On Mon, Jul 15, 2019 at 10:37:01AM -0400, Joel Fernandes (Google) wrote:
> list_for_each_entry_rcu has built-in RCU and lock checking. Make use of
> it in driver core.
>
> Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
This one looks ready.
Thanx, Paul
> ---
> drivers/base/base.h | 1 +
> drivers/base/core.c | 10 ++++++++++
> drivers/base/power/runtime.c | 15 ++++++++++-----
> 3 files changed, 21 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/base/base.h b/drivers/base/base.h
> index b405436ee28e..0d32544b6f91 100644
> --- a/drivers/base/base.h
> +++ b/drivers/base/base.h
> @@ -165,6 +165,7 @@ static inline int devtmpfs_init(void) { return 0; }
> /* Device links support */
> extern int device_links_read_lock(void);
> extern void device_links_read_unlock(int idx);
> +extern int device_links_read_lock_held(void);
> extern int device_links_check_suppliers(struct device *dev);
> extern void device_links_driver_bound(struct device *dev);
> extern void device_links_driver_cleanup(struct device *dev);
> diff --git a/drivers/base/core.c b/drivers/base/core.c
> index da84a73f2ba6..85e82f38717f 100644
> --- a/drivers/base/core.c
> +++ b/drivers/base/core.c
> @@ -68,6 +68,11 @@ void device_links_read_unlock(int idx)
> {
> srcu_read_unlock(&device_links_srcu, idx);
> }
> +
> +int device_links_read_lock_held(void)
> +{
> + return srcu_read_lock_held(&device_links_srcu);
> +}
> #else /* !CONFIG_SRCU */
> static DECLARE_RWSEM(device_links_lock);
>
> @@ -91,6 +96,11 @@ void device_links_read_unlock(int not_used)
> {
> up_read(&device_links_lock);
> }
> +
> +int device_links_read_lock_held(void)
> +{
> + return lock_is_held(&device_links_lock);
> +}
> #endif /* !CONFIG_SRCU */
>
> /**
> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
> index 952a1e7057c7..7a10e8379a70 100644
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -287,7 +287,8 @@ static int rpm_get_suppliers(struct device *dev)
> {
> struct device_link *link;
>
> - list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
> + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
> + device_links_read_lock_held()) {
> int retval;
>
> if (!(link->flags & DL_FLAG_PM_RUNTIME) ||
> @@ -309,7 +310,8 @@ static void rpm_put_suppliers(struct device *dev)
> {
> struct device_link *link;
>
> - list_for_each_entry_rcu(link, &dev->links.suppliers, c_node) {
> + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
> + device_links_read_lock_held()) {
> if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND)
> continue;
>
> @@ -1640,7 +1642,8 @@ void pm_runtime_clean_up_links(struct device *dev)
>
> idx = device_links_read_lock();
>
> - list_for_each_entry_rcu(link, &dev->links.consumers, s_node) {
> + list_for_each_entry_rcu(link, &dev->links.consumers, s_node,
> + device_links_read_lock_held()) {
> if (link->flags & DL_FLAG_STATELESS)
> continue;
>
> @@ -1662,7 +1665,8 @@ void pm_runtime_get_suppliers(struct device *dev)
>
> idx = device_links_read_lock();
>
> - list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
> + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
> + device_links_read_lock_held())
> if (link->flags & DL_FLAG_PM_RUNTIME) {
> link->supplier_preactivated = true;
> refcount_inc(&link->rpm_active);
> @@ -1683,7 +1687,8 @@ void pm_runtime_put_suppliers(struct device *dev)
>
> idx = device_links_read_lock();
>
> - list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
> + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,
> + device_links_read_lock_held())
> if (link->supplier_preactivated) {
> link->supplier_preactivated = false;
> if (refcount_dec_not_one(&link->rpm_active))
> --
> 2.22.0.510.g264f2c817a-goog
>
