Merge tag 'driver-core-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-coreHEADmaster

Pull driver core updates from Danilo Krummrich:
 "Arch Topology:
   - Move parse_acpi_topology() from arm64 to common code for reuse in
     RISC-V

  CPU:
   - Expose housekeeping CPUs through /sys/devices/system/cpu/housekeeping
   - Print a newline (or 0x0A) instead of '(null)' reading
     /sys/devices/system/cpu/nohz_full when nohz_full= is not set

  debugfs
   - Remove (broken) 'no-mount' mode
   - Remove redundant access mode checks in debugfs_get_tree() and
     debugfs_create_*() functions

  Devres:
   - Remove unused devm_free_percpu() helper
   - Move devm_alloc_percpu() from device.h to devres.h

  Firmware Loader:
   - Replace simple_strtol() with kstrtoint()
   - Do not call cancel_store() when no upload is in progress

  kernfs:
   - Increase struct super_block::maxbytes to MAX_LFS_FILESIZE
   - Fix a missing unwind path in __kernfs_new_node()

  Misc:
   - Increase the name size in struct auxiliary_device_id to 40
     characters
   - Replace system_unbound_wq with system_dfl_wq and add WQ_PERCPU to
     alloc_workqueue()

  Platform:
   - Replace ERR_PTR() with IOMEM_ERR_PTR() in platform ioremap
     functions

  Rust:
   - Auxiliary:
      - Unregister auxiliary device on parent device unbind
      - Move parent() to impl Device; implement device context aware
        parent() for Device<Bound>
      - Illustrate how to safely obtain a driver's device private data
        when calling from an auxiliary driver into the parant device
        driver

   - DebugFs:
      - Implement support for binary large objects

   - Device:
      - Let probe() return the driver's device private data as pinned
        initializer, i.e. impl PinInit<Self, Error>
      - Implement safe accessor for a driver's device private data for
        Device<Bound> (returned reference can't out-live driver binding
        and guarantees the correct private data type)
      - Implement AsBusDevice trait, to be used by class device
        abstractions to derive the bus device type of the parent device

   - DMA:
      - Store raw pointer of allocation as NonNull
      - Use start_ptr() and start_ptr_mut() to inherit correct
        mutability of self

   - FS:
      - Add file::Offset type alias

   - I2C:
      - Add abstractions for I2C device / driver infrastructure
      - Implement abstractions for manual I2C device registrations

   - I/O:
      - Use "kernel vertical" style for imports
      - Define ResourceSize as resource_size_t
      - Move ResourceSize to top-level I/O module
      - Add type alias for phys_addr_t
      - Implement Rust version of read_poll_timeout_atomic()

   - PCI:
      - Use "kernel vertical" style for imports
      - Move I/O and IRQ infrastructure to separate files
      - Add support for PCI interrupt vectors
      - Implement TryInto<IrqRequest<'a>> for IrqVector<'a> to convert
        an IrqVector bound to specific pci::Device into an IrqRequest
        bound to the same pci::Device's parent Device
      - Leverage pin_init_scope() to get rid of redundant Result in IRQ
        methods

   - PinInit:
      - Add {pin_}init_scope() to execute code before creating an
        initializer

   - Platform:
      - Leverage pin_init_scope() to get rid of redundant Result in IRQ
        methods

   - Timekeeping:
      - Implement abstraction of udelay()

   - Uaccess:
      - Implement read_slice_partial() and read_slice_file() for
        UserSliceReader
      - Implement write_slice_partial() and write_slice_file() for
        UserSliceWriter

  sysfs:
   - Prepare the constification of struct attribute"

* tag 'driver-core-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (75 commits)
  rust: pci: fix build failure when CONFIG_PCI_MSI is disabled
  debugfs: Fix default access mode config check
  debugfs: Remove broken no-mount mode
  debugfs: Remove redundant access mode checks
  driver core: Check drivers_autoprobe for all added devices
  driver core: WQ_PERCPU added to alloc_workqueue users
  driver core: replace use of system_unbound_wq with system_dfl_wq
  tick/nohz: Expose housekeeping CPUs in sysfs
  tick/nohz: avoid showing '(null)' if nohz_full= not set
  sysfs/cpu: Use DEVICE_ATTR_RO for nohz_full attribute
  kernfs: fix memory leak of kernfs_iattrs in __kernfs_new_node
  fs/kernfs: raise sb->maxbytes to MAX_LFS_FILESIZE
  mod_devicetable: Bump auxiliary_device_id name size
  sysfs: simplify attribute definition macros
  samples/kobject: constify 'struct foo_attribute'
  samples/kobject: add is_visible() callback to attribute group
  sysfs: attribute_group: enable const variants of is_visible()
  sysfs: introduce __SYSFS_FUNCTION_ALTERNATIVE()
  sysfs: transparently handle const pointers in ATTRIBUTE_GROUPS()
  sysfs: attribute_group: allow registration of const attribute
  ...

1 files changed, 252 insertions, 0 deletions

diff --git a/rust/kernel/pci/irq.rs b/rust/kernel/pci/irq.rs
new file mode 100644
index 000000000000..d9230e105541
--- /dev/null
+++ b/rust/kernel/pci/irq.rs
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! PCI interrupt infrastructure.
+
+use super::Device;
+use crate::{
+    bindings,
+    device,
+    device::Bound,
+    devres,
+    error::to_result,
+    irq::{
+        self,
+        IrqRequest, //
+    },
+    prelude::*,
+    str::CStr,
+    sync::aref::ARef, //
+};
+use core::ops::RangeInclusive;
+
+/// IRQ type flags for PCI interrupt allocation.
+#[derive(Debug, Clone, Copy)]
+pub enum IrqType {
+    /// INTx interrupts.
+    Intx,
+    /// Message Signaled Interrupts (MSI).
+    Msi,
+    /// Extended Message Signaled Interrupts (MSI-X).
+    MsiX,
+}
+
+impl IrqType {
+    /// Convert to the corresponding kernel flags.
+    const fn as_raw(self) -> u32 {
+        match self {
+            IrqType::Intx => bindings::PCI_IRQ_INTX,
+            IrqType::Msi => bindings::PCI_IRQ_MSI,
+            IrqType::MsiX => bindings::PCI_IRQ_MSIX,
+        }
+    }
+}
+
+/// Set of IRQ types that can be used for PCI interrupt allocation.
+#[derive(Debug, Clone, Copy, Default)]
+pub struct IrqTypes(u32);
+
+impl IrqTypes {
+    /// Create a set containing all IRQ types (MSI-X, MSI, and INTx).
+    pub const fn all() -> Self {
+        Self(bindings::PCI_IRQ_ALL_TYPES)
+    }
+
+    /// Build a set of IRQ types.
+    ///
+    /// # Examples
+    ///
+    /// ```ignore
+    /// // Create a set with only MSI and MSI-X (no INTx interrupts).
+    /// let msi_only = IrqTypes::default()
+    ///     .with(IrqType::Msi)
+    ///     .with(IrqType::MsiX);
+    /// ```
+    pub const fn with(self, irq_type: IrqType) -> Self {
+        Self(self.0 | irq_type.as_raw())
+    }
+
+    /// Get the raw flags value.
+    const fn as_raw(self) -> u32 {
+        self.0
+    }
+}
+
+/// Represents an allocated IRQ vector for a specific PCI device.
+///
+/// This type ties an IRQ vector to the device it was allocated for,
+/// ensuring the vector is only used with the correct device.
+#[derive(Clone, Copy)]
+pub struct IrqVector<'a> {
+    dev: &'a Device<Bound>,
+    index: u32,
+}
+
+impl<'a> IrqVector<'a> {
+    /// Creates a new [`IrqVector`] for the given device and index.
+    ///
+    /// # Safety
+    ///
+    /// - `index` must be a valid IRQ vector index for `dev`.
+    /// - `dev` must point to a [`Device`] that has successfully allocated IRQ vectors.
+    unsafe fn new(dev: &'a Device<Bound>, index: u32) -> Self {
+        Self { dev, index }
+    }
+
+    /// Returns the raw vector index.
+    fn index(&self) -> u32 {
+        self.index
+    }
+}
+
+impl<'a> TryInto<IrqRequest<'a>> for IrqVector<'a> {
+    type Error = Error;
+
+    fn try_into(self) -> Result<IrqRequest<'a>> {
+        // SAFETY: `self.as_raw` returns a valid pointer to a `struct pci_dev`.
+        let irq = unsafe { bindings::pci_irq_vector(self.dev.as_raw(), self.index()) };
+        if irq < 0 {
+            return Err(crate::error::Error::from_errno(irq));
+        }
+        // SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`.
+        Ok(unsafe { IrqRequest::new(self.dev.as_ref(), irq as u32) })
+    }
+}
+
+/// Represents an IRQ vector allocation for a PCI device.
+///
+/// This type ensures that IRQ vectors are properly allocated and freed by
+/// tying the allocation to the lifetime of this registration object.
+///
+/// # Invariants
+///
+/// The [`Device`] has successfully allocated IRQ vectors.
+struct IrqVectorRegistration {
+    dev: ARef<Device>,
+}
+
+impl IrqVectorRegistration {
+    /// Allocate and register IRQ vectors for the given PCI device.
+    ///
+    /// Allocates IRQ vectors and registers them with devres for automatic cleanup.
+    /// Returns a range of valid IRQ vectors.
+    fn register<'a>(
+        dev: &'a Device<Bound>,
+        min_vecs: u32,
+        max_vecs: u32,
+        irq_types: IrqTypes,
+    ) -> Result<RangeInclusive<IrqVector<'a>>> {
+        // SAFETY:
+        // - `dev.as_raw()` is guaranteed to be a valid pointer to a `struct pci_dev`
+        //   by the type invariant of `Device`.
+        // - `pci_alloc_irq_vectors` internally validates all other parameters
+        //   and returns error codes.
+        let ret = unsafe {
+            bindings::pci_alloc_irq_vectors(dev.as_raw(), min_vecs, max_vecs, irq_types.as_raw())
+        };
+
+        to_result(ret)?;
+        let count = ret as u32;
+
+        // SAFETY:
+        // - `pci_alloc_irq_vectors` returns the number of allocated vectors on success.
+        // - Vectors are 0-based, so valid indices are [0, count-1].
+        // - `pci_alloc_irq_vectors` guarantees `count >= min_vecs > 0`, so both `0` and
+        //   `count - 1` are valid IRQ vector indices for `dev`.
+        let range = unsafe { IrqVector::new(dev, 0)..=IrqVector::new(dev, count - 1) };
+
+        // INVARIANT: The IRQ vector allocation for `dev` above was successful.
+        let irq_vecs = Self { dev: dev.into() };
+        devres::register(dev.as_ref(), irq_vecs, GFP_KERNEL)?;
+
+        Ok(range)
+    }
+}
+
+impl Drop for IrqVectorRegistration {
+    fn drop(&mut self) {
+        // SAFETY:
+        // - By the type invariant, `self.dev.as_raw()` is a valid pointer to a `struct pci_dev`.
+        // - `self.dev` has successfully allocated IRQ vectors.
+        unsafe { bindings::pci_free_irq_vectors(self.dev.as_raw()) };
+    }
+}
+
+impl Device<device::Bound> {
+    /// Returns a [`kernel::irq::Registration`] for the given IRQ vector.
+    pub fn request_irq<'a, T: crate::irq::Handler + 'static>(
+        &'a self,
+        vector: IrqVector<'a>,
+        flags: irq::Flags,
+        name: &'static CStr,
+        handler: impl PinInit<T, Error> + 'a,
+    ) -> impl PinInit<irq::Registration<T>, Error> + 'a {
+        pin_init::pin_init_scope(move || {
+            let request = vector.try_into()?;
+
+            Ok(irq::Registration::<T>::new(request, flags, name, handler))
+        })
+    }
+
+    /// Returns a [`kernel::irq::ThreadedRegistration`] for the given IRQ vector.
+    pub fn request_threaded_irq<'a, T: crate::irq::ThreadedHandler + 'static>(
+        &'a self,
+        vector: IrqVector<'a>,
+        flags: irq::Flags,
+        name: &'static CStr,
+        handler: impl PinInit<T, Error> + 'a,
+    ) -> impl PinInit<irq::ThreadedRegistration<T>, Error> + 'a {
+        pin_init::pin_init_scope(move || {
+            let request = vector.try_into()?;
+
+            Ok(irq::ThreadedRegistration::<T>::new(
+                request, flags, name, handler,
+            ))
+        })
+    }
+
+    /// Allocate IRQ vectors for this PCI device with automatic cleanup.
+    ///
+    /// Allocates between `min_vecs` and `max_vecs` interrupt vectors for the device.
+    /// The allocation will use MSI-X, MSI, or INTx interrupts based on the `irq_types`
+    /// parameter and hardware capabilities. When multiple types are specified, the kernel
+    /// will try them in order of preference: MSI-X first, then MSI, then INTx interrupts.
+    ///
+    /// The allocated vectors are automatically freed when the device is unbound, using the
+    /// devres (device resource management) system.
+    ///
+    /// # Arguments
+    ///
+    /// * `min_vecs` - Minimum number of vectors required.
+    /// * `max_vecs` - Maximum number of vectors to allocate.
+    /// * `irq_types` - Types of interrupts that can be used.
+    ///
+    /// # Returns
+    ///
+    /// Returns a range of IRQ vectors that were successfully allocated, or an error if the
+    /// allocation fails or cannot meet the minimum requirement.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # use kernel::{ device::Bound, pci};
+    /// # fn no_run(dev: &pci::Device<Bound>) -> Result {
+    /// // Allocate using any available interrupt type in the order mentioned above.
+    /// let vectors = dev.alloc_irq_vectors(1, 32, pci::IrqTypes::all())?;
+    ///
+    /// // Allocate MSI or MSI-X only (no INTx interrupts).
+    /// let msi_only = pci::IrqTypes::default()
+    ///     .with(pci::IrqType::Msi)
+    ///     .with(pci::IrqType::MsiX);
+    /// let vectors = dev.alloc_irq_vectors(4, 16, msi_only)?;
+    /// # Ok(())
+    /// # }
+    /// ```
+    pub fn alloc_irq_vectors(
+        &self,
+        min_vecs: u32,
+        max_vecs: u32,
+        irq_types: IrqTypes,
+    ) -> Result<RangeInclusive<IrqVector<'_>>> {
+        IrqVectorRegistration::register(self, min_vecs, max_vecs, irq_types)
+    }
+}