LXR linux/arch/blackfin/include/asm/thread

   1/*
   2 * Copyright 2004-2009 Analog Devices Inc.
   3 *
   4 * Licensed under the GPL-2 or later.
   5 */
   6
   7#ifndef _ASM_THREAD_INFO_H
   8#define _ASM_THREAD_INFO_H
   9
  10#include <asm/page.h>
  11#include <asm/entry.h>
  12#include <asm/l1layout.h>
  13#include <linux/compiler.h>
  14
  15#ifdef __KERNEL__
  16
  17/* Thread Align Mask to reach to the top of the stack
  18 * for any process
  19 */
  20#define ALIGN_PAGE_MASK         0xffffe000
  21
  22/*
  23 * Size of kernel stack for each process. This must be a power of 2...
  24 */
  25#define THREAD_SIZE_ORDER       1
  26#define THREAD_SIZE             8192    /* 2 pages */
  27#define STACK_WARN              (THREAD_SIZE/8)
  28
  29#ifndef __ASSEMBLY__
  30
  31typedef unsigned long mm_segment_t;
  32
  33/*
  34 * low level task data.
  35 * If you change this, change the TI_* offsets below to match.
  36 */
  37
  38struct thread_info {
  39        struct task_struct *task;       /* main task structure */
  40        struct exec_domain *exec_domain;        /* execution domain */
  41        unsigned long flags;    /* low level flags */
  42        int cpu;                /* cpu we're on */
  43        int preempt_count;      /* 0 => preemptable, <0 => BUG */
  44        mm_segment_t addr_limit;        /* address limit */
  45        struct restart_block restart_block;
  46#ifndef CONFIG_SMP
  47        struct l1_scratch_task_info l1_task_info;
  48#endif
  49};
  50
  51/*
  52 * macros/functions for gaining access to the thread information structure
  53 */
  54#define INIT_THREAD_INFO(tsk)                   \
  55{                                               \
  56        .task           = &tsk,                 \
  57        .exec_domain    = &default_exec_domain, \
  58        .flags          = 0,                    \
  59        .cpu            = 0,                    \
  60        .preempt_count  = INIT_PREEMPT_COUNT,   \
  61        .restart_block  = {                     \
  62                .fn = do_no_restart_syscall,    \
  63        },                                      \
  64}
  65#define init_thread_info        (init_thread_union.thread_info)
  66#define init_stack              (init_thread_union.stack)
  67
  68/* Given a task stack pointer, you can find its corresponding
  69 * thread_info structure just by masking it to the THREAD_SIZE
  70 * boundary (currently 8K as you can see above).
  71 */
  72__attribute_const__
  73static inline struct thread_info *current_thread_info(void)
  74{
  75        struct thread_info *ti;
  76      __asm__("%0 = sp;" : "=da"(ti) :
  77        );
  78        return (struct thread_info *)((long)ti & ~((long)THREAD_SIZE-1));
  79}
  80
  81#endif                          /* __ASSEMBLY__ */
  82
  83/*
  84 * Offsets in thread_info structure, used in assembly code
  85 */
  86#define TI_TASK         0
  87#define TI_EXECDOMAIN   4
  88#define TI_FLAGS        8
  89#define TI_CPU          12
  90#define TI_PREEMPT      16
  91
  92#define PREEMPT_ACTIVE  0x4000000
  93
  94/*
  95 * thread information flag bit numbers
  96 */
  97#define TIF_SYSCALL_TRACE       0       /* syscall trace active */
  98#define TIF_SIGPENDING          1       /* signal pending */
  99#define TIF_NEED_RESCHED        2       /* rescheduling necessary */
 100#define TIF_POLLING_NRFLAG      3       /* true if poll_idle() is polling
 101                                           TIF_NEED_RESCHED */
 102#define TIF_MEMDIE              4
 103#define TIF_RESTORE_SIGMASK     5       /* restore signal mask in do_signal() */
 104#define TIF_FREEZE              6       /* is freezing for suspend */
 105#define TIF_IRQ_SYNC            7       /* sync pipeline stage */
 106
 107/* as above, but as bit values */
 108#define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 109#define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 110#define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 111#define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
 112#define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 113#define _TIF_FREEZE             (1<<TIF_FREEZE)
 114#define _TIF_IRQ_SYNC           (1<<TIF_IRQ_SYNC)
 115
 116#define _TIF_WORK_MASK          0x0000FFFE      /* work to do on interrupt/exception return */
 117
 118#endif                          /* __KERNEL__ */
 119
 120#endif                          /* _ASM_THREAD_INFO_H */
 121