patch-2.4.19 linux-2.4.19/include/asm-ppc64/smplock.h

• Lines: 57
• Date: Fri Aug 2 17:39:45 2002
• Orig file: linux-2.4.18/include/asm-ppc64/smplock.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.18/include/asm-ppc64/smplock.h linux-2.4.19/include/asm-ppc64/smplock.h
@@ -0,0 +1,56 @@
+/*
+ * <asm/smplock.h>
+ *
+ * Default SMP lock implementation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+
+extern spinlock_t kernel_flag;
+
+#define kernel_locked()		spin_is_locked(&kernel_flag)
+
+/*
+ * Release global kernel lock and global interrupt lock
+ */
+#define release_kernel_lock(task, cpu) \
+do { \
+	if (task->lock_depth >= 0) \
+		spin_unlock(&kernel_flag); \
+	release_irqlock(cpu); \
+	__sti(); \
+} while (0)
+
+/*
+ * Re-acquire the kernel lock
+ */
+#define reacquire_kernel_lock(task) \
+do { \
+	if (task->lock_depth >= 0) \
+		spin_lock(&kernel_flag); \
+} while (0)
+
+
+/*
+ * Getting the big kernel lock.
+ *
+ * This cannot happen asynchronously,
+ * so we only need to worry about other
+ * CPU's.
+ */
+extern __inline__ void lock_kernel(void)
+{
+	if (!++current->lock_depth)
+		spin_lock(&kernel_flag);
+}
+
+extern __inline__ void unlock_kernel(void)
+{
+	if (--current->lock_depth < 0)
+		spin_unlock(&kernel_flag);
+}