osfmk/i386/io_emulate.c

   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  * @OSF_COPYRIGHT@
  25  */
  26 /*
  27  * Mach Operating System
  28  * Copyright (c) 1991,1990 Carnegie Mellon University
  29  * All Rights Reserved.
  30  *
  31  * Permission to use, copy, modify and distribute this software and its
  32  * documentation is hereby granted, provided that both the copyright
  33  * notice and this permission notice appear in all copies of the
  34  * software, derivative works or modified versions, and any portions
  35  * thereof, and that both notices appear in supporting documentation.
  36  *
  37  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  38  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  39  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  40  *
  41  * Carnegie Mellon requests users of this software to return to
  42  *
  43  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  44  *  School of Computer Science
  45  *  Carnegie Mellon University
  46  *  Pittsburgh PA 15213-3890
  47  *
  48  * any improvements or extensions that they make and grant Carnegie Mellon
  49  * the rights to redistribute these changes.
  50  */
  51 /*
  52  */
  53
  54 #include <platforms.h>
  55 #include <mach/boolean.h>
  56 #include <mach/port.h>
  57 #include <kern/thread.h>
  58 #include <kern/task.h>
  59
  60 #include <ipc/ipc_port.h>
  61 #include <ipc/ipc_space.h>
  62 #include <ipc/ipc_right.h>
  63 #include <ipc/ipc_object.h>
  64 #include <ipc/ipc_entry.h>
  65
  66 #include <i386/thread.h>
  67 #include <i386/io_port.h>
  68 #include <i386/io_emulate.h>
  69 #include <i386/iopb_entries.h>
  70
  71 #if 1
  72 int
  73 emulate_io(
  74         __unused struct i386_saved_state        *regs,
  75         __unused int                            opcode,
  76         __unused int                            io_port)
  77 {
  78         /* At the moment, we are not allowing I/O emulation
  79          *
  80          * FIXME - this should probably change due to
  81          * the Window Server's need to map I/O ports into its space.
  82          */
  83
  84         return EM_IO_ERROR;
  85 }
  86 #else
  87 int
  88 emulate_io(
  89         struct i386_saved_state *regs,
  90         int                     opcode,
  91         int                     io_port)
  92 {
  93         thread_t        thread = current_thread();
  94         at386_io_lock_state();
  95
  96         if (iopl_emulate(regs, opcode, io_port))
  97             return EM_IO_DONE;
  98
  99         if (iopb_check_mapping(thread, iopl_device))
 100             return EM_IO_ERROR;
 101
 102         /*
 103          *      Check for send rights to the IOPL device port.
 104          */
 105         if (iopl_device_port == IP_NULL)
 106             return EM_IO_ERROR;
 107         {
 108             ipc_space_t space = current_space();
 109             mach_port_name_t    name;
 110             ipc_entry_t entry;
 111             boolean_t   has_rights = FALSE;
 112             ipc_entry_bits_t *capability;
 113
 114             is_write_lock(space);
 115             assert(space->is_active);
 116
 117             if (ipc_right_reverse(space, (ipc_object_t) iopl_device_port,
 118                                   &name, &entry, &capability)) {
 119                 /* iopl_device_port is locked and active */
 120                 if (capability[space->server_id] & MACH_PORT_TYPE_SEND)
 121                     has_rights = TRUE;
 122                 ip_unlock(iopl_device_port);
 123             }
 124
 125             is_write_unlock(space);
 126             if (!has_rights) {
 127                 return EM_IO_ERROR;
 128             }
 129         }
 130
 131         /*
 132          * Map the IOPL port set into the thread.
 133          */
 134
 135         if (i386_io_port_add(thread, iopl_device)
 136             != KERN_SUCCESS)
 137                 return EM_IO_ERROR;
 138
 139         /*
 140          * Make the thread use its IO_TSS to get the IO permissions;
 141          * it may not have had one before this.
 142          */
 143         act_machine_switch_pcb(thread);
 144
 145         return EM_IO_RETRY;
 146 }
 147 #endif