thread_info.h

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/*
 *  arch/arm/include/asm/thread_info.h
 *
 *  Copyright (C) 2002 Russell King.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef __ASM_ARM_THREAD_INFO_H
#define __ASM_ARM_THREAD_INFO_H

#ifdef __KERNEL__

#include <linux/compiler.h>
#include <asm/fpstate.h>

#define THREAD_SIZE_ORDER   1
#define THREAD_SIZE     8192
#define THREAD_START_SP     (THREAD_SIZE - 8)

#ifndef __ASSEMBLY__

struct task_struct;
struct exec_domain;

#include <asm/types.h>
#include <asm/domain.h>

typedef unsigned long mm_segment_t;

struct cpu_context_save {
    __u32   r4;
    __u32   r5;
    __u32   r6;
    __u32   r7;
    __u32   r8;
    __u32   r9;
    __u32   sl;
    __u32   fp;
    __u32   sp;
    __u32   pc;
    __u32   extra[2];       /* Xscale 'acc' register, etc */
};

/*
 * low level task data that entry.S needs immediate access to.
 * __switch_to() assumes cpu_context follows immediately after cpu_domain.
 */
struct thread_info {
    unsigned long       flags;      /* low level flags */
    int         preempt_count;  /* 0 => preemptable, <0 => bug */
    mm_segment_t        addr_limit; /* address limit */
    struct task_struct  *task;      /* main task structure */
    struct exec_domain  *exec_domain;   /* execution domain */
    __u32           cpu;        /* cpu */
    __u32           cpu_domain; /* cpu domain */
    struct cpu_context_save cpu_context;    /* cpu context */
    __u32           syscall;    /* syscall number */
    __u8            used_cp[16];    /* thread used copro */
    unsigned long       tp_value;
#ifdef CONFIG_CRUNCH
    struct crunch_state crunchstate;
#endif
    union fp_state      fpstate __attribute__((aligned(8)));
    union vfp_state     vfpstate;
#ifdef CONFIG_ARM_THUMBEE
    unsigned long       thumbee_state;  /* ThumbEE Handler Base register */
#endif
    struct restart_block    restart_block;
};

#define INIT_THREAD_INFO(tsk)                       \
{                                   \
    .task       = &tsk,                     \
    .exec_domain    = &default_exec_domain,             \
    .flags      = 0,                        \
    .preempt_count  = INIT_PREEMPT_COUNT,               \
    .addr_limit = KERNEL_DS,                    \
    .cpu_domain = domain_val(DOMAIN_USER, DOMAIN_MANAGER) | \
              domain_val(DOMAIN_KERNEL, DOMAIN_MANAGER) |   \
              domain_val(DOMAIN_IO, DOMAIN_CLIENT),     \
    .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) __attribute_const__;

static inline struct thread_info *current_thread_info(void)
{
    register unsigned long sp asm ("sp");
    return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
}

#define thread_saved_pc(tsk)    \
    ((unsigned long)(task_thread_info(tsk)->cpu_context.pc))
#define thread_saved_sp(tsk)    \
    ((unsigned long)(task_thread_info(tsk)->cpu_context.sp))
#define thread_saved_fp(tsk)    \
    ((unsigned long)(task_thread_info(tsk)->cpu_context.fp))

extern void crunch_task_disable(struct thread_info *);
extern void crunch_task_copy(struct thread_info *, void *);
extern void crunch_task_restore(struct thread_info *, void *);
extern void crunch_task_release(struct thread_info *);

extern void iwmmxt_task_disable(struct thread_info *);
extern void iwmmxt_task_copy(struct thread_info *, void *);
extern void iwmmxt_task_restore(struct thread_info *, void *);
extern void iwmmxt_task_release(struct thread_info *);
extern void iwmmxt_task_switch(struct thread_info *);

extern void vfp_sync_hwstate(struct thread_info *);
extern void vfp_flush_hwstate(struct thread_info *);

struct user_vfp;
struct user_vfp_exc;

extern int vfp_preserve_user_clear_hwstate(struct user_vfp __user *,
                       struct user_vfp_exc __user *);
extern int vfp_restore_user_hwstate(struct user_vfp __user *,
                    struct user_vfp_exc __user *);
#endif

/*
 * We use bit 30 of the preempt_count to indicate that kernel
 * preemption is occurring.  See <asm/hardirq.h>.
 */
#define PREEMPT_ACTIVE  0x40000000

/*
 * thread information flags:
 *  TIF_SYSCALL_TRACE   - syscall trace active
 *  TIF_SYSCAL_AUDIT    - syscall auditing active
 *  TIF_SIGPENDING  - signal pending
 *  TIF_NEED_RESCHED    - rescheduling necessary
 *  TIF_NOTIFY_RESUME   - callback before returning to user
 *  TIF_USEDFPU     - FPU was used by this task this quantum (SMP)
 *  TIF_POLLING_NRFLAG  - true if poll_idle() is polling TIF_NEED_RESCHED
 */
#define TIF_SIGPENDING      0
#define TIF_NEED_RESCHED    1
#define TIF_NOTIFY_RESUME   2   /* callback before returning to user */
#define TIF_SYSCALL_TRACE   8
#define TIF_SYSCALL_AUDIT   9
#define TIF_SYSCALL_TRACEPOINT  10
#define TIF_USING_IWMMXT    17
#define TIF_MEMDIE      18  /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 20
#define TIF_SECCOMP     21
#define TIF_SWITCH_MM       22  /* deferred switch_mm */

#define _TIF_SIGPENDING     (1 << TIF_SIGPENDING)
#define _TIF_NEED_RESCHED   (1 << TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME  (1 << TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_TRACE  (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_AUDIT  (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
#define _TIF_USING_IWMMXT   (1 << TIF_USING_IWMMXT)
#define _TIF_SECCOMP        (1 << TIF_SECCOMP)

/* Checks for any syscall work in entry-common.S */
#define _TIF_SYSCALL_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | _TIF_SYSCALL_TRACEPOINT)

/*
 * Change these and you break ASM code in entry-common.S
 */
#define _TIF_WORK_MASK      (_TIF_NEED_RESCHED | _TIF_SIGPENDING | _TIF_NOTIFY_RESUME)

#endif /* __KERNEL__ */
#endif /* __ASM_ARM_THREAD_INFO_H */