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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#include <linux/preempt.h>
12#include <linux/thread_info.h>
13#include <asm/fpu.h>
14#include <asm/ptrace.h>
15
16static inline unsigned long rdusp(void)
17{
18#ifdef CONFIG_COLDFIRE_SW_A7
19 extern unsigned int sw_usp;
20 return sw_usp;
21#else
22 register unsigned long usp __asm__("a0");
23 /* move %usp,%a0 */
24 __asm__ __volatile__(".word 0x4e68" : "=a" (usp));
25 return usp;
26#endif
27}
28
29static inline void wrusp(unsigned long usp)
30{
31#ifdef CONFIG_COLDFIRE_SW_A7
32 extern unsigned int sw_usp;
33 sw_usp = usp;
34#else
35 register unsigned long a0 __asm__("a0") = usp;
36 /* move %a0,%usp */
37 __asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
38#endif
39}
40
41/*
42 * User space process size: 3.75GB. This is hardcoded into a few places,
43 * so don't change it unless you know what you are doing.
44 */
45#ifdef CONFIG_MMU
46#if defined(CONFIG_COLDFIRE)
47#define TASK_SIZE (0xC0000000UL)
48#elif defined(CONFIG_SUN3)
49#define TASK_SIZE (0x0E000000UL)
50#else
51#define TASK_SIZE (0xF0000000UL)
52#endif
53#else
54#define TASK_SIZE (0xFFFFFFFFUL)
55#endif
56
57#ifdef __KERNEL__
58#define STACK_TOP TASK_SIZE
59#define STACK_TOP_MAX STACK_TOP
60#endif
61
62/* This decides where the kernel will search for a free chunk of vm
63 * space during mmap's.
64 */
65#ifdef CONFIG_MMU
66#if defined(CONFIG_COLDFIRE)
67#define TASK_UNMAPPED_BASE 0x60000000UL
68#elif defined(CONFIG_SUN3)
69#define TASK_UNMAPPED_BASE 0x0A000000UL
70#else
71#define TASK_UNMAPPED_BASE 0xC0000000UL
72#endif
73#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
74#else
75#define TASK_UNMAPPED_BASE 0
76#endif
77
78/* Address spaces (or Function Codes in Motorola lingo) */
79#define USER_DATA 1
80#define USER_PROGRAM 2
81#define SUPER_DATA 5
82#define SUPER_PROGRAM 6
83#define CPU_SPACE 7
84
85#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
86/*
87 * Set the SFC/DFC registers for special MM operations. For most normal
88 * operation these remain set to USER_DATA for the uaccess routines.
89 */
90static inline void set_fc(unsigned long val)
91{
92 WARN_ON_ONCE(in_interrupt());
93
94 __asm__ __volatile__ ("movec %0,%/sfc\n\t"
95 "movec %0,%/dfc\n\t"
96 : /* no outputs */ : "r" (val) : "memory");
97}
98
99static inline unsigned long get_fc(void)
100{
101 unsigned long val;
102
103 __asm__ ("movec %/dfc,%0" : "=r" (val) : );
104
105 return val;
106}
107#else
108static inline void set_fc(unsigned long val)
109{
110}
111
112static inline unsigned long get_fc(void)
113{
114 return USER_DATA;
115}
116#endif /* CONFIG_CPU_HAS_ADDRESS_SPACES */
117
118struct thread_struct {
119 unsigned long ksp; /* kernel stack pointer */
120 unsigned long usp; /* user stack pointer */
121 unsigned short sr; /* saved status register */
122 unsigned short fc; /* saved fc (sfc, dfc) */
123 unsigned long crp[2]; /* cpu root pointer */
124 unsigned long esp0; /* points to SR of stack frame */
125 unsigned long faddr; /* info about last fault */
126 int signo, code;
127 unsigned long fp[8*3];
128 unsigned long fpcntl[3]; /* fp control regs */
129 unsigned char fpstate[FPSTATESIZE]; /* floating point state */
130};
131
132#define INIT_THREAD { \
133 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
134 .sr = PS_S, \
135 .fc = USER_DATA, \
136}
137
138/*
139 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be
140 * true on thread creation). We need to set this explicitly.
141 */
142#ifdef CONFIG_COLDFIRE
143#define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0)
144#else
145#define setframeformat(_regs) do { } while (0)
146#endif
147
148/*
149 * Do necessary setup to start up a newly executed thread.
150 */
151static inline void start_thread(struct pt_regs * regs, unsigned long pc,
152 unsigned long usp)
153{
154 regs->pc = pc;
155 regs->sr &= ~0x2000;
156 setframeformat(regs);
157 wrusp(usp);
158}
159
160/* Forward declaration, a strange C thing */
161struct task_struct;
162
163unsigned long __get_wchan(struct task_struct *p);
164void show_registers(struct pt_regs *regs);
165
166#define KSTK_EIP(tsk) \
167 ({ \
168 unsigned long eip = 0; \
169 if ((tsk)->thread.esp0 > PAGE_SIZE && \
170 (virt_addr_valid((tsk)->thread.esp0))) \
171 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
172 eip; })
173#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
174
175#define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
176
177#define cpu_relax() barrier()
178
179#endif