LXR linux/arch/tile/include/asm/thread

   1/*
   2 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
   3 * Copyright 2010 Tilera Corporation. All Rights Reserved.
   4 *
   5 *   This program is free software; you can redistribute it and/or
   6 *   modify it under the terms of the GNU General Public License
   7 *   as published by the Free Software Foundation, version 2.
   8 *
   9 *   This program is distributed in the hope that it will be useful, but
  10 *   WITHOUT ANY WARRANTY; without even the implied warranty of
  11 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  12 *   NON INFRINGEMENT.  See the GNU General Public License for
  13 *   more details.
  14 */
  15
  16#ifndef _ASM_TILE_THREAD_INFO_H
  17#define _ASM_TILE_THREAD_INFO_H
  18
  19#include <asm/processor.h>
  20#include <asm/page.h>
  21#ifndef __ASSEMBLY__
  22
  23/*
  24 * Low level task data that assembly code needs immediate access to.
  25 * The structure is placed at the bottom of the supervisor stack.
  26 */
  27struct thread_info {
  28        struct task_struct      *task;          /* main task structure */
  29        struct exec_domain      *exec_domain;   /* execution domain */
  30        unsigned long           flags;          /* low level flags */
  31        unsigned long           status;         /* thread-synchronous flags */
  32        __u32                   homecache_cpu;  /* CPU we are homecached on */
  33        __u32                   cpu;            /* current CPU */
  34        int                     preempt_count;  /* 0 => preemptable,
  35                                                   <0 => BUG */
  36
  37        mm_segment_t            addr_limit;     /* thread address space
  38                                                   (KERNEL_DS or USER_DS) */
  39        struct restart_block    restart_block;
  40        struct single_step_state *step_state;   /* single step state
  41                                                   (if non-zero) */
  42};
  43
  44/*
  45 * macros/functions for gaining access to the thread information structure.
  46 */
  47#define INIT_THREAD_INFO(tsk)                   \
  48{                                               \
  49        .task           = &tsk,                 \
  50        .exec_domain    = &default_exec_domain, \
  51        .flags          = 0,                    \
  52        .cpu            = 0,                    \
  53        .preempt_count  = INIT_PREEMPT_COUNT,   \
  54        .addr_limit     = KERNEL_DS,            \
  55        .restart_block  = {                     \
  56                .fn = do_no_restart_syscall,    \
  57        },                                      \
  58        .step_state     = NULL,                 \
  59}
  60
  61#define init_thread_info        (init_thread_union.thread_info)
  62#define init_stack              (init_thread_union.stack)
  63
  64#endif /* !__ASSEMBLY__ */
  65
  66#if PAGE_SIZE < 8192
  67#define THREAD_SIZE_ORDER (13 - PAGE_SHIFT)
  68#else
  69#define THREAD_SIZE_ORDER (0)
  70#endif
  71#define THREAD_SIZE_PAGES (1 << THREAD_SIZE_ORDER)
  72
  73#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
  74#define LOG2_THREAD_SIZE (PAGE_SHIFT + THREAD_SIZE_ORDER)
  75
  76#define STACK_WARN             (THREAD_SIZE/8)
  77
  78#ifndef __ASSEMBLY__
  79
  80void arch_release_thread_info(struct thread_info *info);
  81
  82/* How to get the thread information struct from C. */
  83register unsigned long stack_pointer __asm__("sp");
  84
  85#define current_thread_info() \
  86  ((struct thread_info *)(stack_pointer & -THREAD_SIZE))
  87
  88/* Sit on a nap instruction until interrupted. */
  89extern void smp_nap(void);
  90
  91/* Enable interrupts racelessly and nap forever: helper for cpu_idle(). */
  92extern void _cpu_idle(void);
  93
  94#else /* __ASSEMBLY__ */
  95
  96/*
  97 * How to get the thread information struct from assembly.
  98 * Note that we use different macros since different architectures
  99 * have different semantics in their "mm" instruction and we would
 100 * like to guarantee that the macro expands to exactly one instruction.
 101 */
 102#ifdef __tilegx__
 103#define EXTRACT_THREAD_INFO(reg) mm reg, zero, LOG2_THREAD_SIZE, 63
 104#else
 105#define GET_THREAD_INFO(reg) mm reg, sp, zero, LOG2_THREAD_SIZE, 31
 106#endif
 107
 108#endif /* !__ASSEMBLY__ */
 109
 110#define PREEMPT_ACTIVE          0x10000000
 111
 112/*
 113 * Thread information flags that various assembly files may need to access.
 114 * Keep flags accessed frequently in low bits, particular since it makes
 115 * it easier to build constants in assembly.
 116 */
 117#define TIF_SIGPENDING          0       /* signal pending */
 118#define TIF_NEED_RESCHED        1       /* rescheduling necessary */
 119#define TIF_SINGLESTEP          2       /* restore singlestep on return to
 120                                           user mode */
 121#define TIF_ASYNC_TLB           3       /* got an async TLB fault in kernel */
 122#define TIF_SYSCALL_TRACE       4       /* syscall trace active */
 123#define TIF_SYSCALL_AUDIT       5       /* syscall auditing active */
 124#define TIF_SECCOMP             6       /* secure computing */
 125#define TIF_MEMDIE              7       /* OOM killer at work */
 126#define TIF_NOTIFY_RESUME       8       /* callback before returning to user */
 127#define TIF_SYSCALL_TRACEPOINT  9       /* syscall tracepoint instrumentation */
 128
 129#define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 130#define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 131#define _TIF_SINGLESTEP         (1<<TIF_SINGLESTEP)
 132#define _TIF_ASYNC_TLB          (1<<TIF_ASYNC_TLB)
 133#define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 134#define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
 135#define _TIF_SECCOMP            (1<<TIF_SECCOMP)
 136#define _TIF_MEMDIE             (1<<TIF_MEMDIE)
 137#define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
 138#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
 139
 140/* Work to do on any return to user space. */
 141#define _TIF_ALLWORK_MASK \
 142  (_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SINGLESTEP|\
 143   _TIF_ASYNC_TLB|_TIF_NOTIFY_RESUME)
 144
 145/* Work to do at syscall entry. */
 146#define _TIF_SYSCALL_ENTRY_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)
 147
 148/* Work to do at syscall exit. */
 149#define _TIF_SYSCALL_EXIT_WORK (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_TRACEPOINT)
 150
 151/*
 152 * Thread-synchronous status.
 153 *
 154 * This is different from the flags in that nobody else
 155 * ever touches our thread-synchronous status, so we don't
 156 * have to worry about atomic accesses.
 157 */
 158#ifdef __tilegx__
 159#define TS_COMPAT               0x0001  /* 32-bit compatibility mode */
 160#endif
 161#define TS_POLLING              0x0004  /* in idle loop but not sleeping */
 162#define TS_RESTORE_SIGMASK      0x0008  /* restore signal mask in do_signal */
 163
 164#ifndef __ASSEMBLY__
 165#define HAVE_SET_RESTORE_SIGMASK        1
 166static inline void set_restore_sigmask(void)
 167{
 168        struct thread_info *ti = current_thread_info();
 169        ti->status |= TS_RESTORE_SIGMASK;
 170        WARN_ON(!test_bit(TIF_SIGPENDING, &ti->flags));
 171}
 172static inline void clear_restore_sigmask(void)
 173{
 174        current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
 175}
 176static inline bool test_restore_sigmask(void)
 177{
 178        return current_thread_info()->status & TS_RESTORE_SIGMASK;
 179}
 180static inline bool test_and_clear_restore_sigmask(void)
 181{
 182        struct thread_info *ti = current_thread_info();
 183        if (!(ti->status & TS_RESTORE_SIGMASK))
 184                return false;
 185        ti->status &= ~TS_RESTORE_SIGMASK;
 186        return true;
 187}
 188#endif  /* !__ASSEMBLY__ */
 189
 190#endif /* _ASM_TILE_THREAD_INFO_H */
 191