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| author | Alice Ryhl <aliceryhl@google.com> | 2024-10-16 11:34:25 +0000 |
|---|---|---|
| committer | Miguel Ojeda <ojeda@kernel.org> | 2024-10-21 20:34:46 +0200 |
| commit | 6e86292f212cf121cafe881c18381b5972b18d4f (patch) | |
| tree | cdff55ee619a34bee1dd4ecf3fff057be7c27ec3 | |
| parent | d4d7c05f9656fd8e14c6977a54986264eb296ec8 (diff) | |
rust: page: add Rust version of PAGE_ALIGN
This is a useful for helper for working with indices into buffers that
consist of several pages. I forgot to include it when I added PAGE_SIZE
and PAGE_MASK for the same purpose in commit fc6e66f4696b ("rust: add
abstraction for `struct page`").
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241016-page-align-v2-1-e0afe85fc4b4@google.com
[ Added intra-doc links, formatted comment and replaced "Brackets" with
"Parentheses" as discussed in the list. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
| -rw-r--r-- | rust/kernel/page.rs | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/rust/kernel/page.rs b/rust/kernel/page.rs index 208a006d587c..fdac6c375fe4 100644 --- a/rust/kernel/page.rs +++ b/rust/kernel/page.rs @@ -20,6 +20,16 @@ pub const PAGE_SIZE: usize = bindings::PAGE_SIZE; /// A bitmask that gives the page containing a given address. pub const PAGE_MASK: usize = !(PAGE_SIZE - 1); +/// Round up the given number to the next multiple of [`PAGE_SIZE`]. +/// +/// It is incorrect to pass an address where the next multiple of [`PAGE_SIZE`] doesn't fit in a +/// [`usize`]. +pub const fn page_align(addr: usize) -> usize { + // Parentheses around `PAGE_SIZE - 1` to avoid triggering overflow sanitizers in the wrong + // cases. + (addr + (PAGE_SIZE - 1)) & PAGE_MASK +} + /// A pointer to a page that owns the page allocation. /// /// # Invariants |