x86: change write_gdt_entry signature.

This patch changes the write_gdt_entry function signature.
Instead of the old "a" and "b" parameters, it now receives
a pointer to a desc_struct, and the size of the entry being
handled. This is because x86_64 can have some 16-byte entries
as well as 8-byte ones.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
CC: Zachary Amsden <zach@vmware.com>
CC: Jeremy Fitzhardinge <Jeremy.Fitzhardinge.citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 6 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index b7b7346d8cd..7f98c63f638 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -475,22 +475,21 @@ static void xen_load_idt(const struct desc_ptr *desc)
 /* Write a GDT descriptor entry.  Ignore LDT descriptors, since
    they're handled differently. */
 static void xen_write_gdt_entry(struct desc_struct *dt, int entry,
-                                u32 low, u32 high)
+                                const void *desc, int type)
 {
         preempt_disable();
 
-        switch ((high >> 8) & 0xff) {
-        case DESCTYPE_LDT:
-        case DESCTYPE_TSS:
+        switch (type) {
+        case DESC_LDT:
+        case DESC_TSS:
                 /* ignore */
                 break;
 
         default: {
                 xmaddr_t maddr = virt_to_machine(&dt[entry]);
-                u64 desc = (u64)high << 32 | low;
 
                 xen_mc_flush();
-                if (HYPERVISOR_update_descriptor(maddr.maddr, desc))
+                if (HYPERVISOR_update_descriptor(maddr.maddr, *(u64 *)desc))
                         BUG();
         }