[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>

1 files changed, 40 insertions, 38 deletions

diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 23ca60a45552..320fde05dc63 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -44,9 +44,7 @@
 
 #include <asm/asm-offsets.h>
 
-.globl system_call, buserr, trap
-.globl resume, ret_from_exception
-.globl ret_from_signal
+.globl system_call, buserr, trap, resume
 .globl inthandler, sys_call_table
 .globl sys_fork, sys_clone, sys_vfork
 .globl ret_from_interrupt, bad_interrupt
@@ -58,7 +56,7 @@ ENTRY(buserr)
         movel   %sp,%sp@-               | stack frame pointer argument
         bsrl    buserr_c
         addql   #4,%sp
-        jra     ret_from_exception
+        jra     .Lret_from_exception
 
 ENTRY(trap)
         SAVE_ALL_INT
@@ -66,7 +64,7 @@ ENTRY(trap)
         movel   %sp,%sp@-               | stack frame pointer argument
         bsrl    trap_c
         addql   #4,%sp
-        jra     ret_from_exception
+        jra     .Lret_from_exception
 
         | After a fork we jump here directly from resume,
         | so that %d1 contains the previous task
@@ -75,30 +73,31 @@ ENTRY(ret_from_fork)
         movel   %d1,%sp@-
         jsr     schedule_tail
         addql   #4,%sp
-        jra     ret_from_exception
+        jra     .Lret_from_exception
 
-badsys:
-        movel   #-ENOSYS,%sp@(PT_D0)
-        jra     ret_from_exception
-
-do_trace:
+do_trace_entry:
         movel   #-ENOSYS,%sp@(PT_D0)    | needed for strace
         subql   #4,%sp
         SAVE_SWITCH_STACK
         jbsr    syscall_trace
         RESTORE_SWITCH_STACK
         addql   #4,%sp
-        movel   %sp@(PT_ORIG_D0),%d1
-        movel   #-ENOSYS,%d0
-        cmpl    #NR_syscalls,%d1
-        jcc     1f
-        jbsr    @(sys_call_table,%d1:l:4)@(0)
-1:      movel   %d0,%sp@(PT_D0)         | save the return value
-        subql   #4,%sp                  | dummy return address
+        movel   %sp@(PT_ORIG_D0),%d0
+        cmpl    #NR_syscalls,%d0
+        jcs     syscall
+badsys:
+        movel   #-ENOSYS,%sp@(PT_D0)
+        jra     ret_from_syscall
+
+do_trace_exit:
+        subql   #4,%sp
         SAVE_SWITCH_STACK
         jbsr    syscall_trace
+        RESTORE_SWITCH_STACK
+        addql   #4,%sp
+        jra     .Lret_from_exception
 
-ret_from_signal:
+ENTRY(ret_from_signal)
         RESTORE_SWITCH_STACK
         addql   #4,%sp
 /* on 68040 complete pending writebacks if any */
@@ -111,7 +110,7 @@ ret_from_signal:
         addql   #4,%sp
 1:
 #endif
-        jra     ret_from_exception
+        jra     .Lret_from_exception
 
 ENTRY(system_call)
         SAVE_ALL_SYS
@@ -120,30 +119,34 @@ ENTRY(system_call)
         | save top of frame
         movel   %sp,%curptr@(TASK_THREAD+THREAD_ESP0)
 
-        tstb    %curptr@(TASK_SYSCALL_TRACE)
-        jne     do_trace
+        | syscall trace?
+        tstb    %curptr@(TASK_INFO+TINFO_FLAGS+2)
+        jmi     do_trace_entry
         cmpl    #NR_syscalls,%d0
         jcc     badsys
+syscall:
         jbsr    @(sys_call_table,%d0:l:4)@(0)
         movel   %d0,%sp@(PT_D0)         | save the return value
-
+ret_from_syscall:
         |oriw   #0x0700,%sr
-        movel   %curptr@(TASK_WORK),%d0
+        movew   %curptr@(TASK_INFO+TINFO_FLAGS+2),%d0
         jne     syscall_exit_work
 1:      RESTORE_ALL
 
 syscall_exit_work:
         btst    #5,%sp@(PT_SR)          | check if returning to kernel
         bnes    1b                      | if so, skip resched, signals
-        tstw    %d0
-        jeq     do_signal_return
-        tstb    %d0
-        jne     do_delayed_trace
-
+        lslw    #1,%d0
+        jcs     do_trace_exit
+        jmi     do_delayed_trace
+        lslw    #8,%d0
+        jmi     do_signal_return
         pea     resume_userspace
-        jmp     schedule
+        jra     schedule
+
 
-ret_from_exception:
+ENTRY(ret_from_exception)
+.Lret_from_exception:
         btst    #5,%sp@(PT_SR)          | check if returning to kernel
         bnes    1f                      | if so, skip resched, signals
         | only allow interrupts when we are really the last one on the
@@ -152,19 +155,18 @@ ret_from_exception:
         andw    #ALLOWINT,%sr
 
 resume_userspace:
-        movel   %curptr@(TASK_WORK),%d0
-        lsrl    #8,%d0
+        moveb   %curptr@(TASK_INFO+TINFO_FLAGS+3),%d0
         jne     exit_work
 1:      RESTORE_ALL
 
 exit_work:
         | save top of frame
         movel   %sp,%curptr@(TASK_THREAD+THREAD_ESP0)
-        tstb    %d0
-        jeq     do_signal_return
-
+        lslb    #1,%d0
+        jmi     do_signal_return
         pea     resume_userspace
-        jmp     schedule
+        jra     schedule
+
 
 do_signal_return:
         |andw   #ALLOWINT,%sr
@@ -254,7 +256,7 @@ ret_from_interrupt:
 
         /* check if we need to do software interrupts */
         tstl    irq_stat+CPUSTAT_SOFTIRQ_PENDING
-        jeq     ret_from_exception
+        jeq     .Lret_from_exception
         pea     ret_from_exception
         jra     do_softirq