[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>

1 files changed, 8 insertions, 0 deletions

diff --git a/include/asm-i386/delay.h b/include/asm-i386/delay.h
index 9ae5e3782ed8..32d6678d0bbf 100644
--- a/include/asm-i386/delay.h
+++ b/include/asm-i386/delay.h
@@ -16,6 +16,13 @@ extern void __ndelay(unsigned long nsecs);
 extern void __const_udelay(unsigned long usecs);
 extern void __delay(unsigned long loops);
 
+#if defined(CONFIG_PARAVIRT) && !defined(USE_REAL_TIME_DELAY)
+#define udelay(n) paravirt_ops.const_udelay((n) * 0x10c7ul)
+
+#define ndelay(n) paravirt_ops.const_udelay((n) * 5ul)
+
+#else /* !PARAVIRT || USE_REAL_TIME_DELAY */
+
 /* 0x10c7 is 2**32 / 1000000 (rounded up) */
 #define udelay(n) (__builtin_constant_p(n) ? \
         ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \
@@ -25,6 +32,7 @@ extern void __delay(unsigned long loops);
 #define ndelay(n) (__builtin_constant_p(n) ? \
         ((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \
         __ndelay(n))
+#endif
 
 void use_tsc_delay(void);