@@ -9,6 +9,7 @@
#include <kunit/test.h>
#include <linux/cred.h>
#include <linux/cpu.h>
+#include <linux/cpufreq.h>
#include <linux/device.h>
#include <linux/errname.h>
#include <linux/ethtool.h>
@@ -24,6 +24,7 @@
#include <linux/bug.h>
#include <linux/build_bug.h>
#include <linux/cpumask.h>
+#include <linux/cpufreq.h>
#include <linux/cred.h>
#include <linux/device.h>
#include <linux/err.h>
@@ -315,6 +316,20 @@ void rust_helper_cpumask_setall(struct cpumask *dstp)
}
EXPORT_SYMBOL_GPL(rust_helper_cpumask_setall);
+#ifdef CONFIG_CPU_FREQ
+unsigned int rust_helper_cpufreq_table_len(struct cpufreq_frequency_table *freq_table)
+{
+ return cpufreq_table_len(freq_table);
+}
+EXPORT_SYMBOL_GPL(rust_helper_cpufreq_table_len);
+
+void rust_helper_cpufreq_register_em_with_opp(struct cpufreq_policy *policy)
+{
+ cpufreq_register_em_with_opp(policy);
+}
+EXPORT_SYMBOL_GPL(rust_helper_cpufreq_register_em_with_opp);
+#endif
+
#ifndef CONFIG_OF_DYNAMIC
struct device_node *rust_helper_of_node_get(struct device_node *node)
{
new file mode 100644
@@ -0,0 +1,1090 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! CPU frequency scaling.
+//!
+//! This module provides bindings for interacting with the cpufreq subsystem.
+//!
+//! C header: [`include/linux/cpufreq.h`](../../../../../../include/linux/cpufreq.h)
+
+use crate::{
+ bindings,
+ device::{Device, RawDevice},
+ error::{code::*, from_err_ptr, from_result, to_result, Result, VTABLE_DEFAULT_ERROR},
+ prelude::*,
+ types::ForeignOwnable,
+};
+
+use core::{
+ cell::UnsafeCell,
+ marker::{PhantomData, PhantomPinned},
+ pin::Pin,
+ ptr::{self, addr_of_mut},
+};
+
+use macros::vtable;
+
+/// Default transition latency value.
+pub const ETERNAL_LATENCY: u32 = bindings::CPUFREQ_ETERNAL as u32;
+
+/// Container for cpufreq driver flags.
+pub mod flags {
+ use crate::bindings;
+
+ /// Set by drivers that need to update internal upper and lower boundaries along with the
+ /// target frequency and so the core and governors should also invoke the driver if the target
+ /// frequency does not change, but the policy min or max may have changed.
+ pub const NEED_UPDATE_LIMITS: u16 = bindings::CPUFREQ_NEED_UPDATE_LIMITS as _;
+
+ /// Set by drivers for platforms where loops_per_jiffy or other kernel "constants" aren't
+ /// affected by frequency transitions.
+ pub const CONST_LOOPS: u16 = bindings::CPUFREQ_CONST_LOOPS as _;
+
+ /// Set by drivers that want the core to automatically register the cpufreq driver as a thermal
+ /// cooling device.
+ pub const IS_COOLING_DEV: u16 = bindings::CPUFREQ_IS_COOLING_DEV as _;
+
+ /// Set by drivers for platforms that have multiple clock-domains, i.e. supporting multiple
+ /// policies. With this sysfs directories of governor would be created in cpu/cpuN/cpufreq/
+ /// directory and so they can use the same governor with different tunables for different
+ /// clusters.
+ pub const HAVE_GOVERNOR_PER_POLICY: u16 = bindings::CPUFREQ_HAVE_GOVERNOR_PER_POLICY as _;
+
+ /// Set by drivers which do POSTCHANGE notifications from outside of their ->target() routine.
+ pub const ASYNC_NOTIFICATION: u16 = bindings::CPUFREQ_ASYNC_NOTIFICATION as _;
+
+ /// Set by drivers that want cpufreq core to check if CPU is running at a frequency present in
+ /// freq-table exposed by the driver. For these drivers if CPU is found running at an out of
+ /// table freq, the cpufreq core will try to change the frequency to a value from the table.
+ /// And if that fails, it will stop further boot process by issuing a BUG_ON().
+ pub const NEED_INITIAL_FREQ_CHECK: u16 = bindings::CPUFREQ_NEED_INITIAL_FREQ_CHECK as _;
+
+ /// Set by drivers to disallow use of governors with "dynamic_switching" flag set.
+ pub const NO_AUTO_DYNAMIC_SWITCHING: u16 = bindings::CPUFREQ_NO_AUTO_DYNAMIC_SWITCHING as _;
+}
+
+/// CPU frequency selection relations. Each value contains a `bool` argument which corresponds to
+/// the Relation being efficient.
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum Relation {
+ /// Select the lowest frequency at or above target.
+ Low(bool),
+ /// Select the highest frequency below or at target.
+ High(bool),
+ /// Select the closest frequency to the target.
+ Close(bool),
+}
+
+impl Relation {
+ // Converts from a value compatible with the C code.
+ fn new(val: u32) -> Result<Self> {
+ let efficient = val & bindings::CPUFREQ_RELATION_E != 0;
+
+ Ok(match val & !bindings::CPUFREQ_RELATION_E {
+ bindings::CPUFREQ_RELATION_L => Self::Low(efficient),
+ bindings::CPUFREQ_RELATION_H => Self::High(efficient),
+ bindings::CPUFREQ_RELATION_C => Self::Close(efficient),
+ _ => return Err(EINVAL),
+ })
+ }
+
+ /// Converts to a value compatible with the C code.
+ pub fn val(&self) -> u32 {
+ let (mut val, e) = match self {
+ Self::Low(e) => (bindings::CPUFREQ_RELATION_L, e),
+ Self::High(e) => (bindings::CPUFREQ_RELATION_H, e),
+ Self::Close(e) => (bindings::CPUFREQ_RELATION_C, e),
+ };
+
+ if *e {
+ val |= bindings::CPUFREQ_RELATION_E;
+ }
+
+ val
+ }
+}
+
+/// Equivalent to `struct cpufreq_policy_data` in the C code.
+#[repr(transparent)]
+pub struct PolicyData(*mut bindings::cpufreq_policy_data);
+
+impl PolicyData {
+ /// Creates new instance of [`PolicyData`].
+ ///
+ /// # Safety
+ ///
+ /// Callers must ensure that `ptr` is valid and non-null.
+ pub unsafe fn from_ptr(ptr: *mut bindings::cpufreq_policy_data) -> Self {
+ Self(ptr)
+ }
+
+ /// Returns the raw pointer to the C structure.
+ pub fn as_ptr(&self) -> *mut bindings::cpufreq_policy_data {
+ self.0
+ }
+}
+
+/// Builder for the `struct cpufreq_frequency_table` in the C code.
+#[repr(transparent)]
+pub struct TableBuilder {
+ entries: Vec<bindings::cpufreq_frequency_table>,
+}
+
+impl TableBuilder {
+ /// Creates new instance of [`TableBuilder`].
+ pub fn new() -> Self {
+ Self {
+ entries: Vec::new(),
+ }
+ }
+
+ /// Adds a new entry to the table.
+ pub fn add(&mut self, frequency: u32, flags: u32, driver_data: u32) -> Result<()> {
+ // Adds new entry to the end of the vector.
+ Ok(self.entries.try_push(bindings::cpufreq_frequency_table {
+ flags,
+ driver_data,
+ frequency,
+ })?)
+ }
+
+ /// Creates [`Table`] from [`TableBuilder`].
+ pub fn into_table(mut self) -> Result<Table> {
+ // Add last entry to the table.
+ self.add(bindings::CPUFREQ_TABLE_END as u32, 0, 0)?;
+ Table::from_builder(self.entries)
+ }
+}
+
+/// A simple implementation of the cpufreq table, equivalent to the `struct
+/// cpufreq_frequency_table` in the C code.
+pub struct Table {
+ #[allow(dead_code)]
+ // Dynamically created table.
+ entries: Option<Pin<Vec<bindings::cpufreq_frequency_table>>>,
+
+ // Pointer to the statically or dynamically created table.
+ ptr: *mut bindings::cpufreq_frequency_table,
+
+ // Number of entries in the table.
+ len: usize,
+}
+
+impl Table {
+ /// Creates new instance of [`Table`] from [`TableBuilder`].
+ fn from_builder(entries: Vec<bindings::cpufreq_frequency_table>) -> Result<Self> {
+ let len = entries.len();
+ if len == 0 {
+ return Err(EINVAL);
+ }
+
+ // Pin the entries to memory, since we are passing its pointer to the C code.
+ let mut entries = Pin::new(entries);
+
+ // The pointer is valid until the table gets dropped.
+ let ptr = entries.as_mut_ptr();
+
+ Ok(Self {
+ entries: Some(entries),
+ ptr,
+ // The last entry in table is reserved for `CPUFREQ_TABLE_END`.
+ len: len - 1,
+ })
+ }
+
+ /// Creates new instance of [`Table`] from raw pointer.
+ ///
+ /// # Safety
+ ///
+ /// Callers must ensure that `ptr` is valid and non-null for the lifetime of the [`Table`].
+ pub unsafe fn from_raw(ptr: *mut bindings::cpufreq_frequency_table) -> Self {
+ Self {
+ entries: None,
+ ptr,
+ // SAFETY: The pointer is guaranteed to be valid for the lifetime of `Self`.
+ len: unsafe { bindings::cpufreq_table_len(ptr) } as usize,
+ }
+ }
+
+ // Validate the index.
+ fn validate(&self, index: usize) -> Result<()> {
+ if index >= self.len {
+ Err(EINVAL)
+ } else {
+ Ok(())
+ }
+ }
+
+ /// Returns raw pointer to the `struct cpufreq_frequency_table` compatible with the C code.
+ pub fn as_ptr(&self) -> *mut bindings::cpufreq_frequency_table {
+ self.ptr
+ }
+
+ /// Returns `frequency` at index in the [`Table`].
+ pub fn freq(&self, index: usize) -> Result<u32> {
+ self.validate(index)?;
+
+ // SAFETY: The pointer is guaranteed to be valid for the lifetime of `self` and `index` is
+ // also validated before this and is guaranteed to be within limits of the frequency table.
+ Ok(unsafe { (*self.ptr.add(index)).frequency })
+ }
+
+ /// Returns `flags` at index in the [`Table`].
+ pub fn flags(&self, index: usize) -> Result<u32> {
+ self.validate(index)?;
+
+ // SAFETY: The pointer is guaranteed to be valid for the lifetime of `self` and `index` is
+ // also validated before this and is guaranteed to be within limits of the frequency table.
+ Ok(unsafe { (*self.ptr.add(index)).flags })
+ }
+
+ /// Returns `data` at index in the [`Table`].
+ pub fn data(&self, index: usize) -> Result<u32> {
+ self.validate(index)?;
+
+ // SAFETY: The pointer is guaranteed to be valid for the lifetime of `self` and `index` is
+ // also validated before this and is guaranteed to be within limits of the frequency table.
+ Ok(unsafe { (*self.ptr.add(index)).driver_data })
+ }
+}
+
+/// A simple implementation of `struct clk` from the C code.
+#[repr(transparent)]
+pub struct Clk(*mut bindings::clk);
+
+impl Clk {
+ fn new(dev: &Device, name: Option<&CStr>) -> Result<Self> {
+ let con_id = if let Some(name) = name {
+ name.as_ptr() as *const _
+ } else {
+ ptr::null()
+ };
+
+ // SAFETY: It is safe to call `clk_get()`, on a device pointer earlier received from the C
+ // code.
+ Ok(Self(from_err_ptr(unsafe {
+ bindings::clk_get(dev.raw_device(), con_id)
+ })?))
+ }
+
+ fn as_ptr(&self) -> *mut bindings::clk {
+ self.0
+ }
+}
+
+impl Drop for Clk {
+ fn drop(&mut self) {
+ // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to
+ // relinquish it now.
+ unsafe { bindings::clk_put(self.0) };
+ }
+}
+
+/// A simple implementation of `struct cpumask` from the C code.
+#[repr(transparent)]
+pub struct Cpumask(*mut bindings::cpumask);
+
+impl Cpumask {
+ /// Creates cpumask from raw pointer.
+ ///
+ /// # Safety
+ ///
+ /// Callers must ensure that `ptr` is valid, and non-null.
+ pub unsafe fn new(ptr: *mut bindings::cpumask) -> Self {
+ Self(ptr)
+ }
+
+ /// Returns pointer to the underlying cpumask from the C code.
+ pub fn as_ptr(&self) -> *const bindings::cpumask {
+ self.0
+ }
+
+ /// Returns mutable pointer to the underlying cpumask from the C code.
+ pub fn as_mut_ptr(&mut self) -> *mut bindings::cpumask {
+ self.0
+ }
+}
+
+/// Equivalent to `struct cpufreq_policy` in the C code.
+pub struct Policy {
+ ptr: *mut bindings::cpufreq_policy,
+ put_cpu: bool,
+ cpumask: Cpumask,
+}
+
+impl Policy {
+ /// Creates a new instance of [`Policy`].
+ ///
+ /// # Safety
+ ///
+ /// Callers must ensure that `ptr` is valid and non-null.
+ pub unsafe fn from_ptr(ptr: *mut bindings::cpufreq_policy) -> Self {
+ Self {
+ ptr,
+ put_cpu: false,
+ // SAFETY: The pointer is guaranteed to be valid for the lifetime of `Self`. The `cpus`
+ // pointer is guaranteed to be valid by the C code.
+ cpumask: unsafe { Cpumask::new((*ptr).cpus) },
+ }
+ }
+
+ fn from_cpu(cpu: u32) -> Result<Self> {
+ // SAFETY: It is safe to call `cpufreq_cpu_get()` for any CPU.
+ let ptr = from_err_ptr(unsafe { bindings::cpufreq_cpu_get(cpu) })?;
+
+ // SAFETY: The pointer is guaranteed to be valid by the C code.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ policy.put_cpu = true;
+ Ok(policy)
+ }
+
+ /// Raw pointer to the underlying cpufreq policy.
+ pub fn as_ptr(&self) -> *mut bindings::cpufreq_policy {
+ self.ptr
+ }
+
+ fn as_ref(&self) -> &bindings::cpufreq_policy {
+ // SAFETY: By the type invariants, we know that `self` owns a reference to the pointer.
+ unsafe { &(*self.ptr) }
+ }
+ fn as_mut_ref(&mut self) -> &mut bindings::cpufreq_policy {
+ // SAFETY: By the type invariants, we know that `self` owns a reference to the pointer.
+ unsafe { &mut (*self.ptr) }
+ }
+
+ /// Returns the primary CPU for a cpufreq policy.
+ pub fn cpu(&self) -> u32 {
+ self.as_ref().cpu
+ }
+
+ /// Returns the minimum frequency for a cpufreq policy.
+ pub fn min(&self) -> u32 {
+ self.as_ref().min
+ }
+
+ /// Returns the maximum frequency for a cpufreq policy.
+ pub fn max(&self) -> u32 {
+ self.as_ref().max
+ }
+
+ /// Returns the current frequency for a cpufreq policy.
+ pub fn cur(&self) -> u32 {
+ self.as_ref().cur
+ }
+
+ /// Sets the suspend frequency for a cpufreq policy.
+ pub fn set_suspend_freq(&mut self, freq: u32) {
+ self.as_mut_ref().suspend_freq = freq;
+ }
+
+ /// Returns the suspend frequency for a cpufreq policy.
+ pub fn suspend_freq(&self) -> u32 {
+ self.as_ref().suspend_freq
+ }
+
+ /// Gets raw pointer to cpufreq policy's CPUs mask.
+ pub fn cpus(&mut self) -> &mut Cpumask {
+ &mut self.cpumask
+ }
+
+ /// Sets CPUs mask for a cpufreq policy.
+ ///
+ /// Update the `cpus` mask with a single CPU.
+ pub fn set_cpus(&mut self, cpu: u32) {
+ // SAFETY: The `cpus` pointer is guaranteed to be valid for the lifetime of `self`. And it
+ // is safe to call `cpumask_set_cpus()` for any CPU.
+ unsafe { bindings::cpumask_set_cpu(cpu, self.cpus().as_mut_ptr()) };
+ }
+
+ /// Sets CPUs mask for a cpufreq policy.
+ ///
+ /// Update the `cpus` mask with a single CPU if `cpu` is set to `Some(cpu)`, else sets all
+ /// CPUs.
+ pub fn set_all_cpus(&mut self) {
+ // SAFETY: The `cpus` pointer is guaranteed to be valid for the lifetime of `self`. And it
+ // is safe to call `cpumask_setall()`.
+ unsafe { bindings::cpumask_setall(self.cpus().as_mut_ptr()) };
+ }
+
+ /// Sets clock for a cpufreq policy.
+ pub fn set_clk(&mut self, dev: &Device, name: Option<&CStr>) -> Result<Clk> {
+ let clk = Clk::new(dev, name)?;
+ self.as_mut_ref().clk = clk.as_ptr();
+ Ok(clk)
+ }
+
+ /// Allows frequency switching code to run on any CPU.
+ pub fn set_dvfs_possible_from_any_cpu(&mut self) {
+ self.as_mut_ref().dvfs_possible_from_any_cpu = true;
+ }
+
+ /// Sets transition latency for a cpufreq policy.
+ pub fn set_transition_latency(&mut self, latency: u32) {
+ self.as_mut_ref().cpuinfo.transition_latency = latency;
+ }
+
+ /// Returns the cpufreq table for a cpufreq policy. The cpufreq table is recreated in a
+ /// light-weight manner from the raw pointer. The table in C code is not freed once this table
+ /// is dropped.
+ pub fn freq_table(&self) -> Result<Table> {
+ if self.as_ref().freq_table == ptr::null_mut() {
+ return Err(EINVAL);
+ }
+
+ // SAFETY: The `freq_table` is guaranteed to be valid.
+ Ok(unsafe { Table::from_raw(self.as_ref().freq_table) })
+ }
+
+ /// Sets the cpufreq table for a cpufreq policy.
+ ///
+ /// The cpufreq driver must guarantee that the frequency table does not get freed while it is
+ /// still being used by the C code.
+ pub fn set_freq_table(&mut self, table: &Table) {
+ self.as_mut_ref().freq_table = table.as_ptr();
+ }
+
+ /// Returns the data for a cpufreq policy.
+ pub fn data<T: ForeignOwnable>(&mut self) -> Option<<T>::Borrowed<'_>> {
+ if self.as_ref().driver_data.is_null() {
+ None
+ } else {
+ // SAFETY: The data is earlier set by us from [`set_data()`].
+ Some(unsafe { T::borrow(self.as_ref().driver_data) })
+ }
+ }
+
+ // Sets the data for a cpufreq policy.
+ fn set_data<T: ForeignOwnable>(&mut self, data: T) -> Result<()> {
+ if self.as_ref().driver_data.is_null() {
+ // Pass the ownership of the data to the foreign interface.
+ self.as_mut_ref().driver_data = <T as ForeignOwnable>::into_foreign(data) as _;
+ Ok(())
+ } else {
+ Err(EBUSY)
+ }
+ }
+
+ // Returns the data for a cpufreq policy.
+ fn clear_data<T: ForeignOwnable>(&mut self) -> Option<T> {
+ if self.as_ref().driver_data.is_null() {
+ None
+ } else {
+ // SAFETY: The data is earlier set by us from [`set_data()`]. It is safe to take back
+ // the ownership of the data from the foreign interface.
+ let data =
+ Some(unsafe { <T as ForeignOwnable>::from_foreign(self.as_ref().driver_data) });
+ self.as_mut_ref().driver_data = ptr::null_mut();
+ data
+ }
+ }
+}
+
+impl Drop for Policy {
+ fn drop(&mut self) {
+ if self.put_cpu {
+ // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to
+ // relinquish it now.
+ unsafe { bindings::cpufreq_cpu_put(self.as_ptr()) };
+ }
+ }
+}
+
+/// Operations to be implemented by a cpufreq driver.
+#[vtable]
+pub trait DriverOps {
+ /// Driver specific data.
+ ///
+ /// Corresponds to the data retrieved via the kernel's
+ /// `cpufreq_get_driver_data()` function.
+ ///
+ /// Require that `Data` implements `ForeignOwnable`. We guarantee to
+ /// never move the underlying wrapped data structure.
+ type Data: ForeignOwnable = ();
+
+ /// Policy specific data.
+ ///
+ /// Require that `PData` implements `ForeignOwnable`. We guarantee to
+ /// never move the underlying wrapped data structure.
+ type PData: ForeignOwnable = ();
+
+ /// Policy's init callback.
+ fn init(policy: &mut Policy) -> Result<Self::PData>;
+
+ /// Policy's exit callback.
+ fn exit(_policy: &mut Policy, _data: Option<Self::PData>) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's online callback.
+ fn online(_policy: &mut Policy) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's offline callback.
+ fn offline(_policy: &mut Policy) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's suspend callback.
+ fn suspend(_policy: &mut Policy) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's resume callback.
+ fn resume(_policy: &mut Policy) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's ready callback.
+ fn ready(_policy: &mut Policy) {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's verify callback.
+ fn verify(data: &mut PolicyData) -> Result<()>;
+
+ /// Policy's setpolicy callback.
+ fn setpolicy(_policy: &mut Policy) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's target callback.
+ fn target(_policy: &mut Policy, _target_freq: u32, _relation: Relation) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's target_index callback.
+ fn target_index(_policy: &mut Policy, _index: u32) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's fast_switch callback.
+ fn fast_switch(_policy: &mut Policy, _target_freq: u32) -> u32 {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's adjust_perf callback.
+ fn adjust_perf(_policy: &mut Policy, _min_perf: u64, _target_perf: u64, _capacity: u64) {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's get_intermediate callback.
+ fn get_intermediate(_policy: &mut Policy, _index: u32) -> u32 {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's target_intermediate callback.
+ fn target_intermediate(_policy: &mut Policy, _index: u32) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's get callback.
+ fn get(_policy: &mut Policy) -> Result<u32> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's update_limits callback.
+ fn update_limits(_policy: &mut Policy) {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's bios_limit callback.
+ fn bios_limit(_policy: &mut Policy, _limit: &mut u32) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's set_boost callback.
+ fn set_boost(_policy: &mut Policy, _state: i32) -> Result<()> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Policy's register_em callback.
+ fn register_em(_policy: &mut Policy) {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+}
+
+/// Registration of a cpufreq driver.
+pub struct Registration<T: DriverOps> {
+ registered: bool,
+ drv: UnsafeCell<bindings::cpufreq_driver>,
+ _p: PhantomData<T>,
+ _pin: PhantomPinned,
+}
+
+// SAFETY: `Registration` doesn't offer any methods or access to fields when shared between threads
+// or CPUs, so it is safe to share it.
+unsafe impl<T: DriverOps> Sync for Registration<T> {}
+
+// SAFETY: Registration with and unregistration from the cpufreq subsystem can happen from any thread.
+// Additionally, `T::Data` (which is dropped during unregistration) is `Send`, so it is okay to move
+// `Registration` to different threads.
+#[allow(clippy::non_send_fields_in_send_ty)]
+unsafe impl<T: DriverOps> Send for Registration<T> {}
+
+impl<T: DriverOps> Default for Registration<T> {
+ fn default() -> Self {
+ Self::new()
+ }
+}
+
+impl<T: DriverOps> Registration<T> {
+ /// Creates new [`Registration`] but does not register it yet.
+ ///
+ /// It is allowed to move.
+ pub fn new() -> Self {
+ Self {
+ registered: false,
+ drv: UnsafeCell::new(bindings::cpufreq_driver::default()),
+ _pin: PhantomPinned,
+ _p: PhantomData,
+ }
+ }
+
+ /// Registers a cpufreq driver with the rest of the kernel.
+ pub fn register(
+ self: Pin<&mut Self>,
+ name: &'static CStr,
+ data: T::Data,
+ flags: u16,
+ boost: bool,
+ ) -> Result {
+ // SAFETY: We never move out of `this`.
+ let this = unsafe { self.get_unchecked_mut() };
+
+ if this.registered {
+ return Err(EINVAL);
+ }
+
+ let drv = this.drv.get_mut();
+
+ // Account for the trailing null character.
+ let len = name.len() + 1;
+ if len > drv.name.len() {
+ return Err(EINVAL);
+ };
+
+ // SAFETY: `name` is a valid Cstr, and we are copying it to an array of equal or larger
+ // size.
+ let name = unsafe { &*(name.as_bytes_with_nul() as *const [u8] as *const [i8]) };
+ drv.name[..len].copy_from_slice(name);
+
+ drv.boost_enabled = boost;
+ drv.flags = flags;
+
+ // Allocate an array of 3 pointers to be passed to the C code.
+ let mut attr = Box::try_new([ptr::null_mut(); 3])?;
+ let mut next = 0;
+
+ // SAFETY: The C code returns a valid pointer here, which is again passed to the C code in
+ // an array.
+ attr[next] =
+ unsafe { addr_of_mut!(bindings::cpufreq_freq_attr_scaling_available_freqs) as *mut _ };
+ next += 1;
+
+ if boost {
+ // SAFETY: The C code returns a valid pointer here, which is again passed to the C code
+ // in an array.
+ attr[next] =
+ unsafe { addr_of_mut!(bindings::cpufreq_freq_attr_scaling_boost_freqs) as *mut _ };
+ next += 1;
+ }
+ attr[next] = ptr::null_mut();
+
+ // Pass the ownership of the memory block to the C code. This will be freed when
+ // the [`Registration`] object goes out of scope.
+ drv.attr = Box::leak(attr) as *mut _;
+
+ // Initialize mandatory callbacks.
+ drv.init = Some(Self::init_callback);
+ drv.verify = Some(Self::verify_callback);
+
+ // Initialize optional callbacks.
+ drv.setpolicy = if T::HAS_SETPOLICY {
+ Some(Self::setpolicy_callback)
+ } else {
+ None
+ };
+ drv.target = if T::HAS_TARGET {
+ Some(Self::target_callback)
+ } else {
+ None
+ };
+ drv.target_index = if T::HAS_TARGET_INDEX {
+ Some(Self::target_index_callback)
+ } else {
+ None
+ };
+ drv.fast_switch = if T::HAS_FAST_SWITCH {
+ Some(Self::fast_switch_callback)
+ } else {
+ None
+ };
+ drv.adjust_perf = if T::HAS_ADJUST_PERF {
+ Some(Self::adjust_perf_callback)
+ } else {
+ None
+ };
+ drv.get_intermediate = if T::HAS_GET_INTERMEDIATE {
+ Some(Self::get_intermediate_callback)
+ } else {
+ None
+ };
+ drv.target_intermediate = if T::HAS_TARGET_INTERMEDIATE {
+ Some(Self::target_intermediate_callback)
+ } else {
+ None
+ };
+ drv.get = if T::HAS_GET {
+ Some(Self::get_callback)
+ } else {
+ None
+ };
+ drv.update_limits = if T::HAS_UPDATE_LIMITS {
+ Some(Self::update_limits_callback)
+ } else {
+ None
+ };
+ drv.bios_limit = if T::HAS_BIOS_LIMIT {
+ Some(Self::bios_limit_callback)
+ } else {
+ None
+ };
+ drv.online = if T::HAS_ONLINE {
+ Some(Self::online_callback)
+ } else {
+ None
+ };
+ drv.offline = if T::HAS_OFFLINE {
+ Some(Self::offline_callback)
+ } else {
+ None
+ };
+ drv.exit = if T::HAS_EXIT {
+ Some(Self::exit_callback)
+ } else {
+ None
+ };
+ drv.suspend = if T::HAS_SUSPEND {
+ Some(Self::suspend_callback)
+ } else {
+ None
+ };
+ drv.resume = if T::HAS_RESUME {
+ Some(Self::resume_callback)
+ } else {
+ None
+ };
+ drv.ready = if T::HAS_READY {
+ Some(Self::ready_callback)
+ } else {
+ None
+ };
+ drv.set_boost = if T::HAS_SET_BOOST {
+ Some(Self::set_boost_callback)
+ } else {
+ None
+ };
+ drv.register_em = if T::HAS_REGISTER_EM {
+ Some(Self::register_em_callback)
+ } else {
+ None
+ };
+
+ // Set driver data before registering the driver, as the cpufreq core may call few
+ // callbacks before `cpufreq_register_driver()` returns.
+ this.set_data(data)?;
+
+ // SAFETY: It is safe to register the driver with the cpufreq core in the C code.
+ to_result(unsafe { bindings::cpufreq_register_driver(this.drv.get_mut()) })?;
+
+ this.registered = true;
+ Ok(())
+ }
+
+ /// Returns the previous set data for a cpufreq driver.
+ pub fn data<D: ForeignOwnable>() -> Option<<D>::Borrowed<'static>> {
+ // SAFETY: The driver data is earlier set by us from [`set_data()`].
+ let data = unsafe { bindings::cpufreq_get_driver_data() };
+ if data.is_null() {
+ None
+ } else {
+ // SAFETY: The driver data is earlier set by us from [`set_data()`].
+ Some(unsafe { D::borrow(data) })
+ }
+ }
+
+ // Sets the data for a cpufreq driver.
+ fn set_data(&mut self, data: T::Data) -> Result<()> {
+ let drv = self.drv.get_mut();
+
+ if drv.driver_data.is_null() {
+ // Pass the ownership of the data to the foreign interface.
+ drv.driver_data = <T::Data as ForeignOwnable>::into_foreign(data) as _;
+ Ok(())
+ } else {
+ Err(EBUSY)
+ }
+ }
+
+ // Clears and returns the data for a cpufreq driver.
+ fn clear_data(&mut self) -> Option<T::Data> {
+ let drv = self.drv.get_mut();
+
+ if drv.driver_data.is_null() {
+ None
+ } else {
+ // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to
+ // relinquish it now.
+ let data = Some(unsafe { <T::Data as ForeignOwnable>::from_foreign(drv.driver_data) });
+ drv.driver_data = ptr::null_mut();
+ data
+ }
+ }
+}
+
+// cpufreq driver callbacks.
+impl<T: DriverOps> Registration<T> {
+ // Policy's init callback.
+ extern "C" fn init_callback(ptr: *mut bindings::cpufreq_policy) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+
+ let data = T::init(&mut policy)?;
+ policy.set_data(data)?;
+ Ok(0)
+ })
+ }
+
+ // Policy's exit callback.
+ extern "C" fn exit_callback(ptr: *mut bindings::cpufreq_policy) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+
+ let data = policy.clear_data();
+ T::exit(&mut policy, data).map(|_| 0)
+ })
+ }
+
+ // Policy's online callback.
+ extern "C" fn online_callback(ptr: *mut bindings::cpufreq_policy) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::online(&mut policy).map(|_| 0)
+ })
+ }
+
+ // Policy's offline callback.
+ extern "C" fn offline_callback(ptr: *mut bindings::cpufreq_policy) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::offline(&mut policy).map(|_| 0)
+ })
+ }
+
+ // Policy's suspend callback.
+ extern "C" fn suspend_callback(ptr: *mut bindings::cpufreq_policy) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::suspend(&mut policy).map(|_| 0)
+ })
+ }
+
+ // Policy's resume callback.
+ extern "C" fn resume_callback(ptr: *mut bindings::cpufreq_policy) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::resume(&mut policy).map(|_| 0)
+ })
+ }
+
+ // Policy's ready callback.
+ extern "C" fn ready_callback(ptr: *mut bindings::cpufreq_policy) {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::ready(&mut policy);
+ }
+
+ // Policy's verify callback.
+ extern "C" fn verify_callback(ptr: *mut bindings::cpufreq_policy_data) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut data = unsafe { PolicyData::from_ptr(ptr) };
+ T::verify(&mut data).map(|_| 0)
+ })
+ }
+
+ // Policy's setpolicy callback.
+ extern "C" fn setpolicy_callback(ptr: *mut bindings::cpufreq_policy) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::setpolicy(&mut policy).map(|_| 0)
+ })
+ }
+
+ // Policy's target callback.
+ extern "C" fn target_callback(
+ ptr: *mut bindings::cpufreq_policy,
+ target_freq: u32,
+ relation: u32,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::target(&mut policy, target_freq, Relation::new(relation)?).map(|_| 0)
+ })
+ }
+
+ // Policy's target_index callback.
+ extern "C" fn target_index_callback(
+ ptr: *mut bindings::cpufreq_policy,
+ index: u32,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::target_index(&mut policy, index).map(|_| 0)
+ })
+ }
+
+ // Policy's fast_switch callback.
+ extern "C" fn fast_switch_callback(
+ ptr: *mut bindings::cpufreq_policy,
+ target_freq: u32,
+ ) -> core::ffi::c_uint {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::fast_switch(&mut policy, target_freq)
+ }
+
+ // Policy's adjust_perf callback.
+ extern "C" fn adjust_perf_callback(cpu: u32, min_perf: u64, target_perf: u64, capacity: u64) {
+ if let Some(mut policy) = Policy::from_cpu(cpu).ok() {
+ T::adjust_perf(&mut policy, min_perf, target_perf, capacity);
+ }
+ }
+
+ // Policy's get_intermediate callback.
+ extern "C" fn get_intermediate_callback(
+ ptr: *mut bindings::cpufreq_policy,
+ index: u32,
+ ) -> core::ffi::c_uint {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::get_intermediate(&mut policy, index)
+ }
+
+ // Policy's target_intermediate callback.
+ extern "C" fn target_intermediate_callback(
+ ptr: *mut bindings::cpufreq_policy,
+ index: u32,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::target_intermediate(&mut policy, index).map(|_| 0)
+ })
+ }
+
+ // Policy's get callback.
+ extern "C" fn get_callback(cpu: u32) -> core::ffi::c_uint {
+ // SAFETY: Get the policy for a CPU.
+ Policy::from_cpu(cpu).map_or(0, |mut policy| T::get(&mut policy).map_or(0, |f| f))
+ }
+
+ // Policy's update_limit callback.
+ extern "C" fn update_limits_callback(cpu: u32) {
+ // SAFETY: Get the policy for a CPU.
+ if let Some(mut policy) = Policy::from_cpu(cpu).ok() {
+ T::update_limits(&mut policy);
+ }
+ }
+
+ // Policy's bios_limit callback.
+ extern "C" fn bios_limit_callback(cpu: i32, limit: *mut u32) -> core::ffi::c_int {
+ from_result(|| {
+ let mut policy = Policy::from_cpu(cpu as u32)?;
+
+ // SAFETY: The pointer is guaranteed by the C code to be valid.
+ T::bios_limit(&mut policy, &mut (unsafe { *limit })).map(|_| 0)
+ })
+ }
+
+ // Policy's set_boost callback.
+ extern "C" fn set_boost_callback(
+ ptr: *mut bindings::cpufreq_policy,
+ state: i32,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::set_boost(&mut policy, state).map(|_| 0)
+ })
+ }
+
+ // Policy's register_em callback.
+ extern "C" fn register_em_callback(ptr: *mut bindings::cpufreq_policy) {
+ // SAFETY: `ptr` is valid by the contract with the C code. `policy` is alive only for the
+ // duration of this call, so it is guaranteed to remain alive for the lifetime of
+ // `ptr`.
+ let mut policy = unsafe { Policy::from_ptr(ptr) };
+ T::register_em(&mut policy);
+ }
+}
+
+impl<T: DriverOps> Drop for Registration<T> {
+ // Removes the registration from the kernel if it has completed successfully before.
+ fn drop(&mut self) {
+ let drv = self.drv.get_mut();
+
+ if self.registered {
+ // SAFETY: The driver was earlier registered from `register()`.
+ unsafe { bindings::cpufreq_unregister_driver(drv) };
+ }
+
+ // Free the previously leaked memory to the C code.
+ if !drv.attr.is_null() {
+ // SAFETY: The pointer was earlier initialized from the result of `Box::leak`.
+ unsafe { drop(Box::from_raw(drv.attr)) };
+ }
+
+ // Free data
+ drop(self.clear_data());
+ }
+}
@@ -34,6 +34,8 @@
#[cfg(not(testlib))]
mod allocator;
mod build_assert;
+#[cfg(CONFIG_CPU_FREQ)]
+pub mod cpufreq;
pub mod cred;
pub mod device;
pub mod driver;
This commit adds Rust bindings for the cpufreq core. The current implementation doesn't implement Rust wrappers for all the APIs, but mostly the ones usable by the cpufreq-dt driver. The missing APIs will be added later once required. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- rust/bindings/bindings_helper.h | 1 + rust/helpers.c | 15 + rust/kernel/cpufreq.rs | 1090 +++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 2 + 4 files changed, 1108 insertions(+) create mode 100644 rust/kernel/cpufreq.rs