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// SPDX-License-Identifier: GPL-2.0
//! Extensions to the [`alloc`] crate.
#[cfg(not(test))]
#[cfg(not(testlib))]
mod allocator;
pub mod box_ext;
pub mod vec_ext;
/// Indicates an allocation error.
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub struct AllocError;
/// Flags to be used when allocating memory.
///
/// They can be combined with the operators `|`, `&`, and `!`.
///
/// Values can be used from the [`flags`] module.
#[derive(Clone, Copy)]
pub struct Flags(u32);
impl Flags {
/// Get the raw representation of this flag.
pub(crate) fn as_raw(self) -> u32 {
self.0
}
}
impl core::ops::BitOr for Flags {
type Output = Self;
fn bitor(self, rhs: Self) -> Self::Output {
Self(self.0 | rhs.0)
}
}
impl core::ops::BitAnd for Flags {
type Output = Self;
fn bitand(self, rhs: Self) -> Self::Output {
Self(self.0 & rhs.0)
}
}
impl core::ops::Not for Flags {
type Output = Self;
fn not(self) -> Self::Output {
Self(!self.0)
}
}
/// Allocation flags.
///
/// These are meant to be used in functions that can allocate memory.
pub mod flags {
use super::Flags;
/// Zeroes out the allocated memory.
///
/// This is normally or'd with other flags.
pub const __GFP_ZERO: Flags = Flags(bindings::__GFP_ZERO);
/// Allow the allocation to be in high memory.
///
/// Allocations in high memory may not be mapped into the kernel's address space, so this can't
/// be used with `kmalloc` and other similar methods.
///
/// This is normally or'd with other flags.
pub const __GFP_HIGHMEM: Flags = Flags(bindings::__GFP_HIGHMEM);
/// Users can not sleep and need the allocation to succeed.
///
/// A lower watermark is applied to allow access to "atomic reserves". The current
/// implementation doesn't support NMI and few other strict non-preemptive contexts (e.g.
/// raw_spin_lock). The same applies to [`GFP_NOWAIT`].
pub const GFP_ATOMIC: Flags = Flags(bindings::GFP_ATOMIC);
/// Typical for kernel-internal allocations. The caller requires ZONE_NORMAL or a lower zone
/// for direct access but can direct reclaim.
pub const GFP_KERNEL: Flags = Flags(bindings::GFP_KERNEL);
/// The same as [`GFP_KERNEL`], except the allocation is accounted to kmemcg.
pub const GFP_KERNEL_ACCOUNT: Flags = Flags(bindings::GFP_KERNEL_ACCOUNT);
/// For kernel allocations that should not stall for direct reclaim, start physical IO or
/// use any filesystem callback. It is very likely to fail to allocate memory, even for very
/// small allocations.
pub const GFP_NOWAIT: Flags = Flags(bindings::GFP_NOWAIT);
}
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