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/preempt.h>
 12#include <linux/thread_info.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
 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 */
 90static 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
 99static inline unsigned long get_fc(void)
100{
101	unsigned long val;
102
103	__asm__ ("movec %/dfc,%0" : "=r" (val) : );
104
105	return val;
106}
107#else
108static inline void set_fc(unsigned long val)
109{
110}
111
112static inline unsigned long get_fc(void)
113{
114	return USER_DATA;
115}
116#endif /* CONFIG_CPU_HAS_ADDRESS_SPACES */
117
118struct thread_struct {
119	unsigned long  ksp;		/* kernel stack pointer */
120	unsigned long  usp;		/* user stack pointer */
121	unsigned short sr;		/* saved status register */
122	unsigned short fc;		/* saved fc (sfc, dfc) */
123	unsigned long  crp[2];		/* cpu root pointer */
124	unsigned long  esp0;		/* points to SR of stack frame */
125	unsigned long  faddr;		/* info about last fault */
126	int            signo, code;
127	unsigned long  fp[8*3];
128	unsigned long  fpcntl[3];	/* fp control regs */
129	unsigned char  fpstate[FPSTATESIZE];  /* floating point state */
130};
131
132#define INIT_THREAD  {							\
133	.ksp	= sizeof(init_stack) + (unsigned long) init_stack,	\
134	.sr	= PS_S,							\
135	.fc	= USER_DATA,						\
136}
137
138/*
139 * ColdFire stack format sbould be 0x4 for an aligned usp (will always be
140 * true on thread creation). We need to set this explicitly.
141 */
142#ifdef CONFIG_COLDFIRE
143#define setframeformat(_regs)	do { (_regs)->format = 0x4; } while(0)
144#else
145#define setframeformat(_regs)	do { } while (0)
146#endif
147
148/*
149 * Do necessary setup to start up a newly executed thread.
150 */
151static inline void start_thread(struct pt_regs * regs, unsigned long pc,
152				unsigned long usp)
153{
154	regs->pc = pc;
155	regs->sr &= ~0x2000;
156	setframeformat(regs);
157	wrusp(usp);
158}
159
160/* Forward declaration, a strange C thing */
161struct task_struct;
162
163unsigned long __get_wchan(struct task_struct *p);
164void show_registers(struct pt_regs *regs);
165
166#define	KSTK_EIP(tsk)	\
167    ({			\
168	unsigned long eip = 0;	 \
169	if ((tsk)->thread.esp0 > PAGE_SIZE && \
170	    (virt_addr_valid((tsk)->thread.esp0))) \
171	      eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
172	eip; })
173#define	KSTK_ESP(tsk)	((tsk) == current ? rdusp() : (tsk)->thread.usp)
174
175#define task_pt_regs(tsk)	((struct pt_regs *) ((tsk)->thread.esp0))
176
177#define cpu_relax()	barrier()
178
179#endif