x86: introduce fill_ldt

This patch introduces fill_ldt(), which populates a ldt descriptor
from a user_desc in once, instead of relying in the LDT_entry_a and
LDT_entry_b macros

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 29 insertions, 0 deletions

diff --git a/include/asm-x86/desc.h b/include/asm-x86/desc.h
index 6065c5092265..47086d2d9298 100644
--- a/include/asm-x86/desc.h
+++ b/include/asm-x86/desc.h
@@ -1,5 +1,34 @@
+#ifndef _ASM_DESC_H_
+#define _ASM_DESC_H_
+
+#ifndef __ASSEMBLY__
+#include <asm/desc_defs.h>
+#include <asm/ldt.h>
+
+static inline void fill_ldt(struct desc_struct *desc, struct user_desc *info)
+{
+	desc->limit0 = info->limit & 0x0ffff;
+	desc->base0 = info->base_addr & 0x0000ffff;
+
+	desc->base1 = (info->base_addr & 0x00ff0000) >> 16;
+	desc->type = (info->read_exec_only ^ 1) << 1;
+	desc->type |= info->contents << 2;
+	desc->s = 1;
+	desc->dpl = 0x3;
+	desc->p = info->seg_not_present ^ 1;
+	desc->limit = (info->limit & 0xf0000) >> 16;
+	desc->avl = info->useable;
+	desc->d = info->seg_32bit;
+	desc->g = info->limit_in_pages;
+	desc->base2 = (info->base_addr & 0xff000000) >> 24;
+}
+
+#endif
+
 #ifdef CONFIG_X86_32
 # include "desc_32.h"
 #else
 # include "desc_64.h"
 #endif
+
+#endif