5 //! Rust API for bitmap.
7 //! C headers: [`include/linux/bitmap.h`](srctree/include/linux/bitmap.h).
17 /// Represents a C bitmap. Wraps underlying C bitmap API.
24 pub struct Bitmap {  struct
28 impl Bitmap {  impl
29     /// Borrows a C bitmap.
35     /// * the array must not be freed for the lifetime of this [`Bitmap`]
37     pub unsafe fn from_raw<'a>(ptr: *const usize, nbits: usize) -> &'a Bitmap {  in from_raw()  argument
44         // We are casting `*const [()]` to `*const Bitmap`. The `Bitmap`  in from_raw()
50         // pointer as `&Bitmap` is safe given the caller's guarantees.  in from_raw()
51         unsafe { &*(data as *const Bitmap) }  in from_raw()  constant
54     /// Borrows a C bitmap exclusively.
60     /// * the array must not be freed for the lifetime of this [`Bitmap`]
62     pub unsafe fn from_raw_mut<'a>(ptr: *mut usize, nbits: usize) -> &'a mut Bitmap {  in from_raw_mut()  argument
71         // Similar to `from_raw`, casting `*mut [()]` to `*mut Bitmap` is  in from_raw_mut()
72         // safe because `Bitmap` is a ZST with a `data: [()]` field,  in from_raw_mut()
74         unsafe { &mut *(data as *mut Bitmap) }  in from_raw_mut()
77     /// Returns a raw pointer to the backing [`Bitmap`].
79         core::ptr::from_ref::<Bitmap>(self).cast::<usize>()  in as_ptr()
82     /// Returns a mutable raw pointer to the backing [`Bitmap`].
84         core::ptr::from_mut::<Bitmap>(self).cast::<usize>()  in as_mut_ptr()
87     /// Returns length of this [`Bitmap`].
94 /// Holds either a pointer to array of `unsigned long` or a small bitmap.
97     bitmap: usize,
121 /// Represents an owned bitmap.
123 /// Wraps underlying C bitmap API. See [`Bitmap`] for available
132 /// use kernel::bitmap::BitmapVec;
157     /// Representation of bitmap.
159     /// Length of this bitmap. Must be `<= i32::MAX`.
164     type Target = Bitmap;
166     fn deref(&self) -> &Bitmap {  in deref()  argument
168             // SAFETY: Bitmap is represented inline.  in deref()
171                 core::ptr::addr_of!(self.repr.bitmap)  in deref()
174             // SAFETY: Bitmap is represented as array of `unsigned long`.  in deref()
178         // SAFETY: We got the right pointer and invariants of [`Bitmap`] hold.  in deref()
179         // An inline bitmap is treated like an array with single element.  in deref()
180         unsafe { Bitmap::from_raw(ptr, self.nbits) }  in deref()
185     fn deref_mut(&mut self) -> &mut Bitmap {  in deref_mut()  argument
187             // SAFETY: Bitmap is represented inline.  in deref_mut()
190                 core::ptr::addr_of_mut!(self.repr.bitmap)  in deref_mut()
193             // SAFETY: Bitmap is represented as array of `unsigned long`.  in deref_mut()
198         // An inline bitmap is treated like an array with single element.  in deref_mut()
199         unsafe { Bitmap::from_raw_mut(ptr, self.nbits) }  in deref_mut()
205 /// SAFETY: We own the underlying bitmap representation.
210 /// SAFETY: `deref()` will return a reference to a [`Bitmap`]. Its methods
237                 repr: BitmapRepr { bitmap: 0 },  in new()
255     /// Returns length of this [`Bitmap`].
262     /// Fills this `Bitmap` with random bits.
278 impl Bitmap {  implementation
381     /// Copy `src` into this [`Bitmap`] and set any remaining bits to zero.
387     /// use kernel::bitmap::BitmapVec;
402     pub fn copy_and_extend(&mut self, src: &Bitmap) {  in copy_and_extend()  argument
421     /// use kernel::bitmap::BitmapVec;
423     /// let bitmap = BitmapVec::new(64, GFP_KERNEL)?;
425     /// match bitmap.last_bit() {
430     ///         pr_info!("All bits in this bitmap are 0.\n");
499         let b = unsafe { Bitmap::from_raw(fake_bitmap.as_ptr(), 2 * BITS_PER_LONG) };  in bitmap_borrow()
508         let b = unsafe { Bitmap::from_raw(core::ptr::addr_of!(fake_bitmap), 8) };  in bitmap_copy()