osfmk/atm/atm.c

   1 /*
   2  * Copyright (c) 2012-2013 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,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include <atm/atm_internal.h>
  30 #include <machine/commpage.h>
  31 #include <pexpert/pexpert.h>
  32
  33 /*
  34  * Global that is set by diagnosticd and readable by userspace
  35  * via the commpage.
  36  */
  37 static uint32_t atm_diagnostic_config;
  38 static bool disable_atm;
  39
  40 /*
  41  * Routine: atm_init
  42  * Purpose: Initialize the atm subsystem.
  43  * Returns: None.
  44  */
  45 void
  46 atm_init(void)
  47 {
  48         char temp_buf[20];
  49
  50         /* Disable atm if disable_atm present in device-tree properties or in boot-args */
  51         if ((PE_get_default("kern.disable_atm", temp_buf, sizeof(temp_buf))) ||
  52             (PE_parse_boot_argn("-disable_atm", temp_buf, sizeof(temp_buf)))) {
  53                 disable_atm = true;
  54         }
  55
  56         if (!PE_parse_boot_argn("atm_diagnostic_config", &atm_diagnostic_config, sizeof(atm_diagnostic_config))) {
  57                 if (!PE_get_default("kern.atm_diagnostic_config", &atm_diagnostic_config, sizeof(atm_diagnostic_config))) {
  58                         atm_diagnostic_config = 0;
  59                 }
  60         }
  61
  62         kprintf("ATM subsystem is initialized\n");
  63 }
  64
  65 /*
  66  * Routine: atm_reset
  67  * Purpose: re-initialize the atm subsystem (e.g. for userspace reboot)
  68  * Returns: None.
  69  */
  70 void
  71 atm_reset(void)
  72 {
  73         atm_init();
  74         commpage_update_atm_diagnostic_config(atm_diagnostic_config);
  75 }
  76
  77 /*
  78  * Routine: atm_set_diagnostic_config
  79  * Purpose: Set global atm_diagnostic_config and update the commpage to reflect
  80  *          the new value.
  81  * Returns: Error if ATM is disabled.
  82  */
  83 kern_return_t
  84 atm_set_diagnostic_config(uint32_t diagnostic_config)
  85 {
  86         if (disable_atm) {
  87                 return KERN_NOT_SUPPORTED;
  88         }
  89
  90         atm_diagnostic_config = diagnostic_config;
  91         commpage_update_atm_diagnostic_config(atm_diagnostic_config);
  92
  93         return KERN_SUCCESS;
  94 }
  95
  96 /*
  97  * Routine: atm_get_diagnostic_config
  98  * Purpose: Get global atm_diagnostic_config.
  99  * Returns: Diagnostic value
 100  */
 101 uint32_t
 102 atm_get_diagnostic_config(void)
 103 {
 104         return atm_diagnostic_config;
 105 }