Merge tag 'driver-core-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updatesk from Greg KH:
 "Here is the big set of driver core updates for 6.15-rc1. Lots of stuff
  happened this development cycle, including:

   - kernfs scaling changes to make it even faster thanks to rcu

   - bin_attribute constify work in many subsystems

   - faux bus minor tweaks for the rust bindings

   - rust binding updates for driver core, pci, and platform busses,
     making more functionaliy available to rust drivers. These are all
     due to people actually trying to use the bindings that were in
     6.14.

   - make Rafael and Danilo full co-maintainers of the driver core
     codebase

   - other minor fixes and updates"

* tag 'driver-core-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (52 commits)
  rust: platform: require Send for Driver trait implementers
  rust: pci: require Send for Driver trait implementers
  rust: platform: impl Send + Sync for platform::Device
  rust: pci: impl Send + Sync for pci::Device
  rust: platform: fix unrestricted &mut platform::Device
  rust: pci: fix unrestricted &mut pci::Device
  rust: device: implement device context marker
  rust: pci: use to_result() in enable_device_mem()
  MAINTAINERS: driver core: mark Rafael and Danilo as co-maintainers
  rust/kernel/faux: mark Registration methods inline
  driver core: faux: only create the device if probe() succeeds
  rust/faux: Add missing parent argument to Registration::new()
  rust/faux: Drop #[repr(transparent)] from faux::Registration
  rust: io: fix devres test with new io accessor functions
  rust: io: rename `io::Io` accessors
  kernfs: Move dput() outside of the RCU section.
  efi: rci2: mark bin_attribute as __ro_after_init
  rapidio: constify 'struct bin_attribute'
  firmware: qemu_fw_cfg: constify 'struct bin_attribute'
  powerpc/perf/hv-24x7: Constify 'struct bin_attribute'
  ...

1 files changed, 13 insertions, 3 deletions

diff --git a/rust/kernel/faux.rs b/rust/kernel/faux.rs
index 5acc0c02d451..8a50fcd4c9bb 100644
--- a/rust/kernel/faux.rs
+++ b/rust/kernel/faux.rs
@@ -19,16 +19,25 @@ use core::ptr::{addr_of_mut, null, null_mut, NonNull};
 /// `self.0` always holds a valid pointer to an initialized and registered [`struct faux_device`].
 ///
 /// [`struct faux_device`]: srctree/include/linux/device/faux.h
-#[repr(transparent)]
 pub struct Registration(NonNull<bindings::faux_device>);
 
 impl Registration {
     /// Create and register a new faux device with the given name.
-    pub fn new(name: &CStr) -> Result<Self> {
+    #[inline]
+    pub fn new(name: &CStr, parent: Option<&device::Device>) -> Result<Self> {
         // SAFETY:
         // - `name` is copied by this function into its own storage
         // - `faux_ops` is safe to leave NULL according to the C API
-        let dev = unsafe { bindings::faux_device_create(name.as_char_ptr(), null_mut(), null()) };
+        // - `parent` can be either NULL or a pointer to a `struct device`, and `faux_device_create`
+        //   will take a reference to `parent` using `device_add` - ensuring that it remains valid
+        //   for the lifetime of the faux device.
+        let dev = unsafe {
+            bindings::faux_device_create(
+                name.as_char_ptr(),
+                parent.map_or(null_mut(), |p| p.as_raw()),
+                null(),
+            )
+        };
 
         // The above function will return either a valid device, or NULL on failure
         // INVARIANT: The device will remain registered until faux_device_destroy() is called, which
@@ -50,6 +59,7 @@ impl AsRef<device::Device> for Registration {
 }
 
 impl Drop for Registration {
+    #[inline]
     fn drop(&mut self) {
         // SAFETY: `self.0` is a valid registered faux_device via our type invariants.
         unsafe { bindings::faux_device_destroy(self.as_raw()) }