[PATCH v6 5/7] rust: id_pool: take a NonZero capacity in with_capacity

[Eliot Courtney <ecourtney@nvidia.com>]

There is no good reason to allocate an IdPool with zero capacity.
Reflect this in IdPool::with_capacity.

Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
 rust/kernel/id_pool.rs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/rust/kernel/id_pool.rs b/rust/kernel/id_pool.rs
index a4a2ff417fe8..1423a5fbca69 100644
--- a/rust/kernel/id_pool.rs
+++ b/rust/kernel/id_pool.rs
@@ -29,10 +29,11 @@
 /// Basic usage
 ///
 /// ```
+/// use core::num::NonZero;
 /// use kernel::alloc::AllocError;
 /// use kernel::id_pool::{IdPool, UnusedId};
 ///
-/// let mut pool = IdPool::with_capacity(64, GFP_KERNEL)?;
+/// let mut pool = IdPool::with_capacity(NonZero::new(64).unwrap(), GFP_KERNEL)?;
 /// for i in 0..64 {
 ///     assert_eq!(i, pool.find_unused_id(i).ok_or(ENOSPC)?.acquire());
 /// }
@@ -117,8 +118,8 @@ pub fn new() -> Self {
     ///
     /// [`MAX_INLINE_LEN`]: BitmapVec::MAX_INLINE_LEN
     #[inline]
-    pub fn with_capacity(num_ids: usize, flags: Flags) -> Result<Self, AllocError> {
-        let num_ids = usize::max(num_ids, BitmapVec::MAX_INLINE_LEN);
+    pub fn with_capacity(num_ids: NonZero<usize>, flags: Flags) -> Result<Self, AllocError> {
+        let num_ids = usize::max(num_ids.get(), BitmapVec::MAX_INLINE_LEN);
         let map = BitmapVec::new(num_ids, flags)?;
         Ok(Self { map })
     }
@@ -138,6 +139,7 @@ pub fn capacity(&self) -> usize {
     /// # Examples
     ///
     /// ```
+    /// use core::num::NonZero;
     /// use kernel::{
     ///     alloc::AllocError,
     ///     bitmap::BitmapVec,
@@ -147,7 +149,7 @@ pub fn capacity(&self) -> usize {
     ///     },
     /// };
     ///
-    /// let mut pool = IdPool::with_capacity(1024, GFP_KERNEL)?;
+    /// let mut pool = IdPool::with_capacity(NonZero::new(1024).unwrap(), GFP_KERNEL)?;
     /// let alloc_request = pool.shrink_request().ok_or(AllocError)?;
     /// let resizer = alloc_request.realloc(GFP_KERNEL)?;
     /// pool.shrink(resizer);

-- 
2.55.0