LXR linux/arch/nios2/include/asm/thread

   1/*
   2 * NiosII low-level thread information
   3 *
   4 * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
   5 * Copyright (C) 2004 Microtronix Datacom Ltd.
   6 *
   7 * Based on asm/thread_info_no.h from m68k which is:
   8 *
   9 * Copyright (C) 2002 David Howells <dhowells@redhat.com>
  10 *
  11 * This file is subject to the terms and conditions of the GNU General Public
  12 * License.  See the file "COPYING" in the main directory of this archive
  13 * for more details.
  14 */
  15
  16#ifndef _ASM_NIOS2_THREAD_INFO_H
  17#define _ASM_NIOS2_THREAD_INFO_H
  18
  19#ifdef __KERNEL__
  20
  21/*
  22 * Size of the kernel stack for each process.
  23 */
  24#define THREAD_SIZE_ORDER       1
  25#define THREAD_SIZE             8192 /* 2 * PAGE_SIZE */
  26
  27#ifndef __ASSEMBLY__
  28
  29typedef struct {
  30        unsigned long seg;
  31} mm_segment_t;
  32
  33/*
  34 * low level task data that entry.S needs immediate access to
  35 * - this struct should fit entirely inside of one cache line
  36 * - this struct shares the supervisor stack pages
  37 * - if the contents of this structure are changed, the assembly constants
  38 *   must also be changed
  39 */
  40struct thread_info {
  41        struct task_struct      *task;          /* main task structure */
  42        unsigned long           flags;          /* low level flags */
  43        __u32                   cpu;            /* current CPU */
  44        int                     preempt_count;  /* 0 => preemptable,<0 => BUG */
  45        mm_segment_t            addr_limit;     /* thread address space:
  46                                                  0-0x7FFFFFFF for user-thead
  47                                                  0-0xFFFFFFFF for kernel-thread
  48                                                */
  49        struct pt_regs          *regs;
  50};
  51
  52/*
  53 * macros/functions for gaining access to the thread information structure
  54 *
  55 * preempt_count needs to be 1 initially, until the scheduler is functional.
  56 */
  57#define INIT_THREAD_INFO(tsk)                   \
  58{                                               \
  59        .task           = &tsk,                 \
  60        .flags          = 0,                    \
  61        .cpu            = 0,                    \
  62        .preempt_count  = INIT_PREEMPT_COUNT,   \
  63        .addr_limit     = KERNEL_DS,            \
  64}
  65
  66/* how to get the thread information struct from C */
  67static inline struct thread_info *current_thread_info(void)
  68{
  69        register unsigned long sp asm("sp");
  70
  71        return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
  72}
  73#endif /* !__ASSEMBLY__ */
  74
  75/*
  76 * thread information flags
  77 * - these are process state flags that various assembly files may need to
  78 *   access
  79 * - pending work-to-be-done flags are in LSW
  80 * - other flags in MSW
  81 */
  82#define TIF_SYSCALL_TRACE       0       /* syscall trace active */
  83#define TIF_NOTIFY_RESUME       1       /* resumption notification requested */
  84#define TIF_SIGPENDING          2       /* signal pending */
  85#define TIF_NEED_RESCHED        3       /* rescheduling necessary */
  86#define TIF_MEMDIE              4       /* is terminating due to OOM killer */
  87#define TIF_SECCOMP             5       /* secure computing */
  88#define TIF_SYSCALL_AUDIT       6       /* syscall auditing active */
  89#define TIF_NOTIFY_SIGNAL       7       /* signal notifications exist */
  90#define TIF_RESTORE_SIGMASK     9       /* restore signal mask in do_signal() */
  91
  92#define TIF_POLLING_NRFLAG      16      /* true if poll_idle() is polling
  93                                           TIF_NEED_RESCHED */
  94
  95#define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
  96#define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
  97#define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
  98#define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
  99#define _TIF_SECCOMP            (1 << TIF_SECCOMP)
 100#define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 101#define _TIF_NOTIFY_SIGNAL      (1 << TIF_NOTIFY_SIGNAL)
 102#define _TIF_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
 103#define _TIF_POLLING_NRFLAG     (1 << TIF_POLLING_NRFLAG)
 104
 105/* work to do on interrupt/exception return */
 106#define _TIF_WORK_MASK          0x0000FFFE
 107
 108/* work to do on any return to u-space */
 109# define _TIF_ALLWORK_MASK      0x0000FFFF
 110
 111#endif /* __KERNEL__ */
 112
 113#endif /* _ASM_NIOS2_THREAD_INFO_H */
 114