arch/riscv/include/asm/thread_info.h

   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
  31 typedef 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  */
  41 struct 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 */