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_SW_A7 24 extern unsigned int sw_usp; 25 return sw_usp; 26 #else 27 register unsigned long usp __asm__("a0"); 28 /* move %usp,%a0 */ 29 __asm__ __volatile__(".word 0x4e68" : "=a" (usp)); 30 return usp; 31 #endif 32 } 33 34 static inline void wrusp(unsigned long usp) 35 { 36 #ifdef CONFIG_COLDFIRE_SW_A7 37 extern unsigned int sw_usp; 38 sw_usp = usp; 39 #else 40 register unsigned long a0 __asm__("a0") = usp; 41 /* move %a0,%usp */ 42 __asm__ __volatile__(".word 0x4e60" : : "a" (a0) ); 43 #endif 44 } 45 46 /* 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. 49 */ 50 #ifdef CONFIG_MMU 51 #if defined(CONFIG_COLDFIRE) 52 #define TASK_SIZE (0xC0000000UL) 53 #elif defined(CONFIG_SUN3) 54 #define TASK_SIZE (0x0E000000UL) 55 #else 56 #define TASK_SIZE (0xF0000000UL) 57 #endif 58 #else 59 #define TASK_SIZE (0xFFFFFFFFUL) 60 #endif 61 62 #ifdef __KERNEL__ 63 #define STACK_TOP TASK_SIZE 64 #define STACK_TOP_MAX STACK_TOP 65 #endif 66 67 /* This decides where the kernel will search for a free chunk of vm 68 * space during mmap's. 69 */ 70 #ifdef CONFIG_MMU 71 #if defined(CONFIG_COLDFIRE) 72 #define TASK_UNMAPPED_BASE 0x60000000UL 73 #elif defined(CONFIG_SUN3) 74 #define TASK_UNMAPPED_BASE 0x0A000000UL 75 #else 76 #define TASK_UNMAPPED_BASE 0xC0000000UL 77 #endif 78 #define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr) 79 #else 80 #define TASK_UNMAPPED_BASE 0 81 #endif 82 83 struct thread_struct { 84 unsigned long ksp; /* kernel stack pointer */ 85 unsigned long usp; /* user stack pointer */ 86 unsigned short sr; /* saved status register */ 87 unsigned short fs; /* saved fs (sfc, dfc) */ 88 unsigned long crp[2]; /* cpu root pointer */ 89 unsigned long esp0; /* points to SR of stack frame */ 90 unsigned long faddr; /* info about last fault */ 91 int signo, code; 92 unsigned long fp[8*3]; 93 unsigned long fpcntl[3]; /* fp control regs */ 94 unsigned char fpstate[FPSTATESIZE]; /* floating point state */ 95 }; 96 97 #define INIT_THREAD { \ 98 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 99 .sr = PS_S, \ 100 .fs = __KERNEL_DS, \ 101 } 102 103 /* 104 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be 105 * true on thread creation). We need to set this explicitly. 106 */ 107 #ifdef CONFIG_COLDFIRE 108 #define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0) 109 #else 110 #define setframeformat(_regs) do { } while (0) 111 #endif 112 113 #ifdef CONFIG_MMU 114 /* 115 * Do necessary setup to start up a newly executed thread. 116 */ 117 static inline void start_thread(struct pt_regs * regs, unsigned long pc, 118 unsigned long usp) 119 { 120 regs->pc = pc; 121 regs->sr &= ~0x2000; 122 setframeformat(regs); 123 wrusp(usp); 124 } 125 126 extern int handle_kernel_fault(struct pt_regs *regs); 127 128 #else 129 130 #define start_thread(_regs, _pc, _usp) \ 131 do { \ 132 (_regs)->pc = (_pc); \ 133 setframeformat(_regs); \ 134 if (current->mm) \ 135 (_regs)->d5 = current->mm->start_data; \ 136 (_regs)->sr &= ~0x2000; \ 137 wrusp(_usp); \ 138 } while(0) 139 140 static inline int handle_kernel_fault(struct pt_regs *regs) 141 { 142 /* Any fault in kernel is fatal on non-mmu */ 143 return 0; 144 } 145 146 #endif 147 148 /* Forward declaration, a strange C thing */ 149 struct task_struct; 150 151 /* Free all resources held by a thread. */ 152 static inline void release_thread(struct task_struct *dead_task) 153 { 154 } 155 156 /* 157 * Free current thread data structures etc.. 158 */ 159 static inline void exit_thread(void) 160 { 161 } 162 163 extern unsigned long thread_saved_pc(struct task_struct *tsk); 164 165 unsigned long get_wchan(struct task_struct *p); 166 167 #define KSTK_EIP(tsk) \ 168 ({ \ 169 unsigned long eip = 0; \ 170 if ((tsk)->thread.esp0 > PAGE_SIZE && \ 171 (virt_addr_valid((tsk)->thread.esp0))) \ 172 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \ 173 eip; }) 174 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp) 175 176 #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0)) 177 178 #define cpu_relax() barrier() 179 180 #endif 181