1. 根目录:
2. arch
3. cris
4. include
5. asm
6. thread_info.h

/* thread_info.h: CRIS low-level thread information
 *
 * Copyright (C) 2002  David Howells (dhowells@redhat.com)
 * - Incorporating suggestions made by Linus Torvalds and Dave Miller
 * 
 * CRIS port by Axis Communications
 */

#ifndef _ASM_THREAD_INFO_H
#define _ASM_THREAD_INFO_H

#ifdef __KERNEL__

#define __HAVE_ARCH_THREAD_INFO_ALLOCATOR

#ifndef __ASSEMBLY__
#include <asm/types.h>
#include <asm/processor.h>
#include <arch/thread_info.h>
#include <asm/segment.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 */
	int			preempt_count;	/* 0 => preemptable, <0 => BUG */
	__u32			tls;		/* TLS for this thread */

	mm_segment_t		addr_limit;	/* thread address space:
					 	   0-0xBFFFFFFF for user-thead
						   0-0xFFFFFFFF for kernel-thread
						*/
	struct restart_block    restart_block;
	__u8			supervisor_stack[0];
};

#endif

#define PREEMPT_ACTIVE		0x10000000

/*
 * 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,				\
	.preempt_count	= INIT_PREEMPT_COUNT,		\
	.addr_limit	= KERNEL_DS,			\
	.restart_block = {				\
		       .fn = do_no_restart_syscall,	\
	},						\
}

#define init_thread_info	(init_thread_union.thread_info)

/* thread information allocation */
#define alloc_thread_info(tsk, node) ((struct thread_info *) __get_free_pages(GFP_KERNEL,1))
#define free_thread_info(ti) free_pages((unsigned long) (ti), 1)

#endif /* !__ASSEMBLY__ */

/*
 * 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_RESTORE_SIGMASK	9	/* restore signal mask in do_signal() */
#define TIF_POLLING_NRFLAG	16	/* true if poll_idle() is polling TIF_NEED_RESCHED */
#define TIF_MEMDIE		17	/* is terminating due to OOM killer */
#define TIF_FREEZE		18	/* is freezing for suspend */

#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_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
#define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
#define _TIF_FREEZE		(1<<TIF_FREEZE)

#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 */