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
117
118
119
120
121
122
123
124
125
126
127
128
129
130
use proc_macro2::TokenStream;
use quote::{quote, ToTokens};
use syn::{Ident, Type};

use crate::cls_offset_expr;

pub(crate) fn int_functions(ty: &Type, name: &Ident) -> Option<TokenStream> {
    let ((x86_64_asm_width, x86_64_reg_class), (aarch64_reg_modifier, aarch64_instr_width)) =
        match ty.to_token_stream().to_string().as_ref() {
            "u8" => (("byte", quote! { reg_byte }), (":w", "b")),
            "u16" => (("word", quote! { reg }), (":w", "w")),
            "u32" => (("dword", quote! { reg }), (":w", "")),
            "u64" => (("qword", quote! { reg }), ("", "")),
            _ => {
                return None;
            }
        };
    let x86_64_width_modifier = format!("{x86_64_asm_width} ptr ");
    let offset_expr = cls_offset_expr(name);

    Some(quote! {
        #[inline]
        pub fn load(&self) -> #ty {
            let offset = #offset_expr;
            #[cfg(target_arch = "x86_64")]
            {
                let ret;
                unsafe {
                    ::core::arch::asm!(
                        ::core::concat!("mov {ret}, gs:[{offset}]"),
                        ret = out(#x86_64_reg_class) ret,
                        offset = in(reg) offset,
                        options(readonly, preserves_flags, nostack),
                    )
                };
                ret
            }
            #[cfg(target_arch = "aarch64")]
            {
                let ret;
                unsafe {
                    ::core::arch::asm!(
                        "2:",
                        // Load value.
                        "mrs {tp_1}, tpidr_el1",
                        "add {ptr}, {tp_1}, {offset}",
                        concat!(
                            "ldr", #aarch64_instr_width,
                            " {ret", #aarch64_reg_modifier,"},",
                            " [{ptr}]",
                        ),

                        // Make sure task wasn't migrated between mrs and ldr.
                        "mrs {tp_2}, tpidr_el1",
                        "cmp {tp_1}, {tp_2}",
                        "b.ne 2b",

                        tp_1 = out(reg) _,
                        ptr = out(reg) _,
                        offset = in(reg) offset,
                        ret = out(reg) ret,
                        tp_2 = out(reg) _,

                        options(readonly, nostack),
                    )
                };
                ret
            }
        }

        #[inline]
        pub fn fetch_add(&self, mut operand: #ty) -> #ty {
            let offset = #offset_expr;
            #[cfg(target_arch = "x86_64")]
            {
                unsafe {
                    ::core::arch::asm!(
                        ::core::concat!("xadd ", #x86_64_width_modifier, "gs:[{offset}], {operand}"),
                        offset = in(reg) offset,
                        operand = inout(#x86_64_reg_class) operand,
                        options(nostack),
                    )
                };
                operand
            }
            #[cfg(target_arch = "aarch64")]
            {
                let ret;
                unsafe {
                    ::core::arch::asm!(
                        "2:",
                        // Load value.
                        "mrs {tp_1}, tpidr_el1",
                        "add {ptr}, {tp_1}, {offset}",
                        concat!("ldxr", #aarch64_instr_width, " {value", #aarch64_reg_modifier,"}, [{ptr}]"),

                        // Make sure task wasn't migrated between msr and ldxr.
                        "mrs {tp_2}, tpidr_el1",
                        "cmp {tp_1}, {tp_2}",
                        "b.ne 2b",

                        // Compute and store value (reuse tp_1 register).
                        "add {tp_1}, {value}, {operand}",
                        concat!("stxr", #aarch64_instr_width, " {cond:w}, {tp_1", #aarch64_reg_modifier,"}, [{ptr}]"),

                        // Make sure task wasn't migrated between ldxr and stxr.
                        "cbnz {cond}, 2b",

                        tp_1 = out(reg) ret,
                        ptr = out(reg) _,
                        offset = in(reg) offset,
                        value = out(reg) ret,
                        tp_2 = out(reg) _,
                        operand = in(reg) operand,
                        cond = out(reg) _,

                        options(nostack),
                    )
                };
                ret
            }
        }

        #[inline]
        pub fn fetch_sub(&self, mut operand: #ty) -> #ty {
            operand = operand.overflowing_neg().0;
            self.fetch_add(operand)
        }
    })
}