sys/arch/sparc/include/userret.h

   1 /*      $NetBSD: userret.h,v 1.7 2007/10/17 19:57:13 garbled Exp $ */
   2
   3 /*
   4  * Copyright (c) 1996
   5  *      The President and Fellows of Harvard College. All rights reserved.
   6  * Copyright (c) 1992, 1993
   7  *      The Regents of the University of California.  All rights reserved.
   8  *
   9  * This software was developed by the Computer Systems Engineering group
  10  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
  11  * contributed to Berkeley.
  12  *
  13  * All advertising materials mentioning features or use of this software
  14  * must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Lawrence Berkeley Laboratory.
  17  *      This product includes software developed by Harvard University.
  18  *
  19  * Redistribution and use in source and binary forms, with or without
  20  * modification, are permitted provided that the following conditions
  21  * are met:
  22  * 1. Redistributions of source code must retain the above copyright
  23  *    notice, this list of conditions and the following disclaimer.
  24  * 2. Redistributions in binary form must reproduce the above copyright
  25  *    notice, this list of conditions and the following disclaimer in the
  26  *    documentation and/or other materials provided with the distribution.
  27  * 3. All advertising materials mentioning features or use of this software
  28  *    must display the following acknowledgement:
  29  *      This product includes software developed by the University of
  30  *      California, Berkeley and its contributors.
  31  *      This product includes software developed by Harvard University.
  32  * 4. Neither the name of the University nor the names of its contributors
  33  *    may be used to endorse or promote products derived from this software
  34  *    without specific prior written permission.
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  37  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  39  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  40  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  42  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  46  * SUCH DAMAGE.
  47  *
  48  *      @(#)trap.c      8.4 (Berkeley) 9/23/93
  49  */
  50
  51 #include <sys/userret.h>
  52
  53 static __inline void userret(struct lwp *, int,  u_quad_t);
  54 static __inline void share_fpu(struct lwp *, struct trapframe *);
  55
  56
  57 /*
  58  * Define the code needed before returning to user mode, for
  59  * trap, mem_access_fault, and syscall.
  60  */
  61 static __inline void
  62 userret(struct lwp *l, int pc, u_quad_t oticks)
  63 {
  64         struct proc *p = l->l_proc;
  65
  66  again:
  67         mi_userret(l);
  68
  69         if (cpuinfo.ci_want_ast) {
  70                 cpuinfo.ci_want_ast = 0;
  71                 if (l->l_pflag & LP_OWEUPC) {
  72                         l->l_pflag &= ~LP_OWEUPC;
  73                         ADDUPROF(l);
  74                 }
  75         }
  76         if (cpuinfo.ci_want_resched) {
  77                 /*
  78                  * We are being preempted.
  79                  */
  80                 preempt();
  81                 goto again;
  82         }
  83
  84         /*
  85          * If profiling, charge recent system time to the trapped pc.
  86          */
  87         if (p->p_stflag & PST_PROFIL)
  88                 addupc_task(l, pc, (int)(p->p_sticks - oticks));
  89 }
  90
  91 /*
  92  * If someone stole the FPU while we were away, do not enable it
  93  * on return.  This is not done in userret() above as it must follow
  94  * the ktrsysret() in syscall().  Actually, it is likely that the
  95  * ktrsysret should occur before the call to userret.
  96  */
  97 static __inline void share_fpu(struct lwp *l, struct trapframe *tf)
  98 {
  99         if ((tf->tf_psr & PSR_EF) != 0 && cpuinfo.fplwp != l)
 100                 tf->tf_psr &= ~PSR_EF;
 101 }