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>
16 #include <asm/processor.h>
20 * low level task data that entry.S needs immediate access to
21 * - this struct should fit entirely inside of one cache line
22 * - this struct shares the supervisor stack pages
23 * - if the contents of this structure are changed, the assembly constants must also be changed
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 cpu; /* current CPU */
33 __s32 preempt_count; /* 0 => preemptable, <0 => BUG */
36 mm_segment_t addr_limit; /* thread address space:
37 0-0xBFFFFFFF for user-thead
38 0-0xFFFFFFFF for kernel-thread
40 void *sysenter_return;
41 struct restart_block restart_block;
43 unsigned long previous_esp; /* ESP of the previous stack in case
44 of nested (IRQ) stacks
46 __u8 supervisor_stack[0];
49 #else /* !__ASSEMBLY__ */
51 #include <asm/asm_offsets.h>
55 #define PREEMPT_ACTIVE 0x4000000
56 #define THREAD_SIZE (1<<CONFIG_STACK_SIZE_SHIFT)
57 #define STACK_WARN (CONFIG_STACK_WARN)
58 #define STACK_PANIC (0x200ul)
61 * macros/functions for gaining access to the thread information structure
63 * preempt_count needs to be 1 initially, until the scheduler is functional.
67 #define INIT_THREAD_INFO(tsk) \
70 .exec_domain = &default_exec_domain, \
74 .addr_limit = KERNEL_DS, \
76 .fn = do_no_restart_syscall, \
80 #define init_thread_info (init_thread_union.thread_info)
81 #define init_stack (init_thread_union.stack)
84 /* how to get the thread information struct from C */
85 static inline struct thread_info *current_thread_info(void)
87 struct thread_info *ti;
88 __asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));
92 /* how to get the current stack pointer from C */
93 static inline unsigned long current_stack_pointer(void)
96 __asm__("movl %%esp,%0; ":"=r" (ti) : );
100 /* thread information allocation */
101 #ifdef CONFIG_DEBUG_STACK_USAGE
102 #define alloc_thread_info(tsk) \
104 struct thread_info *ret; \
106 ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
108 memset(ret, 0, THREAD_SIZE); \
112 #define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
115 #define free_thread_info(info) kfree(info)
116 #define get_thread_info(ti) get_task_struct((ti)->task)
117 #define put_thread_info(ti) put_task_struct((ti)->task)
119 #else /* !__ASSEMBLY__ */
121 /* how to get the thread information struct from ASM */
122 #define GET_THREAD_INFO(reg) \
123 movl $-THREAD_SIZE, reg; \
126 /* use this one if reg already contains %esp */
127 #define GET_THREAD_INFO_WITH_ESP(reg) \
128 andl $-THREAD_SIZE, reg
133 * thread information flags
134 * - these are process state flags that various assembly files may need to access
135 * - pending work-to-be-done flags are in LSW
136 * - other flags in MSW
138 #define TIF_SYSCALL_TRACE 0 /* syscall trace active */
139 #define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
140 #define TIF_SIGPENDING 2 /* signal pending */
141 #define TIF_NEED_RESCHED 3 /* rescheduling necessary */
142 #define TIF_SINGLESTEP 4 /* restore singlestep on return to user mode */
143 #define TIF_IRET 5 /* return with iret */
144 #define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
145 #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */
147 #define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
148 #define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
149 #define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
150 #define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
151 #define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
152 #define _TIF_IRET (1<<TIF_IRET)
153 #define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
154 #define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
156 /* work to do on interrupt/exception return */
157 #define _TIF_WORK_MASK \
158 (0x0000FFFF & ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP))
159 #define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
162 * Thread-synchronous status.
164 * This is different from the flags in that nobody else
165 * ever touches our thread-synchronous status, so we don't
166 * have to worry about atomic accesses.
168 #define TS_USEDFPU 0x0001 /* FPU was used by this task this quantum (SMP) */
170 #endif /* __KERNEL__ */
172 #endif /* _ASM_THREAD_INFO_H */