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 SPEFSCR to the PCB 63 */ 64 #define EVSTDW(n) __asm ("evstdw %1,0(%0)" \ 65 :: "b"(pcb->pcb_vec.vr[n]), "n"(n)); 66 EVSTDW(0); EVSTDW(1); EVSTDW(2); EVSTDW(3); 67 EVSTDW(4); EVSTDW(5); EVSTDW(6); EVSTDW(7); 68 EVSTDW(8); EVSTDW(9); EVSTDW(10); EVSTDW(11); 69 EVSTDW(12); EVSTDW(13); EVSTDW(14); EVSTDW(15); 70 EVSTDW(16); EVSTDW(17); EVSTDW(18); EVSTDW(19); 71 EVSTDW(20); EVSTDW(21); EVSTDW(22); EVSTDW(23); 72 EVSTDW(24); EVSTDW(25); EVSTDW(26); EVSTDW(27); 73 EVSTDW(28); EVSTDW(29); EVSTDW(30); EVSTDW(31); 74 #undef EVSTDW 75 76 __asm ( "evxor 0,0,0\n" 77 "evaddumiaaw 0,0\n" 78 "evstdd 0,0(%0)" :: "b"(&pcb->pcb_vec.vr[17][0])); 79 pcb->pcb_vec.vscr = mfspr(SPR_SPEFSCR); 80 81 /* 82 * Disable vector unit again 83 */ 84 isync(); 85 mtmsr(msr); 86 87 } 88 89 void 90 enable_vec(struct thread *td) 91 { 92 int msr; 93 struct pcb *pcb; 94 struct trapframe *tf; 95 96 pcb = td->td_pcb; 97 tf = trapframe(td); 98 99 /* 100 * Save the thread's SPE CPU number, and set the CPU's current 101 * vector thread 102 */ 103 td->td_pcb->pcb_veccpu = PCPU_GET(cpuid); 104 PCPU_SET(vecthread, td); 105 106 /* 107 * Enable the vector unit for when the thread returns from the 108 * exception. If this is the first time the unit has been used by 109 * the thread, initialise the vector registers and VSCR to 0, and 110 * set the flag to indicate that the vector unit is in use. 111 */ 112 tf->srr1 |= PSL_VEC; 113 if (!(pcb->pcb_flags & PCB_VEC)) { 114 memset(&pcb->pcb_vec, 0, sizeof pcb->pcb_vec); 115 pcb->pcb_flags |= PCB_VEC; 116 } 117 118 /* 119 * Temporarily enable the vector unit so the registers 120 * can be restored. 121 */ 122 msr = mfmsr(); 123 mtmsr(msr | PSL_VEC); 124 isync(); 125 126 /* Restore SPEFSCR and ACC. Use %r0 as the scratch for ACC. */ 127 mtspr(SPR_SPEFSCR, pcb->pcb_vec.vscr); 128 __asm __volatile("evldd 0, 0(%0); evmra 0,0\n" 129 :: "b"(&pcb->pcb_vec.vr[17][0])); 130 131 /* 132 * The lower half of each register will be restored on trap return. Use 133 * %r0 as a scratch register, and restore it last. 134 */ 135 #define EVLDW(n) __asm __volatile("evldw 0, 0(%0); evmergehilo "#n",0,"#n \ 136 :: "b"(&pcb->pcb_vec.vr[n])); 137 EVLDW(1); EVLDW(2); EVLDW(3); EVLDW(4); 138 EVLDW(5); EVLDW(6); EVLDW(7); EVLDW(8); 139 EVLDW(9); EVLDW(10); EVLDW(11); EVLDW(12); 140 EVLDW(13); EVLDW(14); EVLDW(15); EVLDW(16); 141 EVLDW(17); EVLDW(18); EVLDW(19); EVLDW(20); 142 EVLDW(21); EVLDW(22); EVLDW(23); EVLDW(24); 143 EVLDW(25); EVLDW(26); EVLDW(27); EVLDW(28); 144 EVLDW(29); EVLDW(30); EVLDW(31); EVLDW(0); 145 #undef EVLDW 146 147 isync(); 148 mtmsr(msr); 149 } 150 151 void 152 save_vec(struct thread *td) 153 { 154 struct pcb *pcb; 155 156 pcb = td->td_pcb; 157 158 save_vec_int(td); 159 160 /* 161 * Clear the current vec thread and pcb's CPU id 162 * XXX should this be left clear to allow lazy save/restore ? 163 */ 164 pcb->pcb_veccpu = INT_MAX; 165 PCPU_SET(vecthread, NULL); 166 } 167 168 /* 169 * Save SPE state without dropping ownership. This will only save state if 170 * the current vector-thread is `td'. 171 */ 172 void 173 save_vec_nodrop(struct thread *td) 174 { 175 struct thread *vtd; 176 177 vtd = PCPU_GET(vecthread); 178 if (td != vtd) { 179 return; 180 } 181 182 save_vec_int(td); 183 } 184