x86: introduce ldt_write accessor

Create a ldt write accessor like the 32 bit one.

Preparatory patch for merging ldt.c and anyway necessary for
64bit paravirt ops.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/asm-x86/desc_64.h b/include/asm-x86/desc_64.h
index bb2009ecbbca..7d48df72aef2 100644
--- a/include/asm-x86/desc_64.h
+++ b/include/asm-x86/desc_64.h
@@ -38,6 +38,15 @@ extern struct desc_struct default_ldt[];
 extern struct gate_struct idt_table[];
 extern struct desc_ptr cpu_gdt_descr[];
 
+static inline void write_ldt_entry(struct desc_struct *ldt,
+                                   int entry, u32 entry_low, u32 entry_high)
+{
+        __u32 *lp = (__u32 *)((entry << 3) + (char *)ldt);
+
+        lp[0] = entry_low;
+        lp[1] = entry_high;
+}
+
 /* the cpu gdt accessor */
 #define cpu_gdt(_cpu) ((struct desc_struct *)cpu_gdt_descr[_cpu].address)