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/altivec.h> 45 #include <machine/pcb.h> 46 #include <machine/psl.h> 47 48 static void 49 save_vec_int(struct thread *td) 50 { 51 int msr; 52 struct pcb *pcb; 53 54 pcb = td->td_pcb; 55 56 /* 57 * Temporarily re-enable the vector unit during the save 58 */ 59 msr = mfmsr(); 60 mtmsr(msr | PSL_VEC); 61 62 /* 63 * Save the vector registers and VSCR to the PCB 64 */ 65 #define STVX(n) __asm ("stvx %1,0,%0" \ 66 :: "b"(pcb->pcb_vec.vr[n]), "n"(n)); 67 STVX(0); STVX(1); STVX(2); STVX(3); 68 STVX(4); STVX(5); STVX(6); STVX(7); 69 STVX(8); STVX(9); STVX(10); STVX(11); 70 STVX(12); STVX(13); STVX(14); STVX(15); 71 STVX(16); STVX(17); STVX(18); STVX(19); 72 STVX(20); STVX(21); STVX(22); STVX(23); 73 STVX(24); STVX(25); STVX(26); STVX(27); 74 STVX(28); STVX(29); STVX(30); STVX(31); 75 #undef STVX 76 77 __asm __volatile("mfvscr 0; stvewx 0,0,%0" :: "b"(&pcb->pcb_vec.vscr)); 78 79 /* 80 * Disable vector unit again 81 */ 82 isync(); 83 mtmsr(msr); 84 85 } 86 87 void 88 enable_vec(struct thread *td) 89 { 90 int msr; 91 struct pcb *pcb; 92 struct trapframe *tf; 93 94 pcb = td->td_pcb; 95 tf = trapframe(td); 96 97 /* 98 * Save the thread's Altivec CPU number, and set the CPU's current 99 * vector thread 100 */ 101 td->td_pcb->pcb_veccpu = PCPU_GET(cpuid); 102 PCPU_SET(vecthread, td); 103 104 /* 105 * Enable the vector unit for when the thread returns from the 106 * exception. If this is the first time the unit has been used by 107 * the thread, initialise the vector registers and VSCR to 0, and 108 * set the flag to indicate that the vector unit is in use. 109 */ 110 tf->srr1 |= PSL_VEC; 111 if (!(pcb->pcb_flags & PCB_VEC)) { 112 memset(&pcb->pcb_vec, 0, sizeof pcb->pcb_vec); 113 pcb->pcb_flags |= PCB_VEC; 114 } 115 116 /* 117 * Temporarily enable the vector unit so the registers 118 * can be restored. 119 */ 120 msr = mfmsr(); 121 mtmsr(msr | PSL_VEC); 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 } 146 147 void 148 save_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 */ 168 void 169 save_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