obp/obp/arch/sun4u/switchcpu.fth

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\ Hypervisor Software File: switchcpu.fth
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id: @(#)switchcpu.fth 1.14 02/09/20
purpose:
copyright: Copyright 1995-2002 Sun Microsystems, Inc.  All Rights Reserved
copyright: Use is subject to license terms.

headerless

: cpu-status?   ( cpu status -- flag )
   over mid-ok? if
      swap >cpu-struct >cpu-status @ =
   else
      2drop false
   then
;

: cpu-started? ( cpu# -- flag )  CPU-STARTED cpu-status?  ;
: cpu-idled?   ( cpu# -- flag )  CPU-PARKED  cpu-status?  ;
: idle-cpu ( cpu# -- )
   dup cpu-started?  over mid@ <>  and if       ( cpu# )
      xcall-idle-cpu                            ( fail? )
   then  drop                                   ( )
;
: resume-cpu ( cpu# -- )
   dup cpu-idled?  over mid@ <>  and if         ( cpu# )
      xcall-resume-cpu                          ( fail? )
   then  drop                                   ( )
;

: idle-other-cpus ( -- )        ['] idle-cpu  do-foreach-cpu  ;
: resume-other-cpus ( -- )      ['] resume-cpu  do-foreach-cpu ;

headers

: switch-cpu ( cpu# -- )
   \ Simply return if cpu# is the currently running CPU
   dup mid@ =  if  drop exit  then
   dup mid-ok? if                               ( cpu# )
      dup xcall-get-pc  0= if                   ( cpu# pc )
         drop                                   ( cpu# )
         dup idle-cpu                           ( cpu# )
         dup >cpu-struct >cpu-status @          ( cpu# status )
         CPU-IDLING <>  if                      ( cpu# )
            d# 5 0 do dup cpu-idled? ?leave d# 100 ms loop
            dup cpu-idled?                      ( cpu# switch? )
         else                                   ( cpu# )
            true                                ( cpu# true )
         then                                   ( cpu# switch? )
         if  master-release-prom  else  drop  then
      then
   then                                         ( )
  drop ." CPU not responding" cr
;

chain: enterforth-chain
   idle-other-cpus
;

chain: go-chain
   resume-other-cpus
;