xen: Clean up SMP/hotplug headers and implementation a bit.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

1 files changed, 7 insertions, 65 deletions

diff --git a/xen/include/xen/smp.h b/xen/include/xen/smp.h
index 3e7de77ec8..6ab913a430 100644
--- a/xen/include/xen/smp.h
+++ b/xen/include/xen/smp.h
@@ -1,23 +1,10 @@
-#ifndef __LINUX_SMP_H
-#define __LINUX_SMP_H
-
-/*
- *	Generic SMP support
- *		Alan Cox. <alan@redhat.com>
- */
+#ifndef __XEN_SMP_H__
+#define __XEN_SMP_H__
 
 #include <xen/config.h>
-
-#ifdef CONFIG_SMP
-
 #include <asm/smp.h>
 
 /*
- * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
- * (defined in asm header):
- */ 
-
-/*
  * stops all CPUs but the current one:
  */
 extern void smp_send_stop(void);
@@ -66,38 +53,6 @@ extern int on_selected_cpus(
  */
 void smp_prepare_boot_cpu(void);
 
-#else
-
-/*
- *	These macros fold the SMP functionality into a single CPU system
- */
-
-#define smp_send_event_check_mask(m)            ((void)0)
-#define smp_send_event_check_cpu(p)             ((void)0) 
-#define raw_smp_processor_id()			0
-#define hard_smp_processor_id()			0
-#define smp_call_function(func,info,retry,wait)	({ do {} while (0); 0; })
-#define num_booting_cpus()			1
-#define smp_prepare_boot_cpu()			do {} while (0)
-
-static inline int on_selected_cpus(
-    cpumask_t selected,
-    void (*func) (void *info),
-    void *info,
-    int retry,
-    int wait)
-{
-    if ( cpu_isset(0, selected) )
-    {
-        local_irq_disable();
-        func(info);
-        local_irq_enable();
-    }
-    return 0;
-}
-
-#endif
-
 /*
  * Call a function on all processors
  */
@@ -112,21 +67,8 @@ static inline int on_each_cpu(
 
 #define smp_processor_id() raw_smp_processor_id()
 
-#ifdef CONFIG_HOTPLUG_CPU
-extern spinlock_t cpu_add_remove_lock;
-/*
- * FIXME: need a better lock mechanism when real cpu hotplug is later
- * supported, since spinlock may cause dead lock:
- *     cpu0: in stop_machine with lock held. Wait for cpu1 to respond
- *           to stop request
- *     cpu1: spin loop on lock upon cpu hotplug request from guest,
- *           without chance to handle softirq
- * ...
- */
-#define lock_cpu_hotplug() spin_lock(&cpu_add_remove_lock);
-#define unlock_cpu_hotplug() spin_unlock(&cpu_add_remove_lock);
-#else
-#define lock_cpu_hotplug() do { } while ( 0 )
-#define unlock_cpu_hotplug() do { } while ( 0 )
-#endif
-#endif
+/* No Xen contexts can be preempted by CPU hotplug. */
+#define lock_cpu_hotplug() ((void)0)
+#define unlock_cpu_hotplug() ((void)0)
+
+#endif /* __XEN_SMP_H__ */