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
46static void
47save_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
86void
87enable_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
147void
148save_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 */
168void
169save_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}
180