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: stable/10/sys/powerpc/powerpc/altivec.c 188860 2009-02-20 17:48:40Z nwhitehorn $");
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 void
enable_vec(struct thread * td)47 enable_vec(struct thread *td)
48 {
49 int msr;
50 struct pcb *pcb;
51 struct trapframe *tf;
52
53 pcb = td->td_pcb;
54 tf = trapframe(td);
55
56 /*
57 * Save the thread's Altivec CPU number, and set the CPU's current
58 * vector thread
59 */
60 td->td_pcb->pcb_veccpu = PCPU_GET(cpuid);
61 PCPU_SET(vecthread, td);
62
63 /*
64 * Enable the vector unit for when the thread returns from the
65 * exception. If this is the first time the unit has been used by
66 * the thread, initialise the vector registers and VSCR to 0, and
67 * set the flag to indicate that the vector unit is in use.
68 */
69 tf->srr1 |= PSL_VEC;
70 if (!(pcb->pcb_flags & PCB_VEC)) {
71 memset(&pcb->pcb_vec, 0, sizeof pcb->pcb_vec);
72 pcb->pcb_flags |= PCB_VEC;
73 }
74
75 /*
76 * Temporarily enable the vector unit so the registers
77 * can be restored.
78 */
79 msr = mfmsr();
80 mtmsr(msr | PSL_VEC);
81 isync();
82
83 /*
84 * Restore VSCR by first loading it into a vector and then into VSCR.
85 * (this needs to done before loading the user's vector registers
86 * since we need to use a scratch vector register)
87 */
88 __asm __volatile("vxor 0,0,0; lvewx 0,0,%0; mtvscr 0" \
89 :: "b"(&pcb->pcb_vec.vscr));
90
91 #define LVX(n) __asm ("lvx " #n ",0,%0" \
92 :: "b"(&pcb->pcb_vec.vr[n]));
93 LVX(0); LVX(1); LVX(2); LVX(3);
94 LVX(4); LVX(5); LVX(6); LVX(7);
95 LVX(8); LVX(9); LVX(10); LVX(11);
96 LVX(12); LVX(13); LVX(14); LVX(15);
97 LVX(16); LVX(17); LVX(18); LVX(19);
98 LVX(20); LVX(21); LVX(22); LVX(23);
99 LVX(24); LVX(25); LVX(26); LVX(27);
100 LVX(28); LVX(29); LVX(30); LVX(31);
101 #undef LVX
102
103 isync();
104 mtmsr(msr);
105 }
106
107 void
save_vec(struct thread * td)108 save_vec(struct thread *td)
109 {
110 int msr;
111 struct pcb *pcb;
112
113 pcb = td->td_pcb;
114
115 /*
116 * Temporarily re-enable the vector unit during the save
117 */
118 msr = mfmsr();
119 mtmsr(msr | PSL_VEC);
120 isync();
121
122 /*
123 * Save the vector registers and VSCR to the PCB
124 */
125 #define STVX(n) __asm ("stvx %1,0,%0" \
126 :: "b"(pcb->pcb_vec.vr[n]), "n"(n));
127 STVX(0); STVX(1); STVX(2); STVX(3);
128 STVX(4); STVX(5); STVX(6); STVX(7);
129 STVX(8); STVX(9); STVX(10); STVX(11);
130 STVX(12); STVX(13); STVX(14); STVX(15);
131 STVX(16); STVX(17); STVX(18); STVX(19);
132 STVX(20); STVX(21); STVX(22); STVX(23);
133 STVX(24); STVX(25); STVX(26); STVX(27);
134 STVX(28); STVX(29); STVX(30); STVX(31);
135 #undef STVX
136
137 __asm __volatile("mfvscr 0; stvewx 0,0,%0" :: "b"(&pcb->pcb_vec.vscr));
138
139 /*
140 * Disable vector unit again
141 */
142 isync();
143 mtmsr(msr);
144
145 /*
146 * Clear the current vec thread and pcb's CPU id
147 * XXX should this be left clear to allow lazy save/restore ?
148 */
149 pcb->pcb_veccpu = INT_MAX;
150 PCPU_SET(vecthread, NULL);
151 }
152
153