arch/metag/include/asm/thread_info.h

   1 /* thread_info.h: Meta 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  * Meta port by Imagination Technologies
   7  */
   8
   9 #ifndef _ASM_THREAD_INFO_H
  10 #define _ASM_THREAD_INFO_H
  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, the assembly constants must
  24  *   also be changed
  25  */
  26 #ifndef __ASSEMBLY__
  27
  28 /* This must be 8 byte aligned so we can ensure stack alignment. */
  29 struct thread_info {
  30         struct task_struct *task;       /* main task structure */
  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, <0 => BUG */
  35
  36         mm_segment_t addr_limit;        /* thread address space */
  37
  38         u8 supervisor_stack[0] __aligned(8);
  39 };
  40
  41 #else /* !__ASSEMBLY__ */
  42
  43 #include <generated/asm-offsets.h>
  44
  45 #endif
  46
  47 #ifdef CONFIG_4KSTACKS
  48 #define THREAD_SHIFT            12
  49 #else
  50 #define THREAD_SHIFT            13
  51 #endif
  52
  53 #if THREAD_SHIFT >= PAGE_SHIFT
  54 #define THREAD_SIZE_ORDER       (THREAD_SHIFT - PAGE_SHIFT)
  55 #else
  56 #define THREAD_SIZE_ORDER       0
  57 #endif
  58
  59 #define THREAD_SIZE             (PAGE_SIZE << THREAD_SIZE_ORDER)
  60
  61 #define STACK_WARN              (THREAD_SIZE/8)
  62 /*
  63  * macros/functions for gaining access to the thread information structure
  64  */
  65 #ifndef __ASSEMBLY__
  66
  67 #define INIT_THREAD_INFO(tsk)                   \
  68 {                                               \
  69         .task           = &tsk,                 \
  70         .flags          = 0,                    \
  71         .cpu            = 0,                    \
  72         .preempt_count  = INIT_PREEMPT_COUNT,   \
  73         .addr_limit     = KERNEL_DS,            \
  74 }
  75
  76 #define init_thread_info        (init_thread_union.thread_info)
  77 #define init_stack              (init_thread_union.stack)
  78
  79 /* how to get the current stack pointer from C */
  80 register unsigned long current_stack_pointer asm("A0StP") __used;
  81
  82 /* how to get the thread information struct from C */
  83 static inline struct thread_info *current_thread_info(void)
  84 {
  85         return (struct thread_info *)(current_stack_pointer &
  86                                       ~(THREAD_SIZE - 1));
  87 }
  88
  89 #define __HAVE_ARCH_KSTACK_END
  90 static inline int kstack_end(void *addr)
  91 {
  92         return addr == (void *) (((unsigned long) addr & ~(THREAD_SIZE - 1))
  93                                  + sizeof(struct thread_info));
  94 }
  95
  96 #endif
  97
  98 /*
  99  * thread information flags
 100  * - these are process state flags that various assembly files may need to
 101  *   access
 102  * - pending work-to-be-done flags are in LSW
 103  * - other flags in MSW
 104  */
 105 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
 106 #define TIF_SIGPENDING          1       /* signal pending */
 107 #define TIF_NEED_RESCHED        2       /* rescheduling necessary */
 108 #define TIF_SINGLESTEP          3       /* restore singlestep on return to user
 109                                            mode */
 110 #define TIF_SYSCALL_AUDIT       4       /* syscall auditing active */
 111 #define TIF_SECCOMP             5       /* secure computing */
 112 #define TIF_RESTORE_SIGMASK     6       /* restore signal mask in do_signal() */
 113 #define TIF_NOTIFY_RESUME       7       /* callback before returning to user */
 114 #define TIF_MEMDIE              8       /* is terminating due to OOM killer */
 115 #define TIF_SYSCALL_TRACEPOINT  9       /* syscall tracepoint instrumentation */
 116
 117
 118 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 119 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 120 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 121 #define _TIF_SINGLESTEP         (1<<TIF_SINGLESTEP)
 122 #define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
 123 #define _TIF_SECCOMP            (1<<TIF_SECCOMP)
 124 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 125 #define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 126 #define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
 127
 128 /* work to do in syscall trace */
 129 #define _TIF_WORK_SYSCALL_MASK  (_TIF_SYSCALL_TRACE | _TIF_SINGLESTEP | \
 130                                  _TIF_SYSCALL_AUDIT | _TIF_SECCOMP | \
 131                                  _TIF_SYSCALL_TRACEPOINT)
 132
 133 /* work to do on any return to u-space */
 134 #define _TIF_ALLWORK_MASK       (_TIF_SYSCALL_TRACE | _TIF_SIGPENDING      | \
 135                                  _TIF_NEED_RESCHED  | _TIF_SYSCALL_AUDIT   | \
 136                                  _TIF_SINGLESTEP    | _TIF_RESTORE_SIGMASK | \
 137                                  _TIF_NOTIFY_RESUME)
 138
 139 /* work to do on interrupt/exception return */
 140 #define _TIF_WORK_MASK          (_TIF_ALLWORK_MASK & ~(_TIF_SYSCALL_TRACE | \
 141                                  _TIF_SYSCALL_AUDIT | _TIF_SINGLESTEP))
 142
 143 #endif /* _ASM_THREAD_INFO_H */