2 * Copyright (C) 1996 Wolfgang Solfrank.
3 * Copyright (C) 1996 TooLs GmbH.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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.
31 * $NetBSD: fpu.c,v 1.5 2001/07/22 11:29:46 wiz Exp $
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/limits.h>
42 #include <machine/fpu.h>
43 #include <machine/pcb.h>
44 #include <machine/psl.h>
47 enable_fpu(struct thread *td)
57 * Save the thread's FPU CPU number, and set the CPU's current
60 td->td_pcb->pcb_fpcpu = PCPU_GET(cpuid);
61 PCPU_SET(fputhread, td);
64 * Enable the FPU for when the thread returns from the exception.
65 * If this is the first time the FPU has been used by the thread,
66 * initialise the FPU registers and FPSCR to 0, and set the flag
67 * to indicate that the FPU is in use.
70 if (!(pcb->pcb_flags & PCB_FPU)) {
71 memset(&pcb->pcb_fpu, 0, sizeof pcb->pcb_fpu);
72 pcb->pcb_flags |= PCB_FPU;
76 * Temporarily enable floating-point so the registers
84 * Load the floating point registers and FPSCR from the PCB.
85 * (A value of 0xff for mtfsf specifies that all 8 4-bit fields
86 * of the saved FPSCR are to be loaded from the FPU reg).
88 __asm __volatile ("lfd 0,0(%0); mtfsf 0xff,0"
89 :: "b"(&pcb->pcb_fpu.fpscr));
91 #define LFP(n) __asm ("lfd " #n ", 0(%0)" \
92 :: "b"(&pcb->pcb_fpu.fpr[n]));
93 LFP(0); LFP(1); LFP(2); LFP(3);
94 LFP(4); LFP(5); LFP(6); LFP(7);
95 LFP(8); LFP(9); LFP(10); LFP(11);
96 LFP(12); LFP(13); LFP(14); LFP(15);
97 LFP(16); LFP(17); LFP(18); LFP(19);
98 LFP(20); LFP(21); LFP(22); LFP(23);
99 LFP(24); LFP(25); LFP(26); LFP(27);
100 LFP(28); LFP(29); LFP(30); LFP(31);
108 save_fpu(struct thread *td)
116 * Temporarily re-enable floating-point during the save
123 * Save the floating-point registers and FPSCR to the PCB
125 #define SFP(n) __asm ("stfd " #n ", 0(%0)" \
126 :: "b"(&pcb->pcb_fpu.fpr[n]));
127 SFP(0); SFP(1); SFP(2); SFP(3);
128 SFP(4); SFP(5); SFP(6); SFP(7);
129 SFP(8); SFP(9); SFP(10); SFP(11);
130 SFP(12); SFP(13); SFP(14); SFP(15);
131 SFP(16); SFP(17); SFP(18); SFP(19);
132 SFP(20); SFP(21); SFP(22); SFP(23);
133 SFP(24); SFP(25); SFP(26); SFP(27);
134 SFP(28); SFP(29); SFP(30); SFP(31);
136 __asm __volatile ("mffs 0; stfd 0,0(%0)" :: "b"(&pcb->pcb_fpu.fpscr));
139 * Disable floating-point again
145 * Clear the current fp thread and pcb's CPU id
146 * XXX should this be left clear to allow lazy save/restore ?
148 pcb->pcb_fpcpu = INT_MAX;
149 PCPU_SET(fputhread, NULL);