LXR linux/arch/xtensa/include/asm/thread

   1/*
   2 * include/asm-xtensa/thread_info.h
   3 *
   4 * This file is subject to the terms and conditions of the GNU General Public
   5 * License.  See the file "COPYING" in the main directory of this archive
   6 * for more details.
   7 *
   8 * Copyright (C) 2001 - 2005 Tensilica Inc.
   9 */
  10
  11#ifndef _XTENSA_THREAD_INFO_H
  12#define _XTENSA_THREAD_INFO_H
  13
  14#include <asm/kmem_layout.h>
  15
  16#define CURRENT_SHIFT KERNEL_STACK_SHIFT
  17
  18#ifndef __ASSEMBLY__
  19# include <asm/processor.h>
  20#endif
  21
  22/*
  23 * low level task data that entry.S needs immediate access to
  24 * - this struct should fit entirely inside of one cache line
  25 * - this struct shares the supervisor stack pages
  26 * - if the contents of this structure are changed, the assembly constants
  27 *   must also be changed
  28 */
  29
  30#ifndef __ASSEMBLY__
  31
  32#if XTENSA_HAVE_COPROCESSORS
  33
  34typedef struct xtregs_coprocessor {
  35        xtregs_cp0_t cp0;
  36        xtregs_cp1_t cp1;
  37        xtregs_cp2_t cp2;
  38        xtregs_cp3_t cp3;
  39        xtregs_cp4_t cp4;
  40        xtregs_cp5_t cp5;
  41        xtregs_cp6_t cp6;
  42        xtregs_cp7_t cp7;
  43} xtregs_coprocessor_t;
  44
  45#endif
  46
  47struct thread_info {
  48        struct task_struct      *task;          /* main task structure */
  49        unsigned long           flags;          /* low level flags */
  50        unsigned long           status;         /* thread-synchronous flags */
  51        __u32                   cpu;            /* current CPU */
  52        __s32                   preempt_count;  /* 0 => preemptable,< 0 => BUG*/
  53
  54        mm_segment_t            addr_limit;     /* thread address space */
  55
  56        unsigned long           cpenable;
  57
  58        /* Allocate storage for extra user states and coprocessor states. */
  59#if XTENSA_HAVE_COPROCESSORS
  60        xtregs_coprocessor_t    xtregs_cp;
  61#endif
  62        xtregs_user_t           xtregs_user;
  63};
  64
  65#endif
  66
  67/*
  68 * macros/functions for gaining access to the thread information structure
  69 */
  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/* how to get the thread information struct from C */
  83static inline struct thread_info *current_thread_info(void)
  84{
  85        struct thread_info *ti;
  86         __asm__("extui %0, a1, 0, "__stringify(CURRENT_SHIFT)"\n\t"
  87                 "xor %0, a1, %0" : "=&r" (ti) : );
  88        return ti;
  89}
  90
  91#else /* !__ASSEMBLY__ */
  92
  93/* how to get the thread information struct from ASM */
  94#define GET_THREAD_INFO(reg,sp) \
  95        extui reg, sp, 0, CURRENT_SHIFT; \
  96        xor   reg, sp, reg
  97#endif
  98
  99
 100/*
 101 * thread information flags
 102 * - these are process state flags that various assembly files may need to access
 103 * - pending work-to-be-done flags are in LSW
 104 * - other flags in MSW
 105 */
 106#define TIF_SYSCALL_TRACE       0       /* syscall trace active */
 107#define TIF_SIGPENDING          1       /* signal pending */
 108#define TIF_NEED_RESCHED        2       /* rescheduling necessary */
 109#define TIF_SINGLESTEP          3       /* restore singlestep on return to user mode */
 110#define TIF_MEMDIE              5       /* is terminating due to OOM killer */
 111#define TIF_RESTORE_SIGMASK     6       /* restore signal mask in do_signal() */
 112#define TIF_NOTIFY_RESUME       7       /* callback before returning to user */
 113#define TIF_DB_DISABLED         8       /* debug trap disabled for syscall */
 114
 115#define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 116#define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 117#define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 118#define _TIF_SINGLESTEP         (1<<TIF_SINGLESTEP)
 119
 120#define _TIF_WORK_MASK          0x0000FFFE      /* work to do on interrupt/exception return */
 121#define _TIF_ALLWORK_MASK       0x0000FFFF      /* work to do on any return to u-space */
 122
 123/*
 124 * Thread-synchronous status.
 125 *
 126 * This is different from the flags in that nobody else
 127 * ever touches our thread-synchronous status, so we don't
 128 * have to worry about atomic accesses.
 129 */
 130#define TS_USEDFPU              0x0001  /* FPU was used by this task this quantum (SMP) */
 131
 132#define THREAD_SIZE KERNEL_STACK_SIZE
 133#define THREAD_SIZE_ORDER (KERNEL_STACK_SHIFT - PAGE_SHIFT)
 134
 135#endif  /* _XTENSA_THREAD_INFO */
 136