1#ifndef __M68K_ENTRY_H
2#define __M68K_ENTRY_H
3
4#include <linux/config.h>
5#include <asm/setup.h>
6#include <asm/page.h>
7
8/*
9 * Stack layout in 'ret_from_exception':
10 *
11 *	This allows access to the syscall arguments in registers d1-d5
12 *
13 *	 0(sp) - d1
14 *	 4(sp) - d2
15 *	 8(sp) - d3
16 *	 C(sp) - d4
17 *	10(sp) - d5
18 *	14(sp) - a0
19 *	18(sp) - a1
20 *	1C(sp) - a2
21 *	20(sp) - d0
22 *	24(sp) - orig_d0
23 *	28(sp) - stack adjustment
24 *	2C(sp) - sr
25 *	2E(sp) - pc
26 *	32(sp) - format & vector
27 */
28
29/*
30 * 97/05/14 Andreas: Register %a2 is now set to the current task throughout
31 *		     the whole kernel.
32 */
33
34/* the following macro is used when enabling interrupts */
35#if defined(MACH_ATARI_ONLY) && !defined(CONFIG_HADES)
36	/* block out HSYNC on the atari */
37#define ALLOWINT 0xfbff
38#define	MAX_NOINT_IPL	3
39#else
40	/* portable version */
41#define ALLOWINT 0xf8ff
42#define	MAX_NOINT_IPL	0
43#endif /* machine compilation types */
44
45#ifdef __ASSEMBLY__
46
47#define curptr a2
48
49LFLUSH_I_AND_D = 0x00000808
50LSIGTRAP = 5
51
52/* process bits for task_struct.ptrace */
53PT_TRACESYS_OFF = 3
54PT_TRACESYS_BIT = 1
55PT_PTRACED_OFF = 3
56PT_PTRACED_BIT = 0
57PT_DTRACE_OFF = 3
58PT_DTRACE_BIT = 2
59
60#define SAVE_ALL_INT save_all_int
61#define SAVE_ALL_SYS save_all_sys
62#define RESTORE_ALL restore_all
63/*
64 * This defines the normal kernel pt-regs layout.
65 *
66 * regs a3-a6 and d6-d7 are preserved by C code
67 * the kernel doesn't mess with usp unless it needs to
68 */
69
70/*
71 * a -1 in the orig_d0 field signifies
72 * that the stack frame is NOT for syscall
73 */
74.macro	save_all_int
75	clrl	%sp@-		| stk_adj
76	pea	-1:w		| orig d0
77	movel	%d0,%sp@-	| d0
78	moveml	%d1-%d5/%a0-%a1/%curptr,%sp@-
79.endm
80
81.macro	save_all_sys
82	clrl	%sp@-		| stk_adj
83	movel	%d0,%sp@-	| orig d0
84	movel	%d0,%sp@-	| d0
85	moveml	%d1-%d5/%a0-%a1/%curptr,%sp@-
86.endm
87
88.macro	restore_all
89	moveml	%sp@+,%a0-%a1/%curptr/%d1-%d5
90	movel	%sp@+,%d0
91	addql	#4,%sp		| orig d0
92	addl	%sp@+,%sp	| stk adj
93	rte
94.endm
95
96#define SWITCH_STACK_SIZE (6*4+4)	/* includes return address */
97
98#define SAVE_SWITCH_STACK save_switch_stack
99#define RESTORE_SWITCH_STACK restore_switch_stack
100#define GET_CURRENT(tmp) get_current tmp
101
102.macro	save_switch_stack
103	moveml	%a3-%a6/%d6-%d7,%sp@-
104.endm
105
106.macro	restore_switch_stack
107	moveml	%sp@+,%a3-%a6/%d6-%d7
108.endm
109
110.macro	get_current reg=%d0
111	movel	%sp,\reg
112	andw	#-KTHREAD_SIZE,\reg
113	movel	\reg,%curptr
114.endm
115
116#else /* C source */
117
118#define STR(X) STR1(X)
119#define STR1(X) #X
120
121#define PT_OFF_ORIG_D0	 0x24
122#define PT_OFF_FORMATVEC 0x32
123#define PT_OFF_SR	 0x2C
124#define SAVE_ALL_INT				\
125	"clrl	%%sp@-;"    /* stk_adj */	\
126	"pea	-1:w;"	    /* orig d0 = -1 */	\
127	"movel	%%d0,%%sp@-;" /* d0 */		\
128	"moveml	%%d1-%%d5/%%a0-%%a2,%%sp@-"
129#define GET_CURRENT(tmp) \
130	"movel	%%sp,"#tmp"\n\t" \
131	"andw	#-"STR(KTHREAD_SIZE)","#tmp"\n\t" \
132	"movel	"#tmp",%%a2"
133
134#endif
135
136#endif /* __M68K_ENTRY_H */
137