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/segment.h>
13 #include <asm/fpu.h>
14 #include <asm/ptrace.h>
15
16 static 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
29 static 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 struct thread_struct {
79 unsigned long ksp; /* kernel stack pointer */
80 unsigned long usp; /* user stack pointer */
81 unsigned short sr; /* saved status register */
82 unsigned short fs; /* saved fs (sfc, dfc) */
83 unsigned long crp[2]; /* cpu root pointer */
84 unsigned long esp0; /* points to SR of stack frame */
85 unsigned long faddr; /* info about last fault */
86 int signo, code;
87 unsigned long fp[8*3];
88 unsigned long fpcntl[3]; /* fp control regs */
89 unsigned char fpstate[FPSTATESIZE]; /* floating point state */
90 };
91
92 #define INIT_THREAD { \
93 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
94 .sr = PS_S, \
95 .fs = __KERNEL_DS, \
96 }
97
98 /*
99 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be
100 * true on thread creation). We need to set this explicitly.
101 */
102 #ifdef CONFIG_COLDFIRE
103 #define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0)
104 #else
105 #define setframeformat(_regs) do { } while (0)
106 #endif
107
108 /*
109 * Do necessary setup to start up a newly executed thread.
110 */
111 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
112 unsigned long usp)
113 {
114 regs->pc = pc;
115 regs->sr &= ~0x2000;
116 setframeformat(regs);
117 wrusp(usp);
118 }
119
120 /* Forward declaration, a strange C thing */
121 struct task_struct;
122
123 /* Free all resources held by a thread. */
124 static inline void release_thread(struct task_struct *dead_task)
125 {
126 }
127
128 unsigned long get_wchan(struct task_struct *p);
129
130 #define KSTK_EIP(tsk) \
131 ({ \
132 unsigned long eip = 0; \
133 if ((tsk)->thread.esp0 > PAGE_SIZE && \
134 (virt_addr_valid((tsk)->thread.esp0))) \
135 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
136 eip; })
137 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
138
139 #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
140
141 #define cpu_relax() barrier()
142
143 #endif
144
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