include/asm-x86_64/thread_info.h

   1 /* thread_info.h: x86_64 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 <asm/page.h>
  13 #include <asm/types.h>
  14 #include <asm/pda.h>
  15
  16 /*
  17  * low level task data that entry.S needs immediate access to
  18  * - this struct should fit entirely inside of one cache line
  19  * - this struct shares the supervisor stack pages
  20  */
  21 #ifndef __ASSEMBLY__
  22 struct task_struct;
  23 struct exec_domain;
  24 #include <asm/mmsegment.h>
  25
  26 struct thread_info {
  27         struct task_struct      *task;          /* main task structure */
  28         struct exec_domain      *exec_domain;   /* execution domain */
  29         __u32                   flags;          /* low level flags */
  30         __u32                   status;         /* thread synchronous flags */
  31         __u32                   cpu;            /* current CPU */
  32         int                     preempt_count;  /* 0 => preemptable, <0 => BUG */
  33
  34         mm_segment_t            addr_limit;
  35         struct restart_block    restart_block;
  36 };
  37 #endif
  38
  39 /*
  40  * macros/functions for gaining access to the thread information structure
  41  * preempt_count needs to be 1 initially, until the scheduler is functional.
  42  */
  43 #ifndef __ASSEMBLY__
  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 static inline struct thread_info *current_thread_info(void)
  61 {
  62         struct thread_info *ti;
  63         ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
  64         return ti;
  65 }
  66
  67 /* do not use in interrupt context */
  68 static inline struct thread_info *stack_thread_info(void)
  69 {
  70         struct thread_info *ti;
  71         __asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
  72         return ti;
  73 }
  74
  75 /* thread information allocation */
  76 #ifdef CONFIG_DEBUG_STACK_USAGE
  77 #define alloc_thread_info(tsk)                                  \
  78     ({                                                          \
  79         struct thread_info *ret;                                \
  80                                                                 \
  81         ret = ((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER)); \
  82         if (ret)                                                \
  83                 memset(ret, 0, THREAD_SIZE);                    \
  84         ret;                                                    \
  85     })
  86 #else
  87 #define alloc_thread_info(tsk) \
  88         ((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER))
  89 #endif
  90
  91 #define free_thread_info(ti) free_pages((unsigned long) (ti), THREAD_ORDER)
  92
  93 #else /* !__ASSEMBLY__ */
  94
  95 /* how to get the thread information struct from ASM */
  96 #define GET_THREAD_INFO(reg) \
  97         movq %gs:pda_kernelstack,reg ; \
  98         subq $(THREAD_SIZE-PDA_STACKOFFSET),reg
  99
 100 #endif
 101
 102 /*
 103  * thread information flags
 104  * - these are process state flags that various assembly files may need to access
 105  * - pending work-to-be-done flags are in LSW
 106  * - other flags in MSW
 107  * Warning: layout of LSW is hardcoded in entry.S
 108  */
 109 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
 110 #define TIF_NOTIFY_RESUME       1       /* resumption notification requested */
 111 #define TIF_SIGPENDING          2       /* signal pending */
 112 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
 113 #define TIF_SINGLESTEP          4       /* reenable singlestep on user return*/
 114 #define TIF_IRET                5       /* force IRET */
 115 #define TIF_SYSCALL_AUDIT       7       /* syscall auditing active */
 116 #define TIF_SECCOMP             8       /* secure computing */
 117 #define TIF_RESTORE_SIGMASK     9       /* restore signal mask in do_signal */
 118 /* 16 free */
 119 #define TIF_IA32                17      /* 32bit process */
 120 #define TIF_FORK                18      /* ret_from_fork */
 121 #define TIF_ABI_PENDING         19
 122 #define TIF_MEMDIE              20
 123 #define TIF_DEBUG               21      /* uses debug registers */
 124 #define TIF_IO_BITMAP           22      /* uses I/O bitmap */
 125 #define TIF_FREEZE              23      /* is freezing for suspend */
 126
 127 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 128 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 129 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 130 #define _TIF_SINGLESTEP         (1<<TIF_SINGLESTEP)
 131 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 132 #define _TIF_IRET               (1<<TIF_IRET)
 133 #define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
 134 #define _TIF_SECCOMP            (1<<TIF_SECCOMP)
 135 #define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 136 #define _TIF_IA32               (1<<TIF_IA32)
 137 #define _TIF_FORK               (1<<TIF_FORK)
 138 #define _TIF_ABI_PENDING        (1<<TIF_ABI_PENDING)
 139 #define _TIF_DEBUG              (1<<TIF_DEBUG)
 140 #define _TIF_IO_BITMAP          (1<<TIF_IO_BITMAP)
 141 #define _TIF_FREEZE             (1<<TIF_FREEZE)
 142
 143 /* work to do on interrupt/exception return */
 144 #define _TIF_WORK_MASK \
 145   (0x0000FFFF & ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP|_TIF_SECCOMP))
 146 /* work to do on any return to user space */
 147 #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
 148
 149 /* flags to check in __switch_to() */
 150 #define _TIF_WORK_CTXSW (_TIF_DEBUG|_TIF_IO_BITMAP)
 151
 152 #define PREEMPT_ACTIVE     0x10000000
 153
 154 /*
 155  * Thread-synchronous status.
 156  *
 157  * This is different from the flags in that nobody else
 158  * ever touches our thread-synchronous status, so we don't
 159  * have to worry about atomic accesses.
 160  */
 161 #define TS_USEDFPU              0x0001  /* FPU was used by this task this quantum (SMP) */
 162 #define TS_COMPAT               0x0002  /* 32bit syscall active */
 163 #define TS_POLLING              0x0004  /* true if in idle loop and not sleeping */
 164
 165 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
 166
 167 #endif /* __KERNEL__ */
 168
 169 #endif /* _ASM_THREAD_INFO_H */