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userret.h revision 1.3.2.1 
      1 /*	$NetBSD: userret.h,v 1.3.2.1 2006/02/18 15:38:48 yamt Exp $ */
      2 
      3 /*
      4  * Copyright (c) 1996-2002 Eduardo Horvath.  All rights reserved.
      5  * Copyright (c) 1996
      6  *	The President and Fellows of Harvard College. All rights reserved.
      7  * Copyright (c) 1992, 1993
      8  *	The Regents of the University of California.  All rights reserved.
      9  *
     10  * This software was developed by the Computer Systems Engineering group
     11  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
     12  * contributed to Berkeley.
     13  *
     14  * All advertising materials mentioning features or use of this software
     15  * must display the following acknowledgement:
     16  *	This product includes software developed by the University of
     17  *	California, Lawrence Berkeley Laboratory.
     18  *	This product includes software developed by Harvard University.
     19  *
     20  * Redistribution and use in source and binary forms, with or without
     21  * modification, are permitted provided that the following conditions
     22  * are met:
     23  * 1. Redistributions of source code must retain the above copyright
     24  *    notice, this list of conditions and the following disclaimer.
     25  * 2. Redistributions in binary form must reproduce the above copyright
     26  *    notice, this list of conditions and the following disclaimer in the
     27  *    documentation and/or other materials provided with the distribution.
     28  * 3. All advertising materials mentioning features or use of this software
     29  *    must display the following acknowledgement:
     30  *	This product includes software developed by the University of
     31  *	California, Berkeley and its contributors.
     32  *	This product includes software developed by Harvard University.
     33  * 4. Neither the name of the University nor the names of its contributors
     34  *    may be used to endorse or promote products derived from this software
     35  *    without specific prior written permission.
     36  *
     37  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     38  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     39  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     40  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     41  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     42  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     43  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     45  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     46  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     47  * SUCH DAMAGE.
     48  *
     49  *	@(#)trap.c	8.4 (Berkeley) 9/23/93
     50  */
     51 
     52 #include <sys/userret.h>
     53 
     54 static __inline void userret __P((struct lwp *, int,  u_quad_t));
     55 /*
     56  * Define the code needed before returning to user mode, for
     57  * trap, mem_access_fault, and syscall.
     58  */
     59 static __inline void
     60 userret(struct lwp *l, int pc, u_quad_t oticks)
     61 {
     62 	struct proc *p = l->l_proc;
     63 
     64 	mi_userret(l);
     65 
     66 	if (want_ast) {
     67 		want_ast = 0;
     68 		if (p->p_flag & P_OWEUPC) {
     69 			p->p_flag &= ~P_OWEUPC;
     70 			ADDUPROF(p);
     71 		}
     72 	}
     73 
     74 	/*
     75 	 * If profiling, charge recent system time to the trapped pc.
     76 	 */
     77 	if (p->p_flag & P_PROFIL)
     78 		addupc_task(p, pc, (int)(p->p_sticks - oticks));
     79 
     80 	curcpu()->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
     81 }
     82 
     83 static __inline void share_fpu __P((struct lwp *, struct trapframe64 *));
     84 /*
     85  * If someone stole the FPU while we were away, do not enable it
     86  * on return.  This is not done in userret() above as it must follow
     87  * the ktrsysret() in syscall().  Actually, it is likely that the
     88  * ktrsysret should occur before the call to userret.
     89  *
     90  * Oh, and don't touch the FPU bit if we're returning to the kernel.
     91  */
     92 static __inline void
     93 share_fpu(struct lwp *l, struct trapframe64 *tf)
     94 {
     95 	if (!(tf->tf_tstate & (PSTATE_PRIV << TSTATE_PSTATE_SHIFT)) &&
     96 	    fplwp != l)
     97 		tf->tf_tstate &= ~(PSTATE_PEF << TSTATE_PSTATE_SHIFT);
     98 }
     99