@@ -478,6 +478,7 @@ export rust_common_flags := --edition=2021 \
 			    -Wunreachable_pub \
 			    -Wclippy::all \
 			    -Wclippy::as_ptr_cast_mut \
+			    -Wclippy::as_underscore \
 			    -Wclippy::ignored_unit_patterns \
 			    -Wclippy::mut_mut \
 			    -Wclippy::needless_bitwise_bool \

@@ -101,7 +101,7 @@ impl<T: Operations> OperationsVTable<T> {
         if let Err(e) = ret {
             e.to_blk_status()
         } else {
-            bindings::BLK_STS_OK as _
+            bindings::BLK_STS_OK as u8
         }
     }
 

@@ -125,7 +125,7 @@ pub fn end_ok(this: ARef<Self>) -> Result<(), ARef<Self>> {
         // success of the call to `try_set_end` guarantees that there are no
         // `ARef`s pointing to this request. Therefore it is safe to hand it
         // back to the block layer.
-        unsafe { bindings::blk_mq_end_request(request_ptr, bindings::BLK_STS_OK as _) };
+        unsafe { bindings::blk_mq_end_request(request_ptr, bindings::BLK_STS_OK as u8) };
 
         Ok(())
     }

@@ -82,7 +82,7 @@ impl<T: RawDeviceId, U, const N: usize> IdArray<T, U, N> {
             unsafe {
                 raw_ids[i]
                     .as_mut_ptr()
-                    .byte_offset(T::DRIVER_DATA_OFFSET as _)
+                    .byte_add(T::DRIVER_DATA_OFFSET)
                     .cast::<usize>()
                     .write(i);
             }

@@ -45,7 +45,7 @@ struct DevresInner<T> {
 /// # Example
 ///
 /// ```no_run
-/// # use kernel::{bindings, c_str, device::Device, devres::Devres, io::{Io, IoRaw}};
+/// # use kernel::{bindings, c_str, device::Device, devres::Devres, ffi::c_void, io::{Io, IoRaw}};
 /// # use core::ops::Deref;
 ///
 /// // See also [`pci::Bar`] for a real example.

@@ -59,19 +59,19 @@ struct DevresInner<T> {
 ///     unsafe fn new(paddr: usize) -> Result<Self>{
 ///         // SAFETY: By the safety requirements of this function [`paddr`, `paddr` + `SIZE`) is
 ///         // valid for `ioremap`.
-///         let addr = unsafe { bindings::ioremap(paddr as _, SIZE as _) };
+///         let addr = unsafe { bindings::ioremap(paddr as u64, SIZE) };
 ///         if addr.is_null() {
 ///             return Err(ENOMEM);
 ///         }
 ///
-///         Ok(IoMem(IoRaw::new(addr as _, SIZE)?))
+///         Ok(IoMem(IoRaw::new(addr as usize, SIZE)?))
 ///     }
 /// }
 ///
 /// impl<const SIZE: usize> Drop for IoMem<SIZE> {
 ///     fn drop(&mut self) {
 ///         // SAFETY: `self.0.addr()` is guaranteed to be properly mapped by `Self::new`.
-///         unsafe { bindings::iounmap(self.0.addr() as _); };
+///         unsafe { bindings::iounmap(self.0.addr() as *mut c_void); };
 ///     }
 /// }
 ///

@@ -115,8 +115,9 @@ fn new(dev: &Device, data: T, flags: Flags) -> Result<Arc<DevresInner<T>>> {
 
         // SAFETY: `devm_add_action` guarantees to call `Self::devres_callback` once `dev` is
         // detached.
-        let ret =
-            unsafe { bindings::devm_add_action(dev.as_raw(), Some(inner.callback), data as _) };
+        let ret = unsafe {
+            bindings::devm_add_action(dev.as_raw(), Some(inner.callback), data.cast_mut().cast())
+        };
 
         if ret != 0 {
             // SAFETY: We just created another reference to `inner` in order to pass it to

@@ -130,7 +131,7 @@ fn new(dev: &Device, data: T, flags: Flags) -> Result<Arc<DevresInner<T>>> {
     }
 
     fn as_ptr(&self) -> *const Self {
-        self as _
+        self
     }
 
     fn remove_action(this: &Arc<Self>) {

@@ -152,7 +152,7 @@ pub(crate) fn to_blk_status(self) -> bindings::blk_status_t {
     /// Returns the error encoded as a pointer.
     pub fn to_ptr<T>(self) -> *mut T {
         // SAFETY: `self.0` is a valid error due to its invariant.
-        unsafe { bindings::ERR_PTR(self.0.get() as _).cast() }
+        unsafe { bindings::ERR_PTR(self.0.get() as isize).cast() }
     }
 
     /// Returns a string representing the error, if one exists.

@@ -61,7 +61,7 @@ fn request_internal(name: &CStr, dev: &Device, func: FwFunc) -> Result<Self> {
 
         // SAFETY: `pfw` is a valid pointer to a NULL initialized `bindings::firmware` pointer.
         // `name` and `dev` are valid as by their type invariants.
-        let ret = unsafe { func.0(pfw as _, name.as_char_ptr(), dev.as_raw()) };
+        let ret = unsafe { func.0(pfw, name.as_char_ptr(), dev.as_raw()) };
         if ret != 0 {
             return Err(Error::from_errno(ret));
         }

@@ -5,7 +5,7 @@
 //! C header: [`include/asm-generic/io.h`](srctree/include/asm-generic/io.h)
 
 use crate::error::{code::EINVAL, Result};
-use crate::{bindings, build_assert};
+use crate::{bindings, build_assert, ffi::c_void};
 
 /// Raw representation of an MMIO region.
 ///

@@ -56,7 +56,7 @@ pub fn maxsize(&self) -> usize {
 /// # Examples
 ///
 /// ```no_run
-/// # use kernel::{bindings, io::{Io, IoRaw}};
+/// # use kernel::{bindings, ffi::c_void, io::{Io, IoRaw}};
 /// # use core::ops::Deref;
 ///
 /// // See also [`pci::Bar`] for a real example.

@@ -70,19 +70,19 @@ pub fn maxsize(&self) -> usize {
 ///     unsafe fn new(paddr: usize) -> Result<Self>{
 ///         // SAFETY: By the safety requirements of this function [`paddr`, `paddr` + `SIZE`) is
 ///         // valid for `ioremap`.
-///         let addr = unsafe { bindings::ioremap(paddr as _, SIZE as _) };
+///         let addr = unsafe { bindings::ioremap(paddr as u64, SIZE) };
 ///         if addr.is_null() {
 ///             return Err(ENOMEM);
 ///         }
 ///
-///         Ok(IoMem(IoRaw::new(addr as _, SIZE)?))
+///         Ok(IoMem(IoRaw::new(addr as usize, SIZE)?))
 ///     }
 /// }
 ///
 /// impl<const SIZE: usize> Drop for IoMem<SIZE> {
 ///     fn drop(&mut self) {
 ///         // SAFETY: `self.0.addr()` is guaranteed to be properly mapped by `Self::new`.
-///         unsafe { bindings::iounmap(self.0.addr() as _); };
+///         unsafe { bindings::iounmap(self.0.addr() as *mut c_void); };
 ///     }
 /// }
 ///

@@ -119,7 +119,7 @@ pub fn $name(&self, offset: usize) -> $type_name {
             let addr = self.io_addr_assert::<$type_name>(offset);
 
             // SAFETY: By the type invariant `addr` is a valid address for MMIO operations.
-            unsafe { bindings::$name(addr as _) }
+            unsafe { bindings::$name(addr as *const c_void) }
         }
 
         /// Read IO data from a given offset.

@@ -131,7 +131,7 @@ pub fn $try_name(&self, offset: usize) -> Result<$type_name> {
             let addr = self.io_addr::<$type_name>(offset)?;
 
             // SAFETY: By the type invariant `addr` is a valid address for MMIO operations.
-            Ok(unsafe { bindings::$name(addr as _) })
+            Ok(unsafe { bindings::$name(addr as *const c_void) })
         }
     };
 }

@@ -148,7 +148,7 @@ pub fn $name(&self, value: $type_name, offset: usize) {
             let addr = self.io_addr_assert::<$type_name>(offset);
 
             // SAFETY: By the type invariant `addr` is a valid address for MMIO operations.
-            unsafe { bindings::$name(value, addr as _, ) }
+            unsafe { bindings::$name(value, addr as *mut c_void) }
         }
 
         /// Write IO data from a given offset.

@@ -160,7 +160,7 @@ pub fn $try_name(&self, value: $type_name, offset: usize) -> Result {
             let addr = self.io_addr::<$type_name>(offset)?;
 
             // SAFETY: By the type invariant `addr` is a valid address for MMIO operations.
-            unsafe { bindings::$name(value, addr as _) }
+            unsafe { bindings::$name(value, addr as *mut c_void) }
             Ok(())
         }
     };

@@ -33,7 +33,7 @@ impl MiscDeviceOptions {
     pub const fn into_raw<T: MiscDevice>(self) -> bindings::miscdevice {
         // SAFETY: All zeros is valid for this C type.
         let mut result: bindings::miscdevice = unsafe { MaybeUninit::zeroed().assume_init() };
-        result.minor = bindings::MISC_DYNAMIC_MINOR as _;
+        result.minor = bindings::MISC_DYNAMIC_MINOR as i32;
         result.name = self.name.as_char_ptr();
         result.fops = create_vtable::<T>();
         result

@@ -22,7 +22,7 @@ unsafe impl RawDeviceId for DeviceId {
     const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::of_device_id, data);
 
     fn index(&self) -> usize {
-        self.0.data as _
+        self.0.data as usize
     }
 }
 

@@ -34,10 +34,10 @@ pub const fn new(compatible: &'static CStr) -> Self {
         // SAFETY: FFI type is valid to be zero-initialized.
         let mut of: bindings::of_device_id = unsafe { core::mem::zeroed() };
 
-        // TODO: Use `clone_from_slice` once the corresponding types do match.
+        // TODO: Use `copy_from_slice` once stabilized for `const`.
         let mut i = 0;
         while i < src.len() {
-            of.compatible[i] = src[i] as _;
+            of.compatible[i] = src[i];
             i += 1;
         }
 

@@ -166,7 +166,7 @@ unsafe impl RawDeviceId for DeviceId {
     const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::pci_device_id, driver_data);
 
     fn index(&self) -> usize {
-        self.0.driver_data as _
+        self.0.driver_data
     }
 }
 

@@ -201,7 +201,10 @@ macro_rules! pci_device_table {
 ///     MODULE_PCI_TABLE,
 ///     <MyDriver as pci::Driver>::IdInfo,
 ///     [
-///         (pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, bindings::PCI_ANY_ID as _), ())
+///         (
+///             pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, bindings::PCI_ANY_ID as u32),
+///             (),
+///         )
 ///     ]
 /// );
 ///

@@ -317,7 +320,7 @@ unsafe fn do_release(pdev: &Device, ioptr: usize, num: i32) {
         // `ioptr` is valid by the safety requirements.
         // `num` is valid by the safety requirements.
         unsafe {
-            bindings::pci_iounmap(pdev.as_raw(), ioptr as _);
+            bindings::pci_iounmap(pdev.as_raw(), ioptr as *mut kernel::ffi::c_void);
             bindings::pci_release_region(pdev.as_raw(), num);
         }
     }

@@ -692,9 +692,9 @@ fn new() -> Self {
     pub(crate) unsafe fn from_ptrs(pos: *mut u8, end: *mut u8) -> Self {
         // INVARIANT: The safety requirements guarantee the type invariants.
         Self {
-            beg: pos as _,
-            pos: pos as _,
-            end: end as _,
+            beg: pos as usize,
+            pos: pos as usize,
+            end: end as usize,
         }
     }
 

@@ -719,7 +719,7 @@ pub(crate) unsafe fn from_buffer(buf: *mut u8, len: usize) -> Self {
     ///
     /// N.B. It may point to invalid memory.
     pub(crate) fn pos(&self) -> *mut u8 {
-        self.pos as _
+        self.pos as *mut u8
     }
 
     /// Returns the number of bytes written to the formatter.

@@ -198,7 +198,7 @@ pub fn enqueue<W, const ID: u64>(&self, w: W) -> W::EnqueueOutput
         unsafe {
             w.__enqueue(move |work_ptr| {
                 bindings::queue_work_on(
-                    bindings::wq_misc_consts_WORK_CPU_UNBOUND as _,
+                    bindings::wq_misc_consts_WORK_CPU_UNBOUND as i32,
                     queue_ptr,
                     work_ptr,
                 )