thread_info.h

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/*
 * Copyright (C) 2006 Atmark Techno, Inc.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#ifndef _ASM_MICROBLAZE_THREAD_INFO_H
#define _ASM_MICROBLAZE_THREAD_INFO_H

#ifdef __KERNEL__

/* we have 8k stack */
#define THREAD_SHIFT        13
#define THREAD_SIZE     (1 << THREAD_SHIFT)
#define THREAD_SIZE_ORDER   1

#ifndef __ASSEMBLY__
# include <linux/types.h>
# 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 cpu_context {
    __u32   r1; /* stack pointer */
    __u32   r2;
    /* dedicated registers */
    __u32   r13;
    __u32   r14;
    __u32   r15;
    __u32   r16;
    __u32   r17;
    __u32   r18;
    /* non-volatile registers */
    __u32   r19;
    __u32   r20;
    __u32   r21;
    __u32   r22;
    __u32   r23;
    __u32   r24;
    __u32   r25;
    __u32   r26;
    __u32   r27;
    __u32   r28;
    __u32   r29;
    __u32   r30;
    /* r31 is used as current task pointer */
    /* special purpose registers */
    __u32   msr;
    __u32   ear;
    __u32   esr;
    __u32   fsr;
};

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 */
    unsigned long       flags; /* low level flags */
    unsigned long       status; /* thread-synchronous flags */
    __u32           cpu; /* current CPU */
    __s32           preempt_count; /* 0 => preemptable,< 0 => BUG*/
    mm_segment_t        addr_limit; /* thread address space */
    struct restart_block    restart_block;

    struct cpu_context  cpu_context;
};

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

/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
    register unsigned long sp asm("r1");

    return (struct thread_info *)(sp & ~(THREAD_SIZE-1));
}

/* thread information allocation */
#endif /* __ASSEMBLY__ */

#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_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 */
/* restore singlestep on return to user mode */
#define TIF_SINGLESTEP      4
#define TIF_MEMDIE      6   /* is terminating due to OOM killer */
#define TIF_SYSCALL_AUDIT   9       /* syscall auditing active */
#define TIF_SECCOMP     10      /* secure computing */

/* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_POLLING_NRFLAG  16

#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_SYSCALL_AUDIT  (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP        (1 << TIF_SECCOMP)

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

/* work to do on interrupt/exception return */
#define _TIF_WORK_MASK      0x0000FFFE

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

/*
 * 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.
 */
/* FPU was used by this task this quantum (SMP) */
#define TS_USEDFPU      0x0001
#define TS_RESTORE_SIGMASK  0x0002

#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));
}
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

#endif /* __KERNEL__ */
#endif /* _ASM_MICROBLAZE_THREAD_INFO_H */