1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116

// SPDX-License-Identifier: Apache-2.0 OR MIT
//
// Copyright (c) 2018-2022 by the author(s)
//
// Author(s):
//   - Jorge Aparicio
//   - Andre Richter <andre.o.richter@gmail.com>

//! Wrappers around ARMv8-A instructions.

pub mod barrier;

#[cfg(feature = "nightly")]
pub mod random;

/// The classic no-op
#[inline(always)]
pub fn nop() {
    #[cfg(target_arch = "aarch64")]
    unsafe {
        core::arch::asm!("nop", options(nomem, nostack))
    }

    #[cfg(not(target_arch = "aarch64"))]
    unimplemented!()
}

/// Wait For Interrupt
///
/// For more details on wfi, refer to [here](http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0802a/CIHEGBBF.html).
#[inline(always)]
pub fn wfi() {
    #[cfg(target_arch = "aarch64")]
    unsafe {
        core::arch::asm!("wfi", options(nomem, nostack))
    }

    #[cfg(not(target_arch = "aarch64"))]
    unimplemented!()
}

/// Wait For Event
///
/// For more details of wfe - sev pair, refer to [here](http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0802a/CIHEGBBF.html).
#[inline(always)]
pub fn wfe() {
    #[cfg(target_arch = "aarch64")]
    unsafe {
        core::arch::asm!("wfe", options(nomem, nostack))
    }

    #[cfg(not(target_arch = "aarch64"))]
    unimplemented!()
}

/// Send EVent.Locally
///
/// SEV causes an event to be signaled to the local core within a multiprocessor system.
///
/// For more details of wfe - sev/sevl pair, refer to [here](http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0802a/CIHEGBBF.html).
#[inline(always)]
pub fn sevl() {
    #[cfg(target_arch = "aarch64")]
    unsafe {
        core::arch::asm!("sevl", options(nomem, nostack))
    }

    #[cfg(not(target_arch = "aarch64"))]
    unimplemented!()
}

/// Send EVent.
///
/// SEV causes an event to be signaled to all cores within a multiprocessor system.
///
/// For more details of wfe - sev pair, refer to [here](http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0802a/CIHEGBBF.html).
#[inline(always)]
pub fn sev() {
    #[cfg(target_arch = "aarch64")]
    unsafe {
        core::arch::asm!("sev", options(nomem, nostack))
    }

    #[cfg(not(target_arch = "aarch64"))]
    unimplemented!()
}

/// Exception return
///
/// Will jump to wherever the corresponding link register points to, and therefore never return.
#[inline(always)]
pub fn eret() -> ! {
    #[cfg(target_arch = "aarch64")]
    unsafe {
        core::arch::asm!("eret", options(nomem, nostack));
        core::hint::unreachable_unchecked()
    }

    #[cfg(not(target_arch = "aarch64"))]
    unimplemented!()
}

/// Function return
///
/// Will jump to wherever the corresponding link register points to, and therefore never return.
#[inline(always)]
pub fn ret() -> ! {
    #[cfg(target_arch = "aarch64")]
    unsafe {
        core::arch::asm!("ret", options(nomem, nostack));
        core::hint::unreachable_unchecked()
    }

    #[cfg(not(target_arch = "aarch64"))]
    unimplemented!()
}