xref: /xnu-11215.1.10/osfmk/atm/atm.c (revision 8d741a5de7ff4191bf97d57b9f54c2f6d4a15585)
1 /*
2  * Copyright (c) 2012-2024 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,
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23  * Please see the License for the specific language governing rights and
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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 #if CONFIG_EXCLAVES
34 extern kern_return_t exclaves_oslog_set_trace_mode(uint32_t);
35 #endif // CONFIG_EXCLAVES
36 
37 /*
38  * Global that is set by diagnosticd and readable by userspace
39  * via the commpage.
40  */
41 static uint32_t atm_diagnostic_config;
42 static bool disable_atm;
43 
44 /*
45  * Routine: atm_init
46  * Purpose: Initialize the atm subsystem.
47  * Returns: None.
48  */
49 void
atm_init(void)50 atm_init(void)
51 {
52 	char temp_buf[20];
53 
54 	/* Disable atm if disable_atm present in device-tree properties or in boot-args */
55 	if ((PE_get_default("kern.disable_atm", temp_buf, sizeof(temp_buf))) ||
56 	    (PE_parse_boot_argn("-disable_atm", temp_buf, sizeof(temp_buf)))) {
57 		disable_atm = true;
58 	}
59 
60 	if (!PE_parse_boot_argn("atm_diagnostic_config", &atm_diagnostic_config, sizeof(atm_diagnostic_config))) {
61 		if (!PE_get_default("kern.atm_diagnostic_config", &atm_diagnostic_config, sizeof(atm_diagnostic_config))) {
62 			atm_diagnostic_config = 0;
63 		}
64 	}
65 
66 	kprintf("ATM subsystem is initialized\n");
67 }
68 
69 /*
70  * Routine: atm_reset
71  * Purpose: re-initialize the atm subsystem (e.g. for userspace reboot)
72  * Returns: None.
73  */
74 void
atm_reset(void)75 atm_reset(void)
76 {
77 	atm_init();
78 	commpage_update_atm_diagnostic_config(atm_diagnostic_config);
79 #if CONFIG_EXCLAVES
80 	exclaves_oslog_set_trace_mode(atm_diagnostic_config);
81 #endif // CONFIG_EXCLAVES
82 }
83 
84 /*
85  * Routine: atm_set_diagnostic_config
86  * Purpose: Set global atm_diagnostic_config and update the commpage to reflect
87  *          the new value.
88  * Returns: Error if ATM is disabled.
89  */
90 kern_return_t
atm_set_diagnostic_config(uint32_t diagnostic_config)91 atm_set_diagnostic_config(uint32_t diagnostic_config)
92 {
93 	if (disable_atm) {
94 		return KERN_NOT_SUPPORTED;
95 	}
96 
97 	atm_diagnostic_config = diagnostic_config;
98 	commpage_update_atm_diagnostic_config(atm_diagnostic_config);
99 #if CONFIG_EXCLAVES
100 	return exclaves_oslog_set_trace_mode(diagnostic_config);
101 #else
102 	return KERN_SUCCESS;
103 #endif // CONFIG_EXCLAVES
104 }
105 
106 /*
107  * Routine: atm_get_diagnostic_config
108  * Purpose: Get global atm_diagnostic_config.
109  * Returns: Diagnostic value
110  */
111 uint32_t
atm_get_diagnostic_config(void)112 atm_get_diagnostic_config(void)
113 {
114 	return atm_diagnostic_config;
115 }
116