xen64: register callbacks in arch-independent way

Use callback_op hypercall to register callbacks in a 32/64-bit
independent way (64-bit doesn't need a code segment, but that detail
is hidden in XEN_CALLBACK).

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 17 insertions, 10 deletions

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index f52f3855fb6b..bea3d4f779db 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -91,19 +91,25 @@ static void __init fiddle_vdso(void)
         *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
 }
 
-void xen_enable_sysenter(void)
+static __cpuinit int register_callback(unsigned type, const void *func)
 {
-        int cpu = smp_processor_id();
-        extern void xen_sysenter_target(void);
-        /* Mask events on entry, even though they get enabled immediately */
-        static struct callback_register sysenter = {
-                .type = CALLBACKTYPE_sysenter,
-                .address = XEN_CALLBACK(__KERNEL_CS, xen_sysenter_target),
+        struct callback_register callback = {
+                .type = type,
+                .address = XEN_CALLBACK(__KERNEL_CS, func),
                 .flags = CALLBACKF_mask_events,
         };
 
+        return HYPERVISOR_callback_op(CALLBACKOP_register, &callback);
+}
+
+void __cpuinit xen_enable_sysenter(void)
+{
+        int cpu = smp_processor_id();
+        extern void xen_sysenter_target(void);
+
         if (!boot_cpu_has(X86_FEATURE_SEP) ||
-            HYPERVISOR_callback_op(CALLBACKOP_register, &sysenter) != 0) {
+            register_callback(CALLBACKTYPE_sysenter,
+                              xen_sysenter_target) != 0) {
                 clear_cpu_cap(&cpu_data(cpu), X86_FEATURE_SEP);
                 clear_cpu_cap(&boot_cpu_data, X86_FEATURE_SEP);
         }
@@ -120,8 +126,9 @@ void __init xen_arch_setup(void)
         if (!xen_feature(XENFEAT_auto_translated_physmap))
                 HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3);
 
-        HYPERVISOR_set_callbacks(__KERNEL_CS, (unsigned long)xen_hypervisor_callback,
-                                 __KERNEL_CS, (unsigned long)xen_failsafe_callback);
+        if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
+            register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
+                BUG();
 
         xen_enable_sysenter();