/* thread_info.h: x86_64 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__

#include <asm/page.h>

#include <asm/types.h>

#include <asm/pda.h>

/*

 * 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

 */

#ifndef __ASSEMBLY__

struct task_struct;

struct exec_domain;

#include <asm/mmsegment.h>

struct thread_info {

	struct task_struct	*task;		/* main task structure */

	struct exec_domain	*exec_domain;	/* execution domain */

	__u32			flags;		/* low level flags */

	__u32			status;		/* thread synchronous flags */

	__u32			cpu;		/* current CPU */

	int 			preempt_count;	/* 0 => preemptable, <0 => BUG */

	mm_segment_t		addr_limit;	

	struct restart_block    restart_block;

};

#endif

/*

 * macros/functions for gaining access to the thread information structure

 * preempt_count needs to be 1 initially, until the scheduler is functional.

 */

#ifndef __ASSEMBLY__

#define INIT_THREAD_INFO(tsk)			\

{						\

	.task	       = &tsk,			\

	.exec_domain   = &default_exec_domain,	\

	.flags	       = 0,			\

	.cpu	       = 0,			\

	.preempt_count = 1,			\

	.addr_limit     = KERNEL_DS,		\

	.restart_block = {			\

		.fn = do_no_restart_syscall,	\

	},					\

}

#define init_thread_info	(init_thread_union.thread_info)

#define init_stack		(init_thread_union.stack)

#if !defined(__VMKLNX__)

static inline struct thread_info *current_thread_info(void)

{ 

	struct thread_info *ti;

	ti = (void *)(read_pda(kernelstack) + PDA_STACKOFFSET - THREAD_SIZE);

	return ti; 

}

/* do not use in interrupt context */

static inline struct thread_info *stack_thread_info(void)

{

	struct thread_info *ti;

	__asm__("andq %%rsp,%0; ":"=r" (ti) : "0" (~(THREAD_SIZE - 1)));

	return ti;

}

/* thread information allocation */

#ifdef CONFIG_DEBUG_STACK_USAGE

#define alloc_thread_info(tsk)					\

    ({								\

	struct thread_info *ret;				\

								\

	ret = ((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER)); \

	if (ret)						\

		memset(ret, 0, THREAD_SIZE);			\

	ret;							\

    })

#else

#define alloc_thread_info(tsk) \

	((struct thread_info *) __get_free_pages(GFP_KERNEL,THREAD_ORDER))

#endif

#define free_thread_info(ti) free_pages((unsigned long) (ti), THREAD_ORDER)

#else /* !__ASSEMBLY__ */

/* how to get the thread information struct from ASM */

#define GET_THREAD_INFO(reg) \

	movq %gs:pda_kernelstack,reg ; \

	subq $(THREAD_SIZE-PDA_STACKOFFSET),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

 * Warning: layout of LSW is hardcoded in entry.S

 */

#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_SINGLESTEP		4	/* reenable singlestep on user return*/

#define TIF_IRET		5	/* force IRET */

#define TIF_SYSCALL_AUDIT	7	/* syscall auditing active */

#define TIF_SECCOMP		8	/* secure computing */

#define TIF_RESTORE_SIGMASK	9	/* restore signal mask in do_signal */

/* 16 free */

#define TIF_IA32		17	/* 32bit process */ 

#define TIF_FORK		18	/* ret_from_fork */

#define TIF_ABI_PENDING		19

#define TIF_MEMDIE		20

#define TIF_FORCED_TF		21	/* true if TF in eflags artificially */

#define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)

#define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)

#define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)

#define _TIF_SINGLESTEP		(1<<TIF_SINGLESTEP)

#define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)

#define _TIF_IRET		(1<<TIF_IRET)

#define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)

#define _TIF_SECCOMP		(1<<TIF_SECCOMP)

#define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)

#define _TIF_IA32		(1<<TIF_IA32)

#define _TIF_FORK		(1<<TIF_FORK)

#define _TIF_ABI_PENDING	(1<<TIF_ABI_PENDING)

#define _TIF_FORCED_TF		(1<<TIF_FORCED_TF)

/* work to do on interrupt/exception return */

#define _TIF_WORK_MASK \

  (0x0000FFFF & ~(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP|_TIF_SECCOMP))

/* work to do on any return to user space */

#define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)

#define PREEMPT_ACTIVE     0x10000000

/*

 * Thread-synchronous status.

 *

 * This is different from the flags in that nobody else

 * ever touches our thread-synchronous status, so we don't

 * have to worry about atomic accesses.

 */

#define TS_USEDFPU		0x0001	/* FPU was used by this task this quantum (SMP) */

#define TS_COMPAT		0x0002	/* 32bit syscall active */

#define TS_POLLING		0x0004	/* true if in idle loop and not sleeping */

#define tsk_is_polling(t) ((t)->thread_info->status & TS_POLLING)

#endif /* __KERNEL__ */

#endif /* !defined(__VMKLNX__) */

#endif /* _ASM_THREAD_INFO_H */