/* $OpenBSD: process.S,v 1.8 2001/03/09 05:44:42 smurph Exp $ */ /* * Copyright (c) 1996 Nivas Madhur * All rights reserved. * * 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 Nivas Madhur. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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. * */ #ifndef ASSEMBLER #define ASSEMBLER #endif /* ASSEMBLER */ #include "assym.s" #include "machine/asm.h" #include "machine/psl.h" #include "machine/intr.h" data align 4 Lsw0: string "cpu_switch\n" align 4 swchanpanic: string "switch wchan %x\n" align 4 swsrunpanic: string "switch SRUN %x\n" text align 8 Lswchanpanic: or.u r2, r0, hi16(swchanpanic) or r2, r2, lo16(swchanpanic) or r3, r0, r9 bsr _panic Lswsrunpanic: or.u r2, r0, hi16(swsrunpanic) or r2, r2, lo16(swsrunpanic) or r3, r0, r9 bsr _panic /* * At exit of a process, do a cpu_switch for the last time. * The mapping of the pcb at p->p_addr has already been deleted, * and the memory for the pcb+stack has been freed. * The ipl is high enough to prevent the memory from being reallocated. * switch_exit(proc * p) */ ENTRY(switch_exit) /* * Change pcb to idle u. area, i.e., set r31 to top of stack * and set curpcb to point to _idle_u. r2 contains proc *p. */ or.u r30, r0, hi16(_idle_u) or r30, r30,lo16(_idle_u) addu r31, r30, UPAGES * NBPG /* now on idle_u stack */ or.u r10, r0, hi16(_curpcb) st r30, r10,lo16(_curpcb) /* curpcb = &idle_u */ or.u r10, r0, hi16(_curproc) st r0, r10, lo16(_curproc) /* curproc = NULL */ /* Schedule the vmspace and stack to be freed. */ bsr.n _exit2 /* call exit2(p); */ subu r31, r31, 48 /* allocate stack */ addu r31, r31, 48 /* restore stack */ bsr.n _cpu_switch /* goto final switch */ or r2, r0, r10 #if 0 /* * When no processes are on the runq, switch * idles here watiing for something to come ready. */ LABEL(idle) or.u r10, r0, hi16(_curproc) st r0, r10, lo16(_curproc) /* curproc = NULL */ bsr.n _setipl /* unblock all interrupts */ or r2, r0, 0 /* spin reading whichqs until != 0 */ 1: or.u r10, r0, hi16(_whichqs) ld r11, r10,lo16(_whichqs) bcnd eq0, r11, 1b bsr.n _setipl or r2, r0, IPL_HIGH /* block all ints */ br Lsw1 #endif /* 0 */ /* * cpu_switch() * XXX - Arg 1 is a proc pointer (curproc) but this doesn't use it. * XXX - how about using stack for saving spl and last proc? * XXX rewrite this whole mess in C nivas */ ENTRY(cpu_switch) /* * Save state of previous process in its pcb. */ or.u r10, r0, hi16(_curpcb) ld r10,r10, lo16(_curpcb) st r1, r10, PCB_PC /* save r1 in pcb */ st.d r14,r10, PCB_R14 st.d r16,r10, PCB_R16 st.d r18,r10, PCB_R18 st.d r20,r10, PCB_R20 st.d r22,r10, PCB_R22 st.d r24,r10, PCB_R24 st.d r26,r10, PCB_R26 st.d r28,r10, PCB_R28 st.d r30,r10, PCB_R30 /* save frame pointer & stack pointer */ or r14,r10, 0 /* save r10 in r14 */ bsr _getipl st r2, r14, PCB_IPL /* save ipl in pcb */ or.u r11, r0, hi16(_curproc) ld r11,r11, lo16(_curproc) or.u r12, r0, hi16(_lastproc) st r11, r12, lo16(_lastproc)/* lastproc = curproc */ or.u r11, r0, hi16(_curproc) st r0, r11, lo16(_curproc) /* curproc = NULL */ or.u r11, r0, hi16(_curpcb) st r0, r11, lo16(_curpcb) /* curpcb = NULL */ Lidleloop: /* * Find the highest-priority queue that isn't empty, * then take the first proc from that queue. */ or.u r7, r0, hi16(_whichqs) ld r7, r7, lo16(_whichqs) bcnd ne0, r7, Ldoneloop Lloopchk: /* if whichqs is zero, keep checking */ bsr.n _setipl /* enable all ints */ or r2, r0, 0 br Lidleloop Ldoneloop: bsr.n _setipl /* disable ints */ or r2, r0, IPL_HIGH or.u r7, r0, hi16(_whichqs) /* reload whichqs */ ld r7, r7, lo16(_whichqs) bcnd eq0, r7, Lloopchk /* keep spinning for whichqs to be !=0*/ xor r6, r6, r6 /* set r6 to 0 */ 1: bb1 0, r7, 2f /* if rightmost bit set, done */ extu r7, r7, 0<1> /* else, right shift whichqs, */ br.n 1b /* increment r6, and repeat */ addu r6, r6, 1 2: or.u r7, r0, hi16(_qs) or r7, r7, lo16(_qs) /* * Need to make * p->p_forw->p_back = p->p_back and * p->p_back->p_forw = p->p_forw where * p is q->p_forw. * Remember that q->p_forw == p and p->p_back == q. */ lda.d r8, r7[r6] /* r8 = &qs[ff1(whichqs)] */ ld r9, r8, P_FORW /* r8 is q, r9 is p */ ld r12, r9, P_FORW /* r12 = p->p_forw */ st r8, r12, P_BACK /* p->p_forw->p_back = q (p->p_back) */ st r12, r8, P_FORW /* q->p_forw = p->p_forw */ lda.d r8, r7[r6] /* reload r8 with qs[ff1(whichqs)] */ ld r12, r8, P_FORW /* q->p_forw */ cmp r12, r12, r8 /* q == q->p_forw; anyone left on queue? */ bb1 ne, r12, Lsw2 /* yes, skip clearing bit in whichqs */ or r12, r0, 1 /* r12 is 1 now */ 1:bcnd eq0, r6, 2f mak r12, r12, 0<1> /* shift left by 1 */ br.n 1b subu r6, r6, 1 /* keep doing this while r6 != 0 */ 2: /* * NOTE: we could have just used "mak r12, r12, r6" instead of the * loop above. But that will break if NQS is made > 32. I can use * preprocessor to do the right thing, but that means I have to * include sys/proc.h in this file. XXX nivas */ or.u r7, r0, hi16(_whichqs) ld r8, r7, lo16(_whichqs) and.c r8, r8, r12 /* whichqs &= ~the bit */ st r8, r7, lo16(_whichqs) /* reset bit in whichqs */ Lsw2: ld r2, r9, P_WCHAN bcnd ne0, r2, Lswchanpanic ld.b r2, r9, P_STAT cmp r2, r2, SRUN bb1 ne, r2, Lswsrunpanic or.u r11, r0, hi16(_want_resched) st r0, r11, lo16(_want_resched) /* clear want_resched */ or.u r11, r0, hi16(_curproc) st r9, r11,lo16(_curproc) /* curproc = p */ #ifdef notyet or.u r2, r0, hi16(_lastproc) ld r2, r2, lo16(_lastproc) #endif /* notyet */ /* huh??? */ or.u r10, r0, hi16(_curpcb) ld r10,r10, lo16(_curpcb) #ifdef notyet cmp r2, r2, r9 bb1 eq, r2, Lswsameproc #endif /* notyet */ /* r9 is curproc */ st r0, r9, P_BACK /* p->p_back = 0 */ ld r3, r9, P_ADDR or.u r10, r0, hi16(_curpcb) st r3, r10, lo16(_curpcb) /* curpcb = p->p_addr */ /* see if pmap_activate needs to be called */ /* _pmap_activate() now has proc * as parameter 01-11-2000 smurph */ /* No more VM_PMAP to contend with!!! */ or r2, r0, r9 /* r2 = p */ or r14, r0, r9 /* save p in r14 */ subu r31, r31,48 /* r2 = pmap, r3 = pcb, r4 = cpu number */ bsr _pmap_activate /* _pmap_activate(proc *p)*/ addu r31, r31,48 or r9, r0, r14 /* restore p saved in r14 */ Lswnochg: or.u r31, r0, hi16(_intstack_end) or r31,r31, lo16(_intstack_end)/* now goto a tmp stack for NMI */ subu r31, r31,48 bsr.n _load_u_area /* load_u_area(p) */ or r2, r0, r9 addu r31, r31,48 /* flush tlb of any user addresses */ or r2, r0, 0 /* 0 = user space */ or r3, r0, 0 /* start at addr 0 */ subu r31, r31,48 /* r2 = 1 : kernel ? user, r3 = address, r4 = size */ /* cmmu_flush_tlb(0, 0, 0xffff) */ bsr.n _cmmu_flush_tlb or r4, r0, 0xffff /* cmmu_flush_tlb flushes entire tlb */ /* for sizes > 4096 */ addu r31, r31,48 or.u r10, r0, hi16(_curpcb) ld r10, r10, lo16(_curpcb) /* XXX Is this correct/necessary? */ st r10, r14, P_ADDR /* p->p_addr = curpcb; restore p_addr */ /* restore from the current context */ ld r1,r10, PCB_PC ld.d r14,r10, PCB_R14 ld.d r16,r10, PCB_R16 ld.d r18,r10, PCB_R18 ld.d r20,r10, PCB_R20 ld.d r22,r10, PCB_R22 ld.d r24,r10, PCB_R24 ld.d r26,r10, PCB_R26 ld.d r28,r10, PCB_R28 ld.d r30,r10, PCB_R30 /* restore frame pointer & stack */ /* XXX should we postpone restoring stack till after ipl is restored? The stack access could fault */ Lswsameproc: subu r31,r31,48 st r1, r31,36 /* save r1 on stack */ ld r2, r10, PCB_IPL /* restore interrupt mask */ bsr _setipl /* restore ipl */ ld r1, r31,36 /* restore r1 from stack */ addu r31,r31,48 jmp.n r1 or r2, r0, 1 /* return 1 (for alternate returns) */ /* * savectx(pcb) * Update pcb, saving current processor state. */ ENTRY(savectx) /* get the spl mask */ subu r31,r31,48 /* allocate stack for r1 and args */ st r1,r31,36 /* save return address */ st r2,r31,32 /* save r2 */ bsr _getipl /* get the current interrupt mask */ ld r1,r31,36 /* recover return address */ ld r10,r31,32 /* recover r2 into r10 */ addu r31,r31,48 /* put stack pointer back */ st r1, r10, PCB_PC /* save return address */ st.d r14,r10, PCB_R14 st.d r16,r10, PCB_R16 st.d r18,r10, PCB_R18 st.d r20,r10, PCB_R20 st.d r22,r10, PCB_R22 st.d r24,r10, PCB_R24 st.d r26,r10, PCB_R26 st.d r28,r10, PCB_R28 st.d r30,r10, PCB_R30 /* save frame pointer and sp */ st r2, r10, PCB_IPL /* save interrupt mask */ jmp.n r1 or r2,r0,r0