driver core: Replace dev->state_synced with dev_state_synced()

In C, bitfields are not necessarily safe to modify from multiple
threads without locking. Switch "state_synced" over to the "flags"
field so modifications are safe.

Cc: Saravana Kannan <saravanak@kernel.org>
Reviewed-by: Rafael J. Wysocki (Intel) <rafael@kernel.org>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patch.msgid.link/20260406162231.v5.6.Idb4818e1159fef104c7756bfd6e7ba8f374bebcd@changeid
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

3 files changed, 12 insertions, 13 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 43bbd1716f37..7517738dfcd2 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1123,7 +1123,7 @@ static void __device_links_queue_sync_state(struct device *dev,
 
 	if (!dev_has_sync_state(dev))
 		return;
-	if (dev->state_synced)
+	if (dev_state_synced(dev))
 		return;
 
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
@@ -1138,7 +1138,7 @@ static void __device_links_queue_sync_state(struct device *dev,
 	 * than once. This can happen if new consumers get added to the device
 	 * and probed before the list is flushed.
 	 */
-	dev->state_synced = true;
+	dev_set_state_synced(dev);
 
 	if (WARN_ON(!list_empty(&dev->links.defer_sync)))
 		return;
@@ -1779,7 +1779,7 @@ static int fw_devlink_dev_sync_state(struct device *dev, void *data)
 	struct device *sup = link->supplier;
 
 	if (!device_link_test(link, DL_FLAG_MANAGED) ||
-	    link->status == DL_STATE_ACTIVE || sup->state_synced ||
+	    link->status == DL_STATE_ACTIVE || dev_state_synced(sup) ||
 	    !dev_has_sync_state(sup))
 		return 0;
 
@@ -1793,7 +1793,7 @@ static int fw_devlink_dev_sync_state(struct device *dev, void *data)
 		return 0;
 
 	dev_warn(sup, "Timed out. Forcing sync_state()\n");
-	sup->state_synced = true;
+	dev_set_state_synced(sup);
 	get_device(sup);
 	list_add_tail(&sup->links.defer_sync, data);
 
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index bce1e63b4230..5799a60fd058 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -569,12 +569,10 @@ static ssize_t state_synced_store(struct device *dev,
 		return -EINVAL;
 
 	device_lock(dev);
-	if (!dev->state_synced) {
-		dev->state_synced = true;
+	if (!dev_test_and_set_state_synced(dev))
 		dev_sync_state(dev);
-	} else {
+	else
 		ret = -EINVAL;
-	}
 	device_unlock(dev);
 
 	return ret ? ret : count;
@@ -586,7 +584,7 @@ static ssize_t state_synced_show(struct device *dev,
 	bool val;
 
 	device_lock(dev);
-	val = dev->state_synced;
+	val = dev_state_synced(dev);
 	device_unlock(dev);
 
 	return sysfs_emit(buf, "%u\n", val);
diff --git a/include/linux/device.h b/include/linux/device.h
index 099533cbdd2f..fc4334ff3351 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -524,6 +524,9 @@ struct device_physical_location {
  *		optional (if the coherent mask is large enough) also for dma
  *		allocations. This flag is managed by the dma ops instance from
  *		->dma_supported.
+ * @DEV_FLAG_STATE_SYNCED: The hardware state of this device has been synced to
+ *		match the software state of this device by calling the
+ *		driver/bus sync_state() callback.
  * @DEV_FLAG_COUNT: Number of defined struct_device_flags.
  */
 enum struct_device_flags {
@@ -532,6 +535,7 @@ enum struct_device_flags {
 	DEV_FLAG_DMA_IOMMU = 2,
 	DEV_FLAG_DMA_SKIP_SYNC = 3,
 	DEV_FLAG_DMA_OPS_BYPASS = 4,
+	DEV_FLAG_STATE_SYNCED = 5,
 
 	DEV_FLAG_COUNT
 };
@@ -615,9 +619,6 @@ enum struct_device_flags {
  * @offline:	Set after successful invocation of bus type's .offline().
  * @of_node_reused: Set if the device-tree node is shared with an ancestor
  *              device.
- * @state_synced: The hardware state of this device has been synced to match
- *		  the software state of this device by calling the driver/bus
- *		  sync_state() callback.
  * @dma_coherent: this particular device is dma coherent, even if the
  *		architecture supports non-coherent devices.
  * @flags:	DEV_FLAG_XXX flags. Use atomic bitfield operations to modify.
@@ -727,7 +728,6 @@ struct device {
 	bool			offline_disabled:1;
 	bool			offline:1;
 	bool			of_node_reused:1;
-	bool			state_synced:1;
 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
     defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL)
@@ -764,6 +764,7 @@ __create_dev_flag_accessors(can_match, DEV_FLAG_CAN_MATCH);
 __create_dev_flag_accessors(dma_iommu, DEV_FLAG_DMA_IOMMU);
 __create_dev_flag_accessors(dma_skip_sync, DEV_FLAG_DMA_SKIP_SYNC);
 __create_dev_flag_accessors(dma_ops_bypass, DEV_FLAG_DMA_OPS_BYPASS);
+__create_dev_flag_accessors(state_synced, DEV_FLAG_STATE_SYNCED);
 
 #undef __create_dev_flag_accessors