From a4a806bef7e0829e71dd24a249afacb96cb0cd29 Mon Sep 17 00:00:00 2001
From: NAKAMURA Gou <go.nakamura.yw@hitachi-solutions.com>
Date: Tue, 10 Feb 2015 15:59:23 +0900
Subject: [PATCH] support vsyscall_getcpu() vsyscall.  refs #385

This version simply calls getcpu() system call, so that it's not fast.
---
 arch/x86/kernel/vsyscall.c     | 14 ++++++++++++++
 kernel/config/attached-mic.lds |  3 +++
 kernel/config/builtin-mic.lds  |  3 +++
 kernel/config/builtin-x86.lds  |  3 +++
 kernel/config/smp-x86.lds      |  3 +++
 5 files changed, 26 insertions(+)

diff --git a/arch/x86/kernel/vsyscall.c b/arch/x86/kernel/vsyscall.c
index c192e97e..98153be4 100644
--- a/arch/x86/kernel/vsyscall.c
+++ b/arch/x86/kernel/vsyscall.c
@@ -58,3 +58,17 @@ long vsyscall_time(void *tp)
 
 	return t;
 }
+
+extern int vsyscall_getcpu(unsigned *cpup, unsigned *nodep, void *tcachep)
+	__attribute__ ((section (".vsyscall.getcpu")));
+
+int vsyscall_getcpu(unsigned *cpup, unsigned *nodep, void *tcachep)
+{
+	int error;
+
+	asm ("syscall" : "=a" (error)
+			: "a" (__NR_getcpu), "D" (cpup), "S" (nodep), "d" (tcachep)
+			: "%rcx", "%r11", "memory");
+
+	return error;
+}
diff --git a/kernel/config/attached-mic.lds b/kernel/config/attached-mic.lds
index ed3f0623..3390a869 100644
--- a/kernel/config/attached-mic.lds
+++ b/kernel/config/attached-mic.lds
@@ -30,6 +30,9 @@ SECTIONS
 		. = vsyscall_page + 0x400;
 		*(.vsyscall.time)
 
+		. = vsyscall_page + 0x800;
+		*(.vsyscall.getcpu)
+
 		. = ALIGN(4096);
 	} : data = 0xf4
 
diff --git a/kernel/config/builtin-mic.lds b/kernel/config/builtin-mic.lds
index ed3f0623..3390a869 100644
--- a/kernel/config/builtin-mic.lds
+++ b/kernel/config/builtin-mic.lds
@@ -30,6 +30,9 @@ SECTIONS
 		. = vsyscall_page + 0x400;
 		*(.vsyscall.time)
 
+		. = vsyscall_page + 0x800;
+		*(.vsyscall.getcpu)
+
 		. = ALIGN(4096);
 	} : data = 0xf4
 
diff --git a/kernel/config/builtin-x86.lds b/kernel/config/builtin-x86.lds
index ed3f0623..3390a869 100644
--- a/kernel/config/builtin-x86.lds
+++ b/kernel/config/builtin-x86.lds
@@ -30,6 +30,9 @@ SECTIONS
 		. = vsyscall_page + 0x400;
 		*(.vsyscall.time)
 
+		. = vsyscall_page + 0x800;
+		*(.vsyscall.getcpu)
+
 		. = ALIGN(4096);
 	} : data = 0xf4
 
diff --git a/kernel/config/smp-x86.lds b/kernel/config/smp-x86.lds
index ed3f0623..3390a869 100644
--- a/kernel/config/smp-x86.lds
+++ b/kernel/config/smp-x86.lds
@@ -30,6 +30,9 @@ SECTIONS
 		. = vsyscall_page + 0x400;
 		*(.vsyscall.time)
 
+		. = vsyscall_page + 0x800;
+		*(.vsyscall.getcpu)
+
 		. = ALIGN(4096);
 	} : data = 0xf4