1 /* thread_info.h: i386 low-level thread information
3 * Copyright (C) 2002 David Howells (dhowells@redhat.com)
4 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
7 #ifndef _ASM_THREAD_INFO_H
8 #define _ASM_THREAD_INFO_H
12 #include <linux/config.h>
13 #include <linux/compiler.h>
17 #include <asm/processor.h>
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 must also be changed
29 struct task_struct *task; /* main task structure */
30 struct exec_domain *exec_domain; /* execution domain */
31 unsigned long flags; /* low level flags */
32 unsigned long status; /* thread-synchronous flags */
33 __u32 cpu; /* current CPU */
34 __s32 preempt_count; /* 0 => preemptable, <0 => BUG */
37 mm_segment_t addr_limit; /* thread address space:
38 0-0xBFFFFFFF for user-thead
39 0-0xFFFFFFFF for kernel-thread
41 void *sysenter_return;
42 struct restart_block restart_block;
44 unsigned long previous_esp; /* ESP of the previous stack in case
45 of nested (IRQ) stacks
47 __u8 supervisor_stack[0];
50 #else /* !__ASSEMBLY__ */
52 #include <asm/asm_offsets.h>
56 #define PREEMPT_ACTIVE 0x10000000
57 #define THREAD_SIZE (1<<CONFIG_STACK_SIZE_SHIFT)
58 #define STACK_WARN (CONFIG_STACK_WARN)
59 #define STACK_PANIC (0x200ul)
62 * macros/functions for gaining access to the thread information structure
64 * preempt_count needs to be 1 initially, until the scheduler is functional.
68 #define INIT_THREAD_INFO(tsk) \
71 .exec_domain = &default_exec_domain, \
75 .addr_limit = KERNEL_DS, \
77 .fn = do_no_restart_syscall, \
81 #define init_thread_info (init_thread_union.thread_info)
82 #define init_stack (init_thread_union.stack)
85 /* how to get the thread information struct from C */
86 static inline struct thread_info *current_thread_info(void)
88 struct thread_info *ti;
89 __asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
93 /* how to get the current stack pointer from C */
94 register unsigned long current_stack_pointer asm("esp") __attribute_used__;
96 /* thread information allocation */
97 #ifdef CONFIG_DEBUG_STACK_USAGE
98 #define alloc_thread_info(tsk) \
100 struct thread_info *ret; \
102 ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
104 memset(ret, 0, THREAD_SIZE); \
108 #define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
111 #define free_thread_info(info) kfree(info)
112 #define get_thread_info(ti) get_task_struct((ti)->task)
113 #define put_thread_info(ti) put_task_struct((ti)->task)
115 #else /* !__ASSEMBLY__ */
117 /* how to get the thread information struct from ASM */
118 #define GET_THREAD_INFO(reg) \
119 movl $-THREAD_SIZE, reg; \
122 /* use this one if reg already contains %esp */
123 #define GET_THREAD_INFO_WITH_ESP(reg) \
124 andl $-THREAD_SIZE, reg
129 * thread information flags
130 * - these are process state flags that various assembly files may need to access
131 * - pending work-to-be-done flags are in LSW
132 * - other flags in MSW
134 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
135 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
136 #define TIF_SIGPENDING 2 /* signal pending */
137 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
138 #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
139 #define TIF_IRET 5 /* return with iret */
140 #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
141 #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
143 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
144 #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
145 #define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
146 #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
147 #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
148 #define _TIF_IRET (1<<TIF_IRET)
149 #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
150 #define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
152 /* work to do on interrupt/exception return */
153 #define _TIF_WORK_MASK \
154 (0x0000FFFF & ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP))
155 #define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
158 * Thread-synchronous status.
160 * This is different from the flags in that nobody else
161 * ever touches our thread-synchronous status, so we don't
162 * have to worry about atomic accesses.
164 #define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */
166 #endif /* __KERNEL__ */
168 #endif /* _ASM_THREAD_INFO_H */