This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / arch / x86_64 / kernel / irqflags-xen.c

diff --git a/arch/x86_64/kernel/irqflags-xen.c b/arch/x86_64/kernel/irqflags-xen.c
new file mode 100644 (file)
index 0000000..e3b7ab5
--- /dev/null
+++ b/arch/x86_64/kernel/irqflags-xen.c
@@ -0,0 +1,100 @@
+#include <linux/module.h>
+#include <linux/smp.h>
+#include <asm/irqflags.h>
+#include <asm/hypervisor.h>
+
+/* 
+ * The use of 'barrier' in the following reflects their use as local-lock
+ * operations. Reentrancy must be prevented (e.g., __cli()) /before/ following
+ * critical operations are executed. All critical operations must complete
+ * /before/ reentrancy is permitted (e.g., __sti()). Alpha architecture also
+ * includes these barriers, for example.
+ */
+
+unsigned long __raw_local_save_flags(void)
+{
+       struct vcpu_info *_vcpu;
+       unsigned long flags;
+
+       preempt_disable();
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];
+       flags = _vcpu->evtchn_upcall_mask;
+       preempt_enable();
+
+       return flags;
+}
+EXPORT_SYMBOL(__raw_local_save_flags);
+
+void raw_local_irq_restore(unsigned long flags)
+{
+       struct vcpu_info *_vcpu;
+       preempt_disable();
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];
+       if ((_vcpu->evtchn_upcall_mask = flags) == 0) {
+               barrier(); /* unmask then check (avoid races) */
+               if ( unlikely(_vcpu->evtchn_upcall_pending) )
+                       force_evtchn_callback();
+               preempt_enable();
+       } else
+               preempt_enable_no_resched();
+}
+EXPORT_SYMBOL(raw_local_irq_restore);
+
+void raw_local_irq_disable(void)
+{
+       struct vcpu_info *_vcpu;
+
+       preempt_disable();
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];
+       _vcpu->evtchn_upcall_mask = 1;
+       preempt_enable_no_resched();
+}
+EXPORT_SYMBOL(raw_local_irq_disable);
+
+void raw_local_irq_enable(void)
+{
+       struct vcpu_info *_vcpu;
+
+       preempt_disable();
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];
+       _vcpu->evtchn_upcall_mask = 0;
+       barrier(); /* unmask then check (avoid races) */
+       if ( unlikely(_vcpu->evtchn_upcall_pending) )
+               force_evtchn_callback();
+       preempt_enable();
+}
+EXPORT_SYMBOL(raw_local_irq_enable);
+
+/*
+ * For spinlocks, etc.:
+ */
+
+unsigned long __raw_local_irq_save(void)
+{
+       struct vcpu_info *_vcpu;
+       unsigned long flags;
+
+       preempt_disable();
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];
+       flags = _vcpu->evtchn_upcall_mask;
+       _vcpu->evtchn_upcall_mask = 1;
+       preempt_enable_no_resched();
+
+       return flags;
+}
+EXPORT_SYMBOL(__raw_local_irq_save);
+
+/* Cannot use preempt_enable() here as we would recurse in preempt_sched(). */
+int raw_irqs_disabled(void)
+{
+       struct vcpu_info *_vcpu;
+       int disabled;
+
+       preempt_disable();
+       _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id];
+       disabled = (_vcpu->evtchn_upcall_mask != 0);
+       preempt_enable_no_resched();
+
+       return disabled;
+}
+EXPORT_SYMBOL(raw_irqs_disabled);