LXR linux/arch/mn10300/include/asm/thread

   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__
  37typedef struct {
  38        unsigned long   seg;
  39} mm_segment_t;
  40
  41struct 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
  88extern struct thread_info *__current_ti;
  89
  90/* how to get the thread information struct from C */
  91static inline __attribute__((const))
  92struct 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
 103static inline __attribute__((const))
 104struct pt_regs *current_frame(void)
 105{
 106        return current_thread_info()->frame;
 107}
 108
 109/* how to get the current stack pointer from C */
 110static 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
 118void arch_release_thread_info(struct thread_info *ti);
 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 */
 163