/* MN10300 Low-level thread information
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells ([email protected])
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

#ifdef __KERNEL__

#include <asm/page.h>

#ifdef CONFIG_4KSTACKS
#define THREAD_SIZE (4096)
#define THREAD_SIZE_ORDER (0)
#else
#define THREAD_SIZE (8192)
#define THREAD_SIZE_ORDER (1)
#endif

#define STACK_WARN (THREAD_SIZE / 8)

/*
* low level task data that entry.S needs immediate access to
* - this struct should fit entirely inside of one cache line
* - this struct shares the supervisor stack pages
* - if the contents of this structure are changed, the assembly constants
* must also be changed
*/
#ifndef __ASSEMBLY__
typedef struct {
unsigned long seg;
} mm_segment_t;

struct thread_info {
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
struct pt_regs *frame; /* current exception frame */
unsigned long flags; /* low level flags */
__u32 cpu; /* current CPU */
__s32 preempt_count; /* 0 => preemptable, <0 => BUG */

mm_segment_t addr_limit; /* thread address space:
0-0xBFFFFFFF for user-thead
0-0xFFFFFFFF for kernel-thread
*/
struct restart_block restart_block;

__u8 supervisor_stack[0];
};

#define thread_info_to_uregs(ti) \
((struct pt_regs *) \
((unsigned long)ti + THREAD_SIZE - sizeof(struct pt_regs)))

#else /* !__ASSEMBLY__ */

#ifndef __ASM_OFFSETS_H__
#include <asm/asm-offsets.h>
#endif

#endif

/*
* macros/functions for gaining access to the thread information structure
*/
#ifndef __ASSEMBLY__

#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \
.exec_domain = &default_exec_domain, \
.flags = 0, \
.cpu = 0, \
.preempt_count = INIT_PREEMPT_COUNT, \
.addr_limit = KERNEL_DS, \
.restart_block = { \
.fn = do_no_restart_syscall, \
}, \
}

#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
#define init_uregs \
((struct pt_regs *) \
((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))

extern struct thread_info *__current_ti;

/* how to get the thread information struct from C */
static inline __attribute__((const))
struct thread_info *current_thread_info(void)
{
struct thread_info *ti;
asm("mov sp,%0\n"
"and %1,%0\n"
: "=d" (ti)
: "i" (~(THREAD_SIZE - 1))
: "cc");
return ti;
}

static inline __attribute__((const))
struct pt_regs *current_frame(void)
{
return current_thread_info()->frame;
}

/* how to get the current stack pointer from C */
static inline unsigned long current_stack_pointer(void)
{
unsigned long sp;
asm("mov sp,%0; ":"=r" (sp));
return sp;
}

#ifndef CONFIG_KGDB
void arch_release_thread_info(struct thread_info *ti);
#endif
#define get_thread_info(ti) get_task_struct((ti)->task)
#define put_thread_info(ti) put_task_struct((ti)->task)

#else /* !__ASSEMBLY__ */

#ifndef __VMLINUX_LDS__
/* how to get the thread information struct from ASM */
.macro GET_THREAD_INFO reg
mov sp,\reg
and -THREAD_SIZE,\reg
.endm
#endif
#endif

/*
* thread information flags
* - these are process state flags that various assembly files may need to
* access
* - pending work-to-be-done flags are in LSW
* - other flags in MSW
*/
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
#define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
#define TIF_RESTORE_SIGMASK 5 /* restore signal mask in do_signal() */
#define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE 17 /* is terminating due to OOM killer */

#define _TIF_SYSCALL_TRACE +(1 << TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME +(1 << TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING +(1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED +(1 << TIF_NEED_RESCHED)
#define _TIF_SINGLESTEP +(1 << TIF_SINGLESTEP)
#define _TIF_POLLING_NRFLAG +(1 << TIF_POLLING_NRFLAG)

#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */

#endif /* __KERNEL__ */

#endif /* _ASM_THREAD_INFO_H */