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 46 static void 47 save_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 86 void 87 enable_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 } 146 147 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