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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 06:16:15 +0000
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2012-02-19 06:16:15 +0000
commit34e3b522eca7e8741cecb7c2241091f181d1bd1f (patch)
tree3b64ac3aa4603539b8f8f384bc39998e29948900 /libdde_linux26/contrib/include/linux/smp_lock.h
parentd4e6a14eb3fad1b43a21214db139db441025baf5 (diff)
parent6fafeb146e9efd59140ea58cebd7dd38ae9a6379 (diff)
Merge branch 'upstream-merged'
Diffstat (limited to 'libdde_linux26/contrib/include/linux/smp_lock.h')
-rw-r--r--libdde_linux26/contrib/include/linux/smp_lock.h52
1 files changed, 52 insertions, 0 deletions
diff --git a/libdde_linux26/contrib/include/linux/smp_lock.h b/libdde_linux26/contrib/include/linux/smp_lock.h
new file mode 100644
index 00000000..813be59b
--- /dev/null
+++ b/libdde_linux26/contrib/include/linux/smp_lock.h
@@ -0,0 +1,52 @@
+#ifndef __LINUX_SMPLOCK_H
+#define __LINUX_SMPLOCK_H
+
+#ifdef CONFIG_LOCK_KERNEL
+#include <linux/sched.h>
+
+#define kernel_locked() (current->lock_depth >= 0)
+
+extern int __lockfunc __reacquire_kernel_lock(void);
+extern void __lockfunc __release_kernel_lock(void);
+
+/*
+ * Release/re-acquire global kernel lock for the scheduler
+ */
+#define release_kernel_lock(tsk) do { \
+ if (unlikely((tsk)->lock_depth >= 0)) \
+ __release_kernel_lock(); \
+} while (0)
+
+static inline int reacquire_kernel_lock(struct task_struct *task)
+{
+ if (unlikely(task->lock_depth >= 0))
+ return __reacquire_kernel_lock();
+ return 0;
+}
+
+extern void __lockfunc lock_kernel(void) __acquires(kernel_lock);
+extern void __lockfunc unlock_kernel(void) __releases(kernel_lock);
+
+/*
+ * Various legacy drivers don't really need the BKL in a specific
+ * function, but they *do* need to know that the BKL became available.
+ * This function just avoids wrapping a bunch of lock/unlock pairs
+ * around code which doesn't really need it.
+ */
+static inline void cycle_kernel_lock(void)
+{
+ lock_kernel();
+ unlock_kernel();
+}
+
+#else
+
+#define lock_kernel() do { } while(0)
+#define unlock_kernel() do { } while(0)
+#define release_kernel_lock(task) do { } while(0)
+#define cycle_kernel_lock() do { } while(0)
+#define reacquire_kernel_lock(task) 0
+#define kernel_locked() 1
+
+#endif /* CONFIG_LOCK_KERNEL */
+#endif /* __LINUX_SMPLOCK_H */