linux/arch/m68k/include/asm/entry_no.h
Greg Ungerer f941f5caa0 m68k: merge MMU and non MMU versions of system.h
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>
2011-07-25 11:20:40 +10:00

181 lines
4.1 KiB
C

#ifndef __M68KNOMMU_ENTRY_H
#define __M68KNOMMU_ENTRY_H
#include <asm/setup.h>
#include <asm/page.h>
/*
* Stack layout in 'ret_from_exception':
*
* This allows access to the syscall arguments in registers d1-d5
*
* 0(sp) - d1
* 4(sp) - d2
* 8(sp) - d3
* C(sp) - d4
* 10(sp) - d5
* 14(sp) - a0
* 18(sp) - a1
* 1C(sp) - a2
* 20(sp) - d0
* 24(sp) - orig_d0
* 28(sp) - stack adjustment
* 2C(sp) - [ sr ] [ format & vector ]
* 2E(sp) - [ pc-hiword ] [ sr ]
* 30(sp) - [ pc-loword ] [ pc-hiword ]
* 32(sp) - [ format & vector ] [ pc-loword ]
* ^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^
* M68K COLDFIRE
*/
#define ALLOWINT (~0x700)
#ifdef __ASSEMBLY__
#define SWITCH_STACK_SIZE (6*4+4) /* Includes return address */
/*
* This defines the normal kernel pt-regs layout.
*
* regs are a2-a6 and d6-d7 preserved by C code
* the kernel doesn't mess with usp unless it needs to
*/
#ifdef CONFIG_COLDFIRE
#ifdef CONFIG_COLDFIRE_SW_A7
/*
* This is made a little more tricky on older ColdFires. There is no
* separate supervisor and user stack pointers. Need to artificially
* construct a usp in software... When doing this we need to disable
* interrupts, otherwise bad things will happen.
*/
.globl sw_usp
.globl sw_ksp
.macro SAVE_ALL
move #0x2700,%sr /* disable intrs */
btst #5,%sp@(2) /* from user? */
bnes 6f /* no, skip */
movel %sp,sw_usp /* save user sp */
addql #8,sw_usp /* remove exception */
movel sw_ksp,%sp /* kernel sp */
subql #8,%sp /* room for exception */
clrl %sp@- /* stkadj */
movel %d0,%sp@- /* orig d0 */
movel %d0,%sp@- /* d0 */
lea %sp@(-32),%sp /* space for 8 regs */
moveml %d1-%d5/%a0-%a2,%sp@
movel sw_usp,%a0 /* get usp */
movel %a0@-,%sp@(PT_OFF_PC) /* copy exception program counter */
movel %a0@-,%sp@(PT_OFF_FORMATVEC)/*copy exception format/vector/sr */
bra 7f
6:
clrl %sp@- /* stkadj */
movel %d0,%sp@- /* orig d0 */
movel %d0,%sp@- /* d0 */
lea %sp@(-32),%sp /* space for 8 regs */
moveml %d1-%d5/%a0-%a2,%sp@
7:
.endm
.macro RESTORE_USER
move #0x2700,%sr /* disable intrs */
movel sw_usp,%a0 /* get usp */
movel %sp@(PT_OFF_PC),%a0@- /* copy exception program counter */
movel %sp@(PT_OFF_FORMATVEC),%a0@-/*copy exception format/vector/sr */
moveml %sp@,%d1-%d5/%a0-%a2
lea %sp@(32),%sp /* space for 8 regs */
movel %sp@+,%d0
addql #4,%sp /* orig d0 */
addl %sp@+,%sp /* stkadj */
addql #8,%sp /* remove exception */
movel %sp,sw_ksp /* save ksp */
subql #8,sw_usp /* set exception */
movel sw_usp,%sp /* restore usp */
rte
.endm
.macro RDUSP
movel sw_usp,%a3
.endm
.macro WRUSP
movel %a3,sw_usp
.endm
#else /* !CONFIG_COLDFIRE_SW_A7 */
/*
* Modern ColdFire parts have separate supervisor and user stack
* pointers. Simple load and restore macros for this case.
*/
.macro SAVE_ALL
move #0x2700,%sr /* disable intrs */
clrl %sp@- /* stkadj */
movel %d0,%sp@- /* orig d0 */
movel %d0,%sp@- /* d0 */
lea %sp@(-32),%sp /* space for 8 regs */
moveml %d1-%d5/%a0-%a2,%sp@
.endm
.macro RESTORE_USER
moveml %sp@,%d1-%d5/%a0-%a2
lea %sp@(32),%sp /* space for 8 regs */
movel %sp@+,%d0
addql #4,%sp /* orig d0 */
addl %sp@+,%sp /* stkadj */
rte
.endm
.macro RDUSP
/*move %usp,%a3*/
.word 0x4e6b
.endm
.macro WRUSP
/*move %a3,%usp*/
.word 0x4e63
.endm
#endif /* !CONFIG_COLDFIRE_SW_A7 */
.macro SAVE_SWITCH_STACK
lea %sp@(-24),%sp /* 6 regs */
moveml %a3-%a6/%d6-%d7,%sp@
.endm
.macro RESTORE_SWITCH_STACK
moveml %sp@,%a3-%a6/%d6-%d7
lea %sp@(24),%sp /* 6 regs */
.endm
#else /* !CONFIG_COLDFIRE */
/*
* Standard 68k interrupt entry and exit macros.
*/
.macro SAVE_ALL
clrl %sp@- /* stkadj */
movel %d0,%sp@- /* orig d0 */
movel %d0,%sp@- /* d0 */
moveml %d1-%d5/%a0-%a2,%sp@-
.endm
.macro RESTORE_ALL
moveml %sp@+,%a0-%a2/%d1-%d5
movel %sp@+,%d0
addql #4,%sp /* orig d0 */
addl %sp@+,%sp /* stkadj */
rte
.endm
.macro SAVE_SWITCH_STACK
moveml %a3-%a6/%d6-%d7,%sp@-
.endm
.macro RESTORE_SWITCH_STACK
moveml %sp@+,%a3-%a6/%d6-%d7
.endm
#endif /* !COLDFIRE_SW_A7 */
#endif /* __ASSEMBLY__ */
#endif /* __M68KNOMMU_ENTRY_H */