From 31d94d8f586df55e7dce47a67a8428f46d09f906 Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Wed, 27 Mar 2024 22:35:54 -0300 Subject: rust: kernel: move `allocator` module under `alloc` We will add more to the `alloc` module in subsequent patches (e.g., allocation flags and extension traits). Reviewed-by: Benno Lossin Signed-off-by: Wedson Almeida Filho Link: https://lore.kernel.org/r/20240328013603.206764-2-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda --- rust/kernel/alloc.rs | 7 +++++++ 1 file changed, 7 insertions(+) create mode 100644 rust/kernel/alloc.rs (limited to 'rust/kernel/alloc.rs') diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs new file mode 100644 index 000000000000..9aa5077d4a4c --- /dev/null +++ b/rust/kernel/alloc.rs @@ -0,0 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Extensions to the [`alloc`] crate. + +#[cfg(not(test))] +#[cfg(not(testlib))] +mod allocator; -- cgit From 03989773a94490383b062912feb0c4d175f20845 Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Wed, 27 Mar 2024 22:35:55 -0300 Subject: rust: alloc: introduce the `VecExt` trait Make `try_with_capacity`, `try_push`, and `try_extend_from_slice` methods available in `Vec` even though it doesn't implement them. It is implemented with `try_reserve` and `push_within_capacity`. This is in preparation for switching to the upstream `alloc` crate. Reviewed-by: Benno Lossin Suggested-by: Gary Guo Signed-off-by: Wedson Almeida Filho Link: https://lore.kernel.org/r/20240328013603.206764-3-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda --- rust/kernel/alloc.rs | 1 + 1 file changed, 1 insertion(+) (limited to 'rust/kernel/alloc.rs') diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs index 9aa5077d4a4c..2c99635f9fd3 100644 --- a/rust/kernel/alloc.rs +++ b/rust/kernel/alloc.rs @@ -5,3 +5,4 @@ #[cfg(not(test))] #[cfg(not(testlib))] mod allocator; +pub mod vec_ext; -- cgit From b6a006e21b822d1dd262fa249ff71a2991e7b319 Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Wed, 27 Mar 2024 22:35:58 -0300 Subject: rust: alloc: introduce allocation flags We'll use them when allocating `Box`, `Arc`, and `UniqueArc` instances, as well as when allocating memory for `Vec` elements. These changes will come in subsequent patches. Reviewed-by: Benno Lossin Signed-off-by: Wedson Almeida Filho Link: https://lore.kernel.org/r/20240328013603.206764-6-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda --- rust/kernel/alloc.rs | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'rust/kernel/alloc.rs') diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs index 2c99635f9fd3..fd5541991a22 100644 --- a/rust/kernel/alloc.rs +++ b/rust/kernel/alloc.rs @@ -6,3 +6,64 @@ #[cfg(not(testlib))] mod allocator; pub mod vec_ext; + +/// 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 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; + use crate::bindings; + + /// Zeroes out the allocated memory. + /// + /// This is normally or'd with other flags. + pub const __GFP_ZERO: Flags = Flags(bindings::__GFP_ZERO); + + /// 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); + + /// Ror 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); +} -- cgit From 08d3f54928796557fc832467ad54f04908fc14e4 Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Wed, 27 Mar 2024 22:35:59 -0300 Subject: rust: alloc: introduce the `BoxExt` trait Make fallible versions of `new` and `new_uninit` methods available in `Box` even though it doesn't implement them because we build `alloc` with the `no_global_oom_handling` config. They also have an extra `flags` parameter that allows callers to pass flags to the allocator. Signed-off-by: Wedson Almeida Filho Reviewed-by: Boqun Feng Reviewed-by: Benno Lossin Link: https://lore.kernel.org/r/20240328013603.206764-7-wedsonaf@gmail.com [ Used `Box::write()` to avoid one `unsafe` block as suggested by Boqun. ] Signed-off-by: Miguel Ojeda --- rust/kernel/alloc.rs | 1 + 1 file changed, 1 insertion(+) (limited to 'rust/kernel/alloc.rs') diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs index fd5541991a22..9bc1b48b5641 100644 --- a/rust/kernel/alloc.rs +++ b/rust/kernel/alloc.rs @@ -5,6 +5,7 @@ #[cfg(not(test))] #[cfg(not(testlib))] mod allocator; +pub mod box_ext; pub mod vec_ext; /// Flags to be used when allocating memory. -- cgit From 2c1092853f163762ef0aabc551a630ef233e1be3 Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Wed, 27 Mar 2024 22:36:03 -0300 Subject: rust: kernel: remove usage of `allocator_api` unstable feature With the adoption of `BoxExt` and `VecExt`, we don't need the functions provided by this feature (namely the methods prefixed with `try_` and different allocator per collection instance). We do need `AllocError`, but we define our own as it is a trivial empty struct. Reviewed-by: Benno Lossin Signed-off-by: Wedson Almeida Filho Link: https://lore.kernel.org/r/20240328013603.206764-11-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda --- rust/kernel/alloc.rs | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'rust/kernel/alloc.rs') diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs index 9bc1b48b5641..f1c2c4aa22d2 100644 --- a/rust/kernel/alloc.rs +++ b/rust/kernel/alloc.rs @@ -8,6 +8,10 @@ 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 `!`. -- cgit From 00280272a0e5d98055e4d47db38a9b4b5517520e Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Mon, 1 Apr 2024 23:23:02 +0200 Subject: rust: kernel: remove redundant imports Rust's `unused_imports` lint covers both unused and redundant imports. In the upcoming 1.78.0, the lint detects more cases of redundant imports [1], e.g.: error: the item `bindings` is imported redundantly --> rust/kernel/print.rs:38:9 | 38 | use crate::bindings; | ^^^^^^^^^^^^^^^ the item `bindings` is already defined by prelude Most cases are `use crate::bindings`, plus a few other items like `Box`. Thus clean them up. Note that, in the `bindings` case, the message "defined by prelude" above means the extern prelude, i.e. the `--extern` flags we pass. Link: https://github.com/rust-lang/rust/pull/117772 [1] Reviewed-by: Alice Ryhl Link: https://lore.kernel.org/r/20240401212303.537355-3-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- rust/kernel/alloc.rs | 1 - 1 file changed, 1 deletion(-) (limited to 'rust/kernel/alloc.rs') diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs index f1c2c4aa22d2..531b5e471cb1 100644 --- a/rust/kernel/alloc.rs +++ b/rust/kernel/alloc.rs @@ -46,7 +46,6 @@ impl core::ops::Not for Flags { /// These are meant to be used in functions that can allocate memory. pub mod flags { use super::Flags; - use crate::bindings; /// Zeroes out the allocated memory. /// -- cgit