From 247b365dc8dc442412c88fe02346cd2bddac7bd6 Mon Sep 17 00:00:00 2001 From: Wedson Almeida Filho Date: Fri, 11 Feb 2022 20:25:34 +0100 Subject: rust: add `kernel` crate MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The `kernel` crate currently includes all the abstractions that wrap kernel features written in C. These abstractions call the C side of the kernel via the generated bindings with the `bindgen` tool. Modules developed in Rust should never call the bindings themselves. In the future, as the abstractions grow in number, we may need to split this crate into several, possibly following a similar subdivision in subsystems as the kernel itself and/or moving the code to the actual subsystems. Reviewed-by: Greg Kroah-Hartman Co-developed-by: Alex Gaynor Signed-off-by: Alex Gaynor Co-developed-by: Geoffrey Thomas Signed-off-by: Geoffrey Thomas Co-developed-by: Finn Behrens Signed-off-by: Finn Behrens Co-developed-by: Adam Bratschi-Kaye Signed-off-by: Adam Bratschi-Kaye Co-developed-by: Sven Van Asbroeck Signed-off-by: Sven Van Asbroeck Co-developed-by: Gary Guo Signed-off-by: Gary Guo Co-developed-by: Boris-Chengbiao Zhou Signed-off-by: Boris-Chengbiao Zhou Co-developed-by: Boqun Feng Signed-off-by: Boqun Feng Co-developed-by: Fox Chen Signed-off-by: Fox Chen Co-developed-by: Viktor Garske Signed-off-by: Viktor Garske Co-developed-by: Dariusz Sosnowski Signed-off-by: Dariusz Sosnowski Co-developed-by: Léo Lanteri Thauvin Signed-off-by: Léo Lanteri Thauvin Co-developed-by: Niklas Mohrin Signed-off-by: Niklas Mohrin Co-developed-by: Milan Landaverde Signed-off-by: Milan Landaverde Co-developed-by: Morgan Bartlett Signed-off-by: Morgan Bartlett Co-developed-by: Maciej Falkowski Signed-off-by: Maciej Falkowski Co-developed-by: Nándor István Krácser Signed-off-by: Nándor István Krácser Co-developed-by: David Gow Signed-off-by: David Gow Co-developed-by: John Baublitz Signed-off-by: John Baublitz Co-developed-by: Björn Roy Baron Signed-off-by: Björn Roy Baron Signed-off-by: Wedson Almeida Filho Co-developed-by: Miguel Ojeda Signed-off-by: Miguel Ojeda --- rust/kernel/allocator.rs | 64 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 rust/kernel/allocator.rs (limited to 'rust/kernel/allocator.rs') diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs new file mode 100644 index 000000000000..397a3dd57a9b --- /dev/null +++ b/rust/kernel/allocator.rs @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Allocator support. + +use core::alloc::{GlobalAlloc, Layout}; +use core::ptr; + +use crate::bindings; + +struct KernelAllocator; + +unsafe impl GlobalAlloc for KernelAllocator { + unsafe fn alloc(&self, layout: Layout) -> *mut u8 { + // `krealloc()` is used instead of `kmalloc()` because the latter is + // an inline function and cannot be bound to as a result. + unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 } + } + + unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) { + unsafe { + bindings::kfree(ptr as *const core::ffi::c_void); + } + } +} + +#[global_allocator] +static ALLOCATOR: KernelAllocator = KernelAllocator; + +// `rustc` only generates these for some crate types. Even then, we would need +// to extract the object file that has them from the archive. For the moment, +// let's generate them ourselves instead. +// +// Note that `#[no_mangle]` implies exported too, nowadays. +#[no_mangle] +fn __rust_alloc(size: usize, _align: usize) -> *mut u8 { + unsafe { bindings::krealloc(core::ptr::null(), size, bindings::GFP_KERNEL) as *mut u8 } +} + +#[no_mangle] +fn __rust_dealloc(ptr: *mut u8, _size: usize, _align: usize) { + unsafe { bindings::kfree(ptr as *const core::ffi::c_void) }; +} + +#[no_mangle] +fn __rust_realloc(ptr: *mut u8, _old_size: usize, _align: usize, new_size: usize) -> *mut u8 { + unsafe { + bindings::krealloc( + ptr as *const core::ffi::c_void, + new_size, + bindings::GFP_KERNEL, + ) as *mut u8 + } +} + +#[no_mangle] +fn __rust_alloc_zeroed(size: usize, _align: usize) -> *mut u8 { + unsafe { + bindings::krealloc( + core::ptr::null(), + size, + bindings::GFP_KERNEL | bindings::__GFP_ZERO, + ) as *mut u8 + } +} -- cgit