1 files changed, 65 insertions, 8 deletions

diff --git a/unmodified_drivers/linux-2.6/platform-pci/machine_reboot.c b/unmodified_drivers/linux-2.6/platform-pci/machine_reboot.c
index d14bdbf1d9..c6b1f91b7f 100644
--- a/unmodified_drivers/linux-2.6/platform-pci/machine_reboot.c
+++ b/unmodified_drivers/linux-2.6/platform-pci/machine_reboot.c
@@ -1,24 +1,81 @@
 #include <linux/config.h>
+#include <linux/stop_machine.h>
+#include <xen/evtchn.h>
+#include <xen/gnttab.h>
 #include <xen/xenbus.h>
 #include "platform-pci.h"
 #include <asm/hypervisor.h>
 
-int __xen_suspend(int fast_suspend)
+/*
+ * Spinning prevents, for example, APs touching grant table entries while
+ * the shared grant table is not mapped into the address space imemdiately
+ * after resume.
+ */
+static void ap_suspend(void *_ap_spin)
+{
+	int *ap_spin = _ap_spin;
+
+	BUG_ON(!irqs_disabled());
+
+	while (*ap_spin) {
+		cpu_relax();
+		HYPERVISOR_yield();
+	}
+}
+
+static int bp_suspend(void)
 {
 	int suspend_cancelled;
 
-	xenbus_suspend();
-	platform_pci_suspend();
+	BUG_ON(!irqs_disabled());
 
 	suspend_cancelled = HYPERVISOR_shutdown(SHUTDOWN_suspend);
 
-	if (suspend_cancelled) {
-		platform_pci_suspend_cancel();
-		xenbus_suspend_cancel();
-	} else {
+	if (!suspend_cancelled) {
 		platform_pci_resume();
-		xenbus_resume();
+		gnttab_resume();
+		irq_resume();
+	}
+
+	return suspend_cancelled;
+}
+
+int __xen_suspend(int fast_suspend)
+{
+	int err, suspend_cancelled, ap_spin;
+
+	xenbus_suspend();
+
+	preempt_disable();
+
+	/* Prevent any races with evtchn_interrupt() handler. */
+	disable_irq(xen_platform_pdev->irq);
+
+	ap_spin = 1;
+	smp_mb();
+
+	err = smp_call_function(ap_suspend, &ap_spin, 0, 0);
+	if (err < 0) {
+		preempt_enable();
+		xenbus_suspend_cancel();
+		return err;
 	}
 
+	local_irq_disable();
+	suspend_cancelled = bp_suspend();
+	local_irq_enable();
+
+	smp_mb();
+	ap_spin = 0;
+
+	enable_irq(xen_platform_pdev->irq);
+
+	preempt_enable();
+
+	if (!suspend_cancelled)
+		xenbus_resume();
+	else
+		xenbus_suspend_cancel();
+
 	return 0;
 }