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* Save and restore PCPU_GET(current_pmap) in pcb_pmap so that we don't

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lose if a process is preempted while pmap is temporarily switched to
  another pmap.
* For SMP, drop the high-fp state when a thread is switched away from
  so that if another cpu resumes that thread, it doesn't have to play
  games with IPI to get ahold of the correct register values.
This commit is contained in:
Doug Rabson 2002-03-14 19:33:03 +00:00
parent 1719980ed9
commit 92e814dcb6
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=92285
1 changed files with 24 additions and 12 deletions
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36
sys/ia64/ia64/swtch.s
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@ -164,8 +164,11 @@ ENTRY(cpu_switch, 0)
st8 [r17]=r2,8 ;; // ar.pfs
st8 [r17]=r18,8 ;; // ar.bspstore
st8 [r17]=r19,8 ;; // our NaT bits
add r3=PC_CURRENT_PMAP,r13
st8 [r17]=r16,8 ;; // ar.rnat
st8 [r17]=r20 ;; // pr
ld8 r3=[r3]
st8 [r17]=r20,8 ;; // pr
st8 [r17]=r3 // current pmap
mov ar.rsc=3 // turn RSE back on
@ -196,21 +199,30 @@ ENTRY(cpu_switch, 0)
br.call.sptk.few rp=choosethread
3:
add r14=PC_CURTHREAD,r13 ;;
st8 [r14]=ret0 // set r13->pc_curthread
mov ar.k7=ret0
alloc r15=ar.pfs,0,0,2,0 // create temporary output frame
mov r4=ret0 // save from call
;;
alloc r15=ar.pfs,0,0,1,0 // create temporary output frame
#ifdef SMP
;;
mov out0=1 // clear fpcurthread
br.call.sptk.few rp=ia64_fpstate_save
#endif
add r14=PC_CURTHREAD,r13
;;
mov out0=r4
br.call.sptk.few rp=pmap_activate // install RIDs etc.
ld8 out0=[r14]
mov out1=1
br.call.sptk.few rp=ia64_fpstate_save // clear fpcurthread
#endif
;;
add r14=PC_CURTHREAD,r13 ;;
st8 [r14]=r4 // set r13->pc_curthread
mov ar.k7=r4
;;
add r15=TD_PCB,r4
;;
ld8 r15=[r15]
;;
add r15=PCB_PMAP,r15 // &pcb_pmap
;;
ld8 out0=[r15]
br.call.sptk.few rp=pmap_install // install RIDs etc.
add r15=TD_PCB,r4
add r16=TD_KSTACK,r4 ;;