patch-2.1.114 linux/include/asm-alpha/smplock.h

• Lines: 50
• Date: Mon Aug 3 12:28:20 1998
• Orig file: v2.1.113/linux/include/asm-alpha/smplock.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.113/linux/include/asm-alpha/smplock.h linux/include/asm-alpha/smplock.h
@@ -0,0 +1,49 @@
+/*
+ * <asm/smplock.h>
+ *
+ * Default SMP lock implementation
+ */
+#include <linux/interrupt.h>
+#include <asm/spinlock.h>
+
+extern spinlock_t 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);
+}