LXR linux/arch/metag/include/asm/thread

   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. */
  29struct 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 */
  80register unsigned long current_stack_pointer asm("A0StP") __used;
  81
  82/* how to get the thread information struct from C */
  83static 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
  90static 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 */
 144