[PATCH v4 01/13] rust: pass module name to `Module::init`

[Danilo Krummrich <dakr@kernel.org>]

In a subsequent patch we introduce the `Registration` abstraction used
to register driver structures. Some subsystems require the module name on
driver registration (e.g. PCI in __pci_register_driver()), hence pass
the module name to `Module::init`.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
 drivers/block/rnull.rs          |  2 +-
 rust/kernel/lib.rs              | 14 ++++++++++----
 rust/kernel/net/phy.rs          |  2 +-
 rust/kernel/sync/lock/global.rs |  6 ++++--
 rust/macros/lib.rs              |  6 ++++--
 rust/macros/module.rs           |  7 +++++--
 samples/rust/rust_minimal.rs    |  2 +-
 samples/rust/rust_print_main.rs |  2 +-
 8 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/drivers/block/rnull.rs b/drivers/block/rnull.rs
index 5de7223beb4d..0e0e9ed7851e 100644
--- a/drivers/block/rnull.rs
+++ b/drivers/block/rnull.rs
@@ -36,7 +36,7 @@ struct NullBlkModule {
 }
 
 impl kernel::Module for NullBlkModule {
-    fn init(_module: &'static ThisModule) -> Result<Self> {
+    fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> {
         pr_info!("Rust null_blk loaded\n");
         let tagset = Arc::pin_init(TagSet::new(1, 256, 1), flags::GFP_KERNEL)?;
 
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index e1065a7551a3..686db6aa3323 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -90,7 +90,7 @@ pub trait Module: Sized + Sync + Send {
     /// should do.
     ///
     /// Equivalent to the `module_init` macro in the C API.
-    fn init(module: &'static ThisModule) -> error::Result<Self>;
+    fn init(name: &'static str::CStr, module: &'static ThisModule) -> error::Result<Self>;
 }
 
 /// A module that is pinned and initialised in-place.
@@ -98,13 +98,19 @@ pub trait InPlaceModule: Sync + Send {
     /// Creates an initialiser for the module.
     ///
     /// It is called when the module is loaded.
-    fn init(module: &'static ThisModule) -> impl init::PinInit<Self, error::Error>;
+    fn init(
+        name: &'static str::CStr,
+        module: &'static ThisModule,
+    ) -> impl init::PinInit<Self, error::Error>;
 }
 
 impl<T: Module> InPlaceModule for T {
-    fn init(module: &'static ThisModule) -> impl init::PinInit<Self, error::Error> {
+    fn init(
+        name: &'static str::CStr,
+        module: &'static ThisModule,
+    ) -> impl init::PinInit<Self, error::Error> {
         let initer = move |slot: *mut Self| {
-            let m = <Self as Module>::init(module)?;
+            let m = <Self as Module>::init(name, module)?;
 
             // SAFETY: `slot` is valid for write per the contract with `pin_init_from_closure`.
             unsafe { slot.write(m) };
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
index b89c681d97c0..0f41df2e6b96 100644
--- a/rust/kernel/net/phy.rs
+++ b/rust/kernel/net/phy.rs
@@ -903,7 +903,7 @@ struct Module {
                 [$($crate::net::phy::create_phy_driver::<$driver>()),+];
 
             impl $crate::Module for Module {
-                fn init(module: &'static ThisModule) -> Result<Self> {
+                fn init(_name: &'static CStr, module: &'static ThisModule) -> Result<Self> {
                     // SAFETY: The anonymous constant guarantees that nobody else can access
                     // the `DRIVERS` static. The array is used only in the C side.
                     let drivers = unsafe { &mut DRIVERS };
diff --git a/rust/kernel/sync/lock/global.rs b/rust/kernel/sync/lock/global.rs
index 480ee724e3cc..feff4638e20b 100644
--- a/rust/kernel/sync/lock/global.rs
+++ b/rust/kernel/sync/lock/global.rs
@@ -187,6 +187,7 @@ pub fn get_mut(&mut self) -> &mut T {
 /// ```
 /// # mod ex {
 /// # use kernel::prelude::*;
+/// # use kernel::str;
 /// kernel::sync::global_lock! {
 ///     // SAFETY: Initialized in module initializer before first use.
 ///     unsafe(uninit) static MY_COUNTER: Mutex<u32> = 0;
@@ -199,7 +200,7 @@ pub fn get_mut(&mut self) -> &mut T {
 /// }
 ///
 /// impl kernel::Module for MyModule {
-///     fn init(_module: &'static ThisModule) -> Result<Self> {
+///     fn init(_name: &'static str::CStr, _module: &'static ThisModule) -> Result<Self> {
 ///         // SAFETY: Called exactly once.
 ///         unsafe { MY_COUNTER.init() };
 ///
@@ -216,6 +217,7 @@ pub fn get_mut(&mut self) -> &mut T {
 /// # mod ex {
 /// # use kernel::prelude::*;
 /// use kernel::sync::{GlobalGuard, GlobalLockedBy};
+/// # use kernel::str;
 ///
 /// kernel::sync::global_lock! {
 ///     // SAFETY: Initialized in module initializer before first use.
@@ -239,7 +241,7 @@ pub fn get_mut(&mut self) -> &mut T {
 /// }
 ///
 /// impl kernel::Module for MyModule {
-///     fn init(_module: &'static ThisModule) -> Result<Self> {
+///     fn init(_name: &'static str::CStr, _module: &'static ThisModule) -> Result<Self> {
 ///         // SAFETY: Called exactly once.
 ///         unsafe { MY_MUTEX.init() };
 ///
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index 4ab94e44adfe..d669f9cd1726 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -32,6 +32,7 @@
 ///
 /// ```
 /// use kernel::prelude::*;
+/// use kernel::str;
 ///
 /// module!{
 ///     type: MyModule,
@@ -45,7 +46,7 @@
 /// struct MyModule(i32);
 ///
 /// impl kernel::Module for MyModule {
-///     fn init(_module: &'static ThisModule) -> Result<Self> {
+///     fn init(_name: &'static str::CStr, _module: &'static ThisModule) -> Result<Self> {
 ///         let foo: i32 = 42;
 ///         pr_info!("I contain:  {}\n", foo);
 ///         Ok(Self(foo))
@@ -65,6 +66,7 @@
 ///
 /// ```
 /// use kernel::prelude::*;
+/// use kernel::str;
 ///
 /// module!{
 ///     type: MyDeviceDriverModule,
@@ -78,7 +80,7 @@
 /// struct MyDeviceDriverModule;
 ///
 /// impl kernel::Module for MyDeviceDriverModule {
-///     fn init(_module: &'static ThisModule) -> Result<Self> {
+///     fn init(_name: &'static str::CStr, _module: &'static ThisModule) -> Result<Self> {
 ///         Ok(Self)
 ///     }
 /// }
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index 2587f41b0d39..1f14ef55341a 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -333,8 +333,11 @@ mod __module_init {{
                     ///
                     /// This function must only be called once.
                     unsafe fn __init() -> kernel::ffi::c_int {{
-                        let initer =
-                            <{type_} as kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
+                        let initer = <{type_} as kernel::InPlaceModule>::init(
+                            kernel::c_str!(\"{name}\"),
+                            &super::super::THIS_MODULE
+                        );
+
                         // SAFETY: No data race, since `__MOD` can only be accessed by this module
                         // and there only `__init` and `__exit` access it. These functions are only
                         // called once and `__exit` cannot be called before or during `__init`.
diff --git a/samples/rust/rust_minimal.rs b/samples/rust/rust_minimal.rs
index 4aaf117bf8e3..1577dc34e563 100644
--- a/samples/rust/rust_minimal.rs
+++ b/samples/rust/rust_minimal.rs
@@ -17,7 +17,7 @@ struct RustMinimal {
 }
 
 impl kernel::Module for RustMinimal {
-    fn init(_module: &'static ThisModule) -> Result<Self> {
+    fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> {
         pr_info!("Rust minimal sample (init)\n");
         pr_info!("Am I built-in? {}\n", !cfg!(MODULE));
 
diff --git a/samples/rust/rust_print_main.rs b/samples/rust/rust_print_main.rs
index aed90a6feecf..0853d767439b 100644
--- a/samples/rust/rust_print_main.rs
+++ b/samples/rust/rust_print_main.rs
@@ -41,7 +41,7 @@ fn arc_print() -> Result {
 }
 
 impl kernel::Module for RustPrint {
-    fn init(_module: &'static ThisModule) -> Result<Self> {
+    fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> {
         pr_info!("Rust printing macros sample (init)\n");
 
         pr_emerg!("Emergency message (level 0) without args\n");
-- 
2.47.0