linux/arch/mn10300/include/asm/frame.inc
David Howells 7c7fcf762e MN10300: Save frame pointer in thread_info struct rather than global var
Save the current exception frame pointer in the thread_info struct rather than
in a global variable as the latter makes SMP tricky, especially when preemption
is also enabled.

This also replaces __frame with current_frame() and rearranges header file
inclusions to make it all compile.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
2010-10-27 17:29:01 +01:00

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/* MN10300 Microcontroller core system register definitions -*- asm -*-
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_FRAME_INC
#define _ASM_FRAME_INC
#ifndef __ASSEMBLY__
#error not for use in C files
#endif
#ifndef __ASM_OFFSETS_H__
#include <asm/asm-offsets.h>
#endif
#include <asm/thread_info.h>
#define pi break
#define fp a3
###############################################################################
#
# build a stack frame from the registers
# - the caller has subtracted 4 from SP before coming here
#
###############################################################################
.macro SAVE_ALL
add -4,sp # next exception frame ptr save area
movm [other],(sp)
mov usp,a1
mov a1,(sp) # USP in MOVM[other] dummy slot
movm [d2,d3,a2,a3,exreg0,exreg1,exother],(sp)
mov sp,fp # FRAME pointer in A3
add -12,sp # allow for calls to be made
# push the exception frame onto the front of the list
GET_THREAD_INFO a1
mov (TI_frame,a1),a0
mov a0,(REG_NEXT,fp)
mov fp,(TI_frame,a1)
# disable the FPU inside the kernel
and ~EPSW_FE,epsw
# we may be holding current in E2
#ifdef CONFIG_MN10300_CURRENT_IN_E2
mov (__current),e2
#endif
.endm
###############################################################################
#
# restore the registers from a stack frame
#
###############################################################################
.macro RESTORE_ALL
# peel back the stack to the calling frame
# - this permits execve() to discard extra frames due to kernel syscalls
GET_THREAD_INFO a0
mov (TI_frame,a0),fp
mov fp,sp
mov (REG_NEXT,fp),d0
mov d0,(TI_frame,a0) # userspace has regs->next == 0
#ifndef CONFIG_MN10300_USING_JTAG
mov (REG_EPSW,fp),d0
btst EPSW_T,d0
beq 99f
or EPSW_NMID,epsw
movhu (DCR),d1
or 0x0001, d1
movhu d1,(DCR)
99:
#endif
movm (sp),[d2,d3,a2,a3,exreg0,exreg1,exother]
# must restore usp even if returning to kernel space,
# when CONFIG_PREEMPT is enabled.
mov (sp),a1 # USP in MOVM[other] dummy slot
mov a1,usp
movm (sp),[other]
add 8,sp
rti
.endm
#endif /* _ASM_FRAME_INC */