1 /*-
2 * Copyright (C) 1996 Wolfgang Solfrank.
3 * Copyright (C) 1996 TooLs GmbH.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by TooLs GmbH.
17 * 4. The name of TooLs GmbH may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 * $NetBSD: fpu.c,v 1.5 2001/07/22 11:29:46 wiz Exp $
32 */
33
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD: releng/11.0/sys/powerpc/powerpc/altivec.c 276634 2015-01-03 21:06:06Z jhibbits $");
36
37 #include <sys/param.h>
38 #include <sys/proc.h>
39 #include <sys/systm.h>
40 #include <sys/limits.h>
41
42 #include <machine/altivec.h>
43 #include <machine/pcb.h>
44 #include <machine/psl.h>
45
46 static void
47 save_vec_int(struct thread *td)
48 {
49 int msr;
50 struct pcb *pcb;
51
52 pcb = td->td_pcb;
53
54 /*
55 * Temporarily re-enable the vector unit during the save
56 */
57 msr = mfmsr();
58 mtmsr(msr | PSL_VEC);
59 isync();
60
61 /*
62 * Save the vector registers and VSCR to the PCB
63 */
64 #define STVX(n) __asm ("stvx %1,0,%0" \
65 :: "b"(pcb->pcb_vec.vr[n]), "n"(n));
66 STVX(0); STVX(1); STVX(2); STVX(3);
67 STVX(4); STVX(5); STVX(6); STVX(7);
68 STVX(8); STVX(9); STVX(10); STVX(11);
69 STVX(12); STVX(13); STVX(14); STVX(15);
70 STVX(16); STVX(17); STVX(18); STVX(19);
71 STVX(20); STVX(21); STVX(22); STVX(23);
72 STVX(24); STVX(25); STVX(26); STVX(27);
73 STVX(28); STVX(29); STVX(30); STVX(31);
74 #undef STVX
75
76 __asm __volatile("mfvscr 0; stvewx 0,0,%0" :: "b"(&pcb->pcb_vec.vscr));
77
78 /*
79 * Disable vector unit again
80 */
81 isync();
82 mtmsr(msr);
83
84 }
85
86 void
87 enable_vec(struct thread *td)
88 {
89 int msr;
90 struct pcb *pcb;
91 struct trapframe *tf;
92
93 pcb = td->td_pcb;
94 tf = trapframe(td);
95
96 /*
97 * Save the thread's Altivec CPU number, and set the CPU's current
98 * vector thread
99 */
100 td->td_pcb->pcb_veccpu = PCPU_GET(cpuid);
101 PCPU_SET(vecthread, td);
102
103 /*
104 * Enable the vector unit for when the thread returns from the
105 * exception. If this is the first time the unit has been used by
106 * the thread, initialise the vector registers and VSCR to 0, and
107 * set the flag to indicate that the vector unit is in use.
108 */
109 tf->srr1 |= PSL_VEC;
110 if (!(pcb->pcb_flags & PCB_VEC)) {
111 memset(&pcb->pcb_vec, 0, sizeof pcb->pcb_vec);
112 pcb->pcb_flags |= PCB_VEC;
113 }
114
115 /*
116 * Temporarily enable the vector unit so the registers
117 * can be restored.
118 */
119 msr = mfmsr();
120 mtmsr(msr | PSL_VEC);
121 isync();
122
123 /*
124 * Restore VSCR by first loading it into a vector and then into VSCR.
125 * (this needs to done before loading the user's vector registers
126 * since we need to use a scratch vector register)
127 */
128 __asm __volatile("vxor 0,0,0; lvewx 0,0,%0; mtvscr 0" \
129 :: "b"(&pcb->pcb_vec.vscr));
130
131 #define LVX(n) __asm ("lvx " #n ",0,%0" \
132 :: "b"(&pcb->pcb_vec.vr[n]));
133 LVX(0); LVX(1); LVX(2); LVX(3);
134 LVX(4); LVX(5); LVX(6); LVX(7);
135 LVX(8); LVX(9); LVX(10); LVX(11);
136 LVX(12); LVX(13); LVX(14); LVX(15);
137 LVX(16); LVX(17); LVX(18); LVX(19);
138 LVX(20); LVX(21); LVX(22); LVX(23);
139 LVX(24); LVX(25); LVX(26); LVX(27);
140 LVX(28); LVX(29); LVX(30); LVX(31);
141 #undef LVX
142
143 isync();
144 mtmsr(msr);
145 }
146
147 void
148 save_vec(struct thread *td)
149 {
150 struct pcb *pcb;
151
152 pcb = td->td_pcb;
153
154 save_vec_int(td);
155
156 /*
157 * Clear the current vec thread and pcb's CPU id
158 * XXX should this be left clear to allow lazy save/restore ?
159 */
160 pcb->pcb_veccpu = INT_MAX;
161 PCPU_SET(vecthread, NULL);
162 }
163
164 /*
165 * Save altivec state without dropping ownership. This will only save state if
166 * the current vector-thread is `td'.
167 */
168 void
169 save_vec_nodrop(struct thread *td)
170 {
171 struct thread *vtd;
172
173 vtd = PCPU_GET(vecthread);
174 if (td != vtd) {
175 return;
176 }
177
178 save_vec_int(td);
179 }
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