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/* thread_info.h: i386 low-level thread information
*
* Copyright (C) 2002 David Howells (dhowells@redhat.com)
* - Incorporating suggestions made by Linus Torvalds and Dave Miller
*/
#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
#include <asm/processor.h>
#endif
/*
* low level task data that entry.S needs immediate access to
* - this struct should fit entirely inside of one cache line
* - this struct shares the supervisor stack pages
* - if the contents of this structure are changed, the assembly constants must also be changed
*/
#ifndef __ASSEMBLY__
struct thread_info {
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
unsigned long flags; /* low level flags */
__u32 cpu; /* current CPU */
__s32 preempt_count; /* 0 => preemptable, <0 => BUG */
mm_segment_t addr_limit; /* thread address space:
0-0xBFFFFFFF for user-thead
0-0xFFFFFFFF for kernel-thread
*/
__u8 supervisor_stack[0];
};
#else /* !__ASSEMBLY__ */
/* offsets into the thread_info struct for assembly code access */
#define TI_TASK 0x00000000
#define TI_EXEC_DOMAIN 0x00000004
#define TI_FLAGS 0x00000008
#define TI_CPU 0x0000000C
#define TI_PRE_COUNT 0x00000010
#define TI_ADDR_LIMIT 0x00000014
#endif
/*
* macros/functions for gaining access to the thread information structure
*/
#ifndef __ASSEMBLY__
#define INIT_THREAD_INFO(tsk) \
{ \
task: &tsk, \
exec_domain: &default_exec_domain, \
flags: 0, \
cpu: 0, \
addr_limit: KERNEL_DS, \
}
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
struct thread_info *ti;
__asm__("andl %%esp,%0; ":"=r" (ti) : "0" (~8191UL));
return ti;
}
/* thread information allocation */
#define THREAD_SIZE (2*PAGE_SIZE)
#define alloc_thread_info() ((struct thread_info *) __get_free_pages(GFP_KERNEL,1))
#define free_thread_info(ti) free_pages((unsigned long) (ti), 1)
#define get_thread_info(ti) get_task_struct((ti)->task)
#define put_thread_info(ti) put_task_struct((ti)->task)
#else /* !__ASSEMBLY__ */
/* how to get the thread information struct from ASM */
#define GET_THREAD_INFO(reg) \
movl $-8192, reg; \
andl %esp, reg
#endif
/*
* thread information flags
* - these are process state flags that various assembly files may need to access
* - pending work-to-be-done flags are in LSW
* - other flags in MSW
*/
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
#define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_USEDFPU 16 /* FPU was used by this task this quantum (SMP) */
#define TIF_POLLING_NRFLAG 17 /* true if poll_idle() is polling TIF_NEED_RESCHED */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_USEDFPU (1<<TIF_USEDFPU)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_WORK_MASK 0x0000FFFE /* work to do on interrupt/exception return */
#define _TIF_ALLWORK_MASK 0x0000FFFF /* work to do on any return to u-space */
#endif /* __KERNEL__ */
#endif /* _ASM_THREAD_INFO_H */
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