/*
* include/asm-m68k/processor.h
*
* Copyright (C) 1995 Hamish Macdonald
*/

#ifndef __ASM_M68K_PROCESSOR_H
#define __ASM_M68K_PROCESSOR_H

/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() ({ __label__ _l; _l: &&_l;})

#include <linux/thread_info.h>
#include <asm/segment.h>
#include <asm/fpu.h>
#include <asm/ptrace.h>

static inline unsigned long rdusp(void)
{
#ifdef CONFIG_COLDFIRE_SW_A7
extern unsigned int sw_usp;
return sw_usp;
#else
register unsigned long usp __asm__("a0");
/* move %usp,%a0 */
__asm__ __volatile__(".word 0x4e68" : "=a" (usp));
return usp;
#endif
}

static inline void wrusp(unsigned long usp)
{
#ifdef CONFIG_COLDFIRE_SW_A7
extern unsigned int sw_usp;
sw_usp = usp;
#else
register unsigned long a0 __asm__("a0") = usp;
/* move %a0,%usp */
__asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
#endif
}

/*
* User space process size: 3.75GB. This is hardcoded into a few places,
* so don't change it unless you know what you are doing.
*/
#ifdef CONFIG_MMU
#if defined(CONFIG_COLDFIRE)
#define TASK_SIZE (0xC0000000UL)
#elif defined(CONFIG_SUN3)
#define TASK_SIZE (0x0E000000UL)
#else
#define TASK_SIZE (0xF0000000UL)
#endif
#else
#define TASK_SIZE (0xFFFFFFFFUL)
#endif

#ifdef __KERNEL__
#define STACK_TOP TASK_SIZE
#define STACK_TOP_MAX STACK_TOP
#endif

/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#ifdef CONFIG_MMU
#if defined(CONFIG_COLDFIRE)
#define TASK_UNMAPPED_BASE 0x60000000UL
#elif defined(CONFIG_SUN3)
#define TASK_UNMAPPED_BASE 0x0A000000UL
#else
#define TASK_UNMAPPED_BASE 0xC0000000UL
#endif
#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
#else
#define TASK_UNMAPPED_BASE 0
#endif

struct thread_struct {
unsigned long ksp; /* kernel stack pointer */
unsigned long usp; /* user stack pointer */
unsigned short sr; /* saved status register */
unsigned short fs; /* saved fs (sfc, dfc) */
unsigned long crp[2]; /* cpu root pointer */
unsigned long esp0; /* points to SR of stack frame */
unsigned long faddr; /* info about last fault */
int signo, code;
unsigned long fp[8*3];
unsigned long fpcntl[3]; /* fp control regs */
unsigned char fpstate[FPSTATESIZE]; /* floating point state */
};

#define INIT_THREAD { \
.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
.sr = PS_S, \
.fs = __KERNEL_DS, \
}

/*
* ColdFire stack format sbould be 0x4 for an aligned usp (will always be
* true on thread creation). We need to set this explicitly.
*/
#ifdef CONFIG_COLDFIRE
#define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0)
#else
#define setframeformat(_regs) do { } while (0)
#endif

#ifdef CONFIG_MMU
/*
* Do necessary setup to start up a newly executed thread.
*/
static inline void start_thread(struct pt_regs * regs, unsigned long pc,
unsigned long usp)
{
regs->pc = pc;
regs->sr &= ~0x2000;
setframeformat(regs);
wrusp(usp);
}

extern int handle_kernel_fault(struct pt_regs *regs);

#else

#define start_thread(_regs, _pc, _usp) \
do { \
(_regs)->pc = (_pc); \
setframeformat(_regs); \
if (current->mm) \
(_regs)->d5 = current->mm->start_data; \
(_regs)->sr &= ~0x2000; \
wrusp(_usp); \
} while(0)

static inline int handle_kernel_fault(struct pt_regs *regs)
{
/* Any fault in kernel is fatal on non-mmu */
return 0;
}

#endif

/* Forward declaration, a strange C thing */
struct task_struct;

/* Free all resources held by a thread. */
static inline void release_thread(struct task_struct *dead_task)
{
}

/*
* Free current thread data structures etc..
*/
static inline void exit_thread(void)
{
}

extern unsigned long thread_saved_pc(struct task_struct *tsk);

unsigned long get_wchan(struct task_struct *p);

#define KSTK_EIP(tsk) \
({ \
unsigned long eip = 0; \
if ((tsk)->thread.esp0 > PAGE_SIZE && \
(virt_addr_valid((tsk)->thread.esp0))) \
eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
eip; })
#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)

#define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))

#define cpu_relax() barrier()

#endif