[PATCH -mm -v2 2/5] llist, Define macro to check NMI safe cmpxchg

Huang Ying
2011-09-08T06:01:04Z

To make code cleaner and reduce code duplication. Thanks Peter
Zijlstra for reminding.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
---
include/linux/llist.h | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)

--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -70,6 +70,12 @@ struct llist_node {
#define LLIST_HEAD_INIT(name) { NULL }
#define LLIST_HEAD(name) struct llist_head name = LLIST_HEAD_INIT(name)

+#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
+#define CHECK_NMI_SAFE_CMPXCHG()
+#else
+#define CHECK_NMI_SAFE_CMPXCHG() BUG_ON(in_nmi())
+#endif
+
/**
* init_llist_head - initialize lock-less list head
* @head: the head for your lock-less list
@@ -147,9 +153,7 @@ static inline void llist_add(struct llis
{
struct llist_node *entry, *old_entry;

-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
- BUG_ON(in_nmi());
-#endif
+ CHECK_NMI_SAFE_CMPXCHG();

entry = head->first;
do {
@@ -171,9 +175,7 @@ static inline void llist_add_batch(struc
{
struct llist_node *entry, *old_entry;

-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
- BUG_ON(in_nmi());
-#endif
+ CHECK_NMI_SAFE_CMPXCHG();

entry = head->first;
do {
@@ -201,9 +203,7 @@ static inline struct llist_node *llist_d
{
struct llist_node *entry, *old_entry, *next;

-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
- BUG_ON(in_nmi());
-#endif
+ CHECK_NMI_SAFE_CMPXCHG();

entry = head->first;
do {
@@ -227,9 +227,7 @@ static inline struct llist_node *llist_d
*/
static inline struct llist_node *llist_del_all(struct llist_head *head)
{
-#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG
- BUG_ON(in_nmi());
-#endif
+ CHECK_NMI_SAFE_CMPXCHG();

return xchg(&head->first, NULL);
}