplier_sync_state_pause(void);
 void device_links_supplier_sync_state_resume(void);
 void device_link_wait_removal(void);
 
+static inline bool device_link_test(const struct device_link *link, u32 flags)
+{
+	return !!(link->flags & flags);
+}
+
 /* Create alias, so I can be autoloaded. */
 #define MODULE_ALIAS_CHARDEV(major,minor) \
 	MODULE_ALIAS("char-major-" __stringify(major) "-" __stringify(minor))