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Revert "drivers: base: Fix device link removal"

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This reverts commit d007150b4e which is
commit 80dd33cf72d1ab4f0af303f1fa242c6d6c8d328f upstream.

It breaks the abi and will be brought back at the proper time that we
can.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I5b49602baf86e11e10eecb1c300ea8634826dbd2
This commit is contained in:
Greg Kroah-Hartman
2021-06-03 13:36:10 +02:00
parent c5d480cd47
commit 28e408cd4c
2 changed files with 18 additions and 25 deletions
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37
drivers/base/core.c
View File

@@ -191,11 +191,6 @@ int device_links_read_lock_held(void)
{ {
return srcu_read_lock_held(&device_links_srcu); return srcu_read_lock_held(&device_links_srcu);
} }
static void device_link_synchronize_removal(void)
{
synchronize_srcu(&device_links_srcu);
}
#else /* !CONFIG_SRCU */ #else /* !CONFIG_SRCU */
static DECLARE_RWSEM(device_links_lock); static DECLARE_RWSEM(device_links_lock);
@@ -226,10 +221,6 @@ int device_links_read_lock_held(void)
return lockdep_is_held(&device_links_lock); return lockdep_is_held(&device_links_lock);
} }
#endif #endif
static inline void device_link_synchronize_removal(void)
{
}
#endif /* !CONFIG_SRCU */ #endif /* !CONFIG_SRCU */
static bool device_is_ancestor(struct device *dev, struct device *target) static bool device_is_ancestor(struct device *dev, struct device *target)
@@ -451,13 +442,8 @@ static struct attribute *devlink_attrs[] = {
}; };
ATTRIBUTE_GROUPS(devlink); ATTRIBUTE_GROUPS(devlink);
static void device_link_release_fn(struct work_struct *work) static void device_link_free(struct device_link *link)
{ {
struct device_link *link = container_of(work, struct device_link, rm_work);
/* Ensure that all references to the link object have been dropped. */
device_link_synchronize_removal();
while (refcount_dec_not_one(&link->rpm_active)) while (refcount_dec_not_one(&link->rpm_active))
pm_runtime_put(link->supplier); pm_runtime_put(link->supplier);
@@ -466,19 +452,24 @@ static void device_link_release_fn(struct work_struct *work)
kfree(link); kfree(link);
} }
#ifdef CONFIG_SRCU
static void __device_link_free_srcu(struct rcu_head *rhead)
{
device_link_free(container_of(rhead, struct device_link, rcu_head));
}
static void devlink_dev_release(struct device *dev) static void devlink_dev_release(struct device *dev)
{ {
struct device_link *link = to_devlink(dev); struct device_link *link = to_devlink(dev);
INIT_WORK(&link->rm_work, device_link_release_fn); call_srcu(&device_links_srcu, &link->rcu_head, __device_link_free_srcu);
/*
* It may take a while to complete this work because of the SRCU
* synchronization in device_link_release_fn() and if the consumer or
* supplier devices get deleted when it runs, so put it into the "long"
* workqueue.
*/
queue_work(system_long_wq, &link->rm_work);
} }
#else
static void devlink_dev_release(struct device *dev)
{
device_link_free(to_devlink(dev));
}
#endif
static struct class devlink_class = { static struct class devlink_class = {
.name = "devlink", .name = "devlink",

6
include/linux/device.h
View File

@@ -566,7 +566,7 @@ struct device {
* @flags: Link flags. * @flags: Link flags.
* @rpm_active: Whether or not the consumer device is runtime-PM-active. * @rpm_active: Whether or not the consumer device is runtime-PM-active.
* @kref: Count repeated addition of the same link. * @kref: Count repeated addition of the same link.
* @rm_work: Work structure used for removing the link. * @rcu_head: An RCU head to use for deferred execution of SRCU callbacks.
* @supplier_preactivated: Supplier has been made active before consumer probe. * @supplier_preactivated: Supplier has been made active before consumer probe.
*/ */
struct device_link { struct device_link {
@@ -579,7 +579,9 @@ struct device_link {
u32 flags; u32 flags;
refcount_t rpm_active; refcount_t rpm_active;
struct kref kref; struct kref kref;
struct work_struct rm_work; #ifdef CONFIG_SRCU
struct rcu_head rcu_head;
#endif
bool supplier_preactivated; /* Owned by consumer probe. */ bool supplier_preactivated; /* Owned by consumer probe. */
ANDROID_KABI_RESERVE(1); ANDROID_KABI_RESERVE(1);
ANDROID_KABI_RESERVE(2); ANDROID_KABI_RESERVE(2);