Discussion:
[uClinux-dev] [PATCH v2 00/03]: clean up and merge the MMU and non-MMU versions of entry.S
gerg
2012-05-18 04:22:48 UTC
Permalink
With a little cleanup we can use much of the entry.S code on both the
MMU and non-MMU m68k targets.

This is the second iteration of this patch set. I have limited the
changes converting to use the ret_from_exception function entry point
over the label. I have only changed those shared by both the MMU and
non-MMU code. Andreas, does this look more acceptable?

---
arch/m68k/kernel/entry.S | 453 +++++++++++++++++++++++++++++++++++++++++++-
arch/m68k/kernel/entry_mm.S | 423 -----------------------------------------
arch/m68k/kernel/entry_no.S | 130 ------------
3 files changed, 452 insertions(+), 554 deletions(-)
gerg
2012-05-18 04:22:49 UTC
Permalink
From: Greg Ungerer <gerg at uclinux.org>

The ret_from_excption code is referenced by its function name, or by a label
set at the start of its code. The non-MMU code can share some of this code
if we make direct calls to ret_from_exception instead of the associated label.
The effected function paths are: buserr, trap and ret_from_fork. So change
these to branch directly to ret_from_exception.

Signed-off-by: Greg Ungerer <gerg at uclinux.org>
---
arch/m68k/kernel/entry_mm.S | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/m68k/kernel/entry_mm.S b/arch/m68k/kernel/entry_mm.S
index 675a854..f3cd173 100644
--- a/arch/m68k/kernel/entry_mm.S
+++ b/arch/m68k/kernel/entry_mm.S
@@ -57,7 +57,7 @@ ENTRY(buserr)
movel %sp,%sp at - | stack frame pointer argument
bsrl buserr_c
addql #4,%sp
- jra .Lret_from_exception
+ jra ret_from_exception

ENTRY(trap)
SAVE_ALL_INT
@@ -65,7 +65,7 @@ ENTRY(trap)
movel %sp,%sp at - | stack frame pointer argument
bsrl trap_c
addql #4,%sp
- jra .Lret_from_exception
+ jra ret_from_exception

| After a fork we jump here directly from resume,
| so that %d1 contains the previous task
@@ -74,7 +74,7 @@ ENTRY(ret_from_fork)
movel %d1,%sp at -
jsr schedule_tail
addql #4,%sp
- jra .Lret_from_exception
+ jra ret_from_exception

do_trace_entry:
movel #-ENOSYS,%sp@(PT_OFF_D0)| needed for strace
--
1.7.0.4
Geert Uytterhoeven
2012-05-20 09:19:44 UTC
Permalink
Post by gerg
From: Greg Ungerer <gerg at uclinux.org>
The ret_from_excption code is referenced by its function name, or by a label
set at the start of its code. The non-MMU code can share some of this code
if we make direct calls to ret_from_exception instead of the associated label.
The effected function paths are: buserr, trap and ret_from_fork. So change
these to branch directly to ret_from_exception.
Signed-off-by: Greg Ungerer <gerg at uclinux.org>
Acked-by: Geert Uytterhoeven <geert at linux-m68k.org>

Gr{oetje,eeting}s,

? ? ? ? ? ? ? ? ? ? ? ? Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
? ? ? ? ? ? ? ? ? ? ? ? ? ?? ?? -- Linus Torvalds
gerg
2012-05-18 04:22:50 UTC
Permalink
From: Greg Ungerer <gerg at uclinux.org>

There is a few places that the m68k entry code uses the bsrl instruction
to call other functions. That instruction is only supported on 68020 and
higher CPU types. If we use jbsr instead the code will be clean for all
68k and ColdFire CPU types.

Signed-off-by: Greg Ungerer <gerg at uclinux.org>
---
arch/m68k/kernel/entry_mm.S | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/m68k/kernel/entry_mm.S b/arch/m68k/kernel/entry_mm.S
index f3cd173..2385539 100644
--- a/arch/m68k/kernel/entry_mm.S
+++ b/arch/m68k/kernel/entry_mm.S
@@ -55,7 +55,7 @@ ENTRY(buserr)
SAVE_ALL_INT
GET_CURRENT(%d0)
movel %sp,%sp at - | stack frame pointer argument
- bsrl buserr_c
+ jbsr buserr_c
addql #4,%sp
jra ret_from_exception

@@ -63,7 +63,7 @@ ENTRY(trap)
SAVE_ALL_INT
GET_CURRENT(%d0)
movel %sp,%sp at - | stack frame pointer argument
- bsrl trap_c
+ jbsr trap_c
addql #4,%sp
jra ret_from_exception
--
1.7.0.4
Geert Uytterhoeven
2012-05-20 09:15:44 UTC
Permalink
Post by gerg
From: Greg Ungerer <gerg at uclinux.org>
There is a few places that the m68k entry code uses the bsrl instruction
to call other functions. That instruction is only supported on 68020 and
higher CPU types. If we use jbsr instead the code will be clean for all
68k and ColdFire CPU types.
Signed-off-by: Greg Ungerer <gerg at uclinux.org>
Acked-by: Geert Uytterhoeven <geert at linux-m68k.org>

Gr{oetje,eeting}s,

? ? ? ? ? ? ? ? ? ? ? ? Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
? ? ? ? ? ? ? ? ? ? ? ? ? ?? ?? -- Linus Torvalds
gerg
2012-05-18 04:22:51 UTC
Permalink
From: Greg Ungerer <gerg at uclinux.org>

Some of the entry.S code is common to both MMU and non-MMU builds.
So merge the entry_no.S and entry_mm.S files back into a single file.
With a little code movement we only need a single #ifdef.

Signed-off-by: Greg Ungerer <gerg at uclinux.org>
---
arch/m68k/kernel/{entry_mm.S => entry.S} | 105 ++++++++++++++++--------
arch/m68k/kernel/entry_no.S | 130 ------------------------------
2 files changed, 69 insertions(+), 166 deletions(-)
rename arch/m68k/kernel/{entry_mm.S => entry.S} (94%)
delete mode 100644 arch/m68k/kernel/entry_no.S

diff --git a/arch/m68k/kernel/entry_mm.S b/arch/m68k/kernel/entry.S
similarity index 94%
rename from arch/m68k/kernel/entry_mm.S
rename to arch/m68k/kernel/entry.S
index 2385539..e871701 100644
--- a/arch/m68k/kernel/entry_mm.S
+++ b/arch/m68k/kernel/entry.S
@@ -51,6 +51,42 @@
.globl user_irqvec_fixup

.text
+ENTRY(sys_fork)
+ SAVE_SWITCH_STACK
+ pea %sp@(SWITCH_STACK_SIZE)
+ jbsr m68k_fork
+ addql #4,%sp
+ RESTORE_SWITCH_STACK
+ rts
+
+ENTRY(sys_clone)
+ SAVE_SWITCH_STACK
+ pea %sp@(SWITCH_STACK_SIZE)
+ jbsr m68k_clone
+ addql #4,%sp
+ RESTORE_SWITCH_STACK
+ rts
+
+ENTRY(sys_vfork)
+ SAVE_SWITCH_STACK
+ pea %sp@(SWITCH_STACK_SIZE)
+ jbsr m68k_vfork
+ addql #4,%sp
+ RESTORE_SWITCH_STACK
+ rts
+
+ENTRY(sys_sigreturn)
+ SAVE_SWITCH_STACK
+ jbsr do_sigreturn
+ RESTORE_SWITCH_STACK
+ rts
+
+ENTRY(sys_rt_sigreturn)
+ SAVE_SWITCH_STACK
+ jbsr do_rt_sigreturn
+ RESTORE_SWITCH_STACK
+ rts
+
ENTRY(buserr)
SAVE_ALL_INT
GET_CURRENT(%d0)
@@ -76,6 +112,38 @@ ENTRY(ret_from_fork)
addql #4,%sp
jra ret_from_exception

+#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
+
+#ifdef TRAP_DBG_INTERRUPT
+
+.globl dbginterrupt
+ENTRY(dbginterrupt)
+ SAVE_ALL_INT
+ GET_CURRENT(%d0)
+ movel %sp,%sp at - /* stack frame pointer argument */
+ jsr dbginterrupt_c
+ addql #4,%sp
+ jra ret_from_exception
+#endif
+
+ENTRY(reschedule)
+ /* save top of frame */
+ pea %sp@
+ jbsr set_esp0
+ addql #4,%sp
+ pea ret_from_exception
+ jmp schedule
+
+ENTRY(ret_from_user_signal)
+ moveq #__NR_sigreturn,%d0
+ trap #0
+
+ENTRY(ret_from_user_rt_signal)
+ movel #__NR_rt_sigreturn,%d0
+ trap #0
+
+#else
+
do_trace_entry:
movel #-ENOSYS,%sp@(PT_OFF_D0)| needed for strace
subql #4,%sp
@@ -274,42 +342,6 @@ ENTRY(bad_inthandler)
RESTORE_ALL


-ENTRY(sys_fork)
- SAVE_SWITCH_STACK
- pea %sp@(SWITCH_STACK_SIZE)
- jbsr m68k_fork
- addql #4,%sp
- RESTORE_SWITCH_STACK
- rts
-
-ENTRY(sys_clone)
- SAVE_SWITCH_STACK
- pea %sp@(SWITCH_STACK_SIZE)
- jbsr m68k_clone
- addql #4,%sp
- RESTORE_SWITCH_STACK
- rts
-
-ENTRY(sys_vfork)
- SAVE_SWITCH_STACK
- pea %sp@(SWITCH_STACK_SIZE)
- jbsr m68k_vfork
- addql #4,%sp
- RESTORE_SWITCH_STACK
- rts
-
-ENTRY(sys_sigreturn)
- SAVE_SWITCH_STACK
- jbsr do_sigreturn
- RESTORE_SWITCH_STACK
- rts
-
-ENTRY(sys_rt_sigreturn)
- SAVE_SWITCH_STACK
- jbsr do_rt_sigreturn
- RESTORE_SWITCH_STACK
- rts
-
resume:
/*
* Beware - when entering resume, prev (the current task) is
@@ -417,3 +449,4 @@ resume:

rts

+#endif /* CONFIG_MMU && !CONFIG_COLDFIRE */
diff --git a/arch/m68k/kernel/entry_no.S b/arch/m68k/kernel/entry_no.S
deleted file mode 100644
index d80cba4..0000000
--- a/arch/m68k/kernel/entry_no.S
+++ /dev/null
@@ -1,130 +0,0 @@
-/*
- * linux/arch/m68knommu/kernel/entry.S
- *
- * Copyright (C) 1999-2002, Greg Ungerer (gerg at snapgear.com)
- * Copyright (C) 1998 D. Jeff Dionne <jeff at lineo.ca>,
- * Kenneth Albanowski <kjahds at kjahds.com>,
- * Copyright (C) 2000 Lineo Inc. (www.lineo.com)
- *
- * Based on:
- *
- * linux/arch/m68k/kernel/entry.S
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file README.legal in the main directory of this archive
- * for more details.
- *
- * Linux/m68k support by Hamish Macdonald
- *
- * 68060 fixes by Jesper Skov
- * ColdFire support by Greg Ungerer (gerg at snapgear.com)
- * 5307 fixes by David W. Miller
- * linux 2.4 support David McCullough <davidm at snapgear.com>
- */
-
-#include <linux/linkage.h>
-#include <asm/errno.h>
-#include <asm/setup.h>
-#include <asm/segment.h>
-#include <asm/asm-offsets.h>
-#include <asm/entry.h>
-#include <asm/unistd.h>
-
-.text
-
-.globl buserr
-.globl trap
-.globl ret_from_exception
-.globl ret_from_signal
-.globl sys_fork
-.globl sys_clone
-.globl sys_vfork
-
-ENTRY(buserr)
- SAVE_ALL_INT
- GET_CURRENT(%d0)
- movel %sp,%sp at - /* stack frame pointer argument */
- jsr buserr_c
- addql #4,%sp
- jra ret_from_exception
-
-ENTRY(trap)
- SAVE_ALL_INT
- GET_CURRENT(%d0)
- movel %sp,%sp at - /* stack frame pointer argument */
- jsr trap_c
- addql #4,%sp
- jra ret_from_exception
-
-#ifdef TRAP_DBG_INTERRUPT
-
-.globl dbginterrupt
-ENTRY(dbginterrupt)
- SAVE_ALL_INT
- GET_CURRENT(%d0)
- movel %sp,%sp at - /* stack frame pointer argument */
- jsr dbginterrupt_c
- addql #4,%sp
- jra ret_from_exception
-#endif
-
-ENTRY(reschedule)
- /* save top of frame */
- pea %sp@
- jbsr set_esp0
- addql #4,%sp
- pea ret_from_exception
- jmp schedule
-
-ENTRY(ret_from_fork)
- movel %d1,%sp at -
- jsr schedule_tail
- addql #4,%sp
- jra ret_from_exception
-
-ENTRY(sys_fork)
- SAVE_SWITCH_STACK
- pea %sp@(SWITCH_STACK_SIZE)
- jbsr m68k_fork
- addql #4,%sp
- RESTORE_SWITCH_STACK
- rts
-
-ENTRY(sys_vfork)
- SAVE_SWITCH_STACK
- pea %sp@(SWITCH_STACK_SIZE)
- jbsr m68k_vfork
- addql #4,%sp
- RESTORE_SWITCH_STACK
- rts
-
-ENTRY(sys_clone)
- SAVE_SWITCH_STACK
- pea %sp@(SWITCH_STACK_SIZE)
- jbsr m68k_clone
- addql #4,%sp
- RESTORE_SWITCH_STACK
- rts
-
-ENTRY(sys_sigreturn)
- SAVE_SWITCH_STACK
- jbsr do_sigreturn
- RESTORE_SWITCH_STACK
- rts
-
-ENTRY(sys_rt_sigreturn)
- SAVE_SWITCH_STACK
- jbsr do_rt_sigreturn
- RESTORE_SWITCH_STACK
- rts
-
-ENTRY(ret_from_user_signal)
- moveq #__NR_sigreturn,%d0
- trap #0
-
-ENTRY(ret_from_user_rt_signal)
- movel #__NR_rt_sigreturn,%d0
- trap #0
-
--
1.7.0.4
Geert Uytterhoeven
2012-05-20 09:22:01 UTC
Permalink
Post by gerg
From: Greg Ungerer <gerg at uclinux.org>
Some of the entry.S code is common to both MMU and non-MMU builds.
So merge the entry_no.S and entry_mm.S files back into a single file.
With a little code movement we only need a single #ifdef.
Signed-off-by: Greg Ungerer <gerg at uclinux.org>
Acked-by: Geert Uytterhoeven <geert at linux-m68k.org>

Gr{oetje,eeting}s,

? ? ? ? ? ? ? ? ? ? ? ? Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
? ? ? ? ? ? ? ? ? ? ? ? ? ?? ?? -- Linus Torvalds

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