thread_info.h

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#ifndef __ASM_SH_THREAD_INFO_H
#define __ASM_SH_THREAD_INFO_H

/* SuperH version
 * Copyright (C) 2002  Niibe Yutaka
 *
 * The copyright of original i386 version is:
 *
 *  Copyright (C) 2002  David Howells ([email protected])
 *  - Incorporating suggestions made by Linus Torvalds and Dave Miller
 */
#ifdef __KERNEL__

#include <asm/page.h>

/*
 * Page fault error code bits
 */
#define FAULT_CODE_WRITE    (1 << 0)    /* write access */
#define FAULT_CODE_INITIAL  (1 << 1)    /* initial page write */
#define FAULT_CODE_ITLB     (1 << 2)    /* ITLB miss */
#define FAULT_CODE_PROT     (1 << 3)    /* protection fault */
#define FAULT_CODE_USER     (1 << 4)    /* user-mode access */

#ifndef __ASSEMBLY__
#include <asm/processor.h>

struct thread_info {
    struct task_struct  *task;      /* main task structure */
    struct exec_domain  *exec_domain;   /* execution domain */
    unsigned long       flags;      /* low level flags */
    __u32           status;     /* thread synchronous flags */
    __u32           cpu;
    int         preempt_count; /* 0 => preemptable, <0 => BUG */
    mm_segment_t        addr_limit; /* thread address space */
    struct restart_block    restart_block;
    unsigned long       previous_sp;    /* sp of previous stack in case
                           of nested IRQ stacks */
    __u8            supervisor_stack[0];
};

#endif

#define PREEMPT_ACTIVE      0x10000000

#if defined(CONFIG_4KSTACKS)
#define THREAD_SHIFT    12
#else
#define THREAD_SHIFT    13
#endif

#define THREAD_SIZE (1 << THREAD_SHIFT)
#define STACK_WARN  (THREAD_SIZE >> 3)

/*
 * 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,            \
    .status     = 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)

/* how to get the current stack pointer from C */
register unsigned long current_stack_pointer asm("r15") __used;

/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
    struct thread_info *ti;
#if defined(CONFIG_SUPERH64)
    __asm__ __volatile__ ("getcon   cr17, %0" : "=r" (ti));
#elif defined(CONFIG_CPU_HAS_SR_RB)
    __asm__ __volatile__ ("stc  r7_bank, %0" : "=r" (ti));
#else
    unsigned long __dummy;

    __asm__ __volatile__ (
        "mov    r15, %0\n\t"
        "and    %1, %0\n\t"
        : "=&r" (ti), "=r" (__dummy)
        : "1" (~(THREAD_SIZE - 1))
        : "memory");
#endif

    return ti;
}

#define THREAD_SIZE_ORDER   (THREAD_SHIFT - PAGE_SHIFT)

extern void arch_task_cache_init(void);
extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
extern void arch_release_task_struct(struct task_struct *tsk);
extern void init_thread_xstate(void);

#endif /* __ASSEMBLY__ */

/*
 * Thread information flags
 *
 * - Limited to 24 bits, upper byte used for fault code encoding.
 *
 * - _TIF_ALLWORK_MASK and _TIF_WORK_MASK need to fit within 2 bytes, or
 *   we blow the tst immediate size constraints and need to fix up
 *   arch/sh/kernel/entry-common.S.
 */
#define TIF_SYSCALL_TRACE   0   /* syscall trace active */
#define TIF_SIGPENDING      1   /* signal pending */
#define TIF_NEED_RESCHED    2   /* rescheduling necessary */
#define TIF_SINGLESTEP      4   /* singlestepping active */
#define TIF_SYSCALL_AUDIT   5   /* syscall auditing active */
#define TIF_SECCOMP     6   /* secure computing */
#define TIF_NOTIFY_RESUME   7   /* callback before returning to user */
#define TIF_SYSCALL_TRACEPOINT  8   /* for ftrace syscall instrumentation */
#define TIF_POLLING_NRFLAG  17  /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE      18  /* is terminating due to OOM killer */

#define _TIF_SYSCALL_TRACE  (1 << TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING     (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED   (1 << TIF_NEED_RESCHED)
#define _TIF_SINGLESTEP     (1 << TIF_SINGLESTEP)
#define _TIF_SYSCALL_AUDIT  (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP        (1 << TIF_SECCOMP)
#define _TIF_NOTIFY_RESUME  (1 << TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)

/* work to do in syscall trace */
#define _TIF_WORK_SYSCALL_MASK  (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
                 _TIF_SYSCALL_AUDIT | _TIF_SECCOMP    | \
                 _TIF_SYSCALL_TRACEPOINT)

/* work to do on any return to u-space */
#define _TIF_ALLWORK_MASK   (_TIF_SYSCALL_TRACE | _TIF_SIGPENDING      | \
                 _TIF_NEED_RESCHED  | _TIF_SYSCALL_AUDIT   | \
                 _TIF_SINGLESTEP    | _TIF_NOTIFY_RESUME   | \
                 _TIF_SYSCALL_TRACEPOINT)

/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK      (_TIF_ALLWORK_MASK & ~(_TIF_SYSCALL_TRACE | \
                 _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP))

/*
 * Thread-synchronous status.
 *
 * This is different from the flags in that nobody else
 * ever touches our thread-synchronous status, so we don't
 * have to worry about atomic accesses.
 */
#define TS_RESTORE_SIGMASK  0x0001  /* restore signal mask in do_signal() */
#define TS_USEDFPU      0x0002  /* FPU used by this task this quantum */

#ifndef __ASSEMBLY__

#define HAVE_SET_RESTORE_SIGMASK    1
static inline void set_restore_sigmask(void)
{
    struct thread_info *ti = current_thread_info();
    ti->status |= TS_RESTORE_SIGMASK;
    WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
}

#define TI_FLAG_FAULT_CODE_SHIFT    24

/*
 * Additional thread flag encoding
 */
static inline void set_thread_fault_code(unsigned int val)
{
    struct thread_info *ti = current_thread_info();
    ti->flags = (ti->flags & (~0 >> (32 - TI_FLAG_FAULT_CODE_SHIFT)))
        | (val << TI_FLAG_FAULT_CODE_SHIFT);
}

static inline unsigned int get_thread_fault_code(void)
{
    struct thread_info *ti = current_thread_info();
    return ti->flags >> TI_FLAG_FAULT_CODE_SHIFT;
}

static inline void clear_restore_sigmask(void)
{
    current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
}
static inline bool test_restore_sigmask(void)
{
    return current_thread_info()->status & TS_RESTORE_SIGMASK;
}
static inline bool test_and_clear_restore_sigmask(void)
{
    struct thread_info *ti = current_thread_info();
    if (!(ti->status & TS_RESTORE_SIGMASK))
        return false;
    ti->status &= ~TS_RESTORE_SIGMASK;
    return true;
}

#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)

#endif  /* !__ASSEMBLY__ */

#endif /* __KERNEL__ */

#endif /* __ASM_SH_THREAD_INFO_H */