]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/ppc/skiplists.s
projects / apple / xnu.git / blobdiff
? search:
summary | shortlog | log | commit | commitdiff | tree
raw | inline | side by side
xnu-792.18.15.tar.gz
[apple/xnu.git] / osfmk / ppc / skiplists.s
diff --git a/osfmk/ppc/skiplists.s b/osfmk/ppc/skiplists.s
index 4bb4a78082d82ec52c95faa6f93d864ff3957db6..69a9dccbbd16856213f0abf45fd95e845b63eb57 100644 (file)
--- a/osfmk/ppc/skiplists.s
+++ b/osfmk/ppc/skiplists.s
@@ -1,16 +1,19 @@
 /*
 /*
- * Copyright (c) 2002 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2002-2004 Apple Computer, Inc. All rights reserved.
  *
  *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
@@ -20,7 +23,7 @@
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 
 /* skiplists.s
  */
 
 /* skiplists.s
@@ -152,28 +155,26 @@ mapSrch64d:
             ; never for the most-common case of finding a scalar mapping.  The full searches
             ; must check _in_ the inner loop, to get the prev ptrs right.
 
             ; never for the most-common case of finding a scalar mapping.  The full searches
             ; must check _in_ the inner loop, to get the prev ptrs right.
 
-            mr.                r9,r9                                   ; was there a prev ptr?
-            li         r3,0                                    ; assume we are going to return null
-            ld         r4,pmapSkipLists(r6)    ; assume prev ptr null... so next is first
-            beq--      mapSrch64Exit                   ; prev ptr was null, search failed
-            lwz                r0,mpFlags(r9)                  ; get flag bits from prev mapping
-            ld         r10,mpVAddr(r9)                 ; re-fetch base address of prev ptr
-            ld         r4,mpList0(r9)                  ; get 64-bit ptr to next mapping, if any
-            andi.      r0,r0,mpBlock+mpNest    ; block mapping or nested pmap?
-            lhz                r11,mpBSize(r9)                 ; get #pages/#segments in block/submap mapping
-            rldicr     r10,r10,0,51                    ; zero low 12 bits of mapping va
-            beq                mapSrch64Exit                   ; prev mapping was just a scalar page, search failed
-            cmpwi      r0,mpBlock                              ; block mapping or nested pmap?
-            sldi       r0,r11,12                               ; assume block mapping, get size in bytes - 4k
-            beq                mapSrch64f                              ; we guessed right, it was a block mapping
-            addi       r11,r11,1                               ; mpBSize is 1 too low
-            sldi       r11,r11,28                              ; in a nested pmap, mpBSize is in units of segments
-            subi       r0,r11,4096                             ; get address of last page in submap
-mapSrch64f:
-            add                r10,r10,r0                              ; r10 <- last page in this mapping
-            cmpld      r5,r10                                  ; does this mapping cover our page?
-            bgt                mapSrch64Exit                   ; no, search failed
-            mr         r3,r9                                   ; yes, we found it
+                       mr.             r9,r9                                   ; was there a prev ptr?
+                       li              r3,0                                    ; assume we are going to return null
+                       ld              r4,pmapSkipLists(r6)    ; assume prev ptr null... so next is first
+                       beq--   mapSrch64Exit                   ; prev ptr was null, search failed
+                       lwz             r0,mpFlags(r9)                  ; get flag bits from prev mapping
+                       lhz             r11,mpBSize(r9)                 ; get #pages/#segments in block/submap mapping
+                       
+                       rlwinm  r0,r0,mpBSub+1,31,31    ; 0 if 4K bsu or 1 if 32MB bsu
+                       ld              r10,mpVAddr(r9)                 ; re-fetch base address of prev ptr
+                       ori             r0,r0,0x3216                    ; OR in 0x00003216 (0x3200 and a base rotate of 22)
+                       addi    r11,r11,1                               ; Convert 0-based to 1-based
+                       rlwnm   r0,r0,r0,27,31                  ; Rotate to get 12 or 25
+                       ld              r4,mpList0(r9)                  ; get 64-bit ptr to next mapping, if any
+                       sld             r11,r11,r0                              ; Get the length in bytes
+                       rldicr  r10,r10,0,51                    ; zero low 12 bits of mapping va
+                       subi    r0,r11,4096                             ; get offset last page in mapping
+                       add             r10,r10,r0                              ; r10 <- last page in this mapping
+                       cmpld   r5,r10                                  ; does this mapping cover our page?
+                       bgt             mapSrch64Exit                   ; no, search failed
+                       mr              r3,r9                                   ; yes, we found it
 
             ; found the mapping
             ;   r2 = count of nodes visited
 
             ; found the mapping
             ;   r2 = count of nodes visited
@@ -242,28 +243,26 @@ mapSrch32d:
             ; never for the most-common case of finding a scalar mapping.  The full searches
             ; must check _in_ the inner loop, to get the prev ptrs right.
 
             ; never for the most-common case of finding a scalar mapping.  The full searches
             ; must check _in_ the inner loop, to get the prev ptrs right.
 
-            mr.                r9,r9                                   ; was there a prev ptr?
-            li         r3,0                                    ; assume we are going to return null
-            lwz                r4,pmapSkipLists+4(r6)  ; assume prev ptr null... so next is first
-            beq-       mapSrch32Exit                   ; prev ptr was null, search failed
-            lwz                r0,mpFlags(r9)                  ; get flag bits from prev mapping
-            lwz                r10,mpVAddr+4(r9)               ; re-fetch base address of prev ptr
-            andi.      r0,r0,mpBlock+mpNest    ; block mapping or nested pmap?
-            lwz                r4,mpList0+4(r9)                ; get ptr to next mapping, if any
-            beq                mapSrch32Exit                   ; prev mapping was just a scalar page, search failed
-            lhz                r11,mpBSize(r9)                 ; get #pages/#segments in block/submap mapping
-            cmpwi      r0,mpBlock                              ; block mapping or nested pmap?
-            rlwinm     r10,r10,0,0,19                  ; zero low 12 bits of block mapping va
-            slwi       r0,r11,12                               ; assume block mapping, get size in bytes - 4k
-            beq                mapSrch32f                              ; we guessed right, it was a block mapping
-            addi       r11,r11,1                               ; mpBSize is 1 too low
-            slwi       r11,r11,28                              ; in a nested pmap, mpBSize is in units of segments
-            subi       r0,r11,4096                             ; get address of last page in submap
-mapSrch32f:
-            add                r10,r10,r0                              ; r10 <- last page in this mapping
-            cmplw      r5,r10                                  ; does this mapping cover our page?
-            bgt                mapSrch32Exit                   ; no, search failed
-            mr         r3,r9                                   ; yes, we found it
+                       mr.             r9,r9                                   ; was there a prev ptr?
+                       li              r3,0                                    ; assume we are going to return null
+                       lwz             r4,pmapSkipLists+4(r6)  ; assume prev ptr null... so next is first
+                       beq-    mapSrch32Exit                   ; prev ptr was null, search failed
+                       lwz             r0,mpFlags(r9)                  ; get flag bits from prev mapping
+                       lhz             r11,mpBSize(r9)                 ; get #pages/#segments in block/submap mapping
+                       lwz             r10,mpVAddr+4(r9)               ; re-fetch base address of prev ptr
+                       
+                       rlwinm  r0,r0,mpBSub+1,31,31    ; Rotate to get 0 if 4K bsu or 1 if 32MB bsu
+                       addi    r11,r11,1                               ; Convert 0-based to 1-based
+                       ori             r0,r0,0x3216                    ; OR in 0x00003216 (0x3200 and a base rotate of 22)
+                       rlwnm   r0,r0,r0,27,31                  ; Rotate to get 12 or 25
+                       lwz             r4,mpList0+4(r9)                ; get ptr to next mapping, if any
+                       slw             r11,r11,r0                              ; Get length in bytes
+                       rlwinm  r10,r10,0,0,19                  ; zero low 12 bits of block mapping va
+                       subi    r0,r11,4096                             ; get address of last page in submap
+                       add             r10,r10,r0                              ; r10 <- last page in this mapping
+                       cmplw   r5,r10                                  ; does this mapping cover our page?
+                       bgt             mapSrch32Exit                   ; no, search failed
+                       mr              r3,r9                                   ; yes, we found it
 
             ; found the mapping
             ;   r2 = count of nodes visited
 
             ; found the mapping
             ;   r2 = count of nodes visited
@@ -369,27 +368,36 @@ LEXT(mapSearchFull)
             ;  r7 = current skip list number * 8
             ;  r8 = ptr to skip list vector of mapping pointed to by r9
             ;  r9 = prev ptr, ie highest mapping that comes before search target (initially the pmap)
             ;  r7 = current skip list number * 8
             ;  r8 = ptr to skip list vector of mapping pointed to by r9
             ;  r9 = prev ptr, ie highest mapping that comes before search target (initially the pmap)
-            ;  r10 = prev mappings va, or 0 if r9==pmap 
+            ;  r10 = lowest expected next va, 0 at the beginning of the search
             ;  r12 = ptr to the skipListPrev vector in the per-proc
             
             .align     5
 mapSrchFull64a:                                                                ; loop over each mapping
             ;  r12 = ptr to the skipListPrev vector in the per-proc
             
             .align     5
 mapSrchFull64a:                                                                ; loop over each mapping
-            ld         r4,mpVAddr(r3)                  ; get va for this mapping (plus flags in low 12 bits)
-            addi       r2,r2,1                                 ; count mappings visited
-            lwz                r0,mpFlags(r3)                  ; get mapping flag bits
-            cmpld      cr0,r10,r4                              ; make sure VAs come in strictly ascending order
+                       addi    r2,r2,1                                 ; count mappings visited
+                       lwz             r0,mpFlags(r3)                  ; get mapping flag bits
+                       lhz             r11,mpBSize(r3)                 ; get #pages/#segments in block/submap mapping
+                       ld              r4,mpVAddr(r3)                  ; get va for this mapping (plus flags in low 12 bits)
+
+                       rlwinm  r0,r0,mpBSub+1,31,31    ; Rotate to get 0 if 4K bsu or 1 if 32MB bsu
+                       addi    r11,r11,1                               ; Convert 0-based to 1-based
+                       ori             r0,r0,0x3216                    ; OR in 0x00003216 (0x3200 and a base rotate of 22)
+                       rlwnm   r0,r0,r0,27,31                  ; Rotate to get 12 or 25
+                       sld             r11,r11,r0                              ; Get the length in bytes
             rldicr     r4,r4,0,51                              ; zero low 12 bits of mapping va
             rldicr     r4,r4,0,51                              ; zero low 12 bits of mapping va
+            addic.     r0,r11,-4096                    ; get offset last page in mapping (set cr0_eq if 1 page)
+
+            cmpld      cr5,r10,r4                              ; make sure VAs come in strictly ascending order
             cmpld      cr1,r5,r4                               ; compare the vas
             cmpld      cr1,r5,r4                               ; compare the vas
-            bge--      cr0,mapSkipListPanic    ; die if keys are out of order
-            andi.      r0,r0,mpBlock+mpNest    ; is it a scalar mapping? (ie, of a single page)
+            bgt--      cr5,mapSkipListPanic    ; die if keys are out of order
+
             blt                cr1,mapSrchFull64d              ; key is less, try next list
             beq                cr1,mapSrchFull64Found  ; this is the correct mapping
             blt                cr1,mapSrchFull64d              ; key is less, try next list
             beq                cr1,mapSrchFull64Found  ; this is the correct mapping
-            bne--      cr0,mapSrchFull64e              ; handle block mapping or nested pmap
+            bne--      cr0,mapSrchFull64e              ; handle mapping larger than one page
 mapSrchFull64b:
             la         r8,mpList0(r3)                  ; point to skip list vector in this mapping
             mr         r9,r3                                   ; current becomes previous
             ldx                r3,r7,r8                                ; get ptr to next mapping in current list
 mapSrchFull64b:
             la         r8,mpList0(r3)                  ; point to skip list vector in this mapping
             mr         r9,r3                                   ; current becomes previous
             ldx                r3,r7,r8                                ; get ptr to next mapping in current list
-            mr         r10,r4                                  ; remember prev ptrs VA
+            addi       r10,r4,0x1000                   ; Get the lowest VA we can get next
 mapSrchFull64c:
             mr.                r3,r3                                   ; was there another mapping on current list?
             bne++      mapSrchFull64a                  ; was another, so loop
 mapSrchFull64c:
             mr.                r3,r3                                   ; was there another mapping on current list?
             bne++      mapSrchFull64a                  ; was another, so loop
@@ -410,14 +418,6 @@ mapSrchFull64d:
             ; the end of the block to see if key fits within it.
 
 mapSrchFull64e:            
             ; the end of the block to see if key fits within it.
 
 mapSrchFull64e:            
-            lhz                r11,mpBSize(r3)                 ; get #pages/#segments in block/submap mapping (if nonscalar)
-            cmpwi      r0,mpBlock                              ; distinguish between block mapping and nested pmaps
-            sldi       r0,r11,12                               ; assume block mapping, get size in bytes - 4k
-            beq                mapSrchFull64f                  ; we guessed right, it was a block mapping
-            addi       r11,r11,1                               ; mpBSize is 1 too low
-            sldi       r11,r11,28                              ; in a nested pmap, mpBSize is in units of segments
-            subi       r0,r11,4096                             ; get address of last page in submap
-mapSrchFull64f:
             add                r4,r4,r0                                ; r4 <- last page in this mapping
             cmpld      r5,r4                                   ; does this mapping cover our page?
             bgt                mapSrchFull64b                  ; no, try next mapping (r4 is advanced to end of range)
             add                r4,r4,r0                                ; r4 <- last page in this mapping
             cmpld      r5,r4                                   ; does this mapping cover our page?
             bgt                mapSrchFull64b                  ; no, try next mapping (r4 is advanced to end of range)
@@ -451,27 +451,36 @@ mapSrchFull64Found:                                                       ; WARNING: can drop down to here
             ;  r7 = current skip list number * 8
             ;  r8 = ptr to skip list vector of mapping pointed to by r9
             ;  r9 = prev ptr, ie highest mapping that comes before search target (initially the pmap)
             ;  r7 = current skip list number * 8
             ;  r8 = ptr to skip list vector of mapping pointed to by r9
             ;  r9 = prev ptr, ie highest mapping that comes before search target (initially the pmap)
-            ;  r10 = prev mappings va, or 0 if r9==pmap 
+            ;  r10 = lowest expected next va, 0 at the beginning of the search
             ;  r12 = ptr to the skipListPrev vector in the per-proc
             
             .align     4
 mapSrchFull32a:                                                                ; loop over each mapping
             ;  r12 = ptr to the skipListPrev vector in the per-proc
             
             .align     4
 mapSrchFull32a:                                                                ; loop over each mapping
-            lwz                r4,mpVAddr+4(r3)                ; get va for this mapping (plus flags in low 12 bits)
-            addi       r2,r2,1                                 ; count mappings visited
-            lwz                r0,mpFlags(r3)                  ; get mapping flag bits
-            cmplw      cr0,r10,r4                              ; make sure VAs come in strictly ascending order
-            rlwinm     r4,r4,0,0,19                    ; zero low 12 bits of mapping va
-            cmplw      cr1,r5,r4                               ; compare the vas
-            bge-       cr0,mapSkipListPanic    ; die if keys are out of order
-            andi.      r0,r0,mpBlock+mpNest    ; is it a scalar mapping? (ie, of a single page)
-            blt                cr1,mapSrchFull32d              ; key is less than this va, try next list
-            beq-       cr1,mapSrchFull32Found  ; this is the correct mapping
-            bne-       cr0,mapSrchFull32e              ; handle block mapping or nested pmap
+                       addi    r2,r2,1                                 ; count mappings visited
+                       lwz             r0,mpFlags(r3)                  ; get mapping flag bits
+                       lhz             r11,mpBSize(r3)                 ; get #pages/#segments in block/submap mapping
+                       lwz             r4,mpVAddr+4(r3)                ; get va for this mapping (plus flags in low 12 bits)
+                                               
+                       rlwinm  r0,r0,mpBSub+1,31,31    ; Rotate to get 0 if 4K bsu or 1 if 32MB bsu
+                       addi    r11,r11,1                               ; Convert 0-based to 1-based
+                       ori             r0,r0,0x3216                    ; OR in 0x00003216 (0x3200 and a base rotate of 22)
+                       rlwnm   r0,r0,r0,27,31                  ; Rotate to get 12 or 25
+                       slw             r11,r11,r0                              ; Get the length in bytes
+                       rlwinm  r4,r4,0,0,19                    ; zero low 12 bits of mapping va
+            addic.     r0,r11,-4096                    ; get offset last page in mapping (set cr0_eq if 1 page)
+
+                       cmplw   cr0,r10,r4                              ; make sure VAs come in strictly ascending order
+                       cmplw   cr1,r5,r4                               ; compare the vas
+                       bgt-    cr0,mapSkipListPanic    ; die if keys are out of order
+                       
+                       blt             cr1,mapSrchFull32d              ; key is less than this va, try next list
+                       beq             cr1,mapSrchFull32Found  ; this is the correct mapping
+                       bne-    cr0,mapSrchFull32e              ; handle mapping larger than one page
 mapSrchFull32b:
             la         r8,mpList0+4(r3)                ; point to skip list vector in this mapping
             mr         r9,r3                                   ; current becomes previous
             lwzx       r3,r7,r8                                ; get ptr to next mapping in current list
 mapSrchFull32b:
             la         r8,mpList0+4(r3)                ; point to skip list vector in this mapping
             mr         r9,r3                                   ; current becomes previous
             lwzx       r3,r7,r8                                ; get ptr to next mapping in current list
-            mr         r10,r4                                  ; remember prev ptrs VA
+            addi       r10,r4,0x1000                                   ; Get the lowest VA we can get next
 mapSrchFull32c:
             mr.                r3,r3                                   ; next becomes current
             bne+       mapSrchFull32a                  ; was another, so loop
 mapSrchFull32c:
             mr.                r3,r3                                   ; next becomes current
             bne+       mapSrchFull32a                  ; was another, so loop
@@ -492,14 +501,6 @@ mapSrchFull32d:
             ; the end of the block to see if our key fits within it.
 
 mapSrchFull32e:            
             ; the end of the block to see if our key fits within it.
 
 mapSrchFull32e:            
-            lhz                r11,mpBSize(r3)                 ; get #pages/#segments in block/submap mapping (if nonscalar)
-            cmpwi      r0,mpBlock                              ; distinguish between block mapping and nested pmaps
-            slwi       r0,r11,12                               ; assume block mapping, get size in bytes - 4k
-            beq                mapSrchFull32f                  ; we guessed right, it was a block mapping
-            addi       r11,r11,1                               ; mpBSize is 1 too low
-            slwi       r11,r11,28                              ; in a nested pmap, mpBSize is in units of segments
-            subi       r0,r11,4096                             ; get address of last page in submap
-mapSrchFull32f:
             add                r4,r4,r0                                ; r4 <- last page in this mapping
             cmplw      r5,r4                                   ; does this mapping cover our page?
             bgt                mapSrchFull32b                  ; no, try next mapping
             add                r4,r4,r0                                ; r4 <- last page in this mapping
             cmplw      r5,r4                                   ; does this mapping cover our page?
             bgt                mapSrchFull32b                  ; no, try next mapping
@@ -1066,20 +1067,17 @@ mapVer64a:
             ; Do some additional checks (so we only do them once per mapping.)
             ; First, if a block mapping or nested pmap, compute block end.
             
             ; Do some additional checks (so we only do them once per mapping.)
             ; First, if a block mapping or nested pmap, compute block end.
             
-            andi.      r29,r29,mpBlock+mpNest  ; is it block mapping or nested pmap?
-            subi       r21,r21,1                               ; count mappings in this pmap
-            beq++      mapVer64b                               ; not nested or pmap
-            lhz                r27,mpBSize(r26)                ; get #pages or #segments
-            cmpwi      r29,mpBlock                             ; which one is it?
-            sldi       r29,r27,12                              ; assume block mapping, units are (pages-1)
-            beq                mapVer64b                               ; guessed correctly
-            addi       r27,r27,1                               ; units of nested pmap are (#segs-1)
-            sldi       r29,r27,28                              ; convert to #bytes
-            subi       r29,r29,4096                    ; get offset to last byte in nested pmap
+                       lhz             r27,mpBSize(r26)                ; get #pages or #segments
+                       rlwinm  r29,r29,mpBSub+1,31,31  ; Rotate to get 0 if 4K bsu or 1 if 32MB bsu
+                       addi    r27,r27,1                               ; units of nested pmap are (#segs-1)
+                       ori             r29,r29,0x3216                  ; OR in 0x00003216 (0x3200 and a base rotate of 22)
+                       rlwnm   r29,r29,r29,27,31               ; Rotate to get 12 or 25
+                       subi    r21,r21,1                               ; count mappings in this pmap
+                       sld             r29,r27,r29                             ; Get the length in bytes
+                       subi    r29,r29,4096                    ; get offset to last byte in nested pmap
             
             ; Here with r29 = size of block - 4k, or 0 if mapping is a scalar page.
 
             
             ; Here with r29 = size of block - 4k, or 0 if mapping is a scalar page.
 
-mapVer64b:
             add                r24,r28,r29                             ; r24 <- address of last valid page in this mapping
             la         r28,mpList0(r26)                ; get base of this mappings vector            
             lwz                r27,mpFlags(r26)                ; Get the number of lists
             add                r24,r28,r29                             ; r24 <- address of last valid page in this mapping
             la         r28,mpList0(r26)                ; get base of this mappings vector            
             lwz                r27,mpFlags(r26)                ; Get the number of lists
@@ -1185,27 +1183,22 @@ mapVer32a:
             ; Do some additional checks (so we only do them once per mapping.)
             ; First, make sure upper words of the mpList vector are 0.
 
             ; Do some additional checks (so we only do them once per mapping.)
             ; First, make sure upper words of the mpList vector are 0.
 
-            subi       r21,r21,1                               ; count mappings in this pmap
+                       lhz             r27,mpBSize(r26)                ; get #blocks
+                       rlwinm  r29,r29,mpBSub+1,31,31  ; Rotate to get 0 if 4K bsu or 1 if 32MB bsu
+                       addi    r27,r27,1                               ; units of nested pmap are (#segs-1)
+                       ori             r29,r29,0x3216                  ; OR in 0x00003216 (0x3200 and a base rotate of 22)
+                       rlwnm   r29,r29,r29,27,31               ; Rotate to get 12 or 25
+                       subi    r21,r21,1                               ; count mappings in this pmap
+                       slw             r29,r27,r29                             ; Get the length in bytes
+                       subi    r29,r29,4096                    ; get offset to last byte in nested pmap
+
             lwz                r24,mpFlags(r26)                ; Get number of lists
             la         r30,mpList0(r26)                ; point to base of skiplist vector
                        andi.   r24,r24,mpLists                 ; Clean the number of lists
                        bl              mapVerUpperWordsAre0    ; make sure upper words are all 0 (uses r24 and r27)
             lwz                r24,mpFlags(r26)                ; Get number of lists
             la         r30,mpList0(r26)                ; point to base of skiplist vector
                        andi.   r24,r24,mpLists                 ; Clean the number of lists
                        bl              mapVerUpperWordsAre0    ; make sure upper words are all 0 (uses r24 and r27)
-            
-            ; Then, if a block mapping or nested pmap, compute block end.
-            
-            andi.      r29,r29,mpBlock+mpNest  ; is it block mapping or nested pmap?
-            beq+       mapVer32b                               ; no
-            lhz                r27,mpBSize(r26)                ; get #pages or #segments
-            cmpwi      r29,mpBlock                             ; which one is it?
-            slwi       r29,r27,12                              ; assume block mapping, units are pages
-            beq                mapVer32b                               ; guessed correctly
-            addi       r27,r27,1                               ; units of nested pmap are (#segs-1)
-            slwi       r29,r27,28                              ; convert to #bytes
-            subi       r29,r29,4096                    ; get offset to last byte in nested pmap
-            
+                        
             ; Here with r29 = size of block - 4k, or 0 if mapping is a scalar page.
 
             ; Here with r29 = size of block - 4k, or 0 if mapping is a scalar page.
 
-mapVer32b:
             add                r24,r28,r29                             ; r24 <- address of last valid page in this mapping
             la         r28,mpList0+4(r26)              ; get base of this mappings vector            
             lwz                r27,mpFlags(r26)                ; Get the number of lists
             add                r24,r28,r29                             ; r24 <- address of last valid page in this mapping
             la         r28,mpList0+4(r26)              ; get base of this mappings vector            
             lwz                r27,mpFlags(r26)                ; Get the number of lists
mirror of XNU