Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: vdso: Remove unused variable
  x86-64: Optimize vDSO time()
  x86-64: Add time to vDSO
  x86-64: Turn off -pg and turn on -foptimize-sibling-calls for vDSO
  x86-64: Move vread_tsc into a new file with sensible options
  x86-64: Vclock_gettime(CLOCK_MONOTONIC) can't ever see nsec < 0
  x86-64: Don't generate cmov in vread_tsc
  x86-64: Remove unnecessary barrier in vread_tsc
  x86-64: Clean up vdso/kernel shared variables

5 files changed, 58 insertions, 26 deletions

diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h
index 83e2efd..9db5583 100644
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -51,6 +51,10 @@ extern int unsynchronized_tsc(void);
 extern int check_tsc_unstable(void);
 extern unsigned long native_calibrate_tsc(void);
 
+#ifdef CONFIG_X86_64
+extern cycles_t vread_tsc(void);
+#endif
+
 /*
  * Boot-time check whether the TSCs are synchronized across
  * all CPUs/cores:
diff --git a/arch/x86/include/asm/vdso.h b/arch/x86/include/asm/vdso.h
index 9064052..bb05228 100644
--- a/arch/x86/include/asm/vdso.h
+++ b/arch/x86/include/asm/vdso.h
@@ -1,20 +1,6 @@
 #ifndef _ASM_X86_VDSO_H
 #define _ASM_X86_VDSO_H
 
-#ifdef CONFIG_X86_64
-extern const char VDSO64_PRELINK[];
-
-/*
- * Given a pointer to the vDSO image, find the pointer to VDSO64_name
- * as that symbol is defined in the vDSO sources or linker script.
- */
-#define VDSO64_SYMBOL(base, name)					\
-({									\
-	extern const char VDSO64_##name[];				\
-	(void *)(VDSO64_##name - VDSO64_PRELINK + (unsigned long)(base)); \
-})
-#endif
-
 #if defined CONFIG_X86_32 || defined CONFIG_COMPAT
 extern const char VDSO32_PRELINK[];
 
diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h
index 3d61e20..646b4c1 100644
--- a/arch/x86/include/asm/vgtod.h
+++ b/arch/x86/include/asm/vgtod.h
@@ -23,8 +23,6 @@ struct vsyscall_gtod_data {
 	struct timespec wall_to_monotonic;
 	struct timespec wall_time_coarse;
 };
-extern struct vsyscall_gtod_data __vsyscall_gtod_data
-__section_vsyscall_gtod_data;
 extern struct vsyscall_gtod_data vsyscall_gtod_data;
 
 #endif /* _ASM_X86_VGTOD_H */
diff --git a/arch/x86/include/asm/vsyscall.h b/arch/x86/include/asm/vsyscall.h
index d0983d2..d555973 100644
--- a/arch/x86/include/asm/vsyscall.h
+++ b/arch/x86/include/asm/vsyscall.h
@@ -16,27 +16,19 @@ enum vsyscall_num {
 #ifdef __KERNEL__
 #include <linux/seqlock.h>
 
-#define __section_vgetcpu_mode __attribute__ ((unused, __section__ (".vgetcpu_mode"), aligned(16)))
-#define __section_jiffies __attribute__ ((unused, __section__ (".jiffies"), aligned(16)))
-
 /* Definitions for CONFIG_GENERIC_TIME definitions */
-#define __section_vsyscall_gtod_data __attribute__ \
-	((unused, __section__ (".vsyscall_gtod_data"),aligned(16)))
-#define __section_vsyscall_clock __attribute__ \
-	((unused, __section__ (".vsyscall_clock"),aligned(16)))
 #define __vsyscall_fn \
 	__attribute__ ((unused, __section__(".vsyscall_fn"))) notrace
 
 #define VGETCPU_RDTSCP	1
 #define VGETCPU_LSL	2
 
-extern int __vgetcpu_mode;
-extern volatile unsigned long __jiffies;
-
 /* kernel space (writeable) */
 extern int vgetcpu_mode;
 extern struct timezone sys_tz;
 
+#include <asm/vvar.h>
+
 extern void map_vsyscall(void);
 
 #endif /* __KERNEL__ */
diff --git a/arch/x86/include/asm/vvar.h b/arch/x86/include/asm/vvar.h
new file mode 100644
index 0000000..341b355
--- /dev/null
+++ b/arch/x86/include/asm/vvar.h
@@ -0,0 +1,52 @@
+/*
+ * vvar.h: Shared vDSO/kernel variable declarations
+ * Copyright (c) 2011 Andy Lutomirski
+ * Subject to the GNU General Public License, version 2
+ *
+ * A handful of variables are accessible (read-only) from userspace
+ * code in the vsyscall page and the vdso.  They are declared here.
+ * Some other file must define them with DEFINE_VVAR.
+ *
+ * In normal kernel code, they are used like any other variable.
+ * In user code, they are accessed through the VVAR macro.
+ *
+ * Each of these variables lives in the vsyscall page, and each
+ * one needs a unique offset within the little piece of the page
+ * reserved for vvars.  Specify that offset in DECLARE_VVAR.
+ * (There are 896 bytes available.  If you mess up, the linker will
+ * catch it.)
+ */
+
+/* Offset of vars within vsyscall page */
+#define VSYSCALL_VARS_OFFSET (3072 + 128)
+
+#if defined(__VVAR_KERNEL_LDS)
+
+/* The kernel linker script defines its own magic to put vvars in the
+ * right place.
+ */
+#define DECLARE_VVAR(offset, type, name) \
+	EMIT_VVAR(name, VSYSCALL_VARS_OFFSET + offset)
+
+#else
+
+#define DECLARE_VVAR(offset, type, name)				\
+	static type const * const vvaraddr_ ## name =			\
+		(void *)(VSYSCALL_START + VSYSCALL_VARS_OFFSET + (offset));
+
+#define DEFINE_VVAR(type, name)						\
+	type __vvar_ ## name						\
+	__attribute__((section(".vsyscall_var_" #name), aligned(16)))
+
+#define VVAR(name) (*vvaraddr_ ## name)
+
+#endif
+
+/* DECLARE_VVAR(offset, type, name) */
+
+DECLARE_VVAR(0, volatile unsigned long, jiffies)
+DECLARE_VVAR(8, int, vgetcpu_mode)
+DECLARE_VVAR(128, struct vsyscall_gtod_data, vsyscall_gtod_data)
+
+#undef DECLARE_VVAR
+#undef VSYSCALL_VARS_OFFSET