linux-kernel - [PATCH V9 16/17] rust: opp: Extend OPP abstractions with cpufreq support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <e88fae38cb339ff88cb64fcd506ce767b458f310.1744366572.git.viresh.kumar@linaro.org>
Date: Fri, 11 Apr 2025 16:25:15 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: "Rafael J. Wysocki" <rafael@...nel.org>,
	Miguel Ojeda <miguel.ojeda.sandonis@...il.com>,
	Danilo Krummrich <dakr@...hat.com>,
	Viresh Kumar <vireshk@...nel.org>,
	Nishanth Menon <nm@...com>,
	Stephen Boyd <sboyd@...nel.org>,
	Miguel Ojeda <ojeda@...nel.org>,
	Alex Gaynor <alex.gaynor@...il.com>,
	Boqun Feng <boqun.feng@...il.com>,
	Gary Guo <gary@...yguo.net>,
	Björn Roy Baron <bjorn3_gh@...tonmail.com>,
	Benno Lossin <benno.lossin@...ton.me>,
	Andreas Hindborg <a.hindborg@...nel.org>,
	Alice Ryhl <aliceryhl@...gle.com>,
	Trevor Gross <tmgross@...ch.edu>,
	Danilo Krummrich <dakr@...nel.org>
Cc: Viresh Kumar <viresh.kumar@...aro.org>,
	linux-pm@...r.kernel.org,
	Vincent Guittot <vincent.guittot@...aro.org>,
	rust-for-linux@...r.kernel.org,
	Manos Pitsidianakis <manos.pitsidianakis@...aro.org>,
	Erik Schilling <erik.schilling@...aro.org>,
	Alex Bennée <alex.bennee@...aro.org>,
	Joakim Bech <joakim.bech@...aro.org>,
	Rob Herring <robh@...nel.org>,
	Yury Norov <yury.norov@...il.com>,
	Burak Emir <bqe@...gle.com>,
	Rasmus Villemoes <linux@...musvillemoes.dk>,
	Russell King <linux@...linux.org.uk>,
	linux-clk@...r.kernel.org,
	Michael Turquette <mturquette@...libre.com>,
	linux-kernel@...r.kernel.org
Subject: [PATCH V9 16/17] rust: opp: Extend OPP abstractions with cpufreq support

Extend the OPP abstractions to include support for interacting with the
cpufreq core, including the ability to retrieve frequency tables from
OPP table.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 rust/kernel/opp.rs | 67 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)

diff --git a/rust/kernel/opp.rs b/rust/kernel/opp.rs
index 7bf612fa0cc5..a46ac28d4464 100644
--- a/rust/kernel/opp.rs
+++ b/rust/kernel/opp.rs
@@ -20,6 +20,12 @@
     types::{ARef, AlwaysRefCounted, Opaque},
 };
 
+#[cfg(CONFIG_CPU_FREQ)]
+use crate::cpufreq;
+
+#[cfg(CONFIG_CPU_FREQ)]
+use core::ops::Deref;
+
 use core::{marker::PhantomData, ptr};
 
 use macros::vtable;
@@ -497,6 +503,60 @@ extern "C" fn config_regulators(
     }
 }
 
+/// OPP frequency table.
+///
+/// A [`cpufreq::Table`] created from [`Table`].
+#[cfg(CONFIG_CPU_FREQ)]
+pub struct FreqTable {
+    dev: ARef<Device>,
+    ptr: *mut bindings::cpufreq_frequency_table,
+}
+
+#[cfg(CONFIG_CPU_FREQ)]
+impl FreqTable {
+    /// Creates a new instance of [`FreqTable`] from [`Table`].
+    fn new(table: &Table) -> Result<Self> {
+        let mut ptr: *mut bindings::cpufreq_frequency_table = ptr::null_mut();
+
+        // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety
+        // requirements.
+        to_result(unsafe {
+            bindings::dev_pm_opp_init_cpufreq_table(table.dev.as_raw(), &mut ptr)
+        })?;
+
+        Ok(Self {
+            dev: table.dev.clone(),
+            ptr,
+        })
+    }
+
+    // Returns a reference to the underlying [`cpufreq::Table`].
+    #[inline]
+    fn table(&self) -> &cpufreq::Table {
+        // SAFETY: The `ptr` is guaranteed by the C code to be valid.
+        unsafe { cpufreq::Table::from_raw(self.ptr) }
+    }
+}
+
+#[cfg(CONFIG_CPU_FREQ)]
+impl Deref for FreqTable {
+    type Target = cpufreq::Table;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        self.table()
+    }
+}
+
+#[cfg(CONFIG_CPU_FREQ)]
+impl Drop for FreqTable {
+    fn drop(&mut self) {
+        // SAFETY: The pointer was created via `dev_pm_opp_init_cpufreq_table`, and is only freed
+        // here.
+        unsafe { bindings::dev_pm_opp_free_cpufreq_table(self.dev.as_raw(), &mut self.as_raw()) };
+    }
+}
+
 /// A reference-counted OPP table.
 ///
 /// Rust abstraction for the C `struct opp_table`.
@@ -752,6 +812,13 @@ pub fn adjust_voltage(
         })
     }
 
+    /// Creates [`FreqTable`] from [`Table`].
+    #[cfg(CONFIG_CPU_FREQ)]
+    #[inline]
+    pub fn cpufreq_table(&mut self) -> Result<FreqTable> {
+        FreqTable::new(self)
+    }
+
     /// Configures device with [`OPP`] matching the frequency value.
     #[inline]
     pub fn set_rate(&self, freq: Hertz) -> Result<()> {
-- 
2.31.1.272.g89b43f80a514