include/asm-xtensa/thread_info.h

   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 #ifdef __KERNEL__
  15
  16 #ifndef __ASSEMBLY__
  17 # include <asm/processor.h>
  18 #endif
  19
  20 /*
  21  * low level task data that entry.S needs immediate access to
  22  * - this struct should fit entirely inside of one cache line
  23  * - this struct shares the supervisor stack pages
  24  * - if the contents of this structure are changed, the assembly constants
  25  *   must also be changed
  26  */
  27
  28 #ifndef __ASSEMBLY__
  29
  30 struct thread_info {
  31         struct task_struct      *task;          /* main task structure */
  32         struct exec_domain      *exec_domain;   /* execution domain */
  33         unsigned long           flags;          /* low level flags */
  34         unsigned long           status;         /* thread-synchronous flags */
  35         __u32                   cpu;            /* current CPU */
  36         __s32                   preempt_count;  /* 0 => preemptable,< 0 => BUG*/
  37
  38         mm_segment_t            addr_limit;     /* thread address space */
  39         struct restart_block    restart_block;
  40
  41
  42 };
  43
  44 #else /* !__ASSEMBLY__ */
  45
  46 /* offsets into the thread_info struct for assembly code access */
  47 #define TI_TASK          0x00000000
  48 #define TI_EXEC_DOMAIN   0x00000004
  49 #define TI_FLAGS         0x00000008
  50 #define TI_STATUS        0x0000000C
  51 #define TI_CPU           0x00000010
  52 #define TI_PRE_COUNT     0x00000014
  53 #define TI_ADDR_LIMIT    0x00000018
  54 #define TI_RESTART_BLOCK 0x000001C
  55
  56 #endif
  57
  58 #define PREEMPT_ACTIVE          0x10000000
  59
  60 /*
  61  * macros/functions for gaining access to the thread information structure
  62  *
  63  * preempt_count needs to be 1 initially, until the scheduler is functional.
  64  */
  65
  66 #ifndef __ASSEMBLY__
  67
  68 #define INIT_THREAD_INFO(tsk)                   \
  69 {                                               \
  70         .task           = &tsk,                 \
  71         .exec_domain    = &default_exec_domain, \
  72         .flags          = 0,                    \
  73         .cpu            = 0,                    \
  74         .preempt_count  = 1,                    \
  75         .addr_limit     = KERNEL_DS,            \
  76         .restart_block = {                      \
  77                 .fn = do_no_restart_syscall,    \
  78         },                                      \
  79 }
  80
  81 #define init_thread_info        (init_thread_union.thread_info)
  82 #define init_stack              (init_thread_union.stack)
  83
  84 /* how to get the thread information struct from C */
  85 static inline struct thread_info *current_thread_info(void)
  86 {
  87         struct thread_info *ti;
  88          __asm__("extui %0,a1,0,13\n\t"
  89                  "xor %0, a1, %0" : "=&r" (ti) : );
  90         return ti;
  91 }
  92
  93 /* thread information allocation */
  94 #define alloc_thread_info(tsk) ((struct thread_info *) __get_free_pages(GFP_KERNEL,1))
  95 #define free_thread_info(ti) free_pages((unsigned long) (ti), 1)
  96
  97 #else /* !__ASSEMBLY__ */
  98
  99 /* how to get the thread information struct from ASM */
 100 #define GET_THREAD_INFO(reg,sp) \
 101         extui reg, sp, 0, 13; \
 102         xor   reg, sp, reg
 103 #endif
 104
 105
 106 /*
 107  * thread information flags
 108  * - these are process state flags that various assembly files may need to access
 109  * - pending work-to-be-done flags are in LSW
 110  * - other flags in MSW
 111  */
 112 #define TIF_SYSCALL_TRACE       0       /* syscall trace active */
 113 #define TIF_SIGPENDING          1       /* signal pending */
 114 #define TIF_NEED_RESCHED        2       /* rescheduling necessary */
 115 #define TIF_SINGLESTEP          3       /* restore singlestep on return to user mode */
 116 #define TIF_IRET                4       /* return with iret */
 117 #define TIF_MEMDIE              5
 118 #define TIF_RESTORE_SIGMASK     6       /* restore signal mask in do_signal() */
 119 #define TIF_POLLING_NRFLAG      16      /* true if poll_idle() is polling TIF_NEED_RESCHED */
 120
 121 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 122 #define _TIF_SIGPENDING         (1<<TIF_SIGPENDING)
 123 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 124 #define _TIF_SINGLESTEP         (1<<TIF_SINGLESTEP)
 125 #define _TIF_IRET               (1<<TIF_IRET)
 126 #define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
 127 #define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 128
 129 #define _TIF_WORK_MASK          0x0000FFFE      /* work to do on interrupt/exception return */
 130 #define _TIF_ALLWORK_MASK       0x0000FFFF      /* work to do on any return to u-space */
 131
 132 /*
 133  * Thread-synchronous status.
 134  *
 135  * This is different from the flags in that nobody else
 136  * ever touches our thread-synchronous status, so we don't
 137  * have to worry about atomic accesses.
 138  */
 139 #define TS_USEDFPU              0x0001  /* FPU was used by this task this quantum (SMP) */
 140
 141 #define THREAD_SIZE 8192        //(2*PAGE_SIZE)
 142
 143 #endif  /* __KERNEL__ */
 144 #endif  /* _XTENSA_THREAD_INFO */