/* $OpenBSD: cpuswitch7.S,v 1.18 2023/10/24 13:20:09 claudio Exp $ */ /* $NetBSD: cpuswitch.S,v 1.41 2003/11/15 08:44:18 scw Exp $ */ /* * Copyright 2003 Wasabi Systems, Inc. * All rights reserved. * * Written by Steve C. Woodford for Wasabi Systems, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed for the NetBSD Project by * Wasabi Systems, Inc. * 4. The name of Wasabi Systems, Inc. may not be used to endorse * or promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Copyright (c) 1994-1998 Mark Brinicombe. * Copyright (c) 1994 Brini. * All rights reserved. * * This code is derived from software written for Brini by Mark Brinicombe * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Brini. * 4. The name of the company nor the name of the author may be used to * endorse or promote products derived from this software without specific * prior written permission. * * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * RiscBSD kernel project * * cpuswitch.S * * cpu switching functions * * Created : 15/10/94 */ #include "assym.h" #include #include #include #include #include /* LINTSTUB: include */ #define IRQdisableALL \ cpsid if #define IRQenableALL \ cpsie if .text .Lcpufuncs: .word cpufuncs .Lcpu_do_powersave: .word cpu_do_powersave /* * Idle loop, exercised while waiting for a process to wake up. */ ENTRY(cpu_idle_enter) mov pc, lr ENTRY(cpu_idle_cycle) stmfd sp!, {r6, lr} ldr r6, .Lcpu_do_powersave ldr r6, [r6] /* r6 = cpu_do_powersave */ teq r6, #0 /* cpu_do_powersave non zero? */ ldrne r6, .Lcpufuncs ldrne r6, [r6, #(CF_SLEEP)] teq r6, #0 /* Powersave idle? */ beq .Lidle_return /* Nope. Just continue. */ /* * Before going into powersave idle mode, disable interrupts. */ IRQdisableALL mov lr, pc mov pc, r6 /* If so, do powersave idle */ IRQenableALL .Lidle_return: ldmfd sp!, {r6, pc} ENTRY(cpu_idle_leave) mov pc, lr /* * cpu_switchto(struct proc *oldproc, struct proc *newproc) * * Performs a process context switch from oldproc (which may be NULL) * to newproc. * * Arguments: * r0 'struct proc *' of the context to switch from * r1 'struct proc *' of the context to switch to */ ENTRY(cpu_switchto) /* check if old context needs to be saved */ teq r0, #0 beq 1f /* create switchframe */ stmfd sp!, {r4-r7, lr} sub sp, sp, #4 mrc CP15_TPIDRPRW(r2) /* load curcpu */ ldr r5, [r2, #(CI_CURPCB)] /* save old stack pointer */ mrs r3, cpsr cpsid i, #(PSR_UND32_MODE) str sp, [r5, #(PCB_UND_SP)] msr cpsr_c, r3 add r6, r5, #(PCB_R8) stmia r6, {r8-r13} 1: mrc CP15_TPIDRPRW(r2) /* load curcpu */ mov r5, #SONPROC strb r5, [r1, #(P_STAT)] /* mark new on cpu */ str r2, [r1, #(P_CPU)] ldr r5, [r1, #(P_ADDR)] /* load new pcb */ str r5, [r2, #(CI_CURPCB)] str r1, [r2, #(CI_CURPROC)] ldr r4, [r5, #(PCB_TCB)] mcr CP15_TPIDRURO(r4) /* load user tls */ add r6, r5, #PCB_R8 ldmia r6, {r8-r13} /* load new stack pointer */ mrs r3, cpsr cps #(PSR_UND32_MODE) ldr sp, [r5, #(PCB_UND_SP)] msr cpsr_c, r3 IRQdisableALL ldr r0, [r5, #(PCB_PAGEDIR)] ldr r3, .Lcpufuncs mov lr, pc ldr pc, [r3, #CF_CONTEXT_SWITCH] IRQenableALL add sp, sp, #4 ldmfd sp!, {r4-r7, pc} ENTRY(savectx) /* * r0 = pcb */ /* Push registers.*/ stmfd sp!, {r4-r7, lr} sub sp, sp, #4 /* Store all the registers in the process's pcb */ add r2, r0, #(PCB_R8) stmia r2, {r8-r13} /* Pull the regs of the stack */ add sp, sp, #4 ldmfd sp!, {r4-r7, pc} ENTRY(proc_trampoline) bl proc_trampoline_mi mov r0, r5 mov r1, sp mov lr, pc mov pc, r4 /* Kill irq's */ cpsid i PULLFRAME movs pc, lr /* Exit */ dsb nsh isb