rust-for-linux.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Wedson Almeida Filho <wedsonaf@gmail.com>
To: rust-for-linux@vger.kernel.org
Cc: "Miguel Ojeda" <ojeda@kernel.org>,
	"Alex Gaynor" <alex.gaynor@gmail.com>,
	"Boqun Feng" <boqun.feng@gmail.com>,
	"Gary Guo" <gary@garyguo.net>,
	"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
	"Benno Lossin" <benno.lossin@proton.me>,
	"Andreas Hindborg" <a.hindborg@samsung.com>,
	"Alice Ryhl" <aliceryhl@google.com>,
	linux-kernel@vger.kernel.org,
	"Wedson Almeida Filho" <walmeida@microsoft.com>
Subject: [PATCH v2 05/10] rust: alloc: introduce allocation flags
Date: Tue, 26 Mar 2024 23:35:26 -0300	[thread overview]
Message-ID: <20240327023531.187880-6-wedsonaf@gmail.com> (raw)
In-Reply-To: <20240327023531.187880-1-wedsonaf@gmail.com>

From: Wedson Almeida Filho <walmeida@microsoft.com>

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 <benno.lossin@proton.me>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
---
 rust/bindings/bindings_helper.h |  3 ++
 rust/kernel/alloc.rs            | 56 +++++++++++++++++++++++++++++++++
 rust/kernel/prelude.rs          |  2 +-
 3 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 65b98831b975..ddb5644d4fd9 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -20,5 +20,8 @@
 
 /* `bindgen` gets confused at certain things. */
 const size_t RUST_CONST_HELPER_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN;
+const gfp_t RUST_CONST_HELPER_GFP_ATOMIC = GFP_ATOMIC;
 const gfp_t RUST_CONST_HELPER_GFP_KERNEL = GFP_KERNEL;
+const gfp_t RUST_CONST_HELPER_GFP_KERNEL_ACCOUNT = GFP_KERNEL_ACCOUNT;
+const gfp_t RUST_CONST_HELPER_GFP_NOWAIT = GFP_NOWAIT;
 const gfp_t RUST_CONST_HELPER___GFP_ZERO = __GFP_ZERO;
diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs
index 2c99635f9fd3..0502bcf00bce 100644
--- a/rust/kernel/alloc.rs
+++ b/rust/kernel/alloc.rs
@@ -6,3 +6,59 @@
 #[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;
+
+    /// 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);
+}
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index c85b5972c0d3..827e4dfd77df 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -14,7 +14,7 @@
 #[doc(no_inline)]
 pub use core::pin::Pin;
 
-pub use crate::alloc::vec_ext::VecExt;
+pub use crate::alloc::{flags::*, vec_ext::VecExt};
 
 #[doc(no_inline)]
 pub use alloc::{boxed::Box, vec::Vec};
-- 
2.34.1


  parent reply	other threads:[~2024-03-27  2:36 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-27  2:35 [PATCH v2 00/10] Allocation APIs Wedson Almeida Filho
2024-03-27  2:35 ` [PATCH v2 01/10] rust: kernel: move `allocator` module under `alloc` Wedson Almeida Filho
2024-03-27  2:35 ` [PATCH v2 02/10] rust: alloc: introduce the `VecExt` trait Wedson Almeida Filho
2024-03-27 16:45   ` Benno Lossin
2024-03-27  2:35 ` [PATCH v2 03/10] kbuild: use the upstream `alloc` crate Wedson Almeida Filho
2024-03-27  2:35 ` [PATCH v2 04/10] rust: alloc: remove our fork of the " Wedson Almeida Filho
2024-03-27  2:35 ` Wedson Almeida Filho [this message]
2024-03-27  2:35 ` [PATCH v2 06/10] rust: alloc: introduce the `BoxExt` trait Wedson Almeida Filho
2024-03-27 17:09   ` Benno Lossin
2024-03-27 18:43     ` Wedson Almeida Filho
2024-03-27  2:35 ` [PATCH v2 07/10] rust: alloc: update `VecExt` to take allocation flags Wedson Almeida Filho
2024-03-27  3:48   ` Boqun Feng
2024-03-27 10:49     ` Miguel Ojeda
2024-03-27 18:19     ` Wedson Almeida Filho
2024-03-27  2:35 ` [PATCH v2 08/10] rust: sync: update `Arc` and `UniqueArc` " Wedson Almeida Filho
2024-03-27  2:35 ` [PATCH v2 09/10] rust: init: update `init` module " Wedson Almeida Filho
2024-03-27  2:35 ` [PATCH v2 10/10] rust: kernel: remove usage of `allocator_api` unstable feature Wedson Almeida Filho
2024-03-27 17:19   ` Benno Lossin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240327023531.187880-6-wedsonaf@gmail.com \
    --to=wedsonaf@gmail.com \
    --cc=a.hindborg@samsung.com \
    --cc=alex.gaynor@gmail.com \
    --cc=aliceryhl@google.com \
    --cc=benno.lossin@proton.me \
    --cc=bjorn3_gh@protonmail.com \
    --cc=boqun.feng@gmail.com \
    --cc=gary@garyguo.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=ojeda@kernel.org \
    --cc=rust-for-linux@vger.kernel.org \
    --cc=walmeida@microsoft.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).