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("$FreeBSD$");
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
46void
47enable_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
107void
108save_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