Add SZ_4G constant defined as SZ_2G * 2. This constant will be used by
the Tyr driver for calculating user and kernel VA layout.

Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
---
 rust/kernel/sizes.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/rust/kernel/sizes.rs b/rust/kernel/sizes.rs
index 661e680d93306..872f5bb181ecf 100644
--- a/rust/kernel/sizes.rs
+++ b/rust/kernel/sizes.rs
@@ -48,3 +48,5 @@
 pub const SZ_1G: usize = bindings::SZ_1G as usize;
 /// 0x80000000
 pub const SZ_2G: usize = bindings::SZ_2G as usize;
+/// 0x100000000
+pub const SZ_4G: usize = SZ_2G * 2;

-- 
2.43.0