From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Add separate macros for walking links to suppliers and consumers of a
device to help device links users to avoid exposing the internals of
struct dev_links_info in their code and possible coding mistakes related
to that.

Accordingly, use the new macros to replace open-coded device links list
walks in the core power management code.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/base/base.h          |    8 ++++++++
 drivers/base/power/main.c    |   18 +++++++-----------
 drivers/base/power/runtime.c |    3 +--
 3 files changed, 16 insertions(+), 13 deletions(-)

--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -251,6 +251,14 @@
 void fw_devlink_drivers_done(void);
 void fw_devlink_probing_done(void);
 
+#define dev_for_each_link_to_supplier(__link, __dev)	\
+	list_for_each_entry_srcu(__link, &(__dev)->links.suppliers, c_node, \
+				 device_links_read_lock_held())
+
+#define dev_for_each_link_to_consumer(__link, __dev)	\
+	list_for_each_entry_srcu(__link, &(__dev)->links.consumers, s_node, \
+				 device_links_read_lock_held())
+
 /* device pm support */
 void device_pm_move_to_tail(struct device *dev);
 
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -40,10 +40,6 @@
 
 typedef int (*pm_callback_t)(struct device *);
 
-#define list_for_each_entry_srcu_locked(pos, head, member) \
-	list_for_each_entry_srcu(pos, head, member, \
-			device_links_read_lock_held())
-
 /*
  * The entries in the dpm_list list are in a depth first order, simply
  * because children are guaranteed to be discovered after parents, and
@@ -281,7 +277,7 @@
 	 * callbacks freeing the link objects for the links in the list we're
 	 * walking.
 	 */
-	list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node)
+	dev_for_each_link_to_supplier(link, dev)
 		if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 			dpm_wait(link->supplier, async);
 
@@ -338,7 +334,7 @@
 	 * continue instead of trying to continue in parallel with its
 	 * unregistration).
 	 */
-	list_for_each_entry_srcu_locked(link, &dev->links.consumers, s_node)
+	dev_for_each_link_to_consumer(link, dev)
 		if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 			dpm_wait(link->consumer, async);
 
@@ -675,7 +671,7 @@
 	idx = device_links_read_lock();
 
 	/* Start processing the device's "async" consumers. */
-	list_for_each_entry_srcu_locked(link, &dev->links.consumers, s_node)
+	dev_for_each_link_to_consumer(link, dev)
 		if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 			dpm_async_with_cleanup(link->consumer, func);
 
@@ -1330,7 +1326,7 @@
 	idx = device_links_read_lock();
 
 	/* Start processing the device's "async" suppliers. */
-	list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node)
+	dev_for_each_link_to_supplier(link, dev)
 		if (READ_ONCE(link->status) != DL_STATE_DORMANT)
 			dpm_async_with_cleanup(link->supplier, func);
 
@@ -1384,7 +1380,7 @@
 
 	idx = device_links_read_lock();
 
-	list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node)
+	dev_for_each_link_to_supplier(link, dev)
 		link->supplier->power.must_resume = true;
 
 	device_links_read_unlock(idx);
@@ -1813,7 +1809,7 @@
 
 	idx = device_links_read_lock();
 
-	list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node) {
+	dev_for_each_link_to_supplier(link, dev) {
 		spin_lock_irq(&link->supplier->power.lock);
 		link->supplier->power.direct_complete = false;
 		spin_unlock_irq(&link->supplier->power.lock);
@@ -2065,7 +2061,7 @@
 
 	idx = device_links_read_lock();
 
-	list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node) {
+	dev_for_each_link_to_supplier(link, dev) {
 		if (!device_link_test(link, DL_FLAG_PM_RUNTIME))
 			continue;
 
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -1903,8 +1903,7 @@
 
 	idx = device_links_read_lock();
 
-	list_for_each_entry_srcu(link, &dev->links.suppliers, c_node,
-				 device_links_read_lock_held())
+	dev_for_each_link_to_supplier(link, dev)
 		if (device_link_test(link, DL_FLAG_PM_RUNTIME)) {
 			link->supplier_preactivated = true;
 			pm_runtime_get_sync(link->supplier);

On Tue, 2 Sept 2025 at 15:45, Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Add separate macros for walking links to suppliers and consumers of a
> device to help device links users to avoid exposing the internals of
> struct dev_links_info in their code and possible coding mistakes related
> to that.
>
> Accordingly, use the new macros to replace open-coded device links list
> walks in the core power management code.
>
> No intentional functional impact.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

Kind regards
Uffe

> ---
>  drivers/base/base.h          |    8 ++++++++
>  drivers/base/power/main.c    |   18 +++++++-----------
>  drivers/base/power/runtime.c |    3 +--
>  3 files changed, 16 insertions(+), 13 deletions(-)
>
> --- a/drivers/base/base.h
> +++ b/drivers/base/base.h
> @@ -251,6 +251,14 @@
>  void fw_devlink_drivers_done(void);
>  void fw_devlink_probing_done(void);
>
> +#define dev_for_each_link_to_supplier(__link, __dev)   \
> +       list_for_each_entry_srcu(__link, &(__dev)->links.suppliers, c_node, \
> +                                device_links_read_lock_held())
> +
> +#define dev_for_each_link_to_consumer(__link, __dev)   \
> +       list_for_each_entry_srcu(__link, &(__dev)->links.consumers, s_node, \
> +                                device_links_read_lock_held())
> +
>  /* device pm support */
>  void device_pm_move_to_tail(struct device *dev);
>
> --- a/drivers/base/power/main.c
> +++ b/drivers/base/power/main.c
> @@ -40,10 +40,6 @@
>
>  typedef int (*pm_callback_t)(struct device *);
>
> -#define list_for_each_entry_srcu_locked(pos, head, member) \
> -       list_for_each_entry_srcu(pos, head, member, \
> -                       device_links_read_lock_held())
> -
>  /*
>   * The entries in the dpm_list list are in a depth first order, simply
>   * because children are guaranteed to be discovered after parents, and
> @@ -281,7 +277,7 @@
>          * callbacks freeing the link objects for the links in the list we're
>          * walking.
>          */
> -       list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node)
> +       dev_for_each_link_to_supplier(link, dev)
>                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
>                         dpm_wait(link->supplier, async);
>
> @@ -338,7 +334,7 @@
>          * continue instead of trying to continue in parallel with its
>          * unregistration).
>          */
> -       list_for_each_entry_srcu_locked(link, &dev->links.consumers, s_node)
> +       dev_for_each_link_to_consumer(link, dev)
>                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
>                         dpm_wait(link->consumer, async);
>
> @@ -675,7 +671,7 @@
>         idx = device_links_read_lock();
>
>         /* Start processing the device's "async" consumers. */
> -       list_for_each_entry_srcu_locked(link, &dev->links.consumers, s_node)
> +       dev_for_each_link_to_consumer(link, dev)
>                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
>                         dpm_async_with_cleanup(link->consumer, func);
>
> @@ -1330,7 +1326,7 @@
>         idx = device_links_read_lock();
>
>         /* Start processing the device's "async" suppliers. */
> -       list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node)
> +       dev_for_each_link_to_supplier(link, dev)
>                 if (READ_ONCE(link->status) != DL_STATE_DORMANT)
>                         dpm_async_with_cleanup(link->supplier, func);
>
> @@ -1384,7 +1380,7 @@
>
>         idx = device_links_read_lock();
>
> -       list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node)
> +       dev_for_each_link_to_supplier(link, dev)
>                 link->supplier->power.must_resume = true;
>
>         device_links_read_unlock(idx);
> @@ -1813,7 +1809,7 @@
>
>         idx = device_links_read_lock();
>
> -       list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node) {
> +       dev_for_each_link_to_supplier(link, dev) {
>                 spin_lock_irq(&link->supplier->power.lock);
>                 link->supplier->power.direct_complete = false;
>                 spin_unlock_irq(&link->supplier->power.lock);
> @@ -2065,7 +2061,7 @@
>
>         idx = device_links_read_lock();
>
> -       list_for_each_entry_srcu_locked(link, &dev->links.suppliers, c_node) {
> +       dev_for_each_link_to_supplier(link, dev) {
>                 if (!device_link_test(link, DL_FLAG_PM_RUNTIME))
>                         continue;
>
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -1903,8 +1903,7 @@
>
>         idx = device_links_read_lock();
>
> -       list_for_each_entry_srcu(link, &dev->links.suppliers, c_node,
> -                                device_links_read_lock_held())
> +       dev_for_each_link_to_supplier(link, dev)
>                 if (device_link_test(link, DL_FLAG_PM_RUNTIME)) {
>                         link->supplier_preactivated = true;
>                         pm_runtime_get_sync(link->supplier);
>
>
>