text: /*
   * Copyright (c) 2000-2012 Apple Inc. All rights reserved.
   *
   * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   * 
   * This file contains Original Code and/or Modifications of Original Code
   * as defined in and that are subject to the Apple Public Source License
   * Version 2.0 (the 'License'). You may not use this file except in
   * compliance with the License. The rights granted to you under the License
   * may not be used to create, or enable the creation or redistribution of,
   * unlawful or unlicensed copies of an Apple operating system, or to
   * circumvent, violate, or enable the circumvention or violation of, any
   * terms of an Apple operating system software license agreement.
   * 
   * Please obtain a copy of the License at
   * http://www.opensource.apple.com/apsl/ and read it before using this file.
   * 
   * The Original Code and all software distributed under the License are
   * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
   * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
   * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
   * Please see the License for the specific language governing rights and
   * limitations under the License.
   * 
   * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
   */
  /*
   * @OSF_COPYRIGHT@
   */
  /* 
   * Mach Operating System
   * Copyright (c) 1991,1990,1989 Carnegie Mellon University
   * All Rights Reserved.
   * 
   * Permission to use, copy, modify and distribute this software and its
   * documentation is hereby granted, provided that both the copyright
   * notice and this permission notice appear in all copies of the
   * software, derivative works or modified versions, and any portions
   * thereof, and that both notices appear in supporting documentation.
   * 
   * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
   * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
   * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
   * 
   * Carnegie Mellon requests users of this software to return to
   * 
   *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
   *  School of Computer Science
   *  Carnegie Mellon University
   *  Pittsburgh PA 15213-3890
   * 
   * any improvements or extensions that they make and grant Carnegie Mellon
   * the rights to redistribute these changes.
   */
  /*
   */
  
  /*
   *	File:	machine/thread.h
   *
   *	This file contains the structure definitions for the thread
   *	state as applied to I386 processors.
   */
  
  #ifndef	_I386_THREAD_H_
  #define _I386_THREAD_H_
  
  #include <mach/boolean.h>
  #include <mach/i386/vm_types.h>
  #include <mach/i386/fp_reg.h>
  #include <mach/thread_status.h>
  
  #include <kern/simple_lock.h>
  
  #include <i386/iopb.h>
  #include <i386/seg.h>
  #include <i386/tss.h>
  #include <i386/eflags.h>
  
  #include <i386/cpu_data.h>
  
  #include <machine/pal_routines.h>
  
  /*
   *	x86_kernel_state:
   *
   *	This structure corresponds to the state of kernel registers
   *	as saved in a context-switch.  It lives at the base of the stack.
   */
  
  struct x86_kernel_state {
  	uint64_t	k_rbx;	/* kernel context */
  	uint64_t	k_rsp;
  	uint64_t	k_rbp;
  	uint64_t	k_r12;
  	uint64_t	k_r13;
  	uint64_t	k_r14;
  	uint64_t	k_r15;
  	uint64_t	k_rip;
  };
  
  /*
   * Maps state flavor to number of words in the state:
   */
  extern unsigned int _MachineStateCount[];
  
  /*
   * The machine-dependent thread state - registers and all platform-dependent
   * state - is saved in the machine thread structure which is embedded in
   * the thread data structure. For historical reasons this is also referred to
   * as the PCB.
   */
  struct machine_thread {
  	x86_saved_state_t	*iss;
  	void			*ifps;
  	void			*ids;
  	decl_simple_lock_data(,lock);		/* protects ifps and ids */
  	uint64_t		iss_pte0;
  	uint64_t		iss_pte1;
  
  #ifdef	MACH_BSD
  	uint64_t		cthread_self;	/* for use of cthread package */
          struct real_descriptor	cthread_desc;
  	unsigned long		uldt_selector;	/* user ldt selector to set */
  	struct real_descriptor	uldt_desc;	/* actual user setable ldt */
  #endif
  
  	struct pal_pcb		pal_pcb;
  	uint32_t		specFlags;
  #define		OnProc		0x1
  #define		CopyIOActive 	0x2 /* Checked to ensure DTrace actions do not re-enter copyio(). */
  	uint64_t		thread_gpu_ns;
  #if NCOPY_WINDOWS > 0
          struct {
  	        user_addr_t	user_base;
  	} copy_window[NCOPY_WINDOWS];
          int			nxt_window;
          int			copyio_state;
  #define		WINDOWS_DIRTY	0
  #define		WINDOWS_CLEAN	1
  #define		WINDOWS_CLOSED	2
  #define		WINDOWS_OPENED	3
          uint64_t		physwindow_pte;
          int			physwindow_busy;
  #endif
  };
  typedef struct machine_thread *pcb_t;
  
  #define	THREAD_TO_PCB(Thr)	(&(Thr)->machine)
  
  #define USER_STATE(Thr)		((Thr)->machine.iss)
  #define USER_REGS32(Thr)	(saved_state32(USER_STATE(Thr)))
  #define USER_REGS64(Thr)	(saved_state64(USER_STATE(Thr)))
  
  #define	user_pc(Thr)		(is_saved_state32(USER_STATE(Thr)) ?	\
  					USER_REGS32(Thr)->eip :		\
  					USER_REGS64(Thr)->isf.rip )
  
  extern void *get_user_regs(thread_t);
  
  extern void *act_thread_csave(void);
  extern void act_thread_catt(void *ctx);
  extern void act_thread_cfree(void *ctx);
  
  
  /*
   *	On the kernel stack is:
   *	stack:	...
   *		struct x86_kernel_state
   *	stack+kernel_stack_size
   */
  
  #define STACK_IKS(stack)	\
  	((struct x86_kernel_state *)((stack) + kernel_stack_size) - 1)
  
  /*
   * Return the current stack depth including x86_kernel_state
   */
  static inline vm_offset_t
  current_stack_depth(void)
  {
  	vm_offset_t	stack_ptr;
  
  	assert(get_preemption_level() > 0 || !ml_get_interrupts_enabled());
  
  #if defined(__x86_64__)
         __asm__ volatile("mov %%rsp, %0" : "=m" (stack_ptr));
  #else
         __asm__ volatile("mov %%esp, %0" : "=m" (stack_ptr));
  #endif
  	return (current_cpu_datap()->cpu_kernel_stack
  		+ sizeof(struct x86_kernel_state)
  		- stack_ptr); 
  }
  
  /*
   * Return address of the function that called current function, given
   *	address of the first parameter of current function.
   */
  #define	GET_RETURN_PC(addr)	(__builtin_return_address(0))
  
  #endif	/* _I386_THREAD_H_ */
  