Gather futex helpers into lock.h

Based-on-patch-from: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrey Vagin <avagin@openvz.org>

cr-restore.c

@@ -31,6 +31,7 @@
 #include "syscall.h"
 #include "restorer.h"
 #include "sockets.h"
+#include "lock.h"
 
 #include "crtools.h"
 
@@ -1679,7 +1680,7 @@ static void sigreturn_restore(pid_t pstree_pid, pid_t pid)
 		self_vmas_path,
 		sizeof(task_args->self_vmas_path));
 
-	rst_mutex_init(&task_args->rst_lock);
+	cr_mutex_init(&task_args->rst_lock);
 
 	strncpy(task_args->ns_last_pid_path,
 		LAST_PID_PATH,

include/atomic.h

@@ -1,6 +1,8 @@
 #ifndef ATOMIC_H__
 #define ATOMIC_H__
 
+#include "types.h"
+
 #define atomic_set(mem, v)					\
 	({							\
 		asm volatile ("lock xchg %0, %1\n"		\

include/lock.h

@@ -0,0 +1,107 @@
+#ifndef CR_LOCK_H_
+#define CR_LOCK_H_
+
+#include <linux/futex.h>
+#include <sys/time.h>
+#include <limits.h>
+#include <errno.h>
+
+#include "types.h"
+#include "atomic.h"
+#include "syscall.h"
+#include "util.h"
+
+/*
+ * Set futex @v value to @val and wake up all waiters
+ */
+static always_inline void cr_wait_set(u32 *v, u32 val)
+{
+	int ret;
+
+	atomic_set(v, val);
+
+	ret = sys_futex(v, FUTEX_WAKE, INT_MAX, NULL, NULL, 0);
+	BUG_ON(ret < 0);
+}
+
+/*
+ * Decrement futex @v value to @val and wake up all waiters
+ */
+static always_inline void cr_wait_dec(u32 *v)
+{
+	int ret;
+
+	atomic_dec(v);
+
+	ret = sys_futex(v, FUTEX_WAKE, INT_MAX, NULL, NULL, 0);
+	BUG_ON(ret < 0);
+}
+
+/*
+ * Wait until futex @v value become @val
+ */
+static always_inline void cr_wait_until(u32 *v, u32 val)
+{
+	int ret;
+	u32 tmp;
+
+	while (1) {
+		tmp = *v;
+		if (tmp == val)
+			break;
+		ret = sys_futex(v, FUTEX_WAIT, tmp, NULL, NULL, 0);
+		BUG_ON(ret < 0 && ret != -EWOULDBLOCK);
+	}
+}
+
+/*
+ * Wait while futex @v value is @val
+ */
+static always_inline void cr_wait_while(u32 *v, u32 val)
+{
+	int ret;
+
+	while (*v == val) {
+		ret = sys_futex(v, FUTEX_WAIT, val, NULL, NULL, 0);
+		BUG_ON(ret < 0 && ret != -EWOULDBLOCK);
+	}
+}
+
+/*
+ * Init @mutex value
+ */
+static void always_inline cr_mutex_init(u32 *mutex)
+{
+	u32 c = 0;
+	atomic_set(mutex, c);
+}
+
+/*
+ * Lock @mutex
+ */
+static void always_inline cr_mutex_lock(u32 *mutex)
+{
+	u32 c;
+	int ret;
+
+	while ((c = atomic_inc(mutex))) {
+		ret = sys_futex(mutex, FUTEX_WAIT, c + 1, NULL, NULL, 0);
+		BUG_ON(ret < 0 && ret != -EWOULDBLOCK);
+	}
+}
+
+/*
+ * Unlock @mutex
+ */
+static void always_inline cr_mutex_unlock(u32 *mutex)
+{
+	u32 c = 0;
+	int ret;
+
+	atomic_set(mutex, c);
+
+	ret = sys_futex(mutex, FUTEX_WAKE, 1, NULL, NULL, 0);
+	BUG_ON(ret < 0);
+}
+
+#endif /* CR_LOCK_H_ */

include/restorer.h

@@ -7,6 +7,7 @@
 #include "compiler.h"
 #include "types.h"
 #include "image.h"
+#include "lock.h"
 #include "util.h"
 
 #ifndef CONFIG_X86_64
@@ -49,15 +50,13 @@ struct restore_mem_zone {
 #define first_on_heap(ptr, heap)	((typeof(ptr))heap)
 #define next_on_heap(ptr, prev)		((typeof(ptr))((long)(prev) + sizeof(*(prev))))
 
-typedef u32 rst_mutex_t;
-
 /* Make sure it's pow2 in size */
 struct thread_restore_args {
 	struct restore_mem_zone		mem_zone;
 
 	int				pid;
 	int				fd_core;
-	rst_mutex_t			*rst_lock;
+	u32				*rst_lock;
 } __aligned(sizeof(long));
 
 struct task_restore_core_args {
@@ -72,7 +71,7 @@ struct task_restore_core_args {
 	};
 	char				ns_last_pid_path[PATH_MAX];
 	bool				restore_threads;	/* if to restore threads */
-	rst_mutex_t			rst_lock;
+	u32				rst_lock;
 
 	/* threads restoration */
 	int				nr_threads;		/* number of threads */
@@ -288,29 +287,6 @@ static void always_inline write_hex_n(unsigned long num)
 	sys_write(STDERR_FILENO, &c, 1);
 }
 
-#define FUTEX_WAIT		0
-#define FUTEX_WAKE		1
-
-static void always_inline rst_mutex_init(rst_mutex_t *mutex)
-{
-	u32 c = 0;
-	atomic_set(mutex, c);
-}
-
-static void always_inline rst_mutex_lock(rst_mutex_t *mutex)
-{
-	u32 c;
-	while ((c = atomic_inc(mutex)))
-		sys_futex(mutex, FUTEX_WAIT, c + 1, NULL, NULL, 0);
-}
-
-static void always_inline rst_mutex_unlock(rst_mutex_t *mutex)
-{
-	u32 c = 0;
-	atomic_set(mutex, c);
-	sys_futex(mutex, FUTEX_WAKE, 1, NULL, NULL, 0);
-}
-
 /* We need own handler */
 
 #ifdef BUG_ON_HANDLER

restorer.c

@@ -15,6 +15,7 @@
 #include "image.h"
 
 #include "crtools.h"
+#include "lock.h"
 #include "restorer.h"
 
 /*
@@ -95,7 +96,7 @@ long restore_thread(long cmd, struct thread_restore_args *args)
 			goto core_restore_end;
 		}
 
-		rst_mutex_unlock(args->rst_lock);
+		cr_mutex_unlock(args->rst_lock);
 
 		new_sp = (long)rt_sigframe + 8;
 		asm volatile(
@@ -454,7 +455,7 @@ self_len_end:
 				if (thread_args[i].pid == args->pid)
 					continue;
 
-				rst_mutex_lock(&args->rst_lock);
+				cr_mutex_lock(&args->rst_lock);
 
 				new_sp =
 					RESTORE_ALIGN_STACK((long)thread_args[i].mem_zone.stack,