osfmk/ppc/AltiAssist.s

   1 /*
   2  * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_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. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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  23  * Please see the License for the specific language governing rights and
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  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29         AltiAssist.s
  30
  31         Do the VMX assists
  32
  33         Lovingly crafted by Bill Angell using traditional methods and only natural or recycled materials.
  34         No animal products are used other than rendered otter bile and deep fried pork lard.
  35
  36 */
  37
  38 #include <ppc/asm.h>
  39 #include <ppc/proc_reg.h>
  40 #include <ppc/exception.h>
  41 #include <mach/machine/vm_param.h>
  42 #include <assym.s>
  43
  44 ;
  45 ;
  46 ;                       General stuff what happens here:
  47 ;                               1)      All general context saved, interrupts off, translation off
  48 ;                               2)      Vector and floating point disabled, but there may be live context.
  49 ;                                       This code is responsible for saving and restoring what is used. This
  50 ;                                       includes exception states, java mode, etc.
  51 ;                               3)      No attempt is made to resolve page faults.  PTE misses are handled
  52 ;                                       automatically, but actual faults (ala copyin/copyout) are not. If
  53 ;                                       a fault does occur, the exception that caused entry to the emulation
  54 ;                                       routine is remapped to either an instruction or data miss (depending
  55 ;                                       upon the stage detected) and redriven through the exception handler.
  56 ;                                       The only time that an instruction fault can happen is when a different
  57 ;                                       processor removes a mapping between our original fault and when we
  58 ;                                       fetch the assisted instruction. For an assisted instruction, data
  59 ;                                       faults should not occur (except in the MP case).  For a purely
  60 ;                                       emulated instruction, faults can occur.
  61 ;
  62 ;                       Emulation algorithms cloned from MacOS 9 code.
  63 ;
  64 ;                       Assumes that R2 = per_proc_area
  65 ;
  66 ;
  67
  68
  69                         .align  5
  70                         .globl  EXT(AltivecAssist)
  71
  72 LEXT(AltivecAssist)
  73
  74                         li                      r10,emvr0                                       ; Point to the vector savearea
  75
  76                         li                      r11,emvr1                                       ; Another savearea
  77                         stvxl           v0,r10,r2                                       ; Save V0
  78                         stvxl           v1,r11,r2                                       ; Save V1
  79                         vspltisw        v0,1                                            ; Set a 1 in V0
  80                         vspltisw        v1,8                                            ; Get half of the shift
  81                         vslw            v0,v0,v1                                        ; Shift half way
  82                         vslw            v0,v0,v1                                        ; Shift the rest of the way (we now have 0x00010000)
  83                         mfvscr          v1                                                      ; Get the VSCR
  84                         vor                     v1,v1,v0                                        ; Turn off Java mode
  85                         lvxl            v0,r10,r2                                       ; Restore V0
  86                         mtvscr          v1                                                      ; Set Java mode off
  87                         lvxl            v1,r11,r2                                       ; Restore V1
  88
  89                         li                      r11,T_IN_VAIN                           ; We are all done
  90                         b                       EXT(EmulExit)                           ; We are done, no tracing on...
  91