osfmk/ppc/AltiAssist.s

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 /*
  24         AltiAssist.s
  25
  26         Do the VMX assists
  27
  28         Lovingly crafted by Bill Angell using traditional methods and only natural or recycled materials.
  29         No animal products are used other than rendered otter bile and deep fried pork lard.
  30
  31 */
  32
  33 #include <ppc/asm.h>
  34 #include <ppc/proc_reg.h>
  35 #include <ppc/exception.h>
  36 #include <mach/machine/vm_param.h>
  37 #include <assym.s>
  38
  39 ;
  40 ;
  41 ;                       General stuff what happens here:
  42 ;                               1)      All general context saved, interrupts off, translation off
  43 ;                               2)      Vector and floating point disabled, but there may be live context.
  44 ;                                       This code is responsible for saving and restoring what is used. This
  45 ;                                       includes exception states, java mode, etc.
  46 ;                               3)      No attempt is made to resolve page faults.  PTE misses are handled
  47 ;                                       automatically, but actual faults (ala copyin/copyout) are not. If
  48 ;                                       a fault does occur, the exception that caused entry to the emulation
  49 ;                                       routine is remapped to either an instruction or data miss (depending
  50 ;                                       upon the stage detected) and redriven through the exception handler.
  51 ;                                       The only time that an instruction fault can happen is when a different
  52 ;                                       processor removes a mapping between our original fault and when we
  53 ;                                       fetch the assisted instruction. For an assisted instruction, data
  54 ;                                       faults should not occur (except in the MP case).  For a purely
  55 ;                                       emulated instruction, faults can occur.
  56 ;
  57 ;                       Emulation algorithms cloned from MacOS 9 code.
  58 ;
  59 ;                       Assumes that R2 = per_proc_area
  60 ;
  61 ;
  62
  63
  64                         .align  5
  65                         .globl  EXT(AltivecAssist)
  66
  67 LEXT(AltivecAssist)
  68
  69                         li                      r10,emvr0                                       ; Point to the vector savearea
  70
  71                         li                      r11,emvr1                                       ; Another savearea
  72                         stvxl           v0,r10,r2                                       ; Save V0
  73                         stvxl           v1,r11,r2                                       ; Save V1
  74                         vspltisw        v0,1                                            ; Set a 1 in V0
  75                         vspltisw        v1,8                                            ; Get half of the shift
  76                         vslw            v0,v0,v1                                        ; Shift half way
  77                         vslw            v0,v0,v1                                        ; Shift the rest of the way (we now have 0x00010000)
  78                         mfvscr          v1                                                      ; Get the VSCR
  79                         vor                     v1,v1,v0                                        ; Turn off Java mode
  80                         lvxl            v0,r10,r2                                       ; Restore V0
  81                         mtvscr          v1                                                      ; Set Java mode off
  82                         lvxl            v1,r11,r2                                       ; Restore V1
  83
  84                         li                      r11,T_IN_VAIN                           ; We are all done
  85                         b                       EXT(EmulExit)                           ; We are done, no tracing on...
  86
  87
  88
  89