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| Rev | Author | Line No. | Line |
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| 422 | giacomo | 1 | /* thread_info.h: i386 low-level thread information |
| 2 | * |
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| 3 | * Copyright (C) 2002 David Howells (dhowells@redhat.com) |
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| 4 | * - Incorporating suggestions made by Linus Torvalds and Dave Miller |
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| 5 | */ |
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| 6 | |||
| 7 | #ifndef _ASM_THREAD_INFO_H |
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| 8 | #define _ASM_THREAD_INFO_H |
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| 9 | |||
| 10 | #ifdef __KERNEL__ |
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| 11 | |||
| 12 | #ifndef __ASSEMBLY__ |
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| 13 | #include <asm/processor.h> |
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| 14 | #endif |
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| 15 | |||
| 16 | /* |
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| 17 | * low level task data that entry.S needs immediate access to |
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| 18 | * - this struct should fit entirely inside of one cache line |
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| 19 | * - this struct shares the supervisor stack pages |
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| 20 | * - if the contents of this structure are changed, the assembly constants must also be changed |
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| 21 | */ |
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| 22 | #ifndef __ASSEMBLY__ |
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| 23 | |||
| 24 | struct thread_info { |
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| 25 | struct task_struct *task; /* main task structure */ |
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| 26 | struct exec_domain *exec_domain; /* execution domain */ |
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| 27 | unsigned long flags; /* low level flags */ |
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| 28 | unsigned long status; /* thread-synchronous flags */ |
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| 29 | __u32 cpu; /* current CPU */ |
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| 30 | __s32 preempt_count; /* 0 => preemptable, <0 => BUG */ |
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| 31 | |||
| 32 | mm_segment_t addr_limit; /* thread address space: |
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| 33 | 0-0xBFFFFFFF for user-thead |
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| 34 | 0-0xFFFFFFFF for kernel-thread |
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| 35 | */ |
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| 36 | struct restart_block restart_block; |
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| 37 | |||
| 38 | __u8 supervisor_stack[0]; |
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| 39 | }; |
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| 40 | |||
| 41 | #else /* !__ASSEMBLY__ */ |
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| 42 | |||
| 43 | /* offsets into the thread_info struct for assembly code access */ |
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| 44 | #define TI_TASK 0x00000000 |
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| 45 | #define TI_EXEC_DOMAIN 0x00000004 |
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| 46 | #define TI_FLAGS 0x00000008 |
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| 47 | #define TI_STATUS 0x0000000C |
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| 48 | #define TI_CPU 0x00000010 |
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| 49 | #define TI_PRE_COUNT 0x00000014 |
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| 50 | #define TI_ADDR_LIMIT 0x00000018 |
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| 51 | #define TI_RESTART_BLOCK 0x000001C |
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| 52 | |||
| 53 | #endif |
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| 54 | |||
| 55 | #define PREEMPT_ACTIVE 0x4000000 |
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| 56 | |||
| 57 | /* |
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| 58 | * macros/functions for gaining access to the thread information structure |
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| 59 | * |
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| 60 | * preempt_count needs to be 1 initially, until the scheduler is functional. |
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| 61 | */ |
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| 62 | #ifndef __ASSEMBLY__ |
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| 63 | |||
| 64 | #define INIT_THREAD_INFO(tsk) \ |
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| 65 | { \ |
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| 66 | .task = &tsk, \ |
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| 67 | .exec_domain = &default_exec_domain, \ |
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| 68 | .flags = 0, \ |
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| 69 | .cpu = 0, \ |
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| 70 | .preempt_count = 1, \ |
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| 71 | .addr_limit = KERNEL_DS, \ |
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| 72 | .restart_block = { \ |
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| 73 | .fn = do_no_restart_syscall, \ |
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| 74 | }, \ |
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| 75 | } |
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| 76 | |||
| 77 | #define init_thread_info (init_thread_union.thread_info) |
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| 78 | #define init_stack (init_thread_union.stack) |
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| 79 | |||
| 80 | /* how to get the thread information struct from C */ |
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| 81 | static inline struct thread_info *current_thread_info(void) |
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| 82 | { |
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| 83 | struct thread_info *ti; |
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| 84 | __asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~8191UL)); |
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| 85 | return ti; |
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| 86 | } |
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| 87 | |||
| 88 | /* thread information allocation */ |
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| 89 | #define THREAD_SIZE (2*PAGE_SIZE) |
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| 90 | #define alloc_thread_info(task) ((struct thread_info *)kmalloc(THREAD_SIZE, GFP_KERNEL)) |
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| 91 | #define free_thread_info(info) kfree(info) |
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| 92 | #define get_thread_info(ti) get_task_struct((ti)->task) |
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| 93 | #define put_thread_info(ti) put_task_struct((ti)->task) |
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| 94 | |||
| 95 | #else /* !__ASSEMBLY__ */ |
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| 96 | |||
| 97 | /* how to get the thread information struct from ASM */ |
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| 98 | #define GET_THREAD_INFO(reg) \ |
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| 99 | movl $-8192, reg; \ |
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| 100 | andl %esp, reg |
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| 101 | |||
| 102 | #endif |
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| 103 | |||
| 104 | /* |
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| 105 | * thread information flags |
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| 106 | * - these are process state flags that various assembly files may need to access |
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| 107 | * - pending work-to-be-done flags are in LSW |
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| 108 | * - other flags in MSW |
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| 109 | */ |
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| 110 | #define TIF_SYSCALL_TRACE 0 /* syscall trace active */ |
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| 111 | #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */ |
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| 112 | #define TIF_SIGPENDING 2 /* signal pending */ |
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| 113 | #define TIF_NEED_RESCHED 3 /* rescheduling necessary */ |
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| 114 | #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */ |
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| 115 | #define TIF_IRET 5 /* return with iret */ |
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| 116 | #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ |
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| 117 | |||
| 118 | #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE) |
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| 119 | #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME) |
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| 120 | #define _TIF_SIGPENDING (1<<TIF_SIGPENDING) |
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| 121 | #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED) |
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| 122 | #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP) |
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| 123 | #define _TIF_IRET (1<<TIF_IRET) |
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| 124 | #define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG) |
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| 125 | |||
| 126 | #define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */ |
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| 127 | #define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */ |
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| 128 | |||
| 129 | /* |
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| 130 | * Thread-synchronous status. |
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| 131 | * |
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| 132 | * This is different from the flags in that nobody else |
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| 133 | * ever touches our thread-synchronous status, so we don't |
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| 134 | * have to worry about atomic accesses. |
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| 135 | */ |
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| 136 | #define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */ |
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| 137 | |||
| 138 | #endif /* __KERNEL__ */ |
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| 139 | |||
| 140 | #endif /* _ASM_THREAD_INFO_H */ |