obp/obp/cpu/sparc/ultra4v/tte-lookup.fth

\ ========== Copyright Header Begin ==========================================
\
\ Hypervisor Software File: tte-lookup.fth
\
\ Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
\
\  - Do no alter or remove copyright notices
\
\  - Redistribution and use of this software in source and binary forms, with
\    or without modification, are permitted provided that the following
\    conditions are met:
\
\  - Redistribution of source code must retain the above copyright notice,
\    this list of conditions and the following disclaimer.
\
\  - Redistribution 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.
\
\    Neither the name of Sun Microsystems, Inc. or the names of contributors
\ may be used to endorse or promote products derived from this software
\ without specific prior written permission.
\
\     This software is provided "AS IS," without a warranty of any kind.
\ ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
\ INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
\ PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
\ MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
\ ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
\ DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN
\ OR ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR
\ FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
\ DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
\ ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
\ SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
\
\ You acknowledge that this software is not designed, licensed or
\ intended for use in the design, construction, operation or maintenance of
\ any nuclear facility.
\
\ ========== Copyright Header End ============================================
id: @(#)tte-lookup.fth 1.2 06/10/13
purpose:
copyright: Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved
copyright: Use is subject to license terms.

headerless

\ tte-lookup
\
\   You *MUST* preserve %o7 before calling this routine.
\   You have %g5 available for this purpose.
\
\   before calling this routine you *MUST* patch the first 4 nops
\   with instructions that result in %g7 having the PA of the VPT root.
\
\ In:
\   %g4 = VA to resolve
\ Out:
\   %g3 = tte or 0.
\   all other registers are trashed, except %g5
\
0 value vpt-patch-pt
label tte-lookup
   nop nop nop nop nop nop
   %g0  1                       %g1     sub
   %g1  d# 64 pageshift -       %g2     srlx            \ page mask
   %g0                          %g3     move
   %g1  #vabits pageshift - tteshift + %g1  sllx        \ %g1 = vpt-base
   %g4  %g1                     %g0     subcc
   u<                                   if
      %g1  pageshift tteshift - %g6     srax            \ %g6 = vpt
      %g4  pageshift tteshift - 3 * tteshift + %g1 srlx
      %g1  tteshift             %g1     sllx
      %g1  %g2                  %g6     and             \ root VPT offset
      %g7  %g6 memory-asi       %g3     ldxa            \ L2 vpt tte
      %g3  %g0                  %g0     subcc
      0<  if
         %g4  pageshift tteshift - 2 * tteshift + %g1 srlx
         %g1  tteshift          %g1     sllx
         %g1  %g2               %g6     and             \ L2 VPT offset
         %g3  d# 64 #vabits -   %g3     sllx
         %g3  d# 64 #vabits -   %g3     srlx
         %g3  %g2               %g7     andn            \ recover PA
         %g7  %g6 memory-asi    %g3     ldxa            \ L1 vpt tte
         %g3  %g0               %g0     subcc
         0<  if
            %g4  pageshift      %g1     srlx
            %g1  tteshift       %g1     sllx
            %g1  %g2            %g6     and             \ L2 VPT offset
            %g3  d# 64 #vabits - %g3    sllx
            %g3  d# 64 #vabits - %g3    srlx
            %g3  %g2            %g7     andn            \ recover PA
            retl
            %g7  %g6 memory-asi %g3     ldxa            \ VA tte
         then
      then
   else
      nop
      %g4  %g6                  %g0     subcc
      u<                                if
         %g1  pageshift tteshift - %g6  srax            \ %g6 = vpt-L2
         %g4  pageshift tteshift - 2 * tteshift + %g1 srlx
         %g1  tteshift          %g1     sllx
         %g1  %g2               %g6     and             \ root VPT offset
         %g7  %g6 memory-asi    %g3     ldxa            \ L2 vpt tte
         %g3  %g0               %g0     subcc
         0<  if
            %g4  pageshift      %g1     srlx
            %g1  tteshift       %g1     sllx
            %g1  %g2            %g6     and             \ L2 VPT offset
            %g3  d# 64 #vabits - %g3    sllx
            %g3  d# 64 #vabits - %g3    srlx
            %g3  %g2            %g7     andn            \ recover PA
            retl
            %g7  %g6 memory-asi %g3     ldxa            \ L1 vpt tte
         then
      else
         nop
         %g0  1                 %g6     sub
         %g6  pageshift 1+      %g6     sllx            \ VPT root PA
         %g4  pageshift         %g1     srlx
         %g1  pageshift         %g3     sllx
         %g3  %g6               %g0     subcc           \ in VPT root?
         0= if
           %g1  tteshift        %g1     sllx            \ miss PFN
           here tte-lookup - is vpt-patch-pt
           nop                                          \ TTE patched later!!
           nop
           nop
           nop
           nop                                          \ THESE WILL BE SWAPPED
           retl                                         \ WATCHOUT!!
           nop
         then
         %g1  %g2               %g6     and             \ offset
         retl
         %g7  %g6 memory-asi    %g3     ldxa            \ L2 vpt tte
      then
   then
   retl
   %g0                          %g3     move            \ invalid
end-code

\ we have to assemble/patch the mmu lookup routines
\ this requires that the assembler be available..
\ this is horrible, but the vpt root access is in the fast path, and the tte
\ formation is ugly, so we patch the instructions as efficiently as
\ we can - including the swap of the retl to use the setx delay slot
: setup-root-vpt ( pa -- )
   here >r tte-lookup dp !
   [ also assembler ]
   ( n ) dup %g6 %g7 setx
   tte-lookup vpt-patch-pt + dp !
   >tte-cp >tte-cv >tte-writable >tte-soft >tte-priv >tte-valid
   %g6 %g3 setx
   here /l - dup l@ swap dp ! retl l,
   \ The last patched instruction may not be flushed, flush it all the time
   here i-flush
   [ previous ]
   r> dp !
;