xen: SMP guest support

This is a fairly straightforward Xen implementation of smp_ops.

Xen has its own IPI mechanisms, and has no dependency on any
APIC-based IPI.  The smp_ops hooks and the flush_tlb_others pv_op
allow a Xen guest to avoid all APIC code in arch/i386 (the only apic
operation is a single apic_read for the apic version number).

One subtle point which needs to be addressed is unpinning pagetables
when another cpu may have a lazy tlb reference to the pagetable. Xen
will not allow an in-use pagetable to be unpinned, so we must find any
other cpus with a reference to the pagetable and get them to shoot
down their references.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andi Kleen <ak@suse.de>
diff --git a/arch/i386/xen/xen-ops.h b/arch/i386/xen/xen-ops.h
index 7667abd3..4069be8b 100644
--- a/arch/i386/xen/xen-ops.h
+++ b/arch/i386/xen/xen-ops.h
@@ -3,6 +3,12 @@
 
 #include <linux/init.h>
 
+/* These are code, but not functions.  Defined in entry.S */
+extern const char xen_hypervisor_callback[];
+extern const char xen_failsafe_callback[];
+
+void xen_copy_trap_info(struct trap_info *traps);
+
 DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu);
 DECLARE_PER_CPU(unsigned long, xen_cr3);
 
@@ -13,6 +19,8 @@
 void __init xen_arch_setup(void);
 void __init xen_init_IRQ(void);
 
+void xen_setup_timer(int cpu);
+void xen_setup_cpu_clockevents(void);
 unsigned long xen_cpu_khz(void);
 void __init xen_time_init(void);
 unsigned long xen_get_wallclock(void);
@@ -28,5 +36,22 @@
 	return x86_read_percpu(xen_lazy_mode);
 }
 
+void __init xen_fill_possible_map(void);
+
+void xen_vcpu_setup(int cpu);
+void xen_smp_prepare_boot_cpu(void);
+void xen_smp_prepare_cpus(unsigned int max_cpus);
+int xen_cpu_up(unsigned int cpu);
+void xen_smp_cpus_done(unsigned int max_cpus);
+
+void xen_smp_send_stop(void);
+void xen_smp_send_reschedule(int cpu);
+int xen_smp_call_function (void (*func) (void *info), void *info, int nonatomic,
+			   int wait);
+int xen_smp_call_function_single(int cpu, void (*func) (void *info), void *info,
+				 int nonatomic, int wait);
+
+int xen_smp_call_function_mask(cpumask_t mask, void (*func)(void *),
+			       void *info, int wait);
 
 #endif /* XEN_OPS_H */