include/asm-mips/thread_info.h

   1 /* thread_info.h: MIPS low-level thread information
   2  *
   3  * Copyright (C) 2002  David Howells (dhowells@redhat.com)
   4  * - Incorporating suggestions made by Linus Torvalds and Dave Miller
   5  */
   6
   7 #ifndef _ASM_THREAD_INFO_H
   8 #define _ASM_THREAD_INFO_H
   9
  10 #ifdef __KERNEL__
  11
  12 #include <linux/config.h>
  13
  14 #ifndef __ASSEMBLY__
  15
  16 #include <asm/processor.h>
  17
  18 /*
  19  * low level task data that entry.S needs immediate access to
  20  * - this struct should fit entirely inside of one cache line
  21  * - this struct shares the supervisor stack pages
  22  * - if the contents of this structure are changed, the assembly constants
  23  *   must also be changed
  24  */
  25 struct thread_info {
  26         struct task_struct      *task;          /* main task structure */
  27         struct exec_domain      *exec_domain;   /* execution domain */
  28         unsigned long           flags;          /* low level flags */
  29         __u32                   cpu;            /* current CPU */
  30         int                     preempt_count;  /* 0 => preemptable, <0 => BUG */
  31
  32         mm_segment_t            addr_limit;     /* thread address space:
  33                                                    0-0xBFFFFFFF for user-thead
  34                                                    0-0xFFFFFFFF for kernel-thread
  35                                                 */
  36         struct restart_block    restart_block;
  37 };
  38
  39 /*
  40  * macros/functions for gaining access to the thread information structure
  41  *
  42  * preempt_count needs to be 1 initially, until the scheduler is functional.
  43  */
  44 #define INIT_THREAD_INFO(tsk)                   \
  45 {                                               \
  46         .task           = &tsk,                 \
  47         .exec_domain    = &default_exec_domain, \
  48         .flags          = 0,                    \
  49         .cpu            = 0,                    \
  50         .preempt_count  = 1,                    \
  51         .addr_limit     = KERNEL_DS,            \
  52         .restart_block  = {                     \
  53                 .fn = do_no_restart_syscall,    \
  54         },                                      \
  55 }
  56
  57 #define init_thread_info        (init_thread_union.thread_info)
  58 #define init_stack              (init_thread_union.stack)
  59
  60 /* How to get the thread information struct from C.  */
  61 register struct thread_info *__current_thread_info __asm__("$28");
  62 #define current_thread_info()  __current_thread_info
  63
  64 /* thread information allocation */
  65 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_32BIT)
  66 #define THREAD_SIZE_ORDER (1)
  67 #endif
  68 #if defined(CONFIG_PAGE_SIZE_4KB) && defined(CONFIG_64BIT)
  69 #define THREAD_SIZE_ORDER (2)
  70 #endif
  71 #ifdef CONFIG_PAGE_SIZE_8KB
  72 #define THREAD_SIZE_ORDER (1)
  73 #endif
  74 #ifdef CONFIG_PAGE_SIZE_16KB
  75 #define THREAD_SIZE_ORDER (0)
  76 #endif
  77 #ifdef CONFIG_PAGE_SIZE_64KB
  78 #define THREAD_SIZE_ORDER (0)
  79 #endif
  80
  81 #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
  82 #define THREAD_MASK (THREAD_SIZE - 1UL)
  83
  84 #ifdef CONFIG_DEBUG_STACK_USAGE
  85 #define alloc_thread_info(tsk)                                  \
  86 ({                                                              \
  87         struct thread_info *ret;                                \
  88                                                                 \
  89         ret = kmalloc(THREAD_SIZE, GFP_KERNEL);                 \
  90         if (ret)                                                \
  91                 memset(ret, 0, THREAD_SIZE);                    \
  92         ret;                                                    \
  93 })
  94 #else
  95 #define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
  96 #endif
  97
  98 #define free_thread_info(info) kfree(info)
  99 #define get_thread_info(ti) get_task_struct((ti)->task)
 100 #define put_thread_info(ti) put_task_struct((ti)->task)
 101
 102 #endif /* !__ASSEMBLY__ */
 103
 104 #define PREEMPT_ACTIVE          0x10000000
 105
 106 /*
 107  * thread information flags
 108  * - these are process state flags that various assembly files may need to
 109  *   access
 110  * - pending work-to-be-done flags are in LSW
 111  * - other flags in MSW
 112  */
 113 #define TIF_NOTIFY_RESUME       1       /* resumption notification requested */
 114 #define TIF_SIGPENDING          2       /* signal pending */
 115 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
 116 #define TIF_SYSCALL_AUDIT       4       /* syscall auditing active */
 117 #define TIF_USEDFPU             16      /* FPU was used by this task this quantum (SMP) */
 118 #define TIF_POLLING_NRFLAG      17      /* true if poll_idle() is polling TIF_NEED_RESCHED */
 119 #define TIF_MEMDIE              18
 120 #define TIF_SYSCALL_TRACE       31      /* syscall trace active */
 121
 122 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 123 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 124 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 125 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 126 #define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
 127 #define _TIF_USEDFPU            (1<<TIF_USEDFPU)
 128 #define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
 129
 130 #define _TIF_WORK_MASK          0x0000ffef      /* work to do on
 131                                                    interrupt/exception return */
 132 #define _TIF_ALLWORK_MASK       0x8000ffff      /* work to do on any return to
 133                                                    u-space */
 134
 135 #endif /* __KERNEL__ */
 136
 137 #endif /* _ASM_THREAD_INFO_H */