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Subject[PATCH 02/27] x86: segment selector macros
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This copies into asm-x86/segment_64.h some macros from asm-x86/segment_32.h
for dissecting segment selectors. This lets other code use these macros
uniformly on 32/64-bit rather than duplicating the constants elsewhere.

Signed-off-by: Roland McGrath <roland@redhat.com>
---
include/asm-x86/segment_64.h | 11 +++++++++++
1 files changed, 11 insertions(+), 0 deletions(-)
diff --git a/include/asm-x86/segment_64.h b/include/asm-x86/segment_64.h
index 04b8ab2..dce7421 100644
--- a/include/asm-x86/segment_64.h
+++ b/include/asm-x86/segment_64.h
@@ -50,4 +50,15 @@
#define GDT_SIZE (GDT_ENTRIES * 8)
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)

+/* Bottom two bits of selector give the ring privilege level */
+#define SEGMENT_RPL_MASK 0x3
+/* Bit 2 is table indicator (LDT/GDT) */
+#define SEGMENT_TI_MASK 0x4
+
+/* User mode is privilege level 3 */
+#define USER_RPL 0x3
+/* LDT segment has TI set, GDT has it cleared */
+#define SEGMENT_LDT 0x4
+#define SEGMENT_GDT 0x0
+
#endif
-
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