1 /*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (C) 1996 Wolfgang Solfrank.
5 * Copyright (C) 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 * $NetBSD: fpu.c,v 1.5 2001/07/22 11:29:46 wiz Exp $
34 */
35
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38
39 #include <sys/param.h>
40 #include <sys/proc.h>
41 #include <sys/systm.h>
42 #include <sys/limits.h>
43
44 #include <machine/fpu.h>
45 #include <machine/pcb.h>
46 #include <machine/psl.h>
47
48 static void
49 save_fpu_int(struct thread *td)
50 {
51 int msr;
52 struct pcb *pcb;
53
54 pcb = td->td_pcb;
55
56 /*
57 * Temporarily re-enable floating-point during the save
58 */
59 msr = mfmsr();
60 if (pcb->pcb_flags & PCB_VSX)
61 mtmsr(msr | PSL_FP | PSL_VSX);
62 else
63 mtmsr(msr | PSL_FP);
64
65 /*
66 * Save the floating-point registers and FPSCR to the PCB
67 */
68 if (pcb->pcb_flags & PCB_VSX) {
69 #define SFP(n) __asm ("stxvw4x " #n ", 0,%0" \
70 :: "b"(&pcb->pcb_fpu.fpr[n]));
71 SFP(0); SFP(1); SFP(2); SFP(3);
72 SFP(4); SFP(5); SFP(6); SFP(7);
73 SFP(8); SFP(9); SFP(10); SFP(11);
74 SFP(12); SFP(13); SFP(14); SFP(15);
75 SFP(16); SFP(17); SFP(18); SFP(19);
76 SFP(20); SFP(21); SFP(22); SFP(23);
77 SFP(24); SFP(25); SFP(26); SFP(27);
78 SFP(28); SFP(29); SFP(30); SFP(31);
79 #undef SFP
80 } else {
81 #define SFP(n) __asm ("stfd " #n ", 0(%0)" \
82 :: "b"(&pcb->pcb_fpu.fpr[n]));
83 SFP(0); SFP(1); SFP(2); SFP(3);
84 SFP(4); SFP(5); SFP(6); SFP(7);
85 SFP(8); SFP(9); SFP(10); SFP(11);
86 SFP(12); SFP(13); SFP(14); SFP(15);
87 SFP(16); SFP(17); SFP(18); SFP(19);
88 SFP(20); SFP(21); SFP(22); SFP(23);
89 SFP(24); SFP(25); SFP(26); SFP(27);
90 SFP(28); SFP(29); SFP(30); SFP(31);
91 #undef SFP
92 }
93 __asm __volatile ("mffs 0; stfd 0,0(%0)" :: "b"(&pcb->pcb_fpu.fpscr));
94
95 /*
96 * Disable floating-point again
97 */
98 isync();
99 mtmsr(msr);
100 }
101
102 void
103 enable_fpu(struct thread *td)
104 {
105 int msr;
106 struct pcb *pcb;
107 struct trapframe *tf;
108
109 pcb = td->td_pcb;
110 tf = trapframe(td);
111
112 /*
113 * Save the thread's FPU CPU number, and set the CPU's current
114 * FPU thread
115 */
116 td->td_pcb->pcb_fpcpu = PCPU_GET(cpuid);
117 PCPU_SET(fputhread, td);
118
119 /*
120 * Enable the FPU for when the thread returns from the exception.
121 * If this is the first time the FPU has been used by the thread,
122 * initialise the FPU registers and FPSCR to 0, and set the flag
123 * to indicate that the FPU is in use.
124 */
125 pcb->pcb_flags |= PCB_FPU;
126 if (pcb->pcb_flags & PCB_VSX)
127 tf->srr1 |= PSL_FP | PSL_VSX;
128 else
129 tf->srr1 |= PSL_FP;
130 if (!(pcb->pcb_flags & PCB_FPREGS)) {
131 memset(&pcb->pcb_fpu, 0, sizeof pcb->pcb_fpu);
132 pcb->pcb_flags |= PCB_FPREGS;
133 }
134
135 /*
136 * Temporarily enable floating-point so the registers
137 * can be restored.
138 */
139 msr = mfmsr();
140 if (pcb->pcb_flags & PCB_VSX)
141 mtmsr(msr | PSL_FP | PSL_VSX);
142 else
143 mtmsr(msr | PSL_FP);
144
145 /*
146 * Load the floating point registers and FPSCR from the PCB.
147 * (A value of 0xff for mtfsf specifies that all 8 4-bit fields
148 * of the saved FPSCR are to be loaded from the FPU reg).
149 */
150 __asm __volatile ("lfd 0,0(%0); mtfsf 0xff,0"
151 :: "b"(&pcb->pcb_fpu.fpscr));
152
153 if (pcb->pcb_flags & PCB_VSX) {
154 #define LFP(n) __asm ("lxvw4x " #n ", 0,%0" \
155 :: "b"(&pcb->pcb_fpu.fpr[n]));
156 LFP(0); LFP(1); LFP(2); LFP(3);
157 LFP(4); LFP(5); LFP(6); LFP(7);
158 LFP(8); LFP(9); LFP(10); LFP(11);
159 LFP(12); LFP(13); LFP(14); LFP(15);
160 LFP(16); LFP(17); LFP(18); LFP(19);
161 LFP(20); LFP(21); LFP(22); LFP(23);
162 LFP(24); LFP(25); LFP(26); LFP(27);
163 LFP(28); LFP(29); LFP(30); LFP(31);
164 #undef LFP
165 } else {
166 #define LFP(n) __asm ("lfd " #n ", 0(%0)" \
167 :: "b"(&pcb->pcb_fpu.fpr[n]));
168 LFP(0); LFP(1); LFP(2); LFP(3);
169 LFP(4); LFP(5); LFP(6); LFP(7);
170 LFP(8); LFP(9); LFP(10); LFP(11);
171 LFP(12); LFP(13); LFP(14); LFP(15);
172 LFP(16); LFP(17); LFP(18); LFP(19);
173 LFP(20); LFP(21); LFP(22); LFP(23);
174 LFP(24); LFP(25); LFP(26); LFP(27);
175 LFP(28); LFP(29); LFP(30); LFP(31);
176 #undef LFP
177 }
178
179 isync();
180 mtmsr(msr);
181 }
182
183 void
184 save_fpu(struct thread *td)
185 {
186 struct pcb *pcb;
187
188 pcb = td->td_pcb;
189
190 save_fpu_int(td);
191
192 /*
193 * Clear the current fp thread and pcb's CPU id
194 * XXX should this be left clear to allow lazy save/restore ?
195 */
196 pcb->pcb_fpcpu = INT_MAX;
197 PCPU_SET(fputhread, NULL);
198 }
199
200 /*
201 * Save fpu state without dropping ownership. This will only save state if
202 * the current fpu thread is `td'.
203 */
204 void
205 save_fpu_nodrop(struct thread *td)
206 {
207 struct thread *ftd;
208
209 ftd = PCPU_GET(fputhread);
210 if (td != ftd) {
211 return;
212 }
213
214 save_fpu_int(td);
215 }
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