include/asm-x86/thread_info_32.h

   1 /* thread_info.h: i386 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/compiler.h>
  13 #include <asm/page.h>
  14
  15 #ifndef __ASSEMBLY__
  16 #include <asm/processor.h>
  17 #endif
  18
  19 /*
  20  * low level task data that entry.S needs immediate access to
  21  * - this struct should fit entirely inside of one cache line
  22  * - this struct shares the supervisor stack pages
  23  * - if the contents of this structure are changed,
  24  *   the assembly constants must also be changed
  25  */
  26 #ifndef __ASSEMBLY__
  27
  28 struct thread_info {
  29         struct task_struct      *task;          /* main task structure */
  30         struct exec_domain      *exec_domain;   /* execution domain */
  31         unsigned long           flags;          /* low level flags */
  32         unsigned long           status;         /* thread-synchronous flags */
  33         __u32                   cpu;            /* current CPU */
  34         int                     preempt_count;  /* 0 => preemptable,
  35                                                    <0 => BUG */
  36         mm_segment_t            addr_limit;     /* thread address space:
  37                                                    0-0xBFFFFFFF user-thread
  38                                                    0-0xFFFFFFFF kernel-thread
  39                                                 */
  40         void                    *sysenter_return;
  41         struct restart_block    restart_block;
  42         unsigned long           previous_esp;   /* ESP of the previous stack in
  43                                                    case of nested (IRQ) stacks
  44                                                 */
  45         __u8                    supervisor_stack[0];
  46 };
  47
  48 #else /* !__ASSEMBLY__ */
  49
  50 #include <asm/asm-offsets.h>
  51
  52 #endif
  53
  54 #define PREEMPT_ACTIVE          0x10000000
  55 #ifdef CONFIG_4KSTACKS
  56 #define THREAD_SIZE            (4096)
  57 #else
  58 #define THREAD_SIZE             (8192)
  59 #endif
  60
  61 #define STACK_WARN             (THREAD_SIZE/8)
  62 /*
  63  * macros/functions for gaining access to the thread information structure
  64  *
  65  * preempt_count needs to be 1 initially, until the scheduler is functional.
  66  */
  67 #ifndef __ASSEMBLY__
  68
  69 #define INIT_THREAD_INFO(tsk)                   \
  70 {                                               \
  71         .task           = &tsk,                 \
  72         .exec_domain    = &default_exec_domain, \
  73         .flags          = 0,                    \
  74         .cpu            = 0,                    \
  75         .preempt_count  = 1,                    \
  76         .addr_limit     = KERNEL_DS,            \
  77         .restart_block = {                      \
  78                 .fn = do_no_restart_syscall,    \
  79         },                                      \
  80 }
  81
  82 #define init_thread_info        (init_thread_union.thread_info)
  83 #define init_stack              (init_thread_union.stack)
  84
  85
  86 /* how to get the current stack pointer from C */
  87 register unsigned long current_stack_pointer asm("esp") __used;
  88
  89 /* how to get the thread information struct from C */
  90 static inline struct thread_info *current_thread_info(void)
  91 {
  92         return (struct thread_info *)
  93                 (current_stack_pointer & ~(THREAD_SIZE - 1));
  94 }
  95
  96 /* thread information allocation */
  97 #ifdef CONFIG_DEBUG_STACK_USAGE
  98 #define alloc_thread_info(tsk) ((struct thread_info *)                  \
  99         __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(THREAD_SIZE)))
 100 #else
 101 #define alloc_thread_info(tsk) ((struct thread_info *)                  \
 102         __get_free_pages(GFP_KERNEL, get_order(THREAD_SIZE)))
 103 #endif
 104
 105 #define free_thread_info(info)  free_pages((unsigned long)(info), get_order(THREAD_SIZE))
 106
 107 #else /* !__ASSEMBLY__ */
 108
 109 /* how to get the thread information struct from ASM */
 110 #define GET_THREAD_INFO(reg)     \
 111         movl $-THREAD_SIZE, reg; \
 112         andl %esp, reg
 113
 114 /* use this one if reg already contains %esp */
 115 #define GET_THREAD_INFO_WITH_ESP(reg) \
 116         andl $-THREAD_SIZE, reg
 117
 118 #endif
 119
 120 /*
 121  * thread information flags
 122  * - these are process state flags that various
 123  *   assembly files may need to access
 124  * - pending work-to-be-done flags are in LSW
 125  * - other flags in MSW
 126  */
 127 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
 128 #define TIF_SIGPENDING          1       /* signal pending */
 129 #define TIF_NEED_RESCHED        2       /* rescheduling necessary */
 130 #define TIF_SINGLESTEP          3       /* restore singlestep on return to
 131                                            user mode */
 132 #define TIF_IRET                4       /* return with iret */
 133 #define TIF_SYSCALL_EMU         5       /* syscall emulation active */
 134 #define TIF_SYSCALL_AUDIT       6       /* syscall auditing active */
 135 #define TIF_SECCOMP             7       /* secure computing */
 136 #define TIF_RESTORE_SIGMASK     8       /* restore signal mask in do_signal() */
 137 #define TIF_HRTICK_RESCHED      9       /* reprogram hrtick timer */
 138 #define TIF_MEMDIE              16
 139 #define TIF_DEBUG               17      /* uses debug registers */
 140 #define TIF_IO_BITMAP           18      /* uses I/O bitmap */
 141 #define TIF_FREEZE              19      /* is freezing for suspend */
 142 #define TIF_NOTSC               20      /* TSC is not accessible in userland */
 143 #define TIF_FORCED_TF           21      /* true if TF in eflags artificially */
 144 #define TIF_DEBUGCTLMSR         22      /* uses thread_struct.debugctlmsr */
 145 #define TIF_DS_AREA_MSR         23      /* uses thread_struct.ds_area_msr */
 146 #define TIF_BTS_TRACE_TS        24      /* record scheduling event timestamps */
 147
 148 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
 149 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 150 #define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
 151 #define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
 152 #define _TIF_IRET               (1 << TIF_IRET)
 153 #define _TIF_SYSCALL_EMU        (1 << TIF_SYSCALL_EMU)
 154 #define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 155 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
 156 #define _TIF_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
 157 #define _TIF_HRTICK_RESCHED     (1 << TIF_HRTICK_RESCHED)
 158 #define _TIF_DEBUG              (1 << TIF_DEBUG)
 159 #define _TIF_IO_BITMAP          (1 << TIF_IO_BITMAP)
 160 #define _TIF_FREEZE             (1 << TIF_FREEZE)
 161 #define _TIF_NOTSC              (1 << TIF_NOTSC)
 162 #define _TIF_FORCED_TF          (1 << TIF_FORCED_TF)
 163 #define _TIF_DEBUGCTLMSR        (1 << TIF_DEBUGCTLMSR)
 164 #define _TIF_DS_AREA_MSR        (1 << TIF_DS_AREA_MSR)
 165 #define _TIF_BTS_TRACE_TS       (1 << TIF_BTS_TRACE_TS)
 166
 167 /* work to do on interrupt/exception return */
 168 #define _TIF_WORK_MASK                                                  \
 169         (0x0000FFFF & ~(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT |       \
 170                         _TIF_SECCOMP | _TIF_SYSCALL_EMU))
 171 /* work to do on any return to u-space */
 172 #define _TIF_ALLWORK_MASK       (0x0000FFFF & ~_TIF_SECCOMP)
 173
 174 /* flags to check in __switch_to() */
 175 #define _TIF_WORK_CTXSW                                         \
 176         (_TIF_IO_BITMAP | _TIF_NOTSC | _TIF_DEBUGCTLMSR |       \
 177          _TIF_DS_AREA_MSR | _TIF_BTS_TRACE_TS)
 178 #define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
 179 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW | _TIF_DEBUG)
 180
 181
 182 /*
 183  * Thread-synchronous status.
 184  *
 185  * This is different from the flags in that nobody else
 186  * ever touches our thread-synchronous status, so we don't
 187  * have to worry about atomic accesses.
 188  */
 189 #define TS_USEDFPU              0x0001  /* FPU was used by this task
 190                                            this quantum (SMP) */
 191 #define TS_POLLING              0x0002  /* True if in idle loop
 192                                            and not sleeping */
 193
 194 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
 195
 196 #endif /* __KERNEL__ */
 197
 198 #endif /* _ASM_THREAD_INFO_H */