LXR linux/arch/m68k/include/asm/processor.h

   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
  16static 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
  29static 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
  78struct 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 */
 111static 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 */
 121struct task_struct;
 122
 123/* Free all resources held by a thread. */
 124static inline void release_thread(struct task_struct *dead_task)
 125{
 126}
 127
 128unsigned 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