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Illustrate how a parent driver of an auxiliary driver can take advantage of the device context guarantees given by the auxiliary bus and subsequently safely derive its device private data. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Danilo Krummrich <dakr@kernel.org>
129 lines
3.2 KiB
Rust
129 lines
3.2 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
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//! Rust auxiliary driver sample (based on a PCI driver for QEMU's `pci-testdev`).
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//!
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//! To make this driver probe, QEMU must be run with `-device pci-testdev`.
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use kernel::{
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auxiliary, c_str,
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device::{Bound, Core},
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devres::Devres,
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driver,
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error::Error,
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pci,
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prelude::*,
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InPlaceModule,
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};
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use core::any::TypeId;
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use pin_init::PinInit;
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const MODULE_NAME: &CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
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const AUXILIARY_NAME: &CStr = c_str!("auxiliary");
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struct AuxiliaryDriver;
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kernel::auxiliary_device_table!(
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AUX_TABLE,
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MODULE_AUX_TABLE,
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<AuxiliaryDriver as auxiliary::Driver>::IdInfo,
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[(auxiliary::DeviceId::new(MODULE_NAME, AUXILIARY_NAME), ())]
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);
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impl auxiliary::Driver for AuxiliaryDriver {
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type IdInfo = ();
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const ID_TABLE: auxiliary::IdTable<Self::IdInfo> = &AUX_TABLE;
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fn probe(adev: &auxiliary::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> {
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dev_info!(
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adev.as_ref(),
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"Probing auxiliary driver for auxiliary device with id={}\n",
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adev.id()
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);
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ParentDriver::connect(adev)?;
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Ok(Self)
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}
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}
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#[pin_data]
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struct ParentDriver {
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private: TypeId,
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#[pin]
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_reg0: Devres<auxiliary::Registration>,
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#[pin]
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_reg1: Devres<auxiliary::Registration>,
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}
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kernel::pci_device_table!(
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PCI_TABLE,
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MODULE_PCI_TABLE,
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<ParentDriver as pci::Driver>::IdInfo,
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[(pci::DeviceId::from_id(pci::Vendor::REDHAT, 0x5), ())]
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);
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impl pci::Driver for ParentDriver {
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type IdInfo = ();
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const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
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fn probe(pdev: &pci::Device<Core>, _info: &Self::IdInfo) -> impl PinInit<Self, Error> {
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try_pin_init!(Self {
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private: TypeId::of::<Self>(),
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_reg0 <- auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 0, MODULE_NAME),
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_reg1 <- auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 1, MODULE_NAME),
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})
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}
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}
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impl ParentDriver {
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fn connect(adev: &auxiliary::Device<Bound>) -> Result {
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let dev = adev.parent();
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let pdev: &pci::Device<Bound> = dev.try_into()?;
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let drvdata = dev.drvdata::<Self>()?;
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dev_info!(
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dev,
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"Connect auxiliary {} with parent: VendorID={}, DeviceID={:#x}\n",
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adev.id(),
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pdev.vendor_id(),
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pdev.device_id()
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);
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dev_info!(
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dev,
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"We have access to the private data of {:?}.\n",
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drvdata.private
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);
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Ok(())
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}
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}
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#[pin_data]
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struct SampleModule {
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#[pin]
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_pci_driver: driver::Registration<pci::Adapter<ParentDriver>>,
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#[pin]
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_aux_driver: driver::Registration<auxiliary::Adapter<AuxiliaryDriver>>,
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}
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impl InPlaceModule for SampleModule {
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fn init(module: &'static kernel::ThisModule) -> impl PinInit<Self, Error> {
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try_pin_init!(Self {
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_pci_driver <- driver::Registration::new(MODULE_NAME, module),
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_aux_driver <- driver::Registration::new(MODULE_NAME, module),
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})
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}
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}
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module! {
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type: SampleModule,
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name: "rust_driver_auxiliary",
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authors: ["Danilo Krummrich"],
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description: "Rust auxiliary driver",
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license: "GPL v2",
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}
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