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m68k: merge MMU and non MMU versions of system.h

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The non-MMU m68k targets can use the same asm/system.h as the MMU
targets. So switch the current system_mm.h to be system.h and remove
system_no.h.

The assembly support code for the non-MMU resume functions needs to
be modified to match the now common switch_to() macro. Specifically
this means correctly saving and restoring the status flags in the case
of the ColdFire resume, and some reordering of the code to not use
registers before they are saved or after they are restored.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
This commit is contained in:
Greg Ungerer
2011-05-05 22:32:12 +10:00
parent 10f939ff3a
commit f941f5caa0
7 changed files with 222 additions and 380 deletions
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24
arch/m68k/platform/coldfire/entry.S
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@@ -182,21 +182,23 @@ ENTRY(inthandler)
/*
* Beware - when entering resume, prev (the current task) is
* in a0, next (the new task) is in a1,so don't change these
* in a0, next (the new task) is in a1, so don't change these
* registers until their contents are no longer needed.
* This is always called in supervisor mode, so don't bother to save
* and restore sr; user's process sr is actually in the stack.
*/
ENTRY(resume)
movel %a0, %d1 /* get prev thread in d1 */
RDUSP
movel %a2,%a0@(TASK_THREAD+THREAD_USP)
movew %sr,%d1 /* save current status */
movew %d1,%a0@(TASK_THREAD+THREAD_SR)
movel %a0,%d1 /* get prev thread in d1 */
SAVE_SWITCH_STACK
movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */
movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
RESTORE_SWITCH_STACK
RDUSP /* movel %usp,%a3 */
movel %a3,%a0@(TASK_THREAD+THREAD_USP) /* save thread user stack */
movel %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore thread user stack */
WRUSP
movel %a1@(TASK_THREAD+THREAD_USP),%a3 /* restore thread user stack */
WRUSP /* movel %a3,%usp */
movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new kernel stack */
movew %a1@(TASK_THREAD+THREAD_SR),%d7 /* restore new status */
movew %d7,%sr
RESTORE_SWITCH_STACK
rts