[PATCH] m68k: convert thread flags to use bit fields

Remove task_work structure, use the standard thread flags functions and use
shifts in entry.S to test the thread flags.  Add a few local labels to entry.S
to allow gas to generate short jumps.

Finally it changes a number of inline functions in thread_info.h to macros to
delay the current_thread_info() usage, which requires on m68k a structure
(task_struct) not yet defined at this point.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 22 insertions, 118 deletions

diff --git a/include/asm-m68k/processor.h b/include/asm-m68k/processor.h
index 84b4b26df04c..7982285e84ed 100644
--- a/include/asm-m68k/processor.h
+++ b/include/asm-m68k/processor.h
@@ -56,17 +56,6 @@ static inline void wrusp(unsigned long usp)
 #endif
 #define TASK_UNMAPPED_ALIGN(addr, off)  PAGE_ALIGN(addr)
 
-struct task_work {
-        unsigned char sigpending;
-        unsigned char notify_resume;    /* request for notification on
-                                           userspace execution resumption */
-        char          need_resched;
-        unsigned char delayed_trace;    /* single step a syscall */
-        unsigned char syscall_trace;    /* count of syscall interceptors */
-        unsigned char memdie;           /* task was selected to be killed */
-        unsigned char pad[2];
-};
-
 struct thread_struct {
         unsigned long  ksp;             /* kernel stack pointer */
         unsigned long  usp;             /* user stack pointer */
@@ -79,7 +68,6 @@ struct thread_struct {
         unsigned long  fp[8*3];
         unsigned long  fpcntl[3];       /* fp control regs */
         unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
-        struct task_work work;
         struct thread_info info;
 };
 
diff --git a/include/asm-m68k/thread_info.h b/include/asm-m68k/thread_info.h
index 4fdbf55f95e5..9532ca3c45cb 100644
--- a/include/asm-m68k/thread_info.h
+++ b/include/asm-m68k/thread_info.h
@@ -6,12 +6,11 @@
 
 struct thread_info {
         struct task_struct      *task;          /* main task structure */
+        unsigned long           flags;
         struct exec_domain      *exec_domain;   /* execution domain */
         int                     preempt_count;  /* 0 => preemptable, <0 => BUG */
         __u32 cpu; /* should always be 0 on m68k */
         struct restart_block    restart_block;
-
-        __u8                    supervisor_stack[0];
 };
 
 #define PREEMPT_ACTIVE          0x4000000
@@ -49,76 +48,14 @@ struct thread_info {
 
 #define end_of_stack(p) ((unsigned long *)(p)->thread_info + 1)
 
-#define TIF_SYSCALL_TRACE       0       /* syscall trace active */
-#define TIF_DELAYED_TRACE       1       /* single step a syscall */
-#define TIF_NOTIFY_RESUME       2       /* resumption notification requested */
-#define TIF_SIGPENDING          3       /* signal pending */
-#define TIF_NEED_RESCHED        4       /* rescheduling necessary */
-#define TIF_MEMDIE              5
-
-extern int thread_flag_fixme(void);
-
-/*
- * flag set/clear/test wrappers
- * - pass TIF_xxxx constants to these functions
+/* entry.S relies on these definitions!
+ * bits 0-7 are tested at every exception exit
+ * bits 8-15 are also tested at syscall exit
  */
-
-#define __set_tsk_thread_flag(tsk, flag, val) ({        \
-        switch (flag) {                                 \
-        case TIF_SIGPENDING:                            \
-                tsk->thread.work.sigpending = val;      \
-                break;                                  \
-        case TIF_NEED_RESCHED:                          \
-                tsk->thread.work.need_resched = val;    \
-                break;                                  \
-        case TIF_SYSCALL_TRACE:                         \
-                tsk->thread.work.syscall_trace = val;   \
-                break;                                  \
-        case TIF_MEMDIE:                                \
-                tsk->thread.work.memdie = val;          \
-                break;                                  \
-        default:                                        \
-                thread_flag_fixme();                    \
-        }                                               \
-})
-
-#define __get_tsk_thread_flag(tsk, flag) ({             \
-        int ___res;                                     \
-        switch (flag) {                                 \
-        case TIF_SIGPENDING:                            \
-                ___res = tsk->thread.work.sigpending;   \
-                break;                                  \
-        case TIF_NEED_RESCHED:                          \
-                ___res = tsk->thread.work.need_resched; \
-                break;                                  \
-        case TIF_SYSCALL_TRACE:                         \
-                ___res = tsk->thread.work.syscall_trace;\
-                break;                                  \
-        case TIF_MEMDIE:                                \
-                ___res = tsk->thread.work.memdie;\
-                break;                                  \
-        default:                                        \
-                ___res = thread_flag_fixme();           \
-        }                                               \
-        ___res;                                         \
-})
-
-#define __get_set_tsk_thread_flag(tsk, flag, val) ({    \
-        int __res = __get_tsk_thread_flag(tsk, flag);   \
-        __set_tsk_thread_flag(tsk, flag, val);          \
-        __res;                                          \
-})
-
-#define set_tsk_thread_flag(tsk, flag) __set_tsk_thread_flag(tsk, flag, ~0)
-#define clear_tsk_thread_flag(tsk, flag) __set_tsk_thread_flag(tsk, flag, 0)
-#define test_and_set_tsk_thread_flag(tsk, flag) __get_set_tsk_thread_flag(tsk, flag, ~0)
-#define test_tsk_thread_flag(tsk, flag) __get_tsk_thread_flag(tsk, flag)
-
-#define set_thread_flag(flag) set_tsk_thread_flag(current, flag)
-#define clear_thread_flag(flag) clear_tsk_thread_flag(current, flag)
-#define test_thread_flag(flag) test_tsk_thread_flag(current, flag)
-
-#define set_need_resched() set_thread_flag(TIF_NEED_RESCHED)
-#define clear_need_resched() clear_thread_flag(TIF_NEED_RESCHED)
+#define TIF_SIGPENDING          6       /* signal pending */
+#define TIF_NEED_RESCHED        7       /* rescheduling necessary */
+#define TIF_DELAYED_TRACE       14      /* single step a syscall */
+#define TIF_SYSCALL_TRACE       15      /* syscall trace active */
+#define TIF_MEMDIE              16
 
 #endif  /* _ASM_M68K_THREAD_INFO_H */
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index d252f45a0f9b..1c4eb41dbd89 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -27,31 +27,6 @@ extern long do_no_restart_syscall(struct restart_block *parm);
  * - pass TIF_xxxx constants to these functions
  */
 
-static inline void set_thread_flag(int flag)
-{
-        set_bit(flag,&current_thread_info()->flags);
-}
-
-static inline void clear_thread_flag(int flag)
-{
-        clear_bit(flag,&current_thread_info()->flags);
-}
-
-static inline int test_and_set_thread_flag(int flag)
-{
-        return test_and_set_bit(flag,&current_thread_info()->flags);
-}
-
-static inline int test_and_clear_thread_flag(int flag)
-{
-        return test_and_clear_bit(flag,&current_thread_info()->flags);
-}
-
-static inline int test_thread_flag(int flag)
-{
-        return test_bit(flag,&current_thread_info()->flags);
-}
-
 static inline void set_ti_thread_flag(struct thread_info *ti, int flag)
 {
         set_bit(flag,&ti->flags);
@@ -77,15 +52,19 @@ static inline int test_ti_thread_flag(struct thread_info *ti, int flag)
         return test_bit(flag,&ti->flags);
 }
 
-static inline void set_need_resched(void)
-{
-        set_thread_flag(TIF_NEED_RESCHED);
-}
-
-static inline void clear_need_resched(void)
-{
-        clear_thread_flag(TIF_NEED_RESCHED);
-}
+#define set_thread_flag(flag) \
+        set_ti_thread_flag(current_thread_info(), flag)
+#define clear_thread_flag(flag) \
+        clear_ti_thread_flag(current_thread_info(), flag)
+#define test_and_set_thread_flag(flag) \
+        test_and_set_ti_thread_flag(current_thread_info(), flag)
+#define test_and_clear_thread_flag(flag) \
+        test_and_clear_ti_thread_flag(current_thread_info(), flag)
+#define test_thread_flag(flag) \
+        test_ti_thread_flag(current_thread_info(), flag)
+
+#define set_need_resched()      set_thread_flag(TIF_NEED_RESCHED)
+#define clear_need_resched()    clear_thread_flag(TIF_NEED_RESCHED)
 
 #endif