xen: setup percpu data pointers

We need to access percpu data fairly early, so set up the percpu
registers as soon as possible.  We only need to load the appropriate
segment register.  We already have a GDT, but its hard to change it
early because we need to manipulate the pagetable to do so, and that
hasn't been set up yet.

Also, set the kernel stack when bringing up secondary CPUs.  If we
don't they all end up sharing the same stack...

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 11913fc94c14..2f5ef2632ea2 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -10,6 +10,8 @@
 extern const char xen_hypervisor_callback[];
 extern const char xen_failsafe_callback[];
 
+extern void *xen_initial_gdt;
+
 struct trap_info;
 void xen_copy_trap_info(struct trap_info *traps);