diff options
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/arch/m88k/m88k/process.S | 134 |
1 files changed, 70 insertions, 64 deletions
diff --git a/sys/arch/m88k/m88k/process.S b/sys/arch/m88k/m88k/process.S index 93ce7611b78..86309aa5bfe 100644 --- a/sys/arch/m88k/m88k/process.S +++ b/sys/arch/m88k/m88k/process.S @@ -1,4 +1,4 @@ -/* $OpenBSD: process.S,v 1.7 2004/08/09 20:52:11 miod Exp $ */ +/* $OpenBSD: process.S,v 1.8 2005/10/12 19:00:21 miod Exp $ */ /* * Copyright (c) 1996 Nivas Madhur * All rights reserved. @@ -35,6 +35,7 @@ #include <machine/psl.h> #include <machine/intr.h> +#ifdef DIAGNOSTIC data align 4 ASLOCAL(swchanpanic) @@ -42,11 +43,6 @@ ASLOCAL(swchanpanic) align 4 ASLOCAL(swsrunpanic) string "switch SRUN %x\0" -#ifdef DEBUG - align 4 -ASLOCAL(boguspsr) - string "Invalid PSR in idle loop 0x%x\n\0" -#endif text align 8 @@ -61,6 +57,7 @@ ASLOCAL(Lswsrunpanic) or r2, r2, lo16(_ASM_LABEL(swsrunpanic)) bsr.n _C_LABEL(panic) or r3, r0, r9 +#endif /* * At exit of a process, do a cpu_switch for the last time. @@ -73,7 +70,8 @@ ASLOCAL(Lswsrunpanic) 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. + * and set curpcb to point to _idle_u. + * r2 contains proc *p. */ or.u r30, r0, hi16(_C_LABEL(idle_u)) or r30, r30,lo16(_C_LABEL(idle_u)) @@ -85,18 +83,24 @@ ENTRY(switch_exit) or.u r10, r0, hi16(_C_LABEL(curproc)) bsr.n _C_LABEL(exit2) st r0, r10, lo16(_C_LABEL(curproc)) /* curproc = NULL */ - bsr _C_LABEL(cpu_switch) /* goto final switch */ + + /* + * exit2() has acquired the scheduler lock for us. Jump into + * cpu_switch(), after the context save since we do not need + * to save anything. + */ + bsr _ASM_LABEL(cpu_switch_search) /* - * 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 + * void cpu_switch(struct proc *p) + * + * Find a runnable process and switch to it. On entry, the scheduler lock is + * held; it has to be released before returning to the process. */ ENTRY(cpu_switch) - /* - * Save state of previous process in its pcb. + * Save state of previous process in its pcb, and pmap_deactivate() + * the process. */ or.u r2, r0, hi16(_C_LABEL(curpcb)) ld r2, r2, lo16(_C_LABEL(curpcb)) @@ -106,63 +110,66 @@ ENTRY(cpu_switch) or.u r11, r0, hi16(_C_LABEL(curproc)) ld r2, r11, lo16(_C_LABEL(curproc)) - bcnd eq0, r2, 1f - - bsr _C_LABEL(pmap_deactivate) - or.u r11, r0, hi16(_C_LABEL(curproc)) - -1: - st r0, r11, lo16(_C_LABEL(curproc)) /* curproc = NULL */ - -ASLOCAL(Lidleloop) /* - * Find the highest-priority queue that isn't empty, - * then take the first proc from that queue. + * Note that we can still use curpcb as our stack after + * pmap_deactivate() has been called, as it does not affect the u + * area mappings. */ + bsr.n _C_LABEL(pmap_deactivate) + st r0, r11, lo16(_C_LABEL(curproc)) /* curproc = NULL */ +ASLOCAL(cpu_switch_search) + /* + * This is the start of the idle loop. Find the highest-priority + * queue that isn't empty, then take the first proc from that queue. + */ or.u r7, r0, hi16(_C_LABEL(whichqs)) ld r7, r7, lo16(_C_LABEL(whichqs)) - - bcnd ne0, r7, _ASM_LABEL(Ldoneloop) - -ASLOCAL(Lloopchk) /* if whichqs is zero, keep checking */ - bsr.n _C_LABEL(setipl) /* unmask all ints... */ + bcnd ne0, r7, _ASM_LABEL(cpu_switch_found) +1: + /* + * There were no runnable processes. Enable all interrupts and + * busy-wait for this to change. + * Note that, besides doing spl0(), this will actually enable + * interrupts in the psr. Bootstrap of secondary processors + * relies upon this. + */ + bsr.n _C_LABEL(setipl) or r2, r0, IPL_NONE ldcr r2, PSR - bb0 PSR_INTERRUPT_DISABLE_BIT, r2, 1f -#ifdef DEBUG - or r3, r2, r0 - or.u r2, r0, hi16(_ASM_LABEL(boguspsr)) - bsr.n _C_LABEL(printf) - or r2, r2, lo16(_ASM_LABEL(boguspsr)) - ldcr r2, PSR -#endif + bb0.n PSR_INTERRUPT_DISABLE_BIT, r2, 2f + or.u r7, r0, hi16(_C_LABEL(whichqs)) clr r2, r2, 1<PSR_INTERRUPT_DISABLE_BIT> /* ...and enable them */ stcr r2, PSR FLUSH_PIPELINE -1: - br _ASM_LABEL(Lidleloop) - -ASLOCAL(Ldoneloop) +2: + ld r7, r7, lo16(_C_LABEL(whichqs)) + bcnd eq0, r7, 2b + /* XXX run fancy things here, such as page zeroing... */ - bsr.n _C_LABEL(setipl) /* disable ints */ +ASLOCAL(cpu_switch_found) + bsr.n _C_LABEL(setipl) /* disable interrupts */ or r2, r0, IPL_HIGH + /* + * An interrupt could have occured between the last whichqs check + * and the call to setipl(). Check again that whichqs is nonzero. + */ or.u r7, r0, hi16(_C_LABEL(whichqs)) /* reload whichqs */ ld r7, r7, lo16(_C_LABEL(whichqs)) + bcnd eq0, r7, 1b - bcnd eq0, r7, _ASM_LABEL(Lloopchk) /* keep spinning for whichqs to be != 0 */ - + /* XXX use ff1, like powerpc... needs *runqueue() adjustments */ 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) + or.u r7, r0, hi16(_C_LABEL(qs)) + or r7, r7, lo16(_C_LABEL(qs)) /* * Need to make @@ -183,28 +190,20 @@ ASLOCAL(Ldoneloop) cmp r12, r12, r8 /* q == q->p_forw; anyone left on queue? */ bb1 ne, r12, 3f /* 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 r12, r0, 1 + mak r12, r12, r6 or.u r7, r0, hi16(_C_LABEL(whichqs)) ld r8, r7, lo16(_C_LABEL(whichqs)) and.c r8, r8, r12 /* whichqs &= ~the bit */ st r8, r7, lo16(_C_LABEL(whichqs)) 3: +#ifdef DIAGNOSTIC ld r2, r9, P_WCHAN bcnd ne0, r2, _ASM_LABEL(Lswchanpanic) ld.b r2, r9, P_STAT cmp r2, r2, SRUN bb1 ne, r2, _ASM_LABEL(Lswsrunpanic) +#endif or.u r11, r0, hi16(_C_LABEL(want_resched)) st r0, r11, lo16(_C_LABEL(want_resched)) /* clear want_resched */ @@ -215,7 +214,7 @@ ASLOCAL(Ldoneloop) st.b r2, r9, P_STAT /* r9 is curproc */ - st r0, r9, P_BACK /* p->p_back = 0 */ + st r0, r9, P_BACK /* p->p_back = 0 */ ld r3, r9, P_ADDR or.u r10, r0, hi16(_C_LABEL(curpcb)) st r3, r10, lo16(_C_LABEL(curpcb)) /* curpcb = p->p_addr */ @@ -226,15 +225,22 @@ ASLOCAL(Ldoneloop) or r2, r0, r9 or r9, r0, r14 /* restore p saved in r14 */ + /* + * Since we are about to replace the u area mapping, we need to + * switch to a neutral stack now. + */ or.u r31, r0, hi16(_ASM_LABEL(intstack_end)) or r31,r31, lo16(_ASM_LABEL(intstack_end)) + bsr.n _C_LABEL(load_u_area) or r2, r0, r9 +#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) + bsr _C_LABEL(sched_unlock_idle) +#endif + or.u r10, r0, hi16(_C_LABEL(curpcb)) ld r10, r10, lo16(_C_LABEL(curpcb)) - /* XXX Is this correct/necessary? */ - st r10, r14, P_ADDR /* p->p_addr = curpcb; restore p_addr */ /* restore from the current context */ ld r2, r10, PCB_FCR62 @@ -262,9 +268,9 @@ ASLOCAL(Ldoneloop) ld r1, r14, PCB_PC ld r30,r14, PCB_R30 /* restore frame pointer & stack */ ld r31,r14, PCB_SP - ld r14,r14, PCB_R14 + jmp.n r1 - or r2, r0, 1 /* return 1 (for alternate returns) */ + ld r14,r14, PCB_R14 /* * savectx(pcb) |