eonix/crates/eonix_percpu/src/arch.rs

use proc_macro2::TokenStream;
use quote::quote;
use syn::{Ident, Type};

/// Get the base address for percpu variables of the current thread.
pub fn get_percpu_pointer(percpu: &Ident, ty: &Type) -> TokenStream {
    quote! {
        {
            #[cfg(target_arch = "x86_64")]
            {
                let base: *mut #ty;
                ::core::arch::asm!(
                    "mov %gs:0, {address}",
                    "add ${percpu_pointer}, {address}",
                    percpu_pointer = sym #percpu,
                    address = out(reg) base,
                    options(att_syntax)
                );
                base
            }
        }
    }
    .into()
}