[PATCH] time: x86_64: re-enable vsyscall support for x86_64

Cleanup and re-enable vsyscall gettimeofday using the generic clocksource
infrastructure.

[akpm@osdl.org: cleanup]
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/hpet.c b/arch/x86_64/kernel/hpet.c
index c23738899ae9..65a0edd71a17 100644
--- a/arch/x86_64/kernel/hpet.c
+++ b/arch/x86_64/kernel/hpet.c
@@ -458,6 +458,11 @@ static cycle_t read_hpet(void)
         return (cycle_t)readl(hpet_ptr);
 }
 
+static cycle_t __vsyscall_fn vread_hpet(void)
+{
+        return readl((void __iomem *)fix_to_virt(VSYSCALL_HPET) + 0xf0);
+}
+
 struct clocksource clocksource_hpet = {
         .name           = "hpet",
         .rating         = 250,
@@ -466,6 +471,7 @@ struct clocksource clocksource_hpet = {
         .mult           = 0, /* set below */
         .shift          = HPET_SHIFT,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+        .vread          = vread_hpet,
 };
 
 static int __init init_hpet_clocksource(void)