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 /*
  12  * Default implementation of macro that returns current
  13  * instruction pointer ("program counter").
  14  */
  15 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
  16
  17 #include <linux/thread_info.h>
  18 #include <asm/segment.h>
  19 #include <asm/fpu.h>
  20 #include <asm/ptrace.h>
  21
  22 static inline unsigned long rdusp(void)
  23 {
  24 #ifdef CONFIG_COLDFIRE_SW_A7
  25         extern unsigned int sw_usp;
  26         return sw_usp;
  27 #else
  28         register unsigned long usp __asm__("a0");
  29         /* move %usp,%a0 */
  30         __asm__ __volatile__(".word 0x4e68" : "=a" (usp));
  31         return usp;
  32 #endif
  33 }
  34
  35 static inline void wrusp(unsigned long usp)
  36 {
  37 #ifdef CONFIG_COLDFIRE_SW_A7
  38         extern unsigned int sw_usp;
  39         sw_usp = usp;
  40 #else
  41         register unsigned long a0 __asm__("a0") = usp;
  42         /* move %a0,%usp */
  43         __asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
  44 #endif
  45 }
  46
  47 /*
  48  * User space process size: 3.75GB. This is hardcoded into a few places,
  49  * so don't change it unless you know what you are doing.
  50  */
  51 #ifdef CONFIG_MMU
  52 #if defined(CONFIG_COLDFIRE)
  53 #define TASK_SIZE       (0xC0000000UL)
  54 #elif defined(CONFIG_SUN3)
  55 #define TASK_SIZE       (0x0E000000UL)
  56 #else
  57 #define TASK_SIZE       (0xF0000000UL)
  58 #endif
  59 #else
  60 #define TASK_SIZE       (0xFFFFFFFFUL)
  61 #endif
  62
  63 #ifdef __KERNEL__
  64 #define STACK_TOP       TASK_SIZE
  65 #define STACK_TOP_MAX   STACK_TOP
  66 #endif
  67
  68 /* This decides where the kernel will search for a free chunk of vm
  69  * space during mmap's.
  70  */
  71 #ifdef CONFIG_MMU
  72 #if defined(CONFIG_COLDFIRE)
  73 #define TASK_UNMAPPED_BASE      0x60000000UL
  74 #elif defined(CONFIG_SUN3)
  75 #define TASK_UNMAPPED_BASE      0x0A000000UL
  76 #else
  77 #define TASK_UNMAPPED_BASE      0xC0000000UL
  78 #endif
  79 #define TASK_UNMAPPED_ALIGN(addr, off)  PAGE_ALIGN(addr)
  80 #else
  81 #define TASK_UNMAPPED_BASE      0
  82 #endif
  83
  84 struct thread_struct {
  85         unsigned long  ksp;             /* kernel stack pointer */
  86         unsigned long  usp;             /* user stack pointer */
  87         unsigned short sr;              /* saved status register */
  88         unsigned short fs;              /* saved fs (sfc, dfc) */
  89         unsigned long  crp[2];          /* cpu root pointer */
  90         unsigned long  esp0;            /* points to SR of stack frame */
  91         unsigned long  faddr;           /* info about last fault */
  92         int            signo, code;
  93         unsigned long  fp[8*3];
  94         unsigned long  fpcntl[3];       /* fp control regs */
  95         unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
  96 };
  97
  98 #define INIT_THREAD  {                                                  \
  99         .ksp    = sizeof(init_stack) + (unsigned long) init_stack,      \
 100         .sr     = PS_S,                                                 \
 101         .fs     = __KERNEL_DS,                                          \
 102 }
 103
 104 /*
 105  * ColdFire stack format sbould be 0x4 for an aligned usp (will always be
 106  * true on thread creation). We need to set this explicitly.
 107  */
 108 #ifdef CONFIG_COLDFIRE
 109 #define setframeformat(_regs)   do { (_regs)->format = 0x4; } while(0)
 110 #else
 111 #define setframeformat(_regs)   do { } while (0)
 112 #endif
 113
 114 /*
 115  * Do necessary setup to start up a newly executed thread.
 116  */
 117 static inline void start_thread(struct pt_regs * regs, unsigned long pc,
 118                                 unsigned long usp)
 119 {
 120         regs->pc = pc;
 121         regs->sr &= ~0x2000;
 122         setframeformat(regs);
 123         wrusp(usp);
 124 }
 125
 126 /* Forward declaration, a strange C thing */
 127 struct task_struct;
 128
 129 /* Free all resources held by a thread. */
 130 static inline void release_thread(struct task_struct *dead_task)
 131 {
 132 }
 133
 134 unsigned long get_wchan(struct task_struct *p);
 135
 136 #define KSTK_EIP(tsk)   \
 137     ({                  \
 138         unsigned long eip = 0;   \
 139         if ((tsk)->thread.esp0 > PAGE_SIZE && \
 140             (virt_addr_valid((tsk)->thread.esp0))) \
 141               eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
 142         eip; })
 143 #define KSTK_ESP(tsk)   ((tsk) == current ? rdusp() : (tsk)->thread.usp)
 144
 145 #define task_pt_regs(tsk)       ((struct pt_regs *) ((tsk)->thread.esp0))
 146
 147 #define cpu_relax()     barrier()
 148
 149 #endif