arch/mn10300/include/asm/thread_info.h

   1 /* MN10300 Low-level thread information
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11
  12 #ifndef _ASM_THREAD_INFO_H
  13 #define _ASM_THREAD_INFO_H
  14
  15 #ifdef __KERNEL__
  16
  17 #include <asm/page.h>
  18
  19 #ifdef CONFIG_4KSTACKS
  20 #define THREAD_SIZE             (4096)
  21 #define THREAD_SIZE_ORDER       (0)
  22 #else
  23 #define THREAD_SIZE             (8192)
  24 #define THREAD_SIZE_ORDER       (1)
  25 #endif
  26
  27 #define STACK_WARN              (THREAD_SIZE / 8)
  28
  29 /*
  30  * low level task data that entry.S needs immediate access to
  31  * - this struct should fit entirely inside of one cache line
  32  * - this struct shares the supervisor stack pages
  33  * - if the contents of this structure are changed, the assembly constants
  34  *   must also be changed
  35  */
  36 #ifndef __ASSEMBLY__
  37 typedef struct {
  38         unsigned long   seg;
  39 } mm_segment_t;
  40
  41 struct thread_info {
  42         struct task_struct      *task;          /* main task structure */
  43         struct pt_regs          *frame;         /* current exception frame */
  44         unsigned long           flags;          /* low level flags */
  45         __u32                   cpu;            /* current CPU */
  46         __s32                   preempt_count;  /* 0 => preemptable, <0 => BUG */
  47
  48         mm_segment_t            addr_limit;     /* thread address space:
  49                                                    0-0xBFFFFFFF for user-thead
  50                                                    0-0xFFFFFFFF for kernel-thread
  51                                                 */
  52
  53         __u8                    supervisor_stack[0];
  54 };
  55
  56 #define thread_info_to_uregs(ti)                                        \
  57         ((struct pt_regs *)                                             \
  58          ((unsigned long)ti + THREAD_SIZE - sizeof(struct pt_regs)))
  59
  60 #else /* !__ASSEMBLY__ */
  61
  62 #ifndef __ASM_OFFSETS_H__
  63 #include <asm/asm-offsets.h>
  64 #endif
  65
  66 #endif
  67
  68 /*
  69  * macros/functions for gaining access to the thread information structure
  70  */
  71 #ifndef __ASSEMBLY__
  72
  73 #define INIT_THREAD_INFO(tsk)                   \
  74 {                                               \
  75         .task           = &tsk,                 \
  76         .flags          = 0,                    \
  77         .cpu            = 0,                    \
  78         .preempt_count  = INIT_PREEMPT_COUNT,   \
  79         .addr_limit     = KERNEL_DS,            \
  80 }
  81
  82 #define init_thread_info        (init_thread_union.thread_info)
  83 #define init_stack              (init_thread_union.stack)
  84 #define init_uregs                                                      \
  85         ((struct pt_regs *)                                             \
  86          ((unsigned long) init_stack + THREAD_SIZE - sizeof(struct pt_regs)))
  87
  88 extern struct thread_info *__current_ti;
  89
  90 /* how to get the thread information struct from C */
  91 static inline __attribute__((const))
  92 struct thread_info *current_thread_info(void)
  93 {
  94         struct thread_info *ti;
  95         asm("mov sp,%0\n"
  96             "and %1,%0\n"
  97             : "=d" (ti)
  98             : "i" (~(THREAD_SIZE - 1))
  99             : "cc");
 100         return ti;
 101 }
 102
 103 static inline __attribute__((const))
 104 struct pt_regs *current_frame(void)
 105 {
 106         return current_thread_info()->frame;
 107 }
 108
 109 /* how to get the current stack pointer from C */
 110 static inline unsigned long current_stack_pointer(void)
 111 {
 112         unsigned long sp;
 113         asm("mov sp,%0; ":"=r" (sp));
 114         return sp;
 115 }
 116
 117 #ifndef CONFIG_KGDB
 118 void arch_release_thread_stack(unsigned long *stack);
 119 #endif
 120 #define get_thread_info(ti)     get_task_struct((ti)->task)
 121 #define put_thread_info(ti)     put_task_struct((ti)->task)
 122
 123 #else /* !__ASSEMBLY__ */
 124
 125 #ifndef __VMLINUX_LDS__
 126 /* how to get the thread information struct from ASM */
 127 .macro GET_THREAD_INFO reg
 128         mov     sp,\reg
 129         and     -THREAD_SIZE,\reg
 130 .endm
 131 #endif
 132 #endif
 133
 134 /*
 135  * thread information flags
 136  * - these are process state flags that various assembly files may need to
 137  *   access
 138  * - pending work-to-be-done flags are in LSW
 139  * - other flags in MSW
 140  */
 141 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
 142 #define TIF_NOTIFY_RESUME       1       /* resumption notification requested */
 143 #define TIF_SIGPENDING          2       /* signal pending */
 144 #define TIF_NEED_RESCHED        3       /* rescheduling necessary */
 145 #define TIF_SINGLESTEP          4       /* restore singlestep on return to user mode */
 146 #define TIF_RESTORE_SIGMASK     5       /* restore signal mask in do_signal() */
 147 #define TIF_POLLING_NRFLAG      16      /* true if poll_idle() is polling TIF_NEED_RESCHED */
 148 #define TIF_MEMDIE              17      /* is terminating due to OOM killer */
 149
 150 #define _TIF_SYSCALL_TRACE      +(1 << TIF_SYSCALL_TRACE)
 151 #define _TIF_NOTIFY_RESUME      +(1 << TIF_NOTIFY_RESUME)
 152 #define _TIF_SIGPENDING         +(1 << TIF_SIGPENDING)
 153 #define _TIF_NEED_RESCHED       +(1 << TIF_NEED_RESCHED)
 154 #define _TIF_SINGLESTEP         +(1 << TIF_SINGLESTEP)
 155 #define _TIF_POLLING_NRFLAG     +(1 << TIF_POLLING_NRFLAG)
 156
 157 #define _TIF_WORK_MASK          0x0000FFFE      /* work to do on interrupt/exception return */
 158 #define _TIF_ALLWORK_MASK       0x0000FFFF      /* work to do on any return to u-space */
 159
 160 #endif /* __KERNEL__ */
 161
 162 #endif /* _ASM_THREAD_INFO_H */