1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * include/asm-m68k/processor.h
4 *
5 * Copyright (C) 1995 Hamish Macdonald
6 */
7
8 #ifndef __ASM_M68K_PROCESSOR_H
9 #define __ASM_M68K_PROCESSOR_H
10
11 /*
12 * Default implementation of macro that returns current
13 * instruction pointer ("program counter").
14 */
15 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
16
17 #include <linux/thread_info.h>
18 #include <asm/segment.h>
19 #include <asm/fpu.h>
20 #include <asm/ptrace.h>
21
22 static inline unsigned long rdusp(void)
23 {
24 #ifdef CONFIG_COLDFIRE_SW_A7
25 extern unsigned int sw_usp;
26 return sw_usp;
27 #else
28 register unsigned long usp __asm__("a0");
29 /* move %usp,%a0 */
30 __asm__ __volatile__(".word 0x4e68" : "=a" (usp));
31 return usp;
32 #endif
33 }
34
35 static inline void wrusp(unsigned long usp)
36 {
37 #ifdef CONFIG_COLDFIRE_SW_A7
38 extern unsigned int sw_usp;
39 sw_usp = usp;
40 #else
41 register unsigned long a0 __asm__("a0") = usp;
42 /* move %a0,%usp */
43 __asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
44 #endif
45 }
46
47 /*
48 * User space process size: 3.75GB. This is hardcoded into a few places,
49 * so don't change it unless you know what you are doing.
50 */
51 #ifdef CONFIG_MMU
52 #if defined(CONFIG_COLDFIRE)
53 #define TASK_SIZE (0xC0000000UL)
54 #elif defined(CONFIG_SUN3)
55 #define TASK_SIZE (0x0E000000UL)
56 #else
57 #define TASK_SIZE (0xF0000000UL)
58 #endif
59 #else
60 #define TASK_SIZE (0xFFFFFFFFUL)
61 #endif
62
63 #ifdef __KERNEL__
64 #define STACK_TOP TASK_SIZE
65 #define STACK_TOP_MAX STACK_TOP
66 #endif
67
68 /* This decides where the kernel will search for a free chunk of vm
69 * space during mmap's.
70 */
71 #ifdef CONFIG_MMU
72 #if defined(CONFIG_COLDFIRE)
73 #define TASK_UNMAPPED_BASE 0x60000000UL
74 #elif defined(CONFIG_SUN3)
75 #define TASK_UNMAPPED_BASE 0x0A000000UL
76 #else
77 #define TASK_UNMAPPED_BASE 0xC0000000UL
78 #endif
79 #define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
80 #else
81 #define TASK_UNMAPPED_BASE 0
82 #endif
83
84 struct thread_struct {
85 unsigned long ksp; /* kernel stack pointer */
86 unsigned long usp; /* user stack pointer */
87 unsigned short sr; /* saved status register */
88 unsigned short fs; /* saved fs (sfc, dfc) */
89 unsigned long crp[2]; /* cpu root pointer */
90 unsigned long esp0; /* points to SR of stack frame */
91 unsigned long faddr; /* info about last fault */
92 int signo, code;
93 unsigned long fp[8*3];
94 unsigned long fpcntl[3]; /* fp control regs */
95 unsigned char fpstate[FPSTATESIZE]; /* floating point state */
96 };
97
98 #define INIT_THREAD { \
99 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
100 .sr = PS_S, \
101 .fs = __KERNEL_DS, \
102 }
103
104 /*
105 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be
106 * true on thread creation). We need to set this explicitly.
107 */
108 #ifdef CONFIG_COLDFIRE
109 #define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0)
110 #else
111 #define setframeformat(_regs) do { } while (0)
112 #endif
113
114 /*
115 * Do necessary setup to start up a newly executed thread.
116 */
117 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
118 unsigned long usp)
119 {
120 regs->pc = pc;
121 regs->sr &= ~0x2000;
122 setframeformat(regs);
123 wrusp(usp);
124 }
125
126 /* Forward declaration, a strange C thing */
127 struct task_struct;
128
129 /* Free all resources held by a thread. */
130 static inline void release_thread(struct task_struct *dead_task)
131 {
132 }
133
134 unsigned long get_wchan(struct task_struct *p);
135
136 #define KSTK_EIP(tsk) \
137 ({ \
138 unsigned long eip = 0; \
139 if ((tsk)->thread.esp0 > PAGE_SIZE && \
140 (virt_addr_valid((tsk)->thread.esp0))) \
141 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
142 eip; })
143 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
144
145 #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
146
147 #define cpu_relax() barrier()
148
149 #endif
150
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