osfmk/i386/io_emulate.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * @OSF_COPYRIGHT@
  27  */
  28 /*
  29  * Mach Operating System
  30  * Copyright (c) 1991,1990 Carnegie Mellon University
  31  * All Rights Reserved.
  32  *
  33  * Permission to use, copy, modify and distribute this software and its
  34  * documentation is hereby granted, provided that both the copyright
  35  * notice and this permission notice appear in all copies of the
  36  * software, derivative works or modified versions, and any portions
  37  * thereof, and that both notices appear in supporting documentation.
  38  *
  39  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  40  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  41  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  42  *
  43  * Carnegie Mellon requests users of this software to return to
  44  *
  45  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  46  *  School of Computer Science
  47  *  Carnegie Mellon University
  48  *  Pittsburgh PA 15213-3890
  49  *
  50  * any improvements or extensions that they make and grant Carnegie Mellon
  51  * the rights to redistribute these changes.
  52  */
  53 /*
  54  */
  55
  56 #include <platforms.h>
  57 #include <cpus.h>
  58 #include <mach/boolean.h>
  59 #include <mach/port.h>
  60 #include <kern/thread.h>
  61 #include <kern/task.h>
  62
  63 #include <ipc/ipc_port.h>
  64 #include <ipc/ipc_space.h>
  65 #include <ipc/ipc_right.h>
  66 #include <ipc/ipc_object.h>
  67 #include <ipc/ipc_entry.h>
  68
  69 #include <i386/thread.h>
  70 #include <i386/io_port.h>
  71 #include <i386/io_emulate.h>
  72 #include <i386/iopb_entries.h>
  73
  74 int
  75 emulate_io(
  76         struct i386_saved_state *regs,
  77         int                     opcode,
  78         int                     io_port)
  79 {
  80 #if 1
  81         /* At the moment, we are not allowing I/O emulation
  82          *
  83          * FIXME - this should probably change due to
  84          * the Window Server's need to map I/O ports into its space.
  85          */
  86
  87         return EM_IO_ERROR;
  88 #else
  89         thread_t        thread = current_thread();
  90         at386_io_lock_state();
  91
  92         if (iopl_emulate(regs, opcode, io_port))
  93             return EM_IO_DONE;
  94
  95         if (iopb_check_mapping(thread, iopl_device))
  96             return EM_IO_ERROR;
  97
  98         /*
  99          *      Check for send rights to the IOPL device port.
 100          */
 101         if (iopl_device_port == IP_NULL)
 102             return EM_IO_ERROR;
 103         {
 104             ipc_space_t space = current_space();
 105             mach_port_name_t    name;
 106             ipc_entry_t entry;
 107             boolean_t   has_rights = FALSE;
 108             ipc_entry_bits_t *capability;
 109
 110             is_write_lock(space);
 111             assert(space->is_active);
 112
 113             if (ipc_right_reverse(space, (ipc_object_t) iopl_device_port,
 114                                   &name, &entry, &capability)) {
 115                 /* iopl_device_port is locked and active */
 116                 if (capability[space->server_id] & MACH_PORT_TYPE_SEND)
 117                     has_rights = TRUE;
 118                 ip_unlock(iopl_device_port);
 119             }
 120
 121             is_write_unlock(space);
 122             if (!has_rights) {
 123                 return EM_IO_ERROR;
 124             }
 125         }
 126
 127         /*
 128          * Map the IOPL port set into the thread.
 129          */
 130
 131         if (i386_io_port_add(thread, iopl_device)
 132             != KERN_SUCCESS)
 133                 return EM_IO_ERROR;
 134
 135         /*
 136          * Make the thread use its IO_TSS to get the IO permissions;
 137          * it may not have had one before this.
 138          */
 139         act_machine_switch_pcb(thread->top_act);
 140
 141         return EM_IO_RETRY;
 142 #endif
 143 }