1/*
2 * Copyright (c) 2017 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#ifndef _COMMPAGE_H
29#define _COMMPAGE_H
30
31#ifdef PRIVATE
32
33#include <stdint.h>
34
35#define _COMM_PAGE32_SIGNATURE_STRING "commpage 32-bit"
36#define _COMM_PAGE64_SIGNATURE_STRING "commpage 64-bit"
37
38typedef volatile struct commpage_timeofday_data {
39 uint64_t TimeStamp_tick;
40 uint64_t TimeStamp_sec;
41 uint64_t TimeStamp_frac;
42 uint64_t Ticks_scale;
43 uint64_t Ticks_per_sec;
44} new_commpage_timeofday_data_t;
45
46/*!
47 * @macro COMM_PAGE_SLOT_TYPE
48 *
49 * @brief
50 * Macro that expands to the proper type for a pointer to a commpage slot,
51 * to be used in a local variable declaration.
52 *
53 * @description
54 * Usage is something like:
55 * <code>
56 * COMM_PAGE_SLOT_TYPE(uint64_t) slot = COMM_PAGE_SLOT(uint64_t, FOO);
57 * </code>
58 *
59 * @param type The scalar base type for the slot.
60 */
61#if __has_feature(address_sanitizer)
62#define COMM_PAGE_SLOT_TYPE(type_t) type_t __attribute__((address_space(1))) volatile *
63#else
64#define COMM_PAGE_SLOT_TYPE(type_t) type_t volatile *
65#endif
66
67/*!
68 * @macro COMM_PAGE_SLOT
69 *
70 * @brief
71 * Macro that expands to the properly typed address for a commpage slot.
72 *
73 * @param type The scalar base type for the slot.
74 * @param name The slot name, without its @c _COMM_PAGE_ prefix.
75 */
76#define COMM_PAGE_SLOT(type_t, name) ((COMM_PAGE_SLOT_TYPE(type_t))_COMM_PAGE_##name)
77
78/*!
79 * @macro COMM_PAGE_READ
80 *
81 * @brief
82 * Performs a single read from the commpage in a way that doesn't trip
83 * address sanitizers.
84 *
85 * @description
86 * Typical use looks like this:
87 * <code>
88 * uint64_t foo_value = COMM_PAGE_READ(uint64_t, FOO);
89 * </code>
90 *
91 * @param type The scalar base type for the slot.
92 * @param name The slot name, without its @c _COMM_PAGE_ prefix.
93 */
94#define COMM_PAGE_READ(type_t, slot) (*(COMM_PAGE_SLOT(type_t, slot)))
95
96#endif
97
98#endif
99