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Diffstat (limited to 'rust/kernel/opp.rs')
| -rw-r--r-- | rust/kernel/opp.rs | 1146 |
1 files changed, 1146 insertions, 0 deletions
diff --git a/rust/kernel/opp.rs b/rust/kernel/opp.rs new file mode 100644 index 000000000000..a566fc3e7dcb --- /dev/null +++ b/rust/kernel/opp.rs @@ -0,0 +1,1146 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Operating performance points. +//! +//! This module provides rust abstractions for interacting with the OPP subsystem. +//! +//! C header: [`include/linux/pm_opp.h`](srctree/include/linux/pm_opp.h) +//! +//! Reference: <https://docs.kernel.org/power/opp.html> + +use crate::{ + clk::Hertz, + cpumask::{Cpumask, CpumaskVar}, + device::Device, + error::{code::*, from_err_ptr, from_result, to_result, Error, Result, VTABLE_DEFAULT_ERROR}, + ffi::c_ulong, + prelude::*, + str::CString, + types::{ARef, AlwaysRefCounted, Opaque}, +}; + +#[cfg(CONFIG_CPU_FREQ)] +/// Frequency table implementation. +mod freq { + use super::*; + use crate::cpufreq; + use core::ops::Deref; + + /// OPP frequency table. + /// + /// A [`cpufreq::Table`] created from [`Table`]. + pub struct FreqTable { + dev: ARef<Device>, + ptr: *mut bindings::cpufreq_frequency_table, + } + + impl FreqTable { + /// Creates a new instance of [`FreqTable`] from [`Table`]. + pub(crate) 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) } + } + } + + impl Deref for FreqTable { + type Target = cpufreq::Table; + + #[inline] + fn deref(&self) -> &Self::Target { + self.table() + } + } + + 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()) + }; + } + } +} + +#[cfg(CONFIG_CPU_FREQ)] +pub use freq::FreqTable; + +use core::{marker::PhantomData, ptr}; + +use macros::vtable; + +/// Creates a null-terminated slice of pointers to [`Cstring`]s. +fn to_c_str_array(names: &[CString]) -> Result<KVec<*const u8>> { + // Allocated a null-terminated vector of pointers. + let mut list = KVec::with_capacity(names.len() + 1, GFP_KERNEL)?; + + for name in names.iter() { + list.push(name.as_ptr() as _, GFP_KERNEL)?; + } + + list.push(ptr::null(), GFP_KERNEL)?; + Ok(list) +} + +/// The voltage unit. +/// +/// Represents voltage in microvolts, wrapping a [`c_ulong`] value. +/// +/// ## Examples +/// +/// ``` +/// use kernel::opp::MicroVolt; +/// +/// let raw = 90500; +/// let volt = MicroVolt(raw); +/// +/// assert_eq!(usize::from(volt), raw); +/// assert_eq!(volt, MicroVolt(raw)); +/// ``` +#[derive(Copy, Clone, PartialEq, Eq, Debug)] +pub struct MicroVolt(pub c_ulong); + +impl From<MicroVolt> for c_ulong { + #[inline] + fn from(volt: MicroVolt) -> Self { + volt.0 + } +} + +/// The power unit. +/// +/// Represents power in microwatts, wrapping a [`c_ulong`] value. +/// +/// ## Examples +/// +/// ``` +/// use kernel::opp::MicroWatt; +/// +/// let raw = 1000000; +/// let power = MicroWatt(raw); +/// +/// assert_eq!(usize::from(power), raw); +/// assert_eq!(power, MicroWatt(raw)); +/// ``` +#[derive(Copy, Clone, PartialEq, Eq, Debug)] +pub struct MicroWatt(pub c_ulong); + +impl From<MicroWatt> for c_ulong { + #[inline] + fn from(power: MicroWatt) -> Self { + power.0 + } +} + +/// Handle for a dynamically created [`OPP`]. +/// +/// The associated [`OPP`] is automatically removed when the [`Token`] is dropped. +/// +/// ## Examples +/// +/// The following example demonstrates how to create an [`OPP`] dynamically. +/// +/// ``` +/// use kernel::clk::Hertz; +/// use kernel::device::Device; +/// use kernel::error::Result; +/// use kernel::opp::{Data, MicroVolt, Token}; +/// use kernel::types::ARef; +/// +/// fn create_opp(dev: &ARef<Device>, freq: Hertz, volt: MicroVolt, level: u32) -> Result<Token> { +/// let data = Data::new(freq, volt, level, false); +/// +/// // OPP is removed once token goes out of scope. +/// data.add_opp(dev) +/// } +/// ``` +pub struct Token { + dev: ARef<Device>, + freq: Hertz, +} + +impl Token { + /// Dynamically adds an [`OPP`] and returns a [`Token`] that removes it on drop. + fn new(dev: &ARef<Device>, mut data: Data) -> Result<Self> { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { bindings::dev_pm_opp_add_dynamic(dev.as_raw(), &mut data.0) })?; + Ok(Self { + dev: dev.clone(), + freq: data.freq(), + }) + } +} + +impl Drop for Token { + fn drop(&mut self) { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + unsafe { bindings::dev_pm_opp_remove(self.dev.as_raw(), self.freq.into()) }; + } +} + +/// OPP data. +/// +/// Rust abstraction for the C `struct dev_pm_opp_data`, used to define operating performance +/// points (OPPs) dynamically. +/// +/// ## Examples +/// +/// The following example demonstrates how to create an [`OPP`] with [`Data`]. +/// +/// ``` +/// use kernel::clk::Hertz; +/// use kernel::device::Device; +/// use kernel::error::Result; +/// use kernel::opp::{Data, MicroVolt, Token}; +/// use kernel::types::ARef; +/// +/// fn create_opp(dev: &ARef<Device>, freq: Hertz, volt: MicroVolt, level: u32) -> Result<Token> { +/// let data = Data::new(freq, volt, level, false); +/// +/// // OPP is removed once token goes out of scope. +/// data.add_opp(dev) +/// } +/// ``` +#[repr(transparent)] +pub struct Data(bindings::dev_pm_opp_data); + +impl Data { + /// Creates a new instance of [`Data`]. + /// + /// This can be used to define a dynamic OPP to be added to a device. + pub fn new(freq: Hertz, volt: MicroVolt, level: u32, turbo: bool) -> Self { + Self(bindings::dev_pm_opp_data { + turbo, + freq: freq.into(), + u_volt: volt.into(), + level, + }) + } + + /// Adds an [`OPP`] dynamically. + /// + /// Returns a [`Token`] that ensures the OPP is automatically removed + /// when it goes out of scope. + #[inline] + pub fn add_opp(self, dev: &ARef<Device>) -> Result<Token> { + Token::new(dev, self) + } + + /// Returns the frequency associated with this OPP data. + #[inline] + fn freq(&self) -> Hertz { + Hertz(self.0.freq) + } +} + +/// [`OPP`] search options. +/// +/// ## Examples +/// +/// Defines how to search for an [`OPP`] in a [`Table`] relative to a frequency. +/// +/// ``` +/// use kernel::clk::Hertz; +/// use kernel::error::Result; +/// use kernel::opp::{OPP, SearchType, Table}; +/// use kernel::types::ARef; +/// +/// fn find_opp(table: &Table, freq: Hertz) -> Result<ARef<OPP>> { +/// let opp = table.opp_from_freq(freq, Some(true), None, SearchType::Exact)?; +/// +/// pr_info!("OPP frequency is: {:?}\n", opp.freq(None)); +/// pr_info!("OPP voltage is: {:?}\n", opp.voltage()); +/// pr_info!("OPP level is: {}\n", opp.level()); +/// pr_info!("OPP power is: {:?}\n", opp.power()); +/// +/// Ok(opp) +/// } +/// ``` +#[derive(Copy, Clone, Debug, Eq, PartialEq)] +pub enum SearchType { + /// Match the exact frequency. + Exact, + /// Find the highest frequency less than or equal to the given value. + Floor, + /// Find the lowest frequency greater than or equal to the given value. + Ceil, +} + +/// OPP configuration callbacks. +/// +/// Implement this trait to customize OPP clock and regulator setup for your device. +#[vtable] +pub trait ConfigOps { + /// This is typically used to scale clocks when transitioning between OPPs. + #[inline] + fn config_clks(_dev: &Device, _table: &Table, _opp: &OPP, _scaling_down: bool) -> Result { + build_error!(VTABLE_DEFAULT_ERROR) + } + + /// This provides access to the old and new OPPs, allowing for safe regulator adjustments. + #[inline] + fn config_regulators( + _dev: &Device, + _opp_old: &OPP, + _opp_new: &OPP, + _data: *mut *mut bindings::regulator, + _count: u32, + ) -> Result { + build_error!(VTABLE_DEFAULT_ERROR) + } +} + +/// OPP configuration token. +/// +/// Returned by the OPP core when configuration is applied to a [`Device`]. The associated +/// configuration is automatically cleared when the token is dropped. +pub struct ConfigToken(i32); + +impl Drop for ConfigToken { + fn drop(&mut self) { + // SAFETY: This is the same token value returned by the C code via `dev_pm_opp_set_config`. + unsafe { bindings::dev_pm_opp_clear_config(self.0) }; + } +} + +/// OPP configurations. +/// +/// Rust abstraction for the C `struct dev_pm_opp_config`. +/// +/// ## Examples +/// +/// The following example demonstrates how to set OPP property-name configuration for a [`Device`]. +/// +/// ``` +/// use kernel::device::Device; +/// use kernel::error::Result; +/// use kernel::opp::{Config, ConfigOps, ConfigToken}; +/// use kernel::str::CString; +/// use kernel::types::ARef; +/// use kernel::macros::vtable; +/// +/// #[derive(Default)] +/// struct Driver; +/// +/// #[vtable] +/// impl ConfigOps for Driver {} +/// +/// fn configure(dev: &ARef<Device>) -> Result<ConfigToken> { +/// let name = CString::try_from_fmt(fmt!("{}", "slow"))?; +/// +/// // The OPP configuration is cleared once the [`ConfigToken`] goes out of scope. +/// Config::<Driver>::new() +/// .set_prop_name(name)? +/// .set(dev) +/// } +/// ``` +#[derive(Default)] +pub struct Config<T: ConfigOps> +where + T: Default, +{ + clk_names: Option<KVec<CString>>, + prop_name: Option<CString>, + regulator_names: Option<KVec<CString>>, + supported_hw: Option<KVec<u32>>, + + // Tuple containing (required device, index) + required_dev: Option<(ARef<Device>, u32)>, + _data: PhantomData<T>, +} + +impl<T: ConfigOps + Default> Config<T> { + /// Creates a new instance of [`Config`]. + #[inline] + pub fn new() -> Self { + Self::default() + } + + /// Initializes clock names. + pub fn set_clk_names(mut self, names: KVec<CString>) -> Result<Self> { + if self.clk_names.is_some() { + return Err(EBUSY); + } + + if names.is_empty() { + return Err(EINVAL); + } + + self.clk_names = Some(names); + Ok(self) + } + + /// Initializes property name. + pub fn set_prop_name(mut self, name: CString) -> Result<Self> { + if self.prop_name.is_some() { + return Err(EBUSY); + } + + self.prop_name = Some(name); + Ok(self) + } + + /// Initializes regulator names. + pub fn set_regulator_names(mut self, names: KVec<CString>) -> Result<Self> { + if self.regulator_names.is_some() { + return Err(EBUSY); + } + + if names.is_empty() { + return Err(EINVAL); + } + + self.regulator_names = Some(names); + + Ok(self) + } + + /// Initializes required devices. + pub fn set_required_dev(mut self, dev: ARef<Device>, index: u32) -> Result<Self> { + if self.required_dev.is_some() { + return Err(EBUSY); + } + + self.required_dev = Some((dev, index)); + Ok(self) + } + + /// Initializes supported hardware. + pub fn set_supported_hw(mut self, hw: KVec<u32>) -> Result<Self> { + if self.supported_hw.is_some() { + return Err(EBUSY); + } + + if hw.is_empty() { + return Err(EINVAL); + } + + self.supported_hw = Some(hw); + Ok(self) + } + + /// Sets the configuration with the OPP core. + /// + /// The returned [`ConfigToken`] will remove the configuration when dropped. + pub fn set(self, dev: &Device) -> Result<ConfigToken> { + let (_clk_list, clk_names) = match &self.clk_names { + Some(x) => { + let list = to_c_str_array(x)?; + let ptr = list.as_ptr(); + (Some(list), ptr) + } + None => (None, ptr::null()), + }; + + let (_regulator_list, regulator_names) = match &self.regulator_names { + Some(x) => { + let list = to_c_str_array(x)?; + let ptr = list.as_ptr(); + (Some(list), ptr) + } + None => (None, ptr::null()), + }; + + let prop_name = self + .prop_name + .as_ref() + .map_or(ptr::null(), |p| p.as_char_ptr()); + + let (supported_hw, supported_hw_count) = self + .supported_hw + .as_ref() + .map_or((ptr::null(), 0), |hw| (hw.as_ptr(), hw.len() as u32)); + + let (required_dev, required_dev_index) = self + .required_dev + .as_ref() + .map_or((ptr::null_mut(), 0), |(dev, idx)| (dev.as_raw(), *idx)); + + let mut config = bindings::dev_pm_opp_config { + clk_names, + config_clks: if T::HAS_CONFIG_CLKS { + Some(Self::config_clks) + } else { + None + }, + prop_name, + regulator_names, + config_regulators: if T::HAS_CONFIG_REGULATORS { + Some(Self::config_regulators) + } else { + None + }, + supported_hw, + supported_hw_count, + + required_dev, + required_dev_index, + }; + + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. The OPP core guarantees not to access fields of [`Config`] after this call + // and so we don't need to save a copy of them for future use. + let ret = unsafe { bindings::dev_pm_opp_set_config(dev.as_raw(), &mut config) }; + if ret < 0 { + Err(Error::from_errno(ret)) + } else { + Ok(ConfigToken(ret)) + } + } + + /// Config's clk callback. + /// + /// SAFETY: Called from C. Inputs must be valid pointers. + extern "C" fn config_clks( + dev: *mut bindings::device, + opp_table: *mut bindings::opp_table, + opp: *mut bindings::dev_pm_opp, + _data: *mut kernel::ffi::c_void, + scaling_down: bool, + ) -> kernel::ffi::c_int { + from_result(|| { + // SAFETY: 'dev' is guaranteed by the C code to be valid. + let dev = unsafe { Device::get_device(dev) }; + T::config_clks( + &dev, + // SAFETY: 'opp_table' is guaranteed by the C code to be valid. + &unsafe { Table::from_raw_table(opp_table, &dev) }, + // SAFETY: 'opp' is guaranteed by the C code to be valid. + unsafe { OPP::from_raw_opp(opp)? }, + scaling_down, + ) + .map(|()| 0) + }) + } + + /// Config's regulator callback. + /// + /// SAFETY: Called from C. Inputs must be valid pointers. + extern "C" fn config_regulators( + dev: *mut bindings::device, + old_opp: *mut bindings::dev_pm_opp, + new_opp: *mut bindings::dev_pm_opp, + regulators: *mut *mut bindings::regulator, + count: kernel::ffi::c_uint, + ) -> kernel::ffi::c_int { + from_result(|| { + // SAFETY: 'dev' is guaranteed by the C code to be valid. + let dev = unsafe { Device::get_device(dev) }; + T::config_regulators( + &dev, + // SAFETY: 'old_opp' is guaranteed by the C code to be valid. + unsafe { OPP::from_raw_opp(old_opp)? }, + // SAFETY: 'new_opp' is guaranteed by the C code to be valid. + unsafe { OPP::from_raw_opp(new_opp)? }, + regulators, + count, + ) + .map(|()| 0) + }) + } +} + +/// A reference-counted OPP table. +/// +/// Rust abstraction for the C `struct opp_table`. +/// +/// # Invariants +/// +/// The pointer stored in `Self` is non-null and valid for the lifetime of the [`Table`]. +/// +/// Instances of this type are reference-counted. +/// +/// ## Examples +/// +/// The following example demonstrates how to get OPP [`Table`] for a [`Cpumask`] and set its +/// frequency. +/// +/// ``` +/// # #![cfg(CONFIG_OF)] +/// use kernel::clk::Hertz; +/// use kernel::cpumask::Cpumask; +/// use kernel::device::Device; +/// use kernel::error::Result; +/// use kernel::opp::Table; +/// use kernel::types::ARef; +/// +/// fn get_table(dev: &ARef<Device>, mask: &mut Cpumask, freq: Hertz) -> Result<Table> { +/// let mut opp_table = Table::from_of_cpumask(dev, mask)?; +/// +/// if opp_table.opp_count()? == 0 { +/// return Err(EINVAL); +/// } +/// +/// pr_info!("Max transition latency is: {} ns\n", opp_table.max_transition_latency_ns()); +/// pr_info!("Suspend frequency is: {:?}\n", opp_table.suspend_freq()); +/// +/// opp_table.set_rate(freq)?; +/// Ok(opp_table) +/// } +/// ``` +pub struct Table { + ptr: *mut bindings::opp_table, + dev: ARef<Device>, + #[allow(dead_code)] + em: bool, + #[allow(dead_code)] + of: bool, + cpus: Option<CpumaskVar>, +} + +/// SAFETY: It is okay to send ownership of [`Table`] across thread boundaries. +unsafe impl Send for Table {} + +/// SAFETY: It is okay to access [`Table`] through shared references from other threads because +/// we're either accessing properties that don't change or that are properly synchronised by C code. +unsafe impl Sync for Table {} + +impl Table { + /// Creates a new reference-counted [`Table`] from a raw pointer. + /// + /// # Safety + /// + /// Callers must ensure that `ptr` is valid and non-null. + unsafe fn from_raw_table(ptr: *mut bindings::opp_table, dev: &ARef<Device>) -> Self { + // SAFETY: By the safety requirements, ptr is valid and its refcount will be incremented. + // + // INVARIANT: The reference-count is decremented when [`Table`] goes out of scope. + unsafe { bindings::dev_pm_opp_get_opp_table_ref(ptr) }; + + Self { + ptr, + dev: dev.clone(), + em: false, + of: false, + cpus: None, + } + } + + /// Creates a new reference-counted [`Table`] instance for a [`Device`]. + pub fn from_dev(dev: &Device) -> Result<Self> { + // SAFETY: The requirements are satisfied by the existence of the [`Device`] and its safety + // requirements. + // + // INVARIANT: The reference-count is incremented by the C code and is decremented when + // [`Table`] goes out of scope. + let ptr = from_err_ptr(unsafe { bindings::dev_pm_opp_get_opp_table(dev.as_raw()) })?; + + Ok(Self { + ptr, + dev: dev.into(), + em: false, + of: false, + cpus: None, + }) + } + + /// Creates a new reference-counted [`Table`] instance for a [`Device`] based on device tree + /// entries. + #[cfg(CONFIG_OF)] + pub fn from_of(dev: &ARef<Device>, index: i32) -> Result<Self> { + // SAFETY: The requirements are satisfied by the existence of the [`Device`] and its safety + // requirements. + // + // INVARIANT: The reference-count is incremented by the C code and is decremented when + // [`Table`] goes out of scope. + to_result(unsafe { bindings::dev_pm_opp_of_add_table_indexed(dev.as_raw(), index) })?; + + // Get the newly created [`Table`]. + let mut table = Self::from_dev(dev)?; + table.of = true; + + Ok(table) + } + + /// Remove device tree based [`Table`]. + #[cfg(CONFIG_OF)] + #[inline] + fn remove_of(&self) { + // SAFETY: The requirements are satisfied by the existence of the [`Device`] and its safety + // requirements. We took the reference from [`from_of`] earlier, it is safe to drop the + // same now. + unsafe { bindings::dev_pm_opp_of_remove_table(self.dev.as_raw()) }; + } + + /// Creates a new reference-counted [`Table`] instance for a [`Cpumask`] based on device tree + /// entries. + #[cfg(CONFIG_OF)] + pub fn from_of_cpumask(dev: &Device, cpumask: &mut Cpumask) -> Result<Self> { + // SAFETY: The cpumask is valid and the returned pointer will be owned by the [`Table`] + // instance. + // + // INVARIANT: The reference-count is incremented by the C code and is decremented when + // [`Table`] goes out of scope. + to_result(unsafe { bindings::dev_pm_opp_of_cpumask_add_table(cpumask.as_raw()) })?; + + // Fetch the newly created table. + let mut table = Self::from_dev(dev)?; + table.cpus = Some(CpumaskVar::try_clone(cpumask)?); + + Ok(table) + } + + /// Remove device tree based [`Table`] for a [`Cpumask`]. + #[cfg(CONFIG_OF)] + #[inline] + fn remove_of_cpumask(&self, cpumask: &Cpumask) { + // SAFETY: The cpumask is valid and we took the reference from [`from_of_cpumask`] earlier, + // it is safe to drop the same now. + unsafe { bindings::dev_pm_opp_of_cpumask_remove_table(cpumask.as_raw()) }; + } + + /// Returns the number of [`OPP`]s in the [`Table`]. + pub fn opp_count(&self) -> Result<u32> { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + let ret = unsafe { bindings::dev_pm_opp_get_opp_count(self.dev.as_raw()) }; + if ret < 0 { + Err(Error::from_errno(ret)) + } else { + Ok(ret as u32) + } + } + + /// Returns max clock latency (in nanoseconds) of the [`OPP`]s in the [`Table`]. + #[inline] + pub fn max_clock_latency_ns(&self) -> usize { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + unsafe { bindings::dev_pm_opp_get_max_clock_latency(self.dev.as_raw()) } + } + + /// Returns max volt latency (in nanoseconds) of the [`OPP`]s in the [`Table`]. + #[inline] + pub fn max_volt_latency_ns(&self) -> usize { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + unsafe { bindings::dev_pm_opp_get_max_volt_latency(self.dev.as_raw()) } + } + + /// Returns max transition latency (in nanoseconds) of the [`OPP`]s in the [`Table`]. + #[inline] + pub fn max_transition_latency_ns(&self) -> usize { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + unsafe { bindings::dev_pm_opp_get_max_transition_latency(self.dev.as_raw()) } + } + + /// Returns the suspend [`OPP`]'s frequency. + #[inline] + pub fn suspend_freq(&self) -> Hertz { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + Hertz(unsafe { bindings::dev_pm_opp_get_suspend_opp_freq(self.dev.as_raw()) }) + } + + /// Synchronizes regulators used by the [`Table`]. + #[inline] + pub fn sync_regulators(&self) -> Result { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { bindings::dev_pm_opp_sync_regulators(self.dev.as_raw()) }) + } + + /// Gets sharing CPUs. + #[inline] + pub fn sharing_cpus(dev: &Device, cpumask: &mut Cpumask) -> Result { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { bindings::dev_pm_opp_get_sharing_cpus(dev.as_raw(), cpumask.as_raw()) }) + } + + /// Sets sharing CPUs. + pub fn set_sharing_cpus(&mut self, cpumask: &mut Cpumask) -> Result { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { + bindings::dev_pm_opp_set_sharing_cpus(self.dev.as_raw(), cpumask.as_raw()) + })?; + + if let Some(mask) = self.cpus.as_mut() { + // Update the cpumask as this will be used while removing the table. + cpumask.copy(mask); + } + + Ok(()) + } + + /// Gets sharing CPUs from device tree. + #[cfg(CONFIG_OF)] + #[inline] + pub fn of_sharing_cpus(dev: &Device, cpumask: &mut Cpumask) -> Result { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { + bindings::dev_pm_opp_of_get_sharing_cpus(dev.as_raw(), cpumask.as_raw()) + }) + } + + /// Updates the voltage value for an [`OPP`]. + #[inline] + pub fn adjust_voltage( + &self, + freq: Hertz, + volt: MicroVolt, + volt_min: MicroVolt, + volt_max: MicroVolt, + ) -> Result { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { + bindings::dev_pm_opp_adjust_voltage( + self.dev.as_raw(), + freq.into(), + volt.into(), + volt_min.into(), + volt_max.into(), + ) + }) + } + + /// 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 { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { bindings::dev_pm_opp_set_rate(self.dev.as_raw(), freq.into()) }) + } + + /// Configures device with [`OPP`]. + #[inline] + pub fn set_opp(&self, opp: &OPP) -> Result { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { bindings::dev_pm_opp_set_opp(self.dev.as_raw(), opp.as_raw()) }) + } + + /// Finds [`OPP`] based on frequency. + pub fn opp_from_freq( + &self, + freq: Hertz, + available: Option<bool>, + index: Option<u32>, + stype: SearchType, + ) -> Result<ARef<OPP>> { + let raw_dev = self.dev.as_raw(); + let index = index.unwrap_or(0); + let mut rate = freq.into(); + + let ptr = from_err_ptr(match stype { + SearchType::Exact => { + if let Some(available) = available { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and + // its safety requirements. The returned pointer will be owned by the new + // [`OPP`] instance. + unsafe { + bindings::dev_pm_opp_find_freq_exact_indexed( + raw_dev, rate, index, available, + ) + } + } else { + return Err(EINVAL); + } + } + + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. The returned pointer will be owned by the new [`OPP`] instance. + SearchType::Ceil => unsafe { + bindings::dev_pm_opp_find_freq_ceil_indexed(raw_dev, &mut rate, index) + }, + + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. The returned pointer will be owned by the new [`OPP`] instance. + SearchType::Floor => unsafe { + bindings::dev_pm_opp_find_freq_floor_indexed(raw_dev, &mut rate, index) + }, + })?; + + // SAFETY: The `ptr` is guaranteed by the C code to be valid. + unsafe { OPP::from_raw_opp_owned(ptr) } + } + + /// Finds [`OPP`] based on level. + pub fn opp_from_level(&self, mut level: u32, stype: SearchType) -> Result<ARef<OPP>> { + let raw_dev = self.dev.as_raw(); + + let ptr = from_err_ptr(match stype { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. The returned pointer will be owned by the new [`OPP`] instance. + SearchType::Exact => unsafe { bindings::dev_pm_opp_find_level_exact(raw_dev, level) }, + + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. The returned pointer will be owned by the new [`OPP`] instance. + SearchType::Ceil => unsafe { + bindings::dev_pm_opp_find_level_ceil(raw_dev, &mut level) + }, + + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. The returned pointer will be owned by the new [`OPP`] instance. + SearchType::Floor => unsafe { + bindings::dev_pm_opp_find_level_floor(raw_dev, &mut level) + }, + })?; + + // SAFETY: The `ptr` is guaranteed by the C code to be valid. + unsafe { OPP::from_raw_opp_owned(ptr) } + } + + /// Finds [`OPP`] based on bandwidth. + pub fn opp_from_bw(&self, mut bw: u32, index: i32, stype: SearchType) -> Result<ARef<OPP>> { + let raw_dev = self.dev.as_raw(); + + let ptr = from_err_ptr(match stype { + // The OPP core doesn't support this yet. + SearchType::Exact => return Err(EINVAL), + + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. The returned pointer will be owned by the new [`OPP`] instance. + SearchType::Ceil => unsafe { + bindings::dev_pm_opp_find_bw_ceil(raw_dev, &mut bw, index) + }, + + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. The returned pointer will be owned by the new [`OPP`] instance. + SearchType::Floor => unsafe { + bindings::dev_pm_opp_find_bw_floor(raw_dev, &mut bw, index) + }, + })?; + + // SAFETY: The `ptr` is guaranteed by the C code to be valid. + unsafe { OPP::from_raw_opp_owned(ptr) } + } + + /// Enables the [`OPP`]. + #[inline] + pub fn enable_opp(&self, freq: Hertz) -> Result { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { bindings::dev_pm_opp_enable(self.dev.as_raw(), freq.into()) }) + } + + /// Disables the [`OPP`]. + #[inline] + pub fn disable_opp(&self, freq: Hertz) -> Result { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { bindings::dev_pm_opp_disable(self.dev.as_raw(), freq.into()) }) + } + + /// Registers with the Energy model. + #[cfg(CONFIG_OF)] + pub fn of_register_em(&mut self, cpumask: &mut Cpumask) -> Result { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. + to_result(unsafe { + bindings::dev_pm_opp_of_register_em(self.dev.as_raw(), cpumask.as_raw()) + })?; + + self.em = true; + Ok(()) + } + + /// Unregisters with the Energy model. + #[cfg(all(CONFIG_OF, CONFIG_ENERGY_MODEL))] + #[inline] + fn of_unregister_em(&self) { + // SAFETY: The requirements are satisfied by the existence of [`Device`] and its safety + // requirements. We registered with the EM framework earlier, it is safe to unregister now. + unsafe { bindings::em_dev_unregister_perf_domain(self.dev.as_raw()) }; + } +} + +impl Drop for Table { + 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::dev_pm_opp_put_opp_table(self.ptr) }; + + #[cfg(CONFIG_OF)] + { + #[cfg(CONFIG_ENERGY_MODEL)] + if self.em { + self.of_unregister_em(); + } + + if self.of { + self.remove_of(); + } else if let Some(cpumask) = self.cpus.take() { + self.remove_of_cpumask(&cpumask); + } + } + } +} + +/// A reference-counted Operating performance point (OPP). +/// +/// Rust abstraction for the C `struct dev_pm_opp`. +/// +/// # Invariants +/// +/// The pointer stored in `Self` is non-null and valid for the lifetime of the [`OPP`]. +/// +/// Instances of this type are reference-counted. The reference count is incremented by the +/// `dev_pm_opp_get` function and decremented by `dev_pm_opp_put`. The Rust type `ARef<OPP>` +/// represents a pointer that owns a reference count on the [`OPP`]. +/// +/// A reference to the [`OPP`], &[`OPP`], isn't refcounted by the Rust code. +/// +/// ## Examples +/// +/// The following example demonstrates how to get [`OPP`] corresponding to a frequency value and +/// configure the device with it. +/// +/// ``` +/// use kernel::clk::Hertz; +/// use kernel::error::Result; +/// use kernel::opp::{SearchType, Table}; +/// +/// fn configure_opp(table: &Table, freq: Hertz) -> Result { +/// let opp = table.opp_from_freq(freq, Some(true), None, SearchType::Exact)?; +/// +/// if opp.freq(None) != freq { +/// return Err(EINVAL); +/// } +/// +/// table.set_opp(&opp) +/// } +/// ``` +#[repr(transparent)] +pub struct OPP(Opaque<bindings::dev_pm_opp>); + +/// SAFETY: It is okay to send the ownership of [`OPP`] across thread boundaries. +unsafe impl Send for OPP {} + +/// SAFETY: It is okay to access [`OPP`] through shared references from other threads because we're +/// either accessing properties that don't change or that are properly synchronised by C code. +unsafe impl Sync for OPP {} + +/// SAFETY: The type invariants guarantee that [`OPP`] is always refcounted. +unsafe impl AlwaysRefCounted for OPP { + fn inc_ref(&self) { + // SAFETY: The existence of a shared reference means that the refcount is nonzero. + unsafe { bindings::dev_pm_opp_get(self.0.get()) }; + } + + unsafe fn dec_ref(obj: ptr::NonNull<Self>) { + // SAFETY: The safety requirements guarantee that the refcount is nonzero. + unsafe { bindings::dev_pm_opp_put(obj.cast().as_ptr()) } + } +} + +impl OPP { + /// Creates an owned reference to a [`OPP`] from a valid pointer. + /// + /// The refcount is incremented by the C code and will be decremented by `dec_ref` when the + /// [`ARef`] object is dropped. + /// + /// # Safety + /// + /// The caller must ensure that `ptr` is valid and the refcount of the [`OPP`] is incremented. + /// The caller must also ensure that it doesn't explicitly drop the refcount of the [`OPP`], as + /// the returned [`ARef`] object takes over the refcount increment on the underlying object and + /// the same will be dropped along with it. + pub unsafe fn from_raw_opp_owned(ptr: *mut bindings::dev_pm_opp) -> Result<ARef<Self>> { + let ptr = ptr::NonNull::new(ptr).ok_or(ENODEV)?; + + // SAFETY: The safety requirements guarantee the validity of the pointer. + // + // INVARIANT: The reference-count is decremented when [`OPP`] goes out of scope. + Ok(unsafe { ARef::from_raw(ptr.cast()) }) + } + + /// Creates a reference to a [`OPP`] from a valid pointer. + /// + /// The refcount is not updated by the Rust API unless the returned reference is converted to + /// an [`ARef`] object. + /// + /// # Safety + /// + /// The caller must ensure that `ptr` is valid and remains valid for the duration of `'a`. + #[inline] + pub unsafe fn from_raw_opp<'a>(ptr: *mut bindings::dev_pm_opp) -> Result<&'a Self> { + // SAFETY: The caller guarantees that the pointer is not dangling and stays valid for the + // duration of 'a. The cast is okay because [`OPP`] is `repr(transparent)`. + Ok(unsafe { &*ptr.cast() }) + } + + #[inline] + fn as_raw(&self) -> *mut bindings::dev_pm_opp { + self.0.get() + } + + /// Returns the frequency of an [`OPP`]. + pub fn freq(&self, index: Option<u32>) -> Hertz { + let index = index.unwrap_or(0); + + // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to + // use it. + Hertz(unsafe { bindings::dev_pm_opp_get_freq_indexed(self.as_raw(), index) }) + } + + /// Returns the voltage of an [`OPP`]. + #[inline] + pub fn voltage(&self) -> MicroVolt { + // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to + // use it. + MicroVolt(unsafe { bindings::dev_pm_opp_get_voltage(self.as_raw()) }) + } + + /// Returns the level of an [`OPP`]. + #[inline] + pub fn level(&self) -> u32 { + // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to + // use it. + unsafe { bindings::dev_pm_opp_get_level(self.as_raw()) } + } + + /// Returns the power of an [`OPP`]. + #[inline] + pub fn power(&self) -> MicroWatt { + // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to + // use it. + MicroWatt(unsafe { bindings::dev_pm_opp_get_power(self.as_raw()) }) + } + + /// Returns the required pstate of an [`OPP`]. + #[inline] + pub fn required_pstate(&self, index: u32) -> u32 { + // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to + // use it. + unsafe { bindings::dev_pm_opp_get_required_pstate(self.as_raw(), index) } + } + + /// Returns true if the [`OPP`] is turbo. + #[inline] + pub fn is_turbo(&self) -> bool { + // SAFETY: By the type invariants, we know that `self` owns a reference, so it is safe to + // use it. + unsafe { bindings::dev_pm_opp_is_turbo(self.as_raw()) } + } +} |