Merge tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core and debugfs updates from Greg KH:
 "Here is the big set of driver core and debugfs updates for 6.14-rc1.

  Included in here is a bunch of driver core, PCI, OF, and platform rust
  bindings (all acked by the different subsystem maintainers), hence the
  merge conflict with the rust tree, and some driver core api updates to
  mark things as const, which will also require some fixups due to new
  stuff coming in through other trees in this merge window.

  There are also a bunch of debugfs updates from Al, and there is at
  least one user that does have a regression with these, but Al is
  working on tracking down the fix for it. In my use (and everyone
  else's linux-next use), it does not seem like a big issue at the
  moment.

  Here's a short list of the things in here:

   - driver core rust bindings for PCI, platform, OF, and some i/o
     functions.

     We are almost at the "write a real driver in rust" stage now,
     depending on what you want to do.

   - misc device rust bindings and a sample driver to show how to use
     them

   - debugfs cleanups in the fs as well as the users of the fs api for
     places where drivers got it wrong or were unnecessarily doing
     things in complex ways.

   - driver core const work, making more of the api take const * for
     different parameters to make the rust bindings easier overall.

   - other small fixes and updates

  All of these have been in linux-next with all of the aforementioned
  merge conflicts, and the one debugfs issue, which looks to be resolved
  "soon""

* tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits)
  rust: device: Use as_char_ptr() to avoid explicit cast
  rust: device: Replace CString with CStr in property_present()
  devcoredump: Constify 'struct bin_attribute'
  devcoredump: Define 'struct bin_attribute' through macro
  rust: device: Add property_present()
  saner replacement for debugfs_rename()
  orangefs-debugfs: don't mess with ->d_name
  octeontx2: don't mess with ->d_parent or ->d_parent->d_name
  arm_scmi: don't mess with ->d_parent->d_name
  slub: don't mess with ->d_name
  sof-client-ipc-flood-test: don't mess with ->d_name
  qat: don't mess with ->d_name
  xhci: don't mess with ->d_iname
  mtu3: don't mess wiht ->d_iname
  greybus/camera - stop messing with ->d_iname
  mediatek: stop messing with ->d_iname
  netdevsim: don't embed file_operations into your structs
  b43legacy: make use of debugfs_get_aux()
  b43: stop embedding struct file_operations into their objects
  carl9170: stop embedding file_operations into their objects
  ...

5 files changed, 431 insertions, 0 deletions

diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig
index b0f74a81c8f9..918dbead2c0b 100644
--- a/samples/rust/Kconfig
+++ b/samples/rust/Kconfig
@@ -20,6 +20,16 @@ config SAMPLE_RUST_MINIMAL
 
 	  If unsure, say N.
 
+config SAMPLE_RUST_MISC_DEVICE
+	tristate "Misc device"
+	help
+	  This option builds the Rust misc device.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_misc_device.
+
+	  If unsure, say N.
+
 config SAMPLE_RUST_PRINT
 	tristate "Printing macros"
 	help
@@ -30,6 +40,27 @@ config SAMPLE_RUST_PRINT
 
 	  If unsure, say N.
 
+config SAMPLE_RUST_DRIVER_PCI
+	tristate "PCI Driver"
+	depends on PCI
+	help
+	  This option builds the Rust PCI driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called driver_pci.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DRIVER_PLATFORM
+	tristate "Platform Driver"
+	help
+	  This option builds the Rust Platform driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_platform.
+
+	  If unsure, say N.
+
 config SAMPLE_RUST_HOSTPROGS
 	bool "Host programs"
 	help
diff --git a/samples/rust/Makefile b/samples/rust/Makefile
index c1a5c1655395..5a8ab0df0567 100644
--- a/samples/rust/Makefile
+++ b/samples/rust/Makefile
@@ -2,7 +2,10 @@
 ccflags-y += -I$(src)				# needed for trace events
 
 obj-$(CONFIG_SAMPLE_RUST_MINIMAL)		+= rust_minimal.o
+obj-$(CONFIG_SAMPLE_RUST_MISC_DEVICE)		+= rust_misc_device.o
 obj-$(CONFIG_SAMPLE_RUST_PRINT)			+= rust_print.o
+obj-$(CONFIG_SAMPLE_RUST_DRIVER_PCI)		+= rust_driver_pci.o
+obj-$(CONFIG_SAMPLE_RUST_DRIVER_PLATFORM)	+= rust_driver_platform.o
 
 rust_print-y := rust_print_main.o rust_print_events.o
 
diff --git a/samples/rust/rust_driver_pci.rs b/samples/rust/rust_driver_pci.rs
new file mode 100644
index 000000000000..1fb6e44f3395
--- /dev/null
+++ b/samples/rust/rust_driver_pci.rs
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust PCI driver sample (based on QEMU's `pci-testdev`).
+//!
+//! To make this driver probe, QEMU must be run with `-device pci-testdev`.
+
+use kernel::{bindings, c_str, devres::Devres, pci, prelude::*};
+
+struct Regs;
+
+impl Regs {
+    const TEST: usize = 0x0;
+    const OFFSET: usize = 0x4;
+    const DATA: usize = 0x8;
+    const COUNT: usize = 0xC;
+    const END: usize = 0x10;
+}
+
+type Bar0 = pci::Bar<{ Regs::END }>;
+
+#[derive(Debug)]
+struct TestIndex(u8);
+
+impl TestIndex {
+    const NO_EVENTFD: Self = Self(0);
+}
+
+struct SampleDriver {
+    pdev: pci::Device,
+    bar: Devres<Bar0>,
+}
+
+kernel::pci_device_table!(
+    PCI_TABLE,
+    MODULE_PCI_TABLE,
+    <SampleDriver as pci::Driver>::IdInfo,
+    [(
+        pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, 0x5),
+        TestIndex::NO_EVENTFD
+    )]
+);
+
+impl SampleDriver {
+    fn testdev(index: &TestIndex, bar: &Bar0) -> Result<u32> {
+        // Select the test.
+        bar.writeb(index.0, Regs::TEST);
+
+        let offset = u32::from_le(bar.readl(Regs::OFFSET)) as usize;
+        let data = bar.readb(Regs::DATA);
+
+        // Write `data` to `offset` to increase `count` by one.
+        //
+        // Note that we need `try_writeb`, since `offset` can't be checked at compile-time.
+        bar.try_writeb(data, offset)?;
+
+        Ok(bar.readl(Regs::COUNT))
+    }
+}
+
+impl pci::Driver for SampleDriver {
+    type IdInfo = TestIndex;
+
+    const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
+
+    fn probe(pdev: &mut pci::Device, info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
+        dev_dbg!(
+            pdev.as_ref(),
+            "Probe Rust PCI driver sample (PCI ID: 0x{:x}, 0x{:x}).\n",
+            pdev.vendor_id(),
+            pdev.device_id()
+        );
+
+        pdev.enable_device_mem()?;
+        pdev.set_master();
+
+        let bar = pdev.iomap_region_sized::<{ Regs::END }>(0, c_str!("rust_driver_pci"))?;
+
+        let drvdata = KBox::new(
+            Self {
+                pdev: pdev.clone(),
+                bar,
+            },
+            GFP_KERNEL,
+        )?;
+
+        let bar = drvdata.bar.try_access().ok_or(ENXIO)?;
+
+        dev_info!(
+            pdev.as_ref(),
+            "pci-testdev data-match count: {}\n",
+            Self::testdev(info, &bar)?
+        );
+
+        Ok(drvdata.into())
+    }
+}
+
+impl Drop for SampleDriver {
+    fn drop(&mut self) {
+        dev_dbg!(self.pdev.as_ref(), "Remove Rust PCI driver sample.\n");
+    }
+}
+
+kernel::module_pci_driver! {
+    type: SampleDriver,
+    name: "rust_driver_pci",
+    author: "Danilo Krummrich",
+    description: "Rust PCI driver",
+    license: "GPL v2",
+}
diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs
new file mode 100644
index 000000000000..8120609e2940
--- /dev/null
+++ b/samples/rust/rust_driver_platform.rs
@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust Platform driver sample.
+
+use kernel::{c_str, of, platform, prelude::*};
+
+struct SampleDriver {
+    pdev: platform::Device,
+}
+
+struct Info(u32);
+
+kernel::of_device_table!(
+    OF_TABLE,
+    MODULE_OF_TABLE,
+    <SampleDriver as platform::Driver>::IdInfo,
+    [(of::DeviceId::new(c_str!("test,rust-device")), Info(42))]
+);
+
+impl platform::Driver for SampleDriver {
+    type IdInfo = Info;
+    const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
+
+    fn probe(pdev: &mut platform::Device, info: Option<&Self::IdInfo>) -> Result<Pin<KBox<Self>>> {
+        dev_dbg!(pdev.as_ref(), "Probe Rust Platform driver sample.\n");
+
+        if let Some(info) = info {
+            dev_info!(pdev.as_ref(), "Probed with info: '{}'.\n", info.0);
+        }
+
+        let drvdata = KBox::new(Self { pdev: pdev.clone() }, GFP_KERNEL)?;
+
+        Ok(drvdata.into())
+    }
+}
+
+impl Drop for SampleDriver {
+    fn drop(&mut self) {
+        dev_dbg!(self.pdev.as_ref(), "Remove Rust Platform driver sample.\n");
+    }
+}
+
+kernel::module_platform_driver! {
+    type: SampleDriver,
+    name: "rust_driver_platform",
+    author: "Danilo Krummrich",
+    description: "Rust Platform driver",
+    license: "GPL v2",
+}
diff --git a/samples/rust/rust_misc_device.rs b/samples/rust/rust_misc_device.rs
new file mode 100644
index 000000000000..40ad7266c225
--- /dev/null
+++ b/samples/rust/rust_misc_device.rs
@@ -0,0 +1,238 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2024 Google LLC.
+
+//! Rust misc device sample.
+
+/// Below is an example userspace C program that exercises this sample's functionality.
+///
+/// ```c
+/// #include <stdio.h>
+/// #include <stdlib.h>
+/// #include <errno.h>
+/// #include <fcntl.h>
+/// #include <unistd.h>
+/// #include <sys/ioctl.h>
+///
+/// #define RUST_MISC_DEV_FAIL _IO('|', 0)
+/// #define RUST_MISC_DEV_HELLO _IO('|', 0x80)
+/// #define RUST_MISC_DEV_GET_VALUE _IOR('|', 0x81, int)
+/// #define RUST_MISC_DEV_SET_VALUE _IOW('|', 0x82, int)
+///
+/// int main() {
+///   int value, new_value;
+///   int fd, ret;
+///
+///   // Open the device file
+///   printf("Opening /dev/rust-misc-device for reading and writing\n");
+///   fd = open("/dev/rust-misc-device", O_RDWR);
+///   if (fd < 0) {
+///     perror("open");
+///     return errno;
+///   }
+///
+///   // Make call into driver to say "hello"
+///   printf("Calling Hello\n");
+///   ret = ioctl(fd, RUST_MISC_DEV_HELLO, NULL);
+///   if (ret < 0) {
+///     perror("ioctl: Failed to call into Hello");
+///     close(fd);
+///     return errno;
+///   }
+///
+///   // Get initial value
+///   printf("Fetching initial value\n");
+///   ret = ioctl(fd, RUST_MISC_DEV_GET_VALUE, &value);
+///   if (ret < 0) {
+///     perror("ioctl: Failed to fetch the initial value");
+///     close(fd);
+///     return errno;
+///   }
+///
+///   value++;
+///
+///   // Set value to something different
+///   printf("Submitting new value (%d)\n", value);
+///   ret = ioctl(fd, RUST_MISC_DEV_SET_VALUE, &value);
+///   if (ret < 0) {
+///     perror("ioctl: Failed to submit new value");
+///     close(fd);
+///     return errno;
+///   }
+///
+///   // Ensure new value was applied
+///   printf("Fetching new value\n");
+///   ret = ioctl(fd, RUST_MISC_DEV_GET_VALUE, &new_value);
+///   if (ret < 0) {
+///     perror("ioctl: Failed to fetch the new value");
+///     close(fd);
+///     return errno;
+///   }
+///
+///   if (value != new_value) {
+///     printf("Failed: Committed and retrieved values are different (%d - %d)\n", value, new_value);
+///     close(fd);
+///     return -1;
+///   }
+///
+///   // Call the unsuccessful ioctl
+///   printf("Attempting to call in to an non-existent IOCTL\n");
+///   ret = ioctl(fd, RUST_MISC_DEV_FAIL, NULL);
+///   if (ret < 0) {
+///     perror("ioctl: Succeeded to fail - this was expected");
+///   } else {
+///     printf("ioctl: Failed to fail\n");
+///     close(fd);
+///     return -1;
+///   }
+///
+///   // Close the device file
+///   printf("Closing /dev/rust-misc-device\n");
+///   close(fd);
+///
+///   printf("Success\n");
+///   return 0;
+/// }
+/// ```
+use core::pin::Pin;
+
+use kernel::{
+    c_str,
+    device::Device,
+    fs::File,
+    ioctl::{_IO, _IOC_SIZE, _IOR, _IOW},
+    miscdevice::{MiscDevice, MiscDeviceOptions, MiscDeviceRegistration},
+    new_mutex,
+    prelude::*,
+    sync::Mutex,
+    types::ARef,
+    uaccess::{UserSlice, UserSliceReader, UserSliceWriter},
+};
+
+const RUST_MISC_DEV_HELLO: u32 = _IO('|' as u32, 0x80);
+const RUST_MISC_DEV_GET_VALUE: u32 = _IOR::<i32>('|' as u32, 0x81);
+const RUST_MISC_DEV_SET_VALUE: u32 = _IOW::<i32>('|' as u32, 0x82);
+
+module! {
+    type: RustMiscDeviceModule,
+    name: "rust_misc_device",
+    author: "Lee Jones",
+    description: "Rust misc device sample",
+    license: "GPL",
+}
+
+#[pin_data]
+struct RustMiscDeviceModule {
+    #[pin]
+    _miscdev: MiscDeviceRegistration<RustMiscDevice>,
+}
+
+impl kernel::InPlaceModule for RustMiscDeviceModule {
+    fn init(_module: &'static ThisModule) -> impl PinInit<Self, Error> {
+        pr_info!("Initialising Rust Misc Device Sample\n");
+
+        let options = MiscDeviceOptions {
+            name: c_str!("rust-misc-device"),
+        };
+
+        try_pin_init!(Self {
+            _miscdev <- MiscDeviceRegistration::register(options),
+        })
+    }
+}
+
+struct Inner {
+    value: i32,
+}
+
+#[pin_data(PinnedDrop)]
+struct RustMiscDevice {
+    #[pin]
+    inner: Mutex<Inner>,
+    dev: ARef<Device>,
+}
+
+#[vtable]
+impl MiscDevice for RustMiscDevice {
+    type Ptr = Pin<KBox<Self>>;
+
+    fn open(_file: &File, misc: &MiscDeviceRegistration<Self>) -> Result<Pin<KBox<Self>>> {
+        let dev = ARef::from(misc.device());
+
+        dev_info!(dev, "Opening Rust Misc Device Sample\n");
+
+        KBox::try_pin_init(
+            try_pin_init! {
+                RustMiscDevice {
+                    inner <- new_mutex!( Inner{ value: 0_i32 } ),
+                    dev: dev,
+                }
+            },
+            GFP_KERNEL,
+        )
+    }
+
+    fn ioctl(me: Pin<&RustMiscDevice>, _file: &File, cmd: u32, arg: usize) -> Result<isize> {
+        dev_info!(me.dev, "IOCTLing Rust Misc Device Sample\n");
+
+        let size = _IOC_SIZE(cmd);
+
+        match cmd {
+            RUST_MISC_DEV_GET_VALUE => me.get_value(UserSlice::new(arg, size).writer())?,
+            RUST_MISC_DEV_SET_VALUE => me.set_value(UserSlice::new(arg, size).reader())?,
+            RUST_MISC_DEV_HELLO => me.hello()?,
+            _ => {
+                dev_err!(me.dev, "-> IOCTL not recognised: {}\n", cmd);
+                return Err(ENOTTY);
+            }
+        };
+
+        Ok(0)
+    }
+}
+
+#[pinned_drop]
+impl PinnedDrop for RustMiscDevice {
+    fn drop(self: Pin<&mut Self>) {
+        dev_info!(self.dev, "Exiting the Rust Misc Device Sample\n");
+    }
+}
+
+impl RustMiscDevice {
+    fn set_value(&self, mut reader: UserSliceReader) -> Result<isize> {
+        let new_value = reader.read::<i32>()?;
+        let mut guard = self.inner.lock();
+
+        dev_info!(
+            self.dev,
+            "-> Copying data from userspace (value: {})\n",
+            new_value
+        );
+
+        guard.value = new_value;
+        Ok(0)
+    }
+
+    fn get_value(&self, mut writer: UserSliceWriter) -> Result<isize> {
+        let guard = self.inner.lock();
+        let value = guard.value;
+
+        // Free-up the lock and use our locally cached instance from here
+        drop(guard);
+
+        dev_info!(
+            self.dev,
+            "-> Copying data to userspace (value: {})\n",
+            &value
+        );
+
+        writer.write::<i32>(&value)?;
+        Ok(0)
+    }
+
+    fn hello(&self) -> Result<isize> {
+        dev_info!(self.dev, "-> Hello from the Rust Misc Device\n");
+
+        Ok(0)
+    }
+}