sh: Consolidate segment modifiers across mmu/nommu systems.

This moves get_fs/set_fs() and friends in to asm/segment.h. The
mm_segment_t definition is likewise consolidated from the _32/_64 split.

This is prepatory groundwork for using the generic address space limit
and verification routines across mmu/nommu configs.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 29 insertions, 1 deletions

diff --git a/include/asm-sh/segment.h b/include/asm-sh/segment.h
index e417eab4c7d7..5e2725f4ac49 100644
--- a/include/asm-sh/segment.h
+++ b/include/asm-sh/segment.h
@@ -1,6 +1,34 @@
 #ifndef __ASM_SH_SEGMENT_H
 #define __ASM_SH_SEGMENT_H
 
-/* Only here because we have some old header files that expect it.. */
+#ifndef __ASSEMBLY__
 
+typedef struct {
+        unsigned long seg;
+} mm_segment_t;
+
+#define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
+
+/*
+ * The fs value determines whether argument validity checking should be
+ * performed or not.  If get_fs() == USER_DS, checking is performed, with
+ * get_fs() == KERNEL_DS, checking is bypassed.
+ *
+ * For historical reasons, these macros are grossly misnamed.
+ */
+#define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFFUL)
+#ifdef CONFIG_MMU
+#define USER_DS         MAKE_MM_SEG(PAGE_OFFSET)
+#else
+#define USER_DS         KERNEL_DS
+#endif
+
+#define segment_eq(a,b) ((a).seg == (b).seg)
+
+#define get_ds()        (KERNEL_DS)
+
+#define get_fs()        (current_thread_info()->addr_limit)
+#define set_fs(x)       (current_thread_info()->addr_limit = (x))
+
+#endif /* __ASSEMBLY__ */
 #endif /* __ASM_SH_SEGMENT_H */