include/asm-x86/thread_info.h

   1 /* thread_info.h: 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_X86_THREAD_INFO_H
   8 #define _ASM_X86_THREAD_INFO_H
   9
  10 #include <linux/compiler.h>
  11 #include <asm/page.h>
  12 #include <asm/types.h>
  13
  14 /*
  15  * low level task data that entry.S needs immediate access to
  16  * - this struct should fit entirely inside of one cache line
  17  * - this struct shares the supervisor stack pages
  18  */
  19 #ifndef __ASSEMBLY__
  20 struct task_struct;
  21 struct exec_domain;
  22 #include <asm/processor.h>
  23
  24 struct thread_info {
  25         struct task_struct      *task;          /* main task structure */
  26         struct exec_domain      *exec_domain;   /* execution domain */
  27         unsigned long           flags;          /* low level flags */
  28         __u32                   status;         /* thread synchronous flags */
  29         __u32                   cpu;            /* current CPU */
  30         int                     preempt_count;  /* 0 => preemptable,
  31                                                    <0 => BUG */
  32         mm_segment_t            addr_limit;
  33         struct restart_block    restart_block;
  34         void __user             *sysenter_return;
  35 #ifdef CONFIG_X86_32
  36         unsigned long           previous_esp;   /* ESP of the previous stack in
  37                                                    case of nested (IRQ) stacks
  38                                                 */
  39         __u8                    supervisor_stack[0];
  40 #endif
  41 };
  42
  43 #define INIT_THREAD_INFO(tsk)                   \
  44 {                                               \
  45         .task           = &tsk,                 \
  46         .exec_domain    = &default_exec_domain, \
  47         .flags          = 0,                    \
  48         .cpu            = 0,                    \
  49         .preempt_count  = 1,                    \
  50         .addr_limit     = KERNEL_DS,            \
  51         .restart_block = {                      \
  52                 .fn = do_no_restart_syscall,    \
  53         },                                      \
  54 }
  55
  56 #define init_thread_info        (init_thread_union.thread_info)
  57 #define init_stack              (init_thread_union.stack)
  58
  59 #else /* !__ASSEMBLY__ */
  60
  61 #include <asm/asm-offsets.h>
  62
  63 #endif
  64
  65 /*
  66  * thread information flags
  67  * - these are process state flags that various assembly files
  68  *   may need to access
  69  * - pending work-to-be-done flags are in LSW
  70  * - other flags in MSW
  71  * Warning: layout of LSW is hardcoded in entry.S
  72  */
  73 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
  74 #define TIF_SIGPENDING          2       /* signal pending */
  75 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
  76 #define TIF_SINGLESTEP          4       /* reenable singlestep on user return*/
  77 #define TIF_IRET                5       /* force IRET */
  78 #ifdef CONFIG_X86_32
  79 #define TIF_SYSCALL_EMU         6       /* syscall emulation active */
  80 #endif
  81 #define TIF_SYSCALL_AUDIT       7       /* syscall auditing active */
  82 #define TIF_SECCOMP             8       /* secure computing */
  83 #define TIF_MCE_NOTIFY          10      /* notify userspace of an MCE */
  84 #define TIF_HRTICK_RESCHED      11      /* reprogram hrtick timer */
  85 #define TIF_NOTSC               16      /* TSC is not accessible in userland */
  86 #define TIF_IA32                17      /* 32bit process */
  87 #define TIF_FORK                18      /* ret_from_fork */
  88 #define TIF_ABI_PENDING         19
  89 #define TIF_MEMDIE              20
  90 #define TIF_DEBUG               21      /* uses debug registers */
  91 #define TIF_IO_BITMAP           22      /* uses I/O bitmap */
  92 #define TIF_FREEZE              23      /* is freezing for suspend */
  93 #define TIF_FORCED_TF           24      /* true if TF in eflags artificially */
  94 #define TIF_DEBUGCTLMSR         25      /* uses thread_struct.debugctlmsr */
  95 #define TIF_DS_AREA_MSR         26      /* uses thread_struct.ds_area_msr */
  96 #define TIF_BTS_TRACE_TS        27      /* record scheduling event timestamps */
  97
  98 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
  99 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
 100 #define _TIF_SINGLESTEP         (1 << TIF_SINGLESTEP)
 101 #define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
 102 #define _TIF_IRET               (1 << TIF_IRET)
 103 #ifdef CONFIG_X86_32
 104 #define _TIF_SYSCALL_EMU        (1 << TIF_SYSCALL_EMU)
 105 #else
 106 #define _TIF_SYSCALL_EMU        0
 107 #endif
 108 #define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
 109 #define _TIF_SECCOMP            (1 << TIF_SECCOMP)
 110 #define _TIF_MCE_NOTIFY         (1 << TIF_MCE_NOTIFY)
 111 #define _TIF_HRTICK_RESCHED     (1 << TIF_HRTICK_RESCHED)
 112 #define _TIF_NOTSC              (1 << TIF_NOTSC)
 113 #define _TIF_IA32               (1 << TIF_IA32)
 114 #define _TIF_FORK               (1 << TIF_FORK)
 115 #define _TIF_ABI_PENDING        (1 << TIF_ABI_PENDING)
 116 #define _TIF_DEBUG              (1 << TIF_DEBUG)
 117 #define _TIF_IO_BITMAP          (1 << TIF_IO_BITMAP)
 118 #define _TIF_FREEZE             (1 << TIF_FREEZE)
 119 #define _TIF_FORCED_TF          (1 << TIF_FORCED_TF)
 120 #define _TIF_DEBUGCTLMSR        (1 << TIF_DEBUGCTLMSR)
 121 #define _TIF_DS_AREA_MSR        (1 << TIF_DS_AREA_MSR)
 122 #define _TIF_BTS_TRACE_TS       (1 << TIF_BTS_TRACE_TS)
 123
 124 /* work to do on interrupt/exception return */
 125 #define _TIF_WORK_MASK                                                  \
 126         (0x0000FFFF &                                                   \
 127          ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP|       \
 128          _TIF_SECCOMP|_TIF_SYSCALL_EMU))
 129
 130 /* work to do on any return to user space */
 131 #define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
 132
 133 /* Only used for 64 bit */
 134 #define _TIF_DO_NOTIFY_MASK                                             \
 135         (_TIF_SIGPENDING|_TIF_SINGLESTEP|_TIF_MCE_NOTIFY|_TIF_HRTICK_RESCHED)
 136
 137 /* flags to check in __switch_to() */
 138 #define _TIF_WORK_CTXSW                                                 \
 139         (_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_BTS_TRACE_TS| \
 140                                                                 _TIF_NOTSC)
 141
 142 #define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
 143 #define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
 144
 145 #define PREEMPT_ACTIVE          0x10000000
 146
 147 /* thread information allocation */
 148 #ifdef CONFIG_DEBUG_STACK_USAGE
 149 #define THREAD_FLAGS (GFP_KERNEL | __GFP_ZERO)
 150 #else
 151 #define THREAD_FLAGS GFP_KERNEL
 152 #endif
 153
 154 #define alloc_thread_info(tsk)                                          \
 155         ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER))
 156
 157 #ifdef CONFIG_X86_32
 158
 159 #define STACK_WARN      (THREAD_SIZE/8)
 160 /*
 161  * macros/functions for gaining access to the thread information structure
 162  *
 163  * preempt_count needs to be 1 initially, until the scheduler is functional.
 164  */
 165 #ifndef __ASSEMBLY__
 166
 167
 168 /* how to get the current stack pointer from C */
 169 register unsigned long current_stack_pointer asm("esp") __used;
 170
 171 /* how to get the thread information struct from C */
 172 static inline struct thread_info *current_thread_info(void)
 173 {
 174         return (struct thread_info *)
 175                 (current_stack_pointer & ~(THREAD_SIZE - 1));
 176 }
 177
 178 #else /* !__ASSEMBLY__ */
 179
 180 /* how to get the thread information struct from ASM */
 181 #define GET_THREAD_INFO(reg)     \
 182         movl $-THREAD_SIZE, reg; \
 183         andl %esp, reg
 184
 185 /* use this one if reg already contains %esp */
 186 #define GET_THREAD_INFO_WITH_ESP(reg) \
 187         andl $-THREAD_SIZE, reg
 188
 189 #endif
 190
 191 #else /* X86_32 */
 192
 193 #include <asm/pda.h>
 194
 195 /*
 196  * macros/functions for gaining access to the thread information structure
 197  * preempt_count needs to be 1 initially, until the scheduler is functional.
 198  */
 199 #ifndef __ASSEMBLY__
 200 static inline struct thread_info *current_thread_info(void)
 201 {
 202         struct thread_info *ti;
 203         ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);
 204         return ti;
 205 }
 206
 207 /* do not use in interrupt context */
 208 static inline struct thread_info *stack_thread_info(void)
 209 {
 210         struct thread_info *ti;
 211         asm("andq %%rsp,%0; " : "=r" (ti) : "0" (~(THREAD_SIZE - 1)));
 212         return ti;
 213 }
 214
 215 #else /* !__ASSEMBLY__ */
 216
 217 /* how to get the thread information struct from ASM */
 218 #define GET_THREAD_INFO(reg) \
 219         movq %gs:pda_kernelstack,reg ; \
 220         subq $(THREAD_SIZE-PDA_STACKOFFSET),reg
 221
 222 #endif
 223
 224 #endif /* !X86_32 */
 225
 226 /*
 227  * Thread-synchronous status.
 228  *
 229  * This is different from the flags in that nobody else
 230  * ever touches our thread-synchronous status, so we don't
 231  * have to worry about atomic accesses.
 232  */
 233 #define TS_USEDFPU              0x0001  /* FPU was used by this task
 234                                            this quantum (SMP) */
 235 #define TS_COMPAT               0x0002  /* 32bit syscall active (64BIT)*/
 236 #define TS_POLLING              0x0004  /* true if in idle loop
 237                                            and not sleeping */
 238 #define TS_RESTORE_SIGMASK      0x0008  /* restore signal mask in do_signal() */
 239
 240 #define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
 241
 242 #ifndef __ASSEMBLY__
 243 #define HAVE_SET_RESTORE_SIGMASK        1
 244 static inline void set_restore_sigmask(void)
 245 {
 246         struct thread_info *ti = current_thread_info();
 247         ti->status |= TS_RESTORE_SIGMASK;
 248         set_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags);
 249 }
 250 #endif  /* !__ASSEMBLY__ */
 251
 252 #ifndef __ASSEMBLY__
 253 extern void arch_task_cache_init(void);
 254 extern void free_thread_info(struct thread_info *ti);
 255 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 256 #define arch_task_cache_init arch_task_cache_init
 257 #endif
 258 #endif /* _ASM_X86_THREAD_INFO_H */