sys_util: move round_to_page_size to sys_util

This function will be used elsewhere in gpu_display.

TEST=None
BUG=None

Change-Id: I58b820511ea5a55a53ad640fdfe7c96d2dbdc73b
Reviewed-on: https://chromium-review.googlesource.com/1105481
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/sys_util/src/lib.rs b/sys_util/src/lib.rs
index 701622b..caef4c2 100644
--- a/sys_util/src/lib.rs
+++ b/sys_util/src/lib.rs
@@ -75,6 +75,14 @@ pub fn pagesize() -> usize {
     unsafe { sysconf(_SC_PAGESIZE) as usize }
 }
 
+
+/// Uses the system's page size in bytes to round the given value up to the nearest page boundary.
+#[inline(always)]
+pub fn round_up_to_page_size(v: usize) -> usize {
+    let page_mask = pagesize() - 1;
+    (v + page_mask) & !page_mask
+}
+
 /// This bypasses `libc`'s caching `getpid(2)` wrapper which can be invalid if a raw clone was used
 /// elsewhere.
 #[inline(always)]