edac,rcu: use synchronize_rcu() instead of call_rcu()+rcu_barrier()

synchronize_rcu() does the stuff as needed.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 18 insertions, 55 deletions

diff --git a/drivers/edac/edac_core.h b/drivers/edac/edac_core.h
index eefa3501916b..55b8278bb172 100644
--- a/drivers/edac/edac_core.h
+++ b/drivers/edac/edac_core.h
@@ -421,10 +421,6 @@ struct mem_ctl_info {
         u32 ce_count;           /* Total Correctable Errors for this MC */
         unsigned long start_time;       /* mci load start time (in jiffies) */
 
-        /* this stuff is for safe removal of mc devices from global list while
-         * NMI handlers may be traversing list
-         */
-        struct rcu_head rcu;
         struct completion complete;
 
         /* edac sysfs device control */
@@ -620,10 +616,6 @@ struct edac_device_ctl_info {
 
         unsigned long start_time;       /* edac_device load start time (jiffies) */
 
-        /* these are for safe removal of mc devices from global list while
-         * NMI handlers may be traversing list
-         */
-        struct rcu_head rcu;
         struct completion removal_complete;
 
         /* sysfs top name under 'edac' directory
@@ -722,10 +714,6 @@ struct edac_pci_ctl_info {
 
         unsigned long start_time;       /* edac_pci load start time (jiffies) */
 
-        /* these are for safe removal of devices from global list while
-         * NMI handlers may be traversing list
-         */
-        struct rcu_head rcu;
         struct completion complete;
 
         /* sysfs top name under 'edac' directory
diff --git a/drivers/edac/edac_device.c b/drivers/edac/edac_device.c
index a7408cf86f37..c3f67437afb6 100644
--- a/drivers/edac/edac_device.c
+++ b/drivers/edac/edac_device.c
@@ -346,30 +346,18 @@ fail1:
 }
 
 /*
- * complete_edac_device_list_del
- *
- *      callback function when reference count is zero
- */
-static void complete_edac_device_list_del(struct rcu_head *head)
-{
-        struct edac_device_ctl_info *edac_dev;
-
-        edac_dev = container_of(head, struct edac_device_ctl_info, rcu);
-        INIT_LIST_HEAD(&edac_dev->link);
-}
-
-/*
  * del_edac_device_from_global_list
- *
- *      remove the RCU, setup for a callback call,
- *      then wait for the callback to occur
  */
 static void del_edac_device_from_global_list(struct edac_device_ctl_info
                                                 *edac_device)
 {
         list_del_rcu(&edac_device->link);
-        call_rcu(&edac_device->rcu, complete_edac_device_list_del);
-        rcu_barrier();
+
+        /* these are for safe removal of devices from global list while
+         * NMI handlers may be traversing list
+         */
+        synchronize_rcu();
+        INIT_LIST_HEAD(&edac_device->link);
 }
 
 /*
diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index 1d8056049072..d69144a09043 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -447,20 +447,16 @@ fail1:
         return 1;
 }
 
-static void complete_mc_list_del(struct rcu_head *head)
-{
-        struct mem_ctl_info *mci;
-
-        mci = container_of(head, struct mem_ctl_info, rcu);
-        INIT_LIST_HEAD(&mci->link);
-}
-
 static void del_mc_from_global_list(struct mem_ctl_info *mci)
 {
         atomic_dec(&edac_handlers);
         list_del_rcu(&mci->link);
-        call_rcu(&mci->rcu, complete_mc_list_del);
-        rcu_barrier();
+
+        /* these are for safe removal of devices from global list while
+         * NMI handlers may be traversing list
+         */
+        synchronize_rcu();
+        INIT_LIST_HEAD(&mci->link);
 }
 
 /**
diff --git a/drivers/edac/edac_pci.c b/drivers/edac/edac_pci.c
index efb5d5650783..2b378207d571 100644
--- a/drivers/edac/edac_pci.c
+++ b/drivers/edac/edac_pci.c
@@ -164,19 +164,6 @@ fail1:
 }
 
 /*
- * complete_edac_pci_list_del
- *
- *      RCU completion callback to indicate item is deleted
- */
-static void complete_edac_pci_list_del(struct rcu_head *head)
-{
-        struct edac_pci_ctl_info *pci;
-
-        pci = container_of(head, struct edac_pci_ctl_info, rcu);
-        INIT_LIST_HEAD(&pci->link);
-}
-
-/*
  * del_edac_pci_from_global_list
  *
  *      remove the PCI control struct from the global list
@@ -184,8 +171,12 @@ static void complete_edac_pci_list_del(struct rcu_head *head)
 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
 {
         list_del_rcu(&pci->link);
-        call_rcu(&pci->rcu, complete_edac_pci_list_del);
-        rcu_barrier();
+
+        /* these are for safe removal of devices from global list while
+         * NMI handlers may be traversing list
+         */
+        synchronize_rcu();
+        INIT_LIST_HEAD(&pci->link);
 }
 
 #if 0