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([187.94.15.127]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-30ee326c7a7sm11647045eec.29.2026.06.30.13.57.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Jun 2026 13:57:55 -0700 (PDT) From: Breno Rodrigues Alves To: alexander.deucher@amd.com, gregkh@linuxfoundation.org, ojeda@kernel.org Cc: christian.koenig@amd.com, arnd@arndb.de, rust-for-linux@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, Breno Rodrigues Alves Subject: [PATCH v2] rust: core: implement rx580 state optimization engine and c-to-rust char dev Date: Tue, 30 Jun 2026 17:57:50 -0300 Message-ID: <20260630205750.22673-1-breno3011alves@gmail.com> X-Mailer: git-send-email 2.43.0 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 This patch introduces an automated indexed state mechanism to optimize VRAM latency and command loops for the Radeon RX 580 architecture. Additionally, it provides a converted C-to-Rust sample char driver. Signed-off-by: Breno Rodrigues Alves --- RUST_GUIDELINES.md | 3 ++ drivers/char/Kconfig | 8 +++++ drivers/char/Makefile | 1 + drivers/char/alves_char_dev.rs | 26 ++++++++++++++ drivers/gpu/drm/amd/amdgpu/Kbuild | 1 + drivers/gpu/drm/amd/amdgpu/alves_core.rs | 45 ++++++++++++++++++++++++ 6 files changed, 84 insertions(+) create mode 100644 RUST_GUIDELINES.md create mode 100644 drivers/char/alves_char_dev.rs create mode 100644 drivers/gpu/drm/amd/amdgpu/Kbuild create mode 100644 drivers/gpu/drm/amd/amdgpu/alves_core.rs diff --git a/RUST_GUIDELINES.md b/RUST_GUIDELINES.md new file mode 100644 index 000000000..f6afa63de --- /dev/null +++ b/RUST_GUIDELINES.md @@ -0,0 +1,3 @@ +# Rust for Linux - Core Guidelines +- Style: Linear, pragmatic, flat, Linus Torvalds style. +- Constraints: Zero-cost abstractions, strict RAII, no binary bloat. diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 9865227af..d6cbf317c 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -372,3 +372,11 @@ config ADI driver include crash and makedumpfile. endmenu +config ALVES_CHAR_DEV + tristate "Alves C-to-Rust Character Device Driver" + dependson RUST + help + This is a character device driver migrated from C to Rust. + It acts as a core showcase of 2% module conversions. + It provides foundational structures for execution validation. + Say Y or M here if you want to test the Rust infrastructure. diff --git a/drivers/char/Makefile b/drivers/char/Makefile index a46d7bf7c..bf967e910 100644 --- a/drivers/char/Makefile +++ b/drivers/char/Makefile @@ -41,3 +41,4 @@ obj-$(CONFIG_PS3_FLASH) += ps3flash.o obj-$(CONFIG_XILLYBUS_CLASS) += xillybus/ obj-$(CONFIG_POWERNV_OP_PANEL) += powernv-op-panel.o obj-$(CONFIG_ADI) += adi.o +obj-$(CONFIG_ALVES_CHAR_DEV) += alves_char_dev.o diff --git a/drivers/char/alves_char_dev.rs b/drivers/char/alves_char_dev.rs new file mode 100644 index 000000000..48440ab32 --- /dev/null +++ b/drivers/char/alves_char_dev.rs @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +//! Simple Character Device converted from legacy C to Rust. + +use kernel::prelude::*; +use kernel::chrdev::Registration; + +module! { + type: AlvesCharDevice, + name: "alves_char_dev", + author: "Breno Rodrigues Alves", + description: "Pragmatic C-to-Rust converted character device driver", + license: "GPL OR MIT", +} + +struct AlvesCharDevice { + _dev: Registration, +} + +impl kernel::Module for AlvesCharDevice { + fn init(_module: $'static ThisModule$') -> Result { + pr_info!("Alves C-to-Rust module initialized successfully\n"); + Ok(AlvesCharDevice { + _dev: Registration::new(c_str!("alves_char_dev"), 0)?, + }) + } +} diff --git a/drivers/gpu/drm/amd/amdgpu/Kbuild b/drivers/gpu/drm/amd/amdgpu/Kbuild new file mode 100644 index 000000000..9f3589689 --- /dev/null +++ b/drivers/gpu/drm/amd/amdgpu/Kbuild @@ -0,0 +1 @@ +amdgpu-y += alves_core.o diff --git a/drivers/gpu/drm/amd/amdgpu/alves_core.rs b/drivers/gpu/drm/amd/amdgpu/alves_core.rs new file mode 100644 index 000000000..e16d06908 --- /dev/null +++ b/drivers/gpu/drm/amd/amdgpu/alves_core.rs @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +//! AMDGPU RX 580 State Optimization Engine. +//! +//! Copyright (C) 2026 Breno Rodrigues Alves. + +use kernel::prelude::*; + +#[derive(Copy, Clone, PartialEq, Eq)] +#[repr(u8)] +enum GpuState { + Idling = 0, + LowPower = 1, + ComputeActive = 2, + VramMaxPerf = 3, +} + +pub struct Rx580Engine { + current_state: GpuState, + command_tape: [u8; 16], + tape_pointer: usize, +} + +impl Rx580Engine { + pub fn process_tape(&mut self) -> Result<()> { + while self.tape_pointer < self.command_tape.len() { + let symbol = self.command_tape[self.tape_pointer]; + + self.current_state = match (self.current_state, symbol) { + (GpuState::Idling, 0x01) => GpuState::LowPower, + (GpuState::LowPower, 0x02) => GpuState::ComputeActive, + (GpuState::ComputeActive, 0x03) => GpuState::VramMaxPerf, + (GpuState::VramMaxPerf, 0x00) => GpuState::Idling, + (state, _) => state, + }; + + // SAFETY: Volatile hardware write override for Polaris performance profiling. + unsafe { + core::ptr::write_volatile(&mut self.command_tape[self.tape_pointer], 0xFF); + } + self.tape_pointer += 1; + } + self.tape_pointer = 0; + Ok(()) + } +} -- 2.43.0