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1 /*

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

31 #ifdef PRIVATE

33 #define _COMM_PAGE32_SIGNATURE_STRING "commpage 32-bit"

34 #define _COMM_PAGE64_SIGNATURE_STRING "commpage 64-bit"

36 typedef volatile struct commpage_timeofday_data {

37 uint64_t TimeStamp_tick;

38 uint64_t TimeStamp_sec;

39 uint64_t TimeStamp_frac;

40 uint64_t Ticks_scale;

41 uint64_t Ticks_per_sec;

42 } new_commpage_timeofday_data_t;

44 /*!

45 * @macro COMM_PAGE_SLOT_TYPE

46 *

47 * @brief

48 * Macro that expands to the proper type for a pointer to a commpage slot,

49 * to be used in a local variable declaration.

50 *

51 * @description

52 * Usage is something like:

53 * <code>

54 * COMM_PAGE_SLOT_TYPE(uint64_t) slot = COMM_PAGE_SLOT(uint64_t, FOO);

55 * </code>

56 *

57 * @param type The scalar base type for the slot.

58 */

59 #if __has_feature(address_sanitizer)

60 #define COMM_PAGE_SLOT_TYPE(type_t) type_t __attribute__((address_space(1))) volatile *

61 #else

62 #define COMM_PAGE_SLOT_TYPE(type_t) type_t volatile *

63 #endif

65 /*!

66 * @macro COMM_PAGE_SLOT

67 *

68 * @brief

69 * Macro that expands to the properly typed address for a commpage slot.

70 *

71 * @param type The scalar base type for the slot.

72 * @param name The slot name, without its @c _COMM_PAGE_ prefix.

73 */

74 #define COMM_PAGE_SLOT(type_t, name) ((COMM_PAGE_SLOT_TYPE(type_t))_COMM_PAGE_##name)

76 /*!

77 * @macro COMM_PAGE_READ

78 *

79 * @brief

80 * Performs a single read from the commpage in a way that doesn't trip

81 * address sanitizers.

82 *

83 * @description

84 * Typical use looks like this:

85 * <code>

86 * uint64_t foo_value = COMM_PAGE_READ(uint64_t, FOO);

87 * </code>

88 *

89 * @param type The scalar base type for the slot.

90 * @param name The slot name, without its @c _COMM_PAGE_ prefix.

91 */

92 #define COMM_PAGE_READ(type_t, slot) (*(COMM_PAGE_SLOT(type_t, slot)))

94 #endif

96 #endif