1 files changed, 95 insertions, 0 deletions

diff --git a/arch/x86/include/asm/desc_defs.h b/arch/x86/include/asm/desc_defs.h
new file mode 100644
index 000000000000..b881db664b46
--- /dev/null
+++ b/arch/x86/include/asm/desc_defs.h
@@ -0,0 +1,95 @@
+/* Written 2000 by Andi Kleen */
+#ifndef ASM_X86__DESC_DEFS_H
+#define ASM_X86__DESC_DEFS_H
+
+/*
+ * Segment descriptor structure definitions, usable from both x86_64 and i386
+ * archs.
+ */
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+
+/*
+ * FIXME: Acessing the desc_struct through its fields is more elegant,
+ * and should be the one valid thing to do. However, a lot of open code
+ * still touches the a and b acessors, and doing this allow us to do it
+ * incrementally. We keep the signature as a struct, rather than an union,
+ * so we can get rid of it transparently in the future -- glommer
+ */
+/* 8 byte segment descriptor */
+struct desc_struct {
+        union {
+                struct {
+                        unsigned int a;
+                        unsigned int b;
+                };
+                struct {
+                        u16 limit0;
+                        u16 base0;
+                        unsigned base1: 8, type: 4, s: 1, dpl: 2, p: 1;
+                        unsigned limit: 4, avl: 1, l: 1, d: 1, g: 1, base2: 8;
+                };
+        };
+} __attribute__((packed));
+
+enum {
+        GATE_INTERRUPT = 0xE,
+        GATE_TRAP = 0xF,
+        GATE_CALL = 0xC,
+        GATE_TASK = 0x5,
+};
+
+/* 16byte gate */
+struct gate_struct64 {
+        u16 offset_low;
+        u16 segment;
+        unsigned ist : 3, zero0 : 5, type : 5, dpl : 2, p : 1;
+        u16 offset_middle;
+        u32 offset_high;
+        u32 zero1;
+} __attribute__((packed));
+
+#define PTR_LOW(x) ((unsigned long long)(x) & 0xFFFF)
+#define PTR_MIDDLE(x) (((unsigned long long)(x) >> 16) & 0xFFFF)
+#define PTR_HIGH(x) ((unsigned long long)(x) >> 32)
+
+enum {
+        DESC_TSS = 0x9,
+        DESC_LDT = 0x2,
+        DESCTYPE_S = 0x10,      /* !system */
+};
+
+/* LDT or TSS descriptor in the GDT. 16 bytes. */
+struct ldttss_desc64 {
+        u16 limit0;
+        u16 base0;
+        unsigned base1 : 8, type : 5, dpl : 2, p : 1;
+        unsigned limit1 : 4, zero0 : 3, g : 1, base2 : 8;
+        u32 base3;
+        u32 zero1;
+} __attribute__((packed));
+
+#ifdef CONFIG_X86_64
+typedef struct gate_struct64 gate_desc;
+typedef struct ldttss_desc64 ldt_desc;
+typedef struct ldttss_desc64 tss_desc;
+#define gate_offset(g) ((g).offset_low | ((unsigned long)(g).offset_middle << 16) | ((unsigned long)(g).offset_high << 32))
+#define gate_segment(g) ((g).segment)
+#else
+typedef struct desc_struct gate_desc;
+typedef struct desc_struct ldt_desc;
+typedef struct desc_struct tss_desc;
+#define gate_offset(g)          (((g).b & 0xffff0000) | ((g).a & 0x0000ffff))
+#define gate_segment(g)         ((g).a >> 16)
+#endif
+
+struct desc_ptr {
+        unsigned short size;
+        unsigned long address;
+} __attribute__((packed)) ;
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* ASM_X86__DESC_DEFS_H */