LXR linux/arch/riscv/include/asm/thread

   1/*
   2 * Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
   3 * Copyright (C) 2012 Regents of the University of California
   4 * Copyright (C) 2017 SiFive
   5 *
   6 *   This program is free software; you can redistribute it and/or
   7 *   modify it under the terms of the GNU General Public License
   8 *   as published by the Free Software Foundation, version 2.
   9 *
  10 *   This program is distributed in the hope that it will be useful,
  11 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 *   GNU General Public License for more details.
  14 */
  15
  16#ifndef _ASM_RISCV_THREAD_INFO_H
  17#define _ASM_RISCV_THREAD_INFO_H
  18
  19#include <asm/page.h>
  20#include <linux/const.h>
  21
  22/* thread information allocation */
  23#define THREAD_SIZE_ORDER       (1)
  24#define THREAD_SIZE             (PAGE_SIZE << THREAD_SIZE_ORDER)
  25
  26#ifndef __ASSEMBLY__
  27
  28#include <asm/processor.h>
  29#include <asm/csr.h>
  30
  31typedef unsigned long mm_segment_t;
  32
  33/*
  34 * low level task data that entry.S needs immediate access to
  35 * - this struct should fit entirely inside of one cache line
  36 * - if the members of this struct changes, the assembly constants
  37 *   in asm-offsets.c must be updated accordingly
  38 * - thread_info is included in task_struct at an offset of 0.  This means that
  39 *   tp points to both thread_info and task_struct.
  40 */
  41struct thread_info {
  42        unsigned long           flags;          /* low level flags */
  43        int                     preempt_count;  /* 0=>preemptible, <0=>BUG */
  44        mm_segment_t            addr_limit;
  45        /*
  46         * These stack pointers are overwritten on every system call or
  47         * exception.  SP is also saved to the stack it can be recovered when
  48         * overwritten.
  49         */
  50        long                    kernel_sp;      /* Kernel stack pointer */
  51        long                    user_sp;        /* User stack pointer */
  52        int                     cpu;
  53};
  54
  55/*
  56 * macros/functions for gaining access to the thread information structure
  57 *
  58 * preempt_count needs to be 1 initially, until the scheduler is functional.
  59 */
  60#define INIT_THREAD_INFO(tsk)                   \
  61{                                               \
  62        .flags          = 0,                    \
  63        .preempt_count  = INIT_PREEMPT_COUNT,   \
  64        .addr_limit     = KERNEL_DS,            \
  65}
  66
  67#endif /* !__ASSEMBLY__ */
  68
  69/*
  70 * thread information flags
  71 * - these are process state flags that various assembly files may need to
  72 *   access
  73 * - pending work-to-be-done flags are in lowest half-word
  74 * - other flags in upper half-word(s)
  75 */
  76#define TIF_SYSCALL_TRACE       0       /* syscall trace active */
  77#define TIF_NOTIFY_RESUME       1       /* callback before returning to user */
  78#define TIF_SIGPENDING          2       /* signal pending */
  79#define TIF_NEED_RESCHED        3       /* rescheduling necessary */
  80#define TIF_RESTORE_SIGMASK     4       /* restore signal mask in do_signal() */
  81#define TIF_MEMDIE              5       /* is terminating due to OOM killer */
  82#define TIF_SYSCALL_TRACEPOINT  6       /* syscall tracepoint instrumentation */
  83
  84#define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
  85#define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
  86#define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
  87#define _TIF_NEED_RESCHED       (1 << TIF_NEED_RESCHED)
  88
  89#define _TIF_WORK_MASK \
  90        (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NEED_RESCHED)
  91
  92#endif /* _ASM_RISCV_THREAD_INFO_H */
  93