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