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 /* 12 * Default implementation of macro that returns current 13 * instruction pointer ("program counter"). 14 */ 15 #define current_text_addr() ({ __label__ _l; _l: &&_l;}) 16 17 #include <linux/thread_info.h> 18 #include <asm/segment.h> 19 #include <asm/fpu.h> 20 #include <asm/ptrace.h> 21 22 static inline unsigned long rdusp(void) 23 { 24 #ifdef CONFIG_COLDFIRE_SW_A7 25 extern unsigned int sw_usp; 26 return sw_usp; 27 #else 28 register unsigned long usp __asm__("a0"); 29 /* move %usp,%a0 */ 30 __asm__ __volatile__(".word 0x4e68" : "=a" (usp)); 31 return usp; 32 #endif 33 } 34 35 static inline void wrusp(unsigned long usp) 36 { 37 #ifdef CONFIG_COLDFIRE_SW_A7 38 extern unsigned int sw_usp; 39 sw_usp = usp; 40 #else 41 register unsigned long a0 __asm__("a0") = usp; 42 /* move %a0,%usp */ 43 __asm__ __volatile__(".word 0x4e60" : : "a" (a0) ); 44 #endif 45 } 46 47 /* 48 * User space process size: 3.75GB. This is hardcoded into a few places, 49 * so don't change it unless you know what you are doing. 50 */ 51 #ifdef CONFIG_MMU 52 #if defined(CONFIG_COLDFIRE) 53 #define TASK_SIZE (0xC0000000UL) 54 #elif defined(CONFIG_SUN3) 55 #define TASK_SIZE (0x0E000000UL) 56 #else 57 #define TASK_SIZE (0xF0000000UL) 58 #endif 59 #else 60 #define TASK_SIZE (0xFFFFFFFFUL) 61 #endif 62 63 #ifdef __KERNEL__ 64 #define STACK_TOP TASK_SIZE 65 #define STACK_TOP_MAX STACK_TOP 66 #endif 67 68 /* This decides where the kernel will search for a free chunk of vm 69 * space during mmap's. 70 */ 71 #ifdef CONFIG_MMU 72 #if defined(CONFIG_COLDFIRE) 73 #define TASK_UNMAPPED_BASE 0x60000000UL 74 #elif defined(CONFIG_SUN3) 75 #define TASK_UNMAPPED_BASE 0x0A000000UL 76 #else 77 #define TASK_UNMAPPED_BASE 0xC0000000UL 78 #endif 79 #define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr) 80 #else 81 #define TASK_UNMAPPED_BASE 0 82 #endif 83 84 struct thread_struct { 85 unsigned long ksp; /* kernel stack pointer */ 86 unsigned long usp; /* user stack pointer */ 87 unsigned short sr; /* saved status register */ 88 unsigned short fs; /* saved fs (sfc, dfc) */ 89 unsigned long crp[2]; /* cpu root pointer */ 90 unsigned long esp0; /* points to SR of stack frame */ 91 unsigned long faddr; /* info about last fault */ 92 int signo, code; 93 unsigned long fp[8*3]; 94 unsigned long fpcntl[3]; /* fp control regs */ 95 unsigned char fpstate[FPSTATESIZE]; /* floating point state */ 96 }; 97 98 #define INIT_THREAD { \ 99 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 100 .sr = PS_S, \ 101 .fs = __KERNEL_DS, \ 102 } 103 104 /* 105 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be 106 * true on thread creation). We need to set this explicitly. 107 */ 108 #ifdef CONFIG_COLDFIRE 109 #define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0) 110 #else 111 #define setframeformat(_regs) do { } while (0) 112 #endif 113 114 /* 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 /* Forward declaration, a strange C thing */ 127 struct task_struct; 128 129 /* Free all resources held by a thread. */ 130 static inline void release_thread(struct task_struct *dead_task) 131 { 132 } 133 134 unsigned long get_wchan(struct task_struct *p); 135 136 #define KSTK_EIP(tsk) \ 137 ({ \ 138 unsigned long eip = 0; \ 139 if ((tsk)->thread.esp0 > PAGE_SIZE && \ 140 (virt_addr_valid((tsk)->thread.esp0))) \ 141 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \ 142 eip; }) 143 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp) 144 145 #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0)) 146 147 #define cpu_relax() barrier() 148 149 #endif 150