1/* $OpenBSD: process.S,v 1.27 2022/12/06 18:50:59 guenther Exp $ */ 2/* 3 * Copyright (c) 1996 Nivas Madhur 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 Nivas Madhur. 17 * 4. The name of the author 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 THE AUTHOR ``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 THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 * 31 */ 32 33#include "assym.h" 34#include <machine/asm.h> 35#include <machine/psl.h> 36 37/* 38 * void cpu_switchto(struct proc *oldproc, struct proc *newproc) 39 * 40 * Switch context from oldproc to newproc. oldproc may be NULL if there is 41 * no need to save the current context. 42 * 43 * Note that this code assumes that oldproc == curproc if not NULL. 44 */ 45ENTRY(cpu_switchto) 46 /* 47 * Save state of previous process in its pcb if required. 48 */ 49 bcnd eq0, %r2, 1f 50 51 ldcr %r2, CPU 52 ld %r2, %r2, CI_CURPCB 53 st %r1, %r2, PCB_PC /* save return address */ 54 bsr __savectx 55 /* note that we don't need to recover r1 at this point */ 56 57 /* inline pmap_deactivate(oldproc) */ 58 ldcr %r11, CPU 59 st %r0, %r11, CI_CURPMAP 60 611: 62 ldcr %r2, PSR 63 set %r2, %r2, 1<PSR_INTERRUPT_DISABLE_BIT> 64 stcr %r2, PSR 65 FLUSH_PIPELINE 66 67 ldcr %r11, CPU 68 st %r3, %r11, CI_CURPROC /* curproc = newproc */ 69 70 or %r2, %r0, SONPROC 71 st.b %r2, %r3, P_STAT 72#ifdef MULTIPROCESSOR 73 st %r11, %r3, P_CPU /* p->p_cpu = curcpu */ 74#endif 75 ld %r2, %r3, P_ADDR 76 st %r2, %r11, CI_CURPCB /* curpcb = p->p_addr */ 77 78 bsr.n pmap_activate /* pmap_activate(newproc) */ 79 or %r2, %r0, %r3 80 81 ldcr %r2, PSR 82 clr %r2, %r2, 1<PSR_INTERRUPT_DISABLE_BIT> 83 stcr %r2, PSR 84 FLUSH_PIPELINE 85 86 ldcr %r10, CPU 87 ld %r10, %r10, CI_CURPCB 88 89 /* restore from the current context */ 90 ld.d %r2, %r10, PCB_FCR62 91 fstcr %r2, %fcr62 92 fstcr %r3, %fcr63 93 ld %r1, %r10, PCB_PC 94 ld.d %r14, %r10, PCB_R14 95 ld.d %r16, %r10, PCB_R16 96 ld.d %r18, %r10, PCB_R18 97 ld.d %r20, %r10, PCB_R20 98 ld.d %r22, %r10, PCB_R22 99 ld.d %r24, %r10, PCB_R24 100 ld.d %r26, %r10, PCB_R26 101 ld.d %r28, %r10, PCB_R28 102 jmp.n %r1 103 ld.d %r30, %r10, PCB_R30 /* restore frame pointer & stack */ 104 105/* 106 * savectx(pcb) 107 * Update pcb, saving current processor state. 108 */ 109ENTRY(savectx) 110 /* 111 * Save preserved general register set. 112 */ 113 st %r1, %r2, PCB_PC /* save return address */ 114ASLOCAL(__savectx) 115 st.d %r14, %r2, PCB_R14 116 st.d %r16, %r2, PCB_R16 117 st.d %r18, %r2, PCB_R18 118 st.d %r20, %r2, PCB_R20 119 st.d %r22, %r2, PCB_R22 120 st.d %r24, %r2, PCB_R24 121 st.d %r26, %r2, PCB_R26 122 st.d %r28, %r2, PCB_R28 123 st.d %r30, %r2, PCB_R30 /* save frame pointer & stack pointer */ 124 125 /* 126 * Save FP state. 127 */ 128 fldcr %r4, %fcr62 129 fldcr %r5, %fcr63 130 jmp.n %r1 131 st.d %r4, %r2, PCB_FCR62 132