rust: WIP(?): Various bits of rust glue for AOP series

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>

Author: WhatAmISupposedToPutHere

rust/bindgen_parameters

@@ -12,6 +12,9 @@
 
 # Packed type cannot transitively contain a `#[repr(align)]` type.
 --opaque-type alt_instr
+--opaque-type snd_codec_options
+--opaque-type snd_codec
+--opaque-type snd_compr_params
 --opaque-type x86_msi_data
 --opaque-type x86_msi_addr_lo
 

rust/bindings/bindings_helper.h

@@ -19,6 +19,8 @@
 #include <linux/file.h>
 #include <linux/firmware.h>
 #include <linux/fs.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/types.h>
 #include <linux/ioport.h>
 #include <linux/jiffies.h>
 #include <linux/jump_label.h>
@@ -47,6 +49,9 @@
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 #include <linux/xarray.h>
+#include <sound/core.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm.h>
 #include <trace/events/rust_sample.h>
 
 #if defined(CONFIG_DRM_PANIC_SCREEN_QR_CODE)
@@ -81,3 +86,10 @@ const xa_mark_t BINDINGS_XA_MARK_2 = XA_MARK_2;
 const xa_mark_t BINDINGS_XA_PRESENT = XA_PRESENT;
 const xa_mark_t BINDINGS_XA_MARK_MAX = XA_MARK_MAX;
 const xa_mark_t BINDINGS_XA_FREE_MARK = XA_FREE_MARK;
+
+const u64 BINDINGS_SNDRV_PCM_FMTBIT_FLOAT_LE = SNDRV_PCM_FMTBIT_FLOAT_LE;
+
+const u32 BINDINGS_IIO_CHAN_INFO_RAW = IIO_CHAN_INFO_RAW;
+const u32 BINDINGS_IIO_CHAN_INFO_PROCESSED = IIO_CHAN_INFO_PROCESSED;
+const u32 BINDINGS_IIO_ANGL = IIO_ANGL;
+const u32 BINDINGS_IIO_LIGHT = IIO_LIGHT;

rust/helpers/device.c

@@ -8,3 +8,8 @@ int rust_helper_devm_add_action(struct device *dev,
 {
 	return devm_add_action(dev, action, data);
 }
+
+void *rust_helper_dev_get_drvdata(struct device *dev)
+{
+	return dev_get_drvdata(dev);
+}

rust/kernel/alloc/kvec.rs

@@ -460,7 +460,7 @@ where
     /// If `new_len` is greater than len, the Vec is extended by the difference,
     /// with each additional slot filled with `value`.
     /// If `new_len` is less than len, the Vec is simply truncated.
-    fn resize(&mut self, new_len: usize, value: T, flags: Flags) -> Result<(), AllocError>
+    pub fn resize(&mut self, new_len: usize, value: T, flags: Flags) -> Result<(), AllocError>
     where
         T: Clone,
     {
@@ -625,6 +625,26 @@ where
             }
         }
     }
+    /// Removes an element from the vector and returns it.
+    ///
+    /// The removed element is replaced by the last element of the vector.
+    ///
+    /// This does not preserve ordering of the remaining elements, but is *O*(1).
+    /// If you need to preserve the element order, use [`remove`] instead.
+    pub fn swap_remove(&mut self, index: usize) -> T {
+        if index > self.len() {
+            panic!("Index out of range");
+        }
+        // SAFETY: index is in range
+        // self.len() - 1 is in range since at last 1 element exists
+        unsafe {
+            let old = ptr::read(self.as_ptr().add(index));
+            let last = ptr::read(self.as_ptr().add(self.len() - 1));
+            ptr::write(self.as_mut_ptr().add(index), last);
+            self.set_len(self.len - 1);
+            old
+        }
+    }
 }
 
 impl<T: Clone, A: Allocator> Vec<T, A> {

rust/kernel/device.rs

@@ -61,7 +61,7 @@ impl Device {
     }
 
     /// Obtain the raw `struct device *`.
-    pub(crate) fn as_raw(&self) -> *mut bindings::device {
+    pub fn as_raw(&self) -> *mut bindings::device {
         self.0.get()
     }
 
@@ -76,6 +76,13 @@ impl Device {
         unsafe { Some(Self::get_device(pdev)) }
     }
 
+    /// Returns the driver_data pointer.
+    pub fn get_drvdata<T>(&self) -> *mut T {
+        // SAFETY: dev_get_drvdata returns a field of the device,
+        //   pointer to which is valid by type invariant
+        unsafe { bindings::dev_get_drvdata(self.as_raw()) as *mut T }
+    }
+
     /// Convert a raw C `struct device` pointer to a `&'a Device`.
     ///
     /// # Safety

rust/kernel/of.rs

@@ -391,6 +391,25 @@ impl<'a> Property<'a> {
     pub fn is_empty(&self) -> bool {
         self.len() == 0
     }
+
+    /// Copy a device-tree property to a slice
+    ///
+    /// Enforces that the length of the property is an exact match of the slice.
+    pub fn copy_to_slice<T: PropertyUnit>(&self, target: &mut [T]) -> Result<()> {
+        if self.len() % T::UNIT_SIZE != 0 {
+            return Err(EINVAL);
+        }
+
+        if self.len() / T::UNIT_SIZE != target.len() {
+            return Err(EINVAL);
+        }
+
+        let val = self.value();
+        for (i, off) in (0..self.len()).step_by(T::UNIT_SIZE).enumerate() {
+            target[i] = T::from_bytes(&val[off..off + T::UNIT_SIZE])?
+        }
+        Ok(())
+    }
 }
 
 /// A trait that represents a value decodable from a property with a fixed unit size.