1 /* 2 * include/asm-m68k/processor.h 3 * 4 * Copyright (C) 1995 Hamish Macdonald 5 */ 6 7 #ifndef __ASM_M68K_PROCESSOR_H 8 #define __ASM_M68K_PROCESSOR_H 9 10 /* 11 * Default implementation of macro that returns current 12 * instruction pointer ("program counter"). 13 */ 14 #define current_text_addr() ({ __label__ _l; _l: &&_l;}) 15 16 #include <linux/thread_info.h> 17 #include <asm/segment.h> 18 #include <asm/fpu.h> 19 #include <asm/ptrace.h> 20 21 static inline unsigned long rdusp(void) 22 { 23 #ifdef CONFIG_COLDFIRE 24 extern unsigned int sw_usp; 25 return sw_usp; 26 #else 27 unsigned long usp; 28 __asm__ __volatile__("move %/usp,%0" : "=a" (usp)); 29 return usp; 30 #endif 31 } 32 33 static inline void wrusp(unsigned long usp) 34 { 35 #ifdef CONFIG_COLDFIRE 36 extern unsigned int sw_usp; 37 sw_usp = usp; 38 #else 39 __asm__ __volatile__("move %0,%/usp" : : "a" (usp)); 40 #endif 41 } 42 43 /* 44 * User space process size: 3.75GB. This is hardcoded into a few places, 45 * so don't change it unless you know what you are doing. 46 */ 47 #ifndef CONFIG_SUN3 48 #define TASK_SIZE (0xF0000000UL) 49 #else 50 #define TASK_SIZE (0x0E000000UL) 51 #endif 52 53 #ifdef __KERNEL__ 54 #define STACK_TOP TASK_SIZE 55 #define STACK_TOP_MAX STACK_TOP 56 #endif 57 58 /* This decides where the kernel will search for a free chunk of vm 59 * space during mmap's. 60 */ 61 #ifdef CONFIG_MMU 62 #ifndef CONFIG_SUN3 63 #define TASK_UNMAPPED_BASE 0xC0000000UL 64 #else 65 #define TASK_UNMAPPED_BASE 0x0A000000UL 66 #endif 67 #define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr) 68 #else 69 #define TASK_UNMAPPED_BASE 0 70 #endif 71 72 struct thread_struct { 73 unsigned long ksp; /* kernel stack pointer */ 74 unsigned long usp; /* user stack pointer */ 75 unsigned short sr; /* saved status register */ 76 unsigned short fs; /* saved fs (sfc, dfc) */ 77 unsigned long crp[2]; /* cpu root pointer */ 78 unsigned long esp0; /* points to SR of stack frame */ 79 unsigned long faddr; /* info about last fault */ 80 int signo, code; 81 unsigned long fp[8*3]; 82 unsigned long fpcntl[3]; /* fp control regs */ 83 unsigned char fpstate[FPSTATESIZE]; /* floating point state */ 84 struct thread_info info; 85 }; 86 87 #define INIT_THREAD { \ 88 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 89 .sr = PS_S, \ 90 .fs = __KERNEL_DS, \ 91 .info = INIT_THREAD_INFO(init_task), \ 92 } 93 94 #ifdef CONFIG_MMU 95 /* 96 * Do necessary setup to start up a newly executed thread. 97 */ 98 static inline void start_thread(struct pt_regs * regs, unsigned long pc, 99 unsigned long usp) 100 { 101 /* reads from user space */ 102 set_fs(USER_DS); 103 104 regs->pc = pc; 105 regs->sr &= ~0x2000; 106 wrusp(usp); 107 } 108 109 #else 110 111 /* 112 * Coldfire stacks need to be re-aligned on trap exit, conventional 113 * 68k can handle this case cleanly. 114 */ 115 #ifdef CONFIG_COLDFIRE 116 #define reformat(_regs) do { (_regs)->format = 0x4; } while(0) 117 #else 118 #define reformat(_regs) do { } while (0) 119 #endif 120 121 #define start_thread(_regs, _pc, _usp) \ 122 do { \ 123 set_fs(USER_DS); /* reads from user space */ \ 124 (_regs)->pc = (_pc); \ 125 ((struct switch_stack *)(_regs))[-1].a6 = 0; \ 126 reformat(_regs); \ 127 if (current->mm) \ 128 (_regs)->d5 = current->mm->start_data; \ 129 (_regs)->sr &= ~0x2000; \ 130 wrusp(_usp); \ 131 } while(0) 132 133 #endif 134 135 /* Forward declaration, a strange C thing */ 136 struct task_struct; 137 138 /* Free all resources held by a thread. */ 139 static inline void release_thread(struct task_struct *dead_task) 140 { 141 } 142 143 /* Prepare to copy thread state - unlazy all lazy status */ 144 #define prepare_to_copy(tsk) do { } while (0) 145 146 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags); 147 148 /* 149 * Free current thread data structures etc.. 150 */ 151 static inline void exit_thread(void) 152 { 153 } 154 155 extern unsigned long thread_saved_pc(struct task_struct *tsk); 156 157 unsigned long get_wchan(struct task_struct *p); 158 159 #define KSTK_EIP(tsk) \ 160 ({ \ 161 unsigned long eip = 0; \ 162 if ((tsk)->thread.esp0 > PAGE_SIZE && \ 163 (virt_addr_valid((tsk)->thread.esp0))) \ 164 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \ 165 eip; }) 166 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp) 167 168 #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0)) 169 170 #define cpu_relax() barrier() 171 172 #endif 173