[PATCH v4 01/11] rust: sizes: add SZ_4G constant

[Ke Sun via B4 Relay]

From: Alvin Sun <alvin.sun@xxxxxxxxx>

SZ_4G is used by Tyr when splitting the GPU VA range into
user and kernel regions. Add a LargeSizeConstants trait, implemented
for u64 since SizeConstants only covers sizes that fit in a u32.

Signed-off-by: Alvin Sun <alvin.sun@xxxxxxxxx>
Reviewed-by: Daniel Almeida <daniel.almeida@xxxxxxxxxxxxx>
Reviewed-by: Gary Guo <gary@xxxxxxxxxxx>
Acked-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
---
 rust/bindings/bindings_helper.h |  1 +
 rust/kernel/sizes.rs            | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 930e63290cdd4..ee99f470ae5f4 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -116,6 +116,7 @@ const size_t RUST_CONST_HELPER_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN;
 const size_t RUST_CONST_HELPER_ARCH_KMALLOC_MINALIGN = ARCH_KMALLOC_MINALIGN;
 const size_t RUST_CONST_HELPER_PAGE_SIZE = PAGE_SIZE;
 const size_t RUST_CONST_HELPER_GENLMSG_DEFAULT_SIZE = GENLMSG_DEFAULT_SIZE;
+const unsigned long long RUST_CONST_HELPER_SZ_4G = SZ_4G;
 const gfp_t RUST_CONST_HELPER_GFP_ATOMIC = GFP_ATOMIC;
 const gfp_t RUST_CONST_HELPER_GFP_KERNEL = GFP_KERNEL;
 const gfp_t RUST_CONST_HELPER_GFP_KERNEL_ACCOUNT = GFP_KERNEL_ACCOUNT;
diff --git a/rust/kernel/sizes.rs b/rust/kernel/sizes.rs
index 521b2b38bfe77..0acc8733d2368 100644
--- a/rust/kernel/sizes.rs
+++ b/rust/kernel/sizes.rs
@@ -132,3 +132,15 @@ impl SizeConstants for $first {
 }
 
 define_sizes!(u32, u64, usize);
+
+/// Large size constants (≥ 4 GiB).
+///
+/// Only implemented for [`u64`].
+pub trait LargeSizeConstants {
+    /// `0x1_0000_0000`.
+    const SZ_4G: Self;
+}
+
+impl LargeSizeConstants for u64 {
+    const SZ_4G: Self = bindings::SZ_4G;
+}

-- 
2.43.0