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