John Hubbard
2025-Aug-19 03:11 UTC
[PATCH v3 1/3] rust: pci: provide access to PCI Class, subclass, implementation values
Allow callers to write Class::STORAGE_SCSI instead of
bindings::PCI_CLASS_STORAGE_SCSI, for example.
New APIs:
Class::STORAGE_SCSI, Class::NETWORK_ETHERNET, etc.
Class::as_u32()
Class: TryFrom<u32> for Class
Class::MASK_FULL, MASK_CLASS_SUBCLASS
DeviceId::from_class_and_vendor()
Device::pci_class_code_raw(), pci_class()
Cc: Danilo Krummrich <dakr at kernel.org>
Cc: Alexandre Courbot <acourbot at nvidia.com>
Signed-off-by: John Hubbard <jhubbard at nvidia.com>
---
rust/kernel/pci.rs | 227 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 227 insertions(+)
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index 887ee611b553..bd34b1a54ecc 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -23,6 +23,204 @@
};
use kernel::prelude::*;
+/// PCI device class codes. Each entry contains the full 24-bit PCI
+/// class code (base class in bits 23-16, subclass in bits 15-8,
+/// programming interface in bits 7-0).
+///
+/// # Examples
+///
+/// ```
+/// # use kernel::{device::Core, pci::{self, Class}, prelude::*};
+/// fn probe_device(pdev: &pci::Device<Core>) -> Result<()>
{
+/// // Get the PCI class for this device
+/// let pci_class = pdev.pci_class();
+/// dev_info!(
+/// pdev.as_ref(),
+/// "Detected PCI class: (0x{:06x})\n",
+/// pci_class.as_u32()
+/// );
+/// Ok(())
+/// }
+/// ```
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(transparent)]
+pub struct Class(u32);
+
+macro_rules! define_all_pci_classes {
+ (
+ $($variant:ident = $binding:expr,)+
+ ) => {
+
+ impl Class {
+ $(
+ #[allow(missing_docs)]
+ pub const $variant: Self =
Self(Self::to_24bit_class($binding));
+ )+
+ }
+
+ /// Try to convert a raw 24-bit class code value to a `Class`.
+ /// Returns `ENODEV` if the value doesn't match any known PCI Class
code.
+ impl TryFrom<u32> for Class {
+ type Error = Error;
+
+ fn try_from(value: u32) -> Result<Self, Self::Error> {
+ match value {
+ $(x if x == Self::$variant.0 => Ok(Self::$variant),)+
+ _ => Err(ENODEV),
+ }
+ }
+ }
+ };
+}
+
+impl Class {
+ /// Match the full class code.
+ pub const MASK_FULL: u32 = 0xffffff;
+
+ /// Match the upper 16 bits of the class code (base class and subclass
only).
+ pub const MASK_CLASS_SUBCLASS: u32 = 0xffff00;
+
+ /// Get the raw 24-bit class code value.
+ pub const fn as_u32(self) -> u32 {
+ self.0
+ }
+
+ // Converts a PCI class constant to 24-bit format.
+ //
+ // Many device drivers use only the upper 16 bits (base class and
subclass), but some
+ // use the full 24 bits. In order to support both cases, store the class
code as a 24-bit
+ // value, where 16-bit values are shifted up 8 bits.
+ const fn to_24bit_class(val: u32) -> u32 {
+ if val > 0xFFFF {
+ val
+ } else {
+ val << 8
+ }
+ }
+}
+
+define_all_pci_classes! {
+ NOT_DEFINED = bindings::PCI_CLASS_NOT_DEFINED,
// 0x000000
+ NOT_DEFINED_VGA = bindings::PCI_CLASS_NOT_DEFINED_VGA,
// 0x000100
+
+ STORAGE_SCSI = bindings::PCI_CLASS_STORAGE_SCSI,
// 0x010000
+ STORAGE_IDE = bindings::PCI_CLASS_STORAGE_IDE,
// 0x010100
+ STORAGE_FLOPPY = bindings::PCI_CLASS_STORAGE_FLOPPY,
// 0x010200
+ STORAGE_IPI = bindings::PCI_CLASS_STORAGE_IPI,
// 0x010300
+ STORAGE_RAID = bindings::PCI_CLASS_STORAGE_RAID,
// 0x010400
+ STORAGE_SATA = bindings::PCI_CLASS_STORAGE_SATA,
// 0x010600
+ STORAGE_SATA_AHCI = bindings::PCI_CLASS_STORAGE_SATA_AHCI,
// 0x010601
+ STORAGE_SAS = bindings::PCI_CLASS_STORAGE_SAS,
// 0x010700
+ STORAGE_EXPRESS = bindings::PCI_CLASS_STORAGE_EXPRESS,
// 0x010802
+ STORAGE_OTHER = bindings::PCI_CLASS_STORAGE_OTHER,
// 0x018000
+
+ NETWORK_ETHERNET = bindings::PCI_CLASS_NETWORK_ETHERNET,
// 0x020000
+ NETWORK_TOKEN_RING = bindings::PCI_CLASS_NETWORK_TOKEN_RING,
// 0x020100
+ NETWORK_FDDI = bindings::PCI_CLASS_NETWORK_FDDI,
// 0x020200
+ NETWORK_ATM = bindings::PCI_CLASS_NETWORK_ATM,
// 0x020300
+ NETWORK_OTHER = bindings::PCI_CLASS_NETWORK_OTHER,
// 0x028000
+
+ DISPLAY_VGA = bindings::PCI_CLASS_DISPLAY_VGA,
// 0x030000
+ DISPLAY_XGA = bindings::PCI_CLASS_DISPLAY_XGA,
// 0x030100
+ DISPLAY_3D = bindings::PCI_CLASS_DISPLAY_3D,
// 0x030200
+ DISPLAY_OTHER = bindings::PCI_CLASS_DISPLAY_OTHER,
// 0x038000
+
+ MULTIMEDIA_VIDEO = bindings::PCI_CLASS_MULTIMEDIA_VIDEO,
// 0x040000
+ MULTIMEDIA_AUDIO = bindings::PCI_CLASS_MULTIMEDIA_AUDIO,
// 0x040100
+ MULTIMEDIA_PHONE = bindings::PCI_CLASS_MULTIMEDIA_PHONE,
// 0x040200
+ MULTIMEDIA_HD_AUDIO = bindings::PCI_CLASS_MULTIMEDIA_HD_AUDIO,
// 0x040300
+ MULTIMEDIA_OTHER = bindings::PCI_CLASS_MULTIMEDIA_OTHER,
// 0x048000
+
+ MEMORY_RAM = bindings::PCI_CLASS_MEMORY_RAM,
// 0x050000
+ MEMORY_FLASH = bindings::PCI_CLASS_MEMORY_FLASH,
// 0x050100
+ MEMORY_CXL = bindings::PCI_CLASS_MEMORY_CXL,
// 0x050200
+ MEMORY_OTHER = bindings::PCI_CLASS_MEMORY_OTHER,
// 0x058000
+
+ BRIDGE_HOST = bindings::PCI_CLASS_BRIDGE_HOST,
// 0x060000
+ BRIDGE_ISA = bindings::PCI_CLASS_BRIDGE_ISA,
// 0x060100
+ BRIDGE_EISA = bindings::PCI_CLASS_BRIDGE_EISA,
// 0x060200
+ BRIDGE_MC = bindings::PCI_CLASS_BRIDGE_MC,
// 0x060300
+ BRIDGE_PCI_NORMAL = bindings::PCI_CLASS_BRIDGE_PCI_NORMAL,
// 0x060400
+ BRIDGE_PCI_SUBTRACTIVE = bindings::PCI_CLASS_BRIDGE_PCI_SUBTRACTIVE,
// 0x060401
+ BRIDGE_PCMCIA = bindings::PCI_CLASS_BRIDGE_PCMCIA,
// 0x060500
+ BRIDGE_NUBUS = bindings::PCI_CLASS_BRIDGE_NUBUS,
// 0x060600
+ BRIDGE_CARDBUS = bindings::PCI_CLASS_BRIDGE_CARDBUS,
// 0x060700
+ BRIDGE_RACEWAY = bindings::PCI_CLASS_BRIDGE_RACEWAY,
// 0x060800
+ BRIDGE_OTHER = bindings::PCI_CLASS_BRIDGE_OTHER,
// 0x068000
+
+ COMMUNICATION_SERIAL = bindings::PCI_CLASS_COMMUNICATION_SERIAL,
// 0x070000
+ COMMUNICATION_PARALLEL = bindings::PCI_CLASS_COMMUNICATION_PARALLEL,
// 0x070100
+ COMMUNICATION_MULTISERIAL = bindings::PCI_CLASS_COMMUNICATION_MULTISERIAL,
// 0x070200
+ COMMUNICATION_MODEM = bindings::PCI_CLASS_COMMUNICATION_MODEM,
// 0x070300
+ COMMUNICATION_OTHER = bindings::PCI_CLASS_COMMUNICATION_OTHER,
// 0x078000
+
+ SYSTEM_PIC = bindings::PCI_CLASS_SYSTEM_PIC,
// 0x080000
+ SYSTEM_PIC_IOAPIC = bindings::PCI_CLASS_SYSTEM_PIC_IOAPIC,
// 0x080010
+ SYSTEM_PIC_IOXAPIC = bindings::PCI_CLASS_SYSTEM_PIC_IOXAPIC,
// 0x080020
+ SYSTEM_DMA = bindings::PCI_CLASS_SYSTEM_DMA,
// 0x080100
+ SYSTEM_TIMER = bindings::PCI_CLASS_SYSTEM_TIMER,
// 0x080200
+ SYSTEM_RTC = bindings::PCI_CLASS_SYSTEM_RTC,
// 0x080300
+ SYSTEM_PCI_HOTPLUG = bindings::PCI_CLASS_SYSTEM_PCI_HOTPLUG,
// 0x080400
+ SYSTEM_SDHCI = bindings::PCI_CLASS_SYSTEM_SDHCI,
// 0x080500
+ SYSTEM_RCEC = bindings::PCI_CLASS_SYSTEM_RCEC,
// 0x080700
+ SYSTEM_OTHER = bindings::PCI_CLASS_SYSTEM_OTHER,
// 0x088000
+
+ INPUT_KEYBOARD = bindings::PCI_CLASS_INPUT_KEYBOARD,
// 0x090000
+ INPUT_PEN = bindings::PCI_CLASS_INPUT_PEN,
// 0x090100
+ INPUT_MOUSE = bindings::PCI_CLASS_INPUT_MOUSE,
// 0x090200
+ INPUT_SCANNER = bindings::PCI_CLASS_INPUT_SCANNER,
// 0x090300
+ INPUT_GAMEPORT = bindings::PCI_CLASS_INPUT_GAMEPORT,
// 0x090400
+ INPUT_OTHER = bindings::PCI_CLASS_INPUT_OTHER,
// 0x098000
+
+ DOCKING_GENERIC = bindings::PCI_CLASS_DOCKING_GENERIC,
// 0x0a0000
+ DOCKING_OTHER = bindings::PCI_CLASS_DOCKING_OTHER,
// 0x0a8000
+
+ PROCESSOR_386 = bindings::PCI_CLASS_PROCESSOR_386,
// 0x0b0000
+ PROCESSOR_486 = bindings::PCI_CLASS_PROCESSOR_486,
// 0x0b0100
+ PROCESSOR_PENTIUM = bindings::PCI_CLASS_PROCESSOR_PENTIUM,
// 0x0b0200
+ PROCESSOR_ALPHA = bindings::PCI_CLASS_PROCESSOR_ALPHA,
// 0x0b1000
+ PROCESSOR_POWERPC = bindings::PCI_CLASS_PROCESSOR_POWERPC,
// 0x0b2000
+ PROCESSOR_MIPS = bindings::PCI_CLASS_PROCESSOR_MIPS,
// 0x0b3000
+ PROCESSOR_CO = bindings::PCI_CLASS_PROCESSOR_CO,
// 0x0b4000
+
+ SERIAL_FIREWIRE = bindings::PCI_CLASS_SERIAL_FIREWIRE,
// 0x0c0000
+ SERIAL_FIREWIRE_OHCI = bindings::PCI_CLASS_SERIAL_FIREWIRE_OHCI,
// 0x0c0010
+ SERIAL_ACCESS = bindings::PCI_CLASS_SERIAL_ACCESS,
// 0x0c0100
+ SERIAL_SSA = bindings::PCI_CLASS_SERIAL_SSA,
// 0x0c0200
+ SERIAL_USB_UHCI = bindings::PCI_CLASS_SERIAL_USB_UHCI,
// 0x0c0300
+ SERIAL_USB_OHCI = bindings::PCI_CLASS_SERIAL_USB_OHCI,
// 0x0c0310
+ SERIAL_USB_EHCI = bindings::PCI_CLASS_SERIAL_USB_EHCI,
// 0x0c0320
+ SERIAL_USB_XHCI = bindings::PCI_CLASS_SERIAL_USB_XHCI,
// 0x0c0330
+ SERIAL_USB_CDNS = bindings::PCI_CLASS_SERIAL_USB_CDNS,
// 0x0c0380
+ SERIAL_USB_DEVICE = bindings::PCI_CLASS_SERIAL_USB_DEVICE,
// 0x0c03fe
+ SERIAL_FIBER = bindings::PCI_CLASS_SERIAL_FIBER,
// 0x0c0400
+ SERIAL_SMBUS = bindings::PCI_CLASS_SERIAL_SMBUS,
// 0x0c0500
+ SERIAL_IPMI_SMIC = bindings::PCI_CLASS_SERIAL_IPMI_SMIC,
// 0x0c0700
+ SERIAL_IPMI_KCS = bindings::PCI_CLASS_SERIAL_IPMI_KCS,
// 0x0c0701
+ SERIAL_IPMI_BT = bindings::PCI_CLASS_SERIAL_IPMI_BT,
// 0x0c0702
+
+ WIRELESS_RF_CONTROLLER = bindings::PCI_CLASS_WIRELESS_RF_CONTROLLER,
// 0x0d1000
+ WIRELESS_WHCI = bindings::PCI_CLASS_WIRELESS_WHCI,
// 0x0d1010
+
+ INTELLIGENT_I2O = bindings::PCI_CLASS_INTELLIGENT_I2O,
// 0x0e0000
+
+ SATELLITE_TV = bindings::PCI_CLASS_SATELLITE_TV,
// 0x0f0000
+ SATELLITE_AUDIO = bindings::PCI_CLASS_SATELLITE_AUDIO,
// 0x0f0100
+ SATELLITE_VOICE = bindings::PCI_CLASS_SATELLITE_VOICE,
// 0x0f0300
+ SATELLITE_DATA = bindings::PCI_CLASS_SATELLITE_DATA,
// 0x0f0400
+
+ CRYPT_NETWORK = bindings::PCI_CLASS_CRYPT_NETWORK,
// 0x100000
+ CRYPT_ENTERTAINMENT = bindings::PCI_CLASS_CRYPT_ENTERTAINMENT,
// 0x100100
+ CRYPT_OTHER = bindings::PCI_CLASS_CRYPT_OTHER,
// 0x108000
+
+ SP_DPIO = bindings::PCI_CLASS_SP_DPIO,
// 0x110000
+ SP_OTHER = bindings::PCI_CLASS_SP_OTHER,
// 0x118000
+
+ ACCELERATOR_PROCESSING = bindings::PCI_CLASS_ACCELERATOR_PROCESSING,
// 0x120000
+
+ OTHERS = bindings::PCI_CLASS_OTHERS,
// 0xff0000
+}
+
/// An adapter for the registration of PCI drivers.
pub struct Adapter<T: Driver>(T);
@@ -157,6 +355,23 @@ pub const fn from_class(class: u32, class_mask: u32) ->
Self {
override_only: 0,
})
}
+
+ /// Create a new `pci::DeviceId` from a class number, mask, and specific
vendor.
+ ///
+ /// This is more targeted than [`DeviceId::from_class`]: in addition to
matching by Vendor, it
+ /// also matches the PCI Class (up to the entire 24 bits, depending on the
mask).
+ pub const fn from_class_and_vendor(class: Class, class_mask: u32, vendor:
u32) -> Self {
+ Self(bindings::pci_device_id {
+ vendor,
+ device: DeviceId::PCI_ANY_ID,
+ subvendor: DeviceId::PCI_ANY_ID,
+ subdevice: DeviceId::PCI_ANY_ID,
+ class: class.as_u32(),
+ class_mask,
+ driver_data: 0,
+ override_only: 0,
+ })
+ }
}
// SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `pci_device_id`
and does not add
@@ -410,6 +625,18 @@ pub fn resource_len(&self, bar: u32) ->
Result<bindings::resource_size_t> {
// - by its type invariant `self.as_raw` is always a valid pointer to a
`struct pci_dev`.
Ok(unsafe { bindings::pci_resource_len(self.as_raw(), bar.try_into()?)
})
}
+
+ /// Returns the full 24-bit PCI class code as stored in hardware.
+ /// This includes base class, subclass, and programming interface.
+ pub fn pci_class_code_raw(&self) -> u32 {
+ // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.
+ unsafe { (*self.as_raw()).class }
+ }
+
+ /// Returns the PCI class as a `Class` struct.
+ pub fn pci_class(&self) -> Class {
+ Class(self.pci_class_code_raw())
+ }
}
impl Device<device::Bound> {
--
2.50.1
Danilo Krummrich
2025-Aug-19 09:09 UTC
[PATCH v3 1/3] rust: pci: provide access to PCI Class, subclass, implementation values
On Tue Aug 19, 2025 at 5:11 AM CEST, John Hubbard wrote:> +/// PCI device class codes. Each entry contains the full 24-bit PCI > +/// class code (base class in bits 23-16, subclass in bits 15-8, > +/// programming interface in bits 7-0). > +/// > +/// # Examples > +/// > +/// ``` > +/// # use kernel::{device::Core, pci::{self, Class}, prelude::*}; > +/// fn probe_device(pdev: &pci::Device<Core>) -> Result<()> { > +/// // Get the PCI class for this device > +/// let pci_class = pdev.pci_class(); > +/// dev_info!( > +/// pdev.as_ref(), > +/// "Detected PCI class: (0x{:06x})\n", > +/// pci_class.as_u32() > +/// );Maybe a bit cleaner to implement Display for pci::Class?> +/// Ok(()) > +/// } > +/// ``` > +#[derive(Debug, Clone, Copy, PartialEq, Eq)] > +#[repr(transparent)] > +pub struct Class(u32);[ Class impl and lots of pci class ids... ] I think we should move all this to a new Rust module (rust/kernel/pci/class.rs) to keep this file reasonably small. You can add use self::class::Class; use self::class::ClassMask; in this file to make it appear as e.g. kernel::pci::Class. Sorry I didn't mention this in the previous version.> /// An adapter for the registration of PCI drivers. > pub struct Adapter<T: Driver>(T); > > @@ -157,6 +355,23 @@ pub const fn from_class(class: u32, class_mask: u32) -> Self { > override_only: 0, > }) > } > + > + /// Create a new `pci::DeviceId` from a class number, mask, and specific vendor. > + /// > + /// This is more targeted than [`DeviceId::from_class`]: in addition to matching by Vendor, it > + /// also matches the PCI Class (up to the entire 24 bits, depending on the mask). > + pub const fn from_class_and_vendor(class: Class, class_mask: u32, vendor: u32) -> Self {I think it would be good if class_mask would be a new type ClassMask that only has the constants that are applicable for this field, i.e. MASK_FULL and MASK_CLASS_SUBCLASS.> + Self(bindings::pci_device_id { > + vendor, > + device: DeviceId::PCI_ANY_ID, > + subvendor: DeviceId::PCI_ANY_ID, > + subdevice: DeviceId::PCI_ANY_ID, > + class: class.as_u32(), > + class_mask, > + driver_data: 0, > + override_only: 0, > + }) > + } > } > > // SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `pci_device_id` and does not add > @@ -410,6 +625,18 @@ pub fn resource_len(&self, bar: u32) -> Result<bindings::resource_size_t> { > // - by its type invariant `self.as_raw` is always a valid pointer to a `struct pci_dev`. > Ok(unsafe { bindings::pci_resource_len(self.as_raw(), bar.try_into()?) }) > } > + > + /// Returns the full 24-bit PCI class code as stored in hardware. > + /// This includes base class, subclass, and programming interface. > + pub fn pci_class_code_raw(&self) -> u32 { > + // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`. > + unsafe { (*self.as_raw()).class } > + }Do we need this method? I think drivers can just call pdev.pci_class().as_u32() instead (which we could also name as_raw()).> + /// Returns the PCI class as a `Class` struct. > + pub fn pci_class(&self) -> Class { > + Class(self.pci_class_code_raw()) > + }This is good! At a first glance the name looks a bit odd or redundant, but people would clearly expect something different when this is called as pdev.class() (i.e. a struct class representation).