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 #else 99 static inline void set_fc(unsigned long val) 100 { 101 } 102 #endif /* CONFIG_CPU_HAS_ADDRESS_SPACES */ 103 104 struct thread_struct { 105 unsigned long ksp; /* kernel stack pointer */ 106 unsigned long usp; /* user stack pointer */ 107 unsigned short sr; /* saved status register */ 108 unsigned short fc; /* saved fc (sfc, dfc) */ 109 unsigned long crp[2]; /* cpu root pointer */ 110 unsigned long esp0; /* points to SR of stack frame */ 111 unsigned long faddr; /* info about last fault */ 112 int signo, code; 113 unsigned long fp[8*3]; 114 unsigned long fpcntl[3]; /* fp control regs */ 115 unsigned char fpstate[FPSTATESIZE]; /* floating point state */ 116 }; 117 118 #define INIT_THREAD { \ 119 .ksp = sizeof(init_stack) + (unsigned long) init_stack, \ 120 .sr = PS_S, \ 121 .fc = USER_DATA, \ 122 } 123 124 /* 125 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be 126 * true on thread creation). We need to set this explicitly. 127 */ 128 #ifdef CONFIG_COLDFIRE 129 #define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0) 130 #else 131 #define setframeformat(_regs) do { } while (0) 132 #endif 133 134 /* 135 * Do necessary setup to start up a newly executed thread. 136 */ 137 static inline void start_thread(struct pt_regs * regs, unsigned long pc, 138 unsigned long usp) 139 { 140 regs->pc = pc; 141 regs->sr &= ~0x2000; 142 setframeformat(regs); 143 wrusp(usp); 144 } 145 146 /* Forward declaration, a strange C thing */ 147 struct task_struct; 148 149 unsigned long __get_wchan(struct task_struct *p); 150 void show_registers(struct pt_regs *regs); 151 152 #define KSTK_EIP(tsk) \ 153 ({ \ 154 unsigned long eip = 0; \ 155 if ((tsk)->thread.esp0 > PAGE_SIZE && \ 156 (virt_addr_valid((tsk)->thread.esp0))) \ 157 eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \ 158 eip; }) 159 #define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp) 160 161 #define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0)) 162 163 #define cpu_relax() barrier() 164 165 #endif 166