1 files changed, 44 insertions, 0 deletions
diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h
new file mode 100644
index 00000000000..2a46ca720af
--- /dev/null
+++ b/arch/x86/include/asm/vsyscall.h
@@ -0,0 +1,44 @@
+#ifndef _ASM_X86_VSYSCALL_H
+#define _ASM_X86_VSYSCALL_H
+
+#include <linux/seqlock.h>
+#include <uapi/asm/vsyscall.h>
+
+#define VGETCPU_RDTSCP	1
+#define VGETCPU_LSL	2
+
+/* kernel space (writeable) */
+extern int vgetcpu_mode;
+extern struct timezone sys_tz;
+
+#include <asm/vvar.h>
+
+extern void map_vsyscall(void);
+
+/*
+ * Called on instruction fetch fault in vsyscall page.
+ * Returns true if handled.
+ */
+extern bool emulate_vsyscall(struct pt_regs *regs, unsigned long address);
+
+#ifdef CONFIG_X86_64
+
+#define VGETCPU_CPU_MASK 0xfff
+
+static inline unsigned int __getcpu(void)
+{
+	unsigned int p;
+
+	if (VVAR(vgetcpu_mode) == VGETCPU_RDTSCP) {
+		/* Load per CPU data from RDTSCP */
+		native_read_tscp(&p);
+	} else {
+		/* Load per CPU data from GDT */
+		asm("lsl %1,%0" : "=r" (p) : "r" (__PER_CPU_SEG));
+	}
+
+	return p;
+}
+#endif /* CONFIG_X86_64 */
+
+#endif /* _ASM_X86_VSYSCALL_H */