osfmk/i386/io_emulate.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50 /*
  51  */
  52
  53 #include <platforms.h>
  54 #include <mach/boolean.h>
  55 #include <mach/port.h>
  56 #include <kern/thread.h>
  57 #include <kern/task.h>
  58
  59 #include <ipc/ipc_port.h>
  60 #include <ipc/ipc_space.h>
  61 #include <ipc/ipc_right.h>
  62 #include <ipc/ipc_object.h>
  63 #include <ipc/ipc_entry.h>
  64
  65 #include <i386/thread.h>
  66 #include <i386/io_port.h>
  67 #include <i386/io_emulate.h>
  68 #include <i386/iopb_entries.h>
  69
  70 #if 1
  71 int
  72 emulate_io(
  73         __unused struct i386_saved_state        *regs,
  74         __unused int                            opcode,
  75         __unused int                            io_port)
  76 {
  77         /* At the moment, we are not allowing I/O emulation
  78          *
  79          * FIXME - this should probably change due to
  80          * the Window Server's need to map I/O ports into its space.
  81          */
  82
  83         return EM_IO_ERROR;
  84 }
  85 #else
  86 int
  87 emulate_io(
  88         struct i386_saved_state *regs,
  89         int                     opcode,
  90         int                     io_port)
  91 {
  92         thread_t        thread = current_thread();
  93         at386_io_lock_state();
  94
  95         if (iopl_emulate(regs, opcode, io_port))
  96             return EM_IO_DONE;
  97
  98         if (iopb_check_mapping(thread, iopl_device))
  99             return EM_IO_ERROR;
 100
 101         /*
 102          *      Check for send rights to the IOPL device port.
 103          */
 104         if (iopl_device_port == IP_NULL)
 105             return EM_IO_ERROR;
 106         {
 107             ipc_space_t space = current_space();
 108             mach_port_name_t    name;
 109             ipc_entry_t entry;
 110             boolean_t   has_rights = FALSE;
 111             ipc_entry_bits_t *capability;
 112
 113             is_write_lock(space);
 114             assert(space->is_active);
 115
 116             if (ipc_right_reverse(space, (ipc_object_t) iopl_device_port,
 117                                   &name, &entry, &capability)) {
 118                 /* iopl_device_port is locked and active */
 119                 if (capability[space->server_id] & MACH_PORT_TYPE_SEND)
 120                     has_rights = TRUE;
 121                 ip_unlock(iopl_device_port);
 122             }
 123
 124             is_write_unlock(space);
 125             if (!has_rights) {
 126                 return EM_IO_ERROR;
 127             }
 128         }
 129
 130         /*
 131          * Map the IOPL port set into the thread.
 132          */
 133
 134         if (i386_io_port_add(thread, iopl_device)
 135             != KERN_SUCCESS)
 136                 return EM_IO_ERROR;
 137
 138         /*
 139          * Make the thread use its IO_TSS to get the IO permissions;
 140          * it may not have had one before this.
 141          */
 142         act_machine_switch_pcb(thread);
 143
 144         return EM_IO_RETRY;
 145 }
 146 #endif