[PATCH] m68knommu: improve syscall entry and fix strace

Here is a patch to the system call handling for 5307/5272/etc to:

- fix the strace support (one tested the wrong bit)
- make all system calls a little bit faster by inlining set_esp0 and
  supporting ENOSYS out of the critical path.
- remove extraneous spaces

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 20 insertions, 26 deletions

diff --git a/arch/m68knommu/platform/5307/entry.S b/arch/m68knommu/platform/5307/entry.S
index 89b180d4ed6a..9ddf5476ef8f 100644
--- a/arch/m68knommu/platform/5307/entry.S
+++ b/arch/m68knommu/platform/5307/entry.S
@@ -4,8 +4,8 @@
  *  Copyright (C) 1999-2002, Greg Ungerer (gerg@snapgear.com)
  *  Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>,
  *                      Kenneth Albanowski <kjahds@kjahds.com>,
- *  Copyright (C) 2000  Lineo Inc. (www.lineo.com) 
- *  Copyright (C) 2004  Macq Electronique SA. (www.macqel.com)
+ *  Copyright (C) 2000  Lineo Inc. (www.lineo.com)
+ *  Copyright (C) 2004-2006  Macq Electronique SA. (www.macqel.com)
  *
  * Based on:
  *
@@ -56,32 +56,27 @@ sw_usp:
 .globl inthandler
 .globl fasthandler
 
+enosys:
+        mov.l   #sys_ni_syscall,%d3
+        bra     1f
+
 ENTRY(system_call)
         SAVE_ALL
         move    #0x2000,%sr             /* enable intrs again */
 
-        movel   #-LENOSYS,%d2
-        movel   %d2,PT_D0(%sp)          /* default return value in d0 */
-                                        /* original D0 is in orig_d0 */
-        movel   %d0,%d2
-
-        /* save top of frame */
-        pea     %sp@
-        jbsr    set_esp0
-        addql   #4,%sp
-
-        cmpl    #NR_syscalls,%d2
-        jcc     ret_from_exception
+        cmpl    #NR_syscalls,%d0
+        jcc     enosys
         lea     sys_call_table,%a0
-        lsll    #2,%d2                  /* movel %a0@(%d2:l:4),%d3 */
-        movel   %a0@(%d2),%d3
-        jeq     ret_from_exception
-        lsrl    #2,%d2
+        lsll    #2,%d0                  /* movel %a0@(%d0:l:4),%d3 */
+        movel   %a0@(%d0),%d3
+        jeq     enosys
 
+1:
         movel   %sp,%d2                 /* get thread_info pointer */
         andl    #-THREAD_SIZE,%d2       /* at start of kernel stack */
         movel   %d2,%a0
-        btst    #TIF_SYSCALL_TRACE,%a0@(TI_FLAGS)
+        movel   %sp,%a0@(THREAD_ESP0)   /* save top of frame */
+        btst    #(TIF_SYSCALL_TRACE%8),%a0@(TI_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
         bnes    1f
 
         movel   %d3,%a0
@@ -126,8 +121,8 @@ Luser_return:
         jne     Lwork_to_do             /* still work to do */
 
 Lreturn:
-        move    #0x2700,%sr             /* disable intrs */
-        movel   sw_usp,%a0              /* get usp */
+        move    #0x2700,%sr             /* disable intrs */
+        movel   sw_usp,%a0              /* get usp */
         movel   %sp@(PT_PC),%a0@-       /* copy exception program counter */
         movel   %sp@(PT_FORMATVEC),%a0@-/* copy exception format/vector/sr */
         moveml  %sp@,%d1-%d5/%a0-%a2
@@ -170,7 +165,7 @@ ENTRY(inthandler)
         movel   %d0,%sp@(PT_ORIG_D0)
         addql   #1,local_irq_count
 
-        movew   %sp@(PT_FORMATVEC),%d0  /* put exception # in d0 */
+        movew   %sp@(PT_FORMATVEC),%d0  /* put exception # in d0 */
         andl    #0x03fc,%d0             /* mask out vector only */
 
         leal    per_cpu__kstat+STAT_IRQ,%a0
@@ -184,7 +179,7 @@ ENTRY(inthandler)
 
         movel   %sp,%sp@-               /* push regs arg onto stack */
         movel   %a0@(8),%sp@-           /* push devid arg */
-        movel   %d0,%sp@-               /* push vector # on stack */
+        movel   %d0,%sp@-               /* push vector # on stack */
 
         movel   %a0@,%a0                /* get function to call */
         jbsr    %a0@                    /* call vector handler */
@@ -201,7 +196,7 @@ ENTRY(inthandler)
 ENTRY(fasthandler)
         SAVE_LOCAL
 
-        movew   %sp@(PT_FORMATVEC),%d0
+        movew   %sp@(PT_FORMATVEC),%d0
         andl    #0x03fc,%d0             /* mask out vector only */
 
         leal    per_cpu__kstat+STAT_IRQ,%a0
@@ -210,7 +205,7 @@ ENTRY(fasthandler)
         movel   %sp,%sp@-               /* push regs arg onto stack */
         clrl    %sp@-                   /* push devid arg */
         lsrl    #2,%d0                  /* calculate real vector # */
-        movel   %d0,%sp@-               /* push vector # on stack */
+        movel   %d0,%sp@-               /* push vector # on stack */
 
         lsll    #4,%d0                  /* adjust for array offset */
         lea     irq_list,%a0
@@ -265,4 +260,3 @@ ENTRY(resume)
         movew   %a1@(TASK_THREAD+THREAD_SR),%d0 /* restore thread status reg */
         movew   %d0, %sr
         rts
-