1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * include/asm-h8300/processor.h
4 *
5 * Copyright (C) 2002 Yoshinori Sato
6 *
7 * Based on: linux/asm-m68nommu/processor.h
8 *
9 * Copyright (C) 1995 Hamish Macdonald
10 */
11
12 #ifndef __ASM_H8300_PROCESSOR_H
13 #define __ASM_H8300_PROCESSOR_H
14
15 #include <linux/compiler.h>
16 #include <asm/segment.h>
17 #include <asm/ptrace.h>
18 #include <asm/current.h>
19
20 static inline unsigned long rdusp(void)
21 {
22 extern unsigned int _sw_usp;
23
24 return _sw_usp;
25 }
26
27 static inline void wrusp(unsigned long usp)
28 {
29 extern unsigned int _sw_usp;
30
31 _sw_usp = usp;
32 }
33
34 /*
35 * User space process size: 3.75GB. This is hardcoded into a few places,
36 * so don't change it unless you know what you are doing.
37 */
38 #define TASK_SIZE (0xFFFFFFFFUL)
39
40 #ifdef __KERNEL__
41 #define STACK_TOP TASK_SIZE
42 #define STACK_TOP_MAX STACK_TOP
43 #endif
44
45 /*
46 * This decides where the kernel will search for a free chunk of vm
47 * space during mmap's. We won't be using it
48 */
49 #define TASK_UNMAPPED_BASE 0
50
51 struct thread_struct {
52 unsigned long ksp; /* kernel stack pointer */
53 unsigned long usp; /* user stack pointer */
54 unsigned long ccr; /* saved status register */
55 unsigned long esp0; /* points to SR of stack frame */
56 struct {
57 unsigned short *addr;
58 unsigned short inst;
59 } breakinfo;
60 };
61
62 #define INIT_THREAD { \
63 .ksp = sizeof(init_stack) + (unsigned long)init_stack, \
64 .usp = 0, \
65 .ccr = PS_S, \
66 .esp0 = 0, \
67 .breakinfo = { \
68 .addr = (unsigned short *)-1, \
69 .inst = 0 \
70 } \
71 }
72
73 /*
74 * Do necessary setup to start up a newly executed thread.
75 *
76 * pass the data segment into user programs if it exists,
77 * it can't hurt anything as far as I can tell
78 */
79 #if defined(CONFIG_CPU_H8300H)
80 #define start_thread(_regs, _pc, _usp) \
81 do { \
82 (_regs)->pc = (_pc); \
83 (_regs)->ccr = 0x00; /* clear all flags */ \
84 (_regs)->er5 = current->mm->start_data; /* GOT base */ \
85 (_regs)->sp = ((unsigned long)(_usp)) - sizeof(unsigned long) * 3; \
86 } while (0)
87 #endif
88 #if defined(CONFIG_CPU_H8S)
89 #define start_thread(_regs, _pc, _usp) \
90 do { \
91 (_regs)->pc = (_pc); \
92 (_regs)->ccr = 0x00; /* clear kernel flag */ \
93 (_regs)->exr = 0x78; /* enable all interrupts */ \
94 (_regs)->er5 = current->mm->start_data; /* GOT base */ \
95 /* 14 = space for retaddr(4), vector(4), er0(4) and exr(2) on stack */ \
96 (_regs)->sp = ((unsigned long)(_usp)) - 14; \
97 } while (0)
98 #endif
99
100 /* Forward declaration, a strange C thing */
101 struct task_struct;
102
103 /* Free all resources held by a thread. */
104 static inline void release_thread(struct task_struct *dead_task)
105 {
106 }
107
108 unsigned long get_wchan(struct task_struct *p);
109
110 #define KSTK_EIP(tsk) \
111 ({ \
112 unsigned long eip = 0; \
113 if ((tsk)->thread.esp0 > PAGE_SIZE && \
114 MAP_NR((tsk)->thread.esp0) < max_mapnr) \
115 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
116 eip; })
117
118 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
119
120 #define cpu_relax() barrier()
121
122 #define HARD_RESET_NOW() ({ \
123 local_irq_disable(); \
124 asm("jmp @@0"); \
125 })
126
127 #endif