osfmk/i386/io_emulate.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /*
  31  * @OSF_COPYRIGHT@
  32  */
  33 /*
  34  * Mach Operating System
  35  * Copyright (c) 1991,1990 Carnegie Mellon University
  36  * All Rights Reserved.
  37  *
  38  * Permission to use, copy, modify and distribute this software and its
  39  * documentation is hereby granted, provided that both the copyright
  40  * notice and this permission notice appear in all copies of the
  41  * software, derivative works or modified versions, and any portions
  42  * thereof, and that both notices appear in supporting documentation.
  43  *
  44  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  45  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  46  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  47  *
  48  * Carnegie Mellon requests users of this software to return to
  49  *
  50  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  51  *  School of Computer Science
  52  *  Carnegie Mellon University
  53  *  Pittsburgh PA 15213-3890
  54  *
  55  * any improvements or extensions that they make and grant Carnegie Mellon
  56  * the rights to redistribute these changes.
  57  */
  58 /*
  59  */
  60
  61 #include <platforms.h>
  62 #include <mach/boolean.h>
  63 #include <mach/port.h>
  64 #include <kern/thread.h>
  65 #include <kern/task.h>
  66
  67 #include <ipc/ipc_port.h>
  68 #include <ipc/ipc_space.h>
  69 #include <ipc/ipc_right.h>
  70 #include <ipc/ipc_object.h>
  71 #include <ipc/ipc_entry.h>
  72
  73 #include <i386/thread.h>
  74 #include <i386/io_port.h>
  75 #include <i386/io_emulate.h>
  76 #include <i386/iopb_entries.h>
  77
  78 #if 1
  79 int
  80 emulate_io(
  81         __unused x86_saved_state32_t            *regs,
  82         __unused int                            opcode,
  83         __unused int                            io_port)
  84 {
  85         /* At the moment, we are not allowing I/O emulation
  86          *
  87          * FIXME - this should probably change due to
  88          * the Window Server's need to map I/O ports into its space.
  89          */
  90
  91         return EM_IO_ERROR;
  92 }
  93 #else
  94 int
  95 emulate_io(
  96         struct i386_saved_state *regs,
  97         int                     opcode,
  98         int                     io_port)
  99 {
 100         thread_t        thread = current_thread();
 101         at386_io_lock_state();
 102
 103         if (iopl_emulate(regs, opcode, io_port))
 104             return EM_IO_DONE;
 105
 106         if (iopb_check_mapping(thread, iopl_device))
 107             return EM_IO_ERROR;
 108
 109         /*
 110          *      Check for send rights to the IOPL device port.
 111          */
 112         if (iopl_device_port == IP_NULL)
 113             return EM_IO_ERROR;
 114         {
 115             ipc_space_t space = current_space();
 116             mach_port_name_t    name;
 117             ipc_entry_t entry;
 118             boolean_t   has_rights = FALSE;
 119             ipc_entry_bits_t *capability;
 120
 121             is_write_lock(space);
 122             assert(space->is_active);
 123
 124             if (ipc_right_reverse(space, (ipc_object_t) iopl_device_port,
 125                                   &name, &entry, &capability)) {
 126                 /* iopl_device_port is locked and active */
 127                 if (capability[space->server_id] & MACH_PORT_TYPE_SEND)
 128                     has_rights = TRUE;
 129                 ip_unlock(iopl_device_port);
 130             }
 131
 132             is_write_unlock(space);
 133             if (!has_rights) {
 134                 return EM_IO_ERROR;
 135             }
 136         }
 137
 138         /*
 139          * Map the IOPL port set into the thread.
 140          */
 141
 142         if (i386_io_port_add(thread, iopl_device)
 143             != KERN_SUCCESS)
 144                 return EM_IO_ERROR;
 145
 146         /*
 147          * Make the thread use its IO_TSS to get the IO permissions;
 148          * it may not have had one before this.
 149          */
 150         act_machine_switch_pcb(thread);
 151
 152         return EM_IO_RETRY;
 153 }
 154 #endif