[PATCH] paravirt: header and stubs for paravirtualisation

Create a paravirt.h header for all the critical operations which need to be
replaced with hypervisor calls, and include that instead of defining native
operations, when CONFIG_PARAVIRT.

This patch does the dumbest possible replacement of paravirtualized
instructions: calls through a "paravirt_ops" structure.  Currently these are
function implementations of native hardware: hypervisors will override the ops
structure with their own variants.

All the pv-ops functions are declared "fastcall" so that a specific
register-based ABI is used, to make inlining assember easier.

And:

+From: Andy Whitcroft <apw@shadowen.org>

The paravirt ops introduce a 'weak' attribute onto memory_setup().
Code ordering leads to the following warnings on x86:

    arch/i386/kernel/setup.c:651: warning: weak declaration of
                `memory_setup' after first use results in unspecified behavior

Move memory_setup() to avoid this.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>

arch/i386/kernel/time.c

@@ -56,6 +56,7 @@
 #include <asm/uaccess.h>
 #include <asm/processor.h>
 #include <asm/timer.h>
+#include <asm/time.h>
 
 #include "mach_time.h"
 
@@ -116,10 +117,7 @@ static int set_rtc_mmss(unsigned long nowtime)
 	/* gets recalled with irq locally disabled */
 	/* XXX - does irqsave resolve this? -johnstul */
 	spin_lock_irqsave(&rtc_lock, flags);
-	if (efi_enabled)
-		retval = efi_set_rtc_mmss(nowtime);
-	else
-		retval = mach_set_rtc_mmss(nowtime);
+	retval = set_wallclock(nowtime);
 	spin_unlock_irqrestore(&rtc_lock, flags);
 
 	return retval;
@@ -223,10 +221,7 @@ unsigned long get_cmos_time(void)
 
 	spin_lock_irqsave(&rtc_lock, flags);
 
-	if (efi_enabled)
-		retval = efi_get_time();
-	else
-		retval = mach_get_cmos_time();
+	retval = get_wallclock();
 
 	spin_unlock_irqrestore(&rtc_lock, flags);
 
@@ -370,7 +365,7 @@ static void __init hpet_time_init(void)
 		printk("Using HPET for base-timer\n");
 	}
 
-	time_init_hook();
+	do_time_init();
 }
 #endif
 
@@ -392,5 +387,5 @@ void __init time_init(void)
 
 	do_settimeofday(&ts);
 
-	time_init_hook();
+	do_time_init();
 }