[Skiboot] [PATCH v4 1/8] opal: Update opal_del_host_sync_notifier() to accept 'void *data'

[Vaibhav Jain]

Current implementation of opal_del_host_sync_notifier() will only
delete the first entry of the 'notify' callback found from opal_syncers
list irrespective of the 'data' of list-node. This is problematic when
multiple notifiers with same callback function but different 'data'
are registered. In this case when the cleanup code will call
opal_del_host_sync_notifier() it cannot be sure if correct opal_syncer
is removed.

Hence this patch updates the function to accept a new argument named
'void *data' which is then used to iterates over the opal_syncers list
and only remove the first node node having the matching value for
'notify' callback as 'data'.

Reviewed-by: Frederic Barrat <fbarrat at linux.ibm.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
Reviewed-by: Christophe Lombard <clombard at linux.vnet.ibm.com>
Reviewed-by: Vasant Hegde <hegdevasant at linux.vnet.ibm.com>
Signed-off-by: Vaibhav Jain <vaibhav at linux.ibm.com>
---
Change-log

v4:
* None. Re-spinning the patchset.

v3:
* None. Re-spinning the patchset.

v2:
* Instead of introducing a new function, update the existing function
  opal_del_host_sync_notifier() to accept 'void *data' [Vasant]
---
 core/opal.c             | 7 +++++--
 include/opal-internal.h | 2 +-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/core/opal.c b/core/opal.c
index 46035e83..78869b52 100644
--- a/core/opal.c
+++ b/core/opal.c
@@ -685,12 +685,15 @@ void opal_add_host_sync_notifier(bool (*notify)(void *data), void *data)
 	list_add_tail(&opal_syncers, &ent->link);
 }
 
-void opal_del_host_sync_notifier(bool (*notify)(void *data))
+/*
+ * Remove a host sync notifier for given callback and data
+ */
+void opal_del_host_sync_notifier(bool (*notify)(void *data), void *data)
 {
 	struct opal_sync_entry *ent;
 
 	list_for_each(&opal_syncers, ent, link) {
-		if (ent->notify == notify) {
+		if (ent->notify == notify && ent->data == data) {
 			list_del(&ent->link);
 			free(ent);
 			return;
diff --git a/include/opal-internal.h b/include/opal-internal.h
index 40bad457..2ce25adb 100644
--- a/include/opal-internal.h
+++ b/include/opal-internal.h
@@ -76,7 +76,7 @@ extern void opal_run_pollers(void);
  * Warning: no locking, only call that from the init processor
  */
 extern void opal_add_host_sync_notifier(bool (*notify)(void *data), void *data);
-extern void opal_del_host_sync_notifier(bool (*notify)(void *data));
+extern void opal_del_host_sync_notifier(bool (*notify)(void *data), void *data);
 
 /*
  * Opal internal function prototype
-- 
2.20.1