thread_info.h

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/* thread_info.h: MIPS low-level thread information
 *
 * Copyright (C) 2002  David Howells ([email protected])
 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
 */

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

#ifdef __KERNEL__


#ifndef __ASSEMBLY__

#include <asm/processor.h>

/*
 * 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
 */
struct thread_info {
    struct task_struct  *task;      /* main task structure */
    struct exec_domain  *exec_domain;   /* execution domain */
    unsigned long       flags;      /* low level flags */
    unsigned long       tp_value;   /* thread pointer */
    __u32           cpu;        /* current CPU */
    int         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;
    struct pt_regs      *regs;
};

/*
 * macros/functions for gaining access to the thread information structure
 */
#define INIT_THREAD_INFO(tsk)           \
{                       \
    .task       = &tsk,         \
    .exec_domain    = &default_exec_domain, \
    .flags      = _TIF_FIXADE,      \
    .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 thread information struct from C.  */
register struct thread_info *__current_thread_info __asm__("$28");
#define current_thread_info()  __current_thread_info

#endif /* !__ASSEMBLY__ */

/* thread information allocation */
#if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_32BIT)
#define THREAD_SIZE_ORDER (1)
#endif
#if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_64BIT)
#define THREAD_SIZE_ORDER (2)
#endif
#ifdef CONFIG_PAGE_SIZE_8KB
#define THREAD_SIZE_ORDER (1)
#endif
#ifdef CONFIG_PAGE_SIZE_16KB
#define THREAD_SIZE_ORDER (0)
#endif
#ifdef CONFIG_PAGE_SIZE_32KB
#define THREAD_SIZE_ORDER (0)
#endif
#ifdef CONFIG_PAGE_SIZE_64KB
#define THREAD_SIZE_ORDER (0)
#endif

#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#define THREAD_MASK (THREAD_SIZE - 1UL)

#define STACK_WARN  (THREAD_SIZE / 8)

#define PREEMPT_ACTIVE      0x10000000

/*
 * 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_SIGPENDING      1   /* signal pending */
#define TIF_NEED_RESCHED    2   /* rescheduling necessary */
#define TIF_SYSCALL_AUDIT   3   /* syscall auditing active */
#define TIF_SECCOMP     4   /* secure computing */
#define TIF_NOTIFY_RESUME   5   /* callback before returning to user */
#define TIF_RESTORE_SIGMASK 9   /* restore signal mask in do_signal() */
#define TIF_USEDFPU     16  /* FPU was used by this task this quantum (SMP) */
#define TIF_MEMDIE      18  /* is terminating due to OOM killer */
#define TIF_FIXADE      20  /* Fix address errors in software */
#define TIF_LOGADE      21  /* Log address errors to syslog */
#define TIF_32BIT_REGS      22  /* also implies 16/32 fprs */
#define TIF_32BIT_ADDR      23  /* 32-bit address space (o32/n32) */
#define TIF_FPUBOUND        24  /* thread bound to FPU-full CPU set */
#define TIF_LOAD_WATCH      25  /* If set, load watch registers */
#define TIF_SYSCALL_TRACE   31  /* syscall trace active */

#define _TIF_SYSCALL_TRACE  (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING     (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED   (1<<TIF_NEED_RESCHED)
#define _TIF_SYSCALL_AUDIT  (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP        (1<<TIF_SECCOMP)
#define _TIF_NOTIFY_RESUME  (1<<TIF_NOTIFY_RESUME)
#define _TIF_USEDFPU        (1<<TIF_USEDFPU)
#define _TIF_FIXADE     (1<<TIF_FIXADE)
#define _TIF_LOGADE     (1<<TIF_LOGADE)
#define _TIF_32BIT_REGS     (1<<TIF_32BIT_REGS)
#define _TIF_32BIT_ADDR     (1<<TIF_32BIT_ADDR)
#define _TIF_FPUBOUND       (1<<TIF_FPUBOUND)
#define _TIF_LOAD_WATCH     (1<<TIF_LOAD_WATCH)

/* work to do in syscall_trace_leave() */
#define _TIF_WORK_SYSCALL_EXIT  (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT)

/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK      \
    (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_NOTIFY_RESUME)
/* work to do on any return to u-space */
#define _TIF_ALLWORK_MASK   (_TIF_WORK_MASK | _TIF_WORK_SYSCALL_EXIT)

#endif /* __KERNEL__ */

#endif /* _ASM_THREAD_INFO_H */