Merge branch 'linus' into core/printk

[sfrench/cifs-2.6.git] / include / linux / kernel.h

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 343df9ef2412393020e90c1ef5227135b3b5a07f..2755165bb291d0783a34fc88396a602af6157461 100644 (file)
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -242,6 +242,19 @@ extern struct ratelimit_state printk_ratelimit_state;
 extern int printk_ratelimit(void);
 extern bool printk_timed_ratelimit(unsigned long *caller_jiffies,
                                   unsigned int interval_msec);
+
+/*
+ * Print a one-time message (analogous to WARN_ONCE() et al):
+ */
+#define printk_once(x...) ({                   \
+       static int __print_once = 1;            \
+                                               \
+       if (__print_once) {                     \
+               __print_once = 0;               \
+               printk(x);                      \
+       }                                       \
+})
+
 #else
 static inline int vprintk(const char *s, va_list args)
        __attribute__ ((format (printf, 1, 0)));
@@ -253,6 +266,10 @@ static inline int printk_ratelimit(void) { return 0; }
 static inline bool printk_timed_ratelimit(unsigned long *caller_jiffies, \
                                          unsigned int interval_msec)   \
                { return false; }
+
+/* No effect, but we still get type checking even in the !PRINTK case: */
+#define printk_once(x...) printk(x)
+
 #endif
 
 extern int printk_needs_cpu(int cpu);
@@ -480,7 +497,8 @@ static inline char *pack_hex_byte(char *buf, u8 byte)
 /*
  * swap - swap value of @a and @b
  */
-#define swap(a, b) ({ typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; })
+#define swap(a, b) \
+       do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0)
 
 /**
  * container_of - cast a member of a structure out to the containing structure