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/preempt.h> 12 #include <linux/thread_info.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 /* Address spaces (or Function Codes in Motorola lingo) */ 79 #define USER_DATA 1 80 #define USER_PROGRAM 2 81 #define SUPER_DATA 5 82 #define SUPER_PROGRAM 6 83 #define CPU_SPACE 7 84 85 #ifdef CONFIG_CPU_HAS_ADDRESS_SPACES 86 /* 87 * Set the SFC/DFC registers for special MM operations. For most normal 88 * operation these remain set to USER_DATA for the uaccess routines. 89 */ 90 static inline void set_fc(unsigned long val) 91 { 92 WARN_ON_ONCE(in_interrupt()); 93 94 __asm__ __volatile__ ("movec %0,%/sfc\n\t" 95 "movec %0,%/dfc\n\t" 96 : /* no outputs */ : "r" (val) : "memory"); 97 } 98 99 static inline unsigned long get_fc(void) 100 { 101 unsigned long val; 102 103 __asm__ ("movec %/dfc,%0" : "=r" (val) : ); 104 105 return val; 106 } 107 #else 108 static inline void set_fc(unsigned long val) 109 { 110 } 111 112 static inline unsigned long get_fc(void) 113 { 114 return USER_DATA; 115 } 116 #endif /* CONFIG_CPU_HAS_ADDRESS_SPACES */ 117 118 struct thread_struct { 119 unsigned long ksp; /* kernel stack pointer */ 120 unsigned long usp; /* user stack pointer */ 121 unsigned short sr; /* saved status register */ 122 unsigned short fc; /* saved fc (sfc, dfc) */ 123 unsigned long crp[2]; /* cpu root pointer */ 124 unsigned long esp0; /* points to SR of stack frame */ 125 unsigned long faddr; /* info about last fault */ 126 int signo, code; 127 unsigned long fp[8*3]; 128 unsigned long fpcntl[3]; /* fp control regs */ 129 unsigned char fpstate[FPSTATESIZE]; /* floating point state */ 130 }; 131 132 #define INIT_THREAD { \ 133 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 134 .sr = PS_S, \ 135 .fc = USER_DATA, \ 136 } 137 138 /* 139 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be 140 * true on thread creation). We need to set this explicitly. 141 */ 142 #ifdef CONFIG_COLDFIRE 143 #define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0) 144 #else 145 #define setframeformat(_regs) do { } while (0) 146 #endif 147 148 /* 149 * Do necessary setup to start up a newly executed thread. 150 */ 151 static inline void start_thread(struct pt_regs * regs, unsigned long pc, 152 unsigned long usp) 153 { 154 regs->pc = pc; 155 regs->sr &= ~0x2000; 156 setframeformat(regs); 157 wrusp(usp); 158 } 159 160 /* Forward declaration, a strange C thing */ 161 struct task_struct; 162 163 unsigned long __get_wchan(struct task_struct *p); 164 void show_registers(struct pt_regs *regs); 165 166 #define KSTK_EIP(tsk) \ 167 ({ \ 168 unsigned long eip = 0; \ 169 if ((tsk)->thread.esp0 > PAGE_SIZE && \ 170 (virt_addr_valid((tsk)->thread.esp0))) \ 171 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \ 172 eip; }) 173 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp) 174 175 #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0)) 176 177 #define cpu_relax() barrier() 178 179 #endif 180