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