rust: addr: Add a module to declare core address types

Encapsulates the core physical/DMA address types, so they can be used by
Rust abstractions.

Signed-off-by: Asahi Lina <[email protected]>

rust/kernel/addr.rs

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Kernel core address types.
+
+use bindings;
+use core::ffi;
+
+/// A physical memory address (which may be wider than the CPU pointer size)
+pub type PhysicalAddr = bindings::phys_addr_t;
+/// A DMA memory address (which may be narrower than `PhysicalAddr` on some systems)
+pub type DmaAddr = bindings::dma_addr_t;
+/// A physical resource size, typically the same width as `PhysicalAddr`
+pub type ResourceSize = bindings::resource_size_t;
+/// A raw page frame number, not to be confused with the C `pfn_t` which also encodes flags.
+pub type Pfn = ffi::c_ulong;

rust/kernel/lib.rs

@@ -40,6 +40,7 @@ compile_error!("Missing kernel configuration for conditional compilation");
 // Allow proc-macros to refer to `::kernel` inside the `kernel` crate (this crate).
 extern crate self as kernel;
 
+pub mod addr;
 pub mod alloc;
 #[cfg(CONFIG_BLOCK)]
 pub mod block;