2 * include/asm-m68k/processor.h
4 * Copyright (C) 1995 Hamish Macdonald
7 #ifndef __ASM_M68K_PROCESSOR_H
8 #define __ASM_M68K_PROCESSOR_H
11 * Default implementation of macro that returns current
12 * instruction pointer ("program counter").
14 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
16 #include <linux/thread_info.h>
17 #include <asm/segment.h>
19 #include <asm/ptrace.h>
21 static inline unsigned long rdusp(void)
23 #ifdef CONFIG_COLDFIRE_SW_A7
24 extern unsigned int sw_usp;
27 register unsigned long usp __asm__("a0");
29 __asm__ __volatile__(".word 0x4e68" : "=a" (usp));
34 static inline void wrusp(unsigned long usp)
36 #ifdef CONFIG_COLDFIRE_SW_A7
37 extern unsigned int sw_usp;
40 register unsigned long a0 __asm__("a0") = usp;
42 __asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
47 * User space process size: 3.75GB. This is hardcoded into a few places,
48 * so don't change it unless you know what you are doing.
52 #define TASK_SIZE (0xF0000000UL)
54 #define TASK_SIZE (0x0E000000UL)
57 #define TASK_SIZE (0xFFFFFFFFUL)
61 #define STACK_TOP TASK_SIZE
62 #define STACK_TOP_MAX STACK_TOP
65 /* This decides where the kernel will search for a free chunk of vm
66 * space during mmap's.
70 #define TASK_UNMAPPED_BASE 0xC0000000UL
72 #define TASK_UNMAPPED_BASE 0x0A000000UL
74 #define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
76 #define TASK_UNMAPPED_BASE 0
79 struct thread_struct {
80 unsigned long ksp; /* kernel stack pointer */
81 unsigned long usp; /* user stack pointer */
82 unsigned short sr; /* saved status register */
83 unsigned short fs; /* saved fs (sfc, dfc) */
84 unsigned long crp[2]; /* cpu root pointer */
85 unsigned long esp0; /* points to SR of stack frame */
86 unsigned long faddr; /* info about last fault */
88 unsigned long fp[8*3];
89 unsigned long fpcntl[3]; /* fp control regs */
90 unsigned char fpstate[FPSTATESIZE]; /* floating point state */
91 struct thread_info info;
94 #define INIT_THREAD { \
95 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \
98 .info = INIT_THREAD_INFO(init_task), \
103 * Do necessary setup to start up a newly executed thread.
105 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
113 extern int handle_kernel_fault(struct pt_regs *regs);
118 * Coldfire stacks need to be re-aligned on trap exit, conventional
119 * 68k can handle this case cleanly.
121 #ifdef CONFIG_COLDFIRE
122 #define reformat(_regs) do { (_regs)->format = 0x4; } while(0)
124 #define reformat(_regs) do { } while (0)
127 #define start_thread(_regs, _pc, _usp) \
129 (_regs)->pc = (_pc); \
130 ((struct switch_stack *)(_regs))[-1].a6 = 0; \
133 (_regs)->d5 = current->mm->start_data; \
134 (_regs)->sr &= ~0x2000; \
140 /* Forward declaration, a strange C thing */
143 /* Free all resources held by a thread. */
144 static inline void release_thread(struct task_struct *dead_task)
148 /* Prepare to copy thread state - unlazy all lazy status */
149 #define prepare_to_copy(tsk) do { } while (0)
151 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
154 * Free current thread data structures etc..
156 static inline void exit_thread(void)
160 extern unsigned long thread_saved_pc(struct task_struct *tsk);
162 unsigned long get_wchan(struct task_struct *p);
164 #define KSTK_EIP(tsk) \
166 unsigned long eip = 0; \
167 if ((tsk)->thread.esp0 > PAGE_SIZE && \
168 (virt_addr_valid((tsk)->thread.esp0))) \
169 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
171 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
173 #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
175 #define cpu_relax() barrier()