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/5.2/sys/powerpc/powerpc/fpu.c 113038 2003-04-03 21:36:33Z obrien $");
36
37 #include <sys/param.h>
38 #include <sys/proc.h>
39 #include <sys/systm.h>
40 #include <sys/user.h>
41
42 #include <machine/fpu.h>
43 #include <machine/psl.h>
44
45 void
46 enable_fpu(struct thread *td)
47 {
48 int msr;
49 struct pcb *pcb;
50 struct trapframe *tf;
51
52 pcb = td->td_pcb;
53 tf = trapframe(td);
54
55 /*
56 * Save the thread's FPU CPU number, and set the CPU's current
57 * FPU thread
58 */
59 td->td_pcb->pcb_fpcpu = PCPU_GET(cpuid);
60 PCPU_SET(fputhread, td);
61
62 /*
63 * Enable the FPU for when the thread returns from the exception.
64 * If this is the first time the FPU has been used by the thread,
65 * initialise the FPU registers and FPSCR to 0, and set the flag
66 * to indicate that the FPU is in use.
67 */
68 tf->srr1 |= PSL_FP;
69 if (!(pcb->pcb_flags & PCB_FPU)) {
70 memset(&pcb->pcb_fpu, 0, sizeof pcb->pcb_fpu);
71 pcb->pcb_flags |= PCB_FPU;
72 }
73
74 /*
75 * Temporarily enable floating-point so the registers
76 * can be restored.
77 */
78 msr = mfmsr();
79 mtmsr(msr | PSL_FP);
80 isync();
81
82 /*
83 * Load the floating point registers and FPSCR from the PCB.
84 * (A value of 0xff for mtfsf specifies that all 8 4-bit fields
85 * of the saved FPSCR are to be loaded from the FPU reg).
86 */
87 __asm __volatile ("lfd 0,0(%0); mtfsf 0xff,0"
88 :: "b"(&pcb->pcb_fpu.fpscr));
89
90 #define LFP(n) __asm ("lfd " #n ", 0(%0)" \
91 :: "b"(&pcb->pcb_fpu.fpr[n]));
92 LFP(0); LFP(1); LFP(2); LFP(3);
93 LFP(4); LFP(5); LFP(6); LFP(7);
94 LFP(8); LFP(9); LFP(10); LFP(11);
95 LFP(12); LFP(13); LFP(14); LFP(15);
96 LFP(16); LFP(17); LFP(18); LFP(19);
97 LFP(20); LFP(21); LFP(22); LFP(23);
98 LFP(24); LFP(25); LFP(26); LFP(27);
99 LFP(28); LFP(29); LFP(30); LFP(31);
100 #undef LFP
101
102 isync();
103 mtmsr(msr);
104 }
105
106 void
107 save_fpu(struct thread *td)
108 {
109 int msr;
110 struct pcb *pcb;
111
112 pcb = td->td_pcb;
113
114 /*
115 * Temporarily re-enable floating-point during the save
116 */
117 msr = mfmsr();
118 mtmsr(msr | PSL_FP);
119 isync();
120
121 /*
122 * Save the floating-point registers and FPSCR to the PCB
123 */
124 #define SFP(n) __asm ("stfd " #n ", 0(%0)" \
125 :: "b"(&pcb->pcb_fpu.fpr[n]));
126 SFP(0); SFP(1); SFP(2); SFP(3);
127 SFP(4); SFP(5); SFP(6); SFP(7);
128 SFP(8); SFP(9); SFP(10); SFP(11);
129 SFP(12); SFP(13); SFP(14); SFP(15);
130 SFP(16); SFP(17); SFP(18); SFP(19);
131 SFP(20); SFP(21); SFP(22); SFP(23);
132 SFP(24); SFP(25); SFP(26); SFP(27);
133 SFP(28); SFP(29); SFP(30); SFP(31);
134 #undef SFP
135 __asm __volatile ("mffs 0; stfd 0,0(%0)" :: "b"(&pcb->pcb_fpu.fpscr));
136
137 /*
138 * Disable floating-point again
139 */
140 isync();
141 mtmsr(msr);
142
143 /*
144 * Clear the current fp thread and pcb's CPU id
145 * XXX should this be left clear to allow lazy save/restore ?
146 */
147 pcb->pcb_fpcpu = NULL;
148 PCPU_SET(fputhread, NULL);
149 }
150
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