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Diffstat (limited to 'arch/x86/entry/vdso/vgetcpu.c')
-rw-r--r--arch/x86/entry/vdso/vgetcpu.c28
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/x86/entry/vdso/vgetcpu.c b/arch/x86/entry/vdso/vgetcpu.c
new file mode 100644
index 000000000000..8ec3d1f4ce9a
--- /dev/null
+++ b/arch/x86/entry/vdso/vgetcpu.c
@@ -0,0 +1,28 @@
+/*
+ * 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/time.h>
+#include <asm/vgtod.h>
+
+notrace long
+__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
+{
+ unsigned int p;
+
+ p = __getcpu();
+
+ if (cpu)
+ *cpu = p & VGETCPU_CPU_MASK;
+ if (node)
+ *node = p >> 12;
+ return 0;
+}
+
+long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
+ __attribute__((weak, alias("__vdso_getcpu")));