From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A8C9D194C73; Mon, 12 Aug 2024 18:24:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723487080; cv=none; b=c6CAXRcmwuO1ktwmneYQOY1X3SZRlWygDWAQhJVOrg+aCfXLTZEg7lARXnzSIRhtO/XnfR7Iwb/CYdauLINyuOMBKOgSJUi0IaYlPzJ9KdMBH3Hgh3GeXnxSjDVwI9zqTHmLTYo5hWCIDChZKnjpi6fdoLbDzd5I4SQip8XuQZY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723487080; c=relaxed/simple; bh=h5pfzEktHmh1N0L77l+cZ8kzDdEbRgd13sQHut0w7XY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HfcR/hNTouGmEFCwE64tBsHxDRnRBMGTQLCPpmdFLtUaRwQHf8TtuoPyL3Td3N3AajKl1BA21m4AN9oU5JGO5/Z0Q7xvpE7/MbSTGaXW9kZilEJF4/PGHFDYZhqXSJAeC1ngp2aWZ7a7dH6/4ktu5o9cOWQ0qgbw3sLMTek8fMM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NFvp3rUV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NFvp3rUV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 975EFC4AF0F; Mon, 12 Aug 2024 18:24:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723487080; bh=h5pfzEktHmh1N0L77l+cZ8kzDdEbRgd13sQHut0w7XY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NFvp3rUVlsJ+UIxsUGlMKE8VTsD2Aq8HQxJ6wXype4vyAHL2JtkK3mOcnqC2DvnGf RmFkZ/Axmc1yYu1S60+J355btuuhvCl8k6va48DkEb1AE+kv7+2ACKRPMVx/RA1Grm 8ju+i4zFpn3C6CpUsSopqqg9VC2Kra0gRKGL1W4dTZsSFnQcsgfnAGX3XZd6bP7Y1Q XOhWkTqlAKYoyI90KBpS3koeohXNoO4UW7OLvdIrC0VU1eFvFuJRTaJnyUP/w1XMaZ +Zcszs4mggLiSYZhQUaYYRApDVKuKQNFVkwynM6kBwM8NIb1v+WthEPX/Jcg0D/T4v rZ4s5Ccnx/0jw== From: Danilo Krummrich To: ojeda@kernel.org, alex.gaynor@gmail.com, wedsonaf@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@samsung.com, aliceryhl@google.com, akpm@linux-foundation.org Cc: daniel.almeida@collabora.com, faith.ekstrand@collabora.com, boris.brezillon@collabora.com, lina@asahilina.net, mcanal@igalia.com, zhiw@nvidia.com, cjia@nvidia.com, jhubbard@nvidia.com, airlied@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-mm@kvack.org, Danilo Krummrich Subject: [PATCH v5 06/26] rust: alloc: implement `Vmalloc` allocator Date: Mon, 12 Aug 2024 20:22:52 +0200 Message-ID: <20240812182355.11641-7-dakr@kernel.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240812182355.11641-1-dakr@kernel.org> References: <20240812182355.11641-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Implement `Allocator` for `Vmalloc`, the kernel's virtually contiguous allocator, typically used for larger objects, (much) larger than page size. All memory allocations made with `Vmalloc` end up in `vrealloc()`. Reviewed-by: Alice Ryhl Signed-off-by: Danilo Krummrich --- rust/helpers.c | 7 +++++++ rust/kernel/alloc/allocator.rs | 28 ++++++++++++++++++++++++++++ rust/kernel/alloc/allocator_test.rs | 1 + 3 files changed, 36 insertions(+) diff --git a/rust/helpers.c b/rust/helpers.c index 9f7275493365..7406943f887d 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -199,6 +200,12 @@ void *rust_helper_krealloc(const void *objp, size_t new_size, gfp_t flags) } EXPORT_SYMBOL_GPL(rust_helper_krealloc); +void *rust_helper_vrealloc(const void *p, size_t size, gfp_t flags) +{ + return vrealloc(p, size, flags); +} +EXPORT_SYMBOL_GPL(rust_helper_vrealloc); + /* * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can * use it in contexts where Rust expects a `usize` like slice (array) indices. diff --git a/rust/kernel/alloc/allocator.rs b/rust/kernel/alloc/allocator.rs index b46883d87715..fdda22c6983f 100644 --- a/rust/kernel/alloc/allocator.rs +++ b/rust/kernel/alloc/allocator.rs @@ -9,6 +9,7 @@ use crate::alloc::{AllocError, Allocator}; use crate::bindings; +use crate::pr_warn; /// The contiguous kernel allocator. /// @@ -16,6 +17,12 @@ /// `bindings::krealloc`. pub struct Kmalloc; +/// The virtually contiguous kernel allocator. +/// +/// The vmalloc allocator allocates pages from the page level allocator and maps them into the +/// contiguous kernel virtual space. +pub struct Vmalloc; + /// Returns a proper size to alloc a new object aligned to `new_layout`'s alignment. fn aligned_size(new_layout: Layout) -> usize { // Customized layouts from `Layout::from_size_align()` can have size < align, so pad first. @@ -55,6 +62,9 @@ impl ReallocFunc { // INVARIANT: `krealloc` satisfies the type invariants. const KREALLOC: Self = Self(bindings::krealloc); + // INVARIANT: `vrealloc` satisfies the type invariants. + const VREALLOC: Self = Self(bindings::vrealloc); + /// # Safety /// /// This method has the same safety requirements as `Allocator::realloc`. @@ -132,6 +142,24 @@ unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 { } } +unsafe impl Allocator for Vmalloc { + unsafe fn realloc( + ptr: Option>, + layout: Layout, + flags: Flags, + ) -> Result, AllocError> { + // TODO: Support alignments larger than PAGE_SIZE. + if layout.align() > bindings::PAGE_SIZE { + pr_warn!("Vmalloc does not support alignments larger than PAGE_SIZE yet.\n"); + return Err(AllocError); + } + + // SAFETY: If not `None`, `ptr` is guaranteed to point to valid memory, which was previously + // allocated with this `Allocator`. + unsafe { ReallocFunc::VREALLOC.call(ptr, layout, flags) } + } +} + #[global_allocator] static ALLOCATOR: Kmalloc = Kmalloc; diff --git a/rust/kernel/alloc/allocator_test.rs b/rust/kernel/alloc/allocator_test.rs index 4785efc474a7..e7bf2982f68f 100644 --- a/rust/kernel/alloc/allocator_test.rs +++ b/rust/kernel/alloc/allocator_test.rs @@ -7,6 +7,7 @@ use core::ptr::NonNull; pub struct Kmalloc; +pub type Vmalloc = Kmalloc; unsafe impl Allocator for Kmalloc { unsafe fn realloc( -- 2.45.2