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