init android origin source code

1 files changed, 35 insertions, 0 deletions

diff --git a/ANDROID_3.4.5/arch/x86/vdso/vgetcpu.c b/ANDROID_3.4.5/arch/x86/vdso/vgetcpu.c
new file mode 100644
index 00000000..5463ad55
--- /dev/null
+++ b/ANDROID_3.4.5/arch/x86/vdso/vgetcpu.c
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2006 Andi Kleen, SUSE Labs.
+ * Subject to the GNU Public License, v.2
+ *
+ * Fast user context implementation of getcpu()
+ */
+
+#include <linux/kernel.h>
+#include <linux/getcpu.h>
+#include <linux/jiffies.h>
+#include <linux/time.h>
+#include <asm/vsyscall.h>
+#include <asm/vgtod.h>
+
+notrace long
+__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
+{
+	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));
+	}
+	if (cpu)
+		*cpu = p & 0xfff;
+	if (node)
+		*node = p >> 12;
+	return 0;
+}
+
+long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
+	__attribute__((weak, alias("__vdso_getcpu")));