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/fpu.h>
  13#include <asm/ptrace.h>
  14
  15static inline unsigned long rdusp(void)
  16{
  17#ifdef CONFIG_COLDFIRE_SW_A7
  18        extern unsigned int sw_usp;
  19        return sw_usp;
  20#else
  21        register unsigned long usp __asm__("a0");
  22        /* move %usp,%a0 */
  23        __asm__ __volatile__(".word 0x4e68" : "=a" (usp));
  24        return usp;
  25#endif
  26}
  27
  28static inline void wrusp(unsigned long usp)
  29{
  30#ifdef CONFIG_COLDFIRE_SW_A7
  31        extern unsigned int sw_usp;
  32        sw_usp = usp;
  33#else
  34        register unsigned long a0 __asm__("a0") = usp;
  35        /* move %a0,%usp */
  36        __asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
  37#endif
  38}
  39
  40/*
  41 * User space process size: 3.75GB. This is hardcoded into a few places,
  42 * so don't change it unless you know what you are doing.
  43 */
  44#ifdef CONFIG_MMU
  45#if defined(CONFIG_COLDFIRE)
  46#define TASK_SIZE       (0xC0000000UL)
  47#elif defined(CONFIG_SUN3)
  48#define TASK_SIZE       (0x0E000000UL)
  49#else
  50#define TASK_SIZE       (0xF0000000UL)
  51#endif
  52#else
  53#define TASK_SIZE       (0xFFFFFFFFUL)
  54#endif
  55
  56#ifdef __KERNEL__
  57#define STACK_TOP       TASK_SIZE
  58#define STACK_TOP_MAX   STACK_TOP
  59#endif
  60
  61/* This decides where the kernel will search for a free chunk of vm
  62 * space during mmap's.
  63 */
  64#ifdef CONFIG_MMU
  65#if defined(CONFIG_COLDFIRE)
  66#define TASK_UNMAPPED_BASE      0x60000000UL
  67#elif defined(CONFIG_SUN3)
  68#define TASK_UNMAPPED_BASE      0x0A000000UL
  69#else
  70#define TASK_UNMAPPED_BASE      0xC0000000UL
  71#endif
  72#define TASK_UNMAPPED_ALIGN(addr, off)  PAGE_ALIGN(addr)
  73#else
  74#define TASK_UNMAPPED_BASE      0
  75#endif
  76
  77/* Address spaces (or Function Codes in Motorola lingo) */
  78#define USER_DATA     1
  79#define USER_PROGRAM  2
  80#define SUPER_DATA    5
  81#define SUPER_PROGRAM 6
  82#define CPU_SPACE     7
  83
  84#ifdef CONFIG_CPU_HAS_ADDRESS_SPACES
  85/*
  86 * Set the SFC/DFC registers for special MM operations.  For most normal
  87 * operation these remain set to USER_DATA for the uaccess routines.
  88 */
  89static inline void set_fc(unsigned long val)
  90{
  91        WARN_ON_ONCE(in_interrupt());
  92
  93        __asm__ __volatile__ ("movec %0,%/sfc\n\t"
  94                              "movec %0,%/dfc\n\t"
  95                              : /* no outputs */ : "r" (val) : "memory");
  96}
  97#else
  98static inline void set_fc(unsigned long val)
  99{
 100}
 101#endif /* CONFIG_CPU_HAS_ADDRESS_SPACES */
 102
 103struct thread_struct {
 104        unsigned long  ksp;             /* kernel stack pointer */
 105        unsigned long  usp;             /* user stack pointer */
 106        unsigned short sr;              /* saved status register */
 107        unsigned short fc;              /* saved fc (sfc, dfc) */
 108        unsigned long  crp[2];          /* cpu root pointer */
 109        unsigned long  esp0;            /* points to SR of stack frame */
 110        unsigned long  faddr;           /* info about last fault */
 111        int            signo, code;
 112        unsigned long  fp[8*3];
 113        unsigned long  fpcntl[3];       /* fp control regs */
 114        unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
 115};
 116
 117#define INIT_THREAD  {                                                  \
 118        .ksp    = sizeof(init_stack) + (unsigned long) init_stack,      \
 119        .sr     = PS_S,                                                 \
 120        .fc     = USER_DATA,                                            \
 121}
 122
 123/*
 124 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be
 125 * true on thread creation). We need to set this explicitly.
 126 */
 127#ifdef CONFIG_COLDFIRE
 128#define setframeformat(_regs)   do { (_regs)->format = 0x4; } while(0)
 129#else
 130#define setframeformat(_regs)   do { } while (0)
 131#endif
 132
 133/*
 134 * Do necessary setup to start up a newly executed thread.
 135 */
 136static inline void start_thread(struct pt_regs * regs, unsigned long pc,
 137                                unsigned long usp)
 138{
 139        regs->pc = pc;
 140        regs->sr &= ~0x2000;
 141        setframeformat(regs);
 142        wrusp(usp);
 143}
 144
 145/* Forward declaration, a strange C thing */
 146struct task_struct;
 147
 148/* Free all resources held by a thread. */
 149static inline void release_thread(struct task_struct *dead_task)
 150{
 151}
 152
 153unsigned long get_wchan(struct task_struct *p);
 154
 155#define KSTK_EIP(tsk)   \
 156    ({                  \
 157        unsigned long eip = 0;   \
 158        if ((tsk)->thread.esp0 > PAGE_SIZE && \
 159            (virt_addr_valid((tsk)->thread.esp0))) \
 160              eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
 161        eip; })
 162#define KSTK_ESP(tsk)   ((tsk) == current ? rdusp() : (tsk)->thread.usp)
 163
 164#define task_pt_regs(tsk)       ((struct pt_regs *) ((tsk)->thread.esp0))
 165
 166#define cpu_relax()     barrier()
 167
 168#endif
 169