Disintegrate asm/system.h for X86
Disintegrate asm/system.h for X86.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
cc: x86@kernel.org
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 5e64171..1654662 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -212,7 +212,61 @@
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10];
-#endif
-#endif
+
+/*
+ * Load a segment. Fall back on loading the zero
+ * segment if something goes wrong..
+ */
+#define loadsegment(seg, value) \
+do { \
+ unsigned short __val = (value); \
+ \
+ asm volatile(" \n" \
+ "1: movl %k0,%%" #seg " \n" \
+ \
+ ".section .fixup,\"ax\" \n" \
+ "2: xorl %k0,%k0 \n" \
+ " jmp 1b \n" \
+ ".previous \n" \
+ \
+ _ASM_EXTABLE(1b, 2b) \
+ \
+ : "+r" (__val) : : "memory"); \
+} while (0)
+
+/*
+ * Save a segment register away
+ */
+#define savesegment(seg, value) \
+ asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
+
+/*
+ * x86_32 user gs accessors.
+ */
+#ifdef CONFIG_X86_32
+#ifdef CONFIG_X86_32_LAZY_GS
+#define get_user_gs(regs) (u16)({unsigned long v; savesegment(gs, v); v;})
+#define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v))
+#define task_user_gs(tsk) ((tsk)->thread.gs)
+#define lazy_save_gs(v) savesegment(gs, (v))
+#define lazy_load_gs(v) loadsegment(gs, (v))
+#else /* X86_32_LAZY_GS */
+#define get_user_gs(regs) (u16)((regs)->gs)
+#define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0)
+#define task_user_gs(tsk) (task_pt_regs(tsk)->gs)
+#define lazy_save_gs(v) do { } while (0)
+#define lazy_load_gs(v) do { } while (0)
+#endif /* X86_32_LAZY_GS */
+#endif /* X86_32 */
+
+static inline unsigned long get_limit(unsigned long segment)
+{
+ unsigned long __limit;
+ asm("lsll %1,%0" : "=r" (__limit) : "r" (segment));
+ return __limit + 1;
+}
+
+#endif /* !__ASSEMBLY__ */
+#endif /* __KERNEL__ */
#endif /* _ASM_X86_SEGMENT_H */