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 /* Free all resources held by a thread. */
release_thread(struct task_struct * dead_task)149 static inline void release_thread(struct task_struct *dead_task)
150 {
151 }
152
153 unsigned long get_wchan(struct task_struct *p);
154
155 #define KSTK_EIP(tsk) \
156 ({ \
157 unsigned long eip = 0; \
158 if ((tsk)->thread.esp0 > PAGE_SIZE && \
159 (virt_addr_valid((tsk)->thread.esp0))) \
160 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
161 eip; })
162 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
163
164 #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
165
166 #define cpu_relax() barrier()
167
168 #endif
169