Home | History | Annotate | Line # | Download | only in include
userret.h revision 1.16.4.1 
      1 /*	$NetBSD: userret.h,v 1.16.4.1 2011/03/05 20:51:37 rmind Exp $	*/
      2 
      3 /*
      4  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
      5  * Copyright (C) 1995, 1996 TooLs GmbH.
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by TooLs GmbH.
     19  * 4. The name of TooLs GmbH may not be used to endorse or promote products
     20  *    derived from this software without specific prior written permission.
     21  *
     22  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
     23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     25  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
     28  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
     29  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
     30  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
     31  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 #include "opt_ppcarch.h"
     35 #include "opt_altivec.h"
     36 
     37 #include <sys/userret.h>
     38 
     39 #include <powerpc/fpu.h>
     40 
     41 #ifdef PPC_BOOKE
     42 #include <powerpc/spr.h>
     43 #include <powerpc/booke/spr.h>
     44 #endif
     45 
     46 /*
     47  * Define the code needed before returning to user mode, for
     48  * trap and syscall.
     49  */
     50 static __inline void
     51 userret(struct lwp *l, struct trapframe *tf)
     52 {
     53 #if defined(PPC_HAVE_FPU) || defined(ALTIVEC) || defined(PPC_HAVE_SPE)
     54 	struct cpu_info * const ci = curcpu();
     55 #endif
     56 
     57 	KASSERTMSG((tf == trapframe(curlwp)),
     58 	    ("tf=%p, trapframe(curlwp)=%p\n", tf, trapframe(curlwp)));
     59 
     60 	/* Invoke MI userret code */
     61 	mi_userret(l);
     62 
     63 	tf->tf_srr1 &= PSL_USERSRR1;	/* clear SRR1 status bits */
     64 
     65 	/*
     66 	 * If someone stole the fp or vector unit while we were away,
     67 	 * disable it.  Note that if the PSL FP/VEC bits aren't set, then
     68 	 * we don't own it.
     69 	 */
     70 #ifdef PPC_HAVE_FPU
     71 	if ((tf->tf_srr1 & PSL_FP) &&
     72 	    (l != ci->ci_fpulwp || l->l_md.md_fpucpu != ci)) {
     73 		tf->tf_srr1 &= ~(PSL_FP|PSL_FE0|PSL_FE1);
     74 	}
     75 #endif
     76 #ifdef ALTIVEC
     77 	/*
     78 	 * We need to manually restore PSL_VEC each time we return
     79 	 * to user mode since PSL_VEC is not preserved in SRR1.
     80 	 */
     81 	if (tf->tf_srr1 & PSL_VEC) {
     82 		if (l != ci->ci_veclwp)
     83 			tf->tf_srr1 &= ~PSL_VEC;
     84 	} else {
     85 		if (l == ci->ci_veclwp)
     86 			tf->tf_srr1 |= PSL_VEC;
     87 	}
     88 
     89 	/*
     90 	 * If the new process isn't the current AltiVec process on this
     91 	 * CPU, we need to stop any data streams that are active (since
     92 	 * it will be a different address space).
     93 	 */
     94 	if (ci->ci_veclwp != &lwp0 && ci->ci_veclwp != l) {
     95 		__asm volatile("dssall;sync");
     96 	}
     97 #endif
     98 #ifdef PPC_BOOKE
     99 	/*
    100 	 * BookE doesn't PSL_SE but it does have a debug instruction completion
    101 	 * exception but it needs PSL_DE to fire.  Since we don't want it to
    102 	 * happen in the kernel, we must disable PSL_DE and let it get
    103 	 * restored by rfi/rfci.
    104 	 */
    105 	if (__predict_false(tf->tf_srr1 & PSL_SE)) {
    106 		extern void booke_sstep(struct trapframe *); /* ugly */
    107 		booke_sstep(tf);
    108 	}
    109 #endif
    110 #ifdef PPC_HAVE_SPE
    111 	/*
    112 	 * We need to manually restore PSL_SPV each time we return
    113 	 * to user mode since PSL_SPV is not preserved in SRR1 since
    114 	 * we don't include it in PSL_USERSRR1 to control its setting.
    115 	 */
    116 	if (tf->tf_srr1 & PSL_SPV) {
    117 		if (l != ci->ci_veclwp)
    118 			tf->tf_srr1 &= ~PSL_SPV;
    119 	} else {
    120 		if (l == ci->ci_veclwp)
    121 			tf->tf_srr1 |= PSL_SPV;
    122 	}
    123 #endif
    124 }
    125