patch-2.4.20 linux-2.4.20/include/asm-x86_64/smplock.h

• Lines: 75
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/include/asm-x86_64/smplock.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/include/asm-x86_64/smplock.h linux-2.4.20/include/asm-x86_64/smplock.h
@@ -0,0 +1,74 @@
+/*
+ * <asm/smplock.h>
+ */
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <asm/current.h>
+
+extern spinlock_cacheline_t kernel_flag_cacheline;  
+#define kernel_flag kernel_flag_cacheline.lock      
+
+#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 1
+	if (!++current->lock_depth)
+		spin_lock(&kernel_flag);
+#else
+	__asm__ __volatile__(
+		"incl %1\n\t"
+		"jne 9f"
+		spin_lock_string
+		"\n9:"
+		:"=m" (__dummy_lock(&kernel_flag)),
+		 "=m" (current->lock_depth));
+#endif
+}
+
+extern __inline__ void unlock_kernel(void)
+{
+	if (current->lock_depth < 0)
+		out_of_line_bug();
+#if 1
+	if (--current->lock_depth < 0)
+		spin_unlock(&kernel_flag);
+#else
+	__asm__ __volatile__(
+		"decl %1\n\t"
+		"jns 9f\n\t"
+		spin_unlock_string
+		"\n9:"
+		:"=m" (__dummy_lock(&kernel_flag)),
+		 "=m" (current->lock_depth));
+#endif
+}