From: Greg Ungerer <[email protected]>

The ColdFire CPU family, and the original 68000, do not support separate
address spaces like the other 680x0 CPU types. Modify the set_fs()/get_fs()
functions and macros to use a thread_info addr_limit for address space
checking. This is pretty much what all other architectures that do not
support separate setable address spaces do.

Signed-off-by: Alexander Stein <[email protected]>
Signed-off-by: Greg Ungerer <[email protected]>
Acked-by: Matt Waddel <[email protected]>
Acked-by: Kurt Mahan <[email protected]>
---
 arch/m68k/include/asm/segment.h     |   30 ++++++++++++++++--------------
 arch/m68k/include/asm/thread_info.h |    3 +++
 2 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/arch/m68k/include/asm/segment.h b/arch/m68k/include/asm/segment.h
index 1a142e9..0fa80e9 100644
--- a/arch/m68k/include/asm/segment.h
+++ b/arch/m68k/include/asm/segment.h
@@ -22,23 +22,26 @@ typedef struct {
 } mm_segment_t;
 
 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
-#define USER_DS                MAKE_MM_SEG(__USER_DS)
-#define KERNEL_DS      MAKE_MM_SEG(__KERNEL_DS)
 
+#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
 /*
  * Get/set the SFC/DFC registers for MOVES instructions
  */
+#define USER_DS                MAKE_MM_SEG(__USER_DS)
+#define KERNEL_DS      MAKE_MM_SEG(__KERNEL_DS)
 
 static inline mm_segment_t get_fs(void)
 {
-#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
        mm_segment_t _v;
        __asm__ ("movec %/dfc,%0":"=r" (_v.seg):);
-
        return _v;
-#else
-       return USER_DS;
-#endif
+}
+
+static inline void set_fs(mm_segment_t val)
+{
+       __asm__ __volatile__ ("movec %0,%/sfc\n\t"
+                             "movec %0,%/dfc\n\t"
+                             : /* no outputs */ : "r" (val.seg) : "memory");
 }
 
 static inline mm_segment_t get_ds(void)
@@ -47,14 +50,13 @@ static inline mm_segment_t get_ds(void)
     return KERNEL_DS;
 }
 
-static inline void set_fs(mm_segment_t val)
-{
-#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
-       __asm__ __volatile__ ("movec %0,%/sfc\n\t"
-                             "movec %0,%/dfc\n\t"
-                             : /* no outputs */ : "r" (val.seg) : "memory");
+#else
+#define USER_DS                MAKE_MM_SEG(TASK_SIZE)
+#define KERNEL_DS      MAKE_MM_SEG(0xFFFFFFFF)
+#define get_ds()       (KERNEL_DS)
+#define get_fs()       (current_thread_info()->addr_limit)
+#define set_fs(x)      (current_thread_info()->addr_limit = (x))
 #endif
-}
 
 #define segment_eq(a,b)        ((a).seg == (b).seg)
 
diff --git a/arch/m68k/include/asm/thread_info.h 
b/arch/m68k/include/asm/thread_info.h
index 01cef3c..29fa6da 100644
--- a/arch/m68k/include/asm/thread_info.h
+++ b/arch/m68k/include/asm/thread_info.h
@@ -3,6 +3,7 @@
 
 #include <asm/types.h>
 #include <asm/page.h>
+#include <asm/segment.h>
 
 /*
  * On machines with 4k pages we default to an 8k thread size, though we
@@ -26,6 +27,7 @@ struct thread_info {
        struct task_struct      *task;          /* main task structure */
        unsigned long           flags;
        struct exec_domain      *exec_domain;   /* execution domain */
+       mm_segment_t            addr_limit;     /* thread address space */
        int                     preempt_count;  /* 0 => preemptable, <0 => BUG 
*/
        __u32                   cpu;            /* should always be 0 on m68k */
        unsigned long           tp_value;       /* thread pointer */
@@ -39,6 +41,7 @@ struct thread_info {
 {                                              \
        .task           = &tsk,                 \
        .exec_domain    = &default_exec_domain, \
+       .addr_limit     = KERNEL_DS,            \
        .preempt_count  = INIT_PREEMPT_COUNT,   \
        .restart_block = {                      \
                .fn = do_no_restart_syscall,    \
-- 
1.7.0.4

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