1 /*
2 * include/asm-h8300/processor.h
3 *
4 * Copyright (C) 2002 Yoshinori Sato
5 *
6 * Based on: linux/asm-m68nommu/processor.h
7 *
8 * Copyright (C) 1995 Hamish Macdonald
9 */
10
11 #ifndef __ASM_H8300_PROCESSOR_H
12 #define __ASM_H8300_PROCESSOR_H
13
14 /*
15 * Default implementation of macro that returns current
16 * instruction pointer ("program counter").
17 */
18 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
19
20 #include <linux/compiler.h>
21 #include <asm/segment.h>
22 #include <asm/fpu.h>
23 #include <asm/ptrace.h>
24 #include <asm/current.h>
25
rdusp(void)26 static inline unsigned long rdusp(void) {
27 extern unsigned int sw_usp;
28 return(sw_usp);
29 }
30
wrusp(unsigned long usp)31 static inline void wrusp(unsigned long usp) {
32 extern unsigned int sw_usp;
33 sw_usp = usp;
34 }
35
36 /*
37 * User space process size: 3.75GB. This is hardcoded into a few places,
38 * so don't change it unless you know what you are doing.
39 */
40 #define TASK_SIZE (0xFFFFFFFFUL)
41
42 #ifdef __KERNEL__
43 #define STACK_TOP TASK_SIZE
44 #define STACK_TOP_MAX STACK_TOP
45 #endif
46
47 /*
48 * This decides where the kernel will search for a free chunk of vm
49 * space during mmap's. We won't be using it
50 */
51 #define TASK_UNMAPPED_BASE 0
52
53 struct thread_struct {
54 unsigned long ksp; /* kernel stack pointer */
55 unsigned long usp; /* user stack pointer */
56 unsigned long ccr; /* saved status register */
57 unsigned long esp0; /* points to SR of stack frame */
58 struct {
59 unsigned short *addr;
60 unsigned short inst;
61 } breakinfo;
62 };
63
64 #define INIT_THREAD { \
65 .ksp = sizeof(init_stack) + (unsigned long)init_stack, \
66 .usp = 0, \
67 .ccr = PS_S, \
68 .esp0 = 0, \
69 .breakinfo = { \
70 .addr = (unsigned short *)-1, \
71 .inst = 0 \
72 } \
73 }
74
75 /*
76 * Do necessary setup to start up a newly executed thread.
77 *
78 * pass the data segment into user programs if it exists,
79 * it can't hurt anything as far as I can tell
80 */
81 #if defined(__H8300H__)
82 #define start_thread(_regs, _pc, _usp) \
83 do { \
84 (_regs)->pc = (_pc); \
85 (_regs)->ccr = 0x00; /* clear all flags */ \
86 (_regs)->er5 = current->mm->start_data; /* GOT base */ \
87 wrusp((unsigned long)(_usp) - sizeof(unsigned long)*3); \
88 } while(0)
89 #endif
90 #if defined(__H8300S__)
91 #define start_thread(_regs, _pc, _usp) \
92 do { \
93 (_regs)->pc = (_pc); \
94 (_regs)->ccr = 0x00; /* clear kernel flag */ \
95 (_regs)->exr = 0x78; /* enable all interrupts */ \
96 (_regs)->er5 = current->mm->start_data; /* GOT base */ \
97 /* 14 = space for retaddr(4), vector(4), er0(4) and ext(2) on stack */ \
98 wrusp(((unsigned long)(_usp)) - 14); \
99 } while(0)
100 #endif
101
102 /* Forward declaration, a strange C thing */
103 struct task_struct;
104
105 /* Free all resources held by a thread. */
release_thread(struct task_struct * dead_task)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 prepare_to_copy(tsk) do { } while (0)
113
114 /*
115 * Free current thread data structures etc..
116 */
exit_thread(void)117 static inline void exit_thread(void)
118 {
119 }
120
121 /*
122 * Return saved PC of a blocked thread.
123 */
124 unsigned long thread_saved_pc(struct task_struct *tsk);
125 unsigned long get_wchan(struct task_struct *p);
126
127 #define KSTK_EIP(tsk) \
128 ({ \
129 unsigned long eip = 0; \
130 if ((tsk)->thread.esp0 > PAGE_SIZE && \
131 MAP_NR((tsk)->thread.esp0) < max_mapnr) \
132 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
133 eip; })
134 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
135
136 #define cpu_relax() barrier()
137
138 #define HARD_RESET_NOW() ({ \
139 local_irq_disable(); \
140 asm("jmp @@0"); \
141 })
142
143 #endif
144