1 /*
2 * include/asm-m68k/processor.h
3 *
4 * Copyright (C) 1995 Hamish Macdonald
5 */
6
7 #ifndef __ASM_M68K_PROCESSOR_H
8 #define __ASM_M68K_PROCESSOR_H
9
10 /*
11 * Default implementation of macro that returns current
12 * instruction pointer ("program counter").
13 */
14 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
15
16 #include <linux/config.h>
17 #include <asm/segment.h>
18 #include <asm/fpu.h>
19 #include <asm/ptrace.h>
20
21 extern inline unsigned long rdusp(void) {
22 unsigned long usp;
23
24 __asm__ __volatile__("move %/usp,%0" : "=a" (usp));
25 return usp;
26 }
27
28 extern inline void wrusp(unsigned long usp) {
29 __asm__ __volatile__("move %0,%/usp" : : "a" (usp));
30 }
31
32 /*
33 * User space process size: 3.75GB. This is hardcoded into a few places,
34 * so don't change it unless you know what you are doing.
35 */
36 #ifndef CONFIG_SUN3
37 #define TASK_SIZE (0xF0000000UL)
38 #else
39 #ifdef __ASSEMBLY__
40 #define TASK_SIZE (0x0E000000)
41 #else
42 #define TASK_SIZE (0x0E000000UL)
43 #endif
44 #endif
45
46 /* This decides where the kernel will search for a free chunk of vm
47 * space during mmap's.
48 */
49 #ifndef CONFIG_SUN3
50 #define TASK_UNMAPPED_BASE 0xC0000000UL
51 #else
52 #define TASK_UNMAPPED_BASE 0x0A000000UL
53 #endif
54 #define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
55
56 /*
57 * Bus types
58 */
59 #define EISA_bus 0
60 #define MCA_bus 0
61
62 /*
63 * if you change this structure, you must change the code and offsets
64 * in m68k/machasm.S
65 */
66
67 struct thread_struct {
68 unsigned long ksp; /* kernel stack pointer */
69 unsigned long usp; /* user stack pointer */
70 unsigned short sr; /* saved status register */
71 unsigned short fs; /* saved fs (sfc, dfc) */
72 unsigned long crp[2]; /* cpu root pointer */
73 unsigned long esp0; /* points to SR of stack frame */
74 unsigned long faddr; /* info about last fault */
75 int signo, code;
76 unsigned long fp[8*3];
77 unsigned long fpcntl[3]; /* fp control regs */
78 unsigned char fpstate[FPSTATESIZE]; /* floating point state */
79 };
80
81 #define INIT_MMAP { &init_mm, 0, 0x40000000, NULL, __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED), VM_READ | VM_WRITE | VM_EXEC, 1, NULL, NULL }
82
83 #define INIT_THREAD { \
84 sizeof(init_stack) + (unsigned long) init_stack, 0, \
85 PS_S, __KERNEL_DS, \
86 }
87
88 /*
89 * Do necessary setup to start up a newly executed thread.
90 */
91 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
92 unsigned long usp)
93 {
94 /* reads from user space */
95 set_fs(USER_DS);
96
97 regs->pc = pc;
98 regs->sr &= ~0x2000;
99 wrusp(usp);
100 }
101
102 /* Forward declaration, a strange C thing */
103 struct task_struct;
104
105 /* Free all resources held by a thread. */
106 static inline void release_thread(struct task_struct *dead_task)
107 {
108 }
109
110 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
111
112 #define copy_segments(tsk, mm) do { } while (0)
113 #define release_segments(mm) do { } while (0)
114
115 /*
116 * Free current thread data structures etc..
117 */
118 static inline void exit_thread(void)
119 {
120 }
121
122 /*
123 * Return saved PC of a blocked thread.
124 */
125 extern inline unsigned long thread_saved_pc(struct thread_struct *t)
126 {
127 extern void scheduling_functions_start_here(void);
128 extern void scheduling_functions_end_here(void);
129 struct switch_stack *sw = (struct switch_stack *)t->ksp;
130 /* Check whether the thread is blocked in resume() */
131 if (sw->retpc > (unsigned long)scheduling_functions_start_here &&
132 sw->retpc < (unsigned long)scheduling_functions_end_here)
133 return ((unsigned long *)sw->a6)[1];
134 else
135 return sw->retpc;
136 }
137
138 unsigned long get_wchan(struct task_struct *p);
139
140 #define KSTK_EIP(tsk) \
141 ({ \
142 unsigned long eip = 0; \
143 if ((tsk)->thread.esp0 > PAGE_SIZE && \
144 (VALID_PAGE(virt_to_page((tsk)->thread.esp0)))) \
145 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
146 eip; })
147 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
148
149 #define THREAD_SIZE (2*PAGE_SIZE)
150
151 /* Allocation and freeing of basic task resources. */
152 #define alloc_task_struct() \
153 ((struct task_struct *) __get_free_pages(GFP_KERNEL,1))
154 #define free_task_struct(p) free_pages((unsigned long)(p),1)
155 #define get_task_struct(tsk) atomic_inc(&virt_to_page(tsk)->count)
156
157 #define init_task (init_task_union.task)
158 #define init_stack (init_task_union.stack)
159
160 #endif
161
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