# HG changeset patch
# User Ben Guthro <ben@guthro.net>
# Date 1348555094 -7200
# Node ID c8d65d91a6f20fa7fae905bbf172e59b335d6371
# Parent  b49f7bf52fa92626517386cba89350243b808871
x86/S3: add cache flush on secondary CPUs before going to sleep

Secondary CPUs, between doing their final memory writes (particularly
updating cpu_initialized) and getting a subsequent INIT, may not write
back all modified data. The INIT itself then causes those modifications
to be lost, so in the cpu_initialized case the CPU would find itself
already initialized, (intentionally) entering an infinite loop instead
of actually coming online.

Signed-off-by: Ben Guthro <ben@guthro.net>

Make acpi_dead_idle() call default_dead_idle() rather than duplicating
the logic there.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Committed-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/acpi/cpu_idle.c
+++ b/xen/arch/x86/acpi/cpu_idle.c
@@ -647,6 +647,12 @@ static void acpi_dead_idle(void)
     }
 
 default_halt:
+    /*
+     * When going into S3, without flushing caches modified data may be
+     * held by the CPUs spinning here indefinitely, and get discarded by
+     * a subsequent INIT.
+     */
+    wbinvd();
     for ( ; ; )
         halt();
 }
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -86,6 +86,12 @@ static void default_idle(void)
 
 static void default_dead_idle(void)
 {
+    /*
+     * When going into S3, without flushing caches modified data may be
+     * held by the CPUs spinning here indefinitely, and get discarded by
+     * a subsequent INIT.
+     */
+    wbinvd();
     for ( ; ; )
         halt();
 }