xref: /netbsd-src/sys/arch/powerpc/include/userret.h (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: userret.h,v 1.10 2004/04/16 08:52:41 hannken 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_altivec.h"
35 
36 #include <sys/userret.h>
37 
38 #include <powerpc/fpu.h>
39 
40 /*
41  * Define the code needed before returning to user mode, for
42  * trap and syscall.
43  */
44 static __inline void
45 userret(struct lwp *l, struct trapframe *frame)
46 {
47 	struct cpu_info * const ci = curcpu();
48 #ifdef PPC_HAVE_FPU
49 	struct pcb * const pcb = &l->l_addr->u_pcb;
50 #endif
51 
52 	/* Invoke MI userret code */
53 	mi_userret(l);
54 
55 	frame->srr1 &= PSL_USERSRR1;	/* clear SRR1 status bits */
56 
57 	/*
58 	 * If someone stole the fp or vector unit while we were away,
59 	 * disable it.  Note that if the PSL FP/VEC bits aren't set, then
60 	 * we don't own it.
61 	 */
62 #ifdef PPC_HAVE_FPU
63 	if ((frame->srr1 & PSL_FP) &&
64 	    (l != ci->ci_fpulwp || pcb->pcb_fpcpu != ci)) {
65 		frame->srr1 &= ~(PSL_FP|PSL_FE0|PSL_FE1);
66 	}
67 #endif
68 #ifdef ALTIVEC
69 	/*
70 	 * We need to manually restore PSL_VEC each time we return
71 	 * to user mode since PSL_VEC is not preserved in SRR1.
72 	 */
73 	if (frame->srr1 & PSL_VEC) {
74 		if (l != ci->ci_veclwp)
75 			frame->srr1 &= ~PSL_VEC;
76 	} else {
77 		if (l == ci->ci_veclwp)
78 			frame->srr1 |= PSL_VEC;
79 	}
80 
81 	/*
82 	 * If the new process isn't the current AltiVec process on this
83 	 * CPU, we need to stop any data streams that are active (since
84 	 * it will be a different address space).
85 	 */
86 	if (ci->ci_veclwp != NULL && ci->ci_veclwp != l) {
87 		__asm __volatile("dssall;sync");
88 	}
89 #endif
90 
91 	ci->ci_schedstate.spc_curpriority = l->l_priority = l->l_usrpri;
92 }
93