1 // SPDX-License-Identifier: GPL-2.0 2 3 //! Extensions to the [`alloc`] crate. 4 5 #[cfg(not(test))] 6 #[cfg(not(testlib))] 7 mod allocator; 8 pub mod vec_ext; 9 10 /// Flags to be used when allocating memory. 11 /// 12 /// They can be combined with the operators `|`, `&`, and `!`. 13 /// 14 /// Values can be used from the [`flags`] module. 15 #[derive(Clone, Copy)] 16 pub struct Flags(u32); 17 18 impl core::ops::BitOr for Flags { 19 type Output = Self; 20 fn bitor(self, rhs: Self) -> Self::Output { 21 Self(self.0 | rhs.0) 22 } 23 } 24 25 impl core::ops::BitAnd for Flags { 26 type Output = Self; 27 fn bitand(self, rhs: Self) -> Self::Output { 28 Self(self.0 & rhs.0) 29 } 30 } 31 32 impl core::ops::Not for Flags { 33 type Output = Self; 34 fn not(self) -> Self::Output { 35 Self(!self.0) 36 } 37 } 38 39 /// Allocation flags. 40 /// 41 /// These are meant to be used in functions that can allocate memory. 42 pub mod flags { 43 use super::Flags; 44 use crate::bindings; 45 46 /// Zeroes out the allocated memory. 47 /// 48 /// This is normally or'd with other flags. 49 pub const __GFP_ZERO: Flags = Flags(bindings::__GFP_ZERO); 50 51 /// Users can not sleep and need the allocation to succeed. 52 /// 53 /// A lower watermark is applied to allow access to "atomic reserves". The current 54 /// implementation doesn't support NMI and few other strict non-preemptive contexts (e.g. 55 /// raw_spin_lock). The same applies to [`GFP_NOWAIT`]. 56 pub const GFP_ATOMIC: Flags = Flags(bindings::GFP_ATOMIC); 57 58 /// Typical for kernel-internal allocations. The caller requires ZONE_NORMAL or a lower zone 59 /// for direct access but can direct reclaim. 60 pub const GFP_KERNEL: Flags = Flags(bindings::GFP_KERNEL); 61 62 /// The same as [`GFP_KERNEL`], except the allocation is accounted to kmemcg. 63 pub const GFP_KERNEL_ACCOUNT: Flags = Flags(bindings::GFP_KERNEL_ACCOUNT); 64 65 /// Ror kernel allocations that should not stall for direct reclaim, start physical IO or 66 /// use any filesystem callback. It is very likely to fail to allocate memory, even for very 67 /// small allocations. 68 pub const GFP_NOWAIT: Flags = Flags(bindings::GFP_NOWAIT); 69 } 70