pid_namespace.c/.h: simplify defines

Move BITS_PER_PAGE from pid_namespace.c to pid_namespace.h, since we can
simplify the define PID_MAP_ENTRIES by using the BITS_PER_PAGE.

[akpm@linux-foundation.org: kernel/pid.c:54:1: warning: "BITS_PER_PAGE" redefined]
Signed-off-by: Raphael S.Carvalho <raphael.scarv@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/pid_namespace.h

@@ -13,7 +13,9 @@ struct pidmap {
        void *page;
 };
 
-#define PIDMAP_ENTRIES         ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)
+#define BITS_PER_PAGE		(PAGE_SIZE * 8)
+#define BITS_PER_PAGE_MASK	(BITS_PER_PAGE-1)
+#define PIDMAP_ENTRIES		((PID_MAX_LIMIT+BITS_PER_PAGE-1)/BITS_PER_PAGE)
 
 struct bsd_acct_struct;
 

kernel/pid.c

@@ -51,9 +51,6 @@ int pid_max = PID_MAX_DEFAULT;
 int pid_max_min = RESERVED_PIDS + 1;
 int pid_max_max = PID_MAX_LIMIT;
 
-#define BITS_PER_PAGE		(PAGE_SIZE*8)
-#define BITS_PER_PAGE_MASK	(BITS_PER_PAGE-1)
-
 static inline int mk_pid(struct pid_namespace *pid_ns,
 		struct pidmap *map, int off)
 {

kernel/pid_namespace.c

@@ -19,8 +19,6 @@
 #include <linux/reboot.h>
 #include <linux/export.h>
 
-#define BITS_PER_PAGE		(PAGE_SIZE*8)
-
 struct pid_cache {
 	int nr_ids;
 	char name[16];