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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/include/linux/rwsem-spinlock.h
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/include/linux/rwsem-spinlock.h')
-rw-r--r--kernel/include/linux/rwsem-spinlock.h45
1 files changed, 45 insertions, 0 deletions
diff --git a/kernel/include/linux/rwsem-spinlock.h b/kernel/include/linux/rwsem-spinlock.h
new file mode 100644
index 000000000..561e86155
--- /dev/null
+++ b/kernel/include/linux/rwsem-spinlock.h
@@ -0,0 +1,45 @@
+/* rwsem-spinlock.h: fallback C implementation
+ *
+ * Copyright (c) 2001 David Howells (dhowells@redhat.com).
+ * - Derived partially from ideas by Andrea Arcangeli <andrea@suse.de>
+ * - Derived also from comments by Linus
+ */
+
+#ifndef _LINUX_RWSEM_SPINLOCK_H
+#define _LINUX_RWSEM_SPINLOCK_H
+
+#ifndef _LINUX_RWSEM_H
+#error "please don't include linux/rwsem-spinlock.h directly, use linux/rwsem.h instead"
+#endif
+
+#ifdef __KERNEL__
+/*
+ * the rw-semaphore definition
+ * - if count is 0 then there are no active readers or writers
+ * - if count is +ve then that is the number of active readers
+ * - if count is -1 then there is one active writer
+ * - if wait_list is not empty, then there are processes waiting for the semaphore
+ */
+struct rw_semaphore {
+ __s32 count;
+ raw_spinlock_t wait_lock;
+ struct list_head wait_list;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+};
+
+#define RWSEM_UNLOCKED_VALUE 0x00000000
+
+extern void __down_read(struct rw_semaphore *sem);
+extern int __down_read_trylock(struct rw_semaphore *sem);
+extern void __down_write(struct rw_semaphore *sem);
+extern void __down_write_nested(struct rw_semaphore *sem, int subclass);
+extern int __down_write_trylock(struct rw_semaphore *sem);
+extern void __up_read(struct rw_semaphore *sem);
+extern void __up_write(struct rw_semaphore *sem);
+extern void __downgrade_write(struct rw_semaphore *sem);
+extern int rwsem_is_locked(struct rw_semaphore *sem);
+
+#endif /* __KERNEL__ */
+#endif /* _LINUX_RWSEM_SPINLOCK_H */