xref: /netbsd/sys/arch/powerpc/include/userret.h (revision 6550d01e)
1 /*	$NetBSD: userret.h,v 1.17 2011/01/18 01:02:54 matt 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 *tf)
46 {
47 #if defined(PPC_HAVE_FPU) || defined(ALTIVEC) || defined(PPC_HAVE_SPE)
48 	struct cpu_info * const ci = curcpu();
49 #endif
50 
51 	KASSERTMSG((tf == trapframe(curlwp)),
52 	    ("tf=%p, trapframe(curlwp)=%p\n", tf, trapframe(curlwp)));
53 
54 	/* Invoke MI userret code */
55 	mi_userret(l);
56 
57 	tf->tf_srr1 &= PSL_USERSRR1;	/* clear SRR1 status bits */
58 
59 	/*
60 	 * If someone stole the fp or vector unit while we were away,
61 	 * disable it.  Note that if the PSL FP/VEC bits aren't set, then
62 	 * we don't own it.
63 	 */
64 #ifdef PPC_HAVE_FPU
65 	if ((tf->tf_srr1 & PSL_FP) &&
66 	    (l != ci->ci_fpulwp || l->l_md.md_fpucpu != ci)) {
67 		tf->tf_srr1 &= ~(PSL_FP|PSL_FE0|PSL_FE1);
68 	}
69 #endif
70 #ifdef ALTIVEC
71 	/*
72 	 * We need to manually restore PSL_VEC each time we return
73 	 * to user mode since PSL_VEC is not preserved in SRR1.
74 	 */
75 	if (tf->tf_srr1 & PSL_VEC) {
76 		if (l != ci->ci_veclwp)
77 			tf->tf_srr1 &= ~PSL_VEC;
78 	} else {
79 		if (l == ci->ci_veclwp)
80 			tf->tf_srr1 |= PSL_VEC;
81 	}
82 
83 	/*
84 	 * If the new process isn't the current AltiVec process on this
85 	 * CPU, we need to stop any data streams that are active (since
86 	 * it will be a different address space).
87 	 */
88 	if (ci->ci_veclwp != NULL && ci->ci_veclwp != l) {
89 		__asm volatile("dssall;sync");
90 	}
91 #endif
92 #ifdef PPC_HAVE_SPE
93 	/*
94 	 * We need to manually restore PSL_SPV each time we return
95 	 * to user mode since PSL_SPV is not preserved in SRR1 since
96 	 * we don't include it in PSL_USERSRR1 to control its setting.
97 	 */
98 	if (tf->tf_srr1 & PSL_SPV) {
99 		if (l != ci->ci_veclwp)
100 			tf->tf_srr1 &= ~PSL_SPV;
101 	} else {
102 		if (l == ci->ci_veclwp)
103 			tf->tf_srr1 |= PSL_SPV;
104 	}
105 #endif
106 }
107