From 496e6c48e64facffb42c715d72a14b0d46497ea9 Mon Sep 17 00:00:00 2001
From: Li Hongyu <543306408@qq.com>
Date: Thu, 29 Sep 2022 11:16:50 +0000
Subject: [PATCH] rust: add initial PCI support

maillist inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5TUIJ
CVE: NA

Reference: https://github.com/Rust-for-Linux/linux/pull/856

----------------------------------------------------------------------

Added minimum abstration APIs for PCI.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: Li Hongyu <543306408@qq.com>
---
 rust/helpers.c                |  13 ++++
 rust/kernel/bindings_helper.h |   1 +
 rust/kernel/lib.rs            |   2 +
 rust/kernel/pci.rs            | 109 ++++++++++++++++++++++++++++++++++
 4 files changed, 125 insertions(+)
 create mode 100644 rust/kernel/pci.rs

diff --git a/rust/helpers.c b/rust/helpers.c
index ead3a64f700c..cfb54a0207d8 100644
--- a/rust/helpers.c
+++ b/rust/helpers.c
@@ -32,6 +32,7 @@
 #include <linux/mutex.h>
 #include <linux/netdevice.h>
 #include <linux/of_device.h>
+#include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/sched/signal.h>
 #include <linux/security.h>
@@ -620,6 +621,18 @@ unsigned int rust_helper_NF_QUEUE_NR(unsigned int n)
 }
 EXPORT_SYMBOL_GPL(rust_helper_NF_QUEUE_NR);
 
+void rust_helper_pci_set_drvdata(struct pci_dev *pdev, void *data)
+{
+    pci_set_drvdata(pdev, data);
+}
+EXPORT_SYMBOL_GPL(rust_helper_pci_set_drvdata);
+
+void *rust_helper_pci_get_drvdata(struct pci_dev *pdev)
+{
+    return pci_get_drvdata(pdev);
+}
+EXPORT_SYMBOL_GPL(rust_helper_pci_get_drvdata);
+
 /*
  * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type
  * as the Rust `usize` type, so we can use it in contexts where Rust
diff --git a/rust/kernel/bindings_helper.h b/rust/kernel/bindings_helper.h
index 73100fa139eb..3bab72c8eced 100644
--- a/rust/kernel/bindings_helper.h
+++ b/rust/kernel/bindings_helper.h
@@ -27,6 +27,7 @@
 #include <linux/netfilter_ipv4.h>
 #include <linux/netfilter_ipv6.h>
 #include <linux/of_platform.h>
+#include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/poll.h>
 #include <linux/random.h>
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 3e01c30de670..6c11382a03f7 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -60,6 +60,8 @@ pub mod mm;
 #[cfg(CONFIG_NET)]
 pub mod net;
 pub mod pages;
+#[cfg(CONFIG_PCI)]
+pub mod pci;
 pub mod power;
 pub mod revocable;
 pub mod security;
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
new file mode 100644
index 000000000000..1dab72181eb1
--- /dev/null
+++ b/rust/kernel/pci.rs
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! PCI devices and drivers.
+//!
+//! C header: [`include/linux/pci.h`](../../../../include/linux/pci.h)
+
+use crate::{
+    bindings, c_types, device, driver,
+    error::{from_kernel_result, Result},
+    str::CStr,
+    to_result,
+    types::PointerWrapper,
+    ThisModule,
+};
+
+/// An adapter for the registration of PCI drivers.
+pub struct Adapter<T: Driver>(T);
+
+impl<T: Driver> driver::DriverOps for Adapter<T> {
+    type RegType = bindings::pci_driver;
+
+    unsafe fn register(
+        reg: *mut bindings::pci_driver,
+        name: &'static CStr,
+        module: &'static ThisModule,
+    ) -> Result {
+        let pdrv: &mut bindings::pci_driver = unsafe { &mut *reg };
+
+        pdrv.name = name.as_char_ptr();
+        pdrv.probe = Some(Self::probe_callback);
+        pdrv.remove = Some(Self::remove_callback);
+        pdrv.id_table = T::PCI_ID_TABLE.as_ptr();
+        to_result(|| unsafe { bindings::__pci_register_driver(reg, module.0, name.as_char_ptr()) })
+    }
+
+    unsafe fn unregister(reg: *mut bindings::pci_driver) {
+        unsafe { bindings::pci_unregister_driver(reg) }
+    }
+}
+
+impl<T: Driver> Adapter<T> {
+    extern "C" fn probe_callback(
+        pdev: *mut bindings::pci_dev,
+        _id: *const bindings::pci_device_id,
+    ) -> c_types::c_int {
+        from_kernel_result! {
+            let mut dev = unsafe { Device::from_ptr(pdev) };
+            let data = T::probe(&mut dev)?;
+            unsafe { bindings::pci_set_drvdata(pdev, data.into_pointer() as _) };
+            Ok(0)
+        }
+    }
+
+    extern "C" fn remove_callback(pdev: *mut bindings::pci_dev) {
+        let ptr = unsafe { bindings::pci_get_drvdata(pdev) };
+        let data = unsafe { T::Data::from_pointer(ptr) };
+        T::remove(&data);
+        <T::Data as driver::DeviceRemoval>::device_remove(&data);
+    }
+}
+
+/// A PCI driver
+pub trait Driver {
+    /// Data stored on device by driver.
+    ///
+    /// Corresponds to the data set or retrieved via the kernel's
+    /// `pci_{set,get}_drvdata()` functions.
+    ///
+    /// Require that `Data` implements `PointerWrapper`. We guarantee to
+    /// never move the underlying wrapped data structure. This allows
+    type Data: PointerWrapper + Send + Sync + driver::DeviceRemoval = ();
+
+    /// The table of device ids supported by the driver.
+    const PCI_ID_TABLE: &'static [bindings::pci_device_id];
+
+    /// PCI driver probe.
+    ///
+    /// Called when a new platform device is added or discovered.
+    /// Implementers should attempt to initialize the device here.
+    fn probe(dev: &mut Device) -> Result<Self::Data>;
+
+    /// PCI driver remove.
+    ///
+    /// Called when a platform device is removed.
+    /// Implementers should prepare the device for complete removal here.
+    fn remove(_data: &Self::Data);
+}
+
+/// A PCI device.
+///
+/// # Invariants
+///
+/// The field `ptr` is non-null and valid for the lifetime of the object.
+pub struct Device {
+    ptr: *mut bindings::pci_dev,
+}
+
+impl Device {
+    unsafe fn from_ptr(ptr: *mut bindings::pci_dev) -> Self {
+        Self { ptr }
+    }
+}
+
+unsafe impl device::RawDevice for Device {
+    fn raw_device(&self) -> *mut bindings::device {
+        // SAFETY: By the type invariants, we know that `self.ptr` is non-null and valid.
+        unsafe { &mut (*self.ptr).dev }
+    }
+}
-- 
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