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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/spinlock_up.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/spinlock_up.h')
-rw-r--r--kernel/include/linux/spinlock_up.h85
1 files changed, 85 insertions, 0 deletions
diff --git a/kernel/include/linux/spinlock_up.h b/kernel/include/linux/spinlock_up.h
new file mode 100644
index 000000000..8b3ac0d71
--- /dev/null
+++ b/kernel/include/linux/spinlock_up.h
@@ -0,0 +1,85 @@
+#ifndef __LINUX_SPINLOCK_UP_H
+#define __LINUX_SPINLOCK_UP_H
+
+#ifndef __LINUX_SPINLOCK_H
+# error "please don't include this file directly"
+#endif
+
+#include <asm/processor.h> /* for cpu_relax() */
+
+/*
+ * include/linux/spinlock_up.h - UP-debug version of spinlocks.
+ *
+ * portions Copyright 2005, Red Hat, Inc., Ingo Molnar
+ * Released under the General Public License (GPL).
+ *
+ * In the debug case, 1 means unlocked, 0 means locked. (the values
+ * are inverted, to catch initialization bugs)
+ *
+ * No atomicity anywhere, we are on UP. However, we still need
+ * the compiler barriers, because we do not want the compiler to
+ * move potentially faulting instructions (notably user accesses)
+ * into the locked sequence, resulting in non-atomic execution.
+ */
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+#define arch_spin_is_locked(x) ((x)->slock == 0)
+
+static inline void arch_spin_lock(arch_spinlock_t *lock)
+{
+ lock->slock = 0;
+ barrier();
+}
+
+static inline void
+arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)
+{
+ local_irq_save(flags);
+ lock->slock = 0;
+ barrier();
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t *lock)
+{
+ char oldval = lock->slock;
+
+ lock->slock = 0;
+ barrier();
+
+ return oldval > 0;
+}
+
+static inline void arch_spin_unlock(arch_spinlock_t *lock)
+{
+ barrier();
+ lock->slock = 1;
+}
+
+/*
+ * Read-write spinlocks. No debug version.
+ */
+#define arch_read_lock(lock) do { barrier(); (void)(lock); } while (0)
+#define arch_write_lock(lock) do { barrier(); (void)(lock); } while (0)
+#define arch_read_trylock(lock) ({ barrier(); (void)(lock); 1; })
+#define arch_write_trylock(lock) ({ barrier(); (void)(lock); 1; })
+#define arch_read_unlock(lock) do { barrier(); (void)(lock); } while (0)
+#define arch_write_unlock(lock) do { barrier(); (void)(lock); } while (0)
+
+#else /* DEBUG_SPINLOCK */
+#define arch_spin_is_locked(lock) ((void)(lock), 0)
+/* for sched/core.c and kernel_lock.c: */
+# define arch_spin_lock(lock) do { barrier(); (void)(lock); } while (0)
+# define arch_spin_lock_flags(lock, flags) do { barrier(); (void)(lock); } while (0)
+# define arch_spin_unlock(lock) do { barrier(); (void)(lock); } while (0)
+# define arch_spin_trylock(lock) ({ barrier(); (void)(lock); 1; })
+#endif /* DEBUG_SPINLOCK */
+
+#define arch_spin_is_contended(lock) (((void)(lock), 0))
+
+#define arch_read_can_lock(lock) (((void)(lock), 1))
+#define arch_write_can_lock(lock) (((void)(lock), 1))
+
+#define arch_spin_unlock_wait(lock) \
+ do { cpu_relax(); } while (arch_spin_is_locked(lock))
+
+#endif /* __LINUX_SPINLOCK_UP_H */